Amir Davarpanah MD, Presenter: Nothing to Disclose

Cormac Thomas Farrelly MD, Abstract Co-Author: Nothing to Disclose

James Christopher Carr MD, Abstract Co-Author: Nothing to Disclose

Vahid Yaghmai MD, Abstract Co-Author: Nothing to Disclose

To investigate the utility of bolus triggering data from pulmonary CTA for predicting RV strain in patients with acute pulmonary thromboembolism

The automated bolus triggering data from pulmonary CTAs of 67 patients were retrospectively evaluated. Scans were evaluated for presence of pulmonary embolism and for evidence of RV strain as evidenced by right heart enlargement and reflux of venous contrast into the hepatic vein. For bolus triggering, a region of interest was placed in the main pulmonary artery and threshold of 100 HU units was selected for starting the scan. Time to threshold (TT), defined as the time from the beginning of injection to the time contrast attenuation exceeds the predefined threshold, was measured. TT values for PE patients with and without evidence of RV strain were then compared with those for the normal subjects by using independent-samples t test, after they were matched in size of the emboli.

37 patients were diagnosed with PE, ranging from segmental to massive saddle emboli and 30 patients had no evidence of PE. RV strain was detected in 15 PE patients. TT values were significantly higher in PE patients with RV strain when compared to normal subjects (11.1±2.3sec vs. 7.5±1.4sec; P<0.001). However, there was no significant difference in TT value between PE patients without RV strain and normal group (7.8±2.4sec vs. 7.5±1.4sec; P>0.05).

Measurement of time to threshold contrast enhancement in pulmonary arteries derived from bolus tracking data on MDCT might provide an adjunctive tool for diagnosing RV strain in patients with pulmonary embolism as an indicator of severity and poor outcome.

Right ventricular (RV) strain in the setting of pulmonary embolism (PE) is associated with adverse short-term outcome and can be detected on pulmonary MDCT angiography (CTA).

Davarpanah, A, Farrelly, C, Carr, J, Yaghmai, V, Bolus Tracking Data on MDCT as an Adjunct for Predicting Right Heart Strain in the Setting of Acute Pulmonary Thromboembolism.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8012891.html