Advances in bladder cancer imaging

Abstract

The purpose of this article is to review the imaging techniques that have changed and are anticipated to change bladder cancer evaluation. The use of multidetector 64-slice computed tomography (CT) and magnetic resonance imaging (MRI) remain standard staging modalities. The development of functional imaging such as dynamic contrast-enhanced MRI, diffusion-weighted MRI and positron emission tomography (PET)-CT allows characterization of tumor physiology and potential genotypic activity, to help stratify and inform future patient management. They open up the possibility of tumor mapping and individualized treatment solutions, permitting early identification of response and allowing timely change in treatment. Further validation of these methods is required however, and at present they are used in conjunction with, rather than as an alternative to, conventional imaging techniques.

Figure 1

Patient with known T2 N0 M0 bladder cancer (left bladder wall): (a) contrast-enhanced computed tomography (CT) scan, (b) axial T2-weighted image performed on a 3 T magnetic resonance imaging (MRI) unit showing a hypointense lesion, (c) corresponding T1 image, (d) axial diffusion-weighted (DW) MRI at b-value 0, (e) axial DW MRI at b-value 100, (f) axial DW MRI at b-value 750, and (g) magnetic resonance virtual cystoscopy (MRVC) of same tumor with three-dimensional reconstruction of tumor bed showing opening into adjacent diverticulum.

Figure 2

Anticipated clinical pathway for staging of confirmed muscle invasive bladder cancer. *Diagnostic investigations for haematuria differ from imaging to determine extent of local and distant disease in confirmed muscle invasive bladder cancer. **Based on European Association of Urology guidelines 2012, available at http://www.uroweb.org/guidelines/online-guidelines/ and http://www.nccn.org/professionals/physician_gls/f_guidelines.asp#site.