Motion correction and motion reduction in a facial region 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;
positioning a mechanical element in contact with the facial region of the patient to establish contact with the patient's chin, the mechanical element including a motion sensor configured to detect motion of the patient's chin;
performing the MR measurement to acquire MR image data of the facial region of the patient;
determining a displacement of the mechanical element due to motion of the patient while performing the MR measurement; and
performing a motion correction, exploiting an accessibility to the facial region of the patient during the MR measurement, to reduce an influence of a patient motion on the MR image data, wherein the motion correction includes a prospective and/or retrospective correction of the MR image data based on the displacement of the mechanical element.
2 . The method according to claim 1 , further comprising another mechanical element that comprises a head rest configured to engage and limit movement of the patient's head, wherein the motion correction is further based on a displacement of the other mechanical element.
3 . The method according to claim 1 , wherein the mechanical element comprises a chin rest configured to engage and limit movement of the patient's chin.
4 . 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 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.
5 . The method according to claim 4 , wherein:
the mouth guard comprises a suction pipe; and
the motion correction 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.
6 . The method according to claim 1 , wherein the motion correction comprises acquiring optical image data of the facial region of the patient using an optical sensor while performing the MR measurement, wherein the prospective and/or retrospective correction of the MR image data is further based on the optical image data.
7 . The method according to claim 6 , wherein the facial region of the patient comprises an eye region of the patient and wherein the optical image data is acquired from the eye of the patient.
8 . The method according to claim 7 , wherein the prospective and/or retrospective correction of the MR image data is further based on a detected motion of a pupil of the eye of the patient.
9 . The method according to claim 1 , 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 further comprises an additional prospective and/or retrospective correction of the separate MR image data based on a rigid model of the lower jaw and the upper jaw of the patient.
10 . The method according to claim 1 , further comprising:
acquiring a projection image of the facial region of the patient, the motion correction including adjusting a projection direction based on a detected motion of the facial region of the patient.
11 . The method according to claim 10 , further comprising:
performing a navigator measurement of the facial region of the patient to acquire navigator data, the motion correction 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.
12 . The method according to claim 1 , further comprising:
performing a navigator measurement of the facial region of the patient to acquire navigator data, the motion correction 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 . 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, the MR scanner including a mechanical element configured to contact the facial region of the patient to establish contact with the patient's chin; and
a controller that is configured to:
control the MR scanner to perform the MR measurement to acquire MR image data of the facial region of the patient positioned in an imaging region of the MR scanner;
determine, based on a displacement of the mechanical element during the MR measurement, a motion of the patient's chin; and
perform motion correction, exploiting an accessibility to the facial region of the patient during the MR measurement, to reduce an influence of a patient motion on the MR image data, wherein the motion correction includes a prospective and/or retrospective correction of the MR image data based on the determined motion of the patient.
14 . The MRI system according to claim 13 , further comprising another mechanical element that comprises a head rest configured to support the patient's head, wherein the motion correction is further based on a displacement of the other mechanical element.
15 . The MRI system according to claim 13 , wherein the mechanical element comprises a chin rest configured to support the patient's chin.
16 . The MRI system according to claim 13 , wherein the facial region comprises the patient's chin or head.
17 . The MRI system according to claim 13 , wherein the mechanical element is a head rest comprising a support configured to support the patient's head and a chin rest configured to support the patient's chin, the support including a first motion sensor configured to detect a first motion of the patient and the chin rest including a second motion sensor configured to detect a second motion of the patient, wherein the displacement is determined based on the first motion and/or the second motion.
18 . 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;
positioning a mechanical element in contact with the facial region of the patient to establish contact with the patient's chin, the mechanical element including a motion sensor, the mechanical element configured to engage and suppress movement of the facial region of the patient;
performing the MR measurement to acquire MR image data of the facial region of the patient;
determining a displacement of the mechanical element due to motion of the patient while performing the MR measurement; and
performing a motion correction, exploiting an accessibility to the facial region of the patient during the MR measurement, to reduce an influence of a patient motion on the MR image data, wherein the motion correction includes a prospective and/or retrospective correction of the MR image data based on the displacement of the mechanical element.