Lumbosacral foraminal ratios and areas using MRI in medium-sized dogs

Abstract

Objective: To examine conventional magnetic resonance imaging planes of the lum-bosacral foramina to obtain objective measurements of foraminal size in medium-sized (20–28 kg) normal dogs. Method: Ten canine cadavers were evaluated using magnetic resonance imaging in neutral, flexed and extended position. For-aminal ratios, areas and lumbosacral angles were calculated and their relationship to body weight was evaluated. Results: Foraminal ratios were found to be independent of body weight in medium sized dogs (p >0.42). Foraminal areas were dependent on body weight (p <0.05). Flexion and extension were shown to significantly change both the foraminal ratio and area. Clinical significance: Lumbosacral forami-nal stenosis is common in working dogs. Foraminal ratios were evaluated in medium-sized dogs and were found to be independent of body weight, which may provide objective evaluation of surgical decompression techniques if calculated pre- and post-surgery. Foraminal areas were not independent of body weight.