title: Analysis of tissue surrounding thyroid nodules by ultrasound digital images.
abstract: Since US is not easily reproducible, the digital image analysis (IA) has been proposed so that the image evaluation is not subjective. In fact, IA meets the criteria of objectivity, accurateness, and reproducibility by a matrix of pixels whose value is displayed in a gray level. This study aims at evaluating via IA the tissue surrounding a thyroid nodule (backyard tissue, BT) from goitres with benign (b-BT) and malignant (m-BT) lesions. Sixty-nine US images of thyroid nodules surrounded by adequate thyroid tissue was classified as normoechoic and homogeneous were enrolled as study group. Forty-three US images from normal thyroid (NT) glands were included as controls. Digital images of 800 × 652 pixels were acquired at a resolution of eight bits with a 256 gray levels depth. By one-way ANOVA, the 43 NT glands were not statistically different (P = 0.91). Mean gray level of normal glands was significantly higher than b-BT (P = 0.026), and m-BT (P = 0.0001), while no difference was found between b-BT and m-BT (P = 0.321). NT tissue boundary external to the nodule was found at 6.0 ± 0.5 mm in cancers and 4.0 ± 0.5 mm in benignancies (P = 0.001). These data should indicate that the tissue surrounding a thyroid nodule may be damaged even when assessed as normal by US. This is of interest to investigate the extranodular effects of thyroid tumors.
authors.affiliation: Section of Endocrinology and Diabetology, Ospedale Israelitico of Rome, Via Fulda, 14, 00148, Rome, Italy, pierpaolo.trimboli@gmail.com.
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Trimboli
authors.forename: Fabiano
authors.initials: F
authors.lastname: Bini
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Andrioli
authors.forename: Luca
authors.initials: L
authors.lastname: Giovanella
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Thorel
authors.forename: Luca
authors.initials: L
authors.lastname: Ceriani
authors.forename: Stefano
authors.initials: S
authors.lastname: Valabrega
authors.forename: Andrea
authors.initials: A
authors.lastname: Lenzi
authors.forename: Francesco Maria
authors.initials: FM
authors.lastname: Drudi
authors.forename: Franco
authors.initials: F
authors.lastname: Marinozzi
authors.forename: Francesco
authors.initials: F
authors.lastname: Romanelli
mesh_terms: D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000592:standards; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods* / Q000592:standards