RADIONUCLIDE ANGIOGRAPHY AND MAGNETIC-RESONANCE-IMAGING - COMPLEMENTARY NONINVASIVE METHODS IN THE DIAGNOSIS OF CONSTRICTIVE PERICARDITIS

Constrictive pericarditis presents with a suggestive clinical picture? and its diagnosis is based on a haemodynamic pattern revealing impair ed ventricular filling. In this study of 15 patients with pure isolate d constrictive pericarditis, we attempted to evaluate the diagnostic v alue of two non-invasive methods not usually employed in this indicati on: radionuclide angiography (RNA) and magnetic resonance imaging (MRI ). Whilst RNA permits analysis of the functional pattern of the global and segmental left ventricular filling impairment, MRI allows measure ment of the thickness of the pericardium. RNA revealed increased early diastolic filling as evidenced by a shorter one-third filling time (T F1/3; P<0.0001 with respect to a normal population), a higher peak fil ling rate (PFR; P<0.01) and its early occurrence (P<0.001), increased one-third and mid diastolic filling fractions (P<0.01), and the ratio of the PFR over the peak ejection rate (P<0.01). During late diastole, the atrial filling fraction decreased (NS). The patients with constri ctive pericarditis also showed a decrease in the physiological filling asynchrony, as assessed by segmental evaluations. Seven patients unde rwent MRI. The pericardium was thickened in all the patients, varying from 6 to 14 mm (normal: 2.5+/-0.7 mm), without any systolo-diastolic variation. Pericardial thickening appeared as a dark low-intensity sig nal band, demonstrating the fibro-calcific nature of the pericardial c ontents. Sagittal and coronal cross-sections were particularly well-su ited to show the non-uniformity of the pericardial thickening. These r esults indicate that RNA and MRI are complementary non-invasive method s, and can provide the functional and anatomical information required for the diagnosis of constrictive pericarditis.