Diagnostic ultrasound ( PDFDrive )

CHAPTER 40 The Fetal Musculoskeletal System 1393
2D
3D
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G H I
FIG. 40.18 Osteogenesis Imperfecta (OI): Spectrum of Appearances of Fractures. (A) Type IIA. Two-dimensional ultrasound image of
extremely shortened femur with at least two bone deformities, consistent with fractures. Note redundant overlying soft tissues. (B) Correlative
three-dimensional ultrasound image demonstrates a midshaft fracture with callus formation. (C) Type I. Nonlethal variant of OI with a mildly
angulated femur of normal length. (D) Correlative three-dimensional ultrasound image demonstrates the angulated healed fracture. (E) Type III.
Multiple fractures in the mildly to moderately shortened femur are evidenced by multiple discontinuities in the cortex. The demineralized shaft
permits visualization of the thickened cortex. Femur bone length is measured between the calipers. (F) Type II. Extremely short and thickened
femur resulting from repetitive callus formation. Acoustic shadowing is still present in this demineralized fragile bone, and thus its presence is not
a reliable sign of normal mineralization. Femur length is measured between the calipers. (G) Type II. At least two discontinuities are present in
the shortened tibia (arrows), consistent with fractures. Note acoustic shadowing present despite generalized demineralization. Femur length is
measured between the calipers. (H) Type II. Cross section of the thorax demonstrates a typical concavity noted at the lateral aspect of the thorax.
This may be caused by repetitive in utero fractures as the elbows “hit” the fragile rib cage. (I) Type II. Cross section of the thorax demonstrates
normal-length ribs with multiple fractures within each rib, resulting in a wavy contour.
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B
FIG. 40.19 Osteogenesis Imperfecta Type IIA at 17 Weeks. (A) Rounded head contour. (B) Gentle transducer compression on the demineralized
calvarium results in lattening of the cranial contour. Note widened fontanelles and sutures, as well as ease of visualization of intracranial contents
in the near ield (which would usually have artifacts caused by shadowing from the ossiied skull).