Biomedical subjects

K J Klose

Publications and source records attributed to K J Klose.

At least 19 recordsLinked to original sources

PubMed2006

[Orthorad--the online reference database of skeletal plain film radiography].

PURPOSE: It is evident that there is a growing need for Internet-based reference databases for reasons of practicability and due to the increasing use of reporting on digital workstations. The main advantages of online databases are expected with respect to plain film radiography and cross-sectional imaging. A reference database of skeletal plain film radiography was to be created using the Orthorad program. MATERIALS AND METHODS: The most important standard settings and special images of young and healthy adults in plain film radiography were collected over one year. All samples were approved for the Orthorad database by a board qualified radiologist. Based on the workflows of radiographers and radiologists, the records were organized by body part ( http://www.idr.med.uni-erlangen.de/orthorad/orthorad.htm ). This logical data structure will ensure that the tool serves as a source of information in two ways: On the one hand, the radiographer can access information on positioning, tube voltage and cassette format. On the other hand, the radiologist receives important knowledge regarding X-ray anatomy, reference data regarding the human skeleton, and information about the correct reporting for an image. RESULTS AND CONCLUSION: Orthorad is used as an online reference database for traumatologic plain film radiography to support radiographers and radiologists in their daily working routines. To date, user feedback has been positive.

Adult↗

PubMed2005

[KIS-RIS-PACS integration: the Marburg approach].

When describing the development of data processing at the Department of Radiology at the Philipps University of Marburg, three phases can be identified covering the areas of patient care, education, and research as well as administrative and organizational aspects. The first phase (1987-1995) was centered on radiology and characterized by the early implementation of the radiology information system (RIS) and installation of a picture archiving and communication system (PACS). The experiences gained during this phase led to intensive discussion on application-oriented information processing. The second phase (1996-2000) describes the changes in the general framework brought by Internet technology and international standards. The course was set for the future of data processing in the hospital setting. The phase ended with implementation of a clinical workplace system (KAS) as the basis for a comprehensive electronic patient record and the switch in radiology to an integrated RIS solution. The third phase (2001-2006) addressed further implementation and development of clinical data management in which both regular documentation of patient data and information processing not related to patients are optimized by making use of Intranet/Internet technology. It includes the hospital wide implementation of PACS and the forthcoming phase of information processing increasingly shaped by workflow and decision support.

Database Management Systems↗

PubMed2004

Integrated outcome assessment after anterior cervical discectomy and fusion: myelocompression but not adjacent instability affect patient-reported quality of life and cervical spine symptoms.

STUDY DESIGN: The authors conducted a cross-sectional study. OBJECTIVE: Integrated assessment of adjacent instability (AI), myelocompression (MC), magnetic resonance imaging (MRI) signs of myelopathy (MRISM), physician-assessed clinical signs and symptoms, including clinical signs of myelopathy (CSM), patients' self-reported symptoms and quality of life after anterior cervical discectomy and fusion (ACDF). MATERIALS AND METHODS: Fifty-four patients who had ACDF between 1986 and 1995 received MRI scans, conventional and flexion/extension radiographs to assess myelocompression, MRISM, fusion, and AI. Clinical outcome was assessed using signs and symptoms based on selected items of Odom's criteria, Oswestry low back pain disability questionnaire, and the neck disability index. Patients reported their quality of life (QL) on a standardized instrument (Profiles of QL of Chronically Ill [PLC]) and by a specific validated Cervical Spine Symptom Scale (CSSS). RESULTS: Myelocompression was found more frequently than expected (24%). MRISM were seen in 2 patients (4%). One of the 2 patients developed CSM. Fusion was achieved in 94% (with kyphosis in 17%). AI was found in 30%. However, only myelocompression but not AI was associated with statistically significant decreases in most QL scores (i.e., everyday capabilities, positive mood) and high cervical spine symptom burden (all P's < 0.05). CONCLUSIONS: The study results underline the need for a better understanding of the biomechanical changes in the adjacent unfused segments. Consensus is needed on postoperative follow-up guidelines, including pain management strategies. Future studies on the outcome of ACDF will profit from an integrated outcome approach, including assessments based on imaging, physicians, and patients.

Adult↗

PubMed2004

The effect of Palamed G bone cement on early migration of tibial components in total knee arthroplasty.

OBJECTIVE: Migration of the tibial component in total knee arthroplasty (TKA) is subject of many studies using roentgen stereophotogrammetric analysis (RSA). In previous studies of cemented and uncemented tibial components, high migration values were found. Improvements in cementing technique, prosthetic design and pre-coating techniques reduced these values as shown in more recent studies. MATERIAL AND SUBJECTS: A total of 35 patients were initially included in the study and operated on between 12/1999 and 10/2000. All patients received a NexGen TKA cemented into the proximal tibia using Palamed G bone cement. The implants and the tibial metaphysis were marked with standard tantalum markers. Radiostereometric analysis was performed post-operatively and after 3, 6 and 12 months using a standard digital radiostereometric analysis. Functional parameters were assessed using the Knee Society Score (KSS) clinical rating system. RESULTS: There were no complications and failures within the first year. After 1 year radiostereometric measurements of the translational parameters along and the rotational parameters around the x-, y- and z-axis revealed: X-Trans -0.19 mm, Y-Trans +0.02 mm, Z-Trans +0.08 mm, X-Rot +0.26 degrees, Y-Rot -0.35 degrees, Z-Rot +0.09 degrees. The maximum total point motion was +0.96 mm and the mean maximum subsidence was -0.23 mm. Except for anterior-posterior, medio-lateral stability and extension leg all endpoints of the KSS clinical rating system showed a significant improvement. CONCLUSIONS: After 12 months, the use of Palamed G bone cement in total knee arthroplasty was demonstrated to be safe. Both the clinical and radiostereometric results were good and comparable to the results reported in other RSA studies in cemented total knee arthroplasty.

Aged↗

PubMed2004

Analysis of mice tumor models using dynamic MRI data and a dedicated software platform*.

PURPOSE: To implement a software platform (DynaVision) dedicated to analyze data from functional imaging of tumors with different mathematical approaches, and to test the software platform in pancreatic carcinoma xenografts in mice with severe combined immunodeficiency disease (SCID). MATERIALS AND METHODS: A software program was developed for extraction and visualization of tissue perfusion parameters from dynamic contrast-enhanced images. This includes regional parameter calculation from enhancement curves, parametric images (e. g., blood flow), animation, 3D visualization, two-compartment modeling, a mode for comparing different datasets (e. g., therapy monitoring), and motion correction. We analyzed xenograft tumors from two pancreatic carcinoma cell lines (BxPC3 and ASPC1) implanted in 14 SCID mice after injection of Gd-DTPA into the tail vein. These data were correlated with histopathological findings. RESULTS: Image analysis was completed in approximately 15 minutes per data set. The possibility of drawing and editing ROIs within the whole data set makes it easy to obtain quantitative data from the intensity-time curves. In one animal, motion artifacts reduced the image quality to a greater extent but data analysis was still possible after motion correction. Dynamic MRI of mice tumor models revealed a highly heterogeneous distribution of the contrast-enhancement curves and derived parameters, which correlated with differences in histopathology. ASPC1 tumors showed a more hypervascular type of curves with faster and higher signal enhancement rate (wash-in) and a faster signal decrease (wash-out). BXPC3 tumors showed a more hypovascular type with slower wash-in and wash-out. This correlated with the biological properties of the tumors. CONCLUSION: With the described software, it was possible to analyze tissue perfusion parameters in small xenograft tumor models in mice. Our data correlated with histopathological data, and the qualitative and quantitative perfusion parameters could distinguish two tumor entities with different growth characteristics.

Animals↗

PubMed2004

[Embolization of pulmonary arteriovenous malformations with electrolytically detachable coils in patients with hereditary hemorrhagic telangiectasia].

BACKGROUND: Pulmonary arteriovenous malformations (PAVM) can be found in approximately 20 % to 35 % of patients with hereditary hemorrhagic telangiectasia (HHT). PAVM should be treated since they are a source of paradoxical embolization, potentially resulting in severe neurologic complications. The treatment of choice is the endovascular embolization with coils. PATIENTS AND METHODS: Seven patients with HHT underwent superselective embolization of PAVM detected during screening for PAVM. Four patients had a single PAVM and one patient 3, 4 and 5 PAVMs, respectively. Electrolytically detachable coils were used for embolization. In addition, coils with synthetic fibers were used during 6 embolizations for completion of embolization. RESULTS: Embolization was technically successful in all patients. Complete primary occlusion was achieved in all PAVM. No coil migration or occlusion of unaffected pulmonary arteries was observed. After embolization, one patient developed a small pleural effusion, which was treated symptomatically. CONCLUSION: As a minimally invasive procedure, superselective embolization is the treatment of choice in treating PAVM in patients with HHT. With the use of electrolytically detachable coils, the ideal coil size can be chosen and exact placement achieved without the risk of coil migration or occlusion of unaffected pulmonary arteries.

Adolescent↗

PubMed2003

Transarterial chemoembolization of advanced liver metastases of neuroendocrine tumors--a retrospective single-center analysis.

BACKGROUND: In neuroendocrine tumors, metastases are a negative prognostic factor for survival and quality of life. Transcatheter arterial chemoembolization (TACE) is thought to be an effective symptomatic and antiproliferative treatment in patients with otherwise progressive disease. METHODS: 62 chemoembolization procedures in 26 patients with progressive neuroendocrine tumors were reviewed. The underlying disease was carcinoid syndrome in 10, non-functional midgut tumor in 2, non-functional pancreatic tumor in 7, malignant insulinoma in 2 patients, non-functional tumor of the stomach in 1 and of unknown origin in 4 patients. Tumor burden of the liver was <25% in 3, 25-50% in 11, 50-75% in 6 and >75% in 6 patients. RESULTS: TACE was technically successful in 57 cases. Four patients developed minor and 5 major complications. The 30-day mortality rate was 7.7%. According to WHO criteria, 14 patients had no change in tumor burden, 2 had regression and 5 progress after chemoembolization. Patients with a tumor burden >75% of the liver did not benefit from TACE due to the development of major complications, whereas patients with low (<50%) tumor burden and high (>50%) lipiodol uptake showed a trend towards longer survival. Five-year survival time after diagnosis was 48%. Patients treated with octreotide and/or alpha-interferon had no benefit from chemoembolization with regard to their carcinoid syndrome. CONCLUSIONS: In this retrospective study, patients with low (<50%) tumor burden and high (>50%) lipiodol uptake responded better to TACE than end-stage patients.

Adult↗

PubMed2003

[From clinical guidelines to clinical pathways: development of a management-oriented algorithm for the treatment of polytraumatized patients in the acute period].

INTRODUCTION: The treatment of polytraumatized patients in the acute period is an exemplary model of multidisciplinary cooperation in a very critical timeframe. Implementing standards formulated in the clinical guidelines of the German Association of Traumatology requires a detailed description of "how to do it." METHODS: Based on the guidelines and validated quality indictors, the optimal standard of care as the goal was defined. A clinical algorithm was developed and personal responsibilities and time limits were clearly assigned to each decision step and action. Checklists, documentation charts, and a full text supplement the algorithm. The complete pathway was adopted by representatives of all occupational groups involved in early trauma care in a consensus process. RESULTS: Improvement potentials were identified in those areas for which the guidelines did not provide explicit recommendations. These represent the key elements of the algorithm. Pathway-specific review criteria (quality indicators) were defined for scheduled reevaluation. CONCLUSIONS: Implementing clinical guidelines at the local level requires a problem-oriented and management-oriented elaboration towards a clinical pathway as the basis for a quantitative process and cost analysis.

Algorithms↗

PubMed2003

[What effect does the hydroxyapatite coating have in cementless knee arthroplasty?].

The goal of this study was to compare the migration of noncemented diffusion sintered titanium fibermesh-coated tibial components with (HA group) and without (non-HA group) additional hydroxyapatite coating. For this purpose digital radiostereometry (DIRSA) was used to compare the migration after 2 and 9 years for the two groups. After 2 years the mean maximum subsidence of the HA-coated components (0.24+/-0.18 mm) was about one-half of the mean maximum subsidence of the non-HA-coated group (0.55+/-0.55 mm). After 9 years the maximum subsidence of the HA-coated components was still smaller, but not as pronounced as before. The same trend was also found for the endpoint maximum total point motion (MTPM). After 2 years the mean MTPM of the HA-coated components was 0.66+/-0.38 mm and of the non-HA group 0.73+/-0.50 mm. After 9 years the mean MTPM for the HA-coated components was 0.54+/-0.15 mm and for the non-HA-coated components 0.74+/-0.20 mm. None of the HA-coated tibial components but one of the non-HA group had to be revised and exchanged due to aseptic loosening.

Aged↗

PubMed2003

[Treatment of malignant biliary occlusion by means of transhepatic percutaneous biliary drainage with insertion of metal stents--results of an 8-year follow-up and analysis of the prognostic parameters].

PURPOSE: To analyze outcome and predictive factors for patient survival and patency rates of unresectable malignant biliary obstruction treated with percutaneous transhepatic insertion of metal stents. MATERIALS AND METHODS: This is a retroslective analysis of 130 patients treated in one interventional radiological center with data collected from patient records and by telephone interviews. The procedure-related data had been prospectively documented in a computer data base. The Kaplan-Meier analysis was performed for univariate and multivariate comparison of survival and patency rates with the log-rank test used for different tumor types. Predictive factors for survival and 30-day mortality were analyzed by a stepwise logistic regression. RESULTS: Underlying causes of malignant biliary obstructions were cholangiocarcinoma in 50, pancreatic carcinoma in 29, liver metastases in 27, gallbladder carcinoma in 20, and other tumors in 4 patients. The technical success rate was 99 %, the complication rate 27 % and the 30-day mortality 11 %. Primary patency rates (406 days with a median of 207 days) did not differ significantly for different tumor types. The survival rates were significantly (p = 0.03 by log-rank test) better for patients with cholangiocarcinoma than for patients with pancreatic carcinoma and liver metastases. Multiple regression analysis revealed no predictive factor for patient survival and 30-day mortality. CONCLUSION: Percutaneous transhepatic insertion of metal biliary endoprostheses offers a good initial and long-term relief of jaundice caused by malignant biliary obstruction. Although survival rates for patients with cholangiocarcinoma are better than for other causes of malignant biliary obstruction, a clear predictive factor is lacking for patients undergoing palliative biliary stent insertion.

Adult↗

PubMed2003

[Virtual organization in the digital age of radiology - principle and solution for radiologic research?].

The research project "VICORA - Virtual Institute for Computer-Assisted Radiology", funded by the German Federal Ministry of Education and Research, was initiated in the year 2000. Its virtual organization brings together physical science, engineering, information technology, clinical radiology and the medical technology industry. In the German radiology research domain VICORA serves as a model for interdisciplinary collaboration for the changing radiology paradigm illustrated by a "radiologycube". The project does not only aim at scientific goals but also considers the infrastructure, components and human resource management within a virtual organization. The common rapid prototyping platform ILAB 4 ensures user-friendly and time-efficient software that assists with the routine radiology work-flow including full DICOM functionality. By offering a new work environment and collaborative culture based on telematics and knowledge exchange in radiology research, VICORA overcomes limitations of traditional research organization.

Diagnosis, Computer-Assisted↗

PubMed2002

["Activity based costing" in radiology].

BACKGROUND: The introduction of diagnosis related groups for reimbursement of hospital services in Germany (g-drg) demands for a reconsideration of utilization of radiological products and costs related to them. METHODS: Traditional cost accounting as approach to internal, department related budgets are compared with the accounting method of activity based costing (ABC). The steps, which are necessary to implement ABC in radiology are developed. CONCLUSIONS: The introduction of a process-oriented cost analysis is feasible for radiology departments. ABC plays a central role in the set-up of decentralized controlling functions within this institutions. The implementation seems to be a strategic challenge for department managers to get more appropriate data for adequate enterprise decisions. The necessary steps of process analysis can be used for other purposes (Certification, digital migration) as well.

Budgets↗

PubMed2002

Magnetic resonance hydrometry: non-invasive quantification of the exocrine pancreatic function.

AIMS: To show the ability of magnetic resonance hydrometry (MRH) to quantify the pancreatic secretion after secretin stimulation in order to distinguish between physiological excretion and reduced output in chronic pancreatitis. METHODS: MRH images were acquired in a 1.0-T-clinical scanner using a body-array coil and a heavily T2-weighted standard single-shot TSE sequence. Thirty-one patients (14 male/17 female) who routinely underwent ERCP for suspected choledocholithiasis (n = 22), recurring abdominal pain (n = 1), icterus (n = 6 and suspected pancreatitis (n = 2) were included. During the investigation 1 CU/kg BW secretin were administered intravenously. Secreted volume of fluid, start of secretion, achievement of a plateau of secretion and a combined score of these parameters (MRH score) were assessed and evaluated. Sensitivity and specificity were calculated for these parameters. RESULTS: 27 patients had no pancreatic pathology, and four suffered from chronic pancreatitis. Patients without pancreatic disorders produced a mean pancreatic fluid volume of 183 plus minus 86 mL, whereas patients with chronic pancreatitis secreted 61 +/- 39 mL. Secretion started after a mean time of 95 +/- 94 seconds (no pancreatic impairment) and 62 +/- 13 seconds (chronic pancreatitis). The MRH score achieved a high accuracy in the detection of chronic pancreatitis. CONCLUSIONS: Our study demonstrated the feasibility of measuring pancreatic output by MRH after stimulation with secretin. Moreover, a distinction between normal secretion and patients with chronic pancreatitis is possible.

Adult↗

PubMed2002

[Secretin-stimulated MR cholangiopancreatography (MRCP): visualization of the normal pancreatic duct in comparison with ERCP].

PURPOSE: To determine whether the application of secretin improves the depiction of the normal pancreatic duct and to document the time course of any possible improved visualisation. PATIENTS AND METHODS: Twenty-eight patients with a normal pancreatic ductal system, proved by ERCP, were prospectively enrolled in our study. MRCP was carried out in a 1.0 Tesla unit using a thick slab single-shot turbo-echo sequence (TR: infinity, TE: 1100 ms, FA: 150 degrees, slab thickness: 65 mm). Following acquisition of a non-enhanced image, 1 clinical unit/kg bodyweight of secretin was injected intravenously. During the subsequent ten minutes the MR measurement was repeated every 30 seconds. The images were independently evaluated by two investigators. RESULTS: The improvement in quality after administration of secretin was statistically significant for both investigators (p < 0.05), but no significant difference was found between both investigators concerning the quality of the images (p = 0.49). Prior to the secretin application, the entire ductal system only be evaluated in ten cases (35.7 %) by both investigators, afterwards in 26 cases (92.9 %). Improvement was achieved after a mean time of 1.5 minutes and lasted until the ninth minute. CONCLUSION: Intravenous application of secretin improves image quality of MRCP also in patients with no pancreatic pathology. Improvement begins after 1.5 minutes and lasts for about seven minutes.

Adult↗

PubMed2001

Feasibility of MRI in the diagnosis of acute diverticulitis: initial results.

PURPOSE: The purpose of this study was to evaluate MRI as a diagnostic tool in patients with suspected acute sigmoid diverticulitis. Furthermore, we sought to develop an optimal imaging protocol in these patients. PATIENTS AND METHODS: Eleven patients with suspected acute diverticulitis were included in the study. All patients were imaged in a 1.0 T clinical scanner using a body-array coil. Imaging sequences were single-shot TSE, HASTE-, STIR- and TrueFisp- sequence. All were obtained in the frontal plane. The diagnosis was verified by a single experienced investigator, using ultrasound, and overall clinicopathological outcome. RESULTS: MRI enabled visualization of signs of an acute diverticulitis in all patients. However, the diagnosis of acute diverticulitis was obtained in 10 patients only. The mean imaging time was 17.5+/-5.5 min. STIR- and TrueFisp-sequences alone displayed all findings, e.g pericolonic exsudation, edema and segmental narrowing, whereas SSTSE and HASTE-sequences showed no additional information. Therefore, it appeared that the imaging protocol could be restricted to STIR- and TrueFisp-sequences. CONCLUSION: MRI is feasible as a fast, accurate and investigator-independent diagnostic tool in patients with suspected acute diverticulitis. To prove its value in comparison to computed tomography or ultrasound, further studies are needed.

Acute Disease↗

PubMed2001

Granulocyte-colony stimulating factor in the prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). Protocol of a controlled clinical trial developed by consensus of an international study group. Part three: individual patient, complication algorithm and quality manage.

GENERAL DESIGN: Presentation of a new type of a study protocol for evaluation of the effectiveness of an immune modifier (rhG-CSF, filgrastim): prevention of postoperative infectious complications and of sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). A randomised, placebo controlled, double-blinded, single-centre study is performed at an University Hospital (n = 40 patients for each group). This part presents the course of the individual patient and a complication algorithm for the management of anastomotic leakage and quality management. OBJECTIVE: In part three of the protocol, the three major sections include: The course of the individual patient using a comprehensive graphic display, including the perioperative period, hospital stay and post discharge outcome. A center based clinical practice guideline for the management of the most important postoperative complication--anastomotic leakage--including evidence based support for each step of the algorithm. Data management, ethics and organisational structure. CONCLUSIONS: Future studies with immune modifiers will also fail if not better structured (reduction of variance) to achieve uniform patient management in a complex clinical scenario. This new type of a single-centre trial aims to reduce the gap between animal experiments and clinical trials or--if it fails--at least demonstrates new ways for explaining the failures.

Algorithms↗

PubMed2001

Measurement of torsion angles of long finger bones using computed tomography.

OBJECTIVE: Rotational dislocation at the fracture site is a complication of long finger bone fractures of the metacarpals and phalanges. To evaluate such deformities, we performed CT of the articular surfaces of these bones to demonstrate the torsion angles. DESIGN: We evaluated 10 pairs of cadaver hands. These were placed flat, with the bones of interest perpendicular to the gantry to acquire axial images. The torsion of the long bone axes was defined as the angle between a tangent positioned parallel to the proximal articular surface and a tangent parallel to the distal articular surface of individual bones. RESULTS: The maximum difference between repeated measurements was 4 degrees. Intraobserver differences measured between right and left hands are less than 3 degrees. CONCLUSION: Side differences in torsion angles exceeding 3 degrees are strongly suspicious of a malrotation after fracture. These measurements might help to plan derotational osteotomy and assess the results of therapy.

Cadaver↗

PubMed2001

Standardisation of imaging in neuroendocrine tumours: results of a European delphi process.

In 1998 and 1999, a delphi consensus procedure was performed to establish guidelines for standardised diagnostic imaging of neuroendocrine tumours. The procedure included four consecutive workshops of a European group of experts in neuroendocrine tumours as well as feedback given by specialists from the departments of radiology, nuclear medicine, surgery and internal medicine of the according home institutions. Diverging approaches among the centres, which became apparent during the discussion, reflect a lack of controlled studies specifically for rare subgroups of neuroendocrine tumours. This paper summarises the standards for diagnostic imaging as developed during the delphi process. In particular, the diagnostic workflows as well as the technical properties of different imaging modalities are described in detail.

Delphi Technique↗