Pelvic lipomatosis or pelvic fibrolipomatosis represents excessive deposition of fat in pelvis due to overgrowth of adipose cells leading to compression of pelvic organs.
The condition usually presents in patients 20-50 years of age. The condition is predominantly (~66% of cases) ...
Pelvic masses in females carry a broad differential diagnosis:
benign adnexal cyst
pelvic inflammatory disease
Extragynaecological masses, e.g. colorectal carcinoma, appendicular abscess, lymp...
A dedicated MRI protocol is crucial for accurate MRI evaluation of endometrial carcinomas.
Imaging is optimally performed after 3 hours of fasting to reduce bowel peristalsis and following administration of an antiperistaltic agent unless contraindicated.
Supine position using a pelvic phased-...
It is important to have a systematic way of approaching a case with pelvic pain in the exam.
Most examinations are performed using ultrasound. Always say that you would further assess the uterus with 3D ultrasound. You may also say that in my department we would perform a sonohysterogram. Only...
Evaluation of known endometriosis with MRI requires a slightly different protocol to a routine pelvic MRI (see Pelvic MRI protocol: routine), and should probably be reserved for known cases of endometriosis rather than for the assessment of pelvic pain.
IV (or IM) Buscopan® is administered to r...
Pelvic ultrasound is usually the initial modality for imaging gynecologic pathology, including acute pelvic pain and chronic pelvic pain. The exam normally involves two components: a transabdominal (TA) evaluation and a transvaginal (TV) / endovaginal (EV) evaluation.
Normal ultrasound anatomy
The term pelvis (plural: pelvises or pelves) can refer to either the bony pelvis or the pelvic cavity.
The bony pelvis is formed by the sacrum and coccyx and a pair of hip bones ("ossa coxae"), which are part of the appendicular skeleton. Its primary function is the transmission of...
Getting a film with pregestational hemorrhage in the exam is one of the many exam set-pieces that can be prepared for.
Transabdominal and transvaginal (TV) pelvic ultrasound shows an anteverted uterus with an intrauterine gestational sac. MSD is 20 mm in TV study with a single, li...
Perinatal lethal hypophosphatasia (PLH) is the most severe form of hypophosphatasia. If untreated, it is lethal in all cases.
The estimated incidence is at ~1:100,000 live births.
As with all hypophosphatasia cases, this is due to a mutation in chromosome 1q3...
The perineum is a diamond-shaped region below the pelvic diaphragm and is divided by an imaginary line drawn between the ischial tuberosities into anteriorly the urogenital triangle and posteriorly the anal triangle.
The perineum is bounded by the pubis anteriorly, the ischial tu...
Peritoneal inclusion cysts, also known as peritoneal pseudocysts, are a type of cyst-like structure that appears in relation to the peritoneal surfaces and results from a non-neoplastic reactive mesothelial proliferation.
The nomenclature for this condition can be confusing due to ...
There are several periurethral cystic lesions. These include:
female genitourinary tract:
Gartner duct cyst
epidermal inclusion cyst of the vagina
Skene duct cyst
Bartholin gland cyst
endometrial cyst of perineal-vulval-vaginal region
male genitourinary trac...
Perivascular epithelioid cells tumors (PEComas) are a group of related mesenchymal tumors and tumor-like conditions found in many locations. This group includes:
clear cell 'sugar' tumor of the lung
clear cell myomelanocytic tumor (CCMMT)
A persistent right umbilical vein (PRUV) is an uncommon vascular anomaly which is often detected in utero.
The estimated prevalence is ~2 per 1000 births 1,2.
In the normal situation, the right umbilical vein begins to obliterate in the ~4th week of gestation and disap...
It is important to have a systematic way of approaching a case with per vaginal (PV) bleeding in the exam.
intrauterine fetal demise
PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET).
PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). Fluorine-18 (F-18) is an unstable radioisotope and has a half-...
Physiological gut herniation is a natural phenomenon that occurs in early pregnancy. It usually occurs from around 6-8 weeks up until 12-13 weeks in-utero, after which the bowel returns to the abdominal cavity.
It occurs as a result of the bowel (particularly ileum) growing faster ...
Physiological pelvic intraperitoneal fluid refers to the presence of a small volume of free fluid in the pelvis, particularly the pouch of Douglas. It occurs in young females of reproductive age and can be a mimic of traumatic free fluid in abdominal trauma.
Unfortunately, pelvic free fluid may...
Getting a film with placental abruption (premature separation of placenta from uterus) in the exam is one of the many exam set-pieces that can be prepared for.
Transabdominal and transvaginal pelvic ultrasound show a single live fetus with gestational age of 27 weeks. The cervix i...
Placental calcification has been considered a manifestation of “aging” of the placenta. It commonly increases with gestational age.
Delayed placental calcification
Accelerated placental calcification
normal placental maturity
maternal thrombotic disorder...
Placental chorioangiomatosis is an extremely rare condition where numerous placental chorioangiomas involve the placenta. The individual chorioangiomas can be of varying size.
Recognized complications include
precipitation of fetal hydrops 2
fetal cerebral emboli 1
Placental fusion is a phenomenon that can occur in a twin pregnancy. This can occur to varying degrees. Determination of chorionicity on ultrasound can sometimes be difficult if there has been a placental fusion.
In a DCDA pregnancy, there are no vascular anastomoses between the twin placentae...
Placental grading (Grannum classification) refers to an ultrasound grading system of the placenta based on its maturity. This primarily affects the extent of calcifications. In some countries, the use of placental grading has fallen out of obstetric practice due to a weak correlation with advers...
Placental infarction refers to a localized area of ischemic villous necrosis. It is a significant cause of placental insufficiency.
A localized infarction can occur in up to ~25% of all placental pathologies and approximately 5-20% of all gestations (on average 12.5%) 6.
Placental mosaicism is a situation where there discrepancy between the chromosomal makeup of the cells in the placenta. According to one study fetal mosaicism was found in 50% of cases with placental mosaicism. When the fetal cells are normal in chromosomal composition, this is then known as con...
Placental septal cysts are placental cysts typically located in the mid-placenta. It forms between the cotyledons of the placenta. The cysts contain gelatinous material and are usually 5-10 mm in diameter. They may be present in 10-20% of placentas from full-term uncomplicated pregnancies.
Placental site trophoblastic tumor (PSTT) is rare and one of the least common (~ 0.2% 7) forms of the gestational trophoblastic disease (GTD).
PSTT typically occurs in women of reproductive age with the average age around 30. It may occur after a normal pregnancy, molar pregnancy ...
Placental surface cysts are often related to cystic change in an area of subchorionic fibrin. They can be variable in size.
subchorionic cyst: commonest type 2
amniotic epithelial inclusion cyst
Treatment and prognosis
Most placental surface cysts are associated with a n...
A placental teratoma is a very rare placental tumor.
A placental teratoma is benign and almost never associated with congenital deformities in the fetus.
May show a heterogeneous mass at the placental margin. Hyperechoic foci consistent w...
Placental thickness tends to gradually increase with gestational age in a linear fashion. Sonographically, this can be seen to be approximately 1 mm per week and the thickness of the placenta can be used to approximate gestational age:
approximate gestational age (in weeks) = placental thicknes...
Placental trophotropism refers to a phenomenon where there is a dynamic migration of the placenta at its insertion through gestation. The placenta tends to grow in areas of good blood supply and nutrition and atrophies in areas with poor blood supply and poor nutrition. It may play a role in the...
There are many tumors that can involve the placenta.
These can be of very different pathology and can include
placental chorioangioma (considered the most common primary tumor of the placenta 1)
placental site trophobla...
Placentomegaly is a term applied to an abnormally-enlarged placenta.
It can be associated with a number of maternal and fetal disorders which include:
chronic intrauterine infections
Polycystic ovarian syndrome (PCOS), recently referred also as hyperandrogenic anovulation, is a chronic anovulation syndrome associated with androgen excess.
The diagnosis of PCOS generally requires any two of the following three criteria for the diagnosis, as well as the exclusion of other et...
Getting a film with polycystic ovarian syndrome in a subfertile patient is one of the many exam set-pieces that can be prepared for.
Transabdominal and transvaginal pelvic ultrasound show an anteverted uterus with a normal size. There is diffuse thickening of the endometrium to 17...
Polycystic ovaries (PCO) or polycystic ovarian morphology is an imaging descriptor of a particular type of change in ovarian morphology. A proportion of women with polycystic ovaries will have the polycystic ovarian syndrome (PCOS), which in turn requires additional clinical, as well as biochemi...
Polyhydramnios refers to a situation where the amniotic fluid volume is more than expected for gestational age.
It is generally defined as:
amniotic fluid index (AFI) >25 cm
largest fluid pocket depth (maximal vertical pocket (MVP)) greater than 8 cm 6: although some centers, particularly in ...
Polysyndactyly refers to the combined presence of polydactyly as well as syndactyly involving either the hands or feet.
Polysyndactyly can be associated with a number of syndromes which includes:
type I: Noack syndrome
type II: Carpenter syndrome (typically...
Popcorn calcification refers to amorphous calcifications often with rings and arcs that resemble popped corn kernels. This type of calcification may be seen in many radiological settings including 1:
chondroid lesions (e.g. enchondroma, chondrosarcoma)
Post-ablation tubal sterilization syndrome (PATSS) is a recognized delayed complication seen in patients who have undergone both endometrial ablation and tubal sterilization. It has been reported in 6-8% of these patients and occurs when bleeding from residual endometrium is obstructed due to su...
Post dates fetus or post-term pregnancy is when the gestation has extended 2 weeks beyond the expected date of delivery (>42 weeks gestation).
The reported prevalence is 7 % of pregnancies 3.
The etiology of post-term pregnancy is still unknown.
Research has shown th...
Posterior urethral valves (PUVs), also referred as congenital obstructing posterior urethral membranes (COPUM), are the most common congenital obstructive lesion of the urethra and a common cause of obstructive uropathy in infancy.
Posterior urethral valves are congenital and only...
Postpartum hemorrhage (PPH) refers to uterine bleeding after delivery and remains one of the major worldwide causes of maternal mortality.
A postpartum hemorrhage can be board classified as primary or secondary.
Primary postpartum hemorrhage
This is the most common ...
The Potter sequence is a constellation of findings demonstrated postnatally as a consequence of severe, prolonged oligohydramnios in utero.
It consists of:
pulmonary hypoplasia: often severe and incompatible with life
growth restriction (IUGR)
abnormal facies (Potter f...
Predominantly solid ovarian neoplasms account for a minority of ovarian neoplasms. They include a wide pathological spectrum:
epithelial tumors: ~28% of all solid ovarian tumors 1
germ cell tumors: ~22% 1
ovarian teratoma: noncystic type
sex cord / strom...
Premature rupture of membranes (PROM) refers to a rupture of the amniotic sac and chorion (membranes) occurring prior to the onset of uterine contractions. When this occurs prior to 37 weeks it is then termed a pre term premature rupture of membranes (PPROM). By this definition, PROM is classifi...
Primary fallopian tube carcinoma (PFTC) is an extremely rare malignancy that arises from the fallopian tube. They account for ~1 (0.2-1.1)% all gynecological malignancies (least common of all gynecological malignancies 3).
The estimated incidence is at ~3-4 per million women 3. It...
The staging used for primary fallopian tubal carcinoma is the FIGO system and is as follows:
stage I: limited to fallopian tubes
stage Ia: limited to lining of one fallopian tube (intraluminal)
stage Ib: limited to inner linings of both tubes (intraluminal)
stage Ic: invasion beyond the inne...
A primary fetal hydrothorax (PFHT) is a rare situation and refers to a primary accumulation of fetal pleural fluid without any underlying abnormality. It can present with a wide spectrum of severity and can be uni or bilateral.
The estimated prevalence is at ~ 1:10,000-15,000 preg...
Primary ovarian lymphoma (POL) refers to involvement of the ovary with lymphoma but without the involvement of any other site. It is an extremely rare yet well-recognized condition.
POL accounts for ~1.5% of ovarian tumors 5.
The rarity of this condition is probably in...
Primary peritoneal neoplasms comprise an uncommon group of heterogeneous entities, which include:
primary (malignant) peritoneal mesothelioma
peritoneal multicystic mesothelioma
primary peritoneal well-differentiated papillary mesothelioma
primary peritoneal adenomat...
A primary serous papillary carcinoma of the peritoneum (PSPCP) is an extremely rare primary peritoneal tumor.
They usually present in postmenopausal women.
Patients tend to present with non-specific complaints such as abdominal pain, anorexia, and abdominal...
Primary vaginal carcinoma, although being a rare overall, is still the 5th commonest gynecological malignancy. A primary vaginal carcinoma is defined as a neoplasm that arises solely from the vagina with no involvement of the external os superiorly or the vulva inferiorly, the importance of this...
Primary vulval cancer is a rare gynecological malignancy that originates from the vulva.
It accounts for ~3-5% of female genital tract malignancies and typically presents in postmenopausal patients peaking around the age of 65-70 years of age 1.
The commonest histolog...
Proboscis is a rare congenital anomaly where an anterior appendage-like structure is seen projecting from the midline fetal face/forehead. Depending on the exact location, this has further been classified into various subtypes (e.g. interorbital proboscis).
Prolonged rupture of membranes refers to a rupture of membranes lasting longer than 18-24 hours (i.e. between time of rupture and time of delivery) 1-2. This situation can occur in either the term or pre-term newborns where in the latter case it is also termed prolonged preterm rupture of membra...
Psammoma bodies are round microscopic calcific collections. It is a form of dystrophic calcification. Necrotic cells form the focus for surrounding calcific deposition. They have a lamellated concentric calcified structure, sometimes large enough to be seen on CT.
Psammoma bodies are found in ...
A pseudodysraphism refers to the splayed appearance of a normal spine created due to excessive craniocaudal angulation during sonographic evaluation. This can erroneously lead to the diagnosis of a spinal neural tube defect.
Pseudo Meigs syndrome refers to a clinical syndrome of pleural effusion, ascites associated with an ovarian tumor that is not a fibroma or a fibroma-like tumor.
Entities that have been reported to result in pseudo Meigs syndrome include
colon carcinoma metastases ...
The pubococcygeal line (PCL) is a reference line for the pelvic floor on imaging studies and helps detect and grade pelvic floor prolapse in defecography studies. It is defined as a line that joins the inferior border of the symphysis pubis to the final coccygeal joint and it is drawn in a midli...
Pulmonary hypoplasia (PH) refers to deficient or incomplete development of parts of the lung. It can develop as a result of a number of other in utero anomalies.
The true prevalence is not well known (1.4% of all births according to Knox et al. 13), but in cases of premature ruptu...
A pure primary ovarian choriocarcinoma is an extremely rare form of ovarian malignancy. It falls under the subcategory of ovarian germ cell tumors.
They are thought to account for less than 1% of ovarian tumors.
They are a type of non gestational choriocarcinoma. As wi...
Pyometrium refers to infection of the endometrial cavity with resulting expansion due to accumulated pus (pyometra).
The postmenopausal demographic are most commonly affected due to the association with uterine malignancy.
endometritis / pelvic inflammatory disease
Pyosalpinx refers to a Fallopian tube that is filled, and often distended, with pus.
A pyosalpinx often tends to be a complication of background pelvic inflammatory disease (PID). Inflammation results in tubal and peritubal adhesions with superimposed obstruction of the fimbrial end....
Pyrexia (or fever) is a clinical sign, indicated by an abnormally elevated core body temperature, which is defined by several medical societies as ≥38.3°C (≥≈101°F). The temperature elevation may be persistent or episodic. If the body temperature is greater than 41.5°C - a rare phenomenon - it i...
Rectovaginal fistulae are a type of colovaginal fistula where there is an abnormal fistulous connection between the rectum and the vagina. It is considered the most common gastrointestinal fistula involving the female genital tract 1.
They can occur from a number of causes that inclu...
Retained products of conception (RPOC) refer to the persistence of placental and/or fetal tissue in the uterus following delivery, termination of pregnancy or a miscarriage.
RPOC complicate ~1-5% of all routine vaginal deliveries 12.
According to one prospective study, RPOC was ...
A retroverted uterus is a normal variation of female pelvic anatomy in which the body of the uterus is tilted backwards (usually leans forward, i.e. anteverted) on itself to match the isthmus of the neck and lower uterine segment. There are variable grades of uterine retroversion.
Rhizomelic dwarfism is a type of dwarfism where the dominant feature is proximal (i.e. femoral and humeral) limb shortening.
certain types of atelosteogenesis
The following conditions fall under the heading of...
Right iliac fossa mass is a common clinical presentation and has a range of differentials that need to be excluded. Radiology plays an important role in this differentiation.
The ring of fire sign, also known as ring of vascularity, signifies a hypervascular lesion with peripheral vascularity on color or pulsed Doppler examination of the adnexa due to low impedance high diastolic flow 1.
This sign can be seen in:
corpus luteum cyst (more commonly)
The risk of malignancy index (RMI) in ovarian tumors is a validated clinical tool used for risk stratification of ovarian lesions, to guide further management 1-3.
The score incorporates the patient's menopausal status (M), ultrasound features of the lesion (U), and the serum CA...
Robinow syndrome is a rare heterogeneous genetic disorder with at least two distinct forms.
The syndrome can affect several systems, including:
mesomelic limb shortening: mesomelia
characteristic facies anomalies
A Rokitansky nodule or dermoid plug refers to a solid protuberance projecting from an ovarian cyst in the context of mature cystic teratoma. It often contains calcific, dental, adipose, hair, and/or sebaceous components 1. This region has the highest propensity to undergo malignant transformatio...
The round ligament is one of the supporting structures of the uterus. It has a function in uterine anteflexion.
It is part of the embryologic remnant of the gubernaculum.
It is a rope-like fibromuscular band which extends from the anterolateral aspect of the uterus a...
Rubinstein-Taybi syndrome (RTS) is a very rare genetic multi-system disorder primarily characterized by intellectual disability, broad and often angulated thumbs and halluces, and distinctive facial features.
The estimated incidence is 1 in 100,000-125,000 live births 5.
Ruptured ovarian cysts are one of the most common causes of acute pelvic pain in premenopausal women. The sonographic appearance depends on whether a simple or hemorrhagic ovarian cyst ruptures, and whether the cyst has completely collapsed. The most important differential consideration is a rup...
A rupture of membranes (ROM) or amniorrhexis is a term used during pregnancy to describe a rupture of the amniotic sac. This can occur as part of normal birth (or "spontaneously") if it occurs at full term at the onset of, or during, labor. It is also colloquially known as "breaking water."
Russell-Silver dwarfism is a very rare syndrome representing a form of primordial dwarfism.
single umbilical artery
intrauterine growth restriction: tends to give an asymmetrical IUGR
postnatal growth restriction
relatively large calvarium: ...
Sacrococcygeal teratoma (SCT) refers to a teratoma arising in the sacrococcygeal region. The coccyx is almost always involved 6.
It is the commonest congenital tumor in fetus 11 and neonate 3. The incidence is estimated at ~1:35000-40000. There is recognized female predilection wi...
Salpingitis refers to inflammation of the fallopian tube, it can be a part of pelvic inflammatory disease.
salpingitis isthmica nodosa
Salpingitis isthmica nodosa (SIN), sometimes also referred to as perisalpingitis isthmica nodosa or diverticulosis of the Fallopian tube, refers to nodular scarring of the Fallopian tubes. In very early stages, the tubes may appear almost normal. As scarring and nodularity progress, the changes ...
Sampson syndrome refers to a type of superficial endometriosis, where multiple superficial plaques may be seen scattered in the peritoneum and pelvic ligaments.
The patient may present with non-specific abdominal pain.
At laparoscopy, they are typi...
A sandal gap deformity, also known as hallux varus, is an imaging observation in antenatal ultrasound (typically second trimester) where there is an expanded first interspace, i.e. the gap between the great toe of the foot from the rest of the toes (likened to the gap caused by a sandal).
Scar endometriosis is a term given to endometriosis occurring in a Cesarian section scar. It can be located in the skin, subcutaneous tissue, rectus muscle/sheath, intraperitoneally, or in the uterine myometrium (within uterine scar).
The reported incidence of abdominal scar endom...
Sclerosing stromal tumor (SST) of the ovary is a rare ovarian neoplasm. It is considered a subtype of ovarian sex cord / stromal tumor and is included in the fibroma-thecoma group of ovarian tumors 9.
It occurs predominantly in young women and its incidence peaks around the 2nd to...
Secondary involvement of the ovary with lymphoma is more common than primary ovarian lymphoma. It usually occurs as a late manifestation of advanced systemic disease and is almost always of the non-Hodgkin type.
Semilobar holoprosencephaly is a subtype of holoprosencephaly characterized by incomplete forebrain division. It is intermediate in severity, being worse than lobar holoprosencephaly and better than alobar holoprosencephaly.
Please refer to the general article of holoprosencephaly...
A septate uterus is a common type of congenital uterine anomaly, and it may lead to an increased rate of pregnancy loss. The main imaging differential diagnoses are arcuate uterus and bicornuate uterus.
It is considered the commonest uterine anomaly (accounts for ~55% of such anom...
Serous inclusion cysts of the ovary are benign cysts typically seen in postmenopausal women. They are typically small (i.e. less than 5 cm), smooth walled and have no septations or solid components. They can alter through time and often disappear.
Sex cord / stromal ovarian tumors are a subtype of ovarian tumors and account for 8-10% of all ovarian tumors. They arise from two groups of cells in the ovary:
primitive sex cords: celomic epithelium
The group of tumors includes
ovarian fibroma-thecoma spectrum
Shading sign is an MRI finding typically seen in an endometrioma. It may also be seen with some endometrioid tumors (e.g endometrioid carcinoma of the ovary).
It helps to distinguish endometriomas from other blood-containing lesions (e.g. hemorrhagic corpus luteum cysts), with a sensitivity of ...
Shorted fetal femur is a morphological descriptor and is usually defined when the femoral length falls below the 5th centile for gestational age (some define it when it is under the 2.5th centile 5) or less than 0.91 predicted by the biparietal diameter (BPD). It can occur in isolated or in asso...