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

Ludger Feyen; Patrick Haage; Patrick Freyhardt; Peter Schott; Marcus Katoh; Christian Blockhaus; Katharina Melber

doi:10.5334/jbsr.2749

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

J Belg Soc Radiol. 2022 Apr 26;106(1):18. doi: 10.5334/jbsr.2749. eCollection 2022.

Authors

Ludger Feyen^{1

2

3}, Patrick Haage^{2

4}, Patrick Freyhardt^{1

2}, Peter Schott¹, Marcus Katoh¹, Christian Blockhaus^{2

5}, Katharina Melber⁶

Affiliations

¹ Helios Klinikum Krefeld, DE.
² University Witten/Herdecke, Faculty of Health, School of Medicine, Alfred-Herrhausen-Straße 50, 58448 Witten, DE.
³ Diagnostic and Interventional Radiology, HELIOS University Hospital Wuppertal, University Witten/Herdecke, Germany, Heusnerstraße 40, 42283 Wuppertal, DE.
⁴ Helios Klinikum Wuppertal, DE.
⁵ Heart Centre Niederrhein, Department of Cardiology, Helios Clinic Krefeld, DE.
⁶ Sana Klinikum Duisburg, DE.

Abstract

Purpose: To evaluate the detection rate of intracranial aneurysms on reconstructed thin slice non enhanced CT (NECT) scans.

Methods: NECT scans from 34 patients with 35 aneurysms and 35 individuals without aneurysms were collected. Thin slice maximum intensity projections of the NECT scans were reconstructed. One observer evaluated the native images twice with a time interval of six month between both passes with respect to the prevalence and location of an aneurysm. The size and location of the aneurysms were evaluated in corresponding CT-Angiography and Time of flight datasets. A logit regression analysis was performed with size and location as dependent variables. 2 × 2 tables were constructed. The sensitivity and false negative rate were calculated for aneurysms with 0-6.9 mm, 7-9.9 mm and 10-20 mm and the under the curve (AUC) was calculated.

Results: The overall detection rate of the aneurysms was 63% for the first pass and 66% for the second pass in the reconstructed NECT scans. The detection rate of aneurysms is size dependent. The sensitivity to detect aneurysms with a size of 0-6.9 mm was 0.09 and 0.03, for aneurysms with a size of 7-9.9. mm was 0.8 and 0.7 and for aneurysms with a size of 10-20 mm was 0.92 for both passes.The AUC was 0.77 for the first pass and 0.78 for the second pass.

Conclusions: NECT scans can be used to detect a significant proportion of intracranial aneurysms larger than 7 mm if properly displayed and reconstructed. These patients should receive further vascular imaging to prevent future aneurysm related subarachnoid hemorrhage.

Keywords: NECT; Phases score; intracranial aneurysm; subarachnoid hemorrhage; unruptured intracranial aneurysm.