Objective To prospectively validate the feasibility and usefulness of the thyroid imaging reporting and data system (TI-RADS) suggested by Kwak. Methods According to the TI-RADS published in Radiology by Kwak et al in 2011, the TI-RADS score of 810 thyroid nodules in 415 patients whose pathologic diagnoses were available were categorized . According to TI-RADS and pathologic results, receiver operating characteristic (ROC) curve was plotted, and the probability of malignancy in each category was calculated. Results Eight hundred and ten pathologically proven thyroid nodules included 649 benign and 161 malignant lesions. Among them, 11 nodules were categorized as TI-RADS 2 (all benign nodules);370 nodules were categorized as TI-RADS 3 (368 benign nodules and 2 malignant nodules);150 nodules were categorized as TI-RADS 4a (143 benign nodules and 7 malignant nodules);116 nodules were categorized as TI-RADS 4b (87 benign nodules and 29 malignant nodules); 146 nodules were categorized as TI-RADS 4c (39 benign nodules and 107 malignant nodules);17 nodules were categorized as TI-RADS 5 (1 benign nodules and 16 malignant nodules). The area under the curve of TI-RADS was 0.89, and the probability of malignancy in nodules with a classiifcation of TI-RADS 2, 3, 4a, 4b, 4c and 5 was 0, 0.5%, 4.6%, 25.0%, 73.0%and 94.0%, respectively. Conclusions The TI-RADS suggested by Kwak has great diagnostic value in diagnosing thyroid nodules. The actual probability of malignancy conforms with the theoretical risk of malignancy.

Objective To explore the value of virtual touch tissue imaging (VTI) of acoustic radiation force impulse (ARFI) elastography in the differential diagnosis of benign and malignant thyroid nodules.Methods VTI features of 77 histologically proven thyroid nodules in 74 patients were analyzed and the VTI features were divided into 6 grades.The higher grade represented higher tissue stiffness.Differences in VTI grade between benign and malignant lesions were analyzed by receiver operator characteristic (ROC) curve,and the sensitivity,specificity and accuracy were calculated.Results 77 pathologically proven thyroid nodules included 61 benign and 16 malignant lesions.VTI images classification included 0 in grade Ⅰ,1 ingrade Ⅱ,1 in grade Ⅲ,9 in grade Ⅳ,3 in grade Ⅴ and 2 in grade Ⅵ for malignant diseases ; and included 18 in grade Ⅰ,28 in grade Ⅱ,10 in grade Ⅲ,1 in grade Ⅳ,2 in grade Ⅴ and 2 in grade Ⅵ for benign diseases.The best diagnostic point of VTI-grade was grade Ⅳ.When VTI-grade Ⅳ or greater was used as the diagnostic criterium for malignancy,the sensitivity,specificity and accuracy rate in differentiation between benign and malignant thyroid nodules were 87.50％,91.80％ and 90.9(％ respectively.Conclusions VTI is useful in the differential diagnosis between benign and malignant thyroid nodules.

Objective To investigate the features of intraductal papillary neoplasm of the bile duct (IPN-B) on baseline ultrasound and contrast-enhanced ultrasound (CEUS).Methods A retrospective analysis of the baseline ultrasound and CEUS in nine pathologically proven IPN-B lesions in eight patients.CEUS was performed with low mechanical index and continuous real-time imaging technique and the contrast agent of SonoVue.Results On conventional ultrasound,5 lesions were appeared as expansion of bile duct type,whose main features were cauliflower shape tumor (n =1) or papillary nodes (n =3) in expanded bile duct with rare blood supply;the other 3 lesions were appeared as complex cystic type,which contained cystic and solid components in the lesions.Many tiny anechoic areas were observed inside the solid lesions.Two lesions were rich in blood supply and another one was rare.All were communicated with adjacent slightly dilated bile duct.On CEUS,solid components of eight lesions appeared homogeneous (n =5) or heterogeneous (n =3) hyper-enhancement in the arterial phase and declined into hypo-enhancement in the portal and late phases.One lesion,on the contrary,was invisible on both conventional ultrasound and CEUS.Conclusions Understanding the ultrasound features of IPN-B is mandatory because of its low preoperative diagnosis rate on CEUS.IPN-B should be taken into consideration when cauliflower shape tumors or papillary nodules in expanded bile duct,as well as hyper-enhancement in the arterial phase and hypo-enhancement in the portal and late phases on CEUS,were demonstrated.

Objective To explore dynamic changes of renal cortex blood perfusion in Goto-Kakizaki rats(GK rats) by contrast-enhanced ultrasonography.The clues for early diagnosis and intervention of diabetic renal impairment may be obtained from the study.Methods Male GK rats were taken as experimental groups,and Wistar male rats were used as controls.Contrast-enhanced agent SonoVue was administered via the femoral vein cannulation in a bolus fashion.Image changes of renal cortex were observed in real time, and dynamic image changes within 0 - 5 minute after injection were observed and stored.The renal cortex blood perfusion changes were analyzed using the time-intensity curve (TIC).Results (1) The kidney was quickly enhanced after the injection of contrast agent.The renal artery, cortex, renal vein were displayed in sequence.(2)The shape of renal perfusion TIC in all the objects was a single peak,steep ascending, flat descending curve.The overall shape of TIC in GK rats was wider than controls and they were wider and wider with age increasing of the GK rats.(3) Compare to controls,the time to peak (TTP)and the half time of peak descending (HDT) in GK rats was longer (P ＜0.01), the slope rates of the ascending curve (S1) and the slope rates of the descending curve (S2) decreased and the area under the curve increased in 12-week-old and 20-week-old GK rats (P ＜ 0.05 or P ＜ 0.01).Conclusions The abnormal blood perfusion of renal cortex microcirculation was present in the early stage of diabetic in GK rats.Real-time contrast-enhanced ultrasonography and TIC could display this change effectively.