Cong X Y, Chen Y, Zhang J, Yu X D, Ye F, Yu W J, Zhang M M, Ouyang H, Zhao X M
Department of Diagnostic Imaging, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
Zhonghua Zhong Liu Za Zhi. 2016 Jun 23;38(6):434-9. doi: 10.3760/cma.j.issn.0253-3766.2016.06.007.
To evaluate the value of parameters derived from intravoxel incoherent motion diffusion-weighted magnetic resonance imaging in differentiating histopathological subtypes of renal cell carcinoma (RCC).
Between May 2014 and December 2015, a total of 69 patients who were surgically and pathologically diagnosed as renal cell carcinoma were recruited for the study. We examined 61 clear cell RCC (ccRCC), and 8 non-clear cell carcinoma (non-ccRCC, including 7 chromophobe RCC and 1 papillary RCC). All the ccRCC were divided into well differentiated group (n=46), moderately differentiated group (n=8), and poorly differentiated group (n=7). In addition to routine renal magnetic resonance imaging examination performed on a 3.0-Tesla MR system, all patients were imaged with axial intravoxel incoherent motion diffusion-weighted imaging. Using biexponential model, we calculated the diffusion coefficient (D), pseudodiffusion coefficient (D(*)), and perfusion fraction (f).
The D and f values of the ccRCC were higher (each P<0.05) than that for non-ccRCC [D (1.29±0.30)×10(-3)mm(2)/s, D() (42.92±20.21)×10(-3)mm(2)/s, and f (35.71±6.61)% versus D (0.78±0.23)×10(-3)mm(2)/s, D() (32.60±11.33)×10(-3)mm(2)/s, and f (21.52±8.44)% ]. In the well differentiated group of ccRCC, we found D of (1.36±0.29)×10(-3)mm(2)/s, D() (38.39±18.51)×10(-3)mm(2)/s, and f (36.40±6.96)%. The D, D(,) f values of moderately differentiated lesions were (1.10±0.24)×10(-3)mm(2)/s, (59.90±20.23)×10(-3) mm(2)/s, and (32.88±4.02)%, respectively, those of the poorly differentiated group were (1.03±0.16)×10(-3)mm(2)/s, (53.28±18.74)×10(-3)mm(2)/s, and (34.42±6.21)%. The well differentiated group of ccRCC showed a higher D value than the moderately differentiated and poorly differentiated groups (each P<0.05). D(*) values were significantly lower for the well differentiated group than for the moderately differentiated group (P<0.05). The sensitivity and specificity of D values were 90.2% and 87.5% when focusing on the differentiation of ccRCC. For the diagnosis of ccRCC, the sensitivity and specificity of f values were 98.4% and 75.0%, respectively.
IVIM-DWI can provide certain reliable value in evaluating pathological subtype and differentiation degree of renal cell carcinomas. D and f values are useful to distinguish ccRCC from non-ccRCC. D value is also promising for estimating the differentiation degree of ccRCC, and to indicate the biological behavior of RCC.
评估体素内不相干运动扩散加权磁共振成像（IVIM-DWI）得出的参数在鉴别肾细胞癌（RCC）组织病理学亚型中的价值。
2014年5月至2015年12月，共纳入69例经手术及病理确诊为肾细胞癌的患者进行研究。其中61例为透明细胞肾细胞癌（ccRCC），8例为非透明细胞癌（非ccRCC，包括7例嫌色细胞肾细胞癌和1例乳头状肾细胞癌）。所有ccRCC又分为高分化组（n = 46）、中分化组（n = 8）和低分化组（n = 7）。除在3.0T磁共振系统上进行常规肾脏磁共振成像检查外，所有患者均行轴位体素内不相干运动扩散加权成像。采用双指数模型计算扩散系数（D）、伪扩散系数（D*）和灌注分数（f）。
ccRCC的D值和f值高于非ccRCC（各P < 0.05）[D（1.29±0.30）×10⁻³mm²/s，D*（42.92±20.21）×10⁻³mm²/s，f（35.71±6.61）%对比D（0.78±0.23）×10⁻³mm²/s，D*（32.60±11.33）×10⁻³mm²/s，f（21.52±8.44）%]。在ccRCC的高分化组中，D值为（1.36±0.29）×10⁻³mm²/s，D值为（38.39±18.51）×10⁻³mm²/s，f值为（36.40±6.96）%。中分化病变的D、D、f值分别为（1.10±0.24）×10⁻³mm²/s、（59.90±20.23）×10⁻³mm²/s和（32.88±4.02）%，低分化组分别为（1.03±0.16）×10⁻³mm²/s、（53.28±18.74）×10⁻³mm²/s和（34.42±6.21）%。ccRCC的高分化组D值高于中分化组和低分化组（各P < 0.05）。高分化组的D*值显著低于中分化组（P < 0.05）。以ccRCC的分化程度为重点时，D值的敏感性和特异性分别为90.2%和87.5%。对于ccRCC的诊断，f值的敏感性和特异性分别为98.4%和75.0%。
IVIM-DWI在评估肾细胞癌的病理亚型和分化程度方面可提供一定可靠价值。D值和f值有助于区分ccRCC与非ccRCC。D值在评估ccRCC的分化程度及提示RCC的生物学行为方面也具有前景。
