Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Oct 2003
Correlation of dynamic contrast enhancement MRI parameters with microvessel density and VEGF for assessment of angiogenesis in breast cancer.
To investigate the association between parameters obtained from dynamic contrast enhanced MRI (DCE-MRI) of breast cancer using different analysis approaches, as well as their correlation with angiogenesis biomarkers (vascular endothelial growth factor and vessel density). ⋯ A consistent analysis strategy was important in the DCE-MRI study. In this series, none of these strategies yielded results for MRI based quantitation of tumor vascularity that were associated with IHC based measurements. Therefore, different analyses could not account for the lack of association.
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J Magn Reson Imaging · Sep 2003
Comparative StudyFat suppression strategies in enhanced MR imaging of the breast: comparison of SPIR and water excitation sequences.
To compare two fat suppression techniques of spectrally-selective inversion pulse (spectral presaturation with inversion recovery-SPIR) and spectral-spatial excitation pulse of water excitation (WE) for contrast-enhanced MR imaging of the breast. ⋯ Compared to SPIR, the WE technique suppressed the subcutaneous fat signal more potently and improved the contrast of the enhanced breast lesion against the parenchyma and the subcutaneous fat. WE will be a powerful fat suppression strategy for enhanced MR imaging of the breast.
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J Magn Reson Imaging · Sep 2003
Sub-acute changes in lesion conspicuity and geometry following MR-guided radiofrequency ablation.
To evaluate MR signal and lesion zone volume evolution through the sub-acute phase following image-guided radiofrequency (RF) thermal ablation. ⋯ 1) There are no significant differences between the apparent zone boundaries in T(2)- and CE T(1)-weighted images; 2) CNR is equal or greater for T(2)-weighted images as compared to CE T(1)-images; and 3) both the inner and outer lesion zone volumes typically increase several days post-ablation.
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J Magn Reson Imaging · Sep 2003
T 1 rho-relaxation mapping of human femoral-tibial cartilage in vivo.
To demonstrate the in vivo feasibility of measuring spin-lattice relaxation time in the rotating frame (T(1rho)); and T(1rho)-dispersion in human femoral cartilage. Furthermore, we aimed to compute the baseline T(1rho)-relaxation times and spin-lock contrast (SLC) maps on healthy volunteers, and compare relaxation times and signal-to-noise ratio (SNR) with corresponding T(2)-weighted images. ⋯ The feasibility of performing in vivo T(1rho) relaxation mapping in femoral cartilage at 1.5T clinical scanner without exceeding Food and Drug Administration (FDA) limits on specific absorption rate (SAR) of RF energy was demonstrated.
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J Magn Reson Imaging · Sep 2003
Single-shot spiral image acquisition with embedded z-shimming for susceptibility signal recovery.
To efficiently and effectively recover the susceptibility-induced signal losses for functional MRI (fMRI) experiments. ⋯ Uniform recovery can be achieved efficiently near air/tissue interfaces where susceptibility-induced spatial gradients are pronounced. We anticipate that our method would be well suited for fMRI studies involving the ventral brain areas.