Periodic Quality Control Methods for SPECT-CT

Summary

This article presents practical monthly SPECT-CT quality control (QC) methods for technicians, including background and uniformity checks, among others. These methods are intended to monitor and maintain the basic operating status of the equipment; however, they cannot replace professional maintenance, which is essential for ensuring equipment and imaging reliability.

Abstract

In the field of medical imaging, gamma cameras, single photon emission computed tomography (SPECT), and SPECT/CT are critical diagnostic tools. Quality control is essential for these devices because equipment malfunctions may lead to degraded image quality, thereby affecting physicians' accurate assessment of medical conditions. The International Atomic Energy Agency (IAEA) and National Electrical Manufacturers Association (NEMA) have recommended standardized, periodic quality control to ensure the stability of equipment operation and the reliability of medical images. By evaluating both planar and tomographic imaging modes, a more comprehensive assessment of equipment performance can be achieved, ensuring stable and accurate operation to provide reliable support for clinical diagnosis.

The importance of quality control is in its capacity to detect equipment issues early, preserve image quality, and guarantee the reliability of diagnostic outcomes. The International Atomic Energy Agency (IAEA) has established pertinent recommendations for quality control and testing of gamma cameras, SPECT, and SPECT/CT systems, emphasizing the importance of testing both planar and tomographic imaging modes of the equipment.

The quality control of medical imaging equipment plays a crucial role in ensuring high-quality images and reliable diagnostic capabilities. By monitoring equipment performance and identifying potential issues promptly, the quality control process helps maintain the image quality of medical imaging and the reliability of clinical diagnostic work. This article outlines the quality control methods employed for SPECT-CT instruments. These methods include background tests, intrinsic uniformity tests, photomultiplier tube gain adjustments, center of rotation tests, CT image quality control, image fusion tests, and other related procedures.

Introduction

Single-photon emission computed tomography-computed tomography (SPECT-CT), as a key device in nuclear medicine diagnosis, directly affects the image quality and the accuracy of diagnostic outcomes^1,2,3,4. Therefore, implementing strict equipment quality control, especially periodic quality control, is crucial for ensuring the stable operation of SPECT/CT equipment and the reliability of diagnostic results⁵. If the problems of the SPECT-CT instrument can be identified and rectified in a timely manner, it cannot only en....

Protocol

1. Preparation

1. Environmental background testing of the machine room
   1. Use a digital multi-function surface contamination meter to test areas around the detector, including the ground, walls, detector shell, racks, inspection beds, and other easily contaminated locations to rule out environmental contamination (Figure 1).
2. Disassembly of the collimator
   NOTE: Prior to operation, remove any obstructions near the inspection bed and detector to ensure sufficient space for bed movement and detector rotation.
   1. Remove the collimator
      1. Use the UP/DO....

Results

Here, we propose a convenient periodic SPECT-CT equipment quality control method for medical technicians to implement. Figure 1 investigates radioactive contamination in machine room environments. Figure 2 illustrates the step-by-step process for detector replacement, Figure 3 shows the installation method of the virtual collimator, Figure 4 depicts the configuration of the point source,

Discussion

SPECT-CT represents a crucial component of the nuclear medicine department's imaging apparatus, particularly in light of the growing integration of diagnosis and treatment. The accuracy of the image, the credibility of the higher requirements, and the equipment quality control serve as a vital guarantee of accurate and reliable equipment imaging. For units that have not purchased the equipment maintenance provided by the manufacturer for various reasons, it is of particular importance for the personnel of these units.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Collimators Cart	GE Health Care	Discovery NM/CT 670	Cart for loading low-energy high-resolution collimators
Collimators LEHR	GE Health Care	Discovery NM/CT 670	Low-energy high-resolution collimator, used for filtering low-energy photons during gamma camera acquisition.
Dry cotton swab	Cixi Huabao Medical Supplies Industry and Trade Development Co., Ltd.	Sterile type 75mm	Used for making point sources, cotton swabs made of absorbent cotton are formed into balls with a diameter of about 2.5 mm for adsorbing 99mTcO4- solution.
Single-use sterile syringe	Zhejiang Longde Pharmaceutical Co., Ltd.	Single-use sterile syringe with needle 2mL	Used for making point sources, the needle cap part of the syringe serves as the carrier for the point source.
SPECT/CT	GE Health Care	Discovery NM/CT 670	The equipment being charged.
Surface Contamination Monitor	IMI International Inc.	Inspector Alert V2	Surface contamination monitoring.
Virtual Collimator	GE Health Care	Discovery NM/CT 670	Accessories used for quality control