scholarly journals Superb Microvascular Imaging as a Novel Tool for the Assessment of Blood Flow Velocity in Patients with Systemic Sclerosis: A Single-Center Feasibility Study

2021 ◽  
Author(s):  
Jan-Gerd Rademacher ◽  
Rosa Marie Buschfort ◽  
Thomas Asendorf ◽  
Viktor Korendovych ◽  
Björn Tampe ◽  
...  
Keyword(s):  
Blood Flow ◽  
Systemic Sclerosis ◽  
Flow Velocity ◽  
Feasibility Study ◽  
Imaging Techniques ◽  
High Specificity ◽  
Flow Quantification ◽  
Single Center ◽  
Flow Measurements ◽  
Test Characteristics

Systemic sclerosis is an autoimmune disease characterized by organ fibrosis and vasculopathy. Almost all patients suffer from Raynaud’s phenomenon (RP). Currently, several imaging techniques are available; nailfold video capillaroscopy (NVC) is the most widely available, but flow quantification is not possible with NVC. Novel imaging techniques are of interest in this population. We performed a single-center feasibility study using Micro Vascular Imaging (MVI) as a novel imaging technique for flow quantification of small fingertip vessels. We compared a group of 20 healthy controls (HCs) with 20 Systemic Sclerosis (SSc) patients. In HCs, flow measurements assessed with MVI were statistically significantly higher in individual fingers and combined for all fingers (p<0.0001). As a cut-off value to discriminate HCs from SSc, a peak systolic (PS) flow velocity of <6.9 cm/s and an end-diastolic (ED) flow velocity of <2.68 cm/s was determined. Test characteristics for PS flow velocity showed moderate sensitivity (0.69, 95% CI 0.58-0.78) but high specificity (0.88, 95% CI 0.79-0.93). Similar test characteristics for ED flow velocity were obtained. The optimal cut-off point was estimated at <2.68 cm/s, sensitivity was moderate (0.65, 95% CI 0.53-0.75), specificity was 0.80 (95% CI 0.70-0.87). Here, we present the first study on the use of MVI to assess blood flow in the fingertips with high specificity in SSc patients. Future studies need to investigate correlations with the risk for organ complications, such as digital ulcers or pulmonary arterial hypertension.

Effects of neuropeptides and vasoactive substances on microcirculation of the callus after tibial osteotomy in rabbits

2009 ◽  
Vol 57 (3) ◽  
pp. 427-439
Author(s):  
Zsolt Vendégh ◽  
András Melly ◽  
Balázs Tóth ◽  
Konrad Wolf ◽  
Tamás Farkas ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Perfusion Pressure ◽  
Tibial Osteotomy ◽  
Peripheral Vascular ◽  
Flow Measurements ◽  
Vasoactive Substances ◽  
Blood Flow Measurements

Previous studies have demonstrated a dynamic ingrowth of vessels into the developing callus. In this study, maturation and development of the regulation of microcirculation were followed in the callus of rabbits. In the first series, the effects of vasoactive substances on blood flow velocity, perfusion pressure, duration of effects and peripheral vascular resistance of the bone marrow in the femur and tibia were compared. In the second series, the same parameters were measured in the femur and in the developing callus 10 and 15 days following gap osteotomy of the tibia. There were no significant differences between the microcirculatory reactions of the intact femur and tibia. Basal blood flow could be verified in the callus on the 10th postoperative day. No vascular reactions could be elicited. Basal blood flow velocity was higher on the 15th day, when compared to the measurements on the 10th day. The substances elicited statistically significant differences in flow velocity, resistance and 50% recovery time in the callus on the 15th day. Blood flow reactions of the ipsilateral femoral and tibial bone marrow are identical, thus the femur can serve as a reference site for blood flow measurements in the callus. Regulation and maturation of callus microcirculation develop rapidly between the 10th and 15th days.

Abstract 12827: Alterations in Flow Patterns and Wall Shear Stress in Pulmonary Artery Visualized With Phase-resolved 3D Cine Phase Contrast MRI (4D-Flow) in Patients With Systemic Sclerosis

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Kenichiro Suwa ◽  
Tomoaki Sakakibara ◽  
Takeji Saitoh ◽  
Yutaro Kaneko ◽  
Makoto Sano ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Systemic Sclerosis ◽  
Wall Shear Stress ◽  
Flow Velocity ◽  
Flow Patterns ◽  
Helical Flow ◽  
4D Flow ◽  
Control Subjects ◽  
Diastolic Phase

Background: The pulmonary circulation is impaired in patients with systemic sclerosis (SSc), and the analysis of pulmonary arterial (PA) blood flow has a great clinical significance. Using 4D-Flow, we studied the changes in PA blood flow velocity vectors and wall shear stress (WSS) in SSc patients. Methods: Twenty one SSc patients (M/F: 1/20, 56±15 years) including 2 PA hypertension, and 7 control subjects underwent 4D-Flow. We set planes traversing the main and first branches of PA, and the velocity vectors were post-processed to delineate streamline images. WSS images were obtained at the surface of PA. The plane-averaged flow velocity at the main PA, surface-averaged WSS, and oscillatory shear index (OSI), the %WSS acting in other directions from the mean WSS vector during a cardiac cycle, were compared. Results: (1) The PA flow showed laminar flow pattern at the early systolic phase in all patients and subjects, but diffuse helical flow in 11 SSc patients (right upper), focal helical flow in 6 SSc patients and 2 control subjects at the late systolic to early diastolic phase. The other 4 SSc patients and 5 control subjects had continuous laminal flow (left upper). (2) The peak systolic PA flow velocity did not differ between them, whereas the diastolic flow velocity was significantly greater in SSc patients (minimum velocity; 26±24 mm/sec vs. -26±52 mm/sec, p<0.01). (3) WSS at the peak systolic flow velocity was significantly lower and spatially heterogeneous in SSc patients (lower figs; 1.1±0.2 Pa vs. 1.4±0.4 Pa, p<0.01). Both WSS at the diastolic phase and OSI were significantly greater in SSc patients (minimum WSS; 0.28±0.07 Pa vs. 0.19±0.04 Pa, p<0.01, OSI; 0.14±0.03% vs. 0.09±0.02%, p<0.05). Conclusions: The 4D-Flow disclosed the different PA flow patterns between SSc patients and control subjects. In SSc patients, WSS at the PA was generally decreased and varied spatially and temporally. 4D-Flow has a potential to detect the subclinical changes of PA flow dynamics in SSc.

scholarly journals Time-domain diffuse correlation spectroscopy (TD-DCS) for noninvasive, depth-dependent blood flow quantification in human tissue in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeed Samaei ◽  
Piotr Sawosz ◽  
Michał Kacprzak ◽  
Żanna Pastuszak ◽  
Dawid Borycki ◽  
...  
Keyword(s):  
Blood Flow ◽  
Time Domain ◽  
Human Tissue ◽  
Correlation Spectroscopy ◽  
Flow Quantification ◽  
Flow Index ◽  
Flow Measurements ◽  
Diffuse Correlation Spectroscopy ◽  
Sensing Applications

AbstractMonitoring of human tissue hemodynamics is invaluable in clinics as the proper blood flow regulates cellular-level metabolism. Time-domain diffuse correlation spectroscopy (TD-DCS) enables noninvasive blood flow measurements by analyzing temporal intensity fluctuations of the scattered light. With time-of-flight (TOF) resolution, TD-DCS should decompose the blood flow at different sample depths. For example, in the human head, it allows us to distinguish blood flows in the scalp, skull, or cortex. However, the tissues are typically polydisperse. So photons with a similar TOF can be scattered from structures that move at different speeds. Here, we introduce a novel approach that takes this problem into account and allows us to quantify the TOF-resolved blood flow of human tissue accurately. We apply this approach to monitor the blood flow index in the human forearm in vivo during the cuff occlusion challenge. We detect depth-dependent reactive hyperemia. Finally, we applied a controllable pressure to the human forehead in vivo to demonstrate that our approach can separate superficial from the deep blood flow. Our results can be beneficial for neuroimaging sensing applications that require short interoptode separation.

Brain Blood Flow

PEDIATRICS ◽  
1984 ◽  
Vol 74 (2) ◽  
pp. 317-317
Author(s):  
NANCY B. HANSEN ◽  
BARBARA S. STONESTREET ◽  
TED S. ROSENKRANTZ ◽  
WILLIAM OH
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Brain Blood Flow ◽  
Flow Measurements ◽  
Correlation Data ◽  
Microsphere Method ◽  
Blood Flow Measurements

In Reply.— We appreciate Rosenfeld's comments on our paper on the validity of Doppler measurements of anterior cerebral artery blood flow velocity. Rosenfeld raised two points regarding the validity of our correlation data between Doppler technique and cerebral blood flow measurements by the microsphere method. (1) Rosenfeld correctly pointed out that when we relate brain blood flow to any of the parameters obtained in the measurement of cerebral blood flow velocity, there is considerable variation in the values observed.

scholarly journals Functional ultrasound speckle decorrelation-based velocimetry of the brain

2019 ◽  
Author(s):  
Jianbo Tang ◽  
Dmitry D. Postnov ◽  
Kivilcim Kilic ◽  
Sefik Evren Erdener ◽  
Blaire Lee ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
High Speed ◽  
Imaging Techniques ◽  
Color Doppler ◽  
Power Doppler ◽  
Frequency Noise ◽  
Velocity Changes

AbstractA high-speed, contrast free, quantitative ultrasound velocimetry (vUS) for blood flow velocity imaging throughout the rodent brain is developed based on the normalized first order temporal autocorrelation function of the ultrasound field signal. vUS is able to quantify blood flow velocity in both transverse and axial directions, and is validated with numerical simulation, phantom experiments, and in vivo measurements. The functional imaging ability of vUS is demonstrated by monitoring blood flow velocity changes during whisker stimulation in awake mice. Compared to existing power Doppler and color Doppler-based functional ultrasound imaging techniques, vUS shows quantitative accuracy in estimating both axial and transverse flow speeds and resistance to acoustic attenuation and high frequency noise.

scholarly journals Unilateral fetal-type circle of Willis anatomy causes right–left asymmetry in cerebral blood flow with pseudo-continuous arterial spin labeling: A limitation of arterial spin labeling-based cerebral blood flow measurements?

2016 ◽  
Vol 36 (9) ◽  
pp. 1570-1578 ◽  
Author(s):  
Jurriaan JH Barkeij Wolf ◽  
Jessica C Foster-Dingley ◽  
Justine EF Moonen ◽  
Matthias JP van Osch ◽  
Anton JM de Craen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Velocity ◽  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Circle Of Willis ◽  
Flow Measurements ◽  
Blood Flow Signal ◽  
Continuous Arterial Spin Labeling ◽  
Blood Flow Measurements

The accuracy of cerebral blood flow measurements using pseudo-continuous arterial spin labeling can be affected by vascular factors other than cerebral blood flow, such as flow velocity and arterial transit time. We aimed to elucidate the effects of common variations in vascular anatomy of the circle of Willis on pseudo-continuous arterial spin labeling signal. In addition, we investigated whether possible differences in pseudo-continuous arterial spin labeling signal could be mediated by differences in flow velocities. Two hundred and three elderly participants underwent magnetic resonance angiography of the circle of Willis and pseudo-continuous arterial spin labeling scans. Mean pseudo-continuous arterial spin labeling-cerebral blood flow signal was calculated for the gray matter of the main cerebral flow territories. Mean cerebellar gray matter pseudo-continuous arterial spin labeling-cerebral blood flow was significantly lower in subjects having a posterior fetal circle of Willis variant with an absent P1 segment. The posterior fetal circle of Willis variants also showed a significantly higher pseudo-continuous arterial spin labeling-cerebral blood flow signal in the ipsilateral flow territory of the posterior cerebral artery. Flow velocity in the basilar artery was significantly lower in these posterior fetal circle of Willis variants. This study indicates that pseudo-continuous arterial spin labeling measurements underestimate cerebral blood flow in the posterior flow territories and cerebellum of subjects with a highly prevalent variation in circle of Willis morphology. Additionally, our data suggest that this effect is mediated by concomitant differences in flow velocity between the supplying arteries.

Sign in / Sign up

Export Citation Format

Share Document