AUTOMATIC TABLE HEIGHT OPTIMIZING TECHNIQUE FOR MEDICAL IMAGING SYSTEMS
Publication Date: 2011-Dec-13
The IP.com Prior Art Database
The invention provides a device and algorithm for automatic centering and height optimization of a patient body in a gantry bore of a medical imaging device. This is achieved by adjusting the height of the table so that the vertical center of the patient body is approximately aligned with the scanner bore center. The presented technique is based on an IR emitter-receiver array installed on the gantry. Further an algorithm is employed to calculate the optimal height for any given patient body and the gantry table height is adjusted automatically.
FIELD OF INVENTION
The invention generally relates to medical imaging systems and more particularly to systems for height optimization of a gantry table.
BACKGROUND OF THE INVENTION
Generally, medical imaging systems such as Computed tomography (CT), Magnetic resonance (MR), Positron emission tomography (PET) and Single-photon emission computed tomography (SPECT), to name a few, employ a gantry and a table. The gantry comprises a bore to accommodate a patient who in turn lies on a table pallet. It is always beneficial to position the patient body in the center of the gantry bore for better image quality. Figure 1 illustrates a patient body in a centered position and Figure 2 illustrates a patient body in a non-centered position. Centered patient positioning is advantageous as truncation of the patient body in the final image is avoided and gives the best image quality.
Few conventional medical imaging systems employ gantry centering or positioning techniques. One such conventional technique utilizes gantry rotation and image reconstruction. However such a technique employs ionizing radiation which is not preferred.
Hence there exists a need for easy to use, versatile technique for height optimization of medical imaging devices.
BRIEF DESCRIPTION OF THE INVENTION
The invention provides a device and algorithm for centering a patient body in a gantry bore of a medical imaging device. The proposed technique optimizes gantry table height.
DETAILED DESCRIPTION OF THE INVENTION
The proposed technique seeks to adjust the height of the table such that the vertical center of the patient body- where patient body refers to the combination of a patient’s body and the table pallet - is approximately aligned with a scanner bore center.
The first part of the invention is a hardware device. Accordingly, an infrared (IR) emitter-receiver array is installed on the gantry. Figure 3 illustrates the IR receiver and IR emitter installed on the gantry of an imaging device. The IR rays between the emitter and receiver arrays cover the upper part of the gantry bore. The position of each IR ray is known, so that when the patient body blocks some of the IR rays, the height of the upper surface of the patient body can be estimated.
For example, assume the height of the lowest IR ray is represented by Hmin and the distance between adjacent rays is represented by d. If only one ray is blocked by the patient body, the patient upper surface height is between Hmin and (Hmin +d). If two rays are blocked, the patient upper surface height is between (Hmin +d) and (Hmin +2d). Therefore, in general, if n rays are blocked, the patient upper surface height is between (Hmin +nd-d) and (Hmin +nd).
Accordingly, the optimal design of the IR emitter and receiver array is considered in terms of the height of the lowest ray (Hmin), height of the highest ray (Hmax), and the inter-ray distance...