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Biomedical subjects

V John

Publications and source records attributed to V John.

At least 73 records · Page 4Linked to original sources
PubMed1983

Computed tomographic imaging in cervical vertebral fractures.

Spinal computed tomography scanning was performed in five patients with different types of cervical fractures. Computed tomography scanning was superior to plain x-ray studies in determining the narrowing of the spinal canal by bone fragments or soft tissues and in determining the involvement of the intervertebral joints. The value of computed tomography was clearly demonstrated in scanning those regions that are difficult to be examined by conventional radiologic methods. A disadvantage of computed tomography scanning is the impossibility of functional diagnostic investigations and examinations after surgery of patients who underwent stabilization with plates and wires.

Adolescent↗
PubMed1983

Computer tomographic evaluation of cervical astrocytoma.

The case of a 35-year-old woman with a cystic astrocytoma of the cervical spinal cord is presented. The use of CT investigations is stressed. The value of reformatting procedures in regard to the differential diagnosis is discussed.

Adult↗
PubMed1983

[Radiotherapy of the hemangioma of the choroid].

For the first time, a report is given on the percutaneous radiotherapy of hemangiomas of the choroid which could not be treated by photocoagulation. Diagnosis and control examinations of these tumors were performed by ophthalmoscopy, fluorescence angiography, and ultrasonography. Ten eyes (nine patients, three out of them with Sturge-Weber's disease) were treated between 1967 and 1982. A first group (five eyes, five patients) treated until 1974 received a target volume dose of 1,65 to 6,5 Gy combined with subsequent photocoagulation. All these eyes could be preserved. In addition, the second group (five eyes, four patients) treated since 1975 with unique radiotherapy showed better results with respect to visual acuity. The average follow-up period was four years (seven months up to nine years). Late effects were not observed. Even in case of advanced disease with retinal ablation and secondary glaucoma, an inactivation of the hemangioma of the choroid and a simultaneous regression of the secondary alterations could be achieved. According to our experiences, enucleations can be prevented by an irradiation with a target volume dose of 20 to 30 Gy.

Adolescent↗
PubMed1983

[Computer tomography contrast media studies for the demonstration and therapy control of angiomatous tumors of the eye using the example of ocular manifestations of Sturge-Weber disease].

Thin-layer computed tomography of the orbit together with contrast representation by computed tomography in form of circulation studies is the only non-invasive method to represent intraocular hemangiomatous tumors hidden under an exsudative detachment of the retina. This method allows to establish exact tumor parameters which are necessary for an efficient therapy. In this case, radiotherapy with Cs137 is applied.

Angiomatosis↗
PubMed1983

[Comparative studies on the patient's exposure to radiation in case of spinal thin-layer computed tomography and of conventional radiologic examination methods].

The doses received by the organs in case of spinal thin-layer computed tomography, conventional tomography and myelography of the inferior lumbar spine (with first portion of the sacrum) were determined with CaF2 thermoluminescence dosemeters in the Alderson Rando phantom. As compared to computed tomography, the organ doses of the conventional examination methods were lower within the region of primary radiation and higher within the region of scattered radiation. Generally, patients examined by spinal thin-layer computed tomography of the inferior lumbar spine run a greater somatic radiation risk than those submitted to conventional examination methods.

Humans↗
PubMed1981

[ROC-analysis in testing and training the interpretation of radiographs with mammography serving as an example (author's transl)].

ROC (receiver operating characteristics) curves taken from the results obtained in evaluating the performance of ten different viewers with different experience in the interpretation of 120 xeromammograms and 120 conventional film mammograms each, serve as a basis to discuss the value of ROC-analysis in evaluating and improving the interpretation skill of individuals reading radiographs.

Mammography↗
PubMed1980

Influence of age, cigarette smoking and the oral contraceptive on plasma concentrations of clomipramine.

The influence of age, cigarette smoking and the oral contraceptive on the plasma profile and tolerability of clomipramine has been studied in depressed patients given the drug daily for four weeks. Older patients tend to have higher plasma concentrations of clomipramine than the younger and tolerate clomipramine less well; this latter is considered to be at least partly due to the increased plasma concentrations of the drug. Clearly elderly patients need a lower dose than the young if a high incidence of side effects is to be avoided. Patients smoking 15 or more cigarettes a day were found to tolerate daily doses of 75 mg clomipramine far better than non-smokers. Perhaps surprisingly, this was not reflected in lower plasma clomipramine concentrations in smokers, possibly owing to the high drop-out rate amongst non-smokers, which biased these data. Finally, no interaction was observed in females between clomipramine and oral contraceptives, the concomitant administration of which did not influence either plasma clomipramine concentrations or its tolerability.

Adolescent↗
PubMed1979

Metoprolol with and without chlorthalidone in hypertension.

After a control period on a placebo, 45 patients with mild to moderate hypertension were treated with metoprolol, 100 mg twice daily alone and in free combination with chlorthalidone 50 mg daily using a double-blind crossover technique. The beta-blocker alone induced a significant fall in blood pressure; the diastolic pressure was reduced to 100 mg Hg or less in 37 of the 45 patients and to 95 mm Hg or less in 19 patients. The addition of chlorthalidone enhanced the antihypertensive effect so that in 33 patients diastolic pressure fell to 95 mm Hg or less. The drugs were well tolerated even by a small number of patients with chronic bronchitis and diabetes mellitus. None of the patients developed cardiac failure. Adding a diuretic caused a small reduction in serum potassium concentrations, and the relevance of this observation is discussed.

Adult↗
PubMed1979

[ROC-analysis in x-ray study of the breast; a comparative study between film and xeromammography].

A comparative radiographic and histological study was carried out in 126 patients with malignant and benign breast lesions. Prior to biopsy an additional film- and xeromammogram, both at oblique projection, were taken of each patient. The X-ray film was Definix Medical (Kodak), processed 5.5 minutes. The xerograms were taken with 1.5 mm aluminium total filtration, and developed by negative mode. The X-ray equipment consisted of a Senograph (CGR). The image evaluation was carried out independently by seven observers of varying experience in mammography by means of ROC-analysis. There is no loss of diagnostic information content in negative mode xeromammography, on the contrary, it seems to be slightly superior to film mammography.

Adult↗
PubMed1978

[Dose reduction in xeromammography (author's transl)].

The use of a total filter of 3 mm of aluminium permits a considerable reduction of the radiation dose in xeromammography using the senographe. In comparison with conventional xeroradiography radiation is reduced by a factor of 2 to 3, in comparison with foilless film by a factor of 10 to 12. The applied tissue dose is between 0.14 and 0.30 rad per exposure. The presently still hypothetic radiogenic risk of carcinoma due to mammography is thus lower for this system than with other systems. The quality of the radiograph and the diagnostic validity are not reduced by this technique.

Female↗
PubMed1978

[Value of different systems of mammography records with regard to their exposure to radiation and their information content (author's transl)].

We learned from our examinations that, if there were optimum conditions, the combination Medichrome MR50 as a form of low dose method offers the same information content as the film without intensifying screens PE 4006. We found out that the discernibleness of details of 70 non selected mammographies which had each been taken by both systems was absolutely identical. By xeroradiography, however, a more precise representation of details, especially if there are microcalcifications, is possible because of its effect which renders the edges more visible. If the Medichrome low dose method was applied, the exposure to radiation of the breast was, depending on the density and width or the organ, only 1/12 to 1/14 of the dose measured if the film without intensifying screens was used. The exposure to radiation connected with xeroradiography is between these two values. We came to the following conclusion: the low dose method is recommended for routine mammographies, and only if there are special problems or if suspicious findings are to be clarified, xeroradiography is applied as supplementary examination method. Before using the film without intensifying screens, one should consider the high radiation exposure which, however, does not involve a greater information content.

Breast Neoplasms↗
PubMed1978

[Duct pattern of the breast. An indicator of patients with increased risk of breast cancer development? A histological and mammographic study with 160 cases of breast cancer (author's transl)].

In 1975 John Wolfe proposed a classification of mammographic findings concerning the distribution of the duct pattern to select patients with high cancer risk. In a retrospective study we classified 160 patients with breast cancer according to the duct pattern classification. Our findings support well the results of Wolfe. Type N (normal duct pattern) is found in only 8,9% of all cancer patients whereas breast cancer was combined in 80% with the P2-DY-type. Our investigation confirms the classification of the duct pattern according to Wolfe as a valuable addition to the mammographic diagnosis of breast cancer.

Adult↗