Comparison of Biexponential and Monoexponential Model of Diffusion-Weighted Imaging for Distinguishing between Common Renal Cell Carcinoma and Fat Poor Angiomyolipoma.
To compare the diagnostic accuracy of intravoxel incoherent motion (IVIM)-derived parameters and apparent diffusion coefficient (ADC) in distinguishing between renal cell carcinoma (RCC) and fat poor angiomyolipoma (AML).



Eighty-three patients with pathologically confirmed renal tumors were included in the study. All patients underwent renal 1.5T MRI, including IVIM protocol with 8 b values (0-800 s/mm2). The ADC, diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) were calculated. One-way ANOVA was used for comparing ADC and IVIM-derived parameters among clear cell RCC (ccRCC), non-ccRCC and fat poor AML. The diagnostic performance of these parameters was evaluated by using receiver operating characteristic (ROC) analysis.



The ADC were significantly greater in ccRCCs than that of non-ccRCCs and fat poor AMLs (eachp< 0.010, respectively). The D and D*among the three groups were significantly different (allp< 0.050). The f of non-ccRCCs were less than that of ccRCCs and fat poor AMLs (eachp< 0.050, respectively). In ROC analysis, ADC and D showed similar area under the ROC curve (AUC) values (AUC = 0.955 and 0.964, respectively,p= 0.589) in distinguishing between ccRCCs and fat poor AMLs. The combination of D > 0.97 × 10-3mm2/s, D*< 28.03 × 10-3mm2/s, and f < 13.61% maximized the diagnostic sensitivity for distinguishing non-ccRCCs from fat poor AMLs. The final estimates of AUC (95% confidence interval), sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the entire cohort were 0.875 (0.719-0.962), 100% (23/23), 75% (9/12), 88.5% (23/26), 100% (9/9), and 91.4% (32/35), respectively.



The ADC and D showed similar diagnostic accuracy in distinguishing between ccRCCs and fat poor AMLs. The IVIM-derived parameters were better than ADC in discriminating non-ccRCCs from fat poor AMLs.
Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai 200032, China.
Yuqin
Y
Ding
Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai 200032, China.
Mengsu
M
Zeng
Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai 200032, China.
Shengxiang
S
Rao
Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai 200032, China.
Caizhong
C
Chen
Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen 518057, China.
Caixia
C
Fu
Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Medical Imaging, Shanghai 200032, China.
Jianjun
J
Zhou
D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D019540:Area Under Curve; D002292:Carcinoma, Renal Cell / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
Angiomyolipoma; DWI; Diffusion-weighted imaging; Intravoxel incoherent motion; Renal cell carcinoma