OBJECTIVE: To establish a fast adaptive active contour model based on local gray difference for parotid duct image segmentation. METHODS: On the basis of the LBF model, we added the mean difference of the local gray scale inside and outside the contour as the energy term of the driving evolution curve, and the local gray-scale variance difference was used to replace and as the control term of the energy parameter value. Two local similarity factors of different neighborhood sizes were introduced to correct the effects of image gray unevenness and boundary blur to improve the segmentation efficiency. RESULTS: During image segmentation, this algorithm allowed for adaptive adjustment of the evolution direction, velocity and the energy weight of the internal and external regions according to the difference of gray mean and variance between the internal and external regions. This algorithm was also capable of detecting the actual boundary in a complex gradient boundary region, thus enabling the evolution curve to approach the target boundary quickly and accurately. CONCLUSIONS The proposed algorithm is superior to the existing segmentation algorithms and allows fast and accurate segmentation of the parotid duct with well-preserved image details.
Algorithms ; Color ; Image Processing, Computer-Assisted ; Parotid Gland ; diagnostic imaging ; Salivary Ducts ; diagnostic imaging

OBJECTIVE: To establish a Parotid Imaging Reporting and Data System (PI-RADS) for CT diagnosis of the parotid gland neoplasms and to investigate the clinical applicable value and feasibility of PI-RADS. METHODS: Patients who had been diagnosed with primary parotid gland neoplasms and had received surgical treatments in Peking University School and Hospital of Stomatology during the period of January 2013 to December 2016 were included in this study. The diagnoses were confirmed by the postoperative pathological examinations in all the patients. The CT imaging data of all patients were retrospectively reviewed and analyzed by two readers in consensus. Imaging characteristics related to the parotid neoplasms were extracted and quantified. Based on comprehensive analysis of the imaging characteristics, the probabilities of the benign and malignant neoplasms were evaluated and classified into six grades, PI-RADS 1-6 (PI-RADS 1: normal parotid gland; PI-RADS 2: confidently benign lesions; PI-RADS 3: probably benign lesions without confirmed evidence of malignancy; PI-RADS 4: suspected malignancy without sufficient evidence of malignancy; PI-RADS 5: confidently malignant lesions; PI-RADS 6: lesions with confirmed pathological evidence of malignancy). RESULTS: A total of 897 patients with 1 003 parotid lesions were included. The lesions included 905 benign and 98 malignant lesions. The proportions of the malignancies in PI-RADS 2, PI-RADS 3, PI-RADS 4 and PI-RADS 5 according to the two readers in consensus were 0.4%, 5.7%, 35.5% and 96.7% respectively. The overall Cohen's Kappa test showed medium consistency between the two independent researchers (κ=0.614, P<0.001, 95%CI: 0.569-0.695). Pearson Chi-square test showed that the proportions of malignancies increased with the diagnostic PI-RADS grades (Cochran-Armitage trend test, Z=-15.579, P<0.001). The results of Pearson Chi-square tests showed significant differences between the grades [PI-RADS 2 and 3 (χ²=12.048, P=0.001); PI-RADS 3 and 4 (χ²=75.231, P<0.001); PI-RADS 4 and 5 (χ²=32.266, P<0.001)]. CONCLUSION PI-RADS can be used to evaluate the risk of malignancy and will be helpful to improve the imaging diagnosis and clinical treatment of parotid gland neoplasms.
Humans ; Magnetic Resonance Imaging ; Male ; Parotid Gland/diagnostic imaging* ; Parotid Neoplasms ; Prostatic Neoplasms ; Retrospective Studies ; Tomography, X-Ray Computed

No abstract available.
Diagnosis, Differential ; Female ; Humans ; Middle Aged ; Neck/diagnostic imaging ; Parotid Gland/*pathology ; Parotid Neoplasms/diagnosis/diagnostic imaging/pathology ; Sarcoidosis/*diagnosis/diagnostic imaging ; Tomography, X-Ray Computed ; Ultrasonography

Salivary gland involvement is a rare presenting clinical feature of Wegener's granulomatosis (WG). Early recognition and identification of any unusual presentations of WG may enable the early commencement of appropriate treatment. We report a case in which the initial manifestation of the disease was parotid gland swelling, and discuss the management of the patient. WG should be considered in the differential diagnosis when salivary gland enlargement occurs with other otolaryngological symptoms.
Adult ; Biopsy ; Diagnosis, Differential ; Female ; Granulomatosis with Polyangiitis ; diagnosis ; Humans ; Parotid Gland ; diagnostic imaging ; pathology ; Tomography, X-Ray Computed

The paper introduces a helical tomotherapy (HT) adaptive system in assessment of parotid gland dose variation in head and neck cancer. The system, which helical therapy unit is equipped with, is based on megavoltage computed tomography (MVCT) images to calculate the actual volume and dose of region of interest (ROI). Whether to change plan is judged on the fact for the realization of adaptive radiotherapy. One case of nasopharyngeal carcinoma was as a sample to evaluate parotid gland dose variation during the treatment. On every week and last time, patient was scanned by MVCT before treatment, a total of eight MVCT images. As the treatment progressed, the parotid gland volume was shrinking and the dose was increasing. The parotids volume variation was negatively related with D50 and V1 (both P < 0.05).
Adult ; Head and Neck Neoplasms ; diagnostic imaging ; Humans ; Male ; Parotid Gland ; diagnostic imaging ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; instrumentation ; methods ; Software ; Tomography, Spiral Computed ; instrumentation ; methods

OBJECTIVETo investigate the clinical and laboratory characteristics of tumor like Sjögren's syndrome (TLSS) patients and non-tumor like Sjögren's syndrome (NTLSS) and the incidence of lymphoma in patients of Sjögren's syndrome (SS).

METHODSA retrospective analysis was carried out in 199 primary SS (including TLSS) patients who were recruited in Peking University School and Hospital of Stomatology from 1998 to 2010. Clinical and laboratory information were collected. The patients were divided into two groups: TLSS (n = 25) and NTLSS (n = 174). Clinical and laboratory characteristics were compared between these two groups by a statistical analysis.

RESULTSOf the 25 TLSS patients, 23 had enlargements of parotid glands and 2 had enlargements of submandibular glands. There were significant differences of salivary scintigraphy appearance (P = 0.018), hypergammaglobulinemia (P = 0.014), rheumatoid factor positive rate (P = 0.001), formation of the ectopic germinal centers (P = 0.014), double positive rate of anti-SSA antibody and anti-SSB antibody (P < 0.001) between the TLSS and NTLSS patients. Among the 25 TLSS patients, 3 developed lymphomas, accounting for 1.5% (3/199) of the total 199 patients and 12% (3/25) of the TLSS patients. Lymphoma subtypes included one diffused large B-cell lymphoma and two mucosa-associated lymphoid tissue lymphoma. There was no lymphoma detected in NTLSS patients.

CONCLUSIONSThere are clinical and laboratory differences between TLSS and NTLSS patients, with a more tendency to develop lymphomas in TLSS patients.

Adult ; Antibodies, Antinuclear ; metabolism ; Female ; Humans ; Hypergammaglobulinemia ; metabolism ; Lymphoma, B-Cell, Marginal Zone ; diagnostic imaging ; etiology ; metabolism ; pathology ; Lymphoma, Large B-Cell, Diffuse ; diagnostic imaging ; etiology ; metabolism ; pathology ; Male ; Middle Aged ; Parotid Gland ; pathology ; Radionuclide Imaging ; Retrospective Studies ; Rheumatoid Factor ; metabolism ; Salivary Glands ; diagnostic imaging ; Sjogren's Syndrome ; complications ; diagnostic imaging ; metabolism ; pathology ; Submandibular Gland ; pathology