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Biomedical subjects

P Bartenstein

Publications and source records attributed to P Bartenstein.

100 records · Page 6Linked to original sources
PubMed1991

Benzodiazepine receptors and cerebral blood flow in partial epilepsy.

It was the aim of this study to compare benzodiazepine (Bz) receptor binding and cerebral perfusion in patients with partial epilepsy. Single photon emission tomography (SPET) studies with the flow-marker technetium 99m hexamethylpropylene amine oxine (99mTc-HMPAO) and with the 123I-labelled Bz-receptor ligand Ro 16-0154 (123I-Iomazenil) were performed in 12 patients with partial epilepsy, all with normal magnetic resonance imaging (MRI) and computed tomography (CT) scans. The SPET studies with 123I-Iomazenil were carried out 5 min and 2 h after injection. At 2 h the distribution of activity was very similar to the expected distribution of Bz-receptors in the human brain, known from positron emission tomography (PET) work and post-mortem studies. Early images showed a significantly higher tracer accumulation in the area of the basal ganglia, cerebellum, and naso-pharyngeal space. This finding is caused by non-specific binding and the contribution of the tracer in the blood pool in this phase. Also after 2 h p.i. of 123I-Iomazenil, 9 of the 12 patients showed a focal decrease of of Bz-receptor binding. Ten patients had focal flow abnormalities with 99mTc-HMPAO SPET. In 8 subjects impairment of flow was seen in sites of reduced 123I-Iomazenil uptake. 123I-Iomazenil is suitable for Bz-receptor mapping. In this series of patients, Bz-receptor mapping with SPET seems to offer no advantage over 99mTc-HMPAO in the detection of epileptic foci.

Adult↗
PubMed1991

Comparison of technetium 99m polyclonal human immunoglobulin and technetium 99m monoclonal antibodies for imaging chronic osteomyelitis. First clinical results.

The accuracy of technetium-99m human immunoglobulin (HIG) for the detection of chronic osteomyelitis (OM) was compared with white blood cell scintigraphy using 99mTc-labelled monoclonal mouse antibodies (MAB). Seventeen patients suspected of having OM in 20 lesions went through three-phase skeletal scintigraphy, HIG scintigraphy and MAB scintigraphy. The final diagnosis was established by open surgery, histology and bacteriology. Chronic OM was proved in 14/20 lesions. Six of these 14 infections were located in peripheral areas without active bone marrow and 8/14 in central areas with active bone marrow. In peripheral OM, 5/6 with HIG and 6/6 with MAB were true positives. In the central skeleton all 8/8 infections appeared as cold lesions in the MAB study, which were defined as being false negative due to their non-specificity. Using HIG, 5/8 central infections were determined to be truly positive by showing photon-rich lesions. These 5 lesions were located in the hip region and in the pelvis, whereas 3 lesions of the spine were missed. There were no false-positive results in either studies. In conclusion, MAB was superior to HIG in peripheral OM concerning sensitivity, anatomical landmarks and differentiation of soft tissue versus bone infection. In central OM MAB detected all lesions accurately, but no differential diagnosis was possible due to the non-specificity of photon-low areas. In this respect HIG seems to be more specific due to the increased accumulation even in central infection sites.

Adult↗
PubMed1991

[In vivo imaging of benzodiazepine receptors of the central type].

Two main types of benzodiazepine receptors exist in the human brain, the central receptor type being responsible for the classical actions of the compound. Although interesting findings have been obtained in epilepsy, hepatic encephalopathy and other clinical conditions, a relevant clinical indication for the in vivo imaging of receptor binding has not yet been defined, with the possible exception of the Lennox-Gastant syndrome.

Brain↗
PubMed1990

[Immunoscintigraphy of the hematopoietic bone marrow in osteomyelofibrosis].

In planning the treatment of splenomegaly in primary or secondary osteomyelofibrosis it is necessary to know whether there is any significant hematopoiesis outside the spleen. In contrast to the measurement of iron kinetics with 59Fe, which is not suitable for imaging, immunoscintigraphy with the monoclonal antibody Bw 250/183 allows specific imaging of the hematopoietic bone marrow. The diagnostic use of this method in addition to iron kinetics is illustrated and discussed in a patient with primary osteomyelofibrosis.

Antibodies, Monoclonal↗
PubMed1989

[Comparison of blood flow and benzodiazepine receptor distribution in focal epilepsy: preliminary results of a SPECT study].

99mTc-HMPAO-SPECT and SPECT with the 123I-labelled benzodiazepine (Bz) receptor ligand Ro 16-0154 were performed in 10 patients suffering from partial epilepsy, without cerebral lesion in MRT or CT.2 h p.i. of Ro 16-0154 the distribution of activity correlated with the known distribution of Bz-receptors in the human brain. Perfusion and receptor-binding were found decreased in 7 patients of each study in the suspicious brain-area. 123I-labelled Ro 16-0154 is suitable for Bz-receptor mapping by SPECT. The decrease of Bz-receptor binding in epileptic foci, as described in PET-studies, was also detected by SPECT in 7 of 10 patients.

Adult↗
PubMed1988

[Intrathoracic goiter in the posterior mediastinum].

Several examination methods are now available for diagnosis of intrathoracic goiter; diagnosis of suspicion is made by conventional plain radiography of the thorax, clinical findings being often normal or non-characteristic. If the iodine scintigram shows accumulation in the tumor, we can be practically sure of the diagnosis of an intrathoracic goiter. In case of a negative iodine scan we can obtain pointers to the nature of the tissue via CT or MR, especially if a connection between cervical thyroid tissue and intrathoracic mass can be demonstrated. Furthermore, these two methods (CT and MR) enable exact determination of the extension of the goiter and show the topographical relation to the neighbouring organs or their displacement.

Goiter, Substernal↗
PubMedDate not supplied

[Age-dependency of isotope drainage in diuretic renograms].

OBJECTIVE: The aim of the study was to establish normal values of the isotope drainage in diuretic scintigrams for children of different age-groups. Isotope drainage was determined 30 minutes after the application of technetium- (99m)MAG 3 as well as 15 minutes after the following application of furosemide. METHODS: We analysed the data from 274 investigations in sonographically normal renal units (RU) contralateral to kidneys with ureteropelvic junction obstruction or non-refluxing primary megaureters. RESULTS: There was a significant age-dependency of isotope drainage during the first weeks of life. In 79 RU the results of the first diuretic renogramm were compared with the follow-up examinations. The reliability of the measurements was lowest in children initially investigated during the first six weeks of life. If both the investigations were performed thereafter, no significant difference was found between the results. CONCLUSIONS: The isotope drainage of the sonographically normal contralateral RU seems to be a sufficient marker for the meaningfulness of the diuretic renogram. In urinary tract dilatation, mistakes regarding the interpretation of isotope drainage may be minimized by taking the measurements in the normal contralateral RU in account and by comparing them with age-referred normal values.

Child↗
PubMedDate not supplied

Reduction of regional cerebral blood flow and cognitive impairment in patients with Alzheimer's disease: evaluation of an observer-independent analytic approach.

The aim of the study was to evaluate an observer-independent semiquantitative analysis of brain imaging by single-photon emission computed tomography (SPECT) in patients with Alzheimer's disease (AD). Patients (n = 45, mean age 70 +/- 11 years) with a clinical diagnosis of AD according to NINCDS/ADRDA criteria were examined by 99mTc-ethylcysteine dimer SPECT. Following anatomic normalization and data extraction using three-dimensional stereotactic surface projection, a pixelwise comparison of ECD uptake was performed with the reference values of 10 cognitive intact controls of comparable age. The global relative decrease of cerebral blood flow in cortical association areas showed a significant inverse association with the overall level of cognitive functioning as assessed with the Mini Mental State Examination and with the cognitive section (CAMCOG) of the Cambridge Mental Disorders of the Elderly Examination. There were significant region-specific associations between left temporoparietal perfusion deficit and language performance and between right temporoparietal regional cerebral blood flow reduction and praxis. The results suggest that this observer-independent analysis of SPECT data provides a valid assessment of the pattern and severity of cortical perfusion abnormalities in patients with AD.

Adult↗
PubMedDate not supplied

Focal metabolic activation in the predominant left auditory cortex in patients suffering from tinnitus: a PET study with [18F]deoxyglucose.

Eleven patients suffering from chronic disabling tinnitus underwent an FDG-PET study (positron emission tomography with [18F]deoxyglucose). Nine tinnitus patients revealed a significantly increased metabolic activity in the left, 1 in the right primary auditory cortex (PAC, Brodmann area 41). These results were statistically significant when compared to 14 healthy control individuals without tinnitus. A negative result was obtained from a chronic tinnitus patient but who had no subjective complaints during the period of PET investigation. One patient was first investigated during a disabling tinnitus period, later during a period with tinnitus relief and again when suffering from severe tinnitus. The metabolic activity of his left PAC was in good accordance with the subjective degree of tinnitus complaints present during each PET investigation. Although for the first time these results give objective evidence of tinnitus sensation and localization, they are difficult to interpret because of the limited research data available that combine functional brain imaging and acoustic stimuli.

Acoustic Stimulation↗