Image generation based on limited data set

Abstract

A method, signal processor, device, and system for estimating a parametric or functional image 47 mapping a biological process on the basis of a limited or incomplete sequence of biological process images 40 recorded as a function of time, e.g. by a PET or SPECT scanner after injection of a radio tracer. One or more kinetic parameters 43 are first extracted by applying a pharmacokinetic model 42 (compartmental model of the underlying tracer kinetics) to the sequence of biological process images 40. Additional data 41 are used in the model, comprising at least a predetermined kinetic parameter range (e.g. from the literature), and optionally an input function or a blood clearance function. Next, an iterative algorithm 44 is applied to arrive at a modified sequence of images 45, e.g. by inserting an estimated image into the incomplete sequence of images, utilizing the one or more kinetic parameters 43. After a stop criterion has been fulfilled, the resulting image 47 is finally estimated 46 from the modified sequence of images 45. The method can be used e.g. to estimate a hypoxia parameter k3 image in the case of a FMISO data set where only late-time images are available. The method may be implemented as part of existing PET, SPECT, CT, MR or Ultrasound scanner software, and since only a limited amount of late time post injection images are necessary to provide a reliable result, the method helps to increase patient comfort and clinical throughput.

Description

Technical field [0001] The present invention relates to the field of generating images that map biological processes for use in clinical medical applications, for example, to aid in treatment and diagnosis. More specifically, the present invention provides a method, a signal processor, a device, and a system for generating images that map biological processes, and will be used in conjunction with the output unit of a scanner for mapping Tracer movement. In particular, the present invention can provide images based on a limited or incomplete data set (for example, an incomplete time series of biological process images). Background technique [0002] In the use of radiolabeled biomolecules as tracers to study and visualize the pathophysiological mechanism in the living body, molecular imaging modalities (such as positron emission tomography (PET) and single photon emission tomography (SPECT)) are Unique. In principle, since anatomical changes (such as changes in tumor size) usually...

AI Technical Summary

Problems solved by technology

However, many tracers employed in PET and SPECT to probe biological processes exhibit complex tracer motions necessitating pharmacokinetic modeling and analysis

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