Yusuke Kawashima

Using Texture Analysis to Determine Human Papillomavirus Status of Oropharyngeal Squamous Cell Carcinomas on CT

BACKGROUND AND PURPOSE: Human papillomavirus–associated oropharyngeal squamous cell carcinoma is increasing in prevalence and typically occurs in younger patients than human papillomavirus–negative squamous cell carcinoma. While imaging features of human papillomavirus–positive versus human papillomavirus–negative squamous cell carcinoma nodal metastases have been described, characteristics distinguishing human papillomavirus–positive from human papillomavirus–negative primary squamous cell carcinomas have not been well established. The purpose of this project was to evaluate the use of texture features to distinguish human papillomavirus–positive and human papillomavirus–negative primary oropharyngeal squamous cell carcinoma. MATERIALS AND METHODS: Following institutional review board approval, 40 patients with primary oropharyngeal squamous cell carcinoma and known human papillomavirus status who underwent contrast-enhanced CT between December 2009 and October 2013 were included in this study. Segmentation of the primary lesion was manually performed with a semiautomated graphical-user interface. Following segmentation, an in-house-developed texture analysis program extracted 42 texture features from each segmented volume. A t test was used to evaluate differences in texture parameters between human papillomavirus–positive and human papillomavirus–negative squamous cell carcinomas. RESULTS: Of the 40 included patients, 29 had human papillomavirus–positive oropharyngeal squamous cell carcinoma and 11 had human papillomavirus–negative oropharyngeal squamous cell carcinoma. Significant differences were seen in the histogram parameters median (P = .006) and entropy (P = .016) and squamous cell carcinoma entropy (P = .043). CONCLUSIONS: There are statistically significant differences in some texture features between human papillomavirus–positive and human papillomavirus–negative oropharyngeal tumors. Texture analysis may be considered an adjunct to the evaluation of human papillomavirus status and characterization of squamous cell carcinoma.

Difference Between HPV-Positive and HPV-Negative Non-Oropharyngeal Head and Neck Cancer: Texture Analysis Features on CT.

Objective To identify the specific texture parameter that shows significant differences between human papillomavirus (HPV)–positive (HPV+) and HPV-negative (HPV-) non-oropharyngeal carcinoma (non-OPC) using texture analysis. Methods Forty-six patients of non-OPC patients (oral cavity, larynx, and hypopharynx) with known HPV status, who underwent contrast-enhanced computed tomography for initial staging, were retrospectively reviewed. Segmentations of the primary lesion were manually performed, and an in-house developed texture analysis program extracted 42 texture features from each segmented volume. A t test was used to evaluate differences between HPV+ and HPV- non-OPCs (P < 0.05). Results Sixteen texture parameters, including 5 histogram features (P ⩽ 0.03), 3 gray-level co-occurrence matrix features (P ⩽ 0.02), 1 gray-level run-length feature (P = 0.009), 2 gray-level gradient matrix features (P ⩽ 0.02), and 5 Law features (P ⩽ 0.04), showed significant differences. Conclusions Texture analysis demonstrated significant differences between HPV+ and HPV- non-OPCs on computed tomography images, which may have a potential to prove morphologic feature differences among HPV-related tumors.

Computed Tomography Findings of Mandibular Nutrient Canals

Introduction:The purpose of this study was to assess computed tomography (CT) findings of mandibular nutrient canals using CT images. Materials and Methods:We retrospectively analyzed the mandibular CT images of 194 consecutive patients. For image analysis such as canal prevalence, location, number, size, shape, and the CT value of nutrient foramina were determined using CT axial images of 0.5 and 3 mm slice thickness. Results:We revealed that the nutrient canals were seen 94.3% in the mandible, mostly seen in the anterior region. By location, nutrient canals were particularly seen between the central and lateral incisors. The mean number of nutrient canals was 2.7. The mean diameter of the nutrient foramen between the central and lateral incisors was 1.0 mm. In about 80% of the cases, foramina between the central and lateral incisors were ovoid. The mean CT value for the nutrient foramina between the central and lateral incisors was 411 HU. Discussion and Conclusions:Mandibular nutrient canals were ovoid shape, and the mean CT value was 411 HU. By preoperative knowledge of the position and anatomy of the mandibular nutrient canals, complications such as injury to the nutrient canals can be avoided.

Parotid Lymphadenopathy Is Associated With Joint Effusion in Non-Neoplastic Temporomandibular Disorders

PURPOSE Lymphadenopathy often occurs in the setting of inflammation, with or without infection. We sought to elucidate any association of parotid lymphadenopathy with joint effusion in temporomandibular joint (TMJ) disorders. MATERIALS AND METHODS We performed a retrospective cohort study. We analyzed the magnetic resonance imaging studies of patients with suspected TMJ disorders performed from April 2006 to March 2007. The degree of joint effusion was graded on sagittal T2-weighted spin echo images according to a commonly used system. On axial short T1-weighted short inversion recovery images, the number and short-axis diameter of the parotid lymph nodes were recorded. We performed analyses of the cluster-correlated data using the Mann-Whitney U test and Spearmans correlation coefficients. P < .05 was considered to indicate significance. To assess the possible predictive value of certain variables, a generalized linear model (generalized estimation equation) was constructed, considering the multiple measurements. RESULTS A total of 402 TMJ disorders were analyzed from 201 patients during the study period. The number and size of the parotid lymph nodes identified was significantly greater in the patients with TMJ effusion (P < .01) than in those without effusion. CONCLUSION In the present study, we found an association between parotid lymphadenopathy and joint effusion in TMJ disorders. These findings indicate that lymphadenopathy should be considered as an inflammation condition commonly associated with joint effusion in TMJ disorders.