Reducing Artifacts during Arterial Phase of Gadoxetate Disodium-enhanced MR Imaging: Dilution Method versus Reduced
Young Kon Kim1, Wei-Chan Lin1, Kyunghyun Sung1
1From the Department of Radiological Sciences, University of California, 10833 Le Conte Ave, Los Angeles, CA 90095-1721 (Y.K.K., W.C.L., K.S., S.S.R., D.M., D.L.); and Biostatistics and Clinical Epidemiology Center, Research Institute for Future Medicine, Samsung Medical Center, Seoul, Korea (Y.L., S.G.).
Insights
Diluting gadoxetic acid contrast material and injecting it at a faster rate significantly reduces arterial phase ghosting artifacts in MR imaging. This improved protocol enhances image quality for better diagnostic accuracy.
Area of Science:
- Radiology
- Medical Imaging
- Diagnostic Imaging
Background:
- Gadoxetic acid-enhanced MR imaging is crucial for liver lesion detection.
- Arterial phase imaging can be affected by ghosting artifacts, potentially impacting diagnostic accuracy.
- Optimizing contrast material administration is key to minimizing these artifacts.
Purpose of the Study:
- To compare the effectiveness of two gadolinium-based contrast agent administration protocols in reducing arterial phase artifacts.
- To evaluate the impact of contrast material dilution and injection rate on ghosting artifact severity in MR imaging.
Main Methods:
- A retrospective cohort study involving 318 patients undergoing gadoxetic acid-enhanced MR imaging.
- Two subcohorts were analyzed: dilution (1:1 with saline, 2.0 mL/sec) and slow injection (undiluted, 1.0 mL/sec).
- Artifact severity was assessed using mean artifact scores and frequency of severe artifacts via patient- and image-based analyses, including intraindividual comparisons.
Main Results:
- The dilution protocol showed significantly lower mean artifact scores (1.46% vs 1.95%) and reduced frequency of severe artifacts (3.8% vs 15.1%) compared to the slow injection protocol (P ≤ .001).
- Intraindividual analysis confirmed decreased artifact scores and severity with the dilution method (P = .007 and P = .001).
- Artifacts were significantly increased with the slow injection method across three MR platforms (P < .05).
Conclusions:
- Diluting gadoxetic acid to 50% and injecting at 2.0 mL/sec significantly reduces ghosting artifacts in the arterial phase of MR imaging.
- This optimized contrast administration protocol improves image quality compared to slow injection of undiluted contrast.
- The findings support the use of the dilution protocol for enhanced diagnostic performance in gadoxetic acid-enhanced MR imaging.
Abstract:
Purpose To compare two contrast material-administration protocols (dilution vs slow injection) in terms of their effectiveness in arterial phase artifact reduction at gadoxetic acid-enhanced magnetic resonance (MR) imaging. Materials and Methods This HIPAA-compliant retrospective case-controlled cohort study was approved by the institutional review board, with a waiver of informed patient consent. A total of 318 consecutive patients undergoing gadoxetic acid-enhanced MR imaging were placed into one of two subcohorts of 159 consecutive patients each: the dilution subcohort (gadoxetic acid was diluted 1:1 with saline and injected at a rate of 2.0 mL/sec) and the slow injection subcohort (gadoxetic acid was not diluted and was injected at a rate of 1.0 mL/sec). Eighty-nine patients in the dilution subcohort also underwent follow-up MR imaging with the slow injection method, and 34 patients in the slow injection subcohort underwent follow-up MR imaging with the dilution method. Both patient- and image-based analyses, as well as intraindividual analysis, were used to compare two parameters-mean artifact score rated by two observers using a five-point scale and frequency of severe artifact-between the dilution and slow injection subcohorts with the Wilcoxon Mann-Whitney test, χ2 test, and generalized estimating equation. Results In both patient- and image-based analyses, the mean artifact score and frequency of severe artifact were lower in the dilution subcohort (mean, 1.46% and 3.8% [six of 159]) than in the slow injection subcohort (mean, 1.95% and 15.1% [24 of 159]) (P ≤ .001 and P < .001, respectively). In intraindividual analysis, both variables were also decreased in the dilution subcohort (P = .007 and P = .001, respectively). We found the two variables to be significantly increased in the slow injection subcohort when compared with that in the dilution subcohort for three different MR platforms (P < .05). Conclusion In comparison with slow injection of undiluted contrast material at a rate of 1.0 mL/sec, gadoxetic acid diluted to 50% and injected at a rate of 2 mL/sec had a significantly less severe ghosting artifact in the arterial phase of gadoxetic acid-enhanced MR imaging. © RSNA, 2016 Online supplemental material is available for this article.
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