5044007 Improved slit radiography assembly having an X-ray source of variable hardness synchronized to varying slit height

5044007 Improved slit radiography assembly having an X-ray source of variable hardness synchronized to varying slit height

New Patents 5042487 5043890 EXAMINATION UNIT INCLUDING POSITIONABLE PATIENT CHAIR, EXAMINATION DEVICE AND SUPPORT SYSTEM COMPENSATION OF COMPUTED ...

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New Patents

5042487

5043890

EXAMINATION UNIT INCLUDING POSITIONABLE PATIENT CHAIR, EXAMINATION DEVICE AND SUPPORT SYSTEM

COMPENSATION OF COMPUTED TOMOGRAPHY DATA FOR OBJECTS POSITIONED OUTSIDE THE FIELD OF VIEW OF THE RECONSTRUCTED IMAGE

Mark R Marquardt Kevin F King assigned to General Electric An apparatus and method is disclosed for medically examining a patient’s spine using a non-invasive technique such as computerized tomography (CT). In this apparatus and method the patient is seated in a generally verticallyoriented chair which is tiltable in a forward and rearward direction, is pivotable relative to a vertical axis, is vertically movable and is stationary so as to adjustably induce gravitational effects on the patient’s back. A pivotable chair back can be included for controllably applying additional loads or flexion to the patient’s back. An annularly-shaped examination device, such as as CT device, is horitonzally positioned on a support frame over the patient who is aligned with a central opening in the device. The device can be positioned about the patient and oriented horizontally or angularly displaced relative to the horizontal for optimizing or adjusting the generated image. The examination device may be tiltable about a horizontal axis transverse to the direction of tilting of the chair. Appropriate mechanisms are provided for the previouslydescribed adjustment.

An x-ray CT system acquires attenuation data over a field of view which is larger than the field of view of the reconstructed image. The data used to reconstruct the image is compensated for the shading effects otherwise caused by objects outside the image, but within the x-ray path. This compensation is accomplished with minimal impact on computation time by using a first order estimation of the convolution of the acquired attenuation data outside the image field of view.

5044007 IMPROVED SLIT RADIOGRAPHY ASSEMBLY HAVING AN X-RAY SOURCE OF VARIABLE HARDNESS SYNCHRONIZED TO VARYING SLIT HEIGHT Ronald J Geluk, Hugo Vlasbloem, Nootdorp, Netherlands assigned to B V Optische Industrie De Oude Delft

5042488 METHODS EMPLOYING DEUTERIUM FOR OBTAINING DIRECT, OBSERVABLE DEUTERIUM MAGNETIC RESONANCE IMAGES IN VIVO AND IN SITU Joseph J H Ackerman assigned to The Washington University A method for in vivo and in situ NMR imaging of body organs or tissues employing direct, observable deuterium magnetic resonance images.

An apparatus for slit radiography is provided with a slot diaphragm to form a fan-shaped Xray beam with which a body can be scanned. Controllable attenuating elements interact with the slit diaphragm to influence sectors of the fanshaped X-ray beam. They are controlled by signals representing the instantaneous transmission of the body in the corresponding sectors. The hardness of the fan-shaped X-ray beam is varied periodically in a predetermined manner. Synchronously with the periodic variation of the hardness of the X-ray beam the attenuating elements are oscillated. The oscillation of the attenuating elements is superimposed at each instant on the instantaneous position determined by the signals representing the instantaneous body transmission. The amplitude of the oscillation is less than the height of the slit of the slit diaphragm. The influence on the X-ray beam is most at the instants at which the hardness is greatest.