Method for carrying out a magnetic resonance imaging examination of an anatomic region of a subject
A magnetic resonance imaging examination of an anatomic region of a subject is performed with a magnetic resonance imaging system. A fast metal detection sequence configured to detect the presence of a metal object within or at the subject is performed. A control unit determines whether a metal object is detected, wherein the control unit initiates a standard examination workflow if no metal object is detected during the fast metal detection sequence, and wherein the control unit initiates a modified examination workflow that is different from the standard examination workflow if a metal object is detected during the fast metal detection sequence.
1 . A method for carrying out a magnetic resonance imaging examination of an anatomic region of a subject with a magnetic resonance imaging system, the method comprising:
carrying out a fast metal detection sequence configured to detect the presence of a metal object within or at the subject;
initiating, by a controller, a modified examination workflow that is different from a standard examination workflow after the metal object is detected during the fast metal detection sequence, wherein the modified examination workflow comprises a metal localizer scan, wherein the metal localizer scan uses a turbo spin echo sequence with high bandwidth excitation and receive parameters to provides at least one scout image with reduced signal voids around the metal object compared to a standard localizer scan, wherein the modified examination workflow further comprises a request for a user to specify a region of interest on the at least one scout image; and
carrying out the modified examination.
2 . The method according to claim 1 , wherein the fast metal detection sequence is configured to have a duration of 0.01 s to 10 s.
3 . The method according to claim 1 , wherein the fast metal detection sequence is configured to have a duration of 1 s to 3 s.
4 . The method according to claim 1 , wherein the fast metal detection sequence is carried out by the magnetic resonance imaging system using a transmit coil, wherein the transmit coil is operated in a pulse mode and/or in a continuous wave mode.
5 . The method according to claim 1 , wherein the fast metal detection sequence is carried out without or with very low spatial resolution having a voxel size larger than 1 cm3 in the anatomical region.
6 . The method according to claim 1 , wherein the fast metal detection sequence is carried out without or with very low spatial resolution having a voxel size larger than 5 to 100 cm3 in the anatomical region.
7 . The method according to claim 1 , wherein the fast metal detection sequence is configured to detect off-resonant signals as an indication for the presence of the metal object.
8 . The method according to claim 1 , wherein the modified examination workflow further comprises at least one additional metal detection scan and wherein the user specified region of interest is used to determine a location for carrying out the additional metal detection scan.
9 . The method according to claim 8 , wherein the modified examination workflow comprises an adapted scan protocol, wherein the adapted scan protocol is adapted based on the results of the at least one additional metal detection scan.
10 . The method according to claim 1 , wherein the controller choses from at least three scan protocols to be carried out,
wherein a first scan protocol is a standard protocol that is carried out as part of a standard examination workflow when no metal object is detected,
wherein a second scan protocol is an adapted scan protocol that is carried out after a metal object is detected that has a first range of influence on a region of interest to be examined,
wherein a third scan protocol is an adapted scan protocol that is carried out after a metal object is detected that has a second range of influence on the region of interest to be examined, the first range of influence being less than the second range.
11 . The method according to claim 1 , wherein the modified examination workflow comprises giving information and/or suggestions to a user, and/or allowing the user to choose from multiple options regarding at least one scan protocol to be carried out, wherein the multiple options comprise choosing from multiple adapted scan protocols to be carried out and/or choosing from multiple adaptions to be applied to the at least one scan protocol.
12 . The method according to claim 1 , wherein, during the modified examination workflow, a user is asked for input to specify the region of interest on a scout image acquired using a metal localizer scan, wherein the user input is used by the controller to determine which adapted scan protocol to apply or how to adapt the scan protocol.
13 . A non-transitory computer-readable medium comprising a computer program with instructions that when carried out on a processor of a magnetic resonance imaging system cause the magnetic resonance imaging system to:
carry out a fast metal detection sequence configured to detect the presence of a metal object within or at a subject;
determine that the metal object is detected,
initiate, by a controller, a modified examination workflow that is different from a standard examination workflow after the metal object is detected during the fast metal detection sequence, wherein the modified examination workflow comprises a metal localizer scan comprising a turbo-spin-echo sequence with high-bandwidth excitation and receive parameters, wherein the metal localizer scan provides at least one scout image with reduced signal voids around the metal object compared to a standard localizer scan, wherein the modified examination workflow further comprises a request for a user to specify a region of interest on the at least one scout image; and
carry out the the modified examination workflow.
14 . A magnetic resonance imaging system for examining a subject, the magnetic resonance imaging system comprising:
a magnetic resonance scanner; and
a controller, wherein the controller is configured to initiate a fast metal detection sequence via the magnetic resonance scanner and/or via a metal detector, and initiate a standard examination workflow including scanning the subject with a standard scan protocol of the magnetic resonance scanner after no metal object is detected during the fast metal detection sequence, and initiate a modified examination workflow that is different from the standard examination workflow, wherein the modified examination workflow is initiated after a metal object is detected during the fast metal detection sequence, wherein the modified examination workflow comprises a metal localizer scan comprising a turbo-spin-echo sequence with high-bandwidth excitation and receive parameters, wherein the metal localizer scan provides at least one scout image with reduced signal voids around the metal object compared to a standard localizer scan, wherein the modified examination workflow further comprises a request for a user to specify a region of interest on the at least one scout image.
15 . The magnetic resonance imaging system according to claim 14 wherein the controller is configured to initiate the modified examination workflow as a scan of the subject with an adapted scan protocol of the magnetic resonance scanner.
16 . The magnetic resonance imaging system according to claim 14 , further comprising:
an output device configured to output optical and/or acoustic information to the user; and
a user input device configured to receive user input,
wherein the controller is configured to output information and/or suggestions for the user via the output device when a metal object is detected, to receive user input via the user input device, and to adapt the scan protocol and/or the examination workflow based on the user input.