title: Double-subtraction maximum intensity projection MR angiography for detecting the artery of Adamkiewicz and differentiating it from the drainage vein.
abstract: OBJECTIVE
  To evaluate the efficacy of double-subtraction magnetic resonance angiography (MRA) (subtraction of the subtracted venous phase image from the subtracted arterial dominant phase image) for depicting the artery of Adamkiewicz and differentiating it from the drainage vein.
  
  
  METHODS
  A total of 170 patients (123 men, 47 women; aged 17-84 years, mean = 67 years), with a thoracoabdominal vascular lesion underwent MRA for detection of the artery of Adamkiewicz. MRA was performed as a five-phase dynamic-enhanced three-dimensional (3D) fast spoiled gradient recalled acquisition in steady state (GRASS) sequence on a 1.5-T system, with double-dose bolus contrast and saline injection. The levels at which the artery of Adamkiewicz and drainage vein originated were determined. Signal intensities of the two vessels were measured with source images to assess the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and necessity of the double-subtraction technique.
  
  
  RESULTS
  The artery of Adamkiewicz was detected in 140 patients (82.4%). Branching occurred at levels T8-T12 on the left and T8-T11 on the right. An additional anterior radiculomedullary artery was detected in 18 patients. The drainage vein was detected in 133 patients (78.2%). It merged at the T9-L2 level on both sides. In six of the 133 patients (4.5%), the drainage vein branched upwardly. Neither SNR nor CNR differed significantly between the artery of Adamkiewicz and the drainage vein in the arterial phase; but on the subtraction image, signal intensity of the artery was higher than that of the drainage vein (P < 0.05).
  
  
  CONCLUSIONS
  Double-subtraction MRA is useful for detecting the artery of Adamkiewicz when it is necessary to differentiate it from the drainage vein.
authors.affiliation: Department of Radiology, Sapporo Medical University, Sapporo, Japan. hyodoh@sapmed.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Hyodoh
authors.forename: Ryuji
authors.initials: R
authors.lastname: Shirase
authors.forename: Hidenari
authors.initials: H
authors.lastname: Akiba
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Tamakawa
authors.forename: Kazusa
authors.initials: K
authors.lastname: Hyodoh
authors.forename: Naoya
authors.initials: N
authors.lastname: Yama
authors.forename: Takaharu
authors.initials: T
authors.lastname: Shonai
authors.forename: Masato
authors.initials: M
authors.lastname: Hareyama
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000784:Aortic Dissection / Q000175:diagnosis / Q000473:pathology; D001014:Aortic Aneurysm / Q000175:diagnosis / Q000473:pathology; D001158:Arteries / Q000473:pathology*; D003287:Contrast Media / Q000494:pharmacology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013382:Subtraction Technique; D014680:Veins / Q000473:pathology*
chemical_list: D003287:Contrast Media