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M Cordes

Publications and source records attributed to M Cordes.

At least 37 records · Page 2Linked to original sources
PubMed1994

[The digital reprocessing of underexposed x-rays. Studies with a fluorescent light scanner].

Incorrect exposure of conventional radiographs frequently leads to repetition of the examination and thereby to increased radiation exposure for the patient. Underexposed films of an Alderson-Rando phantom, an ankle joint and a patella were digitised by means of an inexpensive fluorescent light scanner, and subsequent image manipulation improved quality so as to make the image diagnostically adequate. For the demonstration of markedly underexposed structures digitalisation with subsequent contrast enhancement was used. Well exposed structures are best evaluated in contrast enhanced transmitted light. Our results suggest it should be possible to reduce the number of repeat exposures and thereby to limit radiation exposure.

Ankle Joint↗
PubMed1994

[Presynaptic nigrostriatal function in Parkinson disease and Parkinson-plus syndromes. Comparative studies using positron emission tomography with L-6-(18F)fluorodopa].

L-6-[18F]fluorodopa PET is suitable to assess the presynaptic nigrostriatal function within the living human brain. The purpose of this study was to compare the striatal rate constant Ki for L-6-[18F]fluorodopa in patients with Parkinson's disease (PD), Parkinsonism plus syndromes (PPLUS) and controls. 27 patients (m: 13, f: 14) between 36 and 75 years and 20 controls (m: 10, f: 10) between 20 and 85 years were examined. The clinical severity of the akinesia and rigidity were rated on the modified Columbia scale. In patients with PD the mean value of Ki was determined to be 0.339 +/- 0.098 [ml/striatum/min], in PPLUS 0.161 +/- 0.083, and in controls 0.708 +/- 0.121. The values of Ki were significantly different among the three groups (P = 0.001, ANOVA). The side-to-side difference D % of Ki was calculated to be 9.1% +/- 6.8% in PD, 14.2% +/- 10.9% in PPLUS, and 5.1% +/- 5.5% in controls (P = 0.079 PD vs. controls, 0.172 PD vs. PPLUS, and P = 0.003 PPLUS vs. controls). Ki values and rating on the Columbia scale did not show a strong correlation in both PD and PPLUS. In conclusion, the presynaptic nigrostriatal function seems to be more affected in PPLUS compared with PD. These findings may support the hypothesis of a "levelling-off" of the dopaminergic function in PD.

Adult↗
PubMed1994

Dopamine D2 receptor imaging with iodine-123-iodobenzamide SPECT in idiopathic rotational torticollis.

UNLABELLED: The cause of idiopathic rotational torticollis (IRT) is not completely understood to date. However, basal ganglia are believed to be involved in the pathophysiology of IRT. To elucidate this disorder further, the value of iodobenzamide (IBZM) SPECT was studied for the evaluation of striatal dopamine D2 receptors in these patients. METHODS: Striatal dopamine D2 receptor density was assessed in 10 patients with IRT using 123I-IBZM SPECT. The images were interpreted by a nuclear medicine physician initially to determine IBZM binding within the striatum and the cerebellum and, secondly, interstriatal IBZM binding. The results were correlated with the clinical parameters of the patients and compared with the results obtained from normal controls. RESULTS: No difference was found in average, specific striatal IBZM binding (basal ganglia/cerebellum ratio) between patients and controls. However, interstriatal analysis of IBZM binding revealed a significantly higher binding in the striatum contralateral to the direction of the torticollis (p = 0.026, by chi-square test). CONCLUSION: It was concluded that the striatal dopamine D2 receptor status is altered in patients with IRT.

Adult↗
PubMed1994

[Preoperative evaluation of drug resistant focal epilepsies with 123I-iomazenil SPECT. Comparison with vidio/EEG monitoring and postoperative results].

SPECT with the benzodiazepine receptor antagonist 123I-Iomazenil was performed in 33 patients with intractable partial seizures for pre-operative evaluation. The results combined with MRI and 99mTc-HMPAO-SPECT findings were compared with the video-assisted EEG monitoring ("gold standard") which localised the focus in 25 patients. 11 patients underwent surgical resection of the epileptogenic area and became seizure-free for a period up to 13 months. The Iomazenil SPECT had a significantly higher sensitivity compared to 99mTc-HMPAO in the visualization of an epileptogenic area and should be regularly used in the diagnostic of medically intractable partial seizures.

Adolescent↗
PubMed1994

[(123 I)-anti-NCA95 antibodies in diagnosis of bacterial wound infections after prosthetic vascular replacement. Comparison with computerized tomography].

Immunoscintigraphy (IS) with [123I]-anti-NCA95 labelled autologous granulocytes and computer-tomography (CT) examinations were performed in 21 patients with clinical suspicion of a vascular graft infection. The results of both IS and CT were compared with bacteriological and surgical findings. In this study the sensitivity was higher for IS compared with CT (92% and 67%, respectively). However, specificity was lower in IS compared with CT (89% and 100%, respectively). No false positive results have been found in CT. False positive results were observed in IS within 30 days after vascular surgery and may be due to a unspecific accumulation of granulocytes in perivascular hematomas. In later infection of a vascular graft (i.e. more than 30 days after surgery) no false positive findings were made by IS. In contrast, CT was false negative in two cases. IS with [125I]-anti-NCA95 labelled autologous granulocytes represents a useful tool for the detection of vascular graft infection, since granulocyte accumulation in infected tissue can be visualized with high sensitivity and specificity.

Antibodies, Monoclonal↗
PubMed1994

[Lung activity in 201Tl myocardial scintigraphy: distribution and correlation with hemodynamic parameters].

UNLABELLED: The aim of this study was 1. to investigate whether the pulmonary activity in 201Tl myocardial scintigraphy can be accurately quantified from the anterior SPECT projection, 2. to determine the pattern of the intrapulmonary Tl distribution, and 3. to assess the influence of parameters of left ventricular function on the lung/heart ratio (LHR). Scintigraphic images of 85 patients were analysed. In 24 patients planar anterior imaging of the thorax was performed in addition to myocardial SPECT, in 41 patients radionuclide ventriculography was performed within 4 weeks after Tl scintigraphy. IN CONCLUSION: 1. pulmonary Tl-content can be quantitated from the anterior SPECT projection with sufficient accuracy, 2. a lower thallium activity was registered over the apical part of the lung as compared to the basal part, and 3. in the multiple regression analysis the left ventricular ejection fraction (LVEF) during exercise and heart rate during exercise (HRex) exhibited the strongest relation to LHR. After correction with regard to HRex the elevated LHR points to a pathological LVEF during exercise.

Exercise Test↗
PubMed1994

[123I-iomazenil- and 99mTc-HMPAO in the diagnosis of focal epilepsies: a comparison of untreated and treated patients].

The purpose of this study was to compare HMPAO- and IMZ-SPECT findings in treated and untreated patients with focal epilepsies. We examined 20 patients (untreated 13; treated 7). All patients had a normal CT and/or MRI scan. In all patients both whole-brain activity and regional count density (rcd) were evaluated by SPECT. Furthermore, the specific and non-specific binding of IMZ were calculated for each ROI and the results of both, treated and untreated patients were compared. Our data indicate that the normalized cerebral total binding of IMZ was significantly increased in all regions in the group of treated patients (p < 0.001). In contrast, no difference in the tracer binding was found with HMPAO-SPECT. We conclude that the difference in the IMZ-binding might be due either to exogenous or endogenous factors. In our study IMZ-SPECT had a higher sensitivity and a lower specificity in the detection of decreased rcd in areas with EEG findings that indicate an epileptogenic focus compared with HMPAO-SPECT.

Adolescent↗
PubMed1993

Correlation of clinical response in apomorphine test with D2-receptor status as demonstrated by 123I IBZM-SPECT.

The knowledge of functional capacities of postsynaptic dopaminergic receptors in parkinsonian syndromes is important for differential diagnosis and for planning therapeutic approaches. Subcutaneous apomorphine challenges serve as a pharmacological tool in testing dopaminergic responsiveness, but discrepancies between results of the apomorphine test and long-term levodopa treatment remain. 123I IBZM (I-123 labeled iodobenzamide) as a dopaminergic receptor ligand allows depiction of D2-receptors by means of SPECT methods. The correlation between dopaminergic responsiveness and D2-receptor status as demonstrated by 123I IBZM-SPECT imaging was assessed by applying an apomorphine test to 41 patients with parkinsonian syndromes. All subsequently underwent an 123I IBZM-SPECT. Apomorphine responders showed a significantly higher binding of 123I IBZM than nonresponders, and patients with idiopathic Parkinson's disease (IPD) had higher D2-receptor density as visualized by SPECT than patients with other parkinsonian syndromes. The marked overlap between the groups allowed a reliable prediction only in patients with an abnormally low basal ganglia/frontal cortex ratio of 123I IBZM binding.

Adult↗
PubMed1993

Parametric imaging of the rate constant Ki using [18Fluoro]-L-dopa positron emission tomography in progressive supranuclear palsy.

Positron emission tomography (PET) studies using [18F]-L-dopa were carried out in 9 patients with supranuclear palsy and 13 controls. For quantification of PET data a rate constant Ki was calculated for the radiotracer using a graphical method. Corrections for nonspecific activity were performed in both arterial plasma and brain tissue. The purpose of this study was to test the hypothesis that parametric images of the rate constant K mapping can be obtained on a pixel-by-pixel basis using an appropriate mathematical algorithm. Ki values from these parametric images and the graphical approach were compared. Both correlated closely, with y = 0.013 + 0.947*x, r = 0.992 and y = -0.052 + 1.018*x, r = 0.965 in patients and controls, respectively. Contrast measurements were also performed and showed a striking increase in contrast on parametric images. K mapping offers several advantages over the graphical approach, since parametric images are time-independent, i.e. one image represents the quantitative result of the study. In addition, parametric images of the rate constant are normalized to arterial plasma radioactivity and corrected for tissue metabolites. Thus, parametric images of Ki in different individuals can be compared directly without further processing in order to assess the nigrostriatal integrity.

Aged↗
PubMed1993

[The differential diagnosis of Parkinson diseases--123I-IBZM-SPECT vs. the apomorphine test].

The aim of our study was to compare the striatal dopamine D2-receptor density as measured by 123I-IBZM-SPECT with the results of the apomorphine-test. 30 patients were studied; 21 with idiopathic Parkinson's disease (IPD), 9 with Parkinson plus syndromes (PPS). Patients with IPD showed a significantly higher striatal IBZM binding as compared to patients with PPS (p = 0.006). A good correlation between IBZM binding and outcome of the apomorphine-test was found (p = 0.006). Low striatal IBZM binding indicates reduced dopamine D2-receptor density. This compromises successful dopaminergic medical therapy and is indicative of non-IPD disease. 123I-IBZM-SPECT could be diagnostic aid in the work-up of patients with extrapyramidal movement disorders. The response to dopaminergic drug treatment might be precluded by IBZM-SPECT in patients with Parkinsonian syndromes.

Adult↗
PubMed1993

Single-photon emission computed tomography investigations of alternating hemiplegia of childhood.

Alterations in regional cerebral blood-flow, as determined by single-photon emission computed tomography (SPECT) using technetium [99mTc] hexamethyl propylenamine oxime, were studied in two children presenting with alternating hemiplegia of childhood. Both experienced hemiplegic episodes several times per month, despite marked improvement on flunarizine therapy. SPECT images of both patients revealed focal areas of decreased uptake of the radiotracer, representing impaired regional cerebral blood-flow during, as well as between, seizures. The interictal finding of localized areas of reduced tracer uptake suggest that long-lasting hypoperfusion could be the pathophysiological mechanism by which the slowly resolving hemiplegia, and ultimately the permanent multifocal neurological deficits, are produced.

Brain↗
PubMed1993

[Neurotransmitter-receptor-imaging].

The importance of neuroreceptor imaging in vivo using single photon emission tomography (SPECT) and positron emission tomography (PET) has increased enormously. The principal neurotransmitters, such as dopamine, GABA/benzodiazepine, acetylcholine, and serotonin, are presented with reference to anatomical, biochemical, and physiological features. The main radioligands for SPECT and PET are introduced, and methodological characteristics of both PET and SPECT are summarized. Finally, the results of neurotransmitter receptor imaging obtained so far will be discussed.

Animals↗
PubMed1993

[Hereditary Parkinson disease: report of 3 families with dominant autosomal inheritance].

We have studied three families who ancestors immigrated to North America from contiguous regions of northern Germany and southern Denmark. The pedigrees contain 77,206 and 376 individuals spanning 6, 7 and 8 generations with 7,7 and 11 affected members, respectively. Autosomal dominant inheritance pattern is present in two families and probable in the third. Typical L-dopa-responsive parkinsonism with bradykinesia, rigidity, resting tremor, and impaired postural reflexes uniformly develop in affected individuals from all three families. Further research on these three families, including genetic, pathologic and clinical examinations is planned.

Adult↗
PubMed1992

[The long-term toxicity of polychemotherapy in successfully treated testicular carcinoma].

Of 55 patients with testicular cancer, treated by combination chemotherapy including cisplatin, 21 (mean age 35 [21-51] years) were reexamined for late sequelae of the chemotherapy 1-9 years later. No patient had a recurrence or second malignancy. They all had normal renal function (renal sequence scintigraphy; creatinine clearance). Seven of 20 patients had a polyneuropathy, nine of 18 had high-tone hearing loss. Two patients became fathers after treatment. In nine of 20 patients the serum concentration of follicle-stimulating hormone was raised to above 20 mU/ml, evidence of germ-cell damage. Six of 13 patients had an abnormal ejaculation following retroperitoneal lymphadenectomy or excision of a residual tumour. There was no evidence of any life-limiting toxicity of the chemotherapy.

Adult↗
PubMed1992

Rapidly progressive autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration.

We describe a family with nearly 300 members over 8 generations with 32 affected individuals who have an autosomal dominant neurodegenerative disease characterized by progressive parkinsonism with dystonia unrelated to medications, dementia, ocular motility abnormalities, pyramidal tract dysfunction, frontal lobe release signs, perseverative vocalizations, and urinary incontinence. The course is exceptionally aggressive; symptom onset and death consistently occur in the fifth decade. Positron emission tomographic studies with [18F]6-fluoro-L-dopa (6FD) were performed in 4 patients and 7 individuals at risk for development of the disease. All affected subjects had markedly reduced striatal uptake of 6FD (p less than 0.001). All individuals at risk had normal striatal uptake, but high 6FD uptake rate constants were noted in 3 of the 7 studied. Autopsy findings revealed severe neuronal loss with gliosis in substantia nigra, pontine tegmentum, and globus pallidus, with less involvement of the caudate and the putamen. There were no plaques, tangles, Lewy bodies, or amyloid bodies. This kindred appears to represent a neurodegenerative disease not heretofore described. We propose the following name for this new genetic disease: autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration.

Adult↗
PubMed1992

Transcranial Doppler ultrasound in internal carotid artery and middle cerebral artery disease.

Using noninvasive transcranial Doppler sonography, we studied cerebral collateral patterns in 30 patients with stenosis and/or occlusion of the extracranial internal carotid artery (ICA). All patients with unilateral ICA stenosis less than or equal to 80% had normal transcranial Doppler findings. 80% of patients with unilateral and 50% of patients with bilateral ICA stenosis of more than 80% including those with occlusion showed a collateralization via the ipsilateral anterior and/or posterior cerebral artery. 20% of patients with unilateral and 50% of patients with bilateral ICA stenoses of more than 80% (including occlusion) had two or three collateral pathways, including the ophthalmic artery. Another ten patients with stenosis or spasm of the middle cerebral artery (MCA) showed increased flow velocities with turbulence in the narrow segment. In four patients with severe MCA disease with a systolic peak velocity of more than 200 cm/s, the Doppler waveform distal to the lesion was damped. Decreased regional cerebral blood flow (rCBF) measured by 99mTc-HMPAO-SPECT was found in two patients with severe MCA stenosis. Another patient with moderate MCA stenosis with a systolic peak velocity of 140 cm/s showed a normal cerebral perfusion pattern.

Adolescent↗