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Foundations Case Presentation

Foundations I Course:

Case 44

Presentation Author: Dr. Nicole Bardakos and Dr. Caitlin Howard

Presentation Editor: Dr. E. Liang Liu

Last Revised: Spring 2025

Creative Commons ©Foundations of Medical Education, Inc.

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Case Home Base

ECG

Labs

X-Ray

CT

US

Critical Actions

Initial Vitals

Repeat A

Repeat B

25 yo F presents with abdominal pain

Teaching

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Initial Presentation

HR: 115 BP: 130/75 RR: 18 T: 37 ̊ C

Sat: 98% on RA Wt: 70 kg

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25 yo F presents with abdominal pain

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Reevaluation A

HR: 90 BP: 110/65

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25 yo F presents with abdominal pain

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Reevaluation B

HR: 124 BP: 110/65

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25 yo F presents with abdominal pain

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General Lab Results

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Special Lab Results

Lactate: 1.2

Serum hCG: negative

CRP: 0.10

GC/CT swab: pending

*All other labs are NORMAL

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ECG (Figure 44.1)

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US - FAST (Video 44.3)

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RUQ

LUQ

Pelvis

Subxy

POCUS images courtesy of: Northwestern Emergency Medicine POCUS Image Bank AND Emory Emergency Ultrasound Archive

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US - FAST (Video 44.3)

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POCUS images courtesy of: Northwestern Emergency Medicine POCUS Image Bank AND Emory Emergency Ultrasound Archive

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Pelvic US (Figure 44.4)

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Report: Polycystic right ovary with largest cyst measuring 7.5 cm�Decreased Doppler blood flow, no free fluid

POCUS images courtesy of: Northwestern Emergency Medicine POCUS Image Bank AND Emory Emergency Ultrasound Archive

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XR

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XR Tech is busy in a trauma

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CT

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Significant delay due to multiple trauma patients

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Case Diagnosis:

Ovarian Torsion �

Critical Actions:

Establish IV access
Provide adequate analgesia
Perform a pelvic exam
Obtain a pregnancy test
Order a pelvic ultrasound with Doppler flow
Consult OB/Gyn

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RLQ Pain Differential

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Gynecologic

Ectopic pregnancy +/- rupture
PID, TOA
Ruptured ovarian cyst
Endometriosis

GI

Appendicitis
Diverticulitis, enterocolitis
IBD

Urinary

Nephrolithiasis
Cystitis
Pyelonephritis

What is the clinical presentation of ovarian torsion?

Classically patients present with sudden onset, severe unilateral lower abdominal pain.
Approximately 25% may experience bilateral pain or more subacute symptoms.
Nausea and vomiting is associated with 70% of cases.
Pelvic exam often reveals adnexal fullness or tenderness but this is absent in 30% of cases. Pelvic exam might help distinguish between pelvic and intra-abdominal pathology.
Laboratory findings are nonspecific in torsion and cannot be used to assess tissue necrosis or ischemia.

POCUS Pearls

A female of child bearing age with severe abdominal pain should always get a quick bedside FAST to assess for free fluid given the high risk of ectopic pregnancy
Ultrasound is fast way to gage the severity of a situation by the presence or absence of free fluid
While performing the FAST, you can briefly assess the adnexa for enlarged ovaries
Ovarian torsion is very difficult to diagnose on POCUS. It can also be missed on a formal transvaginal ultrasound since the dual blood supply to the ovary may result in normal Doppler flow despite the presence of torsion.
Ovarian torsion is less likely with normal sized ovaries and most commonly occurs when the ovary is > 5 cm
POCUS should not be used to rule out ovarian torsion but can identify enlarged ovaries which make torsion more likely
Complete absence of Doppler flow to one ovary is diagnostic of ovarian torsion; however presence of flow does not rule out intermittent torsion

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Pathophysiology

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Twisting

Edema

Ischemia

Infarction

Necrosis

Peritonitis

Ovary, fallopian tube (or both) twist on suspending ligament axis Occlusion of low-pressure venous & lymphatic flow

Diagnostic hallmark on imaging is asymmetric enlargement on symptomatic side

Increased swelling & pressure compromises arterial flow Complete loss is uncommon (dual blood supply)

Peritonitis, fever, leukocytosis are late findings!

Pelvic Adnexal Torsion

Definition = “twisting of an ovary, fallopian tube, or para-ovarian cyst on its axis with varying degrees of vascular compromise”

Pathophysiology

Low-pressure venous and lymphatic supplies are cut off first, so the affected area begins to swell with continued arterial inflow.
Swelling, congestion & pressure increases will compromise arterial blood supply, leading to infarction and necrosis of the tissue. Arterial obstruction is a rare and/or late finding due to a dual blood supply to the ovary and because arteries are overall less compressible
Necrosis can lead to hemorrhage (+free fluid on imaging)
THEN can clinical findings of peritonitis, fever, leukocytosis, etc. develop. These are late findings!
The duration of ischemia necessary to cause irreversible tissue necrosis is unknown, but a delay in diagnosis may result in loss of the ovary and fallopian tube.

Ultrasound w/ Doppler

US is 84-92% sensitive: the imaging modality of choice for diagnosis
The most common finding on US is nonspecific ovarian enlargement or edema.

The ovary may appear rounded or edematous and have a heterogeneous appearance.

Abnormal venous flow is nearly 100% sensitive for torsion
Abnormal arterial flow is a late finding and indicator of poor prognosis/need for oophorectomy/salpingectomy.
Normal doppler flow does not rule out torsion!

Only 74-80% specific

Whirlpool sign (visualization of twisted pedicle on doppler) is not as sensitive (up to 90%, technically difficult to find) but 100% specific
Peripheralized follicles (“string of pearls”) occurs due to edema pushing follicles out to the edge of the ovary

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Adnexal Torsion - Facts

2/3 of cases occur on the Right side

N/V is common (70%)

Risks:

Mass/cyst >4 cm in size
PCOS
Pregnancy (OR 18:1)
Prior torsion
Fertility treatments
Hx of Tubal ligation/prior pelvic surgeries

~15% of all cases in pediatric patients

Typically but not always postmenarchal
Up to ½ will have normal ovaries

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Average age ~30 y/o

Direct visualization in OR is gold standard

Fallopian/Paratubal cyst torsion is rare but possible (~1 in 1.5 mil)

Right side is more common because the suspensory (infundibular) ligament is longer, and the descending colon on the left is protective (space-occupying = less room for adnexal torsion)

Pre-pubertal pediatric patients have proportionally longer and more lax ligaments that suspend the adnexal structures. The uterus is small and less space-occupying.

What is the difference between ovarian and adnexal torsion?

Ovarian torsion occurs when the ovary partially or completely rotates on its vascular pedicle.
Adnexal torsion occurs when the fallopian tube twists along with the ovary. Isolated adnexal torsion is less common.

What are the risk factors for ovarian torsion?

An ovarian mass (cyst or neoplasm) is the most common predisposing factor of torsion.

Ovarian cysts > 4 cm and polycystic ovaries are more prone to torsion.
Torsion of a normal-sized ovary is rare but can occur.

Prior ovarian torsion, tubal ligation, and ovarian hyperstimulation syndrome are also risk factors but prior ectopic pregnancies, PID, and endometriosis are not.
Most cases of torsion occur in the early reproductive years, but it can occur at any age.
Pregnancy increases the risk of torsion (odds ratio 18:1).
70% of ovarian torsion cases occur on the right side due to the longer length of the right utero-ovarian ligament and the sigmoid colon residing in the left pelvis.

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Adnexal Torsion - Fiction

Torsion can be ruled out by:

Normal doppler flow on ultrasound
Absence of tenderness or palpable mass

Occurs only in patients of reproductive age

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Prior ectopic, PID, and endometriosis are risk factors

Completely normal adnexa on CT requires US to confidently rule out torsion

Case courtesy of Maulik S Patel, Radiopaedia.org, rID: 85486

Figure 44.5 Enlarged, heterogeneous ovary with twisting of vascular pedicle

Case courtesy of Maulik S Patel, Radiopaedia.org, rID: 85486

https://radiopaedia.org/cases/ovarian-torsion-65?lang=us

Shows classic whirl pool sign, distorsion of the ovarian parenchyma on TV US

CT Scan

often ordered to rule out other differentials (ie appendicitis)
Nearly 100% specific if adnexa are completely normal (sufficient to rule out torsion)
Less ideal compared to US, but there are (+) diagnostic findings:

Edematous/hemorrhagic mass anterior/posterior to uterus, may also see adjacent free fluid or stranding
Abnormal ovarian location, or uterus tilted/pulled toward affected side
Adnexal mass on affected side

Nonspecific adnexal findings warrant further f/u with US. Reasonable to call Gyn based off of (+) CT if findings are more specific, match symptomatic side, and overall clinical concern is high enough… but they’ll probably still want an US.

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References

Additional References

Bridwell RE, Koyfman A, Long B. "High risk and low prevalence diseases: Ovarian Torsion." AJEM. 2022.
Guile SL, Mathai JK. “Ovarian Torsion.” StatPearls. 17 Jul 2023
Robertson JJ, Long B, Koyfman A. Myths in the Evaluation and Management of Ovarian Torsion. J of Emerg Med. 52(4):449-456. Apr 2017.
Strachowski LM, et al. “Pearls and Pitfalls in Imaging of Pelvic Adnexal Torsion: Seven Tips to Tell It’s Twisted.” Radiographics. 1 Mar 2021
Streitz, M. “Ovarian Torsion: Pearls and Pitfalls.” EMDocs.net. 9 Mar 2016
Patel, Maulik. “Ovarian Torsion.” Radiopaedia.org, rID: 85486. https://radiopaedia.org/cases/ovarian-torsion-65?lang=us
OpenStax, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons

Foundations Case #44

Case Author(s): Dr. Alicia Hoban

Editor: Dr. Jacqueline Le

Ultrasound Content: Dr. Rachel Haney, Dr. Sierra Beck, Dr. E. Liang Liu

Editors-in-Chief: Dr. Dana Loke, Dr. Kristen Grabow Moore

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