Pericardial uptake of a gallium-67 scan - a case study

Full text: A 57-year-old female with large B cell lymphoma in the right neck and dyspnoea presented to our department for a Gated Heart Pool Scan (GHPS) and a 67Ga-citrate scan for initial staging. Following the GHPS, 259 M Bq of 67Ga-citrate was administered. At 72 hours post-injection, regional planar images as well as SPECT of the chest and abdomen were acquired. The scan showed intense tracer uptake in the right neck, corresponding to the known lymphoma. In addition, there is moderate gallium uptake surrounding both ventricles of the heart. Tomographic images of the chest confirm that the gallium activity appears to lie within the pericardium. The abnormal gallium uptake may be due to lymphomatous involvement or inflammatory pericarditis of any cause. The GHPS showed normal biventricular systolic and diastolic function, but also showed a pronounced cardiac silhouette surrounding both ventricles. A subsequent echocardiogram confirmed a mild to moderate pericardial effusion. Chest CT revealed a 7mm rim of low attenuation surrounding the heart suggesting the presence of a small pericardial effusion. The overall scan findings suggest that the increased tracer uptake in the pericardium on the gallium scan is consistent with an active pericarditis rather than lymphomatous involvement. Pericarditis has been reported on gallium scans in the nuclear medicine literature but it is a rare scan finding. This case unusual but interesting due to the fact that the active pericarditis (of an unknown cause) was found incidentally to staging a known lymphoma prior to chemotherapy. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc