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Biomedical subjects

A G Osborn

Publications and source records attributed to A G Osborn.

At least 55 records · Page 3Linked to original sources
PubMed1981

Differential diagnosis of lateral orbital masses.

Computed tomography is ideal for demonstrating orbital masses. It provides information regarding lesion location and involvement of intraorbital structures. It therefore can be used in both staging and follow-up of orbital lesions. Mass location, attenuation characteristics, form, and presence or absence of contrast enhancement all may aid the radiologist in the differential diagnosis of orbital lesions by CT. However, this review of lateral orbital masses illustrates that the differential diagnosis can be quite varied. Careful correlation with history and clinical findings may lead one to the proper diagnosis; however, often the exact nature of a lateral orbital mass must await histologic confirmation.

Diagnosis, Differential↗
PubMed1981

Cognitive correlates of diffuse cerebral atrophy determined by computed tomography.

The relationship between severity of diffuse cerebral atrophy determined by computed tomography (CT) and severity of cognitive impairment was examined in 55 men, 50 to 77 years old. Partial correlations, controlling for the effects of age and education, indicated that increased cerebral atrophy was associated with decline in orientation, recent memory, and general level of intellectual functioning. Correlations between degree of atrophy and decline in immediate and remote memory were not significant. Despite significant associations between cerebral atrophy and some aspects of intellectual functioning, considerable variance in performance on cognitive tasks was not explained by cerebral atrophy. Therefore, the degree of diffuse cortical and central atrophy observed on CT scan did not closely predict the degree of cognitive dysfunction, nor did the observation of cerebral atrophy necessarily indicate the presence of dementia.

Aged↗
PubMed1981

Craniofacial venous plexuses: angiographic study.

Venous drainage patterns at the craniocervical junction and skull base have been thoroughly described in the radiographic literature. The facial veins and their important anastomoses with the intracranial venous system are less well appreciated. This study of 54 consecutive normal cerebral angiograms demonstrates that visualization of the pterygoid plexus as well as the anterior facial, lingual, submental, and ophthalmic veins can be normal on common carotid angiograms. In contrast to previous reports, opacification of ophthalmic or orbital veins occurs in most normal internal carotid arteriograms. Visualization of the anterior facial vein at internal carotid angiography can also be normal if the extraocular branches of the ophthalmic artery are prominent and nasal vascularity is marked.

Brain↗
PubMed1981

Pineal region tumors: computed tomographic-pathologic spectrum.

While several computed tomographic (CT) studies of posterior third ventricular neoplasms have included descriptions of pineal tumors, few reports have concentrated on these uncommon lesions. Some authors have asserted that the CT appearance of many pineal tumors is virtually pathognomonic. A series of nine biopsy-proved pineal gland and eight other presumed tumors is presented that illustrates their remarkable heterogeneity in both histopathologic and CT appearance. These tumors included germinomas, teratocarcinomas, hamartomas, and other varieties. They had variable margination, attenuation, calcification, and suprasellar extension. Germinomas have the best response to radiation therapy. Biopsy of pineal region tumors is now feasible and is recommended for treatment planning.

Adolescent↗
PubMed1980

Low-attenuation lesions in the middle cranial fossa: differential diagnosis.

The reliability of cranial computed tomography (CT) in detecting a broad range of intracerebral disorders has been well established (1) and its complementary role with other neuroradiologic procedures has been documented (2). Some attempts at inferring specific histologic diagnosis from static CT scans have been made (3,4). However, other investigators have demonstrated that it is difficult to separate cystic from noncystic, benign from malignant, and neoplastic from non-neoplastic lesions by absorption coefficients alone (5,6). While initial studies utilizing dynamic CT scanning indicate that patterns of contrast accumulation may be helpful in distinguishing enhancing cerebral lesions (7,16), the differential diagnosis of the low-attenuation lesion remains difficult (17). We present a series of hypodense lesions in the middle cranial fossa that demonstrate a broad range of pathologic entities. Their CT features, differential diagnosis, and pathologic correlation are discussed.

Arachnoid↗
PubMed1980

Impact of a "fast" scanner on image quality in pediatric computed tomography.

One hundred children varying in age from newborn through four years were studied without sedation or anesthesia using a three-second CT scanner. Satisfactory scans were obtained in 99. The elimination of the hazards and morbidity of intramuscular sedation more than compensated for the extra effort required to scan these youngsters without any preparation.

Brain Diseases↗
PubMed1980

Direct sagittal computed tomographic scans in the radiographic evaluation of the pelvis.

The authors describe a method for obtaining direct sagittal and coronal computed tomographic (CT) scans of the pelvis using a special accessory table adapted for use in wide-aperture whole-body scanners. In these scans the spatial and density resolution are nearly equivalent to those in axial scans. A case is described in which sagittal scanning helped define a pelvic mass.

Adult↗
PubMed1980

The false falx sign.

When identified on nonenhanced computed tomography (CT), a long, thin band of increased attenuation in the region of the falx cerebri (the falx sign) has been regarded as evidence of subarachnoid hemorrhage. Shorter, wider, or wedge-shaped interhemispheric fluid collections of blood-equivalent attenuation have been considered representative of a subdural hematoma in an abused child. The superior sagittal sinus, straight sinus, and falx cerebri are identified on unenhanced CT scans of pediatric patients without clinical or radiographic evidence of trauma, subarachnoid hemorrhage, bleeding diathesis, or other abnormalities. These structures are often visualized where atrophy or degenerative diseases of the brain provide an adjacent region of diminished attenuation. With the spatial and density resolution of new CT scanners, visualization of the falx cerebri and its dural sinuses is normal.

Dura Mater↗
PubMed1980

The vidian artery: normal and pathologic anatomy.

Arising as a branch of either the distal maxillary artery or the petrous portion of the internal carotid artery, the vidian artery (artery of the pterygoid canal) participates in two complex vascular networks through its anastomoses in the pterygopalatine fossa and oropharyngeal mucosa. The vidian artery may become a major source of blood supply to a variety of deep facial and paracavernous lesions. The embryology, anatomy, and pathology of this vessel are described and implications of its anastomotic patterns in therapeutic embolization procedures are discussed.

Angiography↗
PubMed1980

Dynamic cranial computed tomography: preliminary results.

Recent software additions to a CT scanner with a continuously rotating tube-detector system allow uninterrupted data collection after rapid intravenous contrast material injection. The highly flexible computer program can accommodate as many as 16 consecutive 3 sec scans, or various time intervals can be inserted between individual scans. A variety of intracranial lesions was studied in 35 patients using this dynamic scanning technique and the enhancement of normal gray and white matter was evaluated. Potential applications of this technique are discussed, with emphasis on the possibility of differentiating certain cerebral lesions by their early enhancement patterns and evaluating cerebrovascular occlusive disease.

Brain↗
PubMed1979

Sphenoidal mucoceles with intracranial extension.

Two cases of sphenoid sinus mucocele with intracranial extension are presented. Multiplanar computed tomography scans delineated the extent of these lesions, facilitating both preoperative diagnosis and proper clinical management. One lesion was isodense and the other hyperdense (98 Hounsfield units: 1,000 scale). Neither demonstrated significant enhancement after the administration of contrast medium.

Brain Diseases↗
PubMed1979

Radiology of the pterygoid plates and pterygopalatine fossa.

The pterygopalatine fossa is a major distribution center for the parasympathetic innervation and vascular supply of deep facial structures. Through eight bony canals or foramina, this fossa communicates with the nasal and oral cavities, infra-temporal fossa, orbit, pharynx, and middle cranial fossa. Therefore this important structure provides a natural pathway for dissemination or spread of disease processes to contiguous structures. The normal gross and radiographic anatomy of the pterygopalatine fossa and the adjacent pterygoid plates are considered in detail. Variation in these structures as well as their alterations in a variety of pathologic entities are described.

Bone Diseases↗
PubMed1979

Direct sagittal computed tomography in Graves' ophthalmopathy.

Standard axial transverse orbital computed tomography scans show the medial and lateral rectus muscles very well but section the superior and inferior rectus muscles obliquely. Determining enlargement of the superior and inferior recti in Graves' disease can therefore be difficult on axial transverse scans. We have obtained sagittal, coronal, and axial transverse orbital scans in a series of patients with Graves' ophthalmopathy and have compared the images in each plane. Direct sagittal and coronal scans were obtained without image regeneration from axial transverse sections by using a wide-aperture Varian body scanner and a special accessory table. Sagittal and coronal scans can demonstrate enlargement of the superior or inferior muscles even in cases in which the medial and lateral recti are normal. Since scans performed at approximately 20 degrees to the sagittal plane are parallel to the long axis of the orbit, they demonstrate orbital anatomy better than scans in the true sagittal plane.

Graves Disease↗