The avoidance of true whole body PET/CT image interpretation errors in nuclear oncology

Abstract

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Learning Objectives: 1. Recognize the usual and unusual patterns and locations of physiological uptake that can mimic malignancy on 16 and 64 slice PET/CT. 2. Recognize the patient (pt) movement, software and hardware related fusion and/or attenuation correction artifacts that mimic disease and/or malignant process. Such as head motion resulting in appearance of a large cerebral infarct; focal bowel activity mimicking a liver lesion due to a miss registration-respiratory motion. 3. Recognize the pitfalls in patients with head and neck neoplasm and review the pathologies with physiologic conditions to increase the accuracy. 4. Recognize the estimating the likelihood, probability of malignancy in SPN with Bayesian analysis. Utilize the usage of “lung calculator.” 5. Recognize the physiologic and unusual benign abdominal and pelvic FDG uptakes that mimic malignant lesions i.e. uterine leiomyoma; retrograde urine loculation in vagina; prostatic urethra; functional uterus, ovary; variant focal bowel activity vs metastatic bowel lesion. 6. Recognize the PET-silent and CT-silent lesions on PET/CT studies to improve the accuracy. 7. Recognize the image artifacts, which might seriously degrade the quality of images, at times to the point that diagnostically unusable.

Abstract Body: Physics based artifacts result from the acquisition of the data, i.e., PET truncation and CT truncation artifacts, which might result in incorrect atten. corrections. Patient based artifacts: patient movement or the presence of metallic materials in/on the pt. Scanner based artifacts: from imperfection in scanner function. This exhibit aims to enhance the advanced understanding of the PET/CT reading physicians. By presenting these false positive and false negative cases that we encountered over time as educational examples, we aimed to enhance readers’ ability to differentiate the unusual F18 FDG tissue uptake in numerous physiologic conditions and in variety of disease processes with very unusual presentations, including head and neck and abdomen/pelvis where false positive findings are frequent. Awareness of the conditions that mimic the malignant lesions in PET/CT images might improve the diagnostic accuracy of the PET/CT and potentially improve the patient outcome.