Feasibility of Na18F PET/CT and MRI for Noninvasive In Vivo Quantification of Knee Pathophysiological Bone Metabolism in a Canine Model of Post-traumatic Osteoarthritis.

PURPOSE To assess and quantify by molecular imaging knee osseous metabolic changes serially in an in vivo canine model of posttraumatic osteoarthritis (PTOA) of the knee utilizing sodium fluoride (Na18F) positron emission tomography (PET)/computed tomography (CT) coregistered with magnetic resonance imaging (MRI). MATERIALS AND METHODS Sodium fluoride PET imaging of 5 canines was performed prior to anterior cruciate ligament transection (ACLT) and 2 times post-ACLT (3 and 12 weeks). The PET/CT was coregistered with MRI, enabling serial anatomically guided visual and quantitative three-dimensional (3D) region of interest (ROI) assessment by maximum standardized uptake value. RESULTS Prior to ACLT, every 3D ROI assessed in both knees showed no Na18F uptake above background. The uptake of Na18F in the bone of the ACLT knees increased exponentially, presenting significantly higher uptake at 12 weeks in every region compared to the ACLT knees at baseline. Furthermore, the uninjured contralateral limb and the ipsilateral distal bones and joints presented Na18F uptake at 3 and 12 weeks post-ACLT. CONCLUSION This study demonstrated that Na18F PET/CT coregistered with MRI is a feasible molecular imaging biomarker to assess knee osseous metabolic changes serially in an in vivo canine model of knee PTOA. Moreover, it brings a novel musculoskeletal preclinical imaging methodology that can provide unique insights into PTOA pathophysiology

Cervical Intervertebral Disk to Vertebral Body Ratios of Different Dog Breeds Based on Sagittal Magnetic Resonance Imaging.

To establish sagittal area and length reference values and ratios between apparently normal canine cervical vertebrae and intervertebral disks using magnetic resonance imaging. Retrospective evaluation of cervical vertebral column magnetic resonance imaging studies of 44 dogs representing 5 different breeds (Labrador Retriever, = 10; French Bulldog, = 10; Great Dane, = 9; Chihuahua, = 10; Dachshund, = 5). Mid-sagittal measurements of vertebral body and disk areas were obtained from C3 through C7 vertebrae and C2/C3 through C6/C7 intervertebral disks. Disk to vertebra area ratios were calculated and compared among dog breeds. Additionally, sagittal vertebral body and disk length measurements were obtained and disk to vertebra length ratios calculated. Inter and intra observer variability was assessed. There were significant differences for disk to vertebral body area and length ratios between evaluated dog breeds and cervical vertebral locations ( < 0.001). Mean area ratio of Chihuahuas was significantly larger than all other breeds, while results from Dachshunds were only significantly different than Chihuahuas and Labrador Retrievers. Mean area ratios were statistically different between the cranial and caudal cervical vertebral locations. Regarding length ratios, results from Chihuahuas were significantly different than all breeds except Dachshunds. Mean length ratios were statistically different between all cervical locations, except C2/C3 compared to C3/C4. Intra- and interobserver variability was very good to excellent. There are significant differences in area and length ratios between dog breeds. Differences also exist in area and length ratios between the cranial and caudal cervical vertebral column. These differences may play a role in the development of vertebral column diseases including intervertebral disk disease

Minimally Invasive Spine Surgery in Small Animals.

Minimally invasive spine surgery (MISS) seems to have many benefits for human patients and is currently used for various minor and major spine procedures. For MISS, a change in access strategy to the target location is necessary and it requires intraoperative imaging, special instrumentation, and magnification. Few veterinary studies have evaluated MISS for canine patients for spinal decompression procedures. This article discusses the general requirements for MISS and how these can be applied to veterinary spinal surgery. The current veterinary MISS literature is reviewed and suggestions are made on how to apply MISS to different spinal locations

Zervikaler Bandscheibenvorfall beim Hund

Auch wenn der Großteil intervertebraler degenerativer Diskopathien weiterhin der thorakolumbalen Wirbelsäule vorbehalten bleibt, sind 14–16 % der Fälle akute zervikale Bandscheibenextrusionen. Es gibt viele Ähnlichkeiten in der Pathogenese der Diskopathie beider Lokalisationen, allerdings muss man sich über einige sehr wichtige Unterschiede in der neurologischen Präsentation und Prognose im Klaren sein. Diese beeinflussen die Entscheidungsfindung zur Behandlung von zervikalen Diskopathien erheblich