[Health economics evaluation of magnetic resonance imaging for the staging of prostate cancer for Austria and Germany]. / Gesundheitsökonomische Evaluation der Magnetresonanzbildgebung im Staging von Prostatakarzinomen für Österreich und Deutschland.

PURPOSE: The aim of this study was the health economics analysis of MR imaging in the preoperative staging of patients with prostate carcinoma (PCa). MATERIALS AND METHODS: The health economics analysis consisted of the following steps: modeling, determination of probabilities and parameters based on a detailed literature search, evaluation using the averages of the parameters, and sensitivity analyses of the results over the ranges of values. We performed a cost-utility analysis from health insurance's perspective for Austria and Germany. The population under investigation included patients with confirmed PCa. The alternative was a decision for therapy with or without staging using MR imaging. A localized PCa was treated by prostatectomy and locally advanced PCa by radiation/hormone therapy. The result parameters were quality adjusted life years (QALYs) and costs per patient. RESULTS: The evaluation showed that MR imaging is useful regarding costs and utilities prior to radical prostatectomy which is expensive and may be associated with serious clinical consequences. The costs per patient were lower by € 2635 and the utilities were higher by 0.099 QALYs. The strategy without MR imaging for staging was dominated by the strategy using MR imaging for staging in the evaluation using the base values and in almost all sensitivity analyses. CONCLUSION: For the parameters used and almost all scenarios of the sensitivity analysis, our decision-analytic model revealed a higher cost-utility ratio for the strategy using MR imaging for the staging of PCa.

[Health-economic evaluation of magnetic resonance imaging before biopsy for diagnosis of prostate cancer]. / Gesundheitsökonomische Evaluation einer Magnetresonanzbildgebung vor Biopsie zur Diagnose von Prostatakarzinomen.

PURPOSE: The aim of this study was the health-economic analysis of MR imaging in the diagnostics of suspicious prostate carcinoma (PCa) before execution of a first biopsy. MATERIALS AND METHODS: The health-economic analysis included four steps: modeling, determination of probabilities, evaluation, and sensitivity analyses. We performed an effectiveness analysis from the patient perspective as well as a cost-effectiveness and a cost-utility analysis from the health insurance perspective for Austria and Germany. The effectiveness and cost-effectiveness analysis used a hypothetical cohort of 100,000 patients. The result parameters were number of biopsies, number of detected PCa, and monetary costs. For the cost-efficiency analysis, the result parameters, quality-adjusted life years (QALYs) and costs, were calculated for an individual patient. RESULTS: The efficiency analysis showed that MRI before a first biopsy can prevent ca. 64,000 unnecessary biopsies/ 100,000 patients. The diagnostic efficiency was higher by a factor of 1.7. Due to MRI, eight PCas were additionally detected. From a health insurance perspective, MRI was not cost-effective. Extra costs of ca. 42 m. € per 100,000 patients and of 650 € per prevented biopsy were calculated. The costs per detected PCa were increased by 1395 €. The attainable QALYs were a little higher for the MRI alternative, which was therefore not dominated. CONCLUSION: Our results do not permit a clear recommendation for or against the application of MRI in the diagnostics of PCa. From the patient perspective, it is to be endorsed due to the higher medical efficiency. However, it is connected with higher health insurance costs.

[Dynamic evaluation of the effects of quality management]. / Dynamische Evaluierung der Effekte von Qualitätsmanagement.

PURPOSE: Evaluation of the effects of quality management over time at a radiology department. MATERIALS AND METHODS: Data concerning the performance of the department, entered on a monthly basis, will be compared with entries in the error report system on the basis of time series analysis (regression models taking seasons and auto-correlation effects into account). The observation period consists of 46 homogeneous monthly time pulses. RESULTS: Effects of the suggestions and the total number of reports in the quality assurance system on the performance of the department can be observed with a two-month delay. This association is statistically highly significant (p < 0.01) and, because of the procedures used, not attributable to general developmental trends, seasonal fluctuations or autoregressive processes. CONCLUSION: Evaluation of quality assurance measures is a well justified demand and should be based on the analysis of data collected from quality assurance systems operating on a continuous basis over a long period of time. The analysis of data from a radiology department shows that quality assurance is reflected in the performance of the department.

MR imaging-guided biopsy and therapeutic intervention in a closed-configuration magnet: single-center series of 361 punctures.

OBJECTIVE: The purpose of the study was to evaluate practical experience with interventional MR imaging in a closed-bore 1.5-T imaging system. A total of 361 MR-guided biopsies were performed in 250 patients and analyzed retrospectively. The technique comprised four steps: localization; planning; action (cutting or aspiration biopsy, or instillation of a therapeutic agent), with verification in two perpendicular planes; and obtaining control scans. CONCLUSION: The mean duration of a biopsy was 21 min; there were no major complications. Image contrast, signal, matrix options, and visibility of needle track and tip position permitted uncomplicated orientation. The interventional MR technique could be applied in any puncture setting.

rt-PA thrombolysis in acute thromboembolic upper-extremity arterial occlusion.

PURPOSE: Retrospective analysis of the results of rt-PA thrombolysis in the treatment of acute thromboembolic occlusion of the upper limb. METHODS: Of 55 patients with demonstrated acute embolic arterial occlusion, rt-PA thrombolysis was performed on 40 occlusions in 38 patients (23 women with a mean age of 62 years, range 32-85 years; 15 men with a mean age of 65 years, range 32-92 years) according to the following design: 6 mg rt-PA/hr for 30 min, 3 mg rt-PA/hr for the next 30 min, 1 mg rt-PA/hr for 7 hr, and 0.4 mg rt-PA/hr until the end of lysis. Onset of symptoms varied from 1 to 14 days. Included were three isolated upper-arm occlusions, nine combined brachial and forearm occlusions, and 28 forearm and hand artery occlusions. RESULTS: The overall success rate was 55%. The lysis results for isolated upper arm, combined brachial and forearm occlusions, and forearm and hand artery occlusions were 100%, 66%, and 46%, respectively. In eight patients surgical embolectomy had to be performed after failed thrombolysis. No amputation was required in the follow-up period. No lethal complications occurred. CONCLUSIONS: Interventional rt-PA treatment of proximal upper-extremity arterial occlusions may be performed with comparable success rates to surgical embolectomy and without severe complications. For distal occlusions the results are inferior to the success rates obtained with surgery.

Simple and effective technique of guided biopsy in a closed MRI system.

BACKGROUND: Magnetic resonance (MR)-guided biopsies are generally regarded as complex interventions. We implemented interventional MR (IMR) with the resources available in and for practical application in a large (1100 beds) central hospital. METHODS: This simple and straightforward IMR technique uses a step-by-step approach for localization, access route planning, biopsy, verification in at least two planes, and postoperative control. The technique has been used and evaluated unchanged for more than 400 punctures and interventions. RESULTS: Contrast, signal, matrix options, and visibility of needle track and tip permit uncomplicated orientation. The mean duration of a biopsy is 19 min. The technique can be applied to all radiologic puncture settings without any technical or medical complications. CONCLUSION: The crucial step in implementing IMR is not to contemplate its application but to simply start applying the procedure.

Anatomy of the orbital apex and cavernous sinus on high-resolution magnetic resonance images.

Diseases of the orbital apex and cavernous sinus usually present with involvement of multiple cranial nerves, corresponding to the complex anatomy of the region. In nontraumatic disorders, magnetic resonance imaging is the diagnostic modality of choice. However, its capabilities can be fully used only with thorough knowledge of the complicated topographic relationships in this region. This article describes the imaging anatomy of the cranio-orbital junction and adjacent subarachnoid spaces. High-resolution magnetic resonance images of normal subjects are presented, and the results are compared with findings reported in the literature. The following anatomic structures can be visualized on high-resolution magnetic resonance images: extraocular muscles and corresponding connective tissue, major orbital and cerebral arteries, ophthalmic veins, cavernous sinus, and all sensory and motor cranial nerves of the eye along their intraorbital and intracranial course.

[Simple and effective rt-PA thrombolysis design]. / Einfaches und effektives rt-PA Thrombolyse-Design.

PURPOSE: Assessment of a novel, simple and practical thrombolysis scheme for the purposes of a central hospital. MATERIALS AND METHODS: 314 thromboembolic lower extremity occlusions in 260 consecutive patients were treated by thrombolysis as follows: 6 ml rt-PA/h for 30 min; 3 ml rt-PA/h for another 30 min; 1 ml rt-PA/h for 7 hours, and 0.4 ml rt-PA until vessel patency. Antegrade introduction of a 5 F straight end-hole catheter through a 6 F, constantly heparin-flushed sheath, to the level of occlusion was followed by subsequent advancement of the catheter tip according to progress of lysis at time intervals of 2, 4, and 8 hours. The regimen was continued overnight. RESULTS: 82% of arterial occlusions were completely recanalized at the end of thrombolysis. Then, angioplasty was performed if appropriate. Best results (100% recanalization rate) were achieved by treating occlusions of the superficial femoral artery, even in cases of involvement of the entire length of the vessel, and isolated popliteal occlusions. A recanalization rate of 70% was achieved by treating distal crural vessel occlusion. Bypass grafts were recanalized in 50%. COMPLICATIONS: 3 x major hematoma, 2 x transluminal perforation; 16 x minor hematoma from the puncture site at the sheath, 4 x erythema, obviously reaction to rt-PA (together n = 25; 8%). CONCLUSIONS: We empirically found and solidly evaluated an effective thrombolysis scheme. Our results demonstrate that major advances are possible even in this well-grounded field.

High-resolution MR imaging anatomy of the orbit. Correlation with comparative cryosectional anatomy.

High resolution MR imaging of the orbit enables visualization of anatomic details in the orbit, including important blood vessels, muscles, nerves and connective tissue structures. The best resolution of anatomic details currently is obtained by using surface coils and T1-weighted spin echo sequences. Some examples of clinical applications demonstrate that a detailed knowledge of orbital imaging anatomy is a prerequisite for successful interpretation of clinical MR images. Additionally, this noninvasive diagnostic technique may be used for anatomical in vivo studies.

Malignant biliary obstruction: treatment with self-expandable stainless steel endoprosthesis.

Metal endoprostheses of the Wallstent type were successfully inserted percutaneously and endoscopically in 80 consecutive patients with malignant obstructive biliary stenoses, who were followed for up to 18 months. The indication for treatment was jaundice due to malignant biliary obstruction. Repeat radiological investigations were performed if the patient had symptoms suggesting stent occlusion. After stent implantation, 88% of patients demonstrated a serum bilirubin decrease by more than 50%. We observed a 15% rate of serious complications, including a 10% rate of cholangitis with septicemia. There were no cases of stent migration or occlusion due to encrustation of bile. Recurrent jaundice occurred in 17.5% of patients due to progressive tumor growth after 3-10 months. In 5 of these patients, tumor overgrowth was redilated and/or restented. Of the 80 patients, 34% are alive after 2-12 months (mean: 242 days); of these, two-thirds are free of jaundice. Sixty-six percent of patients died between 3 days and 1.5 years (mean: 133 days). Although autopsy investigations revealed the possibility of tumor growth onto the inner surface of the stent, through the mesh of the endoprosthesis, no stent occlusion by tumor ingrowth into the lumen occurred. Self-expandable stainless steel endoprostheses provide good palliation in patients with malignant obstructive jaundice.

Use of the Wallstent in the venous system including hemodialysis-related stenoses.

Eighteen patients with a total of 23 venous stenoses or occlusions were treated with the Wallstent. In 5 patients treated for malignant stenosis there was one primary failure due to insufficient stent expansion. The other 4 patients showed rapid relief of their inflow obstruction, all remaining asymptomatic despite later stent occlusion in 1 patient. Four patients were treated for benign postoperative stenoses of the iliac or femoral vein. All stents remained patent for a period of 6 weeks-58 months. Nine patients were treated for one or multiple stenoses along the venous outflow tract of hemodialysis fistulas. Of 14 lesions that were eventually stented, 12 are still patent after 3-27 months (mean 19). However, 10 secondary interventions (eight percutaneous transluminal angioplasty (PTA), two stents) and three additional stent procedures for new lesions were necessary. Although our experience is limited, we believe that patients with tumor compression or postoperative strictures of large veins benefit from treatment with stents. Stenting of venous outflow stenoses in hemodialysis fistulas can significantly prolong stent function, however, PTA should always be the first treatment of choice.

Historical overview on the development and characteristics of stents and future outlooks.

The history and development of endovascular stents is described beginning with the Maass double helix spiral prosthesis, the first stent used in human clinical trials in the early 80s. This is followed by a description of the three main groups of stent techniques: the shape memory alloy stents, the balloon-expandable stents, and the self-expanding stainless steel stents. Requirements and new trends for improving clinical results in the future complete this text.

Hemodialysis related venous stenoses: treatment with self-expanding endovascular prostheses.

Seven patients undergoing chronic hemodialysis presented a total of ten venous stenoses which were treated with self-expanding metallic vascular endoprostheses. Four lesions were central (brachiocephalic and subclavian vein). One acute occlusion could be successfully recanalized by PTA. Restenosis prompted seven secondary interventions. Four patients underwent a kidney transplantation between 5 and 8 months after vascular stenting. Definite occlusion occurred in one patient. According to our experience, stenting of large central veins in hemodialysis patients seems less prone to restenosis due to intimal hyperplasia. Despite a high restenosis rate in the peripheral lesions we believe that stenting is a useful tool in the treatment of hemodialysis-related venous stenosis, permitting a significant prolongation of shunt function.

Placement of venous stents: clinical experience with a self-expanding prosthesis.

A self-expanding vascular prosthesis was used to treat 20 venous stenoses or occlusions in 13 patients. The lesions were caused by tumor (n = 5), postoperative fibrous scars (n = 2), and chronic hemodialysis fistulas (n = 13). Follow-up ranged between 6 weeks and 53 months (mean follow-up, 14.9 months). Acute occlusion occurred in two stents, one within a tumor stenosis and one in a dialysis shunt after 3 days and 2 days, respectively. Balloon angioplasty, thrombolysis, and aspiration in the first case and balloon angioplasty and thrombolysis in the second case successfully restored patency. Definite occlusion occurred in these two patients after 8 weeks and 5 months, respectively. Ten secondary interventions were performed in three patients with 10 restenoses who had stenotic arm veins in chronic hemodialysis at presentation. Five of seven patients who received treatment for stenoses associated with hemodialysis underwent successful kidney transplantation 5-27 months after placement of vascular stents. Both patients who received treatment for benign strictures had patent stents at follow-up examinations performed at 45 and 53 months, respectively. Four of five stents placed for malignant stenoses were patent at venography (n = 3) or autopsy (n = 1).

Biliary obstruction: treatment with self-expanding metal prostheses.

The authors percutaneously and endoscopically inserted 58 Wallstent endoprostheses in 42 consecutive patients with benign and malignant obstructive biliary stenoses. The three patients with benign obstructive jaundice were followed up for 48 months. Two of the stents occluded due to sludge formation, prompting percutaneous reentry. The 39 patients with malignant disease were followed up for 18 months. Twenty-six of these patients died 3 days to 1.5 years (mean, 133 days) after the procedure. Thirteen are alive after 2-12 months (mean, 242 days). Recurrent jaundice occurred in 11 patients (28%): in four patients due to tumor growth over the proximal end of the stent, in one patient due to excessive gallbladder hydrops, and in six patients due to liver failure. Although autopsy investigations revealed the possibility of tumor growth onto the inner surface of the stent through the stainless steel mesh of the endoprosthesis, stent occlusion by tumor ingrowth into the lumen was not encountered.

CT-guided percutaneous drainage and fluid aspiration in intensive care patients.

Fifty-two intensive care unit (ICU) patients with clinical signs of sepsis who were considered to be at extremely high risk for operation were subjected to CT-guided interventions. Bedside ultrasound (US) had been performed prior to CT in all patients but diagnoses were equivocal or US-guided interventions had failed. Nineteen patients solely underwent CT-guided diagnostic aspiration of fluid collections to rule out infection. Eighteen patients (72%) with abscess formations after surgery or trauma were cured by catheter drainage alone; 4 patients required additional surgery. Out of 8 patients suffering from acute pancreatitis (after several necrosectomies), abscesses could be cured in 5 (62.5%). Three patients with acute necrotizing pancreatitis (no surgery) were not cured by the interventional procedure and all required surgical debridement. Even patients who required additional surgery after drainage improved clinically after the interventional radiologic procedure. Our overall success rate was 64%, emphasizing the need for CT in the case of equivocal US results or if US-guided procedures have failed in ICU patients with signs of sepsis.

Arterial stent placement with use of the Wallstent: midterm results of clinical experience.

Self-expandable stents of the Wallstent type were used in 26 iliac and 15 femoropopliteal artery lesions of 31 patients to treat stenoses or occlusions. The indications were confined to complex lesions, including residual stenoses and dissections after percutaneous procedures or previous surgery in the iliac artery lesions, and long-segment (mean, 13.5 cm) occlusions with inadequate response to percutaneous recanalization in the femoropopliteal artery lesions. In the iliac artery group, after stent placement, 96% of the lesions were patent at a mean follow-up of 16 months (range, 6-30 months). In the femoropopliteal artery group, of 11 patients available for follow-up, only six had patent stents at 7-26 months (mean, 20 months). Four of these six patients required one to three secondary interventions. Self-expanding endoprostheses are of great value in complex iliac artery lesions where simple balloon dilation is insufficient. Stent placement for long femoral artery lesions should be performed with utmost reserve, and the extent of stent placement should be as short as possible.

[The value of mammography in patients up to the age of 35]. / Stellenwert der Mammographie bei Patientinnen bis zum 35. Lebensjahr.

The use of mammography in young women is under debate. In this prospective study of 220 women aged up to 35 years, the indications for mammography were compared with the final diagnosis. In this way, an attempt was made to define the signs and symptoms that justify mammography in this age group. The results show that mammography is indicated only in the presence of palpable lumps. All other signs or symptoms should not be investigated by means of ionising radiation in this particular age bracket.