Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Apr 2009
fMRI activation mapping as a percentage of local excitation: consistent presurgical motor maps without threshold adjustment.
To evaluate the performance of a relative activation amplitude algorithm, versus standard t-value thresholding, for reliably establishing the location, amplitude, and spatial extent of functional magnetic resonance imaging (fMRI) brain activation for presurgical planning. ⋯ The reproducibility and anatomical specificity of the spatiotemporal pattern of BOLD activation makes relative amplitude fMRI mapping a useful tool for clinical imaging, where accuracy, reproducibility, and quality control are critical concerns.
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J Magn Reson Imaging · Apr 2009
Assessment of iron distribution between liver, spleen, pancreas, bone marrow, and myocardium by means of R2 relaxometry with MRI in patients with beta-thalassemia major.
To investigate the correlation between the degree of hepatic, splenic, pancreatic, vertebral bone marrow (VBM), and myocardial siderosis, as expressed by relaxation rate (R2 = 1/T2) values, in patients with thalassemia. ⋯ Despite positive correlations between the degree of hepatic, splenic, and VBM siderosis, as expressed by respective R2 values, there was variability of iron distribution patterns in thalassemic patients. Unpredictable patterns of iron distribution may be seen, such as normal signal of the spleen in the presence of siderotic liver, resembling primary hemochromatosis. Fatty degeneration of the pancreas was not uncommon.
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J Magn Reson Imaging · Apr 2009
Characterization of chondroblastic osteosarcoma: gadolinium-enhanced versus diffusion-weighted MR imaging.
To detect differences in magnetic resonance imaging (MRI) between chondroblastic osteosarcoma and the other types of osteosarcomas or chondrosarcomas using gadolinium-enhanced versus diffusion-weighted sequences. ⋯ DWI appears to be more useful for differentiating between chondroblastic osteosarcoma and chondrosarcoma or other types of osteosarcoma than Gd-enhanced MRI.
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J Magn Reson Imaging · Apr 2009
High-resolution fMRI with higher-order generalized series imaging and parallel imaging techniques (HGS-parallel).
To develop a novel approach for high-resolution functional MRI (fMRI) using the conventional gradient-echo sequence. ⋯ This study suggests that the proposed method can be used for high-resolution fMRI studies without the geometric distortion and the Nyquist ghost artifacts compared to EPI.