Based on a study published online in the journal Radiology, subtracted 320-detector row volumetric CT angiography (CTA), which enables bone-free imaging, is significantly better to non-subtracted volumetric CTA for the detection of brain aneurysms and should be considered as the first imaging option procedure for assessing potential aneurysms.
The study discovered that CTA was analogous to 3D rotational digital subtraction angiography (DSA), which is presently considered the ‘gold standard despite its invasiveness, complexity and relatively high costs,’ explained Wenhua Chen, MD, of the Third Affiliated Hospital of Suzhou University, Changzhou, China.
“Subtracted volumetric CT angiography could replace invasive digital subtraction angiography as the first-line imaging technique for noninvasive evaluation of suspected cerebral aneurysms because of its high diagnostic sensitivity,” the researchers noted.
Findings were predicated on an assessment of 282 consecutive patients who received CTA for a suspected brain aneurysm between February 2011 and October 2012. All patients also underwent 3D rotational DSA, which was used as the reference standard.
A total of 239 brain aneurysms were found in 198 patients on the basis of 3D DSA. While non-subtracted CTA was able to reveal more than 96 percent of the aneurysms, those that were close to bone tissue went undetected.
“The aneurysms missed at nonsubtracted volumetric CT angiography were generally located in the internal carotid artery. Detection of cerebral aneurysms adjacent to bone tissue was still challenging at nonsubtracted volumetric CT angiography because of the presence of overlying bone structures,” wrote Chen and peers.
Subtracted CTA presented 99.2 percent of aneurysms, while its overall precision was not that much different from 3D DSA.
However, Chen and the rest of research team found slight disadvantages to subtracted CTA. The system has difficulty in detecting microaneurysms, as it missed two during the process of this study. Additionally, subtracted CTA cannot show atherosclerotic plaque or aneurysmal calcification. And while removing bone tissue from images helps in the diagnosis of brain aneurysms, knowing the relationship of the aneurysm to bone structures is still very important for therapy.
“Subtracted 320–detector row volumetric CT angiography is excellent for the detection of cerebral aneurysms and might be considered as a first-line imaging technique for the noninvasive evaluation of cerebral aneurysms because of its high diagnostic accuracy in some circumstances; however, it may still result in some missed microaneurysms,” the researchers concluded.