Fig 2.

SDC in the left parotid gland of a 52-year-old man. He has ipsilateral metastatic lymph nodes and contralateral reactive lymph nodes.

A, Fat-suppression T1-weighted image (340/20, axial plane) shows multiple cervical lymphadenopathies. Metastatic lymph node (arrow) is >10 mm in minimal axial diameter. Reactive lymph node (arrowhead) is <10 mm in minimal axial diameter.

B, On diffusion-weighted image (spin-echo single-shot echo-planar sequence with b factors of 0 and 1000 s/mm²), both lymph nodes show high signal intensity. The ADC value of the metastatic lymph node (region of interest 1) is 1.23 × 10⁻³ mm²/s and that of the reactive lymph node is 0.90 × 10⁻³ mm²/s.

C, Signal intensity graph shows that the washout ratio of region of interest 1 is 2% (type B) and that of region of interest 2 is 48% (type A).