Toshiyuki Horie

A giant left circumflex coronary artery – right atrium arteriovenous fistula detected by multislice spiral computed tomography

A 70-year-old man was referred to our hospital because of symptoms of congestive heart failure. The initial echocardiographic study revealed a dilated and poorly contractile left ventricle, a markedly dilated left circumflex coronary artery (LCx), and an enormously dilated anomalous vessel inferior to the right atrium (RA). Color Doppler flow mapping documented a turbulent flow in the LCx, draining into the RA through the anomalous vessel. An LCx-RA arteriovenous fistula was suspected. Multislice spiral computed tomography (MSCT) imaging was performed using a Somatom Volume Zoom (4-detector-row, Siemens, Stuttgart, Germany) with collimation 1.0 mm, table feed 1.5 mm/rotation, 140 kV, 320 mA, and gantry rotation time 500 ms. Our scan protocol and image reconstruction method have been reported previously. 1 Metoprolol (40 mg) was

Visualization of a coronary collateral channel by multislice spiral computed tomography

motion artifacts which occur during the rapid filling and atrial contraction periods, and allows for a better image quality as compared to the conventional technique which utilizes the R-R interval as a reference. The data were transferred to a computer workstation for post-processing (3D Virtuoso, Siemens, Germany). The scan was completed within 15min and post-processing, including manual reconstruction of volume rendering and curved multiplanar images, required 20min with the use of our image reconstruction method. Figure 1A demonstrates complete occlusion at the proximal portion of the RCA with retrograde contrast enhancement of the distal segments and the right ventricular branch. Figure 1B shows a volume-rendering image of the distal portions of the RCA and the LCx. A well-developed collateral channel connecting the distal portion of the LCx and the atrioventricular node branch of the RCA was visualized. A curved multiplanar reconstruction image also depicted a collateral channel (Fig. 1C). With its excellent spatial resolution, MSCT not only permits visualization of the major coronary artery segments, but also has the potential to detect well-developed collateral channels in patients with complete coronary artery occlusion when artifact-free images are obtained.