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Biomedical subjects

K H Taber

Publications and source records attributed to K H Taber.

At least 19 recordsLinked to original sources

Surgical anatomy of the temporal bone: an atlas.

This atlas demonstrates the usefulness of reconstructed high-resolution CT for planning temporal bone surgery. The first part focuses on a sagittal plane, the second on a rotated longitudinal plane, and the third on a rotated transverse plane. We believe knowledge of temporal bone anatomy in these planes facilitates surgical planning by showing anatomic relationships and providing a customized map for each patient. This decreases the likelihood of surgical mishap and improves teaching.

Anatomy, Artistic↗

Cost-effectiveness of universal cystoscopy to identify ureteral injury at hysterectomy.

OBJECTIVE: To evaluate the cost-effectiveness of routine cystoscopy at the time of abdominal, vaginal, and laparoscopically assisted vaginal hysterectomy in terms of cost per ureteral injury identified and treated. METHODS: Using a hospital-based perspective, a decision-analysis model was constructed to estimate the outcomes and costs of cystoscopy or no cystoscopy at the time of abdominal hysterectomy. A similar model was constructed for vaginal and laparoscopically assisted vaginal hysterectomy to account for the cost of conversion to laparotomy. Cost estimates were based on estimated costs of Duke University Medical Center and from average Medicare reimbursements for similar Diagnostic Related Groups from the Health Care Financing Administration. The incidence of ureteral injury was obtained from a review of the literature. Sensitivity analyses were performed for the following variables: ureteral injury rate, silent ureteral injury rate, cost of cystoscopy, and cost of therapeutic interventions. We assumed a silent renal death rate of 0%. RESULTS: Routine cystoscopy at abdominal hysterectomy was cost-saving above a threshold ureteral injury rate of 1.5%. At a ureteral injury rate of 0.2%, the marginal increase in the cost of routine intraoperative cystoscopy was $108 per abdominal hysterectomy, with an associated cost of $54,000 per ureteral injury identified. In comparison, at a ureteral injury rate of 2%, routine cystoscopy gave a marginal cost savings of $44 per hysterectomy, with a cost savings of $2200 per ureteral injury identified intraoperatively. At the baseline ureteral injury rate of 0.5%, routine cystoscopy had a marginally increased cost of $83 per hysterectomy, with an incremental cost-effectiveness of $16,600 spent per ureteral injury identified. The model constructed for vaginal hysterectomy and laparoscopically assisted vaginal hysterectomy yielded a threshold ureteral injury rate of 2%, above which routine cystoscopy was cost-saving. In both models, the incidence of ureteral injury and the cost of readmission were the two variables with the greatest influence on cost-effectiveness. CONCLUSION: The cost-effectiveness of routine intraoperative cystoscopy depends on the rate of ureteral injury independent of the route of hysterectomy. If that rate exceeds 1.5% for abdominal hysterectomy and 2% for vaginal or laparoscopically assisted vaginal hysterectomy, then routine cystoscopy is cost-effective.

Cost-Benefit Analysis↗

Use of reconstructed sagittal computed tomography images to plan middle cranial fossa surgery.

OBJECTIVE: To facilitate planning in temporal bone surgery for the middle cranial fossa approach by using sagittal reconstructed temporal bone computed tomography images. STUDY DESIGN: Comparison of anatomic measurements on random high-resolution, reformatted computed tomography scans of the temporal bone. METHODS: High-resolution computed tomography of 10 normal temporal bones in the axial and coronal planes was obtained, and two-dimensional sagittal reconstructions were performed using a commercial software program. Eight anatomical relationships between neural and/or vascular structures were measured. Representative images were inverted to recreate the plane of the middle cranial fossa approach. RESULTS: Anatomical relationships among the vestibule, superior semicircular canal, internal auditory canal, internal carotid artery, and middle cranial fossa exhibited a high SD in the 10 subjects. The sample size and the large range for the eight anatomical relationships precluded the detection of a significant difference between right and left temporal bones or sex and age of the patient. CONCLUSION: The present report presents a novel, practical measurement protocol for rapidly evaluating important individual anatomical differences in patients before middle cranial fossa surgery. Inverted sagittal reconstructions facilitate presurgical planning for the middle cranial fossa approach by 1) assessing critical anatomical relationships before surgery and 2) providing customized measurements between vital landmarks and the first in vivo measurements. This decreases the likelihood of surgical mishaps and improves teaching by providing the first in vivo measurements of practical anatomical relationships in the sagittal plane.

Adult↗

In vivo measurements of temporal bone on reconstructed clinical high-resolution computed tomography scans.

PURPOSE: To retrospectively assess the accuracy of measurements of temporal bone anatomy made from reconstructed clinical high-resolution computed tomography (HRCT) scans. METHODS: Nine HRCT scans were performed on unselected clinical cases in which the subjects had a temporal bone study judged to be normal. The orbitomeatal line was prescribed for the direct axial sections. Variations in head position (rotation at the neck and lateral bending of the neck) were corrected by using the software supplied by the manufacturer. All measurements were done on standard 1-mm axial sections and axial reconstructions obtained from 1-mm coronal slices. The images were viewed at 4000 Hounsfield units (HU) window width and 1000 HU window level. Measurements (n = 3) made on 1-mm direct axial HRCT scans were compared with the measurements made on reconstructed axial HRCT images from the same nine patients. These values were also compared with published cadaver data. RESULTS: The measurements obtained from axial reconstructed and direct HRCT series approximated each other in each of the nine individual studies and also fell within the range of published cadaver values. They demonstrated the expected normal temporal bone variability between individuals. CONCLUSION: Useful anatomic approximations can be measured in vivo from reconstructed clinical HRCT images. Pitfalls are improper window settings, head tilt, and rotation. This protocol is widely available and can be implemented retrospectively from clinical HRCT scans.

Adult↗

Functional neuroanatomy of the frontal lobe circuits.

This article summarizes the current theories regarding the locations and functions of the three primary frontal lobe circuits. It forms the framework for structuring functional magnetic resonance imaging investigations. It can be used to assist in (a) detecting subtle lesions of the frontal circuits and (b) applying the current theories of neuropsychiatry to assess prognosis and to plan rehabilitation.

Brain Diseases↗

Spinal disease in neurologically symptomatic HIV-positive patients.

We review the MRI findings of human immunodeficiency virus (HIV)-positive patients with "spinal" symptoms and review the literature. In 23 consecutive HIV-positive patients presenting with acute neurologic complaints thought to be referable to the spine, we reviewed spinal MRI, medical charts, and laboratory, pathologic, and autopsy data. In the early stages of HIV infection, the common causes of spinal complaints (i. e., degenerative spine and disc disease) predominated. However, pathology may be missed without contrast-enhanced MRI of the spine. In more advanced cases, the differential diagnosis includes one or more neoplastic and/or infectious causes which require contrast-enhanced MRI for detection. In these cases, normal cerebrospinal fluid findings should not preclude contrast-enhanced MRI of the spine. Imaging of the brain may also be indicated in cases when the spinal study is negative.

AIDS-Related Opportunistic Infections↗