Diagnostic Ultrasound - Abdomen and Pelvis

Intrauterine Device
Diagnoses: Female Pelvis
TERMINOLOGY
• 2 types of IUDs in United States
○ Copper-containing
○ Levonorgestrel-releasing
• Device inserted into endometrial cavity to prevent
pregnancy
• T-shaped polyethylene frame with polyethylene
monofilament string
IMAGING
• US
○ IUD stem is linear bright echo aligned with endometrial
cavity
○ If difficult to visualize, look for shadowing
○ ≤ 3 mm between top of IUD and fundal endometrium
○ Arms/cross bars extend laterally at fundus
• Radiography
○ KUB helps to differentiate IUD expulsion from
perforation
KEY FACTS
○ Image from diaphragm to pelvis
○ Differentiates expulsion from perforation when IUD is
not seen in uterus on US
• CT: May be helpful in select cases to evaluate for
complications related to perforation and intraabdominal
IUD
• Perforation
○ IUD above pelvic brim, far lateral, or anterior/posterior
CLINICAL ISSUES
• Complications
○ Displacement (25%)
○ Embedment (18%)
○ Uterine expulsion (10%)
○ Complete perforation (0.1%)
DIAGNOSTIC CHECKLIST
• Entire IUD should be visualized within endometrial cavity
with arms in appropriate orientation
(Left) Longitudinal
endovaginal US shows the
typical appearance of well
positioned IUD stem ſt as an
area of reverberation and
posterior acoustic shadowing
st. (Right) Transverse US in
the same patient shows
normal position of arms/cross
bars ſt extending laterally
along the endometrial cavity
at the fundus pointing
towards the cornua. Note
shadowing at the ends that
are typical of the
levonorgestrel-releasing IUD.
(Left) 3D MPR US shows an
IUD in its entirety in the
appropriate position, with the
stem positioned
longitudinally along the canal,
the arms ſt pointing towards
the cornua, and the proximal
end ≤ 3mm from the fundal
endometrium. (Right)
Longitudinal endovaginal US
shows an abnormally low IUD
ſt in the lower uterine
segment extending into the
cervix. Note the echogenic
signature that is typical of a
copper IUD.
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