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W Reiche

Publications and source records attributed to W Reiche.

At least 19 recordsLinked to original sources
PubMed2002

Oligodendrogliomas.

PURPOSE: To study the pattern of contrast enhancement in MR and CT of oligodendrogliomas and to compare this with other imaging findings and with histopathological grading criteria. MATERIAL AND METHODS: 20 patients with oligodendrogliomas (12 low-grade WHO II and 8 anaplastic WHO III) were reviewed. 20 complete MR investigations, 20 non-enhanced CT studies and 16 CTs after contrast enhancement were estimated blindly without knowledge of the tumour histological grades. RESULTS: All anaplastic oligodendrogliomas showed tumour contrast enhancement on MR and CT images. Also in 6/12 low-grade oligodendrogliomas the contrast was enhanced on MR imaging. In 5 of these, tumour calcifications were detected by CT. The remaining 6/12 WHO grade II cases showed no significant MR contrast enhancement. Of the oligodendrogliomas grade II, CT showed contrast uptake in 3 cases and no enhancement in 6, while in 3 cases postcontrast CT was not available. A comparison of contrast enhancement with tumour grade resulted in a p-value of 0.042 for MR and of 0.011 for CT. A combined statistical test of tumour grade and calcifications detected by CT compared with MR contrast enhancement showed a significant correlation (p=0.014). CONCLUSION: These data demonstrated that a clear grading of oligodendrogliomas based on the image criterion MR contrast enhancement was not possible. We suppose that, besides tumour neovascularisation, additional factors such as calcifications may disturb the blood-brain barrier.

Brain Neoplasms↗
PubMed2001

Comparison of color-flow Doppler scanning, power Doppler scanning, and frequency shift for assessment of carotid artery stenosis.

OBJECTIVE: We investigated the accuracy of color-flow Doppler (CD) scanning, power Doppler (PD) scanning, and peak systolic Doppler frequency shift (PSF) in assessment of carotid artery stenosis with angiography used as gold standard, including the measurement techniques used in the North American Symptomatic Carotid Surgery Trial (NASCET) and the European Carotid Surgery Trial (ECST). METHODS: Fifty-eight consecutive patients diagnosed for carotid artery surgery underwent color-coded duplex sonography and angiography. The duplex examination included the assessment of PSF and the videotaping of sagittal images in CD and PD mode from the proximal common carotid artery to the distal internal carotid artery. Two experienced examiners performed the studies, but once one examiner had done the taping, the other examiner was allowed only to review the tape. Separately, each examiner reviewed the tapes and determined by cursor settings each stenosis according to NASCET and ECST. For interobserver agreement kappa statistic was used. To compare with angiography (degree of stenosis 40%, 50%, 60%, 70%, and 80%) sensitivity, specificity, positive and negative predictive values, and overall accuracy were calculated. PSF cut-off frequencies were based on receiver operator curve analysis. RESULTS: Because interobserver agreement in CD and PD was good (chance-corrected kappa > 0.6), further analysis used the between-observer mean value for each stenosis. With the NASCET measurement technique, accuracy of Doppler techniques to distinguish a 50% stenosis was 89% for PSF, 91% for CD, and 93% for PD; for a 70% stenosis it was 83% for PSF, 84% for CD, and 81% for PD. With the ECST measurement technique, accuracy to distinguish a 70% stenosis was 86% for PSF, 88% for CD, and 86% for PD; for an 80% stenosis it was 87% for PSF, 87% for CD, and 77% for PD. CONCLUSION: CD and PD carotid artery stenosis measurements are highly reproducible, and in our hands provided accuracy equal to PSF.

Aged↗
PubMed2000

[Neuroradiological aspects of encephalitis disseminata].

Magnetic resonance imaging (MRI) has developed without doubt to the most important investigation method in multiple sclerosis. MRI is very sensitive to detect MS lesions but unfortunately of limited specificity. The purpose of this review is 1. to work up the MRI characteristics of MS lesions, 2. to derive recommendations for MRT-protocolls for daily radiological work and 3. to discuss new MR developments. MS lesions in the acute inflammatory stage show first an enhancement of GD-DTPA due to break down of the blood brain barrier and develop a T2-hyperintensity due to an edema. The following disease course is categorized in a phase of reparation and remyelinisation respectively, of gliosis and a defect stage. MS-plaques in the remyelinisation and gliotic phase appear as hyperintens lesions on T2-weighted scans. Chronic MS lesions with a defect are also T2-hyperintens and demonstrate additionally due to severe axonal loss a hypointensity on short TR SE scans. MS lesions exhibit a characteristic distribution. They are found typically periventricular, in the corpus callosum and at the calloso-septal interface, cortico-subcortical and infratentorial. The most important MR criteria to predict conversion from suspected (CSMS) to clinical definite MS (CDMS) are GD-DTPA enhancement and juxtacortical lesion localisation followed by the parameter periventricular and infratentorial localisation. Based on guidelines for the use of MRI in drug studies and on equivalent recommendations for the routine diagnostic we suggest rational and economic MRT protocols for cerebral, spinal, and N. opticus investigations. Such standardised protocols shall help to make MRI investigations more efficient and better comparable. New MR developments include measurement of magnetisation transfer and T2-relaxation, diffusion weighted imaging, proton MR spectroscopy, and quantification of lesion load. These methods can analyse more specifically tissue changes in MS plaques and yet can reveal changes in normal appearing white matter.

Brain↗
PubMed2000

Ischemia after carotid endarterectomy: comparison between transcranial Doppler sonography and diffusion-weighted MR imaging.

BACKGROUND AND PURPOSE: Hyperintense signals on diffusion-weighted MR images (DWIs) are believed to correspond accurately with cerebral ischemic events. Intraoperative transcranial Doppler sonography (TCD) can reveal hemodynamic and embolic events during carotid endarterectomy (CEA). Our purpose was to determine whether the occurrence of hyperintense signals on postoperative DWIs corresponds to intraoperative embolic or hemodynamic events. METHODS: Seventy-seven CEAs were monitored intraoperatively with TCD to record blood flow velocity changes after cross clamping to ascertain the presence of adequate collateral flow and to record microembolic signals. DWI was used to classify the hemisphere ipsilateral to the CEA by type: 0, no lesions (n = 51); I, cortical lesions only (n = 2); II, subcortical white matter lesions only (n = 6); III, mixed type with cortical and subcortical lesions (n = 11); IV, large territorial infarcts (n = 6); and V, other types of lesions (n = 1). RESULTS: Neither the five clinical events (one transient ischemic attack, two minor strokes, and two major strokes) nor any DWI type (I-V) showed a relationship to blood velocity decreases after cross clamping or, in patients who were selectively shunted, to total ischemic time necessary for shunt insertion and removal. Total microembolic signal count was significantly higher in the five CEAs with clinical events than in those without. It was also higher on the DWIs showing a hyperintense lesion as compared with DWIs showing no lesion. CONCLUSION: Apart from lesions corresponding to clinical deficits, CEA is associated with a substantial number of small areas of brain tissue at risk for irreversible ischemia. The main cause of intraoperative stroke seems to be embolism, suggesting that microembolic signals in CEA are highly relevant events for brain tissue.

Brain Ischemia↗
PubMed1999

[Retrocochlear deafness in absent cochlear nerve: case report. Role of CISS-3D (Constructive Interference of Steady State) sequence and differential diagnosis].

MRI gains greater importance in the differential diagnosis of retrocochlear hearing loss. Retrocochlear anakusis is rarely caused by aplasia or atrophia of the cochlear nerve. In the following we report about a five year old boy suffering from unilateral deafness, where a strongly T2-weighted CISS-3D MRI sequence demonstrates a missing of the cochlear nerve on the deaf side.

Child, Preschool↗
PubMed1998

[Neuroradiologic diagnosis of primary non-Hodgkin's lymphoma of the brain].

The incidence of primary cerebral lymphomas has risen continuously during the past years. The neuroradiological signs, which are decisive for the differential diagnosis of cerebral lymphomas, are worked up and discussed in this study. Thirty CT and 27 MR investigations of a total of 32 patients (14 males, 18 females, age 60 +/- 15 years) with histopathologically proven cerebral lymphomas were analysed retrospectively. Multiple cerebral lymphomas were detected in 10/32 patients (31%). The cerebral lymphomas appeared on CT scans as hyperdense masses in 28/30 cases (93%). On T2-weighted MR scans 14/27 (52%) lymphomas were slightly hyperintense compared to white matter and 9/27 (33%) inhomogeneously isointense to poorly hyperintense. These were clearly T2-hypointense compared to T2-hyperintense perifocal oedema. In these cases CT density and T2-weighted signal intensity looked like grey matter. All cerebral lymphomas except one case took up contrast medium. An ependymal infiltration or a contact to the ventricle's wall were found in 24/32 cases and an infiltration or a contact to the leptomeningeal space in 15/32 cases. One should consider a cerebral lymphoma as a possible differential diagnosis when a cerebral mass shows the following signs: (1) in CT scans as a hyperdense mass, and on T2-weighted MR images hyperintense compared to white matter and hypointense compared to perifocal edema; (2) clear contrast enhancement and (3) infiltration or broad contact with the ependyma and/or the leptomeningeal space.

Brain Neoplasms↗
PubMed1997

[Cerebral perfusion reserve and collateral circulation in patients with internal carotid stenosis].

The cerebral hemodynamics in patients with carotid disease is influenced by a network of extra- and intracranial collaterals. The purpose of this study was to compare the findings of regional cerebral perfusion reserve (rCPR) with angiographically proven collateral circulation. In 41 patients (28 men, 13 women, age 63 +/- 10 years) with angiographically proven carotid stenoses or occlusions (30 stenoses, 11 occlusions) 24 99mTc-HMPAO-SPECT and 25 dynamic Xe-CT investigations were conducted, both before and after acetazolamide stimulation. rCPR was quantified as the ratio (1) of the absolute rCBF values obtained by Xe-CT and (2) of the count density measured by HMPAO-SPECT of the acetazolamide administration. A rCPR of less than 95% in a vascular territory was classified as compromised rCPR. A recent CT examination was available in all cases. According to the angiographic findings the patients could be classified into (1) group A (n = 9) with residual carotid perfusion, (2) Group B (n = 8) with collateralization via the circle of Willis, and (3) group C (n = 24) with leptomeningeal or ophthalmic artery collateral circulation. The rCPR values were significantly different in groups B and C with both methods, Xe-CT (P = 0.0035) and HMPAO-SPECT (P = 0.0014). rCPR was decreased in 13/14 group C patients investigated with Xe-CT and in 11/14 examined with HMPAO-SPECT. All patients in group B showed normal rCPR according to Xe-CT and HMPAO-SPECT. In group A, six of seven revealed decreased rCPR on Xe-CT, while rCPR values were normal in all four group A-patients examined with HMPAO-SPECT. The cerebral hemodynamics depend on a collateralization network and not only on the degree of internal carotid artery (ICA) stenosis. A decreased CPR in a vascular territory ipsilateral to an ICA stenosis or occlusion correlates strongly with the angiographic finding of leptomeningeal or ophthalmic artery collateral circulation.

Aged↗
PubMed1997

[Pilocytic astrocytoma with subarachnoid dissemination].

Pilocytic Astrocytomas (WHO I) are histopathologically tumors of glial origin occurring predominantly in childhood and adolescence. Normally, they are characterized by a benign clinical course, with a long overall survival time and a high rate of complete remission. The rare case of pilocytic astrocytoma, primarily located in the third ventricular region, with generalized subarachnoidal spread is described. In the 10 years of follow-up, the histopathologic findings of the seedings remained those of a typical pilocytic astrocytoma; tumor progression did not occur.

Astrocytoma↗
PubMed1996

[Dysembryoplastic neuroepithelial tumor (DNT). Pattern of neuroradiologic findings].

Dysembryoplastic neuroepithelial tumors (DNT) were first described as a new tumor entity by Daumas-Duport et al. in 1988 and were introduced into the revised WHO classification of brain tumors in 1993. The purpose of this study was to work out neuroradiological CT and MRT patterns of DNT. Five patients, aged 11-61 years (three female, two male) underwent complete presurgical neuroradiological exploration (5 CT, 4 MRT investigations, 2 angiography) because of brain tumor. Four cases complained of seizures and one of occipital-located headache. Total microsurgical excision was achieved in two cases. Two further lesions were resected subtotally after stereotactic biopsy diagnosis. In one case, stereotactic biopsy alone was carried out. All DNTs were localized cortically: two frontobasal medial in the gyrus rectus, two temporobasal in the gyrus occipitotemporalis lateralis and one infratentorial in the lobus caudalis cerebelli. They were sharply demarcated from the surrounding brain tissue. Cortical localization was better visualized by MRT, especially on coronal and sagittal images. CT scans showed a hypodense lesion, MRT a high-signal intensity in T2, low signal in T1 and in proton-weighted images a hyperintense rim with a slightly hyperintense small cyst. The multinodular tumor architecture was best seen in MRT. Two DNTs presented partial contrast enhancement, while three DNTs did not take up contrast. In two lesions there were focal calcifications. The infratentorial DNT was associated with a bony defect of the tabula interna into which the tumor expanded. Two angiographies showed no pathological tumor neovascularization. A hypodense sharply demarcated lesion with a multinodular pattern in MRT with cortical location and without space-occupying signs is, in combination with the clinical symptom of epileptic seizures, highly suggestive of DNT. As our results demonstrate, DNT can also occur in the infratentorial space.

Adolescent↗
PubMed1996

[Rare intracranial plasmacytoma manifestations. Case reports and review of the literature in diffuse plasmocytoma, in primary solitary extramedullary plasmacytoma in in primary solitary osseous plasmacytoma].

Plasmacytomas can be divided into multiple, solitary osseous and solitary extraosseous/extramedullary plasmacytomas. Intracranial plasmacytomas of the dura, leptomeninx and cerebrum are well known from the literature. They are manifestations of multiple myeloma, intracranial extramedullary plasmacytoma or metastatic disease of extramedullary plasmacytoma in distant locations. We describe a cerebellar manifestation of a solitary plasmacytoma of the bone, and a leptomeningeal carcinomatosis of a multiple plasmacytoma. A summary of the literature concerning intracranial plasmacytomas is given. Dural manifestations of plasmacytoma have the same features as meningiomas in CT or MRI. Cerebral or cerebellar manifestations cannot be differentiated from brain tumors by means of CT or MRI. In CT, plasmacytomas show high-density lesions. T2w-MRI reveals a low-intensity lesion. In T1w-MRI, intense homogeneous contrast enhancement can be demonstrated.

Bone Neoplasms↗
PubMed1996

[Incidence of postmyelography syndrome and postmyelography complaints after lumbar puncture with the Sprotte pencil-like needle in comparison with the Quincke needle].

PURPOSE: Myelography in combination with a postmyelography CT is an important presurgical examination because of its excellent visualisation of the disc, the bone and the contrast-filled dura. Side effects after myelography can be observed in up to 50% of patients. The pathophysiological mechanism is thought to be increased cerebrospinal fluid leakage at the puncture site. Since the introduction by Sprotte in 1979 of the pencil-point needle, a modification of Whitacre's needle, fewer complaints after lumbar puncture have been reported. The aim of the study was to examine the influence of two types of needle points and the temperature (37 degrees C vs 21 degrees C) of the contrast medium (CM; iotrolan, Isovist) on the incidence of side effects of lumbar puncture for myelography. MATERIAL AND METHODS: In a prospective randomized trial the incidence of complaints after lumbar puncture with intrathecal CM application was evaluated by the use of a 21-G pencil-point needle as modified by Sprotte compared to our usual 22-G needle with a Quincke bevel. Some 412 patients (201 female, 211 male; mean age 54.05 +/- 7.4 years) were investigated. Directly after examination and 1. 3 and 5 days later the patients were questioned about complaints (headache, neck stiffness nausea, vomiting, buzzing in the ear and dizziness). The results were tested by the chi square test. RESULTS: A significantly lower incidence of complaints was seen after lumbar puncture with the pencil-point needle/Quincke needle (headache: 6.3%/18.9%, P < 0.0001; headache lasting 3 days: 0.5%/7.8%, P < 0.0001; headache lasting 5 days: 0%/2.4%, P = 0.0305; nausea: 0%/4.9%, P = 0.0009; vomiting: 0%/3.4%, P = 0.0009; dizziness: 0%/3.4%, P = 0.0074; neck stiffness: 0%/3.4%, P = 0.0074). The temperature of the CM had no influence on the complaints. No influence was seen on the quality of the myelogram. No relation to sex and age was found. CONCLUSION: Complaints after lumbar puncture and myelography are caused by the cerebrospinal fluid leakage at the puncture site. The incidence of side effects related to this leakage can be reduced by using a pencil-point needle. The temperature of the CM has no influence on the complaints.

Adolescent↗
PubMed1995

[Diagnosis and spontaneous course of non-traumatic localized myositis ossificans].

Non-traumatic localized myositis ossificans is a rare variant of pseudotumoral muscular ossification. In the early stage it may be misdiagnosed as soft tissue sarcoma or some kind of osteosarcoma. Myositis ossificans itself does not always require therapy; when diagnosed on the basis of the typical features revealed by meticulous non-invasive investigation, biopsy is not mandatory for confirmation of the diagnosis. The diagnostic procedures needed - radiography, ultrasound, MRI, and isotope bone scan - are discussed with reference to three clinical case reports.

Adult↗
PubMed1995

[Dopamine (D2) receptor SPECT with 123I-iodobenzamide (IBZM) in diagnosis of Parkinson syndrome].

For effective drug therapy of Parkinson's syndrome (PS), it is necessary to distinguish between idiopathic and secondary genesis and PS in neuronal systemic degeneration. [123I]Iodobenzamide ([123I] IBZM) is a radiolabelled benzamide and binds specifically to the cerebral dopamine receptor (D2) in the basal ganglia. The purpose of this study was to determine the value of the [123I]IBZM D2-receptor SPECT in the differential diagnosis of PS. A total of 38 patients (20 females, 18 males; age 61 +/- 13.3 years), with typical extrapyramidal symptoms were investigated. Twenty suffered from idiopathic and 11 from secondary PS. Seven patients in whom a neurological disease could be excluded, served as controls. SPECT data were acquired 90 min after i.v. injection of 185-200 MBq [123I]IBZM. After reconstruction with a Butterworth filter (cutoff frequency 0.5) and attenuation correction (coefficient 0.12 cm(-1)) we quantify the IBZM basal ganglia uptake as ratio to teh frontal D2-receptor-free cortex (BG/FC). The patients with idiopathic PS (IPS) and the controls revealed high and specific IBZM uptake in the basal ganglia compared to the adjacent frontal brain tissue (IPS: BG/FC = 1.44 +/- 0.10; controls: BG/FC = 1.48 +/- 0.10). A significant decreased striatal IBZM uptake is found in cases with secondary PS (BG/FC = 1.25 +/- 0.10; p<0.0001, t-test compared to controls and IPS). The patient group with IPS can be subdivided into patients without L-dopatherapy (BG/FC = 1.49 +/- 0.07), patients with longstanding L-dopa-therapy demonstrating significantly decreased striatal IBZM uptake (BG/FC = 1.31 +/- 0.04; p<0.0001, t-test compared to controls and other IPS), which correlates pathophysiological with a reduction of free D2 receptors, and patients with de novo PS showing a slight increased striatal IBZM uptake (BG/FC = 1.56 +/- 0.05), which represents D2-receptor stimulation. [123I]IBZM-SPECT is a sensitive and non-invasive test for striatal D2-receptor density and activity which permits relatively clear discrimination between idiopathic and secondary PS and yields important information for differential therapy.

Adult↗