Magnetic Resonance Imaging of the Thoracic Aorta

Magnetic resonance imaging (MRI) is well-suited for imaging the vascular system and is of particular value in assessing the anatomy and pathologies of the thoracic aorta. The intrinsic contrast between the blood pool and the vascular structures allows excellent depiction of intra- and extravascular anatomy and eliminates the need for intravenous contrast agents. A large field of view provides a complete evaluation of the mediastinum and chest. Both qualitative and quantitative techniques are available, which can yield physiological data in addition to anatomical information. The multiplanar capability offers images in any plane, allowing an accurate assessment of the longitudinal extent of disease and providing images perpendicular to vessels, even when tortuous. MRI currently represents an essential component of the imaging strategies available to assess the thoracic aorta and may come to function as a gold standard for certain conditions. As the technology continues its rapid evolution, MRI will most likely be able to serve as an effective noninvasive evaluation to provide all of the anatomical, pathological, and physiological information required of a comprehensive examination of the thoracic aorta.     

Magnetic Resonance Imaging in Pediatric Pulmonary Hypertension

The present study aims to determine the efficacy and reliability of cardiovascular magnetic resonance imaging in establishing the diagnosis and prognosis of pulmonary hypertension in children.This is a retrospective comparison of 25 children with pulmonary hypertension and a control group comprising 19 healthy children. The diagnosis of pulmonary hypertension was made when the mean pulmonary artery pressure was ≥25 mmHg by catheter angiography.The children with pulmonary hypertension had significantly lower body mass indices than did the healthy children (P=0.048). In addition, the children with pulmonary hypertension had significantly larger main pulmonary artery diameters and ascending aortic diameters (both P=0.001) but statistically similar ratios of main pulmonary artery diameter-to-ascending aortic diameter. If the main pulmonary artery diameter was ≥25 mm, pediatric pulmonary hypertension was diagnosed with 72% sensitivity and 84% specificity. In the event that the ratio of main pulmonary artery diameter-to-ascending aorta diameter was ≥1, pediatric pulmonary hypertension was diagnosed with 60% sensitivity and 53% specificity. When compared with children who had New York Heart Association functional class II pulmonary hypertension, the children with functional class III pulmonary hypertension had significantly larger main (P=0.046), right (P=0.036), and left (P=0.003) pulmonary arteries.Cardiovascular magnetic resonance imaging is useful in the diagnosis of children with pulmonary hypertension. Pediatric pulmonary hypertension can be diagnosed with high sensitivity and specificity when the main pulmonary artery diameter measures ≥25 mm.     

Pulmonary varix: Magnetic resonance findings

The magnetic resonance appearance of a confluent-type pulmonary varix Is correlated with computed tomography and angiographic findings. This case demonstrates the usefulness of magnetic resonance in the evaluation of cardiovascular lesions.     

Usefulness of Cardiovascular Magnetic Resonance Imaging in a Patient with Cardiac Involvement of Systemic Sclerosis

A 72-year-old Japanese woman with systemic sclerosis was admitted to our hospital because of symptoms of heart failure. Cardiovascular magnetic resonance (CMR) imaging had shown that extensive myocardial fibrosis secondary to systemic sclerosis was the main cause of heart failure. One month after CMR, she had complete atrioventricular (AV) block. It was suggested that the progression of fibrosis to the AV node caused complete AV block. This case report has clinical implications in highlighting the fact that CMR is useful for not only evaluating the present pathophysiology but also predicting future adverse events in patients with systemic sclerosis.     

Quantification of Myocardial Area at Risk: Validation of Coronary Angiographic Scores With Cardiovascular Magnetic Resonance Methods

Introduction and objectives

Quantification of myocardial area-at-risk after acute myocardial infarction has major clinical implications and can be determined by cardiovascular magnetic resonance. The Bypass Angioplasty Revascularization Investigation Myocardial Jeopardy Index (BARI) and Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) angiographic scores have been widely used for rapid myocardial area-at-risk estimation but have not been directly validated. Our objective was to compare the myocardial area-at-risk estimated by BARI and APPROACH angiographic scores with those determined by cardiovascular magnetic resonance.

Methods

In a prospective study, cardiovascular magnetic resonance was performed in 70 patients with a first successfully-reperfused ST-segment elevation acute myocardial infarction in the first week after percutaneous coronary intervention. Myocardial area-at-risk was obtained both by analysis of T2-short tau inversion recovery sequences and calculation of infarct endocardial surface area with late enhancement sequences. These results were compared with those of BARI and APPROACH scores.

Results

BARI and APPROACH showed a statistically significant correlation with T2-short tau inversion recovery for myocardial area-at-risk estimation (BARI, intraclass correlation coefficient=0.72; P<.001; APPROACH, intraclass correlation coefficient=0.69; P<.001). Better correlations were observed for anterior acute myocardial infarction than for other locations (BARI, intraclass correlation coefficient=0.73 vs 0.63; APPROACH, intraclass correlation coefficient=0.68 vs 0.50). Infarct endocardial surface area showed a good correlation with both angiographic scores (BARI, intraclass correlation coefficient=0.72; P<.001; with APPROACH, intraclass correlation coefficient=0.70; P<.001).

Conclusions

BARI and APPROACH angiographic scores allow reliable estimation of myocardial area-at-risk in current clinical practice, particularly in anterior infarctions.