Potential value of three-dimensional ultrasonography in diagnosing muscle injuries in comparison to two-dimensional examination--preliminary results.

BACKGROUND: Two-dimensional ultrasonography (2D-US) has become a widely used and accepted diagnostic tool in musculoskeletal disorders. Its utility in the evaluation of muscle injury and pathology is generally recognised. In contrast, the place and role of three-dimensional US imaging (3D-US) in the diagnostic work-up of musculoskeletal conditions are still not recognised even though 3D-US is a well-established technique in, for example, obstetrics. The aim of this study was to find out if it is possible to assess lesions of muscles more accurately and with more detail using the 3D technique in comparison to 2D imaging. MATERIAL AND METHODS: The study involved 14 patients aged 16-39 years (mean age 24.8 yrs) with muscle injuries and 2 volunteers to determine the best technique of performing the examination and acquiring images that can best visualise the structure of muscles. The 2D and 3D images were compared with respect to visualisation of lesions and their size. It was also investigated whether the additional third "Z" plane could furnish relevant information regarding the visible lesion. RESULTS: The results of evaluation of features and size of the lesions in the muscles were very similar and reliable with both modalities. For small lesions, measurements of their size differed slightly. The differences were bigger for bigger lesions. Additional information leading to re-classification of the type of the lesion or more precise delineation of its margins was obtained in 6 of the 14 cases (42.8%). The duration of a 3D study was usually longer with bigger lesions. The 3D-reconstructed model helped in better visualising and understanding the anatomical relations of the injured muscle with surrounding tissues. Recording data as volume scans made possible later re-assessment of images and their independent verification by a consultant at any desired time. CONCLUSIONS: 1. 3D US imaging is as reliable and accurate as the 2D technique in the assessment of muscle injuries. In some cases, especially with smaller lesions, the borders and type of the lesion are better visualized with the additional third plane. Additional information regarding the location of the lesions in the frontal plane can be obtained with 3D imaging. It is more difficult to assess whole lesions of greater size requiring two or more volume scans. The acquisition of volume data enables the reading of images at any desired time and also makes it possible to ask a consultant to verify the findings.