Timing of the hepatic arterial phase at Gd‐EOB‐DTPA‐enhanced hepatic dynamic MRI: Comparison of the test‐injection and the fixed‐time delay method

Abstract

At EOB-enhanced hepatic dynamic MRI, the test-injection method yielded better image quality of hypervascular HCC and improved adequacy of timing of HAP.

Diagnosis of Hepatocellular Carcinoma with Gadoxetic Acid-Enhanced MRI: 2016 Consensus Recommendations of the Korean Society of Abdominal Radiology

“…Additionally, intravenous gadoxetic acid administration is frequently associated with acute transient dyspnea, which results in severe motion artifacts in 12.9–18% of arterial-phase gadoxetic acid-enhanced MR images (112728). These problems have been partially overcome by modification of contrast injection and imaging protocols, including a slower injection rate (1 mL/s rather than 2 mL/s) (2930), detection of arterial phase by test or fluoroscopic bolus monitoring rather than by fixed-scan delay (3132), and multiple short arterial-phase imaging (123334). However, acquisition of optimal arterial-phase gadoxetic acid-enhanced MR images is still challenging in clinical practice.…”

Comparison of the Timing of Hepatic Arterial Phase and Image Quality Using Test-Bolus and Bolus-Tracking Techniques in Gadolinium–Ethoxybenzyl–Diethylenetriamine Pentaacetic Acid–Enhanced Hepatic Dynamic Magnetic Resonance Imaging

“…A previous report suggested that optimal HAP timing was T test_peak + T full_bolus + T tumor − T k_space. 11 T test_peak was defined as the time to peak aortic enhancement from the start of test-bolus injection, T full_bolus as the time delay from peak aortic enhancement of the test bolus to peak aortic enhancement of the full bolus, T tumor as the time delay from peak aortic to peak tumor enhancement, and T k_space as the time to the center of the k-space acquisition. Previous report suggested that T full_bolus was equal to half of the contrast injection duration by evaluating the abdominal aorta of pig.…”

“…14 In addition, we have defined the T tumor as 8 seconds referenced with previous report. 11 Therefore, the optimal HAP was assumed to be T test_peak + T full_bolus + T tumor − T k_space = T test_peak + (half of the contrast injection duration) + 8 − T k_space. 11 Optimal HAP timing for the test-bolus protocol was also defined using the above equation.…”

“…11 Therefore, the optimal HAP was assumed to be T test_peak + T full_bolus + T tumor − T k_space = T test_peak + (half of the contrast injection duration) + 8 − T k_space. 11 Optimal HAP timing for the test-bolus protocol was also defined using the above equation. Using both protocols, portal venous phase and venous phase images were acquired 30 and 150 seconds, respectively, after HAP.…”

“…10,11 The test-bolus method was reported to result in more optimal HAP timing than the fixed-time method. 10,12,13 To date, however, no reports have compared image quality of the test-bolus and bolus-tracking methods in patients undergoing dynamic liver enhanced 3-T MRI.…”