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Biomedical subjects

M Strotzer

Publications and source records attributed to M Strotzer.

At least 19 recordsLinked to original sources
PubMed2006

Should 3K zoom function be used for detection of pneumothorax in cesium iodide/amorphous silicon flat-panel detector radiographs presented on 1K-matrix soft copies?

The purpose of the study was to evaluate observer performance in the detection of pneumothorax with cesium iodide and amorphous silicon flat-panel detector radiography (CsI/a-Si FDR) presented as 1K and 3K soft-copy images. Forty patients with and 40 patients without pneumothorax diagnosed on previous and subsequent digital storage phosphor radiography (SPR, gold standard) had follow-up chest radiographs with CsI/a-Si FDR. Four observers confirmed or excluded the diagnosis of pneumothorax according to a five-point scale first on the 1K soft-copy image and then with help of 3K zoom function (1K monitor). Receiver operating characteristic (ROC) analysis was performed for each modality (1K and 3K). The area under the curve (AUC) values for each observer were 0.7815, 0.7779, 0.7946 and 0.7066 with 1K-matrix soft copies and 0.8123, 0.7997, 0.8078 and 0.7522 with 3K zoom. Overall detection of pneumothorax was better with 3K zoom. Differences between the two display methods were not statistically significant in 3 of 4 observers (p-values between 0.13 and 0.44; observer 4: p = 0.02). The detection of pneumothorax with 3K zoom is better than with 1K soft copy but not at a statistically significant level. Differences between both display methods may be subtle. Still, our results indicate that 3K zoom should be employed in clinical practice.

Adult↗
PubMed2006

[Diagnostic imaging of splenic disease].

Primary diseases of the spleen are relatively rare. More frequently, the spleen is involved secondarily in hematological, oncological, infectious, immunological, vascular, and other systemic diseases. The spleen is the most commonly injured organ in blunt abdominal trauma. Anatomical and physiological basics are explained, in addition to embryological facts with resulting abnormalities, such as accessory and "wandering" spleen, and polysplenia. The most frequent primary and secondary diseases of the spleen, including rare diagnoses, are presented and illustrated. Hemangioma represents the most common primary benign tumor, and lymphoma the most common primary malignant tumor of the spleen. Diagnostic imaging does not a allow safe differentiation between Hodgkin's and non-Hodgkin's lymphoma. One section deals with the clinical value and diagnostic workup of incidentally detected lesions. Simple cysts and calcifications need neither clarification nor a follow-up examination. Atypical cysts should be controlled within 3-6 months. Additional clarification using CT or MRT should be reserved for cases with a strong suspicion of clinically relevant primary or secondary splenic disease.

Diagnosis, Differential↗
PubMed2004

[Reimbursement of radiologically guided vascular interventions within the DRG-system: what will change?].

PURPOSE: To evaluate reimbursement within the DRG-system ("diagnosis-related groups") compared with traditional reimbursement for interventional therapy of hospitalized patients. MATERIALS AND METHODS: Reimbursement calculation was prospectively analyzed in two respects for 30 consecutive patients who underwent percutaneous transluminal angioplasty (PTA) of the lower extremity arteries: (1) based on the DRG-system; (2) based on the traditional system. Additional evaluation was performed for five further, typical vascular procedures on the basis of real documentation and calculation data (stenting of the carotid artery, fibrinolytic therapy of basilar artery occlusion, stenting of renal artery stenosis, angioplasty of hemodialysis-shunt stenosis and aspiration thrombectomy of an infrapopliteal arterial occlusion). RESULTS: In our hospital, the introduction of the DRG system would reduce reimbursement by approximately 1100 euro per PTA patient. However, the other vascular radiological procedures can be expected to increase the payments by up to 4500 euro. CONCLUSION: To minimize imminent reduction of reimbursement for patients with peripheral PTA, complete documentation and economical patient management is mandatory. Payment may increase significantly for patients with the other reported vascular interventional procedures.

Adult↗
PubMed2004

A patient with myelofibrosis complicated by refractory ascites and portal hypertension: to tips or not to tips? A case report with discussion of the mechanism of ascites formation.

In patients with myelofibrosis, clinically significant portal hypertension is known to be predominantly presinusoidal; however, the exact mechanisms are still controversial. The pathophysiology is particularly enigmatic in those patients without histological and angiographic evidence of significant intra- or extrahepatic obstruction to portal blood flow, respectively. Moreover, ascites formation has been reported in such cases, but in general is rare in presinusoidal portal hypertension. Here we present such a patient in which ascites developed even in the presence of unchanged serum protein levels (oncotic pressure) and was refractory to sodium restricted diet and high-dose diuretic treatment. A discussion on the parameters influencing fluid exchange and ascites formation particularly emphasizing the potential importance of the hyperdynamic circulation in this case is given. Finally, the patient was treated by implanting a transjugular intrahepatic shunt (TIPS), exerting a diuretic effect sufficient enough to avoid re-formation of ascites for several months. However, ascites re-accumulated potentially due to the appearance of ectopic peritoneal myeloid metaplasia and the patient died soon afterwards. In conclusion, TIPS may be considered as rescue management for refractory ascites secondary to portal hypertension, but caution in respect to the presence and/or development of peritoneal or other ectopic haematopoesis has to be taken.

Aged↗
PubMed2003

[Evaluation of radiological teaching programs in the Internet].

PURPOSE: Evaluation of web based training programs, which can be contacted from the homepages of radiological departments of German universities. MATERIAL AND METHOD: From June 2000 to January 2002 the 75 web based training programs of 57 providers,which can be contacted from the web pages of the radiological departments of German universities were evaluated in a prospective study. A medical student experienced in using the world wide web examined each training program three times in an interval of six months using the following criteria: availability of the web sites, target group, kind of training program, contents and structure and the technical solution. RESULTS: 51 of the 57 the homepages were fully available at each visit. 64 of the 75 web based training programs which could be connected from these sites were available at all three visits.One program was only partially available at one spot check. 8 of the 75 programs were designed for physicians and medically trained personal, 23 were made for medical students and 44 addressed both target groups (partially more than once mentioned). The number of the presented cases ranged between one single and 3700. In 31 of 75 training programs links to other teaching files were found. A complete presentation of cases was presented by 48 of the 75 web sites.5 of the 75 web sites offered physiological images for comparison. In 20 training programs the pathological changes were optically marked in the x-ray images. A logical and didactical structure was found in 24 teaching files, 14 gave the possibility to check the learning results. No provider made use of the possibility to pass credits to the students or physicians account with regard to official training programs. Multimedia techniques were used in 15 training programs.43 sites used data reduced preview images (thumbnails). The latest update of the site is mentioned in 55 of the 75 web sites. 19 of 57 providers had either no possibility of contact or did not answer to an e-mail. CONCLUSION: From the homepages of the departments of diagnostic radiology of German universities 75 teaching files can be contacted. There is a great variety in quantity and quality. Most sites offer collections of cases. A web based training program which is comparable in quality to a CD-ROM teaching program could not be found. No program used the possibility to give credits to the users with regard to official training programs.

Computer-Assisted Instruction↗
PubMed2003

Selective intraarterial fibrinolysis of acute central retinal artery occlusion.

PURPOSE: To evaluate the outcome of our patients with central retinal artery occlusion after local fibrinolysis and to compare these data with results reported in the literature. MATERIAL AND METHODS: Over a period of 7 years, 22 patients (11 male, 11 female, mean age 64.6 +/- 12.1 years) were treated with super-selective local fibrinolysis. In 1 case, treatment was carried out via the maxillary-ophthalmic anastomoses due to preexisting occlusion of the ipsilateral internal carotid artery. The latency period from the onset of symptoms to the beginning of therapy was 7.6 +/- 1.8 h. Urokinase was used in 7 cases (300,000-1.1 million units) and recombinant tissue plasminogen activator (20-40 mg) was applied in 15 patients. Visual acuity and fundus were examined before and after treatment. RESULTS: One patient (1/22 = 4.6%) recovered completely and regained a visual acuity of 20/20. Six patients (6/22 = 27.3%) showed a marked improvement with a range of visual outcome from 20/800 to 20/320. In 2 cases (2/22 = 9.1%) only a slight improvement was observed, with a visual outcome allowing detection of hand movements. In 13 cases (13/22 = 59.1%) no change in visual acuity as a result of treatment was observed. In 2/22 cases (9.2%) reversible neurological side-effects occurred, in 1 case suffered a stroke, and in another case intracerebral bleeding was observed. CONCLUSION: In our study, the recovery of visual acuity and the complication rate were not as positive as reported in the literature.

Acute Disease↗
PubMed2002

[Evaluation of the Internet presence of diagnostic radiology units at German universities].

PURPOSE: Analyzing the availability and the contents of the internet homepages of the radiological departments of German universities. MATERIAL AND METHOD: In June and July 2001 the internet homepages of 36 radiological departments of German universities were evaluated in a study. A medical student experienced in using the world wide web examined the websites concerning the following criteria: research, teaching, informations for patients, clinical topics and general information. Additionally an evaluation of the technical standard of the presentation was performed. RESULTS: 31 of the 36 radiological departments presented a homepage in the world wide web. The subject research was presented by 29 institutes. Also 29 departments provided information concerning teaching in their presentations. In 24 cases informations especially for patients were given. In all topics there is a huge variety of the quality and quantity of the provided information throughout the different institutions. 21 homepages available without restriction during the study period; 3 were nearly completely under construction. Multimedia techniques were only used in 2 homepages. The structural hierarchy of the webpages was in the average only two or three levels. Only 6 providers presented an additional version of their homepage in english. CONCLUSION: In the moment the possibility of internet-presentation is sub-optimal used by the responsible persons of the radiological institutions. The main emphasis is on research and teaching. There is nearly no use of multimedial elements in the presentations. Only a minority of the homepages can be read by international viewers because of the lack of an english version of the pages.

Germany↗
PubMed2002

Acute pneumatosis cystoides intestinalis following allogeneic transplantation -- the surgeon's dilemma.

Pneumatosis cystoides intestinalis (PCI) is still a poorly understood phenomenon, currently considered to result from primary mucosal insult from varying causes. We report a case of severe PCI in a patient with chronic GVHD after bone marrow transplantation (BMT) performed to treat secondary AML. Post BMT, the patient suffered acute intestinal and cutaneous GVHD, eventually developing intestinal and biopsy-proven cutaneous chronic GVHD, which necessitated continuous steroid therapy. Chronic pancreatitis associated with GVHD was diagnosed by explorative surgery in February 2000 on the basis of increasing epigastric discomfort, tumour marker (CA 125) increase and the CT finding of a suspicious mass in the pancreas. Readmission occurred in April 2000 for rapid onset of inferior abdominal pain with distinct peritoneal signs. Relaparotomy, deemed necessary on the grounds of both clinical and radiological findings, revealed marked PCI of the ascending and transverse colon and attached mesentery in an otherwise intact gastrointestinal tract. Post-operative reconvalescence was uneventful, with no clinical or radiological recurrence of PCI in the following 10 months. In the context of a review of the relevant literature, this case report illustrates the complex underlying pathophysiology, and difficulty in making a differential diagnosis and treating PCI.

Acute Disease↗
PubMed2002

[Thoracic computed tomography in intensive care patients - evaluation of clinical usefulness].

PURPOSE: Computed tomography of intensive care patients requires transportation of the patient to the radiology department. This study analyses, whether this consumption of resources is justified by therapeutical and diagnostic consequences derived from helical computertomography of the chest. METHODS: 558 CT studies of the chest were compared with current bedside chest radiographs. The additional information of CT scans and their consequences were evaluated retrospectively. RESULTS: 388 (69.5 %) of these computed tomographies provided additional information compared with projection radiographs. 374 therapeutical procedures resulted from 266 (68.6 %) out of these 388 CT examinations. These therapeutical interventions were significantly more invasive than those 144 procedures derived from 170 (30.5 %) CT studies which did not show any additional findings compared with bedside chest radiographs. CONCLUSION: In more than two thirds (69.5 %) additional diagnoses were found with computertomography. Nearly one half of the CT studies resulted in additional findings and therapeutical consequences. Invasive therapeutical consequences were based on CT studies significantly more frequently than on bedside chest radiographs.

Adolescent↗
PubMed2002

[Cost analysis of radiological interventional procedures and reimbursement within a clinic].

PURPOSE: Analysis of costs for vascular radiological interventions on a per patient basis and comparison with reimbursement based on GOA (Gebührenordnung für Arzte) and DKG-NT (Deutsche Krankenhausgesellschaft-Nebenkostentarif). MATERIAL AND METHODS: The ten procedures most frequently performed within 12 months were evaluated. Personnel costs were derived from precice costs per hour and estimated procedure time for each intervention. Costs for medical devices were included. Reimbursement based on GOA was calculated using the official conversion factor of 0.114 DM for each specific relative value unit and a multiplication factor of 1.0. The corresponding conversion factor for DKG-NT, determined by the DKG, was 0.168 DM. RESULTS: A total of 832 interventional procedures were included. Marked differences between calculated costs and reimbursement rates were found. Regarding the ten most frequently performed procedures, there was a deficit of 1.06 million DM according GOA data (factor 1.0) and 0.787 million DM according DKG-NT. The percentage of reimbursement was only 34.2 (GOA; factor 1.0) and 51.3 (DKG-NT), respectively. CONCLUSION: Reimbursement of radiological interventional procedures based on GOA and DKG-NT data is of limited value for economic controlling purposes within a hospital.

Angioplasty, Balloon↗
PubMed2002

[Contrast-enhanced MR angiography in the routine work-up of the lower extremity arteries].

PURPOSE: Prospective evaluation of the effectiveness of contrast-enhanced moving-table magnetic resonance angiography (CE-MRA) as the sole routine tool for the diagnosis of peripheral arterial occlusive disease and determination whether it can replace catheter arteriography. SUBJECTS AND METHODS: In a time period of 23 weeks, 100 consecutive patients were evaluated. A total of 112 contrast-enhanced moving-table MR angiograms were performed at 1.5 Tesla. A dedicated vascular coil system was used. It was evaluated in which cases MR angiography was sufficient to determine the treatment plan and in which cases limited quality required additional examinations. RESULTS: In 93.75 % (105/112) of all examinations, the treatment plan was determined by MRA as the sole diagnostic tool. Twenty-two patients underwent surgery or percutaneous angioplasty based on MRA findings. Additional examinations due to impaired quality were performed in seven (6.25 %) cases: two MR angiographies of the pelvic arteries, one MR angiography of the calf, and four selective arteriographies because of venous overlay at the calf. CONCLUSION: Contrast-enhanced MR angiography can take the place of catheter angiography in the routine work-up of patients with peripheral arterial occlusive disease. Further assessment might be necessary in five to ten percent of the cases when the diagnostic quality is inadequate, mostly due to venous overlay in the lower leg.

Adult↗
PubMed2002

[Percutaneous therapy of inoperable biliary stenoses and occlusions with a new self-expanding nitinol stent (SMART)].

OBJECTIVE: To evaluate the treatment of malignant biliary stenoses and occlusions using a new stent. METHODS: In a prospective study, 25 patients with malignant obstructive jaundice were treated with SMART(R) stents. The handling and the quality of stent expansion were documented. Stent function was assessed 2 - 4 days after intervention by cholangiography and laboratory tests. A follow-up was performed three months, after stent placement. RESULTS: All lesions were treated successfully, with a total of 35 stents implanted. In 14 patients a further balloon dilatation was performed after stent placement (8 - 10 mm diameter/ 40 - 80 mm length). The mean serum bilirubin level decreased significantly from 11.6 mg/dl to 4.6 mg/dl after intervention (p < 0.05). The follow-up showed a mean serum bilirubin level at 4.0 mg/dl. In 4 cases (16 %) a further intervention (PTCD or stent) was performed. Six patients died due to tumor progression. The stents proved to be patent in 79 % (n = 15) of patients alive at the time of follow-up. CONCLUSIONS: Placement of the SMART stent for the therapy of malignant biliary lesions yields good technical and clinical results.

Aged↗
PubMed2002

MR imaging of cranial nerve lesions using six different high-resolution T1- and T2(*)-weighted 3D and 2D sequences.

PURPOSE: To find a suitable high-resolution MR protocol for the visualization of lesions of all 12 cranial nerves. MATERIAL AND METHODS: Thirty-eight pathologically changed cranial nerves (17 patients) were studied with MR imaging at 1.5 T using 3D T2*-weighted CISS, T1-weighted 3D MP-RAGE (without and with i.v. contrast medium), T2-weighted 3D TSE, T2-weighted 2D TSE and T1-weighted fat saturation 2D TSE sequences. Visibility of the 38 lesions of the 12 cranial nerves in each sequence was evaluated by consensus of two radiologists using an evaluation scale from 1 (excellently visible) to 4 (not visible). RESULTS: The 3D CISS sequence provided the best resolution of the cranial nerves and their lesions when surrounded by CSF. In nerves which were not surrounded by CSF, the 2D T1-weighted contrast-enhanced fat suppression technique was the best sequence. CONCLUSIONS: A combination of 3D CISS, the 2D T1-weighted fat suppressed sequence and a 3D contrast-enhanced MP-RAGE proved to be the most useful sequence to visualize all lesions of the cranial nerves. For the determination of enhancement, an additional 3D MP-RAGE sequence without contrast medium is required. This sequence is also very sensitive for the detection of hemorrhage.

Contrast Media↗
PubMed2002

Evaluation of arterial bypass grafts of the pelvic and lower extremities with gadolinium-enhanced magnetic resonance angiography: comparison with digital subtraction angiography.

RATIONALE AND OBJECTIVES: The aim of this study was to compare contrast-enhanced magnetic resonance angiography (CE MRA) with digital subtraction angiography (DSA) in the assessment of patency and stenoses in bypass grafts. METHODS: Fifteen patients were examined with both CE MRA and DSA. Fifteen bypass grafts were evaluated by four readers for potential stenosis in five locations. The stenoses were classified in five types: 1 (0% to 24% stenosis), 2 (25% to 49%), 3 (50% to 74%), 4 (75% to 99%), and 5 (occlusion). RESULTS: Using both techniques, 70 of 75 evaluated locations (93.3%) were classified identically. This included six stenoses < 50% and six stenoses > 50%, respectively. Four of five overestimations of stenoses were scaled in DSA as stenoses type 1. One stenosis was categorized as type 3 in DSA. Sensitivity for CE MRA for detecting stenoses >or= 25% was 100% and the specificity 90%. Interobserver agreement for all evaluations was 0.77 (Spearman rank correlation test). CONCLUSION: In the assessment of low-grade stenosis in bypass grafts, CE MRA overestimates stenoses slightly but yields good results in comparison with DSA.

Angiography, Digital Subtraction↗