Study of "4+ 1" integration training mode combining undergraduate and postgraduate for biomedical engineering major / 中华医学教育探索杂志

Chongqing Medical University and University of Dundee have explored the "4+ 1" integration training mode combining undergraduate and postgraduate for biomedical engineering major in 2018, including mode of education, curriculum linkage and credit recognition, contract signing and publicity, process assessment and management, and degree awarding. After repeated communication and argument, Chongqing Medical University and University of Dundee signed the contract of the "4+ 1" integration training mode in 2019. One junior student participated in the "Summer Camp of University of Dundee" in the same year, and one senior student participated in this integration training mode program in 2020. According to the feedback of the first batch of students, the "4+ 1" integration training mode can guide students from different angles, which is conducive to broadening students' international vision and injecting strong power into the cultivation of biomedical engineering talents.

Practice and thinking of clinical skill training in focused ultrasound surgery / 中华医学教育探索杂志

Focused ultrasound surgery (FUS) technology has been used for clinical treatment more than 20 years. Since 2011, relying on the "high intensity focused ultrasound tumor therapy training base", focusing ultrasound surgeons on the treatment of uterine fibroids, based on the basic theories and skills provided by interns who have just access to the qualification of licensed physicians, the training courses are set such as engineering technology principles, biological effects and mechanisms, micro and non-invasive concepts and clinical thinking, image recognition ability, operation training, and postoperative complications management etc.. After strict quality training and performance evaluation, the initial training of focused ultrasound surgeons has been completed. Moreover, the training object can consolidate learning effect through continuing education in order to acquire stable skills and skills.

Experimental study of a novel phase change nanodroplets enhanced high intensity focused ultrasound ablation / 中国介入影像与治疗学

Objective To investigate the effect of lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets for high intensity focused ultrasound (HIFU) ablation.Methods The lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets was prepared with membrane hydration method,and its physicochemical properties were examined.The synergistic effect of HIFU ablation was verified with experiments in vitro and in vivo experiments.For in vitro experiment,the isolated bovine liver tissues were irradiated with HIFU (250 W,10 s,continuous wave).For in vivo experiment,the livers of New Zealand rabbits were irradiated with HIFU (200 W,5 s,continuous wave).The volume of coagulative necrosis,energy efficiency factors (EEF) and the volume of the hyperechoic area after HIFU radiation were measured.And the statistical analysis was performed.Results Phase change nanoparticles were spherical in solution and uniform in size.For in vitro experiment,the coagulative necrosis volume,EEF and hyperechoic area of bovine liver tissue injected with nanodroplets were significantly higher than those of untreated bovine liver tissue (t=28.80,19.55,14.30;P=0.01,0.02,0.02) after HIFU.For in vivo experiment,the coagulative necrosis volume,EEF and hyperechoic area of rabbit liver tissue injected with nanodroplets were significantly higher than those of untreated rabbit liver tissue (t=9.41,13.52,15.67;P=0.02,0.01,0.01) after HIFU.Conclusion The lipid encapsulated 1,1,2-trichlorotrifluoroethane phase change nanodroplets can significantly improve the efficiency of HIFU ablation significantly.

High-intensity focused ultrasound inhibits tumor metastasis in a melanoma-bearing mouse model / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of high-intensity focused ultrasound (HIFU) on tumor metastasis in mouse model bearing melanoma xenograft.</p><p><b>METHODS</b>Mice bearing murine melanoma B16-F10 cell xenograft were randomized for sham-HIFU or HIFU exposure when the tumors grew to a maximum diameter of 7-10 mm, and the tumor size was measured every 3 days. The cumulative survival rate of the mice and tumor metastasis rate were calculated, and the circulating melanoma cells were detected using qRT-PCR. At 14 days after HIFU treatment, B16-F10 cells were retransplanted via the tail vein and the pulmonary metastatic nodules were counted.</p><p><b>RESULTS</b>The median survival time of the mice was 19.00 days (95% CI 17.14-20.86 days) in the sham group and 26.00 days (95%CI 24.76-27.25 days) in HIFU group. The cumulative survival rate in the HIFU group was significantly higher than that in sham-HIFU group (P<0.01), and the tumor size was significantly smaller in HIFU group at 20, 23, and 26 days after HIFU treatment (P<0.05). Compared with the sham-HIFU group, HIFU group had significantly lower levels of MAGE-A3, MART1 and PAX3 at 7 days after HIFU (P<0.05) with still lower MAGE-A3 level at 14 days (P<0.05). HIFU group showed a significantly smaller number of pulmonary metastatic nodules following tumor cell retransplantation than in sham-HIFU group (P<0.01) with a metastasis inhibition rate of 42.4%.</p><p><b>CONCLUSION</b>HIFU treatment can inhibit tumor metastasis in melanoma-bearing mice possibly by reducing tumor cell detachment from the primary tumor site and suppressing colonization of the circulating melanoma cells.</p>

Effect of ablations by pulsed versus continuous high-intensity focused ultrasound on isolated perfused porcine liver / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the effect of ablations with pulsed and continuous high-intensity focused ultrasound (HIFU) on the target area containing large blood vessels in isolated perfused porcine liver.</p><p><b>METHODS</b>An isolated perfused liver model was established by perfusing the isolated porcine liver with autologous blood through the portal vein and hepatic artery using an cardiopulmonary bypass machine. With B-mode ultrasound guidance, a blood vessel about 4 mm in diameter was selected, and pulsed and continuous HIFU ablation at the same dose was delivered along the blood vessel at 3 mm to the vascular wall. After the ablation, the damages of the blood vessels as the acoustic channel and the target area were inspected, and the tissues at the interface of target volume and blood vessels were sampled for pathological examination.</p><p><b>RESULTS</b>Neither pulsed nor continuous HIFU caused noticeable injuries of the acoustic channel vessels, but the volume of necrotic tissues in the target area differed significantly between the two groups (P<0.05). HE staining and vessel staining did not show any injuries of the blood vessels in the pathway of ultrasound ablation in neither of the groups (P>0.05).</p><p><b>CONCLUSION</b>When the target area contains large blood vessels in the pathway of ultrasound ablation, pulsed HIFU can have better therapeutic efficiency to effectively induce tissue damages without affecting the blood vessels.</p>

Effect of high-intensity focused ultrasound combined with gemcitabine on subcutaneous pancreatic cancer in nude mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of high-intensity focused ultrasound (HIFU) and gemcitabine on xenograft growth in nude mice bearing human pancreatic cancer.</p><p><b>METHODS</b>Nude mouse models bearing subcutaneous human pancreatic cancer cell line PANC-1 xenograft were randomized into 4 groups, including a control group and 3 treatment groups subjected to treatments with HIFU, gemcitabine, or both. After the treatments, the tumor was measured on a weekly basis for 5 weeks, and the tumor growth curve was drawn. The tumor inhibition rate was calculated and the expression of vascular endothelial growth factor (VEGF) in the tumor tissue was examined by immunohistochemistry.</p><p><b>RESULTS</b>The tumor volume showed significant differences between the 3 treatment groups (P<0.01), but all significantly smaller than that in the control group; HIFU combined with gemcitabine resulted in the most obvious reduction in the tumor volume. VEGF expression in the tumor tissue was the lowest in the combined treatment group and the highest in the control group.</p><p><b>CONCLUSION</b>HIFU therapy produces definite therapeutic effect on human pancreatic cancer in the nude mouse model, and its combination with chemotherapy is the optimal treatment modality.</p>

Establishment and practice of training mode for students majoring in minimally-invasive and noninvasive medical talents / 中华医学教育探索杂志

Medical treatment technology has made a lot of breakthrough because of the rapid development of the medical devices industrial.Minimally-invasive and noninvasive medicine is the development tendency of the future medicine.To adapt to the needs of the future medicine,Chongqing medical university exerted much efforts on training of minimally-invasive and noninvasive medical talents.We explored and practiced in aspects of fixing educational conception and goal,building curriculum and teaching content,constructing professional teaching team and developing practice and innovation abilities in order to fill the void of personnel training in the minimally-invasive and noninvasive medical field.

Cavitation and boiling of bubbles at the focal region during high intensity focused ultrasound exposure / 生物医学工程学杂志

High intensity focused ultrasound (HIFU) is a very complex transient process and can cause tissue coagulation necrosis. The cavitation and boiling behaviour of bubbles in the focal region play very important roles throughout an injury process. This paper reviews the research done by domestic and foreign scholars on behaviours of bubbles in HIFU irradiation process and summarizes in the focal region bubble cavitation and boiling generation, related detective means and relationships with hyperecho, temperature rise of the focus and injury shape.

A review of research progress of sonoelastography for the monitoring of HIFU therapy / 生物医学工程学杂志

With the development of non-invasive therapeutic means such as high intensity focused ultrasound (HIFU), it has been of an importance how to monitor effectively the therapeutic process and to evaluate the outcome of the therapy. Sonoelastography has been a hot research field in recent years as an effective method for tissue characterization. This article focuses on the research progress of sonoelastography for the guidance of HIFU therapy at present, and reveals the potential possibility of sonoelastograhy guided HIFU Therapy.

The rise of high intensity focused ultrasound (HIFU) non-invasive therapy for solid tumors / 中华肝胆外科杂志

In the 40 years of last centry American scientists put forward a concep of high intensity focused ultrasound (HIFU) therapeutic technique and had done some technical and clinical studies. Since 90 years the HIFU surgery technique treating tumors anew rised abruptly in the world. China firstly put out a comprehensive HIFU tumor treating sistem and successfully treated many solid tumors such as breast cancer, bone tumor, liver cancer etc.. Now the treating sistem has already exported to England, Italy,Spain, Japan, Colea etc. and treated tens thousands tumor patients. In the field of noninvasive ultrasound treating tumor technique China has continually kept the leading position in the world.

Investigation of general practitioner training / 中华医学教育探索杂志

Based on the quality of students, we reasonably arranged thetraining course content and enhanced the training of clinical skills; and at the same time focused on teacher training of general practitioners to strengthen the training bases, so as to improve the overall construction of teaching effect, to adapt to the actual medical need of the community and improve community medical service level to achieve the purpose of general practitioners training.

Analysis of key problem of high intensity focused ultrasound (HIFU) thermal ablation technique / 中华肝胆外科杂志

In 1988, Zhibiao Wang had an inspiration of ablating tumor in vivo non-invasively by high intensity focused ultrasound (HIFU). In the following 10 years, he and his team first proposed concepts such as "biological focal region", "ultrasound therapy dosimetry", "acoustic environment in tissue" and so on. They had broken down the key technical barriers in real-time ultrasound monitoring, treatment system optimization, telemedicine system, clinical protocols and other aspects, making HIFU therapy successfully applied to surgery and accumulated the largest number of clinical cases internationally. They have been playing a leading role around the world in equipment development, clinical application and some basic research in this field.

Role of glycogen synthase kinase-3β signal molecule in myocardial hypertropy / 中国病理生理杂志

Glycogen synthase kinase-3β (GSK-3β) is a serine/threonine protein kinase, which takes part not only in glycogen metabolism, but also in cell proliferation, differentiation and apoptosis. GSK-3β is inhibited by growth factors and hypertrophic stimuli through phosphorylation of its N-terminal end serine (Ser9) residue. It is also activated by phosphorylation of its tyrosine (Tyr216) residue. GSK-3β is profoundly inactivated in mice with hypertrophic cardiomyopathy (HCM) and plays a secondary role in myosin heavy chain mutation. However, the role of GSK-3β in HCM was controversial. Recent studies have demonstrated that the activation of GSK-3β inhibits the myocardial hypertrophy, and is regulated by Wnt/Frizzld and PI3-K/Akt signaling pathways. This article introduces the molecular role of glycogen synthase kinase-3β signaling in myocardial hypertrophy and the different pathways on the activity of glycogen synthase kinase-3β (GSK-3β)

Research on thermal dose for high intensity focused ultrasound treatment based on the temperature-map of magnetic resonance imaging / 生物医学工程学杂志

<p><b>UNLABELLED</b>Based on the T-map of MRI, this research sought to address the relationship between the simulated threshold thermal dose of coagulation and actual the coagulation on histological slides. The MR imaging guided HIFU system was used, the parameters of therapeutic transducer were: frequency--1 MHz, diameter--150 mm, and focal length--150 mm. In fresh beef liver tissue in vitro, sonications were delivered at a fixed depth of 20 mm and at varying powers. The temperature-sensitive MR images obtained during the sonications were used to estimate the temperature, and the thermal dosage of each voxel in the target region was calculated. The thermal dosage of each voxel was compared with the reference threshold thermal dosage, so as to calculate the boundary and area of the coagulated tissue. After the exposure, the tissue was dissected along the maximal section of the coagulation necrosis, and the area of the biological focal region was measured.</p><p><b>RESULTS</b>The occurrence of tissue damage correlated well with the equivalent thermal dose calculation based on the T-mapping of MRI, and they share the same variation tendency.</p><p><b>CONCLUSION</b>The equivalent thermal dose calculation based on the T-Map of MRI correlates well with the actual tissue damage, and so an index to predict the threshold for tissue damage in vivo is provided. This index offers improved online control over minimally invasive thermal treatments and increases the security of the therapy.</p>

Effects of ribs in high intensity focused ultrasound beam path on formation of coagulated necrosis in cattle liver in vitro / 中华超声影像学杂志

Objective To investigate the effects of ribs in high intensity focused ultrasound (HIFU)beam path on formation of coagulative necrosis in cattle liver in vitro in the same acoustic power. Methods The HIFU ablation was carried out in the manner of a single dot in the liver in vitro. The liver was ablated by HIFU in free field,then the ribs were placed between the focal plane and transducer,directing the beam axis through the intercostals space, lied at the rib edge and on the centre of middle rib. For each of these axial arrangements,the plane of the front surface of ribs was placed 3 cm,6 cm or 9 cm in front of the focus. After HIFU exposure,the tissue necrosis rate(TNR),the maximum length,width,depth and position of the coagulated necrosis in the liver were measured. Results ①The TNR was 100% in the free field. When the ribs were placed 3 cm in front of the focal plane,directing the beam axis through the intercostals space, the TNR was 100%. When directing the beam axis lied at the rib edge and on the centre of middle rib,the TNR decreased sharply. When the ribs were placed 6cm and 9cm in front of the focal plane, the TNR was more than 50%. ②When the ribs were placed in HIFU beam path, the volume of necrosis decreased compared with those in free field. The relationship between the ribs and beam axis, the location of ribs placed away from the focal plane different,the volume,length,width and position of the coagulated necrosis different. ③ When the ribs were close to the focal plane,unacceptable damage could been observed on the surface of ribs.When the ribs were far away from the focal plane, the ribs were safe. Conclusions The volume of necrosis decrease when the ribs are placed in HIFU beam path. The relative location of ribs and HIFU beam axis, the location of ribs away from the focal plane are relative with the volume of the coagulated necrosis. When directing the beam axis through the intercostals space, the volume of necrosis is large, and the shape of coagulated necrosis is regulated. When the ribs are closed with the focal plane,ribs are damaged probably.

Effects of high intensity focused ultrasound with SonoVue on blood vessels pathological examinations / 生物医学工程学杂志

The injury of tumor blood vessels will break up the nutrition supply for the tumor. In this paper, we investigated the effects exerted by high intensity focused ultrasound (HIFU) combined with ultrasound microbubble agent on blood vessels. Ultrasound diagnosis was used to find the goat hepatic blood vessels each being approximately 3mm in diameter. HIFU was focused on the blood vessels. The acoustic power was 250W; HIFU irradiating Mode was line scan (the length of the line: 10 mm; speed: 3 mm/s; irradiating time: 30s). In the experimental group, 0.03 ml/kg SonoVue was injected into the goat before HIFU irradiation,while normal saline was given to the control group. The goats were killed at 24h after HIFU irradiation, then goat liver tissues and blood vessels of target area were taken out. HE staining and Victoria's blue and Ponceau's staining of tissue section showed that the endothelial cells of blood vessels dropped off and became necrosed, and the continuity of blood vessels was interrupted. HIFU combined with SonoVue will damage large blood vessels on HIFU focus, but there is no evident discrepancy between the group with SonoVue and the group without SonoVue.

Study on therapeutic dosimetry and biologic effect of high intensity focused ultrasound / 生物医学工程学杂志

This study was aimed at exploring the high intensity focused ultrasound(HIFU) therapeutic dosimetry and its biologic effect. In-vitro, bovine liver was immersed into 0.9% NS and degassed for application. The JC Model-focused ultrasound tumor therapeutic system was used in the experiment. The HIFU parameters were: frequency 1.6 MHz, depth 20 mm, acoustic power from 16.44 W to 196.32 W. Under each power, at radiating times from is to 20 s, bioptic specimens were obtained from all samples. The results showed when the acoustic power was equal to or higher than 179.96 W, only is of radiating is adequate to induce coagulative necrosis, and when the acoustic power was lower than 65.44 W, the radiating time to produce coagulative necrosis was about 7 s. In the range of 65.44-179.96 W, at each time when the acoustic power was set up with an increment of 16.36 W, the time to produce coagulative necrosis was 1-2 s shorter. The form of biological focal region (BFR) varied with the acoustic power and HIFU irradiation time. The size of BFR increased with the increase of HIFU irradiation dosage (acoustic power x exposure time). There is positive correlation between the size of BFR and the dosage of HIFU irradiation (y = 0.0164x(1.05591), R5 = 0.9238, P < 0.05).

High-intensity focused ultrasound transducer / 生物医学工程学杂志

High-intensity focused ultrasound (HIFU) has been used to precisely ablate a targeted area within the body without harming the overlying tissues. In recent years, HIFU, as a noninvasive, effective and feasible modality, has been used for cancer therapy. The development of HIFU transducer is the key technology of HIFU. This paper shows the acoustic lens transducer, spherical auto-focused transducer, pluralistic auto-focused transducer and the electronic phased array transducer in HIFU treatment, and the performance of each of the four HIFU transducers was evaluated.

In vitro study on dosage level of HIFU for formation of line-shaped lesion in bovine liver / 生物医学工程学杂志

The dot-shaped coagulative necrosis induced by a single HIFU exposure can be considered as a basis for HIFU ablation of tumour. For complete ablation of tumour mass with HIFU, the crucial point is to create a complete line-shaped lesion by way of dot-shaped coagulative necrosis. At the beginning of this in vitro study, a dot-shaped coagulative necrosis with focal width (W) 3mm was induced in ox liver by HIFU (acoustical intensity (I(SAL)) 6500W/cm2; exposure time 1s) at focal depth 2cm. And then, we investigated the formation of line-shaped lesion under two different modes, namely, multiple dot-shaped coagulative necrosis overlapping and linear scanning. Under multiple dot-shaped coagulative necrosis overlapping mode, line-shaped lesion is formed by the combination of multiple dot-shaped coagulative necroses. With acoustical intensity (I(SAL)) 6500W/cm2 and exposure time is for each single exposure, different intervals (D) between two successive single exposures (1mm, 2mm, 2.5mm, 3mm, 4.5mm, 5mm) were applied to obtain line-shaped lesion. Under linear scanning mode, the intensity (I(SAL)) 6500W/cm2 and cycle 1 were set constant, and various scanning speeds (V) 1mm/s, 3mm/s, 6mm/s, 7mm/s were adopted to create line-shaped lesion. After the procedures, the tissues were dissected to obtain the maximum section of the line-shaped lesion. The results were as follows: under multiple dot-shaped coagulative necrosis overlapping mode, a complete line-shaped lesion could be formed when D < or = W, while an incomplete line-shape lesion was formed when D > W; under linear scanning mode, a complete line-shaped lesion could be formed using the scanning speed 3mm/s and cycle 1. The results validate that the complete line-shaped lesion can be created with the dosage and exposure parameters optimized for the dimension of a single dot-shaped coagulative necrosis as shown in this study.

Enhancing effects of microbubble contrast agent of different dosage on high-intensity focused ultrasound ablation in goat liver in vivo / 中华超声影像学杂志

Objective To investigate the enhancing effect of microbubble contrast agent SonoVue of different dosage on high-intensity focused ultrasound (HIFU) ablation in goat livers in vivo. Methods Twenty goats were divided into 4 groups randomly. Animals in group 1,2 and 3 were bolus-injected of 0.01 ml/kg,0. 03 ml/kg and 0.05 ml/kg of SonoVue intravenously before HIFU exposure, respectively,and those in group 4 were not given injections as control. After injection 20s, the livers were ablated using HIFU performed in the manner of a single dot set by a computer system using a clinical device. The frequency of HIFU was 0.8 MHz,the intensity of HIFU was 19 100 W/cm2 ,the distance from skin to the target liver tissue was 30 mm,the exposure time was set at 15 s for all animals in the four groups. All animals were euthanized 7 days after HIFU, volumes of coagulated necrosis were measured. Pathological examinations were performed to analysis the exposure regions. Results Under the same parameters of exposure, coagulated volumes in group 1,2 and 3 were larger than those in group 4, the difference was significant (P < 0.05),and the coagulated volumes increased gradually with the dosage of SonoVue increasing from group 1 to group 3, the difference was significant (P<0.05). Pathological examinations confirmed that there were no residual unaffected tissues within the exposed volume. Two remarkable changes were observed in one goat in group 37 days after HIFU:the surrounding adjacent tissue outside the reactive zone necrotized and the skin were destroyed. Conclusions The enhancing effects of microbubble contrast agent in HIFU ablation is related with the dosage of the microbubble contrast agent SonoVue. The higher the SonoVue dosage,the larger the volume destroy in the target tissue.