Lung cancer screening with MRI: Evaluation of MRI for lung cancer screening by comparison of LDCT- and MRI-derived Lung-RADS categories in the first two screening rounds.

PURPOSE: To evaluate MRI for lung cancer screening comparing LDCT- and MRI-derived Lung-RADS categories in the first two screening rounds. MATERIALS AND METHODS: 224 participants in a lung cancer screening study were examined with MRI and low-dose CT (LDCT). Acquired MRI sequences were T2, balanced, T1 and DWI. MRI was prospectively analysed regarding nodules. Minimum nodule size was 4 mm. Nodules were assigned a Lung-RADS score based on appearance and size at baseline and after 3, 6 and 12 months. MRI findings were correlated with LDCT. RESULTS: The early recall rate dropped from 13.8% at baseline to 1.9% in the second screening round with biopsy rates of 3.6% in the first round and 0.5% in the second round. Histology revealed lung cancer in 8/9 participants undergoing biopsy/surgery. All eight cancers were accurately depicted by MRI. The following categories were assigned on MRI (results of LDCT in parentheses): 4B/4X in 10 (10) cases, 4A in 16 (15) cases, 3 in 13 (12) cases, 2 in 77 (92) cases and 1 in 140 (126) cases. Lung-RADS scoring correlated significantly between MRI and CT. The score was overestimated by MRI in one case for category 4A, in two cases for category 3 and in five cases for category 2. MRI-based Lung-RADS score was underestimated for category 1 in 20 cases. CONCLUSION: Lung-RADS might be applied for lung cancer screening with MRI, since findings correlated with LDCT. Relevant findings with a Lung-RADS score of 3 and higher were never missed or underestimated by MRI KEY POINTS: • MRI performed comparably to low-dose CT in a lung cancer-screening programme. • Lung-RADS might be applied for lung cancer screening with MRI. • Lung-RADS findings score of 3 and higher were never missed by MRI.

Lung cancer screening with MRI: characterization of nodules with different non-enhanced MRI sequences.

BACKGROUND: There is increased interest in pulmonary magnetic resonance imaging (MRI) as a radiation-free alternative to computed tomography (CT) for lung cancer screening. PURPOSE: To analyze MRI characteristics of pulmonary nodules with different non-enhanced sequences. MATERIAL AND METHODS: Eighty-two participants of a lung cancer screening were included. MRI datasets of 32 individuals with 46 different nodules ≥ 6 mm were prospectively evaluated together with 50 controls by two readers. Acquired sequences were T2- short tau inversion recovery (STIR), T2, balanced steady-state free precession (bSSFP), 3D-T1, and diffusion-weighted imaging (DWI). Each sequence was randomly and separately viewed blinded to low-dose CT (LDCT). Size, shape, and contrast of nodules were evaluated on each sequence and then correlated with LDCT and histopathology. RESULTS: All eight carcinomas were detected by T2-STIR, T2, and bSSFP, and 7/8 by 3D-T1. Contrast was significantly higher for malignant nodules on all sequences. The highest contrast ratio between malignant and benign nodules was provided by T2-STIR. Of eight carcinomas, seven showed restricted diffusion. Size measurement correlated significantly between MRI and LDCT. Sensitivity/specificity for nodules ≥ 6 mm was 85-89%/92-94% for T2-STIR, 80-87%/93-96% for T2, 65-70%/96-98% for bSSFP, and 63-67%/96-100% for 3D-T1. Seven of eight subsolid nodules were visible on T2-sequences with significantly lower lesion contrast compared to solid nodules. Two of eight subsolid nodules were detected by bSFFP, none by 3D-T1. All three calcified nodules were detected by 3D-T1, one by bSSFP, and none by T2-sequences. CONCLUSION: Malignant as well as calcified and subsolid nodules seem to have distinctive characteristics on different MRI sequences. T2-imaging was most suitable for the detection of nodules ≥ 6 mm.

Revised PROPELLER for T2-weighted imaging of the prostate at 3 Tesla: impact on lesion detection and PI-RADS classification.

PURPOSE: To evaluate revised PROPELLER (RevPROP) for T2-weighted imaging (T2WI) of the prostate as a substitute for turbo spin echo (TSE). MATERIALS AND METHODS: Three-Tesla MR images of 50 patients with 55 cancer-suspicious lesions were prospectively evaluated. Findings were correlated with histopathology after MRI-guided biopsy. T2 RevPROP, T2 TSE, diffusion-weighted imaging, dynamic contrast enhancement, and MR-spectroscopy were acquired. RevPROP was compared to TSE concerning PI-RADS scores, lesion size, lesion signal-intensity, lesion contrast, artefacts, and image quality. RESULTS: There were 41 carcinomas in 55 cancer-suspicious lesions. RevPROP detected 41 of 41 carcinomas (100%) and 54 of 55 lesions (98.2%). TSE detected 39 of 41 carcinomas (95.1%) and 51 of 55 lesions (92.7%). RevPROP showed fewer artefacts and higher image quality (each p < 0.001). No differences were observed between single and overall PI-RADS scores based on RevPROP or TSE (p = 0.106 and p = 0.107). Lesion size was not different (p = 0.105). T2-signal intensity of lesions was higher and T2-contrast of lesions was lower on RevPROP (each p < 0.001). CONCLUSION: For prostate cancer detection RevPROP is superior to TSE with respect to motion robustness, image quality and detection rates of lesions. Therefore, RevPROP might be used as a substitute for T2WI. KEY POINTS: • Revised PROPELLER can be used as a substitute for T2-weighted prostate imaging. • Revised PROPELLER detected more carcinomas and more suspicious lesions than TSE. • Revised PROPELLER showed fewer artefacts and better image quality compared to TSE. • There were no significant differences in PI-RADS scores between revised PROPELLER and TSE. • The lower T2-contrast of revised PROPELLER did not impair its diagnostic quality.

Proton density fat fraction (PDFF) MRI for differentiation of benign and malignant vertebral lesions.

OBJECTIVES: To investigate whether proton density fat fraction (PDFF) measurements using a six-echo modified Dixon sequence can help to differentiate between benign and malignant vertebral bone marrow lesions. METHODS: Sixty-six patients were prospectively enrolled in our study. In addition to conventional MRI at 3.0-Tesla including at least sagittal T2-weighted/spectral attenuated inversion recovery and T1-weighted sequences, all patients underwent a sagittal six-echo modified Dixon sequence of the spine. The mean PDFF was calculated using regions of interest and compared between vertebral lesions. A cut-off value of 6.40% in PDFF was determined by receiver operating characteristic curves and used to differentiate between malignant (< 6.40%) and benign (≥ 6.40%) vertebral lesions. RESULTS: There were 77 benign and 44 malignant lesions. The PDFF of malignant lesions was statistically significant lower in comparison with benign lesions (p < 0.001) and normal vertebral bone marrow (p < 0.001). The areas under the curves (AUC) were 0.97 for differentiating benign from malignant lesions (p < 0.001) and 0.95 for differentiating acute vertebral fractures from malignant lesions (p < 0.001). This yielded a diagnostic accuracy of 96% in the differentiation of both benign lesions and acute vertebral fractures from malignancy. CONCLUSION: PDFF derived from six-echo modified Dixon allows for differentiation between benign and malignant vertebral lesions with a high diagnostic accuracy. KEY POINTS: • Establishing a diagnosis of indeterminate vertebral lesions is a common clinical problem • Benign bone marrow processes may mimic the signal alterations observed in malignancy • PDFF differentiates between benign and malignant lesions with a high diagnostic accuracy • PDFF of non-neoplastic vertebral lesions is significantly higher than that of malignancy • PDFF from six-echo modified Dixon may help avoid potentially harmful bone biopsy.

Cardiac magnetic resonance based evaluation of aortic stiffness and epicardial fat volume in patients with hypertension, diabetes mellitus, and myocardial infarction.

Background Aortic stiffness and epicardial fat relate to cardiovascular risk. Their relationship with each other and their role with hypertension, diabetes mellitus (DM), and myocardial infarction (MI) can be evaluated by cardiac magnetic resonance (CMR). Purpose To explore an association between aortic stiffness and epicardial as well as paracardial fat volume (EFV and ParaFV, respectively) in hypertensive patients and to relate the results to the presence of DM and MI. Material and Methods A total of 156 hypertensive and 20 non-hypertensive participants were examined at 1.5 Tesla. A 2D-velocity-encoded sequence was acquired to assess aortic pulse wave velocity (PWV in m/s) as a measure of aortic stiffness. A 3D-Dixon sequence was used to determine EFV and ParaFV. Results PWV correlated with EFV (R = 0.474; P < 0.001), but not with ParaFV. Fat volumes (in mL/m2) and PWV were lower in non-hypertensive controls compared to hypertensive patients. EFV and PWV were significantly higher in diabetic hypertensive patients without MI (n = 19; PWV: 10.4 ± 2.9; EFV: 92.5 ± 19.3) compared to hypertension-only patients (n = 84 [no DM or MI]; EFV: 64.8 ± 25.1, PWV: 9.0 ± 2.6; P < 0.05). Logistic regression analysis showed a significant association between the presence of a MI and a higher EFV ( P < 0.05), but not with PWV ( P = 0.060) or ParaFV ( P = 0.375). Conclusion A relationship between aortic stiffness and EFV was found in hypertensive patients. Both were increased in the presence of DM; however, only EFV was increased in the presence of MI. This may relate to the PWV lowering effect of the antihypertensive medication used by hypertensive patients and underscores the benefit of EFV assessment in this regard.

CMR based measurement of aortic stiffness, epicardial fat, left ventricular myocardial strain and fibrosis in hypertensive patients.

INTRODUCTION: A combined assessment of different parameters of cardiovascular (CV) risk and prognosis can be supportive and performed with cardiac magnetic resonance (CMR). Aortic stiffness, epicardial fat volume (EFV), left ventricular (LV) strain and fibrosis were evaluated within a single CMR examination and results were related to the presence of hypertension (HTN) and diabetes mellitus (DM). METHODS: 20 healthy controls (57.2 ± 8.2 years(y); 26.2 ± 3.9 kg/m2), 31 hypertensive patients without DM (59.6 ± 6.7 y; 28.4 ± 4.7 kg/m2) and 12 hypertensive patients with DM (58.8 ± 9.9y; 30.7 ± 6.3 kg/m2) were examined at 1.5Tesla. Aortic stiffness was evaluated by calculation of aortic pulse wave velocity (PWV), EFV by a 3D-Dixon sequence. Longitudinal & circumferential systolic myocardial strain (LS; CS) were analyzed and T1-relaxation times (T1) were determined to detect myocardial fibrosis. RESULTS: EFV was highest in hypertensive patients with diabetes (78.4 ± 28.0 ml/m2) followed by only hypertensive patients (64.2 ± 27.3 ml/m2) and lowest in controls (50.3 ± 22.7 ml/m2; p < 0.05). PWV was higher in hypertensive patients with diabetes (9.8 ± 3.3 m/s) compared to only hypertensive patients (8.6 ± 1.7 m/s; p < 0.05) and to controls (8.1 ± 1.9 m/s; p < 0.05). LS&CS were worse in hypertensive patients with diabetes (LS:-20.9 ± 5.1% and CS: -24.4 ± 5.7%) compared to both only hypertensive patients (LS: -24.7 ± 4.6%; CS: -27.1 ± 5.0%; p < 0.05) and to controls (LS: -25.5 ± 3.8; CS: -28.3 ± 4.1%; p < 0.05). Both hypertensive groups with and without DM had higher T1́s (994.0 ± 43.2 ms; 991.6 ± 35.5 ms) than controls (964.6 ± 40.3 ms; p < 0.05). CONCLUSION: CMR revealed increased aortic stiffness and EFV in hypertensive patients, which were even higher in the presence of DM. Also signs of LV myocardial fibrosis and a reduced strain were revealed. These parameters support the assessment of CV risk and prognosis. They can accurately be measured with CMR within a single examination when normally different techniques are needed.

Low-Dose Chest CT for the Diagnosis of COVID-19­A Systematic, Prospective Comparison With PCR

BACKGROUND: Only limited evidence has been available to date on the accuracy of systematic low-dose chest computed tomography (LDCT) use in the diagnosis of COVID-19 in patients with non-specific clinical symptoms. METHODS: The COVID-19 Imaging Registry Study Aachen (COVID-19-Bildgebungs-Register Aachen, COBRA) collects data on imaging in patients with COVID-19. Two of the COBRA partner hospitals (RWTH Aachen University Hospital and Dueren Hospital) systematically perform reverse transcriptase polymerase chain reaction (RT-PCR) from nasopharyngeal swabs as well as LDCT in all patients presenting with manifestations that are compatible with COVID-19. In accordance with the COV-RADS protocol, the LDCT scans were prospectively evaluated before the RT-PCR findings were available in order to categorize the likelihood of COVID-19. RESULTS: From 18 March to 5 May 2020, 191 patients with COVID-19 manifestations (117 male, age 65 ± 16 years) underwent RT-PCR testing and LDCT. The mean time from the submission of the sample to the availability of the RT-PCR findings was 491 minutes (interquartile range [IQR: 276-1066]), while that from the performance of the CT to the availability of its findings was 9 minutes (IQR: 6-11). A diagnosis of COVID-19 was made in 75/191 patients (39%). The LDCT was positive in 71 of these 75 patients and negative in 106 of the 116 patients without COVID-19, corresponding to 94.7% sensitivity (95% confidence interval [86.9; 98.5]), 91.4% specificity [84.7; 95.8], positive and negative predictive values of 87.7% [78.5; 93.9] and 96.4% [91.1; 98.6], respectively, and an AUC (area under the curve) of 0.959 [0.930; 0.988]. The initial RT-PCR test results were falsely negative in six patients, yielding a sensitivity of 92.0% [83.4; 97.0]; these six patients had positive LDCT findings. 47.4% of the LDCTs that were negative for COVID-19 (55/116) exhibited pathological pulmonary changes, including infiltrates, that were correctly distinguished from SARS-CoV-2 related changes. CONCLUSION: In patients with symptoms compatible with COVID-19, LDCT can esablish the diagnosis of COVID-19 with comparable sensitivity to RT-PCR testing. In addition, it offers a high specificity for distinguishing COVID-19 from other diseases associated with the same or similar clinical symptoms. We propose the systematic use of LDCT in addition to RT-PCR testing because it helps correct false-negative RT-PCR results, because its results are available much faster than those of RT-PCRtesting, and because it provides additional diagnostic information useful for treatment planning regardless of the type of the infectious agent.

Quantitative and Qualitative Assessment of Pulmonary Emphysema with T2-Weighted PROPELLER MRI in a High-Risk Population Compared to Low-Dose CT.

PURPOSE: To determine the suitability of T2-weighted PROPELLER MRI for the assessment of pulmonary emphysema. MATERIALS AND METHODS: 60 participants in a lung cancer screening program (30 subjects with pulmonary emphysema, and 30 control subjects without emphysema) were included for this retrospective study. All subjects were examined with low-dose CT (LDCT) and MRI within the screening program. The use of a T2-weighted PROPELLER sequence for the assessment of emphysema was analyzed and correlated with the results of LDCT. The presence and the extent of pulmonary emphysema were first assessed qualitatively using a three-point score, and then quantitatively with a semi-automated software program to obtain emphysema indices. RESULTS: All 30 cases with pulmonary emphysema were accurately detected by MRI. There were 3 cases with emphysema according to MRI without emphysematous changes on LDCT (false-positive results). The qualitative scores as well as the emphysema indices were significantly higher in the emphysema group compared to the control group for MRI and LDCT (p < 0.001). Both the scores and the indices correlated significantly between MRI and LDCT (qualitative score of severity: r = 0.912/p < 0.001 in the emphysema group and r = 0.668/p < 0.001 in the control group; emphysema index: r = 0.960/p < 0.001 in the emphysema group and r = 0.746/p < 0.001 in the control group). CONCLUSION: The presence and the extent of pulmonary emphysema may be assessed qualitatively and quantitatively by T2-weighted PROPELLER MRI with very good correlation to LDCT. KEY POINTS: · T2-weighted PROPELLER MRI may be suitable for the assessment of pulmonary emphysema.. · There was significant correlation between MRI and LDCT regarding qualitative scores and quantitative emphysema indices in our study with correlation coefficients for different subgroups ranging from r = 0.668 to r = 0.960.. · T2-weighted PROPELLER MRI may have the potential to be used for follow-up examinations in patients with severe emphysema to avoid radiation exposure of repeated CTs.. CITATION FORMAT: · Meier-Schroers M, Sprinkart AM, Becker M et al. Quantitative and Qualitative Assessment of Pulmonary Emphysema with T2-Weighted PROPELLER MRI in a High-Risk Population Compared to Low-Dose CT. Fortschr Röntgenstr 2018; 190: 733 - 739.

Lung cancer screening with MRI: results of the first screening round.

PURPOSE: To evaluate the suitability of MRI for lung cancer screening in a high-risk population. MATERIALS AND METHODS: A 5-year lung cancer screening program comparing MRI and low-dose CT (LDCT) in a high-risk population was initiated. 224 subjects were examined with MRI and LDCT. Acquired MRI sequences were T2w MultiVane XD, balanced steady-state-free precession, 3D T1w GRE, and DWI with a maximum in-room-time of 20 min. Categorization and management of nodules were based on Lung-RADS. MRI findings were correlated with LDCT as a reference. Here, we report on the first screening round. RESULTS: MRI accurately detected 61 of 88 nodules 4-5 mm, 20 of 21 nodules 6-7 mm, 12 of 12 nodules 8-14 mm, 4 of 4 nodules ≥ 15 mm (solid nodules), and 8 of 11 subsolid nodules. Sensitivity/specificity of MRI for nodule detection was 69.3/96.4% for 4-5 mm, 95.2/99.6% for 6-7 mm, 100/99.6% for 8-14 mm, 100/100% for ≥ 15 mm (solid nodules), and 72.7/99.2% for subsolid nodules. The early recall rate was 13.8% for MRI and 12.5% for LDCT. Following Lung-RADS recommendations and based on interdisciplinary consensus, histology was obtained in eight subjects. The biopsy rate was 3.6% for MRI and 3.4% for LDCT. In all of these eight cases, the nodules were carcinomas, and all of them were accurately detected by MRI. CONCLUSION: The results of the first screening round suggest that MRI is suitable for lung cancer screening with an excellent sensitivity and specificity for nodules ≥ 6 mm.

Interrelations of Epicardial Fat Volume, Left Ventricular T1-Relaxation Times and Myocardial Strain in Hypertensive Patients: A Cardiac Magnetic Resonance Study.

PURPOSE: This cardiac magnetic resonance study was performed to assess myocardial fibrosis by evaluating T1-relaxation time (T1), to measure left ventricular (LV) strain, and to determine epicardial fat volume (EFV) in hypertensive patients with no history of cardiovascular (CV) events and to relate the results to the presence of coronary atherosclerotic artery disease (CAD) in these patients. MATERIALS AND METHODS: A total of 123 subjects were examined at 1.5 T. Of them, 98 were hypertensive patients (58 men; mean age, 62.9±10.7 y; body mass index, 29.0±5.6 kg/m) and 25 were controls without CV risk factors or disease (13 men; 60.1±10.7 y; 28.1±5.4 kg/m). All patients had a well-treated blood pressure. In the hypertensive group, 56 patients had no CAD, whereas 42 patients had CAD. T1 was assessed by a modified Look-Locker inversion recovery sequence. Longitudinal and circumferential peak systolic strain (LS; CS) was determined with dedicated cardiac magnetic resonance software (feature tracking). EFV (normalized to the body surface area) was assessed by a 3D Dixon sequence. RESULTS: T1 (ms) and EFV (mL/m) were higher and CS and LS (%) were lower in hypertensive patients compared with those in nonhypertensive controls (P<0.05), independent of the presence of CAD (controls: T1=967.2±16.9, LS=-25.2±4.6, CS=-28.7±5.0, EFV=58.2±21.1; hypertensive patients overall: T1=991.3±45.5, LS=-21.0±4.5, CS=-25.0±5.9, EFV=71.1±25.3; hypertensive patients without CAD: T1=991.6±48.4, LS=-21.0±4.7, CS=-24.6±6.3, EFV=71.3±26.6; hypertensive patients with CAD: T1=986.7±39.2, LS=-21.1±4.3, CS=-25.5±5.4, EFV=70.9±23.6). There were no significant differences between hypertensive patients with and those without CAD and between patients grouped according to the number of vessels affected (0-vessel disease, 1-vessel disease, 2-vessel disease, or 3-vessel disease). CONCLUSIONS: Hypertension is associated with signs of myocardial fibrosis and an impaired LV contractility despite a normal LV ejection fraction, as well as with an increased EFV. However, CAD, in the absence of previous pathologies with consecutive myocardial ischemic damage, did not additionally affect these parameters.

MRI of the lung using the PROPELLER technique: Artifact reduction, better image quality and improved nodule detection.

PURPOSE: To evaluate the benefit of the PROPELLER technique (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction, MultiVane, MV) for MR imaging of the lung. MATERIALS AND METHODS: 30 Participants of a lung cancer screening program were recruited for the comparison of T2-MV and T2-Fast Spin Echo (FSE) sequences at 1.5T. Two readers evaluated artifacts, image quality, and pulmonary lesions. Artifacts and image quality were rated using a four-point scale. Lesion detection was correlated to low-dose computed tomography (CT). Wilcoxon rank-test for ratings of artifacts and image quality, sensitivity and specificity values for lesion detection, and Cohen's kappa for inter-rater agreement were used. RESULTS: The MV sequence showed less pulsation and motion artifacts, and higher image quality (p=0.001 for R1, p=0.002 for R2) than FSE (p<0.001 for both readers, R1 and R2). Inter-rater agreement was excellent for lesion detection (0.84-0.95) and good to excellent for artifacts and image quality (0.66-0.84). 17 patients had lesions <8mm, and 7 had lesions >8mm as seen on CT. For R1 and R2, the MV sequence allowed for higher detection rates of pulmonary lesions <8mm with a sensitivity of 56% (R1) and 59% (R2); the FSE sequence achieved 50% (R1) and 53% (R2). Specificity was also higher for MV with 94% (R1) and 83% (R2) compared to 78% (R1) and 76% (R2). Lesions >8mm were detected with a sensitivity of 100% by both readers on both MV and FSE images. For both readers, specificity for larger lesions was higher on MV images with 100% compared to 96%. CONCLUSION: The superior image quality and the very robust artifact reduction make MV a promising technique for MRI of the lung compared to FSE, especially since it is not requiring breathholds. Moreover, MV allows for improved lesion detection.

Differentiation of prostatitis and prostate cancer using the Prostate Imaging-Reporting and Data System (PI-RADS).

PURPOSE: To determine if prostate cancer (PCa) and prostatitis can be differentiated by using PI-RADS. MATERIALS AND METHODS: 3T MR images of 68 patients with 85 cancer suspicious lesions were analyzed. The findings were correlated with histopathology. T2w imaging (T2WI), diffusion weighted imaging (DWI), dynamic contrast enhancement (DCE), and MR-Spectroscopy (MRS) were acquired. Every lesion was given a single PI-RADS score for each parameter, as well as a sum score and a PI-RADS v2 score. Furthermore, T2-morphology, ADC-value, perfusion type, citrate/choline-level, and localization were evaluated. RESULTS: 44 of 85 lesions showed PCa (51.8%), 21 chronic prostatitis (24.7%), and 20 other benign tissue such as hyperplasia or fibromuscular tissue (23.5%). The single PI-RADS score for T2WI, DWI, DCE, as well as the aggregated score including and not including MRS, and the PI-RADS v2-score were all significantly higher for PCa than for prostatitis or other tissue (p<0.001). The single PI-RADS score for MRS and the PI-RADS sum score including MRS were significantly higher for prostatitis than for other tissue (p=0.029 and p=0.020), whereas the other parameters were not different. Prostatitis usually presented borderline pathological PI-RADS scores, showed restricted diffusion with ADC≥900mm(2)/s in 100% of cases, was more often indistinctly hypointense on T2WI (66.7%), and localized in the transitional zone (57.1%). An ADC≥900mm(2)/s achieved the highest predictive value for prostatitis (AUC=0.859). CONCLUSION: Prostatitis can be differentiated from PCa using PI-RADS, since all available parameters are more distinct in cases of cancer. However, there is significant overlap between prostatitis and other benign findings, thus PI-RADS is only suitable to a limited extent for the primary assessment of prostatitis. Restricted diffusion with ADC≥900mm(2)/s is believed to be a good indicator for prostatitis. MRS can help to distinguish between prostatitis and other tissue.

3D-Dixon cardiac magnetic resonance detects an increased epicardial fat volume in hypertensive men with myocardial infarction.

PURPOSE: Using a three-dimensional ECG- and respiratory navigator gated magnetization prepared mDixon-sequence (3D-Dixon) we quantified epi- and pericardial fat volumes (EFV, PFV) in hypertensive men compared to a healthy control group and related the amount of fat volumes in hypertensive men to the presence of coronary artery disease (CAD) and myocardial infarction (MI). MATERIALS AND METHODS: 55 hypertensive men (mean age 63.02±10.73years [y]) with MI (n=22; mean age 61.55±10.50y) and without MI (n=33; mean age 63.17±10.93y), and a group of ten healthy men (mean age 59.00±8.41y) underwent a comprehensive cardiomagnetic resonance (CMR) examination on a 1.5T MR system (Ingenia, Philips). Hypertensive men without MI consisted of patients with CAD (n=15) and without CAD (n=18). EFV and PFV were assessed using 3D-Dixon. Fat only images were reconstructed online at the scanner, and the segmentation of fat volumes was performed based on fat fraction maps. EFV and PFV were normalized to the body surface area (ml/m(2)). RESULTS: Mean EFV and PFV in all hypertensive men (81.8±33.90 and 194.86±83.51) as well as in hypertensive men with no CAD (74.53±26.40 and 174.60±65.70) were significantly higher than in the healthy controls (52.98±19.81 and 115.50±53.57; P<0.05, each). EFV and PFV in hypertensive men with MI (94.14±43.16 and 224.26±100.79) were significantly higher than in hypertensive men with no MI (73.57±23.27 and 175.26±63.07; P<0.05, each). There were no significant differences in age, BMI or heart rate between the groups. CONCLUSION: 3D-Dixon measurements revealed significantly higher epi- and pericardial fat volumes in hypertensive men with myocardial infarction compared to hypertensive men without MI. This finding underscores the role of cardiac fatty tissue as a proinflammatory and metabolically active organ. Non-invasive CMR-based whole volume measurement of epi- and pericardial fat may play a relevant future role in cardiovascular risk stratification and disease management.

In-bore transrectal MRI-guided prostate biopsies: Are there risk factors for complications?

PURPOSE: To systematically analyze risk factors for complications of in-bore transrectal MRI-guided prostate biopsies (MRGB). MATERIALS AND METHODS: 90 patients, who were scheduled for MRGB were included for this study. Exclusion criteria were coagulation disorders, therapy with anticoagulant drugs, and acute infections of the urinary and the lower gastrointestinal tract. Directly after, one week and one year after the biopsy, we assessed biopsy related complications (e.g. hemorrhages or signs of prostatitis). Differences between patients with and without complications were analyzed regarding possible risk factors: age, prostate volume, number of taken samples, biopsy duration, biopsy of more than one lesion, diabetes, arterial hypertension, hemorrhoids, benign prostate hyperplasia, carcinoma or prostatitis (according to histopathological analysis), and lesion localization. Complications were classified according to the Clavien-Dindo classification. RESULTS: We observed 15 grade I complications in 90 biopsies (16.7%) with slight hematuria in 9 cases (10%), minor vasovagal reactions in 4 cases (4.4%), and urinary retention and positioning-related facial dysesthesia in 1 case each (1.1%). One patient showed acute prostatitis requiring antibiotics as the only grade II complication (1.1%). There were no adverse events that occurred later than one week. Complications grade III or higher such as pelvic abscesses, urosepsis or severe hemorrhages were not seen. There were no significant associations between the assessed risk factors and biopsy-related complications. CONCLUSION: In-bore transrectal MRI-guided prostate biopsies can be considered safe procedures in the diagnosis of prostate cancer with very low complication rates. There seem to be no risk factors for complications.

3D-Dixon MRI based volumetry of peri- and epicardial fat.

There is growing evidence that pericardial and epicardial fat volume (PFV, EFV) are associated with cardiovascular risk. We evaluated a novel method for accurate measurement of PFV and EFV using a 3D-Dixon based cardiac magnetic resonance (CMR) approach. An electrocardiography triggered and respiratory navigator gated 3D-gradient echo pulse sequence was used for cardiac Dixon imaging. Based on this sequence, voxels predominantly containing fat were identified and added up for volumetry. After accuracy assessment in phantoms, consisting of muscle tissue and seven different fat samples (50-200 ml), the sequence was acquired in 34 healthy volunteers (22 male, BMI range 14-42 kg/m(2), age range 21-79 years) at 1.5 T. Analysis was performed independently by two readers who draw two 3D-regions of interest, one for EFV and one for PFV. Additionally, EFV and PFV were compared between overweighted and non-overweighted subjects. The phantom study showed an excellent agreement of measured and true fat volumes (maximum difference = 6 %, linear correlation coefficient R = 1.00). PFV over all volunteers was 158.0 ± 126.4 ml and EFV was 77.0 ± 55.3 ml. PFV and EFV were highly correlated (R = 0.96). Inter-reader agreement was good with a mean difference of 0.2 ± 5.6 and 4.5 ± 4.2 ml for PFV/EFV, (R > 0.99, each). EFV and PFV differed significantly between subjects with BMI > 25 kg/m(2) and BMI < 25 kg/m(2), n = 17 each (PFV 219.0 ± 151.8 vs. 96.9 ± 44.7 ml and EFV 102.3 ± 66.3 vs. 51.7 ± 23.6 ml, p < 0.001, each). The proposed 3D-Dixon based method allows accurate measurement of cardiac fat volumes. It provides a valuable tool for cardiovascular risk stratification by CMR.