Contour-based Registration for Left Ventricular Myocardial Extracellular Volume Fraction Using T1 Mapping in Healthy Adults / 中山大学学报(医学科学版)

[Objective]We aimed to evaluate the role of contour-based registration in quantification of myocardial extracellular volume fraction(ECV)based on T1 mapping technique.[Methods]T1 mapping images of the basal,mid-cavity and apical short axis slices of 26 healthy volunteers(16 males and 10 females)were obtained before and after administration of contrast agent using Modified Look-Locker Inversion Recovery(MOLLI)on a 3.0T Magnetic Resonance Imaging system.ECV was calculated by routine method and registered method.For each slice,subjects were divided into the deformation subgroup and the control subgroup.Routine ECVs and registered ECVs were compared for each subgroup.[Results]Left ventricular deformation among T1 mapping images occurred in 16 subjects(61.5%). In all three slices, registered ECV maps had better image quality and more highest grade images than routine ECV maps. Routine ECVs[(26.81 ± 2.78)%,(25.38 ± 3.05)%,(28.66 ± 4.10)%]were statistically different from registered ECVs in global [(25.75±2.42)%,P=0.001],mid-cavity[(24.30±2.45)%,P=0.016]and apical slices[(27.22±3.38)%,P=0.010]. In deformation subgroups of all the 3 slices,registered ECVs were lower than routine ECVs with smaller SDs(P=0.038, 0.012,0.016).The apical ECVs were higher with larger SDs than the other two slices and the global ECVs(routine:F=4.799,P=0.004;registered:F=4.822,P=0.003).[Conclusions]Contour-based registration can improve the image qual-ity and precision of ECV quantification in cases with ventricular shape deformation among source images.

Diagnosis of Right Ventricular Vegetation on Late Gadolinium-Enhanced MR Imaging in a Pediatric Patient after Repair of a Ventricular Septal Defect

We report a case of vegetation in a 4-year-old female with infective endocarditis, diagnosed by late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) imaging. The patient had a history of primary closure for ventricular septal defect and presented with mild febrile sensation. No remarkable clinical symptoms or laboratory findings were noted; however, transthoracic echocardiography demonstrated a 14 mm highly mobile homogeneous mass in the right ventricle. On LGE CMR imaging, the mass showed marginal rim enhancement, which suggested the diagnosis of vegetation rather than thrombus. The extracellular volume fraction (≥ 42%) of the lesion was higher than that of normal myocardium. Based on the patient's clinical history of congenital heart disease and pathologic confirmation of the lesion, a diagnosis of infective endocarditis with vegetation was made.

Detection of Perivalvular Abscess with Late Gadolinium-Enhanced MR Imaging in a Patient with Infective Endocarditis

We report a case of perivalvular abscess in a 66-year-old man with infective endocarditis, diagnosed by late gadolinium-enhanced (LGE) cardiovascular magnetic resonance (CMR) imaging. No clinical features suspicious of infective endocarditis were noted, however, transthoracic echocardiography revealed non-specific echogenic focal wall thickening at mitral-aortic intervalvular fibrosa. Perivalvular abscess in the aortic valve was demonstrated as focal wall thickening between the anterior mitral leaflet and the non-coronary cusp of the aortic valve with peripheral enhancement and central low signal intensity on LGE CMR imaging. Other features suggestive of infective endocarditis, such as neither vegetation nor valvular perforation were present. The perivalvular abscess did not grow after intensive intravenous antibiotics therapy, and the patient was discharged without surgical treatment. CMR with LGE provided an early accurate diagnosis of perivalvular abscess. The diagnosis of perivalvular abscess using LGE CMR imaging was not previously reported in Korea.

Diagnostic performance of stress perfusion cardiovascular magnetic resonance for detection of coronary artery disease:a Meta-analysis / 实用放射学杂志

Objective To evaluate the value of stress perfusion cardiovascular magnetic resonance in the diagnosis of coronary ar-tery disease.Methods Relevant literatures about stress perfusion cardiovascular magnetic resonance in the diagnosis of coronary ar-tery disease were searched.According to the recommended contents of the Cochrane Collaboration,we set inclusion criteria and screen literatures.Using software STATA 12.0 and Meta-disc 1.4,we analyzed the data ,including the heterogeneity,publication bias,subgroup analysis,Meta-regression,clinical application,pooled sensitivity(SEN),specificity(SPE),positive likelihood ratio (PLR),negative likelihood ratio(NLR),diagnostic odds ratio(DOR)and 95%confidence interval(95%CI),we drew the summary receiver operating characteristic curve(SROC)and calculated the area under the curve(AUC).Results Twenty-nine literatures were included,the pooled SEN,SPE,PLR,NLR,DOR and 95%CI were 0.90(0.89~0.92)、0.78(0.75~0.80)、4.03(3.32~4.91)、0.14 (0.11~0.18)、32.54(22.25~47.60)respectively.The AUC of SROC was 0.907 8.Conclusion The current evidence indicates that stress perfusion cardiovascular magnetic resonance has a high diagnostic accuracy for detection coronary artery disease.However, the relatively high false positive rate was found due to the medium specificity.

Left ventricular ejection fraction measurement using cardiovascular magnetic resonance imaging in patients with post-myocardial infarction: assessment of reproducibility by a cardiovascular radiologist and a trained technologist.

Background: Cardiovascular magnetic resonance imaging (CMR) has recently been accepted as a preferential method for evaluation left ventricular ejection fraction (LVEF). The LVEF analysis by CMR is usually performed by trained technologists in many institutions of Thailand. Objective: Assess the reproducibility of LVEF measured by a cardiovascular radiologist and a trained technologist using CMR in patients with post-myocardial infarction (MI). Methods: Twenty-one MI patients (18 men and 3 women) were recruited, where nine patients underwent CMR and left ventriculography to follow-up LVEF two times in six months. Both CMR and left ventriculography were examined within two weeks. LVEF from CMR were measured by a cardiovascular radiologist and a trained technologist and the correlation between the left ventriculography and CMR was determined. Results: In 30 CMR studies, interobserver reliability (intraclass correlation coefficient ICC=0.94) and intraobserver reliability (ICC=0.96) was excellent. LVEF measured by left ventriculography was higher compared with that by CMR, and their correlation was moderate (ICC=0.56). Conclusion: The LVEF measurement by a cardiovascular radiologist and a trained technologist using CMR was very reproducible, but the correlation between CMR and left ventriculography was moderate.