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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5795_Библиотеки_им_академика_М_И_Перельмана.pdf
15 Ultrasound oftheUrogenital Tract inNeonates, Infants, andChildren
441
• Urine inow jet depictable by CDS—helps differentiating ectopic versus ortho-
topic ureterocele and assessing degree of obstruction/patency.
Note (Small) Ureteroceles may collapse with poor diuresis—sufcient bladder ll-
ing, observation over some time during peristaltic wave, and sufcient hydration
essential not to miss e.g. small ureteroceles. May also evert forming a—diverticulum
with increased intravesical pressure (e.g. full bladder, during voiding)—then respective ureter may become reuxing.
15.7.2.6 Persisting Urachus
Foetal remnant, physiologically seen in rst weeks of life, usually regresses.
Considered pathologic if with central lumen that drains bladder to umbilicus, or
persisting into infancy/childhood. Different forms: cyst or ducts.
US Findings
String-like structure seen even with poor bladder lling using high-resolution linear
transducers, coursing in midline close to the abdominal wall, from bladder roof to
umbilicus (Fig.15.47).
For assessment of patency and lumen, good bladder lling essential:
• Potentially need to ll bladder with saline and/or UCA (as done for uoroscopy),
or also by careful injection of umbilical opening.
Remnants of urachus may persist in form of urachal cyst/diverticula—may get
infected, seen as complex cystic/abscess-like structure along course of the
urachus.
Note Physiological remnant of the urachus may cause pseudotumourous nodule in
the bladder wall at bladder roof—physiologic, should not be mistaken for bladder tumour.
Fig. 15.47 Urachus. (a, b) Typical appearance of band-like structure (++) connecting bladder
roof to umbilicus. Close-up (a) and overview (b); no lumen visualised—however this may be
missed with poor bladder lling. (c) Axial section through full bladder: tumour-like nodule in the
bladder wall on bladder roof, consistent with a physiological urachal remnant—not to be mistaken
for tumour
442
M. Riccabona
15.7.2.7 Megaureter
Dilatation of distal ureter, varying dilatation in the middle/proximal portion.
Can be obstructive (stenotic uretero-vesical junction—uretero-vesical junction
obstruction—UVJO), reuxive (high-grade dilating reux with gapping ostium and
changing size), or dysplastic (primary megaureter) with dysplastic segment which
has less muscle and no peristalsis.
US Findings
Dilated ureter, with/without peristalsis; often with some thickening of the urothelium/ureteral wall.
Try to always nd ostium (often associated with slightly altered position, commonly more medially and distally in obstructive types, more lateralised and cranially in reuxive types).
Always assess tortuosity, peristalsis (documentation with M-Mode/cine-loop
clips helpful) as well as varying dilatation of the renal collecting system. May be
associated with duplex kidneys (see Figs.15.10 and 15.18).
Note For depicting and evaluating megaureters (initially and follow-up), stan-
dardised hydration/sufciently lled bladder mandatory.
15.7.2.8 Infravesical Obstruction andUrethra
Most commonly posterior urethral valve (PUV, nearly always in baby boys).
Other forms of infravesical obstructions may be strictures and stenosis (rare),
partial valves/folds, concretions, tumours (arising from prostate or pelvic oor),
urethral malformations (diverticula, duplex urethra, severe hypospadias, etc.).
Rarely stulae may exist—difcult to visualise on US.
US Findings
Suspected by indirect signs (bladder wall thickening, open bladder neck, trabeculation, megaureters, etc.).
Directly visualised on perineal/penile US with open bladder neck, particularly
during/attempts of voiding—shows typical dilatation of the posterior urethra in
PUV (or tumour/site of compression) (see Figs.15.19 and 15.22).
Other urethral and paraurethal pathology can be depicted by US such as paraurethral cysts, urethral dublication or diverticula, etc…—only if assessed during voiding or when urethra is lled retrogradely via catheter (US-urethrography, see ESPR
Task force recommendation, Pediatr Radiol 47, 2017), possibly using a step-by-step
pull-back manoeuvre as known from uoroscopy (Fig.15.19). Some ndings can
be enhanced by 3D/4DUS.
ce-VUS/perineal US can usually reliably depict PUVs when assessed during
Note
voiding.
15 Ultrasound oftheUrogenital Tract inNeonates, Infants, andChildren
443
Additional Investigations
VCUG/urethrography, cystourethroscopy.
For tumours (in future?) MR urethrography.
15.7.2.9 Inflammation
Isolated cystitis or part of UTI involving also upper tract(s).
US/CDS Findings
More or less thickened bladder wall, particular inner mucosal layer.
Echoes within lumen:
• Potentially widening and laxity of ureters, with urothelial sign (wall
thickening).
• Hypervascularity of the bladder wall, ash echoes within lumen, pronounced
urine inow jet from affected kidney; on spectral analysis diastolic hyperaemia
of these vessels.
Note Diagnosis, however, always made by urine analysis. Isolated cystitis not con-
sidered a mandatory indication for VUR testing any longer.
15.7.2.10 Traumatic Changes
Intravesical clots, haematoma of the bladder wall, bladder rupture. The latter (particularly in conjunction with inconsistent history) suspicious for NAI.
US Findings
• Clots: more or less spherical formations of intermediate and potentially inhomo-
geneous echogenicity in the bladder lumen; may be adjacent/xed to wall by
brin layers. Can become large and cause (intermittent) obstruction.
• Wall haematoma appears as tumour-like thickening with changing echo-
genicity—depending on age of haematoma.
• Rupture: site of rupture sometimes difcult to see, only after lling via catheter.
Most common observation—reduced bladder capacity and perivesical uid
(intra- or extraperitoneal).
Filling the bladder with ultrasound contrast agent as done for ce-VUS will help
Tip
to clarify suspected rupture. This can also be used for US urethrography (while
voiding or by catheterisation with retrograde lling or pull-back manoeuvres during
saline/UCA instillation).
15.7.2.11 Vesico-Ureteric Reflux
See respective entry above.
444
M. Riccabona
15.7.3 Paravesical Changes
Sufciently lled bladder—ideal window to deeper pelvic spaces, for assessment of
internal genitalia, rectum/bowel, pouch of Douglas.
Typical US Findings
Free uid, may be simple (no echoes—simple ascites) or complex (with echoes,
sedimentation, brin bands—e.g. after trauma/haemorrhage, in peritonitis/
inammation).
Tip Digital rectal palpation during real-time US may improve potential to dene
origin/entity. Potentially ll bladder/rectum by saline infusion.
15.7.3.1 Abscess Formations
Typical complication of perforated appendicitis, other bowel inammatory conditions with perforation, adnexal inammation; may also arise from urachus remnants—see respective chapters.
US commonly shows formation with typical wall, with hypervascularity on
CDS, centrally lled of complex uid, potentially with sedimentation and some
included air; sometimes coproliths may be found with in abscess.
15.7.3.2 Tumours ofParavesical Region
Most commonly arise from pelvic oor, internal genitalia or prostate (rhabdomyosarcoma, ovarian tumours), sacrum (most commonly sacral teratoma), and neuroblastoma/ganglioneuroblastoma or PNET (which may arise presacrally).
No specic US signs—see respective chapters.
15.7.3.3 Cystic Perivesical Structures
DDx: ventral meningocele, cysts from internal genitalia (e.g. (para-) ovarian cyst,
hydrosalpinx, paravaginal cysts and vaginal atresia, cystic seminal vesicles), mesenteric cyst, cystic venolymphatic vascular malformation, focal ascites collection,
abscess, seroma, dublication cysts, etc.
15.7.4 Role ofUS
Ideal for assessing bladder pathology and depicting all paravesical formations:
• Often origin may be depicted—use full bladder and meticulous scanning tech-
nique with additional perineal access, lling of bladder/rectum, graded compres-
sion, etc.
• Differentiate solid from cystic structures.
Note In suspected malignancy, additional cross-sectional imaging for initial preop-
erative assessment, anatomic information, and staging are often necessary.
15 Ultrasound oftheUrogenital Tract inNeonates, Infants, andChildren
445
15.8 US ofMale Genitals
US used for external genitalia (scrotum, testis, inguinal canal), seminal vesicles:
• Prostate usually only seen in older children—unless in major pathology (e.g.
cystic dysplastic seminal vesicles, ectopic ureteral insertion, prostate calcica-
tions after infections, tumour/rhabdomyosarcoma).
15.8.1 US Technique
Scrotum/Testis
High-resolution linear transducers with highest feasible frequency.
Note Avoid high sound pressure by reducing output gain.
Always assess testis in longitudinal and axial sections, compare both sides, following structure towards inguinal canal. Use of stand-off pad can be cumbersome;
plenty US gel advised.
Tip Respect privacy of patients even if they are not adults!
Volume calculation: ellipsoid equation—depth (cm)×length×width×0.5=volume (mL).
Dynamic investigation of mobility of the testis, reducibility in case of inguinal
position can be assessed; the same for herniated material (reducibility of herniated
bowel/mesentery?).
Prostate/Seminal Vesicle
Commonly curved linear array; (phased) linear transducer preferred if size/bladder
lling allows. Apply age-adapted frequencies. Access area through lled bladder or
by perineal access.
(a) CDS
CDS essential for assessing inammatory conditions and torsion. Spectral analysis
comparing both sides mandatory. Vascular supply assessed by following main vessels into inguinal area/canal.
Always assess both testes; vessels have to be documented in scrotal wall,
Note
testicular capsule, and within parenchyma as well as in epididymis.
446
M. Riccabona
Penile US
Rarely necessary in childhood unless for ureteral problems (see chapter urinary
tract/bladder and entry PUV).
However, haematoma/injury, cysts/diverticula, duplications, postoperative problems can be assessed/visualised.
Note Urethra always best assessable during voiding. Penile US should be comple-
mented by perineal/urinary tract US.
15.8.2 Normal Findings
Testis: ellipsoid with homogeneous echogenicity, with spleen-like appearance,
some increased echogenicity at hilus. Above testis: cape-like or nodular epididymis,
testicular appendices better visible with some hydrocele. Some minor uid around
testis is physiologic.
Size in neonates ~2mL, during childhood increasing with growth, mostly during
early puberty when testicular size reaches ~15mL.Volume calculated by ellipsoid
equation as for kidney.
Depiction of intratesticular vessels depends on equipment and patient maturity.
In neonates intratesticular vessels more difcult to see, whereas during puberty
intratesticular vessels must always be visible.
15.8.3 Common Pathologic Findings
15.8.3.1 Hydrocele
Dened as some uid in scrotum around testis and/or in processus vaginalis, common in neonates—not to be confused with normal minor uid formation (Fig.15.48).
Fluid anechoic, some sedimented echoes may exist particularly in/after chronic
conditions. Hydroceles may contain echoes—e.g., after foetal meconium peritonitis
often echogenic meconium remnants or calcications can be detected.
Giant hydroceles (even if reactive) may impair testicular perfusion—need to be
relieved.
• Spectral Doppler may help in assessing asymmetric ow patterns as a sign of
perfusion impairment.
In older patients secondary to underlying condition (e.g. tumour, torsion,
Note
trauma—haematocele, inammatory process, varicocele).
DDx
Fluid in scrotum secondary to inguinal hernia/ascites; sonographic key—continuity
of uid through inguinal canal into abdominal space.
15 Ultrasound oftheUrogenital Tract inNeonates, Infants, andChildren
447
c
Fig. 15.48 Hydrocele. (a) Axial section—both testes/scrotum: right-sided hydrocele; the mini-
mal uid on the left side is physiologic in neonates. (b) Longitudinal section: uid conned to
scrotum, no funiculocele. Note small cyst of epididymis (c) Echogenic remnants of meconium (*)
after foetal meconium peritonitis oating in hydrocele next to testicle and within inguinal canal
(arrow)—dual image
Fig. 15.49 Undescended testis. Testis seen in inguinal canal (a, + +) or intra-abdominal (b,
+…+) lateral to nearly empty, thick-walled urinary bladder
1
15.8.3.2 Undescended Testes
Common nding in early infancy; may be associated with unstable testicular position. Physiological delay of testicular descend may spontaneously mature/resolve.
US Findings
Testes not located in scrotum:
• Carefully assess inguinal canal, region next to the abdominal wall, near internal
orice of the inguinal canal for testicular structures (Fig.15.49). Non-descended
testis may be smaller and dysplastic, prone to malignant conversion.
448
M. Riccabona
Intra-abdominal testicular position (often adjacent to bladder or psoas muscle) more difcult to depict, particularly as undescended testes may be dysplastic
and small, exhibit somewhat altered echogenicity—thus denite identication
sometimes impossible. May even be found at the lower pole of the spleen
or kidney.
Note This also applies for MRI where typical testicular signal may be lost in small
dysplastic testes. Increasingly value of US (and imaging in general—impact on
treatment?) questioned, as often testicular position estimated higher on US than in
reality—due to cremasteric reex when touched by transducer by pulling testicle up
into inguinal canal or abdomen.
Role of US
• To nd position of testes.
• Potentially to assess for reducibility/mobility.
• Assess size, parenchymal structure, perfusion for depiction of (hypo-)dysplasia.
Note Always perform a basic assessment of the urinary tract, as there may be asso-
ciated conditions.
15.8.3.3 Varicocele
Venous impairment, leading to dilatation and tortuosity of veins of pampiniform
plexus, most commonly found in peripubertal boys. Commonly on the left side:
• May cause hydrocele, eventually infertility.
If in untypical age, on the right side, recurrence after treatment: always assess for
potential underlying abdominal tumours causing congestion of testicular draining
vein (particularly Wilms’ tumour, adenopathy, retroperitoneal tumours such as neuroblastoma/ganglioneuroma or metastases)—perform abdominal survey.
US Findings
“Sack of worms”-like appearance of tubular/circular anechoic structures that may
change size during Valsalva manoeuvre.
Accompanying hydrocele, potentially asymmetric testicular size (Fig.15.50).
CDS
Particularly with Valsalva manoeuvre bidirectional/undulating venous ow/retrograde ow direction visualised (Fig.15.50). Depending on the amount of ow/ow
direction, US can grade varicocele (used for follow-up/indication for surgery):
• Grade I: clinically normal, slight increase of venous plexus structures during
Valsalva.
15 Ultrasound oftheUrogenital Tract inNeonates, Infants, andChildren
Fig. 15.50 Varicocele. (a) “Sack of worms”-like appearance of dilated veins entering into scro-
tum (inguinal cross section). (b) Vivid colour signals with venous ow prole on Valsalva manoeuvre (similar section as a)
449
• Grade II: palpable dilatation of externally visible enlarged veins that can be
sonographically seen even without Valsalva; change of ow direction during
Valsalva.
• Grade III: huge dilatation and tortuosity of veins are obvious on clinical inspec-
tion (sack of worms), constant inverted ow, even without Valsalva manoeuvres.
15.8.3.4 Cystic Dysplasia ofRete Testis andSeminal Vesicles
Cystic dysplasia of rete testis: rare condition, associated with urogenital
malformation.
Note Not tubular ectasia as in adults resulting from obstruction but congenital mal-
formation deriving from failure of fusion of afferent ducts.
US Findings
Multiple, particularly pseudo-conuent cysts/cystic dilatation of rete testis/afferent
ducts, associated with parenchymal atrophy/dysplasia. Cysts often located at testicular mediastinum, may compress surrounding parenchyma.
Note Cysts may contain mucoid material causing atypical US appearance—can be
mistaken for tumour, abscess, microlithiasis (if with speckled echogenicity), can
cause pseudoow on CDS (if high output power is applied).
Cystic dysplasia of seminal vesicles: Rare condition, associated with other urogenital malformations (e.g. ipsilateral MCDK, renal agenesis).
US Findings
Multicystic, often conuent mass at site of seminal vesicle—usually without echoes,
sometimes difcult to differentiate from residual remnant of MCDK in ectopic
position (if no kidney seen further up and large).
450
M. Riccabona
15.8.3.5 Testicular andParatesticular/Epididymal Cysts/
Spermatocele
Rare, present with painless scrotal enlargement.
Appears on US like all cysts, usually anechoic mass=uncomplicated cyst.
Spermatoceles extremely rare in childhood.
Cysts may enlarge, compromise testicular parenchymal growth if large.
Differentiation against cystic tumour (teratoma) or ectatic vascular malformation
may be difcult.
Role of US
To depict reason for scrotal enlargement.
• Differentiate from rare venolymphatic vascular malformations (have echogenic
septations that may also exhibit some ow on CDS, can mimic complex haema-
tocele/hydrocele).
• Differentiate against paratesticular cystic masses (e.g. dermoids–often contain
some debris/sedimentations, epididymal cysts, spermatoceles (commonly seen
only in teenagers), tunical cysts, other causes of enlargement, particularly
tumours).
15.8.3.6 Microlithiasis
Yet undened entity with multiple calcications within testis. Consists of debris
with calcic core in seminiferous tubules. Said to be sometimes precancerous
(under discussion), associated with infertility:
• Some centres recommend follow-up/screening. During course calcication may
increase or decrease.
Maybe associated with number of conditions (e.g. cryptorchidism, pseudoxanthoma elasticum, cystic brosis, chromosomal anomalies, but also after insult to
testis). Not to be confused with focal calcication after trauma/infection/surgery, in
tumours, or paratesticular calcications (e.g. after torsion of testicular appendices
and meconium peritonitis).
US Finding
Multiple stippled small calcications within testis causing blip-like echogenic spots
throughout testis (twinkling sign on CDS) (Fig.15.51). Often bilateral.
In future elastography may be helpful for nding early tumourous changes.
15.8.4 Inflammation—Orchitis, Ependymitis
Often clinically evident by increased size, reddish skin, pain, with typical laboratory
ndings.
US used to differentiate from torsion or detect abscess/necrosis.