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This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2013) |
| Digital subtraction angiography |
| Intervention |
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Example of iodine-based contrast in cerebral angiography
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| MeSH |
D015901 |
Digital subtraction angiography (DSA) is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a 'pre-contrast image' or the mask from later images, once the contrast medium has been introduced into a structure. Hence the term 'digital subtraction angiography'.
Contents
- 1 Procedure
- 1.1 DSA and Fluoroscopy
- 1.2 Intravenous digital subtraction angiography
- 2 Applications
- 3 The future
- 4 See also
- 5 Sources
- 6 References
- 7 External links
Procedure
DSA and Fluoroscopy
In traditional angiography, images are acquired by exposing an area of interest with time-controlled x-rays while injecting contrast medium into the blood vessels. The image obtained would also include all overlying structure besides the blood vessels in this area. This is useful for determining anatomical position and variations but unhelpful for visualizing blood vessels accurately.
In order to remove these distracting structures to see the vessels better, first a mask image is acquired. The mask image is simply an image of the same area before the contrast is administered. The radiological equipment used to capture this is usually an image intensifier, which will then keep producing images of the same area at a set rate (1–6 frames per second), taking all subsequent images away from the original 'mask' image. The radiologist controls how much contrast media is injected and for how long. Smaller structures require less contrast to fill the vessel than others. Images produced appear with a very pale grey background, which produces a high contrast to the blood vessels, which appear a very dark grey.
The images are all produced in real time by the computer, as the contrast is injected into the blood vessels.
Intravenous digital subtraction angiography
Intravenous digital subtraction angiography (IV-DSA) is a form of angiography which was first developed in the late 1970s.
IV-DSA uses a computer technique which compares an x-ray image of a region of the body before and after radiopaque iodine based dye has been injected intravenously into the body. Tissues and blood vessels on the first image are digitally subtracted from the second image, leaving a clear picture of the artery which can then be studied independently and in isolation from the rest of the body.
Some studies have indicated that IV-DSA is not suitable for patients with diabetes or renal insufficiency because the dye load is significantly higher than is used in arteriography. However, IV-DSA has been used successfully to study the vessels of the brain and heart and has helped detect carotid artery obstruction and to map patterns of cerebral blood flow. It also helps detect and diagnose lesions in the carotid arteries which is a potential cause of strokes.
IV-DSA has also been useful in assessing patients prior to surgery and after coronary artery bypass surgery and some transplant operations...
Applications
DSA is primarily used to image blood vessels. It is useful in the diagnosis and treatment of:
- Arterial and venous occlusions, including carotid artery stenosis, pulmonary embolisms and acute limb ischaemia.
- Arterial stenosis, which is particularly useful for potential renal donors in detecting renal artery stenosis. DSA is the gold standard investigation for renal artery stenosis.[1]
- Cerebral aneurysms and arteriovenous malformations (AVM).
The future
DSA is being used less and less routinely in imaging departments. It is being replaced by computed tomography angiography (CTA), which can produce 3D images through a test which is less invasive[2] and stressful for the patient[citation needed]. It is still considered the gold standard for arterial imaging [2]
See also
- Angiography
- Contrast medium
- Image intensifier
- Computed tomography angiography (CTA)
- Peripheral artery occlusive disease
Sources
- Anagnostakos, Nicholas Peter; Tortora, Gerard J. (1990). Principles of Anatomy and Physiology. San Francisco: Harper & Row. ISBN 0-06-046694-4.
- Eddy AC, Nance DR, Goldman MA, et al. (May 1990). "Rapid diagnosis of thoracic aortic transection using intravenous digital subtraction angiography". Am. J. Surg. 159 (5): 500–3. doi:10.1016/S0002-9610(05)81255-3. PMID 2334014.
- Signs of a stroke
- D'Alotto C, Pelz DM, Rankin RN (September 1985). "A comparison of angiography, intravenous digital subtraction angiography and duplex ultrasound in the diagnosis of carotid artery atherosclerosis". J Can Assoc Radiol 36 (3): 200–8. PMID 3900078.
- Zwiebel WJ, Strother CM, Austin CW, Sackett JF (1 July 1985). "Comparison of ultrasound and IV-DSA for carotid evaluation". Stroke 16 (4): 633–43. doi:10.1161/01.STR.16.4.633. PMID 3895593.
References
- ^ Sam, Amir H.; James T.H. Teo (2010). Rapid Medicine. Wiley-Blackwell. ISBN 1405183233.
- ^ a b R. Herzig, S. Burval, B. Krupka, I. Vlachova, K. Urbanek, J. Mares (2004). "Comparison of ultrasonography, CT angiography, and digital subtraction angiography in severe carotid stenoses" (PDF). European Journal of Neurology: 774–5. Retrieved 26 June 2013.
External links
- http://www.droid.cuhk.edu.hk/web/service/angio/dsa.htm
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Vascular surgery ICD-9-CM V3 38–39, ICD-10-PCS 03–6
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Vascular and
Endovascular surgery |
| Arterial disease |
- Vascular bypass
- Angioplasty
- Atherectomy
- Endarterectomy
- Stenting
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| Venous disease |
- Ambulatory phlebectomy
- Laser surgery
- Sclerotherapy
- Vein stripping
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| Arterial and Venous Access |
- Venous cutdown
- Arteriotomy
- Phlebotomy
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| Aortic aneurysm / dissection: |
- Endovascular aneurysm repair
- Open aortic surgery
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| Other |
- Cardiopulmonary bypass
- Cardioplegia
- Extracorporeal membrane oxygenation
- Hemodialysis
- Revascularization
- Glomectomy
- First rib resection
- Seldinger technique
- Vascular snare
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| Medical imaging |
| Angiography |
- Digital subtraction angiography
- Cerebral angiography
- Aortography
- Fluorescein angiography
- Radionuclide angiography
- Magnetic resonance angiography
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| Venography |
- Portography
- Impedance phlebography
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| Ultrasound |
- Intravascular ultrasound
- Carotid ultrasonography
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| Other diagnostic |
- Angioscopy
- Ankle brachial pressure index
- Tilt table test
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Index of the circulatory system
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| Description |
- Anatomy
- Arteries
- head and neck
- arms
- chest
- abdomen
- legs
- Veins
- head and neck
- arms
- chest
- abdomen and pelvis
- legs
- Development
- Cells
- Physiology
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| Disease |
- Congenital
- Neoplasms and cancer
- Lymphatic vessels
- Injury
- Vasculitis
- Other
- Symptoms and signs
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| Treatment |
- Procedures
- Drugs
- beta blockers
- channel blockers
- diuretics
- nonsympatholytic vasodilatory antihypertensives
- peripheral vasodilators
- renin–angiotensin system
- sympatholytic antihypertensives
- vasoprotectives
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