AI (Artificial Intelligence), Cluster Randomized Trial, CT Angiography, Intracranial Aneurysm
Conditions
Keywords
Intracranial aneurysm, AI (Artificial Intelligence), Stepped-wedge cluster-randomized trial
Brief summary
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.
Detailed description
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.
Interventions
DEVICEAI-Assisted CTA Interpretation
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.
DIAGNOSTIC_TESTStandard CTA Interpretation
Head CTA interpretation performed by radiologists using local routine diagnostic workflows without AI support.
Sponsors
Jinling Hospital, China
Study design
Allocation
RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Detection rate of intracranial aneurysms | Day 1 | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Detection rates of other intracranial lesions except aneurysms | Day 1 | 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. |
| Follow-up visits and referrals | At 3-month and 12-month follow-up. | 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). |
| Hospitalization | At 3-month and 12-month follow-up. | Subsequent hospitalization outcomes during patient follow-up, including the rate of hospitalization, rate of hospitalization specifically related to intracranial aneurysms and the length of hospital stay. |
| Invasive DSA examinations | At 3-month and 12-month follow-up. | Rate of patients undergoing digital subtraction angiography (DSA), along with the distribution of findings, including positive identification of aneurysms, other vascular abnormalities, or no detectable abnormalities. |
| Aneurysm treatment decisions | At 3-month and 12-month follow-up. | Distribution of aneurysm management strategies, including conservative treatment, endovascular coiling, surgical clipping, and other approaches. |
| In-hospital morbidity | At 3-month and 12-month follow-up. | In-hospital morbidity, defined as a Modified Rankin Scale (mRS) score of 3-5 at hospital discharge. The Modified Rankin Scale ranges from 0 to 6, with higher scores indicating greater disability (scores of 3-5) or death (score of 6). |
| Postoperative complications | At 3-month and 12-month follow-up. | Postoperative complications, including cerebral edema, intracranial hematoma, hydrocephalus, and recurrent thrombosis. |
| In-hospital mortality | At 3-month and 12-month follow-up. | In-hospital mortality, defined as a Modified Rankin Scale (mRS) score of 6 at hospital discharge. The Modified Rankin Scale ranges from 0 to 6, with a score of 6 indicating death. |
| All-cause mortality | At 3-month and 12-month follow-up. | All-cause mortality during patient follow-up. |
| Aneurysm-related events during follow-up | At 12-month follow-up. | Proportion of patients with aneurysm-related events during follow-up, including aneurysm growth (≥1 mm in any dimension), aneurysm rupture (non-traumatic subarachnoid hemorrhage), stroke (hemorrhagic or ischemic), de novo aneurysm formation, and aneurysm recurrence after treatment. |
| Intraoperative complications | At 3-month and 12-month follow-up. | The rate of aneurysm treatment-related complications-such as intraoperative rupture, , vasospasm, neurological injury, and other adverse events. |
Contacts
Primary ContactLongjiang Zhang, Ph.D, MD
Backup ContactBin Hu, MS
Outcome results
None listed