One of the major drawbacks of Magnetic Resonance Imaging (MRI) has been the lack of a standard and quantifiable interpretation of image intensities. Unlike in other modalities such as x-ray computerized tomography, MR images taken for the same patient on the same scanner at different times may appear different from each other due to a variety of scanner-dependent variations, and therefore, the absolute intensity values do not have a fixed meaning. We have devised a two-step method wherein all images can be transformed in such a way that for the same protocol and body region, in the transformed images similar intensities will have similar tissue meaning. Standardized images can be displayed with fixed windows without the need of per case adjustment. More importantly, extraction of quantitative information with fixed windows without the need of per case adjustment. More importantly, extraction of quantitative information about healthy organs or about abnormalities can be considerably simplified. This paper introduces and compares new variants of this standardizing method that can help to overcome some of the problems with the original method.
[1]
L G Nyúl,et al.
On standardizing the MR image intensity scale
,
1999,
Magnetic resonance in medicine.
[2]
J. K. Udupa,et al.
An approach to standardize the MR image intensity scale
,
1999
.
[3]
Supun Samarasekera,et al.
Multiple sclerosis lesion quantification using fuzzy-connectedness principles
,
1997,
IEEE Transactions on Medical Imaging.
[4]
L O Hall,et al.
Review of MR image segmentation techniques using pattern recognition.
,
1993,
Medical physics.
[5]
R P Velthuizen,et al.
MRI: stability of three supervised segmentation techniques.
,
1993,
Magnetic resonance imaging.
[6]
R. Kikinis,et al.
Routine quantitative analysis of brain and cerebrospinal fluid spaces with MR imaging
,
1992,
Journal of magnetic resonance imaging : JMRI.
[7]
W. Edelstein,et al.
A signal-to-noise calibration procedure for NMR imaging systems.
,
1984,
Medical physics.