The aim of the study is to evaluate and compare the Plain CT based different vascular measurements in patient with probable pulmonary hypertension and in normal subjects. Images acquired using routine NCCT protocol on 16 slice Toshiba Alexion CT machine and. Reconstructed images were studied in full magnification on standardized media stinal window settings of (W:400/L:20). The widest diameters perpendicular to the axis of main pulmonary artery, right pulmonary artery, left pulmonary artery, ascending aorta and descending aorta are measured using calipers. These respective measurements of 50 normal subjects were compared to the 20 probable pulmonary hypertensive group diagnosed using standard2D Echocardiography criteria.
The measurements of MPA,RPA,LPA,MPA/AAo and MPA/DAo in normal subjects are 2.33(SD-0.31),1.84(SD-026),1.74(SD-0.25),0.82(SD-0.10) and 1.06(SD-0.22).The respective measurements in probable pulmonary hypertension group are 3.58(SD-0.30),2.57(SD-0.41),2.71(SD-0.49),1.11(SD-0.16) and 1.47(SD-0.30), which are comparatively higher and statistically significant (P value <0.01).
In our study, except the MPA/Dao, rest all measurements show positive correlation. The data was statistically analyzed using Graph pad Prism 8.4.2 and different tools used are two tailed t test, histogram analysis, Pearson correlation and sensitivities & specificities using receiver operating curves (ROC). The upper limits proposed in our study in predicting pulmonary hypertension are MPA 2.85 (sensitivity -95% and specificity – 96%),RPA2.22 (sensitivity – 80% and specificity – 92%), LPA 2.22 (sensitivity – 85% and specificity – 96%), MPA/AAo 1.04 (sensitivity – 80% and specificity – 92%) and MPA/DAo (sensitivity – 90% and specificity – 90%).
The various Plain CT based vascular measurements have got higher cut offs and are statistically significant in probable pulmonary hypertensive group when compared to normal subjects. Hence, Plain CT chest along with 2D Echocardiography can be used as a preliminary noninvasive evaluation of pulmonary hypertension before going for invasive right heart catheterization and thus delay in management can be prevented.