Bolus Chasing
What is bolus-chasing and how is it used for peripheral MR angiography?
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Bolus-chase CE MRA using 3 stations
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The technique of "bolus-chase" contrast-enhanced MR angiography (CE-MRA) was first described in the late 1990's as a method for imaging lower extremity peripheral arterial disease. The earliest techniques involved injection of a relatively large quantity of intravenous contrast (~40-60 mL) with 3D gradient echo imaging performed sequentially over three stations: pelvis, upper leg, and lower leg. The MR table was manually moved as fast as possible between stations to image the entire vascular tree in one injection.
Over the last 15 years bolus-chase techniques have become more refined and complex, with clinical results rivaling CTA and subtraction angiography. Such advancements are too numerous to fully explain on this website, but several are provided in the references below. These innovations include: 1) continuous table movement; 2) parallel imaging with high acceleration factors; 3) real-time fluoroscopic bolus tracking; 4) time-resolved imaging; 5) hybrid techniques; 6) specific imaging parameters optimized to individual patient physiology; 7) station-specific imaging parameters and view ordering; 8) use of blood-pool contrast agents; and 9) innovative 3D k-space acquisition strategies based on projection-reconstruction and vastly undersampled (sparse data) with compressed sensing.
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With the lesson of nephrogenic systemic fibrosis always in mind, the use of high-volume contrast is no longer a realistic option for most patients. Thus any bolus chase method must be performed using a modest contrast dose, which for an average-size adult limits volumes to about 20 mL. Some sites dilute their contrast by 25-50% allowing higher volumes (but the same total gadolinium dose) to be administered.
At our institution, depending on clinical indication, we generally use a hybrid technique for peripheral CE-MRA. We begin by injecting about ⅓ of the available contrast dose and performing time-resolved imaging over the most distal portion of the extremities. We then inject the remainder of the contrast and image the pelvis and entire lower extremities (3-stations, in that order) using a fluoroscopically-triggered bolus-chase technique. We typically use a spoiled 3D-GRE sequence with primary direction in the coronal plane at short TE and with parallel-imaging acceleration and elliptical-centric view order.
References
Hadizadeh DR, Gieseke J, Lohmaier SH, et al. Peripheral MR angiography with blood pool contrast agent: prospective intraindividual comparative study of high-spatial-resolution steady-state MR angiography versus standard-resolution first-pass MR angiography and DSA. Radiology 2008; 249:701-711.
Ho KYJAM, Leiner T, de Haan MW, et al. Peripheral vascular tree stenoses: evaluation with moving-bed infusion-tracking MR angiography. Radiology 1998; 206:683-692.
Johnson CP, Weavers PT, Borisch EA, et al. Three-station three-dimensional bolus-chase MR angiography with real-time fluoroscopic tracking. Radiology 2014;272:241-251.
Natsuaki Y, Kroeker R, Laub G, et al. Advancements in the ECG-gated contrast-enhanced MR angiography. MAGNETOM Flash 2013; 3:32-39.
Wedeen VJ, Chao YS. Rapid three-dimensional angiography with undersampled MR imaging. J Comput Assist Tomogr 1987; 11:24-30.
Hadizadeh DR, Gieseke J, Lohmaier SH, et al. Peripheral MR angiography with blood pool contrast agent: prospective intraindividual comparative study of high-spatial-resolution steady-state MR angiography versus standard-resolution first-pass MR angiography and DSA. Radiology 2008; 249:701-711.
Ho KYJAM, Leiner T, de Haan MW, et al. Peripheral vascular tree stenoses: evaluation with moving-bed infusion-tracking MR angiography. Radiology 1998; 206:683-692.
Johnson CP, Weavers PT, Borisch EA, et al. Three-station three-dimensional bolus-chase MR angiography with real-time fluoroscopic tracking. Radiology 2014;272:241-251.
Natsuaki Y, Kroeker R, Laub G, et al. Advancements in the ECG-gated contrast-enhanced MR angiography. MAGNETOM Flash 2013; 3:32-39.
Wedeen VJ, Chao YS. Rapid three-dimensional angiography with undersampled MR imaging. J Comput Assist Tomogr 1987; 11:24-30.
Related Questions
How is contrast-enhanced MRA performed?
I know there are different view ordering options for MRA, such as linear and elliptical centric. What do these mean, and when is each used?
How is contrast-enhanced MRA performed?
I know there are different view ordering options for MRA, such as linear and elliptical centric. What do these mean, and when is each used?