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Biomedical subjects

W Hanafee

Publications and source records attributed to W Hanafee.

At least 37 records · Page 2Linked to original sources
PubMed1986

Dynamic-range compression in surface-coil MRI.

The large dynamic range in signal intensity present in MR surface-coil images makes proper windowing and photography difficult. By removing the low-spatial frequency information caused by variations in surface-coil field intensity from the high-spatial frequency information containing the image data, a considerable compression of this dynamic range of signal intensity is possible. To accomplish this, a technique was implemented on a digital computer for use with MR surface-coil image data. The compression was done as a postprocessing option after the patient scan had been completed and therefore did not alter actual scan times. Although the image signal-to-noise was not altered, the ease of photography for most images was improved. Thus, digital dynamic-range compression is a practical technique to aid in surface-coil MRI studies.

Adenocarcinoma↗
PubMed1986

Magnetic resonance imaging of the facial nerve. Normal anatomy and pathology.

Magnetic resonance imaging with surface coils permits visualization of the facial nerve from within the brainstem and continuing through a major portion of the parotid gland. Diagnostic capabilities have been expanded to include white matter disease that affects the tracts of the facial nerve within the brainstem and tumors of the parotid gland that involve the facial nerve trunks after the nerve exists from the stylomastoid foramen.

Facial Nerve↗
PubMed1986

Magnetic resonance imaging of the nasopharynx and skull base.

Ten patients with a normal nasopharynx and 36 patients with pathology of the nasopharynx or skull base were studied with magnetic resonance imaging (MRI). Four millimeter thick axial, coronal, and often sagittal scans were obtained using SE 500/28 and SE 2000/56 pulse sequences. The normal scans were compared with cadaver cryosections. Correlation was made with computed tomography (CT) scans as well as with clinical history and physical examination whenever possible. MRI clearly provided superior information compared with CT and other imaging studies. Advantages of MRI over CT include 1) the delineation of tumor infiltrations of the longus colli muscles, rectus capitus muscles, and muscles of mastication, 2) demonstration of tumor extensions into the skull base or parapharyngeal spaces, and 3) demonstration of both normal and pathologic cranial nerves. For all these reasons, MRI is currently the imaging study of choice for pathology of the nasopharynx and skull base.

Adult↗
PubMed1985

CT-directed fine needle aspiration biopsies of masses in the head and neck.

Fine needle aspiration (FNA) biopsy is a safe, reliable, and cost-effective technique available for the evaluation of head and neck masses. Its utility is enhanced by the use of CT-directed aspiration. Candidates for CT-directed FNA include patients with: 1. deep-seated lesions; 2. distorted anatomy as a result of surgery or irradiation; 3. medical problems which contraindicate general anesthesia. The initial UCLA experience with this modality is reviewed. In certain clinical settings, CT-directed FNA can be a highly productive source of clinical information.

Adenocarcinoma↗
PubMed1984

Computed tomography-guided aspiration cytologic examination in head and neck lesions.

Aspiration cytologic examination, as distinguished from needle biopsy, may be performed with 22- to 25-gauge needles with an extremely low complication rate. For deep-seated lesions, computed tomography guidance is helpful to ensure that the needle tip is correctly within the tumor mass and that vital structures have been avoided. Lesions of the skull base, nasopharyngeal region, and infratemporal fossae are readily accessible with this approach.

Adult↗
PubMed1984

Computed tomography in medial maxilla-orbital fractures.

The frontal process of the maxilla together with the anterior wall of the antrum constitute a major support of the midface. If this is fractured and goes unrecognized, serious facial deformities result. Fractures through this process occurred in 13 of 50 patients who received computed tomographic examination for facial trauma. The fracture had been missed on plain film examination in all but three of the 13 patients. The frontal process is usually displaced directly posteriorly in the more complex midface fractures. It may rotate about its long axis when associated with trimalar fractures and in some of the isolated injuries of the medial maxilla. Computed tomography is the ideal technique for demonstrating these fractures because of ease of examination, optimal anatomical display for demonstrating rotational and posterior displacements, and superior contrast in the severely traumatized facial skeleton.

Facial Injuries↗
PubMed1984

Spread of carcinoma of the base of the tongue as detected by computer tomography.

21 patients with histologically proven carcinoma involving the base of the tongue were studied with computer tomography utilizing a high dose of intravenous infusion of contrast material. Computer tomography demonstrated not only excellent visualization of the primary carcinoma at the base of the tongue, but also its traditional means of spread to contiguous soft tissues of the pharyngeal walls and lymph node metastasis. Computer tomography also demonstrated the unusual spread to the retropharyngeal lymph nodes and nasopharynx. Computer tomography with high-dose intravenous contrast is the best radiographic modality for the evaluation of carcinoma of the base of the tongue.

Adult↗
PubMed1983

High resolution CT scanning for detection of cholesteatoma and complications in the postoperative ear.

Otologists who prefer intact canal wall surgery for removal of cholesteatoma recognize a 12.25% return rate. Revisions often indicated to correct hearing loss are frequently negative for recurrent cholesteatoma. To determine the reliabiity of a noninvasive method of diagnosing recurrent disease and possible complications, 40 patients previously operated on for cholesteatoma using the intact canal wall technique were scanned with a General Electric 8800 scanner. Second procedures were performed on 24 patients and findings compared with preoperative film interpretations. Scans correctly predicted no significant masses in 6 patients and cholesteatoma recurrence in 11; the remaining 6 with diffuse soft tissue changes were incorrectly diagnosed. Focal areas of bone erosion were detectable in 3 cases, indicating active or potential complications. Scans were reliable in detecting cholesteatoma depending upon the pathology.

Cholesteatoma↗
PubMed1983

Cholesteatomas of the temporal bone: role of computed tomography.

Computed tomography (CT) of the temporal bone was performed in 64 patients thought to have a cholesteatoma of the middle ear. Twenty had not had surgery before, while 44 had been operated on; special consideration was given to 21 patients who were scanned immediately before a second operation and had confirmation of the CT findings. Inflammatory disease without cholesteatoma was characterized by absence of erosion of the otic capsule or ossicular chain. Sharply circumscribed cholesteatomas were easily diagnosed by CT. When they were combined with scarring, granulation tissue, or postsurgical changes, the resulting soft-tissue masses were indistinguishable, although cholesteatoma may be suspected if there is evidence of progressive bone erosion about the middle ear. CT can play a major role in postoperative follow-up by confirming that the ear is normal and demonstrating displacement of ossicular grafts or prostheses.

Cholesteatoma↗
PubMed1982

Computed tomography of the tongue and floor of the mouth.

The anatomy of the tongue and floor of the mouth is readily discernible by computed tomography (CT) because of low-density fascial planes that outline the extrinsic musculature, lingual arteries, and hypoglossal nerves. Although the tongue is accessible to the examining finger, few patients can tolerate a detailed palpation. In planning for a partial glossectomy, CT scanning aids the surgeon who must be sure that the tumor is unilateral or that at least one lingual artery and one hypoglossal nerve can be preserved. The CT scans of 30 patients were reviewed for background anatomy. Pathologic changes are summarized for 16 extrinsic lesions and 11 intrinsic tumors. The status of the midline could be confirmed in 28 of the 30 patients. The fascial plane distortions by malignant intrinsic and extrinsic lesions are discussed.

Humans↗
PubMed1982

Comparison of computed tomography and pluridirectional tomography of the temporal bone.

During pluridirectional tomography dense bone creates ghost shadows that simulate chronic disease and soft-tissue masses within the middle ear cavity. This effect was demonstrated in three dried skulls. Cholesteatomas were simulated in three more temporal bones with a mixture of 2% iodine in paraffin. Three different high-resolution computed tomographic scanners clearly demonstrated middle ear anatomy and the simulated soft-tissue masses in the skulls.

Cholesteatoma↗
PubMed1981

CT approach to benign nasopharyngeal masses.

The physical characteristics of the fascial planes of the nasopharynx provide a basis for categorizing growth patterns of the more common benign nasopharyngeal masses. Lymphoid hyperplasias are confined to the surface by the very dense pharyngobasilar fascia that lies beneath the submucosa. It takes a very aggressive process to cross this fascial plane. More laterally throughout the paranasopharyngeal space the loose areolar nature of the buccopharyngeal fascia permits benign tumors in this space to assume a spherical configuration. The carotid sheath is also a loose areolar arrangement that permits free movement of the carotid artery in the neck. Juvenile angiofibromas permeate natural foramina, displace bony septa, and extend widely but do not invade the carotid sheath. Neurogenic tumors and paragangliomas are intimately associated with contents of the carotid sheath; therefore, they obliterate the low density regions surrounding the carotid vessels.

Fascia↗
PubMed1981

CT of cervical lymph node cancer.

This study seeks to establish whether CT can accurately detect cancer in cervical lymph nodes. Retrospective correlation of CT scans and surgical findings in 51 patients with laryngeal cancer undergoing radical neck dissection suggested that the node-bearing areas in the neck can be usefully evaluated with CT scans. An additional 10 patients studied prospectively with carefully correlated CT scans and radical neck dissections were used to evaluate CT specific criteria for cancer in individual nodes. In 13 patients CT correctly predicted surgically confirmed nonpalpable nodal metastases in six. It suggested false-positive nodes in two. These criteria are now being tested in an ongoing evaluation of the clinical value of CT in the management of head and neck tumors.

Carcinoma↗
PubMed1979

Computed tomography of the parotid gland during contrast sialography.

By performing CT scanning during contrast sialography, tumors within the parotid gland can be shown and their configuration in relation to the remaining normal salivary gland and surrounding structures can be appreciated. This permits better evaluation of the relationship of the tumor to the facial nerve, possible extension of tumor beyond the gland, and benign versus malignant growth characteristics

Humans↗
PubMed1979

Lateral wall of the olfactory fossa in determining intracranial extension of sinus carcinomas.

The role of plain skull radiography and pluridirectional tomography in determining anterior cranial fossa extension of paranasal sinus tumors is reassessed. The lateral wall of the olfactory fossa, a thin bony plate forming part of the roof of the ethmoid sinuses, is routinely visualized on plain skull radiography and pluridirectional tomography in the coronal plane and serves as an indicator of intracranial tumor extension. In a series of 47 patients with paranasal sinus tumors, 100% true positive and 3% false negative interpretations of the integrity of the lateral wall of the olfactory fossa were made with pluridirectional tomography. Interpretations with plain skull radiography were 90% true positive and 3% false negative. Assessment of the integrity of the lateral wall of the olfactory fossa by these techniques provides an accurate evaluation of the presence of intracranial tumor extension by this route. Computed tomography in the coronal plane with contrast infusion is a useful adjunct.

Adult↗