High-Frequency Ultrasound Imaging of the Intestine in Normal Subjects and Patients with Intestinal Parasites

High-frequency ultrasound imaging was used to evaluate the intestinal walls of the duodenum and colon in patients with intestinal parasitic infections. Ultrasound images were obtained from 100 consecutive patients with symptomatic intestinal parasitic diseases and 40 healthy controls. High-frequency annular array transducer of 7.5 MHz was used to obtain B-mode ultrasound gray-scale and color images of the duodenum and colon with and without water contrast. The diagnosis of parasitic infections was based on clinical presentation, serial stool microscopy, and finding of parasites in duodenal aspirates. We demonstrated normal duodenum and colon echoanatomy in control subjects. In patients with giardiasis, the lesions of the duodenum and colon were associated with increased dimensions and wall thickness compared to healthy controls (p < 0.05). The ultrasound features of giardial lesions were characterized by increased wall echogenicity, flattening or loss of duodenal folds, and/or colonic haustration, hyperechoic floating foci demonstrating chaotic motility, increased perilesional tissue echogenicity, and altered colonic peristalsis. In amebic lesions there were hyperechoic floating foci with bulk motility. There is loss of wall thickness at amebic ulcer sites or wall thickening at amebic granuloma. Helminths were visualized as large hyperechoic linear or curvilinear foci with serpentine or jolting motility. In conclusion, high-frequency B-mode ultrasound imaging with water contrast demonstrated details of duodenal and colonic echoanatomy in normal subjects and patients with giardiasis