Detection of Local Recurrence in Patients with Head and Neck Squamous Cell Carcinoma Using Voxel-Based Color Maps of Initial and Final Area under the Curve Values Derived from DCE-MRI

Illustration of the steps for generating color maps of initial and final 90-second AUC values using the TSI curve. A, The time course of the contrast index was plotted to obtain a TSI curve and the initial and final 90-second AUC values for each voxel. IAUC₉₀ (diagonal pattern) and FAUC₉₀ (dotted pattern) were defined as the trapezoidal integration of the normalized TSI curve during the initial and final 90 seconds from the onset of contrast enhancement in the voxel. B and C, Voxel-based color maps corresponding to IAUC₉₀ and FAUC₉₀ values were constructed in blue, green, yellow, and red.

A 53-year-old man after hemiglossectomy for squamous cell carcinoma of the oral tongue 12 months previously (T2N0M0; depth of invasion, 10 mm). A and B, T2-weighted and contrast-enhanced fat-suppressed T1-weighted images show an ill-defined enhancing lesion at the operative bed of the oral tongue (arrows). C and D, IAUC₉₀ and FAUC₉₀ images of DCE-MR imaging show contrast washout at the corresponding area. E, The time-signal intensity curve obtained from the enhancing area using a hand-drawn ROI also shows contrast washout. This lesion was confirmed as recurrent tumor on subsequent surgical excision.

A 40-year-old female patient after wide excision for buccal cancer 36 months previously (T1N0M0). T2-weighted image shows a low signal intensity lesion in the right retroantral region (A) with heterogeneous contrast enhancement on contrast-enhanced fat-suppressed T1-weighted imaging (B) (arrows). IAUC₉₀ (C) and FAUC₉₀ (D) images of DCE-MR imaging show a progressive increment pattern. Time-signal intensity curve obtained at the enhancing portion also shows a progressive increment pattern (E). This lesion was confirmed as fibrosis at excisional biopsy.