The Feasibility of Using Millimeter Wave Heating for Non-Invasive Measurement of Skin Blood Flow in Humans

2013 ◽  
Author(s):  
D. A. Nelson ◽  
S. J. Leavesley ◽  
G. T. Hamlin ◽  
J. M. Downey
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Limb Ischemia ◽  
Arterial Disease ◽  
Diagnosis And Management ◽  
Non Invasive ◽  
Wave Heating ◽  
Peripheral Arterial ◽  
Clinical Conditions ◽  
Revascularization Surgery

A non-contacting method to measure skin blood flow (SkBF) in human extremities that is both simple and accurate could be invaluable in the diagnosis and management of several clinical conditions. For excample, measurement of SkBF in the digit(s) can be useful in the diagnosis and management of Peripheral Arterial Disease, often associated with Type 2 diabetes (Petrofsky et al., 2008). Skin blood flow in the foot can be an indicator of successful infrainguinal revascularization surgery in patients with lower limb ischemia (Saucy et al., 2006; Yamada et al., 2008). Assessment of peripheral perfusion can be useful in determining hemodynamic stability of patients suffering from acute circulatory shock (Lima et al., 2009) or circulatory failure (Lima and Bakker, 2005).

scholarly journals 2D-Perfusion Angiography Using Carbon Dioxide (CO2): A Feasible Tool to Monitor Immediate Treatment Response to Endovascular Therapy of Peripheral Arterial Disease?

2020 ◽  
Author(s):  
Cornelia L. A. Dewald ◽  
Lena S. Becker ◽  
Sabine K. Maschke ◽  
Timo C. Meine ◽  
Bernhard C. Meyer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peripheral Arterial Disease ◽  
Contrast Agent ◽  
Treatment Response ◽  
Endovascular Therapy ◽  
Negative Contrast ◽  
Limb Ischemia ◽  
Arterial Disease ◽  
Iodinated Contrast ◽  
Peripheral Arterial

Abstract Purpose Patients with peripheral arterial disease (PAD) or critical limb ischemia (CLI) require revascularization. Traditionally, endovascular therapy (EVT) is performed with iodinated contrast agent (ICM), which can provoke potential deterioration in renal function. CO2 is a safe negative contrast agent to guide vascular procedures, but interpretation of CO2 angiography is challenging. Changes in blood flow following iodine-aided EVT are assessable with 2D-perfusion angiography (2D-PA). The aim of this study was to evaluate 2D-PA as a tool to monitor blood flow changes during CO2-aided EVT. Material and Methods 2D-PA was performed before and after ten EVTs (nine stents; one endoprosthesis; 10/2012–02/2020) in nine patients (six men; 65 ± 10y) with Fontaine stage IIb (n = 8) and IV (n = 1). A reference ROI (ROIINFLOW) was placed in the artery before the targeted obstruction and a target ROI (ROIOUTFLOW) distally. Corresponding ROIs were used pre- and post-EVT. Time to peak (TTP), peak density (PD) and area under the curve (AUC) were computed. The reference/target ROI ratios (TTPOUTFLOW/TTPINFLOW; PDOUTFLOW/PDINFLOW; AUCOUTFLOW/AUCINFLOW) were calculated. Results 2D-PA was technically feasible in all cases. A significant increase of 82% in PDOUTFLOW/PDINFLOW (0.44 ± 0.4 to 0.8 ± 0.63; p = 0.002) and of 132% in AUCOUTFLOW/AUCINFLOW (0.34 ± 0.22 to 0.79 ± 0.59; p = 0.002) was seen. A trend for a decrease in TTPOUTFLOW/TTPINFLOW was observed (− 24%; 5.57 ± 3.66 s–4.25 ± 1.64 s; p = 0.6). Conclusion The presented 2D-PA technique facilitates the assessment of arterial flow in CO2-aided EVTs and has the potential to simplify the assessment of immediate treatment response.

scholarly journals Quantitative optical imaging of vascular response in vivo in a model of peripheral arterial disease

2013 ◽  
Vol 305 (8) ◽  
pp. H1168-H1180 ◽  
Author(s):  
Kristin M. Poole ◽  
Jason M. Tucker-Schwartz ◽  
Wesley W. Sit ◽  
Alex J. Walsh ◽  
Craig L. Duvall ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peripheral Arterial Disease ◽  
Optical Imaging ◽  
Hyperspectral Imaging ◽  
Temporal Dynamics ◽  
Arterial Disease ◽  
Sensor Data ◽  
Morphological Data ◽  
Non Invasive ◽  
Peripheral Arterial

The mouse hind limb ischemia (HLI) model is well established for studying collateral vessel formation and testing therapies for peripheral arterial disease, but there is a lack of quantitative techniques for intravitally analyzing blood vessel structure and function. To address this need, non-invasive, quantitative optical imaging techniques were developed to assess the time-course of recovery in the mouse HLI model. Hyperspectral imaging and optical coherence tomography (OCT) were used to non-invasively image hemoglobin oxygen saturation and microvessel morphology plus blood flow, respectively, in the anesthetized mouse after induction of HLI. Hyperspectral imaging detected significant increases in hemoglobin saturation in the ischemic paw as early as 3 days after femoral artery ligation ( P < 0.01), and significant increases in distal blood flow were first detected with OCT 14 days postsurgery ( P < 0.01). Intravital OCT images of the adductor muscle vasculature revealed corkscrew collateral vessels characteristic of the arteriogenic response to HLI. The hyperspectral imaging and OCT data significantly correlated with each other and with laser Doppler perfusion imaging (LDPI) and tissue oxygenation sensor data ( P < 0.01). However, OCT measurements acquired depth-resolved information and revealed more sustained flow deficits following surgery that may be masked by more superficial measurements (LDPI, hyperspectral imaging). Therefore, intravital OCT may provide a robust biomarker for the late stages of ischemic limb recovery. This work validates non-invasive acquisition of both functional and morphological data with hyperspectral imaging and OCT. Together, these techniques provide cardiovascular researchers an unprecedented and comprehensive view of the temporal dynamics of HLI recovery in living mice.

Abstract 216: Angiogenic Factor AGGF1 Promotes Therapeutic Angiogenesis in a Mouse Limb Ischemia Model for Peripheral Arterial Disease

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Qing Wang ◽  
Qiulun Lu ◽  
Xin Tu ◽  
Qing Wang
Keyword(s):  
Blood Flow ◽  
Limb Ischemia ◽  
Arterial Disease ◽  
Therapeutic Angiogenesis ◽  
Angiogenic Factor ◽  
Control Group ◽  
Hindlimb Ischemia ◽  
Empty Vector ◽  
Muscle Tissues ◽  
Peripheral Arterial

Introduction: Peripheral arterial disease (PAD) is caused by atherosclerosis. PAD is a common disease that affects 12% of the adult population and causes significant morbidity and mortality. The existing treatments for PAD, including pharmacological, interventional and surgical procedures, are not sufficient and many patients are opt for limb amputation. Therapeutic angiogenesis using angiogenic factors has been considered to be a potential treatment option for PAD patients. Hypothesis: In this study, we assessed the potential of a new angiogenic factor AGGF1 for therapeutic angiogenesis in a critical limb ischemia model in mice for PAD. Methods and Results: We generated a unilateral hindlimb ischemia model in mice by ligation of the right common iliac artery and femoral artery. Ischemic mice with intrasmuscular administration of DNA for an expression plasmid for human AGGF1 ( AGGF1 group) resulted in increased expression of both AGGF1 mRNA and protein after the administration compared with control mice of hindlimb ischemia with injection of the empty vector (control group). The blood flow in ischemic hindlimbs was significantly increased in the AGGF1 group compared to control mice at time points of 7, 14, and 28 days after DNA administration. Four weeks after the injection of DNA, the blood flow was approximately 2.19 fold higher in AGGF1 group than that in control. With the increased blood flow in the AGGF1 group, ambulatory impairement were inhibited compared with the control group. Increased AGGF1 expression decreased necrosis in muscle tissues injected with AGGF1 DNA compared with the control tissue injected with the empty vector. CD31-positive capillary vessel density was significantly higher in AGGF1 -injected limbs than in empty vector-injected limbs. Conclusions: These data establish that plasmid DNA-based gene transfer of AGGF1 into mouse skeletal muscles is efficient in increase the expression levels of AGGF1 mRNA and protein. Increased AGGF1 expression increases blood flow by increasing density of CD31-positive vessels and by decreasing necrosis in muscle tissues. These findings suggest that AGGF1 may be used as a candidate therapeutic agent for therapeutic angiogenesis to treat PAD.

scholarly journals In Vivo Matrigel Plug Assay as a Potent Method to Investigate Specific Individual Contribution of Angiogenesis to Blood Flow Recovery in Mice

2021 ◽  
Vol 22 (16) ◽  
pp. 8909
Author(s):  
Zeen Aref ◽  
Paul H. A. Quax
Keyword(s):  
Blood Flow ◽  
Limb Ischemia ◽  
Arterial Disease ◽  
Matrigel Plug ◽  
Peripheral Arterial ◽  
The Sacrifice ◽  
Deficient Mice ◽  
Specific Contribution

Neovascularization restores blood flow recovery after ischemia in peripheral arterial disease. The main two components of neovascularization are angiogenesis and arteriogenesis. Both of these processes contribute to functional improvements of blood flow after occlusion. However, discriminating between the specific contribution of each process is difficult. A frequently used model for investigating neovascularization is the murine hind limb ischemia model (HLI). With this model, it is difficult to determine the role of angiogenesis, because usually the timing for the sacrifice of the mice is chosen to be optimal for the analysis of arteriogenesis. More importantly, the occurring angiogenesis in the distal calf muscles is probably affected by the proximally occurring arteriogenesis. Therefore, to understand and subsequently intervene in the process of angiogenesis, a model is needed which investigates angiogenesis without the influence of arteriogenesis. In this study we evaluated the in vivo Matrigel plug assay in genetic deficient mice to investigate angiogenesis. Mice deficient for interferon regulatory factor (IRF)3, IRF7, RadioProtective 105 (RP105), Chemokine CC receptor CCR7, and p300/CBP-associated factor (PCAF) underwent the in vivo Matrigel model. Histological analysis of the Matrigel plugs showed an increased angiogenesis in mice deficient of IRF3, IRF7, and RP105, and a decreased angiogenesis in PCAF deficient mice. Our results also suggest an involvement of CCR7 in angiogenesis. Comparing our results with results of the HLI model found in the literature suggests that the in vivo Matrigel plug assay is superior in evaluating the angiogenic response after ischemia.

Markers of arterial stiffness in peripheral arterial disease

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 341-348 ◽  
Author(s):  
Marc Husmann ◽  
Vincenzo Jacomella ◽  
Christoph Thalhammer ◽  
Beatrice R. Amann-Vesti
Keyword(s):  
Arterial Stiffness ◽  
Peripheral Arterial Disease ◽  
Pulse Wave ◽  
Augmentation Index ◽  
Arterial Disease ◽  
Care Physician ◽  
Additional Information ◽  
Non Invasive ◽  
Assessment Techniques ◽  
Peripheral Arterial

Abstract. Increased arterial stiffness results from reduced elasticity of the arterial wall and is an independent predictor for cardiovascular risk. The gold standard for assessment of arterial stiffness is the carotid-femoral pulse wave velocity. Other parameters such as central aortic pulse pressure and aortic augmentation index are indirect, surrogate markers of arterial stiffness, but provide additional information on the characteristics of wave reflection. Peripheral arterial disease (PAD) is characterised by its association with systolic hypertension, increased arterial stiffness, disturbed wave reflexion and prognosis depending on ankle-brachial pressure index. This review summarises the physiology of pulse wave propagation and reflection and its changes due to aging and atherosclerosis. We discuss different non-invasive assessment techniques and highlight the importance of the understanding of arterial pulse wave analysis for each vascular specialist and primary care physician alike in the context of PAD.

scholarly journals Hallucal thenar index: A new index to detect peripheral arterial disease using laser speckle flowgraphy

Vascular ◽  
2020 ◽  
pp. 170853812093893
Author(s):  
Kazuhiro Tsunekawa ◽  
Fumio Nagai ◽  
Tamon Kato ◽  
Ikkei Takashimizu ◽  
Daisuke Yanagisawa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peripheral Arterial Disease ◽  
Operating Characteristic ◽  
Ankle Brachial Index ◽  
Arterial Disease ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Skin Perfusion ◽  
Peripheral Arterial ◽  
Cutaneous Blood

Objectives Laser speckle flowgraphy is a technology using reflected scattered light for visualization of blood distribution, which can be used to measure relative velocity of blood flow easily without contact with the skin within a short time. It was hypothesized that laser speckle flowgraphy may be able to identify foot ischemia. This study was performed to determine whether laser speckle flowgraphy could distinguish between subjects with and without peripheral arterial disease. Materials and methods All subjects were classified based on clinical observations using the Rutherford classification: non-peripheral arterial disease, class 0; peripheral arterial disease group, class 2–5. Rutherford class 6 was one of the exclusion criteria. Laser speckle flowgraphy measured the beat strength of skin perfusion as an indicator of average dynamic cutaneous blood flow change synchronized with the heartbeat. The beat strength of skin perfusion indicates the strength of the heartbeat on the skin, and the heartbeat strength calculator in laser speckle flowgraphy uses the blood flow data to perform a Fourier transform to convert the temporal changes in blood flow to a power spectrum. A total of 33 subjects with peripheral arterial disease and 40 subjects without peripheral arterial disease at a single center were prospectively examined. Laser speckle flowgraphy was used to measure hallucal and thenar cutaneous blood flow, and the measurements were repeated three times. The hallucal and thenar index was defined as the ratio of beat strength of skin perfusion value on hallux/beat strength of skin perfusion value on ipsilateral thenar eminence. The Mann–Whitney U-test was used to compare the median values of hallucal and thenar index and ankle brachial index between the two groups. A receiver operating characteristic curve for hallucal and thenar index of beat strength of skin perfusion was plotted, and a cutoff point was set. The correlation between hallucal and thenar index of beat strength of skin perfusion and ankle brachial index was explored in all subjects, the hemodialysis group, and the non-hemodialysis (non-hemodialysis) group. Results The median value of the hallucal and thenar index of beat strength of skin perfusion was significantly different between subjects with and without peripheral arterial disease (0.27 vs. 0.87, respectively; P <  0.001). The median value of ankle brachial index was significantly different between subjects with and without peripheral arterial disease (0.8 vs. 1.1, respectively; P <  0.001). Based on the receiver operating characteristic of hallucal and thenar index, the cutoff was 0.4416 and the sensitivity, specificity, positive predictive value, and negative predictive value were 68.7%, 95%, 91.7%, and 77.6%, respectively. The correlation coefficients of all subjects, the hemodialysis group, and the non-hemodialysis group were 0.486, 0.102, and 0.743, respectively. Conclusions Laser speckle flowgraphy is a noninvasive, rapid, and widely applicable method. Laser speckle flowgraphy using hallucal and thenar index would be helpful to determine the differences between subjects with and without peripheral arterial disease. The correlation between hallucal and thenar index of beat strength of skin perfusion and ankle brachial index indicated that this index was especially useful in the non-hemodialysis group.

scholarly journals CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

2021 ◽  
Author(s):  
Patrick Veit-Haibach ◽  
Martin W. Huellner ◽  
Martin Banyai ◽  
Sebastian Mafeld ◽  
Johannes Heverhagen ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Ct Perfusion ◽  
Arterial Disease ◽  
Lower Leg ◽  
Therapy Control ◽  
Non Invasive ◽  
Before And After ◽  
Invasive Method ◽  
The Mean ◽  
Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

Sign in / Sign up

Export Citation Format

Share Document