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W Hoeffken

Publications and source records attributed to W Hoeffken.

At least 19 recordsLinked to original sources
PubMed1995

[Quality assurance by improved cooperation structures. The example of decentralized early detection mammography].

The German Mammography Study investigated into quality assurance measures for screening mammography, proceeding in a decentralised manner and focussing especially on structure, process and outcome of the study. The field phase lasted for three years, and during this period the technology of the equipment used in mammography improved, also to the indicators of process and of early outcome. The annual interval of examinations was well received. To include mammography into the German cancer screening programme is no easy matter: it requires a comprehensive cooperative quality assurance programme incorporating various institutions of medical care. Appropriate recommendations have been made to the Federal Committee of Physicians and Sickness Insurance Bodies.

Adult↗
PubMed1993

[Determinants of observer variability in early diagnostic mammography--a ROC analysis].

As part of the German mammographic study, the participating doctors were given test films of 30 histologically confirmed cases. Regarding the indications for biopsy there was good sensitivity (the median amongst 25 doctors was 0.87). Specificity (median 0.86) could be improved. Comparison of individual results with the majority showed considerable variability within the group of doctors performing mammography. ROC analysis indicated that there was considerable observer variability which was independent from the specialty or praxis characteristics of the participants. The inclusion of mammography in an early diagnostic programme requires continuing education of the participants in this technique. This should be supported by further methods of quality assurance.

Germany↗
PubMed1980

Growth rate of 147 mammary carcinomas.

In 147 cases of mammary carcinoma, 388 serial mammographies were performed before final treatment. The average retrospective observation time was 27 months with a range of two months to 11 years. The number of serial mammographies per case ranged between two and 11. The tumor volume doubling times (TV); obtained by measuring the growth of the tumor nucleus shadow in the mammographies, ranged from 44 to 1869 days with an average of 212 days. No correlation between volume doubling time and histologic differentiation could be found. One hundred of these cancer patients were found in a screening population of 22,000 women receiving serial mammographies in a time period ranging from two to 16 years. An additional 40 cancer patients surfaced in this group without roentgenologic but with foregoing clinical or thermographic abnormalities before final diagnosis. An additional 21 cancer patients surfaced without any foregoing abnormalities. The follow-up tumor ranged between three months and two years with a mean time of one year and nine months. Not considering tumor size, pathologic-thermographic signs appeared with greater frequency the faster the tumor grew. Theoretically, an average of more than 16 years should elapse before an initial tumor cell develops into a 10-mm primary mammary carcinoma (30 doubling times). Therefore the length of time necessary for a 2-mm tumor to grow to a size of 10-mm is, on the average, four years.

Adolescent↗
PubMed1980

CT-visualization of an intraspinal osteoma-like mass in Paget's disease.

Neuroradiological examination in a case of polyostotic Morbus Paget with compression of the thoracic spinal cord was extended to spinal computed tomography. The use of radiography, myelography, and skeletal scintigraphy as regards diagnostic information is compared to CT. Obviously the use of CT provides a valuable completion for the evaluation of extradural space-occupying spinal lesions. Undisturbed by overlying structures of CT has the potential to differentiate various types of tissues. CT clearly depicts the lesion and aids in the recognition of the type of the compressing foreign body, which in this case was an osteoma-like protrusion.

Diagnosis, Differential↗
PubMed1979

Hyperperfusion and enhancement in dynamic computed tomography of ischemic stroke patients.

The passage of contrast medium was observed using serial computed tomography (CT) in 24 stroke patients. Density--time profiles of various brain regions were plotted. In normal brain tissue, X-ray attenuation showed a maximum increase during the arterial phase (16.4 +/- 11.0%) and was 2.8 +/- 2.2% above control during stable distribution. In hypoperfusion, increase in attenuation was always below 10% in the arterial phase, while hyperperfusion was characterized by an attenuation increase of 25 to 70%. Enhancement was defined by a density increase of 16.8 +/- 14.8% and a tissue/blood ratio between 7 and 60%. An attempt was made to establish a relationship between the serial CT pattern and the prognosis. Enhancement tended to indicate severe morphological changes followed by permanent neurological deficit, whereas hyperperfusion was generally an indicator of probably recovery.

Adult↗
PubMed1977

Mammography.

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Adenocarcinoma, Scirrhous↗
PubMed1976

X-ray therapy of primary bone tumors.

Radiotherapy of bone tumors can now be performed exclusively by megavolt therapy. Giant cell tumors hsould be resected. If the lesion is not completely resectable, surgery should be followed by the administration of a target dose of 3000 rads in 4-6 weeks. Inoperable giant cell tumors are irradiated to a tumor dose of 5000 rads, inoperable giant cell tumors of grade III receive a dose of 8000 rads as do osteosarcomas. Ewing's sarcoma and reticulum cell sarcoma can be totally destroyed by a tumor dose of 6000 rad with sufficient reliability. Combination with chemotherapy may offer a chance of improvement. Osteosarcoma should be resected. If surgery is too late (early distant metastases), a tumor dose of 8000 to 10000 rads would be able to destroy the tumor cells. Histologic control investigations have proved this.

Bone Neoplasms↗
PubMed1976

[Introduction to x-ray diagnosis of primary malignant bone tumor (author's transl)].

Diagnosis of primary malignant bone tumors is based on a synopsis of X-ray findings, clinical symptoms, gross pathology and histology. Osteosarcoma, chondrosarcoma, fibrosarcoma and myelogenic sarcomas have a typical symptomatology and can be diagnosed in the radiograph by localisation, mode of extension, alterations of bone and periosteum.

Adolescent↗