Visualization of the kidneys on Xe-133 ventilation images of a ventilation-perfusion scan

Ventilation-perfusion (V/Q) imaging was performed in a 36-year-old woman who had uncontrolled hypertension, chest pain, and shortness of breath. The findings of chest radiographs were normal. Multiple subsegmental perfusion defects were present bilaterally, with corresponding ventilation abnormalities. A moderate-sized matched defect was also present in the left upper lobe without an associated ventilation abnormality. An intermediate probability for pulmonary embolism was suggested. In addition, the kidneys were visualized on ventilation imaging. A review of her past imaging records indicated that an adenosine sestamibi myocardial scan had been performed 1 day earlier. There was no plausible explanation for renal visualization on ventilation images alone, and this resulted in further investigation. Finally, it was found that Tl-201 had replaced sestamibi as the tracer for the stress test because the latter agent was not available that day. Previous myocardial imaging with Tl-201 and fat absorption of xenon are some of the causes of renal visualization during ventilation scans.