CALIBRATION OF MRI SYSTEMS USING PRE-DEFINED CONCENTRATIONS OF 19F ISOTOPES AS REFERENCE

Abstract

A kit for calibrating a magnetic resonance imaging (MRI) system using defined concentration of .sup.19F isotopes as well as a device for calibrating a MRI system using the kit. Further, a method for calibrating a MRI system employing the kit as well as to an entity comprising a defined concentration of .sup.19F isotopes to be used in the calibration of a MRI system.

Claims

1.-20. (canceled)

21. A kit for calibrating a magnetic resonance imaging (MRI) system, said kit comprising a plurality of entities, wherein two or more of said plurality of entities have a defined concentration of .sup.19F isotopes and a matrix material, wherein the .sup.19F isotopes stem from a contrast agent which is at least partially embedded and/or encapsulated by the matrix material, and wherein two or more of said concentrations are different from each other, and wherein the .sup.19F isotopes stem from a fluorinated contrast agent selected from a group consisting of partially fluorinated carbon compounds, perfluoroalkyl bromide and perfluoroalkyl chloride.

22. The kit according to claim 21, wherein the .sup.19F isotopes stem from a semifluorinated alkan or perfluorooctylbromid (PFOB).

23. The kit according to claim 21, wherein the .sup.19F isotopes stem from a semifluorinated compound of formula (I):
CF.sub.3(CF.sub.2).sub.x(CH.sub.2).sub.yCH.sub.3 (I), wherein x is an integer ranging from 1 to 8 and y is an integer ranging from 2 to 10.

24. The kit according to claim 21, wherein the fluorinated contrast agent is present in the two or more entities in a form of a liquid.

25. The kit according to claim 21, wherein the amount of fluorinated contrast agent in at least one entity is at least 10% by weight based on the total weight of the at least one entity.

26. The kit according to claim 21, wherein the matrix is selected from silicon containing compounds, especially selected from organosilicon compounds.

27. The kit according to claim 21, wherein the matrix is selected from organosilicon compounds.

28. Use of the kit according to claim 21 as an external standard in MRI measurements.

29. A method for producing a kit, the method comprising the following steps: a) providing a plurality of entities, wherein two or more of said plurality of entities have a defined concentration of .sup.19F isotopes and a matrix material, wherein the .sup.19F isotopes stem from a contrast agent which is at least partially embedded and/or encapsulated by the matrix material, and wherein two or more of said concentrations are different from each other, and wherein the .sup.19F isotopes stem from a fluorinated contrast agent selected from a group consisting of partially fluorinated carbon compounds, perfluoroalkyl bromide and perfluoroalkyl chloride; and b) assembling the entities to obtain the kit.

30. The method according to claim 29, wherein two or more of the plurality of entities are obtained by: i) providing a matrix material; ii) providing the fluorinated contrast agent comprising .sup.19F isotopes; and iii) mixing the components of steps i) and ii).

31. The method according to claim 30, further comprising the step of curing the mixture of step iii).

32. The method according to claim 30, further comprising the step of enclosing the mixture of step iii) in a capsule.

33. A device for calibrating a MRI system comprising the following components: i) a detector coil for detecting a concentration of .sup.19F isotopes in a tissue sample, wherein the detector coil is part of an MRI system; ii) a kit comprising a plurality of entities, wherein two or more of said plurality of entities each have a defined concentration of .sup.19F isotopes, and a matrix material, wherein the .sup.19F isotopes stem from a contrast agent which is at least partially embedded and/or encapsulated by the matrix material, said concentrations being different from each other, and wherein the .sup.19F isotopes stem from a fluorinated contrast agent selected from a group consisting of partially fluorinated carbon compounds, perfluoroalkyl bromide and perfluoroalkyl chloride; iii) tissue sample to be examined which has been treated with a .sup.19F-fluorinated contrast agent; wherein the kit and the tissue sample to be examined are both simultaneously present in an area to be scanned by the detector coil.

34. The device according to claim 33 wherein the kit is fixed in place with respect to the tissue sample.

35. A method for calibrating a MRI system comprising the following steps: providing a kit comprising two or more entities, wherein each of said two or more entities have a defined concentration of .sup.19F isotopes, and a matrix material wherein the .sup.19F isotopes stem from a contrast agent which is at least partially embedded and/or encapsulated by the matrix material, said defined concentrations being different from each other, wherein the .sup.19F isotopes stem from a fluorinated contrast agent selected from a group consisting of partially fluorinated carbon compounds, perfluoroalkyl bromide and perfluoroalkyl chloride; providing a sample tissue to be examined wherein the sample tissue has been treated with a .sup.19F-fluorinated contrast agent prior to examination; providing a detection coil which is part of an MRI system; placing the kit and the sample tissue in an area to be scanned by the detection coil; simultaneously detecting signals generated by the .sup.19F isotopes in the kit and the sample tissue by the detection coil; numerically evaluating the signals of the .sup.19F isotopes of the kit; and calibrating the system based on the known concentration of the detected .sup.19F isotopes of the kit.

36. The method according to claim 35, wherein a calibration of the system is conducted with reference to each defined concentration of .sup.19F isotopes of the kit.

37. The method according to claim 35, further comprising the step of: determining the concentration of .sup.19F isotopes in the sample tissue by reference to the defined concentrations of .sup.19F isotopes of the kit.

38. The method according to claim 35, wherein the fluorinated contrast agent is in the form of an aqueous emulsion comprising a semifluorinated compound and a medium chain triglyceride (MCT) which is miscible with the semifluorinated compound at 20 C.

39. An entity comprising a defined concentration of a .sup.19F-containing contrast agent and a matrix material wherein the contrast agent is at least partially embedded and/or encapsulated by the matrix material and wherein the .sup.19F isotopes stem from a fluorinated contrast agent selected from a group consisting of partially fluorinated carbon compounds, perfluoroalkyl bromide and perfluoroalkyl chloride.

40. The entity according to claim 39, wherein the fluorinated contrast agent is selected from a semifluorinated compound of formula (I)
CF.sub.3(CF.sub.2).sub.x(CH.sub.2).sub.yCH.sub.3 (I), wherein x is an integer ranging from 1 to 8 and y is an integer ranging from 2 to 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0114] The invention is best understood when read in connection with the accompanying drawings.

[0115] FIG. 1 shows the inventive kit as well as the inventive entities in the exemplary form of a pad and tablets, respectively.

[0116] FIG. 2 shows the schematic assembly of the inventive kit in form of a pad in relation to a patient and a MRI system, the abbreviation A, B, C, D and E illustrating the single entities of the pad with different concentrations of .sup.19F isotopes.