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Biomedical subjects

W Staffen

Publications and source records attributed to W Staffen.

27 records · Page 2Linked to original sources
PubMed1998

Clinical relevance of 201Tl-chloride SPET in the differential diagnosis of brain tumours.

Magnetic resonance imaging (MRI) and computed tomography (CT) may not be reliable in the differential diagnosis of tumour necrosis, scar and recurrent tumour. We compared 201Tl-chloride SPET with CT and MRI for the differential diagnosis of these cerebral lesions. Brain SPET was performed in 40 patients after the intravenous injection of 201Tl-chloride. All 40 patients also had a CT or MRI scan, and a histological diagnosis was available for 27 of the patients. For each patient, the ratio of counts in the lesion region of interest (ROI) to counts in the contralateral ROI was calculated and found to be between 0.58 and 9.60. The ratios for high-grade gliomas, metastases and meningiomas were high (> 2.7), especially in tumours with good vascularization. A low ratio (< 1.7) was noted in patients with low-grade astrocytoma, necrosis or ischaemic lesions. There were two exceptional cases of ischaemic lesions in the luxury perfusion stage (ratios of 3.61 and 3.87), as verified by HMPAO-SPET. We found that 201Tl-chloride SPET helps to differentiate between malignant tumours, poorly vascularized benign lesions and necrosis. Differentiation between low-grade astrocytoma and non-malignant lesions was not possible, but there was a trend towards differentiating between low-grade astrocytoma and ischaemic infarction. The timing of the investigation is important to avoid false-positive results in hyperperfused ischaemic tissue.

Adult↗
PubMed1997

SPET investigations in extrapyramidal diseases using specific ligands.

Single photon emission tomographic investigations of the extrapyramidal system have become easier to perform since the development of the ligands [123I]-beta-CIT and [123I]-IBZM. Thirty-three patients were investigated with [123I]-IBZM. The images were evaluated visually and semi-quantitatively (ratio of the striatum to front cortex). Ten controls showed a mean (+/- S.D.) ratio of 1.513 +/- 0.06; nine patients with Parkinson's disease had a smaller ratio of 1.425 +/- 0.095; six patients with Huntington's disease had a significantly lower ratio (1.147 +/- 0.105). Eight patients were not classified, because of different nosologic entities. Twenty-three patients were investigated with [123I]-beta-CIT. They were evaluated using standard techniques and the ratio of the striatum to cerebellum. Six controls had a mean ratio of 5.128 +/- 0.787. In 11 Parkinson patients, the ratio was significantly less (3.359 +/- 0.769). Patients with focal dystonia showed normal values. One patient with Huntington's disease had a significantly lower ratio. Receptor studies of the extrapyramidal system may help with diagnoses and could be of relevance therapeutically.

Adult↗
PubMed1997

Clinical and diagnostic findings in a patient with Creutzfeldt-Jakob disease (type Heidenhain).

A 61-year-old woman had Creutzfeldt-Jakob disease, type Heidenhain, that progressed for 4 months until death, 3 of which she spent in a hospital. The diagnosis was verified by autopsy. Consecutive brain computed tomography, magnetic resonance imaging, blood flow measurements, electroencephalography (EEG), and routine laboratory tests were performed. All imaging techniques showed nonspecific pathological changes, whereas EEG revealed alterations indicative for Creutzfeldt-Jakob disease.

Brain↗
PubMed1994

[Functional significance of calcinosis of the basal ganglia via positron emission tomography].

Four patients with symmetrical basal ganglia calcification of different etiologies detected by cranial computed tomography (CT) were clinically evaluated and underwent positron emission tomography (PET) with (18F)-2-fluoro-2-deoxy-D-glucose (FDG). All patients were subjected to extensive laboratory investigation and neuropsychological testing. In two patients we found typical laboratory signs of hypoparathyroidism, the other two patients had no endocrinological alterations. Changes of glucose metabolism were mainly detected only in calcified tissues. Particularly in two patients with test psychologically confirmed psychomotoric retardation we did not find any cortical dysfunction. In conclusion, basal ganglia calcification in contrast to primary degenerative diseases has no influence on metabolic function in tissue that is not calcified.

Adult↗
PubMed1994

[Magnetic resonance tomography and skeletal scintigraphy in spondylodiscitis].

12 patients were diagnosed as suffering from spondylodiscitis by means of clinical and laboratory investigations. Magnetic resonance tomography (MRT) and bone scintigraphy (with Tc 99m-diphosphonate) were performed and 6 patients had further MRT follow up investigations. In the initial state of disease the comparison of MRT and bone scan both revealed a sensitivity of 92%. The specificity was 83% for MRT and 50% for bone scintigraphy, respectively. Therefore we conclude MRT is a more specific diagnostic tool in patients with spondylodiscitis. 6 patients were followed up with additional 13 MRT scans. During the first two months of treatment period in most of the patients more distinct pathological findings were seen in MRT in comparison with MRT at the start. No signs of any improvement despite effective treatment were found in the first three months of therapy.

Adolescent↗
PubMed1993

[The diagnostic value of nuclear magnetic resonance tomography, multimodal evoked potentials and cerebrospinal fluid examination in multiple sclerosis].

Seventy patients with multiple sclerosis (according to Poser's criteria) were clinically assessed and examined with MRI, multimodal evoked potentials (VEP, AEP, SSEP) and CSF analysis (transformed lymphocytes, IgG-Index, oligoclonal banding). In relation to the clinical criteria of McAlpine 40 patients had possible, 16 patients probable and 14 patients definite MS. 81% of the patients (73% possible MS, 94% probable MS, 93% definite MS) had multiple white matter lesions detected by MRI, 79% (78% possible MS, 94% probable MS, 64% definite MS) had an abnormal CSF profile and 67% (60% possible MS, 75% probable MS, 79% definite MS) abnormal results in multimodal EP testing. Of the patients who experienced only one attack (n = 40) 78% had multiple lesions on MRI, 88% had abnormal CSF-findings and 60% had pathologic EPs. Patients with two or more attacks showed in 87% multiple lesions on MRI, in 77% abnormal EPs and in 70% abnormal CSF findings. The number of abnormal MRI and EPs increases with the duration of the disease. 13 patients with a normal MRI were discussed separately. MRI is the most sensitive method in detecting the spatial pattern of disseminated lesions. To monitor the dissemination over time a careful clinical follow-up is still mandatory.

Adolescent↗
PubMed1988

Uncoupling of hexose transport and phosphorylation in human gliomas demonstrated by PET.

Tumor uptake of [18F]2-fluoro-2-deoxy-glucose (FDG) was studied in 20 patients with histologically classified gliomas, using dynamic positron emission tomography (PET). Parametric images of local blood volume, glucose metabolic rate, transport and phosphorylation rate constants were generated by weighted non-linear least-squares fits on a pixel-by-pixel basis. Tumor metabolism, i.e. ratios of tumor peak metabolism to contralateral brain metabolism, corresponded with histological grade. Approximately half of the tumors showed considerable metabolic heterogeneity, and metabolically active areas were found in the periphery of seven tumors. Rate constants of FDG transport and phosphorylation were significantly correlated and were inversely coupled to plasma glucose levels in contralateral brain. In contrast, tumor transport and phosphorylation rate constants varied independently of each other and of plasma glucose concentration. In some tumors large alterations of FDG phosphorylation were observed in presence of nearly normal FDG transport.

Adolescent↗
PubMedDate not supplied

The effect of lidocaine on chronic tinnitus: a quantitative cerebral perfusion study.

The cerebral perfusion of a 55-year-old female patient with chronic tinnitus was investigated quantitatively by single photon emission computed tomography (SPECT) with the xenon133 inhalation method. The first investigation was performed under standard conditions, the second during suppression of tinnitus with intravenous injection of lidocaine. As a reference a healthy volunteer was included under the same conditions. The global cortical perfusion was identical on both sides except for increased perfusion in the auditory cortex, especially on the right side when tinnitus lasted during the first measurement. The second investigation under treatment with lidocaine and during the tinnitus-free interval showed a decrease of the global cortical perfusion with a slightly higher value at the temporal cortex bilaterally. In comparison to the first investigation, a difference between right and left auditory cortex could no longer be demonstrated, and also the difference between regional and global perfusion decreased. A cerebral effect under treatment of tinnitus with lidocaine was shown by the quantitative measurement of brain perfusion. It is debatable whether this effect on cerebral activity results from the medication or as a reaction to the tinnitus-free interval.

Administration, Inhalation↗