The effect of a compression bandage on the distribution of radiodense contrast medium after palmar digital nerve blocks

When radiography and ultrasonography are not enough: the use of computed tomography and magnetic resonance imaging for equine lameness cases

MRI and CT have enhanced our diagnostic abilities for equine lameness beyond what is available using radiography and ultrasonography. This has allowed veterinarians to better prognosticate and treat lameness conditions, improving patient outcomes. This article discusses the basic principles behind MRI and CT, their advantages and disadvantages, the different types of equipment available for clinical use in horses, the typical diagnostic workup prior to pursuing advanced imaging, and common regions where MRI and CT are used clinically. The companion Currents in One Health by Spriet, AJVR, July 2022, discusses even more advanced equine imaging in the form of positron emission tomography. Combined, these future directions of MRI, CT, and positron emission tomography may include improved ability to image standing horses or screen for injury prevention.

Diffusion of Radiodense Contrast Medium Following Perineural Injection of the Deep Branch of the Lateral Plantar Nerve Using Two Different Techniques in Horses: an In Vivo Study

OBJECTIVES

 This article evaluates and compares the diffusion pattern of radiopaque contrast medium following perineural analgesia of the deep branch of the lateral plantar nerve performed using two different techniques: weight-bearing or flexed.

STUDY DESIGN

 This was an in vivo experimental study.

METHODS

 Eight horses were enrolled. Perineural injection of the right and left deep branch lateral plantar nerves was performed with a weight-bearing or flexed technique, using radiopaque contrast medium (iohexol). Radiographic evaluation was performed after 5 (T5), 15 (T15) and 30 (T30) minutes. The diffusion of contrast medium was assessed independently by two blinded readers who analysed the extension of the main contrast medium bulk and the maximum diffusion of contrast medium in both proximal and distal directions. The effect of time and technique employed on contrast medium diffusion was assessed using two-way analysis of variance for repeated measures (p  ≤  0.05).

RESULTS

 There was no significant difference in the diffusion of the contrast medium between the two techniques at T15. However, at T30 the weight-bearing technique resulted in a significantly increased diffusion in the proximal direction (p = 0.02). In one case, belonging to the weight-bearing group, contrast medium was identified within the tarsal sheath. There was no evidence of contrast medium in the tarsometatarsal joint of any horse, regardless of the technique used.

CONCLUSIONS

 The two techniques resulted in a similar diffusion at T15. However, the use of a weight-bearing technique resulted in a significant increase in proximal contrast medium diffusion 30 minutes after injection.