Assessment of operability by means of CTPA and perfusion SPECT in patients with chronic thromboembolic pulmonary hypertension

BackgroundChronic thromboembolic pulmonary hypertension (CTEPH) can potentially be cured by pulmonary thrombendarterectomy (PEA), the criteria for differentiation between operable and non-operable patients are not standardized.PurposeTo retrospectively evaluate the value of rigidly registered computed tomography pulmonary angiography (CTPA) and single photon emission CT (SPECT) in differentiating for PEA.Material and MethodsForty-nine patients with CTEPH (21 men; age, 58 ± 13 years) were evaluated by an interdisciplinary expert board using all available diagnostic information and their consensus statement as gold standard. For SPECT a lobe based perfusion score was visually assessed using the score of 0 (lack of perfusion) to 1 (normal perfusion) calculating percentage of vascular obstruction (PVO). By CTPA, vascular obstruction index (OI) of central, peripheral, and global PA-bed were determined. The accuracy of the alignment between CTPA and SPECT was determined by fusion score (FS) ranging from 1 (no a...