Oral Radiology最新文献

Objectives: The current study was conducted to assess the volume of the tongue, oral cavity, and tongue/oral cavity and their correlation with the volume of the upper airway in cleft subjects compared with the control group.

Methods: The study population included 60 CBCT images from dental school. The sample comprised 30 unilateral cleft patients and 30 sex and age-matched healthy subjects. The CBCT images were imported to the Mimics software in DICOM format. Then, the segmentation process was done in order to create distinct masks for the upper airway, oral cavity, and tongue. The software calculated the volume of the created masks.

Results: The volume of tongue, oral and upper airway were significantly lower in cleft patients than in the control group (P value < 0.05 taken as statistically significant). There was a weak but statistically significant correlation between the U.A.W.V and T.V in both cleft and non-cleft subjects. Additionally, there was a statistically significant correlation between the O.C.V and the U.A.W.V in cleft subjects.

Conclusions: Except than the proportion of tongue/oral cavity volume, other volumetric measurements were significantly lower in cleft subjects than control group. This reveals that clefts are not necessarily more susceptible to obstructive sleep apnea. Also, the positive correlation between the volume of the tongue and oral cavity with the upper airway confirms that early expansion of the maxillary region in clefts helps significantly in increasing their upper airway volume.

Background: There has been an increasing interest in the use of implants to treat edentulous patients. In this regard, the use of cone beam computed tomography (CBCT) offers a variety of advantages compared with other imaging methods. However, the creation of beam-hardening artifacts adversely affects the quality of images. To our knowledge, little is known about the actual effectiveness of the Metal Artifact Reduction (MAR) algorithm on image quality improvement.

Objectives: The objective of this study is to conduct a systematic review to investigate the effectiveness of the MAR algorithm on the magnitude of artifacts generated in CBCT images.

Materials and methods: An electronic search was performed in electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar. For each database, the search strategy was defined specifically. Studies that had the inclusion criteria for this review were imported into Endnote version 20. The risk of bias in the studies included in this systematic review was assessed by two independent reviewers based on the Joanna Briggs Institute (JBI)'s Critical Appraisal checklist. The selected final articles were scored based on the specified checklist. After reviewing selected articles, it was not possible to perform a meta-analysis due to the heterogeneity and multiplicity of the variables, and the studies were included in the systematic review.

Results: A total of 4738 studies were identified. After eliminating duplicate and unrelated articles, 10 articles met the inclusion criteria. Results showed that the use of the MAR algorithm in the preparation of CBCT scans reduces the standard deviation (SD) of gray values. However, no definite result was achieved in relation to the contrast-to-noise ratio (CNR). In fact, it cannot be definitively concluded whether the use of the MAR algorithm will increase the CNR.

Conclusion: The results of this systematic review demonstrated that we cannot provide a definite answer regarding the effect of the MAR algorithm on reducing the artifacts around dental implants. The explanation is that this factor is affected by many variables, whose change can have a significant effect on the magnitude of artifacts generated in the image.

Objective: To compare the fractal analysis data of ultrasonography (USG) images of the submandibular and parotid glands before and after parenchymal stimulation to assess for any changes.

Methods: The study was conducted by taking 240 USG images of bilateral parotid and submandibular glands of 30 patients before and after stimulation. Patients chewed gum for stimulating their salivary glands. Fractal analysis was performed on the USG images, and the data obtained were statistically compared.

Results: The fractal analysis value of the USG images of the parotid gland was 1.45, both before and after stimulation, indicating no statistically significant difference (p = 0.866). In the submandibular gland, this value was the same before and after stimulation (fractal analysis = 1.42), showing no statistically significant difference (p = 0.748). Parotid and submandibular glands were compared. USG fractal analysis values before and after stimulation and the overall values were statistically significantly different between the different salivary glands (p < 0.05).

Conclusion: According to fractal analysis, there was no change in the parenchyma of the submandibular and parotid glands despite the stimulation. Submandibular and parotid glands could be distinguished by fractal analysis.

Objective: We developed a new phantom for technical evaluation of jawbone single-photon emission computed tomography (SPECT) examinations for medication-related osteonecrosis of the jaw (MRONJ). In this study, we verified the utility of the phantom by determining optimal image reconstruction parameters.

Methods: We evaluated the image quality and quantification in jawbone SPECT images obtained by different reconstruction parameters using the phantom. The phantom images were acquired using a SPECT/computed tomography (CT) system and then reconstructed using ordered-subset expectation maximization (OSEM) iterative reconstruction with resolution recovery as well as scatter and attenuation correction with various update numbers and Gaussian filter full width at half maximums (FWHMs). The percent contrast (%contrast) and absolute recovery coefficient were calculated to determine the optimal reconstruction parameters (OSEM_jaw). Nineteen patients with a clinical diagnosis of MRONJ who underwent bone SPECT/CT were enrolled for the clinical study. The performance of OSEM_jaw was verified by comparison with OSEM_current determined by a spherical phantom, using the correlation between the mean standardized uptake value (SUV_mean) and clinical staging and visual assessment as endpoints.

Results: In the phantom study, %contrast and absolute recovery coefficient increased with increasing update numbers. As the Gaussian filter FWHM increased, the quantitative accuracy and image sharpness decreased. The parameter determined by the phantom study (OSEM_jaw) recommended 120 updates and no filter. In the clinical study, the mean and standard deviation of SUV_mean obtained from OSEM_jaw were 8.9 ± 1.4 for stage 1 lesions, 12.9 ± 4.1 for stage 2 lesions, and 13.8 ± 1.4 for stage 3 lesions. For OSEM_current, they were 5.4 ± 2.3 for stage 1 lesions, 8.3 ± 2.5 for stage 2 lesions, and 8.0 ± 0.9 for stage 3 lesions. The SUV_mean obtained from OSEM_jaw had a stronger correlation with clinical stage. Based on visual assessment, the quality of the SPECT images reconstructed by OSEM_jaw (3.7 ± 0.9) was superior to that reconstructed by OSEM_current (2.9 ± 1.1).

Conclusions: We developed a novel phantom and adapted it for technical evaluation. This study demonstrated the utility of the developed phantom.

Objectives: This study aimed to predict the risk of neck metastasis in patients with tongue squamous cell carcinoma by performing radiomics analysis of preoperative magnetic resonance (MR) images.

Methods: In total, 143 patients with primary tongue cancer were enrolled and divided into training and validation groups. The presence of neck metastases was assessed after at least 6-month of follow-up. Using fat-suppressed T2-weighted images, two observers manually set the volume of interest at the tumor site using the 3D Slicer software and extracted 107 image features. The analysis was based on significant differences between patient groups in the presence or absence of neck metastases by the Mann-Whitney U test and good agreement with intra- and inter-observer intra-class correlation coefficients exceeding 0.9. In addition, two characteristics that were determined to be very useful for diagnosing neck metastases were selected by receiver operating characteristic analysis and evaluated for goodness of fit in the validation data.

Results: Neck metastases were identified in 57 of 143 patients and divided into 121 training and 22 validation datasets. Using the combined criteria of Major Axis Length of 3D-shape features and Joint Entropy of the gray-level co-occurrence matrix, neck metastases were identified in 80.7% of the cases; the validation data predicted neck metastases in 80% of the cases.

Conclusions: MR-imaging texture analysis of the primary tumor helps predict neck metastasis in patients with tongue cancer. The proposed criteria are simple yet useful for identifying groups of patients who may require neck dissection.

Objectives: Zirconia oral implants produce larger artifacts on computed tomography (CT) compared to titanium oral implants. This study aimed to compare the effectiveness of metal artifact reduction (MAR) software and dual-energy (DE) methods, which are used in multi-detector CT (MDCT) to reduce the artifacts produced by titanium and zirconia oral implants.

Methods: Oral implants were placed in the lower right second premolar and second molar regions of an acrylic mandible model and evaluated using MDCT. For MAR, Single Energy Metal Artifact Reaction (SEMAR) images were obtained, and for DE, images were obtained at 135 keV. The evaluation was based on 21 regions of interest (ROIs) with sides of 2.8 mm, set at 15, 25, and 35 mm from the center (the lower-right first premolar), with 65°, 90°, 115°, and 145° angles set on the buccal and lingual sides. The evaluation was based on an Artifact Index (AI).

Results: The lingual aspect of the AI tended to be larger compared to the buccal aspect, regardless of the image-processing method. In addition, the SEMAR method tended to have a greater artifact reduction effect than the DE method. The distortion of the mandibular model and occurrence of new artifacts were confirmed using SEMAR.

Conclusions: SEMAR had higher artifact reduction effects on metal artifacts than the DE method. Although SEMAR and dual-energy methods can effectively reduce metal artifacts, they also cause false images and areas that cannot be observed. Therefore, diagnostic and treatment planning, including imaging, is essential before artifact reduction processing.

Objective: This retrospective study compared the thickness and degree of resorption of the mandibular cortex in patients with head and neck cancer (AG), patients with cancer at sites other than the head and neck (BG), and patients with no cancer (CG) to describe and compare the changes in the mandible after antineoplastic therapy and their possible clinical implications.

Materials and methods: A total of 287 panoramic radiographs were examined. The following radiomorphometric indices were analyzed: mental index (MI), panoramic mandibular index (PMI), and mandibular cortical index (MCI). Analysis of variance (ANOVA) and the Kruskal‒Wallis test, with p < 0.05 considered significant, were performed.

Results: Males predominated in the AG (83%), while females predominated in the BG and CG (78.6 and 62%, respectively). In the AG, tongue carcinoma (22.1%) was prevalent, while in the BG, breast carcinoma was predominant (53.8%). All parameters measured in the AG and BG patients were significantly lower than those in the CG patients: MI (p < 0.001), right PMIc/a (p < 0.001), left PMIc/a (p < 0.001), right PMIc/b (p = 0.004), left PMIc/b (p < 0.001), and MCI (p < 0.001).

Conclusions: Radiomorphometric indices MI, PMI, and MCI were significantly lower in panoramic radiographs of patients with head and neck cancer and patients with cancer in other regions of the body than in those of nononcological patients.

Objectives: The nasopalatine canal (NPC) is an anatomical formation with varying morphology. NPC can be visualized using the cone-beam computed tomography (CBCT). Also, CBCT has been used in many studies on artificial intelligence (AI). The "You only look once" (YOLO) is an AI framework that stands out with its speed. This study compared the observer and AI regarding the NPC segmentation and assessment of the NPC furcation status in CBCT images.

Methods: In this study, axial sections of 200 CBCT images were used. These images were labeled and evaluated for the absence or presence of the NPC furcation. These images were then divided into three; 160 images were used as the training dataset, 20 as the validation dataset, and 20 as the test dataset. The training was performed by making 800 epochs using the YOLOv5x-seg model.

Results: Sensitivity, Precision, F1 score, IoU, mAP, and AUC values were determined for NPC detection, segmentation, and classification of the YOLOv5x-seg model. The values were found to be 0.9680, 0.9953, 0.9815, 0.9636, 0.7930, and 0.8841, respectively, for the group with the absence of the NPC furcation; and 0.9827, 0.9975, 0.9900, 0.9803, 0.9637, and 0.9510, for the group with the presence of the NPC furcation.

Conclusions: Our results showed that even when the YOLOv5x-seg model is trained with the NPC furcation and fewer datasets, it achieves sufficient prediction accuracy. The segmentation feature of the YOLOv5 algorithm, which is based on an object detection algorithm, has achieved quite successful results despite its recent development.

Objective: The aim of this study was to evaluate the mandibular condyle and articular eminences of patients diagnosed with medication-related osteonecrosis of the jawbone (MRONJ) and those who use bisphosphonates (BP) but do not have MRONJ findings, by comparing them with a healthy control group.

Methods: The cone beam computed tomography (CBCT) images of 20 patients (15 male, 5 female) who were diagnosed with MRONJ and 20 patients (16 male and 4 female) who were using bisphosphonates but had no MRONJ were included in the study. A control group consisted of 20 age- and gender-matched patients (13 male, 7 female) who had no clinical complaints or signs and symptoms of TMD or rheumatic disease. The imaging characteristics relating to osseous changes of the condyles and in the articular fossa, such as flattening, erosion, osteophytes, subcortical sclerosis, subchondral cyst, loose joint bodies, joint space narrowing, flattening of the articular eminence, and resorption in the articular eminence, were evaluated. SPSS Statistics 20 software was used to statistically evaluate the data collected within the scope of the investigated variables. The results of the analyses were evaluated at 0.05.

Results: Analysis of temporomandibular joint osseous changes in the patient and control groups found statistically significantly higher subcortical sclerosis in both the patient group diagnosed with MRONJ and the patient group using BP, compared with the control group. In addition, a statistically significant difference was found between the patient groups and the control group in terms of condylar flattening, articular eminence flattening, and resorption.

Conclusion: Understanding the changes in physiological bone remodeling of the mandibular condyle after BP administration is crucial in the development of future treatment modalities for degenerative TMJ diseases that cause condylar bone resorption.