The normal pattern of nipple enhancement at magnetic resonance (MR) is defined on the basis of healthy individuals, since it correlates with the structural anatomy of the nipple. Understanding the normal range of nipple morphology and nipple enhancement at MR enables radiologists to better detect abnormalities.

• Nipple morphology refers to the configuration of the nipple as defined on the basis of its outer contour, which is described as everted, flat, or inverted and best assessed on magnetic resonance MIP images [1].
• Nipple enhancement characteristics and intensity can be described by using first post-contrast T1-weighted subtraction MR findings [1].

Superficial linear enhancement (SLE) refers to a thin rim of smooth superficial enhancement of the NAC at the level of the skin, with the intensity of enhancement greater than that in the adjacent skin (figure 1).

Non-enhancing zone (NEZ) refers to the zone without enhancement immediately below the SLE (figure 2).

Internal nipple enhancement (INE) refers to enhancement of the nipple below the NEZ but above the base of the nipple, with discernible linear or patchy enhancing patterns when present (figure 3).

NAC involvement is an added challenge in invasive breast cancer cases, particularly in selecting patients who are appropriately indicated for nipple-sparing mastectomy (NSM) for cosmetic and aesthetic reasons. Several studies have assessed nipple-areola complex (NAC) involvement according to clinical and pathological characteristics [2, 3]. To the best of our knowledge, there has been investigation into the efficacy of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for detecting tumoral NAC involvement [4]. Our aim is to propose a possible standardized language to describe the enhancement of the tumor-infiltrated NAC in MR, and to compare it to CT and PET/CT findings.