Which imaging modality is commonly used to assess cardiac involvement in heartworm disease?

• A. X-ray alone
• B. CT without contrast
• C. MRI without contrast
• D. Echocardiography

Answer: (D)

Echocardiography. This ultrasound-based imaging lets clinicians visualize heart chambers in real time and directly see any worms within the right atrium or ventricle and potentially in the pulmonary arteries. It also assesses heart function, chamber sizes, valve function (such as tricuspid regurgitation), and signs of pulmonary hypertension, all of which are key for evaluating cardiac involvement in heartworm disease.

Other imaging methods can provide supportive information but don’t directly reveal the worms or cardiac function as effectively. X-ray can hint at thoracic changes, like enlarged pulmonary arteries or interstitial patterns, but it isn’t definitive for worm visualization. CT or MRI without contrast are less routinely used for this purpose due to cost, availability, and limited added value in most cases.