Coil system for a magnetic resonance imaging system

• US 4,975,644 A
• Filed: 03/29/1989
• Issued: 12/04/1990
• Est. Priority Date: 03/29/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fox, Timothy R.
• Primary Examiner(s): Tokar, Michael J.
• Application Number:
  US07/330,309
• Time in Patent Office: 615 Days
• Field of Search: 324/300, 324/307, 324/309, 324/312, 324/311, 324/318, 324/322, 128/653
• US Class Current: 324/318
• CPC Class Codes: G01R 33/3415 comprising arrays of sub-coils , i.e. phased-array coils with flexible receiver channels
• CPC Class Codes: G01R 33/3664 Switching for purposes other than coil coupling or decoupling, e.g. switching between a phased array mode and a quadrature mode, switching between surface coil modes of different geometrical shapes, switching from a whole body reception coil to a local reception coil or switching for automatic coil selection in moving table MR or for changing the field-of-view G01R33/3671 takes precedence

Abstract

A coil system for a magnetic resonance imaging (MRI) system includes a plurality of adjacent surface coils for sensing magnetization in a patient. Switches are provided for enabling selected ones of the plurality of coils to output electrical signals. A signal combiner combines the electrical signals from the selected coils into an output signal for further processing. Coupling cancellation networks are provided between adjacent ones of the plurality of coils for cancelling electrical coupling existing therebetween.

Claims

1. A coil system, for a magnetic resonance imaging system, for imaging a selected pattern on an object, comprising:

a plurality of adjacent surface coils for sensing a predetermined condition produced in said object and for outputting electrical signals corresponding thereto;

means for enabling selected ones of said plurality of coils to output said electrical signals based on said selected pattern;

means for combining said electrical signals from the enabled ones of said pluraltiy of coils to provide an output signal; and

means for cancelling electrical coupling between adjacent ones of said plurality of coils.

2. A coil system according to claim 1, further comprising means for amplifying said electrical signals;

wherein said enabling means includes first switch means for selecting said selected ones of said plurality of coils, and second switch means, responsive to an output from said first switch means and to a signal from said MRI system, for causing said selected ones of said plurality of coils to sense said predetermined condition and to output said electrical signals.

3. A coil system according to claim 2, wherein said enabling means further includes third switch means, responsive to said output from said first switch means, for causing said amplifying means to output only electrical signals corresponding to said selected coils.

4. A coil system according to claim 1, wherein said combining means comprises current summing means for adding together currents output by said selected ones of said plurality of coils.

5. A coil system according to claim 1, further comprising tuning means for tuning each of said plurality of coils to an operating frequency.

6. A coil system- according to claim 1, further comprising means for cancelling electrical coupling between alternate ones of said plurality of coils.

7. A coil system according to claim 1, wherein said enabling means includes means for decoupling said selected ones of said plurality of coils from a transmitting coil of said magnetic resonance imaging system when said magnetic resonance imaging system is in a transmitting mode, and for enabling said selected ones of said plurality of coils when said magnetic resonance imaging system is in a receive mode.

8. A coil system according to claim 1, further comprising an additional plurality of adjacent surface coils disposed in a plane parallel to said plurality of adjacent surface coils for sensing said predetermined condition produced in said object and for outputting electrical signals corresponding thereto.

9. A coil system according to claim 8, wherein each of said additional plurality of adjacent surface coils is disposed such that a center line thereof is between adjacent ones of said plurality of adjacent surface coils.