[Experimental study of pseudo-stenosis artifact on three-dimensional DSA]

Area of Science:

• Medical Imaging
• Interventional Neuroradiology
• Biomedical Engineering

Background:

• Rotational three-dimensional digital subtraction angiography (3D-DSA) is crucial for interventional neuroradiology, particularly in treating cerebral aneurysms.
• Clinical observations have noted pseudo-stenosis artifacts in vessels oriented vertically to the rotational axis during 3D-DSA procedures.

Purpose of the Study:

• To experimentally confirm and analyze the pseudo-stenosis artifact observed in 3D-DSA.
• To investigate the relationship between vessel orientation, length, and the occurrence of diameter underestimation in 3D-DSA.

Main Methods:

• Experiments were conducted using 4.5-millimeter diameter vessel phantoms of varying lengths (10-50 mm).
• Attenuation measurements (DSA pixel values) were recorded at 44 angular positions for each phantom.
• DSA pixel values were plotted against phantom length to identify artifact patterns.

Main Results:

• Pseudo-stenosis artifact was experimentally confirmed in vessel phantoms.
• Saturated DSA pixel values were observed in tangent projections of phantoms 30 mm or longer.
• A maximum diameter reduction of 27.4% was measured for a 50 mm phantom, indicating significant underestimation.

Conclusions:

• The study confirms that 2D data perpendicular to the rotational axis are inaccurate for straight, long vessels in 3D-DSA.
• This inaccuracy leads to the display of vessels as smaller than their true diameter, posing a potential issue in endovascular therapy planning.