The Avaibility of Strain Elastography in a Hydatid Cyst - Interobserver Study

To differentiate the hydatid cyst (HC) types by ultrasound elastography using two different sizes (4 mm and 8 mm) of the region of interest (ROI) and asking two different radiologists (interobserver) for their opinion.

Patients with HC were evaluated by USG elastography. The statistical anayses were performed using Strain index (SI) which is the unit of strain elastography.

A total of 26 out of 33 patients were female, and 7 were male. The mean age was 38.85±17.62 (range from 10 to 72 years). Type I: 6, Type 2: 6, Type III: 6, Type IV: 11, Type V: 4. There was no significant difference in HC SI (regardless of types) between O1 and O2, and 4-mm and 8-mm ROI (p>0.05). There was no statistically significant difference between SI of HC types of interobservers (O1-O2) and ROI sizes (4-8 mm) (p>0.05 for all parameters). The highest correlation between HC types and ROI sizes was in ROI size of 4 mm.

The correlation between SI and types was reliable in standard-applied 4-mm ROI. There was no statistically significant difference between interobservers in SI values. Thus, elastography tecnhnique is objective for HC but not appropriate to differentiate the types.