title: Noninvasive gadolinium-enhanced three dimensional computed tomography coronary angiography.
abstract: OBJECTIVE
  Although the use of gadolinium (Gd)-based contrast agents for angiographic studies of abdominal aorta, renal vasculature, and digital subtraction angiography has been reported, no studies have shown their diagnostic efficacy and image quality in coronary computed tomography angiography (CTA). The aim of this study is to evaluate the image quality of Gd-based contrast agents during coronary CTA.
  
  
  METHODS
  A phantom study was done to evaluate the attenuation of serial dilutions of Gd and iodinated agents. This study was done on a 64-slice multirow detector CT (MDCT) scanner and e-speed scanner and CT attenuation Hounsfield units (CTHU) were compared. We evaluated 35 consecutive patients who underwent Gd-enhanced CTA. CTHU of aorta was measured at first, mid, and lowest slice levels with and without contrast administration. The image quality was graded on the basis of visualization of the coronary arteries (scale I-III; III demonstrating diagnostic image quality of the distal-most vessels). In a substudy, four patients with borderline renal insufficiency underwent CTA using Gd and iodinated contrast agents admixed in a 50:50 ratio.
  
  
  RESULTS
  The phantom study showed that enhancement of various dilutions of Gd and iodine resulted in near identical CTHU with both e-speed and 64-slice scanners (r(2) > or = 0.997). Mean CTHU with contrast at the top slice was 116 HU, at middle slice was 125 HU, and at the lower slice was 93 (111.14 +/- 22). Quality evaluation showed 2 grade III, 9 grade II, and 24 grade I images (average quality of images 1.35). Mean CTHU was 222.
  
  
  CONCLUSIONS
  Gd-enhanced contrast medium provides adequate enhancement of coronary vasculature, allowing for diagnostic evaluation of coronary arteries with new CT systems. Use of newer generations of multirow detector CT scanners should further enhance the quality of images.
authors.affiliation: Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor-UCLA, 1124 W. Carson Street, RB2, Torrance, CA 90502, USA.
authors.forename: Khawar M
authors.initials: KM
authors.lastname: Gul
authors.forename: Song S
authors.initials: SS
authors.lastname: Mao
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Gao
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Oudiz
authors.forename: M Leila
authors.initials: ML
authors.lastname: Rasouli
authors.forename: Ambarish
authors.initials: A
authors.lastname: Gopal
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004305:Dose-Response Relationship, Drug; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D019786:Gadolinium DTPA / Q000009:adverse effects; D006801:Humans; D021621:Imaging, Three-Dimensional; D007472:Iohexol / Q000009:adverse effects / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D051437:Renal Insufficiency / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide; D019786:Gadolinium DTPA