Single photon emission computed tomography in the diagnosis of pulmonary thromboembolism.

The use of single photon emission computed tomography (SPECT) as the procedure for screening, assessing the size and number of embolized areas, and evaluating the follow-up of patients with pulmonary thromboembolism (PTE) is reviewed. Details of the technique for acquiring and processing perfusion and ventilation lung SPECTs are presented. The tomographic images produced by SPECT allow the application of a less-expensive diagnostic algorithm than that classically used.

The lung as a metabolic organ.

Recently, the lung has received increasing attention as a metabolic organ. In this role, the lung modulates the composition of the arterial blood by several mechanisms: removing active substances from the plasma, releasing substances into the plasma, temporarily holding substances from circulation, and activating or inactivating substances that pass through the lungs. In this report, the procedures proposed by different investigators for in vivo noninvasive assessment of the lung metabolic functions are reviewed.