Cardiac Magnetic Resonance Evaluation of Cardiac Masses in Patients with Suspicion of Cardiac Masses on Echo or Computed Tomography

Objectives: In recent years, cardiac magnetic resonance (CMR) imaging has emerged as an important tool in the identification and characterization of cardiac masses. No imaging data on cardiac masses are available from Pakistan. We aimed to review the clinical presentation, CMR findings, and outcome of patients referred for CMR due to suspicion of cardiac masses on echocardiogram or computed tomography (CT).

Material and methods: We reviewed all the patients referred for CMR at Aga Khan University Hospital, Karachi, from January 2011 to March 2020, with the suspicion of cardiac mass on echocardiogram and/or CT. Only those with the confirmed diagnosis of cardiac mass on CMR were included in the study.

Results: A total of 27 patients were referred for CMR from January 2011 to March 2020, with the suspicion of cardiac mass on echocardiogram and/or CT. Four patients were excluded as no cardiac mass was found on CMR. Out of 23 cases, majority (n = 15, 65%) were female, age ranging from 3 months to 70 years, with a mean age of 40 ± 22 years. Shortness of breath was the main presenting symptom (n = 19, 83%). Echocardiogram was the initial imaging modality done in all the patients while CT was also performed in 6 patients (26%). Out of 23 patients, 4 (17%) were diagnosed to have thrombus on CMR. In two cases, it was in the left ventricle with evidence of myocardial infarction on late gadolinium images. Myxoma was the most common tumor diagnosed on CMR in 6 patients (26%) followed by rhabdomyoma (n = 3, 13%) and fibroma (n = 2, 8.7%). There were three malignant primary tumors of the heart based on CMR appearances and one with tumor thrombus extension of hepatocellular carcinoma in the right atrium from inferior vena cava. Two patients were diagnosed to have non-neoplastic lesions - one with large intracardiac hydatid cyst and one with possible large fungal vegetation. Among 23 patients, 9 patients (39%) underwent surgery, 5 with myxoma, 2 with rhabdomyoma, 1 with fibroma, and 1 with fibroelastoma. Findings on surgery and histopathology matched the CMR diagnosis in all the patients except the one with the CMR diagnosis of myxoma in which histopathology was consistent with thrombus.

Conclusion: CMR can play an important role in confirming the presence or absence of a mass in the heart. It can also provide differentiation of non-neoplastic and neoplastic lesions and among different types of neoplastic lesions with reasonable accuracy. However, the limitations of CMR must be recognized.

Keywords: Cardiac imaging; Cardiac magnetic resonance; Cardiac masses; Cardiac tumors; Pakistan.