Diagnostic ultrasound ( PDFDrive )

CHAPTER 36 The Fetal Chest 1249
Left
Right
A
Right
B
Left
C
HT
D
Right
Left
E
F
G H I
FIG. 36.4 Congenital Pulmonary Airway Malformation (CPAM). (A) Axial sonogram at 28 weeks shows a homogeneously echogenic mass
(calipers) in the mid–left hemithorax with no large cysts or feeding vessels. There is mild mediastinal shift to the right. (B) Axial sonogram of
right-sided CPAM (arrow) at 20 weeks with small cysts, the largest of which is 8 mm (arrowhead). There is moderate mediastinal shift to the left.
(C) Sagittal oblique sonogram shows CPAM everting the hemidiaphragm (arrow). (D) Transverse view of chest with CPAM containing small cysts
and mild mediastinal shift. (E) and (F) Axial and oblique coronal images at 25 weeks in a macrocystic CPAM (arrow) with eversion of the hemidiaphragm,
trace ascites (arrowhead), and severe mediastinal shift with compression of the heart (HT). (G) Ultrasound-guided percutaneous drainage
of CPAM. A 20-gauge needle was inserted into the largest cyst with relief of cardiac compression. (H) Coronal T2-weighted MRI shows a wellcircumscribed
area of T2 hyperintensity (arrow) in the left upper lobe. (I) Oblique coronal T2-weighted MRI shows a well-circumscribed area of low
T2 signal (arrow) in a fetus with a typical, resolving CPAM. See also Video 36.1.
20 to 26 of gestation, peaking at about 25 weeks, 48,62 and then
growth plateaus and oten regresses. 68 here are no reliable criteria
for determining which lesions will continue to grow versus those
that will stabilize or regress. About 50% of masses persist to
delivery. 49 Fiteen percent of these masses decrease in size during
the late second and the third trimesters; the majority have a
relative decrease in size as a result of normal fetal thoracic growth,
but a few increase in size. 46,62 As masses decrease in size, their
echogenicity can become similar to that of surrounding normal
lung because of an increase in normal lung echogenicity and
decrease in echogenicity of the CPAM. hus they may become
diicult to visualize late in gestation, with residual mass efect
being the main inding on ultrasound.
If the fetus does not develop hydrops before 26 weeks, the
prognosis is generally good. 49,69 Close surveillance of the growth
of these lesions is recommended throughout the second trimester
particularly if the CVR is higher than 1.6. Delivery planning
should be made in conjunction with the neonatology and/or
pediatric surgery teams. If the lung mass has resolved or is small
with no mediastinal shit or hydrops, the presence of a CPAM
itself is not an indication for early delivery or cesarean delivery 69
as neonatal respiratory issues are unlikely.