Scrotal pyoceles are purulent fluid collections in the scrotal sac, that generally occur in conjunction with epididymo-orchitis.
Scrotal pyoceles are typically a complication of epididymo-orchitis or testicular abscess but can also occur following trauma or surgery. The purulent flui...
Scrotal scintigraphy is a radio-isotope examination of the scrotal contents, primarily in patients presenting with scrotal pain.
Although, ultrasound remains the mainstay of scrotal imaging, scintigraphy can be used where the diagnosis is unclear, since ultrasound appearances for s...
Scrotal tunica cysts are paratesticular cystic lesions. They include:
tunica vaginalis cysts
tunica albuginea cysts
Typically seen as a simple appearing paratesticular cystic lesion not in the region of the epididymis.
Scrotoliths, also known as scrotal pearls, are benign incidental extra testicular macro-calcifications within the scrotum. They frequently occupy the potential space of the tunica vaginalis or sinus of the epididymis. They are usually of no clinical significance 1,2.
The scrotum (plural: scrota or scrotums) is a dual-chambered protuberance of skin and muscle that contains the testes, epididymides, and spermatic cord. It consists of two chambers separated by a septum. It is an extension of the perineum and is located between the penis and anus.
Segmental renal hypoplasia, also known as the Ask-Upmark kidney, is a type of renal hypoplasia. It is often found in young females with severe hypertension. The etiology is unknown but has been postulated to be congenital or a sequelae of pyelonephritis. It is associated with severe juvenile hyp...
Segmental testicular infarctions are uncommon testicular lesions that usually result from arterial embolization or thrombosis (as opposed to testicular infarction from torsion, which may originate from venous occlusion).
The causes of a segmental testicular infarct include:
Selenium toxicity (rarely: hyperselenemia) is caused by excessive intake of the non-metallic element selenium (Se) in the diet.
It is less common than selenium deficiency. It is most frequently seen in some parts of India, in which there are naturally high levels of selenium in th...
The seminal vesicles are paired accessory sex glands of the male reproductive system. The seminal vesicle produces over two-thirds of the ejaculate and is very high in fructose.
The seminal vesicle is actually a 10-15 cm long tubular structure but is coiled tightly so it only me...
Seminal vesical abscesses are a complication of seminal vesiculitis.
The associated symptoms can be non-specific and are those typically associated with urinary tract infections:
perineal or abdominal pain
ejaculation of purulent mate...
Seminal vesicle agenesis is a condition that refers to the congenital absence of one or both seminal vesicles.
Seminal vesicle agenesis is a rare finding with a reported incidence of 0.08 % 2.
Developmental anomalies of the ipsilateral urogenital tract may be observ...
Seminal vesicle cysts can be congenital or acquired.
Age of presentation of congenital cysts is during the period of greatest reproductive activity i.e in second and third decades of life, while acquired cysts are most often seen in the elderly age group.
Seminal vesicle fusion is a congenital abnormality that refers to the midline fusion of the seminal vesicles.
This is a very rare anomaly that has been reported in some sporadic case series and case reports in infertile men 2.
Only one case desc...
Seminal vesicle hypoplasia is a congenital anomaly that refers to the underdevelopment of one or both seminal vesicles.
All mesonephric duct maldevelopments may be observed:
seminal vesicle agenesis
seminal vesicle cysts
congenital agenesis of the ...
Seminal vesicle invasion (SVI) is referred to as the secondary involvement of the seminal vesicles and vas deferens by neoplasms not originating from the seminal vesicles themselves and are much more common than their primary counterparts.
Seminal vesicle invasion refers to a tumor...
Seminal vesiculitis is an uncommon entity characterized by inflammation of the seminal vesicles. It is most commonly infective in etiology and often associated with concurrent infection elsewhere in the male genital tract, forming part of the spectrum of male accessory gland inflammation 4. It i...
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...
Sertoli cell tumors of the testis are uncommon sex cord stromal tumors. They are less common than Leydig cell tumors of the testis.
May present in both pediatric and adult males, depending on the histologic subtype.
Testicular mass or firmness. May occasio...
Sex cord stromal tumors of the testis are uncommon testicular neoplasms. Although ~90% of these tumors are benign, they cannot be differentiated from testicular malignancies on imaging, and are therefore usually discovered after orchiectomy.
Leydig cell tumor of the testis (most common, ~30% ho...
Sexual differentiation refers to the embryological development of male and female phenotypes. Unlike sexual genotype which is determined at the time of fertilisation, the male and female phenotypes do not begin to differentiate substantially until the seventh week of gestation.
Sickle cell disease (SCD) (historically known as drepanocytosis) is a hereditary (autosomal recessive) condition resulting in the formation of abnormal hemoglobin (a hemoglobinopathy), which manifests as multisystem ischemia and infarction, as well as hemolytic anemia.
Hemoglobin SC (HbSC) dis...
Abdominal manifestations of sickle cell disease (SCD) are wide and can involve many organs.
For a general discussion, please refer to sickle cell disease.
may occur transiently with the sequestration syndrome, where rapid pooling of blood occurs in the spleen, resulting ...
A sigmoid kidney is an uncommon variant of the horseshoe kidney. Whereas the typical horseshoe kidney is fused only at the lower poles, in a sigmoid kidney both the upper and the lower poles are fused 1.
In the past 15 years sildenafil citrate-induced penile Doppler has emerged as a technique for evaluating erectile dysfunction. It has greater patient acceptability than the usual papaverine-induced color Doppler and is safer.
Sildenafil citrate is a popular vasodilator drug used in treatment of...
Small cell carcinomas of the bladder are rare bladder cancers with a poor prognosis. Its appearance overlaps other bladder cancers, in particular, urothelial/transitional cell carcinoma.
A very rare tumor, it has been estimated at <0.0001% of bladder cancers. It is thought to have...
The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith. The former appears as a calcific density with a surrounding rim of soft tissue which represents the edematous ureteric wall. Phleboliths on the other hand usually have imperceptible walls (although up to 8% ma...
Solitary filling defect with a ureter, as seen on conventional IVU or CT IVU has a few differentials which can be remembered using this mnemonic:
U: ureteric stone
S: sloughed papilla
T: tuberculosis, transitional cell...
Solitary filling defect with a ureter, as seen on conventional IVU or CT IVU has some differentials, including:
within the lumen
within the wall
transitional cell carcinoma (TCC)
When multiple fi...
SpaceOAR is a technique in which a physical space is created between the prostate gland and rectum for electron beam radiotherapy targeted to the prostate gland in cases of prostate cancer.
OAR stands for "organ at risk", and in cases of prostate cancer radiotherapy treatment the rectum is the...
The spaghetti sign may be seen in upper urinary tract bleeding.
It refers to the presence of a linear worm- or spaghetti-like filling defect within a contrast-opacified bladder 1,2. This linear filling defect represents blood clot extruded from the ureter and thereby molded into a tubular shape...
The spermatic cord is the tubular structure that suspends the testes and epididymis in the scrotum from the abdominal cavity.
The spermatic cord arises at the deep inguinal ring, passes through the inguinal canal and exits at the superficial inguinal ring into the scrotum...
Handy mnemonics to recall the contents of the spermatic cord are:
Papers Don't Contribute To A Good Specialist Level
3 arteries, 3 nerves, 3 fascias, 3 other things
Papers Don't Contribute To A Good Specialist Level
P: pampiniform plexus
D: ductus deferens
C: cremasteric artery
A spermatic cord hydrocele refers to a loculated fluid collection along the spermatic cord. It is separated from, and located above, the testis and the epididymis.
It results from aberrant closure of the processus vaginalis.
There are two recognized subtypes
encysted hydrocele - fl...
Spermatic cord leiomyosarcomas are uncommon malignant paratesticular masses.
Accounts for ~10% of spermatic cord sarcomas. The average of a patient at presentation is 58 years old (although has been seen as young as 15 years old).
Patients may have left inguina...
Spermatic cord liposarcomas are the most common malignant tumor of the spermatic cord. Most present as painless, slow-growing masses and can be mistaken for inguinal hernias. They are usually well-differentiated and spread by local extension.
In a large population-based registry,...
Spermatoceles are a common type of extratesticular cyst, and represents cystic dilatation of tubules of the efferent ductules in the head of the epididymis.
Usually a painless, incidental finding but can present as a mass lesion if large 3.
Spermatoceles are u...
Sperm cell granulomas, also called epididymitis nodosa, are benign lesions that can occur in the scrotum; particularly, in those with a prior vasectomy.
They occur after vasectomy in up to 40% of patients 2.
It is considered a form of chronic epididymitis which occurs ...
Spigelian-cryptorchidism syndrome ( also known as Raveenthiran syndrome ) is the association of Spigelian hernias and cryptorchidism in children.
It is reported that ~50% (range 28-75%) range of pediatric patients with Spigelian hernias will have ipsilateral cryptorchidism 1,2.
Spinning top urethra is non-obstructive posterior urethral dilatation seen on voiding cystourethrography, mainly in females. It was initially considered as an indicator of distal urethral narrowing/stenosis. However, it is now believed to be due to functional discoordinate voiding or bladder ins...
Splenogonadal fusion is a rare anomaly that occurs when there is congenital fusion between a portion of the spleen and a gonad or other mesonephric derivative.
Much more common in male patients (~95%), occurs most commonly on the left (98%) and usually involve the testis (95%). Ha...
The split bolus technique is a CT imaging investigation used in patients with hematuria aiming to put together, in a single image acquisition, both the nephrographic and renal excretory phases and thus reducing the radiation dose of the study. It is a CT protocol adopted for some institutions fo...
A spoke wheel pattern in renal imaging refers to a vascular appearance seen with certain renal tumors, typically seen in oncocytomas but can also be seen in renal cell carcinomas.
This appearance refers to a peripheral rim of vessels from which centripetal vessels converge centrally giving the...
Spontaneous retroperitoneal hemorrhage (SRH) is a distinctive clinical pathology of retroperitoneal bleeding without a preceding history of trauma.
For a broader discussion, including other etiologies, please refer to the parental article on retroperitoneal hemorrhage.
Spontaneous rupture of the renal pelvis, also known as pyelosinus backflow, is a rare complication that can occasionally occur with obstructive urolithiasis (usually in the distal third of the ureter) or occasionally infection 1. Leakage of urine can result in a urinoma, and there is an increase...
A spotted nephrogram is a descriptive term indicating an appearance of patchy, segmental and subsegmental renal parenchymal enhancement.
The pattern is indicative of focal areas of cortical ischemia or necrosis, as a result of small vessel occlusion. This abnormal perfusion pattern c...
Squamous cell carcinoma of the penis arises most commonly at the distal end of the penile urethra with local invasion of the glans.
In addition to TNM classification, the following staging is used:
stage I: confined to the glans or foreskin
stage II: invasion of penile shaft
Squamous cell carcinoma of the urinary bladder is rare and accounts for only ~3-8% 1,2 of all bladder cancers (90% are transitional/urothelial cell carcinomas) but nevertheless, SCC is the most common type of non-transitional cell carcinoma involving the bladder 2. SCC of the bladder is observed...
Staghorn calculi, also sometimes called coral calculi, are renal calculi that obtain their characteristic shape by forming a cast of the renal pelvis and calyces, thus resembling the horns of a stag. They refers to struvite calculus involving the renal pelvis and extending into atleast two calyc...
Steinstrasse [stīn′shtra-se] is the German word for "stone street", describing a possible complication of extracorporeal shock wave lithotripsy (ESWL) for urinary tract calculi, wherein a column of stone fragments forms that blocks the ureter.
Steinstrasse usually develops 1 day to 3...
The stipple sign refers to the pointillistic end-on appearance on intravenous pyelography or retrograde pyelography of contrast material tracking into the interstices of a papillary lesion. Because the majority of transitional cell carcinomas (TCC) have a papillary configuration, the presence of...
Strangury (also known as stranguria) describes a symptom of the unintentional agonising micturition of small volumes of urine or marked desire to do so, often without any urine passed. In many cases the bladder is empty or near empty.
It has been described as the urological form of tenesmus, an...
Striated nephrogram is a descriptive term indicating an appearance of alternating linear bands of high and low attenuation in a radial pattern extending through the corticomedullary layers of the kidney on iodine-based intravenous contrast enhanced imaging.
It is important to know that a simila...
The string of beads sign is the description typically given to the appearance of the renal artery in fibromuscular dysplasia (FMD) but may also be used to describe the appearance of splanchnic arteries in segmental arterial mediolysis (SAM). It refers to the appearance arising from the stenoses ...
Stromal tumor of uncertain malignant potential (STUMP) is a rare stromal tumor of the prostate with a broad spectrum of histologic pattern and variable clinical behavior.
Stromal tumor of uncertain malignant potential has been also known as atypical stromal hyperplasia, cystic epit...
A subcapsular perirenal hematoma is a form of perirenal hematoma where blood accumulates beneath the renal capsular margin.
It can arise from a number of causes
trauma, important in assessing renal trauma grading
post procedural, e.g. extracorporeal shock-wave lithotripsy (ESWL) 5,...
The sunburst sign refers to the appearance of arterial blush seen at selective arterial DSA of a renal angiomyolipoma.
Angiomyolipoma is a hypervascular renal mass that shows dense early arterial vascular network of tortuous irregular vessels with micro- or macroaneurysms.
The superficial perineal pouch is an anatomic space below the perineal membrane in the urogenital triangle of the perineum.
The superficial perineal pouch is inferior (superficial) to the perineal membrane in the urogenital triangle, anterior to the transverse line between the is...
The paired superficial transverse perineal muscles (TA: musculus transversus superficialis perinei) lie in the perineum and are important for stabilizing the perineal body.
origin: ischial tuberosity
insertion: the fibers of each muscle meet in the midline at the perineal body and dec...
The superior adrenal (suprarenal) arteries are a group of arteries that together form one of the three adrenal arteries that supply the adrenal gland. There are usually numerous small arteries arising from the inferior phrenic artery.
The superior suprarenal arteries aris...
Supernumerary kidneys are a rare congenital anomaly of the urogenital system, where there are one or two accessory kidneys.
Less than 100 cases are documented.
Patients may be asymptomatic. If present symptoms range from fever, pain to abdominal mass. Thes...
Suprapubic cartilaginous cysts (SPCC) are rare cystic lesions arising from the symphysis pubis thought to be degenerative in origin. They have also been called retropubic or subpubic cysts.
In the small number of cases in the literature, all bar one patient, have been female. The ...
The supravesical fossae are concave depressions of peritoneum in the paravesical space bounded by the median umbilical fold and the medial umbilical folds. It partially overlies the inguinal (Hesselbach’s) triangle. The supravesical fossae are usually occupied by small bowel loops and the urinar...
Surgical hemostatic material is used to control bleeding intraoperatively and is hence frequently intentionally left in the operative bed, not to be confused with a gossypiboma which is caused by foreign material left behind in error. Its use has increased with the advent of minimally invasive s...
There are various classic surgical positions for patients to be placed in for procedures, which have been adopted/repurposed for interventional radiology and some diagnostic procedures:
reverse Trendelenburg position
lateral decubitus position
Syphilis is the result of infection with the gram-negative spirochete Treponema pallidum, subspecies pallidum. It results in a heterogeneous spectrum of disease with many systems that can potentially be involved, which are discussed separately.
Despite the discovery of penicillin...
Systemic lupus erythematosus (SLE) is a complex autoimmune disease with multisystem involvement. Although abnormalities in almost every aspect of the immune system have been found, the key defect is thought to result from a loss of self-tolerance to autoantigens.
There is a strong...
Tamm-Horsfall proteins, also known as uromodulin, may be a cause of echogenic renal pyramids in a neonate.
Tamm-Horsfall proteins are physiologically excreted by the renal tubular epithelium. They are most often encountered on neonatal renal ultrasound, where the concentrated proteins in the re...
Tc-99m DMSA (2,3 dimercaptosuccinic acid) is a technetium radiopharmaceutical used in renal imaging to evaluate renal structure and morphology, particularly in pediatric imaging for detection of scarring and pyelonephritis. DMSA is an ideal agent for assessment of the renal cortex as it binds to...
Tc-99m DTPA (diethylene-triamine-pentaacetate) is one of the technetium radiopharmaceuticals used in renal imaging and primarily used to measure the glomerular filtration rate (GFR).
photon energy: 140 KeV
physical half-life: 6 hours
biological half-life: 2.5 hours
Tc-99m MAG3 (mercaptoacetyltriglycine) is one of the technetium radiopharmaceuticals used in renal imaging. Due to favorable energy and dosimetric characteristics, MAG3 radiolabeled with technetium has replaced the iodide-131 Hippuran for the study of renal function (tubular secretion physiology...
Tc-99m pertechnetate (Na+ 99mTc O4-) is one of the technetium radiopharmaceuticals used in imaging of thyroid, colon, bladder and stomach.
Technetium (99mTc) has eight oxidation states 6, from -1 to +7; specifically, the oxidation state of technetium in the pertechnetate anion (99mTcO4-) is +7....
Technetium agents based on the technetium-99m (Tc-99m) radioisotope are frequently used agents in medical imaging. A radiopharmaceutical labeled with Tc-99m constitutes a co-ordination complex in which ligands bond to a central atom of Tc-99m by co-ordinate covalent bonds 4 .
The radioactive te...
Teratomas are germ cell tumors that arise from ectopic pluripotent stem cells that fail to migrate from yolk sac endoderm to the urogenital ridge during embryogenesis. By definition, they contain elements from all three embryological layers: endoderm, mesoderm and ectoderm although frequently, e...
Testicular abscess is usually a complication of severe epididymo-orchitis and needs to be distinguished from other testicular pathology that may present with similar clinical or imaging features.
The majority of patients develop a testicular abscess as a result of untreated or se...
Testicular adrenal rests are a rare cause of a testicular mass.
Testicular adrenal rests can be known by a variety of terms 2:
testicular adrenal rest tumor (TART)
testicular adrenal rest tissue
testicular tumor of the adrenogenital syndrome
testicular adrenal-like tissue
Testicular and scrotal ultrasound is the primary modality for imaging most of the male reproductive system. It is relatively quick, relatively inexpensive, can be correlated quickly with the patient's signs and symptoms, and, most importantly, does not employ ionizing radiation.
MRI is occasion...
Testicular and epididymal appendages are remnants of embryonic ducts and are quite common, with one or more being present in ~70% of patients 1.
Four such appendages have been described:
testicular appendix (hydatid of Morgagni)
it is a Müllerian duct remnant (paramesonephric d...
A testicular appendix (alternatively called appendix of testis or appendix testis, and historically also known as hydatid of Morgagni) represents a developmental remnant of the paramesonephric duct (Müllerian duct) which is situated in the upper pole of the testis inside a groove between the tes...
The testicular arteries (also known as the spermatic arteries) are the long, small-diameter gonadal arteries in the male that supply the testis alongside the cremasteric artery and the artery to the ductus deferens.
As paired structures they arise symmetrically, slightly...
Testicular cancers are the most common neoplasm in men between the ages of 20 and 34 years.
Testicular cancer is uncommon, accounting for less than 1% of all internal organ malignancies 2.
The demographics of affected individuals depends on the age of the histology of the tumor. ...
The staging for testicular tumors is performed according to the TNM system with staging groupings. It can be remembered in its abbreviated form as:
stage I: confined to testis, epididymis, spermatic cord, scrotum
stage II: lymph nodes involved but no distant metastases and serum tumor markers...
Testicular choriocarcinoma is a type of non-seminomatous germ cell tumor.
Incidence peaks at around 20-30 years of age.
Can be variable with some patients initially presenting with metastates.
It is most commonly detected as a component of a mi...
Simple testicular cysts are usually nonpalpable and thus are detected incidentally.
Testicular cysts require no treatment when discovered.
anechoic with posterior acoustic enhancement
no flow on color Doppler
Testicular descent occurs after the fourth month of fetal life. The testes are derived from the gonadal ridge medial to the mesonephric ridge of the intermediate cell mass. An elongated diverticulum of the peritoneal cavity, the processus vaginalis precedes the testis through the inguinal canal ...
Testicular dislocation is a rare condition in which a testicle is dislocated from its normal position within the scrotum to another location, most commonly the superficial inguinal pouch.
The condition mainly occurs in younger men with a mean age of 25 years 2.
Testicular embryonal cell carcinoma is a type of non-seminomatous germ cell tumor.
Incidence peaks at around 25-30 years.
It may occur as part of a mixed germ cell tumor (more common and may be present as a component in around 80% of mixed germ cell tumors) or very ra...
Testicular epidermoid cysts, also known as keratocysts, are rare benign tumors.
Testicular epidermoid cysts account for around 1-2% of all testicular masses and typically present in mid-adulthood (2nd to 4th decades) 1,2. They are the most common type of benign testicular neoplasm...
Testicular fracture refers to a break in the parenchyma of the testicle as a result of blunt trauma.
A fracture line can be seen as a hypoechoic and avascular area within the testis but is only seen in 17% of cases 1. A tunica albuginea rupture may also be pr...
Testicular germ cell tumors account for 90% of primary tumors of the testes. They are the most common nonhaematologic malignancy in men 15-49 years old.
They are divided into:
testicular seminoma: 40% of germ cell tumors 1
non-seminomatous germ cell tumor: 60% of germ cell tumors
Testicular lipomatosis is a rare condition characterized by homogeneously hyperechoic non-shadowing lesions within the testes on ultrasound without flow on color Doppler. It is seen as a component of PTEN (phosphatase and tensin homolog (gene)) hamartoma tumor syndrome which includes:
Testicular lymphoma is an uncommon testicular malignancy. Lymphoma can involve the testes in three ways:
primary site of extranodal disease (primary testicular lymphoma)
secondary involvement of systemic disease
primary manifestation of subclinical systemic disease
This article is concerned ...
Testicular microlithiasis is a relatively uncommon condition that represents the deposition of multiple tiny calcifications throughout both testes.
The most common criterion for diagnosis is that of five microcalcifications in one testicle, although definitions have varied in the past. In the ...
Testicular mixed germ cell tumors are, as the name suggests, testicular tumors composed of two or more types of germ cell tumor. They are considered to be part of non-seminomatous germ cell tumors, as it is that component which dictates prognosis and treatment.
Overall they account for over 10...