Anomalous origin of the right coronary artery originating from the left coronary sinus of valsalva with an interarterial course: diagnosis and dynamic evaluation using dual-source computed tomography.

Purpose: The purpose of this study was to assess the clinical value of dual-source computed tomography (DSCT) in the detection and dynamic evaluation of the anomalous origin of the right coronary artery originating from the left coronary sinus of Valsalva (ARCAOLS) with an interarterial course.

Materials And Methods: Thirteen patients with ARCAOLS with an interarterial course and 11 controls with normal origin of the right coronary artery (RCA) were included into this study from December 2006 to April 2008. The origin and course of the RCA were determined on maximum intensity projection, volume rendering, and virtual endoscopy images. The diameter of the proximal segment of the RCA was measured dynamically in all phases of the cardiac cycle; the systolic stenostic rate of the proximal RCA was computed. The angle between the aorta and the proximal segment of RCA was also measured.

Results: The average heart rate was 71.92 and 70.76 beats/min for patients and controls, respectively. The systolic image quality score of proximal RCA was 4, whereas the diastolic image quality score of proximal RCA was 3.82. Reformatted images could clearly display the ARCAOLS with a smaller orifice than that of the left coronary artery, coursing in an acute angle between the ascending aorta and the pulmonary artery trunk (P = 0.000). In addition to 2 cases without complete computed tomography data, 11 other cases had complete data being used for dynamic assessment. The average systolic diameter of the proximal RCA in mean (SD) was 1.76 mm (0.54 mm), whereas the diastolic diameter was 2.13 mm (0.62 mm) (P = 0.004) for patients with a stenostic rate of the proximal RCA of 16.83 (13.47). The average systolic diameter of the proximal RCA was 3.49 mm (0.61 mm), whereas the diastolic diameter was 3.78 mm (0.63 mm) (P = 0.000) for 11 controls.

Conclusions: Compared with normal controls, the patients with ARCAOLS had a smaller orifice, an acute angle between the aorta and the RCA, and a narrower diameter of the proximal RCA. Dual-source computed tomography can clearly show the anomalous origin, orifice, angle, and course of RCA and dynamically evaluate the diameter changes of proximal RCA during the cardiac cycle, providing useful clues to clarify the mechanism of myocardial ischemia.