Deep learning-based evaluation of the relationship between mandibular third molar and mandibular canal on CBCT.

OBJECTIVES: The objective of our study was to develop and validate a deep learning approach based on convolutional neural networks (CNNs) for automatic detection of the mandibular third molar (M3) and the mandibular canal (MC) and evaluation of the relationship between them on CBCT. MATERIALS AND METHODS: A dataset of 254 CBCT scans with annotations by radiologists was used for the training, the validation, and the test. The proposed approach consisted of two modules: (1) detection and pixel-wise segmentation of M3 and MC based on U-Nets; (2) M3-MC relation classification based on ResNet-34. The performances were evaluated with the test set. The classification performance of our approach was compared with two residents in oral and maxillofacial radiology. RESULTS: For segmentation performance, the M3 had a mean Dice similarity coefficient (mDSC) of 0.9730 and a mean intersection over union (mIoU) of 0.9606; the MC had a mDSC of 0.9248 and a mIoU of 0.9003. The classification models achieved a mean sensitivity of 90.2%, a mean specificity of 95.0%, and a mean accuracy of 93.3%, which was on par with the residents. CONCLUSIONS: Our approach based on CNNs demonstrated an encouraging performance for the automatic detection and evaluation of the M3 and MC on CBCT. Clinical relevance An automated approach based on CNNs for detection and evaluation of M3 and MC on CBCT has been established, which can be utilized to improve diagnostic efficiency and facilitate the precision diagnosis and treatment of M3.

Comparison of radiographical characteristics and diagnostic accuracy of intraosseous jaw lesions on panoramic radiographs and CBCT.

OBJECTIVE: To investigate the differences in imaging characteristics and the diagnostic accuracy of 225 intraosseous jaw lesions on panoramic radiographs (PAN) versus cone beam computed tomography (CBCT). METHODS: 225 sets of PAN and CBCT images with biopsy-proven histopathological diagnoses were retrospectively compared in terms of radiographic features and diagnostic accuracy. The imaging characteristics of PAN and CBCT were independently evaluated by two oral and maxillofacial radiologists who were required to answer 12 questions and provided up to three differential diagnoses with their confidence scores. RESULTS: Odds ratios (ORs) were statistically significant for border cortication (OR = 1.521; p = .003) and border continuity (OR = 0.421; p = .001), involvement on neurovascular canals (OR = 2.424; p < .001), expansion (OR = 7.948; p < .001), cortical thinning (OR = 20.480; p < .001) as well as its destruction (OR = 25.022; p < .001) and root resorption (OR = 2.477; p < .001). Furthermore, imaging features in the posterior and mandibular regions showed better agreement than those in the anterior and maxillary regions, respectively. The diagnostic accuracy of the first differential diagnosis was higher on CBCT than on PAN (Observer 1:78.7 vs 64.4%; Observer 2: 78.7 vs 70.2% (p < .001)). The observers' confidence scores were also higher at CBCT interpretation compared with PAN. CONCLUSIONS: CBCT demonstrated a greater number of imaging characteristics of intraosseous jaw lesions compared with PAN, especially in the anterior regions of both jaws and in the maxilla. Diagnostic accuracy is improved with CBCT compared to PAN, especially for lesions in the maxilla. Radiologists have greater confidence when using CBCT.

[CT imaging features of diffuse tenosynovial giant cell tumor of temporomandibular joint].

OBJECTIVE: This study aimed to investigate the characteristic features of CT images of diffuse tenosynovial giant cell tumor (D-TSGCT) from the temporomandibular joint (TMJ) to understand CT imaging diagnosis of the disease. METHODS: CT images and clinical information from 10 patients with D-TSGCT of TMJ were recruited for retrospective analysis from March 2013 to March 2017 in Peking University Hospital of Stomatology. All cases were treated by surgery and confirmed by pathology. RESULTS: CT scan demonstrated hyperdense soft-tissue masses and various kinds of calcification in all of the 10 subjects. Contrast-enhanced scan exhibited obvious enhancement in six patients. Bone destruction of the mandibular condyles and skull base was found in seven and six subjects, respectively. CONCLUSIONS: CT appearance of D-TSGCT of the TMJ is characterized by hyperdense soft tissue with calcification, further enhancement in contrast-enhanced scan, and bone destruction in the mandibular condyles and skull base in some cases.

[Analysis of Cut-off Value in Screening of Thalassemia by Capillary Hemoglobin Electrophoresis for Pregnant Women from Shenzhen Region of China].

OBJECTIVE: To investigate the cut-off value in screening of thalassemia in pregnant women from Shenzhen region by capillary hemoglobin electrophoresis. METHODS: The data of capillary hemoglobin electrophoresis and genetic diagnosis of thalassemia from 2122 examined prenatal women were retrospectively analyzed. Capillary hemoglobin electrophoresis and α-, ß- genetic diagnosis of thalassemia were carried out for every woman. Hemoglobin electrophoresis was performed using Capillarys 2 full-automated electrophoresis instrument. Gap polymerase chain reaction and reverse dot blot were used for genetic diagnosis of thalassemia genotyping test. The cut-off value in screening of thalassemia was determined by receiver operating characteristic curve and next to analyze the value of HbA2 and HbF in screening of thalassemia using the decided cut-off value. RESULTS: The areas under the curve (AUC(Roc)) of HbA2 for diagnosis of α-, ß- thalassemia were 0.75 and 0.981 respectively, and the AUC(Roc) of HbF for diagnosis of ß-thalassemia was 0.787. When HbA2 ≤ 2.55 was taken as the cut-off value of HbA2 for diagnosis of α-thalassemia, the sensitivity, specificity, positive likelihood ratio (LR(+)) and negative likelihood ratio (LR(-)) were 89.5%, 54.8%, 1.98, 0.19 respectively. When HbA2 ≥3.9 was taken as the cut off value of HbA2 for diagnosis of ß-thalassemia, the sensitivity, specificity, LR(+) and LR(-) were 96.1%, 99.8% 480.5, 0.04 respectively. When HbF ≥0.75 was taken as the cut off value of HbF for diagnosis of ß-thalassemia, the sensitivity, specificity, LR(+) and LR(-) were 83.6%, 61.8% respectively. CONCLUSION: The cut-off value in screening of thalassemia by capillarys 2 full automated electrophoresis instrument is different from that of the traditional method of hemoglobin electrophoresis, such as cellulose acetate membrane electrophoresis and agarose gel electrophoresis. Each laboratory should establish their own respective cut off value.

Advances in Evaluation of Cognitive Impairment in Patients with Cushing's Disease.

Cushing's disease (CD) is a relatively rare disease,characterized by pathological hypercortisolism secondary to excessive adrenocorticotrophic hormone that is secreted by pituitary adrenocorticotrophic hormone adenoma or hyperplasia. In addition to the typical clinical symptoms such as moon face,buffalo hump,and central obesity,the CD patients may also experience mental disorders and cognitive dysfunction. This review mainly focuses on the cognitive state of CD patients,the mechanisms of cognitive impairment caused by high cortisol levels,and the imaging findings (especially magnetic resonance imaging) for the evaluation of cognitive functions.

[Experimental analysis and countermeasures for EDTA-dependent Pseudothrombocytopenia].

The purpose of this study was to investigate the incidence of clinically common EDTA-dependent pseudo-thrombocytopenia (EDTA-PTCP) and methols for treating this diseese. A total of 1326 cases of thrombocytopenia found at blood routine examination were amalyzed anong 71 535 patients hospitalized in our hospital from January 2010 to May 2013, and 87 cases of PTCP caused EDTA-K anticoagulant were analyzed again by using sodium citrate auticoagulant, at the same time the platelet formation distribution was observed by microscopy of smear with Wright-Giemsa staining. The results showed that the platelet count detected by using EDTA-K anticoagulant in 87 cases was (56 ± 27)×10(9)/L, while the platelet count detected by using sodium citrate was (185 ± 39)×10(9)/L (t = 1.83,P < 0.01). The pseudo-thrombocytopenia incidence cansed by EDTA-K was 0.12%, it was 6.56% for the total number of thrombocytopenia. It is concluded that the incidence of PTCP cansed by EDTA-K is 0.12%, the PTCP is easily misdiagnosed. Therefore, the specimens of platelet count <100 10(9)/L should be tested again. When the platelet aggregation is found, the specimens should be examined again by using sodium citrate in order to avoid misdiagnosis.