A research team from the VU University Medical Center in Amsterdam, the Netherlands recently found that using a combination of assessments for ventricular pressure and pulmonary artery (PA) improves the likelihood of detecting pulmonary hypertension (PH) in patients assessed with computed tomography pulmonary angiography (CTPA).
In their study, Onno Spruijt and colleagues suggest that CTPA alone is not an appropriate primary PH screening tool. However, “CTPA is often performed early in the diagnostic process of patients with unexplained dyspnea,” they said in the International Journal of Cardiovascular Imaging according to a recent news release. “Combining ventricular and PA measurements decreases the chance that the diagnosis of precapillary PH is missed.”
At baseline, the research team examined 51 precapillary patients with PH undergoing CTPA and right heart catheterization. The results were compared with 25 control patients who had no PH clinical evidence.
Results showed that a standard model of CTPA, with a PA diameter to the ascending aorta diameter ratio, results in an accurate method for differentiating patients with symptoms of PH from those without the disease.
Results also showed that complementing the ratio of the highest transverse diameter of the right ventricle to that of the left ventricle (RV/LV) results in further improvement of precision. The RV/LV on axial view was assessed in a manually reconstructed four-chamber view, and the researchers observed similar benefits using both techniques. In this regard, RV/LV assessment in the axial view may be more appropriate since it does not need a manual image reconstruction.
Adding the RV/LV ratio (on axial view) resulted in a significant decrease in the rate of false positives without an increase in the rate of false negatives by between 9 and 24 in every 100 patients, all based on PH baseline probability.
The investigators utilized baseline probabilities (varying from 1% to 20%), and provided more weight to false negatives than to the false positives, because as they said according to news release “missing the diagnosis is worse than performing unnecessary diagnostic tests.”
In terms of diagnosing patients with PH, the use of CTPA is critical in making an accurate diagnosis. This new study offers imaging professionals improved methods for making a more precise PH diagnosis when utilizing CTPA imaging technology. “When there is suspicion of pre capillary PH, and a CTPA is made, we recommend radiologists to assess not only the diameters of the great vessels, but also of both ventricles,” concluded the researchers in the news release.