MAGNETIC RESONANCE SYSTEM AND METHOD FOR COMPREHENSIVE IMPLANTABLE DEVICE SAFETY TESTS AND PATIENT SAFETY MONITORING

• US 20120086449A1
• Filed: 03/31/2010
• Published: 04/12/2012
• Est. Priority Date: 04/01/2009
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Graesslin, Ingmar, Krueger, Sascha
• Application Number:
  US13/260,918
• Publication Number:
  US 20120086449A1
• Time in Patent Office: Days
• US Class Current: 324/309
• CPC Class Codes: G01R 33/285 Invasive instruments, e.g. catheters or biopsy needles, specially adapted for tracking, guiding or visualization by NMR
• CPC Class Codes: G01R 33/288 Provisions within MR facilities for enhancing safety during MR, e.g. reduction of the specific absorption rate [SAR], detection of ferromagnetic objects in the scanner room

Abstract

A magnetic resonance method comprises: performing (C1) a magnetic resonance procedure on a calibration subject including an implant device; detecting (C2) a pick-up coil (PUC) signal at least during a radio frequency transmit phase of operation (C1); performing (C3) three dimensional temperature mapping of the calibration subject using a magnetic resonance sequence configured to detect any temperature change induced in any part of the implant device by operation (C1); generating (C4) an unsafe condition criterion (30) for the detected PUC signal based on correlating a PUC signal characteristic detected by operation (C2) with a temperature change detected by operation (C3); performing (M5) the magnetic resonance procedure on a subject containing an implant device; detecting (M6) a PUC signal at least during a radio frequency transmit phase of operation (M5); and monitoring (M7) for an unsafe condition indicated by the PUC signal detected in operation (M6) satisfying the unsafe condition criterion (30).

Claims

1. A magnetic resonance method comprising:

(i) performing (C1) a magnetic resonance procedure on a calibration subject;

(ii) detecting (C2) a pick-up coil (PUC) signal at least during a radio frequency transmit phase of operation (i); and

(iv) generating (C4) an unsafe condition criterion (30) based on the detected PUC signal.

2. The magnetic resonance method as set forth in claim 1, wherein the magnetic resonance procedure is predetermined to be safe for the calibration subject, and the generating operation (iv) (C4) comprises:

generating the unsafe condition criterion (30) as a selected deviation from a PUC signal characteristic detected by operation (ii).

3. The magnetic resonance method as set forth in claim 2, wherein the calibration subject does not include an implant device.

4. The magnetic resonance method as set forth in claim 1, wherein the calibration subject includes an implant device, the method further comprising:

(iii) performing (C3) three-dimensional temperature mapping of the calibration subject using a magnetic resonance sequence that is configured to detect a temperature change induced in any part of the implant device by operation (i);

wherein the generating operation (iv) (C4) generates the unsafe condition criterion (30) based on correlating a PUC signal characteristic detected by operation (ii) with a temperature change detected by operation (iii).

5. The magnetic resonance method as set forth in claim 4, wherein operation (i) (C1) is repeated with different magnetic resonance sequence parameters until operation (iii) (C3) detects a temperature change induced in at least one part of the implant device.

6. The magnetic resonance method as set forth in claim 4, wherein operation (iv) (C4) comprises:

correlating (C4a) a PUC signal characteristic detected by operation (ii) (C2) with a temperature change detected by operation (iii) (C3); and

generating the unsafe condition criterion (30) by adding (C4b) a selected safety margin to the correlated PUC signal characteristic.

7. The magnetic resonance method as set forth in claim 4, wherein the operation (iv) (C4) generates an unsafe condition criterion (30) for the detected PUC signal based on correlating at least one of (i) a decrease in PUC signal amplitude and (ii) a change in PUC signal phase detected by operation (ii) (C2) with a temperature change detected by operation (iii) (C3).

8. The magnetic resonance method as set forth in claim 4, wherein operation (iii) (C3) comprises:

(iii) performing three-dimensional temperature mapping of the calibration subject using a proton resonance frequency (PRF) based magnetic resonance sequence that is configured to detect a temperature change induced in any part of the implant device by operation (i) (C1).

9. The magnetic resonance method as set forth in claim 8, wherein the calibration subject includes fat and water components and operation (iii) (C3) includes PRF adjustment based on the fat and water component MR signals.

11. The magnetic resonance method as set forth in claim 10, wherein the unsafe condition criterion (30) is generated by a method as set forth in any one of claim 1-9.

12. The magnetic resonance method as set forth in claim 11, wherein operations (i), (ii), and (iv) (C1, C2, C4) are performed using calibration subjects of different body dimensions to generate unsafe condition criterion (30) for the detected PUC signal for subjects of different body dimensions, and monitoring operation (vii) (M7) further includes selecting the unsafe condition criterion (30) for the detected PUC signal corresponding to a body dimension of the subject of performing operation (v) (M5).

13. The magnetic resonance method as set forth in claim 1, wherein:

the operation (ii) (C2) comprises detecting a plurality of PUC signals from a plurality of pick-up coils at least during a radio frequency transmit phase of operation (i) (C1); and

the operation (iv) (C4) generates an unsafe condition criterion (30) for the detected plurality of PUC signals based on at least one coil-to-coil coupling identified based on the plurality of PUC signals detected by operation (ii) (C2).

14. A digital storage medium storing instructions executable by a digital processor to perform a magnetic resonance method as set forth in claim 1.

15. A magnetic resonance system comprising:

a magnetic resonance scanner (10); and

a processor (12, 14, 20) configured to operate in cooperation with the magnetic resonance scanner to perform a magnetic resonance method as set forth in claim 1.

10. A magnetic resonance method comprising:

(v) performing (M5) a magnetic resonance procedure on a subject containing an implant device;

(vi) detecting (M6) a PUC signal at least during a radio frequency transmit phase of operation (v); and

(vii) monitoring (M7) for an unsafe condition during the operation (v) indicated by the PUC signal detected in operation (vi) satisfying an unsafe condition criterion (30).

16. A magnetic resonance system comprising:

a magnetic resonance scanner; and

a processor configured to operate in cooperation with the magnetic resonance scanner to perform a magnetic resonance method as set forth in claim 10.

17. A magnetic resonance system comprising:

a magnetic resonance scanner; and

a processor configured to operate in cooperation with the magnetic resonance scanner, and further configured to;

perform a magnetic resonance procedure on a calibration subject;

detect a pick-up coil signal at least during a radio frequency transmit phase associated with the performance of the magnetic resonance procedure on the calibration subject; and

generate an unsafe condition criterion based on the detected pick-up coil signal.

18. The magnetic resonance system as set forth in claim 17, wherein the calibration subject does not include an implant device.

19. The magnetic resonance system as set forth in claim 17, wherein the calibration subject includes an implant device, and wherein the processor is further configured to:

perform three-dimensional temperature mapping of the calibration subject using a magnetic resonance sequence that is configured to detect a temperature change induced in any part of the implant device; and

generate the unsafe condition criterion based on correlating a pick-up coil signal characteristic with the detected temperature change.

20. The magnetic resonance system as set forth in claim 19, wherein the processor is further configured to repeat the magnetic resonance procedure on the calibration subject with different magnetic resonance sequence parameters.