Diagnostic Testing (VS)
Aorta-Iliac Artery Duplex
Ultrasound is used to directly image the abdominal aorta to help the interpreting physician determine if the aorta has dissected (the inner arterial wall layer has separated from the wall), or if an aneurysm may exist and may have ruptured. Aneurysms are non-symptomatic unless they rupture. An aneurysm of the aorta predisposes the common iliac and femoral artery branches to have aneurysms as well.
Indications for this exam: Known heart and arterial disease, smoking, obesity, > 65 years of age and male, sudden burning pain in the middle of the back, pre-kidney transplant work-up.
Arterial Exam Plethysmography
Blood pressure cuffs are used on each arm and at the ankles to obtain an ankle/brachial index. Doppler waveforms are obtained of the dorsalis pedis and posterior tibial arteries at the ankle and distal portion of the top of each foot. If these waveforms and the ABI are abnormal, we apply blood pressure cuffs to the calves, above the knee and the high thighs. Blood pressures and pulsed volume return waveforms at each level will determine potential areas of arterial occlusive disease. This exam is not performed more than once each year. If a patient has an arterial bypass graft in one or more lower limbs, only an ABI will be obtained with blood pressure cuffs. Abnormal results will prompt a duplex image study to be performed of the graft to look for occlusive disease in the graft or the points of attachment, and any new areas of narrowing that may have formed in the native arteries.
Indications for this exam: Cramping of the calves or high thigh area with walking which is resolved by rest (Claudication). Associated numbness and tingling in the feet with walking. Lack of arterial pulses with symptoms similar to those previously stated
Carotid-Vertebral Artery Exam
Imaging ultrasound is used to image the carotid arteries and the branches in the neck (internal and external carotid arteries). We also look at other related arteries in this exam. Color flow Doppler is used to identify blood flow and its characteristics. Pulsed wave Doppler determines the velocity of blood flow at any point in these vessels. These modalities used together help us demonstrate your vessels and their health for the interpreting physician to assess and make a diagnosis.
Indications for this exam: Stroke (CVA), Tran ischemic Attack (TIA - temporary effects of a stroke that resolve in a very short amount of time); and vertebral artery insufficiency (may result in symptoms of dizziness).
Dialysis Access Fistula/Graft
Once a graft has been placed, access is sometimes difficult. When this happens your physician will refer you for an ultrasound on the graft to see if a clot has obstructed flow.
Indications for this exam: Acute swelling and possible redness of the arm where a graft has been placed and dialysis access has recently been attempted or performed. Swelling of the arm is normal within the first 10 weeks after a graft has been placed.
IVC-Iliac Vein Duplex
Duplex ultrasound is used to directly image and assess the inferior vena cava (IVC) and the distal branches of the IVC (common iliac veins). When a significant clot is found in the common femoral vein (CFV), or in both legs at the groin, the IVC and common iliac veins should be imaged if possible to determine if the clot has extended into these areas. The presence of an acute and/or mobile clot may require a venous filter to be placed into the IVC. Ability to access the IVC through the CFV must be determined. A non-invasive approach to this assessment is always preferred if possible.
Indications for this exam: Pre-kidney transplant work-up, pre-placement of a Greenfield filter or one of a similar type, clot/s in the groin area of one or both legs with bilateral leg swelling and possible pain, or pain and possible swelling.
Duplex ultrasound is used to assess the main mesenteric (abdominal) arteries for significant obstruction in at least two of the three vessels.
Indications for this exam: Extreme cramping of the abdomen shortly after a meal. If this condition exists, cramping would be a constant symptom after eating. Other causes may exist which could also cause this type of cramping. Ultrasound is an excellent tool to non-invasively assess these arteries.
Mesenteric Venous (Portal Vein Hypertension)
Liver failure causes compromise of the portal venous system in the abdomen. Imaging ultrasound is used to locate the portal vein and its branches, the mesenteric and splenic veins. The liver is also imaged, measured and assessed for any cysts or masses, ascities (abnormal fluid collections in the abdomen).
Indications for this exam: Liver failure.
Renal Artery and Intra-Renal (Kidney) Vasculature
Imaging ultrasound is used to directly view and assess the abdominal aorta, superior mesenteric artery, celiac axis, renal arteries and arteries in the kidney (segmental and cortex arcuate arteries). This information helps the interpreting physician obtain the overall understanding of any underlying causes of unresolved (malignant) hypertension.
Indications for this exam: Malignant hypertension.
This exam is performed using oxygen sensors on the surface of the skin. These sensors emit heat, encouraging blood to flow to the surface of the skin where the oxygen saturation may be detected with these sensors. The saturation values are recorded as the exam is performed.
Indications for this exam: The TCP02 test helps determine if the skin involved in arterial caused ulcers will heal in a higher oxygen environment (barometric oxygen chamber treatments covered by Medicare if this test is positive). It also is used to determine the most appropriate level of amputation in cases where arterial grafts are not an option and gangrene has established itself.
Transcranial Doppler (non-imaging)
A non-imaging transducer (looks like a small pencil) is used with ultrasound gel applied to the head in four different locations. Arterial blood flow is recorded with Doppler waveforms to assess velocities in the Circle of Willis. This exam documents flow velocities in the subarachnoid area of the brain. When aneurysms in these vessels rupture, the resulting bleeding can cause arterial vasospasms. Vasospasms may sharply reduce or completely shut off blood flow to important areas of the brain, causing the same symptoms of a stroke. If this is diagnosed, treatment may immediately begin to help ease and possibly eliminate the condition and resulting symptoms.
Indications for this exam: CVA, ruptured aneurysm, clipped aneurysm of the brain.
Imaging ultrasound is used to assess the deep and superficial veins for venous thrombosis and/or reflux (backward flow in the veins). The arms and legs have two venous systems, deep and superficial. Sometimes clots develop in either or both systems due to hypercoagulation, injury, a sedentary lifestyle or prolonged illness, a long flight, work environment where people are sitting for many hours at one time, cardiac conditions causing a back up of blood to the venous system (mitral stenosis, congestive heart failure, pic lines, dialysis access lines in the subclavian and jugular veins, etc Duplex ultrasound allows direct imaging and assessment of these veins, allowing the interpreting physicians to diagnose and instigate treatment of existing clots. It is important if you think you have a clot to seek immediate help. When a clot first begins it may come loose and travel to the heart, then the lungs, causing a pulmonary embolism which may be life threatening.
Indications for this exam: In the majority of cases only one leg is involved, causing obvious swelling of the extremity and sometimes pain. If the condition has lasted more than two weeks, any associated clot is no longer acute, or likely to dislodge. A medical visit should be arranged through your family physician, and a venous ultrasound performed at the earliest possible convenience. If a clot exists, the area affected can expand, delaying the effects of treatment and returning health of the venous system and affected leg.