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Biomedical subjects

J M Taveras

Publications and source records attributed to J M Taveras.

At least 55 records · Page 3Linked to original sources
PubMed1980

Radiological evaluation of orbital metastases, with emphasis on computed tomography.

Metastases to the orbit are found in the choroid, retrobulbar soft tissues, or bony orbit. Choroidal metastases result in retinal detachment and are best evaluated with fundoscopy and ultrasound. Retrobulbar metastases can involve both extraconal and intraconal spaces; they appear as masses having a high absorption value and irregular margins on plain CT scans and show slight contrast enhancement. The greater wing of the sphenoid is the most common site of bone metastases. These lesions often have soft-tissue components in both the lateral extraconal space of the orbit and the middle cranial fossa.

Breast Neoplasms↗
PubMed1980

Metrizamide sagittal tomography: adjunct to CT cisternography of the sellar region.

A total of 30 patients with pituitary adenoma was studied by sagittal polytomography en route to coronal and axial computed tomography (CT) cisternography after a low FDA-approved dose of 6 ml of 170 mg I/ml metrizamide via lumbar injection. The requirement for defining the relation of the optic nerves and chiasm to the intrasellar contents or suprasellar mass before proton beam irradiation or certain surgical approaches was satisfied. Pneumoencephalography as a supplemental procedure to CT and CT cisternography was replaced. The concomitant elimination of conventional sellar polytomography and pneumoencephalography results in decreased total radiation exposure and a more comfortable, expeditious workup.

Adenoma↗
PubMed1979

Computed tomography of masses in the lacrimal gland region.

Twenty patients with mass lesions in the lacrimal gland region were evaluated with computed tomography (CT). The extent of the mass and its relationship to the globe, optic nerve, and extraocular muscles were clearly seen. The CT appearance on plain scan and the presence or absence of contrast enhancement, bone involvement, and cystic components often suggested the specific pathological diagnosis. Although orbital ultrasonography and CT were frequently complementary, ultrasonography was more definitive in inflammatory diseases, while CT demonstrated better extraorbital extension.

Adenocarcinoma↗
PubMed1979

Evaluation of mucoceles of the paranasal sinuses with computed tomography.

Eighteen patients with mucoceles of the paranasal sinuses were studied by plain radiography, pluridirectional tomography, and computed tomography (CT). Sixteen of the lesions had a homogeneous appearance on CT but demonstrated variable absorption characteristics, with acutely infected mucoceles showing rim enhancement. Plain radiography and pluridirectional tomography were usually sufficient for making a diagnosis and defining the extent of the lesion, but CT more accurately demonstrated orbital and intracranial extension. Both transverse and coronal CT are essential for adequate evaluation.

Adolescent↗
PubMed1978

Computed tomography of the orbit with special emphasis on coronal sections.

Computed tomography (CT) is an extremely valuable noninvasive method for evaluating orbital soft-tissue structures. The possibility of scanning in the coronal plane has added a new dimension to the study. Direct enlargement viewing of scans on the display console has disclosed minute anatomic and pathologic details.

Humans↗
PubMed1978

Computed tomography of the paranasal sinuses and face: part I. Normal anatomy.

With the ability to image both bone and soft tissue structures, computed tomography (CT) is capable of visualizing many normal anatomical structures of the paranasal sinuses and face not seen with other radiological techniques. The superficial and deep fat planes, all of the muscles of mastication, and many of the facial muscles are readily identified. The extraocular muscles, optic nerves, and globes are clearly seen. The purpose of this report is to review the normal anatomy of the paranasal sinuses and face imaged by CT in both the transverse and coronal planes.

Face↗
PubMed1978

Computed tomography of the paranasal sinuses and face: part II. Pathological anatomy.

Computed tomography (CT) has added an important new dimension to the radiological evaluation of diseases of the paranasal sinuses and face. Using transverse and coronal scans, accurate assessment of the character and extent of mass lesions in this region can be achieved. Erosion of thin bony lamine and involvement of soft tissue structures of the face can be seen. Most important, CT is capable of precisely defining the extension of lesions into the pterygopalatine fossa, orbit, and cranial cavity, information that is essential for therapeutic planning.

Adult↗
PubMed1978

Computed tomographic evaluation of traumatic spinal injuries.

A full radiological evaluation of patients who sustained traumatic injuries to the spine may be difficult to obtain due to the danger associated with manipulation. Computed tomography offers a new modality for simple and accurate evaluation; valuable information may be gained without the use of invasive methods.

Humans↗
PubMed1978

Computed tomography of herpes simplex encephalitis, with clinicopathological correlation.

The computed tomographic (CT), clinical, and pathologic findings in 9 patients with biopsy-proven herpes simplex encephalitis (HSE) were reviewed. Seventeen scans (5 plain, 12 contrast enhanced) were analyzed. The major CT finding was a low-absorption abnormality, present in 11 of 17 scans (64%), affecting primarily the temporal lobes. Mass effect was evident in 9 of 17 (52%). Of the 12 contrast-enhanced scans, 6 (50%) showed an abnormal enhancement pattern affecting primarily the sylvian fissure and opercular areas. CT abnormalities are characteristic enough that, in the proper clinical setting, they lend support to the correct diagnosis.

Adolescent↗
PubMed1978

A model for regional cerebral oxygen distribution during continuous inhalation of 15O2, C15O, and C15O2.

Equilibrium positron brain scans were obtained during continuous inhalation of C15O, C15O2, and 15O2. Inhalation of C15O labels hemoglobin, whereas C15O2 instantaneously labels stable water to H215O. During the continuous inhalation of 15O2, body tissues extract it from the blood in proportion to local metabolism and ultimately convert it to water of metabolism. After 6-8 min of inhalation, a steady-state equilibrium is established in which the inflow of tracer is balanced by its disappearance due to radioactive decay (T1/2 = 2 min) and biologic removal. Mathematical models of the steady-state distributions of C15O, C15O2/H215O, and 15O/H215O are derived. The major results are: a) The steady-state distribution of C15O is insensitive to variations in blood flow and essentially measures blood volume. b) The distribution of H215O during inhalation of C15O2 is dependent, though nonlinearly, on blood flow. c) The distribution of H215O during inhalation of 15O2 depends linearly on the oxygen extraction fraction and nonlinearly on blood flow. d) The dependence on blood flow in the 15O2 steady-state image can be removed by the division, point by point, of the 15O2 image by the C15O2 image.

Brain↗
PubMed1977

Computed tomography in metrizamide cisternography--importance of coronal and axial views.

Computed tomographic scans were performed in 34 patients following lumbar introduction of metrizamide. Imaging of the cranial spaces was obtained with horizontal and inclined (25 degrees) as well as coronal planes. Mass lesions within and encroaching upon the cisternal spaces were demonstrated, and the ventricular system was shown with varying degrees of opacification. Coronal and semicoronal views facilitated the localization of parasellar and incisural mass lesions.

Brain↗
PubMed1977

Computed tomography of acoustic neuroma.

Review of computed tomographic (CT) scans of 49 consecutive patients with surgically excised acoustic neuromas revealed positive scans in 80% following contrast enhancement, with 20% false negative scans. All tumors over 2 cm in diameter were shown by optimal scans with contrast enhancement. The positive scans were evaluated to determine the accuracy of the size of the lesions as predicted by the scan. A radiological approach to the evaluation of suspected acoustic neuromas is suggested.

Contrast Media↗
PubMed1977

Metrizamide enhancement of cerebrospinal fluid for computer tomography.

Enhancement of CT attenuation values of the CSF cisterns by the lumbar injection of metrizamide has been shown to be of value in demonstrating the anatomy of the cisterns. Tumors involving the cisterns, such as acoustic neurinomas and pituitary adenomas, are clearly defined. Coronal scanning was superior to horizontal views in many cases.

Cerebrospinal Fluid↗
PubMed1977

Cisternography with metrizamide and hypocycloidal tomography.

Cisternography with metrizamide (Amipaque) and hypocycloidal tomography was found to depict cisternal anatomy with detail and precision not obtainable with any other technique. Clinical tolerance is comparable to that of encephalography if suitable precautions are followed. All side effects observed had disappeared 36 hours after injection, and no delayed noxious effects were recorded. This method offers a simple, rapid and precise technique for depicting cisternal anatomy and requires no equipment other than a tilting multidirectional tomographic unit.

Humans↗
PubMed1977

Cerebral angiography in acute cerebral infarction.

Cerebral angiography in the acute phase of clinically diagnosed stroke syndromes was evaluated in a prospective study of 104 consecutive patients over an eight month period at the Massachusetts General Hospital to determine the diagnostic yield. Of 68 patients subsequently documented to have retinal or cerebral hemispheric infarction, 63 (92.6%) had angiographic demonstration of occlusive lesions which appeared to correlate with the clinical deficit. These results are discordant with prior angiographic reports, 2,17,18,20 suggesting that delayed carotid artery angiography fails to show occlusive lesions (embolic) which may be shown acutely.

Acute Disease↗