Paul Michael Bunch MD, Presenter: Nothing to Disclose

Urvi Pravin Fulwadhva MD, Abstract Co-Author: Nothing to Disclose

Jeremy Robert Wortman MD, Abstract Co-Author: Nothing to Disclose

Andrew Primak PhD, Abstract Co-Author: Employee, Siemens AG

Aaron D. Sodickson MD, PhD, Abstract Co-Author: Research Grant, Siemens AG

To compare quantitative measures of cardiac pulsation and respiratory motion artifact in CT pulmonary angiograms (CTPA) performed using a high-pitch dual-source protocol and a single-source protocol.

In this retrospective, IRB-approved, HIPAA-compliant study, 50 CTPA exams were included using each of two protocols: 1) a high-pitch dual-source (DS) protocol and 2) a routine single-source (SS) protocol. Neither protocol used ECG gating. Inclusion criteria were patient age >18 years, both arms elevated above the scan region, and no prior lobectomy or pneumonectomy. All scans were performed in the Emergency Department on a Siemens Definition Flash scanner. Each scan was evaluated for motion artifact producing a “double image” appearance, and when present, the greatest anatomic overlap interval was measured perpendicular to the axis of the ascending aorta, left ventricular lateral wall, and diaphragm. Measurements were performed on axial images for aortic and cardiac motion and on coronal reformatted images for diaphragmatic motion. Statistical analysis was performed using one way ANOVA.

There was no statistically significant difference in patient gender, age, or effective diameter between the two cohorts. High-pitch DS CTPA scans used a mean pitch of 2.9 (range 1.6-3.0), resulting in a mean scan duration of 0.8 seconds (range 0.6-1.7). Routine SS technique used pitch 0.75 for a mean scan duration of 4.6 seconds (range 3.6-5.8). DS outperformed SS technique with respect to quantitative measures of ascending aortic, cardiac, and diaphragmatic motion. Mean distances between motion-artifact double images were reduced at the ascending aorta from 4.1 mm with SS to 0.3 mm with DS, at the left ventricular lateral wall from 5.3 mm with SS to 1.2 mm with DS, and at the diaphragm from 2.2 mm with SS to 0.1 mm with DS, all with p<0.001.

High-pitch dual-source CTPA is an effective means to significantly reduce artifacts resulting from ascending aortic, cardiac, and diaphragmatic motion.

High-pitch dual-source CTPA significantly reduces cardiac and respiratory motion artifact without the need for ECG synchronization, which may result in increased diagnostic confidence during evaluation for pulmonary embolus as well as cardiac and aortic causes of chest pain.

Bunch, P, Fulwadhva, U, Wortman, J, Primak, A, Sodickson, A, Motion Artifact Reduction from High-pitch Dual-source CT Pulmonary Angiography.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016250.html