Know Your Vascular Ultrasound
What is a Specialist Vascular Ultrasound Facility?
A specialist vascular ultrasound practice, or vascular laboratory, is a diagnostic imaging facility that has equipment and personnel trained specifically to diagnose diseases of the major blood vessels of the body. We only assess patients that are suspected of having vascular disease. As this is our sole function, we are able to offer a highly sophisticated service that cannot be matched by general Radiology practices in terms of accuracy and speed of diagnosis and, importantly, our knowledge of vascular disease and interventional procedures. This, combined with our intimate association with vascular surgeons, places us at the vanguard of the diagnosis and management of vascular disease.
What do we do and how do we do it?
There are three main problems that develop within our major blood vessels. These include narrowing or obstruction to blood flow, blood flowing in the wrong direction and finally blood vessels that stretch beyond their normal size. Problems related to these issues vary in nature and severity depending on whether the arteries or veins are involved and whether they are connected to major muscle groups within the arm or leg, major organs within the abdomen, or the brain.
We use ultrasound in four ways:
- To provide the initial diagnosis and determine the severity and extent of the disease
- To enable us to review or assess on-going problems and determine if the disease is stable or has deteriorated
- To assist us directly and indirectly in providing treatment
- To enable us to review or assess the outcomes of treatment
Which vascular structures do we examine?
Examinations of the veins in the legs or arms determine if the blood vessels that help to return blood to the heart are blocked by a blood clot (thrombus), such as in Deep Vein Thrombosis, or if blood is flowing the wrong way, back down the leg - the most likely cause of varicose veins. We also use the ultrasound to guide doctors when they are treating varicose veins by either guiding them when they are injecting the vein or by marking the skin over varicose veins that are not visible to the naked eye prior to surgical treatment. We also use ultrasound to assess treatment.
Ultrasound is used to assess the overall amount of blood flowing to the lower and upper limbs. If this pressure measurement is normal initially, patients are then exercised to try and recreate their signs and symptoms following which the pressure is again measured. The arteries are imaged directly and followed along their course to determine if there is any narrowing or blockage or if the artery is enlarged.
The major arteries that leave your heart run down through your chest and abdomen supplying blood to your arms, legs and major organs, including the liver, spleen, kidney and bowel. Imaging of these arteries tells us if there is a restriction to blood flow or if the main artery (abdominal aorta) is enlarged. We can measure how severe the narrowing is and also how large an artery is.
The brain is supplied by the main artery that runs up the neck (carotid artery). Abnormalities within this artery are the most common cause of a stroke and we know that you are at greater risk of a stroke if the artery is narrowed beyond a certain point. Ultrasound lets us see directly within the artery so that we can measure the degree of narrowing caused by cholesterol deposits.
Haemodialysis and Kidney Transplantation
The escalating incidence of diabetes in the western world is well documented. A common problem related to long term diabetes is kidney failure. Without our kidneys toxins build up in our blood stream. To combat this, doctors transplant a donor kidney, attaching it to a major artery in the pelvis. Ultrasound is used to examine the blood vessel connecting the new kidney and the blood flow within the kidney itself. Unfortunately, however, donors are in short supply and an alternative treatment is to filter blood artificially through a dialysis machine. The best way to do this is by creating a high volume flow vessel, commonly a vein connected to an artery in the arm. Needles are placed within the fistula to accommodate the exchange of old and filtered blood between the patient and the machine. Ultrasound tells us if the flow within the fistula is satisfactory.
Who performs the examination - clinical staff
- Vascular ultrasound examinations are performed by certified sonographers whose sole responsibility is to perform these studies. At KVU our sonographers have been involved in vascular ultrasound since its earliest days in the 1980's and our sonographers individually have at least twenty-five years' experience in this specialty
- Sonographers are accredited with the DMU (Vasc) and AMS (Vascular), and Vascular Surgeons accredited with the DDU or equivalents prepare all reports
- A team of such highly experienced personnel is not found outside of a specialist vascular ultrasound facility
The Medicare Benefits Schedule Scheme
- Our procedures are covered under the Medicare Benefits Schedule. Medicare stipulates that you must have a referral for your ultrasound and you must bring it on the day of your appointment. This is a legal requirement and you can not claim a Medicare rebate for your ultrasound without it
- If you see the Vascular Surgeon on the same day as your ultrasound, the rebate that you receive from Medicare is reduced. In addition to this, if you have more than one "region" examined, e.g. your abdomen and one leg or arm at the same visit, then Medicare again reduces the total rebate that you receive
- Our fees are set above the Medicare Schedule Fee, but below the fees recommended by the Australian Medical Association. You can discuss the costs of your examination with our receptionist when booking your appointment. However, payment on completion of your visit is expected
Patient Preparation - what do you need to do.
Vascular ultrasound examinations are painless and usually straightforward. In some instances a small amount of preparation is required to complete the procedure. Please take note of the following information as we may need to reschedule ultrasound examinations for patients who do not comply with these instructions. Please ask the receptionist if you are unsure of what to do.
- If you have had a vascular ultrasound previously, please bring the films and report with you to your appointment. This is important so that we are able to compare findings and/or the outcomes of treatment.
- If this is the first time that you have had a vascular ultrasound or you require further information about your procedure, please let us know. The sonographer performing your test will be able to answer any questions that you may have related to how the ultrasound examination is performed
- Before performing the ultrasound you will need to remove all clothing from around the area of interest (with the exception of underwear). Often your problem may be caused by an abnormality in a blood vessel well above the site of your problem and, as a result, the examination may extend over a large area. You should wear comfortable, loose-fitting clothing that is easy to remove, and you may be asked to wear a gown during the procedure
- If you have a wound, for example an ulcer on you lower leg, we may need to examine the area directly around it. In these instances you should remove all heavy bandaging and dressings before you come in and cover it with light dressing
Specific instructions for individual procedures
These examinations are usually performed early in the day. No "fizzy" drinks or "fatty" meals should be consumed for 48 hours prior to the appointment and you should fast (nothing to eat or drink) from midnight. Do not use chewing gum/lollies or smoke for 6 hours beforehand. Essential medication can be taken with a sip of water. Diabetic patients should have black tea & toast at 6 am with their normal diabetic medication. It may help if you bring a snack with you to have after your ultrasound has been completed.
Renal/Ovarian or Testicular Vein Ultrasound:
Patients having an examination of the kidney or ovarian veins should follow the instructions for "Abdominal/Pelvic" and not eat any food from midnight, but should drink 300 ml of water 1 hour before their appointment. A full bladder is not necessary for the examination.
Lower Limb Vein Ultrasound:
You must not wear any form of stocking (no matter how light), compression socks or bandages for 12 hours before your appointment. Do not apply cosmetics or moisturisers to your legs on the day of the appointment.
The procedure itself - what to expect.
- If you have not been to our practice previously you will be asked to complete a patient information questionnaire for our medical records. This information is confidential and will not be given to any third party without your permission
- We aim to keep to time with appointments and in most instances you will be seen within 5-10 minutes of your allocated time. Most patients will have an uneventful visit and from start to finish your appointment should be completed within one hour. On occasions that we have emergency cases, we endeavour to keep your waiting time to a minimum, but would hope that you appreciate the special requirements of other patients when the need arises
- There is more to assessing vascular disease than just performing an ultrasound. Before you procedure we will take a brief medical history that includes questions about your immediate problem, your general health, family history, past health concerns and previous vascular issues including treatments. We may also need to examine the area of interest in a good light, for example if you have varicose veins, which gives us an indication of the type and severity of your problem
- The ultrasound itself is always performed in a darkened room and most often you will be lying on your back on an examination bed. However, if you have varicose veins, the ultrasound is performed with you standing and you may need to do so for between 30 to 60 minutes
- Ultrasound gel is first spread over the skin which acts to remove air between the probe and the skin as well as decrease friction. The gel is water based, hypoallergenic, and non-staining and has no added artificial colouring or perfumes. The ultrasound probe is then swept back and forth with slight pressure as the sites of interest are examined. Images of the anatomy are recorded and at various points an audible "whooshing" or "pulsating" sound that varies in volume and pitch will be heard as blood flow is assessed. In some examinations you will be asked to perform certain breathing manoeuvres to assist us whilst at other times the sonographer may squeeze groups of muscles in the leg or arm to push blood through your veins
- On completion of the examination you will be given paper towelling to remove the gel. Almost all patients will be able to dress and leave immediately
- Be aware that the sonographer will not discuss ultrasound findings or management options with patients during or following the ultrasound examination. Whilst many patients are eager to know the results of their examination, the images must be reviewed and reported before a formal report is forwarded on to your doctor
How accurate are vascular ultrasound examinations?
- Several vascular ultrasound procedures are now acknowledged as the "gold standard" or best techniques for assessing vascular disease
- Ultrasound however, is an "operator dependant" technology. This means that the examination and subsequent accuracy of the result are directly related to the experience and knowledge of the person performing the procedure
- Other variables that may affect the outcome include the age and type of equipment used and the experience of the doctor performing the report
- In some patients the anatomy itself may make the examination difficult. This includes very obese patients, excessive bowel gas, surgical incisions and scar tissue or small calcified blood vessels
- The results of the ultrasound studies are compared to invasive tests such as angiograms and to findings at operation. Because of the very close relationship between the vascular ultrasound facility and the vascular surgeon, the accuracy of the result is constantly being assessed