Related Experiment Videos
Non-invasive testing for cerebrovascular disease
1St Vincent's Hospital, Sydney, University of New South Wales, Australia.
Insights
Choosing the right diagnostic test for cerebrovascular disease involves considering cost, accuracy, and patient needs. Intraarterial digital subtraction angiography is the gold standard, but duplex ultrasonography offers comparable accuracy and plaque analysis.
Area of Science:
- Vascular Neurology
- Diagnostic Imaging
- Health Economics
Background:
- Diagnosing occlusive cerebrovascular disease requires careful selection of investigations based on multiple factors.
- Intraarterial digital subtraction angiography (IDSA) is the gold standard for accuracy, but requires precise stenosis measurement.
- Duplex ultrasonography (DU) is a valuable alternative, offering high accuracy and plaque morphology analysis.
Purpose of the Study:
- To evaluate the diagnostic utility and cost-effectiveness of various imaging modalities for cerebrovascular disease.
- To determine appropriate use of diagnostic tests for transient ischemic attacks (TIAs) and asymptomatic carotid stenosis.
- To assess the cost-effectiveness of preoperative and postoperative imaging surveillance.
Main Methods:
- Review of 2651 duplex ultrasonography tests performed in a laboratory setting.
- Analysis of test utilization for different clinical indications including TIAs, amaurosis, cervical bruit, and vertebrobasilar ischemia.
- Comparison of costs and diagnostic accuracy of IDSA, DU, magnetic resonance angiography (MRA), and spiral computed tomography angiography (SCTA).
Main Results:
- DU is nearly as accurate as IDSA and provides plaque morphology data.
- DU was used for various indications, including pre-operative assessment (22.9%) and surveillance (37.7%).
- Routine preoperative brain CT is not cost-effective; postoperative surveillance is justified at $505 per patient over 4 years.
Conclusions:
- Test selection for cerebrovascular disease should balance availability, cost, accuracy, and invasiveness.
- DU is a highly accurate and versatile tool for diagnosing carotid stenosis and assessing plaque.
- Confirming asymptomatic carotid stenosis >60% with IDSA, MRA, or SCTA is recommended; postoperative surveillance is cost-effective.
Abstract:
Selecting the appropriate investigation for diagnosing occlusive cerebrovascular disease depends on the availability, cost, accuracy, invasiveness and the purpose of the test. Intraarterial digital subtraction angiography remains the gold standard, but for accuracy the stenosis should be measured rather than estimated. Duplex ultrasonography is almost as accurate and can additionally analyse plaque morphology. Of 2651 duplex tests carried out in our laboratory, 12.2% were for reversible ischaemic attacks, 2.7% for amaurosis, 12.1% for cervical bruit and 4.3% for vertebrobasilar ischaemia. Duplex within 30 days of operation was carried out on 607 patients (22.9%) and surveillance on 1000 others (37.7%). Asymptomatic carotid stenosis > 60% should be confirmed by intra-arterial digital subtraction angiography, magnetic resonance angiography or spiral computed tomography angiography. For typical transient ischaemic attacks, duplex or angiography alone is adequate but when the clinical presentation is atypical, a confirming test is required. Routine preoperative brain computed tomography is not cost-effective, being equivalent to US$ 4300-11840 per perioperative stroke in our institution. Postoperative surveillance is justified, costing only US$ 505 per patient over 4 years.