title: Anatomy of right superior septal artery demonstrated on the coronary CT scan.
abstract: BACKGROUND
  A coronary CT scan allows for non-invasive visualization of the anatomy of a coronary artery in three dimensions compared to the two dimensions afforded by conventional angiography. The septal artery, the main blood source of the interventricular septum, is usually derived from the left anterior descending artery; however, it is occasionally derived from the right coronary artery.
  
  
  OBJECTIVE
  To analyze the prevalence, origin, diameter, and length of the right superior septal artery (RSSA) demonstrated on a coronary CT scan.
  
  
  METHODS
  The right superior septal artery was retrospectively reviewed on the reconstructed axial scan images (0.5-mm thickness, 0.25-mm interval) in 1290 consecutive patients who underwent coronary CT scans. All patients were scanned on a 320-row CT scanner. The images were transferred to a workstation to trace the vessel to analyze the origin, diameter, and length. We also compared the length of the RSSA between patients with and without coronary artery stenosis.
  
  
  RESULTS
  The RSSA was identified in 51 (3.9%) of 1290 patients. The origin was the proximal portion of the right coronary artery (n = 40) or the right sinus of Valsalva (n = 11). The artery co-existed with the conus artery in 15 (29%) of 51 patients. The length was 16-62 mm (mean 31.2 mm ± 10.5), and the diameter was 0.8-2.0 mm (mean 1.3 mm ± 0.2). Longer RSSAs tended to be demonstrated in the patients with coronary artery stenosis rather than with normal coronary arteries (P < 0.05).
  
  
  CONCLUSIONS
  The right superior septal artery and its anatomical variant could be analyzed with a coronary CT scan. The ability to demonstrate this artery on the coronary CT scan was the same as with coronary angiography. The recognition of this vessel is useful for physicians managing with the diagnosis and treatment of the coronary artery disease.
authors.affiliation: Mitsui Memorial Hospital, Department of Diagnostic Radiology, Tokyo, Japan.
authors.forename: Takaya
authors.initials: T
authors.lastname: Takeguchi
authors.forename: Kenji
authors.initials: K
authors.lastname: Ibukuro
authors.forename: Hozumi
authors.initials: H
authors.lastname: Fukuda
authors.forename: Kimiko
authors.initials: K
authors.lastname: Tobe
authors.forename: Shoko
authors.initials: S
authors.lastname: Abe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001837:Body Weights and Measures; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D006346:Heart Septum / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007479:Iopamidol; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011856:Radiographic Image Enhancement; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007479:Iopamidol