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Biomedical subjects

M F Mafee

Publications and source records attributed to M F Mafee.

At least 55 records · Page 3Linked to original sources
PubMed1995

Applications of MR angiography in head and neck pathology.

MR angiography is a useful examination in the area of head and neck pathology when correctly applied and tailored to a specific clinical problem. Of the cases presented in this article, the most common application is evaluation of vascular invasion or displacement to aid in surgical planning of tumor resection. Applications to evaluation of vascular thrombosis or dissection, assessment of tumor vascularity, and visualization of variant vascular anatomy and acquired vascular disease were also demonstrated.

Adolescent↗
PubMed1995

MR imaging of squamous cell carcinoma of the larynx and hypopharynx.

Despite recent diagnostic advances, the laryngopharynx remains an area where accurate assessment of tumor size and extent is difficult. Computed tomography has proven helpful in delineating lesions in these areas, yet significant limitations exist. In an attempt to more accurately evaluate laryngopharyngeal neoplasms, MR imaging was performed in 25 consecutive patients with squamous cell carcinoma of the larynx and hypopharynx. Mr imaging was analyzed for its utility in clinical staging, assistance in selection of candidates for conservation, Laryngeal surgery, and ability to reliably predict cartilage invasion. MR imaging improved the accuracy of tumor staging by 40% and was valuable in the selection of candidates for conservation surgery. In addition, MR imaging was able to predict cartilage invasion in 6 of 6 patients with pathologic confirmation with a single false-positive case. MR imaging appears to be a reliable indicator of tumor size and location and should be judiciously incorporated into the staging and pretreatment planning of patients presenting with laryngopharyngeal malignancies.

Carcinoma, Squamous Cell↗
PubMed1994

Differential diagnosis of leukokoria: radiologic-pathologic correlation.

Leukokoria is an abnormal pupillary light reflection that usually results from an intraocular abnormality and is seen most often in children. One-half of the cases of childhood leukokoria are caused by retinoblastoma, a malignant tumor of immature retinoblasts that manifests in a normal-sized eye as a calcified mass, is often partially necrotic, and grows into the vitreous and through the choroid. Retinoblastoma enhances with contrast material and, unlike most tumors, may be darker than vitreous on T2-weighted images. When leukokoria is associated with microphthalmia, persistent hyperplastic primary vitreous (PHPV) (28% of cases) or retinopathy of prematurity (ROP) (5% of cases) should be considered. PHPV is a congenital, usually unilateral lesion that appears as a dense tubular mass extending from the lens to the retina along the course of the hyaloid canal. Hemorrhage from PHPV produces a subhyaloid (or subretinal) fluid collection, often with characteristic blood-fluid levels. ROP is bilateral and usually manifests in premature infants who received supplemental oxygen therapy. Coats disease (16% of leukokoria) is a sporadic unilateral idiopathic retinal telangiectasia that produces a lipoproteinaceous subretinal exudate leading to complete retinal detachment. The globe has normal size but increased attenuation and signal intensity from hemorrhage without calcification or enhancement. Toxocaral endophthalmitis (16% of leukokoria) is a granulomatous reaction to the parasite in the vitreous and uveoretinal coat. Retinal astrocytoma (3% of leukokoria), which manifests in a normal-sized globe, is an indolent benign neoplasm commonly associated with phakomatoses (usually tuberous sclerosis).

Child↗
PubMed1994

Epidermoid cyst (cholesteatoma) and cholesterol granuloma of the temporal bone and epidermoid cysts affecting the brain.

Five cases of petrous apex epidermoid cysts, six cases of petrous apex cholesterol granuloma cysts, and seven cases of intradural cerebellopontine angle (CPA) or intracranial epidermoid cysts are reviewed. Petrous epidermoid cysts (cholesteatomas) and cholesterol granuloma cysts cannot be differentiated definitely from each other on CT scans. On MR imaging, epidermoid cysts exhibit long T1 and long T2 characteristics and can be differentiated from cholesterol granuloma cysts, which exhibit short T1 and long T2 characteristics. Intradural epidermoid cysts involving the CPA or other portions of the brain, also demonstrate long T1 and long T2 characteristics on MR scans. Intradural epidermoid cysts exhibit curvilinear areas of higher intensity on T1-weighted images, which were best evaluated on T1-weighted MR images obtained with more averages (6 to 8).

Adolescent↗
PubMed1994

Modern imaging of paranasal sinuses and the role of limited sinus computerized tomography; considerations of time, cost and radiation.

The modern diagnostic radiology department is equipped with a variety of medical imaging systems that can be used for evaluation of diseases of the sinonasal cavities. Each has advantages and disadvantages. The imaging examinations of the paranasal sinuses may include conventional films, complex motion tomography, computed tomography (CT) and magnetic resonance imaging (MRI). The indications for these imaging methods are reviewed, along with a discussion on the role of imaging for endoscopic sinus surgery. A summary of CT anatomy relating to the ethmoidal sinuses and ostiomeatal complex is given, as is a review of the risk of radiation for radiologic sinus imaging.

Carcinoma↗
PubMed1994

Orbital and optic pathway sarcoidosis: MR findings.

PURPOSE: To identify and characterize the MR findings of sarcoidosis when it involves the orbit and visual pathways. METHODS: The MR scans of 15 patients, 3 with presumed and 12 with proved orbital or optic pathway sarcoidosis were retrospectively reviewed. RESULTS: Eight patients had MR evidence of optic nerve involvement by sarcoid granuloma. Perineural enhancement was seen in four cases, optic atrophy in one. Three who had had unenhanced scans showed optic nerve enlargement. Nine patients had optic chiasmal involvement. One patient had increased T2 signal in the optic radiations. Three patients had orbital masses that had MR signal characteristics similar to pseudotumor. Five patients had periventricular white matter abnormalities closely resembling multiple sclerosis. CONCLUSIONS: Sarcoidosis should be considered in the differential diagnosis of optic nerve or nerve sheath enhancement on MR. Orbital sarcoidosis has MR characteristics very similar to pseudotumor.

Adolescent↗
PubMed1993

MRI and CT in the evaluation of acquired and congenital cholesteatomas of the temporal bone.

Acquired (secondary) cholesteatomas of the middle ear and mastoid are usually a complication of chronic otomastoiditis and are often accompanied by infection from the outset, and their contents show evidence of some inflammatory reaction. Congenital (primary) cholesteatomas of the temporal bone are due to epithelial rest of embryonal origin. There are many sites of occurrence of congenital cholesteatomas (epidermoids) within the temporal bone: (1) middle ear, (2) mastoid, (3) middle ear and mastoid, (4) petrous bone, (5) the squama, and (6) within the tympanic membrane. Intradural (cisternal) congenital cholesteatomas are another type of cholesteatomas that often involve the cerebellopontine angle (CPA) region and cause varying degrees of cochlear and vestibular symptoms and signs. In this paper, we stress the role of magnetic resonance imaging (MRI) and computed tomography (CT) in the evaluation of acquired and congenital cholesteatomas of the temporal bone. It is our opinion that CT remains the study of choice for cholesteatomas of the middle ear cleft. MRI is superior to CT for the evaluations of infected cholesteatomas, petrous apex, and CPA cholesteatomas, as well as for the majority evaluation of cholesteatomatous involvement of the facial nerve, membranous labyrinth, and intracranial structures.

Bone Diseases↗
PubMed1993

Preoperative imaging anatomy of nasal-ethmoid complex for functional endoscopic sinus surgery.

Endoscopic sinus surgery has become an increasingly popular surgical procedure. Functional endoscopic sinus surgery is based on the hypothesis that the ostiomeatal complex is the key area in the pathogenesis of chronic sinusitis. This article discusses the concept of functional endoscopic sinus surgery, the anatomy of the ostiomeatal complex, and the imaging anatomy of the ostiomeatal complex.

Endoscopy↗
PubMed1993

Applications of three-dimensional CT imaging in head and neck pathology.

The advantages of three-dimensional (3-D) imaging in the diagnosis of developmental and posttraumatic craniofacial abnormalities is well established. A brief review of this role of 3-D imaging is presented, followed by a discussion of the use of 3-D imaging in various head and neck disorders.

Facial Bones↗
PubMed1993

Epithelial tumors of the paranasal sinuses and nasal cavity.

This article addresses the various epithelial tumors of the nasal cavity and paranasal sinuses. It emphasizes the radiologic evaluation of patients with these tumors and the radiologic findings of importance. The advantages and disadvantages of the use of computed tomographic (CT) and magnetic resonance (MR) imaging in this evaluation are stressed.

Carcinoma↗
PubMed1993

Nonepithelial tumors of the paranasal sinuses and nasal cavity. Role of CT and MR imaging.

This article reviews some of the applications of computed tomographic (CT) and magnetic resonance (MR) imaging in the clinical investigation of nonepithelial tumors and tumorlike lesions of the sinonasal tract. Sixty selected patients primarily with various nonepithelial tumors of the sinonasal tract were included in this study. The MR characteristics of many of these lesions are described.

Adolescent↗
PubMed1993

Computed tomography and magnetic resonance imaging in the diagnosis of posterior scleritis.

The clinical records of 14 patients with posterior scleritis were reviewed to compare the diagnostic potential of computed tomography (CT) and magnetic resonance imaging (MRI) in this condition. None of these patients had evidence of collagen vascular or other systemic diseases. Done 13 times on 11 patients, CT was diagnostic for posterior scleritis in six patients on seven occasions. We used MRI six times in five patients, and it was not diagnostic for posterior scleritis in any patient. Thus, CT appeared to be more sensitive than MRI in the diagnosis of posterior scleritis. The CT results appeared comparable to ultrasonographic findings (obtained eight times in six patients) in the diagnosis of posterior scleritis. Both CT and MRI, however, detected signs of orbital pseudotumor in six and three patients, respectively. These findings support the concept that posterior scleritis and orbital pseudotumor may represent a continuum of the same disease process.

Adolescent↗
PubMed1992

Congenital anomalies of the branchial apparatus: embryology and pathologic anatomy.

Various congenital anomalies of branchial origin are found in the neck region. Understanding the varied radiologic appearances of these anomalies is greatly aided by familiarity with their embryologic origins. By considering the anatomic location and radiologic appearance, the precise embryologic origin can be accurately predicted. Defects of the branchial apparatus include branchial, thymic, and parathyroid anomalies, which may manifest as cysts, sinuses, fistulas, and ectopic glands. The embryologic model is used to explain the origins of all branchial apparatus anomalies. The most accepted theory proposes that vestigial remnants result from incomplete obliteration of the branchial apparatus or buried cell rests, and, thus, if cells are trapped in the branchial apparatus during the embryologic stage, they can form branchial cysts later in life. By understanding the embryologic basis for these defects, the radiologist is better able to interpret the findings encountered with the various imaging modalities used in the evaluation of these anomalies.

Branchial Region↗
PubMed1992

Congenital malformations of the cervicothoracic lymphatic system: embryology and pathogenesis.

Familiarity with the embryology of the lymphatic system is helpful in understanding the pathogenesis and radiologic appearance of lymphangiomas of the cervicothoracic region. By considering anatomic location and radiologic appearance, one can predict the type of lymphangioma present, the primordial lymph sac from which the malformation arose, and when it formed in embryonic life. Cystic hygromas are composed of large, dilated lymphatic spaces. They form when a primordial lymph sac fails to reestablish communication with the central venous system from which it arose. These lesions may also result from an aberrant bud arising from a primordial lymph sac. Cavernous and capillary lymphangiomas are composed of smaller lymphatic channels. They form from abnormally sequestered buds of the developing lymphatic mesenchyme responsible for the fine meshwork of terminal branches in the periphery of the embryo. Their growth may be inhibited by the relatively tougher tissues in the periphery (eg, skin and muscle) compared with the relatively loose fatty connective tissue in which cystic hygromas form. Not only can all types of lymphangioma occur in one lesion, but lymphatic and vascular malformations may also coexist.

Humans↗