Restrictive cardiomyopathy
– Normal ventricular size and contractility
But a diastolic relaxation abnormality (Hallmark of restrictive CMP)
– Myocardial deposition of specific material
– Earilest form : neither dialated nor hypertrophied (seems like okay)
– Disease progressed : enlargement and a thick ventricular wall
Purpose of MR imaging of RCMP
– To determine phenotypes such as myocardial infiltrative disease
; amyloidosis, sarcoidosis, endomyocardial fibrosis, eosinophilic endocarditis
– To differentiat from constrictive perdicarditis
; RCM : thickening of myocardium including atriums (≥ 6mm)
; constrictive pericarditis : normal myocardium, thickening of pericardium (≥ 4mm), characteristic paradoxical septal motion
Cardiac sarcoidosis
What is cardiac sarcoidosis?
Multisystemic noncaseating granulomatous disease of unknown etiology with symptomatic cardiac involvement in 7% of patients.
Cardiac involvement indicates poor prognosiss: heart failure, conduction abnormalities (mainly atrioventricular block), sudden cardiac death → early diagnosis is important.
Three histological stages
: edema → noncaseating granulomatous infiltration → patchy myocardial fibrosis
Abnormal wall motion, Left ventricular dilatation or thinning
MRI findings of cardiac sarcoidosis
DE-MRI : Several patchy enhancement affecting basal, subepicardial layer
– very intense enhancement
– papillary muscle and RV area rarely involved
Role of cardiac MR in sarcoidosis
– Sensitive detection of myocardial involvement: cardiac MR can show three histological stages (edema, noncaseating granulomatous infiltration, and patchy myocardial fibrosis) on T2-weighted and delayed enhancement MRI
– Characteristic findings: preferential involvement of basal and subepicardial layer on delayed enhancement MRI
– Myocardial damage detected by delayed enhancement MRI is helpful in guiding endomyocardial biopsy as well as prognostication
Differential diagnosis
– Myocarditis
– Constrictive pericarditis
| Restrictive CMP | Constrictive pericarditis | |
| Etiology | Amyloidosis, Sarcoidosis… | Tuberculosis… |
| Myocardial wall thickening | ++ | ± |
| Pericardial wall thickening | ± | ++ (> 4 mm) |
| MRI finding | Global or Multiple patchy enhancement Combined MR, TR | No myocardial enhance, Pericardial enhancement and calcification Paradoxical septal motion |
Treatment
– Steroid therapy
Reference)
-Chest 2002;122;1895-1901
AJR 2005;184:249–254
RadioGraphics 2006; 26:795–810
