High spatial resolution MRA of renal arteries using contrast behavior between fat and water during transient phase before reaching a steady state
| Autor: | Yoshiharu Azuma, Sachiko Goto, Katsuhiro Kida |
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| Rok vydání: | 2012 |
| Předmět: |
Adult
Male media_common.quotation_subject computer.software_genre Sensitivity and Specificity Magnetic resonance angiography Imaging phantom Renal Artery Flip angle Voxel Image Interpretation Computer-Assisted Humans Medicine Contrast (vision) Radiology Nuclear Medicine and imaging Image resolution Aged media_common medicine.diagnostic_test business.industry Isotropy Reproducibility of Results Water General Medicine Middle Aged Image Enhancement Adipose Tissue Subtraction Technique Maximum intensity projection Female business computer Algorithms Magnetic Resonance Angiography Biomedical engineering |
| Zdroj: | European Journal of Radiology. 81:846-850 |
| ISSN: | 0720-048X |
| DOI: | 10.1016/j.ejrad.2011.02.031 |
| Popis: | Purpose Our aim is high spatial resolution imaging of maximum intensity projection (MIP) images in renal magnetic resonance angiography (MRA) by constructing a protocol for acquiring three-dimensional volume data with isotropic voxels. Materials and methods We eliminated water-selective excitation (WATS) and utilized effective contrast behavior between fat and water before reaching a steady state—that is, during the transient phase—to cover fat suppression by WATS. In a phantom study, the optimal flip angle was investigated under the “low-high Y” profile order using distilled water and baby oil to construct a protocol with isotropic voxels. Signal intensity, contrast, noise and signal-to-noise ratio were investigated to compare image qualities between the conventional and the constructed isotropic protocols. In a clinical study, three radiologists and two radiological technologists visually evaluated clinical images of 20 volunteers for spatial resolution, contrast and overall reader confidence in two protocols. Results We constructed an isotropic protocol with voxel dimensions of 0.78 mm × 0.78 mm × 0.78 mm at a flip angle of 90°. We maintained the scan time but enlarged the x – y pixel dimensions from 0.59 mm × 0.59 mm to 0.78 mm × 0.78 mm and shortened image height from 48 mm to 42.9 mm. Data from the phantom study were worse in the isotropic protocol than in the conventional protocol. However, overall reader confidence in the clinical images was significantly better in the isotropic protocol than in the conventional protocol ( p Conclusion Our study indicated the value of addressing high spatial resolution imaging of MIP images for renal MRA by constructing an isotropic protocol. |
| Databáze: | OpenAIRE |
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