CT in tuberculous constrictive pericarditis

Constrictive pericarditis (CP) and restrictive cardiomyopathy have the same pathophysiological disorder (impaired diastolic filling) and a similar presentation. To determine the value of a noninvasive technique, CT, in differentiating between the two, we reviewed the CT scans of 212 patients with clinical signs and symptoms of CP and/or restrictive cardiomyopathy, after 26 cases that did not proceed to surgery were excluded. Computed tomography showed pericardial thickening (greater than 3 mm) in 157 patients with proven tuberculous CP. In two children with proven constriction, the pericardium measured between 2 and 3 mm. We determined that pericardial thickening, in the correct clinical setting, is the only CT sign necessary to diagnose CP. Other CT signs, inferior vena cava dilatation (97%), and deviation of the interventricular septum (15%) were confirmatory. Computed tomography accurately differentiates between CP and restrictive myocardial disease, making more invasive modalities such as cardiac catheterization and endomyocardial biopsy, with few exceptions, unnecessary.