Multiple historic studies have shown that chest radiography is a useful study in the initial evaluation of PH [13-19]. Miniati et al [20] found that chest radiography has a high sensitivity (96.9%) and specificity (99.1%) for detection of moderate to severe PH. Additionally, chest radiography can show findings of diffuse lung diseases that can be associated with PH, such as interstitial fibrosis and emphysema [10,13]. Although chest radiography does well in detecting the presence/absence of PH in moderate and severe cases of PH, it performs poorly in estimating the PH severity [14]. Additionally, it is known to be insensitive in the detection of mild PH. Thus, a normal chest radiograph does not exclude PH, and further imaging evaluation should be pursued if there are persistent unexplained symptoms such as dyspnea or risk factors for PH [13,15,17,20,21]. Findings of PH on chest radiography include enlargement of the central pulmonary arteries, with or without rapid tapering (pruning), and right heart chamber enlargement [10,17,19,21]. A study by Schmidt et al [17] found that the main PA (MPA) was enlarged (>35 mm from midline to left lateral border of the PA on posterior anterior radiograph) 96% of the time in PH. A measurement of the right descending PA >15 mm in women (>16 mm in men) at the hilum on a posterior anterior view has good sensitivity, specificity, and accuracy for PH (93%, 88%, and 92%, respectively) and is considered to be a very useful finding [16-18]. A diameter of the left descending PA >18 mm on the lateral view is also suggestive of PH, but although it has good sensitivity (93%), the specificity (67%) and accuracy (87%) are poorer [16]. Other studies, such as that of Schmidt et al [17], have found poorer sensitivity for the left descending PA measurement. Miniati et al [20] found the most prevalent radiographic findings in patients with PH were enlarged MPA (97%), enlarged right ventricle (95%), and enlarged right descending PA (93%).
Suspected Pulmonary Hypertension. Multiple historic studies have shown that chest radiography is a useful study in the initial evaluation of PH [13-19]. Miniati et al [20] found that chest radiography has a high sensitivity (96.9%) and specificity (99.1%) for detection of moderate to severe PH. Additionally, chest radiography can show findings of diffuse lung diseases that can be associated with PH, such as interstitial fibrosis and emphysema [10,13]. Although chest radiography does well in detecting the presence/absence of PH in moderate and severe cases of PH, it performs poorly in estimating the PH severity [14]. Additionally, it is known to be insensitive in the detection of mild PH. Thus, a normal chest radiograph does not exclude PH, and further imaging evaluation should be pursued if there are persistent unexplained symptoms such as dyspnea or risk factors for PH [13,15,17,20,21]. Findings of PH on chest radiography include enlargement of the central pulmonary arteries, with or without rapid tapering (pruning), and right heart chamber enlargement [10,17,19,21]. A study by Schmidt et al [17] found that the main PA (MPA) was enlarged (>35 mm from midline to left lateral border of the PA on posterior anterior radiograph) 96% of the time in PH. A measurement of the right descending PA >15 mm in women (>16 mm in men) at the hilum on a posterior anterior view has good sensitivity, specificity, and accuracy for PH (93%, 88%, and 92%, respectively) and is considered to be a very useful finding [16-18]. A diameter of the left descending PA >18 mm on the lateral view is also suggestive of PH, but although it has good sensitivity (93%), the specificity (67%) and accuracy (87%) are poorer [16]. Other studies, such as that of Schmidt et al [17], have found poorer sensitivity for the left descending PA measurement. Miniati et al [20] found the most prevalent radiographic findings in patients with PH were enlarged MPA (97%), enlarged right ventricle (95%), and enlarged right descending PA (93%).