Bolus shaping of contrast medium to adapt k-space sampling: adjusting injection protocol of magnetic resonance angiography for optimal images in a 3-T system

Purpose To explore the possibility of shaping bolus of contrast medium to adapt k-space sampling to improve image quality in a 3-T system. Materials and Methods Eighty patients suspected of having renal arterial disease or atherosclerosis were divided into four groups and underwent imaging with different high-spatial-resolution three-dimensional contrast-enhanced magnetic resonance angiography (MRA) scanning and injection protocol combinations. A group of 20 patients were injected single-dose contrast medium with a centric view ordering for k-space filling. Another group of 20 patients underwent MRA with double-dose and centric-view ordering. The bolus of contrast medium was shaped by adjusting injection protocol to adapt centric and sequential view ordering of sampling k-space, respectively, for other two groups. Then, the quality of image got with different protocols combination was compared, and the dose of contrast medium used in latter two groups was compared with single- and double-dose prescription basing on body weight. Result Bolus shaped adapting to centric view ordering and sequential view ordering brings more homogeneous vessel signal. Individualized dose is lower than the double dose but higher than the single dose. Dose does not necessarily correlate with body weight. Conclusion Under certain scanning protocol, appropriate shape of contrast medium passing through target vessel leads to higher-quality image and save contrast medium.