Stroke Audit Finds Long CT-to-CTA Times

A regional UK audit found wide variation in imaging intervals among patients referred for mechanical thrombectomy and identified potentially modifiable barriers to timely vascular imaging.

By
Andrea Surnit
July 14, 2026
5 min

Conexiant

Objective:

To evaluate the intervals between computed tomography (CT) and computed tomography angiography (CTA) in patients with large-vessel occlusion stroke referred for mechanical thrombectomy.

Approach:

Study Design: A regional retrospective audit of 200 consecutive patients referred from 18 primary stroke centers to a London comprehensive stroke center between January 2022 and March 2023.
Patient Selection: 179 patients with acute large-vessel occlusion ischemic stroke were included after excluding 21 patients with missing timing data.
Primary Measure: The interval from CT to CTA at the referring hospital was measured, with operational definitions for 'excellent' and 'adequate' intervals established.
Data Analysis: Mean and median CT-to-CTA intervals were calculated, and hospital-level comparisons were made among centers referring more than eight patients.

Key Findings:

The mean CT-to-CTA interval at referring centers was 62 minutes, with a median of 55 minutes.
At the comprehensive stroke center, the mean and median intervals were 1 minute.
Approximately 55% of patients received CTA within 10 minutes; 45% had longer intervals, with 30% waiting at least 60 minutes.
One primary stroke center had a mean interval of 5 minutes or less, and four had a mean interval of 10 minutes or less.

Interpretation:

Limitations:

Retrospective design and small, uneven hospital samples.
Missing timing data and lack of adjustment for patient- and hospital-level factors.
Low survey response rate and failure to measure time to referral, transfer, groin puncture, reperfusion, or functional recovery.