Diffusion-weighted imaging for different pathologic stage and histologic grade of bladder cancer / 实用放射学杂志

ABSTRACT

Objective To explore the value of the apparent diffusion coefficient (ADC)of MRI diffusion-weighted (DW)in diag-nosing pathologic stage and histologic grade of bladder cancer.Methods 42 patients with confirmed bladder cancer underwent pelvic MRI examination including T2 WI and diffusion-weighted imaging (b values of 0 and 1 000 s/mm2 )Based on pathologic results,42 cases of bladder cancer were divided into three groups of Ta-T1 stage (non-muscle invasive),T2 stage (muscle invasive)and T3-T4 stage (around the bladder and other organizations invasive).Of 42 bladder cancers,36 urothelial carcinomas were divided into papillary urothelial neoplasm with low malignant potential (PUNLMP),low grade urothelial carcinoma and high grade urothelial carcinoma group.Tumor diameter and ADC were measured on DW imaging,and compared among different groups.Results The mean size of high grade tumors (4.52 ± 1.61)cm was significantly larger than that of PUNLMP (2.28 ± 0.51)cm and low grade tumors (1.69 ± 0.53)cm.The mean ADC of high grade tumors (0.83 ± 0.27)×10-3 mm2/s was significantly lower than that of PUNLMP (1.46 ± 0.30)×10-3 mm2/s and low grade tumors (1.17±0.11)×10-3 mm2/s (P<0.01).T3-T4 stage tumors showed significantly lower ADC (0.82±0.21)×10-3 mm2/s than T2 (1.01 ± 0.09)×10 -3 mm2/s and Ta-T1 stage tumors (1.24 ± 0.13)×10 -3 mm2/s (P <0.01).Conclusion DW ima-ging combined with conventional MR sequences is useful for displaying morphology of bladder cancer.DW imaging and ADC are use-ful in evaluation of pathologic stage and histologic grade of bladder cancer.