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Objective:To study the diagnostic value of MR diffusion weighted imaging (DWI) and CT and MR perfusion imaging in patients with different degrees of liver cirrhosis.Methods:A total of 60 patients with liver cirrhosis,who were treated in Ziyang Hospital of West China Hospital of Sichuan University from August 2015 to February 2017 were selected.According to the Child-Pugh classification,32 cases of grade A were mild cirrhosis (denoted as group A),16 cases of grade B and 12 cases of grade C were moderate to severe cirrhosis (denoted as group B),30 healthy volunteers were selected as group C in the same period.All the subjects in the three groups were examined by DWI,CT and MR perfusion imaging.The ADC value,hepatic portal perfusion ratio [SSr (CT) and SSr (MR)] were compared among the three groups,and Spearman correlation analysis was used to analyze the correlation between the indexes.Results:There was no significant difference in ADC values among the three groups (P＞0.05),and the ADC values of group A and B were lower than those of group C,but the difference was not statistically significant (P＞0.05).There was no significant difference in ADC values between group A and B (P＞0.05).The levels of SSr (CT) and SSr (MR) in the three groups were compared,the difference was statistically significant (P＜0.05);the levels of SSr (CT) and SSr (MR) in group B were significantly higher than those in group A and C,the difference was statistically significant (P＜0.05).There was no significant difference in the levels of SSr (CT) and SSr (MR) in group A and C (P＞0.05).Spearman correlation analysis showed that SSr (CT) was positively correlated with SSr (MR) in the patients with liver cirrhosis (r=0.687,P=0.000).Conclusion:CT and MR perfusion imaging can reflect the lesion degree of liver cirrhosis,and diagnostic effects of the two are better than DWI imaging,which is worthy of clinical promotion.
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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.
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Objective To evaluate the value of dynamic susceptibility contrast-enhanced MR imaging (DSC)in evaluation of brain tumor after operation.Methods 41 cases with brain tumors verified histologically,including 8 cases of high-grade gliomas,16 of low-grade gliomas,7 of metastases and 10 of meningiomas underwent DSC examination.All the cases at 3.0T MR unit.All primitive data were sent to ADW4.3 workstation for post-processing.The mean maximal rCBV and rCBF ratios of tumors,1 cm and 2 cm regions of peri-tumor were obtained respectively.The relativity of MR perfusion parameters(rCBV and rCBF)between diferent tumors were statistically evaluated by using Pearson correlative analysis.Results In the solid region of tumors,rCBV and rCBF were statistically significant differences (P<0.05)between low-grade gliomas and the other three groups of tumors; in 1 cm region of peri-tumor between high-grade gliomas and the other three groups,and between low-grade gliomas and metastases,between the solid region and both regions of 1 cm and 2 cm peri-tumors at the same tumor were all of statistically significant differences(P<0.05),between 1 cm and 2 cm region of peri-tumors at high-grade gliomas and metastases,the rCBV and rCBF were also of statistically significant differences.Pearson correlative analysis showed that there were significant positive correlations between the mean maximal rCBV and rCBF ratios at the same region in the same tumor's group.Conclusion DSC is very valuable in evaluation of the histopathological grade and the differentiation of brain tumor.
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PURPOSE: We investigated the predictive values of relative CBV measured with perfusion MR imaging, and relative CBF measured with SPECT for tissue outcome in acute ischemic stroke. MATERIALS AND METHODS: Thirteen patients, who had acute unilateral middle cerebral artery occlusion, underwent perfusion MR imaging, and 99mTc-HMPAO SPECT within 6 hours after the onset of symptoms. Lesion-to-contralateral ratios of perfusion parameters were measured, and best cut-off values of both parameter ratios with their accuracy to discriminate between regions with and without evolving infarction were calculated. RESULTS: Mean relative CBV ratios in regions with evolving infarction and without evolving infarction were 0.58+/-0.27 and 0.99+/-0.17 (p 0.05 between two parameters). CONCLUSION: Measurement of relative CBV and relative CBF may be useful in predicting tissue outcome in acute ischemic stroke.