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Biomedical subjects

M Reiser

Publications and source records attributed to M Reiser.

At least 523 records · Page 29Linked to original sources
PubMed1993

[Value of magnetic resonance tomography for diagnosis of bone tumors].

Primary bone tumors are well investigated with magnetic resonance imaging (MRI). Depending on the tumor site and localization the examination technique has to be tailored to the particular situation. Using MRI, the delineation of extraosseous tumor spread and the intramedullary extension of malignant bone tumors is superior as compared to other imaging modalities.

Bone Marrow↗
PubMed1993

[Magnetic resonance tomography in epilepsy].

The most important causes of focal epilepsy are hippocampal sclerosis, circumscribed tumors, vascular malformations, trauma and perinatal damage. At the moment MRI is the best radiological imaging modality for localizing and characterizing a focus. In many cases, however, even MRI is negative. Especially in hippocampal sclerosis the diagnostic role of MRI is still not well established. Diagnostic criteria are side differences with hippocampal atrophy and circumscribed signal increase on T2-weighted images of the affected temporal lobe. Circumscribed lesions caused by tumors or vascular malformations are demonstrated very reliably by paracoronal T2-weighted sequences. Routine administration of the paramagnetic contrast material Gd-DTPA is not necessary.

Adolescent↗
PubMed1993

["Spectroscopic imaging." A new MR technique in the diagnosis of epilepsy?].

The technique of magnetic resonance spectroscopy fuses spectroscopic methods with the two-dimensional illustration of the metabolite concentrations by parallel acquisition of multiple single voxels from small tissue compartments. Therefore it is not necessary to define a voxel of interest before data acquisition. The interpretation of metabolite images is much easier than the analysis of single spectra, and metabolite concentrations on the right and left sides can be compared. The method has already proved reliable for brain tumors. The application of the procedure to patients suffering from epilepsy is described here in for the first time. Even in the temporal region, where most epileptogenic foci have their origin, one can obtain metabolite images of diagnostic quality without susceptibility artifacts. The epileptogenic focus is lateralized correctly, in accordance with electrophysiological and surgical evaluation, even in those cases where standard magnetic resonance imaging is normal. According to our preliminary findings the epileptogenic focus is characterized by a signal loss of N-acetyl-aspartate and creatine.

Adult↗
PubMed1993

[Intracranial ECoG electrodes. Location determination using three-dimensional reconstruction of MR data of the brain as a component of the presurgical diagnosis of epilepsy].

Subdural strip electrodes or intracerebral electrodes are required in order to precisely localize epileptic foci, which is mandatory for epilepsy surgery. The subdural electrodes are inserted via a borehole and thus precise positioning cannot be directly monitored. Therefore, the location of the electrodes in relation to the gyri and sulci has to be determined by imaging techniques. In this study, a three-dimensional magnetic resonance imaging (3D MRI) technique was used for visualization of intracranial EEG electrodes. A 3D gradient echo sequence with thin slices of 1 mm is required for the assessment of the gyral anatomy of the brain surface. Using a short repetition time of 30 ms good image quality within an acceptable acquisition time of about 15 min was possible. Post-processing with 3D surface reconstruction was performed using a Sun workstation. Three-dimensional reconstruction allows a more precise delineation of the localization of the EEG electrodes and the simultaneous display of the adjacent brain structures. Misplacement of intracranial electrodes is readily detected. 3D MRI with 3D surface reconstruction proved superior to 2D imaging and CT for the assessment of EEG electrode localization.

Electrodes↗
PubMed1993

[Superselective intra-arterial chemotherapy in breast cancer].

Forty-two patients with locally advanced breast cancer (n = 8) or recurrent breast cancer (n = 34) received regional chemotherapy (mitoxantrone 25 mg/m2 per 24 h) via the internal mammary artery or other vessels of the subclavian artery. To prevent artery thrombosis 500-1000 U heparin per hour were administered i.v. Tumour perfusion was monitored by intra-arterial angio-CT. Remission rates (CR + PR) were 100% (primary breast cancer) and 89% (recurrent tumours), respectively. Intra-arterial chemotherapy was well tolerated. No complications were noted.

Adult↗
PubMed1992

[The palliative treatment of primary hepatocellular carcinoma by chemoembolization].

16 patients (12 men, 4 women; mean age 62.8 +/- 9.8 years) with inoperable advanced hepatocellular carcinoma were treated palliatively by chemoembolization. 50 mg/m2 epirubicin, 30 mg/m2 cisplatin, 8 ml fatty acid ethyl ester of iodinated papaver oil and 10 ml nonionic contrast medium were injected under fluoroscopy into the proper hepatic artery. Partial remission was achieved in 10 patients after a median of 4 months. In 4 patients there was no change in the morphological and biochemical findings, in two others the tumour progressed, i.e. an overall response rate of 62.5%. The median survival time was 9 months. There were no serious complications ascribable to the treatment. Chemoembolization is a palliative treatment with few side effects which can also be effective in prolonging survival time in advanced hepatocellular carcinoma.

Aged↗
PubMed1992

TSH-receptor and adhesion molecules in autoimmune thyroid disease.

Using a human TSH receptor (TSH-R) cDNA probe we investigated TSH-R expression levels in 20 human thyroid fragments by Northern blot analysis: 14 Graves' disease, 2 Hashimoto's disease, 3 endemic goiter and 1 healthy thyroid gland. TSH-R expression was low in those thyroids where expression of the major histocompatibility complex class I (MHC I), class II (MHC II) and intercellular adhesion molecule 1 (ICAM-1) was high, whereas expression of the endothelial leukocyte adhesion molecule 1 (ELAM-1) bore no relation to TSH-R expression. In situ hybridization showed that next to lymphocytes (MHC II), thyroid cells (MHC II, ICAM-1) and endothelial cells (ICAM-1, ELAM-1) were the source of transcripts of these T-cell activating antigens. We conclude that next to MHC I and II, the expression of additional T-cell activating antigens such as ICAM-1 and ELAM-1 play a role in the initiation of auto-immune thyroid disease.

Adolescent↗
PubMed1992

[The results of the chemoembolization of advanced hepatocellular carcinomas. The effect on the survival times, morphological findings and tumor markers].

Chemoembolization is a well-recognized therapeutic procedure in the treatment of stage I and stage II hepatocellular carcinoma (HCC). Until now it is rarely used in the treatment of stage III HCC. In a prospective study we analysed the efficacy and the side effects of chemoembolization in 16 patients with stage III HCC. Chemoembolization was performed with an emulsion of lipiodol, 4-epirubicin and cisplatinum. All patients tolerated the treatment without remarkable complications. With 9 months the median survival rate was considerable higher than the survival rate of untreated patients and of patients treated with systemic chemotherapy or with local perfusion.

Aged↗
PubMed1992

[Spontaneous necrosis of the femoral condyle--new findings in T2-weighted spin-echo sequences and gradient-echo studies].

The spontaneous necrosis of the femur condyles might cause diagnostic problems because clinical symptoms precede the radiologic changes on conventional x-ray. MRI offers an early detection of the necrosis of the femur condyle like bone necrosis of other localisation. Nine patients were examined by T1- and T2-weighted spin echo- and by T2*-weighted gradient echo sequences. All patients had reduced signal intensity in the subchondral bone marrow on T1-w SE sequences. In three patients new findings were observed on T2-w SE and gradient echoes respectively. These findings allow better understanding in the underlying pathologic-anatomical changes.

Aged↗
PubMed1992

[Manganese-DPDP in the MR tomography of malignant liver tumors. The initial results with a new hepatobiliary contrast agent].

The new hepatobiliary contrast agent Mangan-DPDP, unlike extracellular Gd-DTPA, leads to a constant increase in signal intensity of normal liver tissue in MR imaging of the liver which lasts at least for 30 minutes. In 19 patients with malignant liver tumors there was no difference in the contrast between tumor and liver when using a dose of 5 or 10 mumol/kg. Contrast enhanced T1-w SE- and T1-w GE sequences show a significant increase in tumor/liver contrast compared with T1-weighted unenhanced sequences. This increase was also significant when compared with T2-w SE sequences. In 16% additional focal lesions were detected on the enhanced scan.

Adult↗
PubMed1992

[Dynamic functional MRT of the cervical spine].

To obtain functional studies of the cervical spine, a device has been developed which allows MRI examinations to be carried out in five different degrees of flexion. T1 and T2* weighted FFE sequences were used. Dynamic functional MRI was performed on 5 normals and 31 patients (5 disc herniation, 4 whiplash injuries, 6 spinal canal stenoses, 14 laminectomies and spinal fusions, 2 rheumatoid arthritis). The relationship of the spinal cord to the bony and ligamentous components in different degrees of flexion was particularly well shown in whiplash injury, spinal stenosis and postoperative situations.

Cervical Vertebrae↗
PubMed1992

[In-vivo 31P-NMR-spectroscopy in patients with dilated cardiomyopathy].

In vivo 31P-NMR spectra of heart muscle were obtained in 7 patients with dilating cardiomyopathies and in 10 normal subjects, using an ISIS technique with a 1.5 Tesla body scanner (Philips Gyroscan S15) and the results of the two groups were compared. These results were easily reproduced. In patients with cardiomyopathy there was a significant (p < 0.05) reduction of the PCr/ATP ratio as an expression of abnormal energy metabolism. Two patients with mild clinical symptoms and only slightly reduced functional measurements showed no significant changes in the 31P-NMR spectrum. The patients with the largest reduction of the PCr/ATP index also showed the most marked changes in functional measurements. The PCr/ATP ratio (as also suggested by animal experiments) appears to be a suitable non-invasive indicator for the diagnosis and staging of myocardial changes in dilating cardiomyopathies.

Adenosine Triphosphate↗
PubMed1992

[Bone marrow edema in MRT].

Like other vascularized organs, bone can react with increasing interstitial fluid to disturbances in permeability caused by various noxae. Signs of bone marrow edema recognizable in magnetic resonance imaging are described for conditions such as trauma, stress, reflex sympathetic dystrophy, ischemia, and infection. A bone marrow edema may be an early or the only sign of a disease entity visible solely on MR images. We made a retrospective study of musculoskeletal MR examinations conducted over a period of 3 months to estimate the incidence of bone marrow edema.

Bone Marrow Diseases↗