ABSTRACT
Objective To explore MR perfusion imaging characteristics of rabbit liver.Methods MR perfusion imaging was performed in 10 New Zealand rabbits)weight:2.5～3.0 kg)respectively.The MR perfusion imaging protocol consisted of T1-weighted fast field echo(FFE)sequences with a field of view of 355 mm×75 mm,matrix 89×256,TR/TE of 4.3/1.4 millisecond,slice thickness of 5 mm,intersection gap of 1 mm,NSA of 1.This sequence was repeated 65 times,in 4 slices(in total,80 seconds).The original data were transmitted to PHILIPS workstation and formed MR perfusion images automatically.The MR perfusion images in different liver tissues were observed and analyzed.Results The rabbit liver profiles were depicted on hepatic blood flow(HBF)and hepatic blood volume(HBV)images.Time-intensity curves derived from ROIs drawn in abdominal aorta appeared as a type of rapid increase and decrease,gradually increase in hepatic vein and slowly increase and decrease in normal liver tissues.The peak of MR signal intensity of abdominal aorta,hepatic vein and normal liver tissues were 496±131,323±92,194±58 separately.Conclusion MR perfusion imaging can be performed for rabbit liver successfully by using MR TFE series.The rabbit liver profiles are depicted by HBF and HBV images.The hemodynamics of different liver tissues can be responded by time-intensity curves preliminarily.
ABSTRACT
Objective: To study the correlation between MR perfusion imaging and pathology after transcatheter arterial chemoembolization (TACE) using VX2 liver cancer model and to provide a theoretical basis to evaluate the curative effect of TACE. Methods; Fifteen New Zealand white rabbits (weight: 2.5-3.0kg) were randomly divided into three groups, with 5 in each group (group 1, pre-TACE; group2, 3 days after TACE; group 3,1 week after TACE). The rabbit VX2 hepatic carcinoma models were presented in all rabbits. All of the three groups received TACE at three weeks after the tumor was implanted. The MR perfusion imaging was performed before chemoembolization, at 3 days and 1 week after chemoembolization respectively for group 1, 2 and 3. Each animal was then sacrificed for pathology observation after MR examination. Results: The lesions assessed before TACE were hyperintense compared with the surrounding liver parenchyma on DWI images. The volume of neoplastic cells became large. Nucleus was hypertrophic with different size and shape. Phase of nucleous mitosis showed in many cells and necrosis was hardly seen. No obvious difference was found between the peripheral area and the core area. At 3 days after TACE, the heterogeneous hypo-intense was observed on DWI images. Many nuclear fragmentation and caryolysis appeared on pathology. Neoplasm necrosis was seen. At 1 week after TACE, the heterogeneous hypo-intense areas became larger. Light microscopy showed incomplete necrosis. There were increased karyopycnosis and nuclear fragmentation. Conclusion: MR perfusion imaging of VX2 liver cancer corresponds well with pathology and can reflect the outcome of liver cancer after TACE.