Method and device for obtaining information about a mammalian body

• US 8,335,554 B2
• Filed: 08/17/2007
• Issued: 12/18/2012
• Est. Priority Date: 08/22/2006
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Pananakis, Dimitrios, Harvey, Paul Royston
• Primary Examiner(s): Casler, Brian
• Assistant Examiner(s): Lamprecht, Joel
• Application Number:
  US12/438,246
• Publication Number:
  US 20090192383A1
• Time in Patent Office: 1,950 Days
• Field of Search: 600/407, 600/410, 600/411, 600/439
• US Class Current: 600/411
• CPC Class Codes: A61B 5/015 By temperature mapping of body part
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61N 1/403 for thermotherapy, e.g. hyperthermia
• CPC Class Codes: G01R 33/4804 Spatially selective measurement of temperature or pH

Abstract

This invention relates to a device for retrieving information about one or more states of a mammalian body comprising: (a) a magnetic resonance imaging device comprising a first set of one or more radio-frequency coils for measuring the body temperature Ti at a selected location of a mammalian body, (b) a local heating means including a second set of one or more radio-frequency coils, said second set comprising at least two channels for delivering focused radio frequency energy to said selected location of said mammalian body and raising the temperature Ti thereof, and (c) means for modulating said radio-frequency energy delivered by said second set of coils as a function of said temperature Ti in order to reach and maintain a predefined temperature Tp above the normal mammalian body temperature Tb.

Claims

1. A radio frequency unit, comprising:

(i) a magnetic resonance imaging device comprising a radio-frequency monitoring coil, the radio-frequency monitoring coil measuring a temperature T₁ at a selected location of a mammalian body and operating at a frequency v₁, wherein the frequency v₁ is a Larmor frequency of a ¹H nucleus and is between 120 and 130 MHz,

(ii) one or more radio-frequency focusing coils delivering focused energy to said selected location of said mammalian body and raising the temperature T₁ thereof, said one or more radio-frequency focusing coils comprising at least two channels and operating at a frequency v₂ at least 50 kHz apart and at most 25000 kHz apart from the frequency v₁ of said radio-frequency monitoring coil, and

(iii) a controller modulating said focused energy delivered by said one or more radio-frequency focusing coils as a function of said temperature T₁ to reach and maintain a predefined temperature T_p above a normal mammalian body temperature T_b.

2. The radio frequency unit according to claim 1, wherein said one or more radio-frequency focusing coils:

1) provide energy at said selected location of said mammalian body and operate at said frequency v₁; and

     2) receive signals containing location-dependent phase information and location-dependent amplitude information, during a calibration stage of said one or more radio-frequency focusing coils.

4. The radio frequency unit according to claim 2, wherein the controller determines from said location-dependent phase information and said location dependent amplitude information, for each channel of said one or more radio-frequency focusing coils, a phase and/or an amplitude required for emitting radio-frequency energy from said each channel to produce maximal radio-frequency energy from said each channel at said selected location of said mammalian body.

7. The radio frequency unit according to claim 1, wherein said magnetic resonance imaging device is configured to utilize an enhanced proton shift technique, the enhanced proton shift technique taking in to account fat phase information for thermometry measurements.

8. An arrangement for thermodynamic therapy comprising:

the radio frequency unit according to claim 1, and

a thermally activatable delivery system which releases one or more agents administered to said mammalian body, said one or more agents administered before said temperature of said selected location of said mammalian body is raised, and said one or more agents being released at the selected location of said mammalian body in response to the temperature T₁ of said selected location of said mammalian body being raised to the predefined temperature T_p above the normal mammalian body temperature T_b,

wherein said radio frequency unit monitors a transient concentration of said one or more agents at said selected location of said mammalian body by a Magnetic Resonance Imaging technique involving said radio-frequency monitoring coil.

9. The arrangement according to claim 8, wherein at least one of the agents are enclosed within a temperature sensitive structure which releases said at least one of the agents in response to the temperature T₁ being raised to the predefined temperature T_p above the normal mammalian body temperature T_b.

10. The arrangement according to claim 8, wherein 36°

C.≦

T_p≦

45°

C.

11. The arrangement according to claim 9, wherein said temperature sensitive structure is a temperature sensitive membrane.

12. The arrangement according to claim 11, wherein said temperature sensitive membrane comprises a liposome.

13. The arrangement according to claim 12, wherein said liposome comprises a lysolipid-containing liposome.

14. The arrangement according to claim 8, wherein said one or more agents is selected from a group consisting of antineoplastic agents, antitumor agents, antibiotics agents antifungals agents, anti-inflammatory agents, immunosuppressive agents, anti-infective agents, antivirals agents, anthelminthic agents, gene for gene therapy and antiparasitic agents.

15. The arrangement according to claim 8, wherein said radio frequency unit monitors said transient concentration of said one or more agents at said selected location of said mammalian body by Magnetic Resonance spectroscopy.

16. The arrangement according to claim 8, wherein said thermally activatable delivery system includes one or more agent concentration markers.

17. The arrangement according to claim 16 wherein said one or more agent concentration markers are selected from a group consisting of gadolinium solutions, gadolinium-impregnated microspheres, ¹³C, ¹⁵N, ³¹P, ²³Na and ¹⁹F containing species.

18. The arrangement according to claim 16, wherein the radio frequency unit controls the transient concentration by monitoring said one or more agent concentration markers by means of the Magnetic Resonance Imaging technique.

19. The arrangement according to claim 8, wherein said one or more radio-frequency focusing coils includes at least one of:

two or more mono-channel radio-frequency coils; and

one or more multi-channel radio-frequency coils.

20. The radio frequency unit according to claim 1, wherein said one or more radio-frequency focusing coils are different than said radio-frequency monitoring coil.

3. A radio frequency unit, comprising:

(i) a magnetic resonance imaging device comprising a radio-frequency monitoring coil, the radio-frequency monitoring coil measuring a temperature T₁ at a selected location of a mammalian body and operating at a frequency v₁, wherein the frequency v₁ is a Lamor frequency of a ¹H nucleus and is between 120 and 130 MHz,

(ii) one or more radio-frequency focusing coils delivering focused energy to said selected location of said mammalian body and raising the temperature T₁ thereof, said one or more radio-frequency focusing coils comprising at least two channels and operating at a frequency v₂ at least 50 kHz apart and at most 25000 kHz apart from the frequency v₁ of said radio-frequency monitoring coil,

(iii) a controller modulating said focused energy delivered by said one or more radio-frequency focusing coils as a function of said temperature T₁ to reach and maintain a predefined temperature T₂ above a normal mammalian body temperature T_b, and

(iv) an additional monitoring coil operating at a frequency v₃ monitoring a transient concentration of one or more agents at said selected location of said mammalian body, wherein the frequency v₃ is a Larmor frequency of a nucleus other than the ¹H nucleus and is at least 50 kHz apart and at most 25000 kHz apart from the frequency v₂.

5. A system for thermodynamic therapy comprising:

(i) a set of one or more radio-frequency focusing coils which focus energy at a frequency v₂ at a selected location of a mammalian body to locally raise a temperature T₁ of said mammalian body at the selected location until a predefined temperature T_p is obtained, and

(ii) a controller which monitors the temperature T₁ of the selected location of the mammalian body by a Magnetic Resonance Imaging technique operating at a frequency v₁ simultaneously with said raising of said temperature T₁ of said selected location of the mammalian body, wherein an absolute difference of the frequency v₂ and the frequency v₁ is between 50 to 25000 kHz, and wherein the frequency v₁ is a ¹H Lamor frequency between 120 and 130 MHz.

6. The system according to claim 5 further including:

a thermally activatable delivery system, the thermally activatable delivery system releasing one or more agents at the selected location of the mammalian body in response to the temperature T₁ of said selected location of said mammalian body being raised to the predefined temperature T_p above a normal mammalian body temperature T_b, wherein the Magnetic Resonance Imaging technique operates to monitor a transient concentration of said one or more agents at said selected location of said mammalian body.