Cardiac magnetic resonance imaging of pericardial diseases: a comprehensive guide.

Cardiac magnetic resonance (CMR) imaging has been established as a valuable diagnostic tool in the assessment of pericardial diseases by providing information on cardiac anatomy and function, surrounding extra-cardiac structures, pericardial thickening and effusion, characterization of pericardial effusion, and the presence of active pericardial inflammation from the same scan. In addition, CMR imaging has excellent diagnostic accuracy for the non-invasive detection of constrictive physiology evading the need for invasive catheterization in most instances. Growing evidence in the field suggests that pericardial enhancement on CMR is not only diagnostic of pericarditis but also has prognostic value for pericarditis recurrence, although such evidence is derived from small patient cohorts. CMR findings could also be used to guide treatment de-escalation or up-titration in recurrent pericarditis and selecting patients most likely to benefit from novel treatments such as anakinra and rilonacept. This article is an overview of the CMR applications in pericardial syndromes as a primer for reporting physicians. We sought to provide a summary of the clinical protocols used and an interpretation of the major CMR findings in the setting of pericardial diseases. We also discuss points that are less well clear and delineate the strengths and weak points of CMR in pericardial diseases.