%0 Journal Article %J RADIOLOGY %D 2000 %T Multiple sclerosis: Magnetization transfer histogram analysis of segmented normal-appearing white matter %A Isabelle Catalaa %A Robert J Grossman %A Dennis L Kolson %A Jayaram K Udupa %A László Gábor Nyúl %A Lougang Wei %A Xuan Zhang %A Marcia Polansky %A Lois J Mannon %A Joseph C McGowan %X PURPOSE: To investigate and characterize the global distributionof magnetization transfer (MT) ratio values of normal-appearing white matter (NAWM) in patients with relapsing-remitting multiple sclerosis (MS) and test the hypothesis that the MT histogram for NAWM reflects disease progression. MATERIALS AND METHODS: Conventional and MT magnetic resonance (MR) images were obtained in 23 patients and 25 healthy volunteers. Clinical tests for comparison with the MT histogram parameters included the Extended Disability Status Scale and the ambulation index. Lesion load calculated with T2-weighted MR images and whole- brain and white matter volumes were measured. RESULTS: The location of the MT histogram peak and the mean MT ratio for NAWM were significantly lower in patients with MS than in control subjects. In longitudinal studies, the histogram peak location and mean MT ratio shifted in the direction of normal values as the duration of disease increased. A mean of 26.5% of the volume of new lesions identified on the later studies were demonstrated to have originated in NAWM corresponding to "lost" pixels on the histogram. CONCLUSION: MT histogram analysis of NAWM, including longitudinal analysis, may provide new prognostic information regarding lesion formation and increase understanding of the course of the disease. %B RADIOLOGY %V 216 %P 351 - 355 %8 2000/// %@ 0033-8419 %G eng %N 2 %! RADIOLOGY %0 Journal Article %J JOURNAL OF MAGNETIC RESONANCE IMAGING %D 2000 %T Numerical tissue characterization in MS via standardization of the MR image intensity scale %A Yiyue Ge %A Jayaram K Udupa %A László Gábor Nyúl %A Lougang Wei %A Robert J Grossman %X Image intensity standardization is a recently developedpostprocessing method that is capable of correcting the signal intensity variations in MR images. We evaluated signal intensity of healthy and diseased tissues in 10 multiple sclerosis (MS) patients based on standardized dual fast spin-echo MR images using a numerical postprocessing technique. The main idea of this technique is to deform the volume image histogram of each study to match a standard histogram and to utilize the resulting transformation to map the image intensities into standard scale. Upon standardization, the coefficients of variation of signal intensities for each segmented tissue (gray matter, white matter, lesion plaques, and diffuse abnormal white matter) in all patients were significantly smaller (2.3-9.2 times) than in the original images, and the same tissues from different patients looked alike, with similar intensity characteristics. Numerical tissue characterizability of different tissues in MS achieved by standardization offers a fixed tissue-specific meaning for the numerical values and can significantly facilitate image segmentation and analysis. %B JOURNAL OF MAGNETIC RESONANCE IMAGING %V 12 %P 715 - 721 %8 2000/// %@ 1053-1807 %G eng %N 5 %! JMRI - J MAGN RESON IM %0 Conference Paper %B International Society for Magnetic Resonance in Medicine: Eight Scientific Meeting and Exhibition %D 2000 %T Numerical Tissue Characterization in MS via Standardization of the MR Image Intensity Scale %A Yiyue Ge %A Jayaram K Udupa %A László Gábor Nyúl %A Lougang Wei %A Robert J Grossman %B International Society for Magnetic Resonance in Medicine: Eight Scientific Meeting and Exhibition %C Berkeley %P 579 %8 Apr 2000 %G eng %0 Generic %D 1999 %T Magnetization Transfer Histogram Analysis of Segmented Normal- Appearing White Matter in Multiple Sclerosis %A Isabelle Catalaa %A Robert J Grossman %A Jayaram K Udupa %A László Gábor Nyúl %A Dennis L Kolson %A Lougang Wei %A Xuan Zhang %A Marcia Polansky %A Lois J Mannon %A Joseph C McGowan %8 1999/// %G eng %0 Conference Paper %B International Society for Magnetic Resonance in Medicine: Seventh Scientific Meeting and Exhibition %D 1999 %T Magnetization Transfer Histogram Analysis of Segmented Normal-Appearing White Matter in Multiple Sclerosis %A Isabelle Catalaa %A Robert J Grossman %A Dennis L Kolson %A László Gábor Nyúl %A Lougang Wei %A Jayaram K Udupa %A Marcia Polansky %A Joseph C McGowan %E *[International Society fo *Medicine] %B International Society for Magnetic Resonance in Medicine: Seventh Scientific Meeting and Exhibition %C Berkeley %P 957 %8 May 1999 %G eng %0 Generic %D 1999 %T Numerical Tissue Characterization in MS via Standardization of the MR Image Intensity Scale %A Yiyue Ge %A Jayaram K Udupa %A László Gábor Nyúl %A Lougang Wei %A Robert J Grossman %8 1999/// %G eng