Localized Fat Deposit in Paralumber Region Presenting as Palpable mass : Sonographic Diagnosis Using Color Doppler Artifact

The purpose of this study was to describe the role of sonographic diagnosis using color Doppler artifact in the evaluation of localized fat deposits resembling masses in the paralumbar regions. Seven patients underwent back sonography with color Doppler imaging because of clinical suspicion of soft tissue, painless masses of the lower back. The sonograms were obtained using a 5MHz linear phased-arry transducer. Color Doppler imaging was performed for the palpable lesions. While compressing and releasing a lesion with a transducer, the sonographer observed the movement of the lesion which was subsequently reviewed on a frame-by-frame basis using a cine loop function. The localized fat deposits were iso echogenic to adjacent subcutaneous fat. The deposits had indistinct margins and formed movable lesions in the deep paralumbar compartment. Color Doppler imaging showed paradoxicalcolor mapping of these lesions during compression studies. Our results suggest that real time sonography and Color Doppler imaging with compression studies are useful in the diagnosis of localized fat deposits and in the differential diagnosis of soft tissue masses