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Biomedical subjects

W E Allen

Publications and source records attributed to W E Allen.

At least 109 records · Page 6Linked to original sources
PubMed1978

Pluridirectional tomography in the evaluation of pituitary tumors.

A series of 110 patients with suspected pituitary tumors was recently evaluated by endocrinologic and neuroradiologic studies. Of the 77 patients in this series who underwent surgery, 74 had confirmed pituitary adenomas, two had suprasella tumors of the influndibulum, and one had an empty sella not previously diagnosed at pneumoencephalography. All 17 patients with normal plain skull films but abnormal thin section tomography who underwent surgery had documented pituitary tumors. This includes six patients who presented with amenorrhea and/or galactorrhea and normal baseline serum prolactin levels; the only abnormality was found on tomography of the sella. In the preoperative evaluation of these patients, pluridirectional tomography of the sella was the most sensitive indicator of intrasellar pathology.

Adenoma↗
PubMed1978

Small hemorrhages vs. small calcifications in brain tumors: difficulty in differentiation by computed tomography.

The difficulty in differentiating multiple small hemorrhages from multiple small calcifications in brain tumors by computed tomography (CT) is discussed. Illustrative CT scans are presented and the theoretical basis for this problem is elaborated. The difficulty is attributed to the relatively large size of the voxel and the ensuing partial volume effect, particularly with small intraparenchymal lesions of different sizes and attenuations.

Adult↗
PubMed1977

Cerebral cortical veins in otologic surgery.

Proximity of the cerebral cortical veins to the overlying dura predisposes them to surgical injury. Labbé's vein, draining a major portion of the posterior temporal and inferior parietal lobes, occurs on the left in 77% and on the right in 66% of patients. Interruption of this vein during otologic surgery may produce devastating neurologic consequences. In this regard, the roentgenographic anatomy of cerebral cortical venous drainage is reviewed. Technical treatment of the temporal dura should include those techniques familiar to the neurosurgeon that ensure the pretection of the temporal lobe and its superficial venous drainage.

Adult↗
PubMed1977

Gray scale ultrasonography, computerized tomography, and nephrotomography in evaluation of polycystic kidney and liver disease.

A comparison of gray scale ultrasonography and computerized axial tomography in adults with known adult-type polycystic disease and of ultrasonography and high-dose nephrotomography in their progeny is being conducted. Although all three modalities have proved capable of demonstrating cysts of the kidney and liver, ultrasound has been the most consistent in identifying these lesions. Ultrasound is valuable in diagnosing polycystic disease in adult with large, poorly functioning kidneys; in addition, since cysts could be identified by ultrasound in children who had normal nephrotograms, it provides a safe and useful method of obtaining information for genetic counseling.

Connecticut↗
PubMed1977

Computerized tomography in the assessment of diseases of the thorax.

Many of the diseases of the chest wall, heart, mediastinum, pleura and lungs can be successfully imaged by computerized tomography. Radiation therapy ports can be calculated and transcutaneous biopsies monitored. This paper deals with the many uses that we have had for computerized tomography in assessing diseases within the chest and thorax.

Adult↗
PubMed1977

Computerized tomography in pulmonary sarcoidosis.

Six patients with documented pulmonary sarcoidosis were selectively studied with the ACTA scanner. The CT scans were correlated with the standard chest radiographs of these patients. CT scans readily confirmed adenopathy, calcification, and pleural disease. Likewise, diffuse and isolated parenchymal disease was detected and in some cases unexpected lung involvement was noted.

Adult↗
PubMed1977

Direct coronal computerized tomography.

The computerized tomographic examination is routinely performed in the axial plane. However, with several available CT units images in the coronal plane are easily obtained. These images are especially useful in the diagnosis of diseases of the facial bones, sinuses, orbits and parasellar area. This paper describes one year's clinical experience with direct coronal computerized tomography.

Aged↗
PubMed1977

Effect of prostaglandin analogue on progesterone-treated pony mares during early pregnancy.

Seven Welsh pony mares (9 pregnancies) received either 50 mg, 100 mg or 150 mg progesterone on alternate days, starting on day 21 of gestation. All but 2 pregnancies failed following prostaglandin administration on day 27. Although both mares were receiving the 150 mg progesterone dose rate, this treatment was not consistently successful in preventing pregnancy failure after prostaglandin administration.

Animals↗
PubMed1977

Polarized projection of stereo cerebral angiograms for audience viewing.

A simple and inexpensive method for producing stereo angiographic images for projection to large audiences is presented. Two 35 mm images are produced using a conventional reflex camera and direct positive film. When properly taken, these film chips can be mounted in stereo mounts and projected using a polarized light stereo projector.

Cerebral Angiography↗
PubMed1976

Evaluation of the neurotoxicity of water-soluble myelographic contrast agents by electrophysiological monitors.

The effects of subarachnoid injection of Conray (methylglucamine iothalamate) and its dimer (methylglucamine locarmate) in various concentrations were compared using electrophysiological monitors of the cortical evoked response (CER) and the H-reflex. Significant concentration-dependent differences were noted in the H-reflex, less marked with the dimer. No significant difference in the CER was noted. This differential alteration in neurophysiological parameters was independent of changes in blood and cerebrospinal fluid pressure, implying that these water-soluble contrast media have a direct toxic effect on the nervous system, possibly situated in the larger (group 1) root fibers.

Animals↗
PubMed1976

The radiology of transsphenoidal hypophysectomy: a review of 100 cases.

This report describing the radiology of transsphenoidal hypophysectomy based on a review of 100 consecutive surgical procedures. Preoperative laminographic evaluation of the sphenoid sinus is an important aid in planning the most direct surgical approach to the pituitary. It is also useful in defining the many anatomic structures that may be injured inadvertently at the time of surgery. Intraoperative radiography or fluoroscopy is helpful in identifying the sella floor and as an aid in preventing loss of orientation within a capacious sinus. Various changes occur within the sphenoid sinus following surgery, some transient and others persistent. The surgical defect is usually difficult to identify on routine roentgenograms but is clearly visible on lateral laminography. A persistent soft tissue mass within the sinus is usually a manifestation of fascia and fat placed as a seal within the sinus.

Humans↗
PubMed1975

Pregnancy failure induced by human chorionic gonadotrophin in pony mares.

Ten pregnant Welsh pony mares were each treated with a series of three intravenous injections of 2000 iu human chorionic gonadotrophin (HCG) on alternate days. In four mares the first dose was given before the 39th day of gestation and conceptual loss followed treatments in all mares. The other six mares were first treated between the 40th and 97th days. No conceptual loss occurred despite five of the mares being given a fourth dose of HCG. Two mares first treated on days 36 and 38 of pregnancy subsequently produced PMSG although foetal death had occurred.

Animals↗