title: Low-dose 3D time-resolved magnetic resonance angiography (MRA) of the supraaortic arteries: correlation with high spatial resolution 3D contrast-enhanced MRA.
abstract: OBJECTIVE
  To evaluate the feasibility of low-dose, 3D time-resolved contrast-enhanced magnetic resonance angiography (TR-CEMRA) in the assessment of the supraaortic vessel, and to compare the results with high-resolution contrast-enhanced MRA (HR-CEMRA).
  
  
  METHODS
  This was an Institutional Review Board-approved retrospective study. Forty-five consecutive patients underwent contrast-enhanced 3D TR-CEMRA and 3D HR-CEMRA for evaluation of neurovascular disease at 3.0 T. Gadobutrol was administered at a constant dose of 1 mL for TR-CEMRA (independent of patient weight), and 0.1 mmol/kg for HR-CEMRA. Two readers evaluated image quality using a four-point scale (from 0 = excellent to 3 = nondiagnostic), and subsequently graded each stenosis into clinically relevant categories: normal (0%), mild stenosis (<50%), moderate to severe (>50%), and occlusion.
  
  
  RESULTS
  The overall image quality for low-dose TR-CEMRA was in the diagnostic range (median 0, range 0-3). On the grading of stenosis, TR-CEMRA using the TWIST sequence correlated with HR-CEMRA (r = 0.668, P < 0.001). In terms of the comparison of TR-CEMRA with HR-CEMRA, of the 675 supraaortic arterial segments evaluated for stenosis or occlusion, agreement occurred in 611 of 675 (90.5%), overestimation in 41 of 675 (6.1%), and underestimation 23 of 675 (3.4%).
  
  
  CONCLUSIONS
  TR-CEMRA achieved by administration of a small contrast dose (1 cc) yields rapid and important functional and anatomical information in the evaluation of supraaortic arteries. Due to limited spatial resolution, TR-CEMRA at the current parameters has a tendency to overestimate the stenosis of smaller intracranial arteries compared to HR-CEMRA.
authors.affiliation: Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Youn-Joo
authors.initials: YJ
authors.lastname: Lee
authors.forename: Gerhard
authors.initials: G
authors.lastname: Laub
authors.forename: So-Lyung
authors.initials: SL
authors.lastname: Jung
authors.forename: Won-Jong
authors.initials: WJ
authors.lastname: Yoo
authors.forename: Young-Joo
authors.initials: YJ
authors.lastname: Kim
authors.forename: Kook-Jin
authors.initials: KJ
authors.lastname: Ahn
authors.forename: Bum-Soo
authors.initials: BS
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000473:pathology*; D001024:Aortic Valve Stenosis / Q000150:complications / Q000473:pathology*; D002561:Cerebrovascular Disorders / Q000209:etiology / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol