Glowing blood vessels in legs representing non-contrast MRI for PAD diagnosis

Cutting-Edge Imaging: Non-Contrast MRI Scans for Peripheral Artery Disease

Reese Marlowe in Health & Wellness November 2025 • 4 min read.

"Discover how non-contrast MRI angiography at 3T offers a safe and accurate alternative for detecting peripheral artery disease, especially for those with kidney concerns."

Peripheral Artery Disease (PAD) affects millions, often requiring imaging to diagnose and manage the condition. Traditionally, Gadolinium-enhanced Magnetic Resonance Angiography (Gd-MRA) has been the standard, but it poses risks, especially for individuals with kidney issues. The accumulation of gadolinium in the brain is also a growing concern.

Fortunately, non-contrast MR angiography techniques are emerging as robust alternatives. These methods, including ECG-gated fast spin echo (ECG-FSE) and quiescent-interval single-shot (QISS), offer detailed visualization of blood vessels without the need for contrast agents. The technology continues to improve, providing better detection of slow-flowing blood and reducing motion artifacts.

Recent studies are focusing on enhancing the accuracy of these non-contrast methods by utilizing 3T MRI scanners, which offer a 2-fold increase in magnetization compared to 1.5T scanners. This article explores the diagnostic accuracy of two established non-contrast MR angiography protocols at 3T for evaluating lower extremity PAD, comparing them to Gd-MRA.

Non-Contrast MRI: A Safer Path to PAD Diagnosis

Glowing blood vessels in legs representing non-contrast MRI for PAD diagnosis

A study published in the Journal of Vascular and Interventional Radiology compared two non-contrast MR angiography protocols—QISS and QIR/ECG-FSE—against the traditional Gd-MRA at 3T. The research involved 20 patients with PAD, focusing on the accuracy of these methods in detecting and characterizing lower extremity arterial disease.

The study assessed several parameters, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy. Key findings revealed that both QISS and QIR/ECG-FSE demonstrated comparable diagnostic accuracy to Gd-MRA, with high specificity.

QISS (Quiescent-Interval Single-Shot): Uses balanced steady-state free precession readout and time-of-flight effects to image arterial blood without image subtraction.
QIR/ECG-FSE (Quadruple Inversion Recovery/Electrocardiogram-Gated Fast Spin Echo): Combines quadruple inversion recovery for the abdominopelvic region with ECG-gated fast spin echo for the extremities.
Gd-MRA (Gadolinium-enhanced Magnetic Resonance Angiography): Traditional method using gadolinium-based contrast agents to enhance image quality.

The results indicated that reader confidence was high across all methods, with QISS showing particularly strong performance. Importantly, the study found no significant statistical difference in assessing disease severity using TASC II criteria between the non-contrast methods and Gd-MRA. This suggests that QISS and QIR/ECG-FSE can serve as reliable alternatives to Gd-MRA for patients with PAD.

The Future of PAD Imaging: Safe, Accurate, and Accessible

Non-contrast MR angiography techniques like QISS and QIR/ECG-FSE offer a promising alternative for diagnosing and managing PAD, especially for patients who cannot undergo gadolinium-based imaging. As technology advances and imaging times decrease, these methods are poised to become more widely adopted, ensuring safer and more accessible care for individuals at risk of peripheral artery disease.

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Everything You Need To Know

What are the primary advantages of using non-contrast MRI angiography, like QISS and QIR/ECG-FSE, for diagnosing Peripheral Artery Disease (PAD)?

Non-contrast MRI angiography, including techniques like QISS and QIR/ECG-FSE, offers several advantages. Primarily, they eliminate the need for Gadolinium-enhanced Magnetic Resonance Angiography (Gd-MRA), avoiding the risks associated with gadolinium-based contrast agents, particularly for patients with kidney issues. Furthermore, they provide detailed visualization of blood vessels, offering comparable diagnostic accuracy to Gd-MRA, as demonstrated in studies. The use of 3T MRI scanners enhances the image quality, improving the detection of slow-flowing blood and reducing motion artifacts. This makes non-contrast methods a safer and equally effective alternative for diagnosing and managing PAD.

How does the diagnostic accuracy of QISS and QIR/ECG-FSE compare to Gd-MRA in the context of Peripheral Artery Disease (PAD) evaluation?

Studies comparing QISS and QIR/ECG-FSE with Gd-MRA, specifically at 3T, reveal that both non-contrast methods demonstrate comparable diagnostic accuracy to the traditional Gd-MRA. The research, which involved patients with PAD, focused on assessing parameters like sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy. The findings indicated that QISS and QIR/ECG-FSE have high specificity, allowing them to be reliable alternatives to Gd-MRA. Moreover, there was no significant statistical difference in assessing disease severity using TASC II criteria, further supporting their effectiveness.

Can you explain the specific techniques used in QISS and QIR/ECG-FSE for non-contrast MRI angiography?

QISS (Quiescent-Interval Single-Shot) utilizes balanced steady-state free precession readout and time-of-flight effects to image arterial blood without the need for image subtraction or contrast agents. It leverages the inherent properties of blood flow to generate detailed images. QIR/ECG-FSE (Quadruple Inversion Recovery/Electrocardiogram-Gated Fast Spin Echo) combines quadruple inversion recovery for the abdominopelvic region with ECG-gated fast spin echo for the extremities. This method employs multiple inversion pulses to null signals from stationary tissues, highlighting the blood vessels. Both methods are designed to visualize blood vessels without the need for gadolinium contrast, making them safer alternatives.

Why is the development of non-contrast MRI techniques like QISS and QIR/ECG-FSE significant for patients with Peripheral Artery Disease (PAD)?

The development of non-contrast MRI techniques, such as QISS and QIR/ECG-FSE, is highly significant for patients with PAD. These methods provide a safer alternative to Gd-MRA, particularly for patients with kidney problems, as they eliminate the risks associated with gadolinium contrast agents. Furthermore, the accumulation of gadolinium in the brain is a growing concern. By offering comparable diagnostic accuracy, QISS and QIR/ECG-FSE ensure that patients can receive accurate diagnoses and management of PAD without the potential adverse effects of contrast agents. This advancement promotes safer and more accessible care for individuals at risk of PAD.

How does the use of 3T MRI scanners improve the performance of non-contrast MR angiography techniques like QISS and QIR/ECG-FSE?

The utilization of 3T MRI scanners significantly enhances the performance of non-contrast MR angiography techniques, including QISS and QIR/ECG-FSE. 3T scanners offer a 2-fold increase in magnetization compared to 1.5T scanners, which translates to improved image quality. This enhanced image quality leads to better detection of slow-flowing blood and reduces motion artifacts, resulting in more accurate and detailed visualization of blood vessels. This advancement allows for more reliable diagnoses and assessments of PAD using non-contrast methods, contributing to the overall effectiveness and safety of these techniques.