How is Critical limb ischemia diagnosed?

Critical limb ischemia (CLI) is a severe form of peripheral arterial disease (PAD) that results in inadequate blood flow to the limbs, typically the legs. Prompt diagnosis of CLI is crucial to prevent complications such as tissue loss and amputation. The diagnosis of CLI involves a combination of clinical evaluation, imaging tests, and specialized procedures.

Clinical evaluation: A healthcare professional will begin by taking a detailed medical history and conducting a physical examination. They will assess the patient's symptoms, such as leg pain, non-healing wounds, or gangrene. The presence of risk factors like smoking, diabetes, high blood pressure, and high cholesterol will also be considered.

Imaging tests: Various imaging techniques are used to evaluate blood flow and identify blockages in the arteries. These may include:

• Ultrasound: This non-invasive test uses sound waves to create images of blood vessels and measure blood flow. It can help identify narrowed or blocked arteries.


• Angiography: In this procedure, a contrast dye is injected into the arteries, and X-rays are taken to visualize blood flow. It can provide detailed information about the location and severity of arterial blockages.


• Magnetic resonance angiography (MRA): MRA uses magnetic fields and radio waves to create detailed images of blood vessels. It can help assess blood flow and detect blockages.


• Computed tomography angiography (CTA): CTA combines X-rays and computer technology to produce detailed images of blood vessels. It can provide information about the extent and location of arterial blockages.

Specialized procedures: In some cases, additional tests or procedures may be required to confirm the diagnosis and assess the severity of CLI. These may include:

• Ankle-brachial index (ABI): This test compares the blood pressure in the ankle with the blood pressure in the arm. A lower ratio indicates reduced blood flow to the legs.


• Treadmill exercise test: This test involves walking on a treadmill while monitoring blood pressure and symptoms. It helps evaluate the severity of CLI and assess the patient's ability to walk.


• Transcutaneous oxygen measurement (TCOM): TCOM measures the oxygen levels in the skin, providing information about tissue perfusion and the severity of CLI.

Overall, the diagnosis of critical limb ischemia involves a comprehensive evaluation of symptoms, medical history, and specialized tests to determine the extent of arterial blockages and assess the severity of the condition. Early diagnosis and intervention are essential to prevent further complications and improve outcomes for individuals with CLI.