Cervical hyperextension injuries are common and often show minimal radiographic abnormalities, even with severe or unstable lesions. Fourteen patients, nine with acceleration hyperextension "whiplash" injuries and five injured by direct frontal head trauma, underwent magnetic resonance (MR) imaging within 4 months of injury. Five of seven patients with anterior spinal column injuries showed characteristic separation of the disk from the vertebral end plate, lesions still evident as late as 9 months after injury. The demonstration of this type of lesion and its delayed resolution may have prognostic and surgical implications. These lesions, anterior longitudinal ligament injuries, anterior annular tears, and occult anterior vertebral end-plate fractures usually occurred at multiple levels except when preexistent degenerative disk narrowing reduced spine mobility. Seven patients had acute cervical disk herniations causing cord impingement. Radiographically occult injuries are well demonstrated with MR imaging, and findings correspond to previously described surgical and anatomical pathologic conditions.

Cervical spine myelopathy (CSM) is a clinical diagnosis made with imaging confirmation. At present, most clinical tests used to identify CSM are specific and no clusters of tests have proven more beneficial than stand alone tests in guiding treatment decision making. This study endeavored to produce a cluster of predictive clinical findings for a sample of patients using a clinical diagnosis/imaging confirmation as the reference standard for cervical spine myelopathy. Data from 249 patients with various conditions associated with cervical spine dysfunction were analyzed to determine which clinical tests and measures, when clustered together, were most diagnostic for CSM. Using multivariate regression analyses and calculations for sensitivity, specificity, and positive and negative likelihood ratios, a definitive cluster was identified. Thirteen clinical findings were investigated for capacity to diagnosis CSM. Five clinical: (1) gait deviation; (2) zHoffmann's test; (3) inverted supinator sign; (4) zBabinski test; and (5) age .45 years, were demonstrated the capacity when clustered into one of five positive tests to rule out CSM (negative likelihood ratio50.18; 95% CI50.12-0.42), and when clustered into three of five positive findings to rule in CSM (positive likelihood ratio530.9; 95% CI55.5-181.8). This study found clustered combinations of clinical findings that could rule in and rule out CSM. These clusters may be useful in identifying patients with this complex diagnosis in similar patient populations.

There are limited data detailing the pattern of age and gender-related changes to the thoracic vertebral bodies and intervertebral discs. A retrospective MR investigation, involving T1-weighted midsagittal images from 169 cases, was undertaken to examine age influences on the anterior wedge (anteroposterior height ratio or Ha\Hp), biconcavity (midposterior height ratio or Hm\Hp), and compression indices ( posterior height\anteroposterior diameter or Hp\D) of the thoracic vertebral bodies. Disc degenerative changes in the annulus, nucleus, end-plate and disc margin were noted on T2-weighted sagittal images for the 169 cases, based on a 3-level grading system. A linear age-related decline in the Ha\Hp and Hm\Hp indices was noted. The Hp\D index increased during the first few decades of life, then decreased gradually thereafter. The prevalence of abnormal findings in the annuli, nuclei and disc margins increased with increasing age, particularly in the mid and lower thoracic discs. Greater disc degenerative changes were observed in males. These findings provide further insight into the nature of thoracic vertebral shape changes across the lifespan, and the typical patterns of degeneration of the thoracic intervertebral discs.

The computed tomographic (CT) appearance of splenic infarction has classically been described as peripheral, wedge-shaped, and low in density. Two investigations were designed to determine the appearance of splenic infarcts: (a) a clinical study of 12 patients and (b) a canine experimental model. In the clinical study, two previously undescribed patterns of splenic infarction were found. The classic peripheral, wedge-shaped defects were seen in four patients; multiple, heterogeneous lesions were seen in five; and massive hypodense lesions were noted in three. In three of the nine patients who had both precontrast and postcontrast CT scans, the unenhanced images alone would not have permitted the diagnosis. Contrast enhancement markedly improved infarct visualization in the remaining six. The experimental study of splenic infarction in dogs indicated that CT images can accurately depict the various phases of an infarct as it evolves through stages of congestion, hemorrhage, inflammation, organization, and fibrosis. In addition, a new contrast material--liposome-encapsulated diatrizoate--was used in one of the dogs and was found to produce greater and more sustained differences between normal and abnormal tissue than did conventional contrast material.

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