Jing Shan, Presenter: Nothing to Disclose

Laurel Burk, Abstract Co-Author: Nothing to Disclose

Yueh Z. Lee MD, PhD, Abstract Co-Author: Research Grant, Carestream Health, Inc

Michael David Heath, Abstract Co-Author: Nothing to Disclose

Xiaohui Wang PhD, Abstract Co-Author: Employee, Carestream Health, Inc

David Foos MS, Abstract Co-Author: Employee, Carestream Health, Inc

Jianping Lu, Abstract Co-Author: Research Grant, Carestream Health, Inc

Otto Zhou PhD, Abstract Co-Author: Board of Directors, XinRay Systems Inc Research Grant, Carestream Health, Inc

We investigated the feasibility of physiologically-gated stationary chest tomosynthesis (s-DCT) with carbon nanotube (CNT) x-ray source array, and studied the image quality improvement from prospective gating.

A bench-top s-DCT system was constructed using a CNT source array and a flat panel detector (Varian Medical Systems Inc., CA). We demonstrated the feasibility of s-DCT using CNT source array. CNT X-ray sources can be electronically switched on/off rapidly, allowing physiological signal gated tomosynthesis imaging. Pig lungs and heart were ventilated inside of an anthropomorphic chest phantom to simulate lung respiration motion with respiration cycle periods and volumes comparable to typical human breath. A pneumatic pressure based respiration signal was acquired using BioVet (m2m Imaging Corp., OH). Small metal beads placed on the lungs quantitatively measured image blur from respiratory motion. AP chest projection images were acquired at various imaging acquisition speeds, breath periods, and respiratory phases, with and without gating. Multiple gated images were acquired per respiration cycle. Tomosynthesis images were reconstructed using commercial software (Realtime Tomography LLC, PA) and analyzed to evaluate the effect of gating on image quality.

Tomosynthesis images acquired of non-gated ventilated lung show blurred airways and vascular structures. Without gating, the beads were blurred to 3.75mm compared to 2mm in motionless control images. When X-ray beams were prospectively gated to end of inhalation phase or the end of exhalation phase of respiration cycle, image quality was greatly improved, with sharper airway edges and more visible structural details. Bead width was 2.25mm for both cases, an 85.7% decrease of motion blur.

When tomosynthesis scanning time equals or exceeds a respiration period, image quality is degraded by motion. We demonstrated the feasibility of physiological gated s-DCT imaging using CNT source array. The s-DCT system allows prospective gating to any phase of the respiration cycle, substantially reducing blur associated with lung motion even with image acquisition over several respiration cycles.

Imaging quality can be greatly improved with physiological gated s-DCT, which can improve the imaging outcome for patients who cannot easily maintain their breath hold.

Shan, J, Burk, L, Lee, Y, Heath, M, Wang, X, Foos, D, Lu, J, Zhou, O, Physiologically Gated Stationary Chest Tomosynthesis System Using CNT X-ray Source Array.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14004754.html