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Statistical evaluations of the reproducibility and reliability of 3-tesla high resolution magnetization transfer brain images: a pilot study on healthy subjects.

Zou KH, Du H, Sidharthan S, Detora LM, Chen Y, Ragin AB, Edelman RR, Wu Y - Int J Biomed Imaging (2010)

Bottom Line: At 3 Tesla (T), MT affords higher resolution and increased tissue contrast associated with macromolecules.Spearman's correlation coefficient, coefficient of variation, and intraclass correlation coefficient (ICC) were computed.Our statistical methods may be generalized to many similar evaluative studies of the reliability and reproducibility of various imaging modalities.

View Article: PubMed Central - PubMed

Affiliation: Pfizer Inc., New York, NY, USA.

ABSTRACT
Magnetization transfer imaging (MT) may have considerable promise for early detection and monitoring of subtle brain changes before they are apparent on conventional magnetic resonance images. At 3 Tesla (T), MT affords higher resolution and increased tissue contrast associated with macromolecules. The reliability and reproducibility of a new high-resolution MT strategy were assessed in brain images acquired from 9 healthy subjects. Repeated measures were taken for 12 brain regions of interest (ROIs): genu, splenium, and the left and right hemispheres of the hippocampus, caudate, putamen, thalamus, and cerebral white matter. Spearman's correlation coefficient, coefficient of variation, and intraclass correlation coefficient (ICC) were computed. Multivariate mixed-effects regression models were used to fit the mean ROI values and to test the significance of the effects due to region, subject, observer, time, and manual repetition. A sensitivity analysis of various model specifications and the corresponding ICCs was conducted. Our statistical methods may be generalized to many similar evaluative studies of the reliability and reproducibility of various imaging modalities.

No MeSH data available.


Related in: MedlinePlus

The Axial (a) and Coronal (b) views of high resolution MTR maps. Twelve brain ROIs are illustrated (white dots).
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fig2: The Axial (a) and Coronal (b) views of high resolution MTR maps. Twelve brain ROIs are illustrated (white dots).

Mentions: (1)MTR=M0−MSM0×100%, where MS and M0 were the signal intensities in a given voxel obtained, with and without the MT saturation pulse, respectively. MTR maps generated based on the high resolution MT are demonstrated in Figure 1. The 12 ROIs were: genu, splenium, left and right hemispheres of the hippocampus, caudate, putamen, thalamus, and cerebral white matter. Figure 2 illustrated the 12 ROIs that were investigated. Each ROI was sized approximately 30 to 43 mm2 and manually and independently placed by Observers 1 and 2 (Authors S.S. and Y.W.) following procedures in classical and standard agreement studies [10]. After an initial consensus decision was drawn regarding the sizes and locations of the 12 ROIs, the observers performed manual segmentations of the ROI independently on each set of images. This ROI placement procedure was repeated by each observer in the following week.


Statistical evaluations of the reproducibility and reliability of 3-tesla high resolution magnetization transfer brain images: a pilot study on healthy subjects.

Zou KH, Du H, Sidharthan S, Detora LM, Chen Y, Ragin AB, Edelman RR, Wu Y - Int J Biomed Imaging (2010)

The Axial (a) and Coronal (b) views of high resolution MTR maps. Twelve brain ROIs are illustrated (white dots).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2821648&req=5

fig2: The Axial (a) and Coronal (b) views of high resolution MTR maps. Twelve brain ROIs are illustrated (white dots).
Mentions: (1)MTR=M0−MSM0×100%, where MS and M0 were the signal intensities in a given voxel obtained, with and without the MT saturation pulse, respectively. MTR maps generated based on the high resolution MT are demonstrated in Figure 1. The 12 ROIs were: genu, splenium, left and right hemispheres of the hippocampus, caudate, putamen, thalamus, and cerebral white matter. Figure 2 illustrated the 12 ROIs that were investigated. Each ROI was sized approximately 30 to 43 mm2 and manually and independently placed by Observers 1 and 2 (Authors S.S. and Y.W.) following procedures in classical and standard agreement studies [10]. After an initial consensus decision was drawn regarding the sizes and locations of the 12 ROIs, the observers performed manual segmentations of the ROI independently on each set of images. This ROI placement procedure was repeated by each observer in the following week.

Bottom Line: At 3 Tesla (T), MT affords higher resolution and increased tissue contrast associated with macromolecules.Spearman's correlation coefficient, coefficient of variation, and intraclass correlation coefficient (ICC) were computed.Our statistical methods may be generalized to many similar evaluative studies of the reliability and reproducibility of various imaging modalities.

View Article: PubMed Central - PubMed

Affiliation: Pfizer Inc., New York, NY, USA.

ABSTRACT
Magnetization transfer imaging (MT) may have considerable promise for early detection and monitoring of subtle brain changes before they are apparent on conventional magnetic resonance images. At 3 Tesla (T), MT affords higher resolution and increased tissue contrast associated with macromolecules. The reliability and reproducibility of a new high-resolution MT strategy were assessed in brain images acquired from 9 healthy subjects. Repeated measures were taken for 12 brain regions of interest (ROIs): genu, splenium, and the left and right hemispheres of the hippocampus, caudate, putamen, thalamus, and cerebral white matter. Spearman's correlation coefficient, coefficient of variation, and intraclass correlation coefficient (ICC) were computed. Multivariate mixed-effects regression models were used to fit the mean ROI values and to test the significance of the effects due to region, subject, observer, time, and manual repetition. A sensitivity analysis of various model specifications and the corresponding ICCs was conducted. Our statistical methods may be generalized to many similar evaluative studies of the reliability and reproducibility of various imaging modalities.

No MeSH data available.


Related in: MedlinePlus