During the course of this experimental study tomograms of extracted teeth were analyzed before and after filling the root canals with an endodontic material and fragments of broken metal instruments for root canal treatment. During the first stage of the experiment, untreated extracted teeth were scanned using conebeam computed tomography and microfocus cone-beam computed tomography. A comparative assessment of capabilities of the two methods of cone-beam computed tomography based on examination of untreated root canals was carried out. The second part of the study is dedicated to visualization of root canals that contain foreign high-density materials.
Between December and September 2018 123 patients with head and neck tumors underwent ultrasound examination. The median age of the patients was 57 years (range 19–76 years). Metastatic lymph nodes were suspected in all patients. A fine needle aspiration biopsy was performed prior to treatment. Aplio 500 (Тoshiba, Japan) ultrasound device was used. According to findings of cytological examination, all patients were divided into 2 groups. Group I consisted of 58 patients with cytologically confirmed metastatic lymph nodes. Group II comprised 65 patients with lymphoid reticular hyperplasia. The values of Young’s modulus for metastatic lymph nodes were: median – 134.2 kPa, 2.5–97.5 percentiles – 7.3–181.7 kPa. The corresponding values for hyperplastic lymph nodes were: 20.1 kPa, 6.9–138.3 kPa. Thus, significant differences in the values of Young’s modulus between metastatic and hyperplastic lymph nodes were detected in patients with head and neck cancer (p<0.001). The best diagnostic values for detecting metastatic lymph nodes in patients with head and neck cancer were achieved with a threshold value of the Young’s modulus of 33.2 kPa (sensitivity – 89.7 %, specificity – 84.6 %), AU C – 0.899. The values of the Young’s modulus in the metastatic lymph nodes did not depend on the primary tumor and on the localization of the lymph nodes studied (submandibular, paratracheal, cervical, supraclavicular groups).
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