Figure 2.

Axial image of an axillary lymph node (ALN) cross-section via (a) cPET and (b) DL-PET of a woman in her 40 s with invasive lobular carcinoma in the right breast: invasive diameter, 18 mm; nuclear grade, 1; lymphatic invasion, positive; vascular invasion, positive; estrogen receptor, positive; progesterone receptor, positive; HER2 receptor, negative; Ki-67 staining, 17.3%; and nodal stage, 1a. Of 18 ALNs, 3 were positive for metastasis; the maximum diameter was 3 mm, and an extranodal invasion was evident. Visual analysis for ipsilateral ALN metastasis was rated on a scale of 1–3 (1 = negative, 2 = intermediate, 3 = positive). For ALN metastasis, reader 1 gave a score of 2 for cPET and 3 for DL-PET, and reader 2 gave a score of 1 for both the PET types. cPET, PET with conventional reconstruction; DL-PET, PET with deep learning restoration.