dxparaspinalus2

The predictive value was 1.53 for positive findings and 0.13 for negative findings (27).

Naidich retrospectively evaluated spinal sonography with myelograms and intraoperative photographs to determine how effectively sonography could display the major features of congenital anomalies in children. Sonography proved useful for confirming the presence of tehtered cord, simple meningocele, lipomyelomeningocele, sacrococcygeal teratoma, and pilonodal sinus (23).

Hides has done extensive evaluation of the paraspinal multifidus muscle utilizing ultrasonography (9-12). If a strict protocol for ultrasound imaging is adhered to, comparison with MRI demonstrated that real-time ultrasound imaging effectively documented muscle size (12). Findings of atrophy have led to implementation of rehabilitative strengthening techniques and have been offered as an explanation for recurrent low back

pain (9,10).

Nazarin computed Receiver - operating - characteristic (ROC) curves generated by data from blinded reading of images to conclude that paraspinal ultrasonography is neither a sensitive nor specific modality for evaluating back pain. Despite this rather broad conclusion, the study was directed toward the use of diagnostic ultrasound for the evaluation of paraspinal inflammation only (34). Due to the blinded nature of the ROC analysis, the ultrasonographically important feature of real-time interpretation was lost.

Proper anatomical structure identification is a necessary component to correct documentation of what was done. Kamei has described soft tissue and bony surface anatomical landmarks for paraspinal ultrasound studies (fig.1) (28) and cadaver studies have been done utilizing ultrasonography to study osseous structures versus paraspinal soft tissue structures (61).

In cases with incomplete spinal ligamentous disruption, MRI is not as sensitive as when complete tear occurs. In patients with severe enough acute traumatic spinal injury to merit immediate investigation, all MRI's

were normal if there was no evidence of spinal instability on clinical exam (54). In the past, radiologists have been cautioned to be judiciously careful in reporting anterior or posterior longitudinal ligament tears,

emphasizing a bias toward minimizing false positives (55). Presently, even with enhancements in MRI, the diagnosis of ligamentous instability still relies upon multiple factors, including X-Ray findings and clincal

assessment.

2. Cost Considerations:

Low back pain has shown high prevalence, longevity and expense. Estimated medical costs exceed $14 billion annually in the United States (40). Finding low cost alternatives to current imaging technologies is one of medical science's main thrusts toward reducing health care costs.

Since, in the hands of experienced operators, diagnostic ultrasonography has repeatedly been proven effective in the measurement of muscle and ligament mass, function and pathology associated with tears, overuse or edema (2-13), it is not surprising that it could be utilized as a cost saving alternative for the study of muscular or ligamentous strain in paraspinal tissues.

Ultrasonography is a noninvasive procedure with one-fifth to one-tenth the cost of MRI and computerized tomography (CT) (40). It allows comparison of the opposite side, uses no radiation, and can be performed at the bedside if necessary. It is important to keep in perspective what the different imaging techniques have to offer, and if one is just as efficacious as the other, the least invasive and least expensive should be chosen when ever possible (41).

3. Literature Review:

Autopsy studies, myelography, CT and MRI have all shown abnormalities in the absence of a spinal pain history (42-44,44,46,47). Studies on MRI have shown some type of disk abnormality in up to 64% of those without symptoms (48). While it is recognized for superior ability to distinguish between disk herniation, epidural fibrosis, arachnoiditis, infection, hematoma, cyst formation and other pathologies (49), other citations conclude that MRI cannot reliably identify the source(s) of discogenic pain, and that significant annular tears often escape detection (50).

Rupture of the supportive ligaments of the spine following trauma can be directly visualized with MRI (51); sagital T2-weighted images are most useful for depicting injury to the anterior and posterior longitudinal ligaments, ligamentum flavum, and interspinous ligaments (52). Hypertrophy and ossification of the ligamentum flavum is also identifiable with MRI (53).

Spinal ultrasonography has been compared with CT scans, discography, MRI and myelography (12,23,27). Tervonen compared transabdominal ultrasound images with CT/discography to determine the ultrasonographic effectiveness in screening for generalized disc lesions. The sensitivity of recognizing a discographically painful and deteriorated disc for ultrasound was 0.95, and its specificity was 0.38.