Fig. 4

A male patient aged 48 years with stage IVA nasopharyngeal carcinoma (T4N2MO). Pathological examinations suggested non-keratinizing undifferentiated squamous cell carcinoma. Before treatment, T2-IDEAL and T1WI images revealed nasopharyngeal masses on the right invading the sphenoid sinus (a and b); the ASL series integrated with BRAVO series revealed high mass perfusion (c) with a TBF value of 170.67 mL·100 g⁻¹·min⁻¹; the maximum primary tumor diameter measured on axial T1WI enhanced imaging was 45.92 mm (d). Re-examinations after the prescribed dose reached 40 Gy revealed notable tumor shrinkage (e and f) and reduced tumor perfusion (g) with a TBF value of 107.73 mL·100 g⁻¹·min.⁻¹; the maximum primary tumor diameter measured on axial T1WI enhanced imaging was 24.34 mm (h). Follow-up examination one month after chemoradiotherapy completion revealed no residual tumor (i)