1. Field of the Invention
The present application relates to magnetic resonance (MR) imaging system, and more specifically to MR imaging system which allows interactive selection of imaging planes during imaging.
2. Description of Related Art
In conventional magnetic resonance (MR) imaging systems, the three dimensional location of a desired region of the patient to be imaged must be provided to the MR imaging system before obtaining the image. In addition to the location, the three dimensional orientation must also be provided. Together these define an `imaging plane`. These locations and orientations typically are either calculated manually, or prescribed graphically, by drawing a line on a previously acquired image. Even though the computations may not be difficult, it makes it cumbersome to produce several images at different orientations. If images are being rapidly acquired in a continuous imaging mode, it is desirable that the operator keep his eyes on the new images as they are displayed, and these imaging-plane prescription techniques do not allow this. Also, the graphic prescription technique described above will only define imaging planes orthogonal to the previously acquired image.
While acquiring images of the heart it is often desirable to adjust the imaging plane interactively while searching for anatomy such as the coronary arteries. Also, with new open magnet MR Imaging systems, as described in U.S. Pat. No. 5,365,927 issued Nov. 22, 1994 "Magnetic Resonance Imaging System With Pointing Device" Roemer et al., assigned to the present Assignee, and hereby incorporated by reference; it is possible to perform medical procedures on a subject and simultaneously acquire a series of continuous MR images. When a medical procedure, such as surgery, is being performed, it is very desirable to minimize the time required to calculate location and orientation of `imaging planes` to acquire images.
Currently there is a need for an MR imaging system which provides MR images along selected orientations through selected internal structures in the heart of a patient, in which an operator may easily indicate location and orientation of an imaging plane, and acquire an image of the subject from that plane.