The use of spectral-detector computed tomography (SDCT) offers a highly accurate method for diagnosing chronic thromboembolic pulmonary hypertension (CTEPH) and should be considered a primary tool in the diagnostic workup of patients with suspected pulmonary hypertension (PH). A retrospective study was conducted in German patients and the results were published in the International Journal of Cardiology.

Recognizing that SDCT allows for comprehensive analysis of the pulmonary vasculature, lung parenchyma, and pulmonary perfusion in a single examination, investigators sought to evaluate whether the additional information provided by SDCT is helpful in the diagnosis of PH, the differentiation of disease subgroups, and the prediction of disease severity.

A total of 60 patients (mean age, 64.6 years) with suspected PH underwent SDCT. Additional diagnostic tests were also performed, including right heart catheterization and ventilation-perfusion single-photon emission computed tomography (VQ-SPECT). Following a complete diagnostic workup, participants were classified into 5 subgroups: precapillary PH (n=21), postcapillary PH (n=5), combined precapillary and postcapillary PH (n=6), CTEPH (n=19), and no PH (n=9). The SDCT examinations were evaluated by 2 blinded readers who determined the diagnosis of CTEPH and scored the extent of perfusion abnormalities.

Using SDCT data, both readers attained a sensitivity of 100% with specificities of 95.1% and 87.8%, respectively, compared with the diagnostic ability of the VQ-SPECT. In contrast, when computed tomography pulmonary angiography images alone were analyzed, the specificity and diagnostic confidence decreased for both readers (specificities, 90.2% and 85.3%), whereas the sensitivity dropped for the less experienced reader only (78.9%).

Patients with PH demonstrated significantly more perfusion abnormalities than did those without PH (16.6±8.4 vs 9.5±8.9; P <.001). The extent of perfusion abnormalities correlated with the mean pulmonary artery pressure (r=0.37; P =.008), demonstrating a weak but significant association.

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The investigators concluded that in the future, the use of more sophisticated quantitative analyses might help to better differentiate between etiologies and disease severities in patients with PH. The use of SDCT holds promise as a “one-stop study” for patients with PH and has the potential to render V/Q scintigraphy obsolete.

Reference

Kröger JR, Gerhardt F, Dumitrescu D, et al. Diagnosis of pulmonary hypertension using spectral-detector CT [published online March 13, 2019]. Int J Cardiol. doi:10.1016/j.ijcard.2019.03.018