MRI and echocardiography in children: how do they compare?

Magnetic resonance imaging of AMS (Aneurysm of the Membranous Septum), review of the literature and case report

Aneurysm of the Membranous Septum (AMS) is a rare cardiac disease, mostly associated with other cardiac anomalies, very rare in the absence of other congenital heart defects. A prompt diagnosis is important, due to severe potential complications, but remain challenging. Most of the cases were earlier diagnosed using ventriculography, but, with the availability of echocardiography and cardiovascular magnetic resonance (CMR), this disease can be accurately assessed non-invasively. We report a case of a 62 years old female patient, without other cardiac congenital disease, who was incidentally diagnosed, by means of CMR with a true and isolated AMS. Our report underlines CMR usefulness in AMS diagnosis, thanks to accurate evaluation (both morphologic and functional) provided by this diagnostic tool, which is able to demonstrate clearly the presence of AMS (aneurysm of the membranous septum) and depict its features.

Clinical feasibility of free-breathing, gadolinium-enhanced magnetic resonance angiography for assessing extracardiac thoracic vascular abnormalities in young children with congenital heart diseases

OBJECTIVE

Congenital heart diseases in pediatric patients are associated with a wide variety of extracardiac thoracic vascular abnormalities. This study analyzed the value of gadolinium-enhanced magnetic resonance angiography during quiet free breathing for assessing extracardiac thoracic vascular abnormalities in young children with congenital heart diseases.

METHODS

Fifty-three children with congenital heart diseases (age range, 1 day-40 months; mean, 10.9 months) associated with extracardiac thoracic vascular abnormalities who had undergone both free-breathing, gadolinium-enhanced magnetic resonance angiography and cardiac catheterization, surgical intervention, or both within 2 weeks were reviewed. Diagnostic findings on gadolinium-enhanced magnetic resonance angiography among patients grouped according to 3 major conditions of conotruncal abnormalities (n = 33), aortic or venous abnormalities (n = 11), and pulmonary vascular abnormalities (n = 9), as well as associated extracardiac thoracic vascular abnormality findings, were compared with findings made by using cardiac catheterization, surgical intervention, or both.

RESULTS

Extracardiac thoracic vascular abnormality findings on gadolinium-enhanced magnetic resonance angiography were similar to those on catheterization, surgical intervention, or both in patients with conotruncal abnormalities (124 vs 127, P = .083), aortic or venous abnormalities (36 vs 33, P = .083), and pulmonary vascular abnormalities (24 vs 25, P = .317). The overall sensitivity of gadolinium-enhanced magnetic resonance angiography for detection of these lesions identified by means of catheterization, surgical intervention, or both was 97.9%. However, gadolinium-enhanced magnetic resonance angiography revealed 11 additional extracardiac thoracic vascular abnormalities that were not found on cardiac catheterization. The kappa coefficient for the correlation of image quality and diagnostic value of gadolinium-enhanced magnetic resonance angiography by using a 4-point-scale (1 = nondiagnostic to 4 = excellent) assessed by 2 independent reviewers was excellent (mean score = 3.66), with superb interobserver agreement (kappa = 0.727-0.874).

CONCLUSIONS

Free-breathing, gadolinium-enhanced magnetic resonance angiography is clinically feasible for detailed anatomic delineation and treatment planning of various extracardiac thoracic vascular abnormalities in young children with congenital heart diseases.

Right ventricular function late after total repair of tetralogy of Fallot

Over the past decades, life expectancy in patients with congenital heart disease has increased dramatically. However, serious complications may develop late after total repair in infancy. These complications are usually the result of longstanding pulmonary regurgitation, which leads to dilatation of the right ventricle and an increased risk for severe arrhythmias. Therefore lifelong follow-up in these patients is required. Cardiac magnetic resonance imaging is the current imaging tool of choice because it offers superior imaging quality and enables accurate quantification of functional parameters such as flow volumes and systolic and diastolic performance.

Postoperative evaluation of congenital heart disease by magnetic resonance imaging

In the last four decades the survival of patients with corrected or palliated congenital heart disease has increased dramatically. However, post-operative abnormalities frequently occur and therefore a noninvasive imaging tool is mandatory for the timely detection of morphological as well as functional abnormalities. Magnetic resonance imaging (MRI) is ideally suited for the noninvasive diagnosis and post-operative follow-up of congenital heart disease. Spin-echo MRI is able to visualize structures that may be difficult to assess with other noninvasive image modalities and is sensitive in the detection of post-interventional stenoses or aneurysms. Because the function of the ventricles may deteriorate over time after correction or palliation of a congenital cardiac malformation, the use of gradient-echo MRI is essential in the follow-up after correction or palliation, as no other conventional technique allows such detailed evaluation of ventricular function, without geometrical assumptions. Phase-contrast MRI is well suited to assess valvular function, allowing accurate measurement of regurgitation or stenosis. Shunt quantification is another application of phase-contrast MRI. J. Magn. Reson. Imaging 1999;10:656-666.