Spinal aneurysm of the lateral sacral artery. Case report.

Spinal aneurysms are rare, and those not associated with either an arteriovenous malformation or coarctation of the aorta are particularly rare. In this report, the authors present a case of spinal aneurysm involving the lateral sacral artery. The aneurysm presented as a cauda equina syndrome 6 years after the patient underwent a renal transplant contralateral to the side of the aneurysm parent vessel. To the authors' knowledge, only one similar case has been previously reported. They conclude that spinal aneurysms should be included in the differential diagnosis of an extramedullary spinal mass lesion.

Acute optic neuritis: association with paranasal sinus inflammatory changes on magnetic resonance imaging.

The authors compared the frequency of paranasal sinus inflammatory changes (SIC) on brain magnetic resonance imaging (MRI) obtained from 23 patients with new onset acute optic neuritis (ON) and 48 control patients who underwent outpatient MRI of the brain for reasons other than ON. The authors found a higher frequency of paranasal SIC in patients with ON (83%) than in controls (54%) (p = 0.02). The distribution of paranasal SIC (in ON and in controls) was maxillary (83% and 52%), ethmoid (4% and 2%), frontal (9% and 14%), and sphenoid (4% and 10%). Frequency of the maxillary SIC was significantly higher (p = 0.02) in patients with ON than in controls. Further evaluation of maxillary paranasal SIC with a grading system showed the presence of thickened mucosal lining of the sinuses (grade I) in 17% (ON) and 23% (controls), mucous retention cysts within the sinuses (grade II) in 48% (ON) and 25% (controls), and severe mucosal thickening with complete or near-complete filling of the sinus or an air-fluid level within the sinus (grade III) in 17% (ON) and 4% (controls). Combined frequency of grade II and grade III SIC was significantly higher in the ON group than in controls (p = 0.005), as was the frequency of grade III SIC alone (p = 0.02). Grade I SIC did not significantly differ between the groups. There was a trend (p = 0.09) toward a higher prevalence of bilateral sinus inflammatory changes in patients with bilateral ON. These findings suggest that ON may be associated with sinus inflammatory changes.

Experience with implementation of a radiology speech recognition system.

Recent advances in speech recognition technology have allowed development of computer systems for real-time radiologist-driven generation of reports. The transition to a speech recognition system is a technically complex process with many potential pitfalls that can decrease efficiency and disrupt workflow. In our recent experience with installation of such a system in an academic radiology department, factors that have worked against optimal performance have included environmental logistics, hardware incompatibilities, radiology information system interface problems, lack of suitable training, and inadequate technical support. Communication of our experience is intended to allow radiologists to anticipate complications of these systems and make informed decisions regarding the feasibility of such a system in their practices. With this information, potential buyers should be able to carefully scrutinize specifications for prospective systems and, by avoiding many of the possible pitfalls, make an easier transition to a speech recognition environment.

Granulomatous amebic encephalitis caused by acanthamoeba.

Infections arising from free-living amebae are rare. They generally cause recognizable disease only in chronically ill, debilitated patients who are immune suppressed. Only about 70 cases of granulomatous amebic encephalitis have been reported. We present an unusual case of granulomatous encephalitis in a 35-year-old man. Neurologic examination and laboratory tests were inconclusive. CT demonstrated bilateral low-density areas with mild mass effect in the cortex and subcortical white matter, which showed increased signal on T2-weighted MRI. Craniotomy and brain biopsy revealed granulomatous encephalitis with acanthamoeba organisms. Though non-specific, imaging can support the diagnosis of amebic encephalitis and direct biopsy.

Cervical spondylotic myelopathy treated with corpectomy: technique and results in 44 patients.

Forty-four patients with cervical spondylotic myelopathy who underwent a ventral surgical approach were evaluated with respect to the results of surgery. The neurological status of the patients was categorized according to the modified Japanese Orthopedic Association scale (0-18). Three patients had a functional score of 8, one patient 9, five patients 10, five patients 11, seven patients 12, seven patients 13, seven patients 14, and nine patients had a functional score of 15, preoperatively. Twenty-three patients underwent a one-level corpectomy, 15 patients a two-level corpectomy, and six patients underwent a three-level corpectomy. Forty-one (93.1%) of the 44 patients underwent ventral cervical plate fixation. Complications among the 44 patients included graft- and instrumentation-related complications in seven cases, iliac crest donor-site infection in three cases, and respiratory complications in three cases. The follow-up periods ranged between 7 and 60 months (mean 42.3 months). Overall, the fusion rate was 97.72%. Three patients showed no functional change (6.8%), two patients were worse (4.5%), and 39 patients (88.6%) showed functional improvement in their score between +1 and +6 points (mean 2.16 points). There was no statistically significant difference in the functional improvement score in patients younger or older than 60 years old. The mean improvement in the functional score was found to be +2.857 +/- 1.352, +2.400 +/- 1.454, and +0.5000 +/- 1.871 following one-level corpectomy, two-level, and three-level corpectomies, respectively. There were statistically significant differences in the neurological improvement observed between patients with one-level corpectomy and three-level corpectomy (p < 0.01), as well as between those with two-level and three-level corpectomy (p < 0.05). There was no statistically significant difference in the neurological outcome between patients with one-level and two-level corpectomy (p > 0.05). The results of this study demonstrate a high rate of solid bone fusion and a high rate of functional (neurological) improvement. Five patients underwent reoperation, predominantly for instrumentation failure. The use of instrumentation dictates careful consideration of the risk/benefit ratio associated with its use in each case.

A comparison of fluoroscopy and computed tomography-derived volumetric multiple exposure transmission holography for the guidance of lumbar pedicle screw insertion.

Holographic technology has recently been modified in such a manner that it may now provide clinical use. It allows the visualization of complex structures in three dimensions and permits clinician interaction with the image, which, in turn, provides significant additional geometric and anatomic information. To objectively assess the potential clinical applicability of holography in pedicle screw placement, we studied 11 elderly human cadavers. All of the cadavers, each of which showed significant degenerative disease of the lumbar spine, underwent thin-section computed tomographic scans of the lumbar spine. The acquired digital information was processed, and volumetric multiple exposure transmission holographic images were rendered. Pedicle screws were passed into anatomically acceptable and radiographically visualized L3-L5 pedicles in each cadaver, half using fluoroscopic guidance and half using holographic guidance alone. The accuracy of screw placement was objectively assessed by a three-point grading scale. The total score for the placement of each pedicle screw was determined by both trajectory (location within the pedicle) and accuracy (containment within the vertebral body) of screw tip placement parameters. Three points were possible for each screw placed. Screw placement in the last six cadavers was individually timed for each technique, and fluoroscopic time was also recorded. Each technique was used on 27 pedicles. The total score for fluoroscopic screw placement was 71 (71 of a possible 81; 88%) and for holographic screw placement was 74 (74 of a possible 81; 91%). In the last six cadavers, the screw placement time (per cadaver) was 8 minutes for fluoroscopic placement and 3.6 minutes for holographic placement. Fluoroscopic time averaged 1.9 minutes per cadaver.(ABSTRACT TRUNCATED AT 250 WORDS)

Anatomy of the thoracic pedicle.

Thoracic pedicle anatomy (interpedicular distance, transverse and sagittal pedicle widths, transverse and sagittal pedicle angles, and the distance from the axis of the pedicle to the axis of the transverse process) was assessed in 11 cadavers of elderly people. The cadaveric spines were extensively dissected to augment the accuracy of the measurements via caliper and goniometer. The results were compared with those of previous studies that assessed pedicle anatomy with computed tomography, direct measurement, and three-dimensional morphometry. Between the studies, significant differences were found in transverse pedicle width and transverse and sagittal pedicle angles. These morphometric differences may reflect either the diversity of the techniques used to measure the pedicle anatomy or sampling variation. This article presents a previously unreported morphometric finding, the rostral-caudal distance from the thoracic pedicle to the midpoint of the base of the transverse process. At T1, the transverse process is 5.45 +/- 1.2 mm rostral to the pedicle. This relationship gradually changes as the thoracic spine is descended, so that at T12, the transverse process is 6.6 +/- 2.4 mm caudal to the pedicle. Crossover consistently occurs at the T6-T7 region. Although the transverse process is a reliable external landmark for the location of the pedicle in the lumbar spine, this relationship in the thoracic spine is variable and only moderately predictable.