Multi-detector computed tomography and 3-dimensional imaging in a multi-vendor picture archiving and communications systems (PACS) environment

RATIONALE AND OBJECTIVES: To show the impact of the introduction of multi-detector computed tomography (CT) on radiologic workflow and to demonstrate how this reflects on picture archiving and communications systems (PACS) requirements. MATERIALS AND METHODS: Production measurements were obtained from different CT scanners (first two single-slice CT scanners; from December 2001 single and 4-slice CT; from April 2002 single and 16-slice CT) in number of patients from the radiologic information system. Implications on our PACS were recorded in terms of images and studies stored. Furthermore, our PACS design was made so that optimal use of 3-dimensional imaging within the radiologic workflow was possible. Finally, the number of non-diagnosed studies were recorded every day since the start of the transition to a filmless radiology department. RESULTS: This PACS design achieved a high level of integration between simple viewing and advanced 3-dimensional imaging and is optimized for handling large amounts of data. Overall increase of patients scanned with CT from January 2002-December 2003 was 54%. The number of series increased by 286% from December 2001-April 2003 and by 130% from April 2002-December 2003. From January 2002-February 2003, the number of images per patient increased from 175 to 450 (157%). Non-diagnosed studies decreased from about 100-120 before to practically zero after PACS implementation. CONCLUSION: PACS significantly increases productivity because of availability of the images and elimination of certain manual tasks. These results show that although the amount of examinations increases significantly with the introduction of MDCT, simultaneous introduction of PACS and filmless operation allows radiologists to handle the growth in workload.     

Quality of life in patients with Parkinson's disease: development of a questionnaire.

OBJECTIVES--To develop and test a questionnaire for measuring quality of life in patients with Parkinson's disease. METHODS--An item pool was developed based on the experience of patients with Parkinson's disease and of neurologists; medical literature on the problems of patients with Parkinson's disease; and other quality of life questionnaires. To reduce the item pool, 13 patients identified items that were a problem to them and rated their importance. Items which were most often chosen and rated most important were included in the Parkinson's disease quality of life questionnaire (PDQL). The PDQL consists of 37 items. To evaluate the discriminant validity of the PDQL three groups of severity of disease were compared. To test for convergent validity, the scores of the PDQL were tested for correlation with standard indices of quality of life. RESULTS--The PDQL was filled out by 384 patients with Parkinson's disease. It consisted of four subscales: parkinsonian symptoms, systemic symptoms, emotional functioning, and social functioning. The internal-consistency reliability coefficients of the PDQL subscales were high (0.80-0.87). Patients with higher disease severity had significantly lower quality of life on all PDQL subscales (P < 0.05). Almost all PDQL subscales correlated highly (P < 0.001) with the corresponding scales of the standard quality of life indices. CONCLUSION--The PDQL is a relevant, reliable, and valid measure of the quality of life of patients with Parkinson's disease.     

Ice friction in speed skating: can klapskates reduce ice frictional loss?

PURPOSE: Reducing ice friction was one of the motives for developing the klapskate. However, the magnitude of power dissipation that occurs with conventional skates when a skater plantar flexes his ankle and the tip of the blade is pressed into the ice has not been quantified previously. In this study, we examine how ice friction varies during a single stroke with conventional skates and estimate the reduction in ice friction that might be obtained with klapskates. METHODS: Five elite speed skaters performed a series of trials at constant velocity and a series of maximal accelerations. Energy dissipated to ice friction during a stroke with conventional skates was analyzed using an instrumented skate and high-speed 3D kinematic analysis. The energy that would be dissipated when klapskates were used was estimated from the collected data with conventional skates. RESULTS: The estimated difference in power loss between conventional and klapskates was less dramatic than has been suggested frequently. Pressing the tip of the blade into the ice comprises only 0.84 W of the total power dissipated by ice friction (54 W) during constant velocity speed skating. During an all-out acceleration, this power loss reached 4.55 W. CONCLUSION: We conclude that only a minor part of the benefit of klapskates can be attributed to a reduction in ice friction. It is shown that this relatively small increase in ice friction is related to the large length of the skate blade.     

Heterogeneous spectrum of mutations in the Fanconi anaemia group A gene

Fanconi anaemia (FA) is a genetically heterogeneous autosomal recessive disorder associated with chromosomal fragility, bone-marrow failure, congenital abnormalities and cancer. The gene for complementation group A (FAA), which accounts for 60-65% of all cases, has been cloned, and is composed of an open reading frame of 4.3 kb, which is distributed among 43 exons. We have investigated the molecular pathology of FA by screening the FAA gene for mutations in a panel of 90 patients identified by the European FA research group, EUFAR. A highly heterogeneous spectrum of mutations was identified, with 31 different mutations being detected in 34 patients. The mutations were scattered throughout the gene, and most are likely to result in the absence of the FAA protein. A surprisingly high frequency of intragenic deletions was detected, which removed between 1 and 30 exons from the gene. Most microdeletions and insertions occurred at homopolymeric tracts or direct repeats within the coding sequence. These features have not been observed in the other FA gene which has been cloned to date (FAC) and may be indicative of a higher mutation rate in FAA. This would explain why FA group A is much more common than the other complementation groups. The heterogeneity of the mutation spectrum and the frequency of intragenic deletions present a considerable challenge for the molecular diagnosis of FA. A scan of the entire coding sequence of the FAA gene may be required to detect the causative mutations, and scanning protocols will have to include methods which will detect the deletions in compound heterozygotes.     

Localization of the gene for rapidly progressive autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration to chromosome 17q21

Rapidly progressive autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration (PPND) is a neurodegenerative disorder which begins later in life (> 30 years of age) and is characterized by rapidly progressive parkinsonism, dystonia, dementia, perservative vocalizations and pyramidal tract dysfunction. The disease is observed in a large American family that includes almost 300 members in nine generations with 34 affected individuals. In this kindred evidence for linkage to chromosome 17q21 was obtained with a maximum lod score of 9.08 for the D17S958 locus. Multilocus analysis positions the disease gene in an approximately 10 cM region between D17S250 and D17S943. Notably, the disease locus for a clinically distinct familial neurodegenerative disease named 'disinhibition-dementia-parkinsonism- amyotrophy complex' (DDPAC) was recently mapped to the same region of chromosome 17, suggesting that PPND and DDPAC may possibly originate from mutations in the same gene.      

Effects of short-acting bronchodilators added to maintenance tiotropium therapy

BACKGROUND: Combining bronchodilators has been shown to be beneficial in patients with COPD. The additive effects of short-acting bronchodilators added to maintenance tiotropium therapy, however, are unknown. METHODS: Following 3 weeks of tiotropium pretreatment, 60 patients with COPD (FEV1 40% of predicted) participated in a randomized, placebo-controlled study to assess add-on bronchodilator effects of ipratropium bromide (40 microg) or fenoterol (200 microg). Short-acting bronchodilators were added as a single dose 2 h and 8 h after tiotropium dosing. Serial lung function tests were performed over 9 h. RESULTS: The peak FEV1 add-on response within 6 h with fenoterol was significantly greater than with placebo (137 mL) or ipratropium (84 mL); the response with ipratropium was slightly but significantly larger than with placebo (52 mL). One hour after the second dose of the test drugs, a similar order of treatment responses was found. The peak FVC add-on response was significant for fenoterol (249 mL) but not for ipratropium (42 mL). CONCLUSIONS: In conclusion, both short-acting bronchodilator classes were effective when added to maintenance treatment with tiotropium. The addition of the beta2-adrenergic fenoterol provided greater additional bronchodilatation than the short-acting anticholinergic ipratropium. This is consistent with the expected effects of combining bronchodilators with different pharmacologic mechanisms. This randomized controlled trial was registered at www.clinicaltrials.gov (NCT00274066).     

Predictors of health care utilization in the chronically ill: a review of the literature

The objective of this paper is to identify predictors of health care utilization in the chronically ill. This paper reviews 53 studies on hospitalizations and physician visits, published between 1966 and 1997 and identified by MEDLINE and ClinPSYCH databases. Studies with both univariate and multivariate analyses were included. On the basis of the Andersen-Newman model of health care utilization, the effects of predisposing, enabling and need variables are examined. Most studies reviewed indicate that predisposing factors such as age, sex, and marital status are not predictors of hospital utilization in the chronically ill. The enabling factors income, insurance and social support have not been shown to affect health care utilization, but characteristics of the hospitals could have an effect. Need factors such as disease severity, symptom severity and complications adversely affected health care utilization in the chronically ill, while disease duration and comorbidity do not have such an effect. Quality of life and perceived health might affect hospital utilization and physician use. Finally, depression and psychological distress proved to be among the strongest predictors of hospitalizations and physician visits. In conclusion, both disease severity and psychological well-being are most important in health care utilization. Intervention programs to support depressed or psychologically distressed patients should be considered. These could both help the patient and reduce health care utilization costs.