Ultrasound

CAROTID DUPLEX ULTRASONOGRAPHY

TABLE 70-1 Gray Scale and Doppler Ultrasound (US) Criteria for Diagnosis of Internal Cartoid Artery (ICA) Stenosis

	Primary parameters		Additional parameters
Degree of stenosis (%)	ICA PSV (cm/s)	Plaque estimate (%)	ICA/CCA PSV ratio	ICA EDV (cm/s)
Normal	<125	None	<2.0	<40
<50	<125	<50	<2.0	<40
50-69	125-230	≥50	2.0-4.0	40-100
≥70 but less than near occlusion	>230	≥50	>4.0	>100
Near occlusion	High, low, or undetectable	Visible	Variable	Variable
Total occlusion	Undetectable	Visible, no detectable lumen	Not applicable	Not applicable
PSV, peak systolic velocity; CCA, common cartoid artery; EDV, end diastolic ratio. (From Grant EG, Benson CB, Moneta GL, et al. Radiology 2003;229:340-346.)

ABDOMINAL DUPLEX ULTRASONOGRAPHY

Renal Transplant

Parenchymal resistive indices (RIs) (arcuate and intralobar arteries):

Reversal of diastolic flow in the venous system often indicates renal vein thrombosis. Renal artery anastomosis:

Equal to or greater than 3:1 ratio of PSV between anastomosis: iliac artery equal to stenosis or kinked vessel.
PSV greater than 180-210 cm/second is suggestive of stenosis.
RI is less important.

(Adapted from Friedewald SM, Molmenti EP, Friedewald JJ, et al. J Clin Ultrasound 2005;33:127-139.)

Liver Transplant

Hepatic artery resistive index less than 0.5 suggests central hepatic artery thrombosis or stenosis.

Transjugular Intrahepatic Portosystemic Shunt

Shunt velocity