Free-breathing non-contrast-enhanced flow-independent MR angiography using REACT: A prospective study for pediatric vessel assessment.

In 30 seconds

This prospective, single-centre study compared free-breathing, non-contrast REACT MR angiography with contrast-enhanced multiphasic MRA for extrathoracic vessel assessment in 30 children (mean age 12.3 ± 4 years). Both techniques received median image-quality ratings of 4–5, with no significant difference between ratings (p = 0.12–0.58). Vessel diameter measurements correlated strongly (r = 0.93). REACT acquisition took 2:49 ± 1:03 min, compared with 3:49 ± 1:03 min for CE-MRA; abdominal REACT VANE took 4:51 ± 0:52 min.

Key findings

• Median image-quality ratings were 4–5 for both methods, with no significant difference (p = 0.12–0.58).
• Vessel diameter measurements showed strong correlation between REACT and CE-MRA (r = 0.93); intraclass correlation coefficients were 0.97 for each method.
• REACT acquisition took 2:49 ± 1:03 min; abdominal REACT VANE took 4:51 ± 0:52 min, versus 3:49 ± 1:03 min for CE-MRA.
• REACT showed higher venous SNR and higher arterial and venous CNR (p = 0.001-0.018).

Why it matters

Children may undergo vascular MRI for assessment of extrathoracic vessels, while contrast-enhanced MRA requires gadolinium-based contrast. In this study, free-breathing REACT produced image quality comparable to CE-MRA and closely correlated vessel diameter measurements, supporting its evaluation as a contrast-free imaging option. The findings are relevant to imaging protocols seeking to assess vessels without contrast injection.

What to keep in mind

The study was single-centre and included 30 patients; REACT was assessed against CE-MRA in children already referred for contrast-enhanced MRI.