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Biomedical subjects

M Cordes

Publications and source records attributed to M Cordes.

At least 73 records · Page 4Linked to original sources
PubMed1990

[A comparison of different methods of calculating clearances using 99mTc-mercaptoacetyltriglycine and 123I- or 131I-ortho-iodohippuric acid].

Using labelled MAG3 (n = 172) or OIH (n = 102) the results of three different techniques of calculating renal clearance were compared. The following techniques were used: Tauxe (single plasma concentration determination), Oberhausen (modified, combined partial body and plasma disappearance clearance) and Winkler (partial body clearance). For OIH, linear regression analysis revealed a positive correlation of Tauxe and Oberhausen clearances with a correlation coefficient (r) of 0.90 and a mean ratio (mean) Oberhausen/Tauxe clearances of 1.03. For MAG3, the Oberhausen values were found to be significantly lower than the Tauxe values with an equally good correlation. For this radiopharmaceutical the Winkler values were significantly higher than the Tauxe and Oberhausen values. For OIH, no such difference was noted. However, the correlation coefficient was significantly lower. Whereas with the Tauxe method, a mean ratio MAG3-/OIH clearances of 0.62 was observed in an earlier investigation, from the present data a ratio of 0.53 is calculated for the Oberhausen clearance. The difference between the Tauxe and Oberhausen clearances with MAG3 is of importance when comparing clearance values obtained with clearance calculation techniques and for establishing normal values for the MAG3 clearance.

Adult↗
PubMed1990

[Vascular pedicled pelvic bone span. Value of digital subtraction angiography in pre- and postoperative diagnosis].

The pedicled pelvic bone graft is a new operative technique for the treatment femoral head necrosis. 29 femoral head necroses were examined by i.a. DSA before a pedicled pelvic bone graft was implanted. 11 pedicled pelvic bone grafts were investigated postoperatively. The pre- and postoperative findings are presented. I. a. DSA is a valuable method for the evaluation of the vascularisation of the femoral head before and after surgery.

Adult↗
PubMed1989

[Possibilities for imaging intracardiac thrombi with indium 111 thrombocyte scintigraphy].

Intracardiac thrombi can be localized and quantified by indium-111-labelling of thrombocytes with a high sensitivity and specificity. The scintigraphic procedure has a complementary evidence to echocardiography. Scintigraphy shows activity and age of thrombosis, whereas echocardiography seems to be superior in determination of mass and localization. In older thrombi scintigraphy fails because of organisation and endothelialization of the thrombus surface. For the reason of determination of the age of an intraventricular thrombus this method might have an increasing acceptance.

Aged↗
PubMed1989

Radioimmunoscintigraphy of ovarian cancer with 131-iodine labeled OC-125 antibody fragments.

Radioimmunoscintigraphy (RIS) with 131I labeled OC-125 F(ab')2 monoclonal antibody fragments was prospectively studied in 43 women for primary diagnosis and follow up of ovarian cancer. Total body planar photoscans with a scintillation camera were performed one to seven days after antibody application and results were compared with operation and or CT examination. By the region of interest technique the tumor to non tumor tissue ratio (T/N) was calculated in vivo. Sensitivity in primary diagnosis was 100% (10/10), specificity 33% (1/3). For local recurrency, sensitivity was 86% (19/22), for metastatic loci 80% (17/21). Specificity was 75% and 50%. T/N ratio was in the rage from 1.3 to 2.8. Sensitivity for ovarian cancer is high in primary diagnosis and follow up. By the region of interest technique it is possible to detect small recurrencies and to presume peritoneal carcinosis. Antibody accumulations in diseases different from ovarian cancer however diminish specificity.

Adult↗
PubMed1989

[Subacute cerebral infarct: native and contrast medium-enhanced MRT].

Twenty-five patients with clinical and CT findings indicating supratentorial cerebral infarct were prospectively studied with MR. MR examinations were performed between the 3rd and 150th day after stroke. T2-weighted axial images were compared with T1-weighted sequences after i.v. administration of Gd-DTPA. T2-weighted images demonstrated parenchymal lesions in all 25 patients. Postcontrast T1-weighted images, however, displayed pathologic contrast enhancement in only 19 areas of infarction. In 5 of the 25 patients, the use of Gd-DTPA provided additional diagnostic information by demonstrating gyral contrast enhancement as a pattern typical for ischemia. In 2 of the 25 patients, pathologic contrast enhancement was observed in an area that was isointense to the surrounding brain tissue on the T2-weighted images. In one patient, Gd-DTPA improved differentiation between areas of subacute and chronic infarction. At present, in the patient with suspected cerebral infarction, MR imaging after i.v. administration of Gd-DTPA appears recommended when clinical findings and CT are equivocal.

Acute Disease↗
PubMed1989

Regression of left ventricular hypertrophy under ramipril treatment investigated by nuclear magnetic resonance imaging.

Thirty-two hypertensive subjects with diastolic blood pressure greater than 95 mm Hg were treated with ramipril over a period of 3 months. To determine the effective decrease of blood pressure and for reliable and reproducible demonstration of regression of myocardial hypertrophy during ramipril treatment, we performed parallel measurements with magnetic resonance imaging (MRI) and echocardiography. Measurements were carried out before treatment, 4 h after the first dose, and after 14 days and 3 months of treatment. MRI slices showed a significant decrease of interventricular septal thickness from 19.57 to 15.20 mm, whereas echocardiography demonstrated an equivalent decrease from 18.78 to 14.57 mm. At each measuring point, quantification of wall thickness was performed three times and the means were calculated. The septum and the posterior wall of the left ventricle were also measured at three different points. The values were obtained with negligible scatter and the changes with ramipril treatment were highly significant (p less than 0.001). A concomitant decrease of blood pressure was also observed. The therapeutic aim to reduce diastolic blood pressures below 90 mm Hg was achieved in all patients. In addition to the significant reduction in blood pressure, the angiotensin converting enzyme (ACE) inhibitor ramipril caused a significant regression of pathologic left ventricular hypertrophy demonstrated by magnetic resonance imaging and echocardiography.

Adult↗
PubMed1989

Graves ophthalmopathy: MR imaging of the orbits.

Thirty-nine patients with Graves ophthalmopathy were examined with magnetic resonance (MR) imaging at 0.5 T with use of a surface coil. T1- and T2-weighted spin-echo images were obtained, and T2 relaxation times of eye muscles and retrobulbar fat were calculated from a multiecho sequence. Normal values for T2 relaxation times of eye muscle were obtained by examining nine control subjects. MR imaging demonstrated eye muscle enlargement in 23 patients. Visual examination of T2-weighted and calculated T2 images showed areas of high signal intensity in enlarged eye muscles of 12 of 23 patients. Calculated T2 relaxation times of eye muscles differed significantly between control subjects and patients with stage III and IV disease. Signal intensity characteristics of these changes, as well as their correlation with well-known histologic findings, suggested their interpretation as edema caused by acute inflammation. Since computed tomography is not able to depict eye muscle edema, the MR findings of structural changes within enlarged eye muscles might have an impact on therapeutic decisions concerning the application of anti-inflammatory drugs.

Adult↗
PubMed1989

[EEG and SPECT in cerebral manifestations of AIDS].

The purpose of the presented study was to determine the diagnostic value of correlated EEG and SPECT findings in patients with CNS-manifestations of AIDS. Ten HIV 1 infected patients had been examined. Diagnoses: meningitis (2 x), lymphoma (2 x), necrotizing encephalitis (1 x), toxoplasmosis (7 x) (Some patients had more than one diagnosis). Unenhanced and Gd-DTPA enhanced MR, 99mTc-HM-PAO SPECT and clinical EEG were compared. In 9/10 patients MR demonstrated intracranial lesions. In one patient with necrotizing encephalitis (not detected by MR), SPECT revealed an inhomogeneous cerebral perfusion. Only lymphoma was hyperperfused. Toxoplasmic lesions-when detectable by SPECT-were hypoperfused. Reduced rCBF was also seen in brain regions not affected directly, but functionally associated to altered areas. EEG revealed diffuse signs such as slowing in patients with brain atrophy, but also in those patients with lesions of basal ganglia and thalamus. Focal signs in the EEG were in concordance with imaging findings in only 2/10 patients. In 4/10 patients foci even adjacent to the cortex - as shown by MR - remained undetected by EEG. One patient with an active toxoplasmosis had sharp waves over the affected region. The parallel application of the three methods as suggested in this paper appears useful not only for scientific purposes. In most cases, this procedure provides relevant diagnostic information. It is recommended for AIDS-patients with CNS manifestations of unknown etiology.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Imaging of intra-cardiac thrombi with indium 111 scintigraphy].

Intracardiac thrombi can be localized and quantified by Indium-111-labelling of thrombocytes with a high sensitivity and specificity. The scintigraphic procedure has a complementary evidence to echocardiography. Scintigraphy shows activity and age of thrombosis, whereas echocardiography seems to be superior in determination of mass and localization. In older thrombi scintigraphy fails because of organisation and endothelialization of the thrombus surface. For the reason of determination of the age of an intraventricular thrombus this method might have an increasing acceptance.

Aged↗
PubMed1989

[Diagnostic strategies in liver and pancreatic tumors using imaging procedures--nuclear medicine].

The different biokinetic behaviour of radioactive tracers which can be monitored by nuclear medicine procedures may be helpful in the diagnosis or differential diagnosis of tumours or tumour-like lesions of the liver or pancreas: autologous red blood cells in the detection of haemangiomas; iminodiacetates in delineation of focal nodular hyperplasia, resp. liver adenomas versus other tumours; colloidal albumin in differentiating focal fatty infiltration from diffuse infiltration by metastases; monoclonal antibodies in revealing liver metastases or abscesses, resp. pancreas neoplasms. In general the clinical suspected diagnosis and the result of morphologic imaging modalities determine the use of the appropriate radioactive tracers.

Adenoma↗
PubMed1989

[Postoperative computed tomography control of allogeneic vascular prostheses].

33 CT-studies of 26 patients with alloplastic vascular prostheses were evaluated and compared with postoperative digital subtraction-angiography in 16 cases. 13 patients had no pathologic findings confirmed by further clinical development. In 4 cases bypass infection was diagnosed, which CT findings were perigraft gas (2/4), perigraft fluid (4/4), cm-enhancement (4/4) and fistulas (2/4). 10-21 d. post.-op. sterile hematomas were found in 3 patients. Further 3 cases had 5 weeks-2 post.-op. perigraft seromas. CT was method of first choice for diagnostic of perivascular alterations after bypass surgery. DSA was complementary to CT and should be performed to detect vascular complications.

Aged↗
PubMed1988

[Ischemic brain infarct: combined determination of regional cerebral blood flow and volume by SPECT].

A combined measurement of regional cerebral blood flow (r CBF) and volume (r CBV) by SPECT was performed in 15 patients with ischaemic cerebral infarction. For measurement of r CBF 99mTc-HMPAO was used, and for r CBV 99mTc-labelled red blood cells. Patients with acute or subacute cerebral infarction (n = 10) showed elevation of r CBV whereas r CBF was either reduced or elevated. Patients with chronic cerebral infarction (n = 5) showed reduction of both r CBF and r CBV. The combined measurement of both r CBF and r CBV by SPECT allows imaging and semiquantitative evaluation of haemodynamic changes in ischaemic cerebral infarction at various stages. The resulting data may be helpful in describing the pathophysiologic compensatory mechanisms.

Aged↗
PubMed1988

[Comparative clinical studies of myocardial blood flow in coronary heart disease with two nifedipine preparations].

Clinical, ergometric and scintigraphic examinations were performed before and after oral administration of a commercially available nifedipine preparation used as a standard (reference preparation; dosage: 3 x 10 mg/d) in 21 patients with angiographically verified coronary artery disease. In an open comparison study the same parameters were investigated after a 4 week course of a different nifedipine preparation as a test preparation (Corotrend; dosage: 3 x 10 mg/d). The study was performed in order to determine whether there were quantitative differences in myocardial microperfusion when different galenical preparations of nifedipine were used. There were no statistically significant differences between the two nifedipine preparations in the test parameters recorded. Both substances were associated with highly significant increases in microperfusion as compared to findings in the washout phase. Clinical effects on incidence of chest pain and on reductions in blood pressure were comparable. Patients demonstrated slightly better exercise tolerance with the reference agent, and computerised impulse-rate analysis of the tomoscintigrams demonstrated somewhat better microperfusion with this drug, though the differences between the two agents did not attain statistical significance. As the result of this analysis the two drugs would appear to be equivalent in clinical potency.

Aged↗