Cardiac imaging in myocardial sarcoidosis and other cardiomyopathies.

PURPOSE OF REVIEW: The clinical role of emerging imaging technologies for diagnosing cardiac sarcoidosis and other cardiomyopathies is evolving. An up-to-date review of the role of various imaging modalities in the evaluation of cardiac sarcoidosis and other cardiomyopathies is presented.

RECENT FINDINGS: No study prospectively established the accuracy of each of the various techniques for diagnosing myocardial involvement in patients with suspected cardiac sarcoidosis. Cardiac magnetic resonance imaging (CMR) is demonstrated to have a sensitivity of 100% and specificity of approximately 80%, and positive predictive value of approximately 55% in diagnosing cardiac sarcoidosis. Recent studies have shown that 18F-2-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) has 100% sensitivity of detecting earlier stages of sarcoidosis. Both the FDG-PET and CMR may provide complementary information for the diagnosis and assessment of efficacy of therapy in patients with cardiac involvement from sarcoidosis.

SUMMARY: Clinical and subclinical cardiac involvement is common among patients with sarcoidosis. A structured clinical assessment incorporating advanced cardiac imaging with CMR and FDG-PET scanning is more sensitive than the established clinical criteria. CMR is an established imaging modality in the diagnosis of various other cardiomyopathies. Well designed prospective clinical trials are awaited to define the exact role of these imaging studies in the diagnosis and guidance of therapy.