This is comparable to a prior study by Tunariu et al [36], which found that V/Q scintigraphy was more sensitive than multidetector CTPA in detecting chronic thromboembolic pulmonary disease amenable to surgery, with V/Q scans demonstrating a sensitivity of 96% to 97% and a specificity of 90% to 95% compared with a sensitivity of 51% and specificity of 99% for multidetector CTPA. However, a study that compared V/Q scanning versus CTPA by He et al [37] showed both techniques had good sensitivity, specificity, and accuracy at a center with significant CTEPH experience (100% versus 92%, 94% versus 95%, and 97% versus 94%, respectively). Compared with planar V/Q scanning, V/Q single-photon emission CT improves sensitivity and specificity, resulting in an accuracy of 94% [38]. The slightly lower specificity of V/Q scintigraphy relative to multidetector CTPA is secondary in patients with idiopathic Suspected Pulmonary Hypertension PAH (IPAH) in whom abnormal V/Q scans can also be demonstrated whom can also demonstrate abnormal V/Q scans [33,38]. Although V/Q scintigraphy has excellent sensitivity for CTEPH, its greatest power lies with its negative predictive value. A normal or low-probability scan essentially excludes the diagnosis of CTEPH, although the V/Q scan may be normal in other causes of PH [10,24,33]. CT Chest CT chest is another noninvasive technique that can assess for PH. CT chest can be performed with or without intravenous (IV) contrast but is ideally performed with IV contrast to adequately visualize the pulmonary vasculature. CT chest without IV contrast is not a first-line test for suspected PH but may be useful to help look for etiologies of PH in patients who already hold a diagnosis of PH. There are no data support obtaining a CT chest with and without IV contrast in the setting of suspected PH.
Suspected Pulmonary Hypertension. This is comparable to a prior study by Tunariu et al [36], which found that V/Q scintigraphy was more sensitive than multidetector CTPA in detecting chronic thromboembolic pulmonary disease amenable to surgery, with V/Q scans demonstrating a sensitivity of 96% to 97% and a specificity of 90% to 95% compared with a sensitivity of 51% and specificity of 99% for multidetector CTPA. However, a study that compared V/Q scanning versus CTPA by He et al [37] showed both techniques had good sensitivity, specificity, and accuracy at a center with significant CTEPH experience (100% versus 92%, 94% versus 95%, and 97% versus 94%, respectively). Compared with planar V/Q scanning, V/Q single-photon emission CT improves sensitivity and specificity, resulting in an accuracy of 94% [38]. The slightly lower specificity of V/Q scintigraphy relative to multidetector CTPA is secondary in patients with idiopathic Suspected Pulmonary Hypertension PAH (IPAH) in whom abnormal V/Q scans can also be demonstrated whom can also demonstrate abnormal V/Q scans [33,38]. Although V/Q scintigraphy has excellent sensitivity for CTEPH, its greatest power lies with its negative predictive value. A normal or low-probability scan essentially excludes the diagnosis of CTEPH, although the V/Q scan may be normal in other causes of PH [10,24,33]. CT Chest CT chest is another noninvasive technique that can assess for PH. CT chest can be performed with or without intravenous (IV) contrast but is ideally performed with IV contrast to adequately visualize the pulmonary vasculature. CT chest without IV contrast is not a first-line test for suspected PH but may be useful to help look for etiologies of PH in patients who already hold a diagnosis of PH. There are no data support obtaining a CT chest with and without IV contrast in the setting of suspected PH.