Computed Tomography of Corpus Luteal Cysts

Association of CT findings in patients with hemoperitoneum due to ruptured ovarian cysts with subsequent intervention

PURPOSE

Hemoperitoneum caused by ovarian cyst rupture may necessitate intervention. The literature is lacking in descriptions of CT findings that help guide patient management. The purpose of this study is to consider CT findings associated with a need for intervention (surgical or interventional radiology management) versus conservative treatment (observation, pain management, and blood transfusions).

METHODS

Two radiologists retrospectively and independently reviewed 103 CTs of pre-menopausal women who presented with acute hemoperitoneum related to ruptured ovarian cysts between January 2010 and January 2019. The following imaging features were assessed: ovarian cyst characteristics, sentinel clot, contrast extravasation, and hemoperitoneum size. Findings were correlated with patient demographics, clinical parameters, and management with surgery/interventional radiology procedure (intervention group) versus conservative management (conservative group).

RESULTS

Of the 103 patients with hemoperitoneum from cyst rupture, 16% (n = 16) required intervention, and 84% underwent conservative treatment (n = 87). Length of stay (p = .008) was higher in the intervention group. Statistically significant CT findings in the intervention versus conservative group included (p-value reader 1/p-value reader 2) greatest AP dimension of hemoperitoneum (p = .001/p = 0.02), posterior cul-de-sac AP dimension (p = 0.03/p = .006), total cul-de-sac AP dimension (p = .002/p = .007), and number of spaces with hemoperitoneum (p = .01/p = .02). There was good to excellent inter-reader agreement for these findings (ICC 0.68-0.91). Active contrast extravasation was significant for one reader (p = .02) with poor inter-reader agreement (ICC 0.36). In utilizing ROC curves, thresholds of 107 mm (greatest axial AP dimension of hemoperitoneum) yielded a sensitivity and specificity of 0.81 and 0.62 for reader 1 and 0.69 and 0.55 for reader 2; 45 mm (posterior cul-de-sac AP dimension) yielded a sensitivity and specificity of 0.75 and 0.63 for reader 1 and 0.94 and 0.49 for reader 2; 70 mm (total cul-de-sac AP dimension) yielded a sensitivity and specificity of 0.75 and 0.64 for reader 1 and 0.75 and 0.50 for reader 2; and greater than 5 spaces yielded a sensitivity and specificity of 0.75 and 0.58 for reader 1 and 0.69 and 0.70 for reader 2.

CONCLUSION

CT findings associated with intervention in hemoperitoneum due to ovarian cyst rupture include size of hemoperitoneum, number of abdominopelvic spaces with hemoperitoneum, and contrast extravasation.

Evaluating the added benefit of CT texture analysis on conventional CT analysis to differentiate benign ovarian cysts

PURPOSE

We aimed to evaluate the benefit of adding CT texture analysis on conventional CT features of benign adnexal cystic lesions, especially in identifying mucinous cystadenoma.

METHODS

This retrospective study included patients who underwent surgical removal of benign ovarian cysts (44 mucinous cystadenomas, 32 serous cystadenomas, 16 follicular/simple cysts and 43 endometriotic cysts) at our institution between January 2015 and November 2017. The CT images were independently reviewed by an abdominal radiologist (reviewer 1) and a resident (reviewer 2). Both reviewers recorded the conventional characteristics and performed texture analysis. Based on reviewer 1's results, two decision trees for differential diagnosis were developed. Reviewer 2's results were then applied to the decision trees. The diagnostic performances of each reviewer with and without the decision trees were compared.

RESULTS

Several conventional features and texture analysis parameters showed significant differences between mucinous cystadenomas and other benign adnexal cysts. The first decision tree selected septum number and thickness as significant features, whereas the second decision tree selected septum number and the mean values at spatial scaling factor (SSF) 0. Reviewer 1's performance did not change significantly with or without the use of the decision trees. Reviewer 2's interpretations were significantly less sensitive than reviewer 1's interpretations (p = 0.001). However, when aided by the first and second decision trees, Reviewer 2's interpretations were significantly more sensitive than reviewer 1's interpretations (86.4%, p < 0.001; 72.7%, p = 0.001).

CONCLUSION

This study suggests the benefit of CT texture analysis on conventional images to differentiate mucinous cystadenoma from other benign adnexal cysts, particularly for less experienced radiologists.

Incidental Ovarian and Uterine Findings on Cross-sectional Imaging

Incidental adnexal masses and uterine findings occur with a high frequency on cross-sectional imaging examinations, particularly in postmenopausal women in whom imaging is performed for a different reason. These incidentalomas encompass a gamut of potential pelvic gynecologic disorders. Most are benign ovarian cysts; however, other less commonly encountered disorders and improperly positioned gynecologic devices may be seen. A knowledge of the management recommendations for such pelvic incidental findings is critical to avoid unnecessary imaging and surgical interventions, as well as to avoid failure in diagnosis and management of some of these conditions.

Adnexal incidentalomas on multidetector CT: how to manage and characterise

Although CT is not considered the examination of choice for the detection and characterisation of adnexal diseases, adnexal masses may be incidentally detected during CT examination performed for other clinical indications. Most adnexal incidentalomas are benign, and therefore may not require further investigation, follow-up or intervention; however, few of them may prove malignant. Multidetector CT has improved the diagnostic performance of the technique in the detection and differentiation of adnexal mass lesions. Radiologists should be able to recognise the normal CT appearance of the ovaries and the CT characteristics of various adnexal incidentalomas. This may obviate unnecessary imaging evaluation and allow optimal treatment planning. Regarding the management of adnexal lesions incidentally found on CT, recommendations based on the collective experience of the members of the American College of Radiology Incidental Findings Committee II have recently been presented.

Ruptured Corpus Luteal Cyst: Prediction of Clinical Outcomes with CT

Objective

To evaluate the determinant pretreatment CT findings that can predict surgical intervention for patients suffering from corpus luteal cyst rupture with hemoperitoneum.

Materials and Methods

From January 2009 to December 2014, a total of 106 female patients (mean age, 26.1 years; range, 17–44 years) who visited the emergency room of our institute for acute abdominal pain and were subsequently diagnosed with ruptured corpus luteal cyst with hemoperitoneum were included in the retrospective study. The analysis of CT findings included cyst size, cyst shape, sentinel clot sign, ring of fire sign, hemoperitoneum depth, active bleeding in portal phase and attenuation of hemoperitoneum. The comparison of CT findings between the surgery and conservative management groups was performed with the Mann-Whitney U test or chi-square test. Logistic regression analysis was used to determine significant CT findings in predicting surgical intervention for a ruptured cyst.

Results

Comparative analysis revealed that the presence of active bleeding and the hemoperitoneum depth were significantly different between the surgery and conservative management groups and were confirmed as significant CT findings for predicting surgery, with adjusted odds ratio (ORs) of 3.773 and 1.318, respectively (p < 0.01). On the receiver-operating characteristic curve analysis for hemoperitoneum depth, the optimal cut-off value was 5.8 cm with 73.7% sensitivity and 58.6% specificity (Az = 0.711, p = 0.004). In cases with a hemoperitoneum depth > 5.8 cm and concurrent active bleeding, the OR for surgery increased to 5.786.

Conclusion

The presence of active bleeding and the hemoperitoneum depth on a pretreatment CT scan can be predictive warning signs of surgery for a patient with a ruptured corpus luteal cyst with hemoperitoneum.

Radiological appearances of corpus luteum cysts and their imaging mimics

PURPOSE

To review the radiological appearances of corpus luteum cysts and their imaging mimics.

CONCLUSION

Corpus luteum cysts are normal post-ovulatory structures seen in the ovaries through the second half of the menstrual cycle and the first trimester of pregnancy. The typical appearance, across all modalities, is of a 1- to 3-cm cyst with a thick crenulated vascularized wall. Occasionally, similar imaging findings may be seen with endometrioma, ectopic pregnancy, tuboovarian abscess, red degeneration of a fibroid, and ovarian neoplasia. In most cases, imaging findings are distinctive and allow for a confident and accurate diagnosis that provides reassurance for patients and referring physicians and avoids costly unnecessary follow-up.

Computed Tomography Imaging of the Acute Pelvis in Females

Sonography is the primary imaging modality for the evaluation of pelvic pain in female patients, especially if gynaecological pathology is suspected. However, computed tomography (CT) is frequently used in patients who present to emergency departments (and elsewhere) with otherwise nonspecific abdominal and pelvic pain and may be the first imaging modality to demonstrate an acute gynaecological abnormality. Computed tomography can also be used prospectively in selected patients to further evaluate findings initially identified on sonography, although to reduce radiation exposure, magnetic resonance imaging is being used more frequently in this situation. The purpose of this article is to discuss the spectrum of gynaecological findings of the acute female pelvis that may be identified on CT by the emergency radiologist and by the general radiologist, with a brief review of the imaging literature of each specific diagnosis.

Radiological appearances of gynaecological emergencies

Background

The role of various gynaecological imaging modalities is vital in aiding clinicians to diagnose acute gynaecological disease, and can help to direct medical and surgical treatment where appropriate. It is important to interpret the imaging findings in the context of the clinical signs and patient's pregnancy status.

Methods

Ultrasound and Doppler are readily available in the emergency department, and demonstrate features of haemorrhagic follicular cysts, ovarian cyst rupture, endometriotic cysts and pyosalpinx. Adnexal torsion may also be identified using ultrasound and Doppler, although the diagnosis cannot be safely excluded based on imaging alone. Computed tomography (CT) is not routinely employed in diagnosing acute gynaecological complications. However due to similar symptoms and signs with gastrointestinal and urinary tract pathologies, it is frequently used as the initial imaging modality and recognition of features of gynaecological complications on CT is important.

Results

Although MRI is not frequently used in the emergency setting, it is an important modality in characterising features that are unclear on ultrasound and CT.

Conclusion

MRI is particularly helpful in identifying the site of origin of large pelvic masses, such as haemorrhagic uterine fibroid degeneration and fibroid prolapse or torsion. In this article, we review the imaging appearances of gynaecological emergencies in non-pregnant patients.

Teaching points

• Ultrasonography is easily accessible and can identify life-threatening gynaecological complications.

• Tomography scanners and computed radiography are not routinely used but are important to recognise key features.

• MRI is used for the characterisation of acute gynaecological complications.

• Recognition of the overlap in symptoms between gastrointestinal and gynaecological conditions is essential.

Imaging of acute right lower quadrant abdominal pain: differential diagnoses beyond appendicitis

Evaluation of acute right lower quadrant pain remains a common and challenging clinical scenario for emergency medicine physicians due to frequent nonspecific signs, symptoms, and physical examination findings. Therefore, imaging has evolved to play a pivotal role in the emergency setting. While appendicitis is a common cause for acute pain, there are numerous other important differential considerations with which the radiologist must be aware. The purpose of this review is to list an anatomy-based, encompassing differential diagnosis in addition to acute appendicitis for right lower quadrant pain; demonstrate the key imaging findings of numerous differential considerations; and describe helpful imaging and clinical features useful in narrowing the differential diagnosis.

CT and MRI of early intrauterine pregnancy

OBJECTIVE

The objective of this article is to describe the CT and MRI findings of early intrauterine pregnancy.

CONCLUSION

Early pregnancy should be considered when CT or MRI shows a fluid-filled cystlike structure in the uterus of a woman of reproductive age especially if there is a coexistent ovarian corpus luteum cyst.

CT imaging findings of ruptured ovarian endometriotic cysts: emphasis on the differential diagnosis with ruptured ovarian functional cysts

Objective

The purpose of this study is to assess the prevalence of abnormal CT findings in patients with surgically proven ruptured endometriotic cysts, as compared with those abnormal CT findings of ruptured ovarian functional cysts.

Materials and Methods

This study included 13 retrospectively identified patients with surgically confirmed ruptured ovarian endometriotic cysts and who had also undergone preoperative CT scanning during the previous seven years. As a comparative group, 25 cases of surgically confirmed ruptured ovarian functional cysts were included. We assessed the morphologic features of the cysts and the ancillary findings based on CT.

Results

For the endometriotic cysts, the mean maximum cyst diameter was significantly larger than that of the functional cysts (70.1 mm versus 36.4 mm, respectively, p < 0.05). The endometriotic cysts frequently had a multilocular shape and a thicker cyst wall, as compared to that of functional cysts, and these differences were statistically significant. Among the ancillary findings, endometriotic cysts showed a significantly higher prevalence of loculated ascites, ascites confined to the pelvic cavity without extension to the upper abdomen, and peritoneal strandings and infiltrations (p < 0.05). Although 11 of the 25 cases of functional cysts showed active extravasation of contrast material at the ovarian bleeding site, only one of 13 cases of endometriotic cysts showed active extravasation.

Conclusion

The diagnosis of ruptured endometriotic cyst should be suspected for a woman in whom CT reveals the presence of multilocular or bilateral ovarian cysts with a thick wall and loculated ascites confined to the pelvic cavity with pelvic fat infiltrations.

Frequency and etiology of solitary hot spots in the pelvis at whole-body positron emission tomography/computed tomography imaging

PURPOSE

To determine the frequency and etiology of a single hypermetabolic focus within the pelvis with no other areas of increased 18-fluorodeoxyglucose (FDG) uptake in the reminder of the whole body in an oncological population.

METHOD AND MATERIALS

We retrospectively examined the first 700 whole-body PET/CT scans performed at our institution for baseline staging or follow-up of cancer and identified all patients with a solitary focus of increased FDG uptake in the pelvis. All available medical records and imaging findings in these patients were reviewed in order to determine the etiology of increased FDG uptake.

RESULTS

Eight (1.1%) of the 700 patients had a solitary hot spot in the pelvis at positron emission tomography (PET)/computed tomography (CT) imaging, consisting of seven of 380 women and one of 320 men. In the seven women, increased FDG uptake was due to physiological endometrial uptake (n=2), leiomyoma (n=1), corpus luteum cyst (n=1), physiological ovarian uptake (n=1), urinary leak (n=1), and nonspecific colitis (n=1). In the man, uptake was due to recurrent rectosigmoid adenocarcinoma. None of the 700 patients was found to have metastatic disease in the pelvis.

CONCLUSION

Isolated pelvic hot spots at PET/CT imaging in an oncological population are not common and usually benign; physiological endometrial or ovarian uptake is the single commonest cause.

Role of multidetector CT in the management of acute female pelvic disease

The purpose of this study is to highlight the role of multidetector CT (MDCT) in emergency radiology as a useful tool in the diagnosis and management of acute female pelvic disease and to describe key radiologic signs to improve differential diagnosis. We restrospectively reviewed MDCT findings of acute pelvic disease and its mimics in women reporting to the emergency room at our institution from December 2006 to August 2008. We describe MDCT findings of gynecologic and obstetric disorders such as hemorrhagic ovarian cysts, ovarian torsion, pelvic inflammatory disease, ruptured ectopic pregnancy, intravascular leiomyomatosis, blunt maternal trauma, and postpartum and post-cesarean section complications. We also briefly review gastrointestinal tract entities that may mimic these conditions. Although ultrasound is the imaging modality of choice for the evaluation of female pelvic pain, the role of MDCT remains essential in the management of patients in which gynecologic exploration is not diagnostic or undone since it is not the initial suspicion.

Computed Tomographic and Magnetic Resonance Features of Gynecologic Abnormalities in Women Presenting With Acute or Chronic Abdominal Pain

Advances in technology and improved availability have led to increased use of computed tomography (CT) and magnetic resonance imaging (MRI) to evaluate women presenting to the emergency department or to their primary care provider with abdominal and/or pelvic pain. Computed tomographic examinations are often performed to evaluate the presence of appendicitis or renal stone disease. However, gynecologic abnormalities are frequently identified on these examinations. Although ultrasound remains the primary modality by which complaints specific to the pelvis are evaluated, in many instances, CT and MRI imaging occurs before sonographic evaluation.Historically, because of cost, radiation exposure, and relative ease of use, ultrasound examinations have preceded all other imaging modalities when evaluating pelvic disorders. However, as CT and MRI technology have improved, their use in diagnosing causes of pelvic pain has become equal to that of ultrasound. In some cases, primarily because of historic comfort with sonographic evaluation, gynecologic abnormalities originally diagnosed on CT or MRI may be immediately and unnecessarily reevaluated by ultrasound. For a woman in her reproductive years, the most common adnexal masses are physiological cysts, endometriomas, and cystic teratomas. Although lesions are often asymptomatic and incidentally detected, they can present with pain, and they increase the risk of ovarian torsion. Common causes of chronic pelvic pain in this population include leiomyomata and adenomyosis. In postmenopausal women, ovarian carcinoma, which often does not present clinically until a late stage, has to be included in the differential diagnosis of adnexal masses. If a gynecologic pathology is discovered on CT or MRI, an immediate follow-up ultrasound need not be pursued if the lesion can be characterized as benign, needing immediate surgical intervention, or a variant of normal anatomy. If, on the other hand, findings demonstrate a mass that either is uncharacteristic of a benign lesion, has an indeterminate risk for malignancy, or demonstrates suspicious characteristics for malignancy (such as enhancing mural nodules), further evaluation by serial ultrasound, biochemical marker, and/or CT or MRI is warranted. The purpose of this review is to present a series of commonly encountered gynecologic abnormalities with either CT or MR to make radiologists more familiar with gynecologic pathology on CT and MRI.

A Practical Approach to the Ultrasound Characterization of Adnexal Masses

Because pelvic ultrasound is commonly used to evaluate adnexal masses, it is important to understand the most useful sonographic features for predicting benign and malignant masses. Determining whether an adnexal mass is of ovarian or extraovarian origin is key in arriving at the most likely diagnosis. Most adnexal masses are benign, and each of the most common benign ovarian lesions has a typical sonographic appearance. Additionally, most malignant ovarian neoplasms have a solid component with detectable flow by Doppler ultrasound, allowing one to strongly suggest the diagnosis. We will review an approach to the ultrasound diagnosis of adnexal masses that progresses through a series of 4 questions to help lead one to the most likely diagnosis.

Multidetector CT of the Female Pelvis

In the emergency room setting, multidetector detector CT (MDCT) offers rapid, noninvasive, multiplanar evaluation of female patients who have acute pelvic pain. MDCT has been integrated into several of the major trauma centers, and its use may surpass the use of ultrasound in the trauma evaluation of the pregnant patient. In the nonemergent setting, MDCT can be used to stage gynecologic malignancy and to evaluate tumor recurrence. Multiplanar MDCT has received some acceptance for evaluation of small primary tumor volume and small metastatic implants. MDCT also has a role in the evaluation of pelvic varices and suspected pelvic congestion syndrome.