Objective To explore the characteristics of changes in temperature and stiffness within the microwave-induced ablation region.Methods A type of Thy-ablation microwave antenna was used upon a design of various combination of ablation duration and power to induce heated region in samples of fresh porcine liver.Three special sites were set to assess the corresponding temperature and stiffness in each heated region.The temperature was continuously measured by using electronic thermometer with microwave on going,while stiffness was determined 5min after the ending of ablation by using real-time ultrasonic elastography,strain ratio,a quantitative indicator.Results The SR values and temperature determinations decreased progressively from the central to the peripheral area of the heated region.There was a linear regression between the temperatures (X) and SRs (Y),with Y =0.666 X-37.17.A significant correlation exists between X and Y,with the correlation coefficient being 0.956(P ＜0.001).The stiffness and temperature at the central sites are variable with the changes of both ablation time and power,but little changed at the peripheral sites of heated-region,which we name a phenomenon due to the ending effect of microwave propagation.Conclusions Temperature and stiffness increase considerably following microwave radiation but they are heterogeneously distributed within the ablated region in porcine liver.The characteristic gradient changes are confirmed of both temperature and the elasticity.It is presumable that good recognition and understanding and full utilization of these characteristics are conducive to reasonable control of tumor microwave ablation therapy.

Objective To represent the high-resolution ultrasonic profiles of diffuse sclerosing variant of papillary thyroid carcinoma (DSVPTC) and highlight the importance of ultrasound examination for detecting this rare entity. Methods The document of clinical presentations and thyroid ultrasound imaging information leading to correct diagnosis were reviewed in association with the microscopic findings of excised thyroid specimen. Results The average age of the eight patients was (18.88 ± 3.59) years(range from 12 to 24) with a gender ratio of 2 males to 6 females. Their predominant clinical presentations were enlargement (8/8) and hardening(6/8) of the involved thyroid lobes. The ultrasound imaging features were increase in the width and thickness of involved thyroids, hypoechoic and heterogeneous internal echoes, containing multiple,diffuse,and fine hyperechoic spots but without formation of any masses, and multiple enlarged lymph nodes in the bilateral jugular chains due to cancer cell metastasis. Ultrasound diagnosis of the first case was malignant thyroid tumor, but the following consecutive 7 patients were all definitely interpreted as DSVPTC. Conclusions The clinical presentations alone is less valuable in diagnosis of DSVPTC, but the characteristic features on high-resolution ultrasonography are highly sensitive and indicative.

Objective To investigate the elasticity reduction of liver tissue due to microwave ablation and the relevance to the histographic damages. Methods An experimental study using fresh porcine liver was designed. Elasto-ultrasonography scanning both in color display and strain ratio calculations was conducted before and 5 min after microwave ablation ( 2450 MHz) in manner of antenna insertion under ultrasound guidance to determine the alterations of the liver elasticity, in correspondence with the histopathologic assessment of each ROI. Results Elasto-ultrasonography showed a significant elasticity reduction and hardness augment of the targeted liver tissue and the corresponding histopathology revealed increases in the amount of massive coagulative necrosis and coking of liver cells after microwave irradiation,in proportional to the applied field power and working time. Conclusions Elasto-ultrasonography helps to demonstrate microwave-induced lesion in porcine liver got rapidly hardened. It is possible to estimate the tissue necrosis to the changing of tissue hardening.

Objective To establish a treatment proposal of thyroid adenoma by using percutaneous radiofrequency ablation(RFA) and investigate its techniques and skills, means and steps, and safety and efficacy. Methods Contrast-enhanced ultrasound-guided percutaneous RFA of thyroid adenomas were conducted on 202 patients by using an auto-controlled bi-polar electrode system. The indications of thyroid RFA,the optimal puncture route,the ways of anesthesia administration, protection of vital neck vessels and recurrent laryngeal nerve(RLN) and reduction of bleeding from core biopsy, indicators of ending ablation procedure following a complete ablation were investigated and analyzed. Resalts An adenoma smaller than 20 mm in maximal diameter was the optimal candidate for RFA. Either of two puncture routes could be selected upon the target lesion's location. Areas surrounding to the thyroid capsule needed adequate local anesthesia to kill pain. Liquid-isolating maneuver could effectively protect carotid artery and RLN from core needle cutting and electrode heating injury. Advanced block of supplying arteries with heating markedly reduced bleeding involved in the biopsy. Multipoint and multicenter ablation was essential to a complete coagulation. Filling-defect in the ablated adenoma on CEUS was the key sign to terminate ablation procedure. Conclusions Percutaneous bi-polar RFA was proved feasible, effective, safe and supermicroinvasive for treating thyroid adenoma under the way stated here of puncture and technical points and use of CEUS for monitoring.

Objective To summarize the multimodal ultrasonographic characteristics primary thyroid lymphoma (PTLs), and to discuss the diagnosis and differential diagnosis of PTLs. Methods Multimodal ultrasonographic charactericsits of six cases of PTLs were analyzed retrospectively. All of the patients were examined by the conventional two-dimensional ultrasound (2DUS), color Doppler flow imaging (CDFI), contrast-enhanced ultrasound (CEUS), three-dimensional ultrasound (3DUS) reconstruction and elastography imaging (EI) from October 2011 to February 2016 in Changzheng Hospital, affiliated to Secondary Military Medical University. All diagnoses were confirmed by ultrasound-guided percutaneous biopsy.Results (1) 2DUS: six cases of PTLs without capsule were observed as diffusely enlargement type (two cases), unilateral nodular type (one case, on left lobe),and bilateral multiple nodular type (the other three cases). The margin of the multiple nodules were not clear, and some nodules were fused with each other.There were four cases of heterogeneous (extremely) hypoechogenicity and two cases of mixed echogenicity, All of the lesions were characterized by various striped and reticular hyperechogenicity interiorly on ultrasonograms, and only one case showed slightly posterior enhancement. Except one case, multiple cervical lymphnodes hyperplasia were identified on neck regionⅡ-Ⅴin five cases. (2) CDFI and CEUS:CDFI showed abundant blood flow signals in the PTLs nodules peripherally and internally. The striped blood flow was observed in the lesions, and spectrum showed as artery and veins. The plentiful vascular tree was also found in the enlarged lymphnodes. By using high frequency CEUS, six cases of the PTLs demonstrated diffuse and heterogeneous enhancement significantly, including little necrosis area without prominent contrast agent filling in two cases. (3) 3DUS reconstruction: Various striped and reticular hyperechoic features were found on the surface of six cases of PTL nodules. (4) EI: All lesions were soft in six cases. The ratio of elastic strain rate was 1.28-1.96, average (1.82±0.29).Conclusion The ultrasonographic features of PTLs are of certain characteristics, and multiple modes of ultrasound examination can help to grasp the comprehensive imaging informations of PTLs, which should be encouraged positively to facilitate the early detection, early diagnosis and early treatment for PTLs.