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Digital Subtraction Angiography (DSA) is a fluoroscopy-based imaging technique used to visualize blood vessels in high detail by subtracting pre-contrast ("mask") images from post-contrast images, removing background structures such as bone and soft tissue.

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It remains the gold standard for vascular imaging, especially in interventional radiology and neurovascular applications.

Parameter Description
DSA Digital processing technique that enhances vascular visibility by subtracting background anatomy from angiographic images
Contrast medium Iodinated contrast injected via catheter
Modality Real-time fluoroscopy with digital image processing
Imaging planes 2D (often biplanar), sometimes 3D (rotational DSA)

Technical Principles

  1. Mask image acquired before contrast injection.
  2. Contrast image acquired after contrast enters vessels.
  3. Subtraction algorithm removes common background pixels.
  4. Result: only contrast-filled structures (i.e., blood vessels) remain.

![The procedure of obtaining of the DSA images. a, b and c represent mask image (no contrast agent), live image (full of contrast agent) and DSA image (difference between live image and mask image), respectively

Gao, Y., Song, Y., Yin, X. et al. Deep learning-based digital subtraction angiography image generation. Int J CARS 14, 1775–1784 (2019). https://doi.org/10.1007/s11548-019-02040-x](attachment:d62f38fe-7c4e-455f-ae4e-b26991584d29:11548_2019_2040_Fig1_HTML.webp)

The procedure of obtaining of the DSA images. a, b and c represent mask image (no contrast agent), live image (full of contrast agent) and DSA image (difference between live image and mask image), respectively

Gao, Y., Song, Y., Yin, X. et al. Deep learning-based digital subtraction angiography image generation. Int J CARS 14, 1775–1784 (2019). https://doi.org/10.1007/s11548-019-02040-x

Image Characteristics

Feature DSA Appearance
Stenosis Narrowed lumen, delayed filling
Aneurysm Outpouching with contrast filling
AVM Tangle of early filling veins/arteries
Dissection Intimal flap, double lumen
Occlusion Abrupt cutoff, no distal flow

Procedure Details

Access Common Site
Arterial puncture Femoral artery (most common), radial or brachial in select cases
Catheter placement Guided to target vessel under fluoroscopy
Contrast injection Iodinated contrast (volume depends on region)
Image acquisition Real-time subtraction imaging in multiple projections

Indications

Neurovascular applications: