3D bone subtraction CT angiography for the evaluation of intracranial aneurysms: a comparison study with 2D bone subtraction CT angiography and conventional non-subtracted CT angiography

BACKGROUND: Bone subtraction computed tomography angiography (BSCTA) is better able to facilitate the detection of intracranial aneurysms adjacent to bone structures compared to conventional non-subtracted CTA (CNSCTA). However, the comparison of the diagnostic accuracy of three-dimensional (3D) and two-dimensional (2D) BSCTA and conventional CTA in evaluating intracranial aneurysms remains unclear. PURPOSE: To evaluate whether 3D BSCTA has a superior diagnostic accuracy to those of 2D BSCTA and CNSCTA in a single center with the same instrument. MATERIAL AND METHODS: Sixty-three patients received 3D BSCTA, 2D BSCTA, and NSCTA for the detection and treatment planning of suspected intracranial aneurysms. The angiography readouts were reviewed by two independent radiologists. The sensitivity of CTA in detecting aneurysm was analyzed on a per-aneurysm and per-patient basis, using 3D digital subtraction angiography (DSA) and surgical findings as the gold standard. The potential of endovascular treatment or surgical clipping was also assessed based on information provided by the CTA. RESULTS: A total of 66 aneurysms were detected in 54 patients. The overall sensitivity, specificity, positive, and negative predictive values of 3D BSCTA were all 100%, and these values for 2D BSCTA were 98.1%, 100%, 100%, and 90%, respectively. The total sensitivity, specificity, positive, and negative predictive values of CNSCTA were 94.4%, 100%, 100%, and 75%, respectively. Finally, 100%, 98.1%, and 85.2% patients received appropriate treatment decisions after 3D BSCTA, 2D BSCTA, and CNSCTA imaging, respectively. CONCLUSION: 3D BSCTA has a higher sensitivity for the detection of small aneurysms and aneurysms adjacent to bone compared to 2D BSCTA or CNSCTA, which were still able to obtain sufficient information for the detection of intracranial aneurysms and therapeutic decision-making.