Gynaecological Causes of Acute Pelvic Pain: Common and Not-So-Common Imaging Findings

Abstract

In female patients, acute pelvic pain can be caused by gynaecological, gastrointestinal, and urinary tract pathologies. Due to the variety of diagnostic possibilities, the correct assessment of these patients may be challenging. The most frequent gynaecological causes of acute pelvic pain in non-pregnant women are pelvic inflammatory disease, ruptured ovarian cysts, ovarian torsion, and degeneration or torsion of uterine leiomyomas. On the other hand, spontaneous abortion, ectopic pregnancy, and placental disorders are the most frequent gynaecological entities to cause acute pelvic pain in pregnant patients. Ultrasound (US) is usually the first-line diagnostic technique because of its sensitivity across most common aetiologies and its lack of radiation exposure. Computed tomography (CT) may be performed if ultrasound findings are equivocal or if a gynaecologic disease is not initially suspected. Magnetic resonance imaging (MRI) is an extremely useful second-line technique for further characterisation after US or CT. This pictorial review aims to review the spectrum of gynaecological entities that may manifest as acute pelvic pain in the emergency department and to describe the imaging findings of these gynaecological conditions obtained with different imaging techniques.

Keywords: acute pelvic pain; computed tomography; diagnostic radiology; gynaecology; magnetic resonance imaging; ultrasounds.

Figure 1

Ovarian torsion in an eight-year-old patient presenting at the emergency department with aching right pelvic pain for a few hours. Transabdominal US examination (a,b) shows that the right ovary is grossly enlarged (long axis: 42.9 mm; short axis 34 mm) and abnormally located in the midline. The ovary appears slightly echogenic, with many small cysts at the periphery (yellow arrow). Small volume free fluid with tiny echoes is present in the pelvis (red arrow). During the Doppler US evaluation, no vascular flow was noticed (not shown).

Figure 2

Left ovarian torsion in a 12-year-old woman with acute lower abdominal pain and vomiting. Axial (a), sagittal (b), and coronal (c,d) contrast-enhanced CT images show enlarged and oedematous left adnexa migrated to the midline and anteriorly to the uterus (yellow arrows), with peripherally displaced ovarian follicles. A small amount of free pelvic fluid (blue arrows) is associated. On the coronal plane, the twisted and oedematous ovarian vascular pedicle (red arrow) can be easily detected.

Figure 3

Left ovarian torsion in a thirty-nine-year-old patient with acute pelvic pain. Axial T2-weighted (a) and T1-weighted fat saturated before (b) and after (c) gadolinium MR pelvic images show an enlarged left ovary located in the Douglas pouch (yellow arrows), with and adjacent twisted vascular pedicle (“whirlpool sign”, blue arrow). The ovary presents a peripheral high signal on T1 extending to the pedicle (rim of methaemoglobin) without enhancement upon post-contrast sequences. A large cystic lesion arises from the left ovary with an internal high signal on both T1 and T2 (red arrows) and declivous sediment of low signal on T2, suggestive of a haemorrhagic cyst. The patient underwent a laparoscopic left adnexectomy, and pathology confirmed the diagnosis of ovarian torsion possibly due to the haemorrhagic cyst.

Figure 4

Ruptured ovarian corpus luteal cyst. CT axial (a), sagittal (b), and coronal (c) scans of a twenty-eight-year-old woman with acute right-sided pelvic pain. HCG test was negative. Images show a hypodense cystic lesion in the right adnexa, with thick and enhancing walls (yellow arrows). A focal discontinuity in the posterior wall is observed. Free pelvic fluid is also visible. The patient was treated conservatively.

Figure 5

Bilateral tubo-ovarian abscesses in a 44-year-old woman who presented with fever, leucocytosis, and acute pelvic pain. CT axial (a) and coronal (b) pelvic scans demonstrate thick-walled, peripherally enhancing, multi-cystic, and tubular structures (yellow arrows), which proved to be bilateral tubo-ovarian abscesses at the time of surgery.

Figure 6

Red degenerated leiomyoma in a thirty-one-year-old woman with abdominal pain and vaginal bleeding after a miscarriage. T2-weighted imaging (a) showed an enlarged uterus with degenerated intramural and pedunculated leiomyomas with inhomogeneous intensity (yellow arrow). On T1-weighted sequence (b), a peripheral hyperintense rim surrounding the lesion’s central area of lower signal intensity (red arrows), typical of red degeneration of leiomyomas, is observed. No intralesional enhancement was seen after intravenous contrast injection ((c), blue arrows).

Figure 7

Torsion of a leiomyoma in a 36-year-old woman with acute abdominal and pelvic pain. US (a,b) shows a normal uterus (yellow arrows) surrounded by multiple dilated vessels. In a previous MR (c), a large pedunculated leiomyoma was observed (blue arrows). In a CT scan (d), two pedunculated fibroids are seen; the right one is relatively hypodense, with free fluid in the paracolic gutter (red arrow). Surgery findings confirmed the diagnosis of leiomyoma torsion.

Figure 8

Pyomyoma in an eighty-year-old woman with a history of diabetes and steroid treatments who presented at the emergency department with fever, leucocytosis, and abdominal cramps for a week. A previous X-ray (a) shows a calcific uterine myoma. Axial CT scan (b) demonstrated the presence of air within the myoma (yellow arrow), eliciting the suspicion of an infected myoma. The patient underwent a hysterectomy (c), and the pathological findings confirmed the diagnosis of pyomyoma.

Figure 9

Ruptured ovarian teratoma in a thirty-eight-year-old woman presenting with pelvic pain and fever. CT axial (a,b), coronal (c), and sagittal (d) planes reveal a sizeable pelvic mass (yellow arrows) composed of fat and fluid with discontinued walls (red arrow) and an interior tooth-like calcification (green arrowheads). Subphrenic fatty implants (blue arrows) are also observed (e,f). After adnexectomy, histology confirmed the diagnosis of right mature teratoma.

Figure 10

Advanced uterine cervical cancer in a 58-year-old subject attending the emergency department for abdominal pain and haematuria. CT axial (a), sagittal (b), and coronal (c) non-contrast images reveal the presence of a pelvic mass (blue arrows) and ureter causing ureteral obstruction (yellow arrows). The patient further underwent an MRI examination (d–f), which demonstrated a cervical tumour (blue arrows) invading the parametrium and ureters bilaterally (yellow arrows), the vagina, and the bladder. The uterine cavity was also obstructed and dilatated (red arrows).

Figure 11

Ruptured cervical ectopic pregnancy in a thirty-three-year-old patient who presented at the emergency department with acute pelvic pain and severe vaginal bleeding. MRI sagittal (a) and axial (b) T2-weighted, and sagittal T1-weighted early contrast-enhanced fat-saturated (c) images show an empty uterine cavity and a ruptured ectopic pregnancy within the cervical canal (yellow arrows). This patient was managed with uterine arteries embolisation. Preprocedural images (d) show a hypervascular area in the region of the cervical ectopic pregnancy that is supplied mainly by the right uterine artery. Post-embolisation (e) arteriogram demonstrates complete stasis.

Figure 12

Uterine rupture in a thirty-three-year-old patient presented at the emergency department with acute pelvic pain and abnormal uterine contractions during the 37th week of pregnancy. The patient had a prior history of two previous uterine curettages. MRI T2-weighted sagittal (a) and coronal (b) images show a complete division of the uterine fundus wall with extrusion of the gestational sac (yellow arrows).

Figure 13

Placenta accreta in a 33-year-old patient at 36 weeks of gestation. Sagittal (a,b) T2-weighted MR images show a placenta previa (blue arrows) covering the uterine internal os. Placenta has irregular contours and rounded edges, with a single area of intraplacental dark T2 bands (yellow arrow). No interruptions in the thin hypointense myometrial border are seen. Pathologic examination confirmed the diagnosis of placenta accreta.

Figure 14

Flowchart of acute pelvic pain management in female patients. US, ultrasound; HCG, human chorionic gonadotropin; CT, computed tomography; MR, magnetic resonance; PID, pelvic inflammatory disease.