The influence of image display systems on observers' preference for visualizing subtle dental radiographic abnormalities.

OBJECTIVE: The objectives of this study were to assess observers' preference for standard screens (SSs) or medical displays (MDs) in visualizing difficult-to-diagnose radiographic dental abnormalities and their preference for dental filter tools when utilized with MD systems. STUDY DESIGN: A retrospective data set of 60 in vivo radiographs consisting of intraoral (n = 20), panoramic (n = 20), and cone beam computed tomography (n = 20) images was created. Three image display monitors, including an SS, an MD, and an MD with 3 dental filter configurations (bone-low density enhancement filter, tooth-high density enhancement filter, and a combined filter representing regular MD), were utilized to assess 4 observers' monitor preferences in detecting radiographically subtle dental abnormalities. The data were analyzed by using binomial distribution. A P value ≤.05 was considered statistically significant. RESULTS: Although observers expressed preference for MD for visualizing some abnormalities when examining intraoral and panoramic radiographs, MD was not preferred for detection of any abnormalities with cone beam computed tomography. There were no significant differences in preference for SS or MD overall (P ≥ .2024). Observers expressed significant preference for the filters in visualizing all but 2 abnormalities (P ≤ .0252). CONCLUSIONS: The use of MD monitors enabled with dental filter tools may be preferred for visualizing certain subtle abnormalities.

Observer preference for a dedicated medical display vs a standard screen in the detection of dental radioanatomic features.

OBJECTIVE: The aim of this study was to assess observers' preference for a dentomaxillofacial dedicated medical display (MD) vs a general-purpose standard screen (SS) for in vitro and in vivo observation of normal radioanatomic features. STUDY DESIGN: The in vitro sample consisted of 2-dimensional (2-D) intraoral (n = 15), panoramic (n = 2), cephalometric (n = 2), and 3-dimensional (3-D) cone beam computed tomography (CBCT) (n = 9) data sets, acquired by utilizing commercially available skull and head-and-neck phantoms. The in vivo sample consisted of 80 radiographs (intraoral = 20; panoramic = 20; cephalometric = 20; and CBCT = 20). In vitro and in vivo data sets were both acquired by using Minray, Promax2-D, and Vistapano Ceph for 2-D images and Accuitomo, NewTom VGi evo, and Promax3-D for CBCT images. Five observers entered screen preferences when evaluating the appearance of radioanatomic structures on MD and SS. RESULTS: Both in vitro and in vivo assessments showed good interobserver and excellent intraobserver agreement. In vitro data suggested a significant preference for MD over SS for viewing radioanatomic features on panoramic and CBCT images, whereas MD was significantly preferred for in vivo images of all imaging modalities (P < .001). CONCLUSIONS: Overall, observers preferred MD over SS for both in vitro and in vivo observation of normal radioanatomic features irrespective of the imaging modality.

Validation of a novel imaging approach using multi-slice CT and cone-beam CT to follow-up on condylar remodeling after bimaxillary surgery.

The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography (MSCT) and postoperative cone-beam computed tomography (CBCT) images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients (11 female and 9 male) who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant (P<0.05) mean bone volume decrease of 26.4%±11.4% (502.9 mm3±268.1 mm3). No significant effects of side, sex or age were found. Good to excellent (ICC>0.6) intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel (0.4 mm) for MSCT (0.3 mm±0.2 mm) and CBCT (0.4 mm±0.3 mm), thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.

[Frequency of positive anti thyroid peroxidase antibody titers among normal individuals]. / Alta frecuencia de anticuerpos anti-tiroperoxidasa (ATPO) positivos en sujetos adultos, sin patología tiroidea conocida, de Santiago de Chile.

BACKGROUND: Anti-thyroid peroxidase antibodies have a pathogenic role in Hashimoto thyroiditis. Between 10 and 19% of individuals without thyroid disease, have positive titers of these antibodies. AIM: To study the frequency of positive titers of anti-thyroid peroxidase antibodies in healthy individuals. MATERIAL AND METHODS: A blood sample, to measure anti-thyroid peroxidase antibodies and thyroid stimulating hormone (TSH) by chemoluminiscense assay, was obtained from 67women and 62 men aged 45 +/- 14years, without a personal or familiar history of thyroid diseases and normal thyroid palpation. The cutoff point of the manufacturer to consider positive a titer of anti-thyroid peroxidase antibodies was set at 35 IU/ml. RESULTS: Twenty-eight women and 28 men had positive antibody titers (43% of the sample). Subjects in the upper tercile of anti-thyroid peroxidase antibody titers had a higher TSH than those in the second tercile, although within normal limits (1.73 +/- 0.74 and 1.37 +/- 0.59 mlU/L, respectively p = 0.02) CONCLUSIONS: Forty three percent of the studied subjects without personal or familial history of thyroid diseases had positive titers of anti-thyroid peroxidase antibodies. Further prospective studies should evaluate whether this observation discloses an increase in thyroid autoimmune disease in a population with increased iodine intake.

Alta frecuencia de anticuerpos anti-tiroperoxidasa (ATPO) positivos en sujetos adultos, sin patología tiroidea conocida, de Santiago de Chile / Frequency of positive anti thyroid peroxidase antibody titers among normal individuals

Background: Anti-thyroid peroxidase antibodies have a pathogenic role in Hashimoto thyroiditis. Between 10 and 19 percent of individuals without thyroid disease, have positive titers of these antibodies. Aim: To study the frequency of positive titers of anti-thyroid peroxidase antibodies in healthy individuals. Material and Methods: A blood sample, to measure anti-thyroid peroxidase antibodies and thyroid stimulating hormone (TSH) by chemoluminiscense assay, was obtained from 67women and 62 men aged 45 ± 14years, without a personal or familiar history of thyroid diseases and normal thyroid palpation. The cutoff point of the manufacturer to consider positive a titer of anti-thyroid peroxidase antibodies was set at 35 IU/ml. Results: Twenty-eight women and 28 men had positive antibody titers (43 percent of the sample). Subjects in the upper tercile of anti-thyroid peroxidase antibody titers had a higher TSH than those in the second tercile, although within normal limits (1.73 ± 0.74 and 1.37 ± 0.59 mlU/L, respectively p = 0.02) Conclusions: Forty three percent of the studied subjects without personal or familial history of thyroid diseases had positive titers of anti-thyroid peroxidase antibodies. Further prospective studies should evaluate whether this observation discloses an increase in thyroid autoimmune disease in a population with increased iodine intake.