Investigation of Synthetic Magnetic Resonance Imaging Applied in the Evaluation of the Tumor Grade of Bladder Cancer

Background The histological grade of bladder cancer (BCa) is an important factor associated with the treatment and prognosis. However, accurate determination of the preoperative histological grade of BCa remains a challenge. Purpose To investigate the diagnostic potential of synthetic MRI (SyMRI) in evaluating the histological grade of BCa. Study Type Prospective. Subjects Sixty patients (48 men and 12 women; mean age, 65 ± 11 years) with pathologically confirmed BCa (33 with high‐grade BCa and 27 with low‐grade BCa) were enrolled. Field Strength/Sequence Diffusion‐weighted imaging (DWI) acquired by a single‐shot echo‐planar sequence and SyMRI acquired by a multidynamic multiecho (MDME) sequence at 3.0 T. Assessment Preoperative quantitative longitudinal relaxation time (T 1 ), transverse relaxation time (T 2 ), proton density (PD), and apparent diffusion coefficient (ADC) values of BCa were independently measured by two radiologists. Statistical Tests Interclass correlation coefficient (ICC), independent sample t‐test, Mann–Whitney U test, Delong test, and receiver operating characteristic curve (ROC) analysis were used. Results Significant differences were found in the mean of all the T 1 , T 2 , PD, and ADC values between high‐ and low‐grade BCa. The best diagnostic performance was found for the mean ADC value with an area under the ROC curve (AUC) of 0.869, while the AUC values of the mean PD, T 1 , and T 2 values were 0.755, 0.740, and 0.723, respectively. Data Conclusion SyMRI may be a potential noninvasive technique for evaluating the histological grade of BCa. However, the overall diagnostic performance of SyMRI‐derived parameters was inferior to the ADC value. Levels of Evidence 2. Technical Efficacy Stage 2.