Journal of Ultrasound in Medicine, Vol 19, Issue 3 185-192, Copyright © 2000 by American Institute of Ultrasound in Medicine
Comparison of standard and second harmonic B-mode sonography in the detection of segmental renal infarction with sonographic contrast in a rabbit model
M. S. Girard, R. F. Mattrey, K. G. Baker, T. Peterson, L. H. Deiranieh and G. C. Steinbach
Department of Radiology, University of California, San Diego, USA.
This study compares contrast-enhanced fundamental and second harmonic
B-mode sonography using a rabbit renal infarct model. Segmental renal
infarctions were produced in 13 rabbits by embolizing a 0.7 mm bead into
the renal artery 1 day prior to imaging. An ultrasonographic unit equipped
with an L10-5 transducer and second harmonic imaging capability was used.
Real-time recordings were made during the injection of 0.5 ml of an
experimental formulation of a perfluorohexane vapor-stabilized microbubble
(AF0145) given into the ear vein, and the imaging technique alternated
between standard and harmonic imaging every 20 s. Each rabbit received two
injections 1 h apart. To control for the effect of peak bolus enhancement,
the initial imaging technique used for the first injection was randomized,
and the other technique was used initially for the second injection. The
videointensity difference between the infarcted and the normal cortex was
then calculated and evaluated as a function of time. The infarcted segment
could not be seen before administration of contrast agent with either
technique. Although the infarction could be seen after injection of
contrast agent with either technique, image contrast and contrast duration
were nearly 75% greater for the harmonic technique than for the standard
technique. AF0145 allows the visualization of segmental renal infarction on
standard B-mode imaging. The second harmonic B-mode technique significantly
increases image contrast and contrast duration.
