Investigation of renal lesions by diffusion-weighted magnetic resonance imaging applying intravoxel incoherent motion-derived parameters--initial experience

Eur J Radiol. 2012 Mar;81(3):e310-6. doi: 10.1016/j.ejrad.2011.10.016. Epub 2011 Nov 21.

Abstract

Purpose: Usefulness of biexponentially fitted signal attenuation at different b-values for differentiating the histological characteristics of renal tumors.

Materials and methods: A total of 26 patients with 28 renal masses (histologically proven: 20 clear cell renal cell carcinomas [ccRCC], three transitional cell carcinomas, two oncocytomas, and one papillary RCC) and 30 volunteers with healthy kidneys were examined at 1.5 Tesla using an echo-planar DWI sequence. Using the IVIM model, we calculated the perfusion fraction f and the diffusion coefficient D. Furthermore, the ADC was obtained. These tumor parameters were compared to healthy renal tissue nonparametrically, and a receiver operating characteristic (ROC) analysis was performed.

Results: Healthy renal parenchyma showed higher ADC and D values (p<0.001) than ccRCC (ADC 1.95±0.10 [SD] μm2/ms, f 18.32±2.52%, and D 1.88±0.11 μm2/ms versus ADC 1.45±0.38 μm2/ms, f 18.59±6.16%, and D 1.34±0.38 μm2/ms). When detecting malignancies the area under the curve for D was higher than for ADC. The f values for ccRCC were higher (p<0.001) than for non-ccRCC (ADC 1.52±0.47 μm2/ms, f 8.44±1.24%, and D 1.30±0.18 μm2/ms). Both f and D correlated with ccRCC grading.

Conclusion: IVIM imaging is able to provide reliable diffusion values in the human kidney and may enhance the accuracy of tumor diagnosis. The D value was the best parameter to distinguish renal tumors from healthy renal tissue. The f value is promising for determining the histological subgroups.

MeSH terms

  • Adenoma, Oxyphilic / pathology
  • Adult
  • Aged
  • Aged, 80 and over
  • Area Under Curve
  • Carcinoma, Papillary / pathology
  • Carcinoma, Renal Cell / pathology
  • Carcinoma, Transitional Cell / pathology
  • Case-Control Studies
  • Contrast Media
  • Diffusion Magnetic Resonance Imaging / methods*
  • Female
  • Humans
  • Kidney Neoplasms / pathology*
  • Least-Squares Analysis
  • Male
  • Middle Aged
  • Organometallic Compounds
  • Prospective Studies
  • ROC Curve
  • Sensitivity and Specificity

Substances

  • Contrast Media
  • Organometallic Compounds
  • gadobutrol