Diagnostic ultrasound ( PDFDrive )

1390 PART IV Obstetric and Fetal Sonography
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FIG. 40.14 Thanatophoric Dysplasia at 33 Weeks. (A) Platyspondyly appears on ultrasound as a thin vertebral body (arrows) with relatively
larger hypoechoic intervertebral disc space on either side of the vertebral body. (B) Correlative lateral spine radiograph. Note the short ribs with
wide-cupped metaphyseal ends.
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FIG. 40.15 Temporal Lobe Dysplasia in Thanatophoric Dysplasia at 19 Weeks. (A) Modiied coronal oblique image demonstrates abnormal
temporal lobe gyration with multiple deep sulcation (arrows). (B) Photograph demonstrates correlation with evidence of deep temporal lobe sulcation
(arrows).
demonstration of temporal lobe dysplasia is variable, likely due
to a combination of factors including other striking indings that
distract from the diagnosis, lack of dedicated views, and lack of
awareness of this feature. Wang et al. demonstrated that 79% of
the cases (11/14) had temporal lobe dysplasia detected antenatally
even without routine dedicated views. 61 We suggest that in fetuses
with severe skeletal dysplasia, speciic search for temporal lobe
dysplasia using a low axial plane below the level of the biparietal
diameter (BPD) image and a coronal oblique plane that includes
the cerebellum of midline be added to the institutional protocol
to better visualize the temporal lobe in order to improve speciicity
of diagnosis. hree-dimensional imaging with multiplanar
reformats may also demonstrate these indings.
hanatophoric dysplasia, achondroplasia, and hypochondroplasia
are all related to the FGFR3 gene mutation. 51 Temporal
lobe dysplasia has been described in children with the latter two
conditions; however, the site difers with thanatophoric dysplasia
typically showing the abnormal sulcation in the inferior aspect
of the temporal lobes versus primarily the medial aspect of the
temporal lobes in hypochondroplasia. here is one report of
prenatal identiication of medial temporal lobe dysplasia on MRI
in a case of hypochondroplasia. 63
Other anomalies may include horseshoe kidneys, hydronephrosis,
congenital heart disease (atrial septal defect and
tricuspid insuiciency), radioulnar synostosis, and imperforate
anus. 64