Chen and colleagues1examined the diagnostic value of mean pulmonary artery diameter (MPAD) ≥ 29 mm to predict pulmonary hypertension using Figure 2 from our study.2Given the relatively high sensitivity and negative predictive value obtained by this approach, they astutely point out that CT may have a role in screening for pulmonary hypertension in patients with idiopathic pulmonary fibrosis. This assertion has merit; however, any test can be made sensitive by selecting a low-enough cutoff but, as in this case, at the expense of specificity. Figure 2 only shows 56 of the 65 observations (9 are superimposed). With the entire data set, a MPAD cutoff ≥ 29 mm had sensitivity, specificity, positive predictive value, and negative predictive value for pulmonary hypertension (defined as mean pulmonary artery pressure [MPAP] from right-heart catheterization > 25 mm Hg) of 85 to 100%, 10 to 38%, 34 to 61%, and 60 to 100%, respectively. Only 8 of 65 patients (12%) in the data set had MPADs < 29 mm, and this is reflected by a wide confidence interval for the negative predictive value estimate. Accordingly, the negative predictive value could be as low as 60%; in our opinion, this figure is too small to accept MPAD as a screening tool for a condition with potentially devastating consequences in idiopathic pulmonary fibrosis. Furthermore, as reflected by an unacceptably low specificity, of those without pulmonary hypertension, only 8 of 38 patients (21%) had MPADs < 29 mm. Simpler and less expensive clinical measurements (oxygen saturation using pulse oximetry, percentage of predicted FVC, and percentage of predicted diffusion capacity of the lung for carbon monoxide) can be used to screen for pulmonary hypertension in patients with idiopathic pulmonary fibrosis.3–4 Recently, we validated a formula to predict MPAP from standard lung function measurements.4 A formula-predicted MPAP > 21 mm Hg was associated with a sensitivity, specificity, positive predictive value, and negative predictive value of 74 to 99%, 41 to 73%, 35 to 70%, and 78 to 100%, respectively, for pulmonary hypertension defined as MPAP from right-heart catheterization > 25 mm Hg. We recommend this method over MPAD from CT to screen for pulmonary hypertension in patients with advanced idiopathic pulmonary fibrosis.