Comparison of 2D and 3D digital subtraction angiography in evaluation of intracranial aneurysms

Abstract

Background and purpose: Although digital subtraction angiography (DSA) is considered the criterion standard for depiction of intracranial aneurysms, it is often difficult to determine the relationship of overlapping vessels to aneurysms when using 2D DSA. We compared 2D and 3D DSA in evaluation of intracranial aneurysms.

Methods: Thirty-six consecutive patients with cerebral aneurysms underwent 2D and 3D DSA. After standard 2D DSA, rotational DSA was performed. Maximum intensity projection (MIP) and shaded surface display (SSD) images were created from the rotational DSA data sets. All images were assessed randomly for overall image quality, presence of aneurysm, presence of aneurysmal lobulation, visualization of aneurysmal neck, and relationship to adjacent vessels. Data analysis was conducted for 40 aneurysms treated by clip placement.

Results: One aneurysm that was not detected at 2D DSA was classified as uncertain on the basis of rotational DSA. All aneurysms were classified as probably or definitively present on the basis of MIP and SSD findings. Overall image quality of rotational DSA, MIP, and SSD was statistically inferior to that of the standard 2D DSA for visualization of distal arteries. However, MIP and SSD images were significantly superior to those of standard 2D DSA for all other evaluations. For detection of lobulation, SSD images were significantly superior to other images, and for visualization of aneurysmal neck and relationship to neighboring arteries, SSD images were significantly superior to those of rotational DSA. For evaluation of the relationship to neighboring arteries, MIP images were significantly superior to those of rotational DSA.

Conclusion: Three-dimensional DSA, especially SSD, provided more detailed information for evaluating cerebral aneurysms than did standard 2D and rotational DSA.

Fig 1.

Images from the case of a 64-year-old female patient with multiple aneurysms. A, Anteroposterior standard 2D DSA shows right anterior (arrow) and posterior communicating (double arrows) artery aneurysms, but the right middle cerebral artery aneurysm cannot be visualized (arrowhead). B, Lateral standard 2D DSA shows right anterior (arrow) and posterior communicating (double arrows) artery aneurysms, but the right middle cerebral artery aneurysm cannot be visualized (arrowhead). C, Rotational DSA image, which can be seen stereoscopically, clearly shows the relationship of the right anterior (arrow) and posterior communicating (double arrows) artery aneurysms to the neighboring vessels and to the aneurysmal necks. The right middle cerebral artery aneurysm (arrowhead) can be seen, but the relationship to the neighboring vessels and the aneurysmal neck are obscured by the superimposition of the surrounding arteries. Note that minimal misregistrations are observed. D, MIP image clearly shows the relationship of the right anterior (arrow) and posterior communicating (double arrows) artery aneurysms to the neighboring vessels and to the aneurysmal necks. The right middle cerebral artery aneurysm (arrowhead) can be seen, but the relationship to the neighboring vessels and the aneurysmal neck are obscured by the superimposition of the surrounding arteries. Minimal misregistrations do not create artifacts. E, SSD image clearly shows the relationship of the right anterior (arrow) and posterior communicating (double arrows) artery aneurysms to the neighboring vessels and to the aneurysmal necks. The right middle cerebral artery aneurysm (arrowhead) is seen, and the relationship to the neighboring vessels and aneurysmal neck are easily recognized. Minimal misregistrations do not create artifacts.

Fig 2.

Images from the case of a 67-year-old female patient with a right middle cerebral artery aneurysm. A, Anteroposterior standard 2D DSA image. The aneurysm can be identified (arrow), but the identification of the presence of aneurysmal lobulation and the relationship to neighboring arteries is difficult. B, Lateral standard 2D DSA image. The aneurysm can be identified (arrow), but the presence of aneurysmal lobulation and the relationship to neighboring arteries is difficult to discern. C, Rotational DSA image, which can be seen stereoscopically, clearly shows the aneurysm (arrow), but the superimposition of many neighboring arteries makes it difficult to evaluate the presence of aneurysmal lobulation and the relationship to neighboring arteries. D, MIP image clearly shows the aneurysmal lobulation and relationship to neighboring arteries (arrow). E, SSD image is especially clear in showing the aneurysmal lobulation and relationship to neighboring arteries.

Fig 3.

Images from the case of a 61-year-old male patient with a left anterior communicating artery aneurysm. A, Lateral standard 2D DSA image. Few image artifacts are noted. B, Rotational DSA image. Image artifacts are severe. C, MIP image. Image artifacts create blurring (arrowheads). D, SSD image. Image artifacts create abnormal irregular structures (arrowheads).