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Biomedical subjects

R Unsöld

Publications and source records attributed to R Unsöld.

32 records · Page 2Linked to original sources
PubMed1981

The CT-topography of retrobulbar anesthesia. Anatomic-clinical correlation of complications and suggestion of a modified technique.

The anatomic relationship of an injection needle as traditionally placed in retrobulbar anesthesia to optic nerve, orbital vessels and eye muscles is demonstrated by computed tomography. The clinical complications of retrobulbar injections are reviewed and correlated to the orbital topography in different positions of gaze, as analyzed in anatomic sections and CT images. The results indicate that with the transitional technique of retrobulbar injection the most important orbital structures are in the immediate neighbourhood of the needle. A different injection technique is discussed.

Anesthesia, Local↗
PubMed1981

[On the diagnosis of extraocular muscle disease. Clinical application of computer reformations (author's transl)].

The clinical application and differential diagnostic value of computer reformations in patients with Graves' disease and ocular myositis are demonstrated. Computer reformations parallel to the course of the muscle allow the identification of abnormal soft tissue densities on axial section as a swelling of individual muscles. Computer reformations perpendicular to the course of the muscle demonstrate its true cross sectional diameter. In most clinical instances, the rectus muscles are sufficiently visualized on computer reformations 90 degrees to the orbital axis. The vertical recti are then shown as true cross sections, whereas the horizontal recti are dissected in an equally oblique plane. A swelling of the inferior oblique muscle is well visualized by sagittal reformations lateral to the insertion of the inferior rectus muscle. With the use of computer reformations muscle enlargement can be diagnosed with certainty. They therefore provide valuable information in the evaluation of motility disturbances as well as in the analysis of specific patterns of muscle involvement in various orbital diseases.

Diagnosis, Computer-Assisted↗
PubMed1980

Metastatic infiltration of nerves in the cavernous sinus.

Painful dysesthesia in association with ocular motor palsies characterized intraneural carcinomatous invasion in a 48-year-old man. Transcranial biopsy of the cavernous sinus stopped the pain; the specimen confirmed the diagnosis and provided the rationale for radiation therapy. One year after treatment, the patient was healthy and pain-free, with improved ocular motor function. The source of the carcinoma remains unknown.

Abducens Nerve↗
PubMed1980

Band atrophy of the optic nerve. The histology of temporal hemianopsia.

Cross sections of the orbital portion of the optic nerve, the decussating fibers of which underwent atrophy, have a distinctive histologic pattern. Distally, from the eyeball to the midportion of the optic nerve, this pattern of atrophy consists of a broad-based nasal and a narrow-based temporal sector that form a horizontal band. Proximally, near the optic canal, the pattern changes. The atrophic bundles occupy the nasal and central portions of the optic nerve only.

Carotid Artery Diseases↗
PubMed1980

CT-evaluation of extraocular muscles - anatomic-CT-correlations.

CT evaluation of the extraocular muscles is unsatisfactory in the commonly used axial and coronal planes. Based on the analysis of anatomic and computed tomographic sections and reformations in various planes, optimal examination techniques for the evaluation of the extraocular muscles are discussed. Their anatomic relationship to other clinically and surgically important orbital structures is shown. As a rule, visualization of an eye muscle is optimal if the plane of section or reformation is parallel to its course. Judgments regarding muscle size should be based only on true cross-sections obtained from reformations 90 degrees to the course of the individual muscle.

Diagnosis, Differential↗
PubMed1980

[Differential diagnosis of Graves' disease and orbital pseudotumor: CT findings (author's transl)].

CT scans of 25 clinically typical cases of Graves' disease and 15 cases of orbital pseudotumor (idiopathic orbital inflammation) are analyzed and differential diagnostic criteria evaluated. The CT-findings overlap and are best viewed as a continuous spectrum at both ends of which characteristic patterns can be identified. Massive swelling of ocular muscles, involving of several muscles, usually without density changes of the orbital fat, are diagnostic for Graves' disease. More or less circumscribed masses of soft tissue density surrounding the globe, eye muscles or the optic nerve, severe diffuse increase of density in the retrobulbar space masking orbital structures and calcifications indicate orbital pseudotumor. Localization of the swelling within a muscle, "scleral thickening", enhanced contrast, moderate density changes of the orbital fat, and involvement of the lacrimal gland are of minor differential diagnostic value. CT pictures of clinically typical and histologically proven cases of Graves' disease indicate heterogeneity of this group, probably reflecting different immunologic features. CT shows the extent and degree of the pathologic changes and indicates the optimal approach for tissue biopsy. Evaluation of both diseases by CT requires inclusion of coronal sections.

Adolescent↗
PubMed1980

Multiplanar evaluation of the optic canal from axial transverse CT sections.

High resolution multiplanar images of the optic canal can be obtained using computer transformations of 1.5 mm axial transverse sections through the orbit. Parasagittal sections through the optic canal along the course of the optic nerve or sections perpendicular to the canal are easily and reproducibly obtained. This approach is a much more efficacious means of examining the optic canal both in terms of information yield and reduction in radiation dose.

Humans↗
PubMed1980

CT examination technique of the optic nerve.

The computed tomographic (CT) appearance of the optic nerve was studied in various positions of gaze. In addition, the image quality of CT scans in different axial planes was analyzed. Based on these studies, an optimal examination technique for the clinical CT evaluation of the optic nerve is suggested. A negative angulation of -20 degrees to the orbitomeatal base line with the eye in upgaze position appears to be optimal. With this technique, the optic nerves are stretched and course parallel to the plane of section. They are therefore included in a minimum number of sections.

Humans↗
PubMed1980

Images of the optic nerve: anatomic-CT correlation.

The course of the intraorbital part of the optic nerve, as demonstrated on anatomic sections in various planes, is correlated with the appearance of the nerve in computed tomographic (CT) images. Discrepancies between the anatomic and CT appearance are analyzed and discussed. Since the optic nerve has a sinuous course in both the horizontal and vertical planes, no thin axial or sagittal section can be entirely parallel to the nerve. Any section will transsect the optic nerve obliquely, leading to an apparent hypodensity or "thinning" of certain segments as shown on CT. The appearance of the course of the nerve on reformatted CT images depends on the plane of the original CT section. Computed tomograms that are obtained with the eye in primary position do not allow reliable judgments regarding the course and size of the optic nerve.

Humans↗
PubMed1979

[Ct-criteria of orbital hemangiomas and their importance in differential diagnosis of intraconal tumors (author's transl)].

CT-scans of 29 histologically proven cavernous hemangiomas were evaluated with respect to their location, shape, delineation from surrounding tissue, contrast-enhancement, and secondary changes of the bony orbit. Whenever a round or oval tumor, located in the outer upper muscle cone, sharply delineated from surrounding tissue, unattached to optic nerve and ocular muscles, spares a small triangular space in the orbital apex, it is in all probability a cavernous hemangioma. Evaluation of the tumors shape and its separation from surrounding tissues requires imaging in multiple sections in two planes oriented, if possible, at right angles. -- Changes in position of the optic nerve and eye muscles in different directions of gaze demonstrated by CT rule out significant tumor-attachments. The portion of the intraconal space least affected by optic nerve shifts and muscle contractions during eye movements, as demonstrated by CT, is the upper outer quadrant, the site preferred by the mobile tumor. -- Tumors which cannot be differentiated from cavernous hemangiomas by CT-criteria are rare usually benign. Reports of rare examples of well delineated or encapsulated malignant intraconal lesions indicate the possibility -- however remote -- of mistaking a malignant tumor for a cavernous hemangioma by CT.

Diagnosis, Differential↗
PubMed1979

[Gaze induced monocular obscurations with cavernouse hemangioma of the orbit. Computer-tomographic demonstration of orbital anatomy in various positions of gaze (author's transl)].

A young woman with only minimal proptosis from a cavernous hemangioma of the left orbit complained of monocular obscurations of vision evoked by right alteral gaze. By analysis of the symptoms, we excluded direct compression of the globe, the optic nerve, and the ophthalmic artery as well as a retinal electrophysiologic phenomenon as a cause of the obscuration. Some vascular phenomenon occurring within the muscle cone appeared to be the most likely explanation. Computer tomography in various positions of gaze revealed the dynamic anatomical relationship between optic nerve and tumor. During adduction, the nerve pressed against and shifted beneath the tumor in the region where the ophthalmic artery crosses over it.

Adult↗
PubMed1978

[On the differential diagnosis of inflammatory illness of the orbit. Computer tomographic results (author's transl)].

Selectet CT-findings in inflammatory orbital diseases are demonstrated with special regard to the differential diagnostic importance of details. Based on the criteria-density of retrobulbar fat, swelling of extraocular muscles, dilatation of orbital vessels, representation of osseous borders of the orbit, pneumatisation of paranasal sinuses etc-typical CT-patterns of disease entities are demonstrated. The differentiation of inflammatory diseases, orbital tumors, and vascular disorders is discussed. The limits of diagnostic interpretation are pointed out.

Aged↗
PubMed1976

The laser in the Lowry technique for microdissection of freeze-dried tissue slices.

A new technique for tissue microdissection is described. This procedure, using an u.v.-laser micropreparation instrument, overcomes the extremely time-consuming manual preparation. The u.v.-laser micropreparation design allows fast, precise, reproducible and smear-contamination-free tissue microdissection. The preparation of the tissue sample can be programmed by tracing out the area to be sampled with a non-destructive 0.5 mW He-Ne-laser aiming-beam. The tract is stored in a small electronic unit, which then guides the motor-driven stepping stage on the microscope in the actual dissection run with the u.v.-laser. The laser power is adjustable in the range 4 to 40 kW and controlled by a photo diode displayed on an oscilloscope screen. In the tissue slice, prepared according to Lowry, an unlimited number of cells or tissue compartments can be dissected and afterwards weighed. The procedure described offers a broader use of the quantitative microhistochemical techniques of Lowry and of Neuhoff.

Acid Phosphatase↗