MONITORING A PATIENT IN A MAGNETIC RESONANCE SYSTEM

Abstract

Monitoring a patient in a magnetic resonance system, wherein images of the patient are acquired by a camera in real time, a movement of the patient and a degree of this movement of the patient is determined by evaluating the images, and a symbol symbolizing a part of the patient is depicted, wherein a depicted property of the symbol depicts the degree of movement.

Claims

1. A method for monitoring a patient in a magnetic resonance system, comprising: acquiring images of the patient by a camera in real time; determining a movement of the patient and a degree of the movement of the patient by evaluating the images; and depicting a symbol symbolizing a part of the patient, wherein a depicted property of the symbol depicts the degree of the movement.

2. The method as claimed in claim 1, wherein the symbol is a head symbol of the head of the patient or the property is a color of the symbol.

3. The method as claimed in claim 1, wherein the determination of the movement of the patient comprises the determination of a direction of the movement of the patient, and wherein the depiction of the symbol comprises a depiction of a movement of the symbol, wherein a direction of the movement of the symbol corresponds to a direction of the movement of the patient.

4. The method as claimed in claim 1, wherein the determination and depiction of the degree enables a distinction based on the property of the symbol as follows: the movement of the patient is completely correctable during a measurement with the magnetic resonance system, the movement of the patient is only partially correctable during a measurement with the magnetic resonance system, or the movement of the patient is not correctable in any way during a measurement with the magnetic resonance system.

5. The method as claimed in claim 1, wherein the evaluation of the images comprises the detection of a marker on the patient, and wherein the depiction of the symbol depicts whether the marker is detected or whether the marker is not detected.

6. The method as claimed in claim 1, wherein the evaluation of the images comprises a determination whether the camera is calibrated or whether the camera is not calibrated, and wherein the depiction of the symbol comprises that the symbol depicts whether the camera is calibrated or whether the camera is not calibrated.

7. The method as claimed in claim 1, wherein the determination of the movement of the patient and the degree of the movement of the patient comprises: determining a three-dimensional vector connecting a point of the patient in one of the images acquired at a first time point with the same point of the patient in one of the images acquired at a second time point; and determining the degree of the movement in that the length of the vector is divided by a time period elapsing between the first time point and the second time point.

8. The method as claimed in claim 1, wherein the determination of the movement of the patient and the degree of the movement of the patient comprises: determining a three-dimensional angle, which is spanned by a point of the patient in at least one of the images acquired at a first time point and the same at least one point of the patient in one of the images, acquired at a second time point and a corresponding angle vertex, and determination of the degree of the movement in that a angular width of the three-dimensional angle is divided by a time period elapsing between the first time point and the second time point.

9. The method as claimed in claim 7, wherein a latency elapsing between the acquisition of one of the images and a correction of a movement of the patient detected by means of this image, and wherein the movement of the patient is classed as completely correctable if a quotient of the length of the vector and the latency is below a predetermined threshold value.

10. The method as claimed in claim 7, wherein a latency elapsing between the acquisition of one of the images and a correction of a movement of the patient detected by means of this image, and wherein the movement of the patient is classed as completely correctable if a quotient of the angular width and the latency is below a predetermined threshold value.

11. The method as claimed in claim 1, wherein the determination of the movement of the patient and the degree of the movement of the patient comprises: acquiring a plurality of consecutive movements of the patient, determining for each of these movements in each case a degree of the respective one of the movements by evaluating the images, and determining the degree of a total movement that comprises the detected consecutive movements of the patient as a function of the degrees of these movements and a number of these movements, and wherein the depiction of the symbol comprises: depicting the symbol in that the property of the symbol depicts the degree of the total movement.

12. The method as claimed in claim 1, wherein the steps of the acquisition of the images of the patient, the determination of the movement of the patient, and the degree of the movement of the patient, and the depiction of the symbol, are performed before an actual measurement by means of the magnetic resonance system, and wherein an acquisition strategy with which magnetic resonance data of the patient are acquired by means of the magnetic resonance system is determined as a function of the determined degree of the movement of the patient.

13. A magnetic resonance system for monitoring a patient, wherein the magnetic resonance system comprises a Radio Frequency (RF) controller, a gradient controller, an image sequence controller, a computer, a camera, and a display, wherein the magnetic resonance system is configured to: use the camera to acquire images of the patient located in the magnetic resonance system in real time; use the computer to determine a movement of the patient and a degree of the movement of the patient by evaluating the images; and depict a symbol on the display symbolizing a part of the patient, wherein a depicted property of the symbol depicts the degree of the movement.

14. The magnetic resonance system as claimed in claim 13, wherein the magnetic resonance system is configured to carry out the method as claimed in claim 1.

15. A non-transitory computer program product that comprises a program and loadable directly into a memory of a programmable control facility of a magnetic resonance system with computer configured to execute the steps of the method as claimed in claim 1 when the program is executed in the control facility of the magnetic resonance system.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0047] The present disclosure will now be described in detail with reference to inventive embodiments and with reference to the figures.

[0048] FIG. 1 depicts a magnetic resonance system according to the disclosure.

[0049] FIG. 2 depicts a camera attached inside a magnetic resonance system.

[0050] FIG. 3 depicts a marker attached to a patient.

[0051] FIG. 4 is a flow diagram of the procedure according to the disclosure for monitoring a patient.

DETAILED DESCRIPTION

[0052] FIG. 1 depicts a magnetic resonance system 10 with which, as explained below, a patient can be monitored according to the disclosure. The magnetic resonance system 10 has a magnet 11 for generating a polarization field BO, wherein an examination subject 13 arranged on a bench 12 is moved into the magnet 11 for the recording of spatially encoded magnetic resonance signals or MR data from the examination subject or the patient 13. The coils used for signal recording, such as a whole-body coil or local coils, are not shown for reasons for clarity. The radiation of RF pulses and switching of magnetic field gradients causes the magnetization generated by the polarization field BO to be deflected out of the equilibrium position and spatially encoded and the resultant magnetization is detected by the receiving coils. The way in which MR images can be generated by radiating RF pulses and switching magnetic field gradients in different combinations and sequences is in principle known to the person skilled in the art and will not be explained in further detail here.

[0053] The magnetic resonance system 10 further has a control unit 20 that may be used to control the magnetic resonance system 10. The controller 20 has a gradient control unit 15 for controlling and switching the necessary magnetic field gradients. An RF control unit 14 is provided to control and generate the RF pulses for deflecting the magnetization. An image sequence controller 16 controls the sequence of magnetic field gradients and RF pulses and hence indirectly the gradient control unit 15 and the RF control unit 14. An operator can control the magnetic resonance system 10 via an input unit 17 and MR images and other information required for control purposes can be displayed on a display unit 18. A computing unit 19 with at least one processor unit (not shown) is provided to control the different units in the control unit 20 and to carry out computing operations. Furthermore, a camera 21 is provided with which images of the patient 13 can be acquired. The computing unit 19 is embodied to calculate the MR images from the acquired MR signals and to use the acquired images to determine a movement of the patient 13 and a degree of the movement. A symbol (for example a head symbol) is then used to depict the degree of the movement on the display 18.

[0054] FIG. 2 depicts an in-bore camera arranged on the upper side of the tunnel 1 of the magnetic resonance system 10. This camera acquires the images of the patient by means of four slots or camera windows 2 arranged on the upper side of the tunnel 1 so the camera acquires four different views of the patient 13.

[0055] FIG. 3 depicts the head of a patient 13 wearing a head coil 3 located inside the magnetic resonance system 10. To improve tracking of the movement of the head of the patient 13, the patient 13 wears a kinetic marker 4, which is attached to the patient 13 on the bridge of the nose.

[0056] Whenever the marker 4 is visible to the camera 21, it is possible to track a movement of the head of the patient 13 using the images acquired from the patient 13 in that, for example, a point of this marker 4 is tracked using the images.

[0057] FIG. 4 depicts a flow diagram of a method according to the disclosure for monitoring a patient 13.

[0058] In the first step S1, images of the patient 13 are acquired by means of a camera 21 arranged in a magnetic resonance system 10. Herein, the patient 13 is located in the magnetic resonance system 10 to enable this magnetic resonance system 10 to acquire MR data of a certain part (for example the head) of the patient 13.

[0059] In a second step S2 following the first step S1, these images are evaluated in order to determine a movement of the patient 13 and a degree of this movement in a third step S3. The degree of this movement is then depicted in a fourth step S4 with the aid of a symbol symbolizing a part (for example the head) of the patient 13. Herein, a depicted property of this symbol is used to depict the degree of the movement on the display 21 such that an operator of the magnetic resonance system is advantageously able to detect very quickly whether the degree of the movement is having an adverse effect on the image quality.

[0060] For example, the color of the symbol can change as a function of the movement pattern of the patient 13 determined by means of the images. A green head symbol can, for example, indicate to the operator of the magnetic resonance system 10 that the movement of the patient 13 currently determined by means of the images is not yet having an adverse effect on the image quality. On the other hand, a red head symbol can indicate to the operator that the movement of the patient 13 currently determined is already having an adverse effect on the image quality.