Histogram analysis of apparent diffusion coefficient at 3.0 T in urinary bladder lesions: correlation with pathologic...

Area of Science:

• Radiology and Imaging Science
• Oncology
• Medical Physics

Background:

• Accurate differentiation of bladder cancer from benign lesions is crucial for appropriate patient management.
• Assessing the pathologic T stage of bladder tumors impacts treatment decisions and prognosis.
• Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) analysis offer non-invasive insights into tissue characteristics.

Purpose of the Study:

• To evaluate the utility of histogram analysis of ADC values at standard (700 s/mm²) and high (1500 s/mm²) b-values for distinguishing bladder cancer from benign lesions.
• To assess the capability of ADC histogram parameters in differentiating bladder tumors across various pathologic T stages.
• To determine the diagnostic performance of ADC-based histogram parameters using receiver operating characteristic (ROC) curve analysis.

Main Methods:

• Retrospective analysis of 52 patients with bladder lesions (7 benign, 45 malignant) using 3.0-T MRI.
• Acquisition of diffusion-weighted imaging to generate ADC maps at b-values of 700 s/mm² (ADC-700) and 1500 s/mm² (ADC-1500).
• Histogram analysis of ADC maps to extract parameters including mean, kurtosis, skewness, and entropy; correlation with pathologic findings and ROC analysis.

Main Results:

• Significant differences in mean ADC-700, mean ADC-1500, skewness ADC-1500, and kurtosis ADC-1500 were observed between malignant and benign bladder lesions (P=.002-.032).
• Significant differences in mean ADC-700, mean ADC-1500, and kurtosis ADC-1500 were found among different pathologic T stages of bladder tumors (P=.000-.046).
• The combination of mean ADC-1500 and kurtosis ADC-1500 achieved the highest area under the ROC curve (AUC=0.894) for differentiating benign from malignant lesions, with 77.78% sensitivity and 100% specificity.

Conclusions:

• Histogram analysis of ADC-1500 at 3.0 T is valuable for evaluating bladder lesions.
• A combination of mean ADC-1500 and kurtosis ADC-1500 demonstrates enhanced utility in differentiating benign from malignant bladder lesions.
• Mean ADC-1500 is identified as the most promising parameter for distinguishing low-stage from high-stage bladder cancer.