Rat model of reperfused partial liver infarction: characterization with multiparametric magnetic resonance imaging, microangiography, and histomorphology.
BACKGROUND
Rat model of reperfused partial liver infarction (RPLI) has been increasingly used in studying new diagnostics and therapeutics.


OBJECTIVE
To characterize the RPLI model using magnetic resonance imaging (MRI), microangiography, and histopathology.


METHODS
RPLI was induced in eight rats by occluding hepatic inflow to the right liver lobe for 3 hours. MRI was performed at a 1.5 T clinical scanner 6 hours after reperfusion to obtain T2-weighted (T2WI), T1-weighted (T1WI), contrast-enhanced (CE) T1WI, diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) maps, T1-weighted dynamic contrast-enhanced (T1-DC) perfusion-weighted imaging (PWI), and T2*-weighted dynamic susceptibility contrast-enhanced (T2*-DSC) PWI images. Rats were sacrificed for microangiography and histomorphology. In vivo morphological and functional MRI parameters, including maximum initial slope (MIS), K value, relative blood flow (rBF), relative blood volume (rBV), time to peak (TTP), and mean transit time (MTT), were matched with postmortem findings.


RESULTS
The infarcted lobe was conspicuous from normal liver with lower and higher signal intensity on T1WI (P=0.018) and T2WI (P=0.001), respectively. Contrast between infarcted and normal liver reversed on CE-T1WI after gadolinium injection. The infarction averaged 37.5% of total liver volume. DWI and ADC maps were able to detect subtle perfusion-related differences (P<0.05). With T1-DC-PWI, increased extravasation and vascular permeability were reflected by significantly greater MIS (P=0.034) and K value (P=0.014) in infarction. T2*-DSC-PWI showed lower rBF and rBV with shorter TTP and MTT in infarcted liver (P<0.05). In vivo MRI findings corresponded well with postmortem outcomes.


CONCLUSIONS
RPLI in rats could be characterized by multiparametric MRI and postmortem assessments, with insight into the no-reflow phenomenon, which implies its further application for preclinical assessments of new pharmaceutics.
Wu
X
X
Radiology Section, Department of Medical Diagnostic Sciences, University Hospitals, Catholic University of Leuven, Leuven, Belgium.
Wang
H
H
Chen
F
F
Jin
L
L
Li
J
J
Feng
Y
Y
DeKeyzer
F
F
Yu
J
J
Marchal
G
G
Ni
Y
Y
D015901:Angiography, Digital Subtraction / Q000379:methods*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004195:Disease Models, Animal; D019786:Gadolinium DTPA; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007238:Infarction / Q000175:diagnosis* / Q000473:pathology; D008099:Liver / Q000098:blood supply*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D054318:No-Reflow Phenomenon / Q000175:diagnosis / Q000473:pathology; D012372:ROC Curve; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA