Objectives
To investigate the clinical utility of the Vesical Imaging-Reporting and Data System (VI-RADS) by comparing its diagnostic performance for muscle-invasive bladder cancer (MIBC) between ...radiologists and urologists based on multiparametric MRI, including three-dimensional (3D) fast spin-echo (FSE) T2-weighted acquisitions.
Methods
This study included 66 treatment-naïve patients (60 men, 6 women; mean age 74.0 years) with pathologically proven bladder cancer who underwent multiparametric MRI, including 3D FSE T2-weighted imaging, before transurethral bladder tumour resection between January 2010 and November 2018. The MRI scans were categorised according to the five-point VI-RADS score by four independent readers (two board-certified radiologists and board-certified urologists each), blinded to the histopathological findings. The VI-RADS scores were compared with the postoperative histopathological diagnosis. Interobserver agreement was assessed using weighted kappa coefficients. ROC analysis and generalised estimating equations were used to evaluate the diagnostic performance.
Results
Forty-nine (74.2%) and 17 (25.8%) tumours were confirmed to be non-MIBC and MIBC, respectively, based on pathological examination. The interobserver agreement was good-to-excellent between all pairs of readers (range, 0.73–0.91). The urologists’ sensitivity/specificity values for DCE-MRI VI-RADS scores were significantly lower than those of radiologists. No significant differences were observed for the overall VI-RADS score. The AUC for the overall VI-RADS score was 0.94, 0.92, 0.89, and 0.87 for radiologists 1 and 2 and urologists 1 and 2, respectively.
Conclusions
The VI-RADS score, based on multiparametric MRI including 3D FSE T2-weighted acquisitions, can be useful for radiologists and urologists to determine the bladder cancer muscle invasion status preoperatively.
Key Points
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VI-RADS (using multiparametric MRI including 3D FSE T2-weighted acquisitions) achieves good to excellent interobserver agreement and has similar diagnostic performance for detecting muscle invasion by both radiologists and urologists.
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The diagnostic performance of the overall VI-RADS score is high for both radiologists and urologists, particularly due to the dominant effect of diffusion-weighted imaging on the overall VI-RADS score.
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The sensitivity and specificity values of the T2WI VI-RADS scores for four readers in our study (using 3D FSE T2-weighted acquisitions) were similar (with slightly higher specificity values) to previously published results (using 2D FSE T2-weighted acquisitions).
Cardiac magnetic resonance imaging (CMR) often shows discrepancies between right ventricular outflow tract (RVOT) flow and left ventricular outflow tract flow in patients with late-stage repaired ...tetralogy of Fallot (rTOF), leading to potential errors in pulmonary regurgitation fraction (PRF) assessment. This study aimed to identify the conditions under which RVOT flow can be acutely evaluated using four-dimensional (4D) flow CMR. Twenty-seven consecutive patients with rTOF underwent both two-dimensional phase-contrast (2D PC) and 4D flow CMR between 2016 and 2018, excluding those with peripheral pulmonary artery stenosis, RVOT conduit replacement, unknown surgical method, and an aortic valve regurgitation greater than 20%. Seven healthy controls also underwent only 4D Flow CMR. All healthy controls and fifteen patients with rTOF showed laminar RVOT flow, while seven patients exhibited helical, and four patients exhibited vortical RVOT flow in 4D flow CMR visualization. Flow-volume concordance between the pulmonary artery and aortic flow was significantly lower in patients with rTOF and PRF > 40% in 2D PC CMR. This concordance rate in the suprapulmonary valve was high in both the TOF and control groups, comparing at five RVOT locations in 4D flow CMR. Regarding RVOT flow regurgitation in 4D flow, the whole bulk evaluation exhibited greater variation depending on the flow type compared to the whole pixel-wise evaluation. The study confirmed the flow volume at the upper section of the pulmonary valve as the most accurate correlate of aortic flow volume. Furthermore, the 4D flow CMR using the pixel-wise method demonstrated superior accuracy compared to the traditional bulk flow method.
Background In patients with rotator cuff tears, muscle degeneration is known to be a predictor of irreparable tears and poor outcomes after surgical repair. Fatty infiltration and volume of the whole ...muscles constituting the rotator cuff were quantitatively assessed using 3-dimensional 2-point Dixon magnetic resonance imaging. Methods Ten shoulders with a partial-thickness tear, 10 shoulders with an isolated supraspinatus tear, and 10 shoulders with a massive tear involving supraspinatus and infraspinatus were compared with 10 control shoulders after matching age and sex. With segmentation of muscle boundaries, the fat fraction value and the volume of the whole rotator cuff muscles were computed. After reliabilities were determined, differences in fat fraction, muscle volume, and fat-free muscle volume were evaluated. Results Intra-rater and inter-rater reliabilities were regarded as excellent for fat fraction and muscle volume. Tendon rupture adversely increased the fat fraction value of the respective rotator cuff muscle ( P < .002). In the massive tear group, muscle volume was significantly decreased in the infraspinatus ( P = .035) and increased in the teres minor ( P = .039). With subtraction of fat volume, a significant decrease of fat-free volume of the supraspinatus muscle became apparent with a massive tear ( P = .003). Conclusion Three-dimensional measurement could evaluate fatty infiltration and muscular volume with excellent reliabilities. The present study showed that chronic rupture of the tendon adversely increases the fat fraction of the respective muscle and indicates that the residual capacity of the rotator cuff muscles might be overestimated in patients with severe fatty infiltration.
Background:Hydrogen gas inhalation (HI) reduced infarct size and mitigated adverse left ventricular (LV) remodeling in a rat model of acute myocardial infarction (AMI). We designed a prospective, ...open-label, rater-blinded clinical pilot study in patients experiencing ST-elevated MI (STEMI).Methods and Results:The 20 patients with an initial diagnosis of STEMI were assigned to either an HI group (1.3% H2with 26% oxygen) or a control group (26% oxygen). There were no HI-related severe adverse events. In the full analysis set, the cardiac salvage index as evaluated using cardiac magnetic resonance imaging at 7 days after primary percutaneous coronary intervention (PCI), showed no significant between-group difference (HI: 50.0±24.3%; control: 60.1±20.1%; P=0.43). However, the improvement from day 7 in the HI group was numerically greater than that in the control group in some of the surrogate outcomes at 6-month follow-up, including the LV stroke volume index (HI: 9.2±7.1 mL/m2; control: −1.4±7.2 mL/m2; P=0.03) and the LV ejection fraction (HI: 11.0%±9.3%; control: 1.7%±8.3%; P=0.11).Conclusions:The first clinical study has shown that HI during PCI is feasible and safe and may also promote LV reverse remodeling at 6 months after STEMI. The study was not powered to test efficacy and a further large-scale trial is warranted. (Clinical trials registration: UMIN00006825)
The aims of this study were to evaluate the feasibility of quantitative synthetic magnetic resonance imaging (SyMRI) for characterizing bone lesions in prostate cancer and to discriminate viable ...progressive osteoblastic bone metastasis from nonviable bone metastases with treatment-induced sclerosis during the treatment course.
This institutional review board-approved prospective study included 96 consecutive prostate cancer patients who underwent whole-body MRI including diffusion-weighted imaging at the time of staging at diagnosis or starting a new line of anticancer treatment. Additional synthetic MRI of the lumbosacral spine, pelvis, and proximal femurs was performed. A region of interest of 1.0 cm in diameter was set in each bone lesion by 2 independent readers who were blinded to bone lesions' diagnosis. Differences in SyMRI variables between the different bone lesions were compared with the Wilcoxon rank sum test, and associations of SyMRI variables with active disease were analyzed with logistic regression analysis. Performance of T1, T2, and proton density (PD) for diagnosing active disease was assessed using the area under the receiver operating characteristic curve.
Ninety-three bone lesions were eligible for analysis. The PD values of active (viable) bone metastatic lesions were significantly higher than those of inactive (nonviable) bone metastatic lesions without sclerosis and those of red bone marrow (P < 0.001 for both readers). The PD values of inactive bone metastatic lesions with sclerosis were significantly lower than those of inactive bone metastatic lesions without sclerosis and red bone marrow (P < 0.001 for both readers). The PD value proved to be an independent significant indicator (P < 0.001) for differentiating bone lesions. The areas under the curve of T1/T2/PD for identifying active disease were 0.81/0.69/0.93 for reader 1 and 0.78/0.70/0.92 for reader 2, respectively.
Signal quantification on SyMRI provides objective assessment of bone lesions in the lower trunk. The PD value can be useful to determine the viability of bone metastases in prostate cancer.
BACKGROUND Cardiac death is the leading cause of mortality associated with sarcoidosis in Japan. However, the involvement of sarcoidosis infiltration often remains undetected. Recently, late ...gadolinium enhancement with cardiovascular MRI (LGE-CMR) imaging has been introduced for the detection of myocardial infiltrative disease, as it enables the detection of even minor myocardial damage. We investigated the incidence and prognostic value of LGE-CMR in patients with extracardiac sarcoidosis without cardiac manifestations. METHODS Sixty-one consecutive patients who met the histologic and clinical criteria for sarcoidosis, and who did not have signs or symptoms of cardiovascular involvement, were prospectively recruited. LGE-CMR was performed at the time of enrollment, and patients were classified into positive or negative late gadolinium enhancement groups based on the findings. The study end point was a composite of all-cause death, symptomatic arrhythmia, and heart failure necessitating admission. RESULTS Patients were predominantly middle aged (57 ± 15 years) and female (66%), and most had stable disease activity that did not require treatment with immunosuppressants. LGE-CMR detected cardiac involvement in eight patients (13%). Interventricular septal thinning detected by echocardiography was an independent predictor of LGE-CMR-detected cardiac involvement. During the follow-up period of 50 ± 12 months, no significant difference in adverse events was noted between patients in the LGE-CMR-positive and LGE-CMR-negative groups. CONCLUSIONS LGE-CMR detected cardiac involvement in 13% of patients with sarcoidosis without cardiac manifestation, but both patients with and without LGE had relatively low event rates. TRIAL REGISTRY Japan Primary Registries Network; No.: UMIN000001549; URL: www.umin.ac.jp
Myocardial T1 mapping is clinically valuable for assessing the myocardium, and modified look-locker inversion-recovery (MOLLI) approaches have been commonly used for measuring myocardial T1 values. ...To date, several other sequences have been developed for measuring myocardial T1 values, and saturation-recovery-based sequences have been shown to be less dependent on various factors, such as T2 times and magnetization transfer, than inversion-recovery techniques. Systematic differences in T1 values between different sequences have been reported; therefore, definition of the normal range of native T1 values is required before clinical usage can begin. The purpose of this study was to evaluate the reference range and sex dependency of native T1 values in the myocardium measured using one such saturation-recovery sequence, i.e., saturation method using adaptive recovery times for cardiac T1 mapping (SMART1Map). Myocardial T1 values were compared between SMART1Map and MOLLI in 24 young healthy volunteers at 1.5 T and 3 T, and differences in the T1 values between the sexes were assessed. The mean native T1 values in the myocardium were significantly longer with SMART1Map than MOLLI 1530.4 ± 49.2 vs 1222.1 ± 48.9 ms at 3 T (
p
< 0.001) and 1227.3 ± 41.9 ms vs 1014.8 ± 49.4 ms at 1.5 T (
p
< 0.001). A significant difference between the sexes was observed in the T1 values obtained using each sequence, excluding SMART1Map at 3 T. The SMART1Map has a potential advantage to overcome the shortcoming of MOLLI, which underestimates T1 values; however, the sex-dependent difference remains obscure using SMART1Map.
This study aims to develop and assess a new automated processing technique in MR elastography (MRE), namely coherent-wave auto-selection (CHASE). CHASE enables automatic selection of the region of ...interest (ROI) for stiffness measurement by extraction of the coherent wave region (CHASE ROI), and it improves the reconstruction of stiffness by a directional filter oriented along the main wave in each pixel (CHASE filtering). In this study, MRE of a phantom and of the liver of four healthy volunteers was performed. To investigate the potential of CHASE, this study assessed the CHASE according to three indices through the phantom study: 1) agreement on the ROI settings between CHASE and expert observers, 2) noise dependency, and 3) effect of the CHASE on stiffness variability within the CHASE ROI. The agreements on the ROI settings were analyzed by Cohen's kappa coefficient (κ). The noise dependency was analyzed by the mean absolute percentage errors (MAPEs) within the ROI between low (20%–80% amplitudes) and high vibration amplitudes (100% amplitude). The stiffness variability was assessed by standard deviation (SD) within the ROI. In the volunteer study, agreements on the ROI settings (or stiffness value) and stiffness variability within the CHASE ROI were assessed using κ-value (or intraclass correlation coefficient: ICC) and coefficient of variation, respectively. The results showed close agreement on the ROI settings and stiffness (κ-value: greater than 0.61 in both the phantom and volunteer studies, ICC: 0.97 in the volunteer study). The MAPEs within the CHASE ROI were much smaller than those in the whole region of the phantom (CHASE ROI vs. the whole region at 20% amplitude: 10.3% vs. 50.8%). Moreover, in both the phantom and volunteer studies, the stiffness variation within the CHASE ROI was smaller in the elastogram processed with CHASE filtering than in the unprocessed one. Our results demonstrated that the CHASE has high robustness against noise and the potential to provide ROI settings for stiffness measurement comparable to expert observers, as well as improve the reconstruction of stiffness.
•Technique to automate stiffness measurement and emphasize the main wave.•Automatic selection of the coherent wave region.•Improvement of the reproducibility of stiffness measurements.•High accuracy of stiffness calculation owing to a directional filter.•Applicability to most clinical in vivo MR elastography (MRE) studies.
This study aimed to facilitate research progress in MR elastography (MRE) by providing a versatile and convenient application for MRE reconstruction, namely the MRE research tool (MRE-rTool). It can ...be used for a series of MRE image analyses, including phase unwrapping, arbitrary bandpass and directional filtering, noise assessment of the wave propagation image (motion SNR), and reconstruction of the elastogram in both 2D and 3D MRE acquisitions. To reinforce the versatility of MRE-rTool, the conventional method of motion SNR was modified into a new method that reflects the effects of image filtering.
MRE tests of the phantom and liver were performed using different estimation algorithms for stiffness value (algebraic inversion of the differential equation AIDE, local frequency estimation LFE in MRE-rTool, and multimodel direct inversion MMDI in clinical reconstruction) and acquiring dimensions (2D and 3D acquisitions). This study also tested the accuracy of masking low SNR regions using modified and conventional motion SNR under various mechanical vibration powers.
The stiffness values estimated using AIDE/LFE in MRE-rTool were comparable to that of MMDI (phantom, 3.71 ± 0.74, 3.60 ± 0.32, and 3.60 ± 0.54 kPa in AIDE, LFE, and MMDI; liver, 2.26 ± 0.31, 2.74 ± 0.16, and 2.21 ± 0.26 kPa in AIDE, LFE, and MMDI). The stiffness value in 3D acquisition was independent of the direction of the motion-encoding gradient and was more accurate than that of 2D acquisition. The masking of low SNR regions using the modified motion SNR worked better than that in the conventional motion SNR for each vibration power, especially when using a directional filter.
The performance of MRE-rTool on test data reached the level required in clinical MRE studies. MRE-rTool has the potential to facilitate MRE research, contribute to the future development of MRE, and has been freely released online.
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