Kelly Tung Smith1, Alvin Silva1, Jonathan Flug1, Justin Yu1, and Anshuman Panda1
1Radiology, Mayo Clinic Arizona, PHOENIX, AZ, United States
Synopsis
In this age of specialized imaging sequences such as liver
MR elastography, inexperience with the technical image acquisition and
unawareness of artifacts and pitfalls confound diagnostic accuracy due to poor
image quality. We feel there is a
knowledge gap in those at the front line involved with image acquisition, and that
by defining and filling in this knowledge gap with an educational tutorial
module, MR elastography image quality can be optimized and callback rates can
be decreased. In turn, decreased callbacks will translate into reduced cost for
unnecessary repeated scans; reduced patient time and frustration; and increased
MR scheduling access.
Introduction
Liver magnetic resonance elastography
(MRE) is a highly useful adjunct tool for the evaluation of liver pathology and
fibrosis1-4. In order for the
radiologist to render an accurate diagnosis, the overall quality of a study
must be diagnostic. At our institution,
a radiologist may request a patient call back if they believe the study is not
diagnostic at time of dictation. We
previously evaluated our body MR callback cases over a 9 year period (2010-2018)
and discovered 154 body MR callbacks of 44811 total body MR cases performed. Of these, 22 (of 154) of the callbacks were
secondary to technical issues with the MRE acquisition. We identified the key checkpoints of the MRE
acquisition process to be the MR technologists and their interaction with the
patient, as well the readers of the MR elastography studies. We believed there was a knowledge gap in understanding
how to troubleshoot the MRE exam, and therefore designed a self-paced quality
control tutorial that was distributed to those involved in MRE image
acquisition and interpretation. With the
implementation of the tutorial, we believe there will be an overall improvement
in image quality and decrease in number of MRE callbacks.Methods
We created an educational packet that included the basics of
MR elastography, common artifacts, and a decision-tree algorithm to
troubleshoot and resolve poor image quality (Figure 1). Our test group included all MR technologists
and MR abdomen readers including faculty, fellows, and residents. After completing an initial 21 question
pretest, the group was given 2 weeks to learn from a self-paced tutorial module
on the basics of MR elastography (Figures 2 and 3). This was followed by a 21 question
posttest. We had a total of 18 participants who
completed the study in March 2019. The
number of MRE callbacks April 2019 to the present was compared to historical
values.Results
Prior to the aforementioned intervention, the baseline MR
elastography callback rate was 22 (of 1734 total MRE studies performed) for
2010-2018. In the 18 participants, 30%
scored <50% correct; 66% scored 50-80%; and 4% scored >80% on the pretest. Following administration of the liver MR
elastography quality control learning module, the study group scores increased
with 0% scoring <50% correct; 33% scoring 50-80%; and 67% scoring >80% (Figure
4). Scores improved by a mean of 21 points (standard
deviation (SD) of 17, 95% confidence interval of 13 to 29, p<0.0001 by
two-tailed paired t-test) from a baseline mean of 63 points (SD 13) to a
post-intervention mean of 84 points (SD 14).
Post intervention, the MR elastography callback rate was 0 (of
208 total MRE studies performed) from April-July 2019.Discussion
With introduction of a self-paced Liver MR elastography
quality control learning module, we were able to increase the study group’s basic
knowledge in troubleshooting MRE image quality as evidenced by improved
posttest scores. This has translated to
a decrease in the MR elastography callback rate since the intervention from 14%
to 0%. Furthermore, patient throughput
has been improved as we have defined specific steps for identifying and
resolving poor image quality, with resultant decrease in the number of
unnecessary repeated series. We understand
that only a short time has passed since intervention and the overall callback
rate can be affected by personnel change, but the results are promising that
our liver elastography tutorial module can optimize MRE image
quality/acquisition, with resultant decrease in frequency of patient callbacks.Conclusion
Familiarity and understanding of optimal MRE acquisition
options as well as recognition of MRE artifacts and pitfalls via incorporation
of a quality control learning module can help optimize MRE exams and decrease
unnecessary patient callbacks. Acknowledgements
Lead MR technologists - Vicki Place, Cathy Gustafson
Radiology manager - Chris Tollefson
Statistics - Joseph G. Hentz
References
1. Hoodeshenas, S., Yin, M., & Venkatesh, S. K.
(2018). Magnetic Resonance Elastography of Liver. Topics in Magnetic
Resonance Imaging, 27(5), 319–333.
2. Batheja M, Vargas H, Silva AM, Walker F, Chang YH,
De Petris G, Silva AC. Magnetic resonance elastography (MRE) in assessing
hepatic fibrosis: performance in a cohort of patients with histological data. Abdom Imaging. 2015 40(4):760-5.
3. Gallegos-Orozco JF, Silva AC, Batheja MJ, Chang YH,
Hansen KL, Lam-Himlin D, De Petris G, Aqel BA, Byrne TJ, Carey EJ, Douglas DD,
Mulligan DC, Silva AM, Rakela J, Vargas HE. (2015). Magnetic resonance
elastography can discriminate normal vs. abnormal liver biopsy in candidates
for live liver donation. Abdom Imaging.
40(4):795-802.
4.
Venkatesh,
S. K., Yin, M., & Ehman, R. L. (2013). Magnetic resonance elastography of
liver: Technique, analysis, and clinical applications. Journal of Magnetic
Resonance Imaging, 37(3).