Objective To evaluate the clinical value of high-resolution ultrasound for predicting the extracapsular extension (ETE) of papillary thyroid cancer (PTC).Methods A total of 151 nodules with PTC in 116 patients confirmed by surgery and pathology were enrolled.The ultrasonographic characteristics were retrospectively analyzed,and the percentage of the perimeter of the nodule that abutted the thyroid capsule (A) were observed.Taking A≥1％,A≥25 ％ and A≥ 50％ as cutoff value respectively,the ETE of PTC was predicted.Results Of the 151 nodules with PTC,ETE presented in 59 (59/151,39.07％),while no ETE (non-ETE) was observed in 92 (92/151,60.93％).Nodules in the thyroid parenchyma (A0) which could be observed with ultrasound was 84 (84/151,55.63％),and 1％≤A＜25％,25％≤A＜50％andA≥50％ was 25 (25/151,16.56％),15 (15/151,9.93％),and 27 (27/151,17.88％),respectively.There were statistically significant differences of nodules between the non-ETE and ETE when A≥1％,A≥25 ％ and A≥50％ (all P ＜0.01).Taking A=50％ as the cutoff value for predicting the presence of ETE,the sensitivity,specificity,accuracy,positive predictive value and negative predictive value was 37.29％ (22/59),94.57％ (87/92),72.19％ (109/151),81.48％ (22/27) and 70.16％ (87/124),respectively.Conclusion High frequency ultrasonography can effectively predict whether PTC has been invaded,which provides important reference information for preselected surgical approach and prognosis of patients.

Trans-rectal ultrasound is widely used in the diagnosis of rectal cancer.Elastography technique is based on the endorectal conventional ultrasound and can assess tumor stiffness and further detect the characteristics of tumor.It is helpful to provide more information for the differential diagnosis of rectal cancer,preoperative staging and the chemotherapy efficacy evaluation.The applications of strain elastography in the diagnosis of rectal cancer were reviewed in this article.