IUD-Related Uterine Perforation: Imaging Diagnosis from Ultrasound to X-Ray and CT
Edited by ScholarGen MediAI
When a Missing IUD Is More Than a Missing Device
A young woman presented with abnormal menstrual bleeding after insertion of a hormonal intrauterine device (IUD). Pregnancy testing was negative. Pelvic ultrasound demonstrated a uterus without an identifiable IUD within the endometrial cavity.
At first glance, this may seem like a simple case of IUD expulsion.
It is not.
A subsequent abdominal radiograph demonstrated a T-shaped radiopaque IUD projected over the left lower abdomen and pelvis, well outside the expected uterine location. The device extended across the left iliac bone and sacroiliac joint.
The diagnosis was IUD-related transuterine perforation with extrauterine migration.
This case illustrates a deceptively simple but important principle in medical imaging:
When an IUD is not visualized in the uterine cavity, the diagnostic process has not ended. It has just begun.
Executive Clinical Summary
IUDs are highly effective, long-acting reversible contraceptive devices. Although uterine perforation is uncommon, it is a clinically important complication because an IUD can pass through the myometrium and serosa and subsequently migrate into the peritoneal cavity.
The imaging pathway is usually straightforward:
Pelvic ultrasound → abdominal/pelvic radiography → CT when clinically indicated
Ultrasound is the key first-line examination for assessing IUD position. If an expected IUD cannot be identified within the uterine cavity, expulsion and extrauterine migration should both be considered.
Radiography can provide the critical next clue because most IUDs are radiopaque. Identification of a T-shaped device outside the expected uterine location strongly suggests extrauterine migration.
CT is not required in every case. Its greatest value is defining the three-dimensional relationship between the migrated IUD and adjacent bowel, bladder, omentum, vessels, and other pelvic structures, particularly when surgery is being planned or complications are suspected.
Key Clinical Questions
What should be considered when an IUD string is missing?
What is the significance of an IUD that cannot be identified on ultrasound?
How can radiography distinguish expulsion from extrauterine migration?
When is CT useful in suspected IUD perforation?
What imaging findings should be communicated before surgical removal?
How can radiologists avoid falsely attributing symptoms to incidental pelvic findings?
Introduction
The intrauterine device is one of the most widely used long-acting reversible contraceptive methods. Its effectiveness depends not only on the device itself but also on appropriate positioning within the uterine cavity.
An IUD can become malpositioned in several ways. It may be expelled, displaced within the uterine cavity, embedded partially within the myometrium, or perforate the uterine wall and migrate outside the uterus.
From a radiologic perspective, these entities should not be treated as interchangeable diagnoses.
The distinction between displacement, embedment, perforation, and migration can directly influence clinical management and surgical planning.
The case presented here is particularly valuable because the initial ultrasound was not dramatic. The uterus appeared relatively unremarkable, and no large pelvic mass or obvious inflammatory process was identified. The decisive finding came from recognizing that the expected IUD was absent from the uterine cavity and then using a complementary imaging modality.
Clinical Hook: The Importance of an Absent Finding
In diagnostic imaging, a positive finding often attracts immediate attention.
A mass is visible.
A fracture is visible.
A hemorrhage is visible.
But sometimes the most important finding is the absence of something that should be there.
An IUD is designed to reside within the uterine cavity. Therefore, when an IUD is expected but cannot be identified on ultrasound, the absence itself becomes clinically meaningful.
Possible explanations include:
Expulsion
Extrauterine migration following uterine perforation
An embedded or poorly visualized device
Technical limitations of the examination
An IUD type or configuration that is difficult to visualize
The correct response is not to assume that the device has simply fallen out.
The next question should be:
Where is the IUD now?
Learning Objectives
By the end of this article, readers should be able to:
Recognize the major imaging manifestations of IUD malposition.
Distinguish displacement, embedment, perforation, and extrauterine migration.
Understand the role of pelvic ultrasound as the initial imaging examination.
Recognize when abdominal or pelvic radiography becomes necessary.
Understand the complementary role of CT in evaluating migrated IUDs.
Identify important imaging findings that affect surgical management.
Understanding IUD Malposition
IUD malposition is best understood as a spectrum rather than a single condition.
| Condition | Anatomical Location | Imaging Meaning |
|---|---|---|
| Expulsion | Beyond the cervix and outside the uterus | Partial or complete expulsion |
| Displacement | Within the uterine cavity but away from the expected fundal position | Rotation, low position, or abnormal orientation |
| Embedment | Partial penetration into the myometrium | Device is embedded in the uterine wall |
| Perforation | Traverses the myometrium and serosa | Partial or complete uterine wall perforation |
| Migration | Device has moved outside the uterus | Extrauterine location with possible organ involvement |
The distinction between embedment and perforation is particularly important.
An embedded IUD may extend into the myometrium without crossing the serosal surface. A perforated IUD has traversed the uterine wall and may enter the peritoneal cavity.
Once the device is completely outside the uterus, the clinical problem becomes one of extrauterine foreign-body localization and potential organ interaction.
Pathophysiology: How Does an IUD Perforate the Uterus?
Two broad mechanisms are clinically relevant.
Primary Perforation
Primary perforation occurs during insertion.
The device or insertion instrument may penetrate the uterine wall directly.
Factors that may influence insertion-related perforation include:
Uterine position
Uterine flexion
Uterine size
Myometrial condition
Operator experience
Insertion technique
Force applied during insertion
Postpartum uterine changes
Lactation-associated hypoestrogenic changes
Uterine perforation is uncommon. Historical estimates have often been approximately one event per 1,000 insertions, although reported incidence varies according to study design, follow-up duration, and whether partial perforations are included.
One clinical series involving 17,469 insertions reported complete or partial perforation at approximately 1.6 per 1,000 insertions.
Secondary or Delayed Perforation
A second mechanism involves progressive migration.
An IUD may initially become partially embedded within the uterine wall and subsequently migrate through the myometrium over time, potentially facilitated by local inflammatory reactions and tissue remodeling.
This explains an important clinical point:
Absence of significant pain at the time of insertion does not completely exclude later perforation or migration.
Epidemiology and Risk Factors
Uterine perforation remains an uncommon complication of IUD insertion.
Large cohort studies have nevertheless identified clinical circumstances associated with increased risk.
Frequently discussed risk factors include:
Postpartum insertion
Breastfeeding at the time of insertion
Marked uterine anteflexion or retroflexion
Difficult insertion
Abnormal uterine anatomy
Limited insertion experience
Breastfeeding is particularly relevant because several studies have reported an increased relative risk of perforation in lactating women. However, the absolute risk remains low.
Therefore, counseling should avoid unnecessary alarm:
IUD perforation is uncommon, even when certain risk factors are present.
Clinical Presentation
The clinical presentation is highly variable.
Possible symptoms and clinical clues include:
Lower abdominal pain
Pelvic pain
Abnormal uterine bleeding
Changes in menstrual pattern
Loss of contraceptive effectiveness
Pregnancy
Missing IUD strings
An IUD that cannot be identified during follow-up
Importantly, some patients may have few or no symptoms.
One study cited in the case material reported that 43% of patients with intraperitoneal perforated IUDs were asymptomatic.
This has major implications for imaging practice.
A patient does not need to have acute abdominal pain, fever, or peritoneal signs for extrauterine IUD migration to be present.
Imaging Diagnosis of IUD-Related Uterine Perforation
1. Pelvic Ultrasound: The First-Line Examination
Ultrasound is the primary imaging modality for evaluating IUD position.
It is particularly useful when:
IUD strings cannot be identified
Pelvic pain is present
Abnormal uterine bleeding occurs
IUD malposition is suspected
Pregnancy occurs with an IUD in situ
Both transabdominal and transvaginal approaches may contribute to evaluation, with transvaginal ultrasound providing detailed assessment of the uterus and endometrial cavity.
Three-dimensional ultrasound may provide additional information in selected cases, particularly for subtle malposition such as side-arm embedment.
FIGURE 1
Figure 1. Sagittal ultrasound of the lower uterine segment.
Radiologist Interpretation:
The uterus is anteverted, with a relatively homogeneous myometrial echotexture. The image orientation labels identify sagittal imaging of the lower uterine segment. The expected T-shaped echogenic IUD is not identified within the endometrial cavity.
Clinical Significance:
Failure to visualize the expected IUD should prompt consideration of expulsion, perforation with extrauterine migration, or limited visualization. The absence of the device should not automatically be interpreted as evidence of expulsion.
ALT Text:
Sagittal pelvic ultrasound demonstrating the uterus without a visible IUD within the endometrial cavity.
2. Sagittal Ultrasound: Look for the Expected T Shape
A normally positioned T-shaped IUD should produce a recognizable echogenic configuration within the uterine cavity.
The vertical stem and transverse arms are important landmarks.
When evaluating sagittal images, the radiologist should ask:
Is the device within the endometrial cavity?
Is the stem oriented appropriately?
Is the fundal relationship preserved?
Is there evidence of myometrial penetration?
Are the expected transverse arms visible?
FIGURE 2
Figure 2. Sagittal ultrasound of the uterus.
Radiologist Interpretation:
The uterus is anteverted, and the myometrium demonstrates relatively homogeneous echotexture. A characteristic T-shaped echogenic IUD is not identified within the endometrial cavity.
Clinical Significance:
The absence of an expected IUD from the uterine cavity is a clinically meaningful finding. Correlation with previous imaging and abdominal or pelvic radiography can help distinguish expulsion from extrauterine migration.
ALT Text:
Sagittal ultrasound of the uterus showing no visible IUD within the endometrial cavity.
3. Coronal Ultrasound: Evaluate the Transverse Arms
Coronal imaging is particularly useful for assessing the transverse arms of an IUD.
A normally positioned T-shaped device should demonstrate the expected relationship of the arms to the uterine cavity.
FIGURE 3
Figure 3. Coronal ultrasound of the uterus.
Radiologist Interpretation:
The uterine cavity and myometrium are visualized. The expected T-shaped IUD is not identified within the uterine cavity.
Clinical Significance:
Coronal imaging complements sagittal imaging by providing an additional plane for evaluating the transverse arms. Absence of the expected T-shaped configuration across multiple planes strengthens concern for malposition or extrauterine location.
ALT Text:
Coronal uterine ultrasound demonstrating absence of the expected T-shaped IUD within the uterine cavity.
An Incidental Ovarian Finding Should Not Distract from the Main Diagnosis
The case also demonstrated a small cystic structure associated with peripheral vascularity in the left ovary, compatible with a corpus luteal cyst.
FIGURE 4
Figure 4. Coronal Doppler ultrasound of the left ovary.
Radiologist Interpretation:
A small cystic structure is present in the left ovary with peripheral Doppler vascularity, consistent with a corpus luteal cyst. No significant abnormality was identified in the right ovary.
Clinical Significance:
A corpus luteal cyst is commonly a physiologic finding. In this case, it should not distract from the dominant imaging problem: the expected IUD is absent from the uterine cavity.
This distinction between an incidental finding and the dominant diagnostic finding is fundamental to effective radiologic reasoning.
What Should Happen When the IUD Is Not Seen on Ultrasound?
This algorithm prevents a common diagnostic error: equating a missing ultrasound finding with expulsion.
4. Abdominal Radiography: The Critical Second Step
When an IUD cannot be visualized within the uterus, abdominal or pelvic radiography can be extremely useful.
The reason is simple.
Most IUDs contain radiopaque components that permit identification on plain radiographs.
Radiography therefore answers a different question from ultrasound.
Ultrasound asks:
Is the IUD inside the uterus?
Radiography can help answer:
Is the IUD still somewhere within the abdomen or pelvis?
This complementary approach is particularly valuable when the device is no longer located within the uterine cavity.
FIGURE 5
Figure 5. KUB demonstrating an extrauterine IUD in the left lower abdomen.
Radiologist Interpretation:
A T-shaped radiopaque IUD is projected over the left lower abdomen and pelvis. The transverse arms extend across the region of the left iliac bone and sacroiliac joint. The device is clearly outside the expected location of the uterine cavity.
Clinical Significance:
The combination of a missing IUD on pelvic ultrasound and a T-shaped radiopaque device located outside the uterus strongly supports extrauterine migration following uterine perforation.
ALT Text:
KUB radiograph demonstrating a T-shaped radiopaque IUD in the left lower abdomen outside the expected uterine location.
The Diagnostic Power of Combining Two Imaging Findings
The diagnosis in this case does not depend on an elaborate CT reconstruction.
It comes from connecting two apparently simple observations:
Ultrasound:
The IUD is not present within the uterine cavity.
Radiograph:
A T-shaped IUD is present in an abnormal extrauterine location.
Together, these findings strongly support:
IUD-related uterine perforation with extrauterine migration.
This is an excellent example of multimodality imaging reasoning.
A radiologist should not interpret each examination as an isolated event. The diagnostic value often comes from connecting findings across modalities.
When Is CT Necessary?
CT is not mandatory for every patient with suspected IUD perforation.
Its value increases when the precise location or relationship of the device to adjacent structures is uncertain.
CT may be particularly useful when:
The exact location of the IUD is unclear
Bowel involvement is suspected
Bladder involvement is suspected
Peritonitis is suspected
An abscess is suspected
Bowel obstruction is suspected
Adhesion to an abdominal or pelvic organ is suspected
Preoperative anatomical mapping is required
The key advantage of CT is not simply confirming that the IUD exists.
The important question is:
What is the IUD touching, penetrating, or adhering to?
CT can demonstrate the spatial relationship between the migrated device and:
Small bowel
Colon
Urinary bladder
Omentum
Pelvic organs
Abdominal wall
Other intra-abdominal structures
This information can be highly relevant to surgical planning.
MRI: What Is Its Role?
MRI is generally not the first-line examination for locating an IUD that is not seen on ultrasound.
For most suspected IUD malposition cases, the practical sequence is:
Ultrasound → X-ray → CT when indicated
MRI may have a role when another pelvic condition requires detailed soft-tissue evaluation or when CT is unsuitable for a specific clinical reason.
The key point is that a missing IUD on ultrasound does not automatically mean that MRI should be the next test.
Imaging should remain driven by the clinical question.
Differential Diagnosis
| Diagnosis | Key Imaging Finding | Clinical Clue | Differentiating Point |
|---|---|---|---|
| Expulsion | IUD absent from uterus and abdomen/pelvis on radiography | Missing strings | Device may have exited the genital tract |
| Displacement | IUD remains within uterus but is abnormally positioned | Pelvic symptoms or abnormal bleeding | Device remains intrauterine |
| Embedment | Part of IUD penetrates myometrium | Pain or abnormal bleeding may occur | Device remains partly within uterine wall |
| Perforation | IUD traverses uterine wall | May be symptomatic or asymptomatic | Device extends through myometrium and serosa |
| Extrauterine migration | IUD located outside uterus | Missing strings or abnormal symptoms | Radiography/CT localizes the device outside uterus |
The distinction is important because management depends on anatomy, symptoms, complications, and the relationship of the device to surrounding organs.
Multimodal Imaging Comparison
| Modality | Strength | Limitation | Best Clinical Question |
|---|---|---|---|
| Transvaginal ultrasound | Excellent evaluation of uterine cavity and IUD position | Limited when device is extrauterine | Is the IUD inside the uterus? |
| 3D ultrasound | Better visualization of subtle malposition in selected cases | Availability and operator dependence | Is there subtle embedment or malposition? |
| Abdominal/pelvic X-ray | Rapid localization of radiopaque IUD | Limited soft-tissue detail | Is the IUD still inside the abdomen/pelvis? |
| CT | Precise anatomical localization and organ relationships | Radiation exposure | Where exactly is the migrated IUD and what structures are involved? |
| MRI | Excellent soft-tissue contrast | Not usually first-line for IUD localization | Is another pelvic pathology requiring MRI present? |
No single modality answers every clinical question.
The strength of this imaging strategy lies in complementarity.
Radiologist Interpretation: What Should the Report Say?
A report that simply states:
“IUD not visualized.”
may be technically correct but clinically incomplete.
A more useful interpretation should communicate the diagnostic implication and suggest an appropriate next step.
For example:
No IUD is visualized within the endometrial cavity. Correlation with prior imaging and abdominal/pelvic radiography is recommended to exclude expulsion or extrauterine migration.
If radiography subsequently demonstrates a T-shaped device outside the uterine region, the radiologist should clearly communicate concern for extrauterine migration.
The report should address:
Whether the IUD is intrauterine
Whether uterine wall penetration is suspected
Where the device is located
Whether adjacent organs are involved
Whether complications are present
Whether further imaging is indicated
Imaging Diagnostic Algorithm
Treatment: Location and Complications Determine Management
Once uterine perforation and extrauterine migration have been established, management depends on the location of the device and its relationship to surrounding structures.
Many intraperitoneal IUDs are considered for surgical removal.
Clinical circumstances that increase concern include:
Extrauterine migration
Bowel adhesion
Bladder involvement
Abscess
Peritonitis
Bowel obstruction
Fistula
Suspected visceral injury
Laparoscopic removal is commonly used for intraperitoneal IUDs when feasible.
However, laparotomy may be required when there is bowel perforation, severe infection, complex adhesions, or other complicated anatomy.
The imaging examination therefore has a practical role beyond diagnosis.
It helps determine the surgical map.
Why Long-Term Extrauterine IUD Retention Matters
An extrauterine IUD does not inevitably cause a severe complication.
Nevertheless, retained intraperitoneal devices may be associated with:
Adhesion formation
Bowel adhesion
Abscess
Fistula
Bowel obstruction
Bowel perforation
Bladder involvement
Chronic pelvic pain
Copper-containing IUDs have also been associated with local inflammatory responses and dense adhesion formation in some reports.
Therefore, absence of symptoms should not automatically be interpreted as proof of safety.
Prognosis
When the diagnosis is made appropriately, and the device is managed appropriately, outcomes are generally favorable.
The most important prognostic questions are:
Where is the IUD?
and
Is an adjacent organ involved?
An isolated intraperitoneal device has a different clinical significance from an IUD that has become adherent to or penetrated bowel or bladder.
For this reason, the radiologist should provide more than a simple location.
A clinically useful imaging assessment should communicate:
IUD location + uterine wall involvement + adjacent organ relationship + complications
Artificial Intelligence Perspective
IUD-related uterine perforation is a relatively focused clinical problem, but it illustrates several broader principles relevant to medical imaging AI.
An AI system could potentially assist with:
Detection of radiopaque IUDs on radiographs
Localization of IUDs
Classification of intrauterine versus extrauterine position
Detection of suspected uterine wall penetration
Identification of abnormal device orientation
Automated comparison with prior examinations
Workflow alerts for potentially missing devices
However, these applications should be viewed as decision-support functions rather than autonomous diagnosis.
AI Workflow
The radiologist remains responsible for confirming the finding and integrating it with the clinical history.
AI Failure Modes
An IUD detection model may fail in several ways.
False Negative
A migrated IUD may be missed because of:
Unusual projection
Overlapping bowel gas
Low image quality
Unusual device orientation
Device fragmentation
Limited field of view
False Positive
Other radiopaque structures may mimic an IUD.
Potential sources include:
Surgical clips
Calcifications
Foreign bodies
Metallic artifacts
Anatomical Mislocalization
Detection of the device is not equivalent to knowing its anatomical compartment.
A model may correctly identify an IUD but incorrectly classify it as intrauterine.
Domain Shift
An AI model trained on a narrow set of radiographic appearances may perform less reliably across:
Different hospitals
Different radiographic systems
Different IUD designs
Different patient populations
Different acquisition protocols
This is why external validation and continuous monitoring are essential before clinical deployment.
Enterprise Healthcare Perspective
At hospital scale, the clinically useful objective is not merely “detect IUD.”
The goal is to integrate the detection into an existing imaging workflow without creating unnecessary alerts.
An enterprise implementation should also consider:
DICOM interoperability
PACS integration
RIS integration
EMR connectivity
HL7/FHIR interfaces where applicable
Audit logging
Cybersecurity
Model monitoring
Version control
Performance drift
Human oversight
AI should support the radiologist's reasoning rather than replace it.
Regulatory Perspective
An AI system used to detect or classify medical-device complications may fall within the regulatory framework applicable to medical-device software or Software as a Medical Device, depending on its intended use and jurisdiction.
Regulatory approval should never be assumed simply because a model demonstrates high performance in a research study.
Clinical deployment requires consideration of:
Intended use
Clinical validation
Generalizability
Human oversight
Cybersecurity
Performance monitoring
Change management
Post-market surveillance when applicable
The distinction between a research algorithm and a clinically deployed medical device is fundamental.
Healthcare Economics and ROI
The financial value of an AI-assisted IUD detection workflow should not be expressed using unsupported numerical claims.
A qualitative ROI framework can consider:
ROI = (Financial Benefit − Total Cost of Ownership) / Total Cost of Ownership
Potential benefits may include:
Reduced diagnostic delay
More consistent detection
Improved radiology workflow
Reduced repeat imaging
Earlier identification of device complications
More efficient surgical planning
Potential costs include:
AI licensing
Integration
Infrastructure
Maintenance
Staff training
Monitoring
Cybersecurity
Workflow redesign
The actual return depends on local clinical volume, implementation strategy, adoption, and measurable clinical benefit.
Ten Expert Insights
Expert Insight 1 — Radiologist Perspective
The absence of an expected device can be more diagnostically important than a subtle incidental abnormality. When an IUD should be present but is not, the radiologist should actively investigate the discrepancy.
Expert Insight 2 — Ultrasound Perspective
Sagittal and coronal planes should be interpreted together. A single plane may fail to demonstrate the complete configuration of a T-shaped device.
Expert Insight 3 — Multimodality Perspective
Ultrasound and radiography answer different questions. Ultrasound evaluates the uterine cavity; radiography can establish whether a radiopaque device remains within the abdomen or pelvis.
Expert Insight 4 — Emergency Perspective
Absence of severe abdominal symptoms does not exclude extrauterine IUD migration. Clinical severity should not determine whether the device is localized.
Expert Insight 5 — CT Perspective
CT becomes particularly valuable when the relationship between the migrated IUD and bowel, bladder, omentum, or other pelvic structures must be defined.
Expert Insight 6 — Reporting Perspective
“IUD not visualized” should not necessarily be the endpoint of the report. When clinically appropriate, the report should communicate the possibility of expulsion or extrauterine migration and recommend correlation with radiography.
Expert Insight 7 — Surgical Perspective
The most useful imaging report is not simply a diagnosis. It is a surgical map describing the location of the device and its relationship to adjacent structures.
Expert Insight 8 — AI Deployment Perspective
An AI model that detects an IUD but cannot reliably determine whether it is intrauterine or extrauterine has limited clinical value.
Expert Insight 9 — Clinical Governance Perspective
Any AI alert should remain subject to radiologist verification. False positives can create unnecessary work, while false negatives may delay recognition of a clinically significant complication.
Expert Insight 10 — Future Technology Perspective
The most promising future workflow is multimodal: combining prior IUD documentation, ultrasound, radiography, CT, clinical information, and longitudinal imaging into a single clinical decision-support environment.
Clinical Pearls
A missing IUD string warrants localization rather than immediate assumption of expulsion.
Pelvic ultrasound is an important first-line examination for suspected IUD malposition.
A T-shaped IUD should normally be recognizable within the uterine cavity.
Sagittal and coronal imaging provide complementary information.
Three-dimensional ultrasound may improve detection of selected subtle malpositions.
If the IUD is not visualized in the uterus, abdominal or pelvic radiography can be highly informative.
A radiopaque T-shaped device outside the expected uterine location strongly suggests extrauterine migration.
CT is particularly useful for defining relationships with bowel and bladder.
Asymptomatic presentation does not exclude uterine perforation.
Incidental findings should not distract from the dominant diagnostic problem.
Embedment and perforation are not synonymous.
A radiology report should communicate clinically actionable implications when appropriate.
The imaging goal is not merely device detection but anatomical localization and complication assessment.
Surgical planning benefits from precise localization of the migrated IUD.
AI should assist detection and workflow rather than replace clinical judgment.
Common Diagnostic Pitfalls
Pitfall 1: Assuming Expulsion
A missing IUD is not automatically an expelled IUD.
Pitfall 2: Stopping After Ultrasound
Failure to visualize the device should prompt consideration of complementary imaging when clinically appropriate.
Pitfall 3: Ignoring the Device Location on X-Ray
The skeletal landmarks can provide important orientation when assessing an extrauterine IUD.
Pitfall 4: Overcalling Incidental Ovarian Findings
A small corpus luteal cyst may be physiologic and unrelated to the principal clinical problem.
Pitfall 5: Equating Embedment with Perforation
Myometrial penetration without serosal violation is not identical to complete uterine perforation.
Pitfall 6: Assuming No Pain Means No Perforation
Extrauterine IUD migration may be clinically silent.
Pitfall 7: Ordering MRI Automatically
MRI is not routinely the next examination simply because an IUD is not seen on ultrasound.
Pitfall 8: Failing to Evaluate Adjacent Organs
Once an IUD is extrauterine, the relationship to bowel, bladder, and other structures becomes clinically important.
Pitfall 9: Treating AI Detection as Diagnosis
An AI-generated bounding box or confidence score does not replace radiologic interpretation.
Pitfall 10: Providing an Incomplete Report
The clinically useful report should explain what was found, where it is located, and what additional evaluation may be appropriate.
Featured Snippet Answers
What is IUD-related uterine perforation?
IUD-related uterine perforation occurs when an intrauterine device passes through the uterine wall, potentially crossing the myometrium and serosa and entering the peritoneal cavity. The condition may be symptomatic or asymptomatic and is usually evaluated initially with pelvic ultrasound, followed by radiography and selective CT when necessary.
What is the key imaging finding?
The key imaging pattern is an IUD that is absent from the uterine cavity on ultrasound but identified outside the expected uterine location on abdominal or pelvic radiography. A T-shaped radiopaque device in an abnormal pelvic or abdominal position strongly suggests extrauterine migration.
When is CT indicated?
CT is useful when the precise location of an extrauterine IUD is uncertain or when bowel, bladder, omental involvement, abscess, obstruction, or other complications are suspected. CT is particularly valuable for preoperative anatomical mapping.
Frequently Asked Questions
1. What does it mean if an IUD string cannot be seen?
A missing string can have several explanations, including retraction, expulsion, malposition, or uterine perforation. Imaging may be required to determine the device's location.
2. Is ultrasound the first imaging test for a missing IUD?
Pelvic ultrasound is an important first-line examination for assessing whether the IUD remains within the uterus.
3. What if the IUD is not seen on ultrasound?
If the device is not identified within the uterus, expulsion and extrauterine migration should be considered. Abdominal or pelvic radiography can help determine whether a radiopaque IUD remains within the abdomen or pelvis.
4. Can an IUD perforate the uterus without causing pain?
Yes. Uterine perforation and extrauterine migration can occasionally be asymptomatic.
5. What does an IUD outside the uterus on X-ray mean?
A T-shaped radiopaque IUD outside the expected uterine location strongly suggests extrauterine migration, usually following uterine perforation.
6. Is CT required for every perforated IUD?
No. CT is selected according to the clinical situation, especially when precise localization or evaluation of adjacent organs is required.
7. Can an extrauterine IUD affect the bowel?
It can become adherent to or involve the bowel and, in complicated cases, may be associated with perforation, obstruction, fistula, or infection.
8. Is MRI routinely used to locate a missing IUD?
No. Ultrasound followed by radiography, with CT when indicated, is generally a more practical imaging pathway for suspected IUD migration.
9. Is a small ovarian cyst necessarily responsible for abnormal bleeding?
Not necessarily. Incidental findings should be interpreted in the context of the entire clinical and imaging picture.
10. Why is accurate radiology reporting important in IUD migration?
The report can help clinicians determine whether the device is intrauterine or extrauterine and whether further imaging or surgical evaluation may be necessary.
Quiz
1. A patient with an IUD has a missing string. Pelvic ultrasound does not demonstrate an IUD within the endometrial cavity. What is the most appropriate next imaging consideration?
① Brain MRI
② Abdominal/pelvic radiography
③ Mammography
④ Bone scintigraphy
⑤ PET-CT
Correct Answer: ② Abdominal/pelvic radiography
Explanation: When an expected IUD is not identified within the uterus, expulsion and extrauterine migration should be considered. Radiography can identify a radiopaque IUD elsewhere within the abdomen or pelvis.
① Normal intrauterine IUD
② IUD expulsion
③ Myometrial embedment
④ IUD-related uterine perforation with extrauterine migration
⑤ Uterine fibroid
Correct Answer: ④ IUD-related uterine perforation with extrauterine migration
Explanation: The combination of absence from the uterine cavity and identification of the device outside the expected uterine location strongly supports uterine perforation with extrauterine migration.
① Ignore the finding
② Observe indefinitely
③ Surgical evaluation, including consideration of laparoscopic removal
④ Hormonal therapy alone
⑤ Antihistamine therapy
Correct Answer: ③ Surgical evaluation, including consideration of laparoscopic removal
Explanation: Symptoms combined with suspected bowel involvement increase concern for clinically significant complications and warrant surgical assessment.
① Embedment always means the device has entered the abdomen.
② Perforation means the device remains entirely within the endometrial cavity.
③ Embedment involves myometrial penetration, whereas perforation crosses the uterine wall and serosa.
④ They are radiologically identical.
⑤ Perforation can occur only with copper IUDs.
Correct Answer: ③
Explanation: Embedment and perforation represent different anatomical stages of IUD malposition. The distinction is clinically important because management can differ.
① To replace ultrasound in every patient
② To determine serum hormone levels
③ To identify pregnancy
④ To define the relationship of the IUD to adjacent abdominal and pelvic organs
⑤ To determine menstrual cycle phase
Correct Answer: ④
Explanation: CT provides cross-sectional anatomical information and can demonstrate relationships between the migrated device and bowel, bladder, omentum, and other structures, particularly when surgical planning is required.
The Ultimate Guide to IUD-Related Uterine Perforation
This case can serve as a pillar topic for a broader medical imaging content cluster.
Recommended Supporting Articles
Ultrasound Evaluation of IUD Position: A Practical Imaging Guide
Missing IUD Strings: Imaging Differential Diagnosis
IUD Malposition: Displacement vs Embedment vs Perforation
3D Ultrasound for Subtle IUD Malposition
KUB Radiography in Suspected Extrauterine IUD Migration
CT Evaluation of Migrated Intrauterine Devices
IUD Migration and Bowel Complications
IUD Migration and Urinary Bladder Involvement
Radiology Reporting Guide for Missing IUDs
Artificial Intelligence for Medical Device Detection on Radiographs
Conclusion
IUD-related uterine perforation is an uncommon but important medical-device complication.
The diagnostic challenge is often not a dramatic abnormality.
It is the missing device.
When an IUD is expected but cannot be identified within the uterine cavity, the radiologist should not automatically conclude that it has been expelled.
The practical imaging pathway is:
Pelvic ultrasound
↓
Abdominal/pelvic radiography when the IUD is not visualized
↓
CT when precise localization or complications require cross-sectional assessment
The most important imaging concept is to connect the findings across modalities.
In this case, ultrasound demonstrated that the expected IUD was absent from the uterine cavity. KUB then demonstrated a T-shaped radiopaque device in the left lower abdomen and pelvis, establishing the extrauterine location and strongly supporting uterine perforation with migration.
CT, when clinically indicated, adds another level of information by defining the relationship of the migrated device to bowel, bladder, omentum, and other pelvic structures.
The radiologist's role therefore extends beyond simply identifying whether the IUD is present.
The essential questions are:
Where is the IUD?
Has it crossed the uterine wall?
What structures are nearby?
Is there a complication?
Does the imaging finding change the next clinical step?
Ultimately, the central lesson of this case is simple:
A missing IUD is not a diagnosis. It is a signal to begin localization.
Key Takeaways
IUD malposition includes expulsion, displacement, embedment, perforation, and migration.
Missing IUD strings should prompt appropriate clinical and imaging evaluation.
Pelvic ultrasound is an important first-line imaging examination.
Absence of the IUD from the uterine cavity does not prove expulsion.
Abdominal/pelvic radiography can identify a radiopaque IUD outside the uterus.
An extrauterine T-shaped IUD strongly suggests perforation with migration.
CT is valuable when exact localization and adjacent-organ involvement must be assessed.
Extrauterine IUD migration can be asymptomatic.
Incidental findings should not distract from the dominant diagnostic abnormality.
Imaging reports should provide clinically useful localization and recommendations when appropriate.
AI may assist detection and workflow, but radiologist verification remains essential.
The ultimate imaging objective is not simply device detection but anatomical localization, complication assessment, and clinically meaningful communication.
Medical Disclaimer
This article is provided for medical education and informational purposes only. It does not replace individualized diagnosis, treatment, or medical advice. Patients with suspected IUD malposition, uterine perforation, or extrauterine migration should be evaluated by appropriately qualified gynecologic and radiologic specialists.
References
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