Contrast-enhanced ultrasound evaluation of peripheral microcirculation in diabetic patients: effects of cigarette smoking

Update of Contrast-enhanced Ultrasound in Musculoskeletal Medicine: Clinical Perspectives - A Review

Contrast-enhanced ultrasound (CEUS) uses an intravascular contrast agent to enhance blood flow signals and assess microcirculation in different parts of the human body. Over the past decade, CEUS has become more widely applied in musculoskeletal (MSK) medicine, and the current review aims to systematically summarize current research on the application of CEUS in the MSK field, focusing on 67 articles published between January 2001 and June 2021 in online databases including PubMed, Scopus, and Embase. CEUS has been widely used for the clinical assessment of muscle microcirculation, tendinopathy, fracture nonunions, sports-related injuries, arthritis, peripheral nerves, and tumors, and can serve as an objective and quantitative evaluation tool for prognosis and outcome prediction. Optimal CEUS parameters and diagnostic cut off values for each disease category remain to be confirmed.

Assessment of Microcirculation in the Type 2 Diabetic and Impaired Glucose Tolerance Feet of Elderly Men by CEUS

OBJECTIVE

To evaluate the foot microcirculation in type 2 diabetes mellitus (T2DM) and impaired glucose tolerance patients (IGT) with contrast-enhanced ultrasound (CEUS).

METHODS

The study included 37 patients with T2DM but without diabetic foot (DM group), 15 patients with impaired glucose tolerance (IGT group) and 10 elderly males with normal fasting blood glucose (FBS) and negative glucose tolerance tests (control group). Color Doppler flow imaging (CDFI) and CEUS were performed on the right foot great toes for detecting the blood perfusion performance. CEUS images were recorded and parameters of CDFI and flow time-intensity curves (TICs) were analyzed by the Student's t-test.

RESULTS

There was no significant difference in CDFI parameters pulse index and peak systolic blood flow velocity (PSV) among the three groups (P >0.05). Compared with control group, CEUS images of IGT and DM groups showed lower microvascular density and were pale. Peak intensity (PI) and area under time-intensity curve (AUC) in control, IGT and DM groups were decreased gradually (PI 46.36±10.96 vs 35.26±11.65 vs 28.15±7.94, P = 0.001, AUC 5.12±1.02 vs 3.25±1.60 vs 2.81±1.20, P = 0.001). The arrival times (AT) and time to peak (TTP) tended to be increased with the extension of DM course, but the difference was not statistically significant (AT, P = 0.260, TTP, P = 0.481).

CONCLUSION

CEUS, as a noninvasive and valuable technique, could detect the alterations in foot microcirculation of DM and IGT patients.

Effects of Cytotoxic T Lymphocyte-Associated Antigen 4 Immunoglobulin Combined with Microbubble-Mediated Irradiation on Hemodynamics of the Renal Artery in Rats with Diabetic Nephropathy

Cytotoxic T lymphocyte-associated antigen 4 immunoglobulin (CTLA-4-Ig) can inhibit the effect of B7-1 and improve renal hemodynamics in rats with diabetic nephropathy (DN). Nevertheless, a strategy that could increase the permeation of CTLA-4-Ig through endothelial cells and basement membrane remains to be discovered. We investigated the effect of CTLA-4-Ig combined with microbubble-mediated irradiation on the hemodynamics of renal arteries in DN rats. Rats were treated with CTLA-4-Ig and/or microbubble exposure. After 8 wk of intervention, color Doppler ultrasonography was used to detect peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV), systolic acceleration (SAC), pulsatility index (PI) and resistance index (RI) of the renal artery trunk. The CTLA-4-Ig + microbubble exposure group exhibited significantly higher PSV, EDV and MV than the CTLA-4-Ig group, which had significantly higher values than the non-intervention group. The CTLA-4-Ig + microbubble exposure group exhibited significantly lower SAC, PI and RI than the CTLA-4-Ig group, which had significantly lower values than the non-intervention group. Our results indicate that both CTLA-4-Ig and CTLA-4-Ig + microbubble exposure can reduce the blood flow resistance and improve the blood flow velocity of renal arteries in rats. Moreover, the effect of CTLA-4-Ig + microbubble exposure is better than that of CTLA-4-Ig alone. Our study provides a new, effective and non-invasive strategy for the treatment of DN.

Validation of a novel ultrasound Doppler monitoring device (earlybird) for detection of microvascular circulatory changes

OBJECTIVE

In this proof-of-concept study we aim to validate a novel ultrasound Doppler monitoring device for evaluating microcirculation (earlybird) against LDF and pulsed Doppler.

METHODS

In ten healthy subjects, we measured microcirculatory function at rest and during different autonomic tests (forced respiration, isometric exercise, Valsalva maneuver and cold pressor). Earlybird, LDF and pulsed Doppler were recorded simultaneously. We performed a ZNCC to determine correlation.

RESULTS

The curves for earlybird and LDF or pulsed Doppler correlates visually well. Overall median ZNCC 0.87 (interquartile range 0.77 -0.91) between the LDF and earlybird measurements, and 0.90 (0.82 - 0.95) for pulsed Doppler and earlybird. Median ZNCC for baseline and each provocation test for earlybird against LDF and pulsed Doppler were calculated; baseline: LDF 0.87 (0.73 - 0.97) pulsed Doppler 0.91 (0.81 - 0.94), forced respiration: LDF 0.87 (0.28 - 0.90) pulsed Doppler 0.90 (0.85 - 0.96), isometric exercise: LDF 0.82 (0.59 - 0.90) pulsed Doppler 0.87 (0.68 - 0.94), Valsalva maneuver: LDF 0.88 (0.82 - 0.91) pulsed Doppler 0.94 (0.92 - 0.97) and cold pressor: LDF 0.90 (0.85 - 0.95) pulsed Doppler 0.89 (0.65 - 0.94).

CONCLUSION

Earlybird records vasoconstrictions in healthy subjects as well as LDF and pulsed Doppler.

The Role of Contrast-Enhanced Ultrasound in Managing Vascular Pathologies

INTRODUCTION

Ultrasound is a useful first-line imaging modality for diagnosing and monitoring vascular pathologies. Compared with other modalities, it is relatively low cost, requires no ionizing radiation, is often available at bedside, and is noninvasive. However, the modality can have limitations when differentiating normal from pathologic tissues. In this review, we discuss the role of contrast-enhanced ultrasound (CEUS) in carotid, aortic, and peripheral vascular conditions.

DISCUSSION

CEUS is a developing modality that supersedes standard vascular ultrasound imaging and complements other modalities such as computed topography and magnetic resonance angiograms. Administered intravenously, the contrast are microbubbles filled with gas, surrounded by a stabilizing shell. They have the ability to enhance the quality of images and quantify vascular pathologies by acting as intravascular tracers of ultrasound energy. Based on these properties, CEUS has the potential to play a pivotal role in the management of vascular pathologies through its utility in detection, diagnosis, risk-stratification, follow-up, and monitoring.

CONCLUSION

Studies have suggested that CEUS is superior compared with standard ultrasound and on-par with computed topography angiograms in the detection of vascular pathologies, concluding that CEUS should be part of standardized routine practice.

[CEUS-application possibilities in the musculoskeletal system]

METHODICAL ISSUE

Contrast-enhanced ultrasound (CEUS) offers easily accessible visualization and quantification of the skeletal muscle microcirculation and other tissues in vivo and in real-time with almost no side effects.

AIM

The aim of this review is to present the increasing number of musculoskeletal CEUS applications.

METHODICAL INNOVATIONS/PERFORMANCE

CEUS applications regarding the musculoskeletal system include applications at bone and joints extending beyond the visualization of only the muscular microcirculation. Besides basic muscle physiology, impaired microcirculation in patients with peripheral artery disease or diabetes mellitus and the diagnosis of inflammatory myopathies have been the subject of previous CEUS studies. More recent studies in orthopedics and traumatology have focused on osseous and muscular perfusion characteristics, e. g., in differentiating infected and aseptic non-unions or the impact of different types of implants and prostheses on muscular microcirculation as a surrogate marker of clinical success.

PRACTICAL RECOMMENDATIONS

CEUS of the musculoskeletal system is used in clinical trials or off-label. Therefore, it is not well established in clinical routine. However, considering the increasing number of musculoskeletal CEUS applications, this could change in the future.

Prospects of Contrast-Enhanced Ultrasonography for the Diagnosis of Peripheral Arterial Disease: A Meta-analysis

OBJECTIVES

Contrast-enhanced ultrasonography (CEUS) is a modern diagnostic method that can also be used to study microperfusion. This study compared the time to peak intensity measured by CEUS in patients with peripheral arterial disease (PAD) and healthy control participants.

METHODS

After a comprehensive literature search in multiple electronic databases and study selection, a random-effect meta-analysis was performed to compare the time to peak intensity measured by CEUS in patients with PAD and healthy controls, which followed meta-regression analyses for identification of factors affecting the outcomes.

RESULTS

Fourteen studies (data for 322 patients with PAD and 314 healthy individuals) were used for the meta-analysis. The age of this sample of patients with PAD was 64.92 (95% confidence interval, 62.53, 67.31) years, and that of the healthy controls was 55.32 (51.67, 58.98) years. The times to peak intensity were 18.55 (15.62, 21.48) seconds in healthy controls, 33.40 (27.65, 39.15) seconds in patients with PAD, and 76.22 (36.23, 116.22) seconds in patients with PAD and diabetes mellitus. The difference between patients with PAD and healthy controls in the time to peak intensity was statistically significant (mean difference, 24.80 [10.16, 39.44] seconds; P < .00009). The ABI was not significantly associated with the time to peak intensity in patients with PAD. Age and sex were also not significantly associated with the time to peak intensity.

CONCLUSIONS

Contrast-enhanced ultrasonography is a valuable tool for the diagnosis of PAD based on its ability to differentiate the time to peak intensity between patients with PAD and healthy individuals, but little data are yet available to assess its diagnostic ability in clinical practice.

Quantitative correlational study of microbubble-enhanced ultrasound imaging and magnetic resonance imaging of glioma and early response to radiotherapy in a rat model

PURPOSE

Radiotherapy remains a major treatment method for malignant tumors. Magnetic resonance imaging (MRI) is the standard modality for assessing glioma treatment response in the clinic. Compared to MRI, ultrasound imaging is low-cost and portable and can be used during intraoperative procedures. The purpose of this study was to quantitatively compare contrast-enhanced ultrasound (CEUS) imaging and MRI of irradiated gliomas in rats and to determine which quantitative ultrasound imaging parameters can be used for the assessment of early response to radiation in glioma.

METHODS

Thirteen nude rats with U87 glioma were used. A small thinned skull window preparation was performed to facilitate ultrasound imaging and mimic intraoperative procedures. Both CEUS and MRI with structural, functional, and molecular imaging parameters were performed at preradiation and at 1 day and 4 days postradiation. Statistical analysis was performed to determine the correlations between MRI and CEUS parameters and the changes between pre- and postradiation imaging.

RESULTS

Area under the curve (AUC) in CEUS showed significant difference between preradiation and 4 days postradiation, along with four MRI parameters, T2, apparent diffusion coefficient, cerebral blood flow, and amide proton transfer-weighted (APTw) (all p < 0.05). The APTw signal was correlated with three CEUS parameters, rise time (r = - 0.527, p < 0.05), time to peak (r = - 0.501, p < 0.05), and perfusion index (r = 458, p < 0.05). Cerebral blood flow was correlated with rise time (r = - 0.589, p < 0.01) and time to peak (r = - 0.543, p < 0.05).

CONCLUSIONS

MRI can be used for the assessment of radiotherapy treatment response and CEUS with AUC as a new technique and can also be one of the assessment methods for early response to radiation in glioma.

Analysis of risk factors for perifocal oedema after endovascular embolization of unruptured intracranial arterial aneurysms

Background

Endovascular embolization is a treatment of choice for the management of unruptured intracranial aneurysms, but sometimes is complicated with perianeurysmal oedema. The aim of our study was to establish incidence and outcomes of perianeurysmal oedema after endovascular coiling of unruptured intracranial aneurysms, and to reveal possible risk factors for development of this potentially serious complication.

Methods

In total 119 adult patients with endovascular embolization of unruptured intracranial aneurysm (performed at Department for Interventional Neuroradiology, Clinical Center, Kragujevac, Serbia) were included in our study. The embolizations were made by electrolite-detachable platinum coils: pure platinum, hydrophilic and combination of platinum and hydrophilic coils. Primary outcome variable was perianeurysmal oedema visualized by magnetic resonance imaging (MRI) 7, 30 and 90 days after the embolization.

Results

The perianurysmal oedema appeared in 47.6% of patients treated with hydrophilic coils, in 21.6% of patients treated with platinum coils, and in 53.8% of those treated with mixed type of the coils. The multivariate logistic regression showed that variables associated with occurrence of perianeurysmal oedema are volume of the aneurysm, hypertension, diabetes and smoking habit. Hypertension is the most important independent predictor of the perianeurysmal oedema, followed by smoking and diabetes.

Conclusions

The results of our study suggest that older patients with larger unruptured intracranial aneurysms, who suffer from diabetes mellitus and hypertension, and have the smoking habit, are under much higher risk of having perianeurysmal oedema after endovascular coiling.

Contrast-enhanced ultrasonography to assess blood perfusion of skeletal muscles in normal dogs

This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time-intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0-3 according to the number of vascular signals. A parabolic shape of time-intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions.

Heart failure risk across the spectrum of ankle-brachial index: the ARIC study (Atherosclerosis Risk In Communities)

OBJECTIVES

The aim of this study was to describe the relationship between ankle brachial index (ABI) and the risk for heart failure (HF).

BACKGROUND

The ABI is a simple, noninvasive measure associated with atherosclerotic cardiovascular disease and death; however, the relationship between ABI and risk for HF is less well characterized.

METHODS

Between 1987 and 1989 in the ARIC (Atherosclerosis Risk In Communities) study, an oscillometric device was used to measure blood pressure in a single upper and randomly chosen lower extremity to determine the ABI. Incident HF events were defined by the first hospitalization with an International Classification of Diseases, Ninth Revision, code of 428.x through 2008. The risk for HF was assessed across the ABI range using restricted cubic splines and Cox proportional hazards models.

RESULTS

ABI was available in 13,150 participants free from prevalent HF. Over a mean 17.7 years of follow-up, 1,809 incident HF events occurred. After adjustment for traditional HF risk factors, prevalent coronary heart disease, subclinical carotid atherosclerosis, and interim myocardial infarction, compared with an ABI of 1.01 to 1.40, participants with ABIs ≤0.90 were at increased risk for HF (hazard ratio: 1.40; 95% confidence interval: 1.12 to 1.74), as were participants with ABIs of 0.91 to 1.00 (hazard ratio: 1.36; 95% confidence interval: 1.17 to 1.59).

CONCLUSIONS

In a middle-age community cohort, an ABI ≤1.00 was significantly associated with an increased risk for HF, independent of traditional HF risk factors, prevalent coronary heart disease, carotid atherosclerosis, and interim myocardial infarction. Low ABI may reflect not only overt atherosclerosis but also pathologic processes in the development of HF beyond epicardial atherosclerotic disease and myocardial infarction alone. A low ABI, as a simple, noninvasive measure, may be a risk marker for HF.