[MR-colonography in hospitalized patients: feasibility and sensitivity]. / MR-Kolonografie bei stationären Patienten: Durchführbarkeit und Sensitivität.

INTRODUCTION: Besides conventional colonoscopy, CT and MR colonography offer alternate virtual imaging modalities of the colon. The sensitivity of CT colonography, which is associated with radiation exposure, has been published in prior, large studies. Regarding MR colonography, in particular dark lumen MR colonography with the rectal administration of a water enema as a contrast agent, only limited published data exist. The goal of this study was to compare MR colonography with conventional colonoscopy in the detection of colorectal polyps. In addition the feasibility and image quality in unselected hospitalised patients were assessed. PATIENTS/METHODS: Included were 103 hospitalised patients who had to undergo colonoscopy for various indications. Immediately prior to conventional colonoscopy, MR colonography with rectal water enema and additional intravenous administration of contrast material was performed. Detection rates for polyps and adenomas were documented with both imaging modalities. Image quality and completion rates (practicability) and other (incidental) findings were also recorded. RESULTS: In 15 of 103 patients the MR examination could not be done or was only partially completed. The detection rate of MR colonography for polyps (adenomas) was 2% (4%) for polyps (adenomas) up to 5 mm in diameter, 38% (56%) for polyps (adenomas) 6-10 mm in diameter and 89% (89%) for polyps (adenomas) up to 11 mm in diameter. One flat carcinoma seen with conventional coloscopy was missed on MR colonography. CONCLUSIONS: MR colonography offers the possibility of imaging the colon without exposure to radiation. Polyps and adenomas are detected, similar to the detection rate of CT colonography, with adequate sensitivity only if they are larger than 10 mm in diameter. Therefore this imaging technique is not (yet) suitable as a screening test. Additional limitations are the necessary cooperation of the patient which can reduce the practicability and image quality in selected patients. Further studies like the just started German multicentre trial are needed to assess the position of MR colonography.

Noninvasive follow-up of GDC-treated saccular aneurysms by MR angiography.

The aim of this study was to determine sensitivity and specificity of magnetic resonance angiography (MRA) for the assessment of durable occlusion of intracranial aneurysms with Guglielmi detachable coils (GDC) and to point out the influence of MRA results in re-intervention strategies. Forty-five patients with 54 aneurysms that were previously treated by endovascular occlusion with GDC were selected for this study. All patients underwent digital subtraction angiography (DSA) and MRA examinations on the same day. The time-of-flight MRA studies were performed on a 1-T scanner. The MRA images were first read by radiologists who were not aware of the DSA results. In a second consensus reading by the neuroradiologists who had performed all interventional procedures of this series, the decision was made as to whether re-treatment was necessary. The distribution of aneurysm sizes, configurations and treatment results were sufficient for an unbiased evaluation. The first blinded evaluation revealed a sensitivity of 71% and a specificity of 95% for MRA assessment of aneurysm reperfusion. In the second consensus reading, the sensitivity increased to 92% and the specificity was 98%. The blinded reading indicates that MRA is a useful adjunct to DSA for the assessment of durable results after endovascular treatment of intracranial aneurysms. In the consensus reading it became obvious that sensitivity and specificity of MRA can be increased to 92 and 98%, respectively, if the results were evaluated by experienced neuroradiologists, including prior knowledge of all other examinations. We have already increased the follow-up intervals for DSA and use MRA intermittently, based on these results.

The cost of treatment of Alzheimer's disease in The Netherlands: a regression-based simulation model.

OBJECTIVE: To examine the potential economic impact of treatment of Alzheimer's disease. DESIGN: Regression-based simulation estimation of the long term costs of Alzheimer's disease under a number of treatment scenarios. Data from an epidemiological study conducted in Rotterdam, The Netherlands, was used to simulate disease progression. Comparison of the costs and effectiveness experienced by the patients were used to measure the impact of treatment. PATIENTS AND INTERVENTION: 2 theoretical cohorts of patients with Alzheimer's disease, one of which receives standard treatment, while the other receives a treatment which slows cognitive decline as measured by the Mini-Mental State Examination (MMSE). MAIN OUTCOME MEASURES AND RESULTS: Under one of the scenarios examined, the baseline cost of Alzheimer's disease was 97,866 euro (EUR; 1996 values) per patient over 10 years' follow-up; the cost was almost EUR100,000 under all scenarios. Life expectancy following onset was about 4.5 years and MMSE decline was approximately 2 points per year for a typical prevalent (existing) patient and almost twice as much for incident (newly diagnosed) patients (1.82 vs 3.42 points per year, respectively). Slowing the rate of cognitive decline results in a slightly increased life expectancy, with more time being spent at home and less in a nursing home. Total costs (excluding those of therapy) will decrease, but savings will be modest and may well be less than the cost of therapy. Under the same scenario, total savings were EUR1,571 per patient which corresponds to an annual break-even cost of just EUR453. Decisions regarding the initiation or termination of therapy will affect both the number of patients treated and the costs and potential savings of treatment. CONCLUSIONS: The savings made in treating Alzheimer's disease will almost certainly be small in comparison with total costs and may well be offset by the cost of the treatment itself. Simulation models can be used to estimate the effect of therapy on the costs of care and can be useful tools in clinical decision-making and allocation of resources. These results show the need for further research into the costs and effects of treatment of Alzheimer's disease.

[Model of costs of care for dementia: community-dwelling vs. institutionalization]. / Een kostenmodel van de zorg voor dementerenden: thuiswonen versus opname.

This article describes a model of costs for Alzheimer's Disease. The cost of institutionalization and the cost of living at home for patients with Alzheimer's Disease are calculated and compared. The average yearly cost of living at home is 10,810 Dutch guilders for male patients and 12,771 Dutch guilders for female patients (prices of 1996). Institutionalization is considerably more expensive: the average yearly cost associated with admission to a residential home is 48,180 Dutch guilders and 98,915 versus 102,930 Dutch guilders for costs associated with admission to a specialised respectively nonspecialized nursing home. Differences between men and women could not be taken into account in these last three estimations. The cost of living at home increases when the cost of informal care is included. However, when the cost were valued with a tariff of 29.50 guilders per hour, institutionalisation remains more expensive than living at home. This is also the case for severely demented patients, as the costs of institutions are also related to the level of care.