Renal lesions: characterization with diffusion-weighted imaging versus contrast-enhanced MR imaging

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Renal lesion characterization is crucial for diagnosis and treatment planning.
• Magnetic resonance (MR) imaging, including diffusion-weighted (DW) and contrast-enhanced (CE) techniques, offers valuable insights into renal pathology.

Purpose of the Study:

• To compare the diagnostic performance of DW MR imaging versus CE MR imaging for renal lesions.
• To evaluate the combined diagnostic performance of DW and CE MR imaging.
• To establish histopathology and MR follow-up as reference standards.

Main Methods:

• Retrospective analysis of 109 renal lesions in 64 patients.
• Evaluation using both CE MR imaging and breath-hold DW imaging with various b values.
• Measurement of apparent diffusion coefficients (ADCs) and receiver operating characteristic (ROC) analysis for diagnostic accuracy.

Main Results:

• Mean ADC was significantly lower for renal cell carcinomas (RCCs) (1.41 x 10(-3) mm(2)/sec) compared to benign lesions (2.23 x 10(-3) mm(2)/sec).
• DW imaging achieved an area under the ROC curve (AUC) of 0.856 for RCC diagnosis, while CE MR imaging achieved an AUC of 0.944.
• Combined DW and CE MR imaging demonstrated 96% specificity for characterizing renal lesions.

Conclusions:

• DW imaging is a useful tool for characterizing renal lesions, differentiating solid RCCs from oncocytomas, and identifying RCC subtypes.
• CE MR imaging exhibits higher diagnostic accuracy than DW imaging alone for renal lesions.
• Combined DW and CE MR imaging enhances specificity in characterizing renal lesions.