Masaharu Hirano

Delayed contrast enhancement of MRI in hypertrophic cardiomyopathy

Fibrotic lesions in the myocardium exhibit delayed contrast enhancement (DCE) on MR images. On the other hand, plexiform fibrosis is observed in hypertrophic cardiomyopathy (HCM), indicating an association of this condition with the pathogenesis of heart failure and arrhythmia. To examine the occurrence and extent of DCE and its relation to cardiac function and arrhythmia in HCM, we studied 59 patients with HCM who had undergone MRI. The relationship of DCE to cardiac function and arrhythmia was further investigated. DCE occurred in 45 (76.3%) of the 59 patients with HCM, with a high frequency of localization in regions, where the right ventricle is attached. As for the relationship of DCE to cardiac function, a significant decrease (P=0.007) in cardiac function was observed in the group in which 4 or more segments exhibited DCE, compared with the group in which DCE was observed in 3 or less segments. Regarding the relationship of DCE to arrhythmia, both the occurrence of DCE and the extent of DCE were significantly larger (p<0.05, p=0.026, respectively) in the group with VT. These results indicate that DCE may save to identify severe cases of HCM on the basis of cardiac function, arrhythmia, and pathophysiological aspects.

Assessment of myocardial abnormalities in rheumatoid arthritis using a comprehensive cardiac magnetic resonance approach: a pilot study

IntroductionRheumatoid arthritis (RA) is a multi-organ inflammatory disorder associated with high cardiovascular morbidity and mortality. We sought to assess cardiac involvement using a comprehensive cardiac magnetic resonance imaging (cMRI) approach and to determine its association with disease characteristics in RA patients without symptomatic cardiac disease.MethodsRA patients with no history and/or clinical findings of systemic or pulmonary hypertension, coronary artery disease, severe valvular heart disease, atrial fibrillation, diabetes mellitus, or echocardiographic abnormalities underwent contrast-enhanced cMRI on a 1.5T scanner. Adenosine triphosphate was used to assess perfusion defects due to microvascular impairment or ischemia, and delayed enhanced imaging was obtained for the assessment of myocardial inflammation/fibrosis. We explored the associations of cMRI abnormalities with RA disease activity and severity measures.ResultsEighteen patients (78% female) with a mean age of 57 ± 10 years were studied. Eight patients (45%) demonstrated a myocardial abnormality. Perfusion defects under pharmacologic stress were seen in two patients (11%), one of whom had a circumferential subendocardial perfusion defect and one had a non-segmental subendocardial perfusion defect. Seven patients (39%) were found to have delayed enhancement, only one of whom also demonstrated a perfusion defect. Mean disease activity score (DAS)28 was significantly higher in the group with delayed enhancement compared to the group without by an average of 1.32 DAS28 units (4.77 vs. 3.44 units, respectively; P = 0.011). Corresponding trends to statistical significance were noted in systemic inflammatory markers, with both C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) quantitatively higher in the group with delayed enhancement. Other RA characteristics, such as disease duration, autoantibody status, and current treatments were not significantly associated with cardiac involvement.ConclusionsMyocardial abnormalities, as detected by cMRI, were frequent in RA patients without known cardiac disease. Abnormal cMRI findings were associated with higher RA disease activity, suggesting a role for inflammation in the pathogenesis of myocardial involvement in RA.

Cardiac magnetic resonance imaging with pharmacological stress perfusion and delayed enhancement in asymptomatic patients with systemic sclerosis

Objective. To assess cardiac involvement in asymptomatic patients with systemic sclerosis (SSc) by cardiac magnetic resonance imaging (MRI). Methods. Ten asymptomatic patients with SSc (all female; mean age 59.5 ± 9.4 yrs) underwent contrast enhanced cardiac MRI on a 1.5 T MRI device. Adenosine triphosphate was used for stress and rest perfusion to assess perfusion defects due to microvascular impairment or ischemia, and delayed enhanced (DE) imaging was obtained for the assessment of myocardial necrosis and fibrosis. We evaluated the pathophysiological associations of stress perfusion combined with DE imaging with SSc disease severity measures. Results. Stress perfusion defects were seen in 5 out of 9 patients (56%): 4 had nonsegmental subendocardial perfusion defects and one had a segmental subendocardial perfusion defect. Three patients were found to have DE. DE was not observed in any patient without perfusion defect; and among the 5 patients with perfusion defects, 3 (60%) had DE. Two of the 3 had DE in segments not matching the region of nonsegmental perfusion defects. The remaining one had a segmental subendocardial DE matching the region of a segmental perfusion defect. Perfusion defects were seen in 75% of patients with a history of digital ulceration compared to only 20% of those without history of ulceration. Conclusion. Subclinical myocardial involvement, as detected by cardiac MRI, was frequent in asymptomatic patients with SSc. Cardiac MRI may aid in understanding the pathophysiological mechanism of SSc.

Progressive cardiac dysfunction in adriamycin-induced cardiomyopathy rats.

Cardiotoxicity is a limiting factor in the treatment of cancer with adriamycin. We administered adriamycin by a method which minimizes the risk of peritonitis in an adriamycin‐induced cardiomyopathy rat model. Sixty male Wistar rats were given 1 mg/kg of adriamycin intraperitoneally 15 times over a 3‐week period (total dose, 15 mg/kg) to induce the cardiomyopathy model. Fifteen control rats received 10 ml/kg body wt. saline 15 times over 3 weeks. The animals were observed for 12 weeks and assessed for mortality, and cardiac volume and function was analyzed by echocardiography at 4, 8, and 12 weeks. In rats treated with adriamycin, the cumulative mortality was 35.8% while in the controls, none of the rats died. Left ventricular diameter of the systole (LVDs) was significantly increased at 4 weeks (4.5 vs. 3.3 mm; P<0.001). Left ventricular diameter of the diastole (LVDd) was significantly increased at 12 weeks (7.9 vs. 7.0 mm; P<0.01) and the fractional shortening (FS) was significantly decreased at 8 weeks (33.4% vs. 50.0%; P<0.01) in the adriamycin‐treated rats. This administration method appears to be useful for investigating the cardiac effect of adriamycin while avoiding the influence of peritonitis typically caused by an intraperitoneal injection of higher single doses of adriamycin.

No Delayed Enhancement on Contrast Magnetic Resonance Imaging With Takotsubo Cardiomyopathy

An 88-year-old woman was referred to our hospital because of severe chest pain. The ECG in leads II, III, aVF, and V1 through V5 showed ST elevation (Figure 1). The creatinine kinase and creatinine kinase MB were 324 and 18 IU/L, respectively. Emergency coronary angiography revealed 75% stenosis of the high lateral branch, but left ventriculography confirmed the …

Diagnostic accuracy of stress myocardial perfusion MRI and late gadolinium-enhanced MRI for detecting flow-limiting coronary artery disease: a multicenter study

The aim of this study was to determine the diagnostic performance of stress and rest perfusion magnetic resonance imaging (MRI) and late gadolinium-enhanced (LGE) MRI for identifying patients with obstructive coronary artery disease (CAD). A total of 50 patients with suspected CAD underwent stress-rest perfusion MRI, followed by LGE MRI with a 1.5-T system. Stress-rest perfusion MRI resulted in an area under the receiver-operating characteristic curve (AUC) of 0.92 for observer 1 and 0.84 for observer 2 with sensitivity and specificity of 89% (32/36) and 79% (11/14) by observer 1, 83% (30/36) and 71% (10/14) by observer 2, respectively, showing a moderate interobserver agreement (Cohen’s κ = 0.49). While combination of stress-rest perfusion and LGE MRI did not result in improved accuracy for the prediction of flow-limiting obstructive CAD (AUC 0.81 for observer 1 and 0.80 for observer 2), the sensitivity was increased to 92% in both observers with a substantial interobserver agreement (κ = 0.70). Stress-rest myocardial perfusion MRI is an accurate diagnostic test for identifying patients with obstructive CAD.

Detection of Left Ventricular Regional Dysfunction and Myocardial Abnormalities Using Complementary Cardiac Magnetic Resonance Imaging in Patients with Systemic Sclerosis without Cardiac Symptoms: A Pilot Study

Objective We sought to detect the presence of left ventricular regional dysfunction and myocardial abnormalities in systemic sclerosis (SSc) patients without cardiac symptoms using a complementary cardiac magnetic resonance (CMR) imaging approach. Methods Consecutive patients with SSc without cardiac symptoms and healthy controls underwent CMR on a 1.5 T scanner. The peak systolic regional function in the circumferential and radial strain (Ecc, % and Err, %) were calculated using a feature tracking analysis on the mid-left ventricular slices obtained with cine MRI. In addition, we investigated the myocardial characteristics by contrast MRI. Pharmacological stress and rest perfusion scans were performed to assess perfusion defect (PD) due to micro- or macrovascular impairment, and late gadolinium enhancement (LGE) images were obtained for the assessment of myocarditis and/or fibrosis. Results We compared 15 SSc patients with 10 healthy controls. No statistically significant differences were observed in the baseline characteristics between the patients and healthy controls. The mean peak Err and Ecc of all segments was significantly lower in the patients than the controls (p=0.011 and p=0.003, respectively). Four patients with LGE (28.6%) and seven patients with PD (50.0%) were observed. PD was significantly associated with digital ulcers (p=0.005). Utilizing a linear regression model, the presence of myocardial LGE was significantly associated with the peak Ecc (p=0.024). After adjusting for age, the association between myocardial LGE and the peak Ecc was strengthened. Conclusion A subclinical myocardial involvement, as detected by CMR, was prevalent in the SSc patients without cardiac symptoms. Regional dysfunction might predict the myocardial abnormalities observed in SSc patients without cardiac symptoms.

Association of tocilizumab treatment with changes in measures of regional left ventricular function in rheumatoid arthritis, as assessed by cardiac magnetic resonance imaging

The goal of this study was to determine whether the powerful anti‐inflammatory effect of anti‐interleukin‐6 with tocilizumab (TCZ) might lead to a reduction in left ventricular (LV) dysfunction in patients with rheumatoid arthritis (RA).

Delayed contrast enhancement in a patient with perimyocarditis on contrast-enhanced cardiac MRI: case report

The findings of contrast-enhanced cardiac magnetic resonance imaging of a 19-year-old man with perimyocarditis in the subacute and chronic stage are presented. In perimyocarditis., it is useful to check the presence of delayed contrast enhancement to confirm the presence of the lesion and to evaluate the severity of inflammation in the acute stage as well as to determine the extent of fibrosis in the pericardium and myocardium in the chronic stage.

Three-dimensional T2-weighted imaging using the dark blood method for detecting pulmonary embolisms: comparison with computed tomography angiography

PurposeThe aim of this study was to assess the potential diagnostic value of three-dimensional T2-weighted imaging using the dark blood method for detecting pulmonary embolism (PE).Materials and methodsTen consecutive patients with already diagnosed acute PE (five men, five women; mean age 58.6 years, range 35–79 years) were prospectively enrolled in this study. All patients underwent lung magnetic resonance imaging (MRI) with a 1.5-T scanner. MRI was performed on the same day as CT angiography (CTA), which was undertaken to monitor treatment. Two radiologists performed a consensus evaluation of MRI followed by CTA on a per-vessel basis: the main pulmonary artery (PA), lobar PA, segmental PA, and subsegmental PA. Each modality was evaluated independently on separate days (at least 8 weeks apart). The accuracy of MRI for detecting PE was determined by comparing it with CTA results, which were used as a reference standard. Cohen’s kappa analysis was used for statistical analyses.ResultsAmong the 10 patients, pulmonary emboli were seen in 6 of 20 main arteries, 22 of 60 lobar arteries, 35 of 180 segmental arteries, and 8 of 410 subsegmental arteries on CTA. The sensitivities/specificities of MRI were 100%/100% for the main PA, 90.9%/97.3% for the lobar PA, and 74.2%/97.9% for the segmental PA, respectively. Altogether, 304 (83%) of 410 subsegmental arteries were not visualized on MRI and only 1 of the 8 emboli in the subsegmental branches was depicted. The kappa values for the main, lobar, and segmental arteries were 1.0, 0.89, and 0.77, respectively.ConclusionThree-dimensional T2-weighted imaging using the dark blood method appears to be principally useful for diagnosing main, lobar, and segmental PEs.