title: Multislice computed tomographic findings of the anomalous origins of the right coronary artery: evaluation of possible causes of myocardial ischemia.
abstract: BACKGROUND
  Anomalous right coronary arteries (RCA) arising from the left sinus of Valsalva may cause myocardial ischemia.
  
  
  OBJECTIVE
  We evaluated morphological features of anomalous RCA by using multislice computed tomography (MSCT) in relation to myocardial ischemia provoked by myocardial perfusion single-photon emission computed tomography.
  
  
  METHODS
  MSCT was performed in a total of 3, 212 patients by using an Aquillion 16 and a Light Speed Ultra. Retrospective ECG-gated image reconstruction was performed. Volume rendering, axial and curved multiplanar reformatted images were analyzed for the determination of the origin and course of the RCA, the take-off angle of the RCA from the aorta, and size of the RCA orifice. Furthermore, virtual angioscopic images were also used for the evaluation of the RCA orifice structure.
  
  
  RESULTS
  Anomalous origins of the RCA were found in 15 patients. In 13 patients, the RCA arose from the left sinus of Valsalva, and in 2 patients it arose from the left main coronary artery as a single coronary artery. The RCA coursed anteriorly between the ascending aorta and pulmonary artery in 14 patients, whereas it had a retroaortic course in 1 patient. Acute angle take-off (<30 degrees ) of the RCA from the aorta and the left main coronary artery was observed in 8 patients, intramural course of the RCA within the aortic wall was observed in 6 patients and a small RCA orifice was observed in 4 patients. Exercise-induced myocardial ischemia was present in 5 patients.
  
  
  CONCLUSIONS
  Coursing between the aorta and pulmonary artery, acute angle take-off and intramural course were thought to be major causes of exercise-induced ischemia in patients with anomalous origins of the RCA.
authors.affiliation: Department of Cardiology, Nihon University School of Medicine, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8309, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ichikawa
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sato
authors.forename: Sei
authors.initials: S
authors.lastname: Komatsu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Kodama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saito
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography; D003330:Coronary Vessel Anomalies / Q000150:complications* / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals