Mm

PW.40ttte 6=46* Uwertiert

Fig. 314a-c ICA stenosis.

a Decreased flow velocity with an intact frequency spectrum upstream of the stenosis. b Markedly decreased flow velocity just proximal to the stenosis. c Increased flow velocity in the stenosis, with Vmax up to 140cm/s n ICA occlusion:

• Ipsilateral ICA: spectral waveform cannot be recorded (Figs. 315c and 316f)

• Ipsilateral ECA: turbulence and increased flow velocity (Fig. 315)

• Ipsilateral CCA: spectral waveform resembles that of the ECA (with ICA occlusion, the CCA becomes a pure resistance vessel, Fig. 316)

Turbulent Flow Cca

Fig. 315a-d Typical findings in the cervical vessels associated with occlusion of the ICA. a CDS appearance of the ECA in the presence of an ICA occlusion. Turbulent flow (mixed color pattern) in the ECA. b Spectrum from the ECA: Vmax > 2 m/s c A spectrum cannot be recorded from the ICA. d Spectrum from the CCA in the presence of an ICA occlusion. The spectral waveform resembles that of the ECA (the CCA becomes a pure resistance vessel in cases where the ICA is occluded)

Ica Waveform ImagesOccluded EcaEca Waveform

Fig. 316a-d Typical findings in the cervical vessels associated with occlusion of the ICA. a Abnormal spectrum from the CCA shows an end-diastolic dip with a relatively low diastolic flow velocity. The waveform resembles that of the ECA. b > 50% luminal narrowing of the ICA. Turbulent signals are not detected in this case. c ECA stenosis. The spectrum from the ECA indicates flow acceleration. d Doppler interrogation of the ECA stenosis. The maximum measurable flow velocity in the ECA, at 2.45 cm/s, indicates an approximately 70% stenosis of the ECA

Fig. 316 e, f Typical findings in the cervical vessels associated with occlusion of the ICA. e Longitudinal scan of the CCA shows an abrupt cutoff of blood flow in the ICA with color reversal (blue). f Transverse scan of the ICA and ECA. The ICA appears occluded with echogenic material in cross section, with no evidence of color flow signals. By contrast, the color signals in the ECA indicate flow. An oblique section of the anechoic internal jugular vein (IJV) appears adjacent to the ICA

Fig. 316 e, f Typical findings in the cervical vessels associated with occlusion of the ICA. e Longitudinal scan of the CCA shows an abrupt cutoff of blood flow in the ICA with color reversal (blue). f Transverse scan of the ICA and ECA. The ICA appears occluded with echogenic material in cross section, with no evidence of color flow signals. By contrast, the color signals in the ECA indicate flow. An oblique section of the anechoic internal jugular vein (IJV) appears adjacent to the ICA

n Jugular vein thrombosis following insertion of a central venous catheter:

Jugular Wall
Fig. 317a, b Thrombosis of the jugular vein. a Echogenic thrombus (T) in the jugular vein (JV) following insertion of a CVC. b CDS demonstrates flow (encoded in blue) around the thrombus

Fig. 317 c, d Thrombosis of the jugular vein. c Transverse scan of the jugular vein demonstrates circumferential flow around the thrombus. d Scan at a higher level shows the thrombus adherent to the vessel wall

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