Imaging of the rabbit supraspinatus enthesis at 7 Tesla: a 4-week time course after repair surgery and effect of channeling.
To image the supraspinatus enthesis reformation of rabbit shoulders by magnetic resonance at 7 Tesla (T) using T2 mapping after surgical repair and to assess the effects of channeling aimed at enhancing enthesis reformation.



In 112 rabbits, the distal supraspinatus (SSP) tendon was unilaterally detached and reattached after 1 week. At the first surgery, channeling was performed at the footprint in 64 rabbits. At the second surgery, the SSP tendon of all rabbits was re-attached to the greater tuberosity. The shoulders were harvested at 0, 1, 2, or 4 weeks after the repair surgery and were imaged at 7T. Quantitative T2 mapping was performed using multi slice two-dimensional multi-echo spin-echo sequence with fat saturation. Enthesis regions of interests were drawn on three slices at the footprint to measure T2 relaxation times.



Tendon repair (F(2, 218)= 44; P < 2.2e-16) and postoperative duration (F(3, 218)= 4.8; P = 0.006) both affected significantly the T2 values while channeling had no significant effect. For the time effect, the only pair with a statistical difference was the 0-week and 4-week for the channeling groups (P = 0.023).



Enthesis reformation early after surgical repair of the SSP distal tendon was characterized by increasing T2 values.



2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:461-467.
Bone and Joint Research Laboratory, Department of Medicine, Division of Psychiatry, University of Ottawa, Ottawa, ON, Canada.|The Ottawa Hospital Rehabilitation Center and Ottawa Hospital Research Institute, Ottawa, ON, Canada.
Guy
G
Trudel
Department of Radiology, The Ottawa Hospital, Ottawa, ON, Canada.
Gerd
G
Melkus
Department of Radiology, The Ottawa Hospital, Ottawa, ON, Canada.
Greg O
GO
Cron
Department of Surgery Division of Orthopaedic Surgery, The Ottawa Hospital, Ottawa, ON, Canada.
Hakim
H
Louati
Department of Radiology, The Ottawa Hospital, Ottawa, ON, Canada.
Adnan
A
Sheikh
Department of Radiology, University of California at San Francisco, San Francisco, California, USA.
Peder E Z
PEZ
Larson
Department of Radiology, Stony Brook University NY, New York, New York, USA.
Mark
M
Schweitzer
Department of Surgery Division of Orthopaedic Surgery, The Ottawa Hospital, Ottawa, ON, Canada.
Peter
P
Lapner
Bone and Joint Research Laboratory, Department of Medicine, Division of Psychiatry, University of Ottawa, Ottawa, ON, Canada.
Hans K
HK
Uhthoff
Bone and Joint Research Laboratory, Department of Medicine, Division of Psychiatry, University of Ottawa, Ottawa, ON, Canada.|Department of Biology, University of Ottawa, Ottawa, ON, Canada.
Odette
O
Laneuville
D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D011817:Rabbits; D015203:Reproducibility of Results; D017006:Rotator Cuff / Q000601:surgery*; D000070636:Rotator Cuff Injuries / Q000000981:diagnostic imaging* / Q000601:surgery; D013710:Tendons / Q000000981:diagnostic imaging* / Q000601:surgery*; D013997:Time Factors; D014945:Wound Healing
enthesis; magnetic resonance imaging (MRI) 7 Tesla; rotator cuff; surgical repair