System and Method for Controlling Radiation Dose for Radiological Applications

Abstract

A system and method for reconstructing an image acquired by delivering an irradiating dose of radiation to a subject includes acquiring imaging data using a dose of irradiating radiation and selecting at least one of a plurality of mechanisms for reducing the dose that could be delivered to the subject to acquire additional imaging data. Noise is inserted into the imaging data to simulate the at least one of the plurality of mechanisms for reducing the dose that could be applied to acquire the additional imaging data to thereby generate simulated imaging data at a reduced dose of irradiating radiation. A simulated reduced dose image is reconstructed from the simulated imaging data. A method is provided for utilizing a non-local means filter adapted using a map of local noise to produce denoised medical imaging data reflecting reduced local nose levels from those in originally-acquired medical imaging data.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application is based on, claims priority to, and incorporates herein by reference in its entirety U.S. Provisional Patent Application No. 61 / 595,999, filed Feb. 7, 2012, and entitled “SYSTEM AND METHOD FOR CONTROLLING RADIATION DOSE FOR RADIOLOGICAL APPLICATIONS.”BACKGROUND OF THE INVENTION[0002]The present invention relates to medical imaging and, more particularly, to systems and methods for controlling radiation doses delivered when performing imaging processes using ionizing radiation.[0003]In a computed tomography system, an x-ray source projects a beam which is collimated to lie within an X-Y plane of a Cartesian coordinate system, termed the “imaging plane.” The x-ray beam passes through the object being imaged, such as a medical patient or other non-medical patient or object, such as in industrial CT imaging, and impinges upon an array of radiation detectors. The intensity of the transmitted radiation is dependent upon...

AI Technical Summary

Benefits of technology

The patent describes a method for reconstructing an image using a lower dose of radiation. The method involves using the data acquired from a previous medical imaging session and adding noise to simulate the effect of reducing the dose of radiation. This allows for a reduced risk of radiation exposure to the patient while still reconstructing an image with the same quality as the previous image.

Problems solved by technology

The drastically increased use of CT in modern clinical settings has generated serious public health concerns regarding the cancer risks associated with the radiation exposure from CT.

However, lowering radiation dose alone generally produces a noisier image and may degrade diagnostic performance.

Despite the tremendous effort in the CT community to minimize radiation dose, scanning protocols and radiation doses still vary widely among different CT practices, which poses substantial risks to patient safety.

The substantial variation in protocols and radiation dose is largely attributable to the lack of an efficient and widely available approach to optimizing CT protocols.

This approach requires exploratory low-dose scans on a number of patients, which is tedious and can potentially result in diagnostically compromised image.

The technical details of the tools are not publicly available and the accuracy is usually out of the users' control, which makes their applications rather limited.

However, the effectiveness of denoising mechanisms are widely variable and, more troubling, can make substantial and varied changes to the images.

That is, ineffective or overly aggressive denoising mechanisms can reduce the clinical usefulness and credibility of the images acquired.

In doing so, the difficulty of controlling radiation dose to the patient can be compounded by the need to perform subsequent data acquisitions to replace overly-noisy images.

Images