MR Imaging of Urinary Bladder Carcinoma and Beyond

ArticleinRadiologic Clinics of North America 50(6):1085-110 · November 2012with17 Reads
DOI: 10.1016/j.rcl.2012.08.011 · Source: PubMed
Detection of muscle invasion is a critical aspect in management of urinary bladder cancer. MR imaging has the potential and promise of delivering this premise noninvasively. This article reviews the current status of MR imaging in evaluation of bladder cancer. Also discussed are other important neoplastic and nonneoplastic conditions affecting the bladder.
  • [Show abstract] [Hide abstract] ABSTRACT: The purpose of our study was to investigate whether fast and slow components of the apparent diffusion coefficient (ADC) from diffusion-weighted MR images could predict prostate cancer progression in patients managed by active surveillance. Eighty-one patients managed by active surveillance underwent diffusion-weighted MRI in addition to T2-weighted MRI using an endorectal technique. ADCs from tumor regions of interest were calculated using all b values (ADC(all)), b = 0-300 s/mm(2) (ADC(fast)), and b = 300-800 s/mm(2) (ADC(slow)). These parameters and tumor volumes were compared in those upgraded at subsequent biopsy (n = 14) versus those histologically stable (n = 41) and in evaluable patients who progressed to radical treatment (n = 16) versus those who did not (n = 64). Cox's regression was used to analyze the effect of parameter mean on time to treatment. ADC(all), ADC(fast), and ADC(slow) in patients upgraded on repeat biopsy were significantly lower than those who were stable (1,070 ± 110 vs 1,356 ± 357 × 10(-6)mm(2)/s, p < 0.001; 1,283 ± 188 vs 1,526 ± 397 × 10(-6)mm(2)/s, p = 0.004; 843 ± 74 vs 1,105 ± 285 × 10(-6) mm(2)/s, p < 0.001, respectively). Tumor volume was significantly higher in the upgraded group (0.86 ± 0.9 vs 0.26 ± 0.25 cm(3), p = 0.02). The lower ADC(slow) in patients who subsequently progressed to radical treatment approached significance (922 ± 256 vs 1,054 ± 235 × 10(-6) mm(2)/s, p = 0.053; hazard ratio, 0.991 for time to treatment). Tumor volume was significantly higher in the treated group (0.86 ± 0.85 cm(3) vs 0.32 ± 0.33 cm(3), p = 0.02). ADC(slow) and tumor volume were significant but independent predictors of upgrade on biopsy (p = 0.01 and 0.002, respectively). Both fast and slow diffusion components were significantly lower in tumors that were subsequently upgraded on histology. Both tumor volume and the true diffusion ADC(slow) were significant but independent predictors of histologic progression.
    Article · Mar 2011
  • [Show abstract] [Hide abstract] ABSTRACT: The main imaging modality of the urinary tract in children is ultrasound. When further cross-sectional morphologic examination and/or functional evaluation is required, magnetic resonance (MR) imaging is the logical and optimal second step, particularly in pediatric patients. There are two main exceptions to this. The first one is when after an ultrasound, additional diagnostic imaging for urolithiasis is needed. The second one involves severe polytrauma, including blunt abdominal trauma. In this review, an overview of the MR imaging and computed tomography examinations important for current and future daily pediatric uroradiologic practice is presented.
    Article · Jul 2013
  • [Show abstract] [Hide abstract] ABSTRACT: Objective: To determine the diagnostic accuracy of high-resolution MR imaging done at 1.5T in distinguishing bladderrestricted tumor from non-bladder-restricted tumor and compare the mean short axis dimension of metastatic pelvic lymph nodes with benign pelvic lymph nodes. Study Design: Analytical study. Place and Duration of Study: Shaukat Khanum Memorial Cancer Hospital, Lahore, Pakistan, from March 2008 to July 2011. Methodology: Patients with bladder cancer were enrolled. Based on pathologic T-staging following radical cystectomy, patients were assigned to one of two groups. Patients with stage T1 and T2 disease were assigned to the bladderrestricted tumor (BRT) group and those with stage T3 and T4 disease to the non-bladder-restricted tumor (NBRT). High-resolution unenhanced MR imaging done prior to cystectomy was reviewed retrospectively (1.5 T MRI unit; GE Healthcare). Results from MR imaging-based categorization were compared with pathology reports to fulfill the objective. Mean short-axis diameter of largest visible lymph nodes in patients with nodal metastasis was compared with mean short-axis diameter of largest visible lymph nodes in patients with benign lymph nodes. Results: The accuracy of MRI in differentiating distinguishing bladder-restricted tumor from non-bladder-restricted tumor was 67.72%. The mean short axis diameter of metastatic lymph nodes was greater than that of non-metastatic lymph nodes, i.e., 7.4 mm and 5.4 mm respectively. Conclusion: Conventional high resolution 1.5T MRI does not appear to offer advantage over imaging done at low field strength scanners.
    Article · May 2014
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