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Biomedical subjects

F Grünwald

Publications and source records attributed to F Grünwald.

At least 127 records · Page 7Linked to original sources
PubMed1993

[Brain SPECT with 123I-labelled iodobenzamide (IBZM): aspects of semiquantitative evaluation].

The striatal dopamine-D2-receptor uptake of 123I-IBZM in 32 patients (18 without and 14 under therapy with typical neuroleptics) was measured semiquantitatively using different ROI techniques. The aim of the study was to evaluate the influence of these techniques on the different ratios (striatum/cortex) found by various examiners. Using the same SPECT system no major differences were found between rectangular and manually drawn ROIs of the same size. All ROI techniques could differentiate between patients with and without therapy on a highly significant level. Therefore, the resulting ratio is mainly dependent on the spatial resolution of the camera system and only to a relatively minor extent on the ROI technique. Ratios obtained by different observers are not comparable quantitatively.

Adult↗
PubMed1993

[HMPAO-SPECT in Alzheimer-type dementia and major depression with memory disorders].

The aim of the present study was to see whether HMPAO-SPECT may contribute to the differentiation between dementia of the Alzheimer type (DAT) and major depression (MD). The results in 77 patients with memory impairment were evaluated. 48 patients suffered from DAT and 29 from MD. Initially, the defects in SPECT imaging were attributed to a cerebral region and the degree of decrease was evaluated (-1/-2/-3). Thereafter, the results were classified by 7 categories. In some of these categories an accumulation of cases of either DAT or MD was found. 35% of the patients suffering from DAT had bilateral defects with distinct (> -1) parietal/parietotemporal hypoperfusions, but no patient with MD showed this perfusion pattern. 62% of the patients with MD had unilateral defects but only 31% of the patients with DAT. The present study demonstrates that only 35% of all patients suffering from DAT show a perfusion pattern, thought earlier as "pathognomonic" for this disease. This perfusion pattern--if it exists--may be used as a safe criterion to exclude MD. Beyond that no clearcut ("specific") perfusion pattern may be recognized but unilateral defects point to MD.

Aged↗
PubMed1993

Changes in local cerebral glucose utilization in the awake rat during acute and chronic administration of ethanol.

Local cerebral glucose utilization (LCGU) was measured in 51 structures of the rat brain after acute and/or chronic oral administration of ethanol using the quantitative autoradiographic 2-deoxyglucose method. In the acute experiments, ethanol (3.2 g/kg) was administered via a gastric tube 110 min before the 2-deoxy-D-[1-14C]glucose. The chronic pretreatment was performed using increasing concentrations of ethanol in the drinking water for a period of 20-24 days. The most striking effects on LCGU were seen in the inferior colliculus. Acute and acute plus chronic treatment with ethanol significantly decreased LCGU by 33% and 37%, respectively, whereas chronic treatment significantly increased LCGU by 25%. In general, acute administration of ethanol decreased LCGU in 16 brain structures, particularly of the auditory system. Chronic treatment, besides its effect on the inferior colliculus, only decreased LCGU in the internal capsule. Chronic plus acute administration of ethanol decreased LCGU significantly in 22 structures. It is concluded that an acute oral administration of ethanol has distinct and mainly depressive effects on the functional activity of several brain areas. Chronic administration is less effective.

Administration, Oral↗
PubMed1993

[Single-photon, emission-computed tomography (SPECT) in the diagnosis of epilepsy].

Regional cerebral blood flow can be measured using single photon emission computed tomography (SPECT). Hexamethyl propyleneamine oxime (HMPAO) is commercially available as a 99mTc-labeled tracer and has the advantage of fixing a blood flow pattern during its first passage through the capillaries. This can be used, for example, to evaluate a short-term ictal phase. With dedicated SPECT systems a spatial resolution of 5-8 mm can be achieved. Measurement using 133Xe allows absolute quantification of blood flow values, but the spatial resolution is lower. In about 50-70% of patients suffering from temporal lobe epilepsy a decreased blood flow in the focus can be visualized in the interictal phase. Ictally, focal hyperperfusion can be observed in most cases. The sensitivity and specificity of SPECT in the ictal phase are superior compared with interictal study. During the postictal phase a hyperperfusion of the anterior and mesial parts of the affected temporal lobe with simultaneous lateral hypoperfusion can often be demonstrated. At present, receptor SPECT has not yet reached clinical significance in the diagnosis of epilepsy.

Brain↗
PubMed1992

[Ultrasonic diagnosis of goiter of the tongue base].

Lingual goitre was found in two adolescents suffering from mild dysphagia. Since there were typical changes in lingual sonomorphology, sonographic evaluation was easy to perform. Lingual thyroid was less echogenic than normal thyroid tissue. Ultrasound may support the decision of the initial treatment and is useful to guide further therapy.

Adolescent↗
PubMed1991

The influence of nicotine on local cerebral blood flow in rats.

Local cerebral blood flow (LCBF) was measured in conscious rats during an acute nicotine infusion. LCBF was measured using the autoradiographic iodoantipyrine method. LCBF was unchanged in most brain structures during nicotine infusion compared to controls. Significant (P less than 0.05) increases were found in 3 structures (lateral geniculate body, superior colliculus, anteroventral nucleus of the thalamus). These structures have already shown increases in local glucose utilization in a previous study [2]. The observed increases in LCBF are interpreted to be secondary to metabolic activation by nicotine indicating the lack of a direct action of nicotine on cerebral blood vessels.

Animals↗
PubMed1991

Single photon emission computed tomography imaging of brain tumors.

Five radiotracers may be used for single-photon emission computed tomography (SPECT) imaging of brain tumors, namely technetium 99m pertechnetate, iodine-123 amphetamine derivatives, 99mTc-hexamethyl propylene amine oxime (HMPAO), thallium 201, and 123I alpha methyl tyrosine. Of these, pertechnetate may be considered as an "historical" procedure in brain tumors. However, there may be some equivocal cases in computed tomography or magnetic resonance imaging, where this procedure may still be used. In 1981, 123I isopropyl amphetamine was first used in brain tumors. Further studies showed, however, that IMP is not a useful tool for brain imaging in tumorous lesions. In 1986, 99mTc HMPAO appeared on the European market as a new tumor imaging agent. Some useful clinical results were obtained in patients before and after chemotherapy or radiotherapy. Thallium-201 was incidentally noted to accumulate in tumors. Using a threshold index, this agent can be used to distinguish low-versus high-grade lesions. The most promising agent for brain tumor SPECT is 123I-alpha methyl tyrosine, which shows potential to evaluate therapeutic procedures in brain tumors and may improve the differentiation between abscess and glioblastoma. The most promising aspect is the differentiation of tumor recurrences and scar tissue after brain surgery.

Brain Neoplasms↗
PubMed1991

[HMPAO-SPECT during carotid artery compression (Matas test) in the evaluation of cervical tumor surgery with potential carotid involvement].

For planning the surgical approach in patients with head and neck tumours and extensive cervical metastasis the evaluation of possible vascular involvement is necessary. If the carotid artery is suspected to be infiltrated by the tumour masses its resection or plastic substitute becomes sometimes inevitable. For evaluation of the collateral brain perfusion before a possibly necessary carotid resection we examined 10 patients with neck tumours performing the Matas-Test combined with HMPAO Single-Photon-Emission-Computed-Tomography. During ultrasound-controlled manual compression of the involved common carotid artery 99mTc-labelled HMPAO was injected. The SPECT demonstrated the brain perfusion during the carotid compression time period. 6 patients showed a decreased perfusion of the affected hemisphere with - as far as obtained - normal baseline SPECT-results and balloon occlusion tests. 2 of these patients underwent a carotid artery resection, one of the common carotid artery and one of the internal carotid artery. One patient had a significant perfusion deficit in the SPECT but no pathologic findings in angiography and balloon occlusion test. He suffered from hemiparesis postoperatively. The other patient showed preoperatively a minor decrease in perfusion and had no neurological defects postoperatively. Our findings show that the Matas-Test combined with HMPAO-SPECT is a valuable tool for the preoperative evaluation of the collateral brain perfusion. This technique is not invasive and can be performed in every nuclear medicine department with an ECT camera. The HMPAO-SPECT during carotid compression can add useful information or even replace angiography and the balloon occlusion test.

Aged↗
PubMed1991

Brain SPECT imaging with Tc-99m HMPAO in ophthalmoplegia plus.

In 14 patients with ophthalmoplegia plus Tc-99m hexamethylpropylene amineoxime (HMPAO) brain SPECT imaging was performed. Three patients showed bilateral parieto-occipital hypoperfusions, and two patients had left parietal defects (one with an additional right temporal lesion). Two patients presented with occipital hypoperfusions and one with a distinct hypoperfusion in the medial part of both frontal lobes. Hypoperfusion of the visual cortex might result from permanently decreased input from the degenerated retina. The hypoperfusion in the visual cortex and in other regions alternatively might reflect direct central nervous system (CNS) involvement due to neuronal degeneration or to impaired vascular function caused by morphologically changed mitochondria in smooth muscle and endothelial cells. The data suggest CNS involvement in ophthalmoplegia plus with abnormalities of cerebral blood flow similar to those found in other mitochondrial encephalomyopathies.

Adult↗
PubMed1991

[Nuclear medicine kidney diagnosis in progressive systemic scleroderma].

Kidney involvement is one of the most frequent causes of death in progressive systemic scleroderma (PSS). It is therefore important to detect potential impairment of renal function in PSS very early. In 76 patients referred for nuclear medicine diagnostic procedures, 42 pathologic results were found with 131I-hippurate clearance, while only 14 abnormal results were detected by static 99mTc-DMSA scans. Hippurate clearance is thus a sensitive method of functional renal evaluation in PSS.

Adolescent↗
PubMed1991

[A comparison of 201Tl and 99mTc-MIBI in the follow-up of differentiated thyroid carcinomas].

12 patients with suspected recurrence of differentiated thyroid carcinoma following thyroidectomy, radioiodine therapy and, in some cases, external radiation therapy had 201Tl and 99mTc-MIBI scintigraphy. Except in one case, the findings concerning tumor localization and extension were identical. In all cases, locoregional lymph node metastases as well as osseous metastases were imaged by 201Tl and 99mTc-MIBI scintigraphy. MRI images obtained in all patients with suspected lymph node metastases revealed inoperable situations in 2 cases, whereas there was no correlation in 1 patient with positive 201Tl and 99mTc-MIBI scintigraphy. In contrast, the sensitivity of the two methods was relatively low in the detection of pulmonary metastases which were imaged in 1 out of 3 patients only. Discrepancies between 201Tl and 99mTc-MIBI were observed in a case of axillary lymph node metastasis. Although tumor-/background ratios were slightly higher for 201Tl, 99mTc-MIBI SPECT showed a higher imaging quality compared to 201Tl SPECT, especially in deeply situated tumor lesions. In conclusion, 99mTc-MIBI seems to be a promising alternative imaging agent in the follow-up of differentiated thyroid carcinomas.

Adenocarcinoma↗
PubMed1991

Technetium-99m-HMPAO brain SPECT in medically intractable temporal lobe epilepsy: a postoperative evaluation.

The aim of the present study was to evaluate the predictive value of interictal single-photon emission computed tomography (SPECT) using technetium-99m-labeled hexamethyl propyleneamine oxime (HMPAO) for the outcome after temporal lobectomy in patients with complex partial seizures. Out of 40 patients, 21 underwent right-sided and 19 left-sided temporal lobectomy. EEG and CT/MRI were primarily used to select the side of surgery. SPECT results correlated with temporal lobectomy in 68% of the patients. After surgical intervention, memory function was tested for both sides. Following left-sided temporal lobectomy, verbal memory was impaired in 8% of the patients, if SPECT agreed with the side selected for surgery, but in 83%, if it diverged from it. In the present study, there was no relationship between SPECT concordance with the side of temporal lobectomy and outcome as to seizure frequency and non-verbal memory. We conclude that preoperative interictal HMPAO/SPECT can contribute to the prediction of postoperative verbal memory function and that this method should be considered for use prior to temporal lobectomy.

Adolescent↗
PubMed1990

The creation of a small bowel pouch by tissue expansion--an experimental study in pigs.

Tissue expanders (inflatable silicone balloons) were implanted into a bypassed ileum segment of seven pigs and consecutively filled over 8 to 12 weeks. The mean increase of the volume of the small bowel loops was 12 fold with a maximum of 22.8 times the original volume. The final volume 9 weeks after expander removal still presented an increase of 500%. Histologically there was an increase of the thickness of all layers of the bowel wall, especially in the tunica muscularis. The mucosa showed a value above normal in mean in vitro 14C-resorption capacity per surface area in the reintegrated bowel. Possible clinical applications of the augmentation of the gut by expansion as a rectum substitute after proctocolectomy, as a urinary bladder or stomach substitute, and for the treatment of short bowel syndrome are discussed.

Animals↗
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↗
PubMed1990

[Increased sensitivity of whole-body scintigraphy with I131 for the detection of iodine-accumulating metastases by means of delayed imaging].

In the follow-up of thyroid cancer patients we sometimes observed discrepancies between elevated thyroglobulin levels and negative results of posttherapeutic or diagnostic scans 48 h and 72 h after oral application of 131I routinely. Consequently, delayed 131I scans (96 h and later) were performed in addition. In all cases, delayed 131I scans either showed a higher imaging quality or additional metastatic lesions. Thus, posttherapeutic (and diagnostic) scans should include late images (4 d and later).

Administration, Oral↗