Institute of Clinical Physiology, Biomedical Engineering Division, National Council of Research, 73100 Lecce, Italy.
Magn Reson Imaging. 2010 May;28(4):511-9. doi: 10.1016/j.mri.2009.12.025. Epub 2010 Feb 1.
To improve vessel contrast in high-resolution susceptibility-based brain venography, an automatic phase contrast enhancing procedure is proposed, based on a new phase mask filter suitable for maximizing contrast of venous MR signals. The effectiveness of the new approach was assessed both on digital phantoms and on acquired MR human brain images, and then compared with venographic results of phase masking methods in recent literature. The digital phantom consisted of a simulated MR dataset with given signal-to-noise ratios (SNRs), while real human data were collected by scanning healthy volunteers with a 3.0-T MR system and a 3D gradient echo pulse sequence. The new phase mask (NM) was more effective than the conventional mask (CM) both on the digital phantoms and on the acquired MR images. A quantitative comparison based on phantom venograms indicates how this phase enhancement can lead to a significant increase in the contrast-to-noise ratio (CNR) for all considered phase values as well as for all vessel sizes of clinical interest. Likewise, the in vivo brain venograms reveal a better depiction of the smallest venous vessels and the enhancement of many details undetectable in conventional venograms.
为了提高高分辨率基于磁化率的脑静脉成像中的血管对比度，提出了一种自动相位对比增强方法，该方法基于一种新的相位掩模滤波器，适用于最大限度地提高静脉 MR 信号的对比度。新方法的有效性在数字体模和采集的人脑 MR 图像上进行了评估，然后与最近文献中相位掩模方法的静脉造影结果进行了比较。数字体模由具有给定信噪比 (SNR) 的模拟 MR 数据集组成，而真实的人体数据是通过使用 3.0-T MR 系统和 3D 梯度回波脉冲序列对健康志愿者进行扫描获得的。新的相位掩模 (NM) 在数字体模和采集的 MR 图像上均比传统掩模 (CM) 更有效。基于体模静脉造影图的定量比较表明，这种相位增强如何导致所有考虑的相位值以及所有临床感兴趣的血管大小的对比噪声比 (CNR) 显著增加。同样，体内脑静脉造影图显示出对最小静脉血管的更好描绘，并增强了在常规静脉造影图中无法检测到的许多细节。
