[Diagnostic capabilities of single-photon emission computed tomography/computed tomography in the evaluation of perfusion disorders in pulmonary hypertension]

to study the diagnostic capabilities of single-photon emission computed tomography/computed tomography (SPECT/ CT) in the evaluation of lung perfusion in pulmonary hypertension (PH).

Ten patients with pulmonary hypertension were examined. Its diagnosis was verified in accordance with the Russian guidelines for the diagnosis and treatment of PH, by conducting a set of studies involving right heart catheterization. CT angiopulmonography was carried out in all the patients. At the same time all the patients underwent a radiological study on a combined SPECT/CT scanner with the intravenous injection of the radiotracer 9mTc-MAA (technetium-99m-labelled macroaggregated albumin) with an activity of 2-4 mCi.

CT-angiopulmonography revealed no thrombi in the pulmonary artery lumen in 7 patients and confirmed the diagnosis of pulmonary thromboembolism (PTE) at the level of segmental vessels in 3. SPECT/CT examination identified 5 cases of non-thromboembolic PH and 5 cases of PTE with consideration for SPECT perfusion defects and no visible lung tissue (fibrous or other) changes on a CT scan. It should be noted that the 5 patients diagnosed as having PTE included 2 patients in whom PTE had not previously been diagnosed at CT angiopulmonography. This may be due to that this technique cannot always clearly visualize thrombi in the pulmonary vessel lumen at a subsegmental level.

The inivestigations have indicated that, by clearly ivisualizing pulmonary aanatomy, morphology, and function, combined SPECT/CT imaging is a valuable diagnostic tool in detecting lung pathology.