Fig. 3
F29, NPC with bilateral metastatic RLNs. Axial T2WI before treatment (a) showed an irregular mass with heterogeneous slightly high signal intensity in the left lateral portion of the nasopharyngeal cavity and bilateral RLNs (curved arrows) with the size as long axis × short axis of 7 × 5 mm (right) and 8 × 5 mm (left), respectively. The primary tumor and RLNs demonstrated higher perfusion compared with the surrounding tissue on the fused image obtained by ASL and T2WI (b), and the map of BF (c). ROI of the RLNs were delineated on the map of BF (c) and multi-b-value DWI with b value at 800 s/mm2 (d), acquiring at BF value of 60.63 mL/100 g/min, 67.71 mL/100 g/min, and ADC value of 0.808 × 10−3 mm2/s, 0.812 × 10−3 mm2/s on ADC map (e), respectively. Axial T2WI at three months after radiotherapy (f) showed the lymph nodes (stright arrows) were significantly reduced with the size of 4 × 2 mm (right) and 3 × 2 mm (left), respectively. Meanwhile, the tumor in the nasopharynx has complete regression