Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 183
Filtre
1.
Journal of Kunming Medical University ; (12): 146-150, 2024.
Article Dans Chinois | WPRIM | ID: wpr-1019084

Résumé

Objective To explore the application value of Three-Dimensional rectal cavity ultrasound combined with contrast agent imaging in necrotizing fasciitis of the anal region.Methods Before surgery,standard three-dimensional rectal cavity ultrasound examinations(referred to as the conventional group)and contrast agent imaging examinations(referred to as the imaging group)were conducted for 40 patients clinically diagnosed with anal region necrotizing fasciitis.Separate observations were made for the primary lesion,as well as for the depth and superficial necrosis of the fascia,and injuries to the anal sphincter muscle.Comparative analysis with surgical results was undertaken to assess the diagnostic sensitivity of both the conventional and imaging groups.Results In comparing the conventional group with the imaging group,the rates of primary lesion visibility rose significantly from 70%to 97.5%,deep fascial necrosis visibility increased from 50%to 88.8%,superficial fascia visibility improved from 70%to 100%,and the visibility of anal sphincter muscle injury escalated from 62.5%to 97.2%,all demonstrating statistical significance at P<0.05.Conclusions Three-dimensional rectal cavity ultrasound combined with contrast agent imaging exhibits significantly enhanced accuracy in identifying primary lesions associated with perianal necrotizing fasciitis,as well as the necrosis affecting deep and superficial fascia,in contrast to conventional three-dimensional rectal cavity ultrasound.This advancement offers more precise guidance for clinicians in devising surgical plans,thereby augmenting the success rate of surgical interventions.

2.
Journal of Practical Radiology ; (12): 473-477, 2024.
Article Dans Chinois | WPRIM | ID: wpr-1020241

Résumé

Objective To compare the image quality of carotid contrast-enhanced magnetic resonance angiography(ceMRA)under different flow rates using high relaxation rate contrast agent named Gadobutrol,and to find the best flow rate for carotid ceMRA.Methods Total of 117 patients,who were scheduled to perform carotid ceMRA examination using Gadobutrol with a dosage of 0.1 mL/kg body weight on a 1.5T MR platform,were enrolled in the study.They were divided into four groups according to four kinds of flow rates,which were 1.0 mL/s(n=29),1.5 mL/s(n=30),2.0 mL/s(n=30)and 3.0 mL/s(n=28).The signal-to-noise ratio(SNR)of bilateral carotid initiation and bilateral carotid bifurcation were calculated.The SNR of carotid initiation or carotid bifurca-tion between different flow rates were compared.And the scores of image quality among different flow rates were also compared.Results For bilateral carotid bifurcations and carotid initiations,the SNR under 1.5 mL/s were highest,which were significantly higher than those under 1.0 mL/s,while there were no significant differences between each two other flow rates.For the bilateral carotid bifurca-tions,the SNR under 1.0 mL/s were lower than those under other flow rates,and were significantly lower than those under 1.5 mL/s and 3.0 mL/s.The score of the image quality at 1.0 mL/s was significantly lower than that under other flow rates.The score of the image quality at 1.5 mL/s was the highest,but no significant difference was found compared to that at 2.0 mL/s or 3.0 mL/s.Conclusion The rate of 1.5 mL/s is recommended as the best flow rate for carotid ceMRA with Gadobutrol based on 1.5T MR.

3.
Chinese Journal of Tissue Engineering Research ; (53): 5225-5230, 2024.
Article Dans Chinois | WPRIM | ID: wpr-1021989

Résumé

BACKGROUND:Existing neuroimaging techniques,including magnetic resonance imaging,computed tomography,and high-resolution ultrasound,lack the capability to provide real-time intraoperative positioning images to surgeons.However,the clinical implementation of near-infrared fluorescence imaging technology has made it possible to directly visualize surgical target areas,offering a novel solution for real-time nerve identification during surgery. OBJECTIVE:To provide a summary and overview of the research progress in near-infrared fluorescence imaging technology for intraoperative neuroimaging. METHODS:The first author used the computer to search for the documents published from January 2010 to July 2023 in WanFang,CNKI,and PubMed with the key words of"near-infrared fluorescence imaging,optical imaging,nerve imaging"in Chinese and English.A few classic old documents were also included.Initial screening was performed by reading the titles and abstracts;duplicate,low-quality,and irrelevant content documents were excluded.A total of 69 articles were finally included for review. RESULTS AND CONCLUSION:Near-infrared fluorescence imaging guided by indocyanine green has been clinically used to identify and locate tubular organs such as blood vessels,ureters,and bile ducts,as well as various tumors during surgery.This technique is currently considered a well-established imaging method in precision surgery.In the field of intraoperative neurofluorescence imaging,indocyanine green is currently the only near-infrared fluorescent dye used in clinical research.The ideal neuroimaging agent should possess certain characteristics,including easy administration in the perioperative period,logD between 0.5 and 3 at pH=7.4,molecular mass below 500 Da,excitation and emission wavelengths within the near-infrared window,long-term retention in nerve tissue,high signal-to-background ratio,and high safety.In the future,the development of near-infrared neurofluorescence imaging agents should focus on synthesizing complexes of indocyanine green and neural-specific targets.This technology not only enables intraoperative neurofluorescence imaging,but also holds promising prospects for in-situ monitoring of nerve regeneration and diagnosis of neurological diseases.

4.
Acta Pharmaceutica Sinica ; (12): 581-590, 2024.
Article Dans Chinois | WPRIM | ID: wpr-1016621

Résumé

In the past few decades, microbubbles were widely used as ultrasound contrast agents in the field of tumor imaging. With the development of research, ultrasound targeted microbubble destruction technology combined with drug-loaded microbubbles can achieve precise drug release and play a therapeutic role. As a micron-scale carrier, microbubbles are difficult to penetrate the endothelial cell space of tumors, and nano-scale drug delivery system—nanobubbles came into being. The structure of the two is similar, but the difference in size highlights the unique advantages of nanobubbles in drug delivery. Based on the classification principle of shell materials, this review summarized micro/nanobubbles used for ultrasound diagnosis or treatment and discussed the possible development directions, providing references for the subsequent development.

5.
Chinese Journal of Radiation Oncology ; (6): 7-12, 2024.
Article Dans Chinois | WPRIM | ID: wpr-1027464

Résumé

Objective:To assess the application value of low-dose contrast agent combined with bolus tracking technique in radiotherapy localization for nasopharyngeal carcinoma (NPC).Methods:One hundred patients with NPC for radiotherapy localization were enrolled prospectively and randomly divided into observation ( n = 50) and control ( n = 50) group using random number table. All patients in the control group underwent routine computerized tomography (CT) for radiotherapy localization with an intravenous bolus of 80 ml iodinated contrast media. Images were obtained at a fixed delay of 50 s from the beginning of contrast injection. Patients in the observation group underwent CT scan using a bolus tracking technique with an intravenous bolus of 50-60 ml iodinated contrast media. By observing the time-CT value monitoring curve, the scanning was manually triggered when the peak fell. The score of image quality, enhanced CT value, iodine contrast dose, and dose calculation variance of planning target volume were compared between the two different dose groups. The differences of dose were compared using independent sample t-tests and the differences in graph scores were compared using Wilcoxon rank sum tests. Results:The dosage of iodine contrast agent in the observation group was 28.75% less than that in the control group, and the difference achieved statistical significance ( t=-42.11, P<0.001). The enhanced CT value of carotid artery and jugular vein in the control group increased 32.58% and 21.02% compared with patients in the observation group, respectively ( t=-8.11 and -4.82, P<0.001 for both). No statistically significant differences in the enhanced CT value were found for the gross tumor volume (GTV) of nasopharynx or sternocleidomastoid between the two groups ( P>0.05). The images in both groups can met the requirements of target volume delineation, and the difference of subjective score was not statistically significant ( Z=-1.36, P=0.175). There were no significant differences in the signal-to-noise ratio (SNR) or contrast-to-noise ratio (CNR) of nasopharynx between the two groups ( P>0.05). The results of subjective score and GTV target area showed high consistency between the two doctors with a κ value of 0.77. The differences in dose calculation variance of planning target volume between the two different dose groups was also not statistically significant ( P>0.05). Conclusions:In the radiotherapy localization for nasopharyngeal carcinoma, the application of low-dose contrast agent combined with bolus tracking technique could obtain good images for target delineation and effectively reduce the intake of iodine contrast agent and the risk of adverse reactions. Based on these results, low-dose contrast agent combined with bolus tracking technique has wide range of application.

6.
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery ; (12): 320-324, 2023.
Article Dans Chinois | WPRIM | ID: wpr-979483

Résumé

@#Conventional transcatheter aortic valve replacement is normally recommended with transthoracic echocardiography, and contrast agent mediated fluoroscopy under anesthesia to guide a better implantation of the transcatheter valve. However, iodine-containing contrast agent possibly damages the patient’s kidney, and even induces the acute kidney injury. We reported a 75-year-old patient diagnosed with severe aortic valve stenosis, moderate regurgitation, and chronic renal failure. We performed the aortic valve replacement under the guidance of fluoroscopy and transesophageal ultrasound without contrast agent. Seven days after surgery, the patient recovered well and discharged with alleviated aortic stenosis and fixed transcatheter aortic valve.

7.
Chinese Journal of Postgraduates of Medicine ; (36): 1009-1014, 2023.
Article Dans Chinois | WPRIM | ID: wpr-1023007

Résumé

Objective:To study the optimization of defecation treatment in patients with chronic constipation under different positions and angles by "simulation contrast agent".Methods:The clinical data of 78 patients with chronic constipation in Handan Central Hospital from April 2020 to April 2022 were retrospectively analyzed. Among them, 26 patients were examined by 90°conventional defecography position (conventional position group), 26 patients by 60° to 89° defecography position (61° to 89° position group), and 26 patients by 30° to 59° Asian squat defecography position (Asian squat position group). The results of defecography, constipation score and defecography abnormality were compared among the three groups.Results:The encysted rectum, internal rectal intussusception and descending distance of perineum in 61° to 89° position group and Asian squat position group were significantly lower than those in conventional position group: (2.71 ± 0.25) and (2.11 ± 0.66) mm vs. (3.06 ± 0.23) mm, (9.06 ± 1.78) and (8.55 ± 2.81) mm vs. (10.22 ± 1.59) mm, (11.52 ± 2.70) and (10.52 ± 2.93) mm vs. (12.52 ± 3.43) mm, the indexes in Asian squat position group were significantly lower than those in 61° to 89° position group, and there were statistical differences ( P<0.01); the anal right angle and the anal right angle in force discharge state in 61° to 89° position group and Asian squat position group were significantly higher than those in conventional position group: (120.47 ± 3.35)° and (122.44 ± 3.33)° vs. (118.19 ± 3.66)°, (19.99 ± 3.47)° and (20.25 ± 2.69)° vs. (18.77 ± 2.79)°, the indexes in Asian squat position group were significantly higher than those in 61° to 89° position group, and there were statistical differences ( P<0.01); there was no statistical difference in resting anal right angle among the three groups ( P>0.05). The Longo outlet obstructive constipation score, Wexner constipation score and constipation severity score in 61° to 89° position group and Asian squat position group were significantly lower than those in conventional position group: (14.41 ± 2.66) and (12.24 ± 3.49) scores vs. (16.64 ± 3.37) scores, (13.79 ± 2.74) and (12.83 ± 3.08) scores vs. (15.76 ± 3.56) scores, (13.34 ± 2.72) and (12.31 ± 2.52) scores vs. (16.08 ± 3.57) scores, the indexes in Asian squat position group were significantly lower than those in 61° to 89° position group, and there were statistical differences ( P<0.01). The detection rates of abnormal defecography in conventional position group, 61° to 89° position group and Asian squat position group were 96.15% (25/26), 84.62% (22/26) and 69.23% (18/26), and there was statistical difference ( P<0.05); among them, the detection rate of abnormal defecography in Asian squat position group was significantly lower than that in conventional position group, and there was statistical difference ( P<0.05). Conclusions:The defecation function and imaging indexes are optimized in patients with chronic constipation based on the guidance of "simulation contrast agent" adopted the Asian squat position, and their significantly.

8.
Chinese Journal of Primary Medicine and Pharmacy ; (12): 1134-1138, 2023.
Article Dans Chinois | WPRIM | ID: wpr-991873

Résumé

Objective:To investigate the diagnostic value of cardiac magnetic resonance (CMR) contrast medium perfusion and delayed contrast enhancement for early myocardial ischemia.Methods:Ninety-one patients with coronary artery stenosis diagnosed by coronary angiography (CAG) between March 2020 and March 2022 in Yiwu Central Hospital were included in this study. These patients underwent first-pass perfusion cardiac magnetic resonance imaging and delayed enhancement examination. Arrival time ( t0), accumulative signal intensity (ASI), relative peak enhancement rate (SI%), maximum intensity of signal enhancement (SIp), and maximum curve slope (α) were statistically analyzed in the CMR contrast agent normal-dose perfusion and low-dose perfusion segments. The diagnostic value of CMR contrast agent perfusion versus CAG for early myocardial ischemia was determined. The signal intensity was compared between enhanced and non-enhanced areas of CMR contrast agent perfusion. Results:There were significant differences in ASI, SI%, SIp, and Slope (α) between normal perfusion and low perfusion segments ( t = 9.62, 10.65, 8.67, 6.93, all P < 0.05). There was no significant difference in the detection rate of lesioned vessels in early myocardial ischemia between CMR contrast agent perfusion and CAG [50.42% (120/238) vs. 51.68% (123/238), χ2 = 1.32, P = 0.163). There was a significant difference in the detection rate of lesioned vessels in myocardial ischemia between CMR contrast agent perfusion and CAG ( χ2 = 15.31, P < 0.001, r = 0.71). The signal intensity value in the delayed enhancement segment was significantly higher than that in the non-delayed enhancement segment [(598.43 ± 40.19) vs. (298.64 ± 70.58), t =19.85, P = 0.001). Conclusion:CMR contrast agent perfusion can effectively evaluate the severity of early myocardial ischemia and locate the diseased blood vessels. Delayed enhancement can determine the location and area of early myocardial ischemia, and can objectively reflect the severity of myocardial ischemia.

9.
Chinese Journal of Radiology ; (12): 756-761, 2023.
Article Dans Chinois | WPRIM | ID: wpr-993003

Résumé

Objective:To investigate the feasibility of simultaneous arteriovenous enhancement of neck CT with two-stage injection of contrast agent and its effect on image quality and radiation dose.Methods:A total of 30 patients undergoing neck CT enhancement scan due to space-occupying lesions in Beijing Tongren Hospital, Capital Medical University from February to April 2022 were prospectively included as the experimental group. The neck CT enhancement scan was performed with two-stage injection of contrast agent and arteriovenous simultaneous enhancement. The dosage of contrast agent was calculated according to the patient′s body weight, and the method of two-stage injection was adopted. The dosage of contrast agent in the first stage was 0.7 ml/kg, with normal saline in the middle stage, and the second stage (began at 35 s) was 0.3 ml/kg. A total of 30 patients with gender and age matching with the experimental group from December 2021 to January 2022 were retrospectively collected as the control group. The control group was treated with the traditional arterial phase and venous phase scanning method with the dosage of 1.0 ml/kg contrast agent. The arterial phase was scanned at the 30 s and the venous phase was scanned at the 60 s. The CT values of bilateral carotid arteries and jugular veins in the experimental group were measured, the CT values of bilateral carotid arteries in the arterial phase were measured in the control group, and the CT values of bilateral carotid arteries and jugular veins in the venous phase were measured. Carotid artery enhancement score was performed for images of experimental group and control group in arterial and venous phase, and jugular vein and lesion enhancement score was performed for images of experimental group and control group in venous phase. The effective dose was calculated for both groups. The difference of carotid artery CT values between images was compared by one-way analysis of variance, and LSD method was used for pairwise comparison. The CT values of jugular vein were compared using independent sample t test. Kruskal-Wallis test was used to compare carotid artery enhancement scores, and Nemenyi method was used for pairwise comparison. Jugular vein and lesion enhancement scores and effective dose were compared by Mann-Whitney U test. Results:The CT value of carotid artery of experimental group [left (276±24) HU, right (273±25) HU] was lower than that of control group in arterial phase [left (329±33) HU, right (327±32) HU], and higher than that in the venous phase [left (147±15) HU, right (148±16) HU]. All the differences were statistically significant ( P<0.001). The CT value of jugular vein of experimental group [left (206±18) HU, right (203±19)] was higher than that of control group in the venous phase [left (154±15) HU, right (151±15)], the difference was statistically significant ( t=11.88, 11.76, both P<0.001). There was no significant difference in carotid artery enhancement score between experimental group and control group in arterial phase ( P=0.624), but the carotid artery enhancement score of the experimental group was higher than that of the control group in the venous phase, and the difference was statistically significant ( P<0.001). The scores of jugular vein and lesion enhancement in experimental group were higher than those of control group in venous phase, and the difference was statistically significant ( Z=5.01, P<0.001). The effective dose of the experimental group [2.41(2.04, 2.72) mSv] was decreased by 52.2% compared with the control group [5.04(4.18, 5.44) mSv], and the difference was statistically significant ( Z=-6.24, P<0.001). Conclusions:The neck CT enhanced scan with two-stage injection of contrast agent and arteriovenous simultaneous enhancement method can obtain comprehensive images of arterial and venous phases, and realize simultaneous enhancement of carotid artery, jugular vein and lesions, and reduce radiation dose.

10.
China Medical Equipment ; (12): 42-45, 2023.
Article Dans Chinois | WPRIM | ID: wpr-1026400

Résumé

Objective:To explore the effect of oral contrast agent on the dose distribution and verification pass rate of radiotherapy plan when female patients with pelvic tumor underwent oral contrast agent to assist the delineations for tumors and organ at risk(OAR).Methods:A total of 15 female patients with pelvic tumor were selected.The original computed tomography(CT)images of each patient were the images with oral contrast agent.Based on these images,a 7-field static intensity-modulated radiotherapy plan was designed as plan 1.The intestinal CT values of the original images were modified to simulate the situations without oral contrast agent to obtain new images.The same optimization parameters of plan 1 was used to design a 7-field static intensity-modulated radiotherapy plan as plan 2.The two kinds of plans were normalized to a degree which 95%of volume was covered by 100%dose at the central point of target region.The 9 parameters of dose distribution included the maximum dose(Dmax),and two verification parameters were calculated as statistical method,and then,the effect of contrast agent was assessed.Results:The Dmax values of the target regions of plan 1 and plan 2 were respectively(5457.9±46.41)and(5455.8±46.33).The mean dose(Dmean)values of them were respectively(5185.4±24.39)and(5189.4±22.78).The conformity index(CI)values of them were respectively 1.03±0.03 and(1.03±0.03).The γ(3%/3 mm)pass rates of them were respectively(99.17±0.44)and(98.93±0.81)(P=0.177).The γ(2%/2 mm)pass rates of them were(95.46±1.27)and(94.88±1.87)(P=0.143).The differences of the dose and verification parameters between the designed two plans on the basis of the images with and without oral contrast agent were not statistical significance(P>0.05).Conclusion:Contrast agent does not have statistical effect on the dose distribution and verification pass rate of static intensity-modulated radiotherapy plan for female patients with pelvic tumor.

11.
Chinese Journal of Ultrasonography ; (12): 864-870, 2023.
Article Dans Chinois | WPRIM | ID: wpr-1027138

Résumé

Objective:To investigate the diagnostic value of ultrasound contrast agent enema (UCAE) for anastomotic leakage (AL) after rectal cancer surgery.Methods:From January 2020 to December 2022, a total of 95 patients with presacral fluid collection after rectal cancer surgery in the Sixth Affiliated Hospital of Sun Yat-sen University who received perineal ultrasound (PNUS) and UCAE were retrospectively selected. Among them, 70 patients (73.3%) were diagnosed with AL.After PNUS scanning, all patients received a diluted ultrasound contrast agent administered through the rectum. Receiver operating characteristic (ROC) curve were used to compare the accuracies of PNUS, UCAE, CT, MRI and water-soluble contrast enema in the diagnosis of AL. Factors that may have impacts on the sensitivity of UCAE were thoroughly analyzed.Results:UCAE improved the consistency (Kappa value: 0.757 vs 0.292, P<0.001) and accuracy (AUC: 0.893 vs 0.693, P<0.001) of PNUS in the diagnosis of AL, and its diagnostic accuracy was comparable to that of CT (AUC 0.807), MRI (AUC 0.811) and water-soluble contrast enema (AUC 0.923) (all P>0.05). For mid-to-high AL (anastomotic stoma distance ≥70 mm) and tiny AL (≤3 mm), the sensitivity of UCAE decreased significantly (anastomotic stoma position: 25.0% vs 85.5%, P=0.001; anastomotic leak diameter: 42.9% vs 87.5%, P=0.002). Conclusions:UCAE can significantly improve the diagnostic accuracy and consistency of PNUS for AL after rectal cancer surgery, and its diagnostic sensitivity is affected by the anastomotic stoma distance and the diameter of the leak.

12.
Chinese Journal of Radiological Medicine and Protection ; (12): 812-819, 2023.
Article Dans Chinois | WPRIM | ID: wpr-1027345

Résumé

Objective:Evaluate the image quality of dual-layer spectral detector CT pulmonary angiography with low-dose contrast agents, and explore the influence of pulmonary artery diameter on the image quality.Methods:A total of 91 spectral CT pulmonary angiography from March 2022 to August 2022 were retrospectively analyzed. The cases were divided into Group 1 ( n=34, main pulmonary artery diameter ≥ 30 mm) and Group 2 ( n=57, main pulmonary artery diameter<30 mm). The dosage of contrast agent was 30 ml. The CT attenuation values(CT values), standard deviation(SD), signal-to-noise ratio(SNR), and contrast-to-noise ratio(CNR) values of pulmonary artery from the main trunk to the subsegmental pulmonary artery between two groups were compared. The CT dose index volume(CTDI vol) and dose-length production (DLP) were recorded. Two readers evaluated the image quality using three-point method. The inter-reader agreement was performed by Kappa test. Results:The CT values of the pulmonary trunk and left pulmonary artery between two groups was not significantly different ( P>0.05). The CT values of the left upper lobe artery, segmental artery, and subsegmental artery in Group 1 were lower than those in Group 2 ( t=-2.13, -2.17, Z=-2.33, P<0.05). The SD values of pulmonary trunk and segmental artery in Group 1 were higher than those in Group 2 ( t=2.27, Z=-2.23, P<0.05). The SD values of left pulmonary artery, left upper lobe artery, and subsegmental artery between two groups were not significantly different ( P>0.05). The SNR and CNR values of main pulmonary trunk, left pulmonary artery, left superior lobar artery, and segmental artery in Group 2 were higher than those in Group 1 ( Z=-2.45, -2.57, -2.09, -3.58, P<0.05; Z =-2.33, -2.42, -2.07, -3.45, P<0.05), while these values of the subsegmental artery between two groups were not significantly different ( P>0.05). The two readers had good consistency in evaluating image quality (Kappa value>0.75, P<0.05). Conclusions:Spectral CT pulmonary angiography with 30 ml contrast agent would generate good quality images. However, the distal pulmonary artery would be poorly revealed when the diameter of main pulmonary artery more than 30 mm, especially in patients with suspected pulmonary hypertension.

13.
Tumor ; (12): 478-489, 2023.
Article Dans Chinois | WPRIM | ID: wpr-1030305

Résumé

Malignant tumors have become one of the major diseases that seriously endanger human life.Early diagnosis and treatment can greatly improve the survival rate of patients.Imaging examinations based on fluorescence imaging,CT,photoacoustic imaging,MRI,and PET have been widely studied and applied in the diagnosis of tumors.However,early cancerous tissue and normal tissue have similar imaging signals,which is difficult to be accurately distinguished by conventional imaging.With the development and cross integration of physics,materials science,biology,and medicine,nanomaterials have shown broad application prospects in the diagnosis and treatment of diseases due to their unique physical and chemical properties.The enhanced permeability and retention effect in solid tumor,and the easy modification properties of nanomaterials allow them to accurately"recognize"tumor and accelerate its enrichment at the tumor site;the imaging characteristics allow them to be used as contrast agents to enhance the signal intensity of the tumor site;their responsiveness mechanism can also allow them to distinguish normal from cancerous cells according to the microenvironment in tumor cells.In addition,multimodality imaging based on nanomaterials can compensate for the shortcomings of single modality imaging and achieve real-time and omnidirectional imaging of tumors.With multiple functions integrated,nanomaterials are expected to enhance the imaging signals of early cancerous sites,improve signal-to-noise ratio,and achieve early diagnosis of tumors.

14.
Journal of Biomedical Engineering ; (6): 1209-1216, 2023.
Article Dans Chinois | WPRIM | ID: wpr-1008952

Résumé

Correlation between nonlinear subharmonic scattering of ultrasound contrast agent microbubbles and ambient pressure is expected to be used for local brain tissue pressure monitoring. Although high-frequency ultrasound has achieved high-resolution imaging of intracranial microvessels, the research on high-frequency subharmonic scattering characteristics of microbubbles is insufficient at present, which restricts the research progress of estimating local brain tissue pressure based on high-frequency subharmonic scattering of microbubbles. Therefore, under the excitation of 10 MHz high-frequency ultrasound, the effects of different acoustic pressures and ambient pressures on the high-frequency subharmonic scattering characteristics of three different ultrasound contrast agents including SonoVue, Sonazoid and Huashengxian were investigated in this in vitro study. Results showed that the subharmonic scattering amplitudes of the three microbubbles increased with the increase of ambient pressure at the peak negative acoustic pressures of 696, 766 and 817 kPa, and there was a favorable linear correlation between subharmonic amplitude and ambient pressure. Under the above three acoustic pressures, the highest correlation coefficient of SonoVue was 0.948 ( P = 0.03), the highest sensitivity of pressure measurement was 0.248 dB/mm Hg and the minimum root mean square error (RMSE) was 2.64 mm Hg. Sonazoid's highest correlation coefficient was 0.982 ( P < 0.01), the highest sensitivity of pressure measurement was 0.052 dB/mm Hg and the minimum RMSE was 1.51 mm Hg. The highest correlation coefficient of Huashengxian was 0.969 ( P = 0.02), the highest sensitivity of pressure measurement was 0.098 dB/mm Hg and the minimum RMSE was 2.00 mm Hg. The above in vitro experimental results indicate that by selecting ultrasound contrast agent microbubbles and optimizing acoustic pressure, the correlation between high-frequency subharmonic scattering of microbubbles and ambient pressure can be improved, the sensitivity of pressure measurement can be upgraded, and the measurement error can be reduced to meet the clinical demand for local brain tissue pressure measurement, which provided an important experimental basis for subsequent research in vivo.


Sujets)
Produits de contraste , Microbulles , Échographie/méthodes
15.
Journal of Zhejiang University. Science. B ; (12): 985-997, 2023.
Article Dans Anglais | WPRIM | ID: wpr-1010577

Résumé

Sentinel lymph nodes (SLNs) are the first station of lymph nodes that extend from the breast tumor to the axillary lymphatic drainage. The pathological status of these LNs can predict that of the entire axillary lymph node. Therefore, the accurate identification of SLNs is necessary for sentinel lymph node biopsy (SLNB) to replace axillary lymph node dissection (ALND). The quality of life and prognosis of breast cancer patients are related to proper surgical treatment after the precise identification of SLNs. Some of the SLN tracers that have been identified include radioisotope, nano-carbon, indocyanine green (ICG), and methylene blue (MB). However, these tracers have certain limitations, such as pigmentation, radiation dangers, and the requirement for costly detection equipment. Ultrasound contrast agents (UCAs) have good specificity and sensitivity, and thus can compensate for some shortcomings of the mentioned tracers. This technique is also being applied to SLNB in patients with breast cancer, and can even provide an initial judgment on SLN status. Contrast-enhanced ultrasound (CEUS) has the advantages of high distinguishability, simple operation, no radiation harm, low cost, and accurate localization; therefore, it is expected to replace the traditional biopsy methods. In addition, it can significantly enhance the accuracy of SLN localization and shorten the operation time.


Sujets)
Humains , Femelle , Noeud lymphatique sentinelle/anatomopathologie , Tumeurs du sein/anatomopathologie , Qualité de vie , Biopsie de noeud lymphatique sentinelle/méthodes , Échographie/méthodes , Noeuds lymphatiques/chirurgie
16.
Ann Card Anaesth ; 2022 Mar; 25(1): 77-80
Article | IMSEAR | ID: sea-219181

Résumé

Surgical exclusion of the left atrial appendage (LAA) for stroke prevention in atrial fibrillation is frequently incomplete and remains to be optimized. We present a man who did not tolerate anticoagulant and failed percutaneous occlusion. Intraoperative echocardiographic contrast was used to assist surgical exclusion. Follow?up showed a persistent occlusion.

17.
Malaysian Journal of Medicine and Health Sciences ; : 66-70, 2022.
Article Dans Anglais | WPRIM | ID: wpr-980403

Résumé

@#Introduction: Computed tomography (CT) imaging has progressively developed from only structural imaging tool into hybrid diagnostic imaging such as PET-CT and SPECT to aid clinicians in diagnosis and treatment for cancer. Nowadays, researchers have found that CT might have a good prospect to become a molecular imaging modality. This research aim was to study the effects of gold nanoparticles (AuNPs) as contrast agent in computed tomography (CT) imaging. Methods: Samples of H2 O, hFOB, HeLa, and MCF-7 with and without AuNPs were scanned at 80, 100, 120, and 140 kVp to investigate the influence of tube potential settings towards CT enhancement in Hounsfield (HU) unit. Regions of interests (ROIs) were drawn and the CT values were compared. Results: The results show noticeable contrast enhancements of the samples incubated with AuNPs in CT images compared to the samples without AuNPs. hFOB, HeLa, and MCF-7 with AuNPs show contrast enhancement of 1.3 to 1.5 times greater than the cell lines samples without AuNPs. The outcomes also demonstrate that samples irradiated with 80 kVp yield improved CT values compared to other tube potential settings. Conclusion: The results obtained evidenced AuNPs have the potential to be a contrast agent for CT molecular imaging based on their ability in contrast enhancement.

18.
Chinese Journal of Radiological Health ; (6): 214-218, 2022.
Article Dans Chinois | WPRIM | ID: wpr-973483

Résumé

Objective To investigate the efficacy and safety of iopromide as a contrast agent in gynecological pelvic CT examination. Methods In a retrospective study, 78 patients hospitalized from February 2018 to January 2021 who underwent contrast-enhanced gynecological pelvic CT were involved to investigate the image quality, systemic and local tolerance, and adverse reactions. Results Among the 78 cases, 97.44% had excellent image quality and 97.44% showed tolerance. Mild adverse reactions such as nausea and vomiting, dizziness, headache, local pain, and facial flushing occurred in 8.98% cases. Moderate adverse reactions included severe vomiting with generalized rash (one case) and chest tightness and shortness of breath with generalized rash (one case), and both patients returned to normal after treatment. Conclusion The non-ionic contrast agent iopromide can be used to obtain good image quality in gynecological pelvic CT examination. The incidence of adverse reactions of iopromide is lower than ionic iodine contrast agents, but higher other non-ionic contrast agents.

19.
Organ Transplantation ; (6): 399-2022.
Article Dans Chinois | WPRIM | ID: wpr-923588

Résumé

Objective To investigate the clinical application value of contrast-enhanced ultrasound (CEUS) in hepatic artery thrombosis (HAT) after pediatric liver transplantation. Methods Clinical data of 126 pediatric recipients undergoing liver transplantation were retrospectively analyzed. The incidence of HAT after pediatric liver transplantation was summarized. Color Doppler ultrasound and CEUS manifestations of HAT were compared. Results According to color Doppler ultrasound, 17 cases were highly suspected with HAT. Nine cases were highly suspected with HAT by CEUS, who were subsequently confirmed by CT angiography (CTA) or surgery. CEUS manifestations of HAT showed that hepatic artery was not seen surrounding the portal vein during the arterial phase or even portal venous phase. Hepatocyte necrosis occurred in 4 patients with HAT, and no perfusion of intrahepatic contrast agent was observed on CEUS. Conclusions CEUS yields high clinical application value in the diagnosis of HAT after pediatric liver transplantation. It has significant advantages compared with traditional CTA, which could be widely applied in clinical practice.

20.
Chinese Journal of Biotechnology ; (12): 1589-1601, 2022.
Article Dans Chinois | WPRIM | ID: wpr-927803

Résumé

Gas vesicles are a unique class of gas-filled protein nanostructures which are commonly found in cyanobacteria and Halobacterium. The gas vesicles may scatter sound waves and generate harmonic signals, which enabled them to have the potential to become a novel ultrasound contrast agent. However, the current hypertonic cracking method for isolating gas vesicles contains tedious operational procedures and is of low yield, thus not suitable for large-scale application. To overcome these technical challenges, we developed a rapid and efficient method for isolating gas vesicles from Microcystis. The new H2O2-based method increased the yield by three times and shortened the operation time from 24 hours to 7 hours. The H2O2 method is not only suitable for isolation of gas vesicles from laboratory-cultured Microcystis, but also suitable for colonial Microcystis covered with gelatinous sheath. The gas vesicles isolated by H2O2 method showed good performance in ultrasound contrast imaging. In conclusion, this new method shows great potential for large-scale application due to its high efficiency and wide adaptability, and provides technical support for developing gas vesicles into a biosynthetic ultrasonic contrast agent.


Sujets)
Produits de contraste , Cyanobactéries , Peroxyde d'hydrogène , Microcystis , Protéines/composition chimique
SÉLECTION CITATIONS
Détails de la recherche