title: Quantitative proton MR spectroscopy as a biomarker of tumor necrosis in the rabbit VX2 liver tumor.
abstract: OBJECTIVE
  To compare metabolic magnetic resonance (MR) imaging findings (ie, quantification of tumor choline concentration) with percentage of necrosis on pathologic examination in rabbits bearing VX2 liver tumors.
  
  
  METHODS
  VX2 tumors were implanted in the livers of 16 rabbits. MR imaging was performed with a 1.5-T MR scanner and extremity coil, and a hydrogen-1 ((1)H) proton MR spectroscopy ((1)H MRS) imaging protocol was used. Rabbits were euthanized immediately after imaging, and the tumor was harvested and sliced at 4-mm intervals in the axial plane. Choline concentration was calculated and was compared with the percentage of tumor necrosis on pathologic examination.
  
  
  RESULTS
  Mean tumor size at pathologic examination was 16 mm (range, 12-22 mm). Mean percentage of necrosis at pathologic examination was 22% (range, 4%-44%). Choline concentration showed a relatively high inverse correlation with percentage of necrosis on pathologic examination, with an r value of 0.78 (P < .002).
  
  
  CONCLUSIONS
  Choline concentration showed a relatively high inverse correlation with tumor necrosis on pathologic examination. Therefore, (1)H MRS may be useful to assess tumor necrosis.
authors.affiliation: Russell H Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, 600 N Wolfe St, Room 100, Baltimore, MD 21287, USA.
authors.forename: Manon
authors.initials: M
authors.lastname: Buijs
authors.forename: Josephina A
authors.initials: JA
authors.lastname: Vossen
authors.forename: Jean-Francois H
authors.initials: JF
authors.lastname: Geschwind
authors.forename: Nouha
authors.initials: N
authors.lastname: Salibi
authors.forename: Li
authors.initials: L
authors.lastname: Pan
authors.forename: Veronica Prieto
authors.initials: VP
authors.lastname: Ventura
authors.forename: Eleni
authors.initials: E
authors.lastname: Liapi
authors.forename: Kwang Hun
authors.initials: KH
authors.lastname: Lee
authors.forename: Ihab R
authors.initials: IR
authors.lastname: Kamel
mesh_terms: D000818:Animals; D002794:Choline / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000473:pathology*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009336:Necrosis; D011817:Rabbits; D012044:Regression Analysis
chemical_list: D002794:Choline