# Dual-Energy Computed Tomography for the Detection of Bone Edema-Like Lesions in the Equine Foot: Standing Horses and Cadaveric Specimens

## TL;DR

This study shows that dual-energy computed tomography (DECT) can detect bone marrow edema in horses, though it underestimates mild cases and requires caution in certain conditions.

## Contribution

The study evaluates DECT's effectiveness in detecting bone marrow edema in horses and identifies factors affecting its clinical applicability.

## Key findings

- DECT detected 78.9% of bone marrow edema cases in horses when compared to MRI.
- DECT underestimated the extent of bone marrow edema compared to MRI (p = 0.016).
- DECT was feasible in standing horses and showed no significant difference in image quality compared to post-mortem scans.

## Abstract

Dual-energy computed tomography (DECT) is an emerging imaging technique used to detect bone marrow edema-like lesions (BME), but its use in horses remains limited. This study evaluated the use of DECT to detect BME in horses with foot lameness and investigated factors that could influence its application in clinical practice. DECT scans from 14 standing horses and 5 cadaveric feet were reviewed by two readers in comparison to magnetic resonance imaging (MRI), the current gold standard for BME detection. MRI showed BME in 17/19 cases. Agreement between DECT VNCa and MRI was found in 15/19 feet (78.9%). In the 4 remaining cases, DECT did not match MRI findings due to increased bone density (1/19), a mild BME extent (2/19), and image artifact (1/19). Overall, the extent of BME was significantly underestimated using DECT compared to MRI (p = 0.016). There was no significant relationship between increased bone density and BME extent underestimation on DECT (p = 0.056). Between the live and post-mortem DECT scans, there were no significant differences in image quality or agreement with MRI. In summary, DECT effectively detected moderate and severe BME, and its use was feasible in standing positioning. DECT images should be interpreted with caution in case of increased bone density.

Dual-energy computed tomography (DECT) is a promising advancement for detecting bone edema-like lesions (BME). However, its application in horses remains limited. The aim of this study was to evaluate DECT virtual-non-calcium (VNCa) imaging in the equine foot and establish which confounding factors could influence its applicability in clinical practice. The DECT VNCa map of 14 standing and 5 cadaveric (recumbent) cases with foot-related lameness was scored in consensus by two readers in comparison to MRI. Overall, 17/19 cases demonstrated BME on MRI, whereas 2 did not. Agreement between DECT VNCa and MRI was found in 15/19 feet (78.9%). Disagreement in 4/19 cases with BME was due to sclerosis (1/19), mild BME extent on MRI (2/19), or scan artifacts (1/19). The extent of BME was significantly underestimated using DECT VNCa compared to MRI (p = 0.016). No significant correlation was found between sclerosis score and the BME extent underestimation on DECT (p = 0.056). Between standing and post-mortem cases, there was no significant difference in the agreement between DECT and MRI (p = 0.53) or DECT VNCa image quality (p = 0.22). In conclusion, DECT VNCa effectively identified moderate and severe BME, and its use was feasible in standing positioning. In case of sclerosis, a case-by-case assessment is recommended.