The Application of Digital Infrared Thermal Imaging in Peripheral Artery Disease of the Lower Extremities

Study Overview
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Brief Summary
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Peripheral artery disease (PAD) is highly prevalent. It occurs most often in the lower extremities. Symptoms include intermittent claudication, ischemic pain, ulceration and necrosis. Amputation may be necessary in severe cases. PAD is also an indicator of future cerebrovascular and cardiovascular events. Diabetes mellitus (DM) is one of the major risk factors of PAD. Approximately 5% to 10% of diabetic patients have had foot ulceration, and 1% have undergone amputation. Other risk factors include smoking, old age, male gender, hypertension, dyslipidemia, hyperhomocysteinemia and renal insufficiency. Ankle-brachial index (ABI) is the most popular tool used to screen PAD. Doppler-derived ankle and brachial systolic pressure is obtained. If the ratio is abnormal, further confirmation studies will necessary. Although ABI is recommended as one of the screening tests for diabetic complications in guidelines, its utility is limited in calcified non-compressible vessels, which are common in DM and renal failure patients. Digital infrared thermal imaging (DITI) is used to detect surface temperature because objects of absolute temperatures higher than zero would radiate electromagnetic waves of certain wave lengths according to Plank's law. DITI examination is non-invasive, non-contact and fast. Theoretically, temperature of the perfusion area of the occlusive arteries will decrease. Investigators will analyze DITI of PAD, and observe the relationship between DITI, ABI and vascular duplex examination. The dynamic change of DITI before and after percutaneous transluminal angioplasty of PAD will also be observed. Investigators would like to evaluate the possibility of the clinical application of DITI for PAD screening.

Official Title
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The Application of Digital Infrared Thermal Imaging in Peripheral Artery Disease

Conditions
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Peripheral Artery Disease, Diabetes Mellitus

Intervention / Treatment
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* Procedure: Percutaneous balloon angioplasty


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 20 85 years old Diagnosed with DM Exclusion Criteria: History of lower extremities disease or underwent leg surgery Pregnancy Fever Leg edema Autoimmune disease

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| DM with PAD before angioplasty<br>Diabetic patients diagnosed with peripheral artery disease via vascular Duplex. | |
| DM without PAD<br>Diabetic patients diagnosed without peripheral artery disease via vascular Duplex. | |
| Healthy volunteers<br>Healthy volunteers | |
| DM with PAD after angioplasty<br>Diabetic patients diagnosed with PAD underwent balloon-angioplasty | Procedure: Percutaneous balloon angioplasty<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Digital infrared thermal imaging (DITI) | Digital infrared thermal imaging (DITI) to detect surface temperature | 7 days |