Scaling digital radiographs for templating in total hip arthroplasty using conventional acetate templates independent of calibration markers

We describe a scaling method for templating digital radiographs using conventional acetate templates independent of template magnification without the need for a calibration marker. The mean magnification factor for the radiology department was determined (119.8%, range117%-123.4%). This fixed magnification factor was used to scale the radiographs by the method described. 32 femoral heads on postoperative THR radiographs were then measured and compared to the actual size. The mean absolute accuracy was within 0.5% of actual head size (range 0 to 3%) with a mean absolute difference of 0.16mm (range 0-1mm, SD 0.26mm). Intraclass Correlation Coefficient (ICC) showed excellent reliability for both inter and intraobserver measurements with ICC scores of 0.993 (95% CI 0.988-0.996) for interobserver measurements and intraobserver measurements ranging between 0.990-0.993 (95% CI 0.980-0.997).

Evaluation of digital optical density of bone repair in rats medicated with ketoprofen

O objetivo deste estudo foi avaliar a influência do cetoprofeno sobre o processo de reparação óssea em tíbias de ratos, por meio da análise da densidade óptica digital. Vinte ratos da linhagem Wistar foram divididos em 2 grupos: um grupo controle (sem tratamento) e um grupo tratado com cetoprofeno. Os procedimentos experimentais consistiram de: anestesia, cirurgia, administração do cetoprofeno e exame radiográfico. As imagens radiográficas foram adquiridas empregando-se o sensor digital Visualix GX-S-HDI™ e um aparelho de raios X. As radiografias foram realizadas nos períodos baseline (inicial), 7, 14, 21 e 30 dias pós-operatório, sendo a densidade óptica (DO) avaliada por meio do sistema Vix winTM 1.4. Os valores médios da leitura da do obtidos foram analisados estatisticamente por meio de ANOVA e teste de Tukey com nível de significância de 5%. No grupo controle, houve diferença estatisticamente significante (p=0,001) entre o tempo e a DO, enquanto no grupo tratado com cetoprofeno a diferença não foi estatisticamente significante (p=0,100). O grupo controle apresentou as menores proporções de do (%) no 1º e 7º dias e as maiores proporções de do (%) no 14º, 21º e 30º dias, com diferença estatisticamente significante (p=0,001). Não houve diferença estatisticamente significante (p=0,100) entre as proporções médias de do (%) no grupo tratado, independentemente do período de avaliação. Os achados deste trabalho sugerem que houve influência do cetoprofeno sobre o processo de reparo ósseo, uma vez que na primeira semana o medicamento proporcionou aumento na densidade óptica e provocou atraso na neoformação óssea após o 21º dia.

Digital radiographic evaluation of optical density of porcelains used for fabrication of inlay/onlay prosthesis

The purpose of this article was to compare the mean value of optical density of four porcelains commonly used for fabrication of inlay/ onlay prostheses using direct digital radiograph. The sample consisted of 20 2-mm thick porcelain specimens (measured by digital pachymeter): Empress (Ivoclair), Simbios (Degussa), Vita Omega 900 and Vitadur Alpha (Vita Zahnfabrik). The values of optical density of the specimens were expressed in millimeters aluminum equivalent (mm eq Al). The samples were X-rayed using two charge coupled devices (CCD) - RVG (Trophy) - Visualix (Gendex) and a phosphor plate system - Digora (Soredex). The optical density reading was performed with Image Tool 1.28 in a total of 110 measurements. Statistical analysis showed that there were statistically significant differences in all materials studied (p < 0.05) regardless of the radiographic system used. The highest optical density value was found for Omega 900 (1.8988 mmeqAl - Visualix - Gendex) and the lowest for Vitadur Alpha (0.8647 - Visualix - Gendex). Thus, the material presenting the highest degree of optical density was Omega 900, Empress and Simbios presented intermediate optical density values, Vitadur Alpha presented the lowest value, and the optical density of porcelains was not influenced by the digital radiography systems.

Determinação da profundidade da lesão de cárie oclusal em dentes decíduos por meio de radiografias convencional e digital direta. Efetividade dos recursos de imagem e desempenho do examinador

Pós-graduação em Odontologia - FOAR

Digital radiography for determination of primary tooth length: in vivo and ex vivo studies

Background. Methods for determining the root canal length of the primary tooth should yield accurate and reproducible results. In vitro studies show some limitations, which do not allow their findings to be directly transferred to a clinical situation. Aim. To compare the accuracy of radiographic tooth length obtained from in vivo digital radiograph with that obtained from ex vivo digital radiograph. Method. Direct digital radiographs of 20 upper primary incisors were performed in teeth (2/3 radicular resorption) that were radiographed by an intraoral sensor, according to the long-cone technique. Teeth were extracted, measured, and mounted in a resin block, and then radiographic template was used to standardise the sensor-target distance (30 cm). The apparent tooth length (APTL) was obtained from the computer screen by means of an electronic ruler accompanying the digital radiography software (CDR 2.0), whereas the actual tooth length (ACTL) was obtained by means of a digital calliper following extraction. Data were compared to the ACTL by variance analysis and Pearson’s correlation test. Results. The values for APTL obtained from in vivo radiography were slightly underestimated, whereas those values obtained from ex vivo were slightly overestimated. No significance was observed between APTL and ACTL. Conclusion. The length of primary teeth estimated by in vivo and ex vivo comparisons using digital radiography was found to be similar to the actual tooth length.

Radiographic assessment of bone density around integrated titanium implants after ovariectomy in rats

Objectives:This study evaluated the influence of ovariectomy 8 weeks after implant placement on bone integrated to titanium implants.Materials and methods:Thirty-eight female rats were submitted to a titanium implant at the tibiae proximal methaphysis. After a healing period of 8 weeks the animals were randomly divided into three groups: control (CTL-10 animals), sham-operated (SHAM-14 animals) and ovariectomy (OVX-14 animals). The CTL group was then sacrificed in order to confirm integration of the implant. The SHAM group was submitted to fictitious surgery and the OVX group was submitted to bilateral ovariectomy. After 12 weeks post-implant placement, the SHAM and OVX groups were sacrificed. In order to confirm the systemic osteopenia in rats, a dual-energy X-ray absorptiometry (DXA) was performed. For the evaluation of bone density, digital radiographs were taken. The grey level of the bone adjacent to implant was measured using image software and the bone density was calculated at six points on both sides of the implant.Results:Densitometry measurements of the femur confirmed systemic bone mass loss in the OVX group. Individualized bone analyses of different regions surrounding the implant showed a significantly lower radiographic bone density (P < 0.05) in the cancellous region of the OVX group (77.48 +/- 23.39 grey levels) when compared with the CTL and SHAM groups (91.61 +/- 32.10 and 102.57 +/- 32.50 grey levels, respectively).Conclusions:The present study showed a decrease of the radiographic bone density in the cancellous region of bone around titanium implants placed 8 weeks before ovariectomy in rats.

Reprodutibilidade diagnóstica das imagens radiográficas panorâmicas convencional e digitalizada invertida na detecção do teto do canal da mandíbula e do forame mentual

Pós-graduação em Odontologia - FOAR

Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: An in vitro study

Purpose: This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Materials and Methods: Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. Results: There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC95%:6.04-6.54) and 6.79 mm (IC95%:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64mm (IC95%:6.40-6.89) and 6.79mm(IC95%:6.45-7.11), respectively. Conclusion: The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss. copy; 2012 by Korean Academy of Oral and Maxillofacial Radiology.

Use of an Online Photo Management and Sharing Application to Create a Searchable Digital Dental Radiograph Repository

Problem: Dental radiographs generally display one or more findings/diagnoses, and are linked to a unique set of patient demographics, medical history and other findings not represented by the image. However, this information is not associated with radiographs in any type of meta format, and images are not searchable based on any clinical criteria (1,2). The purpose of this pilot study is to create an online, searchable data repository of dental radiographs to be used for patient care, teaching and research. [See PDF for complete abstract]

Validity and reliability of hallux valgus angle measured on digital photographs

STUDY DESIGN: Controlled laboratory study. OBJECTIVES: To investigate the reliability and concurrent validity of photographic measurements of hallux valgus angle compared to radiographs as the criterion standard. BACKGROUND: Clinical assessment of hallux valgus involves measuring alignment between the first toe and metatarsal on weight-bearing radiographs or visually grading the severity of deformity with categorical scales. Digital photographs offer a noninvasive method of measuring deformity on an exact scale; however, the validity of this technique has not previously been established. METHODS: Thirty-eight subjects (30 female, 8 male) were examined (76 feet, 54 with hallux valgus). Computer software was used to measure hallux valgus angle from digital records of bilateral weight-bearing dorsoplantar foot radiographs and photographs. One examiner measured 76 feet on 2 occasions 2 weeks apart, and a second examiner measured 40 feet on a single occasion. Reliability was investigated by intraclass correlation coefficients and validity by 95% limits of agreement. The Pearson correlation coefficient was also calculated. RESULTS: Intrarater and interrater reliability were very high (intraclass correlation coefficients greater than 0.96) and 95% limits of agreement between photographic and radiographic measurements were acceptable. Measurements from photographs and radiographs were also highly correlated (Pearson r = 0.96). CONCLUSIONS: Digital photographic measurements of hallux valgus angle are reliable and have acceptable validity compared to weight-bearing radiographs. This method provides a convenient and precise tool in assessment of hallux valgus, while avoiding the cost and radiation exposure associated with radiographs.

Caracterización y ajuste del factor de magnificación para radiología digital de cadera

Introducción. Las imágenes obtenidas mediante rayos X, determinan una conducta clínica en ortopedia y son analizadas por parte del cirujano en el momento previo a realizar un acto quirúrgico. El planeamiento pre quirúrgico basado en radiografías de cadera, permite predecir el tamaño de los componentes protésicos a utilizar en un reemplazo de cadera. Con el advenimiento de las radiografías digitales, existe la falsa percepción de que estas tienen corregido el factor de magnificación. La corrección de dicho factor requiere un protocolo de calibración de imágenes, aún no implementado en la Fundación Santa Fe de Bogotá (FSFB). Como consecuencia, las radiografías de cadera actualmente resultan magnificadas. Materiales y métodos. Fueron seleccionados 73 pacientes con reemplazo articular total de la cadera intervenidos en la FSFB. Para cada paciente, se estableció la dimensión de la cabeza protésica en la radiografía de cadera obtenida mediante el sistema de radiología digital (PACS-IMPAX) y su tamaño fue comparado con el de la cabeza femoral implantada. Resultados. La concordancia entre los dos observadores al medir la dimensión radiológica de los componentes protésicos fue excelente y el coeficiente de magnificación promedio de 1.2 (20%). Este será introducido al PACS-IMPAX para ajustar el tamaño definitivo de la radiografía. Conclusión. El ajuste del PACS-IMPAX permite obtener radiografías en las cuales se refleja con mayor precisión el tamaño de los segmentos anatómicos y de los componentes protésicos.

Effect of diabetes mellitus and insulin therapy on bone density around osseointegrated dental implants: a digital subtraction radiography study in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of chronic periapical lesions by digital subtraction radiography by using adobe photoshop CS: A technical report

The purpose of this study was to describe a new technique by using Adobe Photoshop CS (San Jose, CA) image-analysis software to evaluate the radiographic changes of chronic periapical lesions after root canal treatment by digital subtraction radiography. Thirteen upper anterior human teeth with pulp necrosis and radiographic image of chronic periapical lesion were endodontically treated and radiographed 0, 2, 4, and 6 months after root canal treatment by using a film holder. The radiographic films were automatically developed and digitized. The radiographic images taken 0, 2, 4, and 6 months after root canal therapy were submitted to digital subtraction in pairs (0 and 2 months, 2 and 4 months, and 4 and 6 months) choosing image, calculation, subtract, and new document tools from Adobe Photoshop CS image-analysis software toolbar. The resulting images showed areas of periapical healing in all cases. According to this methodology, the healing or expansion of periapical lesions can be evaluated by means of digital subtraction radiography by using Adobe Photoshop CS software.

Total-body digital X-ray in trauma. An experience report on the first operational full body scanner in Europe and its possible role in ATLS

When patients enter our emergency room with suspected multiple injuries, Statscan provides a full body anterior and lateral image for initial diagnosis, and then zooms in on specific smaller areas for a more detailed evaluation. In order to examine the possible role of Statscan in the management of multiply injured patients we implemented a modified ATLS((R)) algorithm, where X-ray of C-spine, chest and pelvis have been replaced by single-total a.p./lat. body radiograph. Between 15 October 2006 and 1 February 2007 143 trauma patients (mean ISS 15+/-14 (3-75)) were included. We compared the time in resuscitation room to 650 patients (mean ISS 14+/-14 (3-75)) which were treated between 1 January 2002 and 1 January 2004 according to conventional ATLS protocol. The total-body scanning time was 3.5 min (3-6 min) compared to 25.7 (8-48 min) for conventional X-rays, The total ER time was unchanged 28.7 min (13-58 min) compared to 29.1 min (15-65 min) using conventional plain radiography. In 116/143 patients additional CT scans were necessary. In 98/116 full body trauma CT scans were performed. In 18/116 patients selective CT scans were ordered based on Statscan findings. In 43/143 additional conventional X-rays had to be performed, mainly due to inadequate a.p. views of fractured bones. All radiographs were transmitted over the hospital network (Picture Archiving and Communication System, PACS) for immediate simultaneous viewing at different places. The rapid availability of images for interpretation because of their digital nature and the reduced need for repeat exposures because of faulty radiography are also felt to be strengths.

Statistical model-based segmentation of the proximal femur in digital antero-posterior (AP) pelvic radiographs.

PURPOSE    Segmentation of the proximal femur in digital antero-posterior (AP) pelvic radiographs is required to create a three-dimensional model of the hip joint for use in planning and treatment. However, manually extracting the femoral contour is tedious and prone to subjective bias, while automatic segmentation must accommodate poor image quality, anatomical structure overlap, and femur deformity. A new method was developed for femur segmentation in AP pelvic radiographs. METHODS    Using manual annotations on 100 AP pelvic radiographs, a statistical shape model (SSM) and a statistical appearance model (SAM) of the femur contour were constructed. The SSM and SAM were used to segment new AP pelvic radiographs with a three-stage approach. At initialization, the mean SSM model is coarsely registered to the femur in the AP radiograph through a scaled rigid registration. Mahalanobis distance defined on the SAM is employed as the search criteria for each annotated suggested landmark location. Dynamic programming was used to eliminate ambiguities. After all landmarks are assigned, a regularized non-rigid registration method deforms the current mean shape of SSM to produce a new segmentation of proximal femur. The second and third stages are iteratively executed to convergence. RESULTS    A set of 100 clinical AP pelvic radiographs (not used for training) were evaluated. The mean segmentation error was [Formula: see text], requiring [Formula: see text] s per case when implemented with Matlab. The influence of the initialization on segmentation results was tested by six clinicians, demonstrating no significance difference. CONCLUSIONS    A fast, robust and accurate method for femur segmentation in digital AP pelvic radiographs was developed by combining SSM and SAM with dynamic programming. This method can be extended to segmentation of other bony structures such as the pelvis.