scholarly journals Computed Tomography Images under Optimized Iterative Reconstruction Algorithm for Blood Flow Field Characteristics in Cerebral Aneurysm before and after Stent Implantation

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Changkun Lin ◽  
Chuizhi Huang ◽  
Yan Chen ◽  
Nailong Jia ◽  
Jinghui Huang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Cerebral Aneurysm ◽  
Blood Flow Velocity ◽  
Stent Implantation ◽  
Shear Force ◽  
Wall Pressure ◽  
Before And After ◽  
Wall Deformation ◽  
The Mean

In order to study the analysis of blood flow field characteristics of cerebral aneurysm patients before and after stent implantation based on CT images of ART-TV-PI, this paper firstly improved the ART-TV algorithm of algebraic reconstruction technology and obtained the ART-TV-PI algorithm, which was compared with the ART algorithm and ART-TV algorithm. Afterwards, the CT images based on the above three algorithms were used to analyze the changes of average blood flow velocity, average wall pressure, average wall deformation, and average shear force of 48 cases of cerebral aneurysm patients before and after stent implantation. The results showed that the mean square error and radiation dose of the ART-TV-PI algorithm (0.00012 and 1.65 mSv) were significantly lower than those of the ART algorithm (0.0031 and 3.09 mSv) and ART-TV algorithm (0.00082 and 2.52 mSv), and the signal-to-noise ratio (23.94) was significantly higher than those of the ART algorithm (11.32) and ART-TV algorithm (16.89), with statistically significant differences ( P < 0.05 ). The differences of mean blood flow velocity, mean wall pressure, mean wall deformation, and mean shear force before and after stent implantation among the three algorithms were not statistically significant ( P > 0.05 ), and the average index of the ART-TV-PI algorithm was the highest. Under the ART-TV-PI algorithm, the mean blood flow velocity (0.044 m/s), the mean wall pressure (71.7 Pa), the mean wall deformation (0.057 mm), and the mean shear force (889 Pa) after stent implantation were significantly lower than those before stent implantation (0.165 m/s, 160.8 Pa, 0.721 mm, and 2690 Pa), with average decreases of 73.3%, 55.4%, 92.1%, and 64.3%, respectively, and the differences were statistically significant ( P < 0.05 ). In conclusion, the images reconstructed by the ART-TV-PI algorithm have good image quality, which provides great convenience for surgical examination of cerebral aneurysm stent implantation and is worthy of clinical application.

The Effect Of Hand Exercise On Grip Strength, Forearm Circumference, Diameter Of Vein, Blood Flow Volume And Velocity In Patient Who Underwent Arteriovenous Fistula Surgery And On Routine Haemodialysis

2019 ◽  
Vol 1 (1) ◽  
pp. 14
Author(s):  
Jufri Febriyanto Poetra ◽  
Andriati Andriati ◽  
Dewi Poerwandari
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Grip Strength ◽  
Blood Flow Velocity ◽  
Intervention Group ◽  
Cephalic Vein ◽  
Flow Volume ◽  
Blood Flow Volume ◽  
Before And After ◽  
Vein Diameter

Background: The arteriovenous fistula (AVF) is considered the gold standard for haemodialysis access. The fistula needs time to be mature and functional. Maturation process respond to increases in blood flow. Exercise stimulates vascular response as such an increase of blood flow. Aims: The purpose of this study is to determine the effectiveness of hand exercise in increasing grip muscle performance, and its effectiveness in supporting maturation process of fistula.Methods: This experimental study done on 14 patients underwent AVF procedure and on routine haemodialysis. Randomly, 7 subjects allocated on intervention group by doing hand exercise using hand gripper (HG) for 5 weeks, and 7 subjects allocated as control group without introduction to hand gripper. Grip strength and forearm circumference were measured before and after 5 weeks of intervention. Cephalic vein diameter, blood flow volume and velocity were measured using Doppler USG on AVF arm. The comparison of intervention effects between groups treatment were analyzed based on effect size (ES).Results: Grip strength and forearm circumference increased significantly on intervention group before and after exercise intervention (p<.001, p=.001). Cephalic vein diameter and blood flow were increased significantly in this group (p=.027, p=.033). Blood flow velocity showed no difference before and after exercise intervention. Significant results were found on increased grip strength, forearm circumference, cephalic vein diameter and blood flow volume in comparison between treated group (p<.001; ES=.94, p<.001; ES=.4, p=.046; ES=.84, p=.035; ES=.53). There were no differences on cephalic vein blood flow velocity between these two groups.Conclusion: Five weeks hand exercise were effective to increase grip strength, forearm circumference, cephalic vein diameter and blood flow volume, nonetheless ineffective to increase cephalic vein blood flow velocity in post AVF procedure patients with routine haemodialysis.

Microvessel mean transit time and blood flow velocity of sulfhemoglobin-RBC

1980 ◽  
Vol 238 (5) ◽  
pp. H745-H749 ◽  
Author(s):  
C. H. Baker ◽  
E. T. Sutton ◽  
D. L. Davis
Keyword(s):  
Blood Flow ◽  
Red Blood Cells ◽  
Flow Velocity ◽  
Transit Time ◽  
Blood Flow Velocity ◽  
Blood Cells ◽  
Optical Measurement ◽  
Mean Transit Time ◽  
The Mean ◽  
Concentration Curves

An indicator dilution technique is described for obtaining time-concentration curves subsequent to bolus injections of sulfhemoglobin red blood cells (SH-RBC), which have a deep greenish-brown color (absorption peak 620 nm vs. 542 and 564 nm for normal red cells). The series- and parallel-coupled microvessels of cat mesentery were studied. This is accomplished by means of video microscopy with a two-window intensity-sensitive video sampler system. The relationship between SH-RBC concentration in blood and optical measurement is linear. Blood flow velocities were calculated from the difference in mean transit times between two points along a vessel. When this technique is used in association with the previously reported method for determining time-concentration curves for the plasma indicator FITC-dextran the mean transit time (t) for red blood cells was less than for plasma in arterioles. The reproducibility of t and flow velocity for both SH-RBC and FITC-dextran from successive injections were reported. The mean transit time ratio of arteriolar SH-RBC to FITC-dextran averages 0.89. Blood flow velocity calculated from SH-RBC is greater than that calculated from FITC-dextran in these same arterioles. The ratio of the velocities averages 1.29.

scholarly journals Effects of LI11 Acupuncture on CO2 reactivity in the anterior and middle cerebral arteries during hyperventilation-induced hypocapnia in normal subjects: A before and after study

2021 ◽  
Vol 42 (4) ◽  
pp. 174-185
Author(s):  
Gyeong-muk Kim ◽  
Woo-Sang Jung ◽  
Seungwon Kwon ◽  
Chul Jin ◽  
Seung-Yeon Cho ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Velocity ◽  
Cerebral Artery ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Cerebral Arteries ◽  
Co2 Reactivity ◽  
Middle Cerebral Arteries ◽  
Before And After

Objectives: The LI11 (Quchi) acupuncture point has always been included in the Seven acupoints for stroke; however, additional LI11 acupuncture research is needed. In this study, the effect of LI11 acupuncture on cerebral blood flow of the anterior cerebral arteries (ACA) and middle cerebral arteries (MCA) was investigated.Method: This study included 10 healthy young male subjects. Cerebral blood flow velocity and cerebrovascular reactivity were measured using transcranial Doppler sonography. Changes in hyperventilation-induced carbon dioxide (CO2) reactivity and modified ACA and MCA blood flow velocity at 40 mmHg (CV40), blood pressure, and heart rate were observed before and after LI11 acupuncture treatment.Results: A statistically significant increase in contralateral anterior cerebral artery CO2 reactivity (p=0.036) and decrease in contralateral middle cerebral artery CV40 (p=0.047) were observed. No significant difference in mean blood pressure was shown. A statistically significant increase in heart rate occurred after LI11 acupuncture; however, it was not clinically significant as there were negligible changes in the heart rhythm.Conclusions: LI11 acupuncture treatment could improve cerebral blood flow velocity. These results might be explained by regulating endothelium-dependent vessel dilation in the anterior cerebral artery region.Trial registration: This trial has been registered with Clinical Research Information Service, a service of the Korea Centers for Disease Control and Prevention: KCT0004494 (retrospectively registered). https://cris.nih.go.kr/cris/search/search_result_st01.jsp?seq=15359

scholarly journals Introduction of precordial Doppler ultrasound to confirm correct peripheral venous access during general anesthesia in children: A preliminary study

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248999
Author(s):  
Taiki Kojima ◽  
Kana Kitamura ◽  
Shogo Ichiyanagi ◽  
Fumio Watanabe ◽  
Yukiko Yamaguchi ◽  
...  
Keyword(s):  
Blood Flow ◽  
General Anesthesia ◽  
Flow Velocity ◽  
Doppler Ultrasound ◽  
Blood Flow Velocity ◽  
Likelihood Ratios ◽  
Peripheral Venous Access ◽  
Before And After ◽  
Preliminary Study ◽  
Sensitivity Specificity

Background Delayed identification of infiltration and dysfunction of peripheral intravenous (PIV) access can lead to serious consequences during general anesthesia in children. This preliminary study aimed to describe the application of precordial Doppler ultrasound during general anesthesia in children to detect and confirm the correct PIV access and to evaluate the accuracy of this method. Methods This was a single-center, preliminary study that was conducted in children (<18 years) who were scheduled for elective surgeries between October 2019 and March 2020. Rater anesthesiologists judged the change in precordial Doppler sound (S test) before and after injection of 0.5 mL/kg of normal saline (NS) via PIV. Blood flow velocity before and after NS injection was recorded, and multiple cutoff points were set to analyze the accuracy of detecting the infiltration and dysfunction of PIV catheter (V test). Results The total incidence of peripheral infiltration and dysfunction of PIV catheter was 7/512 (1.4%). In the S test, the sensitivity, specificity, positive and negative likelihood ratios, and area under the receiver-operating characteristic curves (AUCs) were 5/7 (71.4%; 95% confidence interval [CI], 29.0%–96.3%), 490/505 (97.0%; 95% CI, 95.1%–98.3%), 24.0, 0.29, and 0.84, respectively. The V test showed that the reasonable threshold of blood flow velocity change was 1.0 m/s, with sensitivity, specificity, positive and negative likelihood ratios, and AUC of 4/7 (57.1%; 95% CI, 18.4%–90.1%), 489/505 (96.8%; 95% CI, 94.9%–98.2%), 18.0 and 0.44, and 0.84, respectively. Conclusions This preliminary study demonstrated that precordial Doppler ultrasound is a feasible, easy-to-use, and noninvasive technique with good accuracy to confirm the correct PIV access during general anesthesia in children. However, its accuracy requires further evaluation.

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