Relationship between pulmonary artery volumes at computed tomography and pulmonary artery pressures in patients with- and without pulmonary hypertension.

OBJECTIVES

This study was designed to determine the relationship between pulmonary artery (PA) volumes at computed tomography (CT) and PA pressures at right-sided heart catheterization in patients with and without pulmonary hypertension (PAH) to develop a noninvasive CT method of PA pressure quantification.

MATERIALS AND METHODS

Sixteen patients with chronic sleep apnea syndrome underwent contrast enhanced helical CT (slice thickness 3mm; pitch 2; increment 2mm) at inspiration. Eight patients had PAH while cardiopulmonary disease has been excluded in eight other patients. Vascular volumes were determined using a 3D technique (threshold seeded vascular tracing algorithm; thresholds -600 H [lower] and 3,000 H [upper]). Right-sided heart catheterization measurements were available for linear regression analysis of PA volumes and pressures.

RESULTS

Correlation between PA pressures and volumes (normalized for BMI), was high in both groups (without PAH: r=.85; with PAH .90, Pearson). Compared to elevated PA pressures in patients with pulmonary hypertension (p<.005), PA volumes also were significantly increased (p<.05) among the groups.

CONCLUSIONS

High correlation was found between PA volumes and mean PA pressures in patients with- and without PAH. Significant differences in PA volumes at CT-volumetry may admit non-invasive determination of pulmonary hypertension.