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Biomedical subjects

K Reichmann

Publications and source records attributed to K Reichmann.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Scintigraphy with 123I-labelled fatty acids in coronary heart disease].

Forty-two patients (6 women, 36 men; mean age 55 [39-69] years), with one-, two- or three-vessel disease on coronary angiography, were studied using single-photon emission computer tomography with 15-p-123I-iodophenyl-pentadecanoic acid (IPPA), in order to evaluate this new method of demonstrating abnormalities of myocardial perfusion. The reference range for fatty acid turnover was determined in eleven controls (4 women, 7 men; mean age 41 [20-51] years) with no coronary stenosis. 185 MBq (5 mCi) of IPPA was administered intravenously during submaximal stress on a bicycle ergometer. Comparison between different regions of the tomograms revealed changes in fatty acid utilization typical of ischaemia. The sensitivity, specificity and predictive value of a positive result compared with coronary angiography were 95%, 89% and 93%, respectively, for the area supplied by the anterior interventricular artery, 92%, 91% and 93% for the circumflex branch and 89%, 91% and 90% for the right coronary artery. In 25 out of 31 patients (81%) with myocardial infarction, IPPA scintigraphy infarct localization agreed with the clinical findings. In two cases with unremarkable scintigrams left ventriculography showed hypokinesia, while in four cases neither method demonstrated any abnormality. There was one false-positive scintigram. IPPA scintigraphy has greater sensitivity and specificity than conventional nuclear medicine techniques in the demonstration of coronary heart disease.

Adult↗
PubMed1991

Single photon emission tomography imaging of myocardial oxidative metabolism with 15-(p-[123I]iodophenyl) pentadecanoic acid in patients with coronary artery disease and aorto-coronary bypass graft surgery.

A total of 29 patients with coronary artery disease (CAD) were investigated with 15-(p-[123I] iodophenyl)pentadecanoic acid (123I-IPPA) and sequential single photon emission tomography (SPET). Of these, 19 were studied after aorto-coronary bypass graft surgery. Some 13 patients without evidence of CAD served as a control group. Two SPET studies (early and late) were carried out within 45 min after intravenous administration of 200 MBq 123I-IPPA at peak sub-maximal exercise. Semi-quantification of uptake (related to perfusion) and turnover (linked to metabolism) was obtained by segmental comparison of oblique slices. Taking coronary arteriography as the "gold standard", 123I-IPPA scintigraphy had the following figures of merit for sensitivity and specificity in the diagnosis of CAD: for the left anterior descending artery territory 93% and 95%, for the left circumflex artery region 96% and 92%, and for the right coronary artery territory 77% and 92%, respectively. In all, 90% of the reperfused myocardial segments showed an improvement of uptake. Of these, 61% exhibited increased turnover after revascularization and 39% had pathologic turnover and thus a dissociation of improvement of perfusion and oxidative metabolism after surgery.

Adult↗
PubMed1990

Crossed cerebellar diaschisis in intracarotid sodium amytal procedures: a SPECT study.

Eight patients with drug-resistant complex-partial seizures were subjected to left- and right-sided intracarotid sodium amytal (ISA) procedures during preoperative investigations for surgical treatment. Regional changes of cerebral and cerebellar blood flow during barbiturization were measured by [99mTc]-HMPAO-SPECT. Crossed cerebellar diaschisis (CCD) was observed in 13 out of 16 tests (81%) as well as ipsilateral cerebral hypoperfusion (87%). Thus CCD occurred more frequently in ISA procedures than in previously studied patients with cerebral infarctions and tumors. Since intracarotid injections of sodium amytal lead to hypoperfusion mainly in those areas of the brain that are supplied by the middle cerebral artery, functional suppression of these regions is supposed to be one of the main preconditions of CCD. Our findings suggest that CCD as demonstrated by the SPECT-technique is a common phenomenon in ISA procedures.

Adolescent↗
PubMed1989

Imaging of brain tumors with L-3-[123I]iodo-alpha-methyl tyrosine and SPECT.

Carbon-11-labeled amino acids have been successfully used to image brain tumors by PET. This study was undertaken to evaluate the potential of L-3-[123I]-iodo-alpha-methyl tyrosine (123IMT) for metabolic imaging of brain tumors. Ten patients (glioblastoma, oligodendroglioma, lymphoma, and metastases) had early and delayed brain SPECT with a rotating gamma camera after i.v.-injection of 200-300 MBq 123IMT. In nine patients the tumors showed intense uptake of the radiotracer. Tumor-to-brain tissue ratios were between 1.4 and 2.6. 123IMT shows potentials for monitoring the effects of brain tumor therapy.

Brain Neoplasms↗
PubMed1988

[Nuclear medicine diagnosis of Alzheimer type dementia].

Eleven patients with Alzheimer type dementia were investigated by single-photon-emission computed tomography (SPECT) using 99mTc-hexamethylpropylene-aminoxim (HM-PAO). Nine had a typical, symmetrically reduced enrichment in the parieto-temporo-occipital area. In three of these nine patients a similar pattern was recorded additionally in the frontal, in the remaining two in the temporal or parietal region. In a semi-quantitative evaluation radioactivity concentrations in the cerebrum and cerebellum were compared. It demonstrated that there was in relation to the cerebellum a reduced concentration in seven of the eight studied cerebral regions. The relative blood flow of the parieto-temporo-occipital region was most markedly affected and in patients with Alzheimer type dementia was reduced by 25% below that of normal subjects. The results indicate that cerebral SPECT with HM-PAO is a reasonable method of investigation to confirm the diagnosis of "Alzheimer type dementia" and exclude other cerebral disease, especially if pathognomonic findings are to be obtained.

Alzheimer Disease↗
PubMed1988

Semiquantifying regional cerebral blood flow by 123I-amphetamine (IMP) SPECT in cerebrovascular disorders: correlations with CBF indices by 133Xe inhalation method.

To examine the capacity of detecting regional cerebral blood flow (rCBF) disturbances in stroke, measurements with 133Xe inhalation and 123I-amphetamine (IMP) SPECT were performed within 1-2 days in 19 patients. IMP SPECT images in transverse sections consisting of outer and inner areas were correlated with 32 regions of 133Xe rCBF. 133Xe rCBF was assessed by ISI, CBF15, and F1. Inter hemispheric ratio correlation showed outer IMP uptake correlated better with 133Xe CBF indices than the inner one. With higher ratios of 133Xe rCBF. IMP uptake ratios were variable, suggesting less usefulness of this parameter in evaluation of mild ischemia. Values of IMP in outer regional hypo and hyperemic areas correlated better with those of 133Xe rCBF than the inner ones. In regional ratios of hypo and hyperemic areas from hemispheric mean, outer IMP uptake correlated with 133Xe CBF indices, reflecting regional disturbances of fast clearing tissue perfusion. Regression lines between ratios in 133Xe CBF and IMP uptake were located below one to one correlation, and dissociated more for hyperemic regions. IMP SPECT correlated better with 133Xe rCBF for tissues with reduced perfusion but underestimated hyperemic regions as measured with the 133Xe method. The data suggest outer cerebral IMP uptake evaluated by SPECT could reflect flow disturbances in the brain cortex.

Adult↗
PubMed1988

[Preoperative diagnosis: the Wada test with SPECT control for localizing brain function in therapy-refractory epilepsy].

Extensive diagnostic measures are necessary to clarify the indication for surgery in patients suffering from epilepsy that is refractory to treatment. Within the overall framework of neuropsychological diagnosis we conducted the Wada test, injecting 200 mg (or 3 mg/kg body weight) of sodium amytal on different days, in each case into the left or right internal carotid artery. This results in a 3-5 minute anaesthesia of the relevant hemisphere. By means of a neuropsychological short test it is possible to determine the performance of the non-blocked hemisphere. The extent of the blocking is also determined by simultaneous i.v. injection of HM-PAO (hexamethyl propylene amine oxime) labelled with 99m Tc, the uptake of which by various cerebral regions is visualised via SPECT. The Wada test supplies information on the lateralisation of cognitive functions (speech, memory etc.) whereas the SPECT examination enables additional determinations not only of processes that must be characterised as diaschisis, but also on the extent of blocking of a hemisphere. The results supply clues to expected postoperative cognitive deficits and thus enable a differentiated assessment of the indication for surgery. This is discussed on the basis of two clinical cases.

Adult↗
PubMed1988

[HMPAO-SPECT in cerebral seizures].

In nine patients with suspected psychogenic seizures and in three patients with proven epileptic seizures HMPAO-SPECT was performed prior to and during seizure. In the patients with later on-proven psychogenic seizures no, or only slight, changes of regional cerebral blood flow were found. Patients with proven epilepsy revealed partly normal findings interictally but during seizure a markedly increased circumscript blood flow was found in all patients. Even though PET is superior to SPECT with respect to spatial resolution, in the diagnosis of seizures HMPAO-SPECT has the advantage of enabling injection of the tracer during the seizure and the performance of the SPECT study subsequently.

Epilepsy↗
PubMed1987

Initial experience with 99m Tc-hexamethyl-propylene amine oxime (HM-PAO) single photon emission computed tomography (SPECT) in patients with focal epilepsy.

Brain single photon emission computed tomography (SPECT) was performed in 16 patients with focal epilepsy, as well as EEG, using 99m Tc-HM-PAO SPECT and a rotating gamma camera system. Pathological Tc-HM-PAO SPECT findings were registered in 75%. CT was positive in 25%. MRI was positive in 76%. The results of Tc-HM-PAO SPECT findings were compared with those of CT and MRI. 61% of the MRI findings correlated with the pathological SPECT findings with respect to the side of the hemisphere, and in 75% of the patients the focal EEG abnormality and the pathological Tc-HM-PAO-SPECT findings were localized in the same hemisphere.

Adolescent↗
PubMed1987

Technetium-99m HM-PAO brain SPECT in epileptic patients before and during unilateral hemispheric anesthesia (Wada test): report of three cases.

The lipophilic brain SPECT agent [99mTc]hexamethyl propylene amine oxime (HM-PAO) was used in three cases before and during unilateral anesthesia of one hemisphere for lateralization of speech dominance (Wada test). This procedure led to a decrease of regional cerebral blood flow (rCBF) in each of the hemispheres to 55 and 90%, respectively. Diminution of rCBF was significantly more pronounced in the dominant hemisphere. A second phenomenon observed during the Wada test was crossed cerebellar diaschisis. These findings support the assumption that HM-PAO allows monitoring of brain perfusion, as rapid changes of rCBF due to decreased neuronal activity cause respective alterations of cerebral and cerebellar uptake of this new brain agent.

Adolescent↗
PubMed1986

Assessment of regional cerebral blood flow with 123I amphetamine single photon emission computed tomography in cerebrovascular disease. Semiquantitative analysis comparing IMP SPECT with the 133Xe inhalation method.

To compare the capacity of three-dimensional IMP single photon emission computed tomography (SPECT) with that of the two-dimensional 133Xe method in detecting focal perfusion abnormalities in cerebrovascular disease, flow measurements were performed with both methods in twenty patients. In order to enable correlation with 133Xe regional cerebral blood flow (rCBF) IMP SPECT images were subdivided into areas extending from the outer to the inner part corresponding to 32 regions of the 133Xe Cerebrograph. Between IMP counts/pixel and 133Xe rCBF, inter-hemispheric ratios correlated better in severe ischemia. Absolute mean values correlated in the affected hemisphere but not in the unaffected hemisphere. Regional evaluations revealed tendencies of IMP SPECT to be sensitive for low flow areas but to underestimate high flow areas, i. e. the 'luxury perfusion syndrome', as compared with the 133Xe method.

Amphetamine↗
PubMed1986

[Results of fatty acid SPECT of the myocardium in coronary disease].

New developments in radiopharmacology of 123I-labeled metabolic tracers and single-photon emission computerized tomography (SPECT) allow now-a-days the assessment of parameters of cardiac energy metabolism in well-defined areas of the heart muscle. This article will present a brief outline of the basic pathophysiological principles used in the application of 123I-labeled phenyl fatty acids for the evaluation of CAD. First clinical results suggest an important application of cardiac fatty acid metabolic imaging to the detection, localisation and conceivable quantitation of myocardial ischemia, myocardial infarction and assessment of tissue viability. In addition to the diagnostic applications in CAD, cardiac fatty acid metabolic imaging may provide new perspectives to pathophysiological investigations of the coupling of local flow and substrate utilisation in vivo and the effect of therapeutic interventions.

Coronary Disease↗
PubMed1986

A comparative study of the brain uptake and early kinetics of 99mTc-dl HM-PAO and other PnAO derivatives in baboons.

Derivatives of propylene-amine-oxime (PnAO) have been synthesized which form a neutral lipid-soluble complex with 96mTc and can be supplied as freeze-dried kits. The complexes cross the intact blood-brain barrier. This report shows the brain uptake, early kinetics and biodistribution in normal adult baboons of 5 99mTc-PnAO derivatives and 2 isomers of one of the tested derivatives (HM-PAO). The brain uptake of the favoured dl-isomer of HM-PAO reaches its maximum of 4.3% (whole brain/whole body) 1 min p.i. and a clearance of less than 8% was observed 23 min p.i.

Animals↗
PubMed1984

[Cerebral emission computer tomography (SPECT) with 123I-labeled amphetamines].

Amphetamine is stored by brain tissue and permits its scintigraphic imaging, particularly with the single-photon emission computed tomography (SPECT). A total of 60 scintigraphic investigations in 54 patients were done. Investigations were done using an emission computed tomograph (rotating gamma-camera) after application of 123I-N-isopropyl-amphetamine. In 6 out of 24 patients with epilepsy a focus in agreement with EEG findings could be established despite negative cranial computed tomography (CT). In 4 out of 25 patients with cerebrovascular disease diminished perfusion was demonstrated although cranial CT was normal. In 10 out of 20 cases the extent of functional lesions demonstrated by SPECT was larger than could be assumed by cranial CT findings. Three patients with migraine and negative CT findings showed disorders of perfusion in the amphetamine-SPECT which were in agreement with the EEG. Brain SPECT using 123I-labelled amphetamines thus offers the possibility to demonstrate functional perfusion and metabolic disorders which show no morphologic correlate in the cranial CT. In addition, foci demonstrated in cranial CT can be more precisely defined in their functional extent using the SPECT.

Amphetamines↗
PubMed1984

[Cause of crossed cerebellar diaschisis in cerebrovascular disease].

In 31 patients with completed stroke (n = 30) or PRIND (n = 1) a brain SPECT with 123I-labeled amphetamines was performed. In 14 (= 45%) of the respective patients--suffering from long-lasting hemiplegia--crossed cerebellar diaschisis was present. The interval between onset of the disease and time of examination varied between 1 week and 7 years. On the other hand, patients without crossed cerebellar diaschisis did not, with one exception, suffer from hemiplegia. It is likely that this phenomenon is caused by the reduction of spino-cerebellar stimuli due to the paresis of the respective extremities.

Adult↗
PubMed1984

Cardiac metabolism of 15 (p-I-123 phenyl-) pentadecanoic acid after intracoronary tracer application.

Myocardial turnover of omega-(p123I-Phenyl-) pentadecanoic acid and release of its metabolites into the coronary sinus and peripheral blood has been studied in patients with coronary artery and valvular heart disease. After intracoronary tracer injection myocardial extraction fractions of 45-53% in control subjects were observed. In patients with coronary artery disease (CAD) normal to reduced values (34-61%) were established. Hydrophilic catabolites of I-PPA, probably p123I-benzoic and -hippuric acid as well as small amounts of the non-metabolized tracer were found in coronary sinus and peripheral blood. Myocardial tracer uptake and clearance patterns were clearly different in normal myocardium when compared to that obtained in patients with CAD. Thus, evaluation of myocardial I-PPA metabolism might provide a new diagnostic tool for assessment of integrity of the heart's muscular metabolic function.

Coronary Disease↗