# US 2013/0154638 A1 · Method for computing pharmacokinetic parameters in mri > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154638 A1 - Document ID: US20130154638A1 - Status: Published application - Kind: A1 - Application number: 13/438,338 - Filed: 2012-04-03 - Published: 2013-06-20 - Earliest claimed: 2011-12-16 - Assignees: Rajiv Gandhi Cancer Institute & Research Centre - Inventors: Amarnath Jena; Shashi Bhushan Mehta; Sangeeta Taneja; Urmi Sarkar - Web page: https://patentgrep.com/patent/US20130154638A1 ## CPC - G01R 33/50: based on the determination of relaxation times {, e.g. T1 measurement by IR sequences; T2 measurement by multiple-echo sequences} - G01R 33/4828: {Resolving the MR signals of different chemical species, e.g. water-fat imaging} - G01R 33/56366: {Perfusion imaging} - G01R 33/5601: {involving use of a contrast agent for contrast manipulation, e.g. a paramagnetic, super-paramagnetic, ferromagnetic or hyperpolarised contrast agent} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract The present invention relates to a method of dynamic contrast magnetic resonance imaging aimed to improve characterization of tissue image by improving accuracy of computed pharmacokinetic parameters such as Ktrans (transfer constant across capillary membrane; a pharmacokinetic parameter of tissue perfusion) using T1W Fast DCE-MRI technique to distinguish between malignant, benign and normal tissues. A phantom and a contrast agent are used in the proposed MRI system for computing accurate T1 value of a tissue after the contrast is injected based on an intrinsic T10 value the tissue, wherein the intrinsic T10 value is adjusted and/or normalized to improve accuracy of the T1 value computed, which in turn is used for computation of pharmacokinetic parameters at least one of Ktrans. ## Claims ### Claim 1 A method of computing pharmacokinetic parameters comprising: using a phantom of a known T1 value and computing a deviation factor when said phantom is placed in an MRI system; normalizing intrinsic T1 value of a sample tissue using said computed deviation factor when said sample tissue is placed in the MRI system; and computing said pharmacokinetic parameters using said normalized T1 value of the sample tissue. ### Claim 2 (depends on 1) The method of computing pharmacokinetic parameters of claim 1, wherein T1 value is spin lattice relaxation time. ### Claim 3 (depends on 1) The method of computing pharmacokinetic parameters of claim 1, wherein said intrinsic T1 value of the sample tissue is computed and normalized before and every n seconds after a contrast agent is injected into the sample tissue. ### Claim 4 (depends on 3) The method of computing pharmacokinetic parameters of claim 3, wherein a standard model, a shutter speed model, or a combination thereof are incorporated after the contrast agent is injected into the sample tissue. ### Claim 5 (depends on 3) The method of computing pharmacokinetic parameters of claim 3, wherein a net T1 value is computed based on said normalized intrinsic T1 value of the sample tissue at each of said n seconds after the contrast is injected, and wherein the pharmacokinetic parameters are computed based on said net T1 value. ### Claim 6 (depends on 3) The method of computing pharmacokinetic parameters of claim 3, wherein said contrast agent comprises one or more of Gadolinium (Gd), Gadopentate dimeglumine Gd-DTPA, Omniscan, Multihance, Magnevist, Prohance, OptiMARK, Dotarem. Supermagnetic iron oxide compounds, Cliavist, Combidex, Feridex, Resovist, Supermagnetic iron platinum, and paramagnetic manganese compounds. ### Claim 7 (depends on 1) The method of computing pharmacokinetic parameters of claim 1, wherein said pharmacokinetic parameters are computed to classify the sample tissue as one of malign, benign, or normal tissue. ### Claim 8 (depends on 1) The method of computing pharmacokinetic parameters of claim 1, wherein said pharmacokinetic parameter comprises of one or more of Ktrans, Kep, and Ve. or any tissue parameter using such T1 correction for computation. ### Claim 9 (depends on 1) The method of computing pharmacokinetic parameters of claim 1, further comprising the step of conducting curve smoothening/fitting of signal intensity values computed based on normalized intrinsic T1 values, wherein the signal intensity values are intensity values of the sample tissue. ### Claim 10 (depends on 1) The method of computing pharmacokinetic parameters of claim 1, wherein the phantom is composed of materials having magnetic resonance signal, and wherein said materials comprise of one or more of aqueous paramagnetic solutions, pure gels of gelatin, agar, polyvinyl alcohol, silicone, polyacrylamide, or agarose, organic dopped gels, paramagnetically dopped gels, and reverse micelle solutions. ### Claim 11 A computer system comprising: a processor; and a program storage device readable by the computer system, embodying a program of instructions executable by the processor to perform method steps for computing pharmacokinetic parameters, the method comprising: using a phantom of a known T1 value and computing a deviation factor when said phantom is placed in an MRI system; normalizing intrinsic T1 value of a sample tissue using said computed deviation factor when said sample tissue is placed in the MRI system; and computing said pharmacokinetic parameters using said normalized T1 value of the sample tissue. ### Claim 12 A magnetic resonance imaging (MRI) system comprising a controller for causing computation of pharmacokinetic parameters by the steps of using a phantom of a known T1 value and computing a deviation factor when said phantom is placed in the MRI system; normalizing intrinsic T1 value of a sample tissue using said computed deviation factor when said sample tissue is placed in the MRI system; and computing said pharmacokinetic parameters using said normalized T1 value of the sample tissue.