Patent Application
20080027306
The invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, in which:
The following description will refer to a magnetic resonance imaging (MRI) system, however, the systems and methods described herein may also be used in conjunction with other diagnostic imaging systems such as X-ray systems and CT systems. While a MRI system will be referred to throughout the discussion of various preferred embodiments, it should be understood that the embodiments of the systems and methods for initiating a diagnostic imaging scan are not limited to use with a MRI system.
The operator console 20 communicates through a link 28 with a separate computer system 30 that enables an operator to control the production and display of images on the screen 26. The computer system 30 includes a number of modules that communicate with each other through a backplane 32. These include an image processor module 34, a CPU module 37 and a memory module 38 such as a frame buffer for storing image data arrays. The computer system 30 is linked to a disk storage 33 and a tape drive 35 for storage of image data and programs. Computer system 30 also communicates with a separate system control 40 through a high speed serial link 41. The input device 22 may include a mouse, joystick, keyboard, track ball, touch activated screen, light wand, voice control or any similar or equivalent input device.
The system control 40 includes a set of modules connected together by a backplane 42. These include a CPU module 43 and a pulse generator module 44 that connects to the operator console 20 through a serial link 45. It is through link 45 that the system control 40 receives commands from the operator that indicate the scan sequence that is to be performed. The pulse generator module 44 operates the system components to carry out the desired scan sequence. Pulse generator module 44 produces data that indicates the timing, strength and shape of the RF pulses that are to be produced, and the timing and length of the data acquisition window. Pulse generator module 44 connects to a set of gradient amplifiers 70 to indicate the timing and shape of the gradient pulses to be produced during the scan. Pulse generator module 44 also receives patient data from a physiological acquisition controller 72 that receives signals from a number of different sensors connected to the patient, such as ECG signals from electrodes or respiratory signals from a bellows. In addition, pulse generator module 44 connects to a scan room interface circuit 74 that receives signals from various sensors associated with the condition of the patient and the magnet system. It is also through the scan room interface circuit 74 that a patient positioning system 76 receives commands to move the patient to the desired position for the scan.
The gradient waveforms produced by the pulse generator module 44 are applied to a gradient amplifier system 70 comprised of Gx, Gy and Gz amplifiers. Each gradient amplifier excites a corresponding gradient coil in a gradient coil assembly generally designated 56 to produce the magnetic field gradients used for position encoding acquired signals in the x-axis, y-axis and z-axis, respectively. The gradient coil assembly 56 forms part of a magnet assembly 54 that includes a magnet 58 and a whole-body RF coil 52. The magnet 58 could be a permanent magnet or an electromagnet. A patient or imaging subject 62 may be positioned within the magnet assembly 54, e.g., a bore formed by the magnet assembly 54. A transceiver module 46 in the system control 40 produces pulses that are amplified by an RF amplifier 77 and coupled to the RF coil 52 by a transmit/receive switch 78. The resulting signals radiated by the excited nuclei in the patient 62 may be sensed by the same RF coil 52 and coupled through the transmit/receive switch 78 to a preamplifier 79. The amplified NMR signals are demodulated, filtered and digitized in the receiver section of the transceiver 46. The transmit/receive switch 78 is controlled by a signal from the pulse generator module 44 to electrically connect the RF amplifier 77 to the coil 52 during the transmit mode and to connect the preamplifier 79 to the coil 52 during the receive mode. The transmit/receive switch 78 can also enable a separate RF coil (for example, a head coil or surface coil) to be used in either the transmit or receive mode.
The NMR signals picked up by the RF coil 52 are digitized by the transceiver module 44 and transferred to a memory module 47 in the system control 40. When the scan is completed and an entire array of data has been acquired in the memory module 47, an array processor 48 operates to Fourier transform the data into an array of image data. This image data is conveyed through the serial link 41 to the computer system 30 wherein it is stored in memory, such as the disk storage 33. In response to commands received from the operator console 20, the image data may be archived in long term storage, such as on the tape drive 35, or it may be further processed by the image processor 34 and conveyed to the operator console 20 and presented on the display 26.
Once the patient information and scan parameters are entered, the operator enters the scan room and sets up the patient on the patient table at block 206. The set up of the patient may include assisting the patient with positioning on the patient table, placing ECG leads on the patient, placing respiratory bellows on the patient, etc. At block 208, the operator may provide landmark information and advance to scan using controls provided on the magnet assembly in the scan room. A landmark is typically an anatomical structure used as a point of origin in locating other anatomical structures or used in determining certain measurements. When the operator selects to advance to scan, the patient table moves to an appropriate position within the magnet assembly for the scan. At block 210, if the patient's weight has not been entered at the operator console, the scanner remains idle. Patient weight is required before beginning an MRI scan. If the patient weight has been entered at block 210, the process proceeds to block 212.
At block 212, if the automatic start mode or feature is not on, the scanner remains idle at block 220. If the automatic start mode is on at block 212, then the magnet assembly or system is armed at block 214. When the MRI system detects a predefined event at block 216, the scan starts automatically at block 218. Preferably, the detected event is an event that indicates when the operator is at a predetermined location, for example, when the operator leaves the scan room. Accordingly, the operator does not need to return to the operator console to initiate the scan. In one embodiment, at least the first series of the scan starts at block 218. If a subsequent series of the scan requires the operator to reenter the scan room before the series starts, the automatic start mode may be used to automatically initiate the subsequent series when the operator leaves the scan room.
In one embodiment, a detection device, such as a sensor or camera, may be used to detect when the operator leaves the scan room. A signal may be provided from the detection device to the MRI system computer systems (e.g., computer system 30 or system control 40, both shown in
In another embodiment, the event at block 216 consists of an event followed by a predetermined time period or delay. Upon expiration of the predetermined time period or delay, the scan starts automatically. Preferably, the predetermined time period or delay is a length (e.g., a number of seconds) that allows for the time it takes the operator to leave the scan room. For example, the operator may select a physical control in the scan room, such as a hard key, switch or button on the magnet assembly, a foot switch, a button or menu item on a display, which initiates a predetermined time period. The physical control may provide a signal to a computer system (e.g., computer system 30 or system control 40, both shown in
At block 306, the operator enters the scan room and sets up the patient on the patient table. The set up of the patient may include assisting the patient with positioning on the patient table, placing ECG leads on the patient, placing respiratory bellows on the patient, etc. At block 308, the operator may provide landmark information and advance to scan using controls provided on the magnet assembly in the scan room. At block 310, if the patient's weight has not been entered at the operator console, it is determined whether the patient's weight has been entered in the scan room at block 312, e.g., via a monitor and/or an input device or an input device on the magnet assembly. If the patient's weight has also not been entered in the scan room, the scanner remains idle at block 311. If the patient weight has been entered at the operator console at block 310 or in the scan room at block 312, the process proceeds to block 314.
At block 314, it is determined whether the automatic start mode or feature is on. If the automatic start mode is on, the magnet assembly or system is armed at block 316 in
If the automatic start mode is not appropriate at block 318, the automatic start mode may be turned off at block 320 using controls in the scan room. For example, a monitor 64 and/or an input device 66 (both shown in
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This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. The order and sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments.
Many other changes and modifications may be made to the present invention without departing from the spirit thereof. The scope of these and other changes will become apparent from the appended claims.
