MDCT bolus tracking data as an adjunct for predicting the diagnosis of pulmonary hypertension and concomitant right-heart failure.
OBJECTIVE
The purpose of this study was to investigate the utility of bolus-triggering data from pulmonary CT angiography for predicting the diagnosis of pulmonary hypertension (PH) and right ventricular dysfunction (RVD) and to test its performance against previously established CT signs of PH.


METHODS
Automated bolus-triggering data from pulmonary CT angiograms of 101 patients were correlated with echocardiographic findings and a variety of CT-derived indexes of PH and RVD, including right and left ventricular minor axis diameter; pulmonary artery (PA), aortic, and superior vena caval diameters; right ventricular thickness; contrast reflux; and configuration of the interventricular septum. For bolus triggering, a region of interest was placed in the main PA. Time to threshold, defined as the time from the beginning of contrast injection to the time attenuation exceeded the threshold (100 HU), was measured. On the basis of results of two consecutive echocardiographic studies, subjects were divided into control and PH groups. The latter group was subdivided into PH without RVD and PH with RVD. Time to threshold values were compared between groups and correlated with standard CT-derived parameters.


RESULTS
Significant differences between groups were found in time to threshold, PA and right ventricular diameters, and PA-to-aorta and right ventricular-to-left ventricular ratios. Time to threshold had an incremental pattern from the control group (6.6 ± 1.0 seconds) to PH without RVD (9.2 ± 2.4 seconds) and PH with RVD (12.1 ± 3.4 seconds) (p < 0.001). The optimal diagnostic performance of time to threshold for revealing the presence of PH and RVD was at cutoff values of 7.75 and 8.75 seconds, respectively. Time to threshold had a strong direct correlation with PA diameter. In multivariable analyses, time to threshold was identified as a significant predictor of PH and RVD. The specificity of time to threshold and PA diameter together was higher than that of PA diameter alone.


CONCLUSIONS
Measurement of time to threshold of contrast enhancement derived from bolus-timing data at MDCT may be a useful adjunctive tool for diagnosing PH and consequent RVD.
Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA.
Amir H
AH
Davarpanah
Philip A
PA
Hodnett
Cormac T
CT
Farrelly
Sanjiv J
SJ
Shah
Michael
M
Cuttica
Ann B
AB
Ragin
James C
JC
Carr
Vahid
V
Yaghmai
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000792:Angiography / Q000379:methods*; D003287:Contrast Media; D004452:Echocardiography; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging*
D003287:Contrast Media