Impedance Phlebography

Impedance phlebography, or impedance plethysmography (IPG), is a non-invasive medical test that measures small changes in electrical resistance of the chest, calf or other regions of the body. These measurements reflect blood volume changes, and can indirectly indicate the presence or absence of venous thrombosis. This procedure provides an alternative to venography, which is invasive and requires a great deal of skill to execute adequately and interpret accurately.

For the chest, the technique was developed by NASA to measure the split second impedance changes within the chest, as the heart beats, to calculate both cardiac output and lung water content. This technique has progressed clinically (often now called BioZ, i.e. biologic impedance, as promoted by the leading manufacturer in the US) and allows low cost, non-invasive estimations of cardiac output and total peripheral resistance, using only 4 skin electrodes, oscillometric blood pressure measurement and lung water volumes with minimal removal of clothing in physician offices having the needed equipment.

For leg veins, the test measures blood volume in the lower leg due to temporary venous obstruction. This is accomplished by inflating a pneumatic cuff around the thigh to sufficient pressure to cut off venous flow but not arterial flow, causing the venous blood pressure to rise until it equals the pressure under the cuff. When the cuff is released there is a rapid venous runoff and a prompt return to the resting blood volume. Venous thrombosis will alter the normal response to temporary venous obstruction in a highly characteristic way, causing a delay in emptying of the venous system after the release of the tourniquet. The increase in blood volume after cuff inflation is also usually diminished.

Health science – Medicine · Surgery · Vascular surgery and other vascular procedures (ICD-9-CM V3 38–39, ICD-10-PCS 03–6)
Incision, excision,
and occlusion
of vessels

Peripheral arterial occlusive disease: Balloon embolectomy · Thrombectomy

Carotid stenosis: Endarterectomy (Carotid endarterectomy)

Varicose veins: Ambulatory phlebectomy · Laser ablation · Sclerotherapy · Vein stripping

Venous cutdown

Temporal artery biopsy

Arteriotomy · Phlebotomy
Other operations
on vessels
Shunt/bypass

Peripheral arterial occlusive disease: Peripheral arterial bypass surgery

Portal hypertension: Transjugular intrahepatic portosystemic shunt (TIPS) · Distal splenorenal shunt procedure

Vascular grafting (Human umbilical vein graft)

Blalock–Taussig shunt
Repair

Aortic aneurysm / dissection: Open AAA repair · Endoluminal AAA repair (EVAR)

Peripheral arterial occlusive disease: Angioplasty with/out Stenting

Atherectomy
Auxiliary to
heart surgery
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Carotid stenosis: Carotid stenting

Hemodialysis/Hemofiltration · Revascularization

Glomectomy
Medical imaging

Angiography (Digital subtraction angiography, Cerebral angiography, Aortography, Fluorescein angiography, Radionuclide angiography, Magnetic resonance angiography)

Venography (Portography) · Impedance phlebography

Intravascular ultrasound · Carotid ultrasonography
Other diagnostic Angioscopy · Ankle brachial pressure index · Tilt table test

M: VAS

anat(a:h/u/t/a/l,v:h/u/t/a/l)/phys/devp/cell/prot

noco/syva/cong/lyvd/tumr, sysi/epon, injr

proc, drug(C2s+n/3/4/5/7/8/9)

Medical testing : Medical imaging · Radiology · (ICD-9-CM V3 87–88, ICD-10-PCS B, CPT 70010–79999)
X-ray/
medical radiography/
Industrial radiography
2D

Medical: Pneumoencephalography · Dental radiography · Sialography · Myelography · CXR (Bronchography) · AXR / KUB · DXA/DXR · Upper gastrointestinal series/Small bowel follow-through/Lower gastrointestinal series · Cholangiography/Cholecystography · Mammography · Pyelogram · Cystography · Arthrogram · Hysterosalpingography · Skeletal survey · Angiography (Angiocardiography, Aortography) · Venography · Lymphogram
Industrial: Radiographic testing

3D / XCT

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Industrial: Industrial CT Scanning
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