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Biomedical subjects

W N Hanafee

Publications and source records attributed to W N Hanafee.

18 recordsLinked to original sources

Computed tomography versus standard radiography in the assessment of fractures of the mandible.

Twenty-nine fractures of the mandible were studied by standard radiographs and axial computed tomographic scans (hard copy). Independent reviewers analyzed each study in a blinded, non-paired fashion. When radiographic diagnostic sensitivities were compared on the basis of known surgical findings, the plain films were found to have a higher diagnostic sensitivity (89%) than the hard copy computed tomograms (64%). This difference occurred primarily with images of nondisplaced fractures in posterior portions of the mandible, and is likely the result of tomographic orientation and volume averaging. Though computed tomography has emerged as the standard diagnostic test in evaluating intracranial and maxillofacial trauma, this study demonstrates that computed tomographic scanning alone is inadequate in excluding nondisplaced fractures of the posterior mandible.

Fracture Fixation, Internal

Meckel cave lesions: percutaneous fine-needle-aspiration biopsy cytology.

The authors describe the novel combination of two traditional methods to facilitate diagnosis of Meckel cave lesions, which may otherwise require craniotomy to obtain adequate tissue samples. Fine-needle-aspiration biopsy cytology was performed on tissue obtained with a percutaneous approach via the foramen ovale with use of fluoroscopic guidance and intravenous analgesia during an outpatient procedure. This new application of fine-needle-aspiration biopsy cytology results in decreased patient morbidity and significant cost reduction.

Adult

Nonneoplastic enhancing lesions mimicking intracanalicular acoustic neuroma on gadolinium-enhanced MR images.

The authors describe five patients with nonneoplastic lesions of the facial and/or vestibulocochlear nerves that demonstrated focal enhancement within the internal auditory canal on magnetic resonance (MR) images. MR and surgical findings for four patients with unilateral sensorineural hearing loss and one with Ramsay Hunt syndrome were reviewed. Three patients with hearing loss underwent surgical exploration and decompression of the internal auditory canal. The MR findings in all four patients with hearing loss were similar: Focal enhancement of the internal auditory canal was depicted on postcontrast T1-weighted images. Nonneoplastic lesions of the seventh and eighth cranial nerves may show focal enhancement on MR images, which mimics the appearance of a small intracanalicular neuroma. This potential for misdiagnosis may have important therapeutic implications.

Cranial Nerve Diseases

A comparative evaluation of computed tomography and laryngography.

A prospective study of 66 patients was conducted to evaluate the relative merits of computed tomography (CT) and laryngography in the assessment of laryngeal disorders. CT complemented direct laryngoscopy and biopsy for treatment planning and was superior to both modalities for showing deep infiltration, invasion of cartilage, and extension to the soft tissues of the neck. The subglottic space can be studied adequately by CT, which could also be useful in diagnosis of lymph node metastases. Distortion of the thyroid cartilage can be shown by CT. CT was equal to or better than laryngography in approximately 90% of cases.

False Negative Reactions

Computed tomography of the injured larynx.

Computed tomography (CT) permitted a much more detailed appraisal of laryngeal dysfunction in patients with blunt laryngeal trauma (8 cases) and iatrogenic injury caused by radiation therapy (7 cases), surgery (2 cases), or intubation (1 case). In thyroid cartilage fractures, the fragments may be widely displaced. The cricoid ring breaks in two places, frequently involving the signet. CT facilitates diagnosis of the mechanism of injury based on the site and extent of fractures. The patterns of distortion and fibrosis of the laryngeal cartilage following radiation therapy may be manifested as encroachment on the airway, easily mistaken for recurrent tumor or localized edema. Minor distortion probably escapes detection on clinical examination. The authors consider CT the examination of choice in laryngeal injury.

Adolescent

Extensions of paranasal sinus tumors and inflammatory disease as evaluated by CT and pluridirectional tomography.

CT and pluridirectinal tomography are compared in their ability to show the extent of paranasal sinus tumors or benign aggressive processes. Thirty-one cases are reviewed; CT was superior to pluridirectional tomography in showing spreads of tumor to all clinically important areas, including the infratemporal fossa, nasopharynx, orbit, and intracranial compartment. CT not only consistently allowed less equivocal interpretation, but also enabled us to qualify orbital involvement as intra- or extraconal, and to quantitate better both brain and infratemporal fossa involvement. We feel that CT scanning is the better way to determine the extent of such pathology.

Adult

Dilatation of the nasolacrimal duct under radiographic control.

Obstruction of the nasolacrimal duct is a major cause of epiphora, or tearing. The authors describe a method of dilating obstructions to re-establish drainage of the lacrimal sac which utilizes fluoroscopic control to stay within the natural lumen of the nasolacrimal duct. The procedure is simple to perform under local anesthesia. An unsuccessful dilatation does not interfere with subsequent dacrocystorhinostomy.

Catheterization

Incudostapedial joint in health and disease.

The incudostapedial joint was studied in tomograms of 370 normal and 80 diseased middle ears. The Guillen view was found to be superior to the anteroposterior view in demonstrating this joint in normal middle ears (85% and 62% visualization, respectively). In the presence of disease, visualization was markedly reduced to 19%; this lack of visualization is a nonspecific finding since early cholesteatomas, chronic otitis media, and retraction pockets could not be differentiated radiologically. Nonvisualization of the incudostapedial joint in the Guillen view is a more objective indicator of middle ear disease than such terms as "indistinct of hazy" middle ear cavities.

Ear Diseases

The value of sialography in the diagnosis of parotid tumors. A clinicopathological correlation.

The importance of sialography in the diagnostic evaluation of the condition of a patient with a parotid mass remains uncertain; some proponents advise use of sialography routinely, while others believe it to be worthless. To help resolve these conflicting opinions, a retrospective study of 40 patients was carried out that compared sialographical interpretations with respective surgical-histological findings. The results of this study show that generally reliable information, which may serve to influence therapeutic decisions concerning these patients, can be gleaned from sialography.

Humans

The role of computed tomography in the management of cancer of the larynx.

Computed tomography (CT) offers a unique method of displaying the anatomy of laryngeal cancer. Asymmetrical contours of the thyroid cartilages have been found as a normal variant. Marked asymmetry may indicate buckling of the cartilage which could contribute to acute airway obstruction following radiation therapy. A low-density, soft-tissue plane medial to the thyroid cartilages may prove valuable in evaluating cartilaginous involvement with tumor. Computed tomography should make a significant contribution to more accurate planning of radiation therapy portals by showing the relationship of lymphatic spread to the primary tumors.

Humans

The appendix of the ventricle of the larynx.

A review of 100 consecutive laryngograms showed visualization of the appendix of the laryngeal ventricle in 40% of cases. This high incidence of visulization is related to thorough anesthesia, repeated performance of phonation and the reverse "E" maneuver as well as awareness of the anatomical structure. The appendix of the laryngeal ventricle courses superiorly between the laryngeal vestibule and the thyroid cartilage which differentiates this normal structure from ulcerations and fistulous tracts of laryngeal tumors.

Anesthesia, Local

Phlebographic appearance and pathogenesis of venous malformations in the orbit.

A retrospective clinical and radiographic analysis of 20 patients with orbital venous malformations was performed. The malformations were fed by other veins rather than arteries. They may nearly always be demonstrated by orbital or jugular phlebography, though occasionally they will fill only following direct puncture. There appeared to be varied etiologies. A few were related to trauma or to other causes of increased intraorbital pressure. There is an association with periorbital hemangiomas suggesting developmental or congenital origin.

Adolescent

MR imaging-guided interstitial Nd:YAG laser phototherapy: dosimetry study of acute tissue damage in an in vivo model.

A dosimetry study of acute tissue damage induced by interstitial application of the neodymium-yttrium-aluminum-garnet (Nd:YAG) laser was performed with magnetic resonance (MR) imaging. The MR appearance of the lesion was correlated with gross and histopathologic findings. Seventy-six lesions were induced in rabbit muscle with laser power outputs of 5-20 W and exposure times of 20-600 seconds. MR imaging was performed immediately after laser exposure. T2-weighted spin-echo images clearly showed the acute thermal injuries caused by laser energy deposition and correlated best with histopathologic findings. These images showed three distinct layers, corresponding to central ablation, coagulative necrosis, and interstitial edema, respectively, in the pathologic findings. Lesion diameters measured on MR images showed a linear correlation with those in gross sections. Lesion volume increased not only with increasing total energy delivered but with increasing power output for a fixed total energy delivered. MR imaging is an accurate modality for dosimetry studies of laser-induced acute lesions.

Animals

Diagnosis and treatment of carotid body tumors.

The diagnosis and management of carotid body tumors are discussed, including the importance of good arteriography which allows visualization of all major feeding vessels. These include the carotid bulb, internal and external carotid arteries and the often neglected but important vertebral and ascending cervical arteries. Emphasis is placed on the importance of establishing tourniquet control of the common, internal and external carotid arteries. Surgeons removing carotid body tumors should be experienced in arterial wall repair by means of vascular shunts, end-to-end arterial anastomosis, and vein graft replacement of a segment of arterial wall.

Angiography

Computerized tomography scanning of the temporal bone.

Computerized tomography (CT) scanning has reached a degree of sophistication that requires alteration of technical factors to demonstrate different parameters of temporal bone pathology. The techniques for pontocerebellar angle display, eustachian tube, middle ear pathology, and overall temporal bone display are quite different. Close cooperation between the radiologist and otologic surgeon are required for optimal use of CT scanning advances.

Adult

Fat-suppression failure artifacts simulating pathology on frequency-selective fat-suppression MR images of the head and neck.

PURPOSE: To describe fat-suppression failure artifacts and to caution against their misinterpretation. METHOD: Magnetic-susceptibility artifacts were studied in a phantom model and the results were compared to MR images obtained in clinical cases. FINDINGS: Artifacts manifested themselves as regions of focal fat-suppression failure and appeared as bright signals without geometric distortions at magnetic-susceptibility interfaces along the static field (z) direction. The location and extent of these artifacts were independent of either frequency or phase-encoding direction and are different from those observed in gradient-echo images. CONCLUSIONS: In representative clinical MR exams, these artifacts were identified in the high nasopharynx and low orbit and should not be misinterpreted as pathology.

Artifacts