Design an Adaptive Quality Control Phantom to Optimize QC Test Methods

Abstract

The main objective of this research is to introduce a newly developed device called as "Adaptive Quality Control Phantom" (AQCP) that designed to perform the QC tests. AQCP is a computer-controlled phantom which positions and moves a radioactive source in the FOV of an imaging nuclear medicine device on a definite path to produce any spatial distribution of gamma rays to simulate QC phantoms. To establish and prove the proper functionality as well as the accurate performance of AQCP, different tests including systematic uniformity, collimator hole angulation and the center of rotation tests have been conducted by this device and then the results, findings and differences of such testing when comparing to what achieved by the QC classic method tests have been discussed and analyzed in detail in this paper. According to the different tests done by AQCP, the authors found that the performance of systematic uniformity test shows a considerable reduction in the technologist dose compared to the IAEA-TECDOC-602 method. The collimator hole angulation for LEHR, LEUHR and LEHS collimators were measured by using a point source and the computer-controlled cylindrical positioning and the results achieved indicate that the measurement accuracy for absolute angulation errors was better than 0.018 degrees. A method for center of rotation assessment by AQCP was introduced, the results of such proposed method compared to the routine QC test and their differences have been discussed in detail. Based on all discussed in this paper regarding AQCP, the authors suggest that their presented device would be able to simulate QC phantoms.

Results of the Measurement of the Collimator Hole Angulation for Different Collimators of SPECT with Adaptive Quality Control Phantom

“…AQCP design and structure: AQCP is structured of different parts comprising mechanical, electrical and is equipped with hardware and software systems. From mechanical perspective, the cylindrical coordinates is chosen as a pattern for the motion and simulation of AQCP [9,10,12,13]. A combination of ball screw and reel system is used to position the point source in any desired point in space with a precision of 0.06 mm (Figure 1).…”

“…From electrical stand point, AQCP is equipped with two driver and actuator circuits of step motors which together with other parts help the whole system function and operate properly and accurately. AQCP's overall functions are being controlled by a software interface developed to position the cylindrical coordinates [9][10][11][12][13][14]. The user of the system would be able to define and design a path for moving the radioactive source.…”

“…AQCP was designed to perform a uniform set of procedures that can be used for routine quality control of a scintillation camera-based system. AQCP is an electromechanical device designed to acquire the field uniformity, center of rotation and collimator hole angulation by using some advanced methods of position control [9,[11][12][13]. In order to use AQCP to simulate QC phantoms, the device moves a radioactive source within the Field of View (FOV) of the NM imaging device on a definite path to produce a three-dimensional artificial distribution of γ rays [10,12,14].…”

“…AQCP is an electromechanical device designed to acquire the field uniformity, center of rotation and collimator hole angulation by using some advanced methods of position control [9,[11][12][13]. In order to use AQCP to simulate QC phantoms, the device moves a radioactive source within the Field of View (FOV) of the NM imaging device on a definite path to produce a three-dimensional artificial distribution of γ rays [10,12,14]. AQCP, in fact, can be used to optimize QC tests for the measurement of uniformity, resolution, linearity, absolute size of pixel and center of rotation and can perform the total performance test of Single Photon Emission Computer Tomography (SPECT) [12][13][14].…”

The Precise Methods for the Measurement of Collimator Hole Angulation and Center of Rotation of SPECT by Adaptive Quality Control Phantom

“…AQCP is an electromechanical device designed to acquire the field uniformity, center of rotation and collimator hole angulation by using some advanced methods of position control [9]- [12]. In order to use AQCP to simulate QC phantoms, the device moves a radioactive source within the Field Of View (FOV) of the NM imaging device on a definite path to produce a three-dimensional artificial distribution of γ rays [11] [13] [14]. AQCP, in fact, can be used to optimize QC tests for the measurement of uniformity, resolution, linearity, absolute size of pixel and center of rotation and can perform the total performance test of Single Photon Emission Computer Tomography (SPECT) […”