Abstract #0479

Does Quantification of T2 SNR Decrease After USPIO Administration Allow Differentiation Between Benign and Malignant Normal Sized Pelvic Lymph Nodes?

Johannes M. Froehlich¹, Benedikt Rckriem¹, Maria Triantafyllou¹, Frederic D. Birkhaeuser², Michael von Gunten³, Peter Vermathen⁴, Harriet C. Thoeny¹

¹Institute of Diagnostic, Interventional and Pediatric Radiology, University Hospital, Bern, Switzerland; ²Department of Urology, University Hospital, Bern, Switzerland; ³Institute of Pathology, University Hospital, Bern, Switzerland; ⁴Department of Clinical Research, University Hospital, Bern, Switzerland

Methodologically the staging of lymph nodes based on uptake of USPIO is judged on a qualitative level analyzing signal decrease and distribution on T2/T2*-weighted sequences. Quantification of SI/SNR-decrease in 320 lymph nodes comprising 20 malignant lymph nodes, 57 benign inguinal and 243 benign iliacal lymph nodes revealed significant differences (p<0.05) when comparing benign with malignant lymph nodes. Contrary to iliacal lymph nodes (24.8% 54.6%) inguinal ones presented limited SNR decrease (3.4% 55.4%). Substantial overlap of single data, limit the diagnostic potential of quantification. In practice morphological criteria, fatty content and localization of lymph nodes must be considered.