RIT Magnetic Resonance Laboratory

Patents / Intellectual Property

The intellectual property on this page is available for licensing from RIT and the University of Rochester. For more information, please contact: Marjorie K. Zack, Director of Grants, Contracts, and Intellectual Property, Rochester Institute of Technology, 585 475-7525, mkzgcip@rit.edu.

Resonators for Magnetic Resonance Imaging
Inventors: R.G. Bryant, J.P. Hornak, E.A. Marshall
Assignee: University of Rochester
US Patents: #5,139,024, August 1992; and #5,024,229, June 1991

The single turn solenoid (STS) is a general class of transmit and receive resonator for use in Magnetic resonance imaging (MRI). The STS has very uniform transmit and receive field distributions across its volume, high filling factor, excellent signal-to-noise ratio (SNR), and low transmit power requirements. There are several different forms of the single turn solenoid.

(picture of sts) (picture of perforated sts) (picture of sts pair) (picture of ribbonator)

STS Perforated STS STS Pair Ribbonator
The simple STS is a cylindrical shaped resonator, suitable for MRI of the breast and forearm. The perforated STS is a simple STS with one or more perforations in the cylinder. The perforated STS is suitable for MRI of MRI head, knee, elbow, wrist, and shoulder. The STS pair is, as the name implies, a pair of simple single turn solenoids joined together to resonate as one unit. The STS pair is suitable for MRI of the breasts. The ribbonator is the rectangular shaped STS. The ribbonator can be perforated or joined with another ribbonator to form a pair. The ribbonator is suitable for MRI of the hand and samples. The following images were obtained using STS style resonators as the transmitter and receiver coil on a GE 1.5 T MRI system.

(picture of breast using STS)

As an MRI system designer, what can these coils do for you?

The lower transmit power requirements of this style coil means your system will require a smaller, less expensive RF power amplifier.
The favorable SNR of this style coil means high quality images in less time because fewer averages are needed.
The high filling factor of this style coil means better images with a smaller FOV and higher resolution.

Resonator for Magnetic Resonance Imaging of the Wrist
Inventors: S.D. Szeglowski, J.P. Hornak
Assignee: RIT
US Patent #5,542,424, August 1996

(picture of asym sts) This asymmetric single-turn solenoid style MRI coil is especially suitable for MRI of the human wrist. As is characteristic of single-turn solenoids, this wedge-shaped geometry solenoid has a high filling factor and quality factor, as well as produce images with a favorable signal-to-noise ratio (SNR). The radio frequency (RF) transmitter power required to produce a 90 degree pulse in the solenoid was only 80 mW, thus making the device ideal for smaller clinic sized imagers. The asymmetric solenoid has excellent uniformity in the RF field across its volume, thus producing images with uniform contrast-to-noise ratio. The combination of these four properties of the coil resulted in the production of excellent 1.5-mm thick anatomical images of the wrist.

(MRI of wrist ) Anatomy: human wrist
Coil: asymmetric single turn solenoid (425 cc)
Sequence: spin-echo
Plane: coronal
TR/TE: 2000/27 ms
FOV: 7 cm
Thk: 1.5 mm
Matrix: 256x256
Nex: 1
Imager: 1.5T GE Signa
SNR: muscle=27, adipose=57
Power for p/2 rotation: 80 mW

As an MRI system designer, what can this coil do for you?

The coil's lower transmit power requirements means your system will require a smaller, less expensive RF power amplifier.
The coil's favorable SNR means high quality images in less time because fewer averages are needed.
The coil's high filling factor means better images with a smaller FOV and higher resolution.

Magnetic Resonance Laboratory
Center for Imaging Sciecne
Rochester Institute of Technology
54 Lomb Memorial Drive, Rochester, NY 14623-5604

voice: 585 475-2904 fax: 585 475-5988 e-mail: jphsch@rit.edu