CMR in Cardiac Sarcoidosis

Cardiac involvement is found at autopsy in 20-30% of patients diagnosed with sarcoid and is felt to play a role in sudden death. Recent research has shown that one can find evidence of cardiac sarcoid on MRI in patients with normal echocardiograms.

Echocardiography in cardiac sarcoid shows septal thinning, systolic and diastolic LV dysfunction. There are multiple findings on MR in patients with cardiac sarcoidosis. MR may help with early diagnosis of cardiac sarcoidosis.

Delayed hyperenhancement
Delayed hyperenhancement is consistent with inflammatory or fibrotic areas. Specifically, the regions of hyperenhancement in patients with sarcoidosis do not correspond to a coronary artery territory.

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In a study by Patel et al of 58 consecutive patients with biopsy proven systemic sarcoidosis patients had a two fold higher rate of cardiac involvement by CMR diagnosis than by the Japanese Ministry of Health clinical criteria.
 * Hyperenhancement was found in the mid-myocardial wall or epicardium (ie non-ischemic)

It has also been shown that contrast enhancement decreases in these patients following steroid therapy. (Shimada et al.)

LV dysfunction
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Contrast accumulation
This typically occurs in the intramyocardial and subepicardial layers

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Transmural scarring and thinning of the basal septum
Transmural scarring and thinning of the basal septum is a common finding in patients with cardiac sarcoidosis.

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Javier Sanz reported on a 47 year old woman with recent diagnosis of sarcoidisis. She underwent cardiac MR which revealed transmural scarring. Pubmed image1 - reference Sanz, Javier in Eur Heart Jour

Endomyocardial biopsy subsequently showed areas of focal necrosis that could explain the MR findings.

Ventricular Tachycardia and Cardiac Sarcoidosis
A clinical vignette published by Redheuil and collegues showed the association of ventricular tachycardia and cardiac sarcoidosis using MR to show the relationship.

A 44 year old female with histologically proven pulmonary and mediastinal sarcoidosis who presented with palpitations followed by syncope. MR findings were as follows:
 * Marked delayed enhancement of the basal lateral wall of the RV, basal anteroseptal and basal, mid LV and apical anterior epicardium of the LV.
 * Endocavitary ventricular stimulation induced 2 VT morphologies. The first was compatible with VT originating from the basal lateral wall of the RV and the second was compatible with VT originating from teh basal anteroseptal and or anterior segments of the LV.