Retrospective Reconstruction of High Temporal Resolution Cine Images from Real-Time MRI using Iterative Motion Correction

摘要

Cardiac function has traditionally been evaluated using breath-hold cine acquisitions. However, there is a great need for free breathing techniques in patients who have difficulty holding their breath. Real-time cardiac MRI is a valuable alternative to the traditional breath-hold imaging approach but the real-time images are often inferior in spatial and temporal resolution. This paper presents a general method for reconstruction of high spatial and temporal resolution cine images from a real-time acquisition acquired over multiple cardiac cycles. The method combines parallel imaging and motion correction based on non-rigid registration and can be applied to arbitrary k-space trajectories. The method is demonstrated with real-time Cartesian imaging and Golden Angle radial acquisitions and the motion corrected acquisitions are compared to raw real-time images and breath-hold cine acquisitions in ten (N=10) subjects. Acceptable image quality was obtained in all motion corrected reconstructions and the resulting mean image quality score was a) Cartesian real-time: 2.48, b) Golden Angle real-time: 1.90 (1.00–2.50), c) Cartesian motion correction: 3.92, d) Radial motion correction 4.58, e) Breath-hold cine: 5.00. The proposed method provides a flexible way to obtain high quality, high-resolution cine images in patients with difficulty holding their breath.