MR IMAGING GUIDED THERAPY

• US 20120070058A1
• Filed: 05/27/2010
• Published: 03/22/2012
• Est. Priority Date: 06/02/2009
• Status: Active Grant

• Current Assignee: Profound Medical Inc. (Profound Medical Corp.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Raju, Balasundara, Anand, Ajay, Ehnholm, Gosta Jakob
• Granted Patent: US 8,867,811 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

The invention relates to a therapeutic system comprising: a MR imaging unit arranged to acquire MR signals from a body (10) of a patient positioned in an examination volume, a thermal treatment unit (19, 20) for the deposition of thermal energy within tissue of the body (10). It is an object of the invention to enable continuous temperature monitoring based on MR thermometry even in a situation in which the focus of the thermal treatment is moved. To this end, the invention proposes that the system is arranged to perform the steps of: a) initiating thermal treatment by heating the tissue of the body (10) at the position of a focus within the examination volume, b) selective acquisition of MR signals from a first image plane (24), the position of the focus of the thermal treatment being located within the first image plane (24), c) reconstruction of a thermographic MR image from the MR signals acquired from the first image plane (24), d) computing a baseline thermographic MR image from the temperature distribution within at least one second image plane (25, 26, 27) being different from the first image plane (24), e) moving the focus of the thermal treatment to a new position within the examination volume, f) changing the position and/or orientation of the first image plane (24) corresponding to the new position of the focus of the thermal treatment, g) repeating steps b) and c), wherein the baseline thermographic MR image computed in step d) is used for thermographic image reconstruction in subsequent step c).

Claims

1. Therapeutic system (1) comprising:

a MR imaging unit arranged to acquire MR signals from a body (10) of a patient positioned in an examination volume,

a thermal treatment unit (19, 20) for the deposition of thermal energy within tissue of the body (10),

wherein the system is arranged to perform the steps of;

a) initiating thermal treatment by heating the tissue of the body (10) at the position of a focus within the examination volume,

b) selective acquisition of MR signals from a first image plane (24), the position of the focus of the thermal treatment being located within the first image plane (24),

c) reconstruction of a thermographic MR image from the MR signals acquired from the first image plane (24),

d) computing a baseline thermographic MR image from the temperature distribution within at least one second image plane (25, 26, 27) being different from the first image plane (24),

e) moving the focus of the thermal treatment to a new position within the examination volume,

f) changing the position and/or orientation of the first image plane (24) corresponding to the new position of the focus of the thermal treatment,

g) repeating steps b) and c), wherein the baseline thermographic MR image computed in step d) is used for thermographic image reconstruction in subsequent step c).

2. System of claim 1, further being arranged to compute the baseline thermographic MR image in step d) from MR signals selectively acquired from the at least one second image plane (25, 26, 27).

3. System of claim 1, wherein the first image plane (24) is congruent with the second image plane (25, 26, 27) after changing the position and/or orientation in step f).

4. System of claim 1, wherein the second image plane (25, 26, 27) is oriented essentially perpendicular to the first image plane (24).

5. System of claim 1, further being arranged to acquire MR signals from a set of two or more second image planes (25, 26, 27), the baseline thermographic MR image being computed in step d) by spatial interpolation of thermographic MR images reconstructed from the MR signals acquired from the set of second image planes (25, 26, 27).

6. System of claim 1, further being arranged to repeat steps b) to f) several times, the baseline thermographic MR image computed during each repetition in step d) being used for thermographic image reconstruction in step c) of the respective subsequent repetition.

7. System of claim 6, wherein the position and/or orientation of the at least one second image plane (25, 26, 27) remains fixed during repetitions of steps b) to f).

8. System of claim 1, further being arranged to reconstruct the thermographic images from the local proton resonance frequency shift.

9. Computer program comprising instructions for:

initiating thermal treatment by heating the tissue of a body,

selective acquisition of MR signals from a first region of the body,

reconstruction of a thermographic MR image from the MR signals acquired from the first region,

computing a baseline thermographic MR image from the spatial temperature distribution within a second region of the body,

changing the position and/or orientation of the first region,

selective acquisition of MR signals from the changed first region,

reconstruction of a thermographic MR image from the MR signals acquired from the changed first region by using the baseline thermographic MR image computed from the spatial temperature distribution within the second region.

10. Method of monitoring a thermal treatment of body tissue, including:

—

selective acquisition of MR signals from a first region of the body,

reconstruction of a thermographic MR image from the MR signals acquired from the first region;

computing a baseline thermographic MR image from the spatial temperature distribution within a second region of the body;

changing the position and/or orientation of the first region,

selective acquisition of MR signals from the changed first region,

reconstruction of a thermographic MR image from the MR signals acquired from the changed first region by using the baseline thermographic MR image computed from the spatial temperature distribution within the second region.