Quantitative Assessment of Myocardial Edema by MR T2 Mapping in Children With Kawasaki Disease.

BACKGROUND: Few studies assessed myocardial inflammation using Cardiovascular Magnetic Resonance Imaging in Kawasaki disease (KD) patients. PURPOSE: To quantify myocardial edema in KD patients using T2 mapping and explore the independent predictors of T2 values. STUDY TYPE: Prospective. SUBJECTS: Ninety KD patients including 40 in acute phase (26 males, 65.0%) and 50 in chronic phase (34 males, 68.0%). Thirty-one healthy volunteers (21 males, 70.0%). FIELD STRENGTH/SEQUENCE: 3.0 T T2-weighted Turbo Spin Echo-Short Time of Inversion Recovery sequence, True fast imaging with steady precession flash sequence and fast low-angle shot 3D spoiled gradient echo sequence. ASSESSMENT: T2 values were compared among KD groups and controls. STATISTICAL TEST: Student's t test and Fisher's exact test; One-way analysis of variance; Pearson correlation analysis; Receiver operating curve analysis; Multivariable linear regression. RESULTS: Global T2 value of KD patients in acute phase was the highest, followed by those of chronic-phase patients and controls (38.83 ± 2.41 msec vs. 37.55 ± 2.28 msec vs. 36.05 ± 1.64 msec). Regional T2 values showed a same trend. There were no significant differences in global and regional T2 values between KD patients with and without coronary artery (CA) dilation, no matter in acute or chronic phase (all KD patients: P = 0.51, 0.51, 0.53, 0.72; acute KD: P = 0.61, 0.37, 0.33, 0.83; chronic KD: P = 0.65, 0.79, 0.62, 0.79). No significant difference was observed in global T2 values between KD patients with Z score > 5.0 and 2.0 < Z score ≤ 5.0 (P = 0.65). Multivariate analysis demonstrated that stage of disease (ß = -0.123) and heart rate (ß = 0.280) were independently associated with global T2 values. DATA CONCLUSION: The degree of myocardial edema was more severe in acute-phase than in chronic-phase KD patients. Myocardial edema persists in patients regardless of the existence or degree of CA dilation. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Pulmonary hypertension in late-onset Methylmalonic Aciduria and Homocystinemia: a case report.

BACKGROUND: Methylmalonic Aciduria and Homocystinemia, cobalamin C (cblC) is an inherited disease of vitamin B12 metabolism with a wide spectrum of clinical manifestations. cblC presenting with pulmonary hypertension (PH) as leading sympotom is rare and easily misdiagnosed because of limited awareness. Timely diagnosis is crucial by the relentless progression without appropriate treatment. CASE PRESENTATION: We reported a 12-year-old girl with a 3-year history of progressively reduced activity tolerance and a 3-month history of orthopnea. Metabolic testing revealed increased levels of plasma homocysteine and urine methylmalonic acid. cblC deficiency was subsequently confirmed by genetic testing. The patient was treated with hydroxocobalamin, betaine, folinic acid and levocarnitine for cblC disease. Sildenafil, bosentan, spironolactone and hydrochlorothiazide was administrated for PH and right heart failure. At 3-month follow-up, she had an apparent resolution of dyspnea and cyanosis. Metabolic abnormalities resolved the decrease of plasma homocysteine and urine methylmalonic acid. A right heart catheterization showed a reduced pulmonary pressure. CONCLUSIONS: This case emphasizes the importance of an early diagnosis and initiation of treatment for cblC deficiency. Unexplained PH in children and young adults should prompt metabolic screening for the differential diagnosis.

Accurate identification of myocardial viability after myocardial infarction with novel manganese chelate-based MR imaging.

We developed a novel manganese (Mn2+ ) chelate for magnetic resonance imaging (MRI) assessment of myocardial viability in acute and chronic myocardial infarct (MI) models, and compared it with Gadolinium-based delay enhancement MRI (Gd3+ -DEMRI) and histology. MI was induced in 14 rabbits by permanent occlusion of the left circumflex coronary artery. Gd3+ -DEMRI and Mn2+ chelate-based delayed enhancement MRI (Mn2+ chelate-DEMRI) were performed at 7 days (acute MI, n = 8) or 8 weeks (chronic MI, n = 6) after surgery with sequential injection of 0.15 mmol/kg Gd3+ and Mn2+ chelate. The biodistribution of Mn2+ in tissues and blood was measured at 1.5 and 24 h. Blood pressure, heart rate (HR), left ventricular (LV) function, and infarct fraction (IF) were analyzed, and IF was compared with the histology. The Mn2+ chelate group maintained a stable hemodynamic status during experiment. For acute and chronic MI, all rabbits survived without significant differences in HR or LV function before and after injection of Mn2+ chelate or Gd3+ (p > 0.05). Mn2+ chelate mainly accumulated in the kidney, liver, spleen, and heart at 1.5 h, with low tissue uptake and urine residue at 24 h after injection. In the acute MI group, there was no significant difference in IF between Mn2+ chelate-DEMRI and histology (22.92 ± 2.21% vs. 21.79 ± 2.25%, respectively, p = 0.87), while Gd3+ -DEMRI overestimated IF, as compared with histology (24.54 ± 1.73%, p = 0.04). In the chronic MI group, there was no significant difference in IF between the Mn2+ chelate-DEMRI, Gd3+ -DEMRI, and histology (29.50 ± 11.39%, 29.95 ± 9.40%, and 29.00 ± 10.44%, respectively, p > 0.05), and all three were well correlated (r = 0.92-0.96, p < 0.01). We conclude that the use of Mn2+ chelate-DEMRI is reliable for MI visualization and identifies acute MI more accurately than Gd3+ -DEMRI.

Histologic validation of myocardial fibrosis measured by T1 mapping: a systematic review and meta-analysis.

BACKGROUND: Myocardial fibrosis is being increasingly recognised as a common final pathway of a wide range of diseases. Thus, the development of an accurate and convenient method to evaluate myocardial fibrosis is of major importance. Although T1 mapping is a potential alternative for myocardial biopsy, validation studies are limited to small numbers and vary regarding technical facets, and include only a restricted number of disease. A systematic review and meta-analysis was conducted to objectively and comprehensively evaluate the performance of T1 mapping on the quantification of myocardial fibrosis using cardiovascular magnetic resonance (CMR). METHODS: PubMed, EMBASE and the Cochrane Library databases were searched for studies applying T1 mapping to measure myocardial fibrosis and that validated the results via histological analysis. A pooled correlation coefficient between the CMR and histology measurements was used to evaluate the performance of the T1 mapping. RESULTS: A total of 15 studies, including 308 patients who had CMR and myocardial biopsy were included and the pooled correlation coefficient between ECV measured by T1 mapping and biopsy for the selected studies was 0.884 (95% CI: 0.854, 0.914) and was not notably heterogeneous chi-squared = 7.44; P = 0.489 for the Q test and I^2 = 0.00%). CONCLUSIONS: The quantitative measurement of myocardial fibrosis via T1 mapping is associated with a favourable overall correlation with the myocardial biopsy measurements. Further studies are required to determine the calibration of the T1 mapping results for the biopsy findings of different cardiomyopathies.

Preoperative assessment of coronary arteries in patients undergoing thoraco-abdominal and noncoronary cardiovascular surgery with dual-source computed tomography angiography.

AIMS: To retrospectively evaluate coronary anomalies and coronary wall atheromatous changes by using dual-source computed tomography angiography (DSCTA) for preoperative assessment of patients with thoraco-abdominal and noncoronary cardiovascular disease. MATERIALS AND METHODS: One hundred and eighty-one patients scheduled for elective noncoronary cardiovascular surgery (heart valve disease group, HVD; arrhythmia group, Arrhy; or aortic aneurysm group, AA) underwent a DSCTA examination for preoperative preparation. Anomalous origin of coronary arteries, myocardial bridge (MB), coronary wall atheromatous changes, luminal stenosis, and types of plaques were evaluated and compared among the three groups. RESULTS: Anomalous origin of coronary arteries and MB were observed in 5.1% and 21.5% of patients. Anomalous origin of the coronary artery from the opposite sinus was most common (55.6%). MB was most frequently detected in the distal segment of the left anterior descending artery (LAD) (1.2%). Plaques were most common in the proximal segment of the LAD (16.4%) and LAD branches (42.2%). Diseased vessels and segments were more common in AA group, followed by Arrhy patients and finally HVD groups (p < 0.001 for each group). Multivessel involvement and significant stenosis of AA group were significantly more common than the other two groups. Noncalcified plaque and all grades of stenosis were more common in AA patients. CONCLUSION: DSCTA is useful for preoperative assessment of coronary arteries in patients undergoing thoraco-abdominal and noncoronary cardiovascular surgery. DSCTA detected higher prevalence of coronary artery disease in AA patients than in the other two groups of patients.

[Characteristics of mediastinal lymph nodes enlargement determined by contrast-enhanced multi-detector CT in patients with sarcoidosis].

OBJECTIVE: To determine the enhancement patterns and anatomic distribution of enlarged mediastinal lymph nodes using contrast-enhanced multi-detector CT (MDCT) in patients with sarcoidosis. METHODS: We reviewed the contrast-enhanced MDCT features of 39 patients with pathologically or clinically diagnosed sarcoidosis, including the size, morphology, attenuation, enhancement patterns, and anatomic distribution of the enlarged mediastinal lymph nodes. RESULTS: Of the 39 patients, 85% showed homogenous enhancement and 15% showed homogenous mixed with peripheral enhancement. The enlarged lymph nodes were predominantly distributed in the regions of 10R (95%), 10L (90%), 2R (69%), 7 (69%), and 5 (58%). CONCLUSION: Contrast-enhanced MDCT can detect the enhancement patterns and predominant anatomic distribution of enlarged mediastinal lymph nodes, which is of great value for the diagnosis of sarcoidosis.

Association of myocardial fibrosis detected by late gadolinium-enhanced MRI with clinical outcomes in patients with diabetes: a systematic review and meta-analysis.

OBJECTIVE: This meta-analysis assessed the associations of myocardial fibrosis detected by late gadolinium-enhanced (LGE)-MRI with the risk of major adverse cardiac and cerebrovascular events (MACCEs) and major adverse cardiac events (MACEs) in patients with diabetes. DESIGN: Systematic review and meta-analysis reported in accordance with the guidelines of the Meta-analysis of Observational Studies in Epidemiology statement. DATA SOURCES: We searched the Medline, Embase and Cochrane by Ovid databases for studies published up to 27 August 2021. ELIGIBILITY CRITERIA: Prospective or respective cohort studies were included if they reported the HR and 95% CIs for MACCEs/MACEs in patients with either type 1 or 2 diabetes and LGE-MRI-detected myocardial fibrosis compared with patients without LGE-MRI-detected myocardial fibrosis and if the articles were published in the English language. DATA EXTRACTION AND SYNTHESIS: Two review authors independently extracted data and assessed the quality of the included studies. Pooled HRs and 95% CIs were analysed using a random effects model. Heterogeneity was assessed using forest plots and I2 statistics. RESULTS: Eight studies with 1121 patients with type 1 or type 2 diabetes were included in this meta-analysis, and the follow-up ranged from 17 to 70 months. The presence of myocardial fibrosis detected by LGE-MRI was associated with an increased risk for MACCEs (HR: 2.58; 95% CI 1.42 to 4.71; p=0.002) and MACEs (HR: 5.28; 95% CI 3.20 to 8.70; p<0.001) in patients with diabetes. Subgroup analysis revealed that ischaemic fibrosis detected by LGE was associated with MACCEs (HR 3.80, 95% CI 2.38 to 6.07; p<0.001) in patients with diabetes. CONCLUSIONS: This study demonstrated that ischaemic myocardial fibrosis detected by LGE-MRI was associated with an increased risk of MACCEs/MACEs in patients with diabetes and may be an imaging biomarker for risk stratification. Whether LGE-MRI provides incremental prognostic information with respect to MACCEs/MACEs over risk stratification by conventional cardiovascular risk factors requires further study.

Association of left ventricular systolic dysfunction with coronary artery dilation in Kawasaki disease patients: Assessment with cardiovascular magnetic resonance.

PURPOSE: To quantify global and regional left ventricular (LV) strain parameters in patients with Kawasaki disease (KD) using cardiovascular magnetic resonance (CMR) tissue tracking and assess the association of coronary artery dilation (CA dilation) with LV systolic dysfunction. METHODS: Thirty-one KD patients with CA dilation, 22 patients without CA dilation and 27 age- and sex-matched normal controls underwent 3.0 T CMR examination. Z score of >2 was defined as CA dilation. Global LV strain parameters and regional LV strain parameters in 16 American Heart Association segmentation, including radial, circumferential and longitudinal peak strain (PS) and LV function were measured and compared among groups. RESULTS: No significant difference in LV ejection fraction has been observed among controls, KD patients with CA dilation and without CA dilation (all p > 0.05). However, global longitudinal PS (GLPS) was lower in groups with CA dilation than those without CA dilation (-12.6 ± 4.1% vs -14.9 ± 2.6%, p < 0.05). For regional strain parameters, the segments with CA dilation (n = 301) were lower than those in both normal controls (n = 416) and segments without CA dilation (n = 547) in regional radial, circumferential and longitudinal PS (all p < 0.05). The severity of CA dilation was positively correlated to GLPS and regional longitudinal PS (r = 0.388 and r = 0.222; both p < 0.05) in KD patients. After adjusting for clinical characteristics, the multivariate analysis demonstrated that Z score was independently associated with GLPS in KD patients (ß = 0.469, p = 0.000, model R2 = 0.355). CONCLUSIONS: CMR tissue tracking could sensitively identify subclinical LV dysfunction in KD patients with CA dilation. LV systolic dysfunction occurs particularly in the myocardium dominated by the dilated coronary artery. CA dilation is an independent predictor of LV systolic dysfunction.

Morphologic and functional abnormalities in patients with Ebstein's anomaly with cardiac magnetic resonance imaging: Correlation with tricuspid regurgitation.

PURPOSE: The aim of this study was to assess the correlations of functional and dimensional parameters with the severity of tricuspid regurgitation in patients with Ebstein's anomaly (EA) by using cardiac magnetic resonance (CMR) imaging. MATERIALS AND METHODS: Thirty-three patients with EA without previous cardiac surgery and 25 normal individuals were recruited and underwent both cardiac MR imaging and preoperative transthoracic echocardiography. The left ventricular (LV) functional parameters and dimensions of the right ventricle (RV) and LV were measured using 3.0-T cardiac MR imaging. Tricuspid regurgitation severity grading was estimated by echocardiography. The functional and dimensional parameters were compared between EA patients and controls using independent sample t-tests. Spearman's rank correlation was used to determine the correlations between the functional and dimensional parameters and tricuspid regurgitation. Receiver operating characteristic (ROC) analysis was used to predict tricuspid regurgitation severity using individual functional and dimensional parameters. RESULTS: Statistical analysis revealed significant differences in the functional and dimensional parameters between EA patients and controls. Within the EA group, tricuspid valve regurgitation negatively correlated well with the left ventricular ejection fraction (LVEF) (r=-0.558, p=0.001). The ratio of the right ventricular (functional right ventricle) end-diastolic dimension to the left ventricle end-diastolic dimension (RVEDD/LVEDD) in EA patients also correlated well with the severity of tricuspid valve regurgitation (r=0.492, p=0.004). Moreover, ROC analysis revealed that high sensitivity and specificity were obtained for predicting the severity of tricuspid valve regurgitation with LVEF (78.3%, 90.0%) and RVEDD/LVEDD (78.3%, 94.3%). CONCLUSION: In EA patients, the left and right ventricular functional and dimensional parameters from MRI correlated well with tricuspid regurgitation, which helped predict the severity of EA.

The regional myocardial microvascular dysfunction differences in hypertrophic cardiomyopathy patients with or without left ventricular outflow tract obstruction: assessment with first-pass perfusion imaging using 3.0-T cardiac magnetic resonance.

PURPOSE: To assess regional myocardial microvascular dysfunction differences in hypertrophic cardiomyopathy (HCM) patients with or without left ventricular outflow tract obstruction using 3.0-T cardiac magnetic resonance (CMR) first-pass perfusion imaging. MATERIALS AND METHODS: Forty-two HCM patients, including 25 HCM patients with left ventricular outflow tract obstruction (HOCM), 17 HCM patients without left ventricular outflow tract obstruction (NOHCM), and 14 healthy subjects underwent CMR. The left ventricular (LV) function, left ventricular end-diastolic wall thickness (EDTH), and diameter of left ventricular outflow tract (LVOT) were measured and calculated. Based on the signal-time curve of the first-pass myocardium perfusion imaging, perfusion parameters including upslope, time to peak, and peak intensity, were assessed and compared by using one-way analysis of variance and independent t tests. RESULTS: On the first-pass perfusion imaging, lower upslope and peak intensity and longer time to peak were found in HCM patients compared with normal subjects (all p<0.05). In contrast to the NOHCM group, the average time to peak of the HOCM group was increased (13.30 ± 4.82 s vs 16.28 ± 4.90 s, p<0.05), but first-pass perfusion upslope was reduced (4.96 ± 2.55 vs 2.58 ± 0.77, p<0.05). According to the bull's-eye model, the HOCM group's average thickness of basal segments was thicker than the NOHCM group, especially the anteroseptal, inferolateral, and anterior wall values, with a corresponding lower first-pass perfusion upslope than the NOHCM group (all p<0.05). A significant correlation was observed between first-pass perfusion upslope and LV EDTH (r=-0.551, p<0.001) and LVOT diameter (r=0.472, p<0.001). CONCLUSIONS: The regional myocardial microvascular dysfunction differences in hypertrophic cardiomyopathy (HCM) patients with or without left ventricular outflow tract obstruction can be detected with first-pass perfusion CMR imaging.

Assessing right ventricular function in patients with hypertrophic cardiomyopathy with cardiac MRI: correlation with the New York Heart Function Assessment (NYHA) classification.

PURPOSE: To determine whether 3.0-T magnetic resonance imaging (MRI) could assess right ventricular (RV) function in patients with hypertrophic cardiomyopathy (HCM), and if this assessment is correlated with the New York Heart Function Assessment (NYHA) classification. MATERIALS AND METHODS: Forty-six patients with HCM and 23 normal individuals were recruited. Left and right ventricular function parameters including end-diastolic and end-systolic volumes (EDV, ESV), stroke volume (SV) and ejection fraction (EF) and dimensions were measured and compared using 3.0-T MRI. RV function parameters between HCM patients and controls were compared using independent sample t tests. A one way ANOVA test with Bonferroni correction was used to determine significant differences among different NYHA groups. Receiver operating characteristic analyses calculated the sensitivity and specificity of RV dysfunction on MRI for the prediction of HCM severity. RESULTS: Statistical analysis revealed significant differences of left ventricular (LV) and RV volumetric values and masses between the HCM patients and controls (all p<0.05). Within the HCM group, the simultaneously decreased maximum RVEDD correlated well with the LVEDD (r = 0.53; p<0.001). The function and dimension parameters among Class I to III were not determined to be significantly different (all p>0.05). However, significant differences between the Class IV and I-III groups (all P<0.0167) indicated that the diastolic and systolic function in both the RV and LV were impaired in Class IV patients. ROC analyses identified the EDV, ESV and EDD of both the LV and RV with a high sensitivity cutoff value to predict the HCM patients with severe heart failure (Class IV) with high sensitivity and specificity. CONCLUSIONS: RV involvements were comparable to those of LV global function impairments in patients with HCM. The presence of RV dysfunction and decreased dimension on the MRI helped to predict the severe symptomatic HCM with high sensitivity and specificity.

Tuberculosis versus lymphoma in the abdominal lymph nodes: a comparative study using contrast-enhanced MRI.

PURPOSE: The purpose of this study was to determine the differential characteristics on MRI between tuberculosis and lymphoma in abdominal lymph nodes. MATERIALS AND METHODS: We conducted a retrospective analysis for the counter, size, signal intensity, enhancement patterns, and anatomic distribution of lymph nodes in 57 consecutive patients with documented tuberculosis (28 patients; 49.1%) and newly diagnosed, untreated lymphoma (29 patients; 50.9%). RESULTS: Twenty-four cases (85.7%) in the tuberculosis group were hyperintense on T2-weighted images and either hypointense or isointense on T1-weighted images with respect to the abdominal wall muscle. All cases in the lymphoma group were hyperintense on T2-weighted images and isointense on T1-weighted images with respect to the abdominal wall muscle. Concerning the main anatomic distribution of lymph nodes, the lymph nodes in the lower paraaortic region were more frequently involved in the lymphoma group (48.3%) than in tuberculosis (17.9%, p<0.05). Moreover, mesenteric lymph nodes were more often involved in tuberculosis (32.1%) than in lymphoma (6.9%, p<0.05). Tuberculous lymphadenopathy showed predominantly peripheral enhancement, frequently with a multilocular appearance; whereas lymphomatous adenopathy often demonstrated uniform homogeneous enhancement (all p<0.001). CONCLUSION: Contrast-enhanced MRI can be useful in differentiation between these two entities.