LAST CHANCE: X-ray Interpretation: Elbow Injuries - Half price course offer ends this Sunday!

Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

981 results found
Article

Cystic partially differentiated nephroblastoma

Cystic partially differentiated nephroblastomas are rare pediatric cystic renal tumors. They are distinct from pediatric nephromas although they have very similar imaging appearances. Terminology Evolving terminology regarding cystic nephromas and other cystic renal tumors reflects ongoing cha...
Article

Cystic renal diseases

Cystic renal disease can be confusing. There are many conditions, many of which have similar names or are eponymous, and with a few exceptions, are relatively rare. It is easiest to think of them into two separate demographic: pediatric cystic renal diseases adult cystic renal disease
Article

Cystic renal dysplasia

Cystic renal dysplasia refers to a subgroup of congenital anomalies of the kidney and urinary tract characterized by the dysplastic renal parenchyma and formation of cysts. The most severe form is multicystic dysplastic kidney, in which functional renal parenchyma is absent and only undifferenti...
Article

Cystic renal tumors

Cystic renal neoplasms  comprise of heterogeneous group of renal tumors. They can have variable biological profiles. They may be purely cystic or could be cystic with solid components. They include Benign renal lymphangioma cystic nephroma mixed epithelial and stromal tumor of kidney Malig...
Article

Cystic retroperitoneal lesions

Cystic retroperitoneal lesions can carry a relatively broad differential, which includes: retroperitoneal lymphatic malformation retroperitoneal mucinous cystadenoma retroperitoneal cystic teratoma retroperitoenal cystic mesothelioma pseudomyxoma retroperitonei with cystic change perianal ...
Article

Cystinosis

Cystinosis, also known as Abderhalden Kaufmann Lignac syndrome, is the most common hereditary cause of renal Fanconi syndrome. Cystinosis is one of the lysosomal storage disorders.  Epidemiology It has a reported incidence of 1:192,000 1. Cystinosis is typically diagnosed in infancy.  Clinica...
Article

Cystinuria

Cystinuria is an inherited condition in which there is an excess of cystine in the urine. This excess predisposes to the formation of cysteine stones. Terminology "Cysteine" refers to the amino acid. "Cystine" is the oxidized dimer of the amino acid. Epidemiology It is thought to occur in 1:...
Article

Cystitis cystica

Cystitis cystica is the same condition as ureteritis cystica and closely related to cystitis glandularis. It is a relatively common chronic reactive inflammatory disorders that occur in the setting of chronic irritation of the bladder mucosa. Epidemiology Cystitis cystica is seen in a variety ...
Article

Cystitis glandularis

Cystitis glandularis is a proliferative disorder of the urinary bladder in which there is glandular metaplasia of the transitional cells lining the urinary bladder. This entity is closely related to cystitis cystica, with which it commonly co-exists. It is a relatively common chronic reactive in...
Article

Cystocele

A cystocele, also known as a prolapsed bladder, is a form of pelvic organ prolapse where the bladder descends inferiorly and posteriorly into the vagina and perineum. It may be accompanied by prolapse of other pelvic organs. Radiographic features CT / MRI  Sagittal images are particularly use...
Article

Cystography

Cystography is a fluoroscopic study that images the bladder. It is similar to a voiding cystourethrogram (VCUG), and the difference between the studies is primarily one of emphasis; a cystogram focuses on the bladder and a VCUG focuses on the posterior urethra. The study has been adapted to CT a...
Article

Cystolithotomy

Cystolithotomy is a urologic procedure to remove one or more bladder stones. It is typically performed for a patient with large or numerous bladder stones or if an endoscopic approach has not been successful.  The traditional approach described below is an open cystolithotomy. Other approaches...
Article

Dancing megasperm

Dancing megasperm is the ultrasound finding of continuously oscillating/mobile tiny echogenic foci within dilated tubules of the epididymis. This is seen in post-vasectomy patients and others with obstruction of the spermatic cord and is thought to represent clumps/clusters of trapped spermatozo...
Article

Dartos muscle

The dartos muscle is the thin rugated fascial muscle of the scrotum made of smooth muscle. Hence it is also referred to as dartos fascia or simply the dartos. It forms from the subcutaneous tissue of the scrotum and base of the penis and attaches to the scrotal skin and fibrous midline septum be...
Article

Deep inguinal lymph nodes

The deep inguinal lymph nodes (often shortened to the deep inguinal nodes) form a subgroup of the inguinal lymph node group, and are located within the femoral sheath, medial to the femoral vein. They receive afferent lymphatic drainage from the deep lymphatics of the distal lower extremity and ...
Article

Deep perineal pouch

The deep perineal pouch is an anatomic space superior (deep) to the perineal membrane in the urogenital triangle of the perineum, anterior to the transverse line between the ischial tuberosities. Gross anatomy The deep perineal pouch is above (deep to) the perineal membrane in the urogenital t...
Article

Deep transverse perineal muscle

The paired deep transverse perineal muscles (TA: musculus transversus profundus perinei) lie in the perineum and are important for stabilizing the perineal body. Summary origin: ischial ramus insertion: the fibers of each muscle meet in the midline at the perineal body and decussate to intert...
Article

Delayed nephrogram

A delayed nephrogram, commonly described on plain film urography, but also visible on CT urography, is when there is absence or reduction of the normal renal parenchymal enhancement on nephrographic phase images. Terminology A delayed nephrogram is characteristically unilateral and is usually ...
Article

Detrusor muscle

The detrusor muscle (or detrusor urinae muscle)is the smooth muscle component of the urinary bladder and facilitates contraction of the bladder wall during micturition. Gross anatomy Forms the smooth muscle component of the bladder wall. The urothelial lining overlies it within the bladder cav...
Article

Developmental anomalies of the kidney and ureter

Developmental anomalies of the kidneys and ureters are numerous and not only potentially render image interpretation confusing but also, in many instances, make the kidneys more prone to pathology: number renal agenesis supernumerary kidney fusion horseshoe kidney: most common cross fused ...
Article

Diabetes insipidus

Diabetes insipidus (DI) is the deficiency or resistance to the hormone vasopressin (antidiuretic hormone), which results in polyuria and polydipsia.  Epidemiology DI occurs in 3 per 100,000 people 2.  Pathology DI may be described as 1-3: central/neurogenic/hypothalamic: vasopressin deficie...
Article

Dialysis disequilibrium syndrome

The dialysis disequilibrium syndrome (DDS) is a situation characterized by development of neurological symptoms following the rapid removal of urea during hemodialysis. It develops primarily from an osmotic gradient that develops between the brain and the plasma as a result of rapid haemodialysi...
Article

Diverticulum

Diverticula are outpouchings of a hollow viscus and can be either true or false. Occasionally a diverticulum is used in a more general sense to mean the outpouching of other anatomical structures, e.g. frontal intersinus septal cells are hypothesized to form as diverticula from the frontal sinu...
Article

Dorsal nerve of penis or clitoris

Dorsal nerve of penis or clitoris is one of the two terminal branches of the pudendal nerve that arises from nerve whilst in the pudendal canal. The other terminal branch is the perineal nerve.  Gross anatomy Course Entering the urogenital triangle of the perineum, the dorsal nerve of penis o...
Article

Double contrast cystography

Double contrast cystography (pneumocystography) is an older technique to evaluate the bladder lumen. It has rarely been used (if ever) after the advent of cross-sectional imaging. The exam is performed similarly to a conventional cystogram, but gas is also introduced through the Foley catheter....
Article

Double retroaortic left renal vein

Double retroaortic left renal vein is a very rare entity that is usually clinically silent and detected incidentally at imaging, surgery, or autopsy. The knowledge of anatomical variations helps the surgeon or interventionist to avoid complications during surgery and interventional procedures 4...
Article

Drash syndrome

Drash syndrome, also known as the Denys-Drash syndrome, is associated with an abnormal WT1 gene (Wilms tumor gene) and consists of: Wilms tumor male pseudohermaphroditism progressive glomerulonephritis
Article

Dromedary hump

Dromedary humps are prominent focal bulges on the lateral border of the left kidney. They are normal variants of the renal contour, caused by the splenic impression onto the superolateral left kidney. Dromedary humps are important because they may mimic a renal mass, and as such is considered a...
Article

Drooping lily sign (ureter)

The drooping lily sign is a urographic sign in some patients with a duplicated collecting system. It refers to the inferolateral displacement of the opacified lower pole moiety due to an obstructed (and unopacified) upper pole moiety. The similarity to a lily is further strengthened by the smal...
Article

Drooping moustache sign (endopelvic fascial defect)

The drooping moustache sign refers to the appearance caused on axial pelvic MR images by posterior prolapse of the fat in the retropubic space, akin to the drooping corners of a moustache, due to loss of integrity of the urethral suspensory ligaments and level 3 endopelvic fascia.
Article

Drug-induced renal calculi

Drug-induced renal calculi are a subtype of renal calculi, whereby the stone formation is related to the patient's medication. Two main types of drug-induced calculi are described: medication-containing metabolically-induced Epidemiology Overall drug-induced urolithiasis accounts for 1-2% o...
Article

Ductus deferens

The ductus deferens (plural: ductus deferentes) forms part of the male internal genitalia where it transports sperm from the epididymis to the ejaculatory duct. In modern anatomic nomenclature, it is no longer referred to as the vas deferens (plural: vasa deferentia). Gross anatomy The ductus ...
Article

Ductus deferens calcification

Calcification of the ductus deferens can result from: diabetes mellitus 4 - most common normal aging chronic infection - more frequently irregular; unlike diabetic calcification, inflammatory calcification tends to be unilateral and segmental 3 tuberculosis syphilis gonorrhea schistosomia...
Article

Ductus deferens cyst

A ductus deferens cyst (also known as a vas deferens cyst) is a type of juxtaprostatic - extraprostatic cyst. They are usually located along the course of the ductus deferens and superior to the prostate. They can arise from congenital abnormalities of the vas deferens or acquired causes such as...
Article

Duplex collecting system

A duplex collecting system, or duplicated collecting system, is one of the most common congenital renal tract abnormalities. It is characterized by an incomplete fusion of upper and lower pole moieties resulting in a variety of complete or incomplete duplications of the collecting system. While ...
Article

Dynamic contrast enhancement in prostate cancer

Dynamic contrast enhancement (DCE) MRI is a component of a multiparametric MRI approach for evaluating the extent of primary and recurrent prostate cancer.  Protocol and equipment Typically 3D T1-weighted fast spoiled gradient-echo MRI sequences are used to repeatedly image a volume of interes...
Article

Echogenic renal pyramids (differential)

Echogenic renal pyramids in children can be due to many different causes.  Differential diagnosis Nephrocalcinosis Iatrogenic (most common cause) furosemide (frusemide) vitamin D steroids Non-iatrogenic idiopathic hypercalcemia Williams syndrome hyperparathyroidism milk-alkali syndrom...
Article

Ectopic kidney

An ectopic kidney, also known as renal ectopia, is a congenital renal anomaly characterized by the abnormal location of one or both of the kidneys. They can occur in several forms: cross fused renal ectopia ectopic thoracic kidney pelvic kidney Epidemiology The estimated incidence of an ec...
Article

Ectopic testis

Ectopic testes are a rare congenital anomaly, differing from undescended testis (cryptorchidism) in that ectopic testis is a congenitally abnormally located testis, that has descended from the abdominal cavity away from the normal path of descent while undescended testis are congenitally abnorma...
Article

Ectopic ureter

An ectopic ureter is a congenital renal anomaly that occurs as a result of abnormal caudal migration of the ureteral bud during its insertion to the urinary bladder. Normally the ureter drains via the internal ureteral orifice at the trigone of the urinary bladder.  In females, the most common ...
Article

Ejaculatory duct

The ejaculatory ducts are paired structures of the male reproductive system and convey seminal fluid. Gross anatomy Each ejaculatory duct is formed by the union of the excretory duct of the seminal vesicle and the ampulla of the ductus deferens and is approximately 2 cm long. The ducts course ...
Article

Ejaculatory duct cyst

Ejaculatory duct cysts are a rare type of cyst of the prostate gland. Pathology They occur due to obstruction of the ejaculatory duct which in turn can either be congenital or secondary (e.g. inflammation). They are usually intraprostatic when small but may extend cephalad when large. Radiog...
Article

Ejaculatory duct obstruction

Ejaculatory duct obstruction refers to the congenital or acquired obstruction of the ejaculatory ducts. Epidemiology Ejaculatory duct obstruction is rare, accounting for approximately 5% of infertile patients, but thought to be underdiagnosed 2. Clinical presentation Patients may complain ab...
Article

Ejaculatory pathway of sperm (mnemonic)

A useful mnemonic to remember the ejaculatory pathway of sperm is: SEVEN UP Mnemonic S: seminiferous tubules of the testes E: epididymis V: vas (ductus) deferens E: ejaculatory duct N: nothing U: urethra P: penis
Article

Emphysema (disambiguation)

Emphysema refers to any disease process involving an abnormal accumulation of air/gas in the tissues. When used alone, it is usually taken to mean the lung disease, pulmonary emphysema, which forms part of the spectrum of chronic obstructive pulmonary disease (COPD).  gastric emphysema: include...
Article

Emphysematous cystitis

Emphysematous cystitis refers to a gas-forming infection of the bladder wall. Epidemiology The condition is rare and usually confined to certain patient subgroups. Median age affected is 66 years. More common in women, 2:1 F:M 9. Risk factors Risk factors include: diabetes mellitus conside...
Article

Emphysematous epididymo-orchitis

Emphysematous epididymo-orchitis is a rare gas-forming epididymo-orchitis. The pathology of this condition is unknown. The diagnosis is usually made by ultrasonography with CT as an adjunct, to confirm the diagnosis, evaluate its extent and to rule out a coexistent retroperitoneal infective focu...
Article

Emphysematous prostatitis

Emphysematous prostatitis refers to gas-forming infection of the prostate, nearly always occurring concurrently with prostatic abscess. Epidemiology The condition is rare, most commonly presenting in males aged 50-70 years and usually confined to certain patient subgroups 1,2. Risk factors R...
Article

Emphysematous pyelitis

Emphysematous pyelitis is isolated gas production inside the excretory system, secondary to acute bacterial infection. It is a relatively benign entity and needs accurate differentiation from the far more serious emphysematous pyelonephritis, which is gas production from an infection in the rena...
Article

Emphysematous pyelonephritis

Emphysematous pyelonephritis (plural: emphysematous pyelonephritides) refers to a morbid infection with particular gas formation within or around the kidneys. If not treated early, it may lead to fulminant sepsis and, therefore, carries a high mortality. Clinical presentation The patient usual...
Article

Empyema

Empyemas are purulent inflammatory collections within a body cavity. Contrast this with abscesses, which arise within parenchymal tissue, rather than occupying a pre-existing anatomical space. Terminology Colloquially, the standalone term empyema is used to refer to thoracic empyemas but there...
Article

Endometrial carcinoma (staging)

Endometrial carcinoma staging allows appropriate treatment options to be considered and enables greater prognostic accuracy for endometrial carcinoma.  Staging Staging can be based on the TNM or FIGO system.  MR imaging is the modality of choice for staging with CT having relatively low speci...
Article

Endopelvic fascia

The endopelvic fascia is the enveloping connective tissue network for the pelvic viscera, suspending, supporting and fusing the pelvic organs to the arcus tendineus fasciae pelvis, which itself inserts onto the pelvic sidewalls and pubic bones. The major anterior component is the pubovesical li...
Article

End-stage kidney disease

End-stage kidney disease (ESKD), also referred as end-stage renal failure, corresponds to the last stage of chronic kidney disease (stage 5), when the kidneys' function is no longer sufficient to sustain life (GFR <15 mL/min/1.73m2) and kidney replacement therapy (dialysis or transplant) is requ...
Article

Eosinophilic ureteritis

Eosinophilic ureteritis (and eosinophilic pyelouerteritis) is a rare cause of ureteral inflammation. The clinical presentation and imaging features are non-specific. Clinical presentation Patients are usually atopic or hypereosinophilic with peripheral eosinophilia. Associated with eosinophil...
Article

Epidermoid cyst

Epidermoid cysts are nonneoplastic inclusion cysts derived from ectoderm that are lined solely by squamous epithelium. These are discussed separately by anatomic location: epidermal inclusion cyst intracranial epidermoid cyst splenic epidermoid cyst spinal epidermoid cyst testicular epiderm...
Article

Epididymal abscess

An epididymal abscess is an uncommon complication of epididymitis. Pathology Causative organisms are the same that cause epididymitis: older individuals Escherichia coli Proteus mirabills younger individuals  Chlamydia trachomatis Neisseria gonorrhoeae Other rare etiological agents St...
Article

Epididymal appendix

Epididymal appendices, also known as appendix of the epididymis or appendix epididymis, are an testicular appendage found at the head of the epididymis 1. They represent a developmental remnant of the mesonephric duct (Wolffian duct). In 78% of the cases, it has a stalk configuration and is thus...
Article

Epididymal calcification

Epididymal calcification can be seen on ultrasound as hyperechoic foci within the epididymal head. If the calcifications are large enough, then they may demonstrate acoustic shadowing. Differential diagnosis chronic epididymitis, e.g. bacterial, granulomatous (TB) or genital filariasis  traum...
Article

Epididymal cyst

Epididymal cysts are the most common epididymal mass. Epidemiology Epididymal cysts have been reported in ~30% (range 20-40%) of asymptomatic individuals 5. Pathology They are usually of lymphatic origin 2. The cysts contain clear serous fluid, lymphocytes, spermatozoa and debris. Clinical ...
Article

Epididymal leiomyoma

Epididymal leiomyomas (fibrous pseudotumors) are uncommon smooth muscle tumors that do not have malignant potential. Their imaging features are not specific and, if small, it may be a difficult prospective diagnosis on imaging. They are usually encountered in a differential for epididymal/parate...
Article

Epididymal lesions

Epididymal lesions are most commonly encountered on ultrasonography. Most epididymal lesions are benign; malignant lesions are rare. They can comprise of  Benign solid lesions adenomatoid tumor of the scrotum: most common epididymal mass 4 epididymal leiomyoma papillary cystadenoma of the e...
Article

Epididymis

The epididymis (plural: epididymides) is situated adjacent to the testis within the scrotal sac. Its primary function is the collection, maturation and transport of sperm via the ductus deferens. Gross anatomy The epididymis is an elongated structure, posterolateral to the testis. It can be su...
Article

Epididymitis

Epididymitis refers to inflammation of the epididymis and may be associated with inflammation extending to the testis itself, in which case the term epididymo-orchitis is used. This should be distinguished from isolated orchitis, which is by comparison much less common.  Epidemiology There are...
Article

Epispadias

Epispadias is a rare congenital anomaly that is almost always associated with bladder exstrophy.  Epidemiology It occurs in 1 in 30,000 births, with a male: female ratio of 3:1. Clinical presentation The roof of the urethra is absent and the urethra opens anywhere between the base and the gl...
Article

Epithelioid angiomyolipoma of kidney

Epithelioid angiomyolipomas (EAML) are rare variants of the more common renal angiomyolipoma. They have malignant potential. Pathology Like more common renal angiomyolipomas, EAMLs are considered perivascular epithelioid cell tumors (PEComas). EAMLs were regarded as a separate renal mass entit...
Article

Erased charcoal sign (prostate cancer)

The erased charcoal sign describes the typical appearance of focal prostate cancer in the transition zone characterized as homogeneous hypointensity on T2WI with ill-defined borders, akin to a charcoal pencil drawing smudged with an eraser, often with a lenticular or waterdrop-like shape.
Article

Erectile dysfunction

Erectile dysfunction is a common condition. Doppler ultrasound is a highly accurate means of assessing patients with erectile dysfunction.  Pathology Psychological factors (mental impulse) cause transmission of parasympathetic impulses to the penis. This causes relaxation of arterioles and cor...
Article

Estimated glomerular filtration rate

The estimated glomerular filtration rate (eGFR) is widely used as a surrogate marker of renal function and is mathematically-derived from the patient's serum creatinine, using their age, sex and ethnicity.  Calculation The eGFR is calculated using a four variables Modification of Diet in Renal...
Article

External iliac lymph nodes

The external iliac lymph nodes can be found surrounding the external iliac artery and act as the draining nodes for several regions of the pelvis and lower limb.  Gross anatomy The external iliac lymph nodes lie anterior to the internal iliac lymph nodes and usually form three separate subgrou...
Article

Extra-adrenal myelolipoma

Extra-adrenal myelolipomas are extremely rare myelolipomas that occur outside the adrenal glands, with the most common sites being the retroperitoneum (especially presacral region), perirenal space and the thorax. Epidemiology The exact incidence is unknown. Less than 60 reported cases were re...
Article

Extracorporeal shock wave lithotripsy

Extracorporeal shock wave lithotripsy (ESWL) is a common non-invasive treatment for urolithiasis, and less commonly for pancreatic or salivary ductal stones 4. It is less successful in obese patients and with stones >2 cm. Children respond equally well or better to ESWL than adults 5. The princ...
Article

Extramammary Paget disease

Extramammary Paget disease (EMPD) is the rarer non-breast form of Paget disease of the nipple. It is considered a form of adenocarcinoma of the apocrine glandular tissue. In men, the penis and scrotum are most frequently involved, and in women the vulva. Nodal and distant organ metastatic diseas...
Article

Extraprostatic extension of prostate cancer

Extraprostatic (extracapsular) extension of prostate cancer refers to local tumor growth beyond the fibromuscular pseudocapsule of the prostate gland into the periprostatic soft tissues, in particular, the periprostatic fat and is an established adverse prognostic factor and of importance for pr...
Article

Extrapulmonary tuberculosis

Extrapulmonary tuberculosis (TB) refers to the hematogenous spread of Mycobacterium tuberculosis. Pathology Extrapulmonary tuberculosis can occur as a primary form of the disease, i.e. direct infection of an extrapulmonary organ without the presence of primary pulmonary tuberculosis or it can ...
Article

Extrarenal pelvis

Extrarenal pelvis refers to the presence of the renal pelvis outside the confines of the renal hilum; it is a normal anatomic variant. Epidemiology It is found in ~10% of the population 2.  Radiographic features Ultrasound An extrarenal pelvis usually appears dilated, erroneously suggesting...
Article

Extratesticular cystic lesions (differential)

The differential diagnosis for extratesticular cystic lesions includes: hydrocele epididymal cyst spermatocele hematoma hematocele loop of bowel from an inguinal hernia abscess pyocele post-vasectomy varicocele Very rarely, a scrotal mesothelioma may present as a cystic mass.
Article

Extratesticular scrotal mass (differential)

Extratesticular scrotal masses (non-testicle and non-epididymis) are mostly mesenchymal in origin and benign 1.  Benign lesions lipoma (most common) leiomyoma of the scrotum neurofibroma granular cell tumor angiomyofibroblastoma-like tumor fibrous pseudotumor fibrous hamartoma of infancy...
Article

Faceless kidney

A faceless kidney refers to one in which the normal appearance of the renal sinus on cross-sectional imaging is absent. It was initially described as a sign of duplication of the collecting system 1 (a slice obtained between the two collecting systems will not demonstrate the normal components o...
Article

Falling snow sign (spermatocele)

The falling snow sign describes the appearance of movement of internal echoes in spermatoceles away from the transducer, resulting in an appearance similar to falling snow when color Doppler is applied. The sign can be used to aid in the diagnosis of a spermatocele.
Article

Fallopian (disambiguation)

The eponym Fallopian may refer to: Fallopian canal (facial nerve canal) Fallopian tube (uterine duct) Fallopian ligament (inguinal ligament) History and etymology It is named after Gabriele Falloppio (also known by his Latin name Fallopius), Italian anatomist (1523-1562).
Article

Fanconi syndrome

Fanconi syndrome describes generalized proximal renal tubule dysfunction causing impaired reabsorption of many urinary solutes.  Clinical presentation Clinical features include poor growth, fatigue, dehydration, polyuria, muscle weakness, and bone pain. Features on a basic blood panel include ...
Article

Fat containing renal lesions

There are numerous fat-containing renal lesions, including: renal angiomyolipoma renal cell carcinoma (often has calcifications when contains macroscopic fat) Wilms tumor renal oncocytoma renal or perirenal lipoma/liposarcoma Non-mass lesions may also occasionally contain fat: renal junct...
Article

Female prostate sign

Female prostate sign is a characteristic imaging sign seen in patients with a large urethral diverticulum.  A large urethral diverticulum in females surrounds the urethra, and elevates the base of the bladder, mimicking the typical appearance of enlarged prostate in males.
Article

Female pseudohermaphroditism

Female pseudohermaphroditism (FPH) is a form of disorder of gender development.  Pathology Patients with female pseudohermaphroditism have female internal genitalia and female karyotype (46 XX) with various degree of external genitalia virilization. Causes  congenital adrenal hyperplasia (CA...
Article

Female urethra

The female urethra is a simple short tube, that transports urine out of the body, extending from the internal urethral orifice of the bladder to the external urethral orifice in the vestibule of the vagina.  Gross anatomy The female urethra measures approximately 4 cm in length. It is embedded...
Article

Fetal cystic renal disease

Fetal cystic renal disease can be in included in three of the four types classified according the system by Osathanondh and Potter 1: Potter type I: infantile polycystic kidney disease Potter type II: multicystic dysplastic kidneys Potter type III: adult polycystic kidney disease Potter type...
Article

Fetal hydrocele

A fetal hydrocele refers to a hydrocele present in utero. Epidemiology They may be sonographically identified in ~15% of male fetuses in the third trimester 6. Pathology Often result from a patent processus vaginalis. They are more frequently unilateral.  Associations hydrops fetalis meco...
Article

Fetal hydronephrosis

Fetal hydronephrosis represents the abnormal dilatation of the fetal renal collecting system, with pelviureteric junction obstruction the most commonly encountered cause.  Please, refer to the article on fetal pyelectasis for a dedicated discussion on this relatively common and usually benign f...
Article

Fetal megacystis

Fetal megacystis refers to the presence of an unusually large bladder in a fetus.  Epidemiology The estimated incidence of antenatal imaging is at ~1:1500 pregnancies. Pathology It can result from a number of causes but the main underlying mechanism is either distal stenosis or reflux. Asso...
Article

Fetal pyelectasis

Fetal pyelectasis refers to the prominence of the renal pelvis in utero that is a relatively common finding, which in the majority of cases resolves spontaneously.  Please refer to the article on fetal hydronephrosis for a continued discussion on this matter.  Terminology  Although there is a...
Article

Fetal urachal cyst

A fetal urachal cyst refers to a urachal cyst occuring in utero. It may or may not communicate with the vertex of the fetal bladder. It may also arise within the umbilical cord. Umbilical cord urachal cysts originate from an extra-abdominal urachal system.  See also fetal intra-abdominal cysts...
Article

Fetal urinary ascites

Fetal urinary ascites is one of the causes of fetal ascites and can arise from a number of pathologies: in utero bladder perforation fetal megacystis transudation from the fetal bladder persistent urogenital sinus Radiographic features Ultrasound The presence of fetal ascites without fe...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.