Spectral waveform analysis of blood flow velocity in the major arteries of six healthy, conscious immature micropigs was determined using Doppler ultrasonography. Doppler spectral tracings were recorded from the external iliac artery, femoral artery, and renal arcuate artery. Tracings were also taken from three parts of the common carotid artery and two parts of the abdominal aorta. Spectral Doppler parameters included peak systolic velocity, early diastolic velocity, peak systolic velocity-to-end diastolic velocity ratio, resistive index, and pulsatility index. In addition, the diameter of major arteries and indirect blood pressure were measured. These results from spectral Doppler analysis in major arteries may be useful as reference ranges in the future studies of vascular hemodynamics in immature micropigs.
Animals ; Arteries/physiology/*ultrasonography ; Blood Flow Velocity/physiology/*veterinary ; Male ; Swine ; Swine, Miniature ; Ultrasonography, Doppler, Color/*veterinary

Quantitative measurement of strain distribution of arterial vessel walls due to pulsatile blood flow within the vascular lumen is valuable for evaluating the elasticity of arterial wall and predicting the evolution of plaques. The present paper shows that the three-dimensional (3D) strain distribution are estimated through uni-directional coupling for 3D vessel and blood models reconstructed from intravascular ultrasound (IVUS) images with the computational. fluid dynamics (CFD) numerical simulation technique. The morphology of vessel wall and plaques as well as strain distribution can be visually displayed with pseudo-color coding.
Arteries ; diagnostic imaging ; physiology ; Elasticity ; Hemodynamics ; Humans ; Imaging, Three-Dimensional ; Pulsatile Flow ; Ultrasonography

BACKGROUNDThe offspring of women with gestational diabetes mellitus (GDM) are prone to macrosomia. However, birth weight is difficult to be correctly estimated by ultrasound because of fetal asymmetric growth characteristics. This study aimed to investigate the correlations between fetal hemodynamics, fetal growth indices in late pregnancy, and birth weight in GDM.

METHODSA total of 147 women with GDM and 124 normal controls (NC) were enrolled in this study. Fetal hemodynamic indices, including the systolic/diastolic ratio (S/D), resistance index (RI), pulsatility index (PI) of umbilical artery (UA), middle cerebral artery (MCA), and renal artery (RA), were collected. Fetal growth indices, including biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length, were also measured by ultrasound. Birth weight, newborn gender, and maternal clinical data were collected.

RESULTSThe independent samples t-test showed that BPD, HC, and AC were larger in GDM than in NC (P < 0.05). Fetal hemodynamic indices of the UA and MCA were lower (P < 0.05), but those of the RA were higher (P < 0.001) in GDM than in NC. Birth weight was higher in GDM than in NC (P < 0.001). Pearson's correlation analysis showed that hemodynamic indices of the UA were negatively correlated with birth weight, BPD, HC, and AC in both groups (P < 0.05). MCA (S/D, PI, and RI) was negatively correlated with birth weight, HC, and AC in GDM (r = -0.164, -0.206, -0.200, -0.226, -0.189, -0.179, -0.196, -0.177, and - 0.172, respectively, P< 0.05), but there were no correlations in NC (P > 0.05). RA (S/D, PI, and RI) was positively correlated with birth weight in GDM (r = 0.168, 0.207, and 0.184, respectively, P< 0.05), but there were no correlations in NC (P > 0.05).

CONCLUSIONFetal hemodynamic indices in late pregnancy might be helpful for estimating newborn birth weight in women with GDM.

Adult ; Birth Weight ; physiology ; Cerebral Arteries ; physiology ; Diabetes, Gestational ; physiopathology ; Female ; Fetal Development ; physiology ; Hemodynamics ; physiology ; Humans ; Infant, Newborn ; Male ; Pregnancy ; Pregnancy Outcome ; Renal Artery ; physiology ; Ultrasonography, Prenatal ; Umbilical Arteries ; physiology

Transcranial Doppler (TCD) was carried out to determine the resistive index (RI) values of normal canine cerebral arteries and its reproducibility and to evaluate the change of cerebral vascular resistance following diuretics administration. RI values of rostral cerebral artery (RCA) were compared between fontanelle window and temporal window. Normal ranges and reproducibility of the RI values were examined in the rostal cerebral artery (RCA) and caudal cerebral artery (CCA). And after administration of diuretics, TCD-derived RI values were measured at RCA and CCA. Cerebral vascular RI values of RCA and CCA were 0.55 +/- 0.05 and 0.55 +/- 0.03 in the normal dogs, respectively. There was no significant difference of RI between male and female; between fontanelle window and temporal window. Reproducibility of RI measurements between intraobserver and interobserver were relatively high. The RI of RCA and CCA were significantly increased 15 minutes after mannitol administration (p<0.01) and returned to baseline values by 30 minutes, but it did not significantly change after furosemide and saline administration. The results suggest that TCD is a useful test which can obtain reproducible results from any window and has the advantage of detecting subtle changes in cerebral vascular resistance.
Animals ; Cerebral Arteries/drug effects/*ultrasonography ; Diuretics/pharmacology ; Dogs/*physiology ; Feasibility Studies ; Furosemide/pharmacology ; Mannitol/pharmacology ; Reference Values ; Reproducibility of Results ; Ultrasonography, Doppler/*veterinary ; Vascular Resistance/drug effects/*physiology

Focus on the defects of the extraction method of velocity pulsated signals in the velocity spectrum image of pulsed Doppler ultrasounds (such as the limited data, great amount of work and low reproducibility), we combine the earlier research results and the basic rules of the velocity spectrum image, and employing the visual basics plateau, to design and develop a software to extract the velocity signals from the spectrum image automatically. Compare the mean velocity and RNS between the PIV and the PDU resulting from the method, the correlations are r = 0.93 and r = 0.78 respectively. The study reveals the software increase the amount of valid data, decrease the amount of work and increase reproducibility of the signals extraction. The method may be an effective way to analyse the velocity spectrum image of PDU in clinic.
Arteries ; diagnostic imaging ; Blood Flow Velocity ; physiology ; Humans ; Pulsatile Flow ; Signal Processing, Computer-Assisted ; Software ; Ultrasonography, Doppler, Pulsed ; methods

In order To evaluate whether the parameters of spiral artery blood flow, as measured by transvaginal color Doppler, may be used to assess endometrium receptivity prior to embryo transfer (ET), a retrospective study of 94 infertile women who had undergone ART treatments with different outcomes (pregnant or nonpregnant) was done. Subendometrial blood flow was evaluated. The resistance index (RI), systolic/diastolic ratio (S/D) and pulsatility index (PI) were significantly lower in those who achieved pregnancy as compared with those who did not: 0.62+/-0.04 vs 0.68+/-0.04 (P<0.001), 2.66+/-0.33 vs 3.19+/-0.39 (P<0.01) and 1.15+/-0.17 vs 1.34+/-0.22 (P<0. 05), respectively. Furthermore, when RI>0. 2, PI>1. , and S/D>3. , no pregnancy occurred. These data suggest that the parameters of spiral artery blood flow could be used as a new assay in predicting endometrial receptivity before ET.
Arteries/ultrasonography ; Embryo Implantation/*physiology ; Embryo Transfer ; Endometrium/*blood supply ; Endometrium/*physiology ; Endometrium/ultrasonography ; Fertilization in Vitro ; Infertility, Female/physiopathology ; Regional Blood Flow ; Sperm Injections, Intracytoplasmic ; Treatment Outcome ; Ultrasonography, Doppler, Color

In this study, we characterized cerebral blood flow changes by assessment of blood flow parameters in neck arteries using carotid duplex ultrasonography and predictive factors for these hemodynamic changes. Hemodynamic variables were measured before and during hemodialysis in 81 patients with an arteriovenous access in their arm. Hemodialysis produced significant lowering in peak systolic velocity and flow volume of neck arteries and calculated total cerebral blood flow (1,221.9 ± 344.9 [before hemodialysis] vs. 1,085.8 ± 319.2 [during hemodialysis], P < 0.001). Effects were greater in vessels on the same side as the arteriovenous access and these changes were influenced by arteriovenous access flow during hemodialysis, both in the CCA (r = -0.277, P = 0.015) and the VA (r = -0.239, P = 0.034). The change of total cerebral blood flow during hemodialysis was independently related with age, presence of diabetes, and systemic blood pressure.
Aged ; Carotid Arteries/diagnostic imaging ; Cerebrovascular Circulation/*physiology ; Dizziness/etiology ; Female ; Hemodynamics/*physiology ; Humans ; Kidney Failure, Chronic/*physiopathology ; Male ; Middle Aged ; Renal Dialysis ; Risk Factors ; Ultrasonography, Doppler, Duplex

In this study, we characterized cerebral blood flow changes by assessment of blood flow parameters in neck arteries using carotid duplex ultrasonography and predictive factors for these hemodynamic changes. Hemodynamic variables were measured before and during hemodialysis in 81 patients with an arteriovenous access in their arm. Hemodialysis produced significant lowering in peak systolic velocity and flow volume of neck arteries and calculated total cerebral blood flow (1,221.9 ± 344.9 [before hemodialysis] vs. 1,085.8 ± 319.2 [during hemodialysis], P < 0.001). Effects were greater in vessels on the same side as the arteriovenous access and these changes were influenced by arteriovenous access flow during hemodialysis, both in the CCA (r = -0.277, P = 0.015) and the VA (r = -0.239, P = 0.034). The change of total cerebral blood flow during hemodialysis was independently related with age, presence of diabetes, and systemic blood pressure.
Aged ; Carotid Arteries/diagnostic imaging ; Cerebrovascular Circulation/*physiology ; Dizziness/etiology ; Female ; Hemodynamics/*physiology ; Humans ; Kidney Failure, Chronic/*physiopathology ; Male ; Middle Aged ; Renal Dialysis ; Risk Factors ; Ultrasonography, Doppler, Duplex

OBJECTIVETo evaluate the effect of blood pressure on vascular endothelial function using echo-tracking (ET) technology.

METHODSThirty hypertensive (HP) patients, 30 subjects with high normal blood pressure (HN), and 30 normotensive control (NC) subjects were enrolled in this study. For each subject, conventional two-dimensional ultrasound was performed to measure the intima-media thickness (IMT), and an ET system was utilized to assess the carotid elasticity (Ep, β, AC, AI, and PWVβ).

RESULTSAs the blood pressure increased, IMT, Ep, β, AI, and PWVβ values all increased and AC value decreased. Before excluding the confounding factors, the difference in IMT, Ep, β, AC, AI, and PWVβ values were significant between the 3 groups. After excluding the confounding factors, only PWVβ value was significantly different between HN group and NC group; but between HP and NC group and between HP and HN group, the other parameters still showed significant differences. Systolic blood pressure had significant influences on IMT, Ep, AC, AI, and PWVβ values, diastolic blood pressure significantly affected AI value, and pulse pressure significantly affected Ep and β values.

CONCLUSIONHigh normal blood pressure has no obvious effects on vascular function, and blood pressure is an independent risk factor of vascular endothelial dysfunction only in the stage of early hypertention. In early atherosclerosis, systolic blood pressure is the most significant factors affecting vascular endothelial function, followed by pulse pressure and diastolic blood pressure.

Adult ; Atherosclerosis ; physiopathology ; Blood Pressure ; physiology ; Carotid Arteries ; diagnostic imaging ; Elasticity ; Endothelium, Vascular ; physiopathology ; Female ; Humans ; Hypertension ; complications ; physiopathology ; Male ; Middle Aged ; Ultrasonography

OBJECTIVETo study the rates of receiving doppler signal, flow velocity of cerebral artery and the relationship between flow velocity,age and gender in normal adults in China.

METHODSA total of 1500 normal residents at the community level in Guangdong province were examined, using transcranial doppler. Data was gathered and analyzed.

RESULTSWith the increase of age, the rate of receiving signal in cerebral artery gradually decreased. Difference between males and females was noticed. Mean velocity of cerebral artery decreased in both genders but the velocity was faster in females than in males and the pulsate index increased without difference.

CONCLUSIONThe rates of receiving signal and the flow velocity of cerebral artery were related to age and gender and the findings from this study offered criterion for clinical transcranial doppler.

Aged ; Aging ; Cerebral Arteries ; diagnostic imaging ; physiology ; Female ; Hemodynamics ; Humans ; Male ; Middle Aged ; Sex Characteristics ; Ultrasonography, Doppler, Transcranial ; statistics & numerical data