FIGURE 1. A 77-y-old man with adenocarcinoma of right upper lobe. (A) CT scan shows primary tumor (double arrow) and enlarged paratracheal lymph nodes (single arrows). (B) ^99mTc-Tetrofosmin SPECT in transaxial view demonstrates wide area of increased abnormal uptake corresponding to primary tumor (double arrow). Focal area of increased uptake corresponding to paratracheal metastatic lymph nodes (single arrow) was also observed in anterior upper right mediastinum.