# US 2010/0166284 A1 · Quantitative single image-based magnetization transfer weighted imaging using an inter-subject normalization reference within the image > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166284 A1 - Document ID: US20100166284A1 - Status: Published application - Kind: A1 - Application number: 12/719,610 - Filed: 2010-03-08 - Published: 2010-07-01 - Earliest claimed: 2004-08-17 - Inventors: Seth Smith; Xavier Golay; Peter C.M. van Zijl - Web page: https://patentgrep.com/patent/US20100166284A1 ## CPC - A61B 5/055: involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging - A61B 5/407: {Evaluating the spinal cord (for locating the epidural space A61B5/4896)} - G01R 33/5605: {by transferring coherence or polarization from a spin species to another, e.g. creating magnetization transfer contrast [MTC], polarization transfer using nuclear Overhauser enhancement [NOE]} - G06T 7/0014: {using an image reference approach} - G01R 33/54: Signal processing systems, e.g. using pulse sequences {; Generation or control of pulse sequences; Operator console} - G01R 33/56509: {due to motion, displacement or flow, e.g. gradient moment nulling (G01R33/567 takes precedence)} - G01R 33/5659: {caused by a distortion of the RF magnetic field, e.g. spatial inhomogeneities of the RF magnetic field (G01R33/56509, G01R33/56518, G01R33/56536 take precedence)} - G06T 2207/10088: Magnetic resonance imaging [MRI] - G06T 2207/20104: Interactive definition of region of interest [ROI] - G06T 2207/30004: Biomedical image processing - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract Disclosed is a system and method for generating quantitative imagery of demyelination in the spinal cord. The method includes acquiring a magnetization transfer weighted (MTw) MR image of the spinal column, identifying a reference region of interest within the image corresponding to cerebrospinal fluid (CSF), averaging the signal intensity corresponding to the reference region of interest, and computing a ratio, on a voxel-by-voxel basis, of the signal intensity of each voxel by the averaged reference signal intensity. In doing so, normalized MTw images are obtained such that detrimental artifacts such as motion-induced errors, coil loading, and RF coil sensitivity variations are obviated. ## Claims ### Claim 1 A method for quantifying loss of macromolecular components in tissue, comprising: acquiring an MTw image of the tissue, the MTw image having a plurality of voxels, wherein each voxel has a corresponding MR signal; identifying a reference region of voxels within the plurality of voxels, wherein the region of voxels corresponds to a reference material having a minimal magnetization transfer effect; computing a reference MR signal corresponding to the region of voxels; and computing a normalized MT weighted image, based on the ratio of the MTw image and the reference MR signal. ### Claim 2 (depends on 1) The method of claim 1, wherein computing the reference MR signal comprises computing an average of a plurality of MR signals corresponding to the region of voxels. ### Claim 3 (depends on 1) The method of claim 1, wherein acquiring the MTw image comprises employing an image acquisition scheme with an MT preparation pre-pulse. ### Claim 4 (depends on 1) The method of claim 1, wherein acquiring the MTw image comprises employing a T2* weighted pulse sequence with an MT pre-pulse. ### Claim 5 (depends on 1) The method of claim 1, wherein the tissue comprises spinal cord tissue. ### Claim 6 (depends on 5) The method of claim 5, wherein the reference material comprises cerebrospinal fluid. ### Claim 7 (depends on 1) The method of claim 1, wherein computing the normalized MT weighted image comprises dividing each MTw signal by the reference MR signal. ### Claim 8 (depends on 1) The method of claim 1, further comprising: acquiring a second MR image; and comparing the second MR image with the MT weighted image. ### Claim 9 An MRI system, comprising: a main magnet; a gradient coil; an RF coil; and a computer having a computer readable medium encoded with a program for acquiring an MTw image of the tissue, the MTw image having a plurality of voxels, wherein each voxel has a corresponding MR signal; identifying a reference region of voxels within the plurality of voxels, wherein the region of voxels corresponds to a reference material having a minimal magnetization transfer effect; computing a reference MR signal corresponding to the region of voxels; and computing an MTCSF image, based on the MR image and the reference MR signal. ### Claim 10 (depends on 9) The MRI system of claim 9, wherein the program for computing the reference MR signal comprises a program for computing an average of a plurality of MR signals corresponding to the reference region of voxels. ### Claim 11 (depends on 9) The MRI system of claim 9, wherein the program for computing the MTCSF image comprises a program for dividing each MTw signal by the reference MR signal. ### Claim 12 A method for quantifying demyelination in a spinal cord, comprising: acquiring an MTw image of the spinal cord, the MTw image having a plurality of voxels, wherein each voxel has a corresponding MR signal; identifying a reference region of voxels within the plurality of voxels, wherein the region of voxels corresponds to cerebrospinal fluid; computing a reference MR signal corresponding to the region of voxels; and computing a normalized MT weighted image, based on the ratio of the MTw image and the reference MR signal. ### Claim 13 (depends on 12) The method of claim 12, further comprising identifying a hyperintensity signal region within a portion of the spinal cord that corresponds to white matter. ### Claim 14 (depends on 12) The method of claim 12, further comprising: acquiring a conventional MR image of the spinal cord; and comparing the normalized MT weighted image with the conventional MR image. ### Claim 15 (depends on 14) The method of claim 14, wherein comparing the normalized MT weighted image comprises co-registering the conventional MR image and the normalized MT weighted image.