The role of diffusion-weighted magnetic resonance imaging in T staging and grading of urinary bladder cancer

PurposeTo evaluate the ability of diffusion-weighted imaging (DWI) in T staging of urinary bladder cancer and the correlation between the apparent diffusion coefficient (ADC) and tumor grading.Patients and methodsThis study included 40 patients with bladder mass diagnosed by ultrasonography. MR imaging sequences included, T2WI, DWI, ADC and T1 postcontrast MRI were done. The correlation between magnetic resonance findings and histopathological results was done.ResultsOf all forty patients, 14 patients (35%) were T1, 18 (45%) patients were T2, and 8 (20%) patients were T3. The overall accuracy of T2WI, DWI and postcontrast imaging sequences in differentiating superficial from invasive tumor was 60%, 85% and 75% respectively. The overall accuracy of T2WI, DWI and postcontrast imaging sequences in differentiating organ confined from non-organ confined tumor was 80%, 90% and 70% respectively. The mean ADC value was 0.95 ± 0.13 × 10–3 mm2/s in low grade tumors and 0.69 ± 0.12 × 10–3 mm2/s in high grade tumors.ConclusionDWI has a higher overall accuracy compared to both T2WI and postcontrast T1WI in T staging of bladder cancer, and also ADC value can predict the tumor grade. So, DWI can be recommended as promising MRI sequence in urinary bladder T staging and grading.