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

Abstract

Purpose: To 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 methods: This 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. Results: Of 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 mm 2 /s in low grade tumors and 0.69 ± 0.12 · 10 -3 mm 2 /s in high grade tumors. Conclusion: DWI 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.

Diffusion weighted magnetic resonance imaging in bladder cancer, is it time to replace biopsy?

“…In the current study, all bladder tumors were clearly visible in DWI at a high b value (1000 s/mm 2 ) as a bright SI relative to the bladder wall and surrounding tissue with 98% sensitivity as previously reported by other researchers [ 12 , 20 , 21 ]. Also, and in accordance with others [ 22 , 23 ], there was a statistically significant difference between malignant and benign bladder wall pathologies.…”

“…Regarding differentiation of organ confined from non-organ confined BC, staging accuracy of DWI alone was 77.4% which was higher than El-Assmy's et al (69.6%) [ 30 ] and lower than Abdel-Rahman et al [ 20 ] and Wu et al [ 29 ] who reported accuracy between 90–95%. DWI plus T2WI had a higher accuracy (83%) in differentiating organ confined from non-organ confined tumors as compared to T2WI alone (75.9%) or DWI alone (77.4%).…”

“…These results are in accordance with other investigators [ 13 , 25 , 26 , 29 ]. However, El-Assmy's et al, [ 30 ] and Abdel-Rahman et al [ 20 ] reported accuracy of DWI alone of 63.6% and 75% respectively.…”

“…Abdel-Rahman et al, reported accurate staging in 30 patients (75%), under-staging in 8 (20%) and over-staging in 2 patients (5%) [ 20 ]. This was comparable to our study where DWI staging was accurate in 37 (68.5%) patients.…”

Diagnostic Value of Diffusion-Weighted MR Imaging in Differentiating T- Stage of Urinary Bladder Cancer: With Histopathological Correlation

“…DWI was reported to have an accuracy of 63.6%, 75.7%, 93.7%, and 87.5% for diagnosing tumour stages T1, T2, T3, and T4, respectively. According to Abdel-Rahman et al [16], DWI's accuracy in tumour staging ranged from 85.7% to 77.8% to 50% across stages T1 and T3. In comparison to El-Assmy et al [13] and Abdel-Rahman et al [16], the present study's findings indicated considerably better accuracy for T1 and T2 staging, at 90% and 85.7% respectively, and accuracy for T3 staging, at 66.7%.…”