Objective:To evaluate the performance of the self-developed transcranial ultrasound patch probe as well as its stability and safety in clinical applications.Methods:This study was a cross-sectional study. Fifty healthy subjects in Tangdu Hospital from October to December 2023 were randomly and equally divided into two groups using a simple randomization method. The transcranial Doppler ultrasound (TCD) examinations were performed using the self-developed transcranial ultrasound patch probe and normal TCD probe alternatively in each group from squatting to sitting and then to standing posture. Two experienced sonographers (A, B) each completed one test for the same subject using the above two different probes. The differences of the ultrasound parameters of middle cerebral artery (MCA) blood flow measured by the self-developed transcranial ultrasound patch probe and the normal TCD probe in different postures (squatting, sitting, standing) were compared. At the same time, operator satisfaction with the use of the two probes was assessed in terms of time taken to obtain satisfactory images, operational comfort, and ease of handling. In addition, the subject's comfort during the examination was examined, and the signal acquisition stability of the two probes was comprehensively evaluated.Results:There was no significant difference in detection of various ultrasound parameters of MCA between using the transcranial patch probe and the normal TCD probe (all P>0.05). The overall satisfaction of transcranial ultrasound patch probe and normal TCD probe was quite similar. The transcranial ultrasound patch probe acquired favorable and stable signals. No subjects experienced adverse events/accidents during the examination of the subjects using the transcranial ultrasound patch probe as well as the normal TCD probe.Both probes had good and stable signal acquisition. Conclusions:TCD examinations could be well performed using the transcranial ultrasound patch probe, which might provide a potential new method for real-time monitoring and evaluating of cerebral blood flow of a moving subject.

Objective:To investigate the accuracy and reproducibility of a new method, Automatic Measurement of Arterial Stiffness(AMAS) system, for arterial stiffness automatic measurement based on regional pulse wave velocity (PWV).Methods:A total of 30 hypertensive patients who were hospitalized in the Department of Cardiology in Tangdu Hospital, Air Force Military Medical University from September 1 to 30, 2019 were enrolled as hypertensive group, while 30 healthy participants at the same time were collected as healthy group. Carotid-femoral PWV (cfPWV) was measured in all subjects by two independent observers using the conventional manual method and the AMAS system. The measurements were compared and the agreement was analyzed.Results:There was no significant difference of cfPWV between AMAS system and the manual method, and the intraclass correlation coefficient was 0.953 (95% CI=0.922-0.971). Bland-Altman plots showed good agreement [mean difference: -(0.08±0.40)m/s; limit of agreement: -0.87-0.71 m/s]. Time consumption for cfPWV measurement using the AMAS system was significantly less than that of conventional manual method, saving about 70% of the time. The cfPWV measured by AMAS showed good intra- and inter-observer reproducibility. Conclusions:AMAS system is accurate and reproducible in measuring arterial stiffness. It may provide a noninvasive, rapid, reliable approach for arterial stiffness evaluation in clinical settings.

Objective:To explore the feasibility and accuracy of three-dimensional (3D) modeling methods based on ultrasound imaging data for normal and abnormal fetal cardiac structures, and to construct a methodology system for 3D printing of fetal heart based on ultrasound.Methods:A total of 93 fetuses examined in Tangdu Hospital of Air Force Military Medical University from January to December 2019 were selected. Fetal echocardiography was obtained using spatio-temporal image correlation (STIC). Ninety-three hearts were 3D modeled by blood flow modeling, blood pool modeling and cavity modeling, and printed by stereolithography technique. The data measured on the 3D digital models and 3D printed solid models were compared with the corresponding fetal echocardiographic images respectively in order to evaluate the accuracy of the modeling methods.Results:The fetal cardiac blood flow models based on Doppler flow image data showed the malformation and trend of small blood vessels. The fetal cardiac structure models printed based on blood pool modeling displayed the malformation of heart and large blood vessels. Models printed based on cavity modeling method accurately displayed valve and structural defects.For 83 normal fetal hearts, the long diameters of left and right ventricles measured on echocardiography [(15.3±1.9)mm, (13.2±1.9)mm] were compared with those measured on digital models [(15.1±1.9)mm, (12.9±1.9)mm] and 3D printed models[(15.1±1.9)mm, (13.0±1.9)mm], respectively, and there were no significant differences between any two groups of them ( P>0.05). Bland-Altman showed good consistency for all measurements within and between operators. Conclusions:The three modeling methods, including blood flow modeling, blood pool modeling and cavity modeling, have their own advantages in displaying different types of fetal heart malformations. Appropriate modeling methods should be selected for 3D modeling and printing to make up for the limitations of single modeling method. The consistency between measurements on 3D models and those on echocardiography is high, and the repeatability between operators is good.

Objective    In this study, three-dimensional printed (3DP) titanium implants were used for skeletal reconstructions after wide excision of chest wall. 3DP titanium implants were expected to provide a valid option with perfect anatomic fitting and personalized design in chest wall reconstruction. Methods    There were 13 patients [mean age of 46 (24-78) years with 9 males and 4 females] who underwent adequate radical wide excision for tumors and chest wall reconstruction using 3DP titanium implants. Surgical data including patient demographic characteristics, perioperative clinical data and data from 1-year follow-up were collected and analyzed. Results    Six patients of rib tumors, six patients of sternal tumors and one patient of sternal pyogenic osteomyelitis were finally selected for the study. The chest wall defect area was 221.0±206.0 cm2. All patients were able to maintain the integrity of the chest wall after surgery, and no abnormal breathing was found, achieving personalized and anatomical repair. Thirteen patients were successfully discharged from the hospital. Two patients developed pneumonia in the perioperative period. During the follow-up period in the first year after surgery, no implant related adverse reaction was observed, including implant rupture, implant shift, rejection reaction and allergies. One patient had wound ulcer after chemotherapy. Three patients had tumor recurrence, with the recurrence rate of 25.0%. Two patients died of tumor recurrence, with a mortality rate of 16.7%. Conclusion    3DP titanium implant is a safe and effective material for chest wall reconstruction. 

Objective:To investigate the application of ultrasound imaging in evaluating the curative effect of patients with nutcracker syndrome (NCS) treated with three-dimensional(3D) printing extravascular titanium stents.Methods:From December 2015 to December 2018, a total of 41 NCS patients enrolled in the Second Affiliated Hospital of the Air Force Military Medical University to receive 3D-printing extravascular titanium stents treatment were included in this study. Ultrasound and CT angiography (CTA) were performed before and 1 week after operation to evaluate the compression of left renal vein and related hemodynamic changes.Results:Before the operative, the ultrasound examination showed that the angle between the abdominal aorta and superior mesenteric artery was (21.29±4.53)°, which was significantly improved in 1 week after treatment [(47.42±7.45)°, P<0.001]. Left renal vein was significantly compressed before treatment, with the smallest inner diameter of (1.51±0.49)mm and its peak blood flow velocity was (143.92±50.40)cm/s. Postoperative ultrasound images showed the significant expansion of left renal vein and no high velocity blood flow was observed. Ultrasound examination also showed that the diameter of left renal vein at renal hilum, blood flow velocity at renal hilum and inner diameter of spermatic vein were significantly improved after treatment ( P<0.001). Similar to ultrasound results, CTA also found that the angle between abdominal aorta and superior mesenteric artery increased significantly after treatment[(17.59±4.56)° vs (52.27±9.01)°, P<0.001]. CTA also showed the left renal vein was compressed before treatment, with the smallest inner diameter of (2.09±0.86)mm, and it was significantly expanded after operation. The inner diameter of left renal vein at renal hilum was also significantly reduced after treatment ( P<0.001). Conclusions:Ultrasound imaging can effectively evaluate the LRV compression and related hemodynamic changes before and after 3D printed stent implantation treatment in NCS patients and provide a reliable method to evaluate its clinical efficacy for these patients.

Objective To explore the mechanism of intrathoracic pressure(ITP) influncing cardiac function and facilitate noninvasive determination of ventricular pressure theoretically.Methods With Valsalva and Mueller maneuver,two-dimension images of standard long axis views and the cross-sectional views were recorded in 20 volunteers,aged from 18 to 45 years,at the specific ITP levels(including-20 mmHg、-10 mmHg、0 mmHg、+ 10 mmHg and + 20 mmHg).The subjects were instructed to mantain for at least 10 s,and three successive measurements were recorded and averaged.The stroke volume(SV) and radius of curvature(R) were obtained from further off-line analysis.Results With the ITP maintaining at -20 mmHg,-10 mmHg,0 mmHg(end expiration),+ 10 mmHg and + 20 mmHg respectively,the corresponding radiuses of curvature were (2.35 ±0.24)cm,(2.25 ± 0.23)cm,(2.14 ± 0.21)cm,(2.02 ± 0.21) cm,(1.93 ± 0.19) cm,there were statistically significances between two groups (P =0.006,0.031,0.005 and ＜0.001,respectively].When the ITP were at 0 mmHg(end expiration),+ 10 mmHg and + 20 mmHg,the stroke volume were (71.54±8.81)ml,(73.20±9.52)ml and (78.81± 14.61)ml (P =0.674,0.135).When the intrathoracic pressure decreased from 0 mmHg to-20 mmHg,the stroke volume were (78.81±14.61)ml,(68.28 ±9.28)ml and (59.69±7.52)ml(P =0.029,0.037).Conclusions The ITP has different effects on the two ventricles,and subsequently generates a pressure gradient across the IVS which can alter its shape and position at end-diastole.With the IVS shifting,the preload and filling function of left ventricle gets changed acorrding to the Frank Starling principle.

Objective To propose an accurate method of noninvasive determination of central venous pressure(CVP ) by locating the central point of right atrium (RA ) using echocardiography .Methods Through the 3D reconstruction ,the accurate positions of RA of 30 patients who had been examined by multislice 3‐dimensional computed tomography for chest imaging were recorded .Based on solid geometric principles ,the central point in RA was located by echocardiography and then compared with CT‐location point .The accuracy and feasibility were assessed by absolute distance (Da) ,vertical distance (Dv) and the whole time of location (T) between the two points .Results Mean Da ,Dv and T of the whole subjects were 07.6cm(95% CI:06.2to08.1cm),01.6cm(95% CI:-00.2to03.4cm),and438.0s(95% CI:400.1to 47 4.0 s) ,respectively .Conclusions The echocardiographic method on the basis of solid geometry proposed in this study could be used to locate the central point in RA accurately and simply .Thus it would be helpful to improve the accuracy of noninvasive determination of central venous pressure .

Currently, medical ultrasound teaching focuses on the delivering the image infor-mation itself, while its connection with basic medicine and clinical medicine is neglected. Such a teaching method is not good for students to establish a systemic view. To conduct the ultrasound medi-cine education effectively in undergraduate students, we have tried some reforms, including: perform-ing diseases or problem based teaching, integrating basic medicine, ultrasound medicine and clinical medicine throughout the whole teaching process, providing as many practice opportunities as possible for the graduates and integrating the ultrasound imaging with other medical imaging modalities. The practice shows that with the reform, the students have a better understanding of ultrasonic knowledge itself, a better grasp of the whole medical knowledge structure, and also have a preliminary impression on how to diagnose the disease through reasonable application of different treatments. In addition, students have more passion for study.

Objective To determine the central venous pressure (CVP) noninvasively based on hemodynamics principles using ultrasound location of the collapse point of the internal jugular vein.Methods Forty patients were enrolled in this study.The collapse point of the internal jugular vein was located and marked by a linear transducer,the body mark of right atrium was marked on the right lateral wall of the chest.The noninvasive CVP was calculated according to the vertical distance between those two points.The invasive CVP determination by central venous catheter was also carried out on all the patients.Correlation analysis was used to compare the invasive and noninvasive methods.With invasive determination of CVP as the gold standard,the ROC curve of the noninvasive ultrasound method was sketched to explore the optimal cut-off points.Results The correlation analysis reveal high positive correlation between CVPs determined by ultrasound imaging and central venous catheter (r =0.906,P ＜0.01).By the ROC curve test,fluid column height of 10.75 cm by ultrasound method was determined as the cut-off point,with the sensitivity and specificity of diagnosing elevation of CVP being 88.9％ and 93.5 ％ respectively.The corresponding area under the curve was 0.971.Conclusions Ultrasound imaging could be used to determine CVP noninvasively,which would be helpful in diagnosis of the circulating load of patients.