Uterine Fibroids

Preliminary Diagnosis: Uterine fibroids

I. What imaging technique is first-line for this diagnosis?

Ultrasound (US) of the pelvis with transabdominal imaging +/− transvaginal imaging.

II. Describe the advantages and disadvantages of this technique for diagnosing uterine fibroids.

Advantages

• Can reliably identify, locate, and allow for measuring of uterine fibroids and overall uterine size.

• Relatively short exam and is not significantly impacted by patient motion.

• Does not use ionizing radiation or intravenous contrast.

Disadvantages

• Very operator-dependent and relies heavily on the skill of the technologist or physician performing the exam.

• Image quality can be significantly degraded by patient body habitus and bowel gas content.

III. What are the contraindications for the first-line imaging technique?

• There are no significant contraindications to a transabdominal US examination of the pelvis.

• Transvaginal US is much more sensitive, but may be declined by a subset of patients.

IV. What alternative imaging techniques are available?

Magnetic resonance imaging (MRI) of the pelvis, preferably with intravenous gadolinium contrast to evaluate vascularity for possible management with uterine artery embolization.

V. Describe the advantages and disadvantages of the alternative techniques for diagnosing uterine fibroids.

Magnetic resonance imaging (MRI) of the pelvis

Advantages

• Very sensitive in revealing all uterine fibroids.

• Fibroid location can confidently be characterized, which often alters treatment planning.

• Degree of vascular flow to the fibroids can be shown on MRI with contrast, which can assist in pre-embolization planning.

• Fibroids can be characterized as necrotic on MRI, which may be a cause of acute abdominal pain.

• Additional causes of pelvic pain other than fibroids can be evaluated, such as endometriosis; adenomyosis; and endometrial, cervical, and ovarian pathology.

• Does not utilize ionizing radiation.

• Is considered safe in pregnancy.

Disadvantages

• Expensive.

• Time-consuming.

• Requires significant patient cooperation to minimize motion artifact.

• MRI cannot be performed in a select number of patients with pacemakers and other metallic non-titanium hardware or medical devices.

• MRI gadolinium contrast has been implicated in nephrogenic systemic fibrosis and should not be administered with a GFR<30. Department policies vary for GFR 30-60 and often require a reduced dose.

VI. What are the contraindications for the alternative imaging techniques?

Magnetic resonance imaging (MRI) of the pelvis

• Patients with embedded metallic devices not made of titanium, such as cardiac pacers, stents, and other non-MR approved metallic devices, may not enter the magnet for imaging.

• Patients with GFR <30 cannot receive gadolinium intravenous contrast.