Morphological changes in the muscle layer associated with invasion of bladder cancer

Although multiparametric magnetic resonance imaging (mpMRI) has been validated for depth diagnosis of bladder cancer (BC), this study was performed to examine the morphological changes in the muscle layer in cases with BC and to re-evaluate the diagnostic capability of T2-weighted imaging (T2WI).

The study population consisted of 89 patients with BC examined by preoperative MRI. Morphological findings in the muscle layer were compared between cases of muscle-invasive bladder cancer (MIBC) and non-muscle-invasive bladder cancer (NMIBC), and the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of these findings were calculated.

Localised wall thickening, spinate elevation, and disruption or interruption were more common in MIBC, while NMIBC more commonly showed no such abnormal findings. In addition, the sensitivity, specificity, PPV, NPV, and diagnostic accuracy were 88.9%, 75.0%, 62.1%, 93.6%, and 79.4% for localised wall thickening; 96.0%, 93.8%, 87.6%, 98.1%, and 94.5% for spinate elevation; 100.0%, 83.6%, 73.7%, 100.0%, and 88.7% for disruption or interruption; and 72.9%, 98.1%, 94.6%, 88.8%, and 90.2% for any morphological changes.

Focussing on morphological changes in the bladder wall, T2WI may be useful for depth diagnosis of BC, as well as functional assessments such as diffusion-weighted imaging (DWI), dynamic contrast enhancement (DCE) imaging, and/or mpMRI such as VI-RADS.