Author: "Monica Sigovan" / Topic: radiology, nuclear medicine and imaging - Searchworks@Jio Institute Digital Library Search Results

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32 results on '"Monica Sigovan"'

1. Bicolor K-edge spectral photon-counting CT imaging for the diagnosis of thoracic endoleaks: A dynamic phantom study

Author: Benoit Cosset, Monica Sigovan, Sara Boccalini, Fadi Farhat, Philippe Douek, Loic Boussel, and Salim Aymeric Si-Mohamed
Subjects: Radiological and Ultrasound Technology, Radiology, Nuclear Medicine and imaging, General Medicine
Published: 2023
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2. Feasibility of human vascular imaging of the neck with a large field-of-view spectral photon-counting CT system

Author: Monica Sigovan, Riham Dessouky, Sara Boccalini, Philippe Douek, Loic Boussel, and Salim Si-Mohamed
Subjects: Photons, Large field of view, Vascular imaging, Radiological and Ultrasound Technology, medicine.diagnostic_test, Phantoms, Imaging, business.industry, Imaging diagnostic, Contrast Media, Pilot Projects, General Medicine, Photon counting, Iopamidol, Carotid Arteries, Linear Models, Feasibility Studies, Humans, Medicine, Radiology, Nuclear Medicine and imaging, Tomography, X-Ray Computed, business, Nuclear medicine, Neck, Computed tomography angiography
Published: 2021
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3. Feasibility of lung imaging with a large field-of-view spectral photon-counting CT system

Author: Philippe Coulon, Thomas Broussaud, Pierre-Antoine Rodesch, Monica Sigovan, Philippe Douek, D. Gamondes, Elias Lahoud, Sara Boccalini, Salim Si-Mohamed, Riham Dessouky, Loic Boussel, and Yoad Yagil
Subjects: Image quality, Field of view, Iterative reconstruction, Radiation Dosage, Imaging phantom, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Optical transfer function, Image noise, Image Processing, Computer-Assisted, Idose, Medicine, Humans, Radiology, Nuclear Medicine and imaging, Lung, Radiological and Ultrasound Technology, business.industry, Phantoms, Imaging, General Medicine, Photon counting, chemistry, 030220 oncology & carcinogenesis, Feasibility Studies, Radiographic Image Interpretation, Computer-Assisted, Nuclear medicine, business, Tomography, X-Ray Computed, Algorithms
Abstract: Purpose The purpose of this study was to characterize the technical capabilities and feasibility of a large field-of-view clinical spectral photon-counting computed tomography (SPCCT) prototype for high-resolution (HR) lung imaging. Materials and methods Measurement of modulation transfer function (MTF) and acquisition of a line pairs phantom were performed. An anthropomorphic lung nodule phantom was scanned with standard (120 kVp, 62 mAs), low (120 kVp, 11 mAs), and ultra-low (80 kVp, 3 mAs) radiation doses. A human volunteer underwent standard (120 kVp, 63 mAs) and low (120 kVp, 11 mAs) dose scans after approval by the ethics committee. HR images were reconstructed with 1024 matrix, 300 mm field of view and 0.25 mm slice thickness using a filtered-back projection (FBP) and two levels of iterative reconstruction (iDose 5 and 9). The conspicuity and sharpness of various lung structures (distal airways, vessels, fissures and proximal bronchial wall), image noise, and overall image quality were independently analyzed by three radiologists and compared to a previous HR lung CT examination of the same volunteer performed with a conventional CT equipped with energy integrating detectors (120 kVp, 10 mAs, FBP). Results Ten percent MTF was measured at 22.3 lp/cm with a cut-off at 31 lp/cm. Up to 28 lp/cm were depicted. While mixed and solid nodules were easily depicted on standard and low-dose phantom images, higher iDose levels and slice thicknesses (1 mm) were needed to visualize ground-glass components on ultra-low-dose images. Standard dose SPCCT images of in vivo lung structures were of greater conspicuity and sharpness, with greater overall image quality, and similar image noise (despite a flux reduction of 23%) to conventional CT images. Low-dose SPCCT images were of greater or similar conspicuity and sharpness, similar overall image quality, and lower but acceptable image noise (despite a flux reduction of 89%). Conclusions A large field-of-view SPCCT prototype demonstrates HR technical capabilities and high image quality for high resolution lung CT in human.
Published: 2021
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4. Multicolour imaging with spectral photon-counting CT: a phantom study

Author: Michal Rokni, Ewald Roessl, Valérie Tatard-Leitman, Monica Sigovan, Philippe Coulon, Yoad Yagil, David P. Cormode, Lucie Rascle, Philippe Douek, Ami Altman, Loic Boussel, Pratap C. Naha, Salim Si-Mohamed, Daniel Bar-Ness, Centre Hospitalier Universitaire de Nîmes (CHU Nîmes), Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Philips Healthcare, Department of Radiology, Cardiological Hospital, and Hospices Civils de Lyon
Subjects: lcsh:Medical physics. Medical radiology. Nuclear medicine, Materials science, Gadolinium, media_common.quotation_subject, lcsh:R895-920, chemistry.chemical_element, Iodine, Tomography (x-ray computed), Imaging phantom, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, 0302 clinical medicine, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Contrast (vision), Radiology, Nuclear Medicine and imaging, media_common, business.industry, Attenuation, Ultrasound, Photon counting, chemistry, Colloidal gold, 030220 oncology & carcinogenesis, Original Article, Gold, business, Phantoms (imaging), Biomedical engineering
Abstract: Background To evaluate the feasibility of multicolour quantitative imaging with spectral photon-counting computed tomography (SPCCT) of different mixed contrast agents. Methods Phantoms containing eleven tubes with mixtures of varying proportions of two contrast agents (i.e. two selected from gadolinium, iodine or gold nanoparticles) were prepared so that the attenuation of each tube was about 280 HU. Scans were acquired at 120 kVp and 100 mAs using a five-bin preclinical SPCCT prototype, generating conventional, water, iodine, gadolinium and gold images. The correlation between prepared and measured concentrations was assessed using linear regression. The cross-contamination was measured for each material as the root mean square error (RMSE) of its concentration in the other material images, where no signal was expected. The contrast-to-noise ratio (CNR) relative to a phosphate buffered saline tube was calculated for each contrast agent. Results The solutions had similar attenuations (279 ± 10 HU, mean ± standard deviation) and could not be differentiated on conventional images. However, a distinction was observed in the material images within the same samples, and the measured and prepared concentrations were strongly correlated (R2 ≥ 0.97, 0.81 ≤ slope ≤ 0.95, -0.68 ≤ offset ≤ 0.89 mg/mL). Cross-contamination in the iodine images for the mixture of gold and gadolinium contrast agents (RMSE = 0.34 mg/mL) was observed. CNR for 1 mg/mL of contrast agent was better for the mixture of iodine and gadolinium (CNRiodine = 3.20, CNRgadolinium = 2.80) than gold and gadolinium (CNRgadolinium = 1.67, CNRgold = 1.37). Conclusions SPCCT enables multicolour quantitative imaging. As a result, it should be possible to perform imaging of multiple uptake phases of a given tissue/organ within a single scan by injecting different contrast agents sequentially.
Published: 2018
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5. 3D black blood MR angiography of the carotid arteries. A simple sequence for plaque hemorrhage and stenosis evaluation

Author: Philip M. Robson, Zahi A. Fayad, Clément Bidet, Laura Mechtouff, Monica Sigovan, Sébastien Bros, Philippe Douek, Antoine Millon, Loic Boussel, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Service de Radiologie et IRM, Hospices Civils de Lyon, Hospices Civils de Lyon (HCL), Service de neurologie C [Hôpital Pierre Wertheimer - HCL], Hôpital neurologique et neurochirurgical Pierre Wertheimer [CHU - HCL], Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Department of Radiology and Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA., Icahn School of Medicine at Mount Sinai [New York] (MSSM), Département de chirurgie vasculaire, 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE ), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ), Hospices Civils de Lyon ( HCL ), Service de neurologie C, Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Hospices Civils de Lyon ( HCL ) -Hôpital neurologique et neurochirurgical Pierre Wertheimer [CHU - HCL], and Icahn School of Medicine at Mount Sinai [New York]
Subjects: Male, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, animal diseases, Carotid arteries, Contrast Media, Plaque, Amyloid, Constriction, Pathologic, Intraplaque hemorrhage, 030218 nuclear medicine & medical imaging, 0302 clinical medicine, Image Processing, Computer-Assisted, Medicine, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, Observer Variation, medicine.diagnostic_test, Middle Aged, Magnetic Resonance Imaging, Plaque, Atherosclerotic, Carotid Arteries, Female, Radiology, Artifacts, Adult, medicine.medical_specialty, Black blood, Biomedical Engineering, Biophysics, Color, Hemorrhage, Sensitivity and Specificity, Article, 03 medical and health sciences, Imaging, Three-Dimensional, Carotid stenosis, Humans, Radiology, Nuclear Medicine and imaging, Aged, Sequence (medicine), Models, Statistical, business.industry, Mr angiography, Reproducibility of Results, Atherosclerosis, medicine.disease, nervous system diseases, Stenosis, 3D MRI, Angiography, business, Magnetic Resonance Angiography, 030217 neurology & neurosurgery
Abstract: International audience; ObjectivesTo evaluate the diagnostic performance of a new three-dimensional T1-weighted turbo-spin-echo sequence (3D T1-w TSE) compared to 3D contrast-enhanced angiography (CE-MRA) for stenosis measurement and compared to 2D T1-w TSE for intra-plaque hemorrhage (IPH) detection.MethodsEighty three patients underwent carotid MRI, using a new elliptic-centric phase encoding T1-weighted 3D TSE sequence in addition to the clinical protocol.Two observers evaluated image quality, presence of flow artifacts, and presence of intra-plaque hemorrhage, and computed the NASCET degree of stenosis for CE-MRA and for the new sequence. Inter-observer agreement and correlation between 3D TSE and CE-MRA for NASCET stenosis was estimated using Cohen's kappa, and correlation using linear regression and Bland-Altman plots.Histology was performed on endarterectomy samples for 18 patients. Sensitivity and specificity of 2D and 3D TSE for IPH diagnosis were computed.Results3D TSE showed better image quality than 2D TSE (p
Published: 2017
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6. Simultaneous assessment of microcalcifications and morphological criteria of vulnerability in carotid artery plaque using hybrid 18F-NaF PET/MRI

Author: Alexandre Paccalet, Laura Mechtouff, Emmanuelle Canet-Soulas, Nicolas Costes, Stephane Luong, Antoine Millon, Yves Berthezène, Patrick Feugier, Thomas Bochaton, Salim Si-Mohamed, Claire Crola Da Silva, Alexandre Bani-Sadr, Didier Le Bars, Norbert Nighoghossian, Monica Sigovan, Diane Collet-Benzaquen, David Magne, Adeline Mansuy, Julie Haesebaert, Philippe Douek, Jérémie Tordo, and Hospices Civils de Lyon, Departement de Neurologie (HCL)
Subjects: medicine.diagnostic_test, business.industry, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Magnetic resonance imaging, [SDV.IB.MN]Life Sciences [q-bio]/Bioengineering/Nuclear medicine, 030204 cardiovascular system & hematology, medicine.disease, Asymptomatic, Culprit, 030218 nuclear medicine & medical imaging, body regions, 03 medical and health sciences, Stenosis, 0302 clinical medicine, Carotid artery plaque, medicine, Mineral metabolism, Radiology, Nuclear Medicine and imaging, Tomography, medicine.symptom, Cardiology and Cardiovascular Medicine, business, Nuclear medicine, Stroke, ComputingMilieux_MISCELLANEOUS
Abstract: Previous studies have suggested the role of microcalcifications in plaque vulnerability. This exploratory study sought to assess the potential of hybrid positron-emission tomography (PET)/magnetic resonance imaging (MRI) using 18F-sodium fluoride (18F-NaF) to check simultaneously 18F-NaF uptake, a marker of microcalcifications, and morphological criteria of vulnerability. We included 12 patients with either recently symptomatic or asymptomatic carotid stenosis. All patients underwent 18F-NaF PET/MRI. 18F-NaF target-to-background ratio (TBR) was measured in culprit and nonculprit (including contralateral plaques of symptomatic patients) plaques as well as in other arterial walls. Morphological criteria of vulnerability were assessed on MRI. Mineral metabolism markers were also collected. 18F-NaF uptake was higher in culprit compared to nonculprit plaques (median TBR 2.6 [2.2-2.8] vs 1.7 [1.3-2.2]; P = 0.03) but was not associated with morphological criteria of vulnerability on MRI. We found a positive correlation between 18F-NaF uptake and calcium plaque volume and ratio but not with circulating tissue-nonspecific alkaline phosphatase (TNAP) activity and inorganic pyrophosphate (PPi) levels. 18F-NaF uptake in the other arterial walls did not differ between symptomatic and asymptomatic patients. 18F-NaF PET/MRI may be a promising tool for providing additional insights into the plaque vulnerability.
Published: 2020
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7. Spectral Photon-Counting Computed Tomography for Coronary Stent Imaging: Evaluation of the Potential Clinical Impact for the Delineation of In-Stent Restenosis

Author: Philippe Douek, Gregor Pahn, Salim Si-Mohamed, David Maintz, Alexander C. Bunck, Grischa Bratke, Monica Sigovan, Daniel Bar-Ness, Tilman Hickethier, and Philippe Coulon
Subjects: medicine.medical_specialty, Computed Tomography Angiography, medicine.medical_treatment, Computed tomography, In Vitro Techniques, Coronary Angiography, 030218 nuclear medicine & medical imaging, Coronary Restenosis, 03 medical and health sciences, 0302 clinical medicine, Restenosis, Coronary stent, medicine, Image Processing, Computer-Assisted, Radiology, Nuclear Medicine and imaging, Photons, medicine.diagnostic_test, business.industry, Phantoms, Imaging, General Medicine, equipment and supplies, medicine.disease, Coronary computed tomography, Photon counting, 3. Good health, Angiography, Stents, Radiology, In stent restenosis, business, Artifacts, 030217 neurology & neurosurgery
Abstract: In-stent restenosis (ISR) is one of the main long-term complications after coronary stent placement, and the ability to evaluate ISR noninvasively using coronary computed tomography (CT) angiography remains challenging. For this application, spectral photon-counting CT (SPCCT) has the potential to increase image quality and reduce artifacts due to its advanced detector technology.Our study aimed to verify the technical and clinical potential of a novel SPCCT prototype using an ISR phantom setup.Soft plaque-like restenosis (45 HU; approximately 50% of the stent lumen) were inserted into 10 different coronary stents (3 mm diameter), which were placed in a vessel phantom and filled with a contrast agent (400 HU). A research prototype SPCCT and a clinical dual-layer CT (DLCT; IQon; Philips) with comparable acquisition and reconstruction parameters were used to scan the phantoms. Conventional polyenergetic (PolyE) and monoenergetic (MonoE) images with 4 different energy levels (40, 60, 90, 120 keV) were reconstructed. Qualitative (delineation of the stenosis and adjacent residual lumen using a 5-point Likert scale) and quantitative (image noise, visible lumen diameter, lumen diameter adjacent to the stenosis, contrast-to-noise ratio of the restenosis) parameters were evaluated for both systems.The qualitative results averaged over all reconstructions were significantly superior for SPCCT compared with DLCT (eg, subjective rating of the best reconstruction of each scanner: DLCT PolyE: 2.80 ± 0.42 vs SPCCT MonoE 40 keV: 4.25 ± 1.03). Stenosis could be clearly detected in 9 and suspected in 10 of the 10 stents with both SPCCT and DLCT. The residual lumen next to the stenosis was clearly delineable in 7 of 10 stents (0.64 ± 0.11 mm or 34.97% of the measured stent lumen) with SPCCT, while it was not possible to delineate the residual lumen for all stents using DLCT. The measured diameter of the lumen within the stent was significantly higher for SPCCT compared with DLCT in all reconstructions with the best results for the MonoE 40 keV images (SPCCT: 1.80 ± 0.17 mm; DLCT: 1.50 ± 0.31 mm). The image noise and the contrast-to-noise ratio were better for DLCT than for SPCCT (contrast-to-noise ratio: DLCT MonoE 40: 31.58 ± 12.54; SPCCT MonoE 40: 4.64 ± 1.30).Spectral photon-counting CT allowed for the noninvasive evaluation of ISR with reliable results regarding the residual lumen for most tested stents and the clear identification or suspicion of stenosis for all stents. In contrast, the residual lumen could not be detected for a single stent using DLCT.
Published: 2019

8. Comparison of free breathing 3D mDIXON with single breath-hold 3D inversion recovery sequences for the assessment of Late Gadolinium Enhancement

Author: Monica Sigovan, Philippe Douek, Salim Si-Mohamed, Sara Boccalini, Riham Dessouky, Vincenzo De Stasio, Thomas Broussaud, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Sigovan, Monica, Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)
Subjects: Adult, Male, Wilcoxon signed-rank test, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, Contrast Media, Gadolinium, 030204 cardiovascular system & hematology, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, Imaging, Three-Dimensional, 0302 clinical medicine, Image Interpretation, Computer-Assisted, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, High spatial resolution, medicine, Humans, Late gadolinium enhancement, Radiology, Nuclear Medicine and imaging, ComputingMilieux_MISCELLANEOUS, Aged, 3d inversion, medicine.diagnostic_test, business.industry, Magnetic resonance imaging, General Medicine, Single breath, Middle Aged, Image Enhancement, Magnetic Resonance Imaging, Female, business, Nuclear medicine, Free breathing, Kappa
Abstract: To evaluate the technical and diagnostic performance of three dimensional (3D) mDIXON versus 3D inversion recovery (3D VIAB) and 3D spectral presaturation with inversion recovery (3D SPIR) late gadolinium enhancement (LGE) sequences.A total of 78 patients (50 males and 28 females, age 49 ± 18 years) with 1.5 T CMR examination including three different 3D LGE sequences (3D mDIXON, 3D VIAB, and 3D SPIR) were evaluated for technical and diagnostic performance by two readers. Qualitative scores and quantitative signal and contrast-to-noise ratios were compared among sequences. Qualitative comparisons were made using Friedman and Wilcoxon signed rank tests. Quantitative comparisons were made using one way ANOVA. Reader agreements were tested using Cohen's Kappa. Any p-value0.05 was significant.19 out of 78 patients (24 %) were excluded due to poor (grade 4) image quality and 29 patients were excluded due to absence of LGE. For the remaining 30 patients, free breathing 3D mDIXON showed higher confidence in diagnosis of subepicardial LGE (p-value0.05). 3D mDIXON outperformed 3D SPIR in both visualization of LGE (p = 0.02) and quality of fat suppression (p = 0.001). Nevertheless, 3D mDIXON showed lower image quality compared to the other two sequences.Free breathing 3D mDIXON is a diagnostic problem-solving tool, especially when making a diagnosis of subepicardial enhancement and/or fat suppression is needed, owing to its high spatial resolution and robust fat suppression. Choice of 3D LGE sequence should be based on patient's breath-hold ability, diagnostic needs, and institutional availability considering the strengths and limitations of each sequence.
Published: 2021
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9. MRI-based detection of renal artery abnormalities related to renal denervation by catheter-based radiofrequency ablation in drug resistant hypertensive patients

Author: Loic Boussel, Brahim Harbaoui, Salim Si-Mohamed, Philippe Douek, Pierre Lantelme, Monica Sigovan, Marc Sapoval, Sébastien Bros, Pierre-Yves Courand, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Centre Hospitalier Universitaire de Nîmes (CHU Nîmes), Centre de Recherche et d'Application en Traitement de l'Image et du Signal (CREATIS), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université Paris Descartes - Faculté de Médecine (UPD5 Médecine), Université Paris Descartes - Paris 5 (UPD5), Service de Radiologie [CHU HEGP], Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Service de radiologie cardio-vasculaire [CHU HEGP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Centre Hospitalier Régional Universitaire de Nîmes (CHRU Nîmes), Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpital Européen Georges Pompidou [APHP] (HEGP), and Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)
Subjects: Male, medicine.medical_specialty, Radiofrequency ablation, medicine.medical_treatment, [SDV]Life Sciences [q-bio], Drug Resistance, 030204 cardiovascular system & hematology, Imagerie Coeur - Vaisseaux - Poumons, law.invention, Labex PRIMES, 03 medical and health sciences, Renal Artery, 0302 clinical medicine, law, medicine.artery, medicine, Humans, Radiology, Nuclear Medicine and imaging, Prospective Studies, 030212 general & internal medicine, Sympathectomy, Renal artery, Intraoperative Complications, Antihypertensive Agents, ComputingMilieux_MISCELLANEOUS, Aged, Neuroradiology, Denervation, Analysis of Variance, medicine.diagnostic_test, business.industry, categₘed, reseauₐucun, Magnetic resonance imaging, Interventional radiology, General Medicine, Middle Aged, Ablation, Magnetic Resonance Imaging, 3. Good health, Catheter, Imagerie Ultrasonore, Hypertension, Catheter Ablation, Female, [SDV.IB]Life Sciences [q-bio]/Bioengineering, Radiology, business, Nuclear medicine
Abstract: International audience; OBJECTIVES: Endovascular renal denervation (RDN) using catheter-based radiofrequency (RF) ablation has emerged as a potential treatment option for drug-resistant hypertension. Its efficacy is currently under debate. We aimed to evaluate the capability of contrast-enhanced magnetic resonance imaging (MRI) to assess the effects of RDN on the renal arterial wall in patients presenting with drug-resistant hypertension.METHODS: Patients were included prospectively following institutional review board approval and written informed consent. Renal arteries were imaged using a two-dimensional T1-weighted TSE sequence pre- and post-administration of a gadolinium-based contrast agent, before (D0), 2 days (D2) and 6 months (M6) after RDN. Mean enhancement of the wall (mENH) and mean wall thickness (mWT) were compared across time using an ANOVA with repeated measures and post-hoc paired t-test.RESULTS: Follow-up was completed for 23 patients (median age, 57 years; 16 men). The mENH at D2 (96.3 \textpm 36.0 %) was significantly higher than at D0 (61.1 \textpm 26.3%, p < 0.001) and M6 (66.1\textpm22.7%, p < 0.001). Similarly, mWT was significantly higher at D2 (3.1 \textpm 0.4 m) than at D0 (2.7 \textpm 0.4mm, p < 0.001) and M6 (2.9 \textpm 0. 5 mm, p = 0.002).CONCLUSIONS: MRI demonstrated abnormalities of the arterial wall 2 days after RDN that had resolved at 6 months.KEY POINTS: \textbullet Contrast-enhanced MRI provides anatomic evidence of renal artery RF ablation \textbullet Temperature increase related to RF ablation induces transient arterial wall inflammation \textbullet Morphological effects observed 2 days post RF ablation are not visible after 6 months.
Published: 2018
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10. MR imaging assessment of myocardial edema with T2 mapping

Author: Didier Revel, Patrick Montant, Monica Sigovan, Philippe Douek, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Department of Radiology, Cardiological Hospital, and Hospices Civils de Lyon
Subjects: medicine.medical_specialty, Cardiac magnetic resonance, Biopsy, T2 mapping, Myocardial edema, computer.software_genre, Sensitivity and Specificity, Voxel, Edema, Image Interpretation, Computer-Assisted, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Humans, Medicine, Radiology, Nuclear Medicine and imaging, Cardiac imaging, Radiological and Ultrasound Technology, business.industry, Myocardium, Heart, General Medicine, Magnetic Resonance Imaging, Mr imaging, T2 relaxation, cardiovascular system, Radiology, medicine.symptom, Cardiomyopathies, business, Nuclear medicine, computer, Endocardium
Abstract: Cardiac magnetic resonance (CMR) provides a high signal-to-noise ratio, high spatial and temporal resolutions, as well as a delayed-enhancement sequence and is therefore considered a reference technique in the field of cardiac imaging. However, currently available sequences are not adequate to assess some pathologic conditions, such as myocardial edema. T2 mapping sequences generate parametric images that are based on the transverse relaxation time (T2) for each voxel. In case of edema, the T2 relaxation time is longer. This review summarizes current knowledge on CMR T2 mapping for assessing myocardial edema.
Published: 2015
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11. Extended 3D approach for quantification of abnormal ascending aortic flow

Author: Monica Sigovan, Elaine E. Tseng, Jarrett Wrenn, Petter Dyverfeldt, David Saloner, and Michael D. Hope
Subjects: Adult, Heart Defects, Congenital, Male, Aortic valve, medicine.medical_specialty, Heart Valve Diseases, Biomedical Engineering, Biophysics, Article, Imaging, Three-Dimensional, Bicuspid Aortic Valve Disease, Internal medicine, medicine.artery, Ascending aorta, medicine, Humans, Eccentric, Radiology, Nuclear Medicine and imaging, Displacement (orthopedic surgery), Aorta, Aged, medicine.diagnostic_test, business.industry, Magnetic resonance imaging, Aortic Valve Stenosis, Middle Aged, medicine.disease, Magnetic Resonance Imaging, medicine.anatomical_structure, Flow (mathematics), Aortic Valve, Aortic valve stenosis, cardiovascular system, Cardiology, Female, business, Blood Flow Velocity
Abstract: Flow displacement quantifies eccentric flow, a potential risk factor for aneurysms in the ascending aorta, but only at a single anatomic location. The aim of this study is to extend flow displacement analysis to 3D in patients with aortic and aortic valve pathologies.43 individuals were studied with 4DFlow MRI in 6 groups: healthy, tricuspid aortic valve (TAV) with aortic stenosis (AS) but no dilatation, TAV with dilatation but no AS, and TAV with both AS and dilatation, BAV without AS or dilatation, BAV without AS but with dilation. The protocol was approved by our institutional review board, and informed consent was obtained. Flow displacement was calculated for multiple planes along the ascending aorta, and 2D and 3D analyses were compared.Good correlation was found between 2D flow displacement and both maximum and average 3D values (r0.8). Healthy controls had significantly lower flow displacement values with all approaches (p0.05). The highest flow displacement was seen with stenotic TAV and aortic dilation (0.24±0.02 with maximum flow displacement). The 2D approach underestimated the maximum flow displacement by more than 20% in 13 out of 36 patients (36%).The extended 3D flow displacement analysis offers a more comprehensive quantitative evaluation of abnormal systolic flow in the ascending aorta than 2D analysis. Differences between patient subgroups are better demonstrated, and maximum flow displacement is more reliably assessed.
Published: 2015
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12. Benign and malignant enlarged chest nodes staging by diffusion-weighted MRI: an alternative to mediastinoscopy?

Author: Pia Akl, Caroline Mesmann, Salim Si-Mohamed, Loic Boussel, Philippe Douek, Monica Sigovan, François Tronc, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Service de Radiologie [Hôpital de la Croix-Rousse - HCL], Hôpital de la Croix-Rousse [CHU - HCL], Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Service de chirurgie thoracique (HCL, Hôpital Louis Pradel, Bron), Hospices Civils de Lyon (HCL)-Hôpital Louis Pradel [CHU - HCL], Hospices Civils de Lyon (HCL), Service de Radiologie et IRM [CHU Lyon], and Hôpital Cardiovasculaire Louis Pradel (HCLP)
Subjects: Adult, medicine.medical_specialty, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [SDV.CAN]Life Sciences [q-bio]/Cancer, Sensitivity and Specificity, 030218 nuclear medicine & medical imaging, Mediastinoscopy, 03 medical and health sciences, 0302 clinical medicine, Predictive Value of Tests, medicine, Effective diffusion coefficient, Humans, Radiology, Nuclear Medicine and imaging, Prospective Studies, Aged, Aged, 80 and over, medicine.diagnostic_test, Receiver operating characteristic, Full Paper, business.industry, Mediastinum, General Medicine, Middle Aged, medicine.anatomical_structure, Diffusion Magnetic Resonance Imaging, 030220 oncology & carcinogenesis, Predictive value of tests, Lymphatic Metastasis, Background suppression, Radiology, Lymph Nodes, business, Diffusion MRI
Abstract: International audience; Objective:To evaluate the accuracy of diffusion-weighted MRI with background suppression (DWIBS) in differentiating between malignant and benign mediastinal lymph-nodes.Methods:Consecutive patients with enlarged mediastinal lymph-nodes underwent MRI DWIBS within 10 days prior to mediastinoscopy. Relative contrast ratios (RCRs) were computed on b800 and apparent diffusion coefficient (ADC) maps by dividing the node signal with the chest muscle signal, using manually drawn regions of interest (ROIs) by radiologists, blinded to pathology. Unpaired Student's t-tests were used to compare RCR-b800 and ADC between malignant and benign nodes. Receiver operating characteristic curves analyses were also performed.Results:Six patients were excluded for poor image quality. Analysis was performed for 54 patients. Mean ADC values were significantly higher for benign (1740 ± 401 × 10−6 mm2 s–1) compared with malignant nodes (1266 ± 403 × 10−6 mm2 s–1, p = 0.0001). Mean RCR-b800 values were significantly lower for benign (2.64 ± 1.07) compared with malignant nodes (6.44 ± 3.47, p < 0.0001).Receiver operating characteristic analysis for RCR-b800 (cut-off of 3.6), showed a sensitivity of 90.9%, a specificity 83% and an accuracy 85% for differentiating benign from malignant nodes. For ADC (cut-off of 1285), the sensitivity was 68.2%, the specificity 84.6% and the accuracy 80.4%.Conclusion:DWIBS can accurately differentiate malignant from benign states in enlarged mediastinal lymph-nodes and represents an alternative method in aetiological work-up of mediastinal lymphadenopathies.Advances in knowledge:DWIBS may represent a useful adjunctive imaging modality, particularly for diagnosis of benign mediastinal lymph node, and thus may reduce the frequency of futile mediastinoscopy, which remains an invasive procedure.
Published: 2018
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13. Evaluation of image quality of DWIBS versus DWI sequences in thoracic MRI at 3T

Author: Loic Boussel, Philippe Douek, Adva Abergel, François Tronc, Yves Berthezène, Lise-Prune Berner, Caroline Mesmann, Monica Sigovan, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut d'astrophysique spatiale (IAS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Sud - Paris 11 (UP11), Service de Radiologie [Hôpital de la Croix-Rousse - HCL], Hôpital de la Croix-Rousse [CHU - HCL], Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Imagerie Ultrasonore, Department of Radiology, Cardiological Hospital, Hospices Civils de Lyon, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Adult, Male, medicine.medical_specialty, Image quality, Biomedical Engineering, Biophysics, Fat suppression, 030218 nuclear medicine & medical imaging, Motion, 03 medical and health sciences, 0302 clinical medicine, Image Processing, Computer-Assisted, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, medicine, Humans, Radiology, Nuclear Medicine and imaging, Prospective Studies, Lymph node, Aged, medicine.diagnostic_test, business.industry, Respiration, Mediastinum, Water, Magnetic resonance imaging, Middle Aged, Magnetic Resonance Imaging, Diffusion Magnetic Resonance Imaging, medicine.anatomical_structure, Adipose Tissue, 030220 oncology & carcinogenesis, Mediastinal lymph node, Female, Lymph Nodes, Radiology, Lymph, Artifacts, Nuclear medicine, business, Diffusion MRI
Abstract: To compare diffusion weighted imaging with background suppression (DWIBS) sequence with classic spectral diffusion sequence (DWI) with and without respiratory gating in mediastinal lymph node analysis at 3T.26 patients scheduled for mediastinoscopic lymph node analysis, prospectively undergone a thoracic 3T MRI with DWIBS (FatSat=STIR; TR/TE=6674.1/44.7ms; IR=260 ms) and DWI sequences (FatSat=SPIR; TR/TE=1291/59.6 ms) (b=0-400-800 s/mm2) with and without (free breathing) respiratory gating. Images at b=800 were analyzed by two radiologists. They performed qualitative analysis of fat-sat homogeneity and motion artifacts, rated from 0 to 4, and quantitative evaluation by studying signal to background (STB) of lymph nodes.Quality of fat suppression was significantly higher for DWIBS than for DWI both for free-breathing (score 3.48±0.65 vs. 1.76±0.96, p0.0001) and respiratory-gated scans (3.17±0.77 vs. 1.72±0.73, p=0.0001). Similarly, artifacts were reduced with DWIBS (3.16±0.47 vs. 1.76±0.59, p0.0001; 3.0±0.73 vs. 2.04±0.53, p=0.0001). Quantitative analysis showed higher STB with DWIBS (3.26±1.83 vs. 0.98±0.44, p0.0001; 3.56±, 2.09 vs. 0.92±0.59, p0.0001). Gating did not improve image quality and STB on DWIBS (p0.05).In thoracic MRI, ungated DWIBS sequence improves fat-sat homogeneity, reduces motion artifacts and increases STB of lymph nodes. Respiratory gating does not improve DWIBS image quality.
Published: 2014
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14. MRI hemodynamic markers of progressive bicuspid aortic valve-related aortic disease

Author: S. Jarrett Wrenn, Petter Dyverfeldt, David Saloner, Monica Sigovan, and Michael D. Hope
Subjects: Aortic valve, congenital, hereditary, and neonatal diseases and abnormalities, Aorta, medicine.medical_specialty, medicine.diagnostic_test, business.industry, Disease progression, Hemodynamics, medicine.disease, Aortic disease, Magnetic resonance angiography, medicine.anatomical_structure, Bicuspid aortic valve, medicine.artery, Internal medicine, Cohort, cardiovascular system, Cardiology, Medicine, Radiology, Nuclear Medicine and imaging, cardiovascular diseases, Radiology, business
Abstract: Purpose To determine the reproducibility of MRI aortic hemodynamic markers and to assess their relationship to aortic growth in a cohort of patients with bicuspid aortic valves (BAV).
Published: 2013
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15. Positive contrast with therapeutic iron nanoparticles at 4.7 T

Author: Emmanuelle Canet-Soulas, Monica Sigovan, Delphine Charpigny, Achraf Al Faraj, Hatem Fessi, Misara Hamoudeh, Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire d'automatique et de génie des procédés (LAGEP), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Biophysics, Contrast Media, Nanoparticle, Nanotechnology, Sensitivity and Specificity, 030218 nuclear medicine & medical imaging, Mice, 03 medical and health sciences, 0302 clinical medicine, Nuclear magnetic resonance, Image Interpretation, Computer-Assisted, mental disorders, medicine, Animals, Computer Simulation, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Radiology, Nuclear Medicine and imaging, Magnetite Nanoparticles, Radiological and Ultrasound Technology, medicine.diagnostic_test, Phantoms, Imaging, ACL, Tumor therapy, Dextrans, Magnetic resonance imaging, [SDV.SP]Life Sciences [q-bio]/Pharmaceutical sciences, Image enhancement, Image Enhancement, Magnetic Resonance Imaging, Positive contrast, Feasibility Studies, Magnetic nanoparticles, Female, psychological phenomena and processes, 030217 neurology & neurosurgery, Gradient echo, Superparamagnetism
Abstract: The purpose of the study was to show the feasibility of a positive contrast technique GRadient echo Acquisition for Superparamagnetic particles with Positive contrast (GRASP), for a specific type of magnetic particles, designed for tumor treatment under MRI monitoring.A simulation study was performed to estimate field inhomogeneity intensities induced by increasing concentrations of particles at different static fields. The GRASP sequence was setup on a 4.7 T Bruker system during an in vitro study. Six mice, included in the in vivo study received particles in the left calf muscle and contrast enhancement values, were measured over three time points, for both negative and positive contrast images.Comparing values obtained by simulation at 1.5, 3, and 4.7 T, the strongest susceptibility effect was obtained at 4.7 T. Based on simulation and in vitro data, gradient settings were chosen for in vivo imaging. GRASP resulted in bright regions at and around the injection site, and higher enhancement values, compared to standard GRE imaging. Both contrasts were useful for longitudinal follow-up, with a faster decay over time for GRASP.The magnetic nanoparticles for drug delivery can be detected using positive contrast. Combining imaging sequences, i.e., negative contrast and susceptibility methods, increased imaging specificity of large magnetic particles and enabled their follow-up for theranostic applications.
Published: 2011
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16. M1-Activated Macrophages Migration, A Marker of Aortic Atheroma Progression

Author: Geneviève De Souza, Monica Sigovan, Emmanuelle Canet-Soulas, Hasan Alsaid, Norbert Nighoghossian, Zouher Majd, Serge Nataf, Amine Bessaad, Christine Ménager, Florence Lagarde, Jérôme Honnorat, Nicolas Provost, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche et d'Application en Traitement de l'Image et du Signal (CREATIS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie du Développement de Marseille (IBDM), Aix Marseille Université (AMU)-Collège de France (CdF)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche en neurosciences de Lyon (CRNL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique de l'état condensé (LPEC), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM), Sigovan, Monica, Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche en neurosciences de Lyon - Lyon Neuroscience Research Center (CRNL), and Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Aortic arch, Pathology, medicine.medical_specialty, Apolipoprotein E2, Arteriosclerosis, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, Aortic Diseases, Mice, Transgenic, Proinflammatory cytokine, Mice, In vivo, medicine.artery, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, medicine, Animals, Macrophage, Radiology, Nuclear Medicine and imaging, Gene Knock-In Techniques, medicine.diagnostic_test, business.industry, Macrophages, Histology, Magnetic resonance imaging, General Medicine, Macrophage Activation, medicine.disease, Magnetic Resonance Imaging, Atheroma, Dynamic contrast-enhanced MRI, business, Biomarkers
Abstract: Background: M1-activated Macrophages (M1M) play a major role in atherosclerotic lesions of aortic arch, promoting proinflammatory response. In vivo trafficking of M1M in aortic plaques is therefore critical. Methods: M1M from bone marrow cell culture were magnetically labeled, using iron nanoparticles, intravenously injected and followed up with 3 day magnetic resonance imaging (MRI) in mice developing macrophage-laden atheroma (ApoE2 knock-in mice). M1M recruitment in aortic arch lesions was assessed both by MRI and histology. Results: In all ApoE2 knock-in mice injected with labeled cells, high resolution MRI showed localized signal loss regions in the thickened aortic wall, with a maximal effect at day 2 (―34% ± 7.3% P < 0.001 compared with baseline). This was confirmed with Prussian blue (iron) staining and corresponded to M1M (Major Histo-compatibility Complex II positive). Clear different intraplaque and adventitial dynamic distribution profiles of labeled cells were observed during the 3 days. Conclusion: M1M dynamic MRI is a promising marker to noninvasively assess the macrophage trafficking underlying aortic arch plaque progression.
Published: 2010
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17. Photon counting spectral CT component analysis of coronary artery atherosclerotic plaque samples

Author: Gerhard Martens, Axel Thran, Monica Sigovan, Loic Boussel, Ewald Roessl, Philippe Douek, Philippe Coulon, Service de Radiologie [Hôpital de la Croix-Rousse - HCL], Hôpital de la Croix-Rousse [CHU - HCL], Hospices Civils de Lyon ( HCL ) -Hospices Civils de Lyon ( HCL ), 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE ), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Philips Healthcare, Philips Research [Germany], Philips Research, Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Photon, Materials science, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Contrast Media, Coronary Artery Disease, Coronary artery disease, medicine, Humans, Scattering, Radiation, Radiology, Nuclear Medicine and imaging, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, Photons, Full Paper, business.industry, Compton scattering, General Medicine, medicine.disease, Photon counting, Plaque, Atherosclerotic, Intensity (physics), Coronary arteries, medicine.anatomical_structure, Radiographic Image Interpretation, Computer-Assisted, Tomography, Autopsy, Nuclear medicine, business, Tomography, X-Ray Computed, Artery
Abstract: International audience; Objectives. To evaluate the capabilities of Photon Counting Spectral CT to differentiate components of coronary atherosclerotic plaque based on differences in spectral attenuation and iodine-based contrast agent concentration. Methods. 10 calcified and 13 lipid-rich atheromatous plaques from postmortem human coronary arteries were scanned with a Photon Counting Spectral CT scanner. Individual photons were counted and classified in one of 6 energy bins from 25 to 70 keV.Based on a maximum likelihood approach, maps of Photoelectric Absorption (PA), Compton Scattering (CS) and Iodine Concentration (IC) were reconstructed. Intensity measurements were performed on each map in the vessel wall, the surrounding perivascular fat, the lipid-rich and the calcified plaques. PA and CS values are expressed relative to pure water values. Comparison between these different elements was performed using Kruskal-Wallis tests with pairwise post-hoc Mann-Whitney U tests and Sidak p-values adjustment. Results. Results for vessel wall, surrounding perivascular fat, lipid-rich, and calcified plaques were respectively 1.19+/-0.09, 0.73+/-0.05, 1.08+/-0.14, 17.79+/-6.70 for PA; 0.96+/-0.02, 0.83+/-0.02, 0.91+/-0.03, 2.53+/-0.63 for CS, and 83.3+/-10.1, 37.6+/-8.1, 55.2+/-14.0, 4.9+/-20.0 mmol/l for IC, with significant differences between all tissues for PA, CS and IC (p
Published: 2014
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18. Systolic flow displacement correlates with future ascending aortic growth in patients with bicuspid aortic valves undergoing magnetic resonance surveillance

Author: Nicholas S. Burris, Elaine E. Tseng, Michael D. Hope, Heather A. Knauer, Monica Sigovan, and David Saloner
Subjects: Adult, Gadolinium DTPA, Male, medicine.medical_specialty, Adolescent, Heart Valve Diseases, Contrast Media, Phase contrast magnetic resonance imaging, Young Adult, Imaging, Three-Dimensional, Bicuspid Aortic Valve Disease, medicine.artery, Ascending aorta, medicine, Humans, Radiology, Nuclear Medicine and imaging, In patient, Displacement (orthopedic surgery), Aorta, Aged, Observer Variation, medicine.diagnostic_test, business.industry, Follow up studies, Hemodynamics, Magnetic resonance imaging, General Medicine, Blood flow, Organ Size, Middle Aged, Image Enhancement, Magnetic Resonance Imaging, Regional Blood Flow, Aortic Valve, cardiovascular system, Female, Radiology, business, Blood Flow Velocity, Follow-Up Studies
Abstract: Altered systolic blood flow in the ascending aorta has been correlated with increased aortic growth in patients with bicuspid aortic valves (BAVs). We used conventional, 2-dimensional (2D) phase contrast magnetic resonance imaging (PC-MRI) to assess the relationship between altered flow and future growth in patients with BAV.Aortic MRI data were reviewed for 17 adult patients with BAV with right-left leaflet fusion undergoing surveillance imaging who had 2D PC-MRI through their ascending aortas on an initial study, follow-up studies more than 1 year later, and an initial maximum aortic diameter of less than 4.5 cm. Diameters were measured at standard levels by 2 blinded reviewers. Normalized systolic flow displacement was calculated at peak systole from the PC-MRI data, and correlation with the interval aortic growth was performed, with adjustment for clinical/demographic factors.The average follow-up interval was 2.9 ± 1.3 years. Systolic flow displacement at the initial study strongly correlated with ascending aortic growth rate (r = 0.71, P0.005) with moderate, non-significant correlation between initial diameter and growth (r = 0.45, P = 0.214). Aortic growth was 4 times faster in patients with initial flow displacement of 0.2 or greater (n = 9) compared with those (n = 8) with initial flow displacement less than 0.2 (0.8 ± 0.4 vs 0.2 ± 0.3 mm/y; P = 0.002).Systolic flow displacement calculated from conventional 2D PC-MRI in the ascending aorta correlates with future aortic growth in patients undergoing routine surveillance imaging for BAV. With a cutoff valve of 0.2, flow displacement may be used to identify a subset of patients likely to have elevated growth rates and may better risk-stratify patients with BAV for aortic disease progression than vessel diameter alone.
Published: 2014

19. High-Resolution MRI Visualization of Aneurysmal Thrombosis after Flow Diverter Stent Placement

Author: Monica Sigovan, Guy Courbebaisse, Benjamin Gory, Francis Turjman, Carolina Vallecilla, Department of Interventional Neuroradiology, Hôpital neurologique et neurochirurgical Pierre Wertheimer [CHU - HCL], Hospices Civils de Lyon ( HCL ) -Hospices Civils de Lyon ( HCL ), 1 - Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales ( MOTIVATE ), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé ( CREATIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Hospices Civils de Lyon ( HCL ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: medicine.medical_specialty, Flow diverter stent, genetic structures, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, High resolution, Sensitivity and Specificity, Aneurysm, Occlusion, medicine, Humans, Radiology, Nuclear Medicine and imaging, Treatment Failure, cardiovascular diseases, Thrombus, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, medicine.diagnostic_test, business.industry, Reproducibility of Results, Magnetic resonance imaging, Intracranial Aneurysm, Middle Aged, medicine.disease, Image Enhancement, equipment and supplies, Thrombosis, Magnetic Resonance Imaging, medicine.anatomical_structure, Fundus (uterus), cardiovascular system, Female, Stents, Neurology (clinical), Radiology, Intracranial Thrombosis, business
Abstract: International audience; Flow-diverter stents are the new promising tools in the treatment of intracranial aneurysms allowing progressive aneurysm occlusion. Here, we report a case where high-resolution magnetic resonance imaging showed thrombus at fundus of the aneurysm sac, indicating a progressive intraaneurysmal thrombosis after flow-diverter placement.
Published: 2014
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20. USPIO-enhanced MR Angiography of Arteriovenous Fistulas in Patients with Renal Failure

Author: Hugh F. Alley, Warren J. Gasper, Monica Sigovan, David Saloner, Christopher D. Owens, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)
Subjects: Male, medicine.medical_specialty, Kidney Disease, Anastomosis, medicine.medical_treatment, Contrast Media, Medical and Health Sciences, Sensitivity and Specificity, Magnetite Nanoparticles, Text mining, Clinical Research, Surgical, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, medicine, Humans, Radiology, Nuclear Medicine and imaging, In patient, Renal Insufficiency, Original Research, business.industry, Arteriovenous Anastomosis, Anastomosis, Surgical, Mr angiography, Reproducibility of Results, Dextrans, Image Enhancement, Nuclear Medicine & Medical Imaging, Biomedical Imaging, Female, Radiology, Hemodialysis, business, Magnetic Resonance Angiography
Abstract: PurposeTo determine the feasibility of using ferumoxytol-enhanced magnetic resonance (MR) angiography to depict the vasculature of hemodialysis fistulas and improve image quality compared with nonenhanced time-of-flight (TOF) MR angiography.Materials and methodsThe study was institutional review board approved and was in compliance with HIPAA regulations. All participants provided written informed consent. TOF and first-pass ferumoxytol-enhanced MR angiography were performed in 10 patients with upper extremity autogenous fistulas. Ferumoxytol was administered as a bolus solution containing 430 μmol of elemental iron. A qualitative comparison was performed on maximum intensity projection images. Lumen depiction was evaluated by using a five-point scale. The uniformity of intraluminal signal intensity was measured as the ratio between the mean signal intensity of the entirety of the imaged fistula and its standard deviation. The contrast-to-noise ratio (CNR) between intraluminal signal and adjacent tissue was evaluated as a function of image acquisition time. Lumen depiction scores, luminal signal heterogeneity, and CNR efficiency were compared between TOF and ferumoxytol-enhanced MR angiography by using a Wilcoxon-Mann-Whitney test.ResultsFlow artifacts were greatly reduced by the use of ferumoxytol-enhanced MR angiography. Ferumoxytol-enhanced MR angiography had significantly better performance than TOF MR angiography as measured with the following: lumen depiction scores in all segments (mean, 4.7±0.1 [standard error of the mean]; vs 3.0±0.3 for arterial inflow, 4.1±0.3 vs 1.9±0.3 for arterial outflow, 3.7±0.3 vs 1.8±0.2 for anastomosis, and 4.5±0.2 vs 2.1±0.2 for venous outflow; P
Published: 2012

21. Anti-inflammatory drug evaluation in ApoE-/- mice by ultrasmall superparamagnetic iron oxide-enhanced magnetic resonance imaging

Author: Zouher Majd, Magali Breisse, Eric Lancelot, Monica Sigovan, Claire Corot, Nicolas Provost, Elena A. Kaye, Emmanuelle Canet-Soulas, Sigovan, Monica, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche et d'Application en Traitement de l'Image et du Signal (CREATIS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National de la Recherche Agronomique (INRA)
Subjects: Pathology, medicine.medical_specialty, Angiotensin receptor, Apolipoprotein B, Arteriosclerosis, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, Contrast Media, Tetrazoles, 030204 cardiovascular system & hematology, 030218 nuclear medicine & medical imaging, Renin-Angiotensin System, 03 medical and health sciences, chemistry.chemical_compound, Mice, 0302 clinical medicine, Irbesartan, Apolipoproteins E, In vivo, medicine.artery, medicine, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Animals, Radiology, Nuclear Medicine and imaging, Longitudinal Studies, Magnetite Nanoparticles, 2. Zero hunger, Aorta, medicine.diagnostic_test, biology, Cholesterol, business.industry, Macrophages, Biphenyl Compounds, Antagonist, Magnetic resonance imaging, General Medicine, Magnetic Resonance Imaging, 3. Good health, Disease Models, Animal, chemistry, biology.protein, Disease Progression, Female, business, Angiotensin II Type 1 Receptor Blockers, medicine.drug
Abstract: Objectives: The renin-angiotensin system and local phagocytic activity play a major role in atherosclerotic plaque development. Treatment with irbesartan, an antagonist of angiotensin II receptor, can decrease atherosclerotic lesion formation. Iron oxideYenhanced magnetic resonance imaging (MRI) can be successfully used to evaluate the phagocytic activity in the atherosclerotic plaque in mice. In this study, we used 2 iron oxideYenhanced MRI strategies, in vivo labeling by injection of iron oxide particles and injection of in vitro labeled macrophages, to investigate the effect of irbesartan on both atherosclerotic plaque size and macrophage content in apolipoprotein (Apo) EYdeficient mice. Materials and Methods: ApoEj/j female mice (C57BL/6 background; Charles-River, France) were divided into 2 groups (irbesartan treated [TG] or not treated [NTG]) and started on a high-fat diet (Harlan TD88137 Western Diet, 21% fat, 0.2% cholesterol). Animals underwent magnetic resonance examinations on a 7-T scanner at baseline and at 14 and 28 weeks of treatment. At each time point, 2 MRI sessions were performed, before and 48 hours after administration of an iron oxide agent (P904; Guerbet, France) or magnetically labeled macrophages (M&). At the end of the follow-up, blood samples were taken for plasma lipid dosing and aorta samples for histology. The study was approved by the animal experimentation ethic committee of our institution. Vessel wall area measurements were performed on high-resolution spin echo transverse images. Multiecho gradient echo images acquired with the same geometry were used to calculate T2* maps of the vessel wall using a pixel-by-pixel monoexponential fit. Irbesartan effect on vessel wall area over time was assessed using a factorial analysis of variance test. T2* values of the vessel wall at preY and postYultrasmall superparamagnetic iron oxide (USPIO) administration were analyzed with a 1-way analysis of variance test with Bonferroni post hoc. Results: Irbesartan treatment resulted in significantly smaller vessel wall areas at 28 weeks of treatment (P = 0.04). Postinjection values varied significantly over time for both the NTG-P904 (P = 0.02) and the TG-P904 (P = 0.01) groups. Furthermore, when comparing the TG-P904 with the NTGP904 group at 28 weeks of treatment, a significant difference was obtained for both preY and postYUSPIO administration values (P = 0.01). In the labeledmacrophage group, postinjection T2* values were smaller than the preinjection ones for the NTG animals at 14 weeks of treatment. No T2* changes were observed in the TG-M? group. The difference between preY and postYUSPIO administration T2* values ($T2*) was significantly smaller in the TG-P904 group compared with the NTG-P904 group at 28 weeks of treatment. At this point, a good correlation (R =0 .7,P = 0.03) was found between the $T2* values in the P904 imaging group and the macrophage-covered area by immunohistological analysis. Conclusions: The present study illustrates an MRI follow-up of intraplaque macrophages using in vivo labeling by iron oxide particle injection and macrophage injection after in vitro USPIO labeling in the assessment of a therapeutic effect in a mouse model of atherosclerosis. Even though in vivo labeling is not fully specific of macrophage uptake, it enabled the detection of a treatment-related reduction in the macrophage content of atherosclerotic plaques in ApoEj/j mice.
Published: 2012

22. Comparison of four-dimensional flow parameters for quantification of flow eccentricity in the ascending aorta

Author: David Saloner, Monica Sigovan, Michael D. Hope, Petter Dyverfeldt, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Adult, Male, medicine.medical_specialty, Adolescent, Systole, media_common.quotation_subject, Flow angle, Contrast Media, Magnetic Resonance Imaging, Cine, Aorta, Thoracic, Cardiovascular System, Imaging, Three-Dimensional, medicine.artery, Ascending aorta, medicine, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Image Processing, Computer-Assisted, Thoracic aorta, Eccentric, Humans, Radiology, Nuclear Medicine and imaging, Computer Simulation, Eccentricity (behavior), Aorta, media_common, Mathematics, Models, Statistical, Blood flow, Anatomy, Magnetic Resonance Imaging, Surgery, Flow (mathematics), Female
Abstract: To compare quantitative parameters for assessing the degree of eccentric systolic blood flow in the ascending thoracic aorta (AsAo).Forty-one patients were studied with three-dimensional (3D), cine phase-contract MRI (4D Flow). Analysis was performed at peak systole for a cross-sectional plane in the AsAo just distal to the sinotubular junction. AsAo flow was graded as normal, mildly, or markedly eccentric based on qualitative visual assessment. For quantitative analysis, flow jet angle and normalized flow displacement from the vessel center were calculated.Patients with normal AsAo systolic flow (n = 25) had an average flow jet angle of 13.7 degrees and flow displacement 0.04. These parameters were significantly elevated for patients with mild eccentric systolic flow (n = 6): 24.6 degrees (P = 0.012) and 0.12 (P = 0.001), respectively. However, for patients with marked eccentric flow (n = 10), only flow displacement was significantly elevated compared with the mild eccentric group (0.18; P = 0.04); flow angle was 25.7 degrees.Flow displacement is a more reliable quantitative parameter for measuring eccentric AsAo systolic flow than flow jet angle, and should be evaluated in studies investigating the role of eccentric flow in the promotion of aortic pathology.
Published: 2011

23. Quantification of iron-labeled cells with positive contrast in mouse brains

Author: Yves Berthezène, Emmanuelle Canet-Soulas, Jérôme Honnorat, Virginie Desestret, Monica Sigovan, Emilie Devillard, Monique Touret, Marlène Wiart, Serge Nataf, Adrien Riou, Norbert Nighoghossian, Fabien Chauveau, and Jean-Christophe Brisset
Subjects: Cancer Research, Relaxometry, medicine.medical_specialty, Iron, Contrast Media, Ferric Compounds, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, Mice, 0302 clinical medicine, Nuclear magnetic resonance, Text mining, medicine, Image Processing, Computer-Assisted, Animals, Radiology, Nuclear Medicine and imaging, medicine.diagnostic_test, Staining and Labeling, Chemistry, business.industry, Brain, Magnetic resonance imaging, equipment and supplies, Mice, Inbred C57BL, Oncology, Positive contrast, Nanoparticles, Female, Radiology, business, Artifacts, human activities, 030217 neurology & neurosurgery
Abstract: To quantify small amounts of iron-labeled cells in mouse brains with magnetic resonance imaging (MRI).Iron-labeled cells (from 500 to 7,500) were stereotaxically transplanted into the brain of living mice that were subsequently imaged with MRI at 4.7 T. We compared four quantitative methods: (1) T2 relaxometry, (2) T2* relaxometry, (3) the volume of the cloverleaf hypointense artifact generated on T2*-weighted images, and (4) the volume of the cloverleaf hyperintense artifact generated on positive contrast images.The methods based on relaxometry, whether T2 or T2*, did not correlate with the number of injected cells. By contrast, those based on measurement of cloverleaf artifact volume, whether using negative or positive enhancement, showed a significant linear relationship for the given range of cells (R [0.92-0.95], p 0.05).T2* artifact volume imaging (negative or positive) appears promising for the quantification of magnetically labeled cells following focal injection in the brain.
Published: 2010

24. Assessment of age modulated vascular inflammation in ApoE-/- mice by USPIO-enhanced magnetic resonance imaging

Author: Claire Corot, Eric Lancelot, Monica Sigovan, Bruno Neyran, Emmanuelle Canet-Soulas, Nicolas Provost, Zouher Majd, Hasan Alsaid, Amine Bessaad, Magali Breisse, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche et d'Application en Traitement de l'Image et du Signal (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National de la Recherche Agronomique (INRA), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), and Sigovan, Monica
Subjects: Apolipoprotein E, Pathology, medicine.medical_specialty, Arteriosclerosis, Statistics as Topic, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, Inflammation, 030204 cardiovascular system & hematology, Risk Assessment, 030218 nuclear medicine & medical imaging, Mice, 03 medical and health sciences, Apolipoproteins E, 0302 clinical medicine, Image Processing, Computer-Assisted, medicine, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Animals, Radiology, Nuclear Medicine and imaging, Correlation test, Aorta, Rupture, Analysis of Variance, medicine.diagnostic_test, Apoe mice, Vascular inflammation, business.industry, Macrophages, Age Factors, Thrombosis, Magnetic resonance imaging, General Medicine, medicine.disease, Magnetic Resonance Imaging, Mice, Inbred C57BL, Disease Progression, Feasibility Studies, Analysis of variance, medicine.symptom, Nuclear medicine, business, Software
Abstract: Objective: Inflammation within atherosclerotic lesions increases the risk for plaque rupture and thrombosis. A functional approach to plaque analysis is the intravenous administration of ultrasmall superparamagnetic particles of iron oxide (USPIO) that enables visualization of macrophages residing in the plaques. In this study, we sought to characterize the age-related inflammatory status associated with atherosclerosis lesion progression in ApoE ―/― mice using USPIO-enhanced magnetic resonance imaging (MRI). Materials and Methods: A total of 24 ApoE ―/― mice were divided in 4 groups (N = 6) and were given a high cholesterol diet from 6 weeks of age to the end of the protocol. One group per MR time point was investigated at 10, 16, 24, and 34 weeks of age. Each MR examination was performed on a 4.7 T scanner and consisted of baseline and 48 hours post-USPIO administration imaging sessions. P904, a USPIO contrast agent (Guerbet, Paris, France) with a potential for plaque macrophage targeting, was used. Vessel wall area measurements were performed on high resolution spin echo transverse images. Multi-echo gradient-echo images acquired with the same geometry were used to calculate T2 * maps of the vessel wall using a pixel-by-pixel monoexponential fit. A one-way analysis of variance was performed to characterize the temporal variation of vessel wall area, susceptibility artifact area, baseline, and post-USPIO T2 * values. MR measurements were correlated with the histologic findings. Results: A significant increase was found in the aortic wall area from 1.4 ± 0.2 at 10 weeks to 2.0 ± 0.3 mm 2 at 34 weeks of age (P < 0.05). Concerning the post-USPIO MRI, signal loss regions, with patterns spanning from focal to the complete disappearance of the vessel wall, were observed on all postcontrast images. A significant increase in the size of the susceptibility artifact was observed from 0.5 ± 0.2 to 2.4 ± 1.0 at 24 weeks (P < 0.05) and to 2.0 ± 0.9 mm 2 at 34 weeks (P < 0.05). The T2 * values calculated on the 48 hours post-USPIO images were shorter compared with baseline. The decrease was 34% ± 16% at 10 weeks, 57% ± 11% at 16 weeks, 57% ± 16% at 24 weeks, and 48% ± 13% at 34 weeks. The Pearson's correlation test between measurement of aortic wall area performed on both MR images and histologic analysis showed a statistically significant correlation (r = 0.695 and P < 0.05). A correlation was also obtained between the signal loss area and the macrophages covered area (r = 0.68 and P < 0.05). Conclusions: This study demonstrated the feasibility of USPIO-enhanced MRI in assessing the inflammatory status related to the temporal progression of the atherosclerosis plaque in ApoE ―/― transgenic mice model of atherosclerosis. In our experimental conditions, the vascular inflammation peak, for the ApoE ―/― mice feeding high-fat/high-cholesterol diet is measured between 16 and 24 weeks of age.
Published: 2010

25. Rapid-clearance iron nanoparticles for inflammation imaging of atherosclerotic plaque: initial experience in animal model

Author: Xavier Violas, Danielle Ibarrola, Eric Lancelot, Christine Laclédère, Catherine Desbleds-Mansard, Philippe Douek, Hasan Alsaid, Claire Corot, Jean-Sebastian Raynaud, D. Gamondes, Loic Boussel, Véronique Vives, Dominique Sappey-Marinier, Emmanuelle Canet-Soulas, Monica Sigovan, Abdulrazzaq Sulaiman, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche et d'Application en Traitement de l'Image et du Signal (CREATIS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Supérieure Chimie Physique Électronique de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etude et de Recherche Multimodal Et Pluridisciplinaire en imagerie du vivant (CERMEP - imagerie du vivant), Université de Lyon-Université de Lyon-CHU Grenoble-Hospices Civils de Lyon (HCL)-CHU Saint-Etienne-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Groupe Hospitalier Est, Service de Radiologie, Hospices Civils de Lyon (HCL), Service de Radiologie, Hôpital Louis Pradel [CHU - HCL], Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National de la Recherche Agronomique (INRA), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre d'Exploration et de Recherche Médicales par Émission de Positons (CERMEP), Université Joseph Fourier - Grenoble 1 (UJF)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-CHU Grenoble-Hospices Civils de Lyon (HCL)-CHU Saint-Etienne-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL)
Subjects: Pathology, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Contrast Media, Pilot Projects, 030204 cardiovascular system & hematology, 030218 nuclear medicine & medical imaging, 0302 clinical medicine, Magnetite Nanoparticles, ComputingMilieux_MISCELLANEOUS, Dextrans, Oxides, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], [PHYS.PHYS.PHYS-MED-PH]Physics [physics]/Physics [physics]/Medical Physics [physics.med-ph], [SDV.IB]Life Sciences [q-bio]/Bioengineering, Rabbits, medicine.symptom, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, medicine.medical_specialty, Metabolic Clearance Rate, Iron, Inflammation, [SDV.IB.MN]Life Sciences [q-bio]/Bioengineering/Nuclear medicine, Sensitivity and Specificity, 03 medical and health sciences, Animal model, [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system, Inflammation imaging, Metabolic clearance rate, medicine, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Animals, Humans, Radiology, Nuclear Medicine and imaging, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Aortitis, business.industry, Vascular disease, Reproducibility of Results, medicine.disease, Atherosclerosis, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Ferrosoferric Oxide, Disease Models, Animal, Rabbit model, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, business, Magnetic Resonance Angiography, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
Abstract: To evaluate the use of a recently developed fast-clearing ultrasmall superparamagnetic iron oxide (USPIO) for detection of vascular inflammation in atherosclerotic plaque.The study protocol was approved by the animal experimentation ethics committee. A recently introduced USPIO, P904, and a reference-standard USPIO, ferumoxtran-10, were tested in a rabbit model of induced aortic atherosclerosis. In vivo magnetic resonance (MR) angiography and T2*-weighted plaque MR imaging were performed at baseline and after administration of P904 and ferumoxtran-10 (administered dose for both, 1000 micromol of iron per kilogram of body weight) in 26 hyperlipidemic New Zealand white rabbits. The variation in vessel wall area over time was evaluated with nonparametric testing. Ex vivo MR imaging findings were compared with iron content at linear regression analysis.With in vivo MR imaging, plaque analysis was possible as early as 24 hours after P904 injection. The authors observed a 27.75% increase in vessel wall area due to susceptibility artifacts on day 2 (P = .04) and a 38.81% increase on day 3 (P = .04) after P904 administration compared with a 44.5% increase in vessel wall area on day 7 (P = .04) and a 34.8% increase on day 10 (P = .22) after ferumoxtran-10 administration. These susceptibility artifacts were correlated with intraplaque iron uptake in the corresponding histologic slices. The number of pixels with signal loss on the ex vivo MR images was linearly correlated with the logarithm of the iron concentration (P = .0001; R(2) = 0.93).Plaque inflammation in rabbits can be detected earlier with P904 than with ferumoxtran-10 owing to the faster blood pharmacokinetics and the early uptake of P904 in the reticuloendothelial system.http://radiology.rsnajnls.org/cgi/content/full/252/2/401/DC1.
Published: 2009
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26. Modified electrocardiograph-triggered black-blood turbo spin-echo technique to improve T1-weighting in contrast-enhanced MRI of atherosclerotic carotid arteries

Author: Romaric Loffroy, Gwenael Herigault, Emmanuelle Canet-Soulas, Monica Sigovan, Philippe Douek, Loic Boussel, Sigovan, Monica, Imagerie et modélisation Vasculaires, Thoraciques et Cérébrales (MOTIVATE), Centre de Recherche en Acquisition et Traitement de l'Image pour la Santé (CREATIS), Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Jean Monnet [Saint-Étienne] (UJM)-Hospices Civils de Lyon (HCL)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de radiologie et d'Imagerie médicale diagnostique et thérapeutique (CHU de Dijon), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), Laboratoire Electronique, Informatique et Image [UMR6306] (Le2i), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de Radiologie, Hôpital Louis Pradel [CHU - HCL], Hospices Civils de Lyon (HCL)-Hospices Civils de Lyon (HCL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université de Bourgogne (UB)-École Nationale Supérieure d'Arts et Métiers (ENSAM), HESAM Université (HESAM)-HESAM Université (HESAM)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL)
Subjects: Carotid Artery Diseases, Male, CONTRAST ENHANCED MRI, Image quality, Carotid arteries, media_common.quotation_subject, Black blood, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, Contrast Media, 030218 nuclear medicine & medical imaging, Electrocardiography, 03 medical and health sciences, Meglumine, 0302 clinical medicine, Image Interpretation, Computer-Assisted, Organometallic Compounds, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Humans, Contrast (vision), Medicine, Radiology, Nuclear Medicine and imaging, Aged, media_common, Pulse (signal processing), business.industry, Middle Aged, Fast spin echo, Magnetic Resonance Imaging, Weighting, Female, Artifacts, business, Nuclear medicine, 030217 neurology & neurosurgery
Abstract: Purpose To assess the efficacy of a modified electrocardiograph (EKG)-triggered black-blood T1W (T1W) spin-echo sequence in improving contrast on post-gadolinium high-resolution carotid plaque imaging by implementing heart-rate–independent contrast preparation. Materials and Methods We used a standard EKG-triggered double inversion-recovery (DIR) turbo spin-echo (TSE) sequence modified with the addition of an extra saturation (90°) radio frequency (RF) pulse placed immediately after the DIR module, shortening the repetition time to a fixed value of 400 msec. A total of 10 patients with atherosclerotic disease were included in the study. Postinjection intraplaque contrast measurements were performed on each patient for the standard and the modified sequence. Results Post-gadolinium-injection intraplaque contrast was 31.7 ± 12.8% with the standard T1W sequence (nT1-TSE), and 45.3 ± 17.2% with the modified T1W sequence (mT1-TSE), showing a significant contrast enhancement of 13.6% (P < 0.001) without significant image quality modification. Conclusion The addition of a RF pulse to the standard EKG-triggered T1W TSE sequence increased intraplaque contrast without increasing sequence acquisition time. Furthermore, it appeared to be a robust technique, easy to implement on clinical scanners. J. Magn. Reson. Imaging 2008;28:533–537. © 2008 Wiley-Liss, Inc.
Published: 2008

27. CMR2009: 10.05: Assessment of age modulated vascular inflammation in ApoEâ/âmice by USPIO-enhanced MRI

Author: Monica Sigovan, M. Breisse, B. Neyran, Emmanuelle Canet-Soulas, Hasan Alsaid, Claire Corot, Z. Majd, N. Provost, and Amine Bessaad
Subjects: Pathology, medicine.medical_specialty, Apoe mice, Vascular inflammation, business.industry, Medicine, Radiology, Nuclear Medicine and imaging, business
Published: 2009
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28. CMR 2007: 1.04:In-vivo USPIO's follow-up and optimized MRI protocol for inflammation imaging in atherosclerotic plaques

Author: C. Desbleds-Mansard, Philippe Douek, Monica Sigovan, Emmanuelle Canet-Soulas, Claire Corot, Jean-Sébastien Raynaud, Loic Boussel, D. Ibarrola, Xavier Violas, D. Gamondes, Eric Lancelot, Dominique Sappey-Marinier, and A. Sulaiman
Subjects: Pathology, medicine.medical_specialty, In vivo, business.industry, Inflammation imaging, medicine, Radiology, Nuclear Medicine and imaging, business
Published: 2007
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29. Improved quantification of abnormal aortic flow in 3D compared to standard 2D approach

Author: Michael D. Hope, Petter Dyverfeldt, Jarrett Wrenn, David Saloner, and Monica Sigovan
Subjects: Aortic valve disease, Medicine(all), medicine.medical_specialty, lcsh:Diseases of the circulatory (Cardiovascular) system, Radiological and Ultrasound Technology, business.industry, Aortic flow, medicine.disease, Bioinformatics, Text mining, Bicuspid aortic valve, lcsh:RC666-701, Internal medicine, Poster Presentation, medicine, Cardiology, cardiovascular system, Radiology, Nuclear Medicine and imaging, Cardiology and Cardiovascular Medicine, business, Angiology
Abstract: Author(s): Sigovan, Monica; Hope, Michael D; Wrenn, Jarrett; Dyverfeldt, Petter; Saloner, David
Published: 2013

30. Reproducibility of quantitative analysis of aortic 4D flow data

Author: David Saloner, Monica Sigovan, Petter Dyverfeldt, Jarrett Wrenn, and Michael D. Hope
Subjects: Medicine(all), lcsh:Diseases of the circulatory (Cardiovascular) system, Reproducibility, medicine.medical_specialty, Radiological and Ultrasound Technology, business.industry, Hemodynamics, Blood flow, computer.software_genre, Flow (mathematics), lcsh:RC666-701, Poster Presentation, cardiovascular system, Shear stress, Medicine, Radiology, Nuclear Medicine and imaging, Data mining, Cardiology and Cardiovascular Medicine, business, Quantitative analysis (chemistry), Displacement (fluid), computer, Biomedical engineering, Angiology
Abstract: Background 3D cine phase-contrast CMR ("4D Flow”) permits quantitative assessment of anomalous alterations of aortic blood flow. Two hemodynamic parameters that have been used for this purpose is the wall shear stress (WSS), which is known to regulate endothelial cell function, and the normalized flow displacement from the vessel center, which was recently shown to correlate with increased growth rates of ascending aortic dilation [1,2]. Analysis of these hemodynamic parameters requires that a user 1) positions a 2D plane of interest in the volumetric 4D Flow dataset and 2) delineates the contour of the vascular lumen in this 2D plane. We set out to assess the reproducibility of 4D Flow-based estimation of WSS and normalized flow displacement at these two critical levels of user-interaction. Furthermore, we assessed which of the parameters correlate best with aortic growth.
Published: 2013

31. Response

Author: Michael D. Hope, Monica Sigovan, Petter Dyverfeldt, and David Saloner
Subjects: Radiology, Nuclear Medicine and imaging
Published: 2012
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32. CV-WS-29 Amelioration du contraste T1 en IRM vasculaire haute resolution synchronisee a l’ECG

Author: R. Loffroy, Loic Boussel, Philippe Douek, Emmanuelle Canet-Soulas, G. Herigault, and Monica Sigovan
Subjects: Radiological and Ultrasound Technology, Radiology, Nuclear Medicine and imaging
Abstract: Objectifs En imagerie haute resolution vasculaire, l’intensite de la ponderation T1 des sequences Turbo Spin Echo synchronisees a l’ECG est limitee par la frequence cardiaque du patient. Nous proposons une methode simple pour accroitre la ponderation T1 de ces sequences afin d’ameliorer le contraste entre les differents elements de la plaque atheromateuse carotidienne apres injection de Gadolinium. Materiels et methodes Ajout a la sequence 2D TSE avec double inversion-recuperation et synchronisation ECG d’un pulse de 90 ° entre le module de double inversion-recuperation et le module de lecture TSE de facon a rendre le temps de repetition de la sequence plus court et independant du rythme cardiaque. Validation de la sequence par une etude incluant 10 patients consecutifs presentant une plaque carotidienne avec mesure, par deux observateurs independants, du contraste intra-plaque 5 minutes apres injection intraveineuse de Gadolinium. Resultats Le contraste intra-plaque etait de 31,7 ± 12,8 % avec la sequence standard contre 45,3 ± 17,2 % avec la sequence modifiee soit un gain en contraste de 13,6 % (p Conclusion L’ajout d’un pulse de 90 a a la sequence 2D TSE synchronisee a l’ECG est une methode simple, couramment utilisable, permettant d’accroitre le contraste intra-plaque sans augmenter le temps d’acquisition.
Published: 2007
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32 results on '"Monica Sigovan"'

1. Bicolor K-edge spectral photon-counting CT imaging for the diagnosis of thoracic endoleaks: A dynamic phantom study

2. Feasibility of human vascular imaging of the neck with a large field-of-view spectral photon-counting CT system

3. Feasibility of lung imaging with a large field-of-view spectral photon-counting CT system

4. Multicolour imaging with spectral photon-counting CT: a phantom study

5. 3D black blood MR angiography of the carotid arteries. A simple sequence for plaque hemorrhage and stenosis evaluation

6. Simultaneous assessment of microcalcifications and morphological criteria of vulnerability in carotid artery plaque using hybrid 18F-NaF PET/MRI

7. Spectral Photon-Counting Computed Tomography for Coronary Stent Imaging: Evaluation of the Potential Clinical Impact for the Delineation of In-Stent Restenosis

8. Comparison of free breathing 3D mDIXON with single breath-hold 3D inversion recovery sequences for the assessment of Late Gadolinium Enhancement

9. MRI-based detection of renal artery abnormalities related to renal denervation by catheter-based radiofrequency ablation in drug resistant hypertensive patients

10. MR imaging assessment of myocardial edema with T2 mapping

11. Extended 3D approach for quantification of abnormal ascending aortic flow

12. Benign and malignant enlarged chest nodes staging by diffusion-weighted MRI: an alternative to mediastinoscopy?

13. Evaluation of image quality of DWIBS versus DWI sequences in thoracic MRI at 3T

14. MRI hemodynamic markers of progressive bicuspid aortic valve-related aortic disease

15. Positive contrast with therapeutic iron nanoparticles at 4.7 T

16. M1-Activated Macrophages Migration, A Marker of Aortic Atheroma Progression

17. Photon counting spectral CT component analysis of coronary artery atherosclerotic plaque samples

18. Systolic flow displacement correlates with future ascending aortic growth in patients with bicuspid aortic valves undergoing magnetic resonance surveillance

19. High-Resolution MRI Visualization of Aneurysmal Thrombosis after Flow Diverter Stent Placement

20. USPIO-enhanced MR Angiography of Arteriovenous Fistulas in Patients with Renal Failure

21. Anti-inflammatory drug evaluation in ApoE-/- mice by ultrasmall superparamagnetic iron oxide-enhanced magnetic resonance imaging

22. Comparison of four-dimensional flow parameters for quantification of flow eccentricity in the ascending aorta

23. Quantification of iron-labeled cells with positive contrast in mouse brains

24. Assessment of age modulated vascular inflammation in ApoE-/- mice by USPIO-enhanced magnetic resonance imaging

25. Rapid-clearance iron nanoparticles for inflammation imaging of atherosclerotic plaque: initial experience in animal model

26. Modified electrocardiograph-triggered black-blood turbo spin-echo technique to improve T1-weighting in contrast-enhanced MRI of atherosclerotic carotid arteries

27. CMR2009: 10.05: Assessment of age modulated vascular inflammation in ApoEâ/âmice by USPIO-enhanced MRI

28. CMR 2007: 1.04:In-vivo USPIO's follow-up and optimized MRI protocol for inflammation imaging in atherosclerotic plaques

29. Improved quantification of abnormal aortic flow in 3D compared to standard 2D approach

30. Reproducibility of quantitative analysis of aortic 4D flow data

31. Response

32. CV-WS-29 Amelioration du contraste T1 en IRM vasculaire haute resolution synchronisee a l’ECG

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32 results on '"Monica Sigovan"'

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