What is best for double-orifice mitral valve (DOMV), MRI or CT cardiac?

Cardiac MRI is Superior to CT for Double-Orifice Mitral Valve Evaluation

For double-orifice mitral valve (DOMV), cardiac MRI is the preferred imaging modality over CT due to its superior ability to assess valve morphology, quantify regurgitation, and evaluate ventricular function without radiation exposure.

Advantages of Cardiac MRI for DOMV

• MRI offers unrestricted access to cardiovascular anatomy and function without ionizing radiation, making it well-suited for repeated, lifelong follow-up investigations in DOMV patients 1
• MRI provides versatile measurements of biventricular size and function regardless of chamber geometry, flow volumes, and tissue characterization - critical for DOMV assessment 1
• MRI demonstrates superior multiplanar capacity in demonstrating leaflet morphology and motion, less dependent on patient anatomy than echocardiography 1
• MRI can accurately quantify mitral regurgitation (common in DOMV) with better correlation to post-surgical left ventricular remodeling (r = 0.85, P < .0001) than echocardiography (r = 0.32; P = .1) 1
• MRI provides high inter- and intrareader reproducibility with semiautomated flow measurement, essential for accurate DOMV evaluation 1

Limitations of CT for DOMV

• CT exposes patients to ionizing radiation, making it unsuitable for repeated examinations in young patients with congenital anomalies like DOMV 1
• CT has less versatile tissue characterization compared to MRI, limiting its ability to evaluate the complex valve morphology in DOMV 1
• CT has inferior ability to evaluate cardiovascular physiology and relies on radio-opaque contrast agents 1
• While CT offers excellent spatial resolution, it has lower temporal resolution than MRI for evaluating valve function 1

Clinical Decision Algorithm for DOMV Imaging

1. Initial evaluation with transthoracic echocardiography (TTE) as first-line imaging 1, 2

   • TTE is reliable and sufficient in most cases to diagnose DOMV and determine its type 2
   • Can identify the presence of two orifices and chordal attachments to papillary muscles 3

2. When to proceed to advanced imaging:

   • When echocardiographic study is suboptimal or unable to provide images of sufficient quality 1
   • When echo measurements are borderline or ambiguous 1
   • When there is discrepancy between clinical presentation and echocardiographic findings 4

3. Choose MRI over CT when:

   • Detailed assessment of valve morphology and function is needed 1
   • Quantification of mitral regurgitation is required (common in DOMV) 1, 2
   • Evaluation of ventricular function and remodeling is necessary 1
   • Patient requires long-term follow-up (especially younger patients) 1
   • There is need to assess tissue characteristics or fibrosis 4

4. Consider CT only when:

   • MRI is contraindicated (e.g., pacemaker, defibrillator) 1
   • Rapid acquisition is necessary (e.g., unstable patient) 1
   • Coronary artery evaluation is the primary concern 5

Important Clinical Considerations

• DOMV is often associated with other congenital heart defects, particularly atrioventricular canal defects (AVCD), requiring comprehensive evaluation 6, 7
• Mild to moderate mitral regurgitation is present in most DOMV cases, with some developing moderate to severe mitral stenosis 2
• The incidence of DOMV is estimated at only 0.01% in adult tertiary referral echocardiographic laboratories 2
• Advanced MRI techniques like 4D flow analysis can provide insights into complex flow patterns in DOMV with regurgitation 4
• Surgical management of DOMV depends on accurate imaging assessment of valve morphology, regurgitation severity, and associated defects 6, 7

Common Pitfalls to Avoid

• Relying solely on echocardiography when images are suboptimal or findings are ambiguous 1, 4
• Using CT as the primary advanced imaging modality due to radiation exposure concerns, especially in younger patients who need repeated follow-up 1
• Overlooking the prognostic value of tissue characterization that MRI provides in management decisions 4
• Failing to assess for associated congenital anomalies that frequently accompany DOMV 6, 7
• Underestimating the hemodynamic significance of mitral regurgitation in DOMV, which MRI can more accurately quantify 1, 8