No abstract available.
Magnetic Resonance Imaging* ; Myelography*

A retrospective and cross sectional survey was carried out in 52 patients with cervical disc displacement who were screened by magnetic resonance at Viet Duc Hospital and Military Hospital 103 from Jan 2003 to Oct 2004. Sites of common displacement: C5-C6 (36.61%); C4-C5 (26.79%); C3-C4 (23.21%); C6-C7 (11.61%); C7-D1 (1.79%). Disc displacement in one layer was 42.31%, in two 11.54%, in three layers 34.61%, in four 11.54%, in centre 71.43%, beside centre 25%, in foramen 3.57%. Displacement image was looked clearly in T1W and T2W image. 100 displaced discs reduced signal in T2W image, 63.46% reduced disc height, 42.31% increased medulla signal equal with site of displacemen in T2W image
Magnetic Resonance Imaging ; Spine

The contrast substances have been used in the magnetic resonance imaging (MRI) to increase the sensitivity and specificity of diagnosis. It impacts on the density of proton and spin-spin time (T1 and T2). There were many different substances studied to increase the density of proton such as water, alcohol, hydrocarbon, and sugar or perfluoroctyl bromide. However, only paramagnetic compounds impacts on the spin-spin time were studied much and are being used.
Magnetic Resonance Imaging ; diagnosis

According to many years of MR experience for maintenance, Through careful observations artifacts, according to the easy first principle, use the process of elimination, first check the external environment to the interior of the machine, the layers of delivery in the cause of failure, eliminate the artifact.
Artifacts ; Magnetic Resonance Imaging

No abstract available.
Magnetic Resonance Imaging ; Sacroiliitis*

No abstract available.
Magnetic Resonance Imaging*

PURPOSE: B1 field of birdcage RF (radiofrequency) coil that is used most for brain imaging in magnetic resonance imaging (MRI) decreases toward endring from the coil center. We investigated how much RF B1 homogeneity effect the endcap shield brings form the coil center as it towards to endcap region. MATERIALS AND METHODS: We compared RF B1 field distribution by each finite difference time domain (FDTD) simulations for lowpass, highpass and hybrid birdcage RF coils. We selected the highpass birdcage RF coil that was the highest RF B1 field condition as simulation result, and studied how much RF B1 homogeneity effect was occurred when endcap shield was applied to endring area. RESULTS: B1 field of the highpass birdcage RF coil was higher than other birdcage RF coil types as simulation result. However, the RF B1 homogeneity was lower than other coil types. RF B1 field of highpass birdcage RF coil with endcap shield is similar with RF B1 field of hybrid birdcage RF coil and the overall RF B1 homogeneity in sagittal direction was better. CONCLUSION: In this paper, proposed method can apply improving RF B1 homogeneity of RF coil in clinical examination.
Magnetic Resonance Imaging* ; Neuroimaging

No abstract available.
Magnetic Resonance Imaging*

No abstract available.
Magnetic Resonance Imaging*

No abstract available.
Humans ; Magnetic Resonance Imaging