Prediction of Pulmonary Hypertension in Patients with or without Interstitial Lung Disease: Reliability of CT Findings

Purpose To study the reliability of pulmonary vascular measurements based on computed tomography (CT) in the prediction of pulmonary hypertension (PH) in patients with advanced interstitial lung disease (ILD) compared with those without ILD. Materials and Methods The study was approved by the Institutional Review Board. All patients gave written informed consent. A prospective study of 134 patients who underwent right-sided heart catheterization and chest CT scanning within 72 hours of admission was conducted. Patients were divided into two groups—one with ILD (group A, n = 100) and one without ILD (group B, n = 34). CT measurements of the main pulmonary artery diameter (PAD), the ratio of PAD to the ascending aorta diameter (AAD), right pulmonary artery diameter (RPAD), and left pulmonary artery diameter (LPAD) were obtained. Univariate logistic regression analysis was performed, and receiver operating characteristic curves were constructed to assess the predictive ability of vascular measurements obtained by using CT in the identification of PH. Results Main PAD was significantly greater in patients with PH than in those without PH in both groups (group A, P = .008; group B, P = .02). A PAD greater than 25 mm in patients with ILD was predictive of PH, with a sensitivity of 86.4% (32 of 37), a specificity of 41.2% (26 of 63), a positive predictive value of 46.3% (32 of 69), and a negative predictive value of 83.8% (26 of 31). In patients without ILD, a PAD greater than 31.6 mm and an LPAD greater than 21.4 mm were predictive of PH (sensitivity, 47.3% [nine of 19]; specificity, 93.3% [14 of 15]; positive predictive value, 90.0% [nine of 10]; and negative predictive value, 58.3% [14 of 24]). Conclusion CT-derived vascular measurements were of limited utility in the prediction of PH in patients with ILD compared with those without ILD. © RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11103532/-/DC1