Can MR fluoroscopic triggering technique and slow rate injection provide appropriate arterial phase images with reducing artifacts on gadoxetic acid‐DTPA (Gd‐EOB‐DTPA)‐enhanced hepatic MR imaging?

Abstract

Purpose: To evaluate whether using MR fluoroscopic triggering technique and slow rate injection improves the quality of arterial phase images in gadoxetic acid-DTPAenhanced (Gd-EOB-DTPA) MR imaging because of proper acquisition timing and reduction of artifacts. Materials and Methods:Two hundred sixteen patients undergoing examination for liver diseases were retrospectively reviewed. All MR images were obtained with two Gd-EOB-DTPA injection protocols: (i) a combination protocol, in which the MR fluoroscopic triggering technique and slow rate injection (1 mL/s) were used; and for comparison, (ii) a conventional protocol, in which adjusted fixed scan delay and ordinary rate injection (2 mL/s) were adopted. Signal-to-noise ratio (SNR) of aorta, portal vein, and liver parenchyma on arterial phase images were calculated. Two blinded readers independently evaluated the obtained arterial phase images in terms of acquisition timing and degree of artifacts.Results: The SNRs of aorta and portal vein on arterial phase images were significantly higher in the combination protocol group (aorta/portal: 221.9 6 91.9/197.1 6 89.8) than that in the conventional protocol group (aorta/portal: 169.8 6 97.4/92.7 6 48.5) (P < 0.05). The acquisition timing for arterial phase images with the combination protocol was significantly better than that with the conventional protocol (P < 0.01). The image quality of the combination protocol was significantly higher than that of the conventional protocol (P < 0.01). The occurrence rate of moderate or severe degree of artifacts in the conventional protocol (38.0%) was more prominent than that in the combination protocol (18.5%). Conclusion:The combination of the MR fluoroscopic triggering technique and slow rate injection provides proper arterial phase images and reduces the artifacts in Gd-EOB-DTPA MR imaging.

Transient severe motion during arterial phase in patients with Gadoxetic acid administration: Can a five hepatic arterial subphases technique mitigate the artifact?

“…The prevalence of TSM related to Gd-EOB-DTPA administration has been reported to range from 2 to 19% (15,17,(20)(21)(22)(23)(24)(25). In the present study, prevalence of TSM is 12.4% (47/378) in the overall study population, which shows a lower rate than the studies demonstrated by Haradome et al (20 of 108 patients, 19%) (24) and Davenport et al (17 of 99 patients, 17%) (15).…”

Rules, Roles, and Room for Discussion in Gadoxetic Acid-enhanced Magnetic Resonance Liver Imaging: Current Knowledge and Future Challenges

“…16 How to avoid k-space inhomogeneity Although a saline ‰ush is mandatory after bolus injection, use of a low injection rate will help prolong the injection duration and decrease k-space inhomogeneity. 17,18 On the other hand, a high injection rate, such as 3 mL/s, results in short injection duration-one purported cause of k-space inhomogeneity and truncation artifacts. Recent publications have recommended an injection rate of one mL/s to achieve su‹cient enhancement and improve image quality.…”

“…Recent publications have recommended an injection rate of one mL/s to achieve su‹cient enhancement and improve image quality. 17,19 Use of a square matrix, slower injection rate, shorter scanning time, and sequential view ordering are also reported to reduce artifacts. 14 …”

“…Bolus timing techniques, such as the use of automated bolus detection algorithms or the ‰uoroscopic triggering method, are particularly useful. 13,17 However, there is little information on the optimal time delay after the arrival of the contrast agent to the aorta. Researchers have used delay times ranging from 7 to 15 s. 17,[20][21][22] If bolus timing cannot be manipulated as described above, timing may instead be adjusted via the test-injection method, in which a small amount (e.g., 0.5 mL) of contrast agent is injected before dynamic study to measure the length of time for the agent to reach the aorta.…”

The challenges of novel contrast agents for the imaging diagnosis of hepatocellular carcinoma

“…They found that the arterial enhancement in GA-MR injected at 1 mL/s was comparable to Gd-DTPA. Haradome et al [17] reported in a retrospective study on 216 patients that fluoroscopic triggering GA-MR and slow rate injection provide proper arterial phase images. Schmid-Tannwald et al [18] compared two injection rates (1 and 2 mL/s) for GA-MR dynamic studies in 80 patients and reported higher enhancement in the aorta in the arterial phase with the lower injection rate.…”