An Ultrahigh-Field-Tailored T1 -T2 Dual-Mode MRI Contrast Agent for High-Performance Vascular Imaging

Adv Mater. 2021 Jan;33(2):e2004917. doi: 10.1002/adma.202004917. Epub 2020 Dec 2.


The assessment of vascular anatomy and functions using magnetic resonance imaging (MRI) is critical for medical diagnosis, whereas the commonly used low-field MRI system (≤3 T) suffers from low spatial resolution. Ultrahigh field (UHF) MRI (≥7 T), with significantly improved resolution and signal-to-noise ratio, shows great potential to provide high-resolution vasculature images. However, practical applications of UHF MRI technology for vascular imaging are currently limited by the low sensitivity and accuracy of single-mode (T1 or T2 ) contrast agents. Herein, a UHF-tailored T1 -T2 dual-mode iron oxide nanoparticle-based contrast agent (UDIOC) with extremely small core size and ultracompact hydrophilic surface modification, exhibiting dually enhanced T1 -T2 contrast effect under the 7 T magnetic field, is reported. The UDIOC enables clear visualization of microvasculature as small as ≈140 µm in diameter under UHF MRI, extending the detection limit of the 7 T MR angiography. Moreover, by virtue of high-resolution UHF MRI and a simple double-checking process, UDIOC-based dual-mode dynamic contrast-enhanced MRI is successfully applied to detect tumor vascular permeability with extremely high sensitivity and accuracy, providing a novel paradigm for the precise medical diagnosis of vascular-related diseases.

Keywords: DCE-MRI; MRI contrast agents; dual-mode contrast agents; magnetic nanoparticles; vascular imaging.

MeSH terms

  • Blood Vessels / diagnostic imaging*
  • Contrast Media / chemistry
  • Magnetic Iron Oxide Nanoparticles / chemistry
  • Magnetic Resonance Imaging*
  • Permeability
  • Signal-To-Noise Ratio


  • Contrast Media