The Role of Imaging in Bladder Cancer Diagnosis and Staging

Abstract

Bladder cancer (BC) is the most common cancer of the urinary tract in the United States. Imaging plays a significant role in the management of patients with BC, including the locoregional staging and evaluation for distant metastatic disease, which cannot be assessed at the time of cystoscopy and biopsy/resection. We aim to review the current role of cross-sectional and molecular imaging modalities for the staging and restaging of BC and the potential advantages and limitations of each imaging modality. CT is the most widely available and frequently utilized imaging modality for BC and demonstrates good performance for the detection of nodal and visceral metastatic disease. MRI offers potential value for the locoregional staging and evaluation of muscular invasion of BC, which is critically important for prognostication and treatment decision-making. FDG-PET/MRI is a novel hybrid imaging modality combining the advantages of both MRI and FDG-PET/CT in a single-setting comprehensive staging examination and may represent the future of BC imaging evaluation.

Keywords: cancer staging; computed tomography; magnetic resonance imaging; muscle-invasive bladder cancer; positron emission tomography; urothelial carcinoma.

Figure 1

Axial CT images from the excretory phase of a CT urogram performed for hematuria demonstrating a polypoid filling defect arising near the left ureteral orifice (arrow), highly suspicious for bladder cancer.

Figure 2

Axial T2-weighted (T2W) (A), dynamic-contrast enhanced (B), b2000 diffusion-weighted (C), and apparent diffusion coefficient (D) images of the pelvis in a patient with known multifocal bladder cancer. There are multiple intraluminal masses, one of which (closed arrow) clearly invades through the bladder wall and is consistent with muscle-invasive bladder cancer (MIBC), while the other polypoid mass (open arrow) does not disrupt the T2 hypointense bladder wall, consistent with non-muscle-invasive bladder cancer (NMIBC).

Figure 3

Axial fused FDG-PET/CT (A), CT (B), PET (C), and corresponding T1-fat saturated postcontrast MRI (D) demonstrating an extensive hypermetabolic mass involving nearly all of the bladder wall (open arrow) and multiple pelvic lymph node metastases (closed arrow), some of which measure less than 1 cm in short axis and are more easily identified on PET/CT vs. CT or MRI alone.