A Rare Case of Isolated Pericardial Effusion Detected by SPECT/CT on a Post-Therapeutic Radioiodine Whole-Body Scan.

We reported a rare finding of isolated pericardial uptake detected by SPECT/CT on posttherapeutic radioiodine whole body scan. This case highlights the usefulness of hybrid SPECT/CT, with subsequent correlation with biochemical results, in ruling out metastatic pericardial effusion in the postsurgical radioiodine remnant ablation setting. The effusion was resolved after reinstituted thyroid replacement therapy. Recombinant thyrotropin is recommended to avoid such rare but life-threatening complication.