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Biomedical subjects

D Voth

Publications and source records attributed to D Voth.

At least 37 records · Page 2Linked to original sources

[MR tomography of astrocytic tumors (I-III)].

Magnetic resonance (MR) imaging was performed on 37 patients with histologically confirmed astrocytomas (I-III). In addition, the MR tissue parameters T1, T2 and proton density (RHO) were analysed by an interlaced CPMG spin echo sequence. Characteristic morphologic tumour patterns which subdivide astrocytomas into each different tumour grade are presented. Quantitative analysis of MR tissue parameters provides a statistically proven classification of each tumour grade and allows differentiation between "semibenign" astrocytomas (II) and "relatively malignant" astrocytomas (III), with high accuracy.

Adolescent↗

The Vogt-Koyanagi-Harada syndrome: association with hypothyroidism and diabetes mellitus.

A 45 year old Saudi male with poliosis, alopecia areata, vitiligo, anterior uveitis, inflammatory changes in the posterior pole of the retina and paraparesis presented with features of the Vogt-Koyanagi-Harada syndrome, uncontrolled diabetes mellitus and hypothyroidism. To the best of our knowledge the association of diabetes mellitus and hypothyroidism in this syndrome has not been reported previously.

Diabetes Mellitus, Type 1↗

Magnetic resonance imaging of dysraphic myelodysplasia. Findings in 56 children and adolescents with postrepair meningomyelocele.

The spinal cord in 56 children and adolescents was examined by magnetic resonance imaging (MRI) many years after neonatal surgery on a meningomyelocele (average age 12 years). In a high percentage of cases, the diagnosis "tethered cord" was made. Associated anomalies were found with a frequency of 21%. Typical findings are presented and the impact of these results on therapy planning is discussed.

Child↗

Clinical and ultrastructural observations of maturing human frontal cortex. Part I (Biopsy material of hydrocephalic infants).

Three of 30 human cerebral cortex biopsies from infants treated for hydrocephalus by shunt operation are described. The descriptions include an account of their case history, the clinical methods, and the operational procedures. The biopsy specimens were studied in semithin and ultrathin sections. Attention is drawn to normal synapse formation but also to neuronal degenerative changes due to hydrocephalus.

Biopsy↗

[MR tomography in tumors of the posterior cranial fossa in childhood].

MR tomography was performed on 23 children with tumors in the posterior fossa. In 14 cases, the MR tissue parameters were determined. Astrocytomas can be easily differentiated from medulloblastomas and ependymomas on the basis of their localization and signal intensities. Grading of astrocytomas and distinction between medulloblastomas and ependymomas was not possible. Because of high tissue contrast, multiplanar imaging and minimal artifacts, MR proved to be the method of choice for planning surgery and for the follow-up of tumours in the posterior fossa.

Adolescent↗

[Gadolinium dimeglumine gadopentetate compared to CPMG sequencing and image synthesis].

The skulls of 46 patients were examined by means of ordinary scans and after contrast. 24 of these patients with cerebral abnormalities had scans, using identical planes, with and without contrast and with CPMG sequences. Contrast in intracranial, but extracerebral (extra-axial), tumours (meningiomas, neurinomas) was much better after using contrast, but intracerebral (intra-axial) tumours were mostly shown as well on T2-rated CPMG sequences. Image synthesis has shown that contrast uptake occurred only in solid tumour regions.

Brain Diseases↗

[Proton spin tomography in childhood. Experience with 407 studies in 275 children and adolescents].

Over a period of three years magnetic resonance imaging (MRI), mostly neuroradiological, was performed 407 times in 275 children. It was found that MRI largely replaced previously applied imaging methods for solving oncological and neurological problems. The sensitivity of the method is poor for demonstrating small calcifications (computed tomography is better), for diffuse meningeal lesions (lumbar puncture is better), and diffuse spinal-canal metastases (myelography is better). The great advantage of the method lies in its low x-ray exposure because of the low field strength, and it can therefore be safely used repeatedly.

Adolescent↗

Long-term follow-up of children with magnetic resonance imaging and ultrasound after treatment of brain tumors.

This paper compares the results of MRI and US follow-up examinations of 46 children who had undergone surgery for brain tumors. The cases included 42 posterior fossa tumors, 3 supratentorial tumors and 1 upper cervical spinal cord tumor. US examination proved to be less specific and sensitive than MRI. However, when a "bone window" is available, US is, because of the ease of its application, better suited for frequent routine examinations. Long-term follow-up should, therefore, consist of frequent regular US examinations combined with yearly MRI examinations.

Adolescent↗

Magnetic resonance imaging of postrepair-myelomeningocele--findings in 31 children and adolescents.

Magnetic resonance imaging has clearly demonstrated its efficacy in the diagnosis of pathological processes in the C.N.S. We examined 31 children who had undergone plastic closure of myelomeningocele a few days post partum. We could show that a high percentage of the patients (89%) presented the pathological anatomy of a tethered spinal cord; clinical symptoms of the tethered spinal cord syndrome, i.e. progressive neurological symptoms, however, are rarely observed. Possible revision of neurosurgical treatment of MMC is discussed.

Adolescent↗

[Initial clinical results of tissue characterization by T1, T2 and proton density in nuclear magnetic resonance tomography].

The NMR parameters (proton density, relaxation times T1 and T2) have been assessed by Carr-Purcell-Meiboom-Gill (CPMG) spin echo sequences. A computer assisted analysis of the data of 21 patients with cerebral tumours allowed a classification of tumour tissue in different tumours. The use of quantitative procedures for tissue characterisation allows the differentiation of benign and malignant brain tissue by characteristic colour coding demonstrating morphological details like tumour, edema and necrosis as well as indicating the histological types of the tumours of the central nervous system.

Brain↗

[MR tomography in intracranial meningiomas].

The typical findings of intracranial meningiomas seen in 24 patients are described. The signal intensities at different acquisition parameters are analysed and optimal pulse sequences derived from these data. In 90% of the patients MR-tissue parameters were measured and correlated with the histological findings. Marked prolongation of T2-times was found in tumours showing regressive changes.

Female↗

[Cerebral vasospasm following subarachnoid hemorrhage. New aspects of diagnosis and therapy].

A comprehensive survey of the subject is given. Focal points are the discussions of calcium antagonists, pathophysiology of vasospasm and CBF-monitoring. Moreover, a novel neuromonitor is presented permitting bed-side work. In spite of the still unclarified etiology of vasospasm and the site of action of the calcium antagonists their early application is indicated for the prevention of cerebral vasospasm after subarachnoid haemorrhage.

Calcium Channel Blockers↗

[Chemonucleolysis. Method, indications and results. Review].

Since 1963 Chemonucleolysis [CNL] with discase and collagenase has served as a supplementation to the surgical approach in the treatment of prolapses of lumbar disks. The world-wide stated rates of successful treatments amount to about 70 per cent. For a further correction of the result surgical treatments are considered to be necessary in about 20 per cent of the cases. Our experience gained with these measures shows a success in 70 per cent of the patients. The frequency of operations still lies around 18 per cent in accordance with the international standard. This therapy, however, should not be considered to be a fully valid alternative or substitute. If exact indications are present, it can make a surgical intervention superfluous in selected cases.

Follow-Up Studies↗

MRI studies after treatment of brain tumors in childhood and adolescence.

Forty-seven children and adolescents with brain tumors were examined by magnetic resonance imaging (MRI) after tumor resection. The typical changes and complications after surgery and chemotherapy, as well as the corresponding MRI findings, are discussed. Typical examples of boundary-layer lesions, tumor recurrences, hydrocephalus, porencephalic cysts, and hygromas are given.

Adolescent↗

[Plain imaging of meningioma in NMR tomography--retrospective contrast optimization by image synthesis].

Synthetic images of the tumour region were computed in the case of ten meningiomas for the purpose of determining retrospectively pulse sequences and sequence parameters supplying an optimal contrast between tumour and adjacent tissue in plain imaging. It was found that best results were obtained via the partial saturation/spin-echo sequence with a long recovery time (TR approximately greater than 2,000 msec) and a long maximum echo delay (TE max approximately greater than 200 msec). A comparable contrast quality can be attained by using the inversion-recovery sequence with an inversion time T1 approximately 450 msec. Nevertheless, it was not possible in our study to identify two small meningiomas with a diameter of just below one centimetre by studying the MR tomogram.

Brain↗