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To evaluate the impact of an emergency department (ED) automatic preauthorization policy on after-hours utilization of neuroradiology computed tomography (CT).
All CT studies of the head with contrast facial bones, orbits, spine, and neck requested through the ED and performed between January 1, 2004, and December 31, 2010, were reviewed. The preauthorization policy was instituted on February 25, 2008. A control group of noncontrast CT head studies was used for comparison. Pre- and postpolicy implementation utilization rates were compared between the control group of noncontrast CT head studies and the study group neuroradiology CT studies.
During the study period, 408,501 ED patient visits occurred and 20,703 neuroradiology CT studies were carried out. The pre- and postimplementation groups of noncontrast CT head scans totalled 7,474 and 6,094, respectively, whereas the pre- and postimplementation groups of all other neuroradiology CT studies totalled 3,833 and 3,302, respectively. The CT utilization between the two groups did not differ significantly: the noncontrast head group pre- and postpolicy implementation increased by 0.31 to 3.41%, whereas the utilization of all other neuroradiology CT studies increased by 0.22 to 1.84% (p value = 0.061 for a difference between groups).
Implementation of an automatic preauthorization policy for after-hours neuroradiology CT studies did not result in a statistically significant increase in CT utilization. This suggests that concerns regarding the negative effects of such policiesmay be unfounded, and further research in this area is warranted.
Blunt cerebrovascular injury (BCVI) to the carotid and vertebral arteries is a potentially devastating injury in trauma patients. The optimal management for BCVI has not been standardized. At our institution, 64-slice multi-detector computed tomographic angiography (CTA) has been used as the initial screening exam for BCVI in patients who met predefined screening criteria. The purpose of this study is to review the incidence of CTA-diagnosed BCVI in at-risk patients and to evaluate the treatment and clinical outcome of patients with BCVI.
This study included trauma patients with a positive diagnosis of BCVI on CTA during a 41-month study period. The medical records and relevant radiographic findings were retrospectively reviewed.
Twenty seven of 222 blunt trauma patients evaluated with CTA had a positive diagnosis of BCVI, with an occurrence rate of 12.2%. Traumatic brain injury (72.2%) and basal skull fractures (55.6%) were the most frequent associated injuries with carotid trauma while 100% of blunt vertebral injuries occurred in the setting of cervical fractures. Fourteen (51.8%) patients received medical therapy; Eleven (40.7%) patients received conservative treatment. Endovascular treatment was attempted in a single case of vertebral arteriovenous fistula. BCVI-related stroke was found in four patients (14.8%), one of whom developed an infarct while on medical treatment.
BCVI is found in a significant portion of blunt trauma patients with identifiable risk factors, and screening CTA has high diagnostic yield in detecting these lesions. Medical therapy is the mainstay of treatment at our institution; however, BCVI-related stroke may occur despite treatment.
To compare the efficacy of computed tomographic angiography (CTA) to that of digital subtraction angiography (DSA) in the detection of secondary causes of intracerebral hemorrhage (ICH).
Between January 2001 and February 2007 there were 286 patients that had both CTA and DSA for intracranial hemorrhage of all types. Those with primarily subarachnoid hemorrhage or recent trauma were excluded. Fifty-five patients formed the study cohort. Three reviewers independently analyzed the CTAs in a blinded protocol and classified them based on presence or absence of a secondary etiology. Results were compared with the reference standard DSA and kappa values determined for interobserver variability.
The overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CTA were 89%, 92%, 91%, 91% and 91%, respectively. Kappa value for interobserver agreement ranged from 0.78 to 0.89. Two of four dural arteriovenous fistulas (dAVF) were missed on CTA by all three reviewers.
CTA is nearly as effective as DSA at determining the cause of secondary intracerebral hemorrhage, but with a lower sensitivity for dAVFs. This supports the use of CTA as the first screening test in patients presenting with spontaneous ICH.
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