Holger Haubenreisser, Presenter: Nothing to Disclose

Julia Schafer, Abstract Co-Author: Nothing to Disclose

Stefan Oswald Schoenberg MD, PhD, Abstract Co-Author: Institutional research agreement, Siemens AG

Thomas Henzler MD, Abstract Co-Author: Nothing to Disclose

Mathias Meyer, Abstract Co-Author: Nothing to Disclose

To investigate the impact of a combined CT angiography (CTA) protocol, consisting of a CT pulmonary angiography (CTPA) and a functional 4D cardiac CT angiography (cCTA), on patient and therapy management in patients with suspected pulmonary embolism (PE).

60 patients with suspected PE were prospectively included. The CTPA was performed on a 2nd generation dual source CT (DSCT) system (Somatom Flash, Siemens) using a high pitch acquisition (3.2). This acquisition was subsequently followed by a retrospectively ECG-gated cCTA at 70kV without pulsing but 80% mAs reduction (to 150 reference mAs) during the whole cardiac cycle for solely functional cardiac analysis. A single contrast agent bolus was used for both scans (80ml Iomeprol 400mg/ml, 30ml saline chaser, both 4ml/s flow rate). cCTA data was reconstructed over the entire cardiac cycle, and ventricular function was quantified using an offline workstation (SyngoVia, VA30, Siemens). Two radiologists evaluated the dynamic examination, paying particular attention to myocardial function and the presence of abnormalities, especially of the ventricular septum. Applied radiation dose was recorded and compared to a standard CTPA protocol on a 16 slice single source CT system.

All imaging studies were completed without any complications and contrast enhancement and image quality was rated as diagnostic in all examinations. Mean DLP of the examinations was 309±113mgGy/cm, compared to 358±85mGy/cm for the 16 slice CT. Of the 60 patients, 13 patients tested positive for PE. 11 patients showed a significant reduction in right ventricular ejection fraction. Of these 11 patients, 4 received a cardiac ultrasound, which confirmed right ventricular dysfunction (RVD). The other 7 patients did not receive a cardiac ultrasound, but subsequent intensive care unit admission based on the reported RVD in the radiological report.

Our study demonstrates the feasibility and clinical benefit of performing a comprehensive CT examination protocol for patients with suspected PE. This leads to a better risk stratification in these patients, and subsequently a therapy tailored more closely to patients’ clinical conditions.

A combined high-pitch CTPA and low dose functional cCTA protocol is feasible using a single contrast bolus and allows assessment of cardiac function in patients with PE within accepted radiation dose levels.

Haubenreisser, H, Schafer, J, Schoenberg, S, Henzler, T, Meyer, M, Pulmonary Angiography and 4D Functional Cardiac Parameters with a Single Contrast Media Application: Comprehensive CT Pulmonary Embolism Imaging to Complement Cardiac Ultrasound.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14004434.html