CT Angiography For Cerebral Aneurysms Smaller Than 3 mm

January 22, 2018

CT angiography can help clinicians detect cerebral aneurysms smaller than 3 mm.

CT angiography accurately detects small cerebral aneurysms smaller than 3 mm, according to a study published in Radiology.

Researchers from China performed a retrospective study to assess the accuracy of CT angiography for the diagnosis of cerebral aneurysms that were 5 mm or smaller, using digital subtraction angiography (DSA) as a reference standard.

The study group included 1,366 patients who underwent both CT angiography and DSA. Two readers assessed CT performance for depiction of aneurysms, size, location, and status of rupture.

The results showed DSA detected 711 small aneurysms in 579 patients. Using DSA as the reference standard the researchers found:

CT angiography sensitivity	97.1% (562 of 579 patients)	97.4% (564 of 579 patients)
CT angiography specificity	98.5% (451 of 458)	99.1% (454 of 458)
CT angiography accuracy	97.7% (1013 of 1037)	98.2% (1018 of 1037)
Per-aneurysm basis sensitivity	95.2% (677 of 711)	95.4% (678 of 711)
Per-aneurysm basis specificity	96.6% (451 of 467)	97.0% (454 of 468)
Per-aneurysm basis accuracy	95.8% (1128 of 2278)	96.0% (1132 of 1179)

The researchers noted that the sensitivities of CT angiography were lower for detection of aneurysms smaller than 3 mm and unruptured compared with aneurysms that were 3 to 5 mm and ruptured. There were no differences for the sensitivities of CT angiography for diagnosis of aneurysms in the anterior versus posterior circulation. Excellent or good interreader agreement was found for detection of intracranial aneurysms on a per-patient and per-aneurysm basis.