Biomedical subjects
Publications and source records attributed to M F Mafee.
A case of fracture of the footplate of the stapes resulting in air in the labyrinth is reported. The pneumolabyrinth was demonstrated by CT scan of the temporal bone but not by complex motion tomography. We consider pneumolabyrinth to be a new diagnostic CT finding in stapes footplate fracture.
The ability of CT to depict cross-sectional anatomy allows the radiologist and the laryngologist to build a clear three-dimensional image of the site and extent of laryngeal diseases. This paper reviews normal CT anatomy of the larynx.
Increased accuracy of parathyroid hormone assays has yielded an earlier diagnosis of primary hyperparathyroidism, often in an asymptomatic stage. Non-invasive modalities used to localize parathyroid abnormalities have not been accurate for small adenomas. Although arteriography has been shown to be accurate in detection of adenomas, the invasive nature of the study, as well as possible complications, minimizes its use in preoperative localization of parathyroid abnormalities. The computed tomographic (CT) scan was used preoperatively in eight patients to assess its accuracy in localizing parathyroid abnormalities. The radiographic findings were correlated with surgical and pathologic findings. The conditions of seven patients were correctly diagnosed preoperatively by the CT scan, including that of one patient with diffuse hyperplasia. With the increased accuracy attained by this noninvasive examination, we believe that CT scanning should be a routine part of the preoperative examination of patients with primary hyperparathyroidism.
Computed tomography (CT) has been used to investigate the presence, site, and extent of glomus complex tumors. High resolution CT scanning can accurately evaluate invasion of cervical soft tissues, intratympanic or intracranial extension, and bony involvement of the skull base. Glomus tumors can be differentiated by CT angiographic dynamic study from most other tumors in the head and neck because of their profuse vascularity and their intense enhancement seen on dynamic CT during arterial phase. A glomus tympanicum or extension of a glomus jugulare into the hypotypanum can be best demonstrated by high resolution CT using target review image reconstruction. Glomus tumor in the middle ear can be differentiated from other masses by CT dynamic study and the computer-generated density time curves.
Seven patients with known carcinoma of the larynx underwent computed tomography (CT) of the larynx prior to surgery. Whole-mount sections of the extirpated larynx cut in the horizontal plane were compared with the corresponding level of the preoperative CT sections to demonstrate the validity of CT scanning in the evaluation of tumors of the larynx. The results indicate that CT scanning accurately demonstrates the anatomic location and gross size of laryngeal tumor, although early invasion of the laryngeal cartilages may be difficult to diagnose with CT. It is concluded that preoperative CT scanning of the larynx is the radiologic procedure of choice for evaluating carcinoma of the larynx.
Computed tomographic (CT) scans and tomograms of 60 patients with various soft-tissue masses of the middle ear, including 30 with cholesteatomas, were studied. CT produced excellent images of middle ear soft-tissue masses and appears to be the diagnostic method of choice for cholesteatomas, glomus tympanicum tumors, and other soft-tissue masses. In one patient CT demonstrated pneumolabyrinth resulting from postsurgical fracture of the footplate of the stapes. Pneumolabyrinth is a newly reported CT finding in stapes footplate fracture.
Six of the 12 patients with Usher's syndrome, assessed with computed tomography (CT), demonstrated findings of cerebellar atrophy. Of these, three patients also showed occipital lobe atrophy. Continuous rapid rotational CT scans disclosed seven patients with abnormal hindbrain circulation pattern. Our results suggest that central nervous system (CNS) defects may be among the pleiotropic effects of the Usher's syndrome gene.
The computed tomographic (CT) findings in 5 patients with proven persistent hyperplastic primary vitreous (PHPV) are described. PHPV arises when the embryonic hyaloid vascular system fails to regress normally. Clinically, this condition usually manifests as unilateral or bilateral leukokoria and is one of the more important and frequent conditions mimicking retinoblastoma. The spectrum of CT findings include: (a) soft-tissue replacement (infiltration) of the vitreous body; (b) retrolental soft tissue along the Cloquet canal; (c) absence of abnormal calcification within the orbit; (d) microphthalmus; (e) retrohyaloid layered blood; and (f) hypervascularity of the vitreous humor.
Computerized tomography is acquiring an increasingly important role in the radiographic assessment of the temporal bone. In the latest generation of CT scanners, spacial resolution has been reduced to 0.1 cu mm and slice thickness to 1.5 mm. The main advantages of computerized tomography in comparison to multidirectional tomography are the improved contrast of the images and above all the clear demonstration of soft tissue structures and masses within or adjacent to the temporal bone. The following three applications of computerized tomography will be discussed: 1. Evaluation of intratemporal soft tissue masses. Computerized tomography allows differentiation of fluid filled from solid masses and vascular tumors. 2. Assessment of lesions extending outside the temporal bone or into the temporal bone from adjacent structures. In these cases CT will demonstrate the temporal bone involvement and the presence and extension of the intra or extra cranial component of the lesion. 3. Study of the cerebellopontine angle. Computerized tomography with infusion and combined with pneumocisternography comprise the procedure of choice for the diagnosis of acoustic neuromas and other lesions occurring in this area.
Rapid sequence CT imaging provides information about the vascular anatomy (CT angiography), locates major vessels encased by tumor, and eliminates the possibility of avascular lesions in the differential diagnosis of a head and neck tumor. Furthermore the use of density-time curves allows arterial and venous time. The patterns of density-time curves are characteristic for various lesions. For glomus complex tumors, regardless of the size and location, dynamic CT easily differentiates them from most of the simulating lesions. Angiography therefore is occasionally necessary for verification. Dynamic CT has a risk of complications the same as that of any intravenous injection of contrast material. Cerebral angiography via the femoral approach has been reported to have a risk of major complications of 0.28% and of minor complications of 6.25%.
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Continuous rapid rotational CT brain scanning now permits the study of brain circulation. The parameters studied are related to the transit time of circulation and to blood flow differences within small portions of the brain. For ease of description, this study is called regional brain circulation (rBC). This preliminary report is based on our experience with 75 consecutive cases studied since August 1, 1978. Displays of normal brain, cerebral ischemia, and arteriovenous malformations are analyzed in this paper. The normal graphic display of rBC includes peak concentration, transit time, washin and washout phases. Clinical application to medical-surgical treatment is illustrated.
The carotid body tumor, although uncommon, is frequently considered in the differential diagnosis of cervical masses. When this lesion becomes a serious diagnostic possibility, angiography must be considered. Currently angiography is the only nonsurgical modality that can reliably confirm the clinical diagnosis. We describe the case of a patient in whom a carotid body tumor was diagnosed preoperatively by dynamic computerized tomography. Dynamic computerized tomography, a relatively noninvasive technique, should now be deemed the technique of choice for diagnosis of carotid body tumors, thus avoiding the potential morbidity of angiography. In patients for whom tumor removal is indicated, however, preoperative angiography is still mandatory in order to plan the best operative procedure.
The rational treatment of thyroid diseases requires an understanding of the thyroid function and an accurate evaluation of its functional (endocrine), as well as it morphological alteration. There are several different imaging techniques which are available and are in use in the evaluation of thyroid diseases. In this article we present a protocol for the use of diagnostic imaging to evaluate a focal thyroid mass, a diffusely enlarged gland, regional, and distant metastatic disease. The current diagnostic applications of radionuclide scanning, ultrasound, computed tomography, and magnetic resonance imaging (MRI) will be discussed.
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