MOTION CORRECTION AND MOTION REDUCTION DURING DEDICATED MAGNETIC RESONANCE IMAGING
In a method and system for reducing motion artifacts in magnetic resonance image data acquired from a facial region of a patient, the patient is positioned in an imaging region of a magnetic resonance imaging device configured to perform a magnetic resonance measurement of the facial region of the patient, the magnetic resonance measurement is performed to acquire magnetic resonance image data of the facial region of the patient, and a motion correction technique is employed exploiting an accessibility to the facial region of the patient during the magnetic resonance measurement. The motion correction technique advantageously reduces an influence of a patient motion on the magnetic resonance image data.
1 . A method for reducing motion artifacts in magnetic resonance image data acquired from a facial region of a patient, the method comprising:
positioning the patient in an imaging region of a magnetic resonance imaging (MRI) device configured to perform a magnetic resonance (MR) measurement of the facial region of the patient;
performing the MR measurement to acquire MR image data of the facial region of the patient; and
employing a motion correction technique exploiting an accessibility to the facial region of the patient during the MR measurement, wherein the motion correction technique reduces an influence of a patient motion on the MR image data.
2 . The method according to claim 1 , wherein:
the facial region comprises a teeth region and/or jaw region of the patient; and
the motion correction technique comprises positioning a mouth guard in an intraoral region of the patient to suppress movement of the teeth region and/or the jaw region of the patient while performing the MR measurement.
3 . The method according to claim 2 , wherein:
the mouth guard comprises a suction pipe; and
the motion correction technique comprises draining saliva from the intraoral region of the patient via the suction pipe while performing the MR measurement to reduce a need for swallowing.
4 . The method according to claim 2 , wherein:
the mouth guard comprises a magnetic resonance visible marker;
the motion correction technique comprises detecting the MR visible marker during the MR measurement; and
the motion correction technique comprises a prospective and/or retrospective correction of the MR image data in dependence of a displacement of the MR visible marker due to motion of the patient.
5 . The method according to claim 3 , wherein:
the mouth guard comprises a magnetic resonance visible marker;
the motion correction technique comprises detecting the MR visible marker during the MR measurement; and
the motion correction technique comprises a prospective and/or retrospective correction of the MR image data in dependence of a displacement of the MR visible marker due to motion of the patient.
6 . The method according to claim 1 , wherein the motion correction technique comprises:
positioning a mechanical element in contact with the facial region of the patient, the mechanical element including a motion sensor;
determining a displacement of the mechanical element due to motion of the patient while performing the MR measurement; and
performing a prospective and/or retrospective correction of the MR image data based on the displacement of the mechanical element.
7 . The method according to claim 1 , wherein the motion correction technique comprises:
acquiring optical image data of the facial region of the patient using an optical sensor while performing the MR measurement; and
performing a prospective and/or retrospective correction of the MR image data based on the optical image data.
8 . The method according to claim 7 , wherein the facial region of the patient is an eye region of the patient and wherein the optical image data is acquired from the eye of the patient.
9 . The method according to claim 8 , wherein the motion correction technique comprises a prospective and/or retrospective correction of the MR image data based on a detected motion of a pupil of the eye of the patient.
10 . The method according to claim 2 , wherein:
the MR measurement comprises acquiring separate MR image data from a lower jaw and an upper jaw of the teeth region and/or jaw region; and
the motion correction technique comprises a prospective and/or retrospective correction of the MR image data based on a rigid model of the lower jaw and the upper jaw of the patient.
11 . The method according to claim 2 , further comprising:
acquiring a projection image of the facial region of the patient, the motion correction technique including adjusting a projection direction based on a detected motion of the facial region of the patient.
12 . The method according to claim 11 , further comprising:
performing a navigator measurement of the facial region of the patient to acquire navigator data, the motion correction technique including detecting a displacement of a characteristic feature in the navigator data and prospectively and/or retrospectively correcting the MR image data based on the displacement of the characteristic feature.
13 . The method according to claim 2 , further comprising:
performing a navigator measurement of the facial region of the patient to acquire navigator data, the motion correction technique including detecting a displacement of a characteristic feature in the navigator data and prospectively and/or retrospectively correcting the MR image data based on the displacement of the characteristic feature.
14 . A computer program which includes a program and is directly loadable into a memory of the MRI device, when executed by a processor of the MRI device, causes the processor to perform the method as claimed in claim 1 .
15 . A non-transitory computer-readable storage medium with an executable program stored thereon, that when executed, instructs a processor to perform the method of claim 1 .
16 . A magnetic resonance imaging (MRI) system, comprising:
a magnetic resonance (MR) scanner configured to perform a magnetic resonance (MR) measurement of a facial region of a patient; and
a controller that is configured to:
position a patient in an imaging region of the MR scanner;
control the MR scanner to perform the MR measurement to acquire MR image data of the facial region of the patient; and
preform a motion correction technique exploiting an accessibility to the facial region of the patient during the MR measurement, wherein the motion correction technique reduces an influence of a patient motion on the MR image data.
17 . The MRI system according to claim 16 , wherein the controller is further configured to control the MR scanner to acquire a projection image of the facial region of the patient, wherein the motion correction technique includes adjusting a projection direction based on a detected motion of the facial region of the patient.
18 . The MRI system according to claim 17 , wherein the controller is further configured to control the MR scanner to perform a navigator measurement of the facial region of the patient to acquire navigator data, wherein the motion correction technique includes detecting a displacement of a characteristic feature in the navigator data and prospectively and/or retrospectively correcting the MR image data based on the displacement of the characteristic feature.
19 . The MRI system according to claim 16 , wherein the controller is further configured to control the MR scanner to perform a navigator measurement of the facial region of the patient to acquire navigator data, wherein the motion correction technique includes detecting a displacement of a characteristic feature in the navigator data and prospectively and/or retrospectively correcting the MR image data based on the displacement of the characteristic feature.