Renal masses: characterization with diffusion-weighted MR imaging--a preliminary experience.

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Renal mass characterization is crucial for diagnosis and treatment planning.
• Diffusion-weighted imaging (DWI) provides insights into tissue microstructure.
• Apparent diffusion coefficients (ADCs) quantify water molecule diffusion, reflecting tissue properties.

Purpose of the Study:

• To evaluate the utility of ADCs in distinguishing between viable solid renal tumors, necrotic/cystic tumor areas, and benign cysts.
• To determine if ADC values correlate with T1 signal characteristics of renal lesions.

Main Methods:

• Retrospective analysis of 25 patients undergoing renal MRI with DWI before nephrectomy.
• Measurement of ADC values for whole lesions, enhancing solid tissue, and non-enhancing cystic/necrotic areas.
• Comparison of ADC values between different renal mass types using the Wilcoxon rank sum test.

Main Results:

• Renal tumors exhibited significantly lower ADCs (median, 189.3 x 10(-5) mm(2)/sec) compared to benign cysts (median, 322.8 x 10(-5) mm(2)/sec; P < .001).
• Solid enhancing tumor components had lower ADCs (median, 162.3 x 10(-5) mm(2)/sec) than necrotic/cystic areas (median, 247.7 x 10(-5) mm(2)/sec; P = .007).
• Lesions with higher T1 signal intensity showed lower ADC values.

Conclusions:

• ADC values are significantly different for renal tumors versus benign cysts.
• ADC measurements, potentially in conjunction with T1 signal characteristics, can aid in characterizing and differentiating renal masses.
• DWI-derived ADC may serve as a valuable tool in the non-invasive assessment of renal lesions.