Ectopic pregnancy: MRI findings and clinical utility

Abnormal Uterine Bleeding: A Pictorial Review on Differential Diagnosis and Not-So-Common Cases of Interventional Radiology Management

Abnormal uterine bleeding (AUB) poses a multifaceted challenge in women's health, necessitating an integrated approach that addresses its diverse etiologies and clinical presentations. The International Federation of Gynecology and Obstetrics PALM-COEIN classification system provides a systematic approach to the diagnosis of AUB in non-pregnant women, based on clinical and imaging-based categorization of causes into structural (Polyps, Adenomyosis, Leiomyomas and Malignancy; PALM), and non-structural causes (Coagulopathies, Ovulatory disorders, primary Endometrial disorders, Iatrogenic and Not otherwise classified; COEIN). On the other hand, placental disorders, uterine rupture, ectopic pregnancy and retained products of conceptions are the main causes of uterine bleeding during pregnancy and in the peripartum period. Ultrasound is usually the first-line imaging technique for the differential diagnosis of causes of AUB. Computed Tomography may be useful if ultrasound findings are unclear, especially in emergency settings. Magnetic resonance imaging, when indicated, is an excellent second-line diagnostic tool for a better non-invasive characterization of the underlying cause of AUB. This pictorial review aims to illustrate the main causes of AUB from the point of view of diagnostic imaging and to show not-so-common cases that can be treated by means of interventional radiology.

Imaging of Acute Abdominopelvic Pain in Pregnancy and Puerperium-Part I: Obstetric (Non-Fetal) Complications

Acute abdominopelvic pain in pregnant and postpartum patients presents clinical and therapeutic challenges, often requiring quick and accurate imaging diagnosis. Ultrasound remains the primary imaging investigation. Magnetic resonance imaging (MRI) has been shown to be a powerful diagnostic tool in the setting of acute abdominal pain during pregnancy and puerperium. MRI overcomes some drawbacks of US, avoiding the ionizing radiation exposure of a computed tomography (CT) scan. Although CT is not usually appropriate in pregnant patients, it is crucial in the emergency evaluation of postpartum complications. The aim of this article is to provide radiologists with a thorough familiarity with the common and uncommon pregnancy and puerperium abdominal emergencies by illustrating their imaging appearances. The present first section will review and discuss the imaging findings for acute abdominopelvic pain of obstetric (non-fetal) etiology.

Unruptured ovarian ectopic pregnancy: Two case reports and literature review

In clinical practice, ovarian pregnancy is extremely rare and is always found to be ruptured. A definitive diagnosis for ruptured ovarian pregnancy is difficult to obtain. We present two cases of unruptured ovarian pregnancies detected during laparoscopy and review existing literature to better understand the clinical characteristics of ectopic pregnancies in this rare site. Intrauterine devices, assisted reproductive technology, and intrauterine operations are all high-risk factors in ovarian pregnancy. Moreover, menopause, abdominal pain, and vaginal bleeding are clinical manifestations. Ovarian pregnancy can be diagnosed using serum hCG, transvaginal ultrasound, and magnetic resonance imaging. Laparoscopy is the treatment of choice for ovarian pregnancy. It is recommended that the intact gestational sac be excised and the ovarian function be protected to the greatest extent possible during the operation. More definitive diagnosis of ovarian pregnancy must be reported in order to gain a better understanding of ovarian pregnancy.

Ectopic pregnancy implanted under the diaphragm: A rare case report

BACKGROUND

Abdominal pregnancy is a rare type of ectopic pregnancy. We describe here a case of ectopic pregnancy implanted under the surface of the diaphragm, presenting the particular features of imaging findings from ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI).

CASE SUMMARY

A 30-year-old woman presented with complaint of intermittent abdominal pain, that had begun 5 d earlier. She had no current or abnormal vaginal bleeding, and her serum human chorionic gonadotropin level (13372.08 IU/L) indicated pregnancy. Vaginal ultrasound showed a mixed echogenic mass in the right ovary. CT (plain) scan showed a curved high density mass beneath the subhepatic space. MRI scan showed a curved mixed signal, with restricted diffusion beneath the subhepatic space. Abdominal ultrasound demonstrated a mixed echogenic mass in the right lobe of the liver near the apex of the diaphragm, with a visible yolk sac and germ cell region with a bud. Subsequent laparoscopy visualized a dark red mass under the right diaphragm, which was resected completely. Histopathological examination of the resected mass confirmed an ectopic pregnancy. The recovery was swift and uneventful, and the patient was discharged to home.

CONCLUSION

Ectopic pregnancy should be in the differential diagnostic workup (via multiple imaging modalities) of childbearing woman with unexplained abdominal pain.

Diagnostic Accuracy of Preoperative Conventional MRI for Patients With Ectopic Pregnancy

Objective

To assess the utility of preoperative magnetic resonance imaging (MRI) in the diagnosis of tubal pregnancy.

Summary of background data

Most cases of ectopic pregnancy are tubal pregnancies. Preoperative accurate diagnosis including the location of the tubal pregnancy is important.

Method

We performed a retrospective single-center cohort study evaluating patients who underwent surgery for ectopic pregnancy from April 2004 to March 2016 and who underwent preoperative MRI. Sixty patients were enrolled in the study. Chorion confirmed at the tubal pregnancy site detected by MRI was defined as a correct diagnosis.

Results

Mean estimated gestational age at the time of MRI according to the last menstrual period was 7 weeks (median: 5 weeks; range: 3–10 weeks). Ectopic pregnancy was diagnosed by MRI in 57 cases, and all cases were either left or right tubal pregnancy. In 52 cases, the actual position matched the MRI findings. In 5 cases, the location of tubal ectopic pregnancy was different from that diagnosed by MRI, or no tubal pregnancy was observed intraoperatively. In 2 cases, no ectopic pregnancy site was observed on MRI, but tubal pregnancy was confirmed by surgery. In one case, an ectopic pregnancy site was not found, and the tube showed normal findings on MRI. The sensitivity of MRI diagnosis was 96.2%, specificity was 16.7%, positive predictive value was 91.1%, and negative predictive value was 33.3%.

Conclusion

In cases of ectopic pregnancy treated surgically, the sensitivity of MRI diagnosis, including identification of the location of ectopic pregnancy, is high.

The double corpus luteum: A novel sonographic sign of heterotopic pregnancy

Heterotopic pregnancy is a rare and highly morbid condition with simultaneous intrauterine and extra-uterine pregnancies. The early diagnosis of heterotopic pregnancy is difficult, owing to rarity of the condition and nonspecific clinical and laboratory findings. This case report introduces the "double corpus luteum" sign, a new sonographic and magnetic resonance imaging sign which is easily detectable and should raise the index of suspicion for heterotopic pregnancy. We present a surgically confirmed spontaneous heterotopic and angular pregnancy in a young woman without risk factors or assisted reproductive therapy to illustrate the utility of this novel sign.

Investigation of clinical utility of contrast-enhanced MRI in the diagnosis of ectopic pregnancy

AIM

To investigate whether contrast-enhanced (CE)-magnetic resonance imaging (MRI) improves identification of implantation site of ectopic pregnancy.

MATERIALS AND METHODS

This retrospective study enrolled 63 patients in whom implantation sites had been confirmed at histopathology. Two expert radiologists for gynaecological imaging and two inexpert radiologists independently reviewed non-CE MRI and a combination of non-CE and CE-MRI (non-CE+CE-MRI), then determined implantation site with a confidence level. The following MRI features were also evaluated: extrauterine gestational sac (GS)-like structure (shape, signal intensities at T1-weighted imaging [WI], T2WI, and diffusion-weighted imaging [DWI], presence of the three rings appearance, and distinct low intensity areas at T2WI, presence of tree or dot-like components, degree of contrast enhancement), fallopian tube (dilatation, dilatation with haematoma, degree of contrast enhancement, enhanced components within the tube), and ascites. These findings were compared for non-CE and non-CE+CE-MRI data, and for expert and inexpert groups.

RESULTS

The expert group identified implantation sites correctly in 58/63 (92%) cases for non-CE and non-CE+CE-MRI. In the inexpert group, the correct identification was improved from 54/63 (86%) using non-CE MRI to 58/63 (92%) using non-CE+CE-MRI, but was not significant (p=0.29). In comparison between non-CE and non-CE+CE-MRI, dilation of the fallopian tubes was observed more frequently (p=0.004) and the confidence level was elevated significantly in the non-CE+CE-MRI (p<0.0001) in the inexpert group. Intergroup comparison revealed that confidence level was significantly higher in the expert group than in the inexpert group using non-CE MRI (p<0.0001), although the difference was not significant at non-CE+CE MRI (p=0.49).

CONCLUSION

CE-MRI did not significantly improve correct identification of ectopic pregnancy implantation sites, although the addition of contrast enhancement did enable inexpert radiologists to diagnose confidently.

Primary hepatic ectopic pregnancy in a patient with polycystic ovary syndrome: A case report

RATIONALE

Hepatic ectopic pregnancy is an extremely rare ectopic pregnancy. This study aimed to report a case of primary hepatic pregnancy in a patient with polycystic syndrome.

PATIENT CONCERNS

A 30-year-old woman presented with vaginal bleeding after 63 days of amenorrhea.

DIAGNOSIS

The patient was initially diagnosed with liver ectopic pregnancy using abdominal ultrasound and abdominal computed tomography (CT).

INTERVENTIONS

The patient underwent laparoscopic exploration to reconfirm the gestational sac in the liver and abdominal surgery to remove liver gestation. The postoperative review of abdominal CT and the level of serum human chorionic gonadotropin (hCG) was performed.

OUTCOMES

The postoperative pathological examination revealed a fluffy tissue in the liver tissue and a blood clot. The patient's vital signs were normal, and she was advised regular follow-up after discharge from the hospital. One month later, the serum hCG level reduced to 0.32 mIU/mL (reference range 0-5 mIU/mL).

LESSONS

If the level of beta-human chorionic gonadotropin (β-HCG) is higher than normal in women of childbearing age and no gestational sac is found in the uterine cavity, the location of pregnancy and gestational sac should be positively confirmed. Also, the possibility of ectopic pregnancy in the abdominal cavity should be considered, and the relevant imaging and biochemical examinations should be improved to avoid delay in diagnosis and treatment.

Cross-sectional imaging of acute gynaecologic disorders: CT and MRI findings with differential diagnosis-part I: corpus luteum and haemorrhagic ovarian cysts, genital causes of haemoperitoneum and adnexal torsion

Acute gynaecologic disorders are commonly encountered in daily clinical practice of emergency departments (ED) and predominantly occur in reproductive-age women. Since clinical presentation may be nonspecific and physical findings are often inconclusive, imaging is required for a timely and accurate diagnosis. Although ultrasound is the ideal non-invasive first-line technique, nowadays multidetector computed tomography (CT) is extensively used in the ED, particularly when a non-gynaecologic disorder is suspected and differential diagnosis from gastrointestinal and urologic diseases is needed. As a result, CT often provides the first diagnosis of female genital emergencies. If clinical conditions and scanner availability permit, magnetic resonance imaging (MRI) is superior to CT for further characterisation of gynaecologic abnormalities, due to the excellent soft-tissue contrast, intrinsic multiplanar capabilities and lack of ionising radiation.

The purpose of this pictorial review is to provide radiologists with a thorough familiarity with gynaecologic emergencies by illustrating their cross-sectional imaging appearances. The present first section will review the CT and MRI findings of corpus luteum and haemorrhagic ovarian cysts, gynaecologic haemoperitoneum (from either ruptured corpus luteum or ectopic pregnancy) and adnexal torsion, with an emphasis on differential diagnosis. Additionally, comprehensive and time-efficient MRI acquisition protocols are provided.

Magnetic resonance imaging of tubal ectopic pregnancy: correlation with intraoperative findings

Ectopic pregnancy is defined as a pregnancy that occurs outside of the uterine cavity (ACOG Committee on Practice Bulletins, 2018 [1]). Ectopic pregnancy is occasionally diagnosed with MRI. Particularly, when ultrasound is nondiagnostic, it is essential that radiologists are able to recognize findings of ectopic pregnancy on MRI in the emergent setting. This novel case report demonstrates specific MR imaging signs recently proposed in the literature to help identify a tubal gestational sac, the most common type of ectopic pregnancy, and is the first reported case demonstrating intraoperative correlation with MRI findings of tubal ectopic pregnancy.

Magnetic resonance imaging of common, uncommon, and rare implantation sites in ectopic pregnancy

OBJECTIVE

To review the MRI appearances of tubal and non-tubal implantation sites in ectopic pregnancy.

CONCLUSION

Transvaginal ultrasound is the primary imaging modality in ectopic pregnancy and MRI is used as a problem-solving tool in selected indications as detailed in the article. MRI features of tubal, interstitial, cervical, cesarean scar, cornual, ovarian, abdominal, and heterotopic pregnancies are provided to familiarize the radiologists with their appearances thereby assisting them in making early and accurate diagnosis.

To evaluate the feasibility of magnetic resonance imaging in predicting unusual site ectopic pregnancy: a retrospective cohort study

OBJECTIVE

To evaluate the accuracy of pelvic MRI in the diagnosis of unusual ectopic pregnancy (EP), when ultrasound (US) examination is inconclusive.

METHODS

We retrospectively reviewed the medical records of 150 patients with suspected EP. Clinical, US and MRI features of 15 unusual EPs were analysed. Two radiologists independently reviewed each case resolving by consensus any diagnostic discrepancy. Interobserver agreement was assessed using the Cohen κ test.

RESULTS

MRI displayed a gestational sac-like structure surrounded by a thick wall in all cases. The thick wall displayed hyperintensity in 41 %, isointensity in 35 % and hypointensity in 24 % of cases on T1-weighted images. Diffusion- and fat saturation T1-weighted images were the most accurate sequences, as they enabled identification of 15/15 and 14/15 patients, respectively. Although US was false negative in detecting cervical and uterine infiltration underlying the caesarean scar, MRI was able to identify the invasion. Interobserver agreement was very good for all sequences (κ=0.892-1.0).

CONCLUSIONS

MRI plays an important role in the early diagnosis of unusual EP. It should be considered after negative US findings, providing accurate evaluation of the site and the possible infiltration of these lesions, which help in the management of these patients.

KEY POINTS

• MRI is being increasingly used as a problem-solving modality in ectopic pregnancy. • MRI plays an important role in early diagnosis of unusual ectopic pregnancy. • Knowledge of MRI features in EP is essential to determinate appropriate management.

Diffusion-weighted imaging in ectopic pregnancy: ring of restriction sign

OBJECTIVE

To demonstrate the diffusion-weighted imaging (DWI) findings of ectopic pregnancy (EP) and introduce the "ring of restriction" sign by discussing possible causes.

METHODS

Between January 2014 and January 2017, patients with EP and examined by MRI on a 3T scanner were retrospectively evaluated. MRI and DWI findings were recorded.

RESULTS

A total of 40 patients were diagnosed with EP at our university hospital, 8 of whom (20%) were evaluated by MRI and DWI. All of them were haemodynamically and clinically stable and could be imaged adequately. Locations were ovary (n = 3, 37.5%), tuba (n = 2, 25%), Caesarean section scar (n = 2, 25%) and parauterine (n = 1, 12.5%). In all eight EPs, the gestational sac diameter was compatible with 7-9 weeks. With DWI, the gestational sac was seen as a thick-walled cyst-like structure. The thick wall showed diffusion restrictions in all patients (ring of restriction sign).

CONCLUSIONS

DWI through its cellular and molecular evidence may contribute diagnosis of EP. Advances in knowledge: Being aware of the EP wall shows diffusion restriction (ring of restriction) avoids interpretation errors especially in appropriate clinical setting with no need for contrast material.

Non-oncologic applications of diffusion-weighted imaging (DWI) in the genitourinary system

Diffusion-weighted imaging (DWI) has become an increasingly used tool in abdominal and pelvic magnetic resonance imaging (MRI), primarily in the oncologic setting. DWI sequences are being added to routine MRI protocols at many institutions, and as its use has spread, more non-oncologic applications have been explored. The purpose of this article is to provide a review of DWI applications in inflammatory, infectious, autoimmune-mediated, and ischemic processes affecting the genitourinary system.

Magnetic resonance imaging - A troubleshooter in obstetric emergencies: A pictorial review

The application of magnetic resonance imaging (MRI) in pregnancy faced initial skepticism of physicians because of fetal safety concerns. The perceived fetal risk has been found to be unwarranted and of late, the modality has attained acceptability. Its role in diagnosing fetal anomalies is well recognized and following its safety certification in pregnancy, it is finding increasing utilization during pregnancy and puerperium. However, the use of MRI in maternal emergency obstetric conditions is relatively limited as it is still evolving. In early gestation, ectopic implantation is one of the major life-threatening conditions that are frequently encountered. Although ultrasound (USG) is the accepted mainstay modality, the diagnostic predicament persists in many cases. MRI has a role where USG is indeterminate, particularly in the extratubal ectopic pregnancy. Later in gestation, MRI can be a useful adjunct in placental disorders like previa, abruption, and adhesion. It is a good problem-solving tool in adnexal masses such as ovarian torsion and degenerated fibroid, which have a higher incidence during pregnancy. Catastrophic conditions like uterine rupture can also be preoperatively and timely diagnosed. MRI has a definite role to play in postpartum and post-abortion life-threatening conditions, e.g., retained products of conception, and gestational trophoblastic disease, especially when USG is inconclusive or inadequate.

A Case of Ovarian Pregnancy Diagnosed by MRI

Ovarian pregnancy is a rare form of ectopic pregnancy, causing a great diagnostic challenge. We report a case of ovarian pregnancy in a 42-year-old woman, in whom MRI successfully demonstrated the implantation in the ovary. Transvaginal ultrasonography showed an echogenic mass in the right ovary but failed to demonstrate tubal pregnancy. T2-weighted MR images disclosed a gestational sac structure in the right ovary, which exhibited heterogeneous high intensity intermingled with punctate foci of distinct low intensity. MRI may be a useful tool for diagnosing ovarian pregnancy, by demonstrating a gestational sac in the ovary.

Bilateral tubal and intrauterine pregnancies diagnosed at laparoscopy

A 32-year-old woman had bilateral tubal and intrauterine pregnancies after hyperovulation with clomiphene citrate and subsequent artificial insemination with husband's semen. Laparoscopic surgery revealed bilateral tubal pregnancies. Salpingectomy was performed on the left tube and linear salpingotomy was performed on the right tube. The postoperative course was uneventful. The patient delivered a healthy girl vaginally at 39 weeks' gestation. Only eight cases with bilateral and intrauterine pregnancy have been reported. The live birth rate of bilateral tubal pregnancy and intrauterine pregnancy is 60% (6/10), which is similar to that of heterotopic pregnancy. Laparoscopic surgery is effective for confirming the diagnosis and treating heterotopic pregnancy.