title: Comparison between intravenous and intraarterial contrast injections for dynamic 3D MRI of liver tumors in the VX2 rabbit model.
abstract: OBJECTIVE
  To test the hypothesis that catheter-directed intraarterial (IA) contrast agent injection increases tumor enhancement and conspicuity compared to intravenous (IV) injection.
  
  
  METHODS
  Eight VX2 liver tumors were grown in five rabbits. After positioning a catheter in the hepatic artery, we performed 3D inversion recovery GRE MRI after IA and IV gadopentetate-dimeglumine contrast injections at doses of 0.04 and 0.1 mmol/kg, respectively. Peak enhancement (signal-to-noise ratio (SNR)) and conspicuity (contrast-to-noise ratio (CNR)) were measured for each acquisition.
  
  
  RESULTS
  The peak SNR and CNR were 21.7 +/- 5.8 and 17.0 +/- 4.8 (mean +/- SD) after IA injection, and 16.9 +/- 10.2 and 6.2 +/- 2.6 after IV injection. The IA CNR was significantly greater than the IV CNR (P < 0.05), with a >60% increase in CNR for each tumor. For six of the eight tumors the IA SNR was greater than the IV SNR, but statistical significance was not achieved due to the small sample size of the study (P = 0.07).
  
  
  CONCLUSIONS
  We demonstrated the feasibility of using IA injection techniques to improve tumor conspicuity. This strategy could be employed to enhance the detection of small liver tumors or to conserve contrast agent in future MRI-guided transcatheter liver therapies.
authors.affiliation: Department of Radiology, Northwestern University, Chicago, Illinois, USA. alarson@radiology.northwestern.edu
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Larson
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Rhee
authors.forename: Jie
authors.initials: J
authors.lastname: Deng
authors.forename: Dingxin
authors.initials: D
authors.lastname: Wang
authors.forename: Kent T
authors.initials: KT
authors.lastname: Sato
authors.forename: Riad
authors.initials: R
authors.lastname: Salem
authors.forename: Tatjana
authors.initials: T
authors.lastname: Paunesku
authors.forename: Gayle
authors.initials: G
authors.lastname: Woloschak
authors.forename: Mary F
authors.initials: MF
authors.lastname: Mulcahy
authors.forename: Debiao
authors.initials: D
authors.lastname: Li
authors.forename: Reed A
authors.initials: RA
authors.lastname: Omary
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage* / Q000494:pharmacology; D004195:Disease Models, Animal; D019786:Gadolinium DTPA / Q000494:pharmacology*; D007261:Infusions, Intra-Arterial / Q000379:methods*; D007262:Infusions, Intravenous / Q000379:methods*; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009368:Neoplasm Transplantation; D011817:Rabbits
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA