Application Of Intravoxel Incoherent Motion Diffusion Weighted Imaging For Benign And Malignant Lesions Of Liver

PartⅠIntravoxel Incoherent Motion Diffusion Weighted Imaging in Differentiation between Benign and Malignant Lesions of Liver[Purpose]:To determine the valve of intravoxel incoherent motion (IVIM) diffusion weighted imaging (DWI) in differentiation between benign and malignant lesions of liver.[Materials and methods]:From December 2014 to July 2015,92 patients with 93 liver lesions proved by postsurgical pathology, aspiration biopsy, clinical data or follow-up results were enrolled in our study, and were divided into two groups:malignant group(69 lesions in 69 patients) and benign group (24 lesions in 23 patients).All patients underwent conventional non-enhanced and contrast-enhanced MRI and IVIM-DWI (b=0.20.50.100.200.400.600.800,1200 s/mm2).ROIs were placed on the largest solid part of the lesions and parameters (ADC, D, D* and f) were measured with monoexponential modeling and biexponential modeling respectively. The values of these parameters in the two groups were analyzed and compared using independent samples /-test. The receiver operating characteristic curve (ROC) was used to determine the diagnostic efficacy of these parameters in diagnosis of malignant liver lesions.[Results]:The values of ADC,D,D* and f of benign group were (1.67 ± 0.59) X 10-3 mm2/s,(1.23±0.34) X 10-3 mm2/s.,(36.13 ±17.84) X 10-3mm2/s and (29.96±15.67)% respectively, and those in malignant group were(1.20±0.36) X10-3 mm2/s,(0.88 ±0.21) X10-3 mm2/s, (34.84 ±19.75) X 10"3mm2/s and (21.77 ± 10.07)% respectively. Significant inter-group difference was observed in ADC,D and f (P=0.001.0.000 and 0.023 respectively),the correlated areas under the ROC of ADC,D and f were 0.764. 0.804 and 0.665. Areas under the ROC of D was larger than ADC (p=0.1494).With the cut-off of 1.13 ×10-3mm2/s,the sensitivity, specificity and accuracy of D in diagnosis of malignant lesions of liver were 85.5%,62.5%,79.6% respectively.[Conclusion]:IVIM-DWI is useful to distinguish benign and malignant lesions of liver, and the D value in bieponential model has the best diagnostic efficacy for differentiation.PartⅡIntravoxel Incoherent Motion Diffusion Weighted Imaging in Differentiation of Histologic Grading of Hepatocellular Carcinoma[Purpose]:To determine whether the parameters of intravoxel incoherent motion (IVIM) diffusion weighted imaging (DWI) can differentiate high grade from low grade of hepatocelluar carcinoma.[Materials and methods]:24 patients with 24 hepatocelluar carcinoma (HCC) proved by postsurgical pathology were enrolled in our study, and were divided into two groups: moderately differentiated with 11 patents, and poorly differentiated with 13 patients. All patients underwent conventional non-enhanced and contrast-enhanced MRI and IVIM-DWI (b=(0、 20、50、100、200、400、600、800、1200 s/mm2). Parameters (D, D* and f) were measured with biexponential modeling and compared using independent samples t-test. The receiver operating characteristic curve (ROC) was used to determine the diagnostic efficacy of these parameters in differentiation of histologic grading of HCC.[Results]:The values of D,D and f of moderately differentiated group were (0.93± 0.22) ×10-3mm2/s、 (35.56±15.61)× 10-3mm2/sand (21.08±7.14)% respectively, and those in the poorly differentiated group were (0.87±0.28) ×10-3mm2/s、 (36.09±19.37)× 10-3mm2/s and (14.77±7.13)% respectively. Significant inter-group difference was observed in f (P=0.042), but not in D (p=0.599) or D* (P=0.943).The correlated areas under the ROC of f was 0.748, with the cut-off of 14.75%,the sensitivity, specificity, accuracy of f in diagnosis of poorly differentiated HCC were 61.5%,90.9% and 75%, respectively.[Conclusion]:The intravoxel incoherent motion perfusi on-related parameter f is hopeful for differentiating poorly differentiated HCC from moderately differentiated HCC.