Free-breathing dynamic contrast-enhanced MRI of the abdomen and chest using a radial gradient echo sequence with K-space weighted image contrast (KWIC)

摘要

Objectives: To evaluate the feasibility of free-breathing, dynamic contrast-enhanced (DCE) MRI of the abdomen and thorax using the radial-gradient-echo sequence with k-space weighted image contrast (KWIC) reconstruction. Methods: Institutional review board approval was obtained. Fourteen patients underwent free-breathing radial DCE-MRI. Radial MRI yielded full-frame images by gridding all k-space data and time-resolved subframe images by using KWIC reconstruction technique. Using subframe KWIC images, voxel-wise perfusion maps were created. For comparison, the breath-hold conventional Cartesian 3D-gradient-echo sequence (VIBE) was also performed during the equilibrium phase. The image qualities of radial and conventional VIBE images were compared quantitatively and qualitatively. Results: Radial DCE-MRI provided high spatial resolution (1.4 × 1.4 mm) and temporal resolution (4.1 s for subframe images) allowing voxel-wise perfusion mapping with negligible motion or streaking artefacts. There were no significant differences in SNR between full-frame radial images and conventional VIBE images (79.08 vs 74.80, P > 0.05). Overall image quality score of full-frame radial images was slightly lower than that of conventional VIBE images (3.88 ± 0.59 vs. 4.31 ± 0.97, P < 0.05), but provided clinically useful images. Conclusions: The free-breathing radial DCE-MRI can provide high spatial and temporal resolution while maintaining reasonably high image quality and thus is a feasible technique for DCE-MRI in the abdomen and thorax. Key Points: ? Dynamic contrast-enhanced magnetic resonance imaging (DCE) MRI is important in oncological imaging ? Radial MRI with k-space weighted image contrast (KWIC) reconstruction offers potential improvements ? Radial DCE-MRI provides good image quality, reduced artefacts and high spatial/temporal resolution