Factors Influencing Confidence in Diagnostic Ratings and Retreatment Recommendations in Coiled Aneurysms.

BACKGROUND AND PURPOSE: Angiographic occlusion and retreatment of coiled aneurysms are commonly used as surrogate end points in clinical trials. We aimed to evaluate the influence of aneurysm, patient, and rater characteristics on the confidence of visual evaluation of aneurysm coiling and retreatment decisions. MATERIALS AND METHODS: Twenty-six participants of the Advanced Course in Endovascular Interventional Neuroradiology of the European Society of Neuroradiology were asked to evaluate digital subtraction angiography examinations of patients who had undergone endovascular coiling, by determining the grade of aneurysm occlusion, the change between immediate postprocedural and follow-up angiograms, their level of confidence, the technical difficulty of retreatment, and the best therapeutic approach. The experience, knowledge, and skills of each participant were assessed. The influence of rater and case characteristics on indicated confidence in diagnostic ratings and retreatment recommendations was analyzed. RESULTS: Interrater reliability was moderate regarding the assessment of aneurysm occlusion grade (intraclass correlation coefficient = 0.581) and substantial regarding change (intraclass correlation coefficient = 0.776). Overall confidence in the diagnostic rating was high (median, "very certain"). Confidence was statistically significantly higher in cases that were generally rated as "worse." The odds of recommending retreatment were significantly higher in cases that were generally rated with higher mean confidence. CONCLUSIONS: Although overall confidence in the diagnostic rating was high, our study confirms the suboptimal interrater reliability of visual assessment of aneurysm occlusion as well as retreatment recommendations, rendering both questionable as primary outcome measures. Besides recurrence status, recommendation of retreatment is significantly influenced by patient age, aneurysm neck width, and characteristics of the therapist.

Self-rated health as a predictor of outcomes of type 2 diabetes patient education programmes in Denmark.

OBJECTIVE: To explore if self-rated health (SRH) can predict differences in outcomes of patient education programmes among patients with type 2 diabetes over time. STUDY DESIGN: This is an observational cohort study conducted among 83 patients with type 2 diabetes participating in patient education programmes in the Capital Region of Denmark. METHODS: Questionnaire data were collected by telephone interview at baseline and 2 weeks (77 participants, 93%) and 12 months (66, 80%) after the patient education ended. The seven-scale Health Education Impact Questionnaire (HeiQ) was the primary outcome. The independent variable was SRH, which was dichotomized into optimal or poor SRH. Changes over time were assessed using mean values and standard deviation (SD) at each time point and Cohen effect sizes. Odds ratios and 95% confidence intervals were calculated for the likelihood of having poor SRH for each baseline sociodemographic and health-related variable. RESULTS: Twelve months after patient education programmes, 60 (72%) patients with optimal SRH at baseline demonstrated increased self-management skills, overall acceptance of chronic illness, positive social interaction with others, and improved emotional well-being. Participants with poor SRH (23, 28%) reported no improvements over time. Not being married (odds ratio [OR] 7.79, P < 0.001), living alone (OR 4.93, P = 0.003), having hypertension (OR 8.00, P = 0.031), and being severely obese (OR 4.07, P = 0.009) were significantly associated with having poor SRH. After adjusting for sex, age and vocational training, marital status (OR 9.35, P < 0.001), cohabitation status (OR = 4.96, P = 0.005) and hypertension (OR 10.9, P = 0.03) remained associated with poor SRH. CONCLUSIONS: We found a strong association between SRH and outcomes of patient education, as measured by the HeiQ, at 12 months. Only participants with optimal SRH appeared to benefit from patient education. Other patient characteristics may be responsible to explain the observed difference between patients with optimal and poor SRH.

3D Printing of Intracranial Aneurysms Using Fused Deposition Modeling Offers Highly Accurate Replications.

BACKGROUND AND PURPOSE: As part of a multicenter cooperation (Aneurysm-Like Synthetic bodies for Testing Endovascular devices in 3D Reality) with focus on implementation of additive manufacturing in neuroradiologic practice, we systematically assessed the technical feasibility and accuracy of several additive manufacturing techniques. We evaluated the method of fused deposition modeling for the production of aneurysm models replicating patient-specific anatomy. MATERIALS AND METHODS: 3D rotational angiographic data from 10 aneurysms were processed to obtain volumetric models suitable for fused deposition modeling. A hollow aneurysm model with connectors for silicone tubes was fabricated by using acrylonitrile butadiene styrene. Support material was dissolved, and surfaces were finished by using NanoSeal. The resulting models were filled with iodinated contrast media. 3D rotational angiography of the models was acquired, and aneurysm geometry was compared with the original patient data. RESULTS: Reproduction of hollow aneurysm models was technically feasible in 8 of 10 cases, with aneurysm sizes ranging from 41 to 2928 mm(3) (aneurysm diameter, 3-19 mm). A high level of anatomic accuracy was observed, with a mean Dice index of 93.6% ± 2.4%. Obstructions were encountered in vessel segments of <1 mm. CONCLUSIONS: Fused deposition modeling is a promising technique, which allows rapid and precise replication of cerebral aneurysms. The porosity of the models can be overcome by surface finishing. Models produced with fused deposition modeling may serve as educational and research tools and could be used to individualize treatment planning.

Volume perfusion CT (VPCT) for the differential diagnosis of patients with suspected cerebral vasospasm: qualitative and quantitative analysis of 3D parameter maps.

OBJECT: Cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH) implies high risk for secondary ischemia. It requires early diagnosis to start treatment on time. We aimed to assess the utility of "whole brain" VPCT for detecting localization and characteristics of arterial vasospasm. METHODS: 23 patients received a non-enhanced CT, VPCT and CTA of the brain. The distribution of ischemic lesions was analyzed on 3D-perfusion-parameter-maps of CBF, CBV, MTT, TTS, TTP, and TTD. CT-angiographic axial and coronal maximum-intensity-projections were reconstructed to determine arterial vasospasm. CT-data was compared to DSA, if performed additionally. Volume-of-interest placement was used to obtain quantitative mean VPCT values. RESULTS: 82% patients (n=19) had focal cerebral hypoperfusion. 100% sensitivity and 100% specificity was found for TTS (median 1.9s), MTT (median 5.9s) and TTD (median 7.6s). CBV showed no significant differences. In 78% (n=18) focal vessel aberrations could be detected either on CTA or DSA or on both. CONCLUSION: VPCT is a non-invasive method with the ability to detect focal perfusion deficits almost in the whole brain. While DSA remains to be the gold standard for detection of CV, VPCT has the potential to improve noninvasive diagnosis and treatment decisions.

4D CT angiography more closely defines intracranial thrombus burden than single-phase CT angiography.

BACKGROUND AND PURPOSE: In patients with acute stroke, the location and extent of intravascular thrombi correlate with clinical and imaging outcomes and have been used to predict the success of intravenous thrombolysis. We hypothesized that 4D-CTA reconstructed from whole-brain CTP more closely outlines intracranial thrombi than conventional single-phase CTA. MATERIALS AND METHODS: Sixty-seven patients with anterior circulation occlusion were retrospectively analyzed. For 4D-CTA, temporal maximum intensity projections were calculated that combine all 30 spiral scans of the CTP examination through temporal fusion. Thrombus extent was assessed by a semi-quantitative clot burden score (0-10; in which 0 = complete unilateral anterior circulation occlusion and 10 = patent vasculature). In patients with sufficient collateral flow, the length of the filling defect and corresponding hyperdense middle cerebral artery sign on NCCT were measured. RESULTS: Clot burden on temporal maximum intensity projection (median clot burden score, 7.0; interquartile range, 5.1-8.0) was significantly lower than on single-phase CT angiography (median, 6.0; interquartile range, 4.5-7.0; P < .0001). The length of the hyperdense middle cerebral artery sign (14.30 ± 5.93 mm) showed excellent correlation with the filling defect in the middle cerebral artery on temporal maximum intensity projection (13.40 ± 6.40 mm); this filling defect was larger on single-phase CT angiography (18.08 ± 6.54 mm; P = .043). CONCLUSIONS: As the result of an increased sensitivity for collateral flow, 4D-CTA temporal maximum intensity projection more closely outlines intracranial thrombi than conventional single-phase CT angiography. Our findings can be helpful when planning acute neurointervention. Further research is necessary to validate our data and assess the use of 4D-CTA in predicting response to different recanalization strategies.

Feasibility of flat panel angiographic CT after intravenous contrast agent application in the postoperative evaluation of patients with clipped aneurysms.

BACKGROUND AND PURPOSE: Important findings, such as aneurysm remnants or major arterial occlusion, can be detected on intra- or postoperative angiography after surgical clipping of intracranial aneurysms. The purpose of this study was to evaluate the feasibility of IV-ACT for the postoperative detection of residual aneurysms and parent vessel patency compared with IA-DSA, which was selected as the standard reference method. MATERIALS AND METHODS: Twenty-two patients with 27 aneurysms treated by surgical clipping were examined by using both IA-DSA and IV-ACT. Both diagnostic procedures were performed on an FPD-equipped angiography system. Postprocessing of IV-ACT acquisitions was performed on a dedicated workstation producing multiplanar reformations and maximum intensity projections of the clip region and other intracranial arteries. Three interventional neuroradiologists independently evaluated both procedures. RESULTS: A residual aneurysm was delineated in 10 cases with IA-DSA. Sufficient opacification of the intracranial vessels was assigned in 26 IV-ACT cases. Due to metal artifacts, IV-ACT images were tagged as "not diagnostic" on 8 occasions. In the other 19 aneurysms, a residual aneurysm was delineated in 6 cases-all 6 being true-positive compared with IA-DSA-and was excluded in the remaining 13 cases-all true-negative. Even small aneurysm remnants with a diameter of 1.5 mm were detected with IV-ACT. CONCLUSIONS: Currently IV-ACT cannot be recommended as a routine tool for postoperative evaluation of clipped aneurysms due to metal artifacts in 30% of the examinations. These artifacts appear with multiple normal-sized or large clips. In patients with single or multiple small clips, IV-ACT can reliably show aneurysm remnants.

From shell to cell: neutron scattering studies of biological water dynamics and coupling to activity.

An integrated picture of hydration shell dynamics and of its coupling to functional macromolecular motions is proposed from studies on a soluble protein, on a membrane protein in its natural lipid environment, and on the intracellular environment in bacteria and red blood cells. Water dynamics in multimolar salt solutions was also examined, in the context of the very slow water component previously discovered in the cytoplasm of extreme halophilic archaea. The data were obtained from neutron scattering by using deuterium labelling to focus on the dynamics of different parts of the complex systems examined.

[Incidence of adverse events in hospitals. A retrospective study of medical records]. / Forekomsten af utilsigtede haendelser på sygehuse. En retrospektiv gennemgang af journaler.

INTRODUCTION: Over the past decade a number of studies on the incidence and preventability of adverse events in the health care have been published in the US, Australia and the UK. So far no similar study has been performed in Denmark. In order to determine whether foreign findings could be generalised to Danish health care, a pilot study on adverse events was carried out in Danish acute care hospitals. METHOD: Chart reviews were carried out on 1.097 acute care hospital admissions, sampled from the central Danish National Patient Register. The sample was truly proportional with no over-sampling of high-risks groups. Chart reviews was done in 17 different acute care hospitals, reviewing between 20 and 204 admissions per hospital. Adverse events was identified using a three-step procedure: 1) Nurse screening by 18 criteria identifying high-risk groups. 2) Independent reviews by pairs of consultants. 3) In case of disagreement between second step consultants, two additional independent reviews was performed by new consultants (internist and surgeon) followed by conference. All chart reviews were performed independent of medical specialty. All nurses and doctors were senior and experienced clinicians. RESULTS: In 114 admissions 176 Adverse Events (AEs) were identified. The prevalence of admissions with adverse events were 9.0% of all admissions. Preventability of adverse events was found in 46 of admissions (40.4% of AEs). The adverse events caused on average a 7.0 days prolonged hospital stay. Most adverse events resulted in minor, transient disabilities. Permanent disability or death in relation to adverse event were recorded in 30 admissions. DISCUSSION: The findings from the Danish Adverse Event Study are similar to the results found in Australia, United Kingdom and the United States. It is therefore recommended that further Danish research, is directed towards high-risk groups focussing on narratives and intervention and towards research in primary health care.

Comparison of magnesium and methyldopa for the control of blood pressure in pregnancies complicated with hypertension.

OBJECTIVES: Although magnesium is now the drug of choice for the prevention of eclamptic seizures only few studies have evaluated whether magnesium may reduce blood pressure in pregnancies complicated with hypertension. METHODS: A total of 33 patients with pregnancy-induced hypertension were randomized to either magnesium or methyldopa treatment. Of these 16 received magnesium and 17 methyldopa. The treatment comprised a 48-hour magnesium infusion followed by oral magnesium tablets until 3 days after delivery or 250 mg methyldopa 4 times a day in a similar period. RESULTS: Patients treated with magnesium had 1 day after inclusion a statistically significantly lower systolic blood pressure compared to the level in the methyldopa group (138.1 +/- 11 vs. 147.6 +/- 11 mm Hg; p < 0.05), but no difference was observed in diastolic blood pressure (92.0 +/- 6.6 vs. 96.0 +/- 10.1 mm Hg; NS). From the 5th day of inclusion and until delivery both systolic and diastolic blood pressure were significantly lower in the magnesium group (p < 0.05). Including all blood pressure measurements in a single analysis showed that both systolic (138 +/- 13 vs. 148 +/- 15 mm Hg; p < 0.0001) and diastolic (92 +/- 10 vs. 94 +/- 10 mm Hg; p < 0.05) blood pressure were lower in the magnesium group compared to the methyldopa group. There was no difference between the two groups regarding gestational age at delivery, birth weight, Apgar scores and pH in umbilical cord blood. CONCLUSION: This preliminary study demonstrates that magnesium treatment lowers blood pressure in pregnancies complicated with hypertension. The effect is without any adverse effect on maternal and neonatal well-being.

Prevalence of hypercalcaemia in normal and in hospital populations.

The purpose of the present study was to review the literature with respect to the prevalence of hypercalcaemia in normal and in hospital populations. Pertinent studies were selected from the MEDLINE database (1980 to March 1995) and through the bibliographies of selected articles. Hypercalcaemia is one of the most common metabolic disorders in malignant diseases and develops in 3-30% of such patients. Hypercalcaemia of malignancy is the most common cause of hypercalcaemia followed by primary hyperparathyroidism in hospital populations. The most common cause in normal populations is primary hyperparathyroidism followed by transient hypercalcaemia. The prevalence of hypercalcaemia shows a large variation in hospital populations ranging from 0.17% to 2.92%. The prevalence in normal populations varies between 1.07% and 3.9% and, surprisingly exceeds the level in hospital populations. The discrepancies between prevalences may be due to varying referral patterns, different distribution of specialities causing different hospital populations and different definitions of hypercalcaemia. Hypercalcaemia presents a diagnostic problem. The percentage of cases of hypercalcaemia that are actually diagnosed has been observed to be as low as 25% in hospitals, in which laboratory results remain unreported unless requested. But even when presented, 20-50% of the cases are overlooked.

Combined reports on serum calcium and discriminant functions increase the diagnostic rate of hypercalcaemia.

Hypercalcaemia is a condition easily overlooked by the clinician. Prompted by the observation that computerized reminders could increase the awareness, we have examined whether the combined reporting of increased serum calcium results and the results from diagnostic discriminating calculations could increase the clinical awareness of hypercalcaemia. Albumin-corrected serum calcium was estimated in all 4500 patients admitted to the hospital during a period of 2 months. Eighty-seven patients were found with hypercalcaemia and were assigned randomly to 2 groups: A (40 patients) and B (47 patients). In group A, the increased serum calcium and the results of the discriminant functions were reported; in group B, the serum calcium was reported only if requested and the discrimination diagnosis withheld. The clinical records were examined 3 weeks after admission. At this time the records in group A contained a relevant clinical diagnosis explaining the hypercalcaemia in 81% of the cases. This was in contrast to only 31% of the records in group B. We conclude that this combined reporting leads to a considerable improvement in the clinical awareness of hypercalcaemia and results in a diagnosis explaining the condition in the majority of cases.

Transfer of hypercalcemia discriminant functions between local hospitals.

Transferability of discriminant functions is potentially useful both from an economical point of view and because, in general, medical knowledge, in this case discriminant functions, should be transferable. In the present study we have evaluated the transferability of discriminant functions, estimated from routine laboratory analysis, age and sex in two consecutively recorded populations with hypercalcemia including 162 and 257 patients with hypercalcemia. Discriminant functions were developed for each sex to distinguish between hypercalcemia associated with malignancy and hypercalcemia associated with other medical diseases. The total diagnostic accuracy in Herlev was 82 and 78%, in women and men, and increased to 87 and 86% in both sexes considering cases classified with posterior probability levels of 60%. In Hvidovre the total diagnostic accuracy was 81 and 84% in women and men, and increased to 83 and 89% at posterior probability levels higher than 60%. Transfer of the discrimination functions between the hospitals was followed by a decrease in diagnostic accuracy of 6-16%. At a posterior probability of 60% the diagnostic accuracies were 79% or more in the receiving hospital, in both sexes, except for men in Hvidovre. In relation to these results the concept of genuine and non-genuine transfer factors is introduced and discussed.

Does the plasma concentration of 25-hydroxyvitamin D determine the level of 1,25-dihydroxyvitamin D in primary hyperparathyroidism?

In man, parathyroid hormone (PTH) is one of the main regulators of 1,25-dihydroxyvitamin D (1,25(OH)2D) production. However, conflicting results have been reported concerning the regulatory significance of PTH on 1,25(OH)2D in primary hyperparathyroidism. We measured the plasma concentrations of intact PTH, ionized calcium (pH 7.4), phosphate, creatinine, 25-hydroxyvitamin D (25(OH)D), 1,25(OH)2D and urine creatinine in a standardised regime in 17 patients with primary hyperparathyroidism. The nephrogeneous cyclic adenosine-3,5-monophosphate (NcAMP) was measured and so provides an "in vivo receptor assay' for biologically active PTH in the circulation. Multiple regression analysis was used to identify variables with a possible influence on the plasma concentration of 1,25(OH)2D. The only variable showing a significant correlation to the plasma concentration of 1,25(OH)2D was 25(OH)D (r=0.6, p < 0.03). Our results indicate that the plasma concentration of 25(OH)D may be very central for the regulation of 1,25(OH)2D production in primary hyperparathyroidism.

Within-centre evaluation of hypercalcaemia discriminant functions 5 years after their development.

Diagnostic hypercalcaemia discriminant functions, discriminating between clinically significant and non-significant hypercalcaemia, were tested 5 years after their development in order to evaluate the impact of time on their diagnostic capacity. Two populations, consisting of 257 and 129 patients with hypercalcaemia, were consecutively recorded, during six and three months respectively, 5 years apart under similar circumstances. The prevalence of hypercalcaemia was comparable in both populations, being 2.57 and 2.38% respectively (non-significant) (NS). The female/male ratio was 1.9 and 1.7 (NS). The discriminant functions correctly classified 81 and 80% of the women, respectively (NS) and respectively 75% and 64% of the men (NS) in the first and second recorded populations.

Long-term changes in bone mass after partial gastrectomy in a well-defined population and its relation to tobacco and alcohol consumption.

We studied the long-term effect of partial gastrectomy on bone metabolism in a well defined population of gastrectomized patients compared to an age- and sex-matched group with unoperated peptic ulcers (controls). We selected 61 individuals between 61 and 70 years old at the time of investigation who had been operated on at the same surgical department an average of 20 years earlier. Compared to unoperated ulcer patients, we found reduced bone mass of the distal forearm in the operated groups. The serum level of calcidiol was significantly reduced in Billroth I (BI) operated women and insignificantly lower in the other operated groups. In men, ionized and total calcium was reduced, and 24-hour excretion of hydroxyproline in the urine as increased (p < 0.05). Biochemical signs of osteomalacia were found in one gastrectomized patient only. There were no significant differences between operated and unoperated patients in serum levels of alkaline phosphatases, iPTH, calcitriol, or the 24-hour urine calcium/creatinine excretion, even though there was a trend toward lower 24-hour urine calcium/creatinine ratio and increased levels in iPTH in the operated groups. There was no correlation between the daily alcohol consumption or cumulative tobacco consumption and bone mineral content in each group. Gastrectomized women smoked much more than control women, and smoking may be a determinant factor for the bone loss, as it is in healthy persons. Operated patients had a lower intake of milk products. All patients were exposed to sunlight for more than 3 hours/week. It is suggested that osteopenia after gastrectomy might be caused by calcium depletion rather than lack of vitamin D. The consumption of tobacco but not of alcohol was connected to bone loss.

Quality development based on informatics in health care: steps in the Danish national strategy illustrated by four cases.

The first step for quality development is identification of the quality problem. This should be followed by a set up of criteria and standards and relevant data should be collected to perform quality assessment. The quality-level is evaluated and in cases with non-satisfying results, the problem(s) should be identified and the process repeated [1]. Identification of the best results for continuous quality improvement and professional self-assessment is part of the process [1]. Decentralization of the whole quality development process is an aim. The Ministry of Health is politically responsible for the process and the National Board of Health is responsible for the implementation of the process at the national level. To support continuous quality development, three bills were passed in the government in 1992: 1) Free choice of hospital for the patients; 2) Appropriate local and regional distribution of specialized functions, to ensure optimal treatment of rare and complicated diseases; 3) Coordinated planning and organization of the health services. The strategy for quality development illustrated by four cases. Four projects were identified to illustrate steps in the national strategy for quality development. PROBLEM IDENTIFICATION. ESTEEM [2,3]: Using knowledge-based systems for interpretation of EMG (electromyography) in different laboratories disclosed great variations in clinical usability. The variations could be explained by different examination techniques, test planning protocols, and diagnostic criteria. It was concluded that the use of a EMG-knowledge based system disclosed great problems for standardization of procedures dependent on EMG measurements. QUALITY ASSESSMENT. Hip fracture quality project [unpublished data]: The assumption for the study was that early and active rehabilitation after hip fracture would promote the ability of the patients to cope with activities of daily living (ADL) and prevent development of complications. About 85% of the patients were expected to be able to go home on the 12th day, but this was the case for only 56% of the patients. It was concluded that the pre-set standard was not achieved and that the post-operative care was carried out in an ineffective way. QUALITY IMPROVEMENT. Laboratory quality project [4]: Quality control assessment procedures have been implemented for years in hospital laboratories. The aim of the study was to evaluate the size of analytical bias between two local hospital laboratories using the same reference intervals. The results showed that only a few of the routine analyses meet the goals for acceptance of general reference intervals in a geographical area. The problems were reflected in the quality assessment results but, nevertheless, no action seems to have been taken to minimize the bias. It is concluded that interpretation of quality control data is a great problem. QUALITY MONITORING AND EVALUATION. National databases for health care quality [5]: Principles for development, implementation, and use of national databases has been worked out by The National Board of Health. Clinical departments will get a tool to monitor and improve the daily working routines. National databases for clinical monitoring exist for vascular surgery, laparoscopic surgery, treatment of breast cancer, and surgery for hip fractures.

Do local hospitals meet the analytical goals for the use of common reference intervals?

Blood samples were obtained from 183 blood donors and measured in two hospitals in the same geographical area using identical reference intervals and measuring equipment. The analytical bias of the clinical chemical analyses was investigated through paired measurements. The results showed that out of 15 routine analyses only four meet the goals for acceptance of common reference intervals, of which at least three were of clinical significance. The problems were reflected in the quality assessment results but, nevertheless, no action seems to have been taken.