Key imaging features of acute gynaecological emergencies.

Transcription

1 Key imaging features of acute gynaecological emergencies. Poster No.: C-2200 Congress: ECR 2014 Type: Educational Exhibit Authors: Ó. Roche, N. Bharwani, A. G. Rockall; London/UK Keywords: Acute, Complications, Ultrasound, MR, CT, Genital / Reproductive system female, Abdomen DOI: /ecr2014/C-2200 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 23

2 Learning objectives -To gain familiarity with acute gynaecological emergencies which present to the emergency room (ER) with abdominal pain. - Ultrasound is the most accessible modality however due to the overlap of signs with gastrointestinal pathologies, CT is now commonly being used in the emergency department. MRI is not frequently used in the acute setting but as a problem solver. -Multimodality imaging findings will be presented with a discussion of the differential diagnosis. Background Acute abdominal pain in the non-pregnant female can be secondary to gynaecological and non-gynaecological causes. This pictorial review will discuss multimodality imaging findings in acute gynaecological presentations and the important differential diagnoses to consider. Findings and procedure details Haemorrhagic ovarian cyst A transvaginal ultrasound is often the first imaging modality in patients who are suspected of having an ovarian cyst haemorrhage. In the acute stage,haemorrhage is isoechoic to ovarian stroma. As the clot evolves a typical reticular fine 'lacy net' or 'spider web' pattern is seen (Fig. 1-2). When performing ultrasound, it is important to exclude the presence of intraperitoneal fluid in order to exclude haemorrhagic cyst rupture. CT is often used as a first investigation in the acute setting. Typical appearances are a mixed attenuation mass with a high attenuation component ( HU) within the adnexa, usually with a well-defined smooth outer wall. In the setting of rupture, free fluid is seen in the pelvis (± abdomen) which is of a higher attenuation than simple fluid (Fig 3-4). Magnetic resonance imaging may be used for further characterisation of complex cystic ovarian lesions if there are suspected solid elements. Haemorrhagic cystic lesions are typically bright on T1- Page 2 of 23

3 weighted and intermediate to low on T2-weighted images. The age of the haemorrhage may be estimated by assessing the signal intensity of the haematoma on MRI (Fig 5-6). Adnexal torsion Adnexal torsion is a diagnosis that should be considered when evaluating female patients presenting to the emergency services with lower abdominal pain. Risk factors for adnexal torsion include ovarian tumours (Fig 7-8), most commonly seen with benign tumours such as dermoid cysts (mature teratoma). The imaging features of torsion depend on its chronicity and severity. As the vascular pedicle starts to twist, the lower pressure venous and lymphatic supplies become occluded, obstructing outflow and resulting in engorgement of the ovary. On ultrasound this is typically seen as an increase in ovarian size where the central stroma has increased echogenicity and non-ovulatory follicles are pushed to the periphery. As torsion progresses, the arterial supply is occluded and haemorrhagic infarction occurs with the development of hypoechogenic regions within the ovary. Characteristically Doppler ultrasound demonstrates absence of blood flow to the torted ovary. The characteristic "whirlpool sign" may be seen on colour Doppler where the twisted vascular pedicle gives a corkscrew appearance. However, due to the dual ovarian blood supply (ovarian artery and ovarian branch of the uterine artery) high grade torsion is required to completely occlude arterial supply and therefore the presence of colour Doppler flow within an ovary does not exclude the diagnosis of torsion. CT and MRI imaging appearances include ovarian enlargement (particularly if >5cm), eccentric or concentric wall thickening of the torted adnexal mass, fallopian tube thickening, uterine deviation to the effected side and ascites. There may be eccentric or diffuse poor contrast enhancement of the internal solid component or thickened wall (Fig 7-8) Fibroids: Acute presentations Fibroids (leiomyomas) are the most common pelvic tumours affecting females in the fertile age group (20-40% of females above 30 years of age). They can cause acute pain usually secondary to torsion or acute degeneration resulting in women attending the emergency department. The typical sonographic appearances of a simple fibroid is of a hypoechoic lesion with or without posterior acoustic enhancement. Degeneration of fibroids gives a more complex ultrasound appearance with areas of cystic change and Doppler can show circumferential vascularity. Fibroids that are torted or are necrotic will show absence of flow on Doppler US. Degenerating fibroids on CT may show a cystic appearance of a fibroid mass, with reduced enhancement and hypodense areas (Fig 9). Degenerative fibroids show a great diversity in their MRI appearances with cystic change and areas of non-enhancement (Fig 10). High signal intensity centrally within the fibroid on T1-weighted images is consistent with haemorrhage and reduced signal at the Page 3 of 23

4 periphery on T2-weighted images is indicative of haemosiderin deposition (Fig 11-12). Often there is no enhancement following the administration of gadolinium (Fig 13). Pelvic Inflammatory Disease Pelvic inflammatory disease (PID) is defined as a spread of inflammation from the endometrial cavity and fallopian tubes into the pelvis. The symptoms of pelvic inflammatory disease are general aching pain in the pelvis that varies in severity. Ultrasound can demonstrate dilated fallopian tubes containing heterogeneous fluid with echogenic internal debris typical of pyosalpinx. The fallopian tubes can be folded and demonstrate areas of tube tapering, intraluminal linear echogenic foci may also be visualised (Fig 15). CT appearances of PID are frequently non-specific and can include a small volume of free fluid, parapelvic fatty stranding and thickened uterosacral ligaments. The development of tubo-ovarian abscesses can result in thickened irregularly enhancing complex adnexal masses with septations and thick walls containing complex fluid collections (Fig 16). MRI often shows ill-defined hyperintense areas on T2-weighted fat-suppressed images representing inflamed parametrium. Pyosalpinges are usually dilated, fluid-filled, tortuous C or S-shaped structures (fig 14). The thick-walled fluid-filled abscesses and pyosalpinx may demonstrate heterogeneous signal intensity on T1- and T2-weighting due to haemorrhage, pus and debris. Mural enhancement on gadoliniumenhanced T1-weighted images is also characteristic (Fig 16-17). Images for this section: Page 4 of 23

5 Fig. 1: Fig 1. Haemorrhagic cyst. Transvaginal ultrasound demonstrates patient with internal lacelike reticular internal echoes. Although there is absence of internal blood flow there is circumferential blood flow around the cyst. Page 5 of 23

6 Fig. 2: Fig 2. Haemorrhagic Cyst. Transvaginal ultrasound demonstrates lacelike reticular internal echoes. Page 6 of 23

7 Fig. 3: Fig 3. Female presenting with right iliac fossa pain. CT showed a ruptured corpus luteal cyst on the right ovary. The fluid in pelvis averaged 55HU and fluid in upper abdomen averaged 30HU. This was confirmed at surgery. Page 7 of 23

8 Fig. 4: Fig 4. CT post- contrast, coronal view of the same patient as in figure 3, demonstrating a ruptured corpus luteal cyst on the right ovary. Fluid in pelvis averaged 55HU, fluid in upper abdomen averaged 30HU. This was confirmed at surgery. Page 8 of 23

9 Fig. 5: Fig 5. MRI T2 axial sequences demonstrating bilateral complex adnexal cystic masses demonstrating predominantly high T2. However there is shading effect representing ageing blood products. This is characteristic of endometrioma. Page 9 of 23

10 Fig. 6: Fig 6. Bilateral cystic adnexal lesions demonstrating high T1 signal characteristic of endometrioma. Page 10 of 23

11 Fig. 7: Fig 7.0 A 45 year old female presenting with pelvis pain. T1 fat saturated imaging shows an enlarged right sided tubo-ovarian mass which demonstrates peripheral high signal, signifying peripheral haemorrhage secondary to the torted ovarian mass. Page 11 of 23

12 Fig. 8: Fig 8.0 Post-intravenous contrast T1FS imaging in the same patient as in figure 7 shows a subsequent contrast enhanced MRI which demonstrates enlarged right sided tubo-ovarian mass with only peripheral enhancement. The left sided ovarian metastasis enhances avidly. Page 12 of 23

13 Fig. 9: Fig 9 Cystic fibroid degeneration. This patient presented to A&E with lower abdominal pain and vaginal bleeding. The axial CT demonstrates a large partially cystic pelvic mass. The patient subsequently had an MRI. Page 13 of 23

14 Fig. 10: Fig 10. Sagittal T2 MRI on the same patient demonstrated a large mass emanating from the fundus of the uterus. The mass demonstrates cystic degeneration. Inferiorly we can see the degenerating fibroid is emanating from the uterus (black arrow). Recognising the origin of the mass is key to making the appropriate diagnosis Page 14 of 23

15 Fig. 11: Fig 11. Haemorrhagic fibroid degeneration. This patient was known to have uterine fibroids and presented to A&E with acute lower abdominal pain. MRI T2 sagittal images demonstrates uterine fibroid with cystic degeneration. There is a peripheral low signal rim, signifying haemosideran deposition. Page 15 of 23

16 Fig. 12: Fig 12. The same patient as shown in figure 11, fat suppressed MRI sequence images demonstrates high T1 signal in the fibroid representing haemorrhagic degeneration. Page 16 of 23

17 Fig. 13: Fig 13. Post contrast MRI of the same patient as in figure 12 and 11, demonstrates lack of enhancement in the fibroid, consistent with infarction. Page 17 of 23

18 Fig. 14: Fig 14. Pelvic inflammatory disease. Patient admitted with abdominal pain and vomiting. Transvaginal ultrasound of the left adnexa demonstrates adnexal cyst with internal echogenic material in a tubular pattern, in keeping with a pyosalpinx. Page 18 of 23

19 Fig. 15: Fig 15 Pelvic Inflammatory Disease. This patient had a raised white cell count and CRP. The clinicians suspected an intra-abdominal collection. CT post contrast demonstrates bilateral adnexal complex fluid-filled and thick-walled cysts typical for tuboovarian abscess formation. Page 19 of 23

20 Fig. 16: Fig 16. Pelvic inflammatory Disease in the same patient as shown in figure 15 had an MRI for further assessment. Axial T2 images demonstrates bilateral tubo-ovarian abscesses. Page 20 of 23

21 Fig. 17: Fig 17. Axial T1 MR sequence following gadolinium administration in the same patient as shown in figure 15 and 16, demonstrates low signal intensity within the pus-filled cavities and marked enhancement of the inflammatory walls. The imaging appearances may overlap with ovarian malignancy but the clinical presentation is of sepsis. Page 21 of 23

22 Conclusion Ultrasound is the primary imaging tool in suspected acute gynaecologic emergencies although CT is often used in the ER setting. Appearances on US and CT can aid rapid diagnosis allowing prompt management. The use of MRI is reserved for problem solving in complex cases. Personal information Dr Oran Roche, Barts Health NHS Trust, London, UK. Dr Nishat Bharwani, Consultant Radiologist, Imperial College Healthcare NHS Trust, London, UK. Professor Andrea Rockall,Consultant Radiologist, Imperial College Healthcare NHS Trust, London, UK. References 1. Stenchever M (2001) Comprehensive gynaecology. 2nd edn. Mosby. 2. Hertzberg BS, Kliewer MA, Bowie JD, et al. Adnexal ring sign and hemoperitoneum caused by hemorrhagic ovarian cyst: pitfall in the sonographic diagnosis of ectopic pregnancy. AJR Am J Roentgenol. 1999;173: Kaakaji Y, Nghiem HV, Nodell C, Winter TC. Sonography of obstetric and gynecologic emergencies: Part II, Gynecologic emergencies. AJR Am J Roentgenol.2000;174: Nishino M, Hayakawa K, Iwasaku K, Takasu K. Magnetic resonance imaging findings in gynecologic emergencies. J Comput Assist Tomogr. 2003;27: Chang HC, Bhatt S, Dogra VS. Pearls and pitfalls in diagnosis of ovarian torsion.radiographics. 2008;28: Page 22 of 23

23 6. Rha SE, Byun JY, et al. CT and MR imaging features of adnexal torsion.radiographics. 2002;22: Wilde S, Scott-Barrett S. Radiological appearances of uterine fibroids. Indian J Radiol Imaging. 2009;19: doi: / Tukeva TA, Aronen HJ, Karjalainen PT, Molander P, Paavonen T, Paavonen J. MR imaging in pelvic inflammatory disease: comparison with laparoscopy and US.Radiology. 1999;210: Sam JW, Jacobs JE, Birnbaum BA. Spectrum of CT findings in acute pyogenic pelvic inflammatory disease. Radiographics. 2002;22: Page 23 of 23