Journal of Ultrasound in Medicine, Vol 20, Issue 3 269-274, Copyright © 2001 by American Institute of Ultrasound in Medicine
Ultrasonographic appearance of Ascaris lumbricoides in the small bowel
T. Mahmood, N. Mansoor, S. Quraishy, M. Ilyas and S. Hussain
Karachi Adventist 7th Day Hospital, Pakistan.
Roundworm infestation, one of the most common helminthic diseases
worldwide, is caused by Ascaris lumbricoides, one of the largest parasites
that infests the human bowel. A lumbricoides is virtually universal at some
stage of childhood in semitropical and tropical regions. This study
describes our experience with the ultrasonographic appearance of intestinal
ascariasis in 84 patients, 2.5 to 42 years of age, examined over 2 years
beginning October 1997. The patients' conditions ranged from acute
intestinal obstruction to no clinical features pertaining to obstruction.
Ultrasonographic examination was performed with an Echocee power Doppler
real-time unit with a variable-frequency 3.7-MHz convex, 7.5-MHz linear
probe. In longitudinal section the Ascaris worm presented as a linear
intraluminal mass with 3 or 4 linear echogenic interfaces; in the cross
section, it was round, sometimes appearing as a "target" sign. Some worms
also showed serpentine movements. Sonographic examination of the patients
in the left lateral decubitus position after ingestion of water improved
detection and visualization of the worms in some cases. It is concluded
that A lumbricoides in the small bowel has a sonographic appearance that
can be recognized by the wary observer.
