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Biomedical subjects

B Terwey

Publications and source records attributed to B Terwey.

At least 19 recordsLinked to original sources
PubMed1996

Proton magnetic resonance spectroscopy in patients with glial tumors: a multicenter study.

The authors represent a cooperative group of 15 institutions that examined the feasibility of using metabolic features observed in vivo with 1H-magnetic resonance (MR) spectroscopy to characterize brain tumors of the glial type. The institutions provided blinded, centralized MR spectroscopy data processing long with independent central review of MR spectroscopy voxel placement, composition and contamination by brain, histopathological typing using current World Health Organization criteria, and clinical data. Proton 1H-MR spectroscopy was performed using a spin-echo technique to obtain spectra from 8-cc voxels in the tumor and when feasible in the contralateral brain. Eighty-six cases were assessable, 41 of which had contralateral brain spectra. Glial tumors had significantly elevated intensities of choline signals, decreased intensities of creatine signals, and decreased intensities of N-acetylaspartate compared to brain. Choline signal intensities were highest in astrocytomas and anaplastic astrocytomas, and creatine signal intensities were lowest in glioblastomas. However, whether expressed relative to brain or as intratumoral ratios, these metabolic characteristics exhibited large variations within each subtype of glial tumor. The resulting overlaps precluded diagnostic accuracy in the distinction of low-and high-grade tumors. Although the extent of contamination of the 1H-MR spectroscopy voxel by brain had a marked effect on metabolite concentrations and ratios, selection of cases with minimal contamination did not reduce these overlaps. Thus, each type and grade of tumor is a metabolically hetero-geneous group. Lactate occurred infrequently and in all grades. Mobile lipids, on the other hand, occurred in 41% of high-grade tumors with higher mean amounts found in glioblastomas. This result, coupled with the recent demonstration that intratumoral mobile lipids correlate with microscopic tumor cell necrosis, leads to the hypothesis that mobile lipids observed in vivo in 1H-MR spectroscopy may correlate independently with prognosis of individual patients.

Adolescent↗
PubMed1993

MR imaging related to p.m. findings in angiodysgenetic myelomalacia. A case report.

In a 65-year-old patient with slowly progressive myelopathy of the lower spinal cord MRI revealed slight thickening of the conus medullaris and discrete serpiginous areas of low signal intensity in contact to the surface of the myelon. The T2-weighted axial images demonstrated a zone of high signal intensity within the center of the lumbosacral cord. These findings corresponded to the results of autopsy: cord enlargement, dilatation of wall thickened and partially thrombosed pial veins, edema, damage of the myelin sheath with development of foam cells, areas of hemorrhage and necrosis. Although myelography and spinal digital subtraction angiography had been normal in this case we assume that perhaps a spinal dural av-fistula may have been the cause of MR- and pathological findings which indicate an angiodysgenetic myelomalacia (Morbus Foix-Alajouanine). The pathogenesis of spinal dural av-fistulas is discussed in order to explain why angiography has been negative.

Aged↗
PubMed1991

[Migration disorders of the brain--an evaluation of computed tomographic and magnetic resonance tomographic studies].

Twenty-eight patients with abnormalities of migration were examined with CT and MRI. Thirteen patients had heterotopia, ten patients had agyria/pachygyria, two with unilateral schizencephaly and three with hemimegalencephaly. MRI proved markedly superior because of its wider contrast range and its ability to obtain various imaging planes. The various conditions are described in detail.

Brain↗
PubMed1990

MRI diagnosis of aneurysmal bone cyst.

80-90% of individuals suffering from aneurysmal bone cyst (ABC) are children or adolescents. Primary ABC is a non-neoplastic lesion. Diagnostic assessment and detection of recurrence demands repeated plain x-rays or CT scans. These repeated radiographic examinations expose these young patients to large doses of ionizing radiation. Magnetic resonance imaging (MRI) is found to be an effective and reliable noninvasive technique for the diagnosis and follow-up controls of ABC.

Bone Cysts↗
PubMed1990

[Magnetic resonance tomography of laminar heterotopia].

In one baby and 2 infants who presented with psychomotor retardation and epilepsy laminar heterotopic grey matter was demonstrated via magnetic resonance imaging. Laminar heterotopia is a rare migrational disorder with bilateral symmetric ribbons of grey matter within the centrum semiovale, separated from ventricular walls and from obviously normal-sized cortex by broad layers of white matter. The heterotopic grey matter has a signal intensity which is isointense compared with that of normal cortex irrespective of image weighting. On account of this signal behaviour differentiation against other white matter diseases is easy. The knowledge of these pathognomonic findings facilitates correct diagnosis, especially during the first and the second year of life, when signal intensities of white and grey matter differ from normal findings because of the occasionally delayed myelination process. Therefore, further diagnostic procedures can be avoided and early counseling of parents is possible.

Brain↗
PubMed1988

[Magnetic resonance tomography of the perineural cyst].

It may be difficult to differentiate between symptomatic perineural cysts, arachnoidal cysts, meningoceles, neurinomas and other cystic masses within the spinal canal and spinal foramina. Therefore the impact of MRI on the differential diagnosis of these lesions is discussed on the basis of 15 cases with perineural cysts, 1 case of an arachnoid cyst, 2 cases of meningoceles and 2 cases of neurinomas. The problem of fluid characterisation by the use of special MR measurements is emphasised.

Adult↗
PubMed1988

[Role of nuclear magnetic resonance imaging in the diagnosis of monosymptomatic optic neuritis].

34 patients with monosymptomatic optic neuritis were examined ophthalmologically and by magnetic resonance imaging (MRI). In 18 patients subclinical lesions with a high MRI signal intensity were found. The distribution of these lesions was similar to that seen in multiple sclerosis. Neither the severity of the visual impairment nor the course of remission correlated to the MRI findings. Pathologic MRI findings were more common in patients aged over 27 than in younger patients (57% vs. 42%).

Adolescent↗
PubMed1988

Magnetic resonance imaging (MRI) and high resolution computertomography (HRCT) in cochlear implant candidates.

Cochlear implant candidates must be thoroughly tested for their suitability pre-operatively. Electrical and electrophysiological tests as well as a psychological assessment are of fundamental importance in the selection process. The implantation of an intracochlear electrode requires specific information about the anatomy of the petrous bone and the endocochlear space. Such information can be obtained by using high resolution computed tomography (HRCT) or magnetic resonance imaging (MRI) using a surface coil. Over three years 438 patients were evaluated in our clinic as possible implant candidates. Out of these candidates 251 were evaluated using HRCT and 123 using MRI. In 39 (15.5%) cases we found bony abnormalities of the petrous bone using HRCT scans. 17 (13.8%) of the cases evaluated with MRI had no complete fluid filled spaces in the cochlea. Three patients who where identified as having ossified cochleas were subsequently implanted with an extracochlear device. MRI and HRCT have proved to be fundamental tools in determining patients suitable for implantation of an intracochlear electrode array.

Cochlea↗
PubMed1987

Magnetic resonance imaging in vascular malformations: studies with and without gadolinium-DTPA.

MRI and gadolinium-DTPA enhanced dynamic MRI increase the information available for and from diagnosis of vascular malformations since it appears possible to obtain nearly specific information about these lesions. Further investigations are needed with fast imaging, flow imaging, and MR substraction angiography to obtain information similar to that obtained by angiography and CT. The value of X-ray CT for the diagnosis of vascular malformations seems to be inferior to MRI since MRI can delineate vessels and flow better and also allows direct multiplanar imaging.

Adult↗
PubMed1987

Magnetic resonance imaging in lissencephaly.

In a patient with clinical manifestations suggestive of brain malformation, computer-assisted tomography (CT) showed lissencephaly: agyria, pachygyria, absent opercularization, and colpocephaly. The patient did not have seizures or a typical EEG of hypsarrhythmia. By magnetic resonance imaging (MRI), using a long inversion-recovery sequence, it was possible to verify the CT-findings and to demonstrate heterotopic grey matter and missing claustrum. By MRI it was much easier to estimate the altered ratio of grey and white matter. High grey-white matter contrast of inversion-recovery scans and the possibility of imaging the brain in sagittal, coronal and transverse planes make MRI the method of choice for the evaluation of lissencephaly and other brain malformations. In this case it helped to verify lissencephaly as one aspect of an unknown clinical entity of type-I-lissencephaly, defective structure of lymphatic nodes, a polyarthritis-like clinical picture, hypodontia, and flaring of the ribs.

Brain↗
PubMed1987

[Attempt at preoperative differentiation of malignant melanoma of the choroid. A comparison of nuclear magnetic resonance tomography, ultrasound echography and histopathology].

In a large choroidal melanoma (prominence 12 mm, volume approx. 1,900 mm3) diagnostic sonography revealed an unusual compartmentation, corresponding to the internal reflectivity of the tumor. When NMR imaging was performed, marked differences in signal behavior were seen between the tumor's center and its periphery. Histopathology revealed a highly pigmented spindle B melanoma containing an amelanotic island with signs of necrosis. The ultrasound pattern was explained on the basis of well known physical phenomena, whereas the NMR signals are still not fully understood.

Adult↗
PubMed1987

Tuberous sclerosis: magnetic imaging of the brain.

The results of the magnetic resonance imaging of three patients with proven tuberous sclerosis will be discussed. Cortical tubers and subcortical areas of junctional dysmyelination can be demonstrated clearly by MRI, whereas small calcifications may be missed because of low contrast if the chosen slice thickness should be too large. It is suggested that MRI should be applied to those patients with suspected tuberous sclerosis, in which CT has failed to demonstrate typical subependymal calcifications and to those in which doubts about the definite diagnosis remain. This should be done in order to improve the accuracy of genetic counselling. It may be argued that all patients with tuberous sclerosis have to be referred to MRI, because transformation of subependymal nodules into diffusely infiltrating gliomas can be detected earlier if comparison with a former MRI study is possible.

Adult↗
PubMed1986

Unusual combination of cerebral dysplasias. Report of two cases.

Two types of a rare combination of cerebral malformations originating from parenchymal and/or vascular developmental disorders are described. In the first case, there is a coincidence of aneurysm, AVM, persistent trigeminal artery and arachnoid cyst. In the second case a giant infratentorial aneurysm, dural AVM and haemangioma of the neck are combined. The underlying disturbances of gestation in the multiple dysplasias are discussed in their embryological context. Both cases were considered by neurosurgeons as well as neuroradiologists to be untreatable.

Adolescent↗
PubMed1986

Dynamic studies of cervical spinal canal and spinal cord by magnetic resonance imaging.

In 15 cases dynamic studies of cervical spinal cord and canal in flexion and extension were performed by magnetic resonance imaging (MRI). In addition measurements of the complete spinal cord were made in 5 cases. As compared with extension the cervical spinal canal and spinal cord lengthen 12 mm in average during flexion, whereas the spinal canal lengthens 28 mm in average, which means a difference of about 15 mm. We feel that these results indicate that adverse mechanical tension may occur in the cervical spinal cord during flexion. The impact of these results on surgical treatment for chronic cervical myelopathy is discussed.

Humans↗
PubMed1985

Vascularization of malignant testicular tumors.

Recent studies of malignant testicular tumors report a correlation between vascularization, biologic behavior, radiosensitivity, and chemotherapeutic response of the tumor. Postoperative angiographies of malignant testicular tumor specimens (seminoma n = 4, nonseminoma n = 12) showed the following results: Contrary to the symmetric vascularity pattern of normal testes, seminomas were hypovascular, well-defined from normal testicular tissue and not neovascular. Nonseminomas showed isovascularity (n = 5) or hypovascularity (n = 7) but with focal hypervascular areas in the tumor (n = 10), and pathologic neovascularization. Present angiographic studies reveal marked differences in the vasculature pattern of malignant testicular tumors. In nonseminomas, focal hypervascular or neovascular areas as centers of a high-growth rate correlate well with comparable cell kinetic studies. Assuming a similar growth behavior in metastases, the vascularization type of these growth centers theoretically favors the efficient use of chemotherapeutic agents.

Arteries↗
PubMed1985

[Computed tomography and nuclear spin tomography in peripheral lymphedema].

The first reported findings on CT and N.M.R. in two cases of idiopathic peripheral lymphoedema are described. These methods have compared with the generally available volume estimations (volume estimation according to Kuhnke, immersion plethysmography) and have been considered in relation to visual and lymphographic examinations.

Adult↗