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  • 1
    Electronic Resource
    Electronic Resource
    Comparison of a conventional cardiac-triggered dual spin-echo and a fast STIR sequence in detection of spinal cord lesions in multiple sclerosis (2000)
    Springer
    European radiology 10 (2000), S. 753-758 
    Details
    ISSN: 1432-1084
    Keywords: Key words: Multiple sclerosis ; MR imaging ; Spinal cord
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The current optimal imaging protocol in spinal cord MR imaging in patients with multiple sclerosis includes a long TR conventional spin-echo (CSE) sequence, requiring long acquisition times. Using short tau inversion recovery fast spin-echo (fast STIR) sequences both acquisition time can be shortened and sensitivity in the detection of multiple sclerosis (MS) abnormalities can be increased. This study compares both sequences for the potential to detect both focal and diffuse spinal abnormalities. Spinal cords of 5 volunteers and 20 MS patients were studied at 1.0 T. Magnetic resonance imaging included cardiac-gated sagittal dual-echo CSE and a cardiac-gated fast STIR sequence. Images were scored regarding number, size, and location of focal lesions, diffuse abnormalities and presence/hindrance of artifacts by two experienced radiologists. Examinations were scored as being definitely normal, indeterminate, or definitely abnormal. Interobserver agreement regarding focal lesions was higher for CSE (ϰ = 0.67) than for fast STIR (ϰ = 0.57) but did not differ significantly. Of all focal lesions scored in consensus, 47 % were scored on both sequences, 31 % were only detected by fast STIR, and 22 % only by dual-echo CSE (n. s.). Interobserver agreement for diffuse abnormalities was lower with fast STIR (ϰ = 0.48) than dual-echo CSE (ϰ = 0.65; n. s.). After consensus, fast STIR showed in 10 patients diffuse abnormalities and dual-echo CSE in 3. After consensus, in 19 of 20 patients dual-echo CSE scans were considered as definitely abnormal compared with 17 for fast STIR. The fast STIR sequence is a useful adjunct to dual-echo CSE in detecting focal abnormalities and is helpful in detecting diffuse MS abnormalities in the spinal cord. Due to the frequent occurrence of artifacts and the lower observer concordance, fast STIR cannot be used alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003300050998
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  • 2
    Electronic Resource
    Electronic Resource
    Diurnal volume changes of the lower legs in healthy males with a profession that requires standing (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Skin research and technology 4 (1998), S. 0 
    Details
    ISSN: 1600-0846
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background/aims: The aims of this study are two-fold: To determine intra-individual volume changes of the lower legs in the course of a working day in healthy employees with a standing position at work; to relate complaints of the legs in healthy employees with volume changes in the course of the day.Methods: Physical examination and Doppler ultrasound examination were used to exclude the presence of venous disorders. A questionnaire was used to assess complaints of the legs. The lower leg volume was measured with an optical leg volume meter on 2 or 3 days at the beginning and end of a full working day.Results: Included were 197 male workers with a standing profession and no signs of venous insufficiency. The mean volume change of the lower leg was +1.8% for the left leg and +1.6% for the right leg. This volume increase was significant for both legs (P〈0.05). A volume [1 volume unit (VU) is approximately 1 ml] increase of over 50 VU was found in 46% of the legs, mean 141 VU. An unchanged volume (-50 VU to 50 VU) was found VU was found in 18% of the legs, mean -138 VU. Sixty-four percent of the subjects reported subjective complaints of the legs. A tired feeling in the legs, restless legs and a sensation of swelling of the legs were equally present in all three groups of volume change. A statistically significant correlation between pain and a volume decrease was found for the left leg.Conclusions: Diurnal volume changes of the lower legs were distributed as a Gaussian curve. A volume increase was common, but not obligatory. A volume increase of the legs was not associated with complaints of the legs or clinically evident oedema. This suggests that a volume increase can be a physiological phenomenon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0846.1998.tb00080.x
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  • 3
    Electronic Resource
    Electronic Resource
    The use of magnetic resonance imaging in multiple sclerosis treatment trials: power calculations for annual lesion load measurement (2000)
    Springer
    Journal of neurology 247 (2000), S. 34-40 
    Details
    ISSN: 1432-1459
    Keywords: Key words Multiple sclerosis ; Treatment trial ; Power calculations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Phase III definitive treatment trials of new multiple sclerosis (MS) therapies now routinely incorporate an annual magnetic resonance imaging protocol, with change in T2-weighted brain lesion load providing an important outcome measure. To date the accepted strategy has been to perform a core imaging protocol on all patients in such studies. The aim of this study was to provide power calculations based on this MRI endpoint. Serial MRI data from 128 patients with either relapsing remitting (RR) or secondary progressive (SP) MS were used to calculate sample size requirements using a repeated measures analysis of variance design. We provide sample size calculations based on various follow-up intervals and effect sizes. Sample sizes for the SPMS cohort were substantially larger than for the RRMS group, reflecting the greater variance in lesion load changes between patients in the SPMS group. With a follow-up of 3 years, we estimate that only 12 and 33 patients per arm are needed to show stabilisation of MRI lesion load in the RRMS and SPMS groups, respectively. Our results suggest that ongoing phase III treatment trials are more than adequately powered to detect even subtle treatment effects, and indicate that incorporating measurements from longer follow-up durations increases power substantially. We conclude that an annual imaging protocol provides a robust and powerful tool for assessing effects on the radiological appearance of the disease process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150050007
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  • 4
    Electronic Resource
    Electronic Resource
    Interobserver agreement for diagnostic MRI criteria in suspected multiple sclerosis (1999)
    Springer
    Neuroradiology 41 (1999), S. 347-350 
    Details
    ISSN: 1432-1920
    Keywords: Key words Multiple sclerosis ; Magnetic resonance imaging ; Interobserver variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract MRI is the paraclinical test most widely used to support the diagnosis of multiple sclerosis (MS). We evaluated interobserver agreement in applying diagnostic criteria to MRI obtained at first presentation. Five experienced observers scored 25 sets of images consisting of unenhanced T2- and gadolinium-enhanced T1-weighted images (approximately half the sets were normal). We scored frontal, parietal, temporal, occipital, infratentorial and basal ganglia lesions and the total number of lesions on T2-weighted images; periventricular, callosal, juxtacortical and ovoid lesions and those 〉 5 mm in maximum diameter; contrast-enhancing and hypointense lesions. Based on a combination of imaging findings patients were classified as compatible or not compatible with MS according to composite criteria. Observer concordance was characterised by weighted kappa values (ϰ) and mean average difference to the median (MADM) scores. Using the raw scores, there was poor agreement for the total number of lesions on T2-weighted images, and for occipital, oval, juxtacortical and hypointense lesions. Moderate agreement was found for frontal, callosal, basal ganglia and large lesions on T2 weighting. Good agreement was attained for parietal, temporal, infratentorial and periventricular lesions. After dichotomisation according to accepted cut-off values, most criteria performed better, especially the number of lesions on T2-weighted images (P 〈 0.05). Good agreement was found for the criteria of Paty and Fazekas and moderate agreement for those of Barkhof. While experienced observers may not agree on the total number of lesions, they show quite good agreement for commonly used cut-off points and elements in the composite criteria. This validates the use of MRI in the diagnosis of MS, and the use of dichotomised and composite criteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002340050762
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  • 5
    Electronic Resource
    Electronic Resource
    Visual analysis of serial T2-weighted MRI in multiple sclerosis: intra- and interobserver reproducibility (1999)
    Springer
    Neuroradiology 41 (1999), S. 882-888 
    Details
    ISSN: 1432-1920
    Keywords: Key words Multiple sclerosis ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We evaluated the effect of consensus formation and training on the agreement between observers in scoring the number of new and enlarging multiple sclerosis (MS) lesions on serial T2-weighted MRI studies. The baseline and month 9 MRI studies of 16 patients with a range of MRI activity were used (dual-echo conventional spin-echo sequence, TR 2000, TE 34 and 90 ms, 5 mm contiguous slices, in-plane resolution 1 mm). First, the serial studies were visually analysed for the presence of new and enlarging lesions, on two occasions, by five experienced observers, without adopting any consensus strategy and in isolation. Next, the observers met to identify the common sources of inconsistencies in reporting between observers and formulate consensus rules. Finally, a further independent reading session was performed on the same MRI dataset, this time applying the consensus rules. Agreement between observers was assessed using kappa scores. Without the consensus rules, interobserver kappa scores for the first and second reading sessions for new lesions were only 0.51 and 0.39 respectively; agreement for enlarging lesions was even worse. The mean intraobserver kappa score for new lesions was higher at 0.72, reflecting the fact that the observers were consistently applying their individual assessment strategies. Application of the consensus rules did not lead to a significant improvement in inter observer kappas; the kappa scores adopting the guidelines were 0.46 and 0.21 for new and enlarging lesions respectively. Consensus guidelines thus did not improve the reproducibility of visual analysis of serial T2-weighted MRI, and the level of agreement between observers remained only moderate. Suboptimal repositioning is likely to be a major source of residual variability and this suggests a future role for image registration strategies; until then, a single observer, or pair of observers working in consensus, should be used in MS studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002340050860
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  • 6
    Electronic Resource
    Electronic Resource
    Factor structure of the Disability and Impact Profile in patients with multiple sclerosis (1999)
    Springer
    Quality of life research 8 (1999), S. 141-150 
    Details
    ISSN: 1573-2649
    Keywords: Quality of life ; multiple sclerosis ; disability evaluation ; questionnaires ; factor analysis ; statistical.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The Disability and Impact Profile (DIP) is used for the measurement of quality of life in multiple sclerosis (MS) patients. Data from 211 persons with definite MS from Belgium, Denmark and the Netherlands were used to address three questions. To what extent do the impairment ratings and their complementary weighted scores share common variance? What is the factor structure of the weighted scores? To what extent do disease-related information and information from psychological questionnaires offer concurrent validity for the factors? Correlations between impairment ratings and the weighted item scores were high; for most items the complementary ratings of impact do not supplement information provided by impairment ratings. The DIP weighted scores can be represented to some extent by three independent dimensions: a motor (skeletal movement) or displacement ability factor, a factor relating to sensory–cognitive intactness and a psychological well-being factor. A two-factor solution provides a first factor identical to that of the three-factor solution and a second factor representing psychological well-being. The two factors correlate well with instruments measuring disability and with satisfaction versus emotional distress. Provisional scales based on the factors were constructed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026481029191
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