Dose finding and sequence tailoring in sentinel lymph node detection of tongue cancer using superparagmagnetic iron-oxide particles

To clarify the amount, timing and optimal pulse sequence settings of using interstitial superparamagnetic iron oxide particles (SPIO) as a contrast medium to detect sentinel lymph nodes in head and neck radiology, we injected SPIO peritumorally in six patients with early-stage oral squamous cell carcinoma. Anatomical and T2*-weighted MR images were acquired, and dose was altered after every two patients. Images with different computed echo times were created to determine the signal attenuation effect of SPIO on the sentinel lymph nodes.