T2-weighted axial image shows the axillary lymph node levels I, II, and III. Level I is located laterally to the lateral margin (blue dotted line) of the pectoralis minor muscle (white arrow), level II is located between the lateral (blue dotted line) and the medial margin (yellow dotted line) of the pectoralis minor muscle, and level III is located medially to the medial margin (yellow dotted line) of the pectoralis minor muscle.