@article {1004, title = {Brain atrophy in relapsing-remitting multiple sclerosis: Fractional volumetric analysis of gray matter and white matter}, journal = {RADIOLOGY}, volume = {220}, year = {2001}, note = {UT: 000170616700008ScopusID: 0034866802doi: 10.1148/radiol.2203001776}, month = {2001///}, pages = {606 - 610}, abstract = {PURPOSE: To determine the fractional brain tissue volume changesin the gray matter and white matter of patients with relapsing- remitting multiple sclerosis (MS) and to correlate these measurements with clinical disability and total lesion load. MATERIALS AND METHODS: Thirty patients with relapsing-remitting MS and 25 healthy control subjects underwent magnetic resonance imaging. Fractional brain tissue volumes (tissue volume relative to total intracranial volume) were obtained from the total segmented gray matter and white matter in each group and were analyzed. RESULTS: The fractional volume of white matter versus that of gray matter was significantly lower (-6.4\%) in patients with MS (P <.0001) than in control subjects. Neither gray matter nor white matter fractional volume measurements correlated with clinical disability in the patients with MS. CONCLUSION: Loss of brain parenchymal volume in patients with relapsing-remitting MS is predominantly confined to white matter. Analysis of fractional brain tissue volumes provides additional information useful in characterizing MS and may have potential in evaluating treatment strategies. }, isbn = {0033-8419} } @article {1002, title = {Multiprotocol MR image segmentation in multiple sclerosis: Experience with over 1,000 studies}, journal = {ACADEMIC RADIOLOGY}, volume = {8}, year = {2001}, note = {UT: 000171987900006ScopusID: 0034767131doi: 10.1016/S1076-6332(03)80723-7}, month = {2001///}, pages = {1116 - 1126}, abstract = {RATIONALE AND OBJECTIVES: Multiple sclerosis (MS) is an acquireddisease of the central nervous system. Several clinical measures are commonly used to express the severity of the disease, including the Expanded Disability Status Scale and the ambulation index. These measures are subjective and may be difficult to reproduce. The aim of this research is to investigate the possibility of developing more objective measures derived from MR imaging. MATERIALS AND METHODS: Various magnetic resonance (MR) imaging protocols are being investigated for the study of MS. Seeking to replace the Expanded Disability Status Scale and ambulation index with an objective means to assess the natural course of the disease and its response to therapy, the authors have developed multiprotocol MR image segmentation methods based on fuzzy connectedness to quantify both macrosopic features of the disease (lesions, gray matter, white matter, cerebrospinal fluid, and brain parenchyma) and the microscopic appearance of diseased white matter. Over 1,000 studies have been processed to date. RESULTS: By far the strongest correlations with the clinical measures were demonstrated by the magnetization transfer ratio histogram parameters obtained for the various segmented tissue regions. These findings emphasize the importance of considering the microscopic and diffuse nature of the disease in the individual tissue regions. Brain parenchymal volume also demonstrated a strong correlation with clinical measures, which suggests that brain atrophy is an important disease indicator. CONCLUSION: Fuzzy connectedness is a viable, highly reproducible segmentation method for studying MS. }, isbn = {1076-6332} } @booklet {1076, title = {Brain Atrophy in Relapsing-Remitting Multiple Sclerosis: A Fractional Volumetric Analysis of Gray Matter and White Matter}, year = {2000}, month = {2000///} } @booklet {1074, title = {Magnetization Transfer Ratio Histogram Analysis of Normal Appearing Gray Matter and White Matter in MS}, year = {2000}, month = {2000///} } @inbook {1013, title = {Multiprotocol MR image segmentation in multiple sclerosis: experience with over 1000 studies}, booktitle = {Medical Imaging 2000: Image Processing}, year = {2000}, note = {ScopusID: 0033721228doi: 10.1117/12.387606}, month = {2000///}, pages = {1017 - 1027}, publisher = {SPIE}, organization = {SPIE}, address = {Bellingham; Washington}, abstract = {Multiple Sclerosis (MS) is an acquired disease of the centralnervous system. Subjective cognitive and ambulatory test scores on a scale called EDSS are currently utilized to assess the disease severity. Various MRI protocols are being investigated to study the disease based on how it manifests itself in the images. In an attempt to eventually replace EDSS by an objective measure to assess the natural course of the disease and its response to therapy, we have developed image segmentation methods based on fuzzy connectedness to quantify various objects in multiprotocol MRI. These include the macroscopic objects such as lesions, the gray matter (GM), white matter (WM), cerebrospinal fluid (CSF), and brain parenchyma as well as the microscopic aspects of the diseased WM. Over 1000 studies have been processed to date. By far the strongest correlations with the clinical measures were demonstrated by the Magnetization Transfer Ratio (MTR) histogram parameters obtained for the various segmented tissue regions emphasizing the importance of considering the microscopic/diffused nature of the disease in the individual tissue regions. Brain parenchymal volume also demonstrated a strong correlation with the clinical measures indicating that brain atrophy is an important indicator of the disease. Fuzzy connectedness is a viable segmentation method for studying MS. } } @article {1003, title = {Numerical tissue characterization in MS via standardization of the MR image intensity scale}, journal = {JOURNAL OF MAGNETIC RESONANCE IMAGING}, volume = {12}, year = {2000}, note = {UT: 000171295400008ScopusID: 0033754689doi: 10.1002/1522-2586(200011)12:5\<715::AID-JMRI8\>3.0.CO;2-D}, month = {2000///}, pages = {715 - 721}, abstract = {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. }, isbn = {1053-1807} } @conference {1019, title = {Numerical Tissue Characterization in MS via Standardization of the MR Image Intensity Scale}, booktitle = {International Society for Magnetic Resonance in Medicine: Eight Scientific Meeting and Exhibition}, year = {2000}, month = {Apr 2000}, pages = {579}, address = {Berkeley} } @conference {1018, title = {Tissue Characterization in Relapsing-remitting and Secondary-progressive MS via Magnetization Transfer Ratio}, booktitle = {International Society for Magnetic Resonance in Medicine: Eight Scientific Meeting and Exhibition}, year = {2000}, month = {Apr 2000}, pages = {1189}, address = {Berkeley} } @booklet {1073, title = {Numerical Tissue Characterization in MS via Standardization of the MR Image Intensity Scale}, year = {1999}, month = {1999///} }