Publications by authors named "Akitoshi Katsumata"

Objective: The horizontal tube-shifting technique can be adopted to separate overlapping buccal roots of the maxillary molar from the palatal root. A simulation study was performed to determine an appropriate tube-shift angulation when adopting three-dimensional computed tomography imaging.

Methods: Cone-beam computed tomography images of 21 volunteers were used for simulation.

View Article and Find Full Text PDF

This study aimed to conduct a cross-sectional data analysis of the alveolar bone mineral density (al-BMD) in 225 patients of various ages and different sexes. The al-BMD value in the mandibular incisor region was calculated using a computer-aided measurement system (DentalSCOPE) for intraoral radiography. All participants with intact teeth (101 males and 124 females; age range, 25-89 years) were divided into three age-segregated groups (25-49, 50-74, and > 75 years).

View Article and Find Full Text PDF
Article Synopsis
  • The study introduces a new method for correcting blurring in images captured by energy-resolving photon counting detectors (ERPCDs), which is crucial for accurately analyzing object edges in quantitative images.
  • Current techniques struggle to provide accurate quantitative data due to image blurring, which obscures primary x-ray attenuation information necessary for deriving effective atomic numbers and bone mineral density.
  • The proposed correction method involved analyzing pixel distributions within a 5 × 5 pixel mask, successfully correcting 82% of blurred pixels, and showing effectiveness for images of objects with 4 × 4 pixels or larger, making it a promising tool for quantitative medical diagnostics.
View Article and Find Full Text PDF

Introduction: The purposes of this study were to evaluate the effect of the combined use of object detection for the classification of the C-shaped canal anatomy of the mandibular second molar in panoramic radiographs and to perform an external validation on a multicenter dataset.

Methods: The panoramic radiographs of 805 patients were collected from 4 institutes across two countries. The CBCT data of the same patients were used as "Ground-truth".

View Article and Find Full Text PDF

The application of artificial intelligence (AI) based on deep learning in dental diagnostic imaging is increasing. Several popular deep learning tasks have been applied to dental diagnostic images. Classification tasks are used to classify images with and without positive abnormal findings or to evaluate the progress of a lesion based on imaging findings.

View Article and Find Full Text PDF

Objectives: A videofluoroscopic swallowing study (VFSS) is conducted to detect aspiration. However, aspiration occurs within a short time and is difficult to detect. If deep learning can detect aspirations with high accuracy, clinicians can focus on the diagnosis of the detected aspirations.

View Article and Find Full Text PDF

Purpose: Evaluating the bone mineral density (BMD) of alveolar bone is useful for dental treatments. The DentalSCOPE is an image analysis system developed to evaluate the BMD of alveolar bone. The aim of this study was to evaluate the relationship between cross-sectional anatomical size and BMD value.

View Article and Find Full Text PDF
Article Synopsis
  • A study developed a deep learning model to automate bolus segmentation in videofluorography (VFG) images for evaluating swallowing functions in patients, saving time and effort.
  • The model was trained on 3910 images derived from VFG of 12 patients, utilizing a U-Net neural network over 500 training epochs.
  • Performance metrics for the model showed high accuracy in segmenting bolus areas, with values over 0.9 in measures like the Jaccard index and sensitivity, indicating its effectiveness in assessing swallowing disorders.
View Article and Find Full Text PDF

Objective: The aim of this study was to create and assess a deep learning model using segmentation and transfer learning methods to visualize the proximity of the mandibular canal to an impacted third molar on panoramic radiographs.

Study Design: The panoramic radiographs containing the mandibular canal and impacted third molar were collected from 2 hospitals (Hospitals A and B). A total of 3200 areas were used for creating and evaluating learning models.

View Article and Find Full Text PDF

Objective: This study explored the feasibility of using deep learning for profiling of panoramic radiographs.

Study Design: Panoramic radiographs of 1000 patients were used. Patients were categorized using seven dental or physical characteristics: age, gender, mixed or permanent dentition, number of presenting teeth, impacted wisdom tooth status, implant status, and prosthetic treatment status.

View Article and Find Full Text PDF

The purpose of our study was to analyze dental panoramic radiographs and contribute to dentists' diagnosis by automatically extracting the information necessary for reading them. As the initial step, we detected teeth and classified their tooth types in this study. We propose single-shot multibox detector (SSD) networks with a side branch for 1-class detection without distinguishing the tooth type and for 16-class detection (i.

View Article and Find Full Text PDF
Article Synopsis
  • * The study involved 75 patients (55 female, 20 male) with a history of osteoporotic fractures, divided into primary and secondary osteoporosis groups, and assessed using BMD measurements and panoramic radiography.
  • * Findings revealed that the mandibular cortex index (MCI) and mandibular cortex width (MCW) are effective indicators for identifying osteoporotic conditions, showing similar sensitivity values to lumbar BMD in detecting osteoporosis.
View Article and Find Full Text PDF

Objectives: The aims of the present study were to construct a deep learning model for automatic segmentation of the temporomandibular joint (TMJ) disc on magnetic resonance (MR) images, and to evaluate the performances using the internal and external test data.

Methods: In total, 1200 MR images of closed and open mouth positions in patients with temporomandibular disorder (TMD) were collected from two hospitals (Hospitals A and B). The training and validation data comprised 1000 images from Hospital A, which were used to create a segmentation model.

View Article and Find Full Text PDF

Most of the objects targeted for X-ray examination are composed of soft-tissue and bone. We aimed to develop an algorithm for generating X-ray images which can give quantitative information of soft-tissue and bone using an energy-resolving photon-counting type imaging detector. We used polychromatic X-rays for analysis in which both the beam hardening effect and detector response were properly corrected and then succeeded in virtually treating the amount of measured X-ray attenuation as if it were measured using monochromatic X-rays.

View Article and Find Full Text PDF

Objectives: The aim of the present study was to create and test an automatic system for assessing the technical quality of positioning in periapical radiography of the maxillary canines using deep learning classification and segmentation techniques.

Methods: We created and tested two deep learning systems using 500 periapical radiographs (250 each of good- and bad-quality images). We assigned 350, 70, and 80 images as the training, validation, and test datasets, respectively.

View Article and Find Full Text PDF

To investigate the use of transfer learning when applying a deep learning source model from one institution (institution A) to another institution (institution B) for creating effective models (target models) for the detection of maxillary sinuses and diagnosis of maxillary sinusitis on panoramic radiographs. In addition, to determine appropriate numbers of training data for the transfer learning. Source model was created using 350 panoramic radiographs from institution A as training data.

View Article and Find Full Text PDF

Objective: The present study aimed to verify the classification performance of deep learning (DL) models for diagnosing fractures of the mandibular condyle on panoramic radiographs using data sets from two hospitals and to compare their internal and external validities.

Methods: Panoramic radiographs of 100 condyles with and without fractures were collected from two hospitals and a fivefold cross-validation method was employed to construct and evaluate the DL models. The internal and external validities of classification performance were evaluated as accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC).

View Article and Find Full Text PDF

Osteoporotic fractures are associated with an increased risk of subsequent fractures, a higher rate of mortality, and incremental medical costs. Incidental findings, which include some measurements related to the mandibular inferior cortex and the alveolar trabecular bone pattern of the mandible determined on panoramic radiographs, are considered to be a useful tool for identifying asymptomatic individuals at risk of having osteoporosis and/or fragility fractures. We undertook a worldwide literature survey and present the following clinical recommendations.

View Article and Find Full Text PDF

In this study, we propose an effective atomic number (Z) determination method based on a photon-counting technique. The proposed method can correct for the beam hardening effect and detector response based on polychromatic X-rays to allow high accuracy material identification. To demonstrate the effectiveness of our method, the procedure was applied to X-ray images acquired by a prototype energy-resolving photon-counting detector and we obtained an Z image with accuracy of Z ± 0.

View Article and Find Full Text PDF

Purpose: To assess the mandibular cortical width (MCW) and morphology of the mandibular inferior cortex (MIC) on panoramic views from a large sample of males and females in various age groups by using an automated morphometric grading system for assisting osteoporosis screening. Furthermore, possible predictors and concrete cut-off values to identify the risk for osteoporosis were evaluated.

Materials And Methods: MCW, MIC, tooth loss (TL), and alveolar bone loss (ABL) were retrospectively evaluated in 700 panoramic images from dental patients in Hong Kong using commercially available software.

View Article and Find Full Text PDF

Objective: The first aim of this study was to determine the performance of a deep learning object detection technique in the detection of maxillary sinuses on panoramic radiographs. The second aim was to clarify the performance in the classification of maxillary sinus lesions compared with healthy maxillary sinuses.

Methods: The imaging data for healthy maxillary sinuses (587 sinuses, Class 0), inflamed maxillary sinuses (416 sinuses, Class 1), cysts of maxillary sinus regions (171 sinuses, Class 2) were assigned to training, testing 1, and testing 2 data sets.

View Article and Find Full Text PDF

Objective: This investigation aimed to verify and compare the performance of 3 deep learning systems for classifying maxillary impacted supernumerary teeth (ISTs) in patients with fully erupted incisors.

Study Design: In total, the study included 550 panoramic radiographs obtained from 275 patients with at least 1 IST and 275 patients without ISTs in the maxillary incisor region. Three learning models were created by using AlexNet, VGG-16, and DetectNet.

View Article and Find Full Text PDF

Objective: The aim of this study was to compare time and storage space requirements, diagnostic performance, and consistency among 3 image recognition convolutional neural networks (CNNs) in the evaluation of the relationships between the mandibular third molar and the mandibular canal on panoramic radiographs.

Study Design: Of 600 panoramic radiographs, 300 each were assigned to noncontact and contact groups based on the relationship between the mandibular third molar and the mandibular canal. The CNNs were trained twice by using cropped image patches with sizes of 70 × 70 pixels and 140 × 140 pixels.

View Article and Find Full Text PDF

Purpose: The purpose of this study was to evaluate the morphology of the mandibular cortex in cases of medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis or bone metastases using a computer programme.

Materials And Methods: Fifty-four patients with MRONJ (35 with osteoporosis and 19 with bone metastases) were examined using panoramic radiography. The morphology of the mandibular cortex was evaluated using a computer programme that scanned the mandibular inferior cortex and automatically assessed the mandibular cortical index (MCI) according to the thickness and roughness of the mandibular cortex, as follows: normal (class 1), mildly to moderately eroded (class 2), or severely eroded (class 3).

View Article and Find Full Text PDF

Objectives: Dental state plays an important role in forensic radiology in case of large scale disasters. However, dental information stored in dental clinics are not standardized or electronically filed in general. The purpose of this study is to develop a computerized system to detect and classify teeth in dental panoramic radiographs for automatic structured filing of the dental charts.

View Article and Find Full Text PDF