The Performance of MR Cytometry Imaging in Differentiating High- and Low-Grade Bladder Cancer

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Accurate preoperative grading of bladder cancer is crucial for treatment planning and prognosis.
• Distinguishing between high- and low-grade tumors noninvasively remains a clinical challenge.

Purpose of the Study:

• To evaluate the diagnostic efficacy of MR cytometry imaging in differentiating high-grade from low-grade bladder cancer.
• To assess the performance of MR cytometry-derived microstructural parameters in bladder cancer grading.

Main Methods:

• Prospective study involving 60 participants with pathologically confirmed bladder cancer.
• Utilized 3.0 T MRI with pulsed gradient spin-echo (PGSE) and oscillating gradient spin-echo (OGSE) diffusion-weighted imaging.
• Calculated apparent diffusion coefficients (ADCs) and MR cytometry parameters (cell diameter, intracellular volume fraction [vin], extracellular diffusivity [Dex], and cellularity [ρ]).

Main Results:

• High-grade tumors exhibited significantly higher intracellular volume fraction (vin) and cellularity (ρ), and lower ADCs compared to low-grade tumors.
• Intracellular volume fraction (vin) demonstrated the highest area under the ROC curve (AUC) of 0.89 as a single parameter.
• A combined model using vin, extracellular diffusivity (Dex), and ADCpgse achieved the highest diagnostic accuracy with an AUC of 0.92.

Conclusions:

• MR cytometry serves as a noninvasive tool for differentiating high- from low-grade bladder cancer.
• Intracellular volume fraction (vin) is a promising parameter for bladder cancer grading.
• Combining MR cytometry parameters with ADCpgse enhances preoperative assessment accuracy.