Thin Slice Unenhanced Brain CT Can Detect Aneurysms Larger than 7 mm

Area of Science:

• Neuroradiology
• Medical Imaging
• Cerebrovascular Diseases

Background:

• Intracranial aneurysms pose a significant risk of subarachnoid hemorrhage.
• Early and accurate detection is crucial for effective management.
• Non-enhanced CT (NECT) is a common neuroimaging modality.

Purpose of the Study:

• To evaluate the detection rate of intracranial aneurysms using reconstructed thin-slice NECT scans.
• To assess the influence of aneurysm size on detection rates.
• To determine the diagnostic performance of NECT for intracranial aneurysms.

Main Methods:

• Retrospective analysis of NECT scans from 34 patients with aneurysms and 35 controls.
• Reconstruction of thin-slice maximum intensity projections (MIPs) from NECT data.
• Evaluation of aneurysm prevalence, location, and size by a single observer, with comparison to CT-Angiography and Time-of-Flight datasets.

Main Results:

• Overall detection rates for intracranial aneurysms on NECT were 63% (first pass) and 66% (second pass).
• Detection sensitivity was highly size-dependent: 9% for 0-6.9 mm, 70-80% for 7-9.9 mm, and 92% for 10-20 mm aneurysms.
• Area Under the Curve (AUC) values were 0.77 and 0.78, indicating moderate diagnostic performance.

Conclusions:

• Reconstructed thin-slice NECT scans can effectively detect larger intracranial aneurysms (≥7 mm).
• Smaller aneurysms (<7 mm) have a low detection rate on NECT, necessitating further investigation.
• NECT findings suggestive of larger aneurysms warrant follow-up vascular imaging to prevent hemorrhage.