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OBJECTIVES: BI-RADS 3 is an established assessment category in which the probability of malignancy is equal to or less than 2%. However, monitoring adherence to imaging criteria can be challenging and there are few established benchmarks for auditing BI-RADS 3 assignments. In this study, we explore some parameters that could serve as useful tools for quality control and clinical practice management. MATERIALS AND METHODS: This retrospective study covered a 4-year period (Jan 2014-Dec 2017) and included all women over 40 years who were recalled from a screening exam and had an initial assignment of BI-RADS 3 (probably benign) category after diagnostic workup. A follow-up period of 2 years following the assignment of BI-RADS 3 was used for quantitative quality control metrics. RESULTS: Among 135,765 screening exams, 13,453 were recalled and 1,037 BI-RADS 3 cases met inclusion criteria. The follow-up rate at 24 months was 86.7%. The upgrade rate was 7.4% (77/1,037) [CI: 5.9–9.2%] and the PPV3 was 33.8% (26/77) [CI: 23.4–45.5%]. The cancer yield was 2.51% (26/1,037) [CI: 1.64–3.65%] and did not differ (p=0. 243) from the 2% probability of malignancy. The initial BI-RADS3 per screening exam and per recall from screening were 0.76% (1,037/135,765) [CI: 0.72–0.81%] and 7.7% (1,037/13,453) [CI: 7.26–8.17%], respectively. CONCLUSION: Regular audit of BIRADS 3 metrics has the potential to provide additional insights for clinical practice management. Data from varied clinical settings with input from an expert committee could help establish benchmarks for these metrics.

Dedicated cone-beam breast computed tomography (CBBCT) using short-scan acquisition is being actively investigated to potentially reduce the radiation dose to the breast. This would require determining the optimal x-ray source trajectory for such short-scan acquisition.To quantify the projection angle-dependent normalized glandular dose coefficient (A cohort of 75 CBBCT clinical datasets was segmented and used to generate three breast models - (I) patient-specific breast with heterogeneous fibroglandular tissue distribution and real breast shape, (II) patient-specific breast shape with homogeneous tissue distribution and matched fibroglandular weight fraction, and (III) homogeneous semi-ellipsoidal breast with patient-specific breast dimensions and matched fibroglandular weight fraction, which corresponds to the breast model used in current radiation dosimetry protocols. For each clinical dataset, the angularThe theoretical model predicted that the angularThe heterogeneous tissue distribution affected the angular

Purpose To develop a fast volumetric T1 mapping technique. Materials and methods A stack-of-stars (SOS) Look Locker technique based on the acquisition of undersampled radial data (>30× relative to Nyquist) and an efficient multi-slab excitation scheme is presented. A principal-component based reconstruction is used to reconstruct T1 maps. Computer simulations were performed to determine the best choice of partitions per slab and degree of undersampling. The technique was validated in phantoms against reference T1 values measured with a 2D Cartesian inversion-recovery spin-echo technique. The SOS Look Locker technique was tested in brain (n = 4) and prostate (n = 5). Brain T1 mapping was carried out with and without kz acceleration and results between the two approaches were compared. Prostate T1 mapping was compared to standard techniques. A reproducibility study was conducted in brain and prostate. Statistical analyses were performed using linear regression and Bland Altman analysis. Results Phantom T1 values showed excellent correlations between SOS Look Locker and the inversion-recovery spin-echo reference (r2 = 0.9965; p Conclusion A rapid volumetric T1 mapping technique was developed. The technique enables high-resolution T1 mapping with adequate anatomical coverage in a clinically acceptable time.

Purpose A clinical-prototype, dedicated, cone-beam breast computed tomography (CBBCT) system with offset detector is undergoing clinical evaluation at our institution. This study is to estimate the normalized glandular dose coefficients ( DgN CT ) that provide air kerma-to-mean glandular dose conversion factors using Monte Carlo simulations. Materials and methods The clinical prototype CBBCT system uses 49 kV x-ray spectrum with 1.39 mm 1st half-value layer thickness. Monte Carlo simulations (GATE, version 8) were performed with semi-ellipsoidal, homogeneous breasts of various fibroglandular weight fractions ( f g = 0.01 , 0.15 , 0.5 , 1 ) , chest wall diameters ( d = 8 , 10 , 14 , 18 , 20 cm), and chest wall to nipple length ( l = 0.75 d ), aligned with the axis of rotation (AOR) located at 65 cm from the focal spot to determine the DgN CT . Three geometries were considered - 40 × 30 -cm detector with no offset that served as reference and corresponds to a clinical CBBCT system, 30 × 30 -cm detector with 5 cm offset, and a 30 × 30 -cm detector with 10 cm offset. Results For 5 cm lateral offset, the DgN CT ranged 0.177 - 0.574 mGy/mGy and reduction in DgN CT with respect to reference geometry was observed only for 18 cm ( 6.4 % ± 0.23 % ) and 20 cm ( 9.6 % ± 0.22 % ) diameter breasts. For the 10 cm lateral offset, the DgN CT ranged 0.221 - 0.581 mGy/mGy and reduction in DgN CT was observed for all breast diameters. The reduction in DgN CT was 1.4 % ± 0.48 % , 7.1 % ± 0.13 % , 17.5 % ± 0.19 % , 25.1 % ± 0.15 % , and 27.7 % ± 0.08 % for 8, 10, 14, 18, and 20 cm diameter breasts, respectively. For a given breast diameter, the reduction in DgN CT with offset-detector geometries was not dependent on f g . Numerical fits of DgN CT d , l , f g were generated for each geometry. Conclusion The DgN CT and the numerical fit, D g N CT d , l , f g would be of benefit for current CBBCT systems using the reference geometry and for future generations using offset-detector geometry. There exists a potential for radiation dose reduction with offset-detector geometry, provided the same technique factors as the reference geometry are used, and the image quality is clinically acceptable.

Compressed sensing based iterative reconstruction algorithms for computed tomography such as adaptive steepest descent-projection on convex sets (ASD-POCS) are attractive due to their applicability in incomplete datasets such as sparse-view data and can reduce radiation dose to the patients while preserving image quality. Although IR algorithms reduce image noise compared to analytical Feldkamp-Davis-Kress (FDK) algorithm, they may generate artifacts, particularly along the periphery of the object. One popular solution is to use finer image-grid followed by down-sampling. This approach is computationally intensive but may be compensated by reducing the field of view. Our proposed solution is to replace the algebraic reconstruction technique within the original ASD-POCS by ordered subsets-simultaneous algebraic reconstruction technique (OS-SART) and with initialization using FDK image. We refer to this method as Fast, Iterative, TV-Regularized, Statistical reconstruction Technique (FIRST). In this study, we investigate FIRST for cone-beam dedicated breast CT with large image matrix. The signal-difference to noise ratio (SDNR), the difference of the mean value and the variance of adipose and fibroglandular tissues for both FDK and FIRST reconstructions were determined. With FDK serving as the reference, the root-mean-square error (RMSE), bias, and the full-width at half-maximum (FWHM) of microcalcifications in two orthogonal directions were also computed. Our results suggest that FIRST is competitive to the finer image-grid method with shorter reconstruction time. Images reconstructed using the FIRST do not exhibit artifacts and outperformed FDK in terms of image noise. This suggests the potential of this approach for radiation dose reduction in cone-beam breast CT.

Objective. A dedicated cone-beam breast computed tomography (BCT) using a high-resolution, low-noise detector operating in offset-detector geometry has been developed. This study investigates the effects of varying detector offsets and image reconstruction algorithms to determine the appropriate combination of detector offset and reconstruction algorithm. Approach. Projection datasets (300 projections in 360°) of 30 breasts containing calcified lesions that were acquired using a prototype cone-beam BCT system comprising a 40 × 30 cm flat-panel detector with 1024 × 768 detector pixels were reconstructed using Feldkamp–Davis–Kress (FDK) algorithm and served as the reference. The projection datasets were retrospectively truncated to emulate cone-beam datasets with sinograms of 768 × 768 and 640 × 768 detector pixels, corresponding to 5 cm and 7.5 cm lateral offsets, respectively. These datasets were reconstructed using the FDK algorithm with appropriate weights and an ASD-POCS-based Fast, total variation-Regularized, Iterative, Statistical reconstruction Technique (FRIST), resulting in a total of 4 offset-detector reconstructions (2 detector offsets × 2 reconstruction methods). Signal difference-to-noise ratio (SDNR), variance, and full-width at half-maximum (FWHM) of calcifications in two orthogonal directions were determined from all reconstructions. All quantitative measurements were performed on images in units of linear attenuation coefficient (1/cm). Results. The FWHM of calcifications did not differ (P > 0.262) among reconstruction algorithms and detector formats, implying comparable spatial resolution. For a chosen detector offset, the FRIST algorithm outperformed FDK in terms of variance and SDNR (P Significance. This study indicates the feasibility of using the compressed sensing-based, FRIST algorithm to reconstruct sinograms from offset-detectors. Among the reconstruction methods and detector offsets studied, FRIST reconstructions corresponding to a 30 cm × 30 cm with 5 cm lateral offset, achieved the best performance. A clinical prototype using such an offset geometry has been developed and installed for clinical trials.

Worldwide, radiologists are experiencing increasing clinical workloads with associated increased burnout. This paper will review burnout definitions, prevalence, and causes. We will also share data from a survey of US neuroradiologists as an example of the impact of work-work imbalances from clinical overload. This article examines the impact on several key job indicators and upon the quality of the neuroradiology work environment in one nation. Finally, we will review proposals for ameliorating and preventing radiologist burnout.A survey was sent to members of the American Society of Neuroradiology (ASNR) practicing in the US. Selected measures included workhours and volume, burnout symptoms, subjectively reported errors, participation in non-clinical activities, perceived interpretation quality, results communication, and consideration of early retirement.Survey respondents (n = 412) included 57.5% with teaching responsibilities. Cutbacks in teaching, mentoring, research and/or practice building were reported by 86.2% of respondents. Subjective errors were reported as occurring sometimes or more frequently in the majority of respondents (56.9%) and were increased with faster than optimal speeds of interpretation (P 0.001) and signing (P 0.001). At least one burnout measure was reported by 85.2% of respondents.Increasing clinical demands in conjunction with a more challenging work environment impacts the ability of radiologists to perform core non-interpretive duties that are critical for success in both private and academic practice and is associated with burnout symptoms and adverse effects on quality. While this survey does not prove causation, the trends and findings are concerning and warrant both close monitoring and appropriate intervention.

Advanced glycation end products (AGEs) are major risk factors for vascular complications in diabetes. Its role in gestational diabetes mellitus (GDM) and vascular complications in GDM is not known. The present study was aimed to study the association of AGEs with GDM and vascular inflammation. Plasma samples from normal pregnant and GDM women (n = 50 each) were obtained from two tertiary referral centers in Tamil Nadu, India. Quantification of AGEs, methylglyoxal (MGO), ICAM-1, and malondialdehyde (MDA) were performed by commercially available ELISA kits. The third trimester fasting blood sugar (101.35 ± 26.15 vs. 81.63 ± 6.14, p

OBJECTIVE To investigate the image quality and x-ray dose associated with a transmission computed tomography (CT) component implemented within the same platform of an experimental benchtop x-ray fluorescence CT (XFCT) system for multimodal preclinical imaging applications. METHODS Cone-beam CT scans were performed using an experimental benchtop CT + XFCT system and a cylindrically-shaped 3D-printed polymethyl methacrylate phantom (3 cm in diameter, 7 cm in height) loaded with various concentrations (0.05-1 wt. %) of gold nanoparticles (GNPs). Two commercial CT quality assurance phantoms containing 3D line-pair (LP) targets and contrast targets were also scanned. The x-ray beams of 40 and 62 kVp, both filtered by 0.08 mm Cu and 0.4 mm Al, were used with 17 ms of exposure time per projection at three current settings (2.5, 5, and 10 mA). The ordered-subset simultaneous algebraic reconstruction and total variation-minimization methods were used to reconstruct images. Sparse projection and short scan were considered to reduce the x-ray dose. The contrast-to-noise ratio (CNR) and modulation transfer function (MTF) were calculated. RESULTS The lowest detectable concentration of GNPs (CNR > 5) and the highest spatial resolution (per MTF50%) were 0.10 wt. % and 9.5 LP/CM, respectively, based on the images reconstructed from 360 projections of the 40 kVp beam (or x-ray dose of 3.44 cGy). The background noise for the image resulting in the lowest GNP detection limit was 25 Hounsfield units. CONCLUSION The transmission CT component within the current experimental benchtop CT + XFCT system produced images deemed acceptable for multimodal (CT + XFCT) imaging purposes, with less than 4 cGy of x-ray dose.

Diabetes Mellitus (DM) is one among the supreme metabolic issues observed in history since 3000 BCE and has gained much interest recently due to the increasing number of diabetic cases every year. Glucose is considered as the most iconic biomarker for diabetes detection, and fluctuations in its levels are related to different stages of DM. However, methylglyoxal (MG) is evolving as a diabetes marker since it plays a significant role in biological processes Apart from DM, MG causes several metabolic irregularities like hypertension, neuropathy, nephropathy, oxidative stress. Besides, MG is a predominant precursor of advanced glycation end products (AGEs), which result in protein dysfunction, glycation of vascular tissues and aging. In this background, detection of MG has much importance, and the design of smart models is desirable. MG formation, detoxification, and its glycation effects have paved the way for the development of detection strategies which are described in detail here. The direct and indirect methods of MG measurement have been established in the past. At present, techniques like high-performance liquid chromatography, gas chromatography-mass spectrometry, enzyme-linked immunosorbent assay, capillary electrophoresis, electrochemical biosensors have been used to quantify MG present in the samples. Here, we have tried to correlate the function of MG and detection strategies to explain the major challenges posed towards implementation of easy, efficient and accurate standardization.

Proper vascular function is important for well-being of mother and growing fetus. VEGFTOTAL, and VEGF165b levels and its vascular endothelial complications in gestational diabetes mellitus (GDM) to...

Background Advances in abdominal MRI have enabled rapid, free-breathing imaging without the need for intravenous or oral contrast material. The use of MRI as the primary imaging modality for suspected appendicitis has not been previously studied. Purpose To determine the diagnostic performance of MRI as the initial imaging modality in children suspected of having acute appendicitis. Materials and Methods The study included consecutive patients 18 years of age and younger presenting with acute abdominal pain at a tertiary care institution from January 2013 through June 2016 who subsequently underwent an unenhanced MRI examination as the primary diagnostic imaging modality. Electronic medical records and radiology reports were retrospectively evaluated for the feasibility and diagnostic performance of MRI, with surgical pathology and follow-up electronic records as reference standards. Statistical analyses were performed by using simple binomial proportions to quantify sensitivity, specificity, and accuracy, and exact 95% confidence intervals (CIs) were obtained. Results After exclusions, 402 patients (median age: 13 years; interquartile range [IQR], 9-15 years; 235 female patients; 167 male patients) were included. Sedation for MRI was required in 13 of 402 patients (3.2%; 95% CI: 1.7%, 5.5%). The appendix was visualized in 349 of 402 patients (86.8%; 95% CI: 83.1%, 90%); for the remaining patients, a diagnosis was provided on the basis of secondary signs of appendicitis. The sensitivity, specificity, and accuracy of MRI as the primary diagnostic imaging modality for the evaluation of acute appendicitis were 97.9% (95 of 97; 95% CI: 92.8%, 99.8%), 99% (302 of 305; 95% CI: 97.2%, 99.8%), and 98.8% (397 of 402; 97.1%, 99.6%), respectively. Among patients with negative findings for appendicitis at MRI, an alternate diagnosis was provided in 113 of 304 patients (37.2%; 95% CI: 31.7%, 42.9%). Conclusion When performed as the initial imaging modality in children suspected of having acute appendicitis, MRI examinations had high diagnostic performance for the diagnosis of acute appendicitis and in providing alternative diagnoses. © RSNA, 2019 See also the editorial by Dillman and Trout in this issue.

Hyperglycaemia during pregnancy is the main reason for developing diabetes mediated vascular complications. Advanced glycation end products (AGEs) are formed due to non-enzymatic glycation of proteins, lipids and nucleic acids during hyperglycaemia. It has the potential to damage vasculature by modifying the substrate or by means of AGEs and receptor of AGE (RAGE) interaction. It has been linked with the pathogenesis of various vascular diseases including coronary heart disease, atherosclerosis, restenosis etc. This study was carried out to investigate the role of AGEs-EGR-1 pathway in gestational diabetes mellitus (GDM) vascular inflammation. Human umbilical vein endothelial cells (HuVECs) isolated from normal glucose tolerant mothers were subjected to various treatments including high glucose, silencing of early growth response (EGR)-1, blockade of protein kinase C (PKC) β, blocking extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), and treatment with AGEs and assayed for EGR-1, tissue factor (TF) and soluble intercellular adhesion molecule (sICAM)-1. Similarly, umbilical vein endothelial cells isolated from normal and GDM mothers were assayed for EGR-1, TF, and sICAM-1. There was a significant increase in EGR-1 and TF levels in HuVECs isolated form GDM mother's umbilical cord and normal HuVECs treated with high glucose condition. This was accompanied by elevated levels of sICAM-1 in high glucose treated cells. Our results revealed AGE-mediated activation of EGR-1 and its downstream genes via PKC βII and ERK1/2 signaling pathway. The present study demonstrated a novel mechanism of AGEs/ PKC βII/ ERK1/2/EGR-1 pathway in inducing vascular inflammation in GDM.

To develop and investigate a deep learning approach that uses sparse-view acquisition in dedicated breast computed tomography for radiation dose reduction, we propose a framework that combines 3D sparse-view cone-beam acquisition with a multi-slice residual dense network (MS-RDN) reconstruction. Projection datasets (300 views, full-scan) from 34 women were reconstructed using the FDK algorithm and served as reference. Sparse-view (100 views, full-scan) projection data were reconstructed using the FDK algorithm. The proposed MS-RDN uses the sparse-view and reference FDK reconstructions as input and label, respectively. Our MS-RDN evaluated with respect to fully sampled FDK reference yields superior performance, quantitatively and visually, compared to conventional compressed sensing methods and state-of-the-art deep learning based methods. The proposed deep learning driven framework can potentially enable low dose breast CT imaging.

PURPOSE: To develop a fast volumetric T(1) mapping technique. MATERIALS AND METHODS: A stack-of-stars (SOS) Look Locker technique based on the acquisition of undersampled radial data (>30X relative to Nyquist) and an efficient multi-slab excitation scheme is presented. A principal-component based reconstruction is used to reconstruct T(1) maps. Computer simulations were performed to determine the best choice of partitions per slab and degree of undersampling. The technique was validated in phantoms against reference T(1) values measured with a 2D Cartesian inversion-recovery spin-echo technique. The SOS Look Locker technique was tested in brain (n=4) and prostate (n=5). Brain T(1) mapping was carried out with and without k(z) acceleration and results between the two approaches were compared. Prostate T(1) mapping was compared to standard techniques. A reproducibility study was conducted in brain and prostate. Statistical analyses were performed using linear regression and Bland Altman analysis. RESULTS: Phantom T(1) values showed excellent correlations between SOS Look Locker and the inversion-recovery spin-echo reference (r(2)=0.9965; p

Background Abdominopelvic magnetic resonance imaging (MRI) is increasingly being used to evaluate children with abdominal pain suspected of having acute appendicitis. At our institution, these examinations are preliminarily interpreted by radiology residents, especially when performed after hours. Objective To determine the accuracy of preliminary reports rendered by radiology residents in this setting. Materials and methods Three hundred seventy-seven pediatric abdominopelvic MRI examinations were included. The preliminary (resident) and final (attending) radiology reports were coded as diagnosing acute appendicitis or no acute appendicitis. The concordance between resident and attending radiologist interpretations was calculated. Additionally, both resident and attending reports were compared to available surgical pathology or clinical follow-up data. Results Overall concordance rate for the diagnosis of acute appendicitis was 97.1%. Concordance for verified cases of acute appendicitis was 93.4%. Concordance rates did not differ by residents’ postgraduate year levels. When compared against surgical pathology or clinical follow-up data, residents demonstrated 91.2% sensitivity and 97.6% specificity. There was no statistically significant difference in the sensitivity or specificity of resident or attending radiologist interpretations. Conclusion Radiology residents demonstrate high concordance with attending pediatric radiologists in their interpretations of pediatric abdominopelvic MRI for acute appendicitis. The diagnostic performances of residents and attendings were comparable.

BACKGROUND: High-resolution, low-noise detectors with minimal dead-space at chest-wall could improve posterior coverage and microcalcification visibility in dedicated cone-beam breast CT (CBBCT). However, their smaller field-of-view necessitates laterally-shifted detector geometry to enable optimizing the air-gap for x-ray scatter rejection. OBJECTIVE: To evaluate laterally-shifted detector geometry for CBBCT with clinical projection datasets that provide for anatomical structures and lesions. METHODS: CBBCT projection datasets (n=17 breasts) acquired with a 40×30-cm detector (1024×768-pixels, 0.388-mm pixels) were truncated along the fan-angle to emulate 20.3×30-cm, 22.2×30-cm and 24.1×30-cm detector formats and correspond to 20, 120, 220-pixels overlap in conjugate views, respectively. Feldkamp-Davis-Kress (FDK) algorithm with three different weighting schemes were used for reconstruction. Visual analysis for artifacts and quantitative analysis of root-mean-squared-error (RMSE), absolute difference between truncated and 40×30-cm reconstructions (Diff), and its power spectrum (PS(Diff)) were performed. RESULTS: Artifacts were observed for 20.3×30-cm, but not for other formats. The 24.1×30-cm provided the best quantitative results with RMSE and Diff (both in units of μ, cm(−1)) of 4.39×10(−3)±1.98×10(−3) and 4.95×10(−4)±1.34×10(−4), respectively. The PS(Diff)(>0.3 cycles/mm) was in the order of 10(−14)μ(2)mm(3) and was spatial-frequency independent. CONCLUSIONS: Laterally-shifted detector CBBCT with at least 220-pixels overlap in conjugate views (24.1×30-cm detector format), provides quantitatively accurate and artifact-free reconstruction.

Objective: To jointly optimize collimator design and image reconstruction algorithm in X-ray Fluorescence Computed Tomography (XFCT) for imaging low concentrations of high atomic number (Z) elements in small animal models. Methods: Single pinhole (SPH) collimator and three types of multi-pinhole (MPH) collimators were evaluated. MPH collimators with 5, 7, and 9 pinholes using lead, stainless steel and brass were considered. A digital cylindrical phantom (0.5 mm3 voxels) of 25 mm diameter and 25 mm height with a central 5 mm diameter and 12.5 mm height cylindrical insert containing gold nanoparticles (2:1 insert: background concentration) was modeled. A 125 kVp, 2 mm Sn filtered x-ray spectrum (0.5 cGy/projection) for gold K-shell XFCT was considered. System matrices were implemented using analytical point spread functions (PSF) for each pinhole collimator. Poisson noise was added to the projection data (16 equiangular views) before image reconstruction using Maximum-Likelihood Expectation-Maximization (ML-EM) algorithm. Signal-present and signal-absent images were generated for the detection task performed by a channelized Hotelling observer (CHO) with 10 Dense Difference-of-Gaussian channels. The area under the curve (AUC) in receiver operating characteristic was used as the image quality metric. Results: A stainless steel focusing type MPH with 7 pinholes and 20 iterations of ML-EM provided the highest AUC. Conclusion: MPH collimators outperformed SPH collimators for XFCT and consistently high AUCs were observed with focusing type MPH designs with 7 pinholes. Significance: The combinations of collimator design and image reconstruction parameters that maximized AUC were identified, which could improve the performance of XFCT.

Background T1 mapping is often used in some clinical protocols. Existing techniques are limited in slice coverage, and/or spatial-temporal resolution, or require long acquisitions. Here we present a multi-slice inversion-recovery (IR) radial steady-state free precession (radSSFP) pulse sequence combined with a principal component (PC) based reconstruction that overcomes these limitations. Purpose To develop a fast technique for multi-slice high-resolution T1 mapping. Study type Technical efficacy study done prospectively. Phantom/subjects IR-radSSFP was tested in phantoms, five healthy volunteers, and four patients with abdominal lesions. Field strength/sequence IR-radSSFP was implemented at 3T. Assessment Computer simulations were performed to optimize the flip angle for T1 estimation; testing was done in phantoms using as reference an IR spin-echo pulse sequence. T1 mapping with IR-radSSFP was also assessed in vivo (brain and abdomen) and T1 values were compared with literature. T1 maps were also compared with a radial IR-FLASH technique. Statistical tests A two-tailed t-test was used to compare T1 values in phantoms. A repeatability study was carried out in vivo using Bland-Altman analysis. Results Simulations and phantom experiments showed that a flip angle of 20˚ was optimal for T1 mapping. When comparing single to multi-slice experiments in phantoms there were no significant differences between the means T1 values (P = 0.0475). In vivo results show that T1 maps with spatial resolution as high as 0.69 mm × 0.69 mm × 2.00 mm (brain) and 0.83 mm × 0.83 mm × 3.00 mm (abdomen) can be generated for 84 brain slices in 3 min and 10 abdominal slices in a breath-hold; T1 values were comparable to those reported in literature. The coefficients of variation from the repeatability study were 1.7% for brain and 2.5-2.7% in the abdomen. Data conclusion A multi-slice IR-radSSFP technique combined with a PC-based reconstruction was demonstrated for higher resolution T1 mapping. This technique is fast, motion-insensitive and yields repeatable T1 values comparable to those in literature. Level of evidence 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:239-252.

Early growth response-1 (Egr-1) protein upregulation is reported in diabetes and vascular disorders. This study aims at deciphering its role in hyperglycemia induced changes of retinal endothelium. Human retinal endothelial cells (hRECs) were exposed to hyperglycemia (25mM) and normoglycemia (5.5mM). Gene silencing was done using siRNA against Egr-1. Transcript and protein level analysis of Egr-1 and gene targets were done using qPCR and immunoblotting respectively in hRECs, diabetic and nondiabetic human retina and immunofluorescence for localization in retinal sections. Hyperglycemia induced Egr-1 and vascular endothelial growth factor-A (VEGF-A) but not pigment epithelium derived factor (PEDF) in hRECs. Expression of Egr-1 repressor NGFI-A binding protein-2 (NAB-2) was unaltered. Egr-1 downstream gene targets, tissue factor (TF) and intercellular adhesion molecule-1 (ICAM-1) expression were increased in hRECs which was reduced by Egr-1 silencing in hyperglycemia. Diabetic retina, showed an increase in Egr-1, VEGF-A and gene target TF, ICAM-1 but not NAB-2 and PEDF similar to the changes seen in hyperglycemic hRECs. Hyperglycemic induction of Egr-1 and absence of NAB-2 repression in retinal endothelium, up-regulates downstream genes involved in pro-thrombotic and pro-inflammatory pathways linking Egr-1 in diabetes mediated vascular aberration of retina.

Methylglyoxal (MG) is a predominant precursor for advanced glycation end products (AGEs) due to its protein glycation reactions, which are the major causes of diabetic complications. MG is explored as a significant biomarker towards the prediction of diabetic complications. With this background, a non-enzymatic electrochemical biosensor has been developed to detect MG in human blood plasma samples. Microwave synthesized V2O5 nanoplates were used as interface material in the fabrication of modified gold (Au) working electrode for electrochemical MG biosensor. Orthorhombic crystal structured V2O5 with an oxidation state of +5 exhibited specific MG sensing performance. Cyclic voltammetry and amperometry studies confirmed the electrocatalytic nature of V2O5 nanoplates modified Au electrode in the detection of MG. Non-enzymatic V2O5 modified Au electrode showed a sensitivity of 4.519µAµM-1 with a linear range of 3-30µM, limit of detection (LOD) of 0.24µM, limit of quantification (LOQ) of 0.80µM and a response time less than 8s towards MG. The lifetime and percentage recovery of the sensor was found to be 25 days (90%) and 102.5-108.7% respectively.

Early detection of breast cancers by mammography in conjunction with adjuvant therapy have contributed to reduction in breast cancer mortality. Mammography remains the ‘gold-standard’ for breast cancer screening, but is limited by tissue superposition. Digital breast tomosynthesis and more recently, dedicated breast computed tomography have been developed to alleviate the tissue superposition problem. However, all of these modalities rely upon x-ray attenuation contrast to provide anatomical images and there are ongoing efforts to develop and clinically translate alternative modalities. These emerging modalities could provide for new contrast mechanisms and may potentially improve lesion detection and diagnosis. In this article, several of these emerging modalities are discussed with a focus on technologies that have advanced to the stage of in vivo clinical evaluation.

Our large single-center study demonstrates the safety of performing contrast-enhanced MR imaging with gadobenate dimeglumine in patients with severe chronic kidney disease, with no patients having developed nephrogenic systemic fibrosis at follow-up.

Objectives: Ultrasound (US) is commonly used for diagnostic evaluation of breast lesions. The objective of this study was to investigate the association between US imaging morphology from routine radiologists’ interpretation and biological behavior such as receptor status and tumor grade determined from histopathology in invasive ductal carcinoma (IDC). Material and Methods: This retrospective study included 453 patients with pathology-verified diagnosis of IDC who had undergone US imaging and had surgery over a 5-year period. US and surgical pathology reports were reviewed and compiled. Correlation analyses and age-adjusted multivariable models were used to determine the association between US imaging morphology and receptor status, tumor grade, and germ line mutation of the breast cancer genes (BRCA1 and BRCA2). The odds ratio (OR), area under receiver operating characteristic curve (AUC), and 95% confidence intervals (CI) were obtained. Results: The likelihood for high-grade cancer increased with size (OR: 1.066; CI: 1.042–1.091) and hypo-echogenicity (OR: 2.044; CI: 1.337–3.126), and decreased with angular or spiculated margins (OR: 0.605; CI: 0.393–0.931) and posterior acoustic shadowing (OR: 0.352; CI: 0.238–0.523). These features achieved an AUC of 0.799 (CI: 0.752–0.845) for predicting high-grade tumors. The likelihood for Estrogen Receptor-positive tumors increased with posterior acoustic shadowing (OR: 3.818; CI: 2.206–6.607), angulated or spiculated margins (OR: 2.596; CI: 1.159–5.815) and decreased with US measured tumor size (OR: 0.959; CI: 0.933–0.986) and hypoechoic features (OR: 0.399; CI: 0.198– 0.801), and achieved an AUC of 0.787 (CI: 0.733–0.841). The likelihood for Progesterone Receptor-positive tumors increased with posterior acoustic shadowing (OR: 2.732; CI: 1.744–4.28) and angulated or spiculated margins (OR: 2.618; CI: 1.412–4.852), and decreased with US measured tumor size (OR: 0.961; CI: 0.937–0.985) and hypoechoic features (OR: 0.571; CI: 0.335–0.975), and achieved an AUC of 0.739 (CI: 0.689–0.790). The likelihood for Human epidermal growth factor receptor 2-positive tumors increased with heterogeneous echo texture (OR: 2.141; CI: 1.17– 3.919) and decreased with angulated or spiculated margins (OR: 0.408; CI: 0.177–0.944), and was marginally associated with hypoechoic features (OR: 2.101; CI: 0.98–4.505) and circumscribed margins (OR: 4.225; CI: 0.919–19.4). The model with the aforementioned four US morphological features and achieved an AUC of 0.686 (CI: 0.614–0.758). The likelihood for triple-negative breast cancers increased with hypo-echogenicity (OR: 2.671; CI: 1.249–5.712) and decreased with posterior acoustic shadowing (OR: 0.287; CI: 0.161–0.513), and achieved an AUC of 0.739 (CI: 0.671– 0.806). No statistical association was observed between US imaging morphology and BRCA mutation. Conclusion: In this study of over 450 IDCs, significant statistical associations between tumor grade and receptor status with US imaging morphology were observed and could serve as a surrogate imaging marker for the biological behavior of the tumor.

PurposeThromboembolic complications remain a limitation of flow diverting stents. We hypothesize that phosphorilcholine surface modified flow diverters (Pipeline Flex with Shield Technology, sPED) would have less acute thrombus formation on the device surface compared with the classic Pipeline Embolization device (cPED).MethodsElastase-induced aneurysms were created in 40 rabbits and randomly assigned to receive cPED or sPED devices with and without dual antiplatelet therapy (DAPT) (four groups, n=10/group). Angioplasty was performed to enhance apposition and create intimal injury for a pro-thrombotic environment. Both before and after angioplasty, the flow diverter was imaged with intravascular optical coherence tomography. The outcome measure was the number of predefined segments along the implant relative to the location of the aneurysm with a minimum of 0 (no clot formation) and maximum of 3 (all segments with thrombus). Clot formation over the device at ostia of branch arteries was assessed as either present or absent.ResultsFollowing angioplasty, the number of flow diverter segments with clots was significantly associated with the flow diverter (pConclusionIn the rabbit model, phosphorilcholine surface modified flow diverters are associated with less thrombus formation on the surface of the device.

Purpose The quality of dedicated cone-beam breast CT (CBBCT) imaging is fundamentally limited by x-ray scatter contamination due to the large irradiation volume. In this paper, we propose a scatter correction method for CBBCT using a novel forward-projection model with high correction efficacy and reliability. Method We first coarsely segment the uncorrected, first-pass, reconstructed CBBCT images into binary-object maps and assign the segmented fibroglandular and adipose tissue with the correct attenuation coefficients based on the mean x-ray energy. The modified CBBCT are treated as the prior images toward scatter correction. Primary signals are first estimated via forward projection on the modified CBBCT. To avoid errors caused by inaccurate segmentation, only sparse samples of estimated primary are selected for scatter estimation. A Fourier-Transform based algorithm, herein referred to as local filtration hereafter, is developed to efficiently estimate the global scatter distribution on the detector. The scatter-corrected images are obtained by removing the estimated scatter distribution from measured projection data. Results We evaluate the method performance on six patients with different breast sizes and shapes representing the general population. The results show that the proposed method effectively reduces the image spatial non-uniformity from 8.27 to 1.91% for coronal views and from 6.50 to 3.00% for sagittal views. The contrast-to-deviation ratio is improved by an average factor of 1.41. Comparisons on the image details reveal that the proposed scatter correction successfully preserves fine structures of fibroglandular tissues that are lost in the segmentation process. Conclusion We propose a highly practical and efficient scatter correction algorithm for CBBCT via a forward-projection model. The method is attractive in clinical CBBCT imaging as it is readily implementable on a clinical system without modifications in current imaging protocols or system hardware.

The standard head CT protocol makes detection of a temporal bone fracture difficult. The purposes of our study are to revisit the finding of air in various locations around the temporal bone as an indirect sign of fracture and determine if findings could predict fracture pattern. We searched the radiology reports for the keyword “temporal bone fracture.” We recorded the presence of air in multiple locations around the temporal bone and pneumocephalus, opacification of the mastoid air cells or the middle ear cavity, and dominant fracture pattern. Statistical analyses were performed using statistical software. A total of 135 patients (mean age 40 ± 20.1 years, 101 male, 34 female, range 1–91) had 152 fractures. At least one indirect finding was present in 143 (94.1%) fractures. Air was present adjacent to the styloid process in 94 (61.8%), in the temporomandibular joint in 80 (52.6%), adjacent to the mastoid process in 57 (37.5%), and along the adjacent dural venous sinus in 33 (21.7%) fractures. Mastoid opacification was present in 139 (91.4%) fractures. Opacification of the middle ear cavity was present in 121 (79.6%) fractures. A complex fracture significantly and positively correlated with pneumocephalus. In the setting of trauma, air around the temporal bone and opacification of the mastoid air cells or middle ear cavity should prompt consideration of a temporal bone fracture even if the fracture line is not visible. The presence of pneumocephalus predicts a higher chance of complex fracture pattern.

Evaluation of nodal involvement in early-stage breast cancers (T1 or T2) changed following the Z11 trial; however, not all patients meet the Z11 inclusion criteria. Hence, the relevance of ultrasound imaging of the axilla and fine-needle aspiration biopsy (FNA) in early-stage breast cancers was investigated.In this single-center, retrospective study, 758 subjects had pathology-verified breast cancer diagnosis over a 3-year period, of which 128 subjects with T1 or T2 breast tumors had abnormal axillary lymph nodes on ultrasound, had FNA, and proceeded to axillary surgery. Ultrasound images were reviewed and analyzed using multivariable logistic regression to identify the features predictive of positive FNA. Accuracy of FNA was quantified as the area under the receiver operating characteristic curve with axillary surgery as reference standard.Of 128 subjects, 61 were positive on FNA and 65 were positive on axillary surgery. Sensitivity, specificity, positive predictive value, and negative predictive value of FNA were 52 of 65 (80%), 54 of 63 (85.7%), 52 of 61(85.2%), and 54 of 67 (80.5%), respectively. After adjusting for neoadjuvant chemotherapy between FNA and surgery, a positive FNA was associated with higher likelihood for positive axillary surgery (odds ratio: 22.7; 95% confidence interval [CI]: 7.2-71.3, P .0001), and the accuracy of FNA was 0.801 (95% CI: 0.727-0.876). Among ultrasound imaging features, cortical thickness and abnormal hilum were predictive (P .017) of positive FNA with accuracy of 0.817 (95% CI: 0.741-0.893).Ultrasound imaging and FNA can play an important role in the management of early breast cancers even in the post-Z11 era. Higher weightage can be accorded to cortical thickness and hilum during ultrasound evaluation.

In digital breast tomosynthesis and digital mammography, the x-ray beam filter material and thickness vary between systems. Replacing K-edge filters with Al was investigated with the intent to reduce exposure duration and to simplify system design. Tungsten target x-ray spectra were simulated with K-edge filters (50 µm Rh; 50 µm Ag) and Al filters of varying thickness. Monte Carlo simulations were conducted to quantify the x-ray scatter from various filters alone, scatter-to-primary ratio (SPR) with compressed breasts, and to determine the radiation dose to the breast. These data were used to analytically compute the signal-difference-to-noise ratio (SDNR) at unit (1 mGy) mean glandular dose (MGD) for W/Rh and W/Ag spectra. At SDNR matched between K-edge and Al filtered spectra, the reductions in exposure duration and MGD were quantified for three strategies: (i) fixed Al thickness and matched tube potential in kilovolts (kV); (ii) fixed Al thickness and varying the kV to match the half-value layer (HVL) between Al and K-edge filtered spectra; and, (iii) matched kV and varying the Al thickness to match the HVL between Al and K-edge filtered spectra. Monte Carlo simulations indicate that the SPR with and without the breast were not different between Al and K-edge filters. Modelling for fixed Al thickness (700 µm) and kV matched to K-edge filtered spectra, identical SDNR was achieved with 37-57% reduction in exposure duration and with 2-20% reduction in MGD, depending on breast thickness. Modelling for fixed Al thickness (700 µm) and HVL matched by increasing the kV over (0,4) range, identical SDNR was achieved with 62-65% decrease in exposure duration and with 2-24% reduction in MGD, depending on breast thickness. For kV and HVL matched to K-edge filtered spectra by varying Al filter thickness over (700, 880) µm range, identical SDNR was achieved with 23-56% reduction in exposure duration and 2-20% reduction in MGD, depending on breast thickness. These simulations indicate that increased fluence with Al filter of fixed or variable thickness substantially decreases exposure duration while providing for similar image quality with moderate reduction in MGD.

BACKGROUND AND PURPOSE: Advancements in medical device and imaging technology as well as accruing clinical evidence have accelerated the growth of the endovascular treatment of cerebrovascular diseases. However, the augmented role of these procedures raises concerns about the radiation dose to patients and operators. We evaluated patient doses from an x-ray imaging platform with radiation dose–reduction technology, which combined image noise reduction, motion correction, and contrast-dependent temporal averaging with optimized x-ray exposure settings. MATERIALS AND METHODS: In this single-center, retrospective study, cumulative dose-area product inclusive of fluoroscopy, angiography, and 3D acquisitions for all neurovascular procedures performed during a 2-year period on the dose-reduction platform were compared with a reference platform. Key study features were the following: The neurointerventional radiologist could select the targeted dose reduction for each patient with the dose-reduction platform, and the statistical analyses included patient characteristics and the neurointerventional radiologist as covariates. The analyzed outcome measures were cumulative dose (kerma)-area product, fluoroscopy duration, and administered contrast volume. RESULTS: A total of 1238 neurointerventional cases were included, of which 914 and 324 were performed on the reference and dose-reduction platforms, respectively. Over all diagnostic and neurointerventional procedures, the cumulative dose-area product was significantly reduced by 53.2% (mean reduction, 160.3 Gy × cm(2); P < .0001), fluoroscopy duration was marginally significantly increased (mean increase, 5.2 minutes; P = .0491), and contrast volume was nonsignificantly increased (mean increase, 15.3 mL; P = .1616) with the dose-reduction platform. CONCLUSIONS: A significant reduction in patient radiation dose is achievable during neurovascular procedures by using dose-reduction technology with a minimal impact on workflow.

Acetylation of proteins as a post-translational modification is gaining rapid acceptance as a cellular control mechanism on par with other protein modification mechanisms such as phosphorylation and ubiquitination. Through genetic manipulations and evolving proteomic technologies, identification and consequences of transcription factor acetylation is beginning to emerge. In this review, we summarize the field and discuss newly unfolding mechanisms and consequences of transcription factor acetylation in normal and stressed hearts. This article is part of a Special Issue entitled: The role of post-translational protein modifications on heart and vascular metabolism edited by Jason R.B. Dyck & Jan F.C. Glatz.

The physical examination and pelvic imaging with MRI are often used in the pre-operative evaluation of pelvic organ prolapse. The objective of this study was to compare grading of prolapse on defecography phase of dynamic magnetic resonance imaging (dMRI) with physical examination (PE) grading using both the Pelvic Organ Prolapse Quantification (POP-Q) staging and Baden–Walker (BW) grading systems in the evaluation of pelvic organ prolapse (POP). We retrospectively reviewed the charts of 170 patients who underwent dMRI at our institution. BW grading and POP-Q staging were collected for anterior, apical, and posterior compartments, along with absolute dMRI values and overall grading of dMRI. For the overall grading/staging from dMRI, BW, and POP-Q, Spearman rho (ρ) was used to assess the correlation. The correlations between dMRI grading and POP-Q staging were compared to the correlations between dMRI grading and BW grading using Fisher’s Z transformation. A total of 54 patients were included. dMRI grading was not significantly correlated with BW grading for anterior, apical, and posterior compartment prolapse (p > 0.15). However, overall dMRI grading demonstrated a significant (p = 0.025) and positive correlation (ρ = 0.305) with the POP-Q staging system. dMRI grading for anterior compartment prolapse also demonstrated a positive correlation (p = 0.001, ρ = 0.436) with the POP-Q staging derived from measurement locations Aa and Ba. The overall dMRI grade is better correlated with POP-Q stage than with BW grade (p = 0.024). Overall and anterior compartment grading from dMRI demonstrated a significant and positive correlation with the overall POP-Q staging and anterior compartment POP-Q staging, respectively. The overall dMRI grade is better correlated with POP-Q staging than with BW grading.

To determine the diagnostic accuracy of an abbreviated magnetic resonance imaging (MRI) protocol of the foot for the diagnosis of osteomyelitis in patients with acute foot infection. This retrospective study evaluated adult patients (age 18 and over) visiting an academic medical center from 1 January 2013 to 31 December 2015 who were imaged with MRI for suspected acute pedal osteomyelitis. Examinations were performed utilizing the departmental standard protocol. All examinations were retrospectively interpreted by five radiologists under two protocols: a reference standard protocol consisting of all non-contrast sequences obtained at initial acquisition and an abbreviated protocol consisting of only coronal T1-weighted and sagittal T2-weighted fast multiplanar inversion-recovery (FMPIR) sequences. Interpretation of the two imaging subsets was separated in time by at least 6 weeks for each reader. Each examination was assigned a score to represent one of four diagnostic categories: normal; soft tissue infection without bone changes or bone changes specific to a non-infectious etiology; nonspecific bone marrow changes; or bone changes specific for osteomyelitis. Diagnostic accuracy of both protocols was determined based on clinical diagnosis and treatment of osteomyelitis, and histopathology when available. One hundred and two MRI examinations met inclusion criteria; participants ranged in age from 26 to 91 years, with a mean age of 59 years. Seventy examinations were performed for male participants (69%) and 32 for female participants (31%). Thirty-five had a confirmed diagnosis of osteomyelitis, while the remainder (n = 67) did not. An average of 6 non-contrast sequences was performed during each examination. The most common protocol (53/102 examinations) was comprised of the following 6 sequences: axial T1-weighted, axial fat-saturated proton density, sagittal T1-weighted, sagittal T2-weighted FMPIR, coronal T1-weighted, and coronal fat-saturated proton density. After patient positioning, the abbreviated protocol sequences (sagittal T2-weighted FMPIR and coronal T1-weighted) were performed in an average total of 8 min. The reference standard protocol required an average of 22 min to complete 6 sequences. Averaged across all readers, the AUC for the reference standard full protocol and the abbreviated protocols were 0.843 and 0.873, respectively. The difference in AUC between protocols was not statistically significant (p = 0.1297), with the abbreviated protocol showing a non-significantly greater AUC. An abbreviated MRI protocol, including only coronal T1-weighted and sagittal T2-weighted FMPIR images, is non-inferior to standard MRI protocol for the diagnosis of acute pedal osteomyelitis. It should be considered as a diagnostic alternative for reducing imaging time and improving patient access to MRI.

The process of arteriogenesis is severely compromised in patients with diabetes mellitus (DM). Earlier studies have reported the importance of Egr-1 in promoting collateral outward remodeling. However, the role of Egr-1 in the presence of DM in outward vessel remodeling was not studied. We hypothesized that Egr-1 expression may be compromised in DM which may lead to impaired collateral vessel growth. Here, we investigated the relevance of the transcription factor Egr-1 for the process of collateral artery growth in diabetic mice. Induction of arteriogenesis by femoral artery ligation resulted in an increased expression of Egr-1 on mRNA and protein level but was severely compromised in streptozotocin-induced diabetic mice. Diabetes mellitus mice showed a significantly reduced expression of Egr-1 endothelial downstream genes Intercellular Adhesion Molecule-1 (ICAM-1) and urokinase Plasminogen Activator (uPA), relevant for extravasation of leukocytes which promote arteriogenesis. Fluorescent-activated cell sorting analyses confirmed reduced leukocyte recruitment. Diabetes mellitus mice showed a reduced expression of the proliferation marker Ki-67 in growing collaterals whose luminal diameters were also reduced. The Splicing Factor-1 (SF-1), which is critical for smooth muscle cell proliferation and phenotype switch, was found to be elevated in collaterals of DM mice. Treatment of DM mice with insulin normalized the expression of Egr-1 and its downstream targets and restored leukocyte recruitment. SF-1 expression and the diameter of growing collaterals were normalized by insulin treatment as well. In summary, our results showed that Egr-1 signaling was impaired in DM mice; however, it can be rescued by insulin treatment.

Proper vascular function is important for well-being of mother and growing fetus. VEGF