Virtual 2D angiography from four-dimensional digital subtraction angiography (4D-DSA): A feasibility study

Area of Science:

• Medical Imaging
• Radiology
• Cerebrovascular Imaging

Background:

• Digital subtraction angiography (DSA) is the standard for cerebrovascular evaluation but requires multiple acquisitions, increasing time and radiation exposure.
• Three-dimensional DSA (3D-DSA) provides volumetric data but lacks temporal resolution.
• Four-dimensional DSA (4D-DSA) integrates temporal and volumetric information for time-resolved 3D reconstructions, potentially reducing procedure time and radiation.

Purpose of the Study:

• To evaluate the diagnostic quality of virtual single-frame 4D-DSA images compared to conventional 2D-DSA images.
• To assess the ability of clinicians to diagnose cerebrovascular pathology using 4D-DSA.
• To compare radiation dose between 4D-DSA and 2D-DSA procedures.

Main Methods:

• Two neurointerventional radiologists rated single-frame images from 15 cases of 4D-DSA and corresponding 2D-DSA.
• Image diagnostic quality was graded on a scale from 0 (non-diagnostic) to 3 (good).
• Dose area product (DAP) was recorded for all 2D-DSA and 4D-DSA acquisitions and overall procedures.

Main Results:

• The mean diagnostic quality for 4D-DSA projections was 1.75, significantly lower than 2D-DSA (2.8) (p < 0.001).
• 4D-DSA acquisitions accounted for approximately 30% of the total radiation dose compared to conventional procedures.
• A statistically significant difference in image quality was observed between virtual single-frame 4D-DSA and 2D-DSA.

Conclusions:

• Virtual single-frame 4D-DSA demonstrates a statistically significant difference in image quality compared to 2D-DSA.
• 4D-DSA imaging requires substantially less radiation dose than conventional 2D-DSA procedures.
• 4D-DSA shows promise for reducing radiation exposure in cerebrovascular imaging.