RESUMO
PURPOSE: Ultrasound-guided puncture and punch biopsy pose a particular challenge in ultrasound examination training. These techniques should be learned and performed several times using a simulation model that is as realistic as possible before being applied to patients. While the use of agar-agar-based models is extensively documented in the literature, there is a discernible gap in publications specifically addressing their use in punch biopsy and puncture. The aim was to develop a cost-effective model for the simulation of ultrasound-guided interventions. MATERIALS AND METHODS: The developed simulation model is based on the vegetable gelatine agar-agar. The agar-agar powder is boiled in water and colored. Various objects are added to the mass. Blueberries, olives, tomatoes, and cornichons imitate solid structures. Liquid-filled balloons are used to simulate cystic structures. Adding stones can make the exercises more difficult due to hyperechoic reflexes with distal shadowing. RESULTS: With the model, ultrasound-guided puncture and punch biopsies could be successfully simulated, and ultrasound images can be generated for this purpose. The cost of a single model is about 2 euros. Production takes less than 2 hours, including cooling. The pure processing time is 30 minutes. The durability of the models is limited by mold, which occurs after 5 days when stored at room temperature and after 5 weeks in the refrigerator. CONCLUSION: It was shown that it is possible to produce an inexpensive agar-agar-based ultrasound model in a short time and with easily available ingredients to learn ultrasound-guided puncture and punch biopsies.
RESUMO
(1) Background: Computed tomography (CT) is considered mandatory for assessing the extent of pathologies in the paranasal sinuses (PNS) in chronic rhinosinusitis (CRS). However, there are few evidence-based data on the value of ultrasound (US) in CRS. This multicenter approach aimed to compare diagnostic imaging modalities in relation to findings during surgery. (2) Methods: 127 patients with CRS were included in this prospective multicenter study. Patients received preoperative US and CT scans. The sensitivity and specificity of CT and US were extrapolated from intraoperative data. (3) Results: CT scans showed the highest sensitivity (97%) and specificity (67%) in assessing CRS. Sensitivities of B-scan US were significantly lower regarding the maxillary sinus (88%), the ethmoid sinus (53%), and the frontal sinus (45%). The highest overall sensitivity was observed for assessing the pathology of the maxillary sinus. (4) Conclusions: We observed high accuracy with CT, confirming its importance in preoperative imaging in CRS. Despite the high US expertise of all investigators and a standardized examination protocol, the validity of CT was significantly higher than US. Ultrasound of the PNS sinuses is applicable in everyday clinical practice but lacks diagnostic accuracy. Nevertheless, it might serve as a complementary hands-on screening tool to directly correlate the clinical findings in patients with PNS disease.