Pitfalls in Positron Emission Tomography/Computed Tomo-graphy Imaging： Causes and Their Classifications

• Published in: Chinese medical sciences journal Vol. 24; no. 1; pp. 12 - 19
• Main Author: Tian-ran Li Jia-he Tian Hui Wang Zi-qian Chen Chun-lei Zhao
• Format: Journal Article
• Language: English
• Published: 2009
• Subjects: CT图像; CT显像; 正电子发射断层扫描; 正电子发射断层显像; 脂肪摄取; 计算机层析成像; 计算机断层扫描
• ISSN: 1001-9294

Objective To describe the pitfalls in positron emission tomography/computed tomography （PET/CT） imaging and classify them according to the principles of their generation. Methods We summarized retrospectively the ^18F-fluorodeoxyglucose （FDP） PET/CT imaging pitfalls through reviewing the PET/CT images of 872 patients. The pitfalls were divided into artifacts and infrequent physiological uptake, and the artifacts were further classified according to their causes. Meanwhile, we calculated the incidences of various pitfalls. Whether the PET/CT pitfalls influenced the diagnostic decision was analyzed. The appearances of pitfalls in PET were also described. Results Pitfalls could be found in PET/CT images of 684（78.4%） patients. Artifacts were found in 664 （76.15%） patients, and could be classified into self-factor artifacts and equipment-or technology-related artifacts. Among self-factor artifacts, respiratory motion （57.5%）, postprandial or hyperglycemia artifacts （2.41%）, and metal or high density matter artifacts （1.38%） were frequent. As for equipment-or tectmology-related factors, injection point outleakage or radiotracer contamination （13.88%） and truncation artifacts （1.83%） were most common ones. Infrequent physiological FDG uptakes, including fatty up-take, endometrial uptake, and bilateral breast feeding period uptake, were found in 20 （2.29%） patients. Among all pitfalls, the artifacts in 92 （13.4%） patients and infrequent physiological uptakes in 6 （0.88%） patients affected the diagnostic results. Artifact images in PET could be described as hot or cold area and the images of infrequent physiological uptake were always shown as hot area. Conclusions The incidence of pitfall in PET/CT imaging was high and the causes of pitfalls are various. Among all causes that artifacts generated, respiratory motion is the most common. Some pitfalls may disturb clinical physicians＇ decision, so it is important to recognize artifacts and physiological uptake, and distinguish them from pathological uptakes.