Effect of injection rate on contrast‐enhanced MR angiography image quality: Modulation transfer function analysis

Abstract

Optimal image resolution is achieved at intuitively low, effective injection rates (0.2-0.9 mL/s, dependent on imaging parameters and contrast injection volume). Magn Reson Med 78:357-369, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Evaluation of four injection profiles for uniform contrast‐enhanced signal intensity profiles in MR angiography

“…Prior modeling work suggests that equating GBCA injection duration and acquisition duration when using elliptic‐centric k ‐space acquisition maximizes resolution . This must be balanced against SI, however, as very slow monophasic injections may negatively impact SI.…”

“…Prior modeling work suggests that equating GBCA injection duration and acquisition duration when using elliptic-centric k-space acquisition maximizes resolution. 13 This must be balanced against SI, however, as very slow monophasic injections may negatively impact SI. A previous study 12 using gadoteridol to explore the tailored bolus approach (DT), targeting the same 20-second bolus plateau, achieved a similar although slightly shorter FW80M of 23.0 AE 2.2 seconds (present study 28.3 AE 4.1 sec).…”

“…It is well understood that variations in contrast concentration during acquisition of CE-MRA cause a modulation of the arterial signal intensity (SI) that in turn leads to artifacts such as blurring and ringing. [9][10][11][12][13] Therefore, to maximize image fidelity the arterial contrast concentration should ideally be uniform over the entirety of k-space acquisition. A competing consideration, however, is signal-to-noise ratio (SNR), as it is arterial SI during the acquisition of central k-space that determines the absolute SI of the artery.…”

“…It is well understood that variations in contrast concentration during acquisition of CE‐MRA cause a modulation of the arterial signal intensity (SI) that in turn leads to artifacts such as blurring and ringing . Therefore, to maximize image fidelity the arterial contrast concentration should ideally be uniform over the entirety of k ‐space acquisition.…”

Relationship Between Simulated Gadolinium‐Based Contrast Agent Injection Profile and Achievable Resolution Metrics in Contrast‐Enhanced Magnetic Resonance Angiography

“…shown both theoretically and empirically to influence image quality, mainly through blurring of the vessel edges. [4][5][6] Recent observations, such as those on the unique T1 and T2* behavior of GBCA in blood, particularly at the high concentrations achieved with CE-MRA, have helped refine our understanding of the relationship between how the GBCA is injected and how the resultant intra-arterial signal intensity (SI) evolves. 5,[7][8][9] In particular, rapid GBCA boluses of up to 2-3 mL/second as have often been used for clinical CE-MRA may not increase SI as compared to slower boluses, and instead (for a fixed dose of contrast) only decrease the length of the bolus, thereby leading to increased blurring in the setting of elliptical centric k-space acquisition.…”