Journal of Surgical Simulation 2020; 7: 24 - 32

Published: 02 November 2020


Original article

A low-cost phantom for ultrasound-guided thyroid fine-needle aspiration training: face and construct validity

David Z. Liao, Vikas Mehta, Eugenie Du, Vafa Tabatabaie, I. Martin Levy, Richard V. Smith and Marc J. Gibber
Corresponding author: Marc J. Gibber, 3400 Bainbridge Avenue, 3rd Floor MAP Building, Room 3303, Bronx, NY 10467, USA. Email:


Background: There are currently no formally validated training phantoms for teaching ultrasound-guided thyroid fine-needle aspiration (FNA). We designed and established face and construct validity of a low-cost phantom for ultrasoundguided thyroid fine-needle aspiration. 

Methods: We designed an affordable, gelatin-based thyroid FNA phantom. Participants included 9 medical students, 7 novice residents/fellows (<5 thyroid FNAs), and 7 expert residents/fellows (≥5 thyroid FNAs). Participants performed 6 trials of thyroid FNA, which were scored on completion time, accuracy, and errors. Participants also completed questionnaires to assess the benefit and realism of the simulation. 

Results: Simulation scores at trial 1 significantly discriminated expert participants from novice participants (P = 0.028) and from medical students (P < 0.001). Median novice resident/fellow participant scores increased with repeated trials and were no longer significantly different from expert scores by trial 2. The scores for this group were significantly better compared with medical student scores by trial 4. Between trial 1 and trial 6, significant score improvements were observed in both medical students (P = 0.018) and novice residents (P = 0.018). All participants found the phantom to be beneficial in learning thyroid FNA. Both attending endocrinologists and 6 of 7 expert participants found the ultrasound visualization of the phantom to be realistic. One of two attending endocrinologists and 5 of 7 expert participants found the haptic feedback to be realistic.

Conclusion: We designed a low-cost thyroid FNA phantom that demonstrates face and construct validity. This phantom can be used to train procedural skills in a residency program and can also be used to evaluate skill acquisition.


thyroid fine-needle aspiration; ultrasound; thyroid nodule; simulation phantom; low cost