AJR. American journal of roentgenology
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Infection of the spine is a major category of spinal disease that is difficult to differentiate clinically from degenerative disease, noninfective inflammatory lesions, and spinal neoplasm. The infection can affect the vertebrae, intervertebral disks, paraspinal soft tissues, the epidural space, the meninges, and/or the spinal cord. ⋯ Imaging plays an important role in the overall evaluation of these lesions, and the ideal technique is expected to provide information that will help characterize and delineate the disease process, guide biopsy and/or drainage procedures, suggest method of treatment (medical vs surgical), and assess response to therapy. The aim of this article is to review the advantages and limitations of MR imaging in the management of spinal infections.
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AJR Am J Roentgenol · Jun 1992
MR imaging of the shoulder: appearance of the supraspinatus tendon in asymptomatic volunteers.
MR imaging has been shown to be accurate in the diagnosis of rotator cuff disruption and tear. Uncertainty remains about the significance of increased signal intensity in the critical zone of the supraspinatus tendon without visible disruption of tendon fibers and about the significance of other secondary findings commonly encountered with rotator cuff abnormalities, such as musculotendinous retraction or obliteration and fluid in the subacromial space. We evaluated proton density-weighted and T2-weighted coronal images (obtained on a 1.5-T superconductive MR imager) of 55 shoulders in 32 asymptomatic volunteers for signal intensity in the supraspinatus tendon, location of the musculotendinous junction, fluid in the subacromial-subdeltoid space, and appearance of the fat plane. ⋯ The musculotendinous junction was always located within an area 15 degrees medial to 30 degrees lateral to the highest point (12 o'clock) on the humeral head convexity. A peribursal fat plane was poorly defined or absent in 49%, and fluid in the subacromial-subdeltoid space was found in 20%. Increased signal intensity in the supraspinatus tendon on proton density-weighted images without a corresponding increase on T2-weighted images, the presence of small amounts of fluid in the subacromial space, and the lack of preservation of the subdeltoid fat plane are common findings in asymptomatic shoulders and by themselves are poor predictors of rotator cuff disease.
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AJR Am J Roentgenol · May 1992
ReviewDuplex Doppler evaluation of native kidney dysfunction: obstructive and nonobstructive disease.
Intrarenal duplex Doppler sonography can provide physiologic information reflecting the status of renal vascular resistance. Available data suggest 0.70 as a reasonable upper limit for normal intrarenal resistive index. Complete or significant partial urinary obstruction produces a prompt elevation in the resistive index that is not produced by purely nonobstructive dilatation; hence, Doppler imaging appears useful in evaluating the dilated, possibly obstructed kidney. ⋯ Recent biopsy series, although correlating certain pathologic findings with resistive index, also indicate that renal Doppler sonography is not sensitive or specific enough to replace renal biopsy. To date, Doppler study of renal medical disease has proved most useful in two types of applications: monitoring of patients with renal disease known to produce resistive index elevation and differentiating between renal diseases where one produces more marked Doppler changes than the other. Resistive index is clearly not identical to creatinine level; in some instances the resistive index may provide unique noninvasive information regarding renal arterial resistance not available from conventional laboratory parameters.