Diffusion-weighted imaging versus contrast-enhanced MR imaging for the differentiation of renal oncocytomas and chromophobe renal cell carcinomas
To compare the performance of diffusion-weighted imaging (DWI) with that of contrast-enhanced MRI in differentiating renal oncocytomas from chromophobe renal cell carcinomas (RCCs).
We recruited 48 patients with histopathologically confirmed renal oncocytomas (n=16) and chromophobe RCCs (n=32). All patients underwent preoperative DWI and contrast-enhanced MRI. Apparent diffusion coefficient (ADC) and signal intensity were measured in each patient. ADC ratio and percentage of signal intensity change were calculated.
Mean ADC values for renal oncoctytomas were significantly higher than those for chromophobe RCCs (1.59±0.21 vs. 1.09±0.29× 10−3 mm2/s, p < 0.001). Area under the ROC curve, sensitivity and specificity were 0.931, 87.5% and 84.4%, respectively, for ADC measurement of DW imaging; 0.825, 87.5% and 75%, respectively, for enhancement ratio (p > 0.05). Adding ADC values to the enhancement ratios in the ROC, analysis to differentiate renal oncocytoma from chromophobe RCCs increased specificity from 75 to 87.5% at 87.5% sensitivity without significantly increasing the AUC (0.930).
Both DWI and contrast-enhanced MRI may assist in differentiating renal oncocytomas from chromophobe RCCs, with DWI showing higher diagnostic value. The combination of the two parameters could potentially provide better performance in distinguishing these two tumours.
• ADC values can assist in differentiating renal oncocytomas from chromophobe RCCs.
• DW imaging possesses better specificity than does contrast-enhanced MR imaging.
• Combining the two parameters provides higher specificity regarding the differential diagnosis.
KeywordsRenal cell carcinoma Renal oncocytoma Magnetic resonance imaging Apparent diffusion coefficient Diffusion-weighted imaging
Percentage change in signal intensity
Apparent diffusion coefficient
Area under the curve
Clear cell renal cell carcinoma
Intraclass correlation coefficient (ICC)
Magnetic resonance imaging
Picture Archiving and Communication System
Renal cell carcinoma
Receiver operating characteristic
Region of interest
Segmental enhancement inversion
Jia Wang provided the reproducibility data of ADC measurement of CCRCCs.
Compliance with ethical standards
The scientific guarantor of this publication is Huiyi Ye.
Conflict of interest
The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
The authors state that this work has not received any funding.
Statistics and biometry
No complex statistical methods were necessary for this paper.
Written informed consent was waived by the Institutional Review Board.
Institutional Review Board approval was obtained.
• diagnostic or prognostic study
• performed at one institution
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