Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 28, 2018; 24(8): 929-940
Published online Feb 28, 2018. doi: 10.3748/wjg.v24.i8.929
Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging for predicting histological grade of hepatocellular carcinoma: Comparison with conventional diffusion-weighted imaging
Shao-Cheng Zhu, Yue-Hua Liu, Yi Wei, Lin-Lin Li, She-Wei Dou, Ting-Yi Sun, Da-Peng Shi
Shao-Cheng Zhu, Yue-Hua Liu, Lin-Lin Li, She-Wei Dou, Da-Peng Shi, Department of Radiology, Henan Provincial People’s Hospital, Zhengzhou 450003, Henan Province, China
Yue-Hua Liu, Medical College of Henan University, Kaifeng 475000, Henan Province, China
Yi Wei, Department of Radiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan Province, China
Ting-Yi Sun, Department of Pathology, Henan Provincial People’s Hospital, Zhengzhou 450003, Henan Province, China
Author contributions: All the authors were involved in performing the research; Zhu SC, Liu YH, Wei Y, Li LL and Shi DP participated in the study design; Zhu SC, Liu YH, Wei Y, Li LL and Dou SW conducted the experiments; Zhu SC and Liu YH participated in the MR image analyses; Sun TY analyzed the histopathological images; Zhu SC, Liu YH and Wei Y analyzed the data; Zhu SC and Liu YH prepared the first draft of the manuscript; Zhu SC, Liu YH and Wei Y revised the manuscript. Shao-Cheng Zhu and Yue-Hua Liu contributed equally to this article.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Henan Provincial People’s Hospital.
Informed consent statement: The patients were not required to give informed consent for the study because the analysis used anonymous clinical data that were obtained after each patient agreed to the MRI examination by written consent.
Conflict-of-interest statement: All the authors declare no conflicts of interest related to this article.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Shao-Cheng Zhu, MD, PhD, Chief Doctor, Professor, Department of Radiology, Henan Provincial People’s Hospital, No. 7, Weiwu Road, Zhengzhou 450003, Henan Province, China. 104753150948@vip.henu.edu.cn
Telephone: +86-371-65580790
Received: December 21, 2017
Peer-review started: December 21, 2017
First decision: January 3, 2018
Revised: January 11, 2018
Accepted: January 18, 2018
Article in press: January 18, 2018
Published online: February 28, 2018
Processing time: 67 Days and 23.5 Hours
Abstract
AIM

To compare intravoxel incoherent motion (IVIM)-derived parameters with conventional diffusion-weighted imaging (DWI) parameters in predicting the histological grade of hepatocellular carcinoma (HCC) and to evaluate the correlation between the parameters and the histological grades.

METHODS

A retrospective study was performed. Sixty-two patients with surgically confirmed HCCs underwent diffusion-weighted magnetic resonance imaging with twelve b values (10-1200 s/mm2). The apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were calculated by two radiologists. The IVIM and conventional DWI parameters were compared among the different grades by using analysis of variance (ANOVA) and the Kruskal-Wallis test. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic efficiency of distinguishing between low-grade (grade 1, G1) and high-grade (grades 2 and 3, G2 and G3) HCC. The correlation between the parameters and the histological grades was assessed by using the Spearman correlation test. Bland-Altman analysis was used to evaluate the reproducibility of the two radiologists’ measurements.

RESULTS

The differences in the ADC and D values among the groups with G1, G2, and G3 histological grades of HCCs were statistically significant (P < 0.001). The D* and f values had no significant differences among the different histological grades of HCC (P > 0.05). The ROC analyses demonstrated that the D and ADC values had better diagnostic performance in differentiating the low-grade HCC from the high-grade HCC, with areas under the curve (AUCs) of 0.909 and 0.843, respectively, measured by radiologist 1 and of 0.911 and 0.852, respectively, measured by radiologist 2. The following significant correlations were obtained between the ADC, D, and D* values and the histological grades: r = -0.619 (P < 0.001), r = -0.628 (P < 0.001), and r = -0.299 (P = 0.018), respectively, as measured by radiologist 1; r = -0.622 (P < 0.001), r = -0.633 (P < 0.001), and r = -0.303 (P = 0.017), respectively, as measured by radiologist 2. The intra-class correlation coefficient (ICC) values between the two observers were 0.996 for ADC, 0.997 for D, 0.996 for D*, and 0.992 for f values, which indicated excellent inter-observer agreement in the measurements between the two observers.

CONCLUSION

The IVIM-derived D and ADC values show better diagnostic performance in differentiating high-grade HCC from low-grade HCC, and there is a moderate to good correlation between the ADC and D values and the histological grades.

Keywords: Intravoxel incoherent motion; Diffusion-weighted imaging; Hepatocellular carcinoma; Pathological differentiation grade

Core tip: Intravoxel incoherent motion (IVIM)-based diffusion-weighted imaging (DWI) can yield diffusion and perfusion information simultaneously. The aims of this study were to compare IVIM-derived parameters with conventional DWI parameters for predicting the histological grade of hepatocellular carcinoma (HCC) and to evaluate the correlation between the parameters and the histological grades. Sixty-two patients with surgically confirmed HCC underwent diffusion-weighted magnetic resonance imaging with twelve b values. The differences in the ADC and D values among the groups with G1, G2, and G3 histological grades of HCC were statistically significant (P < 0.001). The D* and f values had no significant differences among the different histological grades of HCC (P > 0.05). A significant correlation was obtained between the ADC, D, and D* values and the histological grades (P < 0.05). The ROC analyses demonstrated that the D and ADC values had better diagnostic performance in differentiating low-grade HCC from high-grade HCC. These results suggested that the IVIM-DWI parameters might be useful in assessing the differentiation grades of HCC, which might be helpful in predicting the patient prognosis.