title: Quantitative sodium MR imaging of native versus transplanted kidneys using a dual-tuned proton/sodium (1H/ 23Na) coil: initial experience.
abstract: OBJECTIVE
  To compare sodium ((23)Na) characteristics between native and transplanted kidneys using dual-tuned proton ((1)H)/sodium MRI.
  
  
  METHODS
  Six healthy volunteers and six renal transplant patients (3 normal function, 3 acute allograft rejection) were included. Proton/sodium MRI was obtained at 3 T using a dual-tuned coil. Signal to noise ratio (SNR), sodium concentration ([(23)Na]) and cortico-medullary sodium gradient (CMSG) were measured. Reproducibility of [(23)Na] measurement was also tested. SNR, [(23)Na] and CMSG of the native and transplanted kidneys were compared.
  
  
  RESULTS
  Proton and sodium images of kidneys were successfully acquired. SNR and [(23)Na] measurements of the native kidneys were reproducible at two different sessions. [(23)Na] and CMSG of the transplanted kidneys was significantly lower than those of the native kidneys: 153.5 ± 11.9 vs. 192.9 ± 9.6 mM (P = 0.002) and 8.9 ± 1.5 vs. 10.5 ± 0.9 mM/mm (P = 0.041), respectively. [(23)Na] and CMSG of the transplanted kidneys with normal function vs. acute rejection were not statistically different.
  
  
  CONCLUSIONS
  Sodium quantification of kidneys was reliably performed using proton/sodium MRI. [(23)Na] and CMSG of the transplanted kidneys were lower than those of the native kidneys, but without a statistically significant difference between patients with or without renal allograft rejection.
  
  
  CONCLUSIONS
  Dual-tuned proton/sodium RF coil enables co-registered proton and sodium MRI. Structural and sodium biochemical property can be acquired by dual-tuned proton/sodium MRI. Sodium and sodium gradient of kidneys can be measured by dual-tuned MRI. Sodium concentration was lower in transplanted kidneys than in native kidneys. Sodium gradient of transplanted kidneys was lower than for native kidneys.
authors.affiliation: Department of Radiology, University of Pittsburgh, 200 Lothrop Street, Presby South tower Suite 3950, Pittsburgh, PA, 15213, USA.
authors.forename: Chan Hong
authors.initials: CH
authors.lastname: Moon
authors.forename: Alessandro
authors.initials: A
authors.lastname: Furlan
authors.forename: Jung-Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Tiejun
authors.initials: T
authors.lastname: Zhao
authors.forename: Ron
authors.initials: R
authors.lastname: Shapiro
authors.forename: Kyongtae Ty
authors.initials: KT
authors.lastname: Bae
mesh_terms: D000328:Adult; D000368:Aged; D004867:Equipment Design; D005260:Female; D006084:Graft Rejection / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007672:Kidney Cortex / Q000378:metabolism / Q000473:pathology*; D007679:Kidney Medulla / Q000378:metabolism / Q000473:pathology*; D016030:Kidney Transplantation; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011522:Protons; D011846:Radio Waves; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D012964:Sodium / Q000378:metabolism*
chemical_list: D011522:Protons; D012964:Sodium