title: A pilot cadaveric study of temperature and adjacent tissue changes after exposure of magnetic-controlled growing rods to MRI.
abstract: To test for possible thermal injury and tissue damage caused by magnetic-controlled growing rods (MCGRs) during MRI scans.
  
  
  
  Three fresh frozen cadavers were utilized. Four MRI scans were performed: baseline, after spinal hardware implantation, and twice after MCGR implantation. Cross connectors were placed at the proximal end and at the distal end of the construct, making a complete circuit hinged at those two points. Three points were identified as potential sites for significant heating: adjacent to the proximal and distal cross connectors and adjacent to the actuators. Data collected included tissue temperatures at baseline (R1), after screw insertion (R2), and twice after rod insertions (R3 and R4). Tissue samples were taken and stained for signs of heat damage.
  
  
  
  There was a slight change in tissue temperature in the regions next to the implants between baseline and after each scan. Average temperatures (°C) increased by 0.94 (0.16-1.63) between R1 and R2, 1.6 (1.23-1.97) between R2 and R3, and 0.39 (0.03-0.83) between R3 and R4. Subsequent histological analysis revealed no signs of heat induced damage.
  
  
  
  Recurrent MRI scans of patients with MCGRs may be necessary over the course of treatment. When implanted into human cadaveric tissue, these rods appear to not be a risk to the patient with respect to heating or tissue damage. Further in vivo study is warranted.
  
  
  
  N/A.
authors.affiliation: Department of Orthopaedics, Shriners Hospitals for Children, 3160 Geneva Street, Los Angeles, CA, 90020, USA. spoon@shrinenet.org.
authors.forename: Selina
authors.initials: S
authors.lastname: Poon
authors.affiliation: Department of Pediatric Orthopaedics, Cohen Children's Medical Center, Lake Success, NY, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Nixon
authors.affiliation: Department of Pediatric Orthopaedics, Cohen Children's Medical Center, Lake Success, NY, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Wendolowski
authors.affiliation: Department of Pediatric Orthopaedics, Cohen Children's Medical Center, Lake Success, NY, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Gecelter
authors.affiliation: Department of Pediatric Orthopaedics, Cohen Children's Medical Center, Lake Success, NY, USA.
authors.forename: Yen Hsun
authors.initials: YH
authors.lastname: Chen
authors.affiliation: Department of Pediatric Orthopaedics, Cohen Children's Medical Center, Lake Success, NY, USA.
authors.forename: Jon-Paul
authors.initials: JP
authors.lastname: DiMauro
authors.affiliation: Department of Pediatric Orthopaedics, Cohen Children's Medical Center, Lake Success, NY, USA.
authors.forename: Terry
authors.initials: T
authors.lastname: Amaral
authors.affiliation: Department of Pediatric Orthopaedics, Cohen Children's Medical Center, Lake Success, NY, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Graver
authors.affiliation: Orthopedic Research Laboratory, The Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Grande
mesh_terms: D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D059346:Magnets / Q000009:adverse effects*; D019857:Osteogenesis, Distraction / Q000295:instrumentation*; D010865:Pilot Projects; D012600:Scoliosis / Q000601:surgery*
keywords: Early onset scoliosis; Growing rods; Magnetic resonance imaging; Magnetic-controlled growing rods; Scoliosis