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Biomedical subjects

M F Mafee

Publications and source records attributed to M F Mafee.

At least 73 records · Page 4Linked to original sources
PubMed1990

Familial trigeminal anesthesia.

Familial congenital trigeminal anesthesia as an isolated abnormality is an unusual disorder. To our knowledge, only one family has previously been reported. We report here a family with three affected members demonstrating facial anesthesia, bilateral corneal changes, and nasal septal damage secondary to self-traumatization. Magnetic resonance imaging demonstrated hypoplasia of gasserian ganglia and trigeminal nerves in the affected father of two affected sons. The pathogenesis of this disorder appears to be congenital hypoplasia of the trigeminal nerves and gasserian ganglia that is inherited in a dominant fashion.

Adult↗
PubMed1990

Photodynamic therapy in the treatment of squamous cell carcinoma of the head and neck.

Photodynamic therapy is an experimental modality for tumor treatment based on the combined action of the tumor-localizing agent, ie, hematoporphyrin derivative, and red light. From 1985 through 1989, 26 patients were treated using hematoporphyrin-derived drugs and 630-nm light delivered by a tunable dye laser. All patients had biopsy-proved squamous cell carcinoma of the head and neck, and they had either failed the traditional treatment modalities or refused conventional therapies. Histological complete responses were achieved in 20 (77%) of 26 patients and partial responses in 5 (19%) of 26 patients for periods up to 48 months. Only minimal toxic reaction was noted in the group. As a guide to treatment planning for a patient group with large tumors, we used an optical dosimetry model based on tissue optics. The rate of complete responses to this treatment was 8 (73%) of 11. Our data indicate that photodynamic therapy is capable of inducing significant clinical and histological responses in the majority of those treated, and in some patients a prolonged response is produced. In certain select head and neck malignancies, photodynamic therapy has an important role as a treatment modality.

Aged↗
PubMed1990

Chondrosarcoma of the larynx. Diagnosis with magnetic resonance imaging and computed tomography.

Chondrosarcomas are the most common sarcomas of the larynx. They are generally slow-growing lesions with insidious onset of symptoms. We are presenting a case of chondrosarcoma that recurred 10 years after excision of a presumed chondroma. Computed tomographic and magnetic resonance imaging (MRI) scans were performed. Both studies delineated the lesion nicely. To the best of our knowledge, this is the first report on MRI characteristics of chondrosarcoma of the larynx. A review of the literature regarding the use of computed tomography in the management of chondrosarcoma is presented. The MRI characteristics are discussed and the two scanning modalities are compared. Computed tomography is an excellent study in its ability to demonstrate the extent of the lesion within the laryngeal skeleton. Furthermore, it is more highly sensitive than plain roentgenograms in the detection of calcifications that are highly suggestive of chondrosarcoma. Alternatively, MRI can also demonstrate the lesion within the larynx but it has the added advantage of superior contrast resolution of the tumor and paralaryngeal tissues. When the three-dimensional imaging capacity of MRI is considered as well, MRI seems to be the superior study.

Aged↗
PubMed1990

CT and MR imaging of intralabyrinthine schwannoma: report of two cases and review of the literature.

Two cases of intralabyrinthine schwannoma were studied with computed tomography (CT) and magnetic resonance (MR) imaging. On CT scans, a soft-tissue mass was identified in the round window niche in both cases. Widening of the basilar turn of the cochlea and characteristic erosion of the promontory were noticed in one case. Preoperative MR imaging (performed in only one case) revealed a soft-tissue mass in the labyrnth, extending into the round window niche. Findings at CT and MR imaging are discussed, and a differential diagnosis is given. The literature is reviewed. The authors' findings suggest that CT and MR imaging may prove very valuable in the previously difficult preoperative diagnosis of these tumors. In the setting of progressive sensorineural hearing loss, atypical Meniere disease, or recurrent vertigo, the presence of a mass in the labyrinth or labyrinthine windows- delineated on CT or MR images, despite a normal internal auditory canal, cerebellopontine angle, or brain stem - is highly suggestive of intralabyrinthine schwannoma.

Aged↗
PubMed1990

Epiglottic laryngoplasty for repair of blunt laryngopharyngeal trauma.

Two unique cases of blunt laryngopharyngeal trauma are presented in which identical injuries were sustained to the supraglottic larynx and hypopharynx. Examination of the patients included the use of magnetic resonance imaging to help define the extent of injury. A successful outcome was achieved in each instance by employing the reconstructive technique of epiglottic laryngoplasty to repair the mucosal defects.

Accidents, Traffic↗
PubMed1990

Rationale for elective neck dissection in 1990.

Elective neck dissection has long been a subject of debate among surgeons. The proponents of elective neck dissection base their rationale on studies that show a 30% incidence of occult disease in those situations for which elective neck dissection is recommended. One hundred eighty-two patients with advanced stages of squamous cell carcinoma of the head and neck were studied. All patients had preoperative computed tomography or magnetic resonance imaging, and all patients had some form of radical neck dissection. The sensitivity of clinical exam was compared with the sensitivity of computed tomography or magnetic resonance imaging in ability to detect nodal disease. The sensitivity of clinical exam alone was 71.7%, while the sensitivity of computed tomography or magnetic resonance imaging was 91.1%. Based on physical exam alone, there would be a 39% rate of occult disease; if computed tomography or magnetic resonance imaging data is combined with physical exam, the occult disease rate would drop to 12%. All centers performing elective neck dissection must reassess their rationale or restudy their occult disease rate with computed tomography or magnetic resonance imaging.

Carcinoma, Squamous Cell↗
PubMed1990

Successful use of nasal-CPAP for obstructive sleep apnea in Hunter syndrome with diffuse airway involvement.

A patient with Hunter syndrome and diffuse airway obstruction had daytime hypersomnolence, snoring, and alveolar hypoventilation. Polysomnography showed severe obstructive sleep apnea. In the past, all reported cases of sleep apnea in patients with mucopolysaccharidoses had been treated with tonsillectomy/adenoidectomy or tracheostomy. This patient, in whom tracheostomy would have been very difficult due to the diffuse nature of his airway involvement, was successfully treated with high pressure nasal CPAP and supplemental oxygen.

Adult↗
PubMed1989

Magnetic resonance imaging of pituitary stalk hypoplasia. A discrete midline anomaly associated with endocrine abnormalities in septo-optic dysplasia.

Septo-optic dysplasia describes optic nerve hypoplasia in association with endocrine disturbances and/or midline brain malformations. Magnetic resonance imaging of the brain was used to study two patients with optic nerve hypoplasia, endocrine abnormalities, and normal midline brain anatomy on prior computed tomographic scan. The magnetic resonance imaging scans showed normal midline brain anatomy except for failure to visualize the pituitary stalk, a structure that magnetic resonance imaging has shown to be 100% sensitive in imaging in our normal controls. We propose that our two patients have endocrine abnormalities due to the discrete anomaly of pituitary stalk hypoplasia.

Child, Preschool↗
PubMed1989

Quantitative and qualitative fat analysis in human leg muscle of neuromuscular diseases by 1H MR spectroscopy in vivo.

1H MR spectra were recorded from human gastrocnemius muscle at 63.86 MHz using the body coil of the Signa scanner as transmitter and a 3-in. surface coil as receiver. The fat content of the muscle was quantified relative to that of water in a selected volume or slice. The fat/water ratio was 0.05-0.07 for normal muscle but increased to 0.5-6.0 in primary and secondary muscular disorders such as Duchenne and myotonic dystrophy, Charcot-Marie-Tooth and polio muscular atrophy, cerebral palsy, and spina bifida. In Werdnig-Hoffmann spinal atrophy the ratio was above 10. Water-suppressed and slice-selective 1H spectroscopy was used for qualitative analysis of fat. The 1H profile of gastrocnemius muscles between healthy individuals and patients with neuromuscular diseases showed two major differences. In the normal muscle spectra, the resonance from the -(CH2)n- protons at 1.6 ppm was the most pronounced, whereas in the diseased muscle spectra resonances also appeared between 1.1 and 1.4 ppm. Some diseased muscle spectra showed multiple resonances from -CH = CH- in polyunsaturated fatty acids between 5.5 and 7.0 ppm. The corresponding resonances from = CH-CH2-, 1.9-2.0 ppm, and = CH-CH2-CH =, 2.7-2.9 ppm, were also seen. These peaks are usually not detected in normal muscle.

Adipose Tissue↗
PubMed1989

Magnetic resonance imaging versus computed tomography of leukocoric eyes and use of in vitro proton magnetic resonance spectroscopy of retinoblastoma.

To evaluate the usefulness of magnetic resonance imaging (MRI) in the evaluation of leukocoric eyes, the authors studied 28 patients with either leukocoria or intraocular mass with a 1.5-tesla (T) MRI imager. Retinoblastomas were reliably distinguished from Coats' disease, toxocariasis, and persistent hyperplastic primary vitreous on the basis of MRI findings. Calcification cannot be reliably detected on MRI scans. Lesions elevated less than 4 mm may not be detected reliably by MRI at this time. Computed tomography (CT) can detect calcification with a high degree of accuracy. Retinoblastomas appeared as moderately hyperintense masses on T1- and proton-weighted MRIs. They became hypointense in T2-weighted MRIs. This MRI characteristic is similar to that of uveal melanoma. Intraocular calcification in children especially younger than 3 years of age is highly suggestive of retinoblastoma. In the diagnosis of retinoblastoma, MRI is not as specific as CT because of its lack of sensitivity in detecting calcification. However, MRI, because of its superior contrast resolution, offers more information in the differentiation of pathologic intraocular conditions responsible for leukocoria. The authors also describe their preliminary work of in vitro proton magnetic resonance spectroscopy of eyes with retinoblastoma and an eye with uveal melanoma in an 18-year-old black woman.

Adolescent↗
PubMed1989

Ventral cleft of the larynx in an adult. Case report.

Congenital clefts of the larynx are rare and usually found dorsally. This case report describes a patient with a partial anterior nonfunsion, or ventral cleft, of the thyroid cartilage. This was first noted on computed tomography of the larynx used for delineation of carcinoma and was confirmed by horizontal whole mount histologic sections of the resected larynx. The thyroid cartilage suggested arrested fusion of the laminae in the middle to late embryonic period. This patient had an adult form of this rarely reported anomaly and the first, to our knowledge, detected with CT scan.

Carcinoma, Squamous Cell↗
PubMed1989

Evaluation of CSF rhinorrhea by computerized tomography with metrizamide.

This study evaluates the ability of metrizamide computerized tomographic cisternography (MCTC) to delineate the site of leakage in patients with cerebrospinal fluid (CSF) rhinorrhea. From 1981 to 1986, thirteen patients were examined by MCTC to localize the site of CSF leakage. A total of 17 studies were performed. Thirteen scans (76%) identified the site of CSF leakage. Nine of these scans were confirmed surgically. The other four scans were performed on patients who refused surgery. Of the 15 scans in patients with active CSF leaks, 13 (87%) were positive. Of the two patients with inactive CSF leaks, neither was positive. One patient is presented in whom MCTC was both diagnostic and therapeutic. In conclusion, MCTC has a high success rate in localizing the site of active CSF leaks.

Adult↗
PubMed1989

Potential use of in vivo proton spectroscopy for head and neck lesions.

Early experience with in vivo MRS has shown its potential for obtaining biochemical information, thus enhancing the diagnostic sensitivity of MRI studies. Further work on combined MRI and in vivo MRS is needed, with the goal of characterization and abnormal conditions according to their spectral patterns and for identification of tumor markers. We presented in this communication our preliminary results. It seems that the resonance from melanin can be used as a marker for melanotic tumors.

Biomarkers, Tumor↗
PubMed1989

Radiologic assessment preoperative to endoscopic sinus surgery.

At our institution, the screening coronal section CT scan has largely replaced the use of the sinus series for the initial evaluation of patients suspected to have sinus pathology. However, in those patients with obvious mucosal disease on endoscopic examination, the screening coronal section CT scan is bypassed and a complete coronal section CT scan obtained. Axial section CT scans are not routinely obtained and bone windows are consistently selected for viewing.

Endoscopy↗
PubMed1988

Quantitation of phosphate metabolites in human leg in vivo.

Slice-selective 31P MR spectra were recorded from human legs with a pulse program which has only a 1.5-ms delay between excitation and acquisition. The volume of the slice was calculated from its thickness and cross-sectional area measured with the aid of a computer program. A phosphate reference standard spectrum was recorded from the same interplanar location as that of the human leg slice. Since signal integral is proportional to the phosphate concentration and to the volume of the slice, metabolite concentrations in the selected slice could be quantitated.

Adenosine Triphosphate↗
PubMed1988

The role of magnetic resonance imaging in the diagnosis and management of ameloblastoma.

Magnetic resonance (MR) images of ameloblastoma are compared with computed tomographic (CT) images with the use of three parameters: artifact degradation, edge definition, and conspicuity. As a basis for comparison, MR imaging characterization of normal tissues is reviewed. The three cases studied demonstrate the importance of weighing heavily on MR for evaluation of tumor-normal tissue interface. MR generally proved to be superior to CT in the evaluation of recurrent disease because of its ability to differentiate tissues on the basis of their proton composition. CT images reflect the electron densities of tissues. Hence, interpreting inflammatory and postsurgical changes and differentiating them from neoplasm may be difficult. At the present time, familiarity with CT dictates that the MR evaluation complement and not substitute the CT evaluation.

Ameloblastoma↗