Improvement of image quality of dentomaxillofacial region in ultra-high resolution computed tomography: A phantom study.

Objectives: The purpose of this study was to compare the image quality of ultra-high-resolution computed tomography (U-HRCT) with that of conventional multi-detector row CT (convCT) and demonstrate its usefulness in the dentomaxillofacial region.

Methods: Phantoms were helically scanned with U-HRCT and convCT scanners using clinical protocols. In U-HRCT, phantoms were scanned in super-high-resolution (SHR) mode, and hybrid iterative reconstruction (HIR) and filtered-back projection (FBP) techniques were performed using a bone kernel (FC81).

Imaging findings in a case of primary intraosseous carcinoma arising from a mandibular cyst.

Primary intraosseous carcinoma not otherwise specified (PIOC NOS) is a rare tumor assumed to arise from the epithelium, such as odontogenic cysts or benign tumors. Its clinical and imaging diagnoses are often challenging, especially in the early stages, as it mimics jaw cysts and benign tumors, and no specific findings have been identified. This report presents the case of a 66-year-old male patient with mandibular PIOC, highlighting the imaging findings over time.

Observational study investigating the relationship between maxillomandibular characteristics and temporomandibular disc conditions in female patients with a skeletal class III pattern.

Objectives: The objective of this study was to analyze the relationship between maxillomandibular characteristics and the severity of temporomandibular disc displacement in female patients with a skeletal class III (SKIII) pattern.

Methods: Fifty-seven samples were included in the study. The evaluation of articular disc conditions was conducted using magnetic resonance imaging, while 25 cephalometric variables from lateral and postero-anterior (P-A) cephalograms were measured to determine their maxillomandibular characteristics.

Relationship between image information content and observer performance in digital intraoral radiography.

Objectives: This study conducted a receiver operating characteristic (ROC) analysis by applying improved cluster signal-to-noise (CSN) analysis to digital intraoral radiographs and develop an observer-free method of analyzing image quality related to the observer performance in the detection task.

Methods: Two aluminum step phantoms with a thickness interval of 1.0 mm were used for this study.

Low-radiation dose scan protocol for preoperative imaging for dental implant surgery using deep learning-based reconstruction in multidetector CT.

Objectives: This study aimed to investigate the impact of a deep learning-based reconstruction (DLR) technique on image quality and reduction of radiation exposure, and to propose a low-dose multidetector-row computed tomography (MDCT) scan protocol for preoperative imaging for dental implant surgery.

Methods: The PB-1 phantom and a Catphan phantom 600 were scanned using volumetric scanning with a 320-row MDCT scanner. All scans were performed with a tube voltage of 120 kV, and the tube current varied from 120 to 60 to 40 to 30 mA.

Long-Term Outcome of Autotransplantation of a Complete Root Formed a Mandibular Third Molar.

Autogenous tooth transplantation is a procedure to reposition an autogenous tooth to another extraction area or surgically created recipient site. The autotransplantation procedures have been documented well in the literature, and the survival rate of the transplanted teeth was reported to be more than 90% after ten years. Therefore, autotransplantation might have been overlooked as a treatment option.

Effect of beam quality and readout direction in the edge profile on the modulation transfer function of photostimulable phosphor systems via the edge method.

The objective of this study was to investigate the effects of (i) the difference in the beam qualities on the presampled modulation transfer function (MTF) using the edge method and (ii) the readout direction of the edge profile for the photostimulable phosphor (PSP) system. The International Electrotechnical Commission (IEC) defined a technique using the "radiation qualities based on a phantom made up of an aluminum added filter" (RQA). A general radiographic system with a tube voltage of 50 kV and 9.

Metal artefact reduction in the oral cavity using deep learning reconstruction algorithm in ultra-high-resolution computed tomography: a phantom study.

Objectives: This study aimed to improve the impact of the metal artefact reduction (MAR) algorithm for the oral cavity by assessing the effect of acquisition and reconstruction parameters on an ultra-high-resolution CT (UHRCT) scanner.

Methods: The mandible tooth phantom with and without the lesion was scanned using super-high-resolution, high-resolution (HR), and normal-resolution (NR) modes. Images were reconstructed with deep learning-based reconstruction (DLR) and hybrid iterative reconstruction (HIR) using the MAR algorithm.

X-ray dose reduction using additional copper filtration for dental cone beam CT.

This study aims to quantitatively evaluate the effect of additional copper-filters (Cu-filters) on the radiation dose and contrast-to-noise ratio (CNR) in a dental cone beam computed tomography (CBCT). The Cu-filter thickness and tube voltage of the CBCT unit were varied in the range of 0.00-0.

Effect of differences in pixel size on image characteristics of digital intraoral radiographic systems: a physical and visual evaluation.

Objectives: To quantify and validate the effect of pixel size on a digital intraoral radiographic system according to International Electrotechnical Commission standards through physical and visual evaluations.

Methods: The digital intraoral radiographic system used was the photostimulable phosphor imaging plate and scanner system. The system had three image capture modes: high-speed (HS), high-resolution (HR), and super high-resolution (SHR) with different pixels.

Improved scan method for dental imaging using multidetector computed tomography: a phantom study.

Objectives: This study aimed to propose an improved scan method to shorten irradiation time and reduce radiation exposure.

Methods: The maxilla of a human head CT phantom and a Catphan phantom were used for qualitative and quantitative assessment, respectively. The phantoms were scanned by a 160-row multidetector CT scanner using volumetric and helical scanning.

The missing link in image quality assessment in digital dental radiography.

Digital radiography is gaining popularity among general dental practitioners. It includes digital intraoral radiography, digital panoramic radiography, digital cephalography, and cone-beam computed tomography. In this study, we focused on the methods to assess image quality of these techniques, except for digital cephalography, in the light of historical issues.

Determination of optimum exposure parameters for dentoalveolar structures of the jaws using the CB MercuRay system with cluster signal-to-noise analysis.

Objective: To determine the optimum cone beam computed tomography exposure parameters for specific diagnostic tasks.

Methods: A Teflon phantom attached to a half-mandible in a large container was scanned in dental (D), implant (I), and panoramic (P) modes. An identical phantom in a small container was scanned in D mode.

Evaluation of cone-beam computed tomography diagnostic image quality using cluster signal-to-noise analysis.

Objectives: (1) We sought to assess correlation among four representative parameters from a cluster signal-to-noise curve (true-positive rate [TPR] corresponding to background noise, accuracy corresponding to background noise, maximum TPR, and maximum accuracy) and the diagnostic accuracy of the identification of the mandibular canal using data from observers in a previous study, under the same exposure conditions. (2) We sought to clarify the relationship between the hole depths of a phantom and diagnostic accuracy.

Methods: CBCT images of a Teflon plate phantom with holes of decreasing depths from 0.

Prediction of detectability of the mandibular canal by quantitative image quality evaluation using cone beam CT.

Objectives: To compare the results of a new quantitative image quality evaluation method that requires no observers with the results of receiver operating characteristic (ROC) analysis in detecting the mandibular canal (MC) in cone beam CT (CBCT) images.

Methods: A Teflon (polytetrafluoroethylene) plate phantom with holes of different depths was scanned with two CBCT systems. One CBCT system was equipped with an image intensifier (Experiment 1), and the other was equipped with a flat panel detector (Experiment 2).

Estimation of proton density fat fraction of the salivary gland.

Objective: Our first objective was to prove the validity of the six-point Dixon method for estimating the proton density fat fraction (PDFF) of the salivary gland. The second objective was to estimate the salivary gland PDFF using Dixon method to evaluate the pathological conditions.

Methods: At first, 12 volunteers underwent two types of sequences: single-voxel magnetic resonance spectroscopy and the Dixon method and the PDFFs obtained by the two methods were compared.

Cluster signal-to-noise analysis for evaluation of the information content in an image.

Objectives: (1) To develop an observer-free method of analysing image quality related to the observer performance in the detection task and (2) to analyse observer behaviour patterns in the detection of small mass changes in cone-beam CT images.

Methods: 13 observers detected holes in a Teflon phantom in cone-beam CT images. Using the same images, we developed a new method, cluster signal-to-noise analysis, to detect the holes by applying various cut-off values using ImageJ and reconstructing cluster signal-to-noise curves.

Effects of exposure parameters and slice thickness on detecting clear and unclear mandibular canals using cone beam CT.

Objectives: The purpose of this study was to clarify the effects of exposure parameters and image-processing methods when using CBCT to detect clear and unclear mandibular canals (MCs).

Methods: 24 dry half mandibles were divided into 2 groups with clear and unclear MCs based on a previous CBCT study. Mandibles were scanned using a CBCT system with varying exposure parameters (tube voltages 60 kV, 70 kV and 90 kV; and tube currents 2 mA, 5 mA, 10 mA and 15 mA) to obtain a total of 144 scans.

A new method to evaluate image quality of CBCT images quantitatively without observers.

Objectives: To develop an observer-free method for quantitatively evaluating the image quality of CBCT images by applying just-noticeable difference (JND).

Methods: We used two test objects: (1) a Teflon (polytetrafluoroethylene) plate phantom attached to a dry human mandible; and (2) a block phantom consisting of a Teflon step phantom and an aluminium step phantom. These phantoms had holes with different depths.

Effectiveness of imaging modalities for screening IgG4-related dacryoadenitis and sialadenitis (Mikulicz's disease) and for differentiating it from Sjögren's syndrome (SS), with an emphasis on sonography.

Introduction: The aim of this study was to clarify the effectiveness of various imaging modalities and characteristic imaging features in the screening of IgG4-related dacryoadenitis and sialadenitis (IgG4-DS), and to show the differences in the imaging features between IgG4-DS and Sjögren's syndrome (SS).

Methods: Thirty-nine patients with IgG4-DS, 51 with SS and 36 with normal salivary glands were enrolled. Images of the parotid and submandibular glands obtained using sonography, 2-[(18)F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT), computed tomography (CT) and magnetic resonance imaging (MRI) were retrospectively analyzed.

The usefulness of three-dimensional imaging in the diagnosis and treatment of clinically ambiguous gingival swelling.

We evaluated and treated a 54-year-old woman with gingival swelling. Conventional intraoral and panoramic radiography did not provide sufficient information for either determining the cause of gingival swelling or planning treatment of clinical symptoms. The 3D Accuitomo XYZ Slice View Tomograph (3DX) is a compact dental computed tomography device that allowed for accurate identification and optimal treatment of the causes of gingival swelling.

Accuracy of linear measurement and the measurement limits of thin objects with cone beam computed tomography: effects of measurement directions and of phantom locations in the fields of view.

Purpose: The directional dependence of accuracy with cone beam computed tomography (CBCT) has not been investigated thoroughly. The purpose of the present study was to clarify the effects of measurement direction and of phantom locations in the fields of view (FOVs) on the accuracy of linear measurement and on the limits of measuring thin objects with CBCT.

Materials And Methods: An aluminum phantom was scanned by CBCT.

[Comparison of a dental cone beam CT with a multi-detector row CT on effective doses and physical image quality].

The purpose of this study was to compare a dental cone beam computed tomography (dental CBCT) and a multi-detector row CT (MDCT) using effective doses and physical image quality. A dental mode (D-mode) and an implant mode (I-mode) were employed for calculating effective doses. Field of view (FOV) size of the MDCT was 150 mm.

A quantitative analysis of sonographic images of the salivary gland: a comparison between sonographic and sialographic findings.

We performed three quantitative analyses (particle analysis, fractional Brownian motion [fBM] model analysis, two-dimensional [2-D] fractal analysis) of the ultrasonographic (US) images of the salivary gland and evaluated whether the obtained indices correlated with the sialographic stage of Rubin-Holt. Our study included 192 patients suspected of having Sjögren's syndrome (SS). In 89 patients, sialography demonstrated abnormal findings.

Sonographic diagnosis for Mikulicz disease.

Objective: The aim was to investigate the diagnostic imaging characteristics of Mikulicz disease (MD), especially sonographic ones, and to clarify the differences between them and those in Sjögren syndrome (SS), based on new criteria of MD.

Study Design: The sonographic and sialographic images, as well as clinical, histopathologic, and serologic findings of 9 patients satisfying the new criteria of MD were analyzed and compared with those in SS.

Results: All swollen submandibular glands showed bilateral nodal hypoechoic areas with high vascularization on sonograms and a parenchymal defect on sialograms, whereas parotid glands showed normal or slight change on both images.