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Biomedical subjects

K Hahn

Publications and source records attributed to K Hahn.

At least 199 records · Page 11Linked to original sources
PubMed1990

Nuclear medicine studies in the differential diagnosis of diseases with spinal involvement.

Plain X-rays computed tomographic and magnetic resonance images all yield information on the pathophysiology of diseases with spinal involvement. Descriptions of the following nuclear medicine methods are presented: Bone scanning with 99 m-technetium labeled phosphonate complexes used for the evaluation of skeletal metastases, primary bone tumors, traumatic, degenerative, and postoperative changes as well as in inflammatory conditions. Specific radionuclides used for the localization of inflammatory conditions are radioactive labeled leucocytes. Iodine total body scans used to detect spinal metastases of follicular and papillary thyroid carcinoma. 201-thalliumchloride is used as a tumor-marker with high affinity and sensitivity in malignant thyroid tumors. 131- or 123-iodine-meta-iodobenzylguanidine scans used in the detection of metastases of pheochromocytoma and neuroblastoma. Immunoscintigraphy with radioactive labeled anti-CEA antibodies used for the specific labelling of metastases of gastrointestinal tract tumors, melanoma, breast, and ovarian carcinoma. The value of the various nuclear medicine methods in the diagnostic schedule is illustrated in case reports.

Humans↗
PubMed1990

A radiopharmaceuticals schedule for imaging in paediatrics. Paediatric Task Group European Association Nuclear Medicine.

There is no standard schedule for the amounts of radiopharmaceutical administered to children at present. Various alternative methods are currently in practice, all with some support from the literature. Optimization of the amount of radiopharmaceutical to be administered is discussed in relation to the radiation burden of such an examination. The Paediatric Task Group of the European Association of Nuclear Medicine has investigated the current situation and now suggests a method for standardization of administered amounts of radiopharmaceutical in paediatrics. The fraction of the adult amount of radiopharmaceutical to be administered should be calculated from the child's body weight according to the accompanying table. In small infants, the minimum amount of a radiopharmaceutical is discussed and suggested amounts to be administered are presented.

Body Weight↗
PubMed1990

[Immunoscintigraphy in colorectal cancers from the viewpoint of the gastroenterologist].

In the last decade radioimmunoscintigraphy developed from an experimental approach to a clinically useful method. First promising results were obtained with Technetium-99m labelled murine monoclonal antibodies against carcinoembryonic antigen (CEA). Routine clinical application is restricted to colorectal carcinoma at the moment. Radioimmunoscintigraphy is recommended in case of recurring disease when conventional methods are ineffective or doubtful, especially in the pelvic region. The availability of monoclonal antibodies to new tumor-associated antigens will extend the spectrum to other gastrointestinal tumors. The possibility to generate recombinant humanized monoclonal antibodies and antibody fragments are encouraging new perspectives. These developments and the use of biological immune response modifiers to increase antigen expression could provide means to consider radioimmunotherapy of gastrointestinal cancers.

Antibodies, Monoclonal↗
PubMed1989

RCBF-quantification with 99mTc-HMPAO-SPECT: theory and first results.

The activity concentrations of 99mTc-HMPAO in brain after intravenous injection were evaluated in 25 patients using SPECT. With additional first pass studies of heart and brain with the short lived isotope 195mAu, the cardiac output and the mean cerebral transit times of the patients were measured a short time before the HMPAO injection. The time dependence of 99mTc-HMPAO activity in the brain was registered during the first 5 min after injection over both hemispheres. Using a simplified three compartment model it was possible to calculate the mean retention fraction of HMPAO in brain from the time activity curves. It could be shown that the regional cerebral blood flow in ml/min per 100 g can be calculated from the activity concentration of HMPAO in the brain, the cardiac output and the retention fraction. In 15 of the 25 cases the rCBF was measured using the planar 133Xe inhalation method as a reference. We found a significant correlation between the mean hemisphere CBF from our method and the mean hemisphere grey matter CBF from the Xenon method with a correlation coefficient of 0.73.

Adolescent↗
PubMed1989

SPECT bone scintigraphy of benign and malignant lesions of the spine.

70 patients were examined with planar and SPECT bone scintigraphy. SPECT proved to be superior over planar bone scanning for imaging of traumatic, inflammatory, and malignant bone lesions. SPECT provides three-dimensional information and, therefore, delineates the exact location and extension of lesions. It also has a higher sensitivity than planar bone scintigraphy. The three-dimensional bone scan generates complementary diagnostic information which often facilitates an adequate therapy protocol.

Adult↗