Comparison of Magnetic Resonance Imaging and Computed Tomography for Evaluation of Cervical Vertebral Nerves and Synovial Tissues in Horses with Cervical Spinal Disease.

Overview

• This research compares the effectiveness of Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) in evaluating cervical vertebral nerves and synovial tissues in horses with cervical spinal disease, focusing on their ability to detect abnormalities and the confidence of radiologists in identifying these tissues.

Background and Purpose

• The cervical spine plays a vital role in horse performance, and disease in this area can result in poor performance, especially in sport horses.
• Imaging technologies such as CT and MRI have improved the diagnosis of musculoskeletal problems.
• CT is primarily used for examining bone (osseous) abnormalities but is limited in assessing soft tissues.
• MRI is considered the gold standard for soft tissue imaging but has not been used for in vivo (antemortem) imaging of equine cervical spines.
• There was a need to explore CT’s potential for evaluating soft tissues of the equine cervical spine, particularly in comparison to MRI.

Methods

• Postmortem MRI scans were conducted on eighteen horses euthanized due to cervical spinal disease diagnosed via clinical and CT myelographic findings.
• Both synovial tissue and vertebral nerve tissue abnormalities were assessed and graded on MRI and CT images.
• Radiologists rated their confidence in identifying synovial tissues and vertebral nerves on both MRI and CT images.
• Hounsfield Unit (HU) measurements, a quantitative value used in CT imaging to characterize tissue density, were taken from synovial and vertebral nerve tissues.

Findings

• MRI outperformed CT in evaluating synovial tissues and vertebral nerves, demonstrating greater clarity and detail in soft tissue visualization.
• Radiologists expressed higher confidence when identifying these tissues using MRI images compared to CT images.
• The agreement or correlation between HU measurements from CT scans was inconsistent and showed the least reliability for vertebral nerves, indicating CT may not reliably distinguish these tissues based on density measurements.

Conclusions and Implications

• The study confirmed that MRI is superior to CT for examining equine cervical vertebral nerves and synovial tissues postmortem.
• Despite CT’s utility in bone imaging, caution is warranted when interpreting CT scans for soft tissue abnormalities in the cervical spine of horses.
• This research highlights the limitations of CT in soft tissue evaluation and supports greater use or development of MRI techniques for accurate diagnosis and treatment planning in equine cervical spinal disease.