Current Problems in Diagnostic Radiology 48 (2019) 473À481 Current Problems in Diagnostic Radiology journal homepage: www.cpdrjournal.com Recognizing the CT Manifestations of Gynecologic Conditions Encountered in the Emergency Department Karen Tran-Harding, MD*, James T. Lee, MD, Joseph Owen, MD Department of Diagnostic Radiology, University of Kentucky Chandler Medical Center, 800 Rose St. HX315E, Lexington, KY ABSTRACT Women commonly present to the emergency room with subacute or acute symptoms of gynecologic origin. Although a pelvic exam and ultrasound (US) are the pre- ferred initial diagnostic tools for gynecologic entities, a CT is often the first line imaging modality in the emergency department. We will provide a review of normal uterine enhancement and normal pregnancy related findings, and then familiarize radiologists with the CT appearances of gynecologic entities classically described on ultrasound that may present to the emergency department. © 2018 Elsevier Inc. All rights reserved. Introduction lower attenuation than myometrium, its thickness varies with the menstrual cycle, and it should not be mistakenly described as blood Pelvic pain is a common reason for women to present to the emer- or fluid in the canal (Fig 1 A/B open arrowhead). During the menstrual gency department. Detailed menstrual, sexual, and surgical history, and cycle, the endometrium can measure anywhere from 1 mm during screening beta-human chorionic gonadotropin (hCG), are essential to menstruation and up to 7-16 mm during the secretory phase.1 differentiate gynecologic pain from other etiologies. Ultrasonography is Four subtypes of myometrial enhancement have been the preferred modality for imaging of gynecologic disease, but in a busy described.2,3 Type 1 is a subendometrial band of enhancement that emergency room setting, computed tomography (CT), may be the initial may be thin or thick (Fig 1 A/B), with or without outer myometrial imaging modality used for women with incomplete history and nonspe- enhancement (Fig 1 C), 30-120 seconds after contrast injection.3 The cific complaints. Furthermore, CT is widely available, fast, and efficient type 1 pattern is seen mainly in premenopausal women.3 Type 2 is and can rule out other causes of pain. Although most radiologists are diffuse enhancement throughout the entire myometrium or enhance- familiar with common gynecologic entities with ultrasonographic imag- ment that progresses from the outer myometrium to the entire myo- ing, recognizing the CT appearance of gynecologic pathology is impor- metrium (Fig 1 D/E), without distinct subendometrial enhancement. tant. Unfortunately, in a very busy emergency department, it is often The type 2 pattern of enhancement is observed equally in pre and easy to overlook subtle abnormality in the female pelvis on CT, even postmenopausal women.3 Type 3 is no or minimal enhancement though, it can often reveal the source of pain or pathology when the rest throughout the myometrium (Fig 1 F). This type is seen in postmeno- of the study is normal. pausal women.3 Type 4 is a patchy, heterogeneous enhancement of the entire myometrium (Fig 1 G/H) and is less well described and less common than the other types.2 The Wide Spectrum of Normal The physiology underlying the wide range of normal enhance- ment patterns is not well understood. Menstrual status, patient age, Patterns of Uterine Enhancement and contrast timing are the most important factors.3 Given the vari- The appearances of the normal uterus vary greatly, especially after ability of myometrial enhancement, recognizing focal mass-like intravenous contrast. Familiarity with the spectrum of normal imag- enhancement, parametrial stranding, and uterine contour abnormal- ing patterns is important to avoid describing a variant of normal as ity are the key to diagnosing gynecologic infection or neoplasm. pathologic. When the uterus has an abnormal appearance on CT, an MRI or ultra- On noncontrast CT, the myometrium appears homogenous and sound is indicated for further characterization. isodense to skeletal muscle. The normal endometrial canal exhibits The vascular structures within the pelvis can also exhibit variabil- ity. Dilated uterine vessels (Fig 1 H) may be encountered incidentally Disclosure of potential conflicts of interest: Author A declares that he/she has no con- and are often seen in multiparous reproductive age women. The flict of interest. Author B declares that he/she has no conflict of interest. Author C increase vascularity associated with pregnancy may cause dilation of fl declares that he/she has no con ict of interest. venous structures in the pelvis and over time lead to incompetent *Reprint requests: Karen Tran-Harding, MD, Department of Diagnostic Radiology, University of Kentucky Chandler Medical Center, 800 Rose St. HX315E, Lexington, KY. venous valves. Dilated uterine veins have been associated with a con- E-mail address: [email protected] (K. Tran-Harding). dition called pelvic venous congestion syndrome, and while the https://doi.org/10.1067/j.cpradiol.2018.07.009 0363-0188/© 2018 Elsevier Inc. All rights reserved. 474 K. Tran-Harding et al. / Current Problems in Diagnostic Radiology 48 (2019) 473À481 FIG 1. Wide range of normal uterine enhancement patterns are observed on contrast enhanced CT. (a) and (b) sagittal and axial CT images of different patients show normal thin (A) and thick (B) subendometrial enhancement (arrow). Also note the variable thickening of the normal hypoattenuating endometrial tissue (open arrowheads), not to be confused with fluid in the endometrial canal. (C) Axial CT image shows a normal retroverted uterus with both subendometrial enhancement (arrow) and outer myometrial (open arrow) enhance- ment. (D) and (E) axial and sagittal CT images of a normal uterus with diffuse myometrial enhancement (black arrows), (F) axial CT image shows minimal diffuse enhancement (asterisk) and dilated pelvic varices (black arrowheads). (G) and (H) Sagittal CT images of different patients show normal patchy heterogeneous enhancement of the myometrium (arrowheads). Note the relative hypoenhancement of the cervix compared to the uterus (brackets) on e and h. majority of women with dilated pelvic vessels are asymptomatic, it millimeters in diameter but may reach 4 cm or more.7 On CT, they may be helpful to raise the possibility of pelvic venous congestion solitary, scattered or clustered cysts, with a thin nonenhancing wall, syndrome in ED patients presenting with engorged pelvic veins.4 The and central fluid attenuation.2 diagnostic criteria for CT consists of at least 4 ipsilateral parauterine On CT, the vaginal mucosa of reproductive age women enhances. veins of varying caliber, with at least 1 measuring more than 4 mm The vaginal wall is may be inseparable from the urethra and rectal in diameter, or an ovarian vein diameter greater than 8 mm.4 wall and is hypoattenuating relative to the mucosa. In postmeno- pausal women, the vaginal mucosa appears similar to the vaginal wall and is hypoenhancing.8 Variability of the Cervix and Upper Vagina The normal cervix measures on average 3 cm and the width of the internal cervical os measures 3 mm.5 Cervical zonal enhancement is Foreign Bodies seen in patients with a type 1 or type 2 uterine enhancement pattern Foreign bodies related to menstruation, pelvic floor laxity, and (Fig 1 A).3 A target-like appearance of the cervix results from relative contraception are often seen incidentally on CT in the emergency hyper-enhancement of the central glandular mucosa and relative room setting. The most common vaginal foreign body is a tampon, hypo-enhancement of the outer fibromuscular stroma.3 The cervical which typically has the attenuation of air, secondary to gas trapped fibromuscular stroma demonstrates gradual enhancement that often between the tampon fibers (Fig 2 A). Occasionally patients will forget lags behind uterine myometrium (Fig 1 E/H).6 to remove a tampon, and it can serve a source of infection. A pessary Nabothian cysts are benign retention cysts resulting from chronic is a device placed into the vagina to prevent pelvic organ prolapse. inflammation on endocervical glands that should not be mistaken for They have variable appearance but most commonly appear as a thick pathology. Nabothin cysts can vary in size, ranging from a few ring of uniform high attenuation in the vagina. (Fig 2 B/C) A FIG 2. Foreign bodies are commonly encounter in the vagina. (A) sagittal CT image shows a mixed attenuation tubular tampon predominately composed of gas in the vagina (arrow- head). (B) and (C) axial and coronal CT images of different patients with pessary devices in the vagina (arrows). (D) sagittal CT image shows a rectangular hyperdense foreign body in the vagina which on physical exam was a piece of candy (open arrowhead). (E) sagittal CT image shows a urinary catheter inadvertently placed in the vagina (asterisk). K. Tran-Harding et al. / Current Problems in Diagnostic Radiology 48 (2019) 473À481 475 FIG 3. Intrauterine devices (IUD) and tubal occlusion devices (TOD) are frequently encountered on CT. (A) axial CT image of the pelvis shows a T-shaped IUD (arrow) in expected position with the 2 limbs extending toward the uterine cornua and the stem within the endometrial canal. (B) sagittal CT image of the pelvis shows an IUD extending from the cer- vix into the posterior myometrium (arrowhead) of the low uterine segment. (C) oblique sagittal CT image shows an IUD (arrow) which has migrated out of the uterus into the peri- toneal cavity. (D) axial CT image shows TOD (open arrow) extending from the cornua of the uterus along the expected course of the fallopian tubes. (E) sagittal CT image shows a TOD which has migrated out of the fallopian tube to an intraperitoneal location inferior to the uterus (open arrowhead). (F) axial CT image shows a TOD which has migrated anterior to the uterus (open arrowhead). contraceptive ring appears similar to a pessary, but is found in peritoneal cavity11 (Fig 3 C).