Clinical Abstracts using Hitachi Real-time Tissue Elastography

Purpose: Ultrasound elastography is a new imaging procedure which allows the reconstruction of elasticity distribution by characterising the difference of hardness between pathological and normaltissue.Materials and Methods: The aim of our study was to apply real-time elastography during endoscopic ultrasound (EUS) examinations and to consequently characterise benign versus malignantlymph nodes. The pattern of real-time EUS elastography images was compared with theconventional EUS aspects of lymph nodes and with the final diagnosis obtained by EUS-FNAcytology analysis and/or by surgical pathology.Results: Patients diagnosed by EUS with cervical, mediastinal or abdominal lymph nodes wereprospectively included, with a total number of 42 lymph nodes examined by EUS elastography. Byusing a qualitative pattern analysis, we were able to differentiate between benign and malignantlymph nodes with a high sensitivity, specificity and accuracy (91.7%, 94.4% and 92.86%, re-spectively), based on five pre-defined patterns obtained on EUS elastography. A quantitativeanalysis based on histograms of the EUS elastography images also allowed an excellent discri-mination between benign and malignant lymph nodes. Based on separate RGB channel histogramvalues, an "elasticity ratio" was further defined and yielded a sensitivity, specificity and accuracy forthe differential diagnosis of 95.8 %, 94.4 % and95.2% respectively, based on a cut-off level of 0.84.Conclusion: EUS elastography is a promising method which allows characterisation and differ-entiation of benign and malignant lymph nodes with a high sensitivity, specificity and accuracy,offering complementary information added to conventional EUS imaging.