T2* quantification using multi-echo gradient echo sequences: a comparative study of different readout gradients.

To quantify T2*, multiple echoes are typically acquired with a multi-echo gradient echo sequence using either monopolar or bipolar readout gradients. The use of bipolar readout gradients achieves a shorter echo spacing time, enabling the acquisition of a larger number of echoes in the same scan time. However, despite their relative time efficiency and the potential for more accurate quantification, a comparative investigation of these readout gradients has not yet been addressed.

A 2D-GRAPPA Algorithm with a Boomerang Kernel for 3D MRI Data Accelerated along Two Phase-Encoding Directions.

For the reconstruction of 3D MRI data that are accelerated along the two phase-encoding directions, the 2D-generalized autocalibrating partially parallel acquisitions (GRAPPA) algorithm can be used to estimate the missing data in the k-space. We propose a new boomerang-shaped kernel based on theoretic and systemic analyses of the shape and dimensions of the kernel. The reconstruction efficiency of the 2D-GRAPPA algorithm with the proposed boomerang-shaped kernel (i.

Setting Criterion for Adolescent Circuit Exercise Program.

The purpose of this study was to develop criteria for an adolescent circuit exercise program. The subjects of this study were 5268 middle- and high-school students. It consisted of three types of circuit exercise programs which were conducted in the physical education class.

Comparison of Male Adolescents' Physical Fitness Using Physical Activity Promotion System and Circuit Exercise Program.

The purpose of this study is to compare the physical fitness level of adolescents through a physical fitness assessment and a circuit exercise program. A total of 142 middle school students participated. Physical education class consists of a physical fitness assessment, namely, physical activity promotion system (PAPS), and a circuit exercise program.

Multi-Exponential Relaxometry Using l -Regularized Iterative NNLS (MERLIN) With Application to Myelin Water Fraction Imaging.

A new parameter estimation algorithm, MERLIN, is presented for accurate and robust multi-exponential relaxometry using magnetic resonance imaging, a tool that can provide valuable insight into the tissue microstructure of the brain. Multi-exponential relaxometry is used to analyze the myelin water fraction and can help to detect related diseases. However, the underlying problem is ill-conditioned, and as such, is extremely sensitive to noise and measurement imperfections, which can lead to less precise and more biased parameter estimates.