Duplex sonography, vascular

Duplex sonography Vascular halo Vascular haloes Normal Reduced vascularity Enhanced vascularity... 

Acute reduction in renal perfusion is considered important in the pathophysiology of contrast agent-induced nephrotoxicity. Color-coded duplex sonography has been used in assessing intrarenal vascular resistance in 10 patients (mean age 51 years) after intravenous injection of 100 ml of the low-osmolar contrast medium iopamidol (iodine 300 mg/ml) (182). The resistive index was measured at 1-minute intervals over 10 minutes after injection in each patient. There was a statistically significant rise in resistive index at 2, 3, 4, and 5 minutes after injection, mean values 0.74, 0.75, 0.72, and 0.75... 

Fig. 1.52. Intussusception. Duplex Doppler sonography. Color Doppler indicates wall vascularity. High resistive index is observed in the vessels within the intussusception. This intussusception could be reduced...

Fig. 19.5a,b. Sonography in haemolytic uremic syndrome (HUS), a Severe thickening of the howel wall caused by severe E. coli enteritis (extended view sonography with tissue harmonic imaging), b Alteration of renal parenchymal echogenicity in HUS, with duplex Doppler sonography showing elevated RI (RI = 0,82) due to reduced diastolic flow velocity and increased renal vascular resistance... 

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