Kim Nhien Vu1, Angela Marie Fast1, Robyn Shaffer2, Deirdre A. Lum3, Berta Chen3, David Hovsepian1, and Pejman Ghanouni1
1Radiology, Stanford University, Stanford, CA, United States, 2Medicine, Stanford University, Stanford, CA, United States, 3Obstetrics & Gynecology, Stanford University, Stanford, CA, United States
Synopsis
Pelvic ultrasounds often represent the first and only
line of imaging for uterine fibroid evaluation. Our study aims to determine the
added value of routine pelvic magnetic resonance imaging (MRI) on diagnosis and
treatment of women presenting with symptomatic uterine fibroids. A
retrospective review was performed on 569 consecutive women referred to our multidisciplinary
fibroid center over a three-year period. Compared to ultrasound alone, MRI
affected diagnosis in over a third of patients, which also altered treatment
options. These findings
justify the use of routine pelvic MRI in women with symptomatic fibroids,
particularly those presenting with dysmenorrhea.
Introduction
Uterine
fibroids are the most common solid tumor of the female pelvis, affecting 80% of
women over the age of 50 and causing symptoms in up to 30%.1,2 Pelvic
ultrasounds often represent the first and only line of imaging for fibroid
evaluation. However, concurrent gynecologic conditions such as adenomyosis and
endometriosis may contribute to the patient’s symptomatology. These conditions often
alter treatment options and are more difficult to detect on ultrasound.3-6
The purpose of this study is to determine the impact of routine pelvic magnetic resonance imaging (MRI) evaluation on
diagnosis and treatment of women presenting with symptomatic uterine fibroids.Methods
This retrospective observational study was approved by
our institutional review board. Our study included 569 consecutive women with a
presumed diagnosis of fibroids referred to our multidisciplinary fibroid center
from April 2013 to July 2017.
All patients underwent pelvic MRI prior to being counseled by
a team comprised of a gynecologist, interventional radiologist, and body MRI radiologist.
Treatment options depended on clinical and imaging findings and included
expectant management, medical treatment, surgery, uterine artery embolization
(UAE), and MR-guided focused ultrasound (MRgFUS). One
hundred twenty-seven patients with no prior pelvic ultrasound imaging or report
available and 99 patients with an interval between ultrasound and MRI exams
greater than a year were excluded from this study. Main presenting symptoms, ultrasound findings,
MRI findings, and choice of treatment were recorded for all patients. Subgroup analyses
were performed comparing patients with a final diagnosis of fibroids alone and
patients for whom MRI provided additional diagnoses. Chi-squared test was used to evaluate for statistical
significance between the subgroups, with a p value ≤ 0.05 considered to be significant.Results
Our final cohort included 343 women with a mean age of 44.0±6.8 years. Average time between ultrasound and MRI studies was 89.2±103.3 days. Pelvic MRI modified ultrasound
diagnosis in 127 patients (37.0%) (Figure
1). The most common additional diagnoses found on MRI were adenomyosis in 94
patients (27.4%), endometriosis in 45 patients (13.1%), and endometrial polyps
in 5 patients (1.5%). Nine patients (2.6%) diagnosed with fibroids on
ultrasound were found to have focal adenomyosis without fibroids on MRI (Figures 2 and 3).
When comparing patients with a final diagnosis of fibroids alone and
patients for whom MRI provided additional diagnoses, no significant age
difference was found between both groups (mean age of 43.9±6.3 versus 44.2±7.7 years, p = 0.6694). In comparison
to patients with isolated fibroids, those with additional MRI diagnoses
presented with dysmenorrhea significantly more frequently (27.3% versus 53.5%,
p < 0.0001) and with bulk-related symptoms significantly less frequently (53.2%
versus 28.3%, p < 0.0001) (Figure 4).
Both groups presented with menorrhagia at a similar rate (73.7% versus 77.2%, p
= 0.4875). Submucosal fibroids were significantly more common in women with
isolated fibroids than those with additional MRI diagnoses (55.6% versus 36.7%,
p = 0.0036). When compared with patients with fibroids only, patients with additional
MRI diagnoses were significantly less likely to be treated with UAE (31.7% versus
9.4%, p < 0.0001) and MRgFUS (4.9% versus 0.8%, p = 0.0434), and
significantly more likely to be managed medically (18.1% versus 7.8%, p = 0.0047)
(Figure 5).
Discussion
Compared to pelvic ultrasound alone, our study found
that pelvic MRI affected diagnosis in over a third of women presenting with
symptomatic uterine fibroids. Adenomyosis, endometriosis, and endometrial
polyps were the most common additional MRI findings. These patients presented with significantly more dysmenorrhea,
whereas patients with isolated symptomatic fibroids presented with
significantly more bulk-related symptoms. Menorrhagia was a common complaint in
both groups with submucosal fibroids being the most common cause in patient
with fibroids alone and adenomyosis as the main explanation in patients with
additional diagnoses. These additional diagnoses affected counseling and
management with medical management being preferred significantly more frequently
and UAE and MRgFUS being chosen significantly less frequently. These findings demonstrate
that in patients with a presumed diagnosis of symptomatic fibroids, the use of
routine pelvic MRI leads to more accurate diagnosis and more appropriate
treatment. In places where MRI is not widely available, further MRI evaluation
would likely be most beneficial in women presenting with dysmenorrhea. The main
limitation of our study is the lack of histopathologic correlation as reference
standard, as many patients with adenomyosis and endometriosis chose medical
management. Conclusion
The use of pelvic MRI, in addition to ultrasound, affects diagnosis
and management in a substantial number of women with symptomatic uterine
fibroids. Implementation of routine pelvic MRI may be particularly justified in
a subgroup of women presenting with dysmenorrhea.Acknowledgements
No acknowledgement found.References
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