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In fibroglandular breast tissue, conventional dynamic contrast-enhanced MR-mammography is known to be affected by water content changes during the menstrual cycle. Likewise, amide proton transfer (APT) chemical exchange saturation transfer (CEST)-MRI might be inherently prone to the menstrual cycle, as CEST signals are indirectly detected via the water signal. The purpose of this study was to investigate the influence of the menstrual cycle on APT CEST-MRI in fibroglandular breast tissue.Ten healthy premenopausal women (19-34 years) were included in this IRB approved prospective study and examined twice during their menstrual cycle. Examination one and two were performed during the first half (day 2-8) and the second half (day 15-21) of the menstrual cycle, respectively. As a reference for the APT signal in malignant breast tumor tissue, previously reported data of nine breast cancer patients were included in this study. CEST-MRI (BThe APT signal showed no significant difference in the fibroglandular breast tissue of healthy premenopausal volunteers throughout the menstrual cycle (p = 1.00) (examination 1 vs. examination 2: mean and standard deviation = 3.24 ± 0.68%Hz vs. 3.30 ± 0.73%Hz, median and IQR = 3.36%Hz and 0.87%Hz vs. 3.38%Hz and 0.71%Hz).The present study provides an important basis for the clinical application of APT CEST-MRI as an additional contrast mechanism in MR-mammography, as menstrual cycle-related APT signal fluctuations seem to be negligible compared to the APT signal increase in breast cancer tissue.

The autosomal dominant inherited Li-Fraumeni syndrome (LFS) increases the lifetime risk of developing a malignancy to almost 100%. Although breast cancer, central nervous system (CNS) tumors and sarcomas are particularly common, tumors can ultimately occur almost anywhere in the body. As causal therapy is not available, the primary focus for improving the prognosis is early cancer detection. To this end, current cancer surveillance recommendations include a series of examinations including regular imaging beginning at birth.Due to the wide range of tumor entities that can occur in individuals affected by LFS, a sensitive detection requires imaging of various tissue contrasts; however, because life-long screening is potentially initiated at a young age, this requirement for comprehensiveness must be balanced against the presumed high psychological burden associated with frequent or invasive examinations. As radiation exposure may lead to an increased (secondary) tumor risk, computed tomography (CT) and X‑ray examinations should be avoided as far as possible.Because annual whole-body magnetic resonance imaging (MRI) has no radiation exposure and yet a high sensitivity for many tumors, it forms the basis of the recommended imaging; however, due to the rarity of the syndrome, expertise is sometimes lacking and whole-body MRI examinations are performed heterogeneously and sometimes with limited diagnostic quality. Optimization and standardization of MRI protocols should therefore be pursued. In addition, the need for an intravenously administered contrast agent has not been conclusively clarified despite its high relevance.HINTERGRUND: Das autosomal-dominant vererbte Li-Fraumeni-Syndrom (LFS) erhöht bei Betroffenen das Lebenszeitrisiko für die Entwicklung eines Malignoms auf nahezu 100 %. Obwohl Mammakarzinome, Tumoren des Zentralnervensystems (ZNS) und Sarkome besonders häufig sind, können Tumoren letztlich nahezu im gesamten Körper auftreten. Da keine kausale Therapie existiert, stellt die Krebsfrüherkennung den wichtigsten Beitrag zur Verbesserung der Prognose dar. Die aktuellen Empfehlungen beinhalten hierzu eine Reihe an Untersuchungen, inklusive regelmäßiger Bildgebung ab der Geburt.Aufgrund der Vielfalt an Tumorentitäten, die bei LFS auftreten können, ist für eine sensitive Detektion die Abbildung verschiedener Gewebekontraste erforderlich. Da das Screening potenziell schon ab einem jungen Alter und für einen langen Zeitraum durchgeführt wird, muss dieser Anspruch auf Ausführlichkeit jedoch im Verhältnis zu der mutmaßlich hohen psychischen Belastung Betroffener durch häufige oder invasive Untersuchungen stehen. Da eine Strahlenexposition zu einem erhöhten (Zweit‑)Tumorrisiko führen kann, sollten CT- und Röntgenuntersuchungen, soweit möglich, vermieden werden.Da eine jährliche Ganzkörper-MRT keine Strahlenbelastung und dennoch eine hohe Sensitivität für die Detektion verschiedener Tumoren hat, bildet sie die Basis der empfohlenen Bildgebung. Aufgrund der Seltenheit des Syndroms fehlt jedoch teilweise die Expertise hierfür, und Ganzkörper-MRT-Untersuchungen werden heterogen und mit zum Teil eingeschränkter diagnostischer Qualität durchgeführt. Daher sollte eine Optimierung und Vereinheitlichung von MRT-Protokollen angestrebt werden. Zudem ist die Notwendigkeit einer intravenösen Kontrastmittelapplikation trotz ihrer hohen Relevanz nicht abschließend geklärt.

Lung magnetic resonance imaging (MRI) examinations are challenging and have not become established in the routine clinical setting. Recent developments in low-field MRI, combined with computer-assisted algorithms for acquisition and evaluation, promise new perspectives for imaging of pulmonary diseases.This review aims to inform about the physical advantages of low-field MRI for imaging the lungs, provide a review of the sparse literature, and present first results from a new low-field MRI scanner.This article provides information on the physical principles, an review of the literature, and our first experiences in lung imaging on a modern 0.55 T MRI.Low-field MRI ( 1 T) may have technical and economic advantages over higher field strength MRI in lung imaging. The physical preconditions of low-field MRI are advantageous for imaging the lungs due to reduced susceptibility effects, increased transversal relaxation times, and lower specific absorption rates. The lower investment and operating costs may enable increased availability and sustainability. Combining modern sequences and computer-based image processing may expand beyond morphological imaging by providing spatially and temporally resolved functional examinations of the lung parenchyma without ionizing radiation. In critical scenarios, like screening and short-term follow-up examinations, and patients at risk, low-field MRI may bridge the gap. These indications may include acute and chronic pulmonary diseases in pediatric patients and suspected pulmonary embolisms in pregnant women.HINTERGRUND: Die Untersuchung der Lunge mit der Magnetresonanztomographie (MRT) geht mit hohen Herausforderungen einher und konnte sich im klinischen Alltag bisher nicht durchsetzen. Aktuelle Entwicklungen der Niederfeld-MRT, in Kombination mit neuen computergestützten Aufnahme- und Auswertungsalgorithmen, versprechen neue Perspektiven für die bildgebende Diagnostik pulmonaler Erkrankungen.Diese Übersichtsarbeit soll ein Verständnis der physikalischen Vorteile der Niederfeld-MRT für die Lungenbildgebung vermitteln, einen Überblick über die spärlich vorhandenen Vorkenntnisse aus der Literatur bieten und erste Ergebnisse eines neu entwickelten Niederfeld-MRT präsentieren.Inhalte dieses Artikels basieren auf physikalischen Grundlagen, Recherchen in Literaturdatenbanken und eigenen Erfahrungen in der Lungenbildgebung mit einem modernen 0,55-T-MRT.Die Niederfeld-MRT ( 1 T) kann technische und ökonomische Vorteile gegenüber höheren Feldstärken für die Lungenbildgebung haben. Die physikalischen Voraussetzungen sind aufgrund geringerer Suszeptibilitätseffekte, längerer transversaler Relaxationszeiten und niedrigerer spezifischer Absorptionsraten besonders für die Anatomie der Lunge vorteilhaft. Die geringeren Anschaffungs- und Betriebskosten haben zudem ein großes Potenzial, die Verfügbarkeit zu erhöhen und gleichzeitig die Nachhaltigkeit zu verbessern. Durch die Kombination moderner Sequenzen und computergestützter Auswertungen kann die morphologische Bildgebung um orts- und zeitaufgelöste funktionelle Untersuchungen der Lunge ohne Strahlenbelastung ergänzt werden. Sowohl für kritische Szenarien, wie Screening und engmaschiges Therapiemonitoring, als auch für besonders gefährdete Patientengruppen könnten Lücken geschlossen werden. Dazu gehören beispielsweise akute und chronische Lungenerkrankungen bei Kindern oder die Abklärung einer Lungenembolie bei Schwangeren.

OBJECTIVES Quantitative T1 relaxometry is the benchmark in imaging potential gadolinium deposition and known to be superior to semiquantitative signal intensity ratio analyses. However, T1 relaxometry studies are rare, commonly limited to a few target structures, and reported results are inconsistent.We systematically investigated quantitative T1 relaxation times (qT1) of a variety of brain nuclei after serial application of gadobutrol. MATERIALS AND METHODS Retrospectively, qT1 measurements were performed in a patient cohort with a mean number of 11 gadobutrol applications (n = 46) and compared with a control group with no prior gadolinium-based contrast agent administration (n = 48). The following target structures were evaluated: dentate nucleus, globus pallidus, thalamus, hippocampus, putamen, caudate, amygdala, and different white matter areas. Subsequently, multivariate regression analysis with adjustment for age, presence of brain metastases and previous cerebral radiotherapy was performed. RESULTS No assessed site revealed a significant correlation between qT1 and number of gadobutrol administrations in multivariate regression analysis. However, a significant negative correlation between qT1 and age was found for the globus pallidus as well as anterior and lateral thalamus (P < 0.05 each). CONCLUSIONS No T1 relaxation time shortening due to gadobutrol injection was found in any of the assessed brain structures after serial administration of 11 doses of gadobutrol.

INTRODUCTION Magnetic resonance imaging (MRI) of the abdomen increasingly incorporates diffusion-weighted imaging (DWI) sequences. Whereas DWI can substantially aid in detecting and characterizing suspicious findings, it remains unclear to what extent the use of ultra-high b-value DWI might further be of aid for the radiologist especially when using DWI sequences with advanced processing. The target of this study was therefore to compare high and ultra-high b-value DWI in abdominal MRI examinations. METHODS This institutional review board-approved, prospective study included abdominal MRI examinations of 70 oncologic patients (mean age, 58 years; range, 21-90 years) examined with a clinical 1.5 T MRI scanner (MAGNETOM Aera, Siemens Healthcare, Erlangen, Germany) with an advanced echo planar DWI sequence (b = 0, 50, 900, and 1500 s/mm) after ex vivo phantom and in vivo volunteer investigations. High b900 and ultra-high b1500 DWIs were compared by a qualitative reading for image quality and lesion conspicuity using a 5-point Likert scale with 2 radiologists as readers. The ratios of apparent signal intensities of suspicious lesions/normal tissue of the same organ (LNTRs) were calculated. Appropriate methods were used for statistical analysis, including Wilcoxon signed-rank test and κ statistic for interreader agreement analysis (P < 0.05/0.0125/0.005 after Bonferroni correction). RESULTS Image quality was significantly increased with b900 as compared with b1500 DWI (P < 0.001) despite using an advanced DWI sequence. A total of 153 suspicious lesions were analyzed. Overall reader confidence for characterization/detection of malignant lesions and, correspondingly, the LNTR (mean, 2.7 ± 1.8 vs 2.4 ± 1.6) were significantly higher with b900 than with b1500 DWI (P < 0.001 and P < 0.001). The increased confidence of lesion recognition and LNTR in the b900 DWI remained significant qualitatively in lymphatic and hepatic lesions and quantitatively in lymphatic, pulmonal, and osseous lesions. CONCLUSIONS Using high b-value DWI (900 s/mm) provided an improved image quality and also lesion conspicuity as compared with ultra-high b-value DWI (1500 s/mm) in oncologic abdominal examinations despite using advanced processing. Consequently, the value for additional ultra-high b-value DWI in oncologic examinations should be critically evaluated in future studies.

Diffusion-weighted (DW) MRI is a rapid technique that measures the mobility of water molecules within tissue, reflecting the cellular microenvironment. At DW MRI, breast cancers typically exhibit reduced diffusivity and appear hyperintense to surrounding tissues. On the basis of this characteristic, DW MRI may offer an unenhanced method to detect breast cancer without the costs and safety concerns associated with dynamic contrast material–enhanced MRI, the current reference standard in the setting of high-risk screening. This application of DW MRI has not been widely explored but is particularly timely given the growing health concerns related to the long-term use of gadolinium-based contrast material. Moreover, increasing breast density notification legislation across the United States is raising awareness of the limitations of mammography in women with dense breasts, emphasizing the need for additional cost-effective supplemental screening examinations. Preliminary studies suggest unenhanced MRI with DW MRI may provide higher sensitivity than screening mammography for the detection of breast malignancies. Larger prospective multicenter trials are needed to validate single-center findings and assess the performance of DW MRI for generalized breast cancer screening. Standardization of DW MRI acquisition and interpretation is essential to ensure reliable sensitivity and specificity, and an optimal approach for screening using readily available techniques is proposed here. © RSNA, 2019 Online supplemental material is available for this article.

Background Diffusion weighted magnetic resonance imaging (DWI) is known to differentiate between malignant and benign lesions via the apparent diffusion coefficient (ADC). Here, the value of diffusion kurtosis imaging (DKI) for differentiation and further characterization of benign and malignant breast lesions and their subtypes in a clinically feasible protocol is investigated. Material and methods This study included 85 patients (with 68 malignant and 73 benign lesions) who underwent 3 T breast DWI using three b values (50, 750, 1500 s/mm2), with a total measurement time Results ADC, DK and K showed significant differences between malignant and benign lesions (p Conclusion DKI parameters and conventional ADC can differentiate between malignant and benign lesions. Differentiation performance was best for ADC. Different tumor grades were significantly different in ADC and DK, which may have an impact on therapy planning and monitoring. In our study, K did not add value to the diagnostic performance of DWI in a clinical setting.

Purpose: The application of amide proton transfer (APT) CEST MRI for diagnosis of breast cancer is of emerging interest. However, APT imaging in the human breast is affected by the ubiquitous fat signal preventing a straightforward application of existing acquisition protocols. Although the spectral region of the APT signal does not coincide with fat resonances, the fat signal leads to an incorrect normalization of the Z‐spectrum, and therefore to distorted APT effects. In this study, we propose a novel normalization for APT‐CEST MRI that corrects for fat signal–induced artifacts in the postprocessing without the need for application of fat saturation schemes or water–fat separation approaches. Methods The novel normalization uses the residual signal at the spectral position of the direct water saturation to estimate the fat contribution. A comprehensive theoretical description of the normalization for an arbitrary phase relation of the water and fat signal is provided. Functionality and applicability of the proposed normalization was demonstrated by in vitro and in vivo experiments. Results In vitro, an underestimation of the conventional APT contrast of approximately −1.2% per 1% fat fraction was observed. The novel normalization yielded an APT contrast independent of the fat contribution, which was also independent of the water‐fat phase relation. This allowed APT imaging in patients with mamma carcinoma corrected for fat signal contribution, field inhomogeneities, spillover dilution, and water relaxation effects. Conclusion The proposed normalization increases the specificity of APT imaging in tissues with varying fat content and represents a time‐efficient and specific absorption rate–efficient alternative to fat saturation and water–fat separation approaches.

Objectives Motivated by the similar appearance of malignant breast lesions in high b-value diffusion-weighted imaging (DWI) and positron emission tomography, the purpose of this work was to evaluate the applicability of a threshold isocontouring approach commonly used in positron emission tomography to analyze DWI data acquired from female human breasts with minimal interobserver variability. Methods Twenty-three female participants (59.4 ± 10.0 years) with 23 lesions initially classified as suggestive of cancers in x-ray mammography screening were subsequently imaged on a 1.5-T magnetic resonance imaging scanner. Diffusion-weighted imaging was performed prior to biopsy with b values of 0, 100, 750, and 1500 s/mm. Isocontouring with different threshold levels was performed on the highest b-value image to determine the voxels used for subsequent evaluation of diffusion metrics. The coefficient of variation was computed by specifying 4 different regions of interest drawn around the lesion. Additionally, a receiver operating statistical analysis was performed. Results Using a relative threshold level greater than or equal to 0.85 almost completely suppresses the intra-individual and inter-individual variability. Among 4 studied diffusion metrics, the diffusion coefficients from the intravoxel incoherent motion model returned the highest area under curve value of 0.9. The optimal cut-off diffusivity was found to be 0.85 μm/ms with a sensitivity of 87.5% and specificity of 90.9%. Conclusion Threshold isocontouring on high b-value maps is a viable approach to reliably evaluate DWI data of suspicious focal lesions in magnetic resonance mammography.

Recent studies showed the potential of diffusion kurtosis imaging (DKI) as a tool for improved classification of suspicious breast lesions. However, in diffusion-weighted imaging of the female breast, sufficient fat suppression is one of the main factors determining the success. In this study, the data of 198 patients examined in two study centres was analysed using standard diffusion and kurtosis evaluation methods and three DKI fitting approaches accounting phenomenologically for fat-related signal contamination of the lesions. Receiver operating characteristic curve analysis showed the highest area under the curve (AUC) for the method including fat correction terms (AUC = 0.85, p p = 0.036) using a fat correction term for the first centre, while no significant difference with no adverse effects was observed for the second centre (AUC 0.89 vs. 0.90, p = 0.95). Contamination of the signal in breast lesions with unsuppressed fat causing a reduction of diagnostic performance of diffusion kurtosis imaging may potentially be counteracted by proposed adapted evaluation methods.

PurposeThe purpose of this study was to investigate whether the cardiac motion artifact that regularly appears in diffusion-weighted imaging of the left liver lobe might be reduced by acquiring images in inspiration, when the coupling between heart and liver might be minimal.Materials and methods43 patients with known or suspected focal liver lesions were examined at 1.5 T with breath hold acquisition, once in inspiration and once in expiration. Data were acquired with a diffusion-weighted echo planar imaging sequence and two b-values (b50 = 50 s/mm² and b800 = 800 s/mm²). The severity of the cardiac motion artifact in the left liver lobe was rated by two experienced radiologists for both b-values with a 5 point Likert scale. Additionally, the normalized signal S(b800)/S(b50) in the left liver lobe was computed. The Wilcoxon signed-rank test was used comparing the scores of the two readers obtained in inspiration and expiration, and to compare the normalized signal in inspiration and expiration.ResultsThe normalized signal in inspiration was slightly higher than in expiration (0.349±0.077 vs 0.336±0.058), which would indicate a slight reduction of the cardiac motion artifact, but this difference was not significant (p = 0.24). In the qualitative evaluation, the readers did not observe a significant difference for b50 (reader 1: p = 0.61; reader 2: p = 0.18). For b800, reader 1 observed a significant difference of small effect size favouring expiration (p = 0.03 with a difference of mean Likert scores of 0.27), while reader 2 observed no significant difference (p = 0.62).ConclusionAcquiring the data in inspiration does not lead to a markedly reduced cardiac motion artifact in diffusion-weighted imaging of the left liver lobe and is in this regard not to be preferred over acquiring the data in expiration.

Background Fibrosis is a delayed side effect of radiation therapy (RT). Connective tissue growth factor (CTGF) promotes the development of fibrosis in multiple settings, including pulmonary radiation injury. Methods To better understand the cellular interactions involved in RT-induced lung injury and the role of CTGF in these responses, microarray expression profiling was performed on lungs of irradiated and non-irradiated mice, including mice treated with the anti-CTGF antibody pamrevlumab (FG-3019). Between group comparisons (Welch’s t-tests) and principal components analyses were performed in Genespring. Results At the mRNA level, the ability of pamrevlumab to prolong survival and ameliorate RT-induced radiologic, histologic and functional lung deficits was correlated with the reversal of a clear enrichment in mast cell, macrophage, dendritic cell and mesenchymal gene signatures. Cytokine, growth factor and matrix remodeling genes that are likely to contribute to RT pneumonitis and fibrosis were elevated by RT and attenuated by pamrevlumab, and likely contribute to the cross-talk between enriched cell-types in injured lung. Conclusions CTGF inhibition had a normalizing effect on select cell-types, including immune cells not typically regarded as being regulated by CTGF. These results suggest that interactions between RT-recruited cell-types are critical to maintaining the injured state; that CTGF plays a key role in this process; and that pamrevlumab can ameliorate RT-induced lung injury in mice and may provide therapeutic benefit in other immune and fibrotic disorders. Electronic supplementary material The online version of this article (10.1186/s12931-018-0720-4) contains supplementary material, which is available to authorized users.

Diffusion-weighted imaging (DWI) in the female breast is a magnetic resonance imaging (MRI) technique that complements clinical routine protocols, and that might provide an independent diagnostic value for specific clinical tasks in breast imaging. To further improve specificity of DWI in the breast, stronger and faster diffusion weighting is advantageous. Here, a dedicated gradient coil is designed, targeted at diffusion weighting in the female breast, with the peak gradient magnitude exceeding that of the current clinical MR scanners by an order of a magnitude. Design of application-tailored gradient coils in MRI has recently attracted increased attention. With the target application in mind, the gradient coil is designed on an irregularly shaped semi-open current-carrying surface. Due to the coil former closely fitting the non-spherical target region, non-linear encoding fields become particularly advantageous for achieving locally exceptionally high gradient strengths. As breast tissue has a predominantly isotropic cellular microstructure, the direction of the diffusion-weighting gradient may be allowed to vary within the target volume. However, due to the quadratic dependency of the b-factor on the gradient strength, variation of the gradient magnitude should be carefully controlled. To achieve the above design goals the corresponding multi-objective optimization problem is reformulated as a constrained optimization, allowing for flexible and precise control of the coil properties. A novel constraint is proposed, limiting gradient magnitude variation within every slice while allowing for variations in both the direction of the gradient within the slice and the magnitude across the slices. These innovations enable the design of a unilateral coil for diffusion weighting in the female breast with local gradient strengths exceeding 1 T/m with highly homogeneous diffusion weighting for imaging in the coronal slice orientation.

Purpose To explore the value and reproducibility of a novel magnetic resonance based attenuation correction (MRAC) using a CAIPIRINHA-accelerated T1-weighted Dixon 3D-VIBE sequence for whole-body PET/MRI compared to the clinical standard. Methods The PET raw data of 19 patients from clinical routine were reconstructed with standard MRAC (MRAC std ) and the novel MRAC (MRAC caipi ), a prototype CAIPIRINHA accelerated Dixon 3D-VIBE sequence, both acquired in 19 s/bed position. Volume of interests (VOIs) for liver, lung and all voxels of the total image stack were created to calculate standardized uptake values (SUV mean ) followed by inter-method agreement (Passing-Bablok regression, Bland-Altman analysis). A voxel-wise SUV comparison per patient was performed for intra-individual correlation between MRAC std and MRAC caipi . Difference images (MRAC std -MRAC caipi ) of attenuation maps and SUV images were calculated. The image quality of in/opposed-phase water and fat images obtained from MRAC caipi was assessed by two readers on a 5-point Likert-scale including intra-class coefficients for inter-reader agreement. Results SUV mean correlations of VOIs demonstrated high linearity (0.95 8 pixels). Outliers could be explained by different physiological conditions between the scans such as different segmentation of air-containing tissue, lungs, kidneys, metal implants, diaphragm edge or small air bubbles in the gastrointestinal tracts that moved between MRAC acquisitions. Nasal sinuses and the trachea were better segmented in MRAC caipi . High-resolution T1w Dixon 3D VIBE images were acquired in all cases and could be used for PET/MRI fusion. MRAC caipi images were of high diagnostic quality (4.2 ± 0.8) with 0.92-0.96 intra-class correlation. Conclusions The novel prototype MRAC caipi extends the value for attenuation correction by providing a high spatial resolution DIXON-based dataset suited for diagnostic assessment towards time-efficient whole-body PET/MRI.

INTRODUCTION Diffusion-weighted imaging (DWI) is an important part of oncological magnetic resonance imaging (MRI) examinations, especially for tertiary cancer prevention in terms of early detection of recurrent disease. However, abdominal studies can be challenged by motion artifacts, poor signal-to-noise ratios, and visibility of retroperitoneal structures, which necessitates sequence optimization depending on the investigated region. This study aims at prospectively evaluating an adapted DWI sequence ex vivo and in vivo in oncologic patients undergoing abdominal MRI. METHODS This institutional review board-approved, prospective study included phantom measurements, volunteer examinations, and oncologic patient examinations of the abdomen. Fifty-seven MRI examinations in 54 patients (mean age, 58 years; range, 21-90 years) were included into the analysis. The MRI examination were performed at a 1.5 T MRI scanner (MAGNETOM Aera; Siemens Healthcare, Erlangen, Germany) and included both a standard EPI-DWI (s-DWI; b = 50, 900 s/mm) and an adapted DWI (opt-DWI; EPI-DWI with b = 0, 50, 900, 1500 s/mm, acquisition with higher spatial resolution and optimized processing for the abdomen including motion correction, adaptive image combination, and background suppression). For b = 900 s/mm, the ratio of signal intensity in the normal tissue and the standard deviation of the noise in the surrounding air was quantitatively calculated; image quality and tissue differentiation parameters were rated by 2 independent, blinded readers using a 5-point Likert scale. Statistics included Wilcoxon signed-rank test and kappa statistic (P < 0.05/0.0125 after Bonferroni correction). RESULTS The DWI phantom demonstrated an optimized contour sharpness and inlay differentiation for opt-DWI. The apparent ratio of normal tissue signal/standard deviation of background noise at b = 900 s/mm of the right/left hemiabdomen was significantly increased in opt-DWI (mean, 71.9 ± 23.5/86.0 ± 43.3) versus s-DWI (mean, 51.4 ± 15.4/63.4 ± 36.5; P < 0.001). Image quality parameters (contour sharpness and tissue differentiation of upper abdominal and retroperitoneal structures) were significantly increased in opt-DWI versus s-DWI (P < 0.001). Interreader reliability test showed good agreement (kappa = 0.768; P < 0.001). DISCUSSION This study prospectively evaluated the potential of adapted DWI for screening in tertiary prevention of oncologic patients. An optimized DWI protocol with advanced processing achieved improved image quality in quantitative and qualitative analyses. Oncological optimization of DWI should be performed before its application in cancer patients to improve both screening and follow-up examinations, to better unleash the diagnostic potential of DWI.

The purpose of this study was to investigate the association of relaxation-compensated chemical exchange saturation transfer (CEST) MRI with overall survival (OS) and progression-free survival (PFS) in newly diagnosed high-grade glioma (HGG) patients. Twenty-six patients with newly diagnosed high-grade glioma (WHO grades III–IV) were included in this prospective IRB-approved study. CEST MRI was performed on a 7.0-T whole-body scanner. Association of patient OS/PFS with relaxation-compensated CEST MRI (amide proton transfer (APT), relayed nuclear Overhauser effect (rNOE)/NOE, downfield-rNOE-suppressed APT (dns-APT)) and diffusion-weighted imaging (apparent diffusion coefficient) were assessed using the univariate Cox proportional hazards regression model. Hazard ratios (HRs) and corresponding 95% confidence intervals were calculated. Furthermore, OS/PFS association with clinical parameters (age, gender, O6-methylguanine-DNA methyltransferase (MGMT) promotor methylation status, and therapy: biopsy + radio-chemotherapy vs. debulking surgery + radio-chemotherapy) were tested accordingly. Relaxation-compensated APT MRI was significantly correlated with patient OS (HR = 3.15, p = 0.02) and PFS (HR = 1.83, p = 0.009). The strongest association with PFS was found for the dns-APT metric (HR = 2.61, p = 0.002). These results still stand for the relaxation-compensated APT contrasts in a homogenous subcohort of n = 22 glioblastoma patients with isocitrate dehydrogenase (IDH) wild-type status. Among the tested clinical parameters, patient age (HR = 1.1, p = 0.001) and therapy (HR = 3.68, p = 0.026) were significant for OS; age additionally for PFS (HR = 1.04, p = 0.048). Relaxation-compensated APT MRI signal intensity is associated with overall survival and progression-free survival in newly diagnosed, previously untreated glioma patients and may, therefore, help to customize treatment and response monitoring in the future. • Amide proton transfer (APT) MRI signal intensity is associated with overall survival and progression in glioma patients. • Relaxation compensation enhances the information value of APT MRI in tumors. • Chemical exchange saturation transfer (CEST) MRI may serve as a non-invasive biomarker to predict prognosis and customize treatment.

Introduction To evaluate the feasibility and accuracy of a semiautomatic, three-dimensional volume of interest (3D sphere) for measuring the apparent diffusion coefficient (ADC) in suspicious breast lesions compared to conventional single-slice two-dimensional regions of interest (2D ROIs). Method This institutional-review-board-approved study included 56 participants with Breast Imaging Reporting and Data System 4/5 lesion. All received diffusion-weighted imaging magnetic resonance imaging prior to biopsy ( b =0–1500 s/mm 2 ). ADC values were measured in the lesions with both methods. Reproducibility and accuracies were compared. Results Area under the curve was 0.93 [95% confidence interval (CI) 0.86–0.99] for the 3D sphere and 0.91 (95% CI 0.84–0.98) for the 2D ROIs without significantly differing reproducibility ( P =.45). Conclusion A semiautomatic 3D sphere could reliably estimate ADC values in suspicious breast lesions without significant difference compared to conventional 2D ROIs.

BACKGROUND The "glymphatic system" (GS), a brain-wide network of cerebrospinal fluid microcirculation, supplies a pathway through and out of the central nervous system (CNS); malfunction of the system is implicated in a variety of neurological disorders. In this exploratory study, we analyzed the potential of a new imaging approach that we coined delayed T2-weighted gadolinium-enhanced imaging to visualize the GS in vivo. METHODS Heavily T2-weighted fluid-attenuated inversion recovery (hT2w-FLAIR) magnetic resonance imaging was obtained before, and 3 hours and 24 hours after intravenous gadolinium-based contrast agent (GBCA) application in 33 neurologically healthy patients and 7 patients with an impaired blood-brain barrier (BBB) due to cerebral metastases. Signal intensity (SI) was determined in various cerebral fluid spaces, and white matter hyperintensities were quantified by applying the Fazekas scoring system. FINDINGS Delayed hT2w-FLAIR showed GBCA entry into the CNS via the choroid plexus and the ciliary body, with GBCA drainage along perineural sheaths of cranial nerves and along perivascular spaces of penetrating cortical arteries. In all patients and all sites, a significant SI increase was found for the 3 hours and 24 hours time points compared with baseline. Although no significant difference in SI was found between neurologically healthy patients and patients with an impaired BBB, a significant positive correlation between Fazekas scoring system and SI increase in the perivascular spaces 3 hours post injection was shown. INTERPRETATION Delayed T2-weighted gadolinium-enhanced imaging can visualize the GBCA pathway into and through the GS. Presence of GBCAs within the GS might be regarded as part of the natural excretion process and should not be mixed up with gadolinium deposition. Rather, the correlation found between deep white matter hyperintensities, an imaging sign of vascular dementia, and GS functioning demonstrated feasibility to exploit the pathway of GBCAs through the GS for diagnostic purposes.

Magnetic resonance imaging (MRI) of the breast represents one of the most sensitive imaging modalities in breast cancer detection. Diffusion-weighted imaging (DWI) is a sequence variation introduced as a complementary MRI technique that relies on mapping the diffusion process of water molecules thereby providing additional information about the underlying tissue. Since water diffusion is more restricted in most malignant tumors than in benign ones owing to the higher cellularity of the rapidly proliferating neoplasia, DWI has the potential to contribute to the identification and characterization of suspicious breast lesions. Thus, DWI might increase the diagnostic accuracy of breast MRI and its clinical value. Future applications including optimized DWI sequences, technical developments in MR devices, and the application of radiomics/artificial intelligence algorithms may expand the potential of DWI in breast imaging beyond its current supplementary role.

Oncologic imaging focused on the detection of breast cancer is of increasing importance, with over 1.7 million new cases detected each year worldwide. MRI of the breast has been described to be one of the most sensitive imaging modalities in breast cancer detection; however, clinical use is limited due to high costs. In the past, the objective and clinical routine of oncologic imaging was to provide one extended imaging protocol covering all potential needs and clinical implications regardless of the specific clinical indication or question. Future protocols might be more focused according to a "keep it short and simple" approach, with a reduction of patient magnet time and a limited number of images to review. Rather than replacing conventional full-diagnostic breast MRI protocols, these approaches aim at introducing a new thinking in oncologic imaging using a diversification of available imaging approaches targeted to the dedicated clinical needs of the individual patient. Here we review current approaches on using abbreviated protocols that aim to increase the clinical availability and use of breast MRI for improved early detection of breast cancer. Level of Evidence: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:647-658.

Purpose To evaluate a radiomics model of Breast Imaging Reporting and Data System (BI-RADS) 4 and 5 breast lesions extracted from breast-tissue-optimized kurtosis magnetic resonance (MR) imaging for lesion characterization by using a sensitivity threshold similar to that of biopsy. Materials and Methods This institutional study included 222 women at two independent study sites (site 1: training set of 95 patients; mean age ± standard deviation, 58.6 years ± 6.6; 61 malignant and 34 benign lesions; site 2: independent test set of 127 patients; mean age, 58.2 years ± 6.8; 61 malignant and 66 benign lesions). All women presented with a finding suspicious for cancer at x-ray mammography (BI-RADS 4 or 5) and an indication for biopsy. Before biopsy, diffusion-weighted MR imaging (b values, 0-1500 sec/mm

Background Early identification of prognostic superior characteristics in glioma patients such as Isocitrate dehydrogenase(IDH)-mutation and O6-methylguanine-DNA-methyltransferase (MGMT) promotor methylation status is of great clinical importance. The study purpose was to investigate the non-invasive predictability of IDH-mutation status, MGMT promotor methylation, and differentiation of lower versus higher grade glioma (LGG vs. HGG) in newly-diagnosed patients employing relaxation-compensated multi-pool Chemical Exchange Saturation Transfer (CEST) magnetic resonance imaging (MRI) at 7.0 Tesla (7T). Methods Thirty-one newly-diagnosed glioma patients were included in this prospective study. CEST MRI was performed at a 7T whole-body scanner. Nuclear Overhauser Effect (NOE) and isolated amide proton transfer (APT, downfield NOE-suppressed APT=dns-APT) CEST signals (mean value and 90th signal percentile) were quantitatively investigated in the whole tumor area with regard to predictability of IDH-mutation, MGMT promotor methylation status, and differentiation of LGG vs. HGG. Statistics were performed using receiver operating characteristic (ROC) and area under the curve (AUC) analysis. Results were compared to advanced MRI methods (apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV) ROC/AUC analysis) obtained at 3T. Results dns-APT CEST contrasts yielded highest AUCs in IDH-mutation status prediction (dns-APTmean=91.84, p0.05). Conclusions Relaxation-compensated multi-pool CEST MRI, particularly dns-APT imaging, enabled prediction of IDH-mutation status and differentiation of LGG vs. HGG and should therefore be considered as non-invasive MR biomarker in the diagnostic workup.

Purpose To evaluate the ability to detect intracerebral regions of increased glucose concentration at T1ρ-weighted dynamic glucose-enhanced (DGE) magnetic resonance (MR) imaging at 7.0 T. Materials and Methods This prospective study was approved by the institutional review board. Nine patients with newly diagnosed glioblastoma and four healthy volunteers were included in this study from October 2015 to July 2016. Adiabatically prepared chemical exchange-sensitive spin-lock imaging was performed with a 7.0-T whole-body unit with a temporal resolution of approximately 7 seconds, yielding the time-resolved DGE contrast. T1ρ-weighted DGE MR imaging was performed with injection of 100 mL of 20% d-glucose via the cubital vein. Glucose enhancement, given by the relative signal intensity change at T1ρ-weighted MR imaging (DGEρ), was quantitatively investigated in brain gray matter versus white matter of healthy volunteers and in tumor tissue versus normal-appearing white matter of patients with glioblastoma. The median signal intensities of the assessed brain regions were compared by using the Wilcoxon rank-sum test. Results In healthy volunteers, the median signal intensity in basal ganglia gray matter (DGEρ = 4.59%) was significantly increased compared with that in white matter tissue (DGEρ = 0.65%) (P = .028). In patients, the median signal intensity in the glucose-enhanced tumor region as displayed on T1ρ-weighted DGE images (DGEρ = 2.02%) was significantly higher than that in contralateral normal-appearing white matter (DGEρ = 0.08%) (P.0001). Conclusion T1ρ-weighted DGE MR imaging in healthy volunteers and patients with newly diagnosed, untreated glioblastoma enabled visualization of brain glucose physiology and pathophysiologically increased glucose uptake and may have the potential to provide information about glucose metabolism in tumor tissue.

Purpose To determine the effect of at least five serial injections of the macrocyclic gadolinium-based contrast agent (GBCA) gadoterate meglumine on the signal intensity (SI) of the dentate nucleus (DN) of the pediatric brain on nonenhanced T1-weighted magnetic resonance (MR) images. Materials and Methods In this retrospective, institutional review board-approved study, 41 pediatric patients (age range, 3-17 years) who were imaged in at least five consecutive 1.5-T MR examinations with the exclusive use of gadoterate meglumine (plus a final additional nonenhanced MR imaging examination) were evaluated. SI ratio differences between the first and last MR examination were calculated for DN-to-pons and DN-to-middle cerebellar peduncle (MCP) ratios in a region-of-interest-based analysis, and one-sample t tests were used to examine if the SI ratio differences differed from 0. Bayes factors were calculated to quantify the strength of evidence for each test. Results Patients underwent a mean of 8.6 ± 3.9 GBCA administrations (mean accumulated dose, 32.07 mmol ± 17.62, with an average of 16.7 weeks ± 7.9 between every administration). Both ratio differences did not differ significantly from 0 (DN-to-pons ratio: -0.0012 ± 0.0101, P = .436; DN-to-MCP ratio: 0.0007 ± 0.0088, P = .604), and one-sided Bayes factors provided substantial evidence against an SI ratio increase (0.10 for DN-to-pons ratio; 0.27 for DN-to-MCP ratio). Conclusion No increase of the SI in the DN was found after a mean of 8.6 serial injections of the macrocyclic GBCA gadoterate meglumine in pediatric patients, confirming previous studies that did not find this effect after serial injections of macrocyclic GBCAs in adults.

Aim To investigate an abbreviated, contrast-agent free diffusion-weighted (DW) breast magnetic resonance imaging (MRI) protocol that provides a single image for the radiologist to read in order to non-invasively examine Breast Imaging-Reporting and Data System (BI-RADS) 4 lesions detected using breast cancer screening X-ray mammography. Materials and methods This retrospective evaluation within a institutional review board-approved, prospective study included 115 women (mean 57 years, range 50–69 years) with BI-RADS 4 findings on X-ray mammography and indication for biopsy over a period of 15 months. Full diagnostic breast MRI (FDP) was performed prior to biopsy (1.5 T). Maximum intensity breast diffusion (MIBD) images were generated from DW images (b = 1,500 mm/s2, 3 mm section thickness) of the breast. MIBD and T2-weighted (T2W) images were read by two radiologists and compared to the diagnostic accuracy of an expert reading of the FDP with histopathology as the reference standard. The acquisition time of MIBD and T2W MRI was about 7 minutes. Results MIBD MRI provided a diagnostic accuracy of 87.93% (95% confidence interval [CI]: 80.58–93.24%) for R1 and 89.66% (95% CI: 82.63–94.54%) for R2. Expert reading of the FDP revealed a similar accuracy of 86.2% (95% CI: 78.67–91.43%). The positive predictive value (PPV) could be increased from 36.2% (95% CI: 28.02–45.28; X-ray mammography alone) to a mean PPV of 80.89% (R1 79.17%, R2 82.16%) using MIBD MRI. Mean reading time was 30 seconds (25%/75 percentile 24.5–41.25). Conclusions MIBD MRI might be of supplemental value if added to the work-up of BI-RADS 4 X-ray mammography screening findings. MIBD MRI might help reduce the false-positive rate prior to biopsy for reference lesions at only limited expense of measurement and reading time.

Purpose To correlate histopathologic findings from biopsy specimens with their corresponding location within enhancing areas, non-enhancing areas and necrotic areas on contrast enhanced T1-weighted MRI scans (cT1). Materials and Methods In 37 patients with newly diagnosed glioblastoma who underwent stereotactic biopsy, we obtained a correlation of 561 1mm3 biopsy specimens with their corresponding position on the intraoperative cT1 image at 1.5 Tesla. Biopsy points were categorized as enhancing (CE), non-enhancing (NE) or necrotic (NEC) on cT1 and tissue samples were categorized as “viable tumor cells”, “blood” or “necrotic tissue (with or without cellular component)”. Cell counting was done semi-automatically. Results NE had the highest content of tissue categorized as viable tumor cells (89% vs. 60% in CE and 30% NEC, respectively). Besides, the average cell density for NE (3764 ± 2893 cells/mm2) was comparable to CE (3506 ± 3116 cells/mm2), while NEC had a lower cell density with 2713 ± 3239 cells/mm2. If necrotic parts and bleeds were excluded, cell density in biopsies categorized as “viable tumor tissue” decreased from the center of the tumor (NEC, 5804 ± 3480 cells/mm2) to CE (4495 ± 3209 cells/mm2) and NE (4130 ± 2817 cells/mm2). Discussion The appearance of a glioblastoma on a cT1 image (circular enhancement, central necrosis, peritumoral edema) does not correspond to its diffuse histopathological composition. Cell density is elevated in both CE and NE parts. Hence, our study suggests that NE contains considerable amounts of infiltrative tumor with a high cellularity which might be considered in resection planning.

Aim To validate a newly developed software prototype that automatically analyses small bowel motility by comparing it directly with manual measurement. Material and methods Forty-five patients with clinical indication for small bowel magnetic resonance imaging (MRI) were retrospectively included in this institutional review board-approved study. MRI was performed using a 1.5 T system following a standard MR-enterography protocol. Small bowel motility parameters (contractions-per-minute, luminal diameter, amplitude) were measured three times each in identical segments using the manual and the semiautomatic software-assisted method. The methods were compared for agreement, repeatability, and time needed for each measurement. All parameters were compared between the methods. Results A total of 91 small-bowel segments were analysed. No significant intra-individual difference ( p > 0.05) was found for peristaltic frequencies between the methods (mean: 4.14/min manual; 4.22/min software-assisted). Amplitudes (5.14 mm; 5.57 mm) and mean lumen diameters (17.39 mm; 14.68) differed due to systematic differences in the definition of the bowel wall. Mean duration of single measurement was significantly ( p 0.01) shorter with the software (6.25 min; 1.30 min). The scattering of repeated measurements was significantly ( p 0.05) lower using the software. Conclusion The software-assisted method accomplished highly reliable, fast and accurate measurement of small bowel motility. Measurement precision and duration differed significantly between the two methods in favour of the software-assisted technique.

To assess radiomics as a tool to determine how well lesions found suspicious on breast cancer screening X-ray mammography can be categorized into malignant and benign with unenhanced magnetic resonance (MR) mammography with diffusion-weighted imaging and TFrom an asymptomatic screening cohort, 50 women with mammographically suspicious findings were examined with contrast-enhanced breast MRI (ceMRI) at 1.5T. Out of this protocol an unenhanced, abbreviated diffusion-weighted imaging protocol (ueMRI) including TThe unconstrained and constrained radiomic classifiers consisted of 11 parameters each and achieved differentiation of malignant from benign lesions with a .632 + bootstrap receiver operating characteristics (ROC) area under the curve (AUC) of 84.2%/85.1%, compared to 77.4% for mean ADC and 95.9%/95.9% for the experienced radiologist using ceMRI/ueMRI.In this pilot study we identified two ueMRI radiomics classifiers that performed well in the differentiation of malignant from benign lesions and achieved higher performance than the mean ADC parameter alone. Classification was lower than the almost perfect performance of a highly experienced breast radiologist. The potential of radiomics to provide a training-independent diagnostic decision tool is indicated. A performance reaching the human expert would be highly desirable and based on our results is considered possible when the concept is extended in larger cohorts with further development and validation of the technique.1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:604-616.

The aim of this study was to evaluate the accuracy and applicability of solitarily reading fused image series of T2-weighted and high-b-value diffusion-weighted sequences for lesion characterization as compared to sequential or combined image analysis of these unenhanced sequences and to contrast- enhanced breast MRI. This IRB-approved study included 50 female participants with suspicious breast lesions detected in screening X-ray mammograms, all of which provided written informed consent. Prior to biopsy, all women underwent MRI including diffusion-weighted imaging (DWIBS, b = 1500s/mm2). Images were analyzed as follows: prospective image fusion of DWIBS and T2-weighted images (FU), side-by-side analysis of DWIBS and T2-weighted series (CO), combination of the first two methods (CO+FU), and full contrast-enhanced diagnostic protocol (FDP). Diagnostic indices, confidence, and image quality of the protocols were compared by two blinded readers. Reading the CO+FU (accuracy 0.92; NPV 96.1 %; PPV 87.6 %) and the CO series (0.90; 96.1 %; 83.7 %) provided a diagnostic performance similar to the FDP (0.95; 96.1 %; 91.3 %; p > 0.05). FU reading alone significantly reduced the diagnostic accuracy (0.82; 93.3 %; 73.4 %; p = 0.023). MR evaluation of suspicious BI-RADS 4 and 5 lesions detected on mammography by using a non-contrast-enhanced T2-weighted and DWIBS sequence protocol is most accurate if MR images were read using the CO+FU protocol. • Unenhanced breast MRI with additional DWIBS/T2w-image fusion allows reliable lesion characterization. • Abbreviated reading of fused DWIBS/T2w-images alone decreases diagnostic confidence and accuracy. • Reading fused DWIBS/T2w-images as the sole diagnostic method should be avoided.

Purpose: Radiotherapy is used for the treatment of lung cancer, but at the same time induces acute pneumonitis and subsequent pulmonary fibrosis, where TGF-β signaling is considered to play an important role. Experimental Design: We irradiated thoraces of C57BL/6 mice (single dose, 20 Gy) and administered them a novel small-molecule TGF-β receptor I serine/threonine kinase inhibitor (LY2109761) orally for 4 weeks before, during, or after radiation. Noninvasive lung imaging including volume computed tomography (VCT) and MRI was conducted 6, 16, and 20 weeks after irradiation and was correlated to histologic findings. Expression profiling analysis and protein analysis was conducted in human primary fibroblasts. Results: Radiation alone induced acute pulmonary inflammation and lung fibrosis after 16 weeks associated with reduced life span. VCT, MRI, and histology showed that LY2109761 markedly reduced inflammation and pulmonary fibrosis resulting in prolonged survival. Mechanistically, we found that LY2109761 reduced p-SMAD2 and p-SMAD1 expression, and transcriptomics revealed that LY2109761 suppressed expression of genes involved in canonical and noncanonical TGF-β signaling and downstream signaling of bone morphogenetic proteins (BMP). LY2109761 also suppressed radiation-induced inflammatory [e.g., interleukin (IL)-6, IL-7R, IL-8] and proangiogenic genes (e.g., ID1) indicating that LY2109761 achieves its antifibrotic effect by suppressing radiation-induced proinflammatory, proangiogenic, and profibrotic signals. Conclusion: Small-molecule inhibitors of the TGF-β receptor I kinase may offer a promising approach to treat or attenuate radiation-induced lung toxicity or other diseases associated with fibrosis. Clin Cancer Res; 18(13); 3616–27. ©2012 AACR.

Background: Radiotherapy is a mainstay for the treatment of lung cancer that can induce pneumonitis or pulmonary fibrosis. The matricellular protein connective tissue growth factor (CTGF) is a central mediator of tissue remodeling. Methods: A radiation-induced mouse model of pulmonary fibrosis was used to determine if transient administration of a human antibody to CTGF (FG-3019) started at different times before or after 20 Gy thoracic irradiation reduced acute and chronic radiation toxicity. Mice (25 mice/group; 10 mice/group in a confirmation study) were examined by computed tomography, histology, gene expression changes, and for survival. In vitro experiments were performed to directly study the interaction of CTGF blockade and radiation. All statistical tests were two-sided. Results: Administration of FG-3019 prevented (∼50%–80%) or reversed (∼50%) lung remodeling, improved lung function, improved mouse health, and rescued mice from lethal irradiation (P < .01). Importantly, when antibody treatment was initiated at 16 weeks after thoracic irradiation, FG-3019 reversed established lung remodeling and restored lung function. CTGF blockade abrogated M2 polarized macrophage influx, normalized radiation-induced gene expression changes, and reduced myofibroblast abundance and Osteopontin expression. Conclusion: These results indicate that blocking CTGF attenuates radiation-induced pulmonary remodeling and can reverse the process after initiation. CTGF has a central role in radiation-induced fibrogenesis, and FG-3019 may benefit patients with radiation-induced pulmonary fibrosis or patients with other forms or origin of chronic fibrotic diseases.

To evaluate the ability of a diagnostic abbreviated magnetic resonance (MR) imaging protocol consisting of maximum intensity projections (MIPs) from diffusion-weighted imaging with background suppression (DWIBS) and unenhanced morphologic sequences to help predict the likelihood of malignancy on suspicious screening x-ray mammograms, as compared with an abbreviated contrast material-enhanced MR imaging protocol and a full diagnostic breast MR imaging protocol.This prospective institutional review board-approved study included 50 women (mean age, 57.1 years; range, 50-69 years), who gave informed consent and who had suspicious screening mammograms and an indication for biopsy, from September 2014 to January 2015. Before biopsy, full diagnostic contrast-enhanced MR imaging was performed that included DWIBS (b = 1500 sec/mm(2)). Two abbreviated protocols (APs) based on MIPs were evaluated regarding the potential to exclude malignancy: DWIBS (AP1) and subtraction images from the first postcontrast and the unenhanced series (AP2). Diagnostic indexes of both methods were examined by using the McNemar test and were compared with those of the full diagnostic protocol and histopathologic findings.Twenty-four of 50 participants had a breast carcinoma. With AP1 (DWIBS), the sensitivity was 0.92 (95% confidence interval [CI]: 0.73, 0.98), the specificity was 0.94 (95% CI: 0.77, 0.99), the negative predictive value (NPV) was 0.92 (95% CI: 0.75, 0.99), and the positive predictive value (PPV) was 0.93 (95% CI: 0.75, 0.99). The mean reading time was 29.7 seconds (range, 4.9-110.0 seconds) and was less than 3 seconds (range, 1.2-7.6 seconds) in the absence of suspicious findings on the DWIBS MIPs. With the AP2 protocol, the sensitivity was 0.85 (95% CI: 0.78, 0.95), the specificity was 0.90 (95% CI: 0.72, 0.97), the NPV was 0.87 (95% CI: 0.69, 0.95), the PPV was 0.89 (95% CI: 0.69, 0.97), and the mean reading time was 29.6 seconds (range, 6.0-100.0 seconds).Unenhanced diagnostic MR imaging (DWIBS mammography), with an NPV of 0.92 and an acquisition time of less than 7 minutes, could help exclude malignancy in women with suspicious x-ray screening mammograms. The method has the potential to reduce unnecessary invasive procedures and emotional distress for breast cancer screening participants if it is used as a complement after the regular screening clarification procedure.

Objective To evaluate a fractional order calculus (FROC) model in diffusion weighted imaging to differentiate between malignant and benign breast lesions in breast cancer screening work-up using recently introduced parameters (βFROC, DFROC and μFROC). Materials and methods This retrospective analysis within a prospective IRB-approved study included 51 participants (mean 58.4 years) after written informed consent. All patients had suspicious screening mammograms and indication for biopsy. Prior to biopsy, full diagnostic contrast-enhanced MRI examination was acquired including diffusion-weighted-imaging (DWI, b = 0,100,750,1500 s/mm2). Conventional apparent diffusion coefficient Dapp and FROC parameters (βFROC, DFROC and μFROC) as suggested further indicators of diffusivity components were measured in benign and malignant lesions. Receiver operating characteristics (ROC) were calculated to evaluate the diagnostic performance of the parameters. Results 29/51 patients histopathologically revealed malignant lesions. The analysis revealed an AUC for Dapp of 0.89 (95% CI 0.80–0.98). For FROC derived parameters, AUC was 0.75 (0.60–0.89) for DFROC, 0.59 (0.43–0.75) for βFROC and 0.59 (0.42–0.77) for μFROC. Comparison of the AUC curves revealed a significantly higher AUC of Dapp compared to the FROC parameters DFROC (p = 0.009), βFROC (p = 0.003) and μFROC (p = 0.001). Conclusion In contrast to recent description in brain tumors, the apparent diffusion coefficient Dapp showed a significantly higher AUC than the recently proposed FROC parameters βFROC, DFROC and μFROC for differentiating between malignant and benign breast lesions. This might be related to the intrinsic high heterogeneity within breast tissue or to the lower maximal b-value used in our study.

Introduction The aim of this study is to investigate if alterations of intra- and prelesionary motility in inflamed small-bowel segments correlate with length, wall-thickness and prelesionary dilatation of inflammatory small bowel lesions in patients suffering from Crohn's disease assessed with MRI. Methods and materials This retrospective IRB approved study included 25 patients (12 males, 18–77y) with inflammatory lesions examined using (MRE) magnetic resonance imaging enterography. Cine MRE was performed using a coronal 2D steady-state free precession sequence (TR 2.9, TE 1.25) on a 1.5T MRI scanner. Small bowel motility was examined using a dedicated MR-motility assessment software (Motasso, Vers. 1.0, Sohard AG, Bern, Switzerland). Motility patterns (contraction frequency, relative occlusion rate and mean diameter) were assessed in correlation to wall thickness, length and prelesionary dilatation of the lesions. Statistical analysis was performed by calculation of the Pearson's-Correlation coefficient. Results The length of the inflammatory segments, the wall thickening and prelesionary dilatation did not correlate with the frequency of the contractions ( r =0.17, p =0.477; r =0.316, p =0.123; r =0.161, p =0.441) or the impairment of luminal occlusion ( r =0.274, p =0.184; r =0.199, p =.0339; r =0.015, p =0.945) and only the prelesionary dilatation ( r =0.410, p =0.042) correlated to the mean luminal diameter of the segment. Conclusion The degree of motility impairment within inflammatory small bowel lesions does not significantly correlate with the extent of the lesion but with the motility measured in prelesionary, non-affected segments, suggesting an interdependent functional aspect of inflammation even in morphologically non-affected small bowel segments.

Magnetic resonance imaging (MRI) of the abdomen is a widely established imaging modality in the diagnostic workup of patients suffering from abdominal disorders. Small-bowel motility analyses using MRI have recently been introduced to provide functional information about the intestine not provided by morphological analyses. This is of clinical importance as motility disorders correlate with inflammation. Yet motility analyses mainly rely on a series of acquisitions in coronal orientation. Temporal displacement of small-bowel loops out of the coronal slice could falsify qualitative and quantitative motility analyses. Thus, our study quantified three-dimensional (3D) dislocation of small-bowel loops during abdominal MRI examinations with the patient lying in prone position to investigate its influence on motility analyses. Our study revealed segmental small-bowel displacement during MRI examinations in prone position to predominantly occur in craniocaudal orientation and in a smaller extent in lateral and ventrodorsal orientation. However, the displacement amplitudes are rather small and might not significantly influence small-bowel motility analyses in 2D coronal plane in general.

AIM: To determine the feasibility of evaluating surgically induced hepatocyte damage using gadoxetate disodium (Gd-EOB-DTPA) as a marker for viable hepatocytes at magnetic resonance imaging (MRI) after liver resection. MATERIAL AND METHODS: Fifteen patients were prospectively enrolled in this institutional review board-approved study prior to elective liver resection after informed consent. Three Tesla MRI was performed 3-7 days after surgery. Three-dimensional (3D) T1-weighted (W) volumetric interpolated breath-hold gradient echo (VIBE) sequences covering the liver were acquired before and 20 min after Gd-EOB-DTPA administration. The signal-to-noise ratio (SNR) was used to compare the uptake of Gd-EOB-DTPA in healthy liver tissue and in liver tissue adjacent to the resection border applying paired Student's t-test. Correlations with potential influencing factors (blood loss, duration of intervention, age, pre-existing liver diseases, postoperative change of resection surface) were calculated using Pearson's correlation coefficient. RESULTS: Before Gd-EOB-DTPA administration the SNR did not differ significantly (p = 0.052) between healthy liver tissue adjacent to untouched liver borders [59.55 ± 25.46 (SD)] and the liver tissue compartment close to the resection surface (63.31 ± 27.24). During the hepatocyte-specific phase, the surgical site showed a significantly (p = 0.04) lower SNR (69.44 ± 24.23) compared to the healthy site (78.45 ± 27.71). Dynamic analyses revealed a significantly lower increase (p = 0.008) in signal intensity in the healthy tissue compared to the resection border compartment. CONCLUSION: EOB-DTPA-enhanced MRI may have the potential to be an effective non-invasive tool for detecting hepatocyte damage after liver resection.

Contraction frequencies are an important parameter for the analysis of bowel motility in MRI. The contraction curve can be rather noisy and the frequency-evaluation might be difficult. The aim was to evaluate manual calculations of small bowel contraction frequency in comparison with automatic calculations using two mathematically established methods.The institutional-review-board approved study consisted of 48 segmental small-bowel motility-plots out of a previous study with 25 patients (15 men/10 women; mean 39 years, standard deviation ± 14.67) undergoing MRI (1.5 T, GE-Medical Systems; two-dimensional-Fiesta, pulse repetition time 2.91, echo time 1.25, flip-angle 45°, matrix 256 × 256, slice thickness 10 mm) were evaluated. Calculations of contraction frequency was performed either manually or using Lomb-Scargle-periodograms and Sinus-Fitting method. The results were compared using intraclass correlation coefficient, Friedman's-test and Wilcoxon-matched-paired-signed-rank-test (P 0.05 considered statistically significant).Mean contraction frequency was 5.69 (standard deviation ± 1.99) for manual calculations showing moderate interreader reliability (intraclass correlation coefficient 0.72; 95% confidence-interval: 0.59;0.82). No significant difference (P = 0.776) was found to Lomb-Scargle-periodograms (5.34 contractions-per-minute [cpm], standard deviation ± 2.47; P = 0.174) and to the sinus-fitting-method (5.47 cpm; standard deviation ± 2.57; P = 0.0779). For the latter calculations failed in 3/48 plots, while manual and Lomb-Scargle-periodograms could be performed successfully in all 48/48 plots.Herein, we could show that Lomb-Scargle-periodograms and Sinus-Fitting are fast and reliable methods to automatically measure small-bowel contraction frequencies even in noisy small bowel motility plots.

AIM: To evaluate the influence of locally active Crohn's disease on systemic small-bowel motility in patients with chronic Crohn's disease compared to healthy individuals. MATERIAL AND METHODS: Fifteen healthy individuals (11 men, four women; mean age 37 years) and 20 patients with histopathologically proven active (n = 15; 10 women, 5 men; mean age 45 years) or chronic (n = 5; four women, one man; mean age 48 years) Crohn's disease were included in this institutional review board-approved, retrospective study. Magnetic resonance imaging (MRI; 1.5 T) was performed after standardized preparation. Two-dimensional (2D) cine sequences for motility acquisition were performed in apnoea (27 s). Motility assessment was performed using dedicated software in three randomly chosen areas of the small-bowel outside known Crohn's disease-affected hotspots. The main quantitative characteristics (frequency, amplitude, occlusion rate) were compared using Student's t-test and one-way analysis of variance (ANOVA). RESULTS: Three randomly chosen segments were analysed in each participant. Patients with active Crohn's disease had significantly (p < 0.05) reduced contraction frequencies (active Crohn's disease: 2.86/min; chronic: 4.14/min; healthy: 4.53/min) and luminal occlusion rates (active: 0.43; chronic: 0.70; healthy: 0.73) compared to healthy individuals and patients with chronic Crohn's disease. Contraction amplitudes were significantly reduced during active Crohn's disease (6.71 mm) compared to healthy participants (10.14 mm), but this only reached borderline significance in comparison to chronic Crohn's disease (8.87 mm). Mean bowel lumen diameter was significantly (p = 0.04) higher in patients with active Crohn's disease (16.91 mm) compared to healthy participants (14.79 mm) but not in comparison to patients with chronic Crohn's disease (13.68). CONCLUSION: The findings of the present study suggest that local inflammatory activity of small-bowel segments in patients with active Crohn's disease alters small-bowel motility in distant, non-affected segments. The motility patterns revealed reduced contraction-wave frequencies, amplitudes, and decreased luminal occlusion rates. Thus evaluation of these characteristics potentially helps to differentiate between chronic and active Crohn's disease.

Background The objective of the study was to correlate MR-detectable motility alterations of the terminal ileum with biopsy-documented active and chronic changes in Crohn's disease. Methods This IRB approved retrospective analysis of 43 patients included magnetic resonance enterography (MRE) and terminal ileum biopsies (

The aim of this study was to evaluate the feasibility of dedicated motility assessment software for quantitative evaluation of basic gastric motility and to validate it using manual measurements.Ten patients (5 males/5 females, mean 41 years) out of a previous series of small bowel MR-enterography examinations with well visible stomachs were included in this Institutional Reviews Board approved, retrospective study. MRI (1.5-T, Siemens Sonata) was performed after standardised oral preparation (3% aqueous mannitol over 1 h). Coronal 2DtrueFISP (TR 283.8/TE 1.89/FOV400/10 mm slice) motility acquisitions covering the entire abdomen were performed in apnoea. For each patient, image analysis for assessment of gastric motility was performed both manually and using the dedicated software either the proximal (n = 5) or in the distal (n = 5) gastric corpus. The main quantitative endpoints (amplitude, frequency) describing gastric motility were compared using (paired) Student's t-Test.All motility curves qualitatively matched each other (10/10). No significant differences (P0.05) were found for amplitudes (mean: 18.17 mm manual; 17.78 mm software), contraction frequencies (5.1/min; 4.7/min) and mean lumen diameters (34.12 mm; 33.13 mm), respectively. Mean duration for a single measurement was significantly (P0.001) lower with the software (6.40 min manual technique; 1.40 min software assisted).The software proves to be feasible for fast and accurate measurement of basic gastric motility parameters providing comparable data in comparison to manual assessment methods. It might help to reduce the time needed for assessment of relevant characteristics of gastric motility.

To assess the value of iterative frequency split-normalized (IFS) metal artifact reduction (MAR) for computed tomography (CT) of hip prostheses.This study had institutional review board and local ethics committee approval. First, a hip phantom with steel and titanium prostheses that had inlays of water, fat, and contrast media in the pelvis was used to optimize the IFS algorithm. Second, 41 consecutive patients with hip prostheses who were undergoing CT were included. Data sets were reconstructed with filtered back projection, the IFS algorithm, and a linear interpolation MAR algorithm. Two blinded, independent readers evaluated axial, coronal, and sagittal CT reformations for overall image quality, image quality of pelvic organs, and assessment of pelvic abnormalities. CT attenuation and image noise were measured. Statistical analysis included the Friedman test, Wilcoxon signed-rank test, and Levene test.Ex vivo experiments demonstrated an optimized IFS algorithm by using a threshold of 2200 HU with four iterations for both steel and titanium prostheses. Measurements of CT attenuation of the inlays were significantly (P.001) more accurate for IFS when compared with filtered back projection. In patients, best overall and pelvic organ image quality was found in all reformations with IFS (P.001). Pelvic abnormalities in 11 of 41 patients (27%) were diagnosed with significantly (P = .002) higher confidence on the basis of IFS images. CT attenuation of bladder (P.001) and muscle (P = .043) was significantly less variable with IFS compared with filtered back projection and linear interpolation MAR. In comparison with that of FBP and linear interpolation MAR, noise with IFS was similar close to and far from the prosthesis (P = .295).The IFS algorithm for CT image reconstruction significantly reduces metal artifacts from hip prostheses, improves the reliability of CT number measurements, and improves the confidence for depicting pelvic abnormalities.

To validate a software prototype allowing for small bowel motility analysis in free breathing by comparing it to manual measurements.In all, 25 patients (15 male, 10 female; mean age 39 years) were included in this Institutional Review Board-approved, retrospective study. Magnetic resonance imaging (MRI) was performed on a 1.5T system after standardized preparation acquiring motility sequences in free breathing over 69-84 seconds. Small bowel motility was analyzed manually and with the software. Functional parameters, measurement time, and reproducibility were compared using the coefficient of variance and paired Student's t-test. Correlation was analyzed using Pearson's correlation coefficient and linear regression.The 25 segments were analyzed twice both by hand and using the software with automatic breathing correction. All assessed parameters significantly correlated between the methods (P0.01), but the scattering of repeated measurements was significantly (P0.01) lower using the software (3.90%, standard deviation [SD] ± 5.69) than manual examinations (9.77%, SD ± 11.08). The time needed was significantly less (P0.001) with the software (4.52 minutes, SD ± 1.58) compared to manual measurement, lasting 17.48 minutes for manual (SD ± 1.75 minutes).The use of the software proves reliable and faster small bowel motility measurements in free-breathing MRI compared to manual analyses. The new technique allows for analyses of prolonged sequences acquired in free breathing, improving the informative value of the examinations by amplifying the evaluable data.

To evaluate the correlation between the levels of C-reactive protein (CRP), calprotectin, and small bowel motility in patients with Crohn's disease assessed with MRI.This prospective institutional review board approved study included magnetic resonance imaging enterography (MRE) and analyses of inflammatory markers in blood (C-reactive protein) and feces (calprotectin). For cine MRE, a coronal 2D-T2w sequence was used on a 1.5 T MRI system. Small bowel motility was analyzed in 13 patients using dedicated magnetic resonance MR-motility assessment software (Motasso). Contraction frequency, amplitude, amplitude diameter ratio, and luminal diameter were determined as well as the blood levels of CRP (mg L(-1) ) and fecal levels of calprotectin (ug g(-1) ). Statistics were calculated using Pearson's correlation coefficient.A significant inverse linear correlation was found between the contraction frequency and both the level of CRP (r = -0.701, P = 0.008) and calprotectin (r = -0.805, P = 0.001). Dilatation of small bowel diameter significantly correlated with calprotectin levels (r = 0.857, P = 0.001) but not with CRP (r = 0.447, P = 0.126). The absolute amplitude of the contractions did not correlate neither with the level of CRP (r = -0.527, P = 0.064) nor with calprotectin (r = -0.612, P = 0.026). The ratio describing the contraction amplitude relatively to the individual luminal diameter significantly correlated with calprotectin (r = 0.736, P = 0.004) and with CRP (r = 0.577, P = 0.039).Alterations of small bowel motility during CD flares significantly correlate with the level of calprotectin and CRP indicating that they represent inflammatory activity.