Pelvic ultrasound (transvaginal): Difference between revisions

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===Transverse scan===
===Transverse scan===
*Rotate probe 90 degrees so probe marker is pointing at 9:00
*Rotate probe 90 degrees counterclockwise so probe marker is pointing at 9:00
*Shows right-sided structures on left side of screen
*Shows right-sided structures on left side of screen
*Start at endometrial stripe and scan throughout uterus
*Start at endometrial stripe and scan throughout uterus
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==Findings==
==Findings==
===Uterus===
===Uterus===
*Fundus pointing to anterior abdominal wall is anteverted
*Anteverted: Fundus pointing to anterior abdominal wall
*Fundus pointing to posterior wall is retroverted
*Retroverted: Fundus pointing to posterior wall  
 
*Endometrial stripe: Measured from thickest echogenic area (from one basal endometrial interface to the other, including canal)
Endometrial stripe: Measured from thickest echogenic area (from one basal endometrial interface to the other, including canal)
**Pre-menopausal:
*Pre-menopausal:
***During menstruation: 2-4mm
**During menstruation: 2-4mm
***Early proliferative phase: 5-7mm
**Early proliferative phase: 5-7mm
***Late proliferative phase: 11mm
**Late proliferative phase: 11mm
***Secretory phase: 7-16mm
**Secretory phase: 7-16mm
***After D&C or SAB: >5mm
**After D&C or SAB: >5mm
****Consider retained POC if thicker
***Consider retained POC if thicker
**Post-menopausal:  
*Post-menopausal:  
***With vaginal bleeding: <5mm
**With vaginal bleeding: <5mm
***Without vaginal bleeding: <11mm
**Without vaginal bleeding: <11mm


===Adnexa===
===Adnexa===
[[File:simple_cyst.jpg|thumb|Simple ovarian cyst]]
[[File:hemorrhagic_cyst.jpg|thumb|Hemorrhagic cyst with blood clot]]
*Simple ovarian cyst: <2.5-3cm
*Simple ovarian cyst: <2.5-3cm
<gallery mode="packed">
File:simple_cyst.jpg|Simple ovarian cyst
File:hemorrhagic_cyst.jpg|Hemorrhagic cyst with blood clot
</gallery>


===Pregnancy (1st trimester)===
===Pregnancy (1st trimester)===
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===Abnormal===
===Abnormal===
[[File:Iarge gestational sac|thumb|Gestational sac greater than 10mm without yolk sac, suggestive of abnormal pregnancy]]
 


====Abnormal Pregnancy====
====Abnormal Pregnancy====
[[File:gestational sac without fetal pole.jpg|thumb|Gestational sac greater than 18mm without fetal pole, suggestive of abnormal pregnancy]]
 
[[File:collapsed gestational sac.jpg|thumb|Collapsed gestational sac, suggestive of abnormal pregnancy]]
[[File:pseudogestational sac.jpg|thumb|Pseudogestational sac, suggestive of abnormal pregnancy]]
[[File:molar pregnancy.jpg|thumb|Molar pregnancy with multiple cystic lesions in endometrium, "sandstorm appearance"]]
*Gestational sac >10mm without visible yolk sac
*Gestational sac >10mm without visible yolk sac
*Gestational sac >18mm without fetal pole
*Gestational sac >18mm without fetal pole
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**Many small, irregular cystic structures in endometrium
**Many small, irregular cystic structures in endometrium
**"Snowstorm appearance"
**"Snowstorm appearance"
<gallery mode="packed">
File:Iarge gestational sac|Gestational sac greater than 10mm without yolk sac, suggestive of abnormal pregnancy
File:gestational sac without fetal pole.jpg|Gestational sac greater than 18mm without fetal pole, suggestive of abnormal pregnancy
File:collapsed gestational sac.jpg|Collapsed gestational sac, suggestive of abnormal pregnancy
File:pseudogestational sac.jpg|Pseudogestational sac, suggestive of abnormal pregnancy
File:molar pregnancy.jpg|Molar pregnancy with multiple cystic lesions in endometrium, "sandstorm appearance"
</gallery>


====Ectopic pregnancy====
====Ectopic pregnancy====
[[File:ectopic pregnancy.jpg|thumb|Ectopic pregnancy]]
 
[[File:cervical ectopic.jpg|thumb|Ectopic pregnancy at the cervix]]
[[File:free_fluid_ectopic.png|thumb|Free fluid in cul-de-sac with no gestational sac visualized in uterus, presumed ectopic pregnancy in patient with positive pregnancy test]]
[[File:tubal ring.jpg|thumb|Ectopic pregnancy between ovary and uterus, suggestive of tubal ectopic]]
*Implantation of blastocyst outside of endometrium
*Implantation of blastocyst outside of endometrium
*Occur in fallopian tubes, cervix, ovaries, peritoneal cavity, or scar of prior uterine surgery
*Occur in fallopian tubes, cervix, ovaries, peritoneal cavity, or scar of prior uterine surgery
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**Can cause life-threatening hemorrhage
**Can cause life-threatening hemorrhage
**Must distinguish between cervical ectopic and spontaneous abortion at level of cervix:
**Must distinguish between cervical ectopic and spontaneous abortion at level of cervix:
<gallery mode="packed">
File:ectopic pregnancy.jpg|Ectopic pregnancy
File:free_fluid_ectopic.png|Free fluid in cul-de-sac with no gestational sac visualized in uterus, presumed ectopic pregnancy in patient with positive pregnancy test
File:tubal ring.jpg|Ectopic pregnancy between ovary and uterus, suggestive of tubal ectopic
File:cervical ectopic.jpg|Ectopic pregnancy at the cervix
</gallery>


==Pearls and Pitfalls==
==Pearls and Pitfalls==

Revision as of 20:05, 18 October 2017

Background

  • Also known as endovaginal ultrasound
  • Used to evaluate female reproductive organs including uterus, ovaries, fallopian tubes, cervix, and vagina

Indications

General

  • Pelvic pain
  • Abnormal pelvic or abdominal exam

Uterus

Ovaries and adnexa

Pregnancy

Technique

General

  • Use 5 MHz endocavitary probe (high frequency, low penetration)
  • Apply surgical lubricant inside and outside probe cover
  • Place patient in lithotomy position
  • Gently advance probe into vaginal canal and position adjacent to cervix
    • May be more comfortable for patient to insert probe into vagina herself
  • Apply gentle pressure to lower abdominal wall with one hand and manipulate probe with other hand

Longitudinal scan

  • Probe marker pointing at 12:00
  • Shows anterior structures on left side of screen
  • Begin midline at endometrial stripe
  • Scan from right to left through uterus
  • Move probe laterally to view adnexa and ovaries

Transverse scan

  • Rotate probe 90 degrees counterclockwise so probe marker is pointing at 9:00
  • Shows right-sided structures on left side of screen
  • Start at endometrial stripe and scan throughout uterus
  • Locate cornual flare (junction of uterus and fallopian tubes)
  • Move probe laterally along fallopian tube to locate ovary
  • Ovaries identified by follicular (anechoic or hypoechoic) structures

Findings

Uterus

  • Anteverted: Fundus pointing to anterior abdominal wall
  • Retroverted: Fundus pointing to posterior wall
  • Endometrial stripe: Measured from thickest echogenic area (from one basal endometrial interface to the other, including canal)
    • Pre-menopausal:
      • During menstruation: 2-4mm
      • Early proliferative phase: 5-7mm
      • Late proliferative phase: 11mm
      • Secretory phase: 7-16mm
      • After D&C or SAB: >5mm
        • Consider retained POC if thicker
    • Post-menopausal:
      • With vaginal bleeding: <5mm
      • Without vaginal bleeding: <11mm

Adnexa

  • Simple ovarian cyst: <2.5-3cm

Pregnancy (1st trimester)

  • 4-5 weeks
    • Gestational sac
      • First sign of early pregnancy, usually seen between 3-5 weeks gestation
    • Double decidual sac sign
      • Two concentric rings (uterine lining and gestation lining) around anechoic gestational sac
      • Highly suggestive of intrauterine pregnancy (before yolk sac or embryo embryo visualized
    • Intradecidual sign
      • Thickened decidua on one side of uterine cavity surrounding anechoeic sac
  • 5-6 weeks:
    • Yolk Sac
      • Circular (or sometimes as two parallel lines) echogenic structure with thick walls within gestational sac
      • Definitive evidence of intrauterine pregnancy
      • Multiple yolk sacs is earliest sign in multiple gestational pregnancy
    • Double bleb sign
      • Yolk sac and amniotic cavity that look like two bubbles within gestational sac
  • 6-7 weeks
    • Fetal Pole
      • First visual manifestation of fetus (or "embryo")
      • Thickening of margin on yolk sac
    • Cardiac activity present (FHR ~100-115 bpm)
      • Crown rump length: ~5mm
  • 8-9 weeks
    • Limb buds appear
    • Head identifiable
  • 9-10 weeks
    • FHR ~170-180 bpm
    • Fetal movement visible
    • End of embryonic period

Images

Normal

Abnormal

Abnormal Pregnancy

  • Gestational sac >10mm without visible yolk sac
  • Gestational sac >18mm without fetal pole
  • Collapsed gestational sac
  • Pseudgestational sac
    • Endometrial breakdown during ectopic pregnancy
    • May be erroneously interpreted as true gestational sac in ectopic pregnancy
    • Irregularly shaped
    • Located in endometrial cavity, instead of eccentrically within endometrium
    • No yolk sac present
    • May not have double decidual sac sign
  • Absence of fetal heart beat in embryo with CRL >5mm
  • FHR <90 bpm
  • Molar pregnancy
    • Many small, irregular cystic structures in endometrium
    • "Snowstorm appearance"

Ectopic pregnancy

  • Implantation of blastocyst outside of endometrium
  • Occur in fallopian tubes, cervix, ovaries, peritoneal cavity, or scar of prior uterine surgery
  • Most definitive sonographic sign is gestational sac with yolk sac, embryo, or fetal heart beat outside of the endometrium
  • Tubal ring
    • Echogenic thick-walled anechoic sac visualized between uterus and ovary (separate from ovary when pressure applied to fallopian tube with probe)
  • Interstitial Pregnancy
  • Cervical Pregnancy
    • Implantation of gestational sac below internal cervical os
    • Can cause life-threatening hemorrhage
    • Must distinguish between cervical ectopic and spontaneous abortion at level of cervix:


Pearls and Pitfalls

Documentation

Normal Exam

Abnormal Exam

Clips

External Links

See Also

References