Diagnostic ultrasound ( PDFDrive )

956 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
C
C
A B C
D E F
FIG. 26.56 Internal Jugular Vein (IJV) Thrombosis: Spectrum of Appearances. (A) Transverse image of an acute left internal jugular vein
thrombus (arrow). The vein is distended and noncompressible. C, Common carotid artery. (B) Longitudinal image of a different patient demonstrates
a hypoechoic thrombus and no Doppler signal. (C) Longitudinal color Doppler image shows a small amount of thrombus arising from the posterior
wall of the IJV. (D) Transverse image shows an echogenic thrombus, indicating chronic thrombus in IJV. (E) Longitudinal image demonstrates a
thrombus (arrow) around jugular vein catheter. (F) Longitudinal images show a thrombus arising from anterior wall. This thrombus probably results
from previous catheter placement in this region.
indistinguishable from lowing blood; however, the characteristic
lack of compressibility and absent Doppler or color Doppler
low in the region of a thrombus quickly lead to the correct
diagnosis. In addition, there is visible loss of vein response to
respiratory maneuvers and venous pulsation. Spectral and color
Doppler interrogations reveal absent low (Fig. 26.56). Collateral
veins may be identiied, particularly in cases of chronic internal
jugular vein thrombosis. Central liquefaction or other heterogeneity
of the thrombus also suggests chronicity. Chronic thrombi
may be diicult to visualize because they tend to organize and
are diicult to separate from echogenic perivascular fatty tissue. 260
he absence of cardiorespiratory plasticity in a patent jugular
or subclavian vein can indicate a more central, nonocclusive
thrombus (Fig. 26.57). he conirmation of bilateral loss of venous
pulsations strongly supports a more central thrombus, which
can be documented by angiographic or magnetic resonance
venography.
A thrombus that is related to catheter insertion is oten
demonstrated at the tip of the catheter, although it may be seen
anywhere along the course of the vein. he catheter can be
visualized as two parallel echogenic lines separated by an anechoic
region. Flow is not usually demonstrated in the catheter, even
if the catheter itself is patent.
Sonography is a reliable means of diagnosing jugular and
subclavian vein thrombosis. Sonography has limited access
and cannot image all portions of the jugular and subclavian
veins, especially those located behind the mandible or below the
clavicle, although knowledge of the full extent of a thrombus is
not typically a critical factor in treatment planning. 251,255 Serial
sonographic examination to evaluate response to therapy ater
the initial assessment can be performed safely and inexpensively.
Sonography can also document venous patency before vascular
line placement, facilitating safer and more successful catheter
insertion.
Acknowledgment
hanks to Kathleen McFadden and Barbara Siede for their
assistance with manuscript preparation.