The ultrasonography (USG) Doppler scan uses high frequency sound waves to measure the amount of blood flow through the arteries and veins which supply blood to the particular limb (arm or leg). Any abnormality can be detected through this vascular (blood flow) study. Irregular blood circulation and blood clots can be detected and diagnosed. Usually, irregular or reduced blood flow to the limb is caused by arterial blockage and blood clotting. Also, the USG Doppler scan can measure the blood pressure within the arteries and veins. Anyone suffering from deep vein thrombosis, superficial thrombophlebitis, arteriosclerosis and thromboangiitis obliterans is recommended this scan.
No special preparation is required. Visit the doctor to discuss your health condition, current medication, addiction and lifestyle with the doctor. Prepare for the USG Doppler scan as per the doctor’s instructions. Smoking is prohibited for many hours leading to the scan. Smoking causes narrowing of blood vessels and this affects the USG Doppler scan report. It’s recommended that you do not wear jewellery and wrist watch while going for the scan. Glasses, contact lenses, dentures and hearing aids are allowed. No fasting is required.
Normal scan report indicates no abnormalities like narrow or blocked veins and arteries, no blood clots. It means blood flow and blood pressure is normal. Abnormal scan report indicates poor blood circulation, narrow and blocked veins and arteries, venous occlusion and abnormal blood pressure.
The method used is painless, non-invasive, bears no risk of any harmful radiation and takes an hour’s time. You will be made to wear a hospital gown and asked to lie down on the examination table. Blood pressure cuffs will be applied to your thigh, calf, ankle and different points along your limb. This allows blood pressure at different points in the limb to be studied easily. The radiologist will apply a water soluble gel to the transducer.
The transducer is connected to a computer screen where images of the scan are visible. When the transducer comes in contact with the skin, the high frequency sound waves are directed to the arteries and veins. The sound waves echo off the blood vessels and scan information is sent through the cable that connects the transducer to the computer screen. The transducer is moved along the limb and the ‘whooshing’ sound of blood flow is heard. Normal activities can be resumed after the USG Doppler scan session.