PubMed Health⌕ Search

Biomedical subjects

C M Strother

Publications and source records attributed to C M Strother.

At least 91 records · Page 5Linked to original sources
PubMed1977

Anatomic considerations for computed tomography of the optic chiasm.

When the clinical distinction between lesions of the optic nerves or the chiasm is not apparent, computed tomographic scans should be performed at both 0 degrees and 25 degrees or 35 degrees to the orbital-meatal line (Reid's baseline). The former plane is preferable for the demonstration of the optic nerves or orbital structures, while the latter allows superior visualization of perichiasmatic structures.

Female↗
PubMed1977

Metrizamide--CSF contrast medium. Analysis of clinical application in 215 patients.

Two-hundred-fifteen patients were evaluated with metrizamide, a new water-soluble contrast agent for use in the subarachnoid spaces. Side effects were reported in 67% of these; 39% were moderate or severe. Cervical injections monitored by fluoroscopy provide the most precise positioning of the medium. The benefits of metrizamide use outweigh its risk.

Cerebrospinal Fluid↗
PubMed1977

Computer tomography and subarachnoid metrizamide for evaluation of cerebrospinal fluid flow.

Twenty-one patients were examined with computer tomography following subarachnoid injection of metrizamide (Amipaque). Five were evaluated because of dementia or possible obstructive hydrocephalus. The remainder were referred for lumbar or cervical myelography and served as controls. Concentration and distribution of the contrast medium within the cranial subarachnoid space and ventricular system depend upon a composite of the physical properties of the contrast medium, patient positioning and activity and CSF physiology.

Cerebrospinal Fluid↗
PubMed1976

Percutaneous embolization to control epistaxis in Rendu-Osler-Weber disease.

Recurrent epistaxis is the most common manifestation of hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease), a disorder characterized by widely scattered visceral, dermal, and mucosal vascular lesions. Emergency measures applied locally may control acute hemorrhage, but seldom result in long-term benefit. Recently, we have had the opportunity of performing bilateral carotid angiographic examination on a patient with hereditary hemorrhagic telangiectasia who was suffereing from severe intractable epistaxis. At the time of angiographic examination, embolization of both internal maxillary arteries was accomplished, and control of the epistaxis was achieved. In the patient with severe epistaxis that is unresponsive to local measures, percutaneous embolization offers substantial advantages over surgical intervention.

Carotid Artery, External↗
PubMed1975

Corticosteroid-induced mediastinal widening in myasthenia gravis.

Corticosteroid-induced mediastinal widening with simulated focal lymphadenopathy was found in a patient having myasthenia gravis. To my knowledge, this is the first report of such changes occurring in a patient having myasthenia gravis. As the use of corticosteroids in the treatment of myasthenia gravis becomes more common, this association can be expected to occur more often. Reemphasis of this phenomenon should help to avoid unnecessary surgical intervention in these patients.

Humans↗
PubMedDate not supplied

The vestibular aqueduct--tomographic evaluation in Meniere's disease--a preliminary report.

Frontal and off-lateral complex motion tomography was performed in 72 consecutive patients selected for endolymphatic sac surgery for episodic vertigo or sensorineural hearing loss. They were selected for this operation because of a fluctuating hearing loss. The morphology and visualization of the vestibular aqueduct and the degree of periaqueductal pneumatization were correlated with surgical results and the presence of bilateral disease. The surgical results were evaluated with use of the classification of the American Academy of Ophthalmology and Otolaryngology. Computer analysis was performed on the data for vestibular aqueduct radiographic anatomy and surgical results or bilateral disease. There was no correlation between visualization or morphology of the vestibular aqueduct and surgical results or presence of bilateral disease.

Follow-Up Studies↗
PubMedDate not supplied

A new guidewire with kink-resistant core and low-friction coating.

A new guidewire constructed from kink-resistant titanium-nickel alloy, polyurethane, and hydrophilic polymer is described. We have used this wire in 119 angiographic and 49 interventional procedures without complications. In numerous applications, it offers significant advantages over other guidewires. It is particularly helpful for angiography and interventional procedures requiring catheterization through markedly tortuous vessels, tight stenoses, or occlusions.

Alloys↗
PubMedDate not supplied

Determination of optimal injection parameters for intraarterial gadolinium-enhanced MR angiography.

PURPOSE: Rapid vascular depiction with use of a minimum of gadolinium (Gd) contrast agent will be required to generate road-map vascular images for magnetic resonance (MR) imaging-guided endovascular interventions. The objective of this study was to optimize intraarterial injections of MR contrast agent during magnetic resonance angiography (MRA), obtained during interventions, by determining the optimal Gd vascular concentration ([Gd]) for vessel depiction. MATERIALS AND METHODS: The authors derived theoretical expressions to estimate the [Gd] resulting in maximal signal in blood. A model was developed to account for flow dilution to estimate [Gd] given the injected Gd concentration, injection rate, and the blood flow rate. Experiments in four animals (three dogs, one pig) were conducted to verify this model with use of both time-resolved two-dimensional (2D) thick-slab and single-phase three-dimensional (3D) MRA acquisitions. The authors also determined the optimal [Gd] required for vessel depiction in animal models. RESULTS: The theoretical expressions yielded optimal [Gd] of 10.2 mmol/L in blood. The animal experiments used the flow dilution model and examined signal enhancement in the aorta and the renal and iliac arteries. Maximal enhancement occurred at [Gd] = 16.2 +/- 4.0 mmol/L (mean +/- SE). CONCLUSIONS: The theoretically predicted values for [Gd]optimal and the flow dilution model were successfully validated. The relationship between injected [Gd], injection rate, and blood flow rate permits rapid intraarterial administration of contrast material, using less overall contrast material than with standard intravenous Gd-enhanced MRA.

Animals↗
PubMedDate not supplied

Intraarterial gadolinium-enhanced 2D and 3D MR angiography: a preliminary study.

PURPOSE: To evaluate, in phantom and canine models, intraarterial gadolinium-enhanced two-dimensional (2D) and three-dimensional (3D) magnetic resonance angiography (MRA). MATERIALS AND METHODS: The in vitro experiments examined gadodiamide solutions ranging in gadolinium (Gd) concentration from 0.1% to 100%. A spoiled gradient-recalled echo (SPGR) sequence was used with various repetition time/echo time (TR/TE) parameters. Signal was measured to determine which concentration yielded the highest signal. For in vivo experiments, pigtail catheters were placed in the abdominal aortae of two dogs. Intraarterial injections of 20-30 mL of 0.5%-25% Gd solutions were performed. We acquired images with use of 2D and 3D SPGR techniques. Depiction of the abdominal aortae and renal vessels was assessed qualitatively and quantitatively. RESULTS: Phantom experiments demonstrated that a 2%-6% solution of Gd produced the highest MR signal, depending on the imaging parameters. In the canine model, a 2% Gd solution was best for 2D techniques, whereas 7%-14% Gd solutions were optimal for 3D techniques. CONCLUSIONS: Intraarterial contrast material-enhanced 2D and 3D MRA can be successfully implemented with use of dilute Gd. Dilution permits the administration of more intraarterial injections per day, without exceeding the dose limit, compared with intravenous Gd-enhanced MRA. Intraarterial injections also limit scan synchronization and contrast material dispersion issues. This technique may have application in MR-guided endovascular procedures.

Animals↗
PubMedDate not supplied

Comparison of ultrasound and IV-DSA for carotid evaluation.

Sixty carotid bifurcations in 34 symptomatic patients were examined prospectively with ultrasound (continuous wave Doppler and high resolution, B-mode imaging) and intravenous digital subtraction angiography (IV-DSA). The overall quality of examination was better with DSA than with ultrasound. Imaging of the external carotid artery was particularly difficult with sonography. For evaluation of the common and internal carotid arteries, eight percent of IV-DSA studies were poor or inadequate as compared with 12% for B-mode imaging. Overall for detection of atherosclerotic plaque, high resolution B-mode sonography was 84% sensitive and DSA 81% sensitive. When only the common and internal carotid arteries were considered, the sensitivity of high resolution sonography improved to 93% and the sensitivity of IV-DSA increased to 86%. Ultrasound (combined high resolution, B-mode sonography and CW Doppler) correctly identified all six internal carotid occlusions in the series. While IV-DSA correctly identified five of the six occlusions, the sensitivity for detection of lesions causing 70% or more stenosis was 95% for both ultrasound and IV-DSA. Sensitivity for 50% or greater obstruction was 79% for ultrasound and 85% for IV-DSA. Ultrasound sensitivity for greater than 50.9% stenoses rose to 87% when only the common and internal carotid were considered while IV-DSA sensitivity remained at 85%. Specificity was good at all levels of obstruction. It may be concluded from this study that the accuracy of ultrasound and IV-DSA are quite similar for evaluation of the carotid bifurcation and that either test is a satisfactory screening method for carotid bifurcation atheromatous disease.

Aged↗