Sclerotherapy can also be performed using microfoam sclerosants under ultrasound guidance to treat larger varicose veins, including the great and small saphenous veins. After a map of the patient's varicose veins is created using ultrasound, these veins are injected whilst real-time monitoring of the injections is undertaken, also using ultrasound. The sclerosant can be observed entering the vein, and further injections performed so that all the abnormal veins are treated. Follow-up ultrasound scans are used to confirm closure of the treated veins, and any residual varicose veins can be identified and treated.