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| ID | Type | Description | Link |
|---|---|---|---|
| 13HH0684 | Other Identifier | Imperial College London |
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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.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Healthy | Active Comparator | Healthy volunteers, deemed to have normal metabolic and cardiovascular biology by trial criteria |
|
| PAD | Active Comparator | Symptomatic peripheral arterial disease |
|
| DM | Active Comparator | Symptomatic diabetic peripheral neuropathy |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Contrast enhanced ultrasound | Procedure | Infusion of microbubbles to enhance blood vessels in the leg for ultrasound |
|
| Measure | Description | Time Frame |
|---|---|---|
| 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. | Baseline, 20 minutes |
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Group 1 - Healthy subjects Inclusion
Exclusion
Group 2 - Peripheral arterial disease subjects Inclusion
Exclusion
Group 3 - Diabetic subjects Inclusion
Exclusion
- ABPI<0.9, previous amputation, current pregnancy or breastfeeding, heart attack within 4 weeks, or unstable angina.
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| Name | Affiliation | Role |
|---|---|---|
| Prof AH Davies | Imperial College London | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Charing Cross Hospital | London | W6 8RF | United Kingdom |
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This study was terminated early after the proof of concept stage. We showed that our methodology worked in healthy subjects, then ran out of time thus no participants were enrolled in either the "Symptomatic peripheral arterial disease" or "Symptomatic diabetic peripheral neuropathy" arms.
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| ID | Title | Description |
|---|---|---|
| FG000 | Healthy | Healthy participants |
| Title | Milestones | Reasons Not Completed | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Overall Study |
|
Poor recruitment. Trial closed early after 5 healthy recruits completed protocol.
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| ID | Title | Description |
|---|---|---|
| BG000 | Healthy Subjects |
| Units | Counts |
|---|---|
| Participants |
|
| Title | Description | Population Description | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Denominator Units Selected | Denominators | Classes |
|---|---|---|---|---|---|---|---|---|---|
| Age, Continuous | Median |
| Type | Title | Description | Population Description | Reporting Status | Anticipated Posting Date | Parameter Type | Dispersion Type | Unit of Measure | Calculate Percentage | Time Frame | Units Analyzed | Denominator Units Selected | Arm/Group Information | Denominators | Classes | Analyses | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary | 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. | 5 recruits imaged and analysed. One recruit of five was excluded due to acquisition error | Posted | Number | Threshold ratio (no units) | Baseline, 20 minutes |
|
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| ID | Title | Description | Deaths (Affected) | Deaths (At Risk) | Serious Events (Affected) | Serious Events (At Risk) | Other Events (Affected) | Other Events (At Risk) |
|---|---|---|---|---|---|---|---|---|
| EG000 | Subject 1 | 0 | 1 |
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| Title | Organization | Phone | Extension | |
|---|---|---|---|---|
| Miss Kate Williams | Imperial College London | k.williams@imperial.ac.uk |
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| ID | Term |
|---|---|
| D005080 | Exercise Test |
| ID | Term |
|---|---|
| D006334 | Heart Function Tests |
| D003935 | Diagnostic Techniques, Cardiovascular |
| D019937 | Diagnostic Techniques and Procedures |
| D003933 | Diagnosis |
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| Treadmill test | Behavioral | Exposes you to exercise in a controlled environment. We will see if we can detect this change with our new ultrasound protocol |
|
| Contrast enhanced ultrasound | Procedure |
|
| years |
|
| Sex: Female, Male | Count of Participants | Participants |
|
| OG001 | Subject 2 |
| OG002 | Subject 3 |
| OG003 | Subject 4 |
|
|
|
| Post-Hoc | Average Percentage Change in Microbubble Track Density Measure (MTD) | The number of pixels identified as having bubble signals was normalised by dividing by area of region of interest (ROI). MTD = pixels with microbubbles / area of ROI Used as a surrogate for active vascular density. The percentage change between rest and exercise (20 minute treadmill protocol) was calculated on each day | One subject out of five excluded for acquisition error | Posted | Mean | Standard Deviation | % change from baseline | Test repeated on consecutive day to measure repeatability |
|
|
|
| 0 |
| 1 |
| 0 |
| 1 |
| EG001 | Subject 2 | 0 | 1 | 0 | 1 | 0 | 1 |
| EG002 | Subject 3 | 0 | 1 | 0 | 1 | 0 | 1 |
| EG003 | Subject 4 | 0 | 1 | 0 | 1 | 0 | 1 |
| EG004 | Subject 5 | 0 | 1 | 0 | 1 | 0 | 1 |
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| D012129 | Respiratory Function Tests |
| D003948 | Diagnostic Techniques, Respiratory System |
| D016552 | Ergometry |
| D008919 | Investigative Techniques |