Evaluation of a computer assisted quantification of multiple sclerosis lesions in cranial MRI

Grimaud, J; Lai, M.; Thorpe, J. W.; Adeleine, P.; McDonald, W. I.; Miller, DH

doi:10.1016/0165-5728(95)99003-2

Cited by 3 publications

(4 citation statements)

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“…This measurement variability was good enough to detect treatment efficacy in a placebo-controlled clinical trial [24]. The intra-observer CV value for T2 lesion load quantification obtained in the present study is similar to those obtained in a previous study using the same local thresholding technique [15], which was significantly lower than that obtained using manual outlining. Similarly, for T1-weighted MRI lesion load quantitation Van Walderveen et al [27], using a seed-growing technique, reported an intra-observer variability of 5.6%.…”

Section: Discussionsupporting

confidence: 88%

“…Recent studies have reported that major sources of variation in lesion volume measurements are errors in repositioning of serial scans [ 14], the use of different MR scanners [ 11 ] and multiple observers [9,15]. While the first two sources of variation are hardly avoidable, the operator-related variability can be significantly reduced by simply using a single rater to perform the measurements for the whole study duration.…”

Section: Introductionmentioning

confidence: 99%

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Intra-observer reproducibility in measuring new putative MR markers of demyelination and axonal loss in multiple sclerosis: a comparison with conventional T2-weighted images

et al. 1997

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New magnetic resonance (MR) measures considered to be putative workers of demyelination and axonal loss were found to be more closely related to clinical disability than T2-weighted MR imaging (MRI) findings in patients with multiple sclerosis (MS). In this study, we evaluated the reproducibility of such measurements in order to assess their reliability for longitudinal studies in MS. The intra-observer coefficients of variation for repeated measurements did not significantly differ among the MR techniques studied [2.6% for T2-weighted MR, 4.38% for unenhanced T1-weighted MRI, 3.65% for magnetisation transfer imaging (MTI) and 2.28% for spinal cord cross-sectional area at C5]. Our findings suggest that non-conventional MR techniques may be reliable outcome measures for clinical trials in MS.

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Section: Discussionsupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Intra-observer reproducibility in measuring new putative MR markers of demyelination and axonal loss in multiple sclerosis: a comparison with conventional T2-weighted images

et al. 1997

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“…Both techniques require human interaction to indicate the site of the lesions and then determine the contour of the lesion according to local signal intensities, which may make them less operator dependent than manual tracing. Preliminary data indicate that local threshold techniques provide intra-observer variability in the order of 3% for long TR/short TE images, and are more reproducible than manual tracing [30,47].…”

Section: Quantitative Measurement Of Lesion Loadmentioning

confidence: 99%

Strategies for optimizing MRI techniques aimed at monitoring disease activity in multiple sclerosis treatment trials

Barkhof

Filippi

Miller

et al. 1997

Journal of Neurology

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Serial magnetic resonance imaging (MRI) detects substantial subclinical disease activity in multiple sclerosis (MS) and is presently included in most treatment trials as an objective outcome measure. Our current knowledge of the role of MRI in MS treatment trials is derived from very limited patient studies, and the aim of this paper is to identify strategies to optimize the use of MRI in monitoring disease activity in treatment trials. The number of active lesions revealed by MRI can be used as the primary outcome measure in exploratory treatment trials. With monthly scanning, the majority of active lesions will be seen by virtue of a limited number of new areas of gadolinium enhancement. The contrast between enhancing lesions and background could be increased by: (1) using higher doses of gadolinium, (2) suppressing the background signal with magnetization transfer, (3) delayed scanning, or (4) a combination of these. Following a systematic comparison of those approaches, the effect on the sensitivity in detecting active lesions should be analysed with reference to the power of treatment trials. We present preliminary results showing marked agreement between observers in reporting enhancing lesions; however, with new acquisition strategies, the observer variation should be re-established in a multicentre fashion. In definitive trials, the increase in total lesion load serves as a secondary outcome measure. Since the majority of lesions making up the total lesion load are inactive during the study, spatial resolution should be maximized in order to preclude any artificial changes in lesion load to be superimposed (noise) upon the relatively small actual change (information). Reduction in measurement error can be attempted by improved acquisition techniques with increased lesion to background contrast. More importantly, improvement in quantitation techniques is warranted. With a 6% coefficient of variation in measuring a baseline lesion load, we calculate the standard error of the mean yearly increase in T2 lesion load (typically 10% in untreated patients) in a treatment arm of 124 patients to be 7.5%. A comparison of several quantitation techniques should be performed in a multicentre longitudinal fashion in order to include variation caused by both scanner and segmentation technique, in addition to biological activity.

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“…Rules have been developed to improve the reproducibility of counting enhancing lesions (Barkhof et al 1997b). For T2 lesion load, automated and semiautomated methods are more reproducible than manual lesion outlining (Grimaud et al 1996;Filippi et al 1995c;Udupa et al 1997;Molyneaux 1998a), but these methods need to be validated for accuracyö failure to do so may give spurious results (Molyneaux et al 1997). Accuracy can be assessed using phantoms of known dimensions or by an experienced observer visually assessing the segmented lesion regions.…”

Section: (C) Accuracy and Reproducibilitymentioning

confidence: 99%

Nuclear magnetic resonance monitoring of treatment and prediction of outcome in multiple sclerosis

Miller

Thompson

1999

Phil. Trans. R. Soc. Lond. B

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Magnetic resonance (MR) techniques provide an objective, sensitive and quantitative assessment of the evolving pathology in multiple sclerosis. There is an increasing de¢nition of the pathological speci¢city of newer techniques, and more robust correlations with clinical evolution are emerging. As the pathophysiological basis of in vivo nuclear MR signal abnormalities is further elucidated, it is likely that the importance of MR as a tool to monitor new therapies will increase.

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Evaluation of a computer assisted quantification of multiple sclerosis lesions in cranial MRI

Cited by 3 publications

References 0 publications

Intra-observer reproducibility in measuring new putative MR markers of demyelination and axonal loss in multiple sclerosis: a comparison with conventional T2-weighted images

Intra-observer reproducibility in measuring new putative MR markers of demyelination and axonal loss in multiple sclerosis: a comparison with conventional T2-weighted images

Strategies for optimizing MRI techniques aimed at monitoring disease activity in multiple sclerosis treatment trials

Nuclear magnetic resonance monitoring of treatment and prediction of outcome in multiple sclerosis

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