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Objective To evaluate the myocardial ischemia in hypertrophic cardiomyopathy (HCM) patients with MR first-pass myocardial perfusion imaging.Methods Totally 20 patients with HCM (HCM group) and 10 healthy volunteers (control group) underwent cardiac MR scanning,including left ventricle short axial cine,first-pass myocardial perfusion imaging and delayed enhanced imaging.Then the left ventricular end-diastolic wall thickness (EDTH) was measured.The blood pool-signal strength curves of the near,middle and far segments of left ventricle were drawn,and then time to peak (tpeak),maximal upslope of time-intensity curve (Slopemax),peak signal intensity (SIpeak) were measured.According to EDTH,different segments of HCM were divided into non-hypertrophic subgroup and hypertrophic subgroup,and patients in hypertrophic subgroup were further divided as slightly (15-19 mm),moderately (20-24 mm) and severely hypertrophic level (25-29 mm).One-way ANOVA analysis was used to analyze the differences of tpeak,Slope SIpeak among groups,as well as every two subgroups and levels.Results The differences of Slopemax,tpeak between control group and non-hypertrophic group were not statistically significant (both P ＞ 0.05).The differences of Slopemax and tpeak between nonhypertrophic group and hypertrophic group were statistically significant (both P＜0.05).In hypertrophic subgroup,Slopemax of slightly hypertrophic level was higher than that of moderately and severely hypertrophic level (both P＜ 0.05),and tpeak of moderately hypertrophic level was higher than that of slightly hypertrophic level (P＜0.05).However,Slopemax and tpeak between moderately and severely hypertrophic level,SIpeak between every two levels were not significantly different (all P＞ 0.05).Conclusion MR first-pass myocardial perfusion imaging can reflect myocardial ischemia of different hypertrophic segments of HCM,contributing to risk stratification,therapy planning and prognosis evaluation of HCM patients.
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Objective To investigate the MRI characteristics of abdominal leiomyosarcoma and literature review.Methods Preoperative MRI data of 9 cases with leiomyosarcoma proved by pathology were analyzed retrospectively.The size,shape,signal intensity and enhancement type of the lesion were analyzed and some related literatures were reviewed in order to summarize its imaging features.Results In the 9 cases,1 was located in the liver,5 cases in the abdominal retroperitoneul space and other 3 case in the pelvic retroperitoneul space.Before operation,6 cases had wrong diagnosis,including 1 case misdiagnosed as hepatocellular carcinoma with intrahepatic metastases,3 cases as ganglioneuroma and 2 cases as uterine myoma.On plain MRI,5 cases showed iso-/slightly hypo-mixed signal and 4 cases showed hypointensity on T1 WI.Five cases showed iso-/slightly hyper-mixed signal and 4 cases showed iso-/slightly hyper/ hyper-mixed signal on T2WI.On diffusion weighted images (DWI),5 cases showed significant diffusion restriction and 4 cases showed moderate diffusion restriction.On contrast-enhanced MRI,3 cases showed obvious peripheral inhomogeneous enhancement,the enhancement degree in portal vein phase was more obvious than that in arterial phase and was sustained in delayed phase.The lesions showed progressive enhancement and the enhancement was higher in peripheral than central areas.Six cases demonstrated obviously inhomogeneous enhancement in arterial phase,no obvious washout was observed in portal vein phase and delayed phase,and non-enhanced area was still observed in late delayed phase.One lesion in the liver had the sign of pseudocapsule.Conclusion Abdominal leiomyosarcoma has certain characteristic MRI manifestations.Leiomyosarcoma should be considered in the differential diagnosis list,when the lesion is large,with cystic degeneration,necrosis,moderate to significant diffusion restriction on DWI and obvious peripheral enhancement.
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Objective To explore MRI manifestations of extrapleural solitary fibrous tumor(SFT)and to analyze the reasons of misdiagnosis.Methods MRI data of 9 cases with extrapleural SFT proved by pathology were analyzed retrospectively.Lesions location, size,shape,intensity,degrees and patterns of enhancement were assessed,and the imaging features and causes of misdiagnosis were also analyzed.Results Among 9 lesions,1 was located in the right cerebellopontine angle region,2 were in subdural-extramedullary region,4 were in the abdominal cavity and 2 were in the pelvic cavity.7 cases were misdiagnosed before operation including 1 as meningioma, 2 as schwannoma,2 as mesenchymal stem cell tumor,1 as pancreatic carcinoma and 1 as Castleman disease.8 lesions were isointense and 1 was mixed iso-or slightly hyperintense on T1WI.3 lesions were isointense,4 were mixed iso-or slightly hyperintense and 2 were mixed slightly hyperintense,iso-or hypointense on T2WI.3 lesions showed significant homogeneous enhancement after the administration of contrast agent,1 lesion showed varying degrees of enhancement and the enhancement was more remarkable in isointense area on T2WI than peripheral hyperintense area.4 lesions showed heterogeneous peripherial enhancement in the early phase,progressive filling in the late phase and finally remarkable homogeneous enhancement.1 lesion showed predominant peripheral striped enhancement in the early phase,and progressive filling and mildly inhomogeneous enhancement with patchy unenhanced area in the center of the lesion in the late phase.Conclusion The MRI features of extrapleural SFT have certain characteristics.It needs to be carefully diagnosed to improve the diagnostic accuracy.
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The myocardial infarction is an important clinical feature of ischemic heart disease,and its various stages of histopathological changes are closely related to the prognosis of patients.In recent years,with the continuous development and improvement of MRI software and hardware techniques,the cardiac MR (CMR) can assess the pathological changes of the myocardial infarction by its multi-parameter and multi-sequence imaging techniques qualitatively and quantitatively.And the CMR can provide the clinical reference information for the patients in short-term diagnosis and long-term prognostic risk assessment accurately and comprehensively.The progresses of CMR in assessing the pathology of myocardial infarction were reviewed in this article.
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ObjectiveTo investigate the correlation between recent cardiac events and the score of myocardial infarction by delayed-enhancement MRI (DE-MRI).Methods DE-MRI was performed in 40 subjects with coronary artery disease.The score of myocardial infarction by DE-MRI,the ejection fraction (EF) by echocardiography,recent cardiac events (the number of weekly nitroglycerin,the number of weekly angina episodes and the onset number of heart failure in the last year),6-minute walking distance,as well as the Seattle angina questionnaire (SAQ) score were assessed.The Spearman correlation test and Kruskal-Wallis test,Mann-Whitney test were used for the statistics.ResultsThere were negative correlation between the myocardial infarction score by DE-MRI (median 12,inter-quartile range:6.0-19.8) and the 6-minute walking distance(378.93 ± 100.53 ),SAQ score (74.55 ± 11.40 ) (r was 0.66 and 0.54,P ＜0.05).The myocardial infarction score by DE-MRI was strongly correlated with the number of weekly nitroglycerin ( median 1 ; inter-quartile range:0-2.8),the number of weekly angina episodes ( median 3,inter-quartile range:1-6.5 ) and the onset number of heart failure in the last year ( median 0,inter-quartile range:0-2) (r was 0.87,0.85 and 0.89,P ＜0.05).EF [(49.2 ± 13.72)％] was negative correlation with the number of weekly nitroglycerin,the number of weekly angina episodes and the onset number of heart failure in the last year (r were 0.67,0.73 and 0.73,P ＜0.05).ConclusionDE-MRI can be used for evaluation and prediction of future cardiac events.
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BACKGROUND: Recent trials and clinical studies have shown that intracoronary transplantation of bone marrow-derived mesenchymal stem cells (MSCs) improves cardiac function following acute myocardial infarction (AMI). However, whether homing of MSCs into the infarcted myocardium or not is still unknown.OBJECTIVE: To study the homing of MSCs intracoronary administration in porcine myocardial infarction model using in vivo magnetic resonance imaging tracking.METHODS: Porcine MSCs were isolated and cultured by the whole bone marrow method. Following labeling by superparamagnetic iron oxide (SPIO), MSCs were treated with trypsinization to adjust the concentration at 10~(10)/L. Myocardial infarction was induced in all 10 pigs. At one week after modeling, the labeled MSCs were delivered via intracoronary infusion with standard over-the-wire (OTW) balloon angioplasty catheters. Prussian blue staining was used to evaluate labeling efficiency, and double echo steady state was used to scan four-chamber and cor biloculare at long axis view, which was considered as locating phase to obtain image of left ventricle at short axis view. RESULTS AND CONCLUSION: MSCs could be efficiently and safely labeled with SPIO. Intracoronary transplantation of MSCs is able to home the sites of myocardial injury and the border between infarcted and normal tissue. MRI can track SPIO-labeled MSCs delivered through intracoronary and were confirmed on pathology. After 5 weeks the injected labeled cells could still be detected with MRI.
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Objective To explore the ischemic myocardial perfusion and viability.Methods Ten successful pigs with myocardial infarction model underwent MRI first-pass myocardial perfusion examinations preoperatively and 24 hours,72 hours and one week postoperation.After MRI examinations,the experimental pigs were executed and the samples underwent TTC staining and pathological examination.Results The preoperative myocardial perfusion in the all of the 10 pigs was nomal,but there were myocardial perfusion decrease and defects in 8 experimental pigs after operation,the perfusion curves in the area with perfusion defects had no obvious peak,but there was gradual increase in the end of the performance.The perfusion peak of the area with perfusion decrease was lower than that of normal inferior and lateral myocardial wall(P＜0.05) and the peak perfusion time was delayed compared with that of normal inferior and lateral myocardial wall (P＜0.05).There was myocardial necrosis in the perfusion defects areas that was certified by TTC staining and pathological examination.The intersititial edema and myocardial degeneration could be seen in the perfusion reduced areas.Conclusion MRI fist-pass myocardial perfusion imaging combined with perfusion curve analysis can evaluate the perfusion changes of the regional myocardial microcirculation.