Accelerated MR whole brain imaging with sheared voxel imaging using aliasing separation gradients.

Purpose: To accelerate data acquisition by undersampling phase encoding (PE) lines in MR imaging, an aliasing separation method by applying additional encoding gradients which result in voxel shape modification is proposed.

Methods: An imaging technique which achieves two directional accelerations by undersampling both PE lines in 3D imaging with aliasing separation gradients is proposed. A simple and fast reconstruction process using shift correction or gridding is followed.

Artifact reduction from metallic dental materials in T1-weighted spin-echo imaging at 3.0 tesla.

Purpose: To investigate and propose a method of artifact reduction arising from metallic dental materials by applying a slice-encoding for metal artifact correction (SEMAC) technique on T1-weighted spin-echo (SE) imaging at 3 Tesla.

Materials And Methods: The view angle tilting (VAT) technique was adapted to conventional T1-weighted spin-echo (SE) sequence to correct the in-plane distortion, and the SEMAC technique was used for correcting the remaining through-plane distortions. Fourier transform based B0 field simulations were performed to estimate the amount of field perturbation and a scout imaging method was developed which guide in selecting the number of slice-encodings needed in SEMAC sequences.

3D imaging using magnetic resonance tomosynthesis (MRT) technique.

Purpose: To introduce an alternative approach to three-dimensional (3D) magnetic resonance (MR) imaging using a method that is similar to x-ray tomosynthesis.

Methods: Variable angle tilted-projection images are acquired using a multiple-oblique view (MOV) pulse sequence. Reconstruction is performed using three methods similar to that of x-ray tomosynthesis, which generate a set of tomographic images with multiple 2D projection images.

Time-varying view angle tilting with spiral readout gradients.

The conventional Fourier-transform-based spin-echo sequence with a view angle tilting gradient during data acquisition can correct the in-plane distortion induced by a chemical shift or B0 field inhomogeneity. However, when extended for 3D applications, alternate k-space sampling can be beneficial for reducing the lengthy scan time. As spiral trajectories have high k-space acquisition efficiency, we investigated the applicability of spiral trajectory on a spin-echo view angle tilting pulse sequence.

Three dimension double inversion recovery gray matter imaging using compressed sensing.

The double inversion recovery (DIR) imaging technique has various applications such as black blood magnetic resonance imaging and gray/white matter imaging. Recent clinical studies show the promise of DIR for high resolution three dimensional (3D) gray matter imaging. One drawback in this case however is the long data acquisition time needed to obtain the fully sampled 3D spatial frequency domain (k-space) data.

Respiratory motion compensated MR cholangiopancreatography at 3.0 Tesla.

Purpose: To reduce irregular respiratory motion-induced artifacts in free-breathing prospective navigator-triggered three-dimensional (3D) MR cholangiopancreatography (MRCP).

Materials And Methods: A reference respiration model was estimated from the first-five respiration periods during the initial navigator scan. With the navigator information acquired before and after triggering, the un-acquired diaphragm position during the actual imaging was interpolated using the amplitude-scaled reference model.