Inductively-Overcoupled Coil for High Resolution Magnetic Resonance Imaging

Technology ID: 06KUMC008

Description:  This novel invention is an inductively-coupled electromagnetic device to produce and acquire high resolution radio frequency magnetic resonance imaging (MRI) signals from a subject under the study.  The system combines an imaging coil and a external coupling coil.  When the imaging coil is placed on the region to be imaged and tuned using the external coil, high quality high resolution magnetic resonance images can be acquired.   Imaging of soft tissues such as muscles or nerves by high resolution magnetic resonance allows the visualization of these areas which can only be visualized by surgical intervention.  This type of imaging is especially important in the treatment of crushing injuries which produce soft tissue damage.

For example, if patient has suffered a crushing hand injury involving injury to the muscles or nerves, this small and simple device can be placed externally on the skin of the hand and held in place by the cast.  This device will allow the monitoring of the healing process by imaging of the healing of the nerves and soft tissues at high resolution over time.  This data will enable the physician to visualize the healing of the tissues at high resolution in a noninvasive manner as healing proceeds and thus proscribe the best course of treatment for the injury.

Patent: Patent pending

Specific Market: Disposable clinical supplies, Magnetic resonance imaging.

Market Size:  Unknown

State of the Art:  Currently available Magnetic Resonance Imaging devices that utilize “inductive overcoupling” to obtain high resolution magnetic resonance images must be surgically implanted within the body.  As such these devices exhibit frequency response characteristics that change with time, motion or placement location. In other words, as the tissue heals and grows around the device the frequency response characteristics change but the device cannot be retuned without surgical intervention in order to match their frequency of response. This drift in frequency response compromises the quality of the acquired data over time thus affecting resolution of the image. 

Benefits: Maintaining the quality of magnetic resonance images acquired with the current embedded coil technology is challenging in longitudinal observations.  To overcome this challenge, the principle of “inductive overcoupling'” had been developed as a method to tune and match a dual coil system.  This presents a practical solution to a real problem in that the tuning and matching properties of the implanted coil can be modified as needed by inductively overcoupling this coil to an external volume coil with tuning and matching capabilities.  Inductive overcoupling provides a unique opportunity for tuning and matching the coil system, and allows reliable and repeatable acquisitions of magnetic resonance data. Thus unlike previous devices, this device can be externally tuned to maintain the high resolution of magnetic resonance images over time.

The device has the flexibility to be manufactured in any size or shape to match the area of the body to be imaged.  For example, small devices could be manufactured to match the back of the hand for hand injuries while larger devices could be made to accommodate back injuries.  Moreover, these devices, which incorporate a very simple design, can be manufactured for very low cost and marketed as high margin disposable devices.

Technical Obstacles:  Clinical studies are needed to affirm the utility of this device in live patients and confirm observations made during studies on cadavers. 

Publications: 

Bilgen, M.  Inductively-overcoupled coil design for high resolution magnetic resonance imaging.  BMC Biomedical Engineering Online.  5:3, 2006.

Bilgen, M.  Magnetic resonance microscopy of spinal cord injury in mouse using a miniaturized implantable rf coil.  J. Neuroscience Methods.  2006.  In press.  doi:10.1016/j.jneumeth.2006.06.024