Patient-specific timing for bolus-chase peripheral MR angiography

Area of Science:

• Medical Imaging
• Radiology
• Vascular Imaging

Background:

• Peripheral artery disease (PAD) diagnosis relies on imaging techniques.
• MR angiography (MRA) offers non-invasive visualization of peripheral arteries.
• Optimizing contrast timing in MRA is crucial for diagnostic image quality.

Purpose of the Study:

• To develop a patient-specific timing algorithm for three-station moving-table MR angiography of the peripheral arteries (pMRA).
• The algorithm aims to optimize arterial opacification while minimizing venous enhancement.
• This addresses a key challenge in achieving high-quality peripheral MRA.

Main Methods:

• A retrospective study involving two patient cohorts (n=71 for development, n=59 for validation).
• A patient-specific timing algorithm was developed using contrast bolus transit times at 1.5 Tesla.
• The algorithm was applied to pMRA protocols, with image quality assessed by blinded readers.

Main Results:

• Patient-specific contrast transit times (aorta-to-foot) varied significantly (mean 17.8 ± 8.2 s).
• The developed algorithm resulted in diagnostic pMRA in all patients, with 81-83% showing no/minimal venous enhancement.
• Ischemic patients exhibited longer transit times and greater venous enhancement.

Conclusions:

• A timing algorithm tailored to individual hemodynamics significantly improves pMRA quality.
• This patient-specific approach effectively minimizes venous enhancement.
• The method enhances diagnostic accuracy for peripheral artery imaging.