Right atrioventricular valve atresia: anatomic evaluation with MR imaging

Area of Science:

• Cardiovascular Imaging
• Pediatric Cardiology
• Congenital Heart Disease

Background:

• Tricuspid atresia presents in various forms, including classical absence of atrioventricular connection, imperforate valve, and Ebstein's malformation.
• Accurate differentiation of these conditions is crucial for appropriate clinical management and surgical planning.
• Distinguishing between these entities using imaging can be challenging.

Purpose of the Study:

• To evaluate the utility of Magnetic Resonance (MR) imaging in differentiating classical tricuspid atresia from other forms of right atrioventricular obstruction.
• To identify specific MR imaging features that aid in the diagnosis of different tricuspid atresia subtypes.

Main Methods:

• ECG-gated, T1-weighted spin-echo MR imaging was performed at 0.3 or 1.0 Tesla.
• Imaging was conducted on patients with classical tricuspid atresia, imperforate tricuspid valve, and Ebstein's malformation.
• Postmortem examination of hearts was used for correlation.

Main Results:

• Classical tricuspid atresia showed increased MR signal intensity in the atrioventricular sulcus due to epicardial fat, separating the right atrium and ventricular mass.
• Patients with imperforate tricuspid valve or Ebstein's malformation had normal-appearing atrioventricular sulci on MR imaging.
• Postmortem findings confirmed epicardial fat in the atrioventricular sulcus in classical tricuspid atresia, absent in Ebstein's malformation.

Conclusions:

• The characteristic MR appearance of epicardial fat adjacent to the right atrium aids in identifying the atrioventricular sulcus.
• MR imaging can reliably differentiate classical tricuspid atresia from imperforate tricuspid valve and Ebstein's malformation.
• This imaging approach enhances diagnostic accuracy for right atrioventricular valve atresia.