Characterization of focal hypermetabolic thyroid incidentaloma: An analysis with F-18 fluorodeoxyglucose positron emission tomography/computed tomography parameters

Figure 1 Examples of focal hypermetabolic thyroid incidentaloma. A: Focal fluorodeoxyglucose (FDG) uptake is observed in the right lower neck on the maximum intensity projection (MIP) image of a 53-year-old woman diagnosed with left breast cancer (FDG uptake in the left breast and axillary fossa); B: On the axial view, the focal FDG uptake is observed in the right thyroid lobe with maximum standardized uptake value (SUV_max) 5.9 and it was diagnosed as a benign nodule by cytological/histological examination; C: Focal FDG uptake is observed in the right lower neck on the MIP image of a 66-year-old woman diagnosed with adenocarcinoma in the right lower lobe of lung as a result of biopsy performed due to abnormal radiologic findings; D: On the axial view, the focal FDG uptake is observed in the right thyroid lobe (SUV_max 8.6) and the cytological/histological examination revealed papillary thyroid cancer.

Figure 2 The receiver operating characteristic curve for maximum standardized uptake value. The area under the curve is 0.702 (95% confidence interval, lower: 0.550, upper: 0.855). The cut-off value for maximum standardized uptake value is 8.5 with a sensitivity of 0.615 and a specificity of 0.789. ROC: Receiver operating characteristic.