For suspected dilated cardiomyopathy, what is the preferred initial diagnostic imaging modality to assess cardiac structure and function?

• A. Chest radiography
• B. Echocardiography
• C. Cardiac MRI
• D. Electrocardiography

Answer: (B)

Transthoracic echocardiography is the initial imaging test of choice when dilated cardiomyopathy is suspected. It provides a real-time, noninvasive view of the heart’s structure and function, allowing you to see LV dilation and assess systolic performance with a calculated ejection fraction. You can also evaluate wall motion, regional abnormalities, valvular disease caused by dilation (such as mitral regurgitation or tricuspid regurgitation), and even detect LV thrombus. This modality is readily available, quick, safe, and free of radiation, making it ideal for establishing the diagnosis and guiding management.

Chest X-ray can hint at cardiomegaly but does not quantify function or structure precisely. ECG shows electrical activity and rhythm, not anatomy or mechanical function. Cardiac MRI offers excellent tissue characterization and can provide more accurate EF assessment and late gadolinium enhancement data, but it is more time-consuming, less accessible, and reserved for cases where echo results are nondiagnostic or when detailed tissue information is needed.