Magnetic resonance imaging and ultrasonography of the lumbar multifidus muscle. Comparison of two different modalities.

STUDY DESIGN

An operator-blinded dual modality trial of measurement of lumbar multifidus muscle cross-sectional area was performed.

OBJECTIVE

To compare two imaging modalities used for measurement of the lumbar multifidus muscle.

METHODS

Ten normal female subjects aged 21-31 years were imaged on two separate days using magnetic resonance imaging and ultrasound imaging. Bilateral measurements were made at each vertebral level from L2-S1.

RESULTS

No significant difference was demonstrated between cross-sectional area measurements made with the two different modalities. Measurements of multifidus were symmetrical between left and right sides of the spine. For both modalities, a significant difference was demonstrated in the cross-sectional area of multifidus between each vertebral level from L2-S1.

CONCLUSIONS

The present study indicated that if a strict protocol for ultrasound imaging is adhered to, real-time ultrasound imaging can be used to document muscle size in young adults. Further studies are required to validate the technique in older subjects and in different conditions.