The utilization of intervertebral joint and longitudinal scanning allows the PLL and ALL tissues to be within the view of the sonogram, since it is not obscured by bony or other hard tissues. Spinal DUS Imaging DUS is noted as a diagnostic imaging modality that has increased sensitivity to pathological changes in regard to soft tissues. The identification of various osseous spinal landmarks has been identified with DUS,6,7,8,9 which is a necessary reference in identifying normal and abnormal conditions. Normal sonographic appearances of muscular, ligamentous and tendinous tissues have been determined and correlation of sonographic and histologic findings in abnormal or pathologic states have been monitored over specific periods of time.6,10 The sonographic appearance of tissue is definitely dependent on its current physiologic state. DUS of the spine is performed by placing a 5.0 MHz linear array transducer over the vertebrae in the transverse plane, aligned perpendicular to the segment being examined.
Acute injuries appear more echoic than resolving or chronic injuries.
The degree of inflammation is directly related to the severity of the lesion and resultant scarring. Sonographically, the PLL is located approximately 4-6 mm deep, anterior to the spinolaminar junction. The ALL is located approximately 7-8 mm deep. The actual location of these structures are dependent on the patient's age and body size. Although most of our understanding concerning the healing characteristics of ligaments comes from our peripheral joints, it can be assumed that spinal ligaments behave much the same.