title: Analysis of allogeneic and syngeneic rat heart transplants using 23Na magnetic resonance spectroscopy.
abstract: This study defines the total sodium-23 magnetic resonance spectroscopy (23Na MRS) signal from in vivo heterotopic rat heart transplants in the early post-transplant period and examines the utility of this noninvasive method for monitoring allograft rejection. Measurements were performed at 4.7 T. Syngeneic (n = 6) and allogeneic (n = 6) donor hearts were transplanted into the neck of recipient rats. There were 27 MRS observations between days 0 and 29 post-transplant. Heart grafts were excised at various intervals post-transplant for histologic examination. Allogeneic heart grafts rejected between days 4 and 5 post-transplant while syngeneic grafts continued to beat. All hearts showed ischemic damage. Allogeneic hearts showed cellular rejection by Day 1. 23Na MRS showed a steady elevation in signal in the 3 days prior to rejection and a sharp rise after rejection. 23Na MRS accurately identified full rejection and was also sensitive to the rejection process.
authors.affiliation: Department of Radiology, Frederik Philips Magnetic Resonance Research Center, Emory University School of Medicine, Atlanta, GA 30322, USA. swaldro@emory.edu
authors.forename: S M
authors.initials: SM
authors.lastname: Waldrop
authors.forename: D Z
authors.initials: DZ
authors.lastname: Alexander
authors.forename: R
authors.initials: R
authors.lastname: Lowry
authors.forename: K J
authors.initials: KJ
authors.lastname: Winn
authors.forename: T C
authors.initials: TC
authors.lastname: Pearson
authors.forename: I
authors.initials: I
authors.lastname: Constantinidis
mesh_terms: D000818:Animals; D016027:Heart Transplantation / Q000473:pathology / Q000502:physiology*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009929:Organ Size; D051381:Rats; D011912:Rats, Inbred ACI; D011917:Rats, Inbred Lew; D017208:Rats, Wistar; D012964:Sodium; D013997:Time Factors; D014184:Transplantation, Homologous / Q000473:pathology / Q000502:physiology; D014185:Transplantation, Isogeneic / Q000473:pathology / Q000502:physiology
chemical_list: D012964:Sodium