title: Pitfalls in positron emission tomography/computed tomography imaging: causes and their classifications.
abstract: 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 technology-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 uptake, 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.
authors.affiliation: Department of Nuclear Medicine, Chinese People's Liberation Army General Hospital, Beijing 100853, China.
authors.forename: Tian-ran
authors.initials: TR
authors.lastname: Li
authors.forename: Jia-he
authors.initials: JH
authors.lastname: Tian
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Zi-qian
authors.initials: ZQ
authors.lastname: Chen
authors.forename: Chun-lei
authors.initials: CL
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D003951:Diagnostic Errors / Q000706:statistics & numerical data; D004340:Drug Contamination; D004717:Endometrium / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D006943:Hyperglycemia; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009068:Movement; D049268:Positron-Emission Tomography; D012119:Respiration; D055815:Young Adult
chemical_list: D005227:Fatty Acids; D019788:Fluorodeoxyglucose F18