CMR role in the diagnosis of eosinphilic endomyocradial fibrosis

A 40-year-old male patient presented with lower limb oedema, underwent echocardiography which revealed right atrial dilatation and right atrial mass.

For tumour characterisation:

T2WI with fat suppression, T1WI, first pass contrast study after injection of contrast 1, 5 and 10 minutes after contrast injection images were acquired.

For thrombus assessment: delayed post-contrast images were acquired with high inversion time (700 msec).

CMR findings

As regard the mass, there were 2 masses, intra-cavitary, larger one is seen in the right atrium and the smaller one is seen in the right ventricle apex. They showed well-defined outlines, not infiltrative, of low T1WI and T2WI signal in correlation to myocardium with no fatty component.

They showed no enhancement in the first pass perfusion, absent enhancement in early post contrast and delayed enhancement images with no central break down. There was no pericardial infiltration, no valve and no myocardial infiltration.

The large right atrial one measured 6.8 x 5.7 x 4.3 cm in CC x AP x transverse respectively. 15 mm distance above the tricuspid valve annulus. The right ventricular one measured 21 x 7 mm.

Pattern suggestive of benign mass lesions, mostly thrombi.

• As regard the remaining cardiac assessment there was a pattern suggestive of underlying hypereosinophilic syndrome with cardiac involvement. 

Endomyocardial fibrosis affects approximately 12 million persons worldwide and is an important cause of restrictive cardiomyopathy in the developing world. It is characterised by apical filling with fibrotic tissue of one or both ventricles (1).

There are well defined known diagnostic criteria of eosinophilic endomyocardial fibrosis by echocardiography which are;

Major criteria (2)

• Endomyocardial plaques >2 mm in thickness
• Thin (≤1 mm) endomyocardial patches affecting more than one ventricular wall
• Obliteration of the right ventricular or left ventricular apex
• Thrombi or spontaneous contrast without severe ventricular dysfunction
• Retraction of the right ventricular apex (right ventricular apical notch)
• Atrioventricular-valve dysfunction due to adhesion of the valvular apparatus to the ventricular wall

Minor criteria (2)

• Thin endomyocardial patches localised to one ventricular wall
• Restrictive flow pattern across mitral or tricuspid valves
• Pulmonary-valve diastolic opening
• Diffuse thickening of the anterior mitral leaflet
• Enlarged atrium with normal-size ventricle
• M-movement of the interventricular septum and flat posterior wall
• Enhanced density of the moderator or other intraventricular bands

• Despite the high diagnostic standard of CMR yet, no consensus as regard diagnostic criteria for endomyocardial fibrosis. In our case we fulfilled echo criteria sufficient for diagnosis plus the tissue characterisation of CMR as regard:

• Endomyocardial thick plaque.
• Resting bi-ventricular subendocardial apical perfusion defect.
• Bi-ventricular apical edema.
• Obliteration of the right ventricular or left ventricular apex.
• Definite fibrosis by delayed enhancement images.
• Retracted right ventricular apex with notch.
• Restrictive right ventricular filling.
• Tricuspid and mitral regurgitation.

 (3) and (4).

This means that there are CMR diagnostic criteria can help and add to echocardiography in case of equivocal cases, obese patients and poor echocardiographic window.

Differential diagnoses are hypertrophic cardiomyopathy but it is excluded as it doesn’t include obliterated apex or apical notch, it was not a tumor as delayed enhancement images revealed absent enhancement supporting thrombi and it was not a simple primary restrictive cardiomyopathy as it fulfilled the diagnostic criteria of endomyocardial fibrosis.

Teaching point:

Endomyocardial fibrosis is a rare type of restrictive cardiomyopathy characterised by progressive interstitial fibrosis involving the Endo-myocardium of ventricles, it has a diagnostic echocardiography checklist of major and minor criteria, yet, there is no consensus about the additive value of tissue characterisation by CMR.