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M Cordes

Publications and source records attributed to M Cordes.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Border-area cerebral ischemia--3D-SPECT for the imaging of the regional cerebral blood flow].

15 patients with suspected cerebral ischaemia were examined using 99mTc-HM-PAO-SPECT to assess cerebral blood flow. Results obtained from SPECT were correlated with CT and Doppler ultrasound findings. A 3D-display algorithm is proposed to enhance the lesion to non-lesion contrast compared to the standard 2D-image interpretation. In all cases contrast was superior on 3D-display to 2D-display (-0.38 versus -0.09). 3D-display of SPECT-data enhances lesion contrast due to postreconstructive data processing and may improve exact interpretation of cerebral blood flow studies.

Adult↗
PubMed1992

[The regional cerebral circulation in infarct patients. Rapid dynamic T2*-weighted MRT after a bolus injection of gadolinium-DTPA].

The aim was to validate the MRI assessment of regional cerebral blood flow. Measurements were performed on a 1.5 T imaging system using a fast T2*-weighted gradient-echo sequence. After intravenous injection of gadolinium-DTPA 30 images were acquired in the same slice position during 84 seconds. In 12 volunteers we observed a symmetrical cortical decrease of signal intensity during the passage of the contrast medium. In 9/23 patients with impairment of cerebral blood flow a circumscribed area of reduced signal intensity decrease (hypoperfusion) was found. In 4/23 patients the decrease of signal intensity was more pronounced than in normals (hyperfusion). In 9/23 patients signal intensity changes were normal. HMPAO-SPECT confirmed successful MRI assessment of cerebral blood flow in 22/23 patients.

Cerebral Infarction↗
PubMed1992

[Magnetic resonance tomographic screening studies of the bone marrow with gradient-echo sequences. II. Gadolinium-DTPA-supported studies of plasmocytoma patients].

MR imaging was performed in 19 patients with proven multiple myeloma. Both plain and Gd-DTPA enhanced in-phase and opposed-phase gradient-echo techniques were used (0.1 mmol Magnevist/kg body weight). Plain, opposed-phase imaging demonstrated more lesions than plain in-phase imaging (35 vs. 16); enhanced opposed-phase imaging demonstrated more lesions than plain opposed-phase and enhanced in-phase imaging (47 vs. 35 and 17 lesions). These results suggest that enhanced opposed-phase images which have a high contrast between normal and infiltrated bone marrow are especially suited for MR screening in multiple myeloma.

Bone Marrow↗
PubMed1992

[The determination of cerebral dopamine (D2) receptor density by using 123I-IBZM-SPECT in Parkinson disease patients].

An alteration of the dopaminergic nigrostriatal system is believed to be the main pathogenetic factor of Parkinson's disease (PD). We report on our initial results on the determination of the post-synaptic dopamine-D2-receptor binding of 123I-IBZM in patients with PD. Drug-native patients showed a significantly higher IBZM binding in the basal ganglia as compared to patients on specific dopaminergic medication. Age, duration of the disease and the severity of the disease do not seem to influence the IBZM-receptor binding. We conclude that 123I-IBZM-SPECT is an extremely useful tool for the evaluation of the functional state of cerebral dopamine-D2-receptors.

Aged↗
PubMed1992

[L-18F-dopa-PET in Parkinson-plus syndromes for the detection of a disordered presynaptic dopaminergic function].

PET examinations using L-18F-DOPA were performed on 14 patients with Parkinsonism-plus syndromes (PPLUS). A rate constant Ki was calculated by a graphical method using an arterial input function. Sequential PET images were obtained and no specific activity was measured both in cortical and cerebellar background regions. These results were compared with those in 20 normal controls and tested for intra- and interobserver variability. All patients with PPLUS showed reduced Ki values with a mean of 0.154 (ml/striatum/min), whereas controls exhibited Ki values with a mean of 0.690 (ml/striatum/min) using cortical background regions. The correlation coefficient was calculated to be r = 0.973 for the intraobserver variability and r = 0.879 for the interobserver variability in controls, and r = 0.989 or = 0.973 in PPLUS, resp. There was no significant difference in the Ki values for cortical and cerebellar background regions (p = 0.1). PET examinations using L-18F-DOPA can reliably assess the extent of nigrostriatal degeneration in vivo. Since this radiotracer binds irreversibly within the striatum PET examinations allow the quantification of a disturbed dopaminergic function which is observer-independent.

Aged↗
PubMed1991

Increased rCBF in gray matter heterotopias detected by SPECT using 99mTc hexamethyl-propylenamine oxime.

Imaging findings of morphology and regional cerebral blood flow in two patients suffering from epileptic seizures are presented. CT and MRI revealed heterotopic gray matter as a probable structural correlate, causing the seizure disorder. 99mTc hexamethyl-propylenamine oxime (HM-PAO) SPECT demonstrated focally increased regional cerebral blood flow in both patients in the areas of their heterotopic lesions. Heterotopic and orthotopic gray matter seem to have similar features in terms of regional perfusion. A focally increased brain perfusion in interictal epileptic patients may indicate an underlying migration anomaly.

Adult↗
PubMed1991

[Transcranial Doppler sonography in cerebrovascular diseases].

A review of our 1 1/2 years' experience with transcranial Doppler sonography (TCD) is given. In total, 619 TCD examinations were performed. Considering physiological variations of blood flow velocities in the intracranial arteries, TCD findings in stenoses and occlusions of the extracranial and intracranial brain-supplying arteries as well as in intracranial vasospasms were evaluated. In patients with leptomeningeal anastomoses demonstrated by TCD in the region of the peripheral middle cerebral artery, the regional cerebral blood flow was measured by 99mTc-HMPAO-SPECT. The value and limitations of TCD in cerebrovascular diseases and the indications to TCD examination of the intracranial arteries are discussed.

Carotid Artery Diseases↗
PubMed1991

Evaluation of a multicentre study with Iomazenil--a benzodiazepine receptor ligand.

After showing in an earlier publication that Iomazenil is a potent benzodiazepine receptor antagonist, the substance has been distributed to 11 clinical centres in Europe for further tests. The protocol asked for volunteers, epileptic cases and patients with Alzheimer's disease. Prior to the Iomazenil examination, flow images by perfusamine or HMPAO were required, and as comparative methods EEG, computed tomography (CT) and magnetic resonance imaging (MRI) were performed. The results allowed first the determination of the normal distribution of the benzodiazepine receptors in the human brain. The highest uptake was found in medial occipital cortex. Second, the evaluation of the epileptic cases shows a 100% positive prediction value for Iomazenil compared to 92% for flow images. Negative prediction values were calculated as 81% for Iomazenil and 54% for flow images. Furthermore, one group reported the successful diagnosis of Alzheimer's disease at an early stage. The visual image examination was tentatively compared to a more objective semiquantitative one based on quotients of corresponding left/right regions of interest. This semiquantitative method has not proved successful yet, but the problems have been identified. A more precise protocol for further studies is therefore proposed.

Adult↗
PubMed1991

Vascular graft infection: detection by 123I-labeled antigranulocyte antibody (anti-NCA95) scintigraphy.

A total of 40 scintigraphic examinations were performed after vascular reconstructive surgery in 27 patients in whom there was a clinical suspicion of vascular graft infection. Whole-body gamma camera images were obtained at 4 and 24 h after i.v. administration of 111 MBq 123I-labeled antigranulocyte antibody Anti-NCA95. Scan results were interpreted without clinical information and were subsequently correlated with computed tomography. Prosthetic vascular graft infection was confirmed in 9 patients and excluded in 18 by surgical findings, bacteriology and/or clinical course. Scintigraphy revealed true-positive results in 16 of 40 and false-negative results in 1 of 40 examinations. True-negative results were found in 19 and 16, false-positive results in 4 and 7 examinations at 4 and 24 h p.i., resp. The sensitivity was calculated to be 94% for both early (4 h) and late (24 h) images whereas the specificity was 83% and 70%, resp. In all cases the application of the murine antibody was safe and no side effects or complications were noted. Limitations of this diagnostic procedure are accumulations of granulocytes in hematomas which may be observed in the non-complicated early course following reconstructive surgery.

Aged↗
PubMed1991

[Radionuclide cisternography: SPECT- and 3D-technique].

Radionuclide cisternography is indicated in the clinical work-up for hydrocephalus, when searching for CSF leaks, and when testing whether or not intracranial cystic lesions are communicating with the adjacent subarachnoid space. This paper demonstrates the feasibility and diagnostic value of SPECT and subsequent 3D surface rendering in addition to conventional rectilinear CSF imaging in eight patients. Planar images allowed the evaluation of CSF circulation and the detection of CSF fistula. They were advantageous in examinations 48 h after application of 111In-DTPA. SPECT scans, generated 4-24 h after tracer application, were superior in the delineation of basal cisterns, especially in early scans; this was helpful in patients with pooling due to CSF fistula and in cystic lesions near the skull base. A major drawback was the limited image quality of delayed scans, when the SPECT data were degraded by a low count rate. 3D surface rendering was easily feasible from SPECT data and yielded high quality images. The presentation of the spatial distribution of nuclide-contaminated CSF proved especially helpful in the area of the basal cisterns.

Adult↗
PubMed1990

[Value of radioimmunoscintigraphy compared to computed tomography in the diagnosis and follow-up of primary ovarian carcinoma].

In this prospective study the diagnostic merit of radioimmunoscintigraphy (RIS) was compared with computed tomography (CT) and operation in the primary diagnostic procedure and follow-up of women with suspected ovarian cancer. In primary diagnosis, sensitivity, specificity, and diagnostic accuracy was 100%, 60% and 90% for RIS. In follow-up, sensitivity for local recurrence was slightly higher in CT than in RIS. It was possible to detect peritoneal carcinosis in the pelvis and lower abdominal region better with RIS, but in the upper abdominal region, peritoneal carcinosis was detected better with CT. If no differentiation between benign or malignant lesion, is possible with CT, differentiation will in many cases be possible with RIS.

Adenocarcinoma, Mucinous↗
PubMed1990

[99mTc-MAG3 and 131I-OIH in patients with kidney insufficiency and with normal kidneys].

Renal clearance of 99mTc-mercaptoacetyltriglycine (MAG3) and 131J-orthoidohippurate (OIH) were compared by simultaneous measurement in 50 patients. Renal time-activity-curves of both radiopharmaceuticals were compared in 50 patients. With regard to the clearance, good correlation (r = 0.95) with a mean ratio MAG3-/OIH-clearance of 0.62 was found. No significant difference between patients with normal (n = 30) and impaired (n = 20) renal function could be demonstrated. Renal time activity curves and relative renal function showed good correspondence in patients with normal (n = 13) and impaired (n = 7) renal function. It is concluded that MAG3 may be used as substitute for OIH in patients with normal and impaired renal function.

Humans↗
PubMed1990

[Magnetic resonance tomographic differentiation of ocular muscle changes in endocrine orbitopathy].

In 50 patients with Graves' Ophthalmopathy and 9 controls both orbits were examined by MR Imaging at 0.5 Tesla using a surface coil. T1-weighted spin-echo images were obtained in transverse and coronal orientation; additionally, a T2-image was calculated from a multi-echo sequence (8 echoes). Signal intensity of eye muscles on both T1-weighted and T2-weighted MR images was evaluated qualitatively. T2-times were then calculated for all inferior rectus muscles. Eye muscle enlargement was found in 28 out of 50 patients. T2-times of inferior rectus muscles in stage III and IV patients were evaluated significantly (p less than 0.05). Areas of high signal intensity were accordingly found in enlarged eye muscles in 19 out of 50 patients; they were interpreted as edematous tissue changes. Areas of low signal intensity were found in enlarged eye muscles of 5 out of 50 patients; these eye muscles were considered fibrotic. Differentiation of eye muscle changes by MR imaging might help to decide between antiinflammatory medication and surgical therapy in patients with Graves' Ophthalmopathy.

Adolescent↗