Glowing blood vessels in legs, non-contrast MRI scan.

Non-Contrast MRI: A Safer Way to Detect Peripheral Artery Disease?

Theo Raines in Health & Wellness November 2025 • 4 min read.

"Discover how non-contrast MRI angiography offers a radiation-free and gadolinium-free alternative for diagnosing PAD, making it safer for patients with kidney concerns."

Peripheral artery disease (PAD) affects millions, often leading to pain and reduced mobility. Traditional diagnosis relies on methods like contrast-enhanced magnetic resonance angiography (MRA), which uses gadolinium-based contrast agents. However, these agents pose risks, especially for individuals with kidney problems.

Gadolinium-based contrast agents have been linked to nephrogenic systemic fibrosis and gadolinium accumulation in the brain, prompting the search for safer alternatives. Non-contrast MRA techniques are emerging as promising options, offering a way to visualize blood vessels without contrast agents.

This article explores the accuracy of non-contrast MRA protocols at 3T (Tesla) for detecting and characterizing lower extremity PAD. We'll delve into how these techniques compare to gadolinium-enhanced MRA, providing insights into their effectiveness and potential benefits for patients.

Understanding Non-Contrast MRI Angiography Techniques

Glowing blood vessels in legs, non-contrast MRI scan.

Non-contrast MRA utilizes various techniques to visualize blood vessels without contrast agents. These methods rely on the natural properties of blood flow and magnetic fields to create images of the arteries. Two established non-contrast MRA protocols are quiescent-interval single-shot (QISS) and a combination of quadruple inversion recovery (QIR) with electrocardiogram-gated fast spin echo (ECG-FSE).

Researchers compared the diagnostic accuracy of QISS and QIR/ECG-FSE protocols against gadolinium-enhanced MRA at 3T for evaluating lower extremity PAD. The study involved 20 patients with PAD and intermittent claudication, who underwent both non-contrast and contrast-enhanced MRA scans.

Quiescent-Interval Single-Shot (QISS): This technique employs balanced steady-state free precession readout, time-of-flight effects, and a tracking saturation band to image inflowing arterial blood. QISS does not require image subtraction, making it less sensitive to motion artifacts.
Quadruple Inversion Recovery (QIR) with ECG-Gated Fast Spin Echo (ECG-FSE): QIR is used for the abdominopelvic station, while ECG-FSE is used for the extremities. ECG-FSE relies on signal intensity differences between fast-flowing arterial blood during systole and slow-flowing blood during diastole. Images of arterial blood are obtained by subtraction, eliminating signal from venous blood and stationary tissues.

Two radiologists independently evaluated the vessel segments for vascular stenosis, diagnosis confidence, graft presence, and Trans-Atlantic Inter-Society Consensus (TASC) II classification for each station. Diagnostic accuracies and agreement were assessed to determine the effectiveness of each non-contrast technique.

The Future of PAD Diagnosis

Non-contrast MRA techniques like QISS and QIR/ECG-FSE offer comparable diagnostic accuracies with high specificity for detecting PAD. Either protocol provides a valuable alternative to gadolinium-enhanced MRA, particularly for patients with kidney concerns or those seeking a radiation-free imaging option. As MRI technology advances, non-contrast methods are poised to play an increasingly important role in vascular imaging.

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Everything You Need To Know

What is non-contrast MRI angiography and why is it important?

Non-contrast MRI angiography is a method used to visualize blood vessels without injecting contrast agents into the body. This is particularly important because traditional contrast agents, especially those containing gadolinium, can pose risks to patients, particularly those with kidney problems. It is significant as it offers a safer alternative for diagnosing conditions like peripheral artery disease (PAD).

What are gadolinium-based contrast agents and why is there a need to avoid them?

Gadolinium-based contrast agents are substances used in traditional MRI to enhance the visibility of blood vessels. However, they have been linked to nephrogenic systemic fibrosis in patients with kidney issues and also to gadolinium accumulation in the brain. Because of these risks, there is a growing need for safer imaging techniques that do not rely on these agents. Non-contrast MRA helps to avoid these risks.

What is QISS (Quiescent-Interval Single-Shot) and why is it significant?

QISS, or Quiescent-Interval Single-Shot, is a non-contrast MRA technique that uses balanced steady-state free precession readout, time-of-flight effects, and a tracking saturation band to image inflowing arterial blood. It is notable because it does not require image subtraction, which makes it less susceptible to motion artifacts. Its significance lies in its ability to provide clear images of blood vessels without the need for contrast agents, reducing risks associated with gadolinium.

What is QIR/ECG-FSE (Quadruple Inversion Recovery with ECG-Gated Fast Spin Echo) and why is it important?

QIR/ECG-FSE, or Quadruple Inversion Recovery with ECG-Gated Fast Spin Echo, is another non-contrast MRA technique. QIR is used for the abdominopelvic station, while ECG-FSE is used for the extremities. ECG-FSE relies on signal intensity differences between fast-flowing arterial blood during systole and slow-flowing blood during diastole. Images of arterial blood are obtained by subtraction, eliminating signal from venous blood and stationary tissues. This method is important because it offers an alternative way to visualize blood vessels without contrast, useful for patients who cannot receive gadolinium.

How effective are non-contrast MRA techniques compared to traditional methods for detecting Peripheral Artery Disease (PAD)?

Non-contrast MRA techniques like QISS and QIR/ECG-FSE offer comparable diagnostic accuracy with high specificity for detecting PAD, similar to traditional gadolinium-enhanced MRA. The significance is that it can reduce the risks associated with gadolinium-based contrast agents, making it a safer option for patients with kidney concerns or those who prefer to avoid radiation. This offers a valuable alternative in vascular imaging.