In the presence of varicose veins, obstruction or damage to the deep veins, an ultrasound scan of the leg is used to identify the blockages or backward flow of blood before medical treatment.

Information for doctors
Duplex scanning with colour flow imaging can detect the presence and anatomic extent of obstruction and reflux. It can demonstrate the variable anatomy of the popliteal fossa and determine the sites of incompetent perforating veins.

Indications
- To determine the sites of deep to superficial reflux. This is essential in patients with recurrent varicose veins.
- To exclude significant reflux or occlusion of deep veins when suspected in patients who are candidates for varicose vein surgery.
- To establish the diagnosis of post thrombotic syndrome
- Preoperative marking of the sapheno-popliteal junction
- Preoperative marking of incompetent perforating veins

Replacing, or grafting of arteries is a surgical treatment for arterial disease. Grafts need to be monitored to identify any potential failures as a result of narrowing (stenosis).

Information for doctors
Patients with infrainguinal bypass grafts should have routine duplex scanning at six weeks, three weeks and six months and then six monthly to identify the development of graft stenoses predisposing to thrombus and occulsion. Stenoses occur in approximately 25% of grafts at two years. Identification of the problem with prompt balloon dilation or surgical intervention can prevent graft occlusion and limb loss.

Indications
- The presence of a functioning infrainguinal bypass graft.

You may be referred for this scan by a doctor if they suspect a blood clot in the vein.

Information for doctors
Duplex scanning with colour flow imaging provides instant visualisation of the veins and blood flow. It can detect the presence of both recent and old thrombi. In symptomatic patients the accuracy of duplex is 96-100% for iliac, femoral and popliteal thrombi and 90% for calf thrombi.

Indications
- Symptoms and / or signs suggestive of acute deep venous thrombosis.
- To monitor calf thrombi in ambulant patients not on treatment.
- Suspected pulmonary embolism in the presence of low ventilation – perfusion scan.
- Superficial thrombophlebitis. Thrombi extend from superficial to the deep veins in 15% of patients.

This scan checks the lower legs for general arterial health including the build up of plaques or thickening of the arterial wall, for people who have been identified as having generalised arterial problems.

Information for doctors
Duplex scanning provides images of the arterial tree and blood velocities from the aorta to calf vessels. In the majority of patients this permits a decision to be made on management, medical, angioplasty or surgery without the need for angiography. Duplex scanning can identify lesions that are suitable for angioplasty.

Indications- Intermittent claudication
- Embolic phenomena
- Subcritical ischaemia

Already mentioned under the AAA scan, this ultrasound scan identifies and monitors aneurysms which can form in any section of the aorta, most commonly in the belly area, an Abdominal Aortic Aneurysm (AAA). If you have already been diagnosed with an aneurysm this scan can be used to monitor its progression and aid medical management.

Information for doctors
Duplex scanning with colour flow imaging provides images of the infrarenal aorta and other peripheral arteries. It provides a means of detecting the presence and size of an aneurysm. In addition it determines the size of a thrombus in the lumen. Repeated examinations at four monthly intervals monitor progression and assess risk.

Indications
- Screening for abdominal aortic aneurysms
- Presence of a palpable pulsatile intraabdominal mass
- Peripheral arterial aneurysm

The arteries in the neck (carotids) are scanned to check blood flow and for the presence of cholesterol plaques. This scan is often used after transient ischaemic attack (TIA or mini-stroke).

Information for doctors

This is an ultrasound scan that can detect the presence of carotid bifurcation disease and determine its severity (% diameter stenosis). In addition it can determine the patency and direction of flow in the vertebral arteries (subclavian steel).

Indications

- Patients with coronary or peripheral vascular disease, diabetes, hypertension or hyperlipidaemia for the presence of asymptomatic carotid stenosis.

- The presence of a cervical bruit or screening of asymptomatic individuals (to identify the presence of carotid bifurcation disease and to detect progression of a known internal carotid stenosis).

- Carotid territory symptoms: Transient monocular blindness, hemispheric sensory or motor TIA’s or non-disabling stroke.

- Symptoms suggestive of vertebrobasilar insufficiency: Dizziness, vertigo, diplopia or drop attacks.