JP2014519859A - Head fixation system and method - Google Patents

Abstract

The head fixation system includes a gantry, a tie ring rotatably connected to a ring mounting portion extending from an upper surface of the gantry, and including a plurality of slots extending around the circumference of the gantry. A first fixation post having a head support constructed for insertion into a first one of the slots in the fixation ring and a first fixation pin for engagement with the patient's skull A first fixation post configured for insertion into a second of the slots in the fixation ring and a second fixation pin for engagement with the patient's skull. A second fixed strut constructed for insertion into a third of the slots in the retaining ring, and a top coil member and a bottom coil that are removably mounted on the mount MRI coil including parts , And a MRI coil with respect to the fixed ring, and then independently rotatable.

Description

  The present invention relates to a surgical work platform. More specifically, the present invention relates to a head fixation system and method for using the same that facilitates the alignment of surgical and observation instruments within a patient.

  Each year, approximately 200,000 patients are diagnosed with brain tumors in the United States. Of these tumors, approximately 17,000 cases are “benign”, ie, the mass is not cancerous. However, the remaining, approximately 183,000, of these tumors are “malignant” (ie, cancerous), ie, can cause or cause death of the patient. About 10% of cancerous brain tumors are “primary” tumors, ie, the tumors have developed in the brain. Primary tumors are typically composed of brain tissue with mutated DNA that grows significantly and eliminates or replaces normal brain tissue. The most common primary tumor is known as a glioma, which indicates cancer of the glial cells of the brain. In most cases, the primary tumor appears as a single mass. However, these single masses can often be very large, irregularly shaped, segmented into multiple pieces, and / or infiltrate the surrounding brain tissue. Primary tumors are generally not diagnosed until the patient experiences symptoms such as headaches, transformation behavior, sensory disturbances. However, when symptoms develop, the tumor may already be large and aggressive.

  One known treatment for cancerous brain tumors is surgery. In particular, surgery involves craniotomy (ie, removal of a portion of the skull), dissection, and total or partial tumor resection. The purpose of surgery includes the removal or reduction of the number of active malignant cells in the brain and the reduction of pain or dysfunction due to the effect of the tumor on adjacent brain structures. However, by its very nature, surgery is highly invasive and risky. Furthermore, for some tumors, surgery is often only partially effective. In other tumors, the surgery itself may not be feasible, may put the patient at risk of injury, may not be tolerated, and / or may involve significant cost and recovery time .

  Another known treatment for cancerous brain tumors is stereotactic radiotherapy (SRS). In particular, SRS is a treatment method in which multiple intersecting radiation beams are directed to the tumor, so that the intersection of the beams receives a lethal radiation dose while the tissue in any single beam path remains harmless. It is. SRS is non-invasive and is typically performed as a single outpatient procedure. However, confirmation that the tumor has been killed or suppressed is often not possible for months after treatment. Furthermore, in situations where high radiation doses may be needed to kill the tumor, such as in multiple or recurrent tumors, the patient reaches a “toxicity threshold” prior to killing all of the tumor. It is common and no further radiation is recommended.

  More recently, treatment of tumors with “fever” (also referred to as hyperthermia or hyperthermia) has been developed. In particular, above 57 ° C., it is known that all living tissue is damaged and killed almost immediately and irreparably through a process called coagulation necrosis or cauterization. Malignant tumors are more susceptible to heat-induced damage than normal tissues because of their high angiogenesis and mutant DNA. Various types of energy sources can be used such as laser, microwave, radio frequency, electrical, and ultrasonic sources. Depending on the application and technique, the heat source can be extracorporeal (ie, outside the body), extracellular (ie, outside the tumor), or intracellular (ie, inside the tumor).

  Interstitial hyperthermia (ITT) is a process designed to heat and destroy tumors from within the tumor. One advantage of this type of treatment is that energy is applied directly to the tumor rather than passing around normal tissue. Another advantage of this type of treatment is that energy deposition is more likely to spread throughout the tumor.

  One exemplary ITT process begins by inserting an optical fiber into a tumor, and the tumor has laser light from an external light source at its “inserted” end, generally perpendicular to the length of the fiber. It has an element that redirects in the direction. In this way, the energy from the laser spreads to the tissue around the terminal or tip to achieve heating. Since energy is directed into the beam confined to a relatively shallow angle, as the fiber rotates, the beam also rotates around the axis of the fiber to achieve heating of different parts of the tumor at locations around the fiber. In this way, the fiber moves and rotates longitudinally to achieve tumor heating throughout the tumor, with the intention of heating the tumor to the required temperature without significantly affecting the surrounding tissue. Can be done.

  The fibers used in the ITT process can be controlled and manipulated by the surgeon with little or no guidance, apart from the surgeon's knowledge of the patient's anatomy and tumor location. Thus, it is difficult for a surgeon to provide controlled heating that causes the entire tumor to be heated to the required level while also minimizing damage to surrounding tissue.

  It is known that the location of tumors and other lesions to be removed can be determined using a magnetic resonance imaging system. These imaging systems are useful to assist the surgeon in determining the location of the tumor to be removed, but the use of the imaging system ends when the tumor location is mapped for the surgeon. . In particular, previous extraction procedures required removal of the patient from the imaging system prior to the start of treatment. However, patient movement, along with some partial removal or coagulation of tissue, can significantly change the location of the tumor to be removed. As a result, any possibility of providing controlled extraction accuracy is eliminated.

  It is also known that magnetic resonance imaging systems can be used by modifying the imaging sequence to determine the temperature of tissue in the image and to determine the change in temperature over time.

  U.S. Pat. No. 5,849,028 (LeBiahan), assigned to the US Department of Health and Human Services and issued on April 3, 1990, discloses a method for determining the temperature in an organization.

  Patent Document 2 (Delannoy), assigned to the US Department of Health and Human Services and issued on February 8, 1994, discloses that an external non-invasive heating system is mounted in a coil of a magnetic resonance imaging system. Discloses a device for hyperthermia of cancer. The present disclosure is an inference about the feasibility of MRI temperature measurement in combination with an external heating system and relates to initial experiments on it. The disclosure of this patent did not lead to a commercially viable thermotherapy system.

  U.S. Pat. Nos. 6,057,028 and 4,096, assigned to General Electric, predict that a point heat source will generate a predetermined heat distribution, and then the actual heat distribution will yield an overall heating of the area to be heated. It relates to an MRI controlled heating system that is monitored to ensure that it follows the heated distribution. Again, this patented arrangement did not lead to a commercially feasible thermosurgical system.

  Patent Document 5 (Fair), assigned to Memorial Hospital for Cancer and Allied Diseases, issued June 9, 1987, discloses a method for non-surgical treatment of tumors in which the tumor is exposed to shock waves. Yes. This type of therapy does not incorporate a monitoring system for monitoring and controlling the effects of shock waves.

  U.S. Patent No. 5,639,056 (Shaunnessey), issued October 20, 1998, which is not assigned, discloses a specially modified endoscope designed to support optical fibers. The optical fiber can be moved longitudinally and rotated at an angle about its axis to emit and direct light energy. The device is used to submit a tumor and the energy is arranged to be sufficient to achieve vaporization of the tumor to be removed. The gas formed during the process is removed by aspiration through the endoscope. Tumor images are acquired by MRI and then used to program the path of fiber movement that occurs during operation. Again, there is no feedback to control the movement of the optical fiber during the procedure, and the operation as a whole depends on the initial analysis. This arrangement has not had commercial or medical success.

  U.S. Pat. No. 6,057,028 (Lennox), assigned to Boston Scientific Corporation and issued on October 3, 1995, discloses a device for use in irradiating a tumor with light energy from an optical fiber. A cooling fluid is supplied through a conduit in the fiber to apply surface cooling and prevent surface damage while allowing an increased level of energy to be applied to deeper tissue. Again, this arrangement also does not provide feedback control of the heating effect.

  U.S. Patent No. 5,677,028 (Bille), assigned to MRC Systems GmbH and issued June 28, 1996, also discloses a specific arrangement of laser beams and lenses for use in brain tumor irradiation. In particular, this arrangement uses fast pulsed laser energy for the photodisintegration effect, but does not disclose a method for energy feedback control.

  Kahn, et al. (Journal of Computer Assisted Tomography 18 (4): 519-532 (July / August 1994)), Kahn, et al. (Journal of Magnetic Resonance Imaging 8: 160-1 64, 160-164). Others (Radiology 209: 381-385 (1998)) all disclose a method of applying thermal energy from a laser to a tumor through a fiber, the temperature at the periphery of the tumor during the application of energy by MRI. Be monitored. McNichols, RJ, et al. (Laser in Surgery and Medicine 34: 48-55 (2005)), in a paper titled “MR Thermometry-Based Feedback Control of LITT at 980 nm”, in a control by RI Is disclosed. In addition, Vogl's paper discloses a cooling system for cooling tissue at the probe end, marketed by Somatex (Berlin, Germany). The system is formed by an inner tube containing fibers mounted within the outer tube. The cooling fluid passes as a continuous flow between the two tubes and inside the inner tube.

  Although highly effective in some applications, the use of ITT to treat brain tumors does not allow energy to be focused exclusively and accurately on the tumor so as to avoid damage to surrounding normal brain tissue Is limited by This is complicated by the fact that the shape of many brain tumors is very irregular.

  Focused laser interstitial hyperthermia (f-LITT) is the next generation improved version of laser-based thermotherapy technology. In particular, f-LITT allows precise control over thermal energy deposition, thereby allowing physicians to exclusively limit cell damage within virtually any size and shape of mass. To do. However, while the doctor accurately fixes the position of the patient's head, at the same time, avoids interference with the trajectory guidance instrument typically used to guide the thermogenic treatment probe into the mass. There is a need for a device that makes it possible.

  Thus, a previously unresolved need is to accurately position the patient's head and provide unimpeded access to the entry point into the patient's head, regardless of where the entry point is. It exists to establish a head fixation device that is capable of. The head fixation device should preferably provide independent rotation relative to the MRI coil around the patient's head. Further, the head fixation system is preferably used in combination with a customizable MRI coil having two or more interchangeable coil sections to accommodate various trajectory lines and entry points into the patient's head. Should be possible.

U.S. Pat. No. 4,914,608 US Pat. No. 5,284,144 US Pat. No. 5,368,031 US Pat. No. 5,291,890 US Pat. No. 4,671,254 US Pat. No. 5,823,941 US Pat. No. 5,454,807 US Pat. No. 5,785,704

  The present invention relates to a gantry, a fixing ring rotatably connected to a ring mounting portion extending from the upper surface of the gantry, and including a plurality of slots extending around the circumference of the gantry, and the fixing ring A first fixation post having a head support constructed for insertion into a first one of the slots therein and a first fixation pin for engagement with a patient's skull; A second fixation having a first fixation post constructed for insertion into a second one of the slots in the fixation ring and a second fixation pin for engagement with the patient's skull A strut comprising a second stationary strut constructed for insertion into a third of the slots in the retaining ring, and a top coil member and a bottom coil member removably mounted on the cradle MRI coil, fixed ring In contrast, and by providing a head fixation system including a MRI coil rotatable independently therefrom, to solve the aforementioned problems.

FIG. 1 is a perspective view of an exemplary trajectory guide that may be used in combination with the head fixation system of the present invention. FIG. 2 illustrates the first step in the planning process, where an MRI scan depicts the identification of a tumor in the patient's brain. FIG. 3 illustrates the second step of the planning process, depicting the visual display generated by the planning software showing the patient's head and the location of the tumor identified in FIG. 4A-D illustrate step 3 in the planning process, in which a virtual trajectory guidance unit is installed on the entry point selected by the user. 5A-D illustrate step 4 of the planning process, where the virtual trajectory guide is adjusted to establish the desired trajectory. 6A-D illustrate step 5 in the planning process, where a patient's head with a trajectory guide is displayed in a virtual head fixation system. FIG. 7A is a perspective view of an exemplary embodiment of a head system according to the present invention. FIG. 7B is a perspective view of an exemplary embodiment of a head fixation system including a head fixation device, an MRI coil, and a moving bed. FIG. 7C is a perspective view of an MRI coil operable in conjunction with the head fixation device of the present invention. 8A-8D illustrate a head fixation device operably coupled to a patient's head. 9-13 illustrate the head fixation system of FIGS. 7A-7C used during operation. 9-13 illustrate the head fixation system of FIGS. 7A-7C used during operation. 9-13 illustrate the head fixation system of FIGS. 7A-7C used during operation. 9-13 illustrate the head fixation system of FIGS. 7A-7C used during operation. 9-13 illustrate the head fixation system of FIGS. 7A-7C used during operation.

  In general, the present invention encompasses systems and methods for orienting and fixing a patient's head in preparation for performing a surgical procedure that requires trajectory alignment. More specifically, the present invention relates to the risk that a surgeon may select almost any entry point (and therefore any trajectory) on the patient's head and interfere with the MRI coil around the patient's head. Without including an adjustable head fixation system that allows a suitable trajectory guide to be installed. While reference is made to brain tumors and brain surgery, those skilled in the art will appreciate that the systems and methods according to the present invention are designed for use in any surgery where head fixation is desired.

  Prior to describing the head fixation system in detail, an exemplary embodiment of a trajectory guide that may be used during a procedure in combination with the head fixation system will be discussed. Several optional “planning” steps up to the procedure are also discussed.

  FIG. 1 generally includes a base plate 11, a plurality of feet 12 that can be attached to a patient's skull or other body part, and a plurality of feet 12 and an equal number of adjustable telescopic legs 14. 1 is a perspective view of an exemplary embodiment of a trajectory guidance unit 10 that includes the same. As illustrated in FIG. 1, the trajectory guide 10 may be oriented to define a trajectory line T for a tool or instrument that requires alignment. Tools or instruments can include, but are not limited to, probes, catheters, biopsy needles, drills, and the like.

  The base plate 11 of the track guide 10 may include a first hinge portion 20 extending from the top clamp 16 that is constructed to mate with a second hinge portion 22 extending from the bottom clamp 18. It includes a top clamp 16 and a bottom clamp 18 that are hingedly connected by means 19. The first and second hinge portions 20 and 22 may be coupled together via any suitable connection means such as pins 24 or similar connection devices. Furthermore, the top clamp 16 and the bottom clamp 18 can be locked together in the closed position by the clamp lock 25 after the trajectory is determined.

  Each of the top and bottom clamps 16 and 18 includes an opening constructed to allow the ball joint movable member 26 to be movably and rotatably mounted therebetween. Ball joint movable member 26 may include an adapter receiving member 28 and a central receiving lumen (not shown in FIG. 1) extending through adapter receiving member 28 and ball joint movable member 26. The adapter receiving member 28 of the ball joint movable member 26 is constructed to receive a central ball adapter 30 therein, and the central ball adapter 30 can be constructed to receive and interface with various tools.

  As shown in FIG. 1, the central ball adapter 30 passes from the top through the ball joint movable member 26 and is constructed to mate with the tubular portion 32 and the adapter receiving member 28 of the ball joint movable member 26. Interface portion 34. The first fastening means 36 may be coupled to an adapter receiving member 28 that is operable to secure the central ball adapter 30 to the ball joint movable member 26 after being inserted therethrough. In particular, the first fastening means 36 can be any suitable fastening means including but not limited to a thumbscrew or the like. After the central ball adapter 30 is fully inserted into the adapter receiving member 28 of the ball joint movable member 26, the thumbscrew can be tightened to lock it in place. The user may then remove the central ball adapter 30 by simply loosening the thumbscrew and sliding the adapter 30 from within the adapter receiving member 28.

  Central ball adapter 30 may include a lumen 38 that extends through tubular portion 32 and an interface portion 34 that is configured to receive a surgical tool. The diameter of the lumen within the various central ball adapters can vary depending on the size of the probe and / or instrument designed and constructed to be received by the lumen. In addition, the central ball adapter 30 may include a second fastening means 40 that is operable to lock the tool in place when positioned within the lumen 38. As will be appreciated by those skilled in the art, the second fastening means 40 may be similar to the first fastening means 36 described above.

  As illustrated in FIG. 1, each adjustable telescopic leg 14 may include a ball joint end 42 and a hinged end 43. The length of each leg 14 can be adjusted and the legs can be locked to the desired length by leg cam locks 44 after the trajectory is determined.

  As further illustrated in FIG. 1, the trajectory guide 10 is optionally designed to assist in proper separation and alignment of the foot 12 during placement of the trajectory guide 10 on the patient. A web assembly 45 may be included.

  In order to determine the proper placement of the trajectory guide 10 on the patient and the desired trajectory of the guide (ie, leg length / orientation and ball joint movable member orientation), several planning steps include: Can be done. Next, exemplary but non-limiting planning steps performed using a custom software program are described.

  In a first planning step, as illustrated in FIG. 2, various MRI scans are taken and uploaded to the planning software. The desired entry point is then determined by the surgeon in a second planning step. As illustrated in FIGS. 3A-3D, the planning software may be designed to display a depiction of the patient's head as well as the location of the tumor 300 therein. Various possible entry points 310 are also displayed. The planning process proceeds to step 3 where a “virtual” trajectory guide is placed over the user selected entry point and displayed to the surgeon as illustrated in FIGS. 4A-4D. Subsequently, as illustrated in FIGS. 5A-5D, the legs of the virtual trajectory guide and the ball joint movable member are adjusted in a fourth planning step to establish the desired trajectory to the tumor. Finally, in the fifth planning step, the patient's head and trajectory guide are displayed in a “virtual” head fixation system, as illustrated in FIG. 6, as will be described in more detail below. The desired location for the fixed strut / pin and the desired fixed ring orientation can be determined.

  As will be appreciated by those skilled in the art, the surgical plan is performed in a “virtual” environment using software, so it can be completed days or even weeks before the actual surgery.

  After the surgical plan is complete, the surgeon may then perform the actual surgical procedure by physically positioning the patient within the head fixation system, or at any time thereafter.

  FIG. 7A is a perspective view illustrating an exemplary but non-limiting embodiment of a head fixation system 100 in accordance with the present invention. As shown in FIG. 7A, the head fixation system 100 generally includes a cradle 102, a head fixation ring 104 rotatably coupled to a ring mounting 106 extending from the upper surface of the cradle 102, a head Part support part 108 and a plurality of fixed support pillars 110 are included. The head fixing ring 104 includes a plurality of slots 112 extending around its circumference. As shown in FIG. 7A, the head support 108 is removably received by a first one of the slots 112 and the first fixed post 110A is received by a second slot of the slots 112. Removably received, the second fixed post 110B is removably received by a third of the slots 112. The first, second, and third slots 112 may be any of the slots around the circumference of the head fixation ring 104 depending on the desired trajectory, and optionally, as described above, the software planning process. Can be selected. As will be appreciated by those skilled in the art, the head fixation system 100 may include fewer or more fixation posts than those shown. For example, in one exemplary alternative embodiment, the head fixation system 100 includes four fixation posts.

  The first fixation post 110A includes a plurality of fixation pin openings 116A along its length that are adapted to receive one or more fixation pins 114A, 114B. The fixation pins 114A, 114B are respectively threadedly received by the fixation pin openings 116A, 116B, and thus may provide various “penetration depths” for setting the fixation pins. After being received by the fixation pin opening, the first adjustable fixation pin 114 </ b> A extends inward toward the center of the head fixation ring 104. In addition to the adjustable “depth of penetration” of the fixation pin 114A, the plurality of fixation pin openings 116A, 116B on the fixation posts 110A, 110B provide the surgeon with various fixation pin placement options. Similarly, the second fixed post 110B is a second adjustable fixed pin that can be removably and receiveably received by one of the plurality of fixed pin openings 116B along the length of the post 110B. 114B is included. As described above, any number of fixed struts can be utilized depending on the nature of the surgery.

  The head fixing ring 104 is positioned in the ring mounting portion 106 so as to be removable and rotatable. The head fixation ring 4104 is rotatable relative to the cradle 102 as indicated by arrow 118 to adjust the angular position of the patient's head. The head fixation ring 104 may be locked in a desired position using one or more ring locking devices 120. In one exemplary embodiment, the ring locking device 120 may be retractable pin or pins (not shown) received by one or more of the plurality of openings 122 along the outer periphery of the head fixation ring 104. A).

  The gantry 102 can be integrally connected to the patient table 105. Alternatively, the cradle 102 can be removably coupled to the patient table 105 by a hinge or similar mechanism known to those skilled in the art. As a further alternative, the cradle 102 may simply be adjacent to the patient table 105, depending on the surgery required. The handle 107 facilitates movement of the patient and the system according to the present invention in use.

  As further illustrated in FIG. 7A, the head fixation system 100 includes a coil support 124 that is integrally or non-integrally / removably coupled to the cradle 102. The coil support 124 is constructed to removably receive the MRI coil thereon. One exemplary coil 125 is illustrated in FIGS. 7B and 7C. The coil 125 includes a bottom coil member 127 and replaceable upper coil members such as upper coil members 129A and 129B illustrated in FIG. 7C. As will be appreciated by those skilled in the art, the upper coil member 129A is preferably used for a trajectory extending from the top of the head, while the upper coil member 129B is preferably the forehead or head. Used for trajectories extending from the side. To operably couple the top coil member 129A or 129B to the bottom coil member 127, the top coil members 129A and 129B are constructed to mate with corresponding pin slots 135 and electrical receptacles 137 in the bottom coil member 127. Alignment pins 131 and electrical connectors 133 are provided. The bottom coil member 127 includes a connector 143 that operably connects to the MRI cable and connects the coil 125 to the MRI system.

  Referring to FIGS. 7A and 7B, the first end 139 of the bottom coil member 127 is constructed to engage the first coil track portion 126 while the second end 141 of the coil is Two coil track portions 128 are constructed to engage. First and second coil track portions 126 and 128 allow coil 125 to rotate relative to and independent of head fixation ring 104. When rotated to the desired position, the coil 125 can be “locked” with one or more coil locking devices 130, such as, for example, friction locks, pins, screws, or other means known to those skilled in the art. .

  8-13 illustrate an exemplary process for physically attaching a patient's head to the head fixation system 100 described above. In particular, the process begins by the head fixation ring 104 being positioned around the head of the patient P as illustrated in FIG. This can be accomplished either when the patient is lying on the patient transfer plate 105 or, alternatively, when the fixation ring 104 is separated from the ring mount 106 and the patient is standing or sitting. This may be performed by being connected to the ring mounting unit 106. Then, as illustrated in FIG. 9, the first and second fixation posts 110A and 110B are inserted into the appropriate slots 112 in the head fixation ring 104, and the first and second fixation pins 114A and 114B. Is attached to the patient's head. As will be appreciated by those skilled in the art, the fixation pin may comprise any suitable attachment means such as, for example, a threaded shaft. If the head fixation ring 104 has not been previously connected to the ring mount 106 (ie, the fixation ring 104 has been separated from the ring mount 106 when attached to the patient's head), the next step Involves positioning the patient P on the gantry 102 and locking the fixation ring 104 to the ring mounting portion 106. Subsequently, the head fixation ring 104 is rotated to provide access to the mounting location (and entry point) for the trajectory guide 10 as illustrated in FIG.

  In the next step of the process, the surgeon attaches the trajectory guide 10 to the head of the patient P based on the information derived during the surgical planning step, as illustrated in FIG. As will be appreciated by those skilled in the art, the head fixation ring 104 may be further rotated as necessary to avoid any potential interference between the treatment probe / instrument and the MRI bore that would be used. Can be done. Once the trajectory guide 10 is attached to the patient's head, the patient can be transported to the MRI room and moved to the MRI platform.

  The process continues and attaches the MRI coil 125 to the patient cradle 102 as illustrated in FIG. As will be appreciated by those skilled in the art, the upper coil member 129B was required in the illustrated embodiment due to the orientation of the trajectory guide 10 on the patient's head. Once the coil 125 is assembled, the surgeon may visually verify that the minimum distance D is maintained between the trajectory guide 10 and the MRI bore B, as illustrated in FIG. Finally, the surgeon can take an MRI scan, confirm the trajectory, and continue the treatment / procedure.

  The foregoing descriptions of exemplary embodiments of the present invention have been presented for purposes of illustration and description only and are intended to be exhaustive or to limit the invention to the precise form disclosed. It is not a thing. Many modifications and variations are possible in light of the above disclosure.

  The embodiments allow the person skilled in the art to make use of the present invention and various embodiments, and are suitable for specific uses devised by various modifications, and the principles of the present invention and their practicality. Selected and explained to explain the different uses. Alternate embodiments will become apparent to those skilled in the art without departing from the spirit and scope thereof.

Claims (31)

A head fixation system,
A cradle having upper and lower surfaces;
A ring mounting portion operably connected to the upper surface of the cradle;
A fixing ring rotatably coupled to the ring mounting portion, the fixing ring including a plurality of fixing ring slots extending around a circumference of the fixing ring;
A first fixed strut receivable within a first of the fixed ring slots;
A head fixation system comprising: a second fixation post receivable in a second of said fixation ring slots.   The head fixation system according to claim 1, further comprising a head support constructed for insertion into a third of the fixation ring slots.   The head fixation system according to claim 1, further comprising at least one fixed column opening through the fixed column.   The head fixation system of claim 3, further comprising at least one fixation pin receivable by the at least one fixation post opening for engagement with a patient's skull.   The head fixation system according to claim 3, wherein the at least one fixed column opening includes a plurality of fixed column openings.   The head fixation system according to claim 5, further comprising a plurality of fixation pins receivable by at least one of the plurality of openings.   The head fixing system according to claim 1, further comprising a moving plate detachably connected to the gantry.   The head fixing system according to claim 1, further comprising a coil support portion connected to the gantry.   The head fixing system according to claim 1, wherein the ring mounting portion further includes first and second coil tracks.   An MRI coil having a top coil member and a bottom coil member that are removably mounted on the cradle, wherein the MRI coil is further rotatable relative to the securing ring and independent of the MRI coil. The head fixation system according to claim 1, comprising:   The MRI coil further comprising a top coil member rotatably engageable with the first coil track and a bottom coil member rotatably engageable with the second coil track. The head fixation system as described in.   The head fixing system according to claim 1, wherein the head fixing ring includes a plurality of fixing ring openings positioned on an entire circumference on an edge of the head fixing ring.   The head fixation system of claim 12, further comprising one or more ring locks receivable by one or more of the plurality of fixation ring openings.   12. The head fixation system of claim 10 or 11, wherein the top coil member includes one or more alignment pins that are matable with corresponding pin slots on the bottom coil member.   12. A head fixation system according to claim 10 or 11, wherein the bottom coil member includes connector means for connecting the MRI coil to an MRI system.   The head fixation system of claim 10, wherein the coil support further comprises one or more coil locking devices for locking the MRI coil in place. A head fixation system,
A cradle having upper and lower surfaces;
A ring mounting portion operably connected to the upper surface of the cradle;
A locking ring rotatably received by the ring mounting portion, the locking ring including a plurality of locking ring slots extending around a circumference of the locking ring;
A first fixation post receivable within a first one of the fixation ring slots, the first fixation post including a first fixation pin for engagement with a patient's skull. A first fixed strut;
A second fixation post receivable within a second one of the fixation ring slots, the second fixation post comprising a second fixation pin for engagement with a patient's skull; A second fixed strut;
An MRI coil that is rotatably received by the cradle and removably mounted thereon, the MRI coil comprising an MRI coil that is rotatable relative to and independent of the securing ring. The head fixation system.   The head fixation system of claim 17, further comprising a head support constructed for insertion into a third of the fixation ring slots.   The head fixation system of claim 17, further comprising: the fixation post including at least one fixation post opening through the fixation post.   20. The head fixation system of claim 19, further comprising at least one fixation pin receivable by the at least one fixation post opening for engagement with a patient's skull.   The head fixation system of claim 19, wherein the at least one fixed column opening includes a plurality of fixed column openings.   The head fixation system of claim 21, further comprising a plurality of fixation pins receivable by at least one of the plurality of openings.   The head fixing system according to claim 17, further comprising a moving plate removably connected to the gantry.   The head fixing system according to claim 1, further comprising a coil support portion connected to the gantry.   The head fixing system according to claim 17, wherein the ring mounting portion further includes first and second coil tracks.   26. The head fixation system of claim 25, wherein the MRI coil includes a top coil member and a bottom coil member, the top and bottom coil members being rotatably received by the first and second coil tracks.   The head fixation system according to claim 17, wherein the head fixation ring includes a plurality of fixation ring openings positioned on an entire circumference on an edge of the head fixation ring.   28. The head fixation system of claim 27, further comprising one or more ring locks receivable by one or more of the plurality of fixation ring openings.   The head fixation system of claim 10, wherein the coil support further comprises one or more coil locking devices for locking the MRI coil in place. A method of using a head fixation system,
Providing a head fixation system, the head fixation system comprising:
A fixing ring, the fixing ring having a plurality of fixing ring slots extending around a circumference of the fixing ring;
A first fixed post that is receivable in a first of the fixed ring slots, the first fixed post including at least one fixed pin;
A second fixed strut receivable in a second of the fixed ring slots, the second fixed strut comprising a second fixed strut including at least one fixing pin; And that
Positioning the head fixation ring around the patient's head;
Inserting the first fixed post into the first one of the fixed ring slots in an adjustable manner;
Inserting the second fixed post into the second of the fixed ring slots in an adjustable manner;
Securing the fixation ring to the patient's head by positioning the fixation pin relative to the patient's head. A method of using a head fixation system,
Positioning a trajectory guide on the patient's head to establish a trajectory for the entry point;
Providing a head fixation device, wherein the head fixation device comprises:
A cradle having upper and lower surfaces, the cradle including an MRI coil receiving track;
A ring mounting portion operably connected to the upper surface of the cradle;
A fixing ring rotatably coupled to the ring mounting portion, the fixing ring including a plurality of fixing ring slots extending around a circumference of the fixing ring;
A first fixed strut receivable within a first of the fixed ring slots;
A second fixed post that is receivable in a second of the fixed ring slots, the fixed post including one or more fixed pins;
And that
Positioning the fixation ring around the patient's head;
Adjusting the first and second fixation posts in the fixation ring slot;
Fixing the fixing column to the patient's head by the fixing pin;
Locking the fixing ring in the ring mounting portion;
Rotating the retaining ring to provide access to the entry point;
Attaching the MRI coil to the cradle by positioning the MRI coil in the MRI coil receiving track;
Performing an MRI scan and confirming the trajectory.

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