tomography scanners and computed radiography are not routinely used but are important to recognise key features . 
acute abdominal pain related to the gynaecological tract is a common presentation in the emergency department .
one of the challenges facing clinicians is the wide range of differential diagnoses that must be considered when assessing abdominal pain
. often it can be difficult to distinguish gynaecological from gastrointestinal emergencies . in conjunction with clinical findings ,
various imaging modalities play an important role in diagnosing the cause of pain . in patients presenting with pain that is thought to originate in the gynaecological tract ,
ultrasound is usually employed as the first imaging modality as it is highly sensitive , fast and easy to access .
ct is seldom used as an initial diagnostic tool in suspected gynaecological emergencies due to the risks associated with irradiating the pelvis .
however , it may be difficult to localise the site of origin of the symptoms to the gynaecological tract due to the significant overlap in symptoms and signs with gastrointestinal pathologies , and ct may be selected as the first imaging modality .
mri is not usually used in the acute setting but may be important in characterisation of abnormalities that remain indeterminate following ultrasound or ct .
are commonly seen as functioning cysts during ultrasound examination , usually grow 2  mm per day until ovulation and measure less than 3  cm in diameter .
if ovulation does not occur , a follicular cyst develops and appears as an anechoic cyst with a thin wall and posterior acoustic enhancement ( seen as an area of increased echogenicity posterior to the cyst ) .
functional or simple cysts are usually single , less than 6  cm in diameter and thin walled ( <3  mm ) .
the corpus luteum forms after ovulation as granulosa cells become luteinized and blood accumulates in the central cavity .
hence , corpus luteal cysts have a thicker , more echogenic wall with increased vascularity seen as peripheral blood flow on doppler .
a haemorrhagic ovarian cyst is suspected if a patient presents with symptoms of acute lower abdominal pain , tenderness and in some cases ascites [ 24 ] .
blood tests often show normocytic anaemia with only mild elevation of inflammatory markers such as crp and leucocytes when compared to conditions such as appendicitis .
measurement of hcg levels is also important in excluding ectopic pregnancy , which can have a similar presentation [ 5 , 6 ] .
a transvaginal ultrasound is often the first imaging modality in patients who are suspected of having an ovarian cyst haemorrhage .
when there is an intracystic haemorrhage the characteristics of the bleed evolve with its age . in the acute stage ,
the haemorrhage is isoechoic in relation to the ovarian stroma and this can often be similar in appearance to an enlarged ovary . as the clot forms , with time the fibrin strands give a typical reticular fine  lacy net or
sometimes a fluid debris level may also be seen and often , as the clot matures , it may attach to the wall of the cyst , giving it a thick - walled appearance [ 2 , 5 , 7 ] .
the use of doppler is often used to help distinguish between malignant and benign ovarian cysts .
doppler us may demonstrate the vascular wall and the avascular internal lace - like appearances of a haemorrhagic corpus luteum cyst . when performing ultrasound , it is important to exclude the presence of intraperitoneal fluid in order to exclude haemorrhagic cyst rupture
. however , ultrasound has its limitations in trying to identify whether a haematoma is originating from the fallopian tube or from the ovary .
in addition , the nonspecific characteristics of the presenting pain can often make ct a more attractive first investigation in the acute setting as it can exclude other intra - abdominal causes.fig .
the patient had a previous history of a right oophorectomy for an ovarian serous tumour .
transvaginal ultrasound of the left ovary demonstrates a cyst with typical lacelike reticular internal echoes ( large white arrow ) .
there is no internal blood flow but circumferential blood flow around the cyst wall is seen ( small white arrow ) ; this is a typical feature in a haemorrhagic corpus luteal cyst haemorrhagic cyst .
the patient had a previous history of a right oophorectomy for an ovarian serous tumour .
transvaginal ultrasound of the left ovary demonstrates a cyst with typical lacelike reticular internal echoes ( large white arrow ) .
there is no internal blood flow but circumferential blood flow around the cyst wall is seen ( small white arrow ) ; this is a typical feature in a haemorrhagic corpus luteal cyst on ct the typical appearance of an ovarian haemorrhagic cyst is a mixed attenuation mass with a high attenuation component ( 45 - 100 hu ) within the adnexa , usually with a well - defined smooth outer wall [ 9 , 10 ] .
depending on the patients symptoms , non - contrast ct may or may not have been acquired and so the presence of high attenuation material within the cyst may be difficult to interpret , as this could represent enhancing soft tissue . however , in some cases , contrast - enhanced ct is useful in delineating the cyst wall and a delayed ct may be useful in demonstrating the pooling of contrast - enhanced blood within the pelvis in cases of cystic rupture .
magnetic resonance imaging is often used when us or ct is unable to characterise a cystic mass and malignancy can not be excluded .
mri shows haemorrhagic cystic lesions as bright on t1-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 [ 1113 ] .
for example , acute haematoma can be seen as a hypointense region in the ovary on t1-weighted images .
as the haematoma becomes chronic its signal becomes bright on both t1- and t2-weighted images .
low t2 signal intensity may also be seen , particularly when haemosiderin deposition has occurred .
haemoperitoneum , a serious complication of ovarian haemorrhagic cyst rupture , may be demonstrated on both us and ct ( fig . 
b ) and should necessitate urgent surgical intervention . in some cases , the original cyst may not be visible . on us ,
the cyst itself may have a crenated appearance . on ct , the free peritoneal fluid has a relatively high attenuation and , on delayed ct images , there may be contrast - enhanced blood pooling in the pelvis .
the limitations of ct are that it can often be difficult to identify the ovaries separately from surrounding anatomical structures .
it can be challenging to distinguish whether a lesion arises from the adnexa or another structure like omentum . as ovarian haemorrhage usually affects women of reproductive age , there are also the risks associated with irradiating the pelvis .fig .
patient presented to the accident and emergency department with a 1-day history of acute right iliac fossa pain and diarrhoea .
a ct following iv contrast administration demonstrates bilateral low - density cystic lesions ( white arrows ) .
b trans - abdominal ultrasound shows free fluid containing low level echoes in the pelvis ( black arrow ) .
there is an adnexal cyst in the pelvis representing the right haemorrhagic ovarian cyst ( white arrow ) .
the smaller right - sided cyst may be the site of rupture as the ruptured cyst may be small or difficult to visualize following rupture rupture of a haemorrhagic cyst .
patient presented to the accident and emergency department with a 1-day history of acute right iliac fossa pain and diarrhoea .
a ct following iv contrast administration demonstrates bilateral low - density cystic lesions ( white arrows ) .
b trans - abdominal ultrasound shows free fluid containing low level echoes in the pelvis ( black arrow ) .
there is an adnexal cyst in the pelvis representing the right haemorrhagic ovarian cyst ( white arrow ) .
the smaller right - sided cyst may be the site of rupture as the ruptured cyst may be small or difficult to visualize following rupture on mri , haemoperitoneum following haemorrhagic cyst rupture will be seen as variable signal intensity free peritoneal fluid with areas of both low and high signal intensity depending on the extent of blood clot formation .
when clots develop , layers of low signal intensity fluid levels are often seen on t2-weighted images mixed with high signal intensity fluid . in the case of haemorrhagic ascites ,
mri enables the pelvic organs to be easily distinguished from each other when compared to ct and us
. this can be advantageous when trying to assess whether the haematoma is intraovarian or extraovarian .
mature cystic teratoma , also known as dermoid cyst , is the most common neoplasm of the ovary .
it is derived from ectodermal differentiation of one or more germ cell layers and hence may contain hair , teeth , fat , thyroid tissue , etc .
most cystic teratomas are asymptomatic but 3% may present as torsion and more rarely as dermoid cyst rupture .
patients present with acute pelvic pain , nausea and/or vomiting [ 15 , 16 ] .
cystic teratomas may appear cystic with hyperechoic areas or hyperechoic densities on ultrasound with loss of through transmission .
ct shows a cystic mass with highly complex irregular solid components and the presence of fat within an adnexal mass is diagnostic .
mri shows very high signal intensity on t1-weighted images due to the sebaceous component , which is characteristic of dermoid cyst .
fat suppression is used to differentiate fat from other haemorrhagic lesions , such as haemorrhagic cysts and endometriomas , which also appear hyperintense on t1-weighted images but remain high in signal intensity on fat - saturated images .
if there is rupture of a cystic teratoma , there may be dispersed globules of fat within the peritoneum and signs of a chemical peritonitis with stranding in the peritoneal fat .
endometriosis is caused by cyclical bleeding of hormonally responsive endometrial cells present outside the uterine lining .
this can lead to complications of blood - filled cysts within the ovaries ( also known as endometriomas or 
common presenting symptoms of this condition include chronic pelvic pain , dyspareunia , dysmenorrhoea and infertility [ 7 , 13 , 19 ] .
endometriosis involves the ovary in more than half the cases ( up to 80% ) . on ultrasound ,
endometriomas have homogeneous low level echogenicity and give an appearance referred to as the  ground glass pattern  ( fig . 
in contrast to haemorrhagic cysts , endometriomas tend to be multiple and have a more stable appearance over time .fig .
a transvaginal ultrasound demonstrates an ovarian cyst with an area of homogeneous internal echogenicity typical of an endometriotic cyst ( black arrow ) .
there is a focal area of clot retraction along the endometriotic cyst wall ( white arrow ) .
b axial t1 image demonstrates bilateral complex adnexal cystic masses which contain high t1 material .
the appearances are in keeping with bilateral haematosalpinges in a patient with endometriosis acute presentation of endometriosis .
a transvaginal ultrasound demonstrates an ovarian cyst with an area of homogeneous internal echogenicity typical of an endometriotic cyst ( black arrow ) .
there is a focal area of clot retraction along the endometriotic cyst wall ( white arrow ) .
b axial t1 image demonstrates bilateral complex adnexal cystic masses which contain high t1 material .
the appearances are in keeping with bilateral haematosalpinges in a patient with endometriosis presentation with a ruptured endometriotic cyst is uncommon but significant as emergency surgery may be required due to severe abdominal pain caused by peritoneal irritation resulting from the flow of the contents of the cyst .
ruptured endometriotic cysts typically are multilocular or bilateral ovarian cysts with a thick wall and have loculated ascites confined to the pelvic cavity with pelvic fat infiltration on ct . on mri , t1 hyperintense cysts with t2 shading or multiple t1 hyperintense cysts regardless of the t2 signal intensity increase the sensitivity and specificity of diagnosis   ( figs . 
adnexal torsion is the rotation of at least one turn of the ovaries , adnexa or the fallopian tube around the line of the tubo - ovarian ligament and the infundibulopelvic ligament .
it is a diagnosis that should be considered when evaluating female patients presenting to the emergency services with lower abdominal pain .
it is important that adnexal torsion is diagnosed early as delay can lead to complications such as loss of adnexa or the ovary with the associated fertility problems . in rare cases , diagnostic delay can cause peritonitis or fatal thrombophlebitis .
initial misdiagnosis of adnexal torsion is common and studies have shown that only 23% to 66% of cases are given the correct presurgical diagnosis [ 25 , 26].fig .
patient with a history of gastric cancer developed lower abdominal discomfort and attended for ct ( a ) , which demonstrates bilateral solid / cystic complex adnexal masses consistent with ovarian metastases .
two months later she presented to the emergency department with acute onset of right iliac fossa pain with nausea and mri of the pelvis was performed ( b  d ) .
b sagittal t2-weighted image demonstrates marked enlargement of the right ovary with high t2 signal intensity in keeping with stromal oedema ( white arrow ) .
c axial t1 image with fat saturation shows central low signal intensity ( white arrow ) surrounded a rim of high signal intensity in the enlarged right ovary consistent with peripheral haemorrhage ( black arrow ) . d axial t1 fat sat image following gadolinium administration confirms lack of enhancement of the right ovary ( black arrow consistent with right ovarian torsion ) .
the left ovarian metastasis enhances avidly ( white arrow ) torsion of an ovarian mass .
patient with a history of gastric cancer developed lower abdominal discomfort and attended for ct ( a ) , which demonstrates bilateral solid / cystic complex adnexal masses consistent with ovarian metastases .
two months later she presented to the emergency department with acute onset of right iliac fossa pain with nausea and mri of the pelvis was performed ( b  d ) .
b sagittal t2-weighted image demonstrates marked enlargement of the right ovary with high t2 signal intensity in keeping with stromal oedema ( white arrow ) .
c axial t1 image with fat saturation shows central low signal intensity ( white arrow ) surrounded a rim of high signal intensity in the enlarged right ovary consistent with peripheral haemorrhage ( black arrow ) .
d axial t1 fat sat image following gadolinium administration confirms lack of enhancement of the right ovary ( black arrow consistent with right ovarian torsion ) .
the left ovarian metastasis enhances avidly ( white arrow ) ultrasound , which is frequently used as the initial imaging investigation , may detect an adnexal mass , often in a relatively midline position .
however , between 9% and 26% of adnexal torsions occurs in normal - sized ovaries and have normal appearances on ultrasound [ 2729 ] .
a characteristic  whirlpool sign  may be seen on colour doppler where a corkscrew appearance of a twisted vascular pedicle is apparent .
however , studies have found that although doppler sonography has a high specificity for diagnosing adnexal torsion , it is not sensitive , missing the diagnosis up to 60% of the time [ 30 , 31 ] .
arterial blood flow may be seen in adnexal torsion for several reasons , leading to false - negative us .
secondly , only one of the two adnexal arteries ( uterine and ovarian ) may be torted .
thirdly , venous thrombosis secondary to torsion may lead to ovarian necrosis before arterial thrombosis occurs .
ct and mri may demonstrate a twisted vascular pedicle and thickened fallopian tube in subacute torsion , and identify an underlying mass .
features of torsion using these modalities include eccentric or concentric wall thickening of the torted adnexal mass , fallopian tube thickening , uterine deviation to the effected side and ascites .
there may also be eccentric or diffuse poor contrast enhancement of the internal solid component or thickened wall   ( fig . 
when using mri to evaluate an indeterminate adnexal lesion following us , it is recommended that sequences include a t1 and fat - suppressed t1-weighted sequence to detect haemorrhage ( fig . 
contrast - enhanced , fat - suppressed , t1-weighted images can be used to detect absence of vascular supply ( fig . 
it should be remembered that haemoperitoneum and haemorrhage with ovarian masses can be demonstrated in other acute emergencies such as a haemorrhagic cysts and rupture .
sagittal mr imaging may be used to detect tubular protrusion from an adnexal mass towards the inferior uterus .
mri can also detect smooth wall thickening of a twisted ovarian mass in cases of adnexal torsion .
other mri features that can suggest haemorrhagic infarction due to torsion include a thickened cyst wall and low enhancement in the solid component of the twisted ovarian mass [ 14 , 32 ] .
fibroids ( leiomyoma ) are the most common pelvic tumours affecting females in the fertile age group .
these benign smooth muscle tumours are sensitive to oestrogens , which are thought to be a main contributory factor to fibroid growth over time
. symptoms usually manifest during the 4th decade . as fibroids may cause acute pain , patients may present at the emergency department .
acute pain may be caused by the degeneration of a fibroid when it outgrows its blood supply , torsion of a pedunculated fibroid or prolapse of a submucosal fibroid .
red ( or haemorrhagic ) degeneration is another type of acute fibroid degeneration seen in pregnancy and in patients on the oral contraceptive pill , caused by thrombosis of the venous outflow and resulting in a rapid increase in the size of the fibroid with acute haemorrhagic infarction .
acute bleeding into fibroids can lead to hypovolaemic shock and cause the death of the patient [ 34 , 35 ] .
a simple fibroid is usually seen as a hypoechoic lesion that may be well defined and arising within the surrounding myometrium .
degeneration of fibroids gives a more complex us 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 . in acute presentation of pain ,
fibroid degeneration on ct may show a cystic appearance of a fibroid mass , with reduced enhancement and hypodense areas .
fibroid degeneration can often be difficult to distinguish from cystic ovarian masses on ct and mri is often needed to distinguish between them ( fig . 
mri can be very helpful in this respect , when investigating suspected acute fibroid complications ( fig . 
the use of multiplanar views can enable localisation of fibroids and can make it possible to distinguish fibroids from ovarian masses .
fibroids that have undergone degeneration show a great diversity in their mri appearances with cystic change and areas of non - enhancement . in cases of red degeneration
mri appearances show high signal intensity centrally within the fibroid on t1-weighted images consistent with blood , with reduced signal at the periphery on t2-weighted images secondary to haemosiderin deposition ( fig . 
6a , b ) . there may be heterogeneous signal intensity on t2 , with no enhancement post - gadolinium administration ( although gadolinium is not given to pregnant patients ) [ 36 , 37].fig .
a ct following iv contrast administration shows demarcated regions of low density within the fibroid representing cystic degeneration ( black arrow ) with enhancing surrounding soft tissue ( white arrow ) .
b sagittal t2 mri demonstrates a large heterogenous mass ( white arrow ) arising from the fundus of the uterus ( black arrow ) .
cystic areas of degeneration are demonstrated by areas of high signal intensity within the fibroid .
this patient , known to have uterine fibroids , presented to the accident and emergency department with low - grade pyrexia , tachycardia and acute lower abdominal pain .
a sagittal t2 image demonstrates a large uterine fibroid with high signal intensity centrally with a very low signal intensity rim suggestive of peripheral haemosiderin .
b axial t1 with fat - saturated image shows high signal intensity within the fibroid consistent with haemorrhage ( black arrow ) .
c axial t1 with fat saturation following gadolinium administration demonstrates lack of enhancement within the fibroid ( black arrow ) , consistent with infarction .
a ct following iv contrast administration shows demarcated regions of low density within the fibroid representing cystic degeneration ( black arrow ) with enhancing surrounding soft tissue ( white arrow ) .
b sagittal t2 mri demonstrates a large heterogenous mass ( white arrow ) arising from the fundus of the uterus ( black arrow ) .
cystic areas of degeneration are demonstrated by areas of high signal intensity within the fibroid .
identifying a connection to the uterus is important in making the correct diagnosis haemorrhagic fibroid degeneration .
this patient , known to have uterine fibroids , presented to the accident and emergency department with low - grade pyrexia , tachycardia and acute lower abdominal pain .
a sagittal t2 image demonstrates a large uterine fibroid with high signal intensity centrally with a very low signal intensity rim suggestive of peripheral haemosiderin .
b axial t1 with fat - saturated image shows high signal intensity within the fibroid consistent with haemorrhage ( black arrow ) .
c axial t1 with fat saturation following gadolinium administration demonstrates lack of enhancement within the fibroid ( black arrow ) , consistent with infarction .
the surrounding myometrium enhances normally ( white arrow ) submucosal pedunculated leiomyomas may prolapse through the cervical canal and even the vaginal canal , and typically present with pain and abnormal vaginal bleeding . a pedunculated submucosal leiomyoma may be detected on clinical gynaecological examination if there is prolapse into the vaginal canal .
the role of imaging is in diagnosis of the lesion origin and identification of the stalk and the uterine attachment of the leiomyoma .
sagittal t2-weighted images demonstrate the prolapsing leiomyoma extending into the endocervical canal , and frequently show the stalk and its uterine attachment ( fig . 
the stalk extends up into the endometrial cavity and typically has multiple linear structures running through it , and the appearance of the stalk and prolapsed fibroid has been described as the  broccoli sign .
the fibroid may become torted and haemorrhagic , and shows heterogeneous signal intensity on mri , with lack of enhancement following contrast administration ( fig . 
mri can provide important clinical information for pre - surgical planning [ 38 , 39].fig .
a sagittal t2 image demonstrates a fibroid arising on a stalk ( white arrow ) that originates in the lower endometrial cavity .
the fibroid has prolapsed into the endocervical canal ( black arrow ) and demonstrates areas of low t2 suggestive of haemorrhage .
b axial t2 image demonstrates the torted fibroid ( white arrow ) surrounded by the ring of cervical stroma ( black arrow ) .
c axial t1 fat - saturated image demonstrates high signal intensity within the fibroid indicating haemorrhage ( black arrow ) .
d axial t1 fat - saturated image following gadolinium administration demonstrates lack of enhancement consistent with torsion ( white arrow ) pedunculated submucosal fibroid with prolapse and torsion .
a sagittal t2 image demonstrates a fibroid arising on a stalk ( white arrow ) that originates in the lower endometrial cavity .
the fibroid has prolapsed into the endocervical canal ( black arrow ) and demonstrates areas of low t2 suggestive of haemorrhage .
b axial t2 image demonstrates the torted fibroid ( white arrow ) surrounded by the ring of cervical stroma ( black arrow ) .
c axial t1 fat - saturated image demonstrates high signal intensity within the fibroid indicating haemorrhage ( black arrow ) .
d axial t1 fat - saturated image following gadolinium administration demonstrates lack of enhancement consistent with torsion ( white arrow ) ct may show a heterogeneously enhancing mass prolapsing into the vagina and perineum .
often the mass can show diffuse low attenuation , which indicates necrosis of the fibroid .
pelvic inflammatory disease ( pid ) is described as a spread of inflammation from the endometrial cavity and fallopian tubes into the pelvis .
it is an umbrella term , which encompasses endometritis , salpingitis and tubo - ovarian abscesses .
it usually affects women in the reproductive age group and accounts for 25% of visits to the emergency departments with gynaecological pain .
the symptoms of pelvic inflammatory disease are general aching pain in the pelvis that varies in severity .
it is also common for sufferers to have vaginal discharge and cervical excitation on examination .
complications of untreated pid can have serious implications for the patient and include infertility , ectopic pregnancy , chronic abdominal pain and the development of tubo - ovarian abscesses requiring surgical intervention .
organisms such as sexually transmitted chlamydia trachomatas and nissera gonorrhoea are causative agents in developing ascending cervicitis .
other conditions that may lead to the development of tubo - ovarian abscess are diverticulitis , appendicitis and tuberculosis [ 37 , 40 ] . in the early phase of infection , it is common for ultrasound and ct appearances to be normal .
as the disease advances , transabdominal ultrasound can demonstrate uterine enlargement and thickening of the endometrium .
ultrasound can also show the loss of tissue plains and an ill - defined uterus .
ultrasound can identify dilated fallopian tubes containing heterogenous fluid with echogenic debris ; features typical of pyosalpinx .
the fallopian tubes may be folded and demonstrate areas of tube tapering , and intraluminal small linear echogenic foci may be visualised ( fig . 
as pyosalpinx develops into tubo - ovarian abscesses , echogenic debris can be seen in the fallopian tubes and ovaries , representing inflammatory exudates , blood and pus .fig .
this patient presented to the emergency department with lower abdominal pain , pyrexia and vomiting .
there are bilateral adenexal cysts that contain low - level echogenic material and have a tubular configuration ( white arrows ) .
the appearance is in keeping with bilateral pyosalpinges , a complication of pelvic inflammatory disease pelvic inflammatory disease with pyosalpinx on ultrasound .
this patient presented to the emergency department with lower abdominal pain , pyrexia and vomiting .
there are bilateral adenexal cysts that contain low - level echogenic material and have a tubular configuration ( white arrows ) .
the appearance is in keeping with bilateral pyosalpinges , a complication of pelvic inflammatory disease in order to reduce exposure to radiation , ct is not usually employed as a first - line imaging investigation in cases of suspected pid .
the ct appearances of pid are often non - specific with parapelvic fat stranding , a small volume of free fluid and thickened uterosacral ligaments .
however , the development of tubo - ovarian abscesses results in thickened irregularly enhancing complex adnexal masses with thick walls and septations containing complex fluid collections ( fig . 
tubo - ovarian abscesses frequently cause anterior displacement of the broad ligament as the mesovarium is positioned more posteriorly , and this can assist in making the diagnosis .fig .
a ct demonstrates bilateral adnexal complex fluid - filled and thick - walled cysts typical for tubo - ovarian abcess formation , a complication of pelvic inflammatory disease .
b coronal reformat of the ct demonstrates bilateral tubo - ovarian abcesses as well as distention of multiple bowel loops due to an associated ileus pelvic inflammatory disease with pyosalpinx on ct .
a ct demonstrates bilateral adnexal complex fluid - filled and thick - walled cysts typical for tubo - ovarian abcess formation , a complication of pelvic inflammatory disease .
b coronal reformat of the ct demonstrates bilateral tubo - ovarian abcesses as well as distention of multiple bowel loops due to an associated ileus on mri , inflammation in the parametrium may be seen as ill - defined hyperintense areas on t2-weighted fat - suppressed images , in addition to enhancement on gadolinium - enhanced t1-weighted images .
a pyosalpinx can be visualised as a dilated , fluid - filled , tortuous c or s - shaped structure .
thick - walled fluid - filled abscesses and pyosalpinx may have heterogeneous signal intensity on both t1 and t2 weighting due to mixtures of pus , haemorrhage and debris .
the thick - walled mass typically demonstrates marked enhancement following iv gadolinium administration ( fig . 
although radiological features of abscess and ovarian malignancy can be similar , the clinical presentation plays an important role in establishing the diagnosis and follow - up imaging following treatment confirms decreasing size of adnexal massses [ 40 , 41].fig .
this patient presented to the emergency department with pyrexia , lower abdominal pain and diarrhoea .
a sagittal t2 image of the pelvis demonstrates multiple fluid - filled cystic structures within the right adnexa ( black arrows ) .
c axial t1 fat - saturated image following gadolinium administration 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 pelvic inflammatory disease with pyosalpinx on mri .
this patient presented to the emergency department with pyrexia , lower abdominal pain and diarrhoea .
a sagittal t2 image of the pelvis demonstrates multiple fluid - filled cystic structures within the right adnexa ( black arrows ) .
c axial t1 fat - saturated image following gadolinium administration demonstrates low signal intensity within the pus - filled cavities and marked enhancement of the inflammatory walls .
are commonly seen as functioning cysts during ultrasound examination , usually grow 2  mm per day until ovulation and measure less than 3  cm in diameter .
if ovulation does not occur , a follicular cyst develops and appears as an anechoic cyst with a thin wall and posterior acoustic enhancement ( seen as an area of increased echogenicity posterior to the cyst ) .
functional or simple cysts are usually single , less than 6  cm in diameter and thin walled ( <3  mm ) .
the corpus luteum forms after ovulation as granulosa cells become luteinized and blood accumulates in the central cavity . hence , corpus luteal cysts have a thicker , more echogenic wall with increased vascularity seen as peripheral blood flow on doppler .
a haemorrhagic ovarian cyst is suspected if a patient presents with symptoms of acute lower abdominal pain , tenderness and in some cases ascites [ 24 ] .
blood tests often show normocytic anaemia with only mild elevation of inflammatory markers such as crp and leucocytes when compared to conditions such as appendicitis .
measurement of hcg levels is also important in excluding ectopic pregnancy , which can have a similar presentation [ 5 , 6 ] .
a transvaginal ultrasound is often the first imaging modality in patients who are suspected of having an ovarian cyst haemorrhage .
when there is an intracystic haemorrhage the characteristics of the bleed evolve with its age . in the acute stage ,
the haemorrhage is isoechoic in relation to the ovarian stroma and this can often be similar in appearance to an enlarged ovary . as the clot forms , with time the fibrin strands give a typical reticular fine  lacy net or
sometimes a fluid debris level may also be seen and often , as the clot matures , it may attach to the wall of the cyst , giving it a thick - walled appearance [ 2 , 5 , 7 ] .
the use of doppler is often used to help distinguish between malignant and benign ovarian cysts .
doppler us may demonstrate the vascular wall and the avascular internal lace - like appearances of a haemorrhagic corpus luteum cyst . when performing ultrasound , it is important to exclude the presence of intraperitoneal fluid in order to exclude haemorrhagic cyst rupture . however , ultrasound has its limitations in trying to identify whether a haematoma is originating from the fallopian tube or from the ovary .
in addition , the nonspecific characteristics of the presenting pain can often make ct a more attractive first investigation in the acute setting as it can exclude other intra - abdominal causes.fig .
the patient had a previous history of a right oophorectomy for an ovarian serous tumour .
transvaginal ultrasound of the left ovary demonstrates a cyst with typical lacelike reticular internal echoes ( large white arrow ) .
there is no internal blood flow but circumferential blood flow around the cyst wall is seen ( small white arrow ) ; this is a typical feature in a haemorrhagic corpus luteal cyst haemorrhagic cyst .
the patient had a previous history of a right oophorectomy for an ovarian serous tumour .
transvaginal ultrasound of the left ovary demonstrates a cyst with typical lacelike reticular internal echoes ( large white arrow ) .
there is no internal blood flow but circumferential blood flow around the cyst wall is seen ( small white arrow ) ; this is a typical feature in a haemorrhagic corpus luteal cyst on ct the typical appearance of an ovarian haemorrhagic cyst is a mixed attenuation mass with a high attenuation component ( 45 - 100 hu ) within the adnexa , usually with a well - defined smooth outer wall [ 9 , 10 ] . depending on the patients symptoms , non - contrast ct may or may not have been acquired and so the presence of high attenuation material within the cyst may be difficult to interpret , as this could represent enhancing soft tissue .
however , in some cases , contrast - enhanced ct is useful in delineating the cyst wall and a delayed ct may be useful in demonstrating the pooling of contrast - enhanced blood within the pelvis in cases of cystic rupture .
magnetic resonance imaging is often used when us or ct is unable to characterise a cystic mass and malignancy can not be excluded .
mri shows haemorrhagic cystic lesions as bright on t1-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 [ 1113 ] .
for example , acute haematoma can be seen as a hypointense region in the ovary on t1-weighted images .
as the haematoma becomes chronic its signal becomes bright on both t1- and t2-weighted images .
low t2 signal intensity may also be seen , particularly when haemosiderin deposition has occurred .
haemoperitoneum , a serious complication of ovarian haemorrhagic cyst rupture , may be demonstrated on both us and ct ( fig . 
the cyst itself may have a crenated appearance . on ct , the free peritoneal fluid has a relatively high attenuation and , on delayed ct images , there may be contrast - enhanced blood pooling in the pelvis . the limitations of ct are that it can often be difficult to identify the ovaries separately from surrounding anatomical structures .
it can be challenging to distinguish whether a lesion arises from the adnexa or another structure like omentum . as ovarian haemorrhage usually affects women of reproductive age , there are also the risks associated with irradiating the pelvis .fig .
patient presented to the accident and emergency department with a 1-day history of acute right iliac fossa pain and diarrhoea .
initially the patient was diagnosed as having an appendicitis . a ct following iv contrast administration demonstrates bilateral low - density cystic lesions ( white arrows ) .
b trans - abdominal ultrasound shows free fluid containing low level echoes in the pelvis ( black arrow ) .
there is an adnexal cyst in the pelvis representing the right haemorrhagic ovarian cyst ( white arrow ) .
the smaller right - sided cyst may be the site of rupture as the ruptured cyst may be small or difficult to visualize following rupture rupture of a haemorrhagic cyst .
patient presented to the accident and emergency department with a 1-day history of acute right iliac fossa pain and diarrhoea .
initially the patient was diagnosed as having an appendicitis . a ct following iv contrast administration demonstrates bilateral low - density cystic lesions ( white arrows ) .
b trans - abdominal ultrasound shows free fluid containing low level echoes in the pelvis ( black arrow ) .
there is an adnexal cyst in the pelvis representing the right haemorrhagic ovarian cyst ( white arrow ) .
the smaller right - sided cyst may be the site of rupture as the ruptured cyst may be small or difficult to visualize following rupture on mri , haemoperitoneum following haemorrhagic cyst rupture will be seen as variable signal intensity free peritoneal fluid with areas of both low and high signal intensity depending on the extent of blood clot formation .
when clots develop , layers of low signal intensity fluid levels are often seen on t2-weighted images mixed with high signal intensity fluid . in the case of haemorrhagic ascites ,
mri enables the pelvic organs to be easily distinguished from each other when compared to ct and us .
this can be advantageous when trying to assess whether the haematoma is intraovarian or extraovarian .
mature cystic teratoma , also known as dermoid cyst , is the most common neoplasm of the ovary .
it is derived from ectodermal differentiation of one or more germ cell layers and hence may contain hair , teeth , fat , thyroid tissue , etc .
most cystic teratomas are asymptomatic but 3% may present as torsion and more rarely as dermoid cyst rupture .
patients present with acute pelvic pain , nausea and/or vomiting [ 15 , 16 ] .
cystic teratomas may appear cystic with hyperechoic areas or hyperechoic densities on ultrasound with loss of through transmission .
ct shows a cystic mass with highly complex irregular solid components and the presence of fat within an adnexal mass is diagnostic .
mri shows very high signal intensity on t1-weighted images due to the sebaceous component , which is characteristic of dermoid cyst .
fat suppression is used to differentiate fat from other haemorrhagic lesions , such as haemorrhagic cysts and endometriomas , which also appear hyperintense on t1-weighted images but remain high in signal intensity on fat - saturated images .
if there is rupture of a cystic teratoma , there may be dispersed globules of fat within the peritoneum and signs of a chemical peritonitis with stranding in the peritoneal fat .
endometriosis is caused by cyclical bleeding of hormonally responsive endometrial cells present outside the uterine lining .
this can lead to complications of blood - filled cysts within the ovaries ( also known as endometriomas or 
common presenting symptoms of this condition include chronic pelvic pain , dyspareunia , dysmenorrhoea and infertility [ 7 , 13 , 19 ] .
endometriosis involves the ovary in more than half the cases ( up to 80% ) . on ultrasound ,
endometriomas have homogeneous low level echogenicity and give an appearance referred to as the  ground glass pattern  ( fig . 
in contrast to haemorrhagic cysts , endometriomas tend to be multiple and have a more stable appearance over time .fig .
a transvaginal ultrasound demonstrates an ovarian cyst with an area of homogeneous internal echogenicity typical of an endometriotic cyst ( black arrow ) .
there is a focal area of clot retraction along the endometriotic cyst wall ( white arrow ) .
b axial t1 image demonstrates bilateral complex adnexal cystic masses which contain high t1 material .
the appearances are in keeping with bilateral haematosalpinges in a patient with endometriosis acute presentation of endometriosis .
a transvaginal ultrasound demonstrates an ovarian cyst with an area of homogeneous internal echogenicity typical of an endometriotic cyst ( black arrow ) .
there is a focal area of clot retraction along the endometriotic cyst wall ( white arrow ) .
b axial t1 image demonstrates bilateral complex adnexal cystic masses which contain high t1 material .
the appearances are in keeping with bilateral haematosalpinges in a patient with endometriosis presentation with a ruptured endometriotic cyst is uncommon but significant as emergency surgery may be required due to severe abdominal pain caused by peritoneal irritation resulting from the flow of the contents of the cyst
. ruptured endometriotic cysts typically are multilocular or bilateral ovarian cysts with a thick wall and have loculated ascites confined to the pelvic cavity with pelvic fat infiltration on ct . on mri , t1 hyperintense cysts with t2 shading or multiple t1 hyperintense cysts regardless of the t2 signal intensity increase the sensitivity and specificity of diagnosis   ( figs . 
adnexal torsion is the rotation of at least one turn of the ovaries , adnexa or the fallopian tube around the line of the tubo - ovarian ligament and the infundibulopelvic ligament .
it is a diagnosis that should be considered when evaluating female patients presenting to the emergency services with lower abdominal pain .
it is important that adnexal torsion is diagnosed early as delay can lead to complications such as loss of adnexa or the ovary with the associated fertility problems . in rare cases ,
initial misdiagnosis of adnexal torsion is common and studies have shown that only 23% to 66% of cases are given the correct presurgical diagnosis [ 25 , 26].fig .
patient with a history of gastric cancer developed lower abdominal discomfort and attended for ct ( a ) , which demonstrates bilateral solid / cystic complex adnexal masses consistent with ovarian metastases .
two months later she presented to the emergency department with acute onset of right iliac fossa pain with nausea and mri of the pelvis was performed ( b  d ) .
b sagittal t2-weighted image demonstrates marked enlargement of the right ovary with high t2 signal intensity in keeping with stromal oedema ( white arrow ) .
c axial t1 image with fat saturation shows central low signal intensity ( white arrow ) surrounded a rim of high signal intensity in the enlarged right ovary consistent with peripheral haemorrhage ( black arrow ) .
d axial t1 fat sat image following gadolinium administration confirms lack of enhancement of the right ovary ( black arrow consistent with right ovarian torsion ) .
the left ovarian metastasis enhances avidly ( white arrow ) torsion of an ovarian mass .
patient with a history of gastric cancer developed lower abdominal discomfort and attended for ct ( a ) , which demonstrates bilateral solid / cystic complex adnexal masses consistent with ovarian metastases .
two months later she presented to the emergency department with acute onset of right iliac fossa pain with nausea and mri of the pelvis was performed ( b  d ) .
b sagittal t2-weighted image demonstrates marked enlargement of the right ovary with high t2 signal intensity in keeping with stromal oedema ( white arrow ) .
c axial t1 image with fat saturation shows central low signal intensity ( white arrow ) surrounded a rim of high signal intensity in the enlarged right ovary consistent with peripheral haemorrhage ( black arrow ) .
d axial t1 fat sat image following gadolinium administration confirms lack of enhancement of the right ovary ( black arrow consistent with right ovarian torsion ) .
the left ovarian metastasis enhances avidly ( white arrow ) ultrasound , which is frequently used as the initial imaging investigation , may detect an adnexal mass , often in a relatively midline position .
however , between 9% and 26% of adnexal torsions occurs in normal - sized ovaries and have normal appearances on ultrasound [ 2729 ] .
a characteristic  whirlpool sign  may be seen on colour doppler where a corkscrew appearance of a twisted vascular pedicle is apparent .
however , studies have found that although doppler sonography has a high specificity for diagnosing adnexal torsion , it is not sensitive , missing the diagnosis up to 60% of the time [ 30 , 31 ] .
arterial blood flow may be seen in adnexal torsion for several reasons , leading to false - negative us .
secondly , only one of the two adnexal arteries ( uterine and ovarian ) may be torted .
thirdly , venous thrombosis secondary to torsion may lead to ovarian necrosis before arterial thrombosis occurs .
ct and mri may demonstrate a twisted vascular pedicle and thickened fallopian tube in subacute torsion , and identify an underlying mass .
features of torsion using these modalities include eccentric or concentric wall thickening of the torted adnexal mass , fallopian tube thickening , uterine deviation to the effected side and ascites .
there may also be eccentric or diffuse poor contrast enhancement of the internal solid component or thickened wall   ( fig . 
when using mri to evaluate an indeterminate adnexal lesion following us , it is recommended that sequences include a t1 and fat - suppressed t1-weighted sequence to detect haemorrhage ( fig . 
contrast - enhanced , fat - suppressed , t1-weighted images can be used to detect absence of vascular supply ( fig . 
it should be remembered that haemoperitoneum and haemorrhage with ovarian masses can be demonstrated in other acute emergencies such as a haemorrhagic cysts and rupture .
sagittal mr imaging may be used to detect tubular protrusion from an adnexal mass towards the inferior uterus .
mri can also detect smooth wall thickening of a twisted ovarian mass in cases of adnexal torsion .
other mri features that can suggest haemorrhagic infarction due to torsion include a thickened cyst wall and low enhancement in the solid component of the twisted ovarian mass [ 14 , 32 ] .
fibroids ( leiomyoma ) are the most common pelvic tumours affecting females in the fertile age group .
these benign smooth muscle tumours are sensitive to oestrogens , which are thought to be a main contributory factor to fibroid growth over time
. symptoms usually manifest during the 4th decade . as fibroids may cause acute pain , patients may present at the emergency department .
acute pain may be caused by the degeneration of a fibroid when it outgrows its blood supply , torsion of a pedunculated fibroid or prolapse of a submucosal fibroid .
red ( or haemorrhagic ) degeneration is another type of acute fibroid degeneration seen in pregnancy and in patients on the oral contraceptive pill , caused by thrombosis of the venous outflow and resulting in a rapid increase in the size of the fibroid with acute haemorrhagic infarction .
acute bleeding into fibroids can lead to hypovolaemic shock and cause the death of the patient [ 34 , 35 ] .
a simple fibroid is usually seen as a hypoechoic lesion that may be well defined and arising within the surrounding myometrium .
degeneration of fibroids gives a more complex us 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 . in acute presentation of pain ,
fibroid degeneration on ct may show a cystic appearance of a fibroid mass , with reduced enhancement and hypodense areas .
fibroid degeneration can often be difficult to distinguish from cystic ovarian masses on ct and mri is often needed to distinguish between them ( fig . 
mri can be very helpful in this respect , when investigating suspected acute fibroid complications ( fig . 
the use of multiplanar views can enable localisation of fibroids and can make it possible to distinguish fibroids from ovarian masses .
fibroids that have undergone degeneration show a great diversity in their mri appearances with cystic change and areas of non - enhancement . in cases of red degeneration
mri appearances show high signal intensity centrally within the fibroid on t1-weighted images consistent with blood , with reduced signal at the periphery on t2-weighted images secondary to haemosiderin deposition ( fig . 
6a , b ) . there may be heterogeneous signal intensity on t2 , with no enhancement post - gadolinium administration ( although gadolinium is not given to pregnant patients ) [ 36 , 37].fig .
a ct following iv contrast administration shows demarcated regions of low density within the fibroid representing cystic degeneration ( black arrow ) with enhancing surrounding soft tissue ( white arrow ) .
b sagittal t2 mri demonstrates a large heterogenous mass ( white arrow ) arising from the fundus of the uterus ( black arrow ) .
cystic areas of degeneration are demonstrated by areas of high signal intensity within the fibroid .
this patient , known to have uterine fibroids , presented to the accident and emergency department with low - grade pyrexia , tachycardia and acute lower abdominal pain . a sagittal t2 image demonstrates a large uterine fibroid with high signal intensity centrally with a very low signal intensity rim suggestive of peripheral haemosiderin .
b axial t1 with fat - saturated image shows high signal intensity within the fibroid consistent with haemorrhage ( black arrow ) .
c axial t1 with fat saturation following gadolinium administration demonstrates lack of enhancement within the fibroid ( black arrow ) , consistent with infarction .
a ct following iv contrast administration shows demarcated regions of low density within the fibroid representing cystic degeneration ( black arrow ) with enhancing surrounding soft tissue ( white arrow ) .
b sagittal t2 mri demonstrates a large heterogenous mass ( white arrow ) arising from the fundus of the uterus ( black arrow ) .
cystic areas of degeneration are demonstrated by areas of high signal intensity within the fibroid .
identifying a connection to the uterus is important in making the correct diagnosis haemorrhagic fibroid degeneration .
this patient , known to have uterine fibroids , presented to the accident and emergency department with low - grade pyrexia , tachycardia and acute lower abdominal pain .
a sagittal t2 image demonstrates a large uterine fibroid with high signal intensity centrally with a very low signal intensity rim suggestive of peripheral haemosiderin .
b axial t1 with fat - saturated image shows high signal intensity within the fibroid consistent with haemorrhage ( black arrow ) .
c axial t1 with fat saturation following gadolinium administration demonstrates lack of enhancement within the fibroid ( black arrow ) , consistent with infarction .
the surrounding myometrium enhances normally ( white arrow ) submucosal pedunculated leiomyomas may prolapse through the cervical canal and even the vaginal canal , and typically present with pain and abnormal vaginal bleeding .
a pedunculated submucosal leiomyoma may be detected on clinical gynaecological examination if there is prolapse into the vaginal canal .
the role of imaging is in diagnosis of the lesion origin and identification of the stalk and the uterine attachment of the leiomyoma .
sagittal t2-weighted images demonstrate the prolapsing leiomyoma extending into the endocervical canal , and frequently show the stalk and its uterine attachment ( fig . 
the stalk extends up into the endometrial cavity and typically has multiple linear structures running through it , and the appearance of the stalk and prolapsed fibroid has been described as the  broccoli sign .
the fibroid may become torted and haemorrhagic , and shows heterogeneous signal intensity on mri , with lack of enhancement following contrast administration ( fig . 
mri can provide important clinical information for pre - surgical planning [ 38 , 39].fig .
a sagittal t2 image demonstrates a fibroid arising on a stalk ( white arrow ) that originates in the lower endometrial cavity .
the fibroid has prolapsed into the endocervical canal ( black arrow ) and demonstrates areas of low t2 suggestive of haemorrhage .
b axial t2 image demonstrates the torted fibroid ( white arrow ) surrounded by the ring of cervical stroma ( black arrow ) . c axial t1 fat - saturated image demonstrates high signal intensity within the fibroid indicating haemorrhage ( black arrow ) .
d axial t1 fat - saturated image following gadolinium administration demonstrates lack of enhancement consistent with torsion ( white arrow ) pedunculated submucosal fibroid with prolapse and torsion .
a sagittal t2 image demonstrates a fibroid arising on a stalk ( white arrow ) that originates in the lower endometrial cavity .
the fibroid has prolapsed into the endocervical canal ( black arrow ) and demonstrates areas of low t2 suggestive of haemorrhage .
b axial t2 image demonstrates the torted fibroid ( white arrow ) surrounded by the ring of cervical stroma ( black arrow ) .
c axial t1 fat - saturated image demonstrates high signal intensity within the fibroid indicating haemorrhage ( black arrow ) .
d axial t1 fat - saturated image following gadolinium administration demonstrates lack of enhancement consistent with torsion ( white arrow ) ct may show a heterogeneously enhancing mass prolapsing into the vagina and perineum .
often the mass can show diffuse low attenuation , which indicates necrosis of the fibroid .
pelvic inflammatory disease ( pid ) is described as a spread of inflammation from the endometrial cavity and fallopian tubes into the pelvis .
it is an umbrella term , which encompasses endometritis , salpingitis and tubo - ovarian abscesses .
it usually affects women in the reproductive age group and accounts for 25% of visits to the emergency departments with gynaecological pain .
the symptoms of pelvic inflammatory disease are general aching pain in the pelvis that varies in severity .
it is also common for sufferers to have vaginal discharge and cervical excitation on examination .
complications of untreated pid can have serious implications for the patient and include infertility , ectopic pregnancy , chronic abdominal pain and the development of tubo - ovarian abscesses requiring surgical intervention .
organisms such as sexually transmitted chlamydia trachomatas and nissera gonorrhoea are causative agents in developing ascending cervicitis .
other conditions that may lead to the development of tubo - ovarian abscess are diverticulitis , appendicitis and tuberculosis [ 37 , 40 ] . in the early phase of infection , it is common for ultrasound and ct appearances to be normal . as the disease advances , transabdominal ultrasound can demonstrate uterine enlargement and thickening of the endometrium .
ultrasound can also show the loss of tissue plains and an ill - defined uterus .
ultrasound can identify dilated fallopian tubes containing heterogenous fluid with echogenic debris ; features typical of pyosalpinx .
the fallopian tubes may be folded and demonstrate areas of tube tapering , and intraluminal small linear echogenic foci may be visualised ( fig . 
as pyosalpinx develops into tubo - ovarian abscesses , echogenic debris can be seen in the fallopian tubes and ovaries , representing inflammatory exudates , blood and pus .fig .
this patient presented to the emergency department with lower abdominal pain , pyrexia and vomiting .
there are bilateral adenexal cysts that contain low - level echogenic material and have a tubular configuration ( white arrows ) .
the appearance is in keeping with bilateral pyosalpinges , a complication of pelvic inflammatory disease pelvic inflammatory disease with pyosalpinx on ultrasound .
this patient presented to the emergency department with lower abdominal pain , pyrexia and vomiting .
there are bilateral adenexal cysts that contain low - level echogenic material and have a tubular configuration ( white arrows ) .
the appearance is in keeping with bilateral pyosalpinges , a complication of pelvic inflammatory disease in order to reduce exposure to radiation , ct is not usually employed as a first - line imaging investigation in cases of suspected pid .
the ct appearances of pid are often non - specific with parapelvic fat stranding , a small volume of free fluid and thickened uterosacral ligaments . however , the development of tubo - ovarian abscesses results in thickened irregularly enhancing complex adnexal masses with thick walls and septations containing complex fluid collections ( fig . 
tubo - ovarian abscesses frequently cause anterior displacement of the broad ligament as the mesovarium is positioned more posteriorly , and this can assist in making the diagnosis .fig .
a ct demonstrates bilateral adnexal complex fluid - filled and thick - walled cysts typical for tubo - ovarian abcess formation , a complication of pelvic inflammatory disease .
b coronal reformat of the ct demonstrates bilateral tubo - ovarian abcesses as well as distention of multiple bowel loops due to an associated ileus pelvic inflammatory disease with pyosalpinx on ct .
the clinicians suspected an intra - abdominal collection . a ct demonstrates bilateral adnexal complex fluid - filled and thick - walled cysts typical for tubo - ovarian abcess formation , a complication of pelvic inflammatory disease .
b coronal reformat of the ct demonstrates bilateral tubo - ovarian abcesses as well as distention of multiple bowel loops due to an associated ileus on mri , inflammation in the parametrium may be seen as ill - defined hyperintense areas on t2-weighted fat - suppressed images , in addition to enhancement on gadolinium - enhanced t1-weighted images .
a pyosalpinx can be visualised as a dilated , fluid - filled , tortuous c or s - shaped structure .
thick - walled fluid - filled abscesses and pyosalpinx may have heterogeneous signal intensity on both t1 and t2 weighting due to mixtures of pus , haemorrhage and debris .
the thick - walled mass typically demonstrates marked enhancement following iv gadolinium administration ( fig . 
although radiological features of abscess and ovarian malignancy can be similar , the clinical presentation plays an important role in establishing the diagnosis and follow - up imaging following treatment confirms decreasing size of adnexal massses [ 40 , 41].fig .
this patient presented to the emergency department with pyrexia , lower abdominal pain and diarrhoea .
a sagittal t2 image of the pelvis demonstrates multiple fluid - filled cystic structures within the right adnexa ( black arrows ) .
c axial t1 fat - saturated image following gadolinium administration 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 pelvic inflammatory disease with pyosalpinx on mri .
this patient presented to the emergency department with pyrexia , lower abdominal pain and diarrhoea .
a sagittal t2 image of the pelvis demonstrates multiple fluid - filled cystic structures within the right adnexa ( black arrows ) . the complex cyst is thick walled and there is adjacent fat stranding .
c axial t1 fat - saturated image following gadolinium administration demonstrates low signal intensity within the pus - filled cavities and marked enhancement of the inflammatory walls .
in cases of suspected acute gynaecological disease , the findings on imaging must be interpreted in association with the clinical presentation .
the pregnancy status of the patient must always be established , in order to exclude ectopic pregnancy and to avoid using imaging modalities , which pose a risk to the foetus .
haemorrhagic ovarian cysts give a characteristic internal reticular pattern on ultrasound with high attenuation contents on non - contrast ct , an enhancing cystic wall and contrast - enhanced blood in the pelvis on delayed phases in cases of cyst rupture ( table  1 ) .
although endometriotic cysts rarely cause an acute presentation , it is important to recognise the ground - glass appearance on ultrasound and characteristic high signal intensity on t1- and shading on t2-weighted images on mri . where adnexal torsion is suspected
contrast - enhanced ct and mri may demonstrate reduced enhancement in the twisted ovarian mass , another diagnostic feature of torsion ( table  1 ) . where torsion is suspected clinically but diagnostic imaging features are not demonstrated , it should be remembered that imaging can not be relied upon to confirm the diagnosis .
red degeneration demonstrates high signal intensity centrally on t1-weighted images due to acute blood and a low signal periphery on t2 due to haemosiderin deposition .
mri appearances of submucosal pedunculated leiomyomas can demonstrate a  broccoli sign  with heterogeneous signal due to the characteristic stalk linking the herniating fibroid with the endometrial cavity ( table  1 ) .
complications of pid can be demonstrated with ultrasound , with dilated fallopian tubes with internal echogenic debris being a typical feature of pyosalpinx .
although ct and mri are not routinely used to investigate pid complications , these modalities may demonstrate typically bilateral dilated fallopian tubes and inflammatory changes in the adjacent fat planes ( table  1 ) . in most presentations of gynaecological emergencies , us , and
occasionally ct , can be the simplest and quickest way to assess the patient , with mri reserved for further characterisation of complex masses and problem - solving .
overlap in the presenting features of acute gynaecologic disease and gastrointestinal disease remains a significant challenge in the emergency department and imaging plays an important diagnostic role.table 1us , ct and mri indications and findingsusctmrisimple ovarian cystsindicatednot indicatednot indicatedanechoic 3 - 6  cm cyst , with thin wall <3 
mm and minimal thin septationswell - defined cystic adnexal mass of low attenuation and smooth well - defined wallwell - defined cystic adnexal mass of low t1 and high t2 signal intensity and smoothly enhancing wallhaemorrhagic ovarian cystindicatednot indicated unless suspected cyst rupture with severe painnot indicated unless a cyst is considered indeterminate on usisoechoic to ovarian stoma when acute .
develops fine , reticular  spider - web  or lace - like pattern . vascular wall with avascular internal clot material .
if ruptured , then free pelvic fluid with low - level echos is seenhyperdense mass within the adnexa .
if ruptured , then high - density free fluid is seen in pelvis and there may be contrast pooling in the pelvis on delayed images in cases of ruptureappearance depends on age of blood .
. cyst rupture may demonstrate a combination of low and high t1 and t2 free fluid in pelvisendometriotic cystsindicatednot indicated unless suspected acute rupturenot indicated unless a cyst is considered indeterminate on usovarian cyst containing ground 
may be multipleruptured endometriotic cyst may be associated with loculated dense ascites often confined to the pelvic cavity due to adhesionstypically t1 hyperintense cysts with t2 shading ; frequently bilateral .
chronic fibrotic changes in pouch of douglas may be seenadnexal torsionindicated although of low sensitivitymay be undertaken due to acute pain with unclear diagnosisnot indicated unless the adnexal mass is considered indeterminatedoppler whirlpool sign with corkscrew appearance of twisted vascular pedicle and an enlarged ovary with peripherally located folliclestwisted vascular pedicleoedema of ovarian stroma .
there may be absence of vascular supply and low level enhancement in the solid component of the ovarian masswall thickening of torted adnexal mass .
poor contrast enhancement of internal solid componentsfibroid ( complications)indicatedmay be undertaken if patient has acute painnot usually indicated .
may be used to differentiate a degenerating fibroid from a complex adnexal massdegeneration gives a complex us appearance with areas of cystic changedegeneration gives cystic hypodense appearance of fibroid masscystic degeneration is seen as complex high t2 signal intensity within a fibroiddoppler shows circumferential vascularitycan be difficult to distinguish from a complex ovarian cyst when largered degeneration within a fibroid is seen asabsence of flow if tortedhigh t1 signal centrally due to blood with low t2 signal at periphery due to haemosiderin depositionsubmucosal pedunculated fibroid may extend into endocervix or vagina from a stalk and may tortpelvic inflammatory diseaseindicatednot usually indicated but may be done if diagnosis is uncertainnot indicated unless the diagnosis is uncertain and us is indeterminateclinical signs are key to diagnosis .
may be seentubo - ovarian abscesses appear as bilateral thick - walled complex enhancing masses with tubal configuration and surrounding inflammationtubo - ovarian abcesses appear as complex thick - walled enhancing adnexal masses with surrounding inflammation us , ct and mri indications and findings
 backgroundthe 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.methodsultrasound 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 can not 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.resultsalthough mri is not frequently used in the emergency setting , it is an important modality in characterising features that are unclear on ultrasound and ct.conclusionmri 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 . 
Teaching points
Introduction
Cyst Emergencies
Functional or simple cysts
Haemorrhagic ovarian cyst
Haemorrhagic cyst rupture
Dermoid cyst rupture
Endometriotic cysts
Adnexal torsion
Fibroids: acute presentations
Pelvic inflammatory disease
Conclusion