Development of a new dental panoramic radiographic system based on a tomosynthesis method

Ogawa, Kōichi; Langlais, Robert P.; McDavid, William D.; Noujeim, Marcel; Seki, Kenji; Okano, Toshio; Yamakawa, Tsutomu; Sue, T.

doi:10.1259/dmfr/12999660

Cited by 46 publications

(41 citation statements)

References 14 publications

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“…As is the case in the tomographic method (2), only anatomical areas of the patient's head positioned within the image layer will appear with sharpness on the radiograph (1,3). Anatomical structures medially or…”

Section: Introductionmentioning

confidence: 99%

“…Panoramic radiography is a simple method of obtaining images by synchronous rotation of the x-ray source and image receptor around the stationary patient. However, there is a magnifying factor associated with image formation, due to the distance between the radiation source, object and image receptor, which can produce image distortion (1).…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of the panoramic image formation in different anatomic positions

et al. 2010

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The aim of this study was to determine size, shape and position of the image layer by evaluation of the radiographic image formation in different anatomic positions. A customized phantom was made of a rectangular acrylic plate measuring 14 cm² and 0.3 cm thick, with holes spaced 0.5 cm away and arranged in rows and columns. Each column was separately filled with 0.315 cm diameter metal spheres to acquire panoramic radiographs using the Orthopantomograph OP 100 unit. The customized phantom was placed on the mental support of the device, with its top surface kept parallel to the horizontal plane, and was radiographed at three different heights from the horizontal plane, i.e., the orbital, occlusal and mandibular symphysis levels. The images of the spheres were measured using a digital caliper to locate the image layer. The recorded data were analyzed statistically by the Student's-t test, ANOVA and Tukey's test (α=0.05). When the image size of spheres in horizontal and vertical axes were compared, statistically significant differences (p<0.05) were observed in all areas, portions of the image layer and heights of horizontal plane evaluated. In the middle portion of the image layer, differences in the image size of spheres were observed only along the horizontal axis (p<0.05), whereas no differences were observed along the vertical axis (p>0.05). The methodology used in this determined the precise size, shape and position of the image layer and differences in magnification were observed in both the horizontal and vertical axes.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evaluation of the panoramic image formation in different anatomic positions

et al. 2010

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“…To measure the shift-amount required for a "shift-and-add" operation in the tomosynthesis method, we used a calibration phantom [8]. In the phantom, several thin wires are located at specified angular positions on the standard imaging plane of the dental arch, and the shift-amount at each position is measured as the distance needed to match the positions of a thin wire between the adjacent frame images.…”

Section: Methodsmentioning

confidence: 99%

“…Using this measurement, we can obtain a table of the shift-amount at each specified angular position. The details are described in the literature [8]. Figure 1 shows an example of the shift-amount table of an actual dental panoramic apparatus.…”

Section: Methodsmentioning

confidence: 99%

“…On the other hand, because the sensitivity and response speed of the latter detector are higher than those of the former one, we can obtain many strip images of an object acquired with slightly different angles. This enables us to reconstruct an image of the teeth and jaw bones focused at a given depth with a tomosynthesis method [7,8]. Once we acquire data of a patient, we can freely reconstruct a desired layer of a given depth, and so application of the tomosynthesis technique is gradually expanding in the field of panoramic imaging.…”

Section: Introductionmentioning

confidence: 99%

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Removal of the Shadow of Cervical Vertebrae from Panoramic X-Ray Images with a Tomosynthesis Method

Ogawa¹,

Yamamoto²,

Yanase³

et al. 2013

OJMI

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The purpose of this study is to remove the shadow of cervical vertebrae from dental panoramic x-ray images with a tomosynthesis method and improve the contrast of details in both the teeth and jaw bones. To measure the shift-amount at each angular position that was required for reconstruction of panoramic x-ray images of the dental arch, strip images of a calibration phantom were acquired. Then, a shift-amount table was prepared from these images, and the other shiftamount table, which was used to reconstruct a panoramic image of the cervical vertebrae, was prepared by inverting the curve of the shift-amount table upside down. Using these two tables, images focused on the dental arch and cervical vertebrae of a patient were made with the original strip data of the patient. The shadow of the cervical vertebrae appearing on the image focused on the dental arch was removed using the two above-mentioned images and blurring functions defined at two focusing geometries. The validity of the proposed method was evaluated with clinically acquired data of two patients. The shadow of the cervical vertebrae was successfully eliminated, and the contrast of the front teeth and detailed structures of the jaw bones was improved. The results of the experiments showed that our proposed method was significantly effective in removing the shadow of the cervical vertebrae from conventional panoramic x-ray images.

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Dynamic focal plane estimation for dental panoramic radiography

Kim

Beom

2019

Medical Physics

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Purpose: The digital panoramic radiography is widely used in dental clinics and provides the anatomical information of the intraoral structure along the predefined arc-shaped path. Since the intraoral structure varies depending on the patient, however, it is nearly impossible to design a common and static focal path or plane fitted to the dentition of all patients. In response, we introduce an imaging algorithm for digital panoramic radiography that can provide a focused panoramic radiographic image for all patients, by automatically estimating the best focal plane for each patient. Methods: The aim of this study is to improve the image quality of dental panoramic radiography based on a three-dimensional (3D) dynamic focal plane. The plane is newly introduced to represent the arbitrary 3D intraoral structure of each patient. The proposed algorithm consists of three steps: preprocessing, focal plane estimation, and image reconstruction. We first perform preprocessing to improve the accuracy of focal plane estimation. The 3D dynamic focal plane is then estimated by adjusting the position of the image plane so that object boundaries in the neighboring projection data are aligned or focused on the plane. Finally, a panoramic radiographic image is reconstructed using the estimated dynamic focal plane. Results: The proposed algorithm is evaluated using a numerical phantom dataset and four clinical human datasets. In order to examine the image quality improvement owing to the proposed algorithm, we generate panoramic radiographic images based on a conventional static focal plane and estimated 3D dynamic focal planes, respectively. Experimental results show that the image quality is dramatically improved for all datasets using the 3D dynamic focal planes that are estimated from the proposed algorithm. Conclusions: We propose an imaging algorithm for digital panoramic radiography that provides improved image quality by estimating dynamic focal planes fitted to each individual patient's intraoral structure.

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Development of a new dental panoramic radiographic system based on a tomosynthesis method

Cited by 46 publications

References 14 publications

Evaluation of the panoramic image formation in different anatomic positions

Evaluation of the panoramic image formation in different anatomic positions

Removal of the Shadow of Cervical Vertebrae from Panoramic X-Ray Images with a Tomosynthesis Method

Dynamic focal plane estimation for dental panoramic radiography

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