Chapter II: Diagnostic methods

Area of Science:

• Vascular Medicine
• Diagnostic Imaging
• Interventional Radiology

Background:

• Critical limb ischaemia (CLI) diagnosis and management rely heavily on vascular assessment.
• Non-invasive studies are crucial for evaluating CLI severity and planning interventions.
• Traditional methods like ankle-brachial index have limitations in specific patient populations.

Purpose of the Study:

• To review the role and efficacy of various non-invasive vascular studies in diagnosing and managing CLI.
• To compare the diagnostic capabilities of different imaging modalities for CLI.
• To provide guidance on selecting appropriate imaging techniques based on patient factors and clinical needs.

Main Methods:

• Review of non-invasive vascular assessment techniques for CLI.
• Discussion of ankle-brachial index, toe-brachial index, and transcutaneous oxygen pressure measurements.
• Evaluation of duplex ultrasound, computed tomography angiography (CTA), and magnetic resonance angiography (MRA) in CLI.
• Comparison with contrast angiography as the gold standard.

Main Results:

• Ankle-brachial index is a first-line test, but toe-brachial index may be superior in diabetic or renal failure patients.
• Duplex ultrasound is a key non-invasive tool, integrating hemodynamics with imaging.
• CTA and MRA provide detailed anatomical information, aiding intervention planning and decision-making, with comparable results to contrast angiography.
• Transcutaneous oxygen pressure is valuable for assessing rest pain and ulcerations.

Conclusions:

• Non-invasive vascular studies, particularly duplex ultrasound, CTA, and MRA, are vital for comprehensive CLI assessment.
• The choice of imaging modality depends on factors like availability, cost, and patient characteristics.
• These advanced techniques improve diagnostic accuracy and facilitate effective treatment planning for CLI.