Evaluation of Musculoskeletal Microcirculation With Ultrasound

N/ATerminatedNCT02086331

Imperial College London5 enrolled

Overview

This study aims to validate the use of Dynamic Contrast-Enhanced Ultrasound in measuring the blood supply to the muscles of the leg, and how this changes with exercise and vascular pathology.

We propose a model for the use of Dynamic Contrast-Enhanced Ultrasound (DCEU) to directly evaluate the microcirculation of the musculoskeletal system. We believe that this will be a valuable research tool into diseases of the microcirculation, and in the future may also offer a clinical benefit by quantifying and monitoring disease over time and after intervention. It may also allow targeting of therapies towards those patients most at risk of ulcers and peripheral neuropathy, and those that would get the maximum benefit from these therapies.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Standardised Claudication Treadmill Test

Interventions

Contrast enhanced ultrasoundPROCEDURE

Infusion of microbubbles to enhance blood vessels in the leg for ultrasound

Treadmill testBEHAVIORAL

Exposes you to exercise in a controlled environment. We will see if we can detect this change with our new ultrasound protocol

Contrast enhanced ultrasoundPROCEDURE

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Group 1 - Healthy subjects Inclusion * 18+ years old Exclusion * Personal history of diabetes or peripheral arterial disease, current pregnancy, previous surgery to the lower limb, heart attack within 4 weeks, or unstable angina Group 2 - Peripheral arterial disease subjects Inclusion * 18+ years old, radiological evidence of peripheral arterial disease (arterial doppler or angiogram), ankle-brachial pressure index (ABPI) 0.5-0.8 Exclusion * Personal history of diabetes, current pregnancy, previous amputation, heart attack within 4 weeks, or unstable angina Group 3 - Diabetic subjects Inclusion * 18+ years old, with a clinical diagnoses of diabetes (1, 2) Exclusion \- ABPI\<0.9, previous amputation, current pregnancy or breastfeeding, heart attack within 4 weeks, or unstable angina.

Locations (1)

Charing Cross Hospital

London, United Kingdom

Outcomes

Primary Outcomes

Threshold of High to Low Frequency Ratio (Threshold HLFR)

Please see published article for in depth method. This ratio is used to classify a given signal as either microbubble or noise. For a pixel containing a micro vessel, as microbubbles occasionally pass this otherwise dark pixel, its temporal signal is expected to have a higher proportion of lower frequency components than white noise. Consequently, the HLFR of the pixel is expected to be smaller than that of noise. A histogram of normalised HLFR shows two expected peaks (one noise, one bubbles). A threshold (Threshold HLFR) is determined to then separate the two peaks. this is done using a double Gaussian model, and where they intercept is deemed the Threshold HLFR.

Time frame: Baseline, 20 minutes

Data from ClinicalTrials.gov

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