ASSESSMENT OF MEASURED TOMOGRAPHIC DATA

Abstract

Disclosed herein is a medical instrument (100, 300, 400, 500) comprising: a memory (110) storing machine executable instructions (120) and a tomographic data assessment module (122) and a processor (106) configured for controlling the medical instrument. Execution of the machine executable instructions causes the processor to receive (200) measured tomographic data (124). The measured tomographic data is configured for being reconstructed into a tomographic image (308) of a subject (418). Execution of the machine executable instructions further causes the processor to receive (202) an image quality indicator (126, 126′, 126″) by inputting the measured tomographic data into the tomographic data assessment module. The tomographic data assessment module is configured for generating the image quality indicator in response to inputting the measured tomographic data. Execution of the machine executable instructions further causes the processor to provide (204) the image quality indicator to an operator using an operator signaling system (108).

Claims

1. A medical instrument comprising: a memory storing machine executable instructions and a tomographic data assessment module; and a processor configured for controlling the medical instrument, wherein execution of the machine executable instructions causes the processor to: receive measured tomographic data, wherein the measured tomographic data is configured for being reconstructed into a tomographic image of a subject; receive an image quality indicator by inputting the measured tomographic data prior to image reconstruction into the tomographic data assessment module, before reconstruction of the tomographic image wherein the tomographic data assessment module is configured for generating the image quality indicator in response to inputting the measured tomographic data; and provide the image quality indicator using an operator signaling system.

2. The medical instrument of claim 1, wherein the medical instrument further comprises a medical imaging system configured for acquiring the measured tomographic data from an imaging zone, wherein the memory further comprises medical imaging system control commands configured for controlling the medical imaging system to acquire the measured tomographic data, wherein execution of the machine executable instructions further causes the processor to acquire the measured tomographic data by controlling the medical imaging system with the medical imaging system control commands.

3. The medical instrument of claim 2, wherein the medical imaging system further comprises a subject support configured for moving at least a portion of the subject within the imaging zone, wherein execution of the machine executable instructions further causes the processor to: control the subject support to move the at least a portion of the subject within the imaging zone before controlling the medical imaging system to acquire the measured tomographic data; and provide the image quality indicator to the operator using an operator signaling system while the subject is still supported at least partially within the imaging zone.

4. The medical instrument of claim 2, wherein the medical imaging system is a magnetic resonance imaging system, wherein the medical imaging system control commands are pulse sequence commands, and wherein the measured tomographic data is k-space data.

5. The medical instrument of claim 4, wherein any one of the following: wherein the pulse sequence commands are according to a compressed sensing magnetic resonance imaging protocol configured for acquiring the measured tomographic data from multiple magnetic resonance imaging antennas, wherein the tomographic data assessment module is configured for at least partially providing the image quality indicator using magnetic resonance data from a single magnetic resonance antenna selected from the multiple magnetic resonance imaging antennas; wherein the pulse sequence commands are according to a self-navigating magnetic resonance imaging protocol that embeds self-navigator data within the k-space data, wherein the tomographic data assessment module is configured for at least partially providing the image quality indicator using the self-navigator data; and combinations thereof.

6. The medical instrument of claim 1, wherein the medical imaging system is a computed tomography imaging system, and wherein the measured tomographic data comprises measured X-ray attenuation profiles.

7. The medical instrument of claim 1, wherein the tomographic data assessment module is configured for accelerating the generation of the image quality indicator using any one of the following: subsampling the measured tomographic data; reconstructing a low-resolution image from the measured tomographic data, wherein the low-resolution image has a lower resolution than the tomographic image; and reconstructing a single slice of the tomographic image from the measured tomographic data.

8. The medical instrument of claim 1, wherein the measured tomographic data comprises redundant data, wherein the tomographic data assessment module is configured to at least partially generate the image quality indicator using the redundant data.

9. The medical instrument of claim 1, wherein the tomographic data assessment module is implemented as at least one selected from a group including: a neural network trained to receive as input the measured tomographic data and in response output the image quality indicator; a predetermined logic module configured to receive as input the measured tomographic data and in response output the image quality indicator; or an operator-controlled module configured to generated and display intermediate images or values for approval by the operator.

10. The medical instrument of claim 1, wherein execution of the machine executable instructions further causes the processor to store the measured tomographic data in a tomographic data database system of a remote processing system if the image quality indicator satisfies a predetermined criterion, and wherein the remote processing system is configured to: retrieve the measured tomographic data from the tomographic data database; and reconstruct the tomographic image from the measured tomographic data.

11. The medical instrument of claim 1, wherein the operator signaling system further comprises a computer display configured for displaying the image quality indicator, wherein execution of the machine executable instructions further causes the processor to: display a reacquire data message to the operator if the image quality indicator does not satisfy the predetermined criterion; and/or display a discharge subject message to the operator if the image quality indicator does not satisfy the predetermined criterion.

12. The medical instrument of claim 11, wherein the memory further comprises an instruction database comprising operator instructions that describe how to improve measured tomographic data quality, wherein execution of the machine executable instructions further causes the processor to: retrieve the operator instructions from the instruction database if the reacquire data message is displayed; and display the operator instructions on the display.

13. The medical instrument of claim 1, wherein the image quality indicator is at least one selected from a group including: a binary indicator indicating a sufficient image quality and an insufficient image quality; a numerical indicator; a lower contrast and/or lower resolution image than the tomographic image; or an operator provided assessment.

14. A method of operating a medical instrument, wherein the method comprises: receiving measured tomographic data, wherein the measured tomographic data is configured for being reconstructed into a tomographic image of a subject; receiving an image quality indicator by inputting the measured tomographic data into a tomographic data assessment module, before reconstruction of the tomographic image wherein the tomographic data assessment module is configured for generating an image quality indicator in response to inputting the measured tomographic data; and providing the image quality indicator to an operator using an operator signaling system.

15. A computer program product comprising machine executable instructions and a tomographic data assessment module, wherein execution of the machine executable instructions causes the processor to: receive measured tomographic data, wherein the measured tomographic data is configured for being reconstructed into a tomographic image of a subject; receive an image quality indicator by inputting the measured tomographic data into the tomographic data assessment module before reconstruction of the tomographic image, wherein the tomographic data assessment module is configured for generating the image quality indicator in response to inputting the measured tomographic data; and provide the image quality indicator using an operator signaling system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In the following preferred embodiments of the invention will be described, by way of example only, and with reference to the drawings in which:

[0068] FIG. 1 illustrates an example of a medical instrument;

[0069] FIG. 2 shows a flow chart which illustrates a method of operating the medical instrument of FIG. 1;

[0070] FIG. 3 illustrates a further example of a medical instrument;

[0071] FIG. 4 illustrates a further example of a medical instrument;

[0072] FIG. 5 illustrates a further example of a medical instrument; and

[0073] FIG. 6 shows a flow chart which illustrates a method of operating the medical instrument of FIG. 3, 4 or 5.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0074] Like numbered elements in these figures are either equivalent elements or perform the same function. Elements which have been discussed previously will not necessarily be discussed in later figures if the function is equivalent.

[0075] FIG. 1 illustrates an example of a medical instrument 100. The medical instrument is shown as comprising a computer 102 that has a processor 106 that is connected to a hardware interface 104, a user interface 108, and a memory 110. The hardware interface 104 may include components that enable the processor 106 to communicate or control them. The hardware interface 104 may also include one or more network interfaces. The processor 106 may be representative of one or more processors and/or processing cores. The user interface 108 may provide a means for an operator to interact with the computer 102. The user interface 108 may therefore provide a display or other operator signaling system. The memory 110 may be any combination of memory which is accessible for use by the processor 106.

[0076] The memory 110 is shown as containing machine-executable instructions 120. The machine-executable instructions 120 contain instructions which enable the processor 106 to control the function of the medical instrument 100 as well as provide various calculation and data processing tasks. The memory 110 is further shown as containing a tomographic data assessment module 122. The tomographic data assessment module receives raw tomographic data or measured tomographic data 124 as input and then outputs an image quality indicator 126. The memory 110 is shown as containing measured tomographic data 124 and then as output from the tomographic data assessment module 122 also contains the image quality indicator 126. The memory 110 is shown as further containing a rendering of the image quality indicator 128 which may be used or displayed using the user interface 108.

[0077] FIG. 2 shows a flowchart which illustrates a method of operating the medical instrument 100 of FIG. 1. First in step 200 the measured tomographic data 124 is received. Next in step 202 the measured tomographic data 124 is input into the tomographic data assessment module 122 and in response the image quality indicator 126 is received. Then finally in step 204, the image quality indicator 126 is provided to the operator. In this example the rendering of the image quality indicator 128 may be displayed using the user interface 108.

[0078] The current workflow of an MRI or CT scan consists of the following steps. [0079] 1. A patient is put in the scanner [0080] 2. A scan is made [0081] 3. The raw data from the scanner is reconstructed into an image [0082] 4. The operator performs a quality check, based on reconstructed image, if the scan was successful [0083] 5. a. If the scan was not successful a new scan needs to be made else the patient is dismissed

[0084] b. If the scan was successful the reconstructed imaged is stored in the hospital's picture archiving and communication system (PACS) [0085] 6. A radiologist retrieves at a later stage the image from the PACS systems and writes a report of his findings/diagnosis. In an alternative the image from the PACS system can also be received in the scanner room, while the patient is still in the medical imaging system.

[0086] A disadvantage of the workflow described above is that the reconstruction process, step 3, can take quite some time. During this time the operator as well as the patient are waiting. This can be very inconvenient for the patient, since he/she is in an uncomfortable position and/or in a noisy and/or claustrophobic environment, particularly for MRI. The operator may feel he/she are wasting their time, while being under time pressure.

[0087] The computer for the above workflow should be as powerful as possible to keep the reconstruction time as short as possible.

[0088] Examples, may replace the current time-consuming reconstruction, step 3 in the workflow above, with an algorithm that determines based on the raw data (measured tomographic data) whether the scan has been successful or not. This algorithm may to require significantly less time than the actual reconstruction of a tomographic image from the measured tomographic data.

[0089] Based on the assessment of the algorithm (the image quality indicator), the patient can be dismissed. Therefore, the patient as well as the operator do not need to wait anymore.

[0090] The actual reconstruction of the tomographic image may be performed at a later moment, but in time for the radiologist to have the image ready when needed. The computer that does the reconstruction can now be less powerful since the reconstruction time is no longer a time critical step in the workflow.

[0091] FIG. 3 illustrates a further example of a medical instrument 300. In addition, a remote processing system 302 is shown. In some cases, the remote processing system 302 can be part of the medical instrument 300. The medical instrument 300 is shown as comprising the computer 102. The items in FIG. 3 are arranged in a functional manner. The medical instrument 300 is further shown as comprising a medical imaging system 310 which is used to acquire the measured tomographic data 124. This is then input into the tomographic data assessment module 122. The tomographic assessment module 122 in this case is used to either provide a sufficient image quality indicator 126′ or an insufficient image quality indicator 126″.

[0092] If the sufficient image quality indicator 126′ is provided then a message to dismiss the subject 314 is displayed. In addition, the raw data or the measured tomographic data 124 is transferred or transmitted to the remote processing system 302. The measured tomographic data 124 is then stored in a tomographic data database 306 for later processing. The remote processing system 302 comprises a computer 304. The computer is configured to retrieve the measured tomographic data 124 from the tomographic data database 306 and construct the tomographic image 308 from it. An advantage of this is that the subject may leave the medical imaging system 310 right away and the measured tomographic data 124 can be processed later, maybe even days later. This relieves the need to have more computing power in the computer 102 as well as enabling more patients per hour to go through the medical imaging system 310.

[0093] If the insufficient image quality indicator 126″ is provided then the operator may be displayed a display reacquire data message 312. The operator can then reacquire the measured tomographic data 124. In some instances, the reacquisition of the measured tomographic data 124 may be automated.

[0094] The workflow with delayed reconstruction as illustrated in FIG. 3 may be summarized as: [0095] 1. A patient is put in the scanner [0096] 2. A scan is made [0097] 3. The raw data from the scanner is used for automatic quality check [0098] 4. a. If the scan was not successful a new scan needs to be made else the patient is dismissed

[0099] b. If the scan was successful the raw data is stored [0100] 5. At a later moment the reconstruction of the tomographic image from the measured tomographic data is done and the reconstructed image (tomographic image) is stores in the hospital's picture archiving and communication system (PACS) [0101] 6. A radiologist retrieves at a later stage the image from the PACS systems and writes a report of his findings/diagnosis

[0102] An example of an algorithm for step 3 would to be to only reconstruct a single slice, without any advanced processing. Another option would be for the scanner to add (a small amount) of additional raw data which allows fast checks. Next to the scanner output, the algorithm could make use of additional sensors (cameras) mounted to the scanner. For example, if the patient has not moved during the scan, it is more likely the scan was successful.

[0103] All these options could be used to judge image quality with full reconstruction and to decide whether a rescan is needed or whether the patient can be dismissed.

[0104] FIG. 4 illustrates a further example of a medical instrument 400. The example shown in FIG. 4 is similar to that illustrated in FIGS. 1 and 3 except the medical instrument 400 additionally comprises a magnetic resonance imaging system 402.

[0105] The magnetic resonance imaging system 402 comprises a magnet 404. The magnet 404 is a superconducting cylindrical type magnet with a bore 406 through it. The use of different types of magnets is also possible; for instance it is also possible to use both a split cylindrical magnet and a so called open magnet. A split cylindrical magnet is similar to a standard cylindrical magnet, except that the cryostat has been split into two sections to allow access to the iso-plane of the magnet, such magnets may for instance be used in conjunction with charged particle beam therapy. An open magnet has two magnet sections, one above the other with a space in-between that is large enough to receive a subject: the arrangement of the two sections area similar to that of a Helmholtz coil. Open magnets are popular, because the subject is less confined. Inside the cryostat of the cylindrical magnet there is a collection of superconducting coils.

[0106] Within the bore 406 of the cylindrical magnet 404 there is an imaging zone 408 where the magnetic field is strong and uniform enough to perform magnetic resonance imaging. The magnetic resonance data that is acquired typically acquired for the field of view.

[0107] Within the bore 406 of the magnet there is also a set of magnetic field gradient coils 410 which is used for acquisition of preliminary magnetic resonance data to spatially encode magnetic spins within the imaging zone 408 of the magnet 404. The magnetic field gradient coils 410 connected to a magnetic field gradient coil power supply 412. The magnetic field gradient coils 410 are intended to be representative. Typically magnetic field gradient coils 410 contain three separate sets of coils for spatially encoding in three orthogonal spatial directions. A magnetic field gradient power supply supplies current to the magnetic field gradient coils. The current supplied to the magnetic field gradient coils 410 is controlled as a function of time and may be ramped or pulsed.

[0108] Adjacent to the imaging zone 408 is a radio-frequency coil 414 for manipulating the orientations of magnetic spins within the imaging zone 408 and for receiving radio transmissions from spins also within the imaging zone 408. The radio frequency antenna may contain multiple coil elements. The radio frequency antenna may also be referred to as a channel or antenna. The radio-frequency coil 414 is connected to a radio frequency transceiver 416. The radio-frequency coil 414 and radio frequency transceiver 416 may be replaced by separate transmit and receive coils and a separate transmitter and receiver. It is understood that the radio-frequency coil 414 and the radio frequency transceiver 416 are representative. The radio-frequency coil 414 is intended to also represent a dedicated transmit antenna and a dedicated receive antenna. Likewise the transceiver 416 may also represent a separate transmitter and receivers. The radio-frequency coil 414 may also have multiple receive/transmit elements and the radio frequency transceiver 416 may have multiple receive/transmit channels. For example if a parallel imaging technique such as SENSE is performed, the radio-frequency could 414 will have multiple coil elements.

[0109] The transceiver 416 and the gradient controller 412 are shown as being connected to the hardware interface 404 of the computer system 402.

[0110] The memory 110 is further shown as containing pulse sequence commands 330. The pulse sequence commands could for example contain a label which may be compared to the subject pose label 142. This may be used as a quality control check. In this example the pulse sequence commands 430 may be considered to be a protocol.

[0111] In this example the measured tomographic data is now k-space data 124′. The memory 110 is further shown as containing pulse sequence commands 430. The pulse sequence commands are an example of the medical imaging system control commands.

[0112] The image quality indicator 126 can be used to determine if the k-space data 124′ is transferred to the remote processing system 302. The remote processing system 302 is also shown as comprising a computer 304 as well as a hardware interface 104′, a processor 106, a user interface 108′, and a memory 110′. The memory 110′ is further shown as containing machine-executable instructions 450. The memory 110′ is further shown as containing the tomographic data database 306. The memory 110′ is further shown as containing the k-space data 124′ that has been transferred from the computer 102. The k-space data 124′ may for example be stored or retrieved from the tomographic data database 306. The machine-executable instructions 450 enable the processor 106′ to reconstruct the tomographic image 308 from the k-space data 124′.

[0113] The memory 110 is further shown as optionally containing an operator instruction database 422. The operator instruction database 422 contains instructions which may be used to provide to the operator for improving the acquisition of the tomographic data when it is reacquired. The memory 110 is further shown as containing operator instructions 424 that have been retrieved from the operator instruction database 422 in response to the image quality indicator 126 not being sufficient and retriggering the reacquisition of the measured tomographic data 124′.

[0114] FIG. 5 illustrates a further example of a medical instrument 500. The example in FIG. 5 is similar to that in FIG. 4 except the magnetic resonance imaging system 402 of FIG. 4 has been replaced with a CT or computed tomography system 502 in FIG. 5.

[0115] The CT system 502 comprises a rotating gantry 504. The gantry 504 rotates about an axis of rotation 506. There is a subject 418 reposing on a subject support 420. Within the gantry 504 is the X-ray tube 510.

[0116] The subject support 420 is shown as being supported by an optional subject support actuator 522. For example, the subject 418 can be brought into the image zone 516. The subject support actuator 522 can hold the subject 418 there until the image quality indicator 126 meets a predetermined criterion and enables it to forward the tomographic data to the remote processing system 302.

[0117] The X-ray tube 510 produces X-rays 514 that pass through the subject 418 and are received by a detector 512. Within the area of the box 516 is an imaging zone where CT or computer tomography images of the subject 418 can be made. The CT system 502 is shown as being controlled by computer system 102. The hardware interface 104 allows the processor 106 to exchange messages and control the CT system 502.

[0118] In FIG. 5 the measured tomographic data is X-ray attenuation profiles 124″. As with FIG. 5, the X-ray attenuation profiles 124″ may be forwarded to the remote processing system 302. The functioning of the tomographic data database 306 is analogous to that of FIG. 4. The computer 304 may then reconstruct the X-ray attenuation profiles 124″ into the tomographic image 308.

[0119] The remote processing system 302 in FIGS. 4 and 5 may sometimes be part of the medical instrument 400 or 500.

[0120] FIG. 6 shows a flowchart which illustrates a method of operating the medical instruments illustrated in FIG. 3, 4 or 5. First in step 600 the medical instrument is controlled to acquire the measured tomographic data 124, 124′ or 124″. Next steps 200-204 are performed as is illustrated in FIG. 2. After step 204 step 206 is performed; this is a decision box. The question is “does the imaging quality indicator satisfy a predetermined criterion?” If the answer is yes then the method proceeds to box 604. In box 604 a message is displayed informing the operator to discharge the subject. Step 604 may be optional. After step 604 step 606 is performed. In step 606 the measured tomographic data 124, 124′, 124″ is stored in the tomographic data database 306. After step 606 step 608 is performed. In this step the tomographic data 124, 124′, 124″ is retrieved from the tomographic data database 306. After step 608 in step 610 the tomographic image 308 is reconstructed from the measured tomographic data 124, 124′, 124″.

[0121] Returning to decision box 602, if the image quality indicator 126 does not satisfy the predetermined criterion then the method proceeds to step 612. Step 612 is optional. In step 612 the measured tomographic data message is displayed to the operator. This informs the operator that the data from the acquisition should be reacquired. Step 614 and step 616 are also optional. In step 614 operator instructions 434 are retrieved from the instruction database 432 in response to the image quality indicator 126 not meeting a predetermined criterion. This information may help the operator to reacquired the data with a higher quality. After steps 612, 614 and 616 are performed the method returns to step 600 and the system reacquires the measured tomographic data 124, 124′, 124″. If steps 612, 614 or 616 are not performed the method proceeds directly from step 602 to step 600.

[0122] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

[0123] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

LIST OF REFERENCE NUMERALS

[0124] 100 medical instrument [0125] 102 computer [0126] 104 hardware interface [0127] 104′ hardware interface [0128] 106 processor [0129] 106′ processor [0130] 108 user interface (operator signaling system) [0131] 110 memory [0132] 110′ memory [0133] 120 machine executable instructions [0134] 122 tomographic data assessment module [0135] 124 measured tomographic data [0136] 124′ k-space data [0137] 124″ X-ray attenuation profiles [0138] 126 image quality indicator [0139] 126′ sufficient image quality indicator [0140] 126″ insufficient image quality indicator [0141] 128 rendering of image quality indicator [0142] 200 receive measured tomographic data [0143] 202 receive an image quality indicator by inputting the measured tomographic data into the tomographic data assessment module response to inputting the measured tomographic data [0144] 204 provide the image quality indicator to an operator using an operator signaling system [0145] 300 medical instrument [0146] 302 remote processing system [0147] 304 computer [0148] 306 tomographic data database [0149] 308 tomographic image [0150] 310 medical imaging system [0151] 312 display reacquire data message [0152] 314 display discharge subject message [0153] 400 medical instrument [0154] 402 magnetic resonance imaging system [0155] 404 magnet [0156] 406 bore of magnet [0157] 408 imaging zone [0158] 409 field of view [0159] 410 magnetic field gradient coils [0160] 412 magnetic field gradient coil power supply [0161] 414 radio-frequency coil [0162] 416 transceiver [0163] 418 subject [0164] 420 subject support [0165] 422 operator instruction database [0166] 424 operator instructions [0167] 430 pulse sequence commands (example of medical imaging system control commands) [0168] 432 instruction database [0169] 434 operator instructions [0170] 450 machine executable instructions [0171] 500 medical instrument [0172] 502 CT system [0173] 504 gantry [0174] 506 axis of rotation [0175] 510 X-ray tube [0176] 512 detector [0177] 514 X-rays [0178] 516 imaging zone [0179] 520 subject support actuator [0180] 530 CT system control commands (example of medical imaging system control commands) [0181] 600 acquire the measured tomographic data by controlling the medical imaging system with the medical imaging system control commands [0182] 602 does the image quality indicator satisfy a predetermined criterion [0183] 604 display a discharge subject message to the operator if the image quality indicator does not satisfy the predetermined criterion [0184] 606 store the measured tomographic data in a tomographic data database system of a remote processing system [0185] 608 retrieve the measured tomographic data from the tomographic data database [0186] 610 reconstruct the tomographic image from the measured tomographic data [0187] 612 display a reacquire data message to the operator if the image quality indicator does not satisfy the predetermined criterion [0188] 614 retrieve the operator instructions from the instruction database if the reacquire data message is displayed [0189] 616 display the operator instructions on the display