PubMed Health⌕ Search

Biomedical subjects

A Kögler

Publications and source records attributed to A Kögler.

12 recordsLinked to original sources
PubMed1997

[Right ventricular function and pulmonary hypertension].

BACKGROUND: Hypothetically the right ventricular function measured by Equilibrium Radionuclide Ventriculography (RNV) is determined by the right ventricular ejection fraction and depends on the afterload. We investigated the possibility to evaluate the increased pulmonary artery pressure (PAP) by using this method. PATIENTS AND METHOD: We examined 109 patients (54.6 +/- 11 years) with chronic obstructive pulmonary disease (COPD). Lung function test, analysis of blood gases, pulmonary artery catheterisation and RNV were done within one week. RESULTS: There are 52 patients with non. 37 with labile and 20 with fixed pulmonary hypertension. Patients with normal PAP and nearly normal RVEF (49.2 +/- 8) were used as control group. Patients with pulmonary hypertension have had a lower mean RVEF, but there was no significant difference to the control group. Furthermore there was no significant correlation between mean PAP and RVEF detectable. By using RNV we diagnosed fixed pulmonary hypertension with a sensitivity of 95% and a specificity of 33% reduced RVEF and partial respiratory failure as a second noninvasive parameter achieved a more precise but not sufficient prediction of pulmonary hypertension, tested in Chi Square-Test. Obviously the RVEF depends not only on the afterload but also on the preload and contractility. However, influences on contractility are multidimensional and difficult to assess and to determine. CONCLUSION: Eventually it is not possible to use the RNV for measuring RVEF to diagnose pulmonary hypertension in COPD.

Adult↗
PubMed1997

Cardiac phase-synchronized myocardial thallium-201 single-photon emission tomography using list mode data acquisition and iterative tomographic reconstruction.

The purpose of this study was to determine whether data acquisition in the list mode and iterative tomographic reconstruction would render feasible cardiac phase-synchronized thallium-201 single-photon emission tomography (SPET) of the myocardium under routine conditions without modifications in tracer dose, acquisition time, or number of steps of the a gamma camera. Seventy non-selected patients underwent 201T1 SPET imaging according to a routine protocol (74 MBq/2 mCi 201T1, 180 degrees rotation of the gamma camera, 32 steps, 30 min). Gamma camera data, ECG, and a time signal were recorded in list mode. The cardiac cycle was divided into eight phases, the end-diastolic phase encompassing the QRS complex, and the end-systolic phase the T wave. Both phase- and non-phase-synchronized tomograms based on the same list mode data were reconstructed iteratively. Phase-synchronized and non-synchronized images were compared. Patients were divided into two groups depending on whether or not coronary artery disease had been definitely diagnosed prior to SPET imaging. The numbers of patients in both groups demonstrating defects visible on the phase-synchronized but not on the non-synchronized images were compared. It was found that both postexercise and redistribution phase tomograms were suited for interpretation. The changes from end-diastolic to end-systolic images allowed a comparative assessment of regional wall motility and tracer uptake. End-diastolic tomograms provided the best definition of defects. Additional defects not apparent on non-synchronized images were visible in 40 patients, six of whom did not show any defect on the non-synchronized images. Of 42 patients in whom coronary artery disease had been definitely diagnosed, 19 had additional defects not visible on the non-synchronized images, in comparison to 21 of 28 in whom coronary artery disease was suspected (P < 0.02; chi 2). It is concluded that cardiac phase-synchronized 201T1 SPET of the myocardium was made feasible by list mode data acquisition and iterative reconstruction. The additional findings on the phase-synchronized tomograms, not visible on the non-synchronized ones, represented genuine defects. Cardiac phase-synchronized 201T1 SPET is advantageous in allowing simultaneous assessment of regional wall motion and tracer uptake, and in visualizing smaller defects.

Algorithms↗
PubMed1996

[123I]IBZM SPET analysis of dopamine D2 receptor occupancy in narcoleptic patients in the course of treatment.

Elevated levels of central D2 dopamine receptors were found on postmortem examination in cases of human narcolepsy. In vivo investigations using positron emission tomography (PET) and single photon emission tomography (SPET) found no changes of D2 binding in the striatal structures. To investigate whether the elevated D2 receptors in postmortem investigations are due to long-term treatment effects, we applied 123I-labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) ([123I]IBZM, a highly selective CNS D2 dopamine receptor ligand) and SPET in narcoleptic patients in the course of treatment with stimulants and/or antidepressants. Before treatment we found no changes in D2 binding in 10 patients (in comparison to 10 normal controls). After treatment (performed in five patients for 3 months) we found changes in D2 binding in four of them, indicating that the results of the postmortem studies could have been influenced by long-term medications. Human narcolepsy seems not to be related to a striatal D2 dopaminergic disturbance.

Adolescent↗
PubMed1996

Assessment of myocardial viability in persistent defects on thallium-201 SPECT after reinjection using gradient-echo MRI.

This prospective study assessed myocardial viability in 30 patients with coronary heart disease and persistent defects despite reinjection on TI-201 single-photon computed tomography (SPECT). In each patient, three observers graded TI-201 uptake in 7 left ventricular wall segments. Gradient-echo magnetic resonance imaging in the region of the persistent defect generated 12 to 16 short axis views representing a cardiac cycle. A total of 120 segments were analyzed. Mean end-diastolic wall thickness and systolic wall thickening (+/-SD) was 11.5 +/- 2.7 mm and 5.8 +/- 3.9 mm in 48 segments with normal TI-201 uptake, 10.1 +/- 3.4 mm and 3.7 +/- 3.1 mm in 31 with reversible lesions, 11.3 +/- 2.8 mm and 3.3 +/- 1.9 mm in 10 with mild persistent defects, 9.2 +/- 2.9 mm and 3.2 +/- 2.2 mm in 15 with moderate persistent defects, 5.8 +/- 1.7 mm and 1.3 +/- 1.4 mm in 16 with severe persistent defects, respectively. Significant differences in mean end-diastolic wall thickness (p < 0.0005) and systolic wall thickening (p < 0.005) were found only between segments with severe persistent defects and all other groups, but not among the other groups. On follow-up in 11 patients after revascularization, 6 segments with mild-to-moderate persistent defects showed improvement in mean systolic wall thickening that was not seen in 6 other segments with severe persistent defects. These data indicate that most myocardial segments with mild and moderate persistent TI-201 defects after reinjection still contain viable tissue. Segments with severe persistent defects, however, represent predominantly nonviable myocardium without contractile function.

Adult↗
PubMed1995

Single photon emission tomography (SPET) imaging of dopamine D2 receptors in the course of dopamine replacement therapy in patients with nocturnal myoclonus syndrome (NMS).

Single photon emission tomography (SPET) permits the in vivo measurements of regional cerebral radioactivity in the human brain following the administration of compounds labeled with photon-emitting isotopes. According to our SPET findings of a reduced binding of [123I]labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) to D2 dopamine receptors in striatal structures in untreated patients with nocturnal myoclonus syndrome (NMS) it seemed to be of interest to investigate whether there are changes in D2 receptor binding under dopamine replacement therapy or not. We studied the uptake and distribution of [123I]IBZM before and in the course of dopamine replacement therapy in four patients with severe insomnia caused by a nocturnal myoclonus syndrome (NMS). We found an increase of the IBZM binding to D2 receptors in the course of treatment, which was associated with an improvement of sleep quality. Reasons for this are discussed. The [123I]IBZM SPET technique in conclusion offers an intersting tool for in vivo investigations of functional changes in the dopaminergic neurotransmitter system in longitudinal studies.

Aged↗
PubMed1995

99mTc-HMPAO-SPECT in the diagnosis of senile dementia of Alzheimer's type--a study under clinical routine conditions.

This study was designed to evaluate, whether investigations of cerebral blood flow can be a helpful diagnostic tool in the differential diagnosis between (senile) dementia of Alzheimer's type [(S)DAT] and geriatric depression with cognitive impairment. Under clinical routine conditions we performed Single Photon Emission Computed Tomography (SPECT) using 99mTc-Hexamethylpropyleneamine Oxime (HMPAO) in 23 patients with (S)DAT (14f, 9m; mean age 68.9 y), 17 patients with geriatric depression (9 f, 8 m; mean age 66.4 y) and 12 age-matched controls (9 f, 3 m; mean age 69.2 y). Semiquantitative analysis (corticocerebellar ratios) of eight different regions of interest (ROI) revealed a significantly (p < 0.05) reduced perfusion in the (S)DAT patients compared to the control group. The depression group exhibited perfusion values between the (S)DAT and control group. The difference between the depression and (S)DAT group was most prominent in the left parieto-occipital ROI (p = 0.008). We discuss the data with extensive regard to the literature and conclude that 99mTc-HMPAO SPECT is a valuable additional tool in the differential diagnosis of depression and dementia in the elderly.

Aged↗
PubMed1995

Nocturnal myoclonus syndrome (periodic movements in sleep) related to central dopamine D2-receptor alteration.

The nocturnal myoclonus syndrome (NMS) consists of stereotyped, repetitive jerks of the lower limbs that occur during sleep or wakefulness. NMS is often related with restless-legs syndrome (RLS) and can cause severe sleep disturbances and daytime sleepiness. The efficacy of dopamine agonists in the treatment points to a dopaminergic dysfunction in NMS. We investigated the central dopamine D2-receptor occupancy with [123I] labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) ([123I]IBZM) and single photon emission tomography (SPET) in 20 patients with NMS and in 10 healthy controls. In most of the patients with NMS there was a lower [123I]IBZM binding in the striatal structures compared to controls. The results indicate that NMS is related to a decrease of central D2-receptor occupancy.

Adult↗
PubMed1995

Changes of central benzodiazepine receptor density in the course of anticonvulsant treatment in temporal lobe epilepsy.

The first investigation of the central-type benzodiazepine (BZ) receptor density before and following 2 months successful treatment with carbamazepine (CBZ) in a patient with temporal lobe epilepsy (TLE) using 123I-labelled Iomazenil (a specific lipophile central BZ receptor compound) and single photon emission tomography (SPET) is reported. First, a focal slowing of the EEG in the left temporal area was noted and a corresponding reduction of the central BZ density of the left temporal lobe was found. After 2 months of treatment the patient was symptom-free, and a normal BZ receptor density and no pathological EEG signs were found. The increase in central BZ receptor binding sites might be related to the anticonvulsant effects of CBZ mediated by the so-called peripheral BZ receptor sites.

Adult↗
PubMed1994

[Nightly myoclonus syndrome (NMS) and restless legs syndrome (RLS)--review and case report].

The paper gives a brief review of the existing literature concerning the nocturnal myoclonus syndrome (NMS). The clinical symptomatology, criteria for differential diagnosis and the relation to the restless legs syndrome (RLS) are discussed. Recently we investigated central dopamine receptor density with 123I-labeled 3'-iodo-6-methoxybenzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) and single photon emission tomography (SPECT) in patients with NMS and found a reduced density of dopamine D2-receptors in the striatal structures, indicating a dopaminergic dysfunction in NMS and RLS. We present a report concerning a 58-year old female with NMS-associated insomnia and present IBZM SPECTs and hypnograms before and after a 3-month treatment with L-dopa and discuss the results with regard to pathophysiological theories.

Epilepsies, Myoclonic↗
PubMed1990

[Myocardial tomography with single photon emission computerized tomography (SPECT) technique in X syndrome].

Compared with the usual planar scintigraphy of the myocardium the single photon emission computer tomography (SPECT) has essential advantages. By means of the SPECT a three-dimensional reconstruction of the intersection image is possible which allows a judgement of the myocardium in the transversal, sagittal and coronary planes of section. The scans of the SPECT are richer in contrast and freer from overshadowings of normally of disturbedly perfused areas of the myocardium. 43 patients with angina pectoris complaints in angiographically normal coronary arteries (syndrome X) were examined by means of the SPECT under bicycle ergometer load and at rest. As radionuclide thallium-201 was used. 28 out of 43 patients (65%) showed disturbances of the perfusion, in which cases 21 patients with reversible ischaemias and 7 ones with cicatrised changes and an ischaemia of the marginal zone were conspicuous. Previous own investigations with the planar Tl-201 scintigraphy of the myocardium showed pathological findings in 66% of the cases with a syndrome X. The nearly identical results speak for the high reliability of the scintigraphy of the myocardium, but against the increase sensitivity of the SPECT in contrast to the planar scintigraphy of the myocardium.

Angina Pectoris↗
PubMedDate not supplied

Cerebrovascular reactivity to acetazolamide in (senile) dementia of Alzheimer's type: relationship to disease severity.

Neuropathological reports about denervation and amyloid angiopathy in dementia of Alzheimer's type (DAT) as well as signs of selective incomplete white matter infarctions point to a vascular involvement within the degenerative process. In order to investigate potential alterations of cerebrovascular function we performed cerebral blood flow measurements before and after intravenous injection of 1 g acetazolamide using technetium-99m hexamethylpropyleneamine oxime and single photon emission tomography in 12 patients (6 female, 6 male; mean age 70.8 +/- 9.6 years) with probable (senile) dementia of Alzheimer's type (SDAT) and 9 controls (7 female, 2 male; mean age 71.2 +/- 8.6 years). SDAT patients revealed significantly reduced cerebrovascular reactivity with lower values with increasing cognitive impairment. We discuss possible underlying mechanisms.

Acetazolamide↗