Coronary Artery Imaging With Flat-Panel Computed Tomography
With the recent introduction of multirow detector systems, helical computed tomography (CT) imaging of the heart has gained renewed interest. A major benefit of such systems is that the entire human heart can be depicted in thin tomographic slices within a single breath-hold. The advent of flat-panel radiographic detectors has opened a new avenue of imaging technology research, including use of such detectors for x-ray CT. With a prototype flat-panel CT system (VCT, GE Global Research), an entire heart can be depicted within a single gantry rotation and a cell pitch factor of 0.2 mm.
A 20-kg domestic pig (Ellegaard, Denmark) was euthanized, the heart excised and rinsed, and the coronary arteries cannulated. The coronary arteries were then filled with a solution of barium sulfate (Micropaque Colon, Guerbet) as an intravascular contrast agent. The concentration of barium sulfate was experimentally adjusted to achieve an intravascular density similar to what is usually found in human arteries after intravenous power injection of iodine containing intravascular contrast agents. Thus, we dissolved 12 g of the barium sulfate powder in 500 mL of tap water to achieve an intraluminal density of 350 Hounsfield units.
This specimen was then depicted using the prototype flat-panel CT system with a 200-mm detector panel. Images were transferred to a dedicated image postprocessing workstation (Advantage Windows V4.01, GE Medical Systems) and used for 3D reconstructions.
Coronary arteries were reproduced down to fifth-degree branches in a static environment, including small septal and intramural branches (Figures 1 and 2⇓). We conclude that the application of flat-panel detector technology for cardiac CT imaging holds promise for the noninvasive diagnosis of coronary artery disease and may overcome some of the limitations of present helical CT methods.
Dr Pfoh is an employee of General Electric Global Research, which manufactured the flat-panel computed tomography system used in this study.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to the Circulation Editorial Office, St Luke’s Episcopal Hospital/Texas Heart Institute, 6720 Bertner Ave, MC1-267, Houston, TX 77030.