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Osteoradionecrosis (ORN) is a serious complication after radiotherapy (RT), even in the era of intensity modulated radiation therapy (IMRT). The purpose of this study was to evaluate whetherOne hundred and five OP/OC SCC patients treated with RT who underwent pretreatmentAmong 105 patients, 14 (13.3 %) developed ORN. The SUVmax of the periodontal region in patients with ORN (3.35 ± 1.23) was significantly higher than patients without ORN (1.92 ± 0.66) (P .01). The corresponding CT stage of periodontitis in patients with ORN was significantly higher (2.71±0.47) than patients without ORN (1.80±0.73) (P .01). ROC analysis revealed the cut-off values of developing ORN were 2.1 in SUVmax, and II in CT stage of periodontitis. The corresponding AUC was 0.86 and 0.82, respectively.Pretreatment

Objective To assess the feasibility of computed diffusion-weighted imaging (cDWI) in comparison with directly acquired DWI for visualizing pancreatic adenocarcinomas. Materials and methods Patients with pancreatic adenocarcinoma underwent DWI at b-values of 0, 1000 (DWI1000), 1500 (DWI1500) and 2000 (DWI2000) s/mm2. From DWIs at b-values of 0 and 1000 s/mm2, we generated cDWIs at b-values of 1500 (cDWI1500) and 2000 (cDWI2000) s/mm2. DWI findings of pancreatic adenocarcinomas (clear hyperintensity; hyperintensity with an unclear distal border; and isointensity), the image quality and the tumor to pancreas contrast ratio (CR) were compared between directly acquired DWI and cDWI. Results Among the 63 included patients, clear hyperintense tumors were seen in 35 on DWI1000, 50 on DWI1500, 50 on cDWI1500, 53 on DWI2000 and 44 on cDWI2000. Incidence of clear hyperintense tumors was significantly higher on cDWI1500 than on DWI1000 (P = 0.013). There was no significant difference in the incidence of clear hyperintense tumors between DWI1500 and cDWI1500 (P > 0.999), but a lower incidence was seen on cDWI2000 than on DWI2000 (P = 0.028). Image quality was lower on cDWI than on DWI at b-values of 1500 (P = 0.002) and 2000 s/mm2 (P Conclusions cDWI1500 generated from b-values of 0 and 1000 s/mm2 should be considered more effective than DWI1000 and at least as effective as DWI1500.

Purpose To evaluate whether diffusion tensor imaging (DTI) can be used to differentiate malignant parotid gland tumors from the benign ones. Materials and methods The study population comprised 59 parotid gland tumors (24 Warthin’s tumors, 19 pleomorphic adenomas, seven other benign tumors, and nine malignant tumors). Single-shot echo-planar DTI was performed with motion-probing gradients along 30 noncollinear directions (b = 1000 s/mm2) at 3.0 T. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values for benign and malignant tumors were compared using the Mann–Whitney U test. Receiver-operating characteristic (ROC) curve analysis was performed to assess the ability of the ADC and FA values to differentiate malignant tumors from the benign ones. Results ADC values showed no significant difference between malignant (0.93 ± 0.21 × 10−3 mm2/s) and benign tumors (1.19 ± 0.50 × 10−3 mm2/s) (p = 0.225). FA values of malignant tumors were significantly higher than those of benign tumors (0.26 ± 0.06 vs. 0.17 ± 0.05, p Conclusions DTI, particularly FA, can help differentiate malignant parotid gland tumors from the benign ones.

To characterize the CT imaging features of head and neck amyloidosis and correlate with extent of disease and clinical outcomes.This retrospective study included 80 patients with head and neck amyloidosis who underwent soft tissue neck CT imaging between November 2003 and April 2018. The CT imaging features including lesion distribution, morphology (focal, diffuse/circumferential, or combined), presence and pattern of calcification, (punctate or diffuse), and thickness of airway lesion were evaluated and compared with the extent of amyloidosis (localized or systemic), and clinical course (stable, no recurrence, or progression requiring repeated surgical treatment).Localized disease (83.8%, 67/80) was most common with AL type (97.6%, 41/42) representing nearly all cases of head and neck amyloidosis. The larynx was the most frequently affected organ (60.0%, 48/80), specifically the glottis (43.8%, 35/80). Calcification was seen in 65.0% of cases (52/80). Non-airway or tongue lesions were significantly associated with systemic (92.3%, 12/13) as opposed to localized amyloidosis (4.5%, 3/67; P 0.001). Repeated surgical treatment was significantly associated with laryngeal amyloidosis (35.3%, 12/34; P = 0.002) and multi-centric disease (33.3%, 10/30; P = 0.048). Airway wall thickness in patients who required repeated surgical treatment was significantly greater than in patients with stable or no recurrent disease (P = 0.016).Knowledge of the imaging features of head and neck amyloidosis can aid the diagnosis, disease monitoring, and prediction of patients requiring repeated surgical intervention.

Purpose Osteoradionecrosis (ORN) is a serious complication after radiotherapy (RT), even in the era of intensity modulated radiation therapy (IMRT). The purpose of this study was to evaluate whether 18F-FDG PET/CT can predict ORN associated with periodontal disease in patients with oropharyngeal or oral cavity squamous cell carcinoma (OP/OC SCC) undergoing RT. Methods One hundred and five OP/OC SCC patients treated with RT who underwent pretreatment 18F-FDG PET/CT between October 2007 and June 2016 were retrospectively reviewed. A post-treatment diagnosis of ORN was made clinically based on presence of exposed irradiated mandibular bone that failed to heal after a period of three months without persistent or recurrent tumor. The maximum standardized uptake value (SUVmax) of periodontal regions identified on PET/CT was measured for all patients. Image-based staging of periodontitis was also performed using American Academy of Periodontology staging system on CT. Results Among 105 patients, 14 (13.3 %) developed ORN. The SUVmax of the periodontal region in patients with ORN (3.35 ± 1.23) was significantly higher than patients without ORN (1.92 ± 0.66) (P Conclusions Pretreatment 18F-FDG PET/CT identification of periodontitis may be helpful to predict the future development of ORN in patients with OP/OC SCC undergoing RT.

Purpose Cystic and cystic-appearing odontogenic lesions of the jaw may appear similar on CT imaging. Accurate diagnosis is often difficult although the relationship of the lesion to the tooth root or crown may offer a clue to the etiology. The purpose of this study was to evaluate CT texture analysis as an aid in differentiating cystic and cystic-appearing odontogenic lesions of the jaw. Methods This was an IRB-approved retrospective study including 42 pathology-proven dentigerous cysts, 37 odontogenic keratocysts, and 19 ameloblastomas. Each lesion was manually segmented on axial CT images, and textural features were analyzed using an in-house-developed Matlab-based texture analysis program that extracted 47 texture features from each segmented volume. Statistical analysis was performed comparing all pairs of the three types of lesions. Results Pairwise analysis revealed that nine histogram features, one GLCM feature, three GLRL features, two Laws features, four GLGM features and two Chi-square features showed significant differences between dentigerous cysts and odontogenic keratocysts. Four histogram features and one Chi-square feature showed significant differences between odontogenic keratocysts and ameloblastomas. Two histogram features showed significant differences between dentigerous cysts and ameloblastomas. Conclusions CT texture analysis may be useful as a noninvasive method to obtain additional quantitative information to differentiate cystic and cystic-appearing odontogenic lesions of the jaw.

Objective To compare the quality of contrast enhancement and hepatic CT images acquired using bolus tracking technique at two different time points and those acquired with fixed scan delay technique using a previous bolus tracking data. Materials and methods Fifty patients who underwent 3 different hepatic CT exams (25-s fixed injection of 600 mg iodine (I)/kg or 100 mL of 370 mg I/mL nonionic contrast medium) were enrolled. The first and second exams were performed with a bolus tracking technique. The third exam was performed with a fixed scan delay technique using the first exam data. Differences in attenuation values in the abdominal organs were examined and evaluated visually on hepatic arterial phase images. Results There was no significant difference in the mean 50-HU threshold times between the first and second bolus tracking exams with intra-patient differences between them (1.3 ± 0.9 s). No significant intra-patient differences were noted in organ attenuation and visual evaluation on hepatic arterial phase images between the 3 exams. Conclusion The fixed scan delay technique using a previous bolus tracking data is feasible for hepatic CT exams to follow up hepatocellular carcinoma.

To determine whether contrast enhancement of CT and apparent diffusion coefficient on diffusion-weighted MR imaging are important parameters that can predict outcomes for patients with pancreatic ductal adenocarcinoma.Ninety-two patients with histologically confirmed pancreatic ductal adenocarcinoma who underwent quadriphasic CT (including unenhanced, pancreatic parenchymal, portal venous and delayed phases) and fat-suppressed single-shot echo-planar diffusion-weighted MR imaging at 3.0 T were retrospectively analyzed to investigate prognostic factors. Overall survival curves were drawn using the Kaplan-Meier method. Effects on survival of variables including age, sex, tumor location, tumor size, TNM stage, carbohydrate antigen 19-9, carcinoembryonic antigen, treatment, tumor contrast enhancement and apparent diffusion coefficient values were analyzed in univariate analysis using the log-rank test. Variables were analyzed in multivariate analyses using the Cox proportional hazards regression model.Median survival for the entire patient population was 18.2 months. Higher contrast enhancement during all phases was associated with significantly longer overall survival (P0.001 for all phases). The difference in overall survival between groups divided by median apparent diffusion coefficient value was not significant (P=0.672). TNM stage (P=0.026) and tumor contrast enhancement on CT (P=0.027) were significantly related to survival in multivariate analysis.Poor enhancement of pancreatic adenocarcinomas on enhanced CT is associated with reduced patient survival.