RT Journal Article SR Electronic T1 Correlation of a scintigraphic pulmonary perfusion index with hemodynamic parameters in patients with pulmonary artery hypertension JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 386P OP 386P VO 49 IS supplement 1 A1 Barry Babchyck A1 Kennedy Omonuwa A1 Kenneth Nichols A1 Christopher Palestro A1 Arunabh Talwar YR 2008 UL http://jnm.snmjournals.org/content/49/supplement_1/386P.4.abstract AB 1630 Objectives: To determine if the perfusion index (PI) can be used as a simple, noninvasive measure of the severity of disease in pts with pulmonary artery hypertension (PAH). Methods: 22 pts were included in this retrospective investigation: 9 controls & 13 pts with PAH. Controls had no evidence of PAH (mean pulmonary arterial pressure (MPAP) <25 mm Hg & pulmonary capillary wedge pressure (PCWP) <=18 mm Hg). Study pts had PAH (MPAP >= 25mm Hg & PCWP <=18 mm Hg) & no diagnosis of pulmonary embolism. Due to the retrospective nature of the study, the PI was calculated from the posterior perfusion image of a ventilation perfusion scan. Each perfusion image was assessed to determine the percent of extrapulmonary activity vs pulmonary activity. If this activity > 10% of maximum lung value, pts were excluded from the investigation (n=27). PI was computed (Fukuchi et al JNM June 2002) as 100 times the sum of the absolute values of the differences versus controls for the 9 deciles above background. Results: Linear correlations vs. PI were significant for the following: pulmonary vascular resistance (r=0.81, p=0.00009), total pulmonary vascular resistance (MPAP/cardiac output) (r=0.80, p=0.00013), pulmonary artery systolic pressure (r=0.73, p=0.00018), MPAP (r=0.72, p=0.00022), pulmonary diastolic pressure (r=0.53, p=0.01) and right atrial pressure (r=0.50, p=0.03). Using logistic regression the PI was significant in separating pts with PAH from control pts (χ2=5.6, p=0.02). Conclusions: The data suggest that PI can be used for the noninvasive diagnosis & measurement of severity of pulmonary artery hypertension.