Genitourinary Trivia Flashcards
What is the most common congenital renal tract anomaly
duplicated collecting system >> characterised by an incomplete fusion of upper and lower pole moieties resulting in a variety of complete or incomplete duplications of the collecting system
complete ureteral duplication:
- upper pole ureter commonly associated with ureterocele and obstruction
- lower pole likely associated with reflux
-ectopic insertion of the upper pole moiety e.g. into the prostatic urethra in males or vaginal vault in females
most common fusion anomaly of the kidneys?
the horseshoe kidney
appears as a variably thick band of renal tissue extending from both lower poles to connect anterior to the aorta below the level of IMA
Hydronephrosis grading
** repeated or long standing obstruction may cause a dilated, ectatic collecting system that persists even when obstruction is relieved.
** caution! prominent renal veins may mimic a dilated renal collecting system >> so use Doppler if suspicious
** look for ureteral jets >> absent in urinary obstruction
Differential Diagnosis for solid renal mass:
- RCC- varied: solid, cystic components +/- calcifications
- Angiomyolipoma (most common benign neoplasm and 2nd to only RCC) - classic appearance: homogenous, well defined mass that is as echogenic as renal fat DDX: deep cortical scars
- Urothelial cell carcinoma-usually too small to be detected on USS
- Oncocytoma- type of adenoma, USS findings overlap w RCC (eg spoke wheel vascularity) >>stellate scar characteristic in 1/3 cases on contrast CT
- Lymphoma- often bilateral, multiple, hypoechoic lesions snd often involves perinephric space, commonly non-Hodgkins
- Metastases
- *Column of Bertin
- Focal Parenchymal hypertrophy
- Focal pyelonephritis
What qualifies as simple renal cysts?
- anechoic lumen
- well-defined back wall
- acoustic enhancement deep to lesion
- no measurable wall thickness
- thin septations are acceptable
Ultrasound findings of Pyelonephritis
Insensitive to the changes of acute pyelonephritis, with most patients having ‘normal’ scans. Abnormalities are identified in only ~25% of cases.
Possible features include:
- particulate matter/debris in the collecting system
- urothelial thickening
- reduced areas of cortical vascularity by using power Doppler
- gas bubbles (emphysematous pyelonephritis)
- abnormal echogenicity of the renal parenchyma
- focal/segmental hypoechoic regions (in oedema) or hyperechoic regions (in haemorrhage)
- mass-like change
Ultrasound most useful in assessing for: causes>> stones may form the nidus for persistent infection local complications >> hydronephrosis, renal abscess, renal infarction, perinephric collections, and thus may guide management.
Emphysematous pyelonephritis vs Emphysematous pyelitis
Emphysematous pyelonephritis: a serious renal infection resulting from formation of gas in renal parenchyma stemming from high-tissue concentration, vascular disease and a necrotising infection with a gas forming organism (E.coli)
Tx: Nephrectomy
USS: dirty echogenic foci with reverberation/ring-down artifacts representing gas (‘dirty shadowing”)
Emphysematous pyelitis: less serious condition in which gas forms in the collecting system BUT not in renal parenchyma
** may be difficult to determine wether gas confined to collecting system or involves renal parenchyma
When looking at an anechoic lesion, how can u differentiate a solid from cystic mass?
Look for acoustic enhancement >> travels through fluid =cyst
Differentials for intraluminal masses in collecting system
- urothelial cell carcinoma
- blood clots
- fungus ball
- fibroepithelial polyps
- malacoplakia
- calculi
**detection of vascularity excludes clots and fungus balls
Differential Diagnosis for Complex Cystic Renal Masses:
- Hemorrhagic cyst
- Infected cyst
- Multisepetated cyst
- Abscess
- Hematoma
- Cystic RCC
- Multilocular cystic nephroma: considered benign, multiple, large non-communicating cystic spaces tend to afflict younger boys and older women
When do you suspect Staghorn calcifications on USS?
When shadowing reflectors are long and either linear or curvilinear
Pitfalls of sonographic detection of renal stones:
- refractive shadowing from renal sinus >> DO NOT take shadow as evidence UNLESS arising from definite echogenic focus
- cysts containing crystal (milk of calcium) can appear echogenic with twinkle artefact >> distinguished from stones as they are located in renal cortex and not in collecting system
- arterial calcifications -confirm with longitudinal and tranverse views
what is Xanthogranulomatous pyelonephritis (XGP)?
a rare form of chronic pyelonephritis and represents a chronic granulomatous disease resulting in a non-functioning kidney
there is a 2:1 female predilection: increased incidence of urinary tract infections, in diabetes mellitus.
common organisms: Proteus miribalis and E.coli
Radiologic features:
- shadowing stone in renal pelvis (usually struvite (staghorn) calculi)
- dilated renal calyces
- perinephric fluid collection
- perinephric inflammatory tissue (thickening of Gerota’s fascia)
- renal enlargement
What normal structure may be mistaken for a renal mass?
Prominent renal papillae (may be mistaken for Urothelial cell CA)
it is a filling defect of the calyces noted in the setting of hydronephrosis, usually appear in all calyces
Ureteral stones impact in distal ureter near ureterovesicle junction
easiest portion of ureter to visualize with moderately distended bladder
look for ureteral jets
unilateral elevation of Resistive Index (RI)
Nephrocalcinosis
calcification of renal parenchyma rather than collecting system:
Cortical (5%)
Medullary (95%) >> 3 most common causes
- medullary sponge kidney (tubular ecstasia)
- renal tubular acidosis
- hyperparathyroid
early stage: increased echogenicity at periphery of the pyramids (** don’t confuse for dilated calyces which will have other obstructive signs)
with disease progression >> progressive calcification with shadowing
What does a normal renal artery waveform look like?
Renal Parenchymal disease
Increased echogenicity noted when Rt kidney more echogenic than liver or when echogenicity of Lt kidney is equal to or greater than that of spleen
alternatively,
echogenicity considered increased of renal pyramids are unusually hypo echoic compared to cortex
small kidneys indicate chronic process
USS progression of Hematomas, in renals or anywhere
- echogenic
- heterogenous
- mixed
- predominantly liquefied
- purely cystic
Renal Artery Stenosis>> patients to Suspect and Doppler findings
Patients with severe hypertension that is poorly controlled or controlled ONLY with multiple medications
Doppler:
Color- focal areas of aliasing and localized perivascular tissue vibration
Then…
Pulsed Doppler analysis of abnormal areas identified of Color D > to determine wether flow velocity is elevated.
* Significant RAS is diagnosed when peak systolic velocity exceeds 200 cm/second and the peak renal artery velocity–to–peak aortic velocity ratio is greater than 3.5.
Limitations to renal artery Doppler Visual findings to renal artery stenosis
- obesity
- dyspnea
- overlying bowel gas (pts must fast before exam)
- extensive arterial calcification that shadows the Doppler signal,
- distal lesions (e.g., fibromuscular dysplasia [FMD]),
and cardiac arrhythmias
What is the parvus tardus effect?
A proximal stenosis will cause blunting/dampening of the waveform of distal arteries >> slowed systolic upstroke and a delayed time to peak systole
What a varicoceles and commonly affected side
Varicoceles are dilated peritesticular veins that form as the result of incompetent valves in the spermatic veins *risk of infertility
Left side: Left spermatic vein drains into the left renal vein Right spermatic vein drains into the IVC.
>>Because the superior mesenteric artery compresses the left renal vein, the pressure on the left side is higher than that on the right >> 85% of the varicoceles are on the left.
Most of the remaining 15% are bilateral.
Describe Testicular Epidermoid Cysts
BENIGN tumors similar to teratomas, but they contain only ectodermal derivatives. > appear as hypoechoic masses with a hyperechoic, variably calcified rim, or multiple concentric internal laminations that simulate an ONioN SLiCE
Types of Testicular Neoplasms
Germ cell tumors: (usually non-tender palpable mass)
- Seminoma >> usually hypo echoic and homogenous
**other germ cells heterogenous with cystic components +/- calcifications
- Mixed germ cell
- Embryonal cell
- Teratoma
- Choriocarcinoma
- Yolk sac
Stromal tumors
- Leydig cell tumor
- Sertoli cell tumor
Lymphoma/leukemia
Metastases
Epidermoid cyst
What is the most common scrotal mass?
Spermatocele
These are cystic lesions that form in the head of the epididymis and are filled with spermatozoa-containing fluid.
May see:
- Low-level echoes especially when the gain is increased.
- Acoustic streaming >> do not confuse with blood flow
- Septations in large spermatoceles.
**Epididymal cysts may also form in the epididymal head as well as in the body and tail. They contain serous fluid and are anechoic and indistinguishable from spermatoceles.
What are Hydroceles?
Collections of fluid that form in the potential space of the tunica vaginalis.
Causes:
- idiopathic (large)
- scrotal inflammatory processes,
- testicular torsion,
- trauma,
- testicular tumors,
**Although variable, hydroceles usually occur in the anterior aspect of the scrotum and displace the testis posteriorly
Crystals can precipitate in the hydrocele fluid and produce mobile low-level reflectors
Complicated hydroceles: pyocele, hematocele
What testicular lesions can mimic tumors
Focal orchitis
Focal atrophy/fibrosis (fairly common, produce hypoechoic regions in the testis that are arranged in a linear pattern producing a striated appearance and may become confluent >thus may be confused for tumor)
Infarct
Abscess
Hematoma
Contusion
Sarcoid
Tuberculosis
Adrenal rest tissue
Calcifications of tunica albuginea and tunica vaginalis
Can present as a palpable mass Referred to as plaque fo tunica
May occur due to previous trauma or infection
Is there an association between testicular tumors and undescended testes?
The risk of germ cell tumors is as much as 40 times greater in this group of patients than the general population, and the risk is even higher for patients with intra-abdominal testes (80% of undescended testes found within the inguinal canal)
The risk of cancer is eliminated if the testis is surgically relocated to the scrotum before 5 years of age.
Between ages 5 and 10, orchiopexy has a diminishing effect on the rate of cancer.
After 10 years of age, orchiectomy is usually performed instead of orchiopexy.
Tubular ectasia of rete testis
Produces tiny cystic/tubular-appearing changes that replace and enlarge the mediastinum.
It is usually bilateral, although it can be quite asymmetric and in a minority of cases can be unilateral.
It is often associated with spermatoceles and with intratesticular cysts.
As with testicular cysts, it is NOT palpable.
Testicular tosion features
Most common anatomic anomaly producing this faulty attachment is the “bell-clapper deformity”.
The likelihood of testicular viability is excellent up to 6 hours, progressively decreases between 6 and 24 hours, and is unlikely after 24 hours
** If the testis is normal or homogeneously hyperechoic>> it is very likely to be viable regardless of the duration of symptoms.
**If the testis is hypoechoic or heterogeneous, it is likely to be infarcted and nonviable.
Features:
-torsion knot (may be confused w enlarged epididymal head)
> solid heterogenous mass adjacent to testis
- testis echogenicity >may be normal, decreased, or increased/ homogeneous or heterogeneous
- use Color Doppler
> by comparing both testes: > clear asymmetrically decreased compared with the other testis
>prolonged torsion > inflammatory reaction that develops in the soft tissue around infarcted testis, producing a hyperaemic srotal wall
Orchitis on USS:
Usually occurs in conjunction with epididymitis
isolated orchitis (mumps)
- enlarged testis
- decreased echogenicity
- heterogeneity (patchy/striated)
- hypervascularity
- pain and tenderness without palpable mass
- testicular abscess
Testicular Trauma USS
Important> is the tunica albuginea intact?
if yes, surgery not usually indicated
Testicular viability can be salvaged >80% of the time if surgery is performed within 72hrs
viability drops to <50% if dx and surgery delayed beyond 72hrs
Findings:
- visible disruption of tunica albuginea >> -contour abnormality indicated extrusion of seminiferous tubules through disrupted tunica a
- heterogeneity WITH contour disruption
- hematocele (fluid collections with diffuse internal echoes, or complex collections)
- focal avascular areas
- trauma may induce testicular torsion
- testicular fracture may or may not be associated with rupture of tunica
Vascular lesions following trauma: pseudo aneurysms and arteriovenous fistula
Emphysematous cystitis on USS
Cystits > bladder wall thickening +/-hyperemia
As expected, the gas in the bladder wall is seen in nondependent locations and will either cast a dirty shadow or produce ring-down artifacts
Epididymitis on USS
- enlargement
- may have decreased echogenicity
- diffuse or focal (focal usually involves the tail)
- hyperemia
Avanced case:
- Small abscess (avascular, complex hypoechoic collections)
- obstruct venous outflow >>testiculad ishemia and infarction
Pitfall >> enlarged epididymis following vasectomy >> can be differentiated from enlargement due to inflammation by noting bilateral involvement and lack of hyperemia.
Bladder Stones USS
Occur most often in the setting of bladder outlet obstruction
Bladder tumors on USS
Patients usually present with hematuria
90%
- Urothelial cell carcinoma
- smoking a predisposing factor in 30-50%
- bladder sones, chronic infection, analgesic abuse, exposure to industrial carcinogens also a risk factor
Features:
- majority arise along the posterior wall
- polypoid or mass extending into bladder lumen
- detectable blood flow
- less frequent infiltrative or plaque-like with diffuse or localized thickening
5%-squamous cell -patients with bladder schistosomiasis, neurogenic bladders, or chronic inflammatory conditions of the bladder.
Primary differential diagnosis for bladder cancer
-blood clots> almost alway mobile with no internal blood flow, unlike cancer
Others:
- fungus balls
- infectious
- TB
- primary inflammatory masses
- BPH
- invasion by adjacent tumors
- endometriosis
- cystitis cystica
Primary Bladder Lymphoma
Rare! Usually MALT (mucosa-associated lymphoid tissue) type.
**Metastatic disease also uncommon.
Hematogenous metastases > most often from the stomach, breast, and lung.
Bladder diverticula
Fluid filled outpouchings usually due to outlet bobstruction and often coexist with thick bladder wall
*urinary stasis in the diverticulum predisposes to infection, stone formation and cancer
Urachal cysts vs Urachal diverticula
*incomplete closure of urachus
U Diverticulum-umbilical segment closes but the vesicular segment does not
U Cyst-the segment between the bladder and umbilicus fails to close
Ureteroceles on USS
Due to dilatation of the INTRAMURAL portion of the distal ureter protruding into the bladder lumen.
In adults, they are usually incidental findings and are located in the expected location of the ureteral orifice.
USS:
- appear as round- or oval-shaped,
- thin-walled cystic structures on the posterior wall of the bladder.
- On real-time scanning> change size as they fill and empty, AND ureteral jets observed intermittently emanating from their orifice
Priprism vs Peyronie on USS
Priaprism
Prolonged partial/full erection without stimulus
evaluated with Doppler > primarily to search for an occult arteriovenous fistula (high-flow priapism), which occurs most often in patients with a history of penile or perineal trauma, or thrombosis of the dorsal penile vein (low-flow priapism).
Peyronie
FIBROSIS of the tunica albuginea of the corpora cavernosa.
an idiopathic condition that typically affects men over the age of 45 years.
Lack of expansion of the tunica albuginea in the area of fibrosis causes the penis to bend toward the plaque during erection and associated pain
Describe the prostate zones
Composed of 4 zones
Peripheral zone:
- largest
- located posteriorly and extends laterally
>> 80% of the cases of prostate cancer occur here
Central zone:
-immediately deep to peripheral zone, predominantly in the base
>>5% cases of cancer
Transitional zone:
>>15% cancer cases
- periurethral zone between base amd apex
- smallest zone
>> BPH occurs here
Anterior aspect of prostate>> composed of nonglandular tissue and is called the fibromuscular stroma.
Seminal vesicles are bilateral symmetric structures situated immediately above the prostate >> They are bulbous laterally and taper medially
Prostate cancer USS visuals
- discrete nodule or infiltrative hypoechoic region
- 70% hypoechoic in peripheral zone
- cystic cancer is very rare
- hypervascular
DDX:
- prostatis
- atrophy
- fibrosis
- infarct
- BPH
Benign Prostatic Hypertrophy
Involves the transitional zone
Usually located in midline
Detectable continuity with prostate
Small “dimple” at origin of urethra
produces:
-enlargement, -inhomogeneity, -calcification, -occasionally cystic changes
** Prostate cancer is not seen on transabdominal scans unless it is extremely advanced and has invaded the bladder or adjacent structures.
Prostatic Cysts USS
Causes:
-Cysts arising in or near the midline of the prostatic base
>> utricle cysts, Müllerian duct cysts, and ejaculatory duct cysts -retention cysts
**difficult to differentiate
