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M Georgi

Publications and source records attributed to M Georgi.

At least 55 records · Page 3Linked to original sources
PubMed1998

Non-invasive imaging of abdominal vascular pathologies.

With the advent of ultrasound (US), Doppler and color-flow Doppler imaging, computed tomography (CT), and magnetic resonance angiography (MRA) the ability for non-invasive studies of the abdominal vasculature has been enhanced considerably. In this paper an overview on various abdominal vascular pathologies is presented. Because of the dramatic improvements in image quality, special emphasis is given on the potential role of breathhold contrast-enhanced three-dimensional (3D) MRA which appears to be a versatile non-invasive alternative to conventional angiography.

Abdomen↗
PubMed1998

Body mass index and percentage fat mass in healthy German schoolchildren and adolescents.

OBJECTIVE: To provide reference data for obesity indices in Mid-European schoolchildren and adolescents, to evaluate the usefulness of body mass index (BMI) as an indicator of obesity in children, and to analyse the patterns of fat accumulation during childhood. DESIGN: Cross-sectional observational study in 2554 healthy schoolchildren and adolescents (age, 6-19 y) living in Heidelberg, Germany in 1989/1990. Centile charts for BMI and skinfold-derived percentage body fat mass (PFM) were constructed using Cole's LMS method for normalised growth standards. RESULTS: The BMI centile values of German children ranged higher than French, lower than North American and Italian, and similar to Swedish and British children. While BMI steadily increased with age, PFM was markedly lower in peripubertal than in pre- and postpubertal boys. BMI predicted PFM with reasonable precision in girls (r=0.84), and in obese boys (r=0.58), but not in the leaner two thirds of the male population (r=0.01, NS). The 75th BMI percentile was the most appropriate cutoff value to screen for the 15% most obese patients by PFM (sensitivity: 82%, specificity: 85%). The pattern of the trunk-to-extremity skinfold ratio across childhood suggested that the typical adult distribution of central and peripheral fat is achieved in mid puberty in girls, but not before the end of adolescence in boys. CONCLUSIONS: The major differences observed between BMI charts obtained in different countries underline the need for population-specific reference data. BMI is of limited usefulness in predicting relative fat mass in individual children. The developmental pattern of fat accumulation and distribution during adolescence is highly dynamic and gender-specific.

Adipose Tissue↗
PubMed1998

[First clinical results of ultrafast, contrast-enhanced 2-phase 3D-angiography of the abdomen].

PURPOSE: To assess the utility of breath-hold abdominal ultrafast three-dimensional (3D) gadolinium-enhanced dual-phase magnetic resonance angiography (MRA). MATERIAL AND METHODS: 125 patients with various abdominal pathologies were imaged using a breath-hold ultrafast gadolinium-enhanced dual-phase 3D-MRA technique. RESULTS: 119 (95%) of 125 MRA's were of good or excellent quality. The sensitivity in the detection of renal artery stenoses as well as stenoses of the celiac trunk and the superior mesenteric artery was 100%. Accessory renal arteries (n = 9) and replaced hepatic arteries (n = 4) were reliably detected by MRA. In 24 (71%) of 34 cases MR-angiographic delineation of the spleno-portal system and hepatic veins was superior compared to conventional angiography. CONCLUSION: Breath-hold gadolinium-enhanced dual-phase 3D-MRA has the potential to replace conventional angiography in the abdomen.

Abdomen↗
PubMed1998

[Ultrafast contrast-enhanced 3D MR angiography in the preoperative diagnosis of liver tumors].

PURPOSE: To evaluate the accuracy of 3D-MRA in preoperative staging in correlation to intraoperative and histological results. METHODS: In 30 patients with focal liver lesions axial and coronal MR sequences (T1w-Flash 2D, T2w-TSE unenhanced. T1w-Flash 2D, TRUE FISP contrast-enhanced) as well as coronal breath-hold MRA were performed. The technical parameters of the MRA were as follows; TR/TE 5/2 ms, flip angle 40 degrees, 32-40 partitions with an effective slice thickness of 2-3 mm, acquisition time 26 s, matrix 128 x 256, FOV 320 x 320 to 400 x 400. RESULTS: In 23/30 patients liver resection was performed. Correct prediction of segmental localization was achieved in preoperative MRI of 22 patients (98%). The presumed histology was correct in 20/23 cases (87%). The evaluation of the hepatic vascular structures was correctly predicted in all cases. By use of multiplanar reconstructions and single image view of the 3D data base of MRA, additional information could be obtained in 13 patients. CONCLUSIONS: Breath-hold 3D-MRA gives certain information on localization and relation of vascular structures to focal hepatic lesions. In presentation of portal venous structures MRA is superior to conventional angiography.

Adult↗
PubMed1998

[Value of dual-phase-helical CT in the preoperative diagnosis of pancreatic cancer--a prospective study].

PURPOSE: A prospective study was performed to evaluate the accuracy of dual phase helical CT in suspected pancreatic cancer. METHODS: Within one year 136 patients underwent helical CT with arterial and portal venous scans after bolus tracking and NaCl bolus injection. Evidence of pancreatic cancer and assessment of resectability were recorded using a standardised protocol. Suspected benign disease was verified by follow-up examination and clinical data, suspected malignant disease was correlated with biopsy or surgery. RESULTS: For the detection of tumor the overall concordance was 92%, the sensitivity 98% and the specificity 70% (6 false positive, 1 false negative). Resectability was correctly assessed in 90% with a sensitivity of 92% and a specificity of 88% (4 false positive, 4 false negative). Vascular invasion was detected correctly in 91% (veins)-94% (arteries), lymph node invasion in 67% and liver metastasis in 94%. CONCLUSION: Dual phase helical CT is a very reliable tool in the assessment of resectability in pancreatic cancer.

Biopsy↗
PubMed1998

[Stereo display of MR angiograms].

PURPOSE: To provide methods for stereoscopic visual demonstration from 3D reconstructed MR angiographic images. METHODS: Stereoscopic viewing can be obtained with pairs of images that are displayed at angles of 15 degrees. Optical devices as stereoscopic binoculars or minor stereoscopes facilitate stereoscopic viewing. The possibility of stereoscopic projections for a larger auditorium is mentioned. RESULTS: Using three clinical examples the advantages of stereoscopic display of MR angiograms are demonstrated. CONCLUSIONS: MR angiography allows stereoscopic viewing with simple methods, like CT- and conventional rotation angiography. This principle, which has been known for 100 years, may thus acquire a new significance.

Adult↗
PubMed1998

[Gorham-Stout syndrome of the spine. Case report and review of the literature].

Two female patients with Gorham-Stout syndrome (GSS) of the spine are described. One 25 year old patient developed progressive osteolysis of the upper cervical spine over a period of several years but despite gross extent of the disease had no neurological complications. Some bone implanted in order to stabilise the spine was absorbed after only a few weeks. A six year old girl with progressive osteolysis of the thoracic spine developed a reversible trans-section syndrome on several occasions. During an active episode, the spine was stabilised by a titanium implant. In both patients the condition arrested spontaneously. A review of the world literature (175 cases) has indicated that, including our two patients, there were only 15 patients with primary involvement of the spine and 27 patients with secondary involvement. The relatively good prognosis of the condition (mortality 13.3%), which often shows spontaneous arrest, becomes much worse if there is involvement of the spine or thorax because of neurological complications or a chylothorax. Involvement of the spine increases mortality to 33.3%, and to 52% if the thorax is involved. Early diagnosis and the institution of appropriate treatment is therefore essential. For involvement of the spine, a combination of radiotherapy and surgical stabilisation with a titanium implant should be performed since in nearly all patients bone transplants are reabsorbed. For this treatment the patient should be transferred to a neuro-orthopaedic centre.

Adult↗
PubMed1998

[Current status and perspectives of conventional radiologic diagnosis of the gastrointestinal tract].

In the last twenty years the basic gastro-intestinal diagnostic procedures have had to record increasing losses. This is why the study of these examinations had becoming more and more endangered. From our experience and from literature review the question arises whether now or in future we can manage without the basic gastrointestinal diagnostic procedures. The answer is that both for efficiency and for costs the continuation of these procedures does not appear acceptable. The preservation of the X-ray techniques of examination should be object of discussion and agreement between radiologists, clinicians, endoscopists, and economically experienced professionals in administration. In order to meet the needs for urgent economic measures in hospitals, the increased use of investigation with water-soluble contrast media seems unavoidable. Therefore the examination techniques should be adjusted and optimised as described.

Contrast Media↗
PubMed1998

Pancreatic cancer: value of dual-phase helical CT in assessing resectability.

PURPOSE: To evaluate the use of dual-phase helical computed tomography (CT) (with or without CT angiography) to assess resectability in patients suspected to have pancreatic cancer. MATERIALS AND METHODS: Tumor resectability was prospectively evaluated in 89 patients who later underwent surgery for suspected pancreatic cancer. Helical CT scans were obtained in the vascular phase and a phase of maximal hepatic enhancement. CT angiograms were produced with multiprojection volume reconstruction and maximum-intensity projection. CT results were correlated with surgical and histopathologic results. RESULTS: Helical CT allowed detection of pancreatic cancer in 74 of 76 cases (97%). There were six false-positive results (positive predictive value, 92%). For prediction of irresectability, helical CT had an accuracy of 91%, negative predictive value of 79%, and sensitivity of 91%. Helical CT allowed detection of liver metastases in 21 of 28 cases (75%), nodal involvement in 13 of 24 cases (54%), and vascular invasion in 35 of 40 cases (88%). CT angiography demonstrated 30 of the 35 cases of vascular invasion detected with helical CT (86%). CONCLUSION: Use of dual-phase helical CT improves prediction of resectability in patients with pancreatic cancer. CT angiography cannot show all of the findings seen on helical scans.

Adenocarcinoma↗
PubMed1998

Teleradiology: results of a questionnaire of German radiologists.

A questionnaire was sent by mail to 4400 radiologists (i.e. to at least 1000 radiological institutions). The response rate was about 5%. The results showed that 47% of respondents felt well informed about teleradiology, 49% not enough and 3% not at all. Image and report transfer as well as interfaces to reference databases, educational applications, technical quality surveillance and product support (maintenance) were considered to be increasingly important areas. Smaller institutions (1-3 doctors) judged expert consultation as more important than bigger institutions. Standardization, system stability and data security were demanded as well as guidelines, for example concerning the linking of report and image, correct documentation and required image quality. Technically most demands can be fulfilled today but this technology is not yet commonly included in teleradiology systems.

Attitude of Health Personnel↗
PubMed1998

[Clinical use of a new analytical method for the determination of bone density by means of quantitative computer tomography].

AIM: Evaluation of the clinical suitability of a new analytical method for the determination of bone mineral density (BMD) by means of SEQCT as well as a comparison with the established method. METHODS: In order to verify the stability of both systems, phantom measurements were performed on a lumbal spine torso as well as on 78 patients. 44 patients were examined by means of the established method and 34 according to the new method. Parallel measurements were possible in 15 patients. RESULTS: The phantom measurements proved a high stability of both methods. Regarding the absolute BMD the new method resulted in higher BMD values. This result was confirmed by parallel measurements in 15 patients. The new method demonstrated increased suitability due to less time consuming preparations. Dose reduced scan parameters could not be achieved in all patients, so that the time saving effect could not be considered. In these cases manual settings were required. CONCLUSION: A substitution of the established method for BMD measurement by means of SEQCT with the new method seems to be possible. However, the results will have to be corrected by the percentage of deviation from the default value of the quality phantom.

Absorptiometry, Photon↗
PubMed1997

[Possible applications of the KAMEDIN teleradiology system with special reference to an economic analysis].

INTRODUCTION: Different concepts and applications of teleradiology systems have been realised. However, their cost-effectiveness is still questionable. Therefore, a cost-benefit analysis of three different scenarios of the new teleradiology system Kamedin (Kooperatives Arbeiten und rechnergestützte Medizinische Diagnostik auf innovativen Netzen der Deutschen Telekom) was performed. METHODS: CT examinations were transmitted from an Advantage Windows (GE) workstation to a Kamedin workstation using DICOM 3 protocol. Afterwards a teleconference was established with a Kamedin workstation in the intensive care unit within the hospital via FDDI/Ethernet, with an external workstation in a radiology department 6 km away via ISDN and with a Kamedin PC located with radiologist on duty 22 km away via ISDN. On average, 36 CT slices per patient were transferred. A break-even analysis was performed with respect to costs of hardware, software, support, use of ISDN and staff, as well as benefits like the decrease in transportation or film documentation costs. RESULTS: Owing to the different reductions in transportation costs, two applications (intensive care unit and external PC) showed a break-even of 1817 and 528 teleconferences/year, respectively. Further optimisation of cost-effectiveness is possible on condition that existing hardware can be used and an automatic data transfer without staff control is available. When all optimisation factors were combined, the break-even decreased to a minimum of 167 and 77 teleconferences/ year, respectively. CONCLUSION: Teleconferences with high image quality can be set up between workstations and PCs using the Kamedin system. Depending on the possible decrease in transportation costs, teleconferencing is cost-effective under certain conditions. Teleradiology has additional advantages, such as the acceleration and optimisation of patient management.

Computer Communication Networks↗
PubMed1997

Isolated oculomotor nerve paralysis in Lyme disease: MRI.

Lyme disease is a cause of illness involving multiple organ systems, including, in 10-15 % of cases, the nervous system. Peripheral radiculoneuritis, cranial neuritis, encephalitis and myelitis are among the neurological manifestations found in the second and third stages. We present the MRI findings in isolated oculomotor nerve involvement by Lyme disease and discuss the differential diagnosis.

Child↗
PubMed1997

Alcohol induces formation of morphine precursors in the striatum of rats.

Dopamine-derived alkaloids, the tetrahydroisoquinolines (TIQs), are suspected to play a role in the pathogenesis of alcoholism. The present study describes the alcohol induced formation of the S-enantiomer of Tetrahydropapaveroline and Norcoclaurine in the rat brain. These compounds are of special interest since both were found as being intermediates in the biosynthesis of morphine in the opium poppy. The concentration of both TIQs were determined in different brain regions of Wistar rats after 6 and 18 months alcohol consumption ad libitum. Gas chromatography/mass spectrometry was used for the detection and quantification of the enantiomers. Tetrahydropapaveroline and norcoclaurine were detected only in the striatum of those rats which had consumed alcohol for 18 month, neither in other brain regions nor in any brain regions of the controls or the short term (6 month) alcohol treated rats. These findings and the fact that those tetrahydroisoquinolines were only detected in the striatum of the alcohol fed rats and were present only as the S-enantiomers suggest that an alcohol induced biosynthetic pathway exists in the mammalian brain.

Alkaloids↗
PubMed1997

[Value of high-resolution CT of the lungs in acute pulmonary symptoms of patients with HIV infections].

PURPOSE: The purpose of this study was to assess the clinical value of HRCT of the lung in patients with known HIV-infection and acute lung disease. In a prospective study a HRCT was performed in 31 patients infected with the HIV-1 virus, mainly stage C (CDC), who had acute pulmonary symptoms. Precondition for the HRCT examination was a normal or non-specific chest radiograph. A provoked sputum as well as bronchoscopy with bronchoalveolar lavage and/or transbronchial biopsy were performed concurrently. In 24 out of 31 cases a pathogenic organism was identified. 19 of these 24 patients showed abnormal HRCT findings. The most frequent pathogenic organism was Pneumocystis carinii (n = 12). 9 out of these 12 patients (75%) showed pathological HRCT findings consisting of ground-glass opacity. Specific patterns of attenuation could not be worked out except for Pneumocystis carinii infection. Compared to bronchoalveolar lavage, the diagnostic value of HRCT is inferior; it is however helpful in the early stage of disease, when the pathogenic organism has not yet been identified, HRCT may demonstrate parenchymal abnormalities in patients with normal radiographic findings. Compared to bronchoalveolar lavage and induced sputum, HRCT can provide conclusive results within a short time.

AIDS-Related Opportunistic Infections↗