Quantitating disease progression from the MRI images of multiple sclerosis patients
Methods and systems are provided for the automated detection and analysis of structural tissue alterations related to myelin and axons/neurons in one or more biological structures of a patient's nervous system obtained from data from a medical imaging system, or the initial sensing or data collection processes such as, those that could be used to generate an image. In some embodiments, the method comprises, at a system having a memory and one or more processor for processing and displaying images of the biological structure, computationally processing at least a T1 weighted magnetic resonance image of the structure and a T2 weighted magnetic resonance image of the structure in order to analyze at least a portion of the structure of the nervous system using a plurality of stored tissue classifier elements to determine if the portion of the structure correlates with the presence of myelin. Such methods are useful for the detection of diseases associated with demyelination.
1. A method of classifying myelin components to determine whether a biological structure of the nervous system contains myelin, the method comprising, at a system having a memory and one or more processor for processing and displaying images of the biological structure: computationally processing at least a T1 weighted magnetic resonance image of the structure and a T2 weighted magnetic resonance image of the structure in order to analyze at least a portion of the structure of the nervous system using a plurality of stored tissue classifier elements developed using statistical modeling to determine if the portion of the structure correlates with the presence of myelin, in which event the portion of the structure is determined to contain myelin, wherein the computational processing includes:
registering the T2 weighted magnetic resonance image with the T1 weighted magnetic resonance image by aligning a voxel in the T2 weighted magnetic resonance image with a corresponding voxel in the T1 weighted magnetic resonance image; and
dividing, for each voxel in the registered T2 weighted image, a first intensity value in the registered T2 weighted image by a second intensity value of the corresponding voxel in the T1 weighted magnetic resonance image to generate a map of the biological structure.
2. The method of claim 1 , wherein said computation processing further includes scaling the map of the biological structure by a constant value.
3. The method of claim 1 , wherein the plurality of stored tissue classifier elements are developed using reference data by multivariate regression.
4. The method of claim 1 , wherein the plurality of stored tissue classifier elements is determined by a process selected from the group consisting of post-operative histological examination, direct tissue inspection, and labeling by one or more experts.
5. The method of claim 1 , wherein the biological structure is the brain or spinal cord.
6. The method of claim 1 , wherein the computation processing further includes applying a mask to identify a specific tissue type in the biological structure.
7. The method of claim 6 , wherein the specific tissue type is white matter.
8. The method of claim 6 , wherein the specific tissue type is gray matter.
9. The method of claim 1 , wherein the computation processing further includes generating a Z-score map by comparing the map of the biological structure to a reference map.
10. The method of claim 9 , wherein the reference map is generated from data of biological structure from a normal subject or a subject having a disease.
11. The method of claim 1 , wherein the biological structure is of the central nervous system.
12. The method of claim 1 , wherein the computation processing further includes applying a mask to suppress noise.
13. The method of claim 1 , further comprising communicating results of the computational processing and determination of whether the biological structure contains myelin to a remote address.
14. A method of assessing effectiveness of a therapeutic regimen, comprising:
a) determining a myelin volume in at least a portion of a biological structure of a patient using the method of claim 1 ;
b) delivering to the patient a therapeutic regimen comprising administration of a drug expected to stabilize or increase myelin volume over the course of the therapeutic regimen; and
c) during and/or at the end of the therapeutic regimen, determining whether the myelin volume has stabilized or been increased, thereby allowing assessment of the effectiveness of the therapeutic regimen.