AJR. American journal of roentgenology
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AJR Am J Roentgenol · May 1992
Meta Analysis Comparative StudyDiagnosis of lumbar spinal stenosis in adults: a metaanalysis of the accuracy of CT, MR, and myelography.
We undertook a literature synthesis of CT, MR, and myelographic studies to evaluate what is known about the diagnostic accuracy of these imaging tests for the diagnosis of lumbar spinal stenosis in adults without prior surgery. From 116 possibly relevant studies, we reviewed 14 articles that included cases of spinal stenosis with a reference standard other than the imaging tests of interest. Of the studies we reviewed, two involved only MR, nine only CT, and three used both; six studies included myelography. ⋯ For the present, the choice between MR or CT depends on issues such as costs, reimbursements, access to equipment, skill of radiologists, and patient safety. Better studies will be needed to document claims for improvements in imaging accuracy as MR technologies evolve. These studies should emphasize larger sample sizes, more attention to research designs that avoid methodologic biases, and the contribution of imaging diagnoses to ultimate clinical outcome.
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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.