Stepped-Wedge Cluster Randomized Trial of AI-Assisted CTA Detection for Intracranial Aneurysms in Regional Hospitals

N/ANot Yet RecruitingNCT07124624

Jinling Hospital, China14,400 enrolled

Overview

This study (IDEAL 2) is a nationwide stepped-wedge cluster-randomized trial designed to prospectively enroll over 14,400 patients undergoing outpatient head CT angiography (CTA). The trial will be conducted across more than 72 regional hospitals in China. Clusters were randomly assigned to nine randomization groups. In accordance with the stepped-wedge design, clusters will sequentially transition from the control condition (standard human diagnosis) to the intervention condition (AI-assisted diagnosis) at regular intervals over a 10-month period, until all clusters receive the intervention. The primary outcome is the detection rate of intracranial aneurysms. Secondary outcomes include patient prognosis and clinical outcomes.

A multicenter, stepped-wedge cluster-randomized trial will be conducted in regional hospitals, specifically prefecture-level and county-level institutions across China. Each cluster (i.e., hospital) will enroll approximately 200 patients undergoing head computed tomography angiography (CTA), yielding a total sample size of at least 14,400 participants. The trial consists of nine steps, each lasting one month. Clusters will transition sequentially from the control condition to the intervention condition based on stratified randomization, until all clusters have received the intervention. In the control group, diagnoses and treatments will follow local standard clinical protocols. In the intervention group, diagnostic procedures will be supported by an artificial intelligence (AI)-assisted system. The primary outcome is the detection rate of intracranial aneurysms, as determined from radiology reports at the patient level. Secondary outcomes include additional diagnostic performance metrics on CTA, such as the detection of intracranial arterial stenosis, occlusion, and tumors. Follow-up evaluations at 3 and 12 months will assess treatment-related indicators-including repeat head CTA or magnetic resonance angiography (MRA), hospitalization rates, and digital subtraction angiography (DSA) utilization-as well as clinical outcomes related to aneurysm events. These measures aim to evaluate both the short- and long-term impacts of AI-assisted diagnosis on routine clinical practice and patient prognosis.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

Interventions

AI-Assisted CTA InterpretationDEVICE

A locked, independently validated deep learning model was used to assist radiologists in interpreting head CTA scans. The model was trained on 16,546 CTA cases and externally validated on an independent set of 900 DSA-verified CTA cases, achieving a patient-level sensitivity of 0.943 and an average of 0.187 false positives per case.

Standard CTA InterpretationDIAGNOSTIC_TEST

Head CTA interpretation performed by radiologists using local routine diagnostic workflows without AI support.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: -Patients in the outpatient setting who are scheduled to undergo head CTA scanning Exclusion Criteria: * Age \< 18 years * History of cerebrovascular surgery involving any metallic implants (e.g., aneurysm embolization, aneurysm clipping, or vascular stenting) * Modified Rankin Scale (mRS) score \> 3 * Refuse to sign written informed consent * Contraindications to CTA examination * CTA scan failure, incomplete imaging data, or image quality insufficient for diagnostic evaluation

Outcomes

Primary Outcomes

Detection rate of intracranial aneurysms

The proportion of patients diagnosed with intracranial aneurysms among all individuals undergoing CTA during the observation period. This outcome is used to compare the diagnostic effectiveness of conventional radiologist interpretation based on local clinical practice versus AI-assisted diagnosis in detecting intracranial aneurysms.

Time frame: Day 1

Secondary Outcomes

Detection rates of other intracranial lesions except aneurysms

The proportion of patients diagnosed with intracranial arterial stenosis, occlusion, arteriovenous malformation (AVM), Moyamoya disease, or other vascular abnormalities among all individuals undergoing CTA during the observation period.

Time frame: Day 1

Follow-up visits and referrals

The number of follow-up or referral visits, including the number of follow-up visits, number of referrals, and repeated noninvasive vascular imaging examinations (e.g., CTA, MRA, or high-resolution vessel wall MRI).