CT and MR imaging findings of head and neck chondrosarcoma.

OBJECTIVES: This study investigated the imaging features of head and neck chondrosarcoma (HNCS) according to its origin and pathologic subtype. METHODS: Patients who were pathologically diagnosed with HNCS between January 2000 and April 2022 were retrospectively reviewed. Lesions were classified based on their origin and pathologic subtype. The size and margin were evaluated on the image. Internal calcification and the effects on adjacent bone were assessed using computed tomography (CT) images, while signal intensity and contrast enhancement patterns were analyzed using magnetic resonance (MR) imaging. RESULTS: Thirteen HNCSs were included in this study: 8 bone tumors (61.5%) and 5 soft tissue tumors (38.5%). The bone tumors were pathologically diagnosed as conventional (n = 5) and mesenchymal type (n = 3). Soft tissue tumors were defined as myxoid type. The main symptoms were swelling (90.9%) and pain (72.7%). The lesions measured 4.5 cm on average. The margins showed benign and well-defined except for the mesenchymal type. On CT, most bone tumors (75%) showed internal calcification with remodeling or destruction of the adjacent bone. No soft tissue tumors, except one case, showed internal calcification or destruction of the adjacent bone. MR imaging features were non-specific (T2 high signal intensity and contrast enhancement). CONCLUSIONS: HCNS showed various imaging findings according to their origin and pathologic subtype. HNCS should be differentiated if a bone tumor shows internal calcification and affects the adjacent bone. When diagnosing slow-growing soft tissue tumors, even if low possibility, HNCS should be considered.

Radiomics-based sialadenitis staging in contrast-enhanced computed tomography and ultrasonography: a preliminary rat model study.

OBJECTIVE: The aim of this study was to measure the ability of radiomics analysis to diagnose different stages of sialadenitis, compare the diagnostic accuracy of computed tomography (CT) and ultrasonography (US), and suggest radiomics features selected through 3 machine learning algorithms that would be helpful in discriminating between stages of sialadenitis with both imaging systems. STUDY DESIGN: Wistar rats were treated to induce acute and chronic sialadenitis in the left and right submandibular glands, respectively. Contrast-enhanced CT and US of the glands were performed, followed by extirpation and histopathologic confirmation. Radiomics feature values of the glands were obtained from all images. Based on 3 feature selection methods, an optimal feature set was defined after a comparison of the receiver operating characteristic area under the curve (AUC) of each combination of 3 deep learning algorithms and 3 classification models. RESULTS: The attribute features for the CT model were 2 gray-level run length matrices and 2 gray-level zone length matrices. In the US model, there were 2 gray-level co-occurrence matrices and 2 gray-level zone length matrices. The most accurate diagnostic models of CT and US yielded outstanding (AUC = 1.000) and excellent (AUC = 0.879) discrimination, respectively. CONCLUSIONS: The radiomics diagnostic model using gray-level zone length matrices-based features conferred clinically outstanding discriminating ability among stages of sialadenitis using CT and excellent discrimination with US in almost all combinations of machine learning feature selections and classification models.

Automatic diagnosis of retention pseudocyst in the maxillary sinus on panoramic radiographs using a convolutional neural network algorithm.

The evaluation of the maxillary sinus is very important in dental practice such as tooth extraction and implantation because of its proximity to the teeth, but it is not easy to evaluate because of the overlapping structures such as the maxilla and the zygoma on panoramic radiographs. When doom-shaped retention pseudocysts are observed in sinus on panoramic radiographs, they are often misdiagnosed as cysts or tumors, and additional computed tomography is performed, resulting in unnecessary radiation exposure and cost. The purpose of this study was to develop a deep learning model that automatically classifies retention pseudocysts in the maxillary sinuses on panoramic radiographs. A total of 426 maxillary sinuses from panoramic radiographs of 213 patients were included in this study. These maxillary sinuses included 86 sinuses with retention pseudocysts, 261 healthy sinuses, and 79 sinuses with cysts or tumors. An EfficientDet model first introduced by Tan for detecting and classifying the maxillary sinuses was developed. The developed model was trained for 200 times on the training and validation datasets (342 sinuses), and the model performance was evaluated in terms of accuracy, sensitivity, and specificity on the test dataset (21 retention pseudocysts, 43 healthy sinuses, and 20 cysts or tumors). The accuracy of the model for classifying retention pseudocysts was 81%, and the model also showed higher accuracy for classifying healthy sinuses and cysts or tumors (98% and 90%, respectively). One of the 21 retention pseudocysts in the test dataset was misdiagnosed as a cyst or tumor. The proposed model for automatically classifying retention pseudocysts in the maxillary sinuses on panoramic radiographs showed excellent diagnostic performance. This model could help clinicians automatically diagnose the maxillary sinuses on panoramic radiographs.

Unemployment risk of all employed working-age cancer survivors after cancer diagnosis in South Korea: a retrospective cohort analysis of population-based administrative data.

PURPOSE: As the cancer survival rate increases, discussions on the employment status of cancer survivors should be actively carried out worldwide. This study examined patients' working status changes after cancer diagnosis to provide the basis for cancer survivors' return to work. METHODS: We established a nationwide cohort to determine long-term work changes after cancer diagnosis. All patients aged 19 to 50 years who were newly diagnosed with cancer while working for the previous 3 years were considered as the case group in 2010. Using propensity score matching (PSM), the cases were matched by sex and age at a ratio of 1:3 with the control group. Kaplan-Meier curve and Cox hazard model analyses were performed to determine the occurrence of unemployment and return to work in the case and control groups on a yearly basis. RESULTS: According to the 6-year follow-up after cancer diagnosis, 26.5% of cancer patients and 23.2% of controls had lost their jobs by the end of the follow-up (P < .0001). Meanwhile, 50.5% of cancer patients and 57.4% of controls had returned to work after unemployment (P < .0001). Subsequently, based on the Cox hazard model, the unemployment risk of cancer patients was 1.42 times higher than that of the general population, while the proportion of those who returned to work was 1.15 times lower. CONCLUSION: Employment is very closely related to the quality of life of cancer survivors. These results highlight the need for a system that can support cancer survivors' work maintenance and return to work after unemployment during the treatment period and the fact that awareness of this must be improved.

Computed tomography and magnetic resonance imaging characteristics of giant cell tumors in the temporomandibular joint complex.

PURPOSE: This study aimed to investigate the computed tomography and magnetic resonance imaging features of giant cell tumors in the temporomandibular joint region to facilitate accurate diagnoses. MATERIALS AND METHODS: From October 2007 to June 2020, 6 patients (2 men and 4 women) at Yonsei University Dental Hospital had histopathologically proven giant cell tumors in the temporomandibular joint. Their computed tomography and magnetic resonance imaging findings were reviewed retrospectively, and the cases were classified into 3 types based on the tumor center and growth pattern observed on the radiologic findings. RESULTS: The age of the 6 patients ranged from 25 to 53 years. Trismus was found in 5 of the 6 cases. One case recurred. The mean size of the tumors, defined based on their greatest diameter, was 32 mm (range, 15-41 mm). The characteristic features of all cases were a heterogeneously-enhancing tumorous mass with a lobulated margin on computed tomographic images and internal multiplicity of signal intensity on T2-weighted magnetic resonance images. According to the site of origin, 3 tumors were bone-centered, 2 were soft tissue-centered, and 1 was peri-articular. CONCLUSION: Computed tomography and magnetic resonance imaging yielded a tripartite classification of giant cell tumors of the temporomandibular joint according to their location on imaging. This study could help clinicians in the differential diagnosis of giant cell tumors and assist in proper treatment planning for tumorous diseases of the temporomandibular joint.

Analysis of three-dimensional imaging findings and clinical symptoms in patients with temporomandibular joint disorders.

BACKGROUND: The purpose of this study was to analyze cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI) findings in temporomandibular joint disorder (TMD) patients and to comprehensively assess the relationships between these imaging findings and clinical symptoms. METHODS: A total of 754 temporomandibular joints (TMJs) in 377 patients with clinical symptoms of TMD who underwent both CBCT and MRI examinations were retrospectively reviewed. Clinical symptoms included TMJ pain, TMJ sound, and limitation of mouth opening. Oral radiologists evaluated osseous changes of the condylar head on CBCT, as well as the disc configuration, internal derangement, and joint effusion on MRI. The frequency of CBCT and MRI findings and the mean and standard deviation of age were analyzed. Logistic regression analysis was used to identify associations between these imaging findings and clinical symptoms using SPSS version 25.0 for Windows (IBM Corp., Armonk, NY, USA). The model fit was evaluated using the Hosmer and Lemeshow test. RESULTS: TMD patients consisted of 294 females and 83 males, and the age group of 20-39 accounted for 47.2% of the patients. Normal findings regarding osseous changes of the condylar head on CBCT were found in 65.1% of the patients. On MRI, a change in disc configuration was found in 54.9% of the patients, internal derangement in 62.6%, and joint effusion in 46.0%. TMJ pain was significantly associated with sclerosis [odds ratio (OR): 3.81], disc displacement without reduction (DDWOR) (OR: 3.22), grade 2 joint effusion (OR: 2.33), and grade 3 joint effusion (OR: 5.54). TMJ sound was significantly associated with disc displacement with reduction (DDWR) (OR: 3.04), DDWOR (OR: 2.50), grade 2 joint effusion (OR: 2.37), and grade 3 joint effusion (OR: 3.23). Limitation of mouth opening was significantly associated with flattened disc configuration (OR: 2.08), folded disc configuration (OR: 2.30), and grade 3 joint effusion (OR: 2.85). CONCLUSIONS: CBCT findings had little to do with clinical symptoms. In contrast, MRI findings, including disc configuration, internal derangement, and joint effusion, were associated with clinical symptoms. These results suggest that MRI should be recommended over CBCT for the proper diagnosis of TMD patients.

Assessment of bone marrow fat fractions in the mandibular condyle head using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method.

The prevalence of temporomandibular joint disorder (TMD) is gradually increasing, and magnetic resonance imaging (MRI) is becoming increasingly common as a modality used to diagnose TMD. Edema and osteonecrosis in the bone marrow of the mandibular condyle have been considered to be precursors of osteoarthritis, but these changes are not evaluated accurately and quantitatively on routine MRI. The iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) method, as a cutting-edge MRI technique, can separate fat and water using three asymmetric echo times and the three-point Dixon method. The purpose of this study was to analyze the quantitative fat fraction (FF) in the mandibular condyle head using the IDEAL-IQ method. Seventy-nine people who underwent MRI using IDEAL-IQ were investigated and divided into 1) the control group, without TMD symptoms, and 2) the TMD group, with unilateral temporomandibular joint (TMJ) pain. In both groups, the FF of the condyle head in the TMJ was analyzed by two oral and maxillofacial radiologists. In the TMD group, 29 people underwent cone-beam computed tomography (CBCT) and the presence or absence of bony changes in the condylar head was evaluated. The FF measurements of the condyle head using IDEAL-IQ showed excellent inter-observer and intra-observer agreement. The average FF of the TMD group was significantly lower than that of the control group (p < 0.05). In the TMD group, the average FF values of joints with pain and joints with bony changes were significantly lower than those of joints without pain or bony changes, respectively (p < 0.05). The FF using IDEAL-IQ in the TMJ can be helpful for the quantitative diagnosis of TMD.

Prognostic Implications of Combined Imaging and Histologic Criteria in Squamous Cell Carcinoma with Mandibular Invasion.

Prognosis prediction of squamous cell carcinoma (SCC) with mandibular invasion is controversial, and a more sophisticated staging system to aid prognosis could be developed with imaging characteristics of bone invasion. Imaging-feature analysis provides practical, stratified results for survival prognosis in oral SCC (OSCC) of the mandible, and imaging advances enable more detailed tumor visualization. We retrospectively evaluated significant bone-invasion features associated with poor outcomes in mandibular OSCC to assess the predictive value of staging criteria that combined imaging features and histologic grade (combined imaging-histology (IH) grade) in 65 patients (39 men, 26 women) with mandibular SCC diagnosed from 2006 to 2016. Clinicopathologic features, including T-stage and histologic grade, and prognosis were retrieved. Tumors were classified into three types by extent of mandibular invasion on pretreatment imaging studies. Moreover, we assessed the involvement of the mandibular canal. We examined the correlation of factors associated with locoregional recurrence and overall mortality. The Harrell Concordance Index (C-index) determined prognostic performance of predictors. Nineteen (29%) patients showed locoregional recurrence and 13 (20%) died. For locoregional recurrence and mortality rates, imaging-detected mandibular canal (MC) involvement is a stronger prognostic factor for recurrence (C-index = 0.61 > 0.58) and survival (C-index = 0.58 > 0.63) than histopathologically confirmed perineural invasion, as was the IH grade, especially IH Grade 3, which was significantly associated with worse locoregional recurrence (p < 0.02). Imaging-based staging showed higher prognostic performance than T-staging (C-index = 0.57 (recurrence), 0.60 (death)), when combined with histologic grading (C-index = 0.69 for both) or used alone (C-index = 0.63 (locoregional recurrence), 0.69 (death)). Overall survival was significantly stratified by Imaging type and IH grade. Therefore, analysis of imaging features provided more specific, practical results for survival prognosis in mandibular OSCC. Imaging advances can potentially provide detailed gross views of tumor masses to facilitate development of prognostic criteria for OSCC.

Site-specific and time-course changes of postmenopausal osteoporosis in rat mandible: comparative study with femur.

Although the effects of osteoporosis on the skeleton are well studied, site-specific and long-term studies on the mandible are still lacking. This study investigated the time-course changes of the bone microarchitecture in the mandibular condyle in comparison to the corresponding changes in the alveolar bone, body of the mandible, and femur. Thirty-six 11-week-old female Sprague-Dawley rats were divided into ovariectomized (OVX) (24 rats) and sham (12 rats) groups. The right femur and mandible were obtained from 6 OVX rats and 3 sham rats at 8, 12, 26, and 36 weeks after surgery, respectively. The histomorphometric analysis was performed using micro-computed tomography and histologic assessments from the (1) distal femur; (2) the alveolar bone and (3) the body of the mandible; (4) the subchondral and (5) the central region of the condyle. The Brown-Forsythe test was used to verify the assumptions for statistical analysis, and the Mann-Whitney U test was then performed. The mandibular condyle showed increased trabecular bone in both the OVX and sham groups, while the bone density was reduced in the distal femur and the mandible interradicular septum and body. When comparing the OVX group to the sham group, only the central condyle showed a significant reduction in bone density at 36 weeks. Osteoporosis behaves in different manners in different parts of the skeleton, and clinicians should be aware that patients displaying osteoporotic changes in the mandible are expected to show severely advanced bone mineral density reduction in other bones, such as the femur.

Prognosis in case of nerve disturbance after mandibular implant surgery in relation to computed tomography findings and symptoms.

PURPOSE: The aim of this study was to evaluate the computed tomography (CT) imaging findings and clinical symptoms of patients who complained of neurosensory disturbances after mandibular implant surgery, and to investigate the relationships of these parameters with the prognosis for recovery. METHODS: CT scans were reviewed in 56 patients with nerve disturbance after mandibular implant surgery. Two oral radiologists classified the imaging findings into intrusion, contact, close, and separate groups according to the distance from the inferior border of the implant to the roof of the mandibular canal (MC). The symptoms of 56 patients were classified into 8 groups and the frequency of each group was investigated. Patients were categorized according to symptom improvement into no recovery and recovery groups, and the relationships of recovery with the CT classification and specific symptom groups were analyzed. RESULTS: Thirty-eight of the 56 nerve disturbance cases showed improvement. The close and separate groups in the CT classification had a strong tendency for recovery (90.9% and 81.8%, respectively) (P<0.05). Although the lowest recovery rate was found in the intrusion group, it was non-negligible, at 50%. The 6 patients with a worm crawling feeling all improved, while the 8 cases with a tightening sensation showed the lowest recovery rate, at 12.5%, and the symptom of a tightening sensation occurred only in the intrusion and contact groups. CONCLUSIONS: The closer the implant fixture was to the MC on CT images, the less likely the patient was to recover. Regarding paresthesia symptoms, while a worm crawling feeling is thought to be a predictor of recovery, a tightening sensation appeared to be associated with a lower recovery rate.

Primary intraosseous squamous cell carcinoma mimicking periapical disease: a case report.

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare carcinoma, which arises within the jaws without connection to the oral mucosa and presumably develops from a remnant of odontogenic epithelium. We present a case of solid type PIOSCC in a 52-year-old male patient complaining of dull pain on his left lower molar. In this case, early stage PIOSCC mimicking a periapical lesion might lead to a one-year delay in treatment due to the misdiagnosis of osteomyelitis after extraction of the third molar. The clinical, radiological, and histologic features are described. In this case, there was initial radiographic evidence for PIOSCC mimicking a periapical lesion. Incautious radiographic interpretation and treatment procedures had delayed the correct diagnosis and resulted in extensive bony destruction during the patient's disease progression.

Highly efficient protein expression and purification using bacterial hemoglobin fusion vector.

Recently developed bacterial hemoglobin (VHb) fusion expression vector has been widely used for the production of many target proteins due to its distinctive properties of expressing fusion protein with red color which facilitates visualization of the steps in purification, and increasing solubility of the target proteins. However, after intensive use of the vector, several defects have been found. In this report, we present a modified VHb fusion vector (pPosKJ) with higher efficiency, in which most of the defects were eliminated. First, it was found that thrombin protease often digests target protein as well as inserted thrombin cleavage site, so it was replaced by a TEV cleavage site for more specific cleavage of VHb from target protein. Second, a glycine-rich linker sequence was inserted between 6x his-tag and VHb to improve the affinity of 6x his-tag to Ni-NTA resin, resulting in higher purity of eluted fusion protein. Third, EcoRI and XhoI restriction sites located elsewhere in the vector were removed to make these restriction sites available for the cloning of target protein coding genes. A pPosKJ vector was fully examined with an anti-apoptotic BCL-2 family member of Caenorhabditis elegans, CED-9. A C-terminal VHb fusion expression vector (pPosKJC) was also constructed for stable expression of target proteins that may be difficult to express with an N-terminal fusion. Vaccinia-related kinase 1 (VRK1) was also successfully expressed and purified using the vector with high yield. Taken together, we suggest that the VHb fusion vector may be well suited for high-throughput protein expression and purification.