Fig. 4

Comparison of local bladder cancer staging (T-stage) on pre-transurethral resection (a, b, c) and post-chemotherapy ¹¹C-acetate PET/MRI (d, e, f) in a 63-year-old male patient (number 12 in primary imaging). A heterogenous lobulated mass on the right side of mid-line with extension (white arrow) to perivesical fat seen on T2-weighted image (a), an area of increased diffusion signal restriction (white arrow) beyond the bladder wall (b - b value 800 s/mm² trace diffusion weighted image), an associated right sided hydroureter, and increased ¹¹C-acetate uptake (c - PET fused with T2-weighted image, SUV is scaled from 0.0 to 3.5) suggestive of T3 stage. On post-chemotherapy ¹¹C-acetate PET/MRI, residual abnormal wall thickening (green arrow) on T2-weighted image (d) and diffusion signal restriction extending to perivesical fat (e - b value 800 s/mm² trace diffusion weighted image) was presented suggestive of T3 stage. The final cystectomy specimen revealed stage T2, thus the findings of ¹¹C-acetate PET/MRI were considered as true positive for muscle invasion