Intravoxel incoherent motion diffusion-weighted imaging and shear wave elastography for evaluating peritumoral liver fibrosis after transarterial chemoembolization in a VX2 rabbit liver tumor model

Abstract

In this study, we sought to evaluate changes in peritumoral fibrosis after transarterial chemoembolization (TACE) in a rabbit VX2 liver tumor model using intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI) and ultrasound shear wave elastography (SWE). A total of 20 rabbits underwent implantation of VX2 tumor tissues in the left lobe of the liver. The rabbits were randomly divided into an experimental group (n = 10) or a control group (n = 10). Those in the experimental group were treated with an emulsion of lipiodol and pirarubicin through a microcatheter 2–3 weeks after implantation; those in the control group were treated with sterile water. Compared with the control group, the true diffusion coefficient (D) and pseudodiffusion coefficient (D*) values in liver tissues were significantly lower (p < 0.05 for all) and liver stiffness values (LSV) (10.58 ± 0.89 kPa) were higher in the experimental group (7.65 ± 0.86 kPa; p < 0.001). The median stage of liver fibrosis based on METAVIR scores was 1 (1,1) in the control group and 2 (2,3) in the experimental group (Z = 4.15, p < 0.001). D, D*, and LSV were significantly correlated with pathologic staining in the assessment of liver fibrosis (r = −0.54 p = 0.015; r = −0.50, p = 0.025; r = 0.91, p < 0.001; respectively). These data suggest that TACE aggravates liver injury and liver fibrosis, especially surrounding the tumor, in a rabbit VX2 liver tumor model. IVIM DWI and SWE can be used to evaluate the change in liver fibrosis.

Combining T1rho and advanced diffusion MRI for noninvasively staging liver fibrosis: an experimental study in rats

“…As a biexponential model for separately assessing the true molecular diffusion and microcirculation perfusion [ 32 ], IVIM has been used to evaluated liver cirrhosis [ 33 ] or fibrosis [ 34 ], as well as for characterizing focal liver lesions [ 35 ]. In our study, we found that there was no statistical significance for D* among varying fibrosis stages ( P = 0.586).…”

Intravoxel incoherent motion imaging used to assess tumor microvascular changes after transarterial chemoembolization in a rabbit VX2 liver tumor model

“…All animals underwent either the control or experimental procedure 2 to 3 weeks after tumor implantation, once a welldelineated solitary tumor (1.5-2.0 cm in diameter) could be detected on ultrasound images (18,19). For these procedures, anesthesia was administered at a concentration of 2.5% to 3.5%, with an oxygen flow rate of 1 L/min.…”

“…Each rabbit was placed on an operating table Erlangen, Germany). The procedure was then performed under fluoroscopic guidance as described in a previous study (19). Briefly, the right femoral artery was selected and punctured with a 20G blood vessel puncture needle.…”

“…All MR examinations were performed with the rabbits under deep sedation. A 3.0T scanner (750 W Discovery, GE Medical Systems, Fayetteville, Wisconsin, USA) with an 8-channel rabbit coil (Wankang Medical Technology Co., Jiangsu, China) was used to scan rabbits in the prone position 2 weeks after treatment, as described previously (19). In brief, an axial T2−weighted HASTE sequence was performed using the following parameters: repetition time/echo time, 4454.0/98.7 ms; field of view, 140 × 140 mm; matrix size, 140 × 140; section thickness, 4 mm; gap, 0 mm; and bandwidth, 41.67 Hz/pixel.…”