Diagnostic ultrasound ( PDFDrive )

CHAPTER 54 Pediatric Pelvic Sonography 1873
Bladder
Fundus
Cervix
TABLE 54.1 Pediatric Uterine
Measurements
Age Uterine Length Fundus-to-Cervix Ratio
Newborn 3.5 cm 1 : 2
Prepubertal a 2.5-3 cm 1 : 1
Postpubertal 5-8 cm 3 : 1
a Beginning at age 2-3 months.
Data from Comstock CH, Boal DK. Pelvic sonography of the pediatric
patient. Semin Ultrasound. 1984;5:54-67 13 ; and Rosenberg HK.
Sonography of the pediatric urinary tract. In: Bush WH, editor.
Urologic imaging and interventional techniques. Baltimore: Urban &
Schwarzenberg; 1989. p. 164-179. 16
FIG. 54.5 Normal Newborn Uterus. Sagittal view shows that ratio
of fundus to cervix is 1 : 2 for length, and the somewhat thick endometrial
lining is prominently echogenic as a result of in utero hormonal stimulation
(arrowheads).
FIG. 54.6 Normal Prepubertal Uterus in 2-Year-Old Girl. Sagittal
sonogram through the bladder demonstrates a fundus-to-cervix ratio of
1 : 1 and shows a pencil-line thin, unstimulated endometrial stripe
(arrowheads).
to 5 to 7 cm, and the fundus-to-cervix ratio becomes 3 : 1 13,16
(Table 54.1). he echogenicity and thickness of the endometrial
lining then vary according to the phase of the menstrual cycle,
as in adult women. he uterus is supplied by bilateral uterine
arteries, which are branches of the internal iliac arteries. Color
Doppler imaging generally demonstrates low in the myometrium,
with little or no low in the endometrium. 15
The Vagina
In children, digital and visual examination of the vagina is diicult.
Oten, physical examination of the vagina is performed with the
patient under general anesthesia. High-resolution, real-time
sonography can now obviate this need in many cases. In the
infant or young girl with an interlabial mass, sonography in
conjunction with other imaging modalities can usually determine
the cause. he vagina is best visualized on midline longitudinal
scans through the distended bladder. It appears as a long, tubular
structure in continuity with the uterine cervix. he apposed
mucosal surfaces cause a long, bright, slender, central linear
echo. Hydrosonovaginography (see Fig. 54.1) under real-time
sonography guidance can provide additional information
about vaginal patency or conirm the presence or absence of a
vaginal mass.
The Ovary
Sonographic visualization of the ovaries in children can vary,
depending on their location, size, and the age of the patient (Fig.
54.7, Video 54.2). Because of a typically long pedicle and a small
pelvis, the neonatal ovaries may be found anywhere between
the lower pole of the kidneys and the true pelvis (Fig. 54.8).
Ovarian size is most reproducible and best described by measurement
of the ovarian volume, which is calculated by a prolate
ellipse formula (Length × Depth × Width [in cm] × 0.523 =
Volume [in mL]).
he mean ovarian volume in neonates and girls younger
than 6 years is usually 1 mL or less. 18 Ovarian volume gradually
begins to increase at about age 6 years. he mean ovarian volume
measurement in premenarchal girls aged 6 to 11 years ranges
from 1.2 to 2.5 mL (Table 54.2). here is marked enlargement
in ovarian size ater puberty; thus ovarian sizes in menstruating
females in late childhood will be larger than their premenarchal
counterparts. Cohen and colleagues 19 reported a mean ovarian
volume of 9.8 mL, with a 95% conidence interval between 2.5
and 21.9 mL, in menstruating females.
Beginning in the neonatal period, the appearance of the typical
ovary is heterogeneous secondary to small cysts. Cohen and
colleagues 17 reported observing ovarian cysts in 84% of children
1 day to 2 years of age and 68% of children 2 to 12 years of age.
Macrocysts (>9 mm) were more frequently seen in the ovaries
of girls in their irst year of life compared with those in their
second year. his probably accounts for the larger mean and
top-normal ovarian volume measurements obtained in girls up
to 3 months of age (mean ovarian volume, 1.06 mL; range,
0.7-3.6 mL) versus those 13 to 24 months of age (mean ovarian
volume, 0.67 mL; range, 0.1-1.7 mL). hese indings probably
result from the higher residual maternal hormone level in younger
infants. Orbak and colleagues 20 concluded that ovarian volume