The present disclosure relates generally to magnetic resonance imaging equipment suitable for use in neonatal care, and, more particularly, to a transfer station for receiving an infant from an incubator and to assist with preparing the infant for an MR scan.
Today premature infants weighing less than 1 kg may be stabilized and allowed to develop in neonatal intensive care units (NICUs). Magnetic resonance imaging (MRI) is a powerful technique for diagnostic purposes but is not routinely performed on these infants due to a number of technical and logistical challenges.
When a mother has a high-risk pregnancy, it is possible that the baby could be born prematurely and would require treatment in a neonatal intensive care unit or NICU. Also, unexpected early delivery may require that an infant be treated in an NICU.
One difficulty in utilizing MRI for these premature infants is monitoring the vital signs and life support of the infant during MR examination. Parameters that must be monitored during examination include electrolyte levels, hydration and temperature. A second difficulty in utilizing MRI is that the infant must be moved from an incubator or isolette into and out of the MR scanner. This movement places the infant at risk for injury.
Despite challenges, MRI has the potential to play an important diagnostic role in the care and management of neonates. The full use of this imaging technique requires that the imaging take place as early as the first few hours of life. At this stage, however, the infants are hemodynamically unstable. Accordingly, transporting and maintaining homeostasis in these fragile infants presents difficulty.
Another challenge in using MRI for neonates is that MRI systems are frequently located in Radiology departments outside of and perhaps distant from the NICU. Consequently, the neonate must be escorted out of the NICU. This may present certain logistical and technical challenges with respect to controlling the neonate's environment. Furthermore, removing staff from the NICU to transfer and attend to one baby outside the NICU can place the remaining babies in the NICU at increased risk of a reduced level of care due to decreased staff coverage.
An MR compatible transport incubator and imaging system has been developed (Dumoulin et. al.) and is currently in use. Concepts in Magnetic Resonance (Magnetic Resonance Engineering), Vol.15 (2) 117-128 (2002). This system is a self-contained MR compatible transport incubator which carries the infant from the NICU to an MR scanner located in or near the NICU. With this approach the baby must first be transferred from its “home” incubator or isolette in the NICU into the transport incubator. The transport incubator is then moved to the MR scanner where it is docked with the scanner. A portion of the transport incubator containing the baby is then moved into the center of the MR imaging system magnet where MR imaging is performed. While this approach has the advantage of not disturbing the baby while it is in the transport incubator, even during MR scanning, it has several limitations including: a) infants must be fully detached from the monitoring equipment in their home incubator to be transferred into the transport incubator, b) the MR system that is used for imaging must have a bore large enough to accommodate the portion of the transport incubator containing the baby (thereby requiring a large heavy magnet), c) the baby and its attending staff need to leave the NICU for scanning, and d) because the transport incubator must be fully MR compatible while providing full life support for the baby, the system is heavy and expensive.
An alternate approach to provide MR imaging to newborn babies has been disclosed by Feenan in U.S. Pat. No. 7,599,728. In this approach a relatively smaller MR magnet is employed and MR-compatible incubators are docked to the magnet thereby permitting the baby to be slid into the magnet for imaging. While this approach has the benefit of providing a magnet that is more easily installed in the NICU, it does have several limitations including the need for MR compatible incubators to be used throughout the NICU, or the transfer of a neonate from a non-MR-compatible home incubator to an MR-compatible incubator. This approach also limits the access to the attending staff as they prepare the infant for MR scanning. In particular, the staff must reach through the incubator to push the baby into and out of the magnet.
In view of the foregoing, it may be understood that improved techniques for neonatal care necessitate improved transfer techniques for neonates in NICUs. In particular there is a need for an MR neonatal imaging system that can be easily sited in the NICU. The NICU magnet should be small, lightweight and acoustically quiet to permit installation within the physical boundaries of the NICU. Furthermore, there is a need for MR imaging of neonates without requiring them to be transferred out of their home incubators, or detaching them from their physiological monitoring systems or intravenous tubes. There is also a need to minimize physical movement of the baby as it enters the MR magnet and to ensure that it stays still during MR scanning. There is an additional need to for a neonatal MR imaging system that will allow babies in the NICU to be imaged without requiring that incubators in the NICU be MR compatible.
A transfer station is disclosed that is suitable for use in association with an MR scanner and an incubator for neonatal infants. The transfer station generally may include a transfer station base and a transfer station platform attached to a top surface of the transfer station base. The transfer station platform may be disposed at substantially the same height as the height of a corresponding patient surface in the incubator. Additionally, a transfer station bed, that may be movable, may be provided atop the transfer station platform.
The present disclosure will now be described in more detail with reference to exemplary embodiments thereof as shown in the accompanying drawings. While the present disclosure is described below with reference to exemplary embodiments, it should be understood that the present disclosure is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional implementations, modifications, and embodiments, as well as other fields of use, which are within the scope of the present disclosure as described herein, and with respect to which the present disclosure may be of significant utility.
In order to facilitate a fuller understanding of the present disclosure, reference is now made to the accompanying drawings, in which like elements are referenced with like numerals. These drawings should not be construed as limiting the present disclosure, but are intended to be exemplary only.
a is a perspective view of an exemplary MR imaging system, an exemplary MRI transfer station, and an exemplary incubator containing a neonate for use with the present disclosure;
b is a perspective view of the present disclosure showing the removal of a portion of the incubator before preparing the neonate for movement and MR scanning;
c is a perspective view showing the placement of the neonate on the MRI transfer station;
d is a perspective view showing the placement of the neonate into the exemplary MR imaging system;
The use of MRI techniques for infants, and in particular neonates, is highly desirable. MRI techniques provide diagnostic information without patient exposure to ionizing radiation, and are suitable for extended and repeated studies.
MR techniques provide excellent anatomic visualization and functional information. They can be used to measure neural fiber track development and have a number of potential clinical uses including, but not limited, to diagnosis of brain trauma, cardiac abnormalities, congenital defects and the assessment of lung development.
There are, however, a number of challenges in the use of MRI for neonatal imaging. Patient access during scanning can be difficult as MR magnets are typically large and surround the patient. Safety concerns include forces on ferromagnetic objects, potential for rf heating and acoustic noise. Also, logistics may be difficult, as MR scanners tend to be in radiology departments, while neonate infants are typically in the NICU.
a-1d depict an exemplary MRI and incubator system 100 in or for which the techniques for the MR imaging of neonates in accordance with the present disclosure may be implemented. The illustrated MRI system comprises an MRI scanner 102. Since the components and operation of the MRI scanner are well-known in the art, only some basic components helpful in the understanding of the system 100 and its operation will be described herein.
The MRI scanner 102 may comprise a cylindrical superconducting magnet 104, which generates a static magnetic field within a bore 105 of the superconducting magnet 104. The superconducting magnet 104 generates a substantially homogeneous magnetic field within the magnet bore 105. The superconducting magnet 104 may be enclosed in a magnet housing 106.
A set of cylindrical magnetic field gradient coils 112 may also be provided within the magnet bore 105. The gradient coils 112 can generate magnetic field gradients of predetermined magnitudes, at predetermined times, and in three mutually orthogonal directions within the magnet bore 105. With the field gradients, different spatial locations can be associated with different precession frequencies, thereby giving an MR image its spatial resolution. An RF transmitter coil 114 is positioned within the gradient coils 112. The RF transmitter coil 114 emits RF energy in the form of a magnetic field for the purpose of exciting MR signals during image acquisition. The RF transmitter coil 114 can also receive MR response signals. The MR response signals are amplified, conditioned and digitized into raw data as is known by those of ordinary skill in the art.
The present disclosure provides an apparatus and a technique for safely and effectively transferring an infant from the primary care area, such as an incubator, to the MR magnet. In one particular embodiment, the present disclosure provides the means to transfer a neonate from the NICU to an MR magnet located either in a radiology department or in the NICU itself The present disclosure may accomplish this by providing an MR-compatible transfer station that may be permanently or releasably attached to the MR magnet. This station may create an MR compatible environment that, if desired, the baby may be moved into without being detached from patient monitoring or life support systems. Once stabilized on the transfer station, the baby may then be moved into the magnet for imaging. Note that in the present disclosure the incubator does not need to be fully MR compatible and may be constructed with some MR incompatible elements such as electrical motors.
Referring again to
b shows the elevation and removal of the top portion of the incubator 130 so as to provide access to the neonate. Alternate means to gain access to the neonate may include folding down or removing one or more side panels, or front panel 136, of the incubator 130.
c shows the placement of the neonate 110 onto a transfer station bed 124 on a transfer station surface 122. The transfer station surface 122 may be supported on a transfer station base 120. In the current embodiment of the present disclosure, neonate 110 may be prepared for MR scanning while in this location. Preparations may include safety checks, swaddling, attachment of additional monitoring equipment, placement of MR receive coils, and/or attachment of hearing protection to the neonate 110. In one embodiment of the disclosure the incubator 130 may be docked or mechanically attached to the transfer station. In another embodiment the incubator 130 may be placed near the transfer station, but does not physically contact it.
d shows the insertion of the neonate 110 and transfer station bed 124 into the MR imaging system 102. Note that during insertion the transfer station bed 124 moves off of transfer station surface 122 and onto a magnet bed support surface 108. Note also that during this insertion the neonate is not moved with respect to the transfer station bed 124 although the transfer station bed is moved into the MR imaging system with the neonate.
The present disclosure is particularly advantageous in that it minimizes the transfer time from the NICU to MR imaging system 102 and may provide less stress on the infant. Another advantage of the present disclosure is that babies may not need to be fully detached from their home incubator, which is shown as incubator 130 in
In particular, the present disclosure relates to a transfer station for preparing an infant, including neonates, prior to transfer into the magnet. In the present disclosure the transfer station may be an auxiliary incubator that is both MR-compatible and if desired, permanently or releasably attached to the MRI scanner 102. The transfer station may have all of the functionality of the neonate's home incubator, but implemented in an MR-compatible and MR-safe manner.
Once the infant is on the transfer station 200, the infant can be prepared for MR scanning. As will be recognized by those skilled in the art of MR scanning, MR scanning frequently requires that several steps be performed before a patient may be inserted into an imaging magnet. These steps may include: a) immobilization of the patient (in the case of neonatal imaging, swaddling is frequently sufficient), b) the optional insertion of IV tubes for contrast injections, c) the attachment of MR imaging coils, d) a safety check to verify that no ferromagnetic objects are present, e) placement of hearing protection, and f) verification of patient stability and comfort. All of these steps may be performed while the patient is near the magnet, and may require access to the patient which is not always possible with most incubator designs.
Another aspect of the transfer station 200 of the present disclosure is that it may provide full environmental control for the neonate. Many neonates are too young to be able to fully control their internal temperature, and it is well known to those skilled in the art that small neonates must be kept warm. In the present disclosure, this may be done with warm air and/or a radiant heater driven by a temperature controller 250. In one embodiment of the disclosure, a thermocouple or similar temperature sensor modified for use in the MR environment with non-ferromagnetic parts and appropriate rf filtering may be used to provide feedback to the temperature controller 250 to provide suitable temperature control. In another embodiment of the present disclosure a physiologic monitoring system 260 may be provided. This system may be MR compatible and MR safe. It can be used if desired in place of the patient monitoring systems found in the neonate's home incubator.
The transfer station 200 of the present disclosure may be placed between incubator 130 and MRI system 102. One major function of the transfer station may be to act as a buffer element to prevent non MR-compatible objects from entering into the magnet while the baby is inside the magnet.
As shown in
Alternatively, the barrier can be augmented with a step design as shown in
The present disclosure has the advantage of working with incubators and isolettes that do not require modification to be made MR compatible. According to the present disclosure, the infant may, in one embodiment, still be tethered to the incubator by life support and monitoring methods, for example IV lines and EKG leads. Alternatively, the transfer station 200 itself may be equipped with the aforementioned and other life support and monitoring methods.
The transfer station may in one embodiment, as shown in
In one embodiment of the disclosure, the incubator may be adapted to dock to the transfer station. This may be accomplished for instance by a mechanical latch which rigidly engages and requires a physical action to unlock, or it could be a simple “tongue and groove” arrangement in which the incubator can be brought close to the magnet with a selected alignment. In such an arrangement, it may be desirable to engage the wheel brakes on the incubator during docking to prevent the incubator from moving unexpectedly.
As mentioned, in one embodiment, the transfer station 200 may be equipped to include life support and monitoring equipment. Such equipment includes, but is not limited to, EKG monitoring, IV tubes, oxygen monitors, ventilators, breathing gases, and bilirubin treatment. If needed, the transfer station 200 can be powered by an external supply or an on-board MR-compatible battery.
In one embodiment of the disclosure, the transfer station 200 may include physical barriers to prevent extraneous objects being sucked into the infant when the infant is inside the magnet. In one embodiment, the barrier may include a full enclosure made of clear engineering plastic that is resistant to impact damage. This feature may provide full visual access of the baby but may provide a barrier to the entry of other objects into the magnet.
In one embodiment, a Faraday cage may be built into the transfer station 200 to prevent RF interference from degrading the MR image. This would be particularly advantageous if the MR system is not placed in an RF screen room. Should a Faraday cage be incorporated into the transfer station, an internal rf tight panel or door may need to be added between the magnet and the transfer station. It may also be desirable to provide penetration filters for monitoring leads to minimize rf interference during MR imaging. In an even further embodiment, the transfer station may incorporate a scale for weighing the infants.
While the foregoing description includes many details and specificities, it is to be understood that these have been included for purposes of explanation only, and are not to be interpreted as limitations of the present disclosure. It will be apparent to those skilled in the art that other modifications to the embodiments described above may be made without departing from the spirit and scope of the disclosure. Accordingly, such modifications are considered within the scope of the disclosure as intended to be encompassed by the following claims and their legal equivalents.
The present disclosure claims priority benefit of U.S. Provisional Patent Application Ser. No. 61/593,911 filed Feb. 2, 2012 and is further related to U.S. Provisional Patent Application Ser. No. 61/429,567 filed Jan. 4, 2011.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US12/52242 | 8/24/2012 | WO | 00 | 8/15/2014 |
| Number | Date | Country | |
|---|---|---|---|
| 61593911 | Feb 2012 | US | |
| 61429567 | Jan 2011 | US |