Differential imaging diagnosis of a swelling after extraction in a breast cancer patient with radiotherapy and chemotherapy / 대한구강악안면방사선학회지

A 60-year-old female, who complained of delayed healing and swelling after extraction of left lower second molar during chemotherapy, visited our department. She had a history of a resection surgery of breast cancer and postoperative radiotherapy. The conventional radiographs showed diffuse permeative bone destruction in posterior mandibular body, which gave the first radiologic impression of osteonecrosis associated with radiotherapy or chemotherapy. And bone metastasis from the breast cancer was also considered in the differential diagnosis. On the enhanced computed tomography (ECT) the posterior mandibular body was occupied by a large expansile lesion showing central low attenuation with peripheral rim enhancement. Magnetic resonance images revealed that the low attenuated area on ECT did not show as high signal intensity as water on T2 weighted image and indicated solid component of a tumor. The final diagnosis was central squamous cell carcinoma. We present the diagnostic imaging features of the patient with special emphasis on the differential diagnosis.

Effect of exposure time and image resolution on fractal dimension / 대한구강악안면방사선학회지

PURPOSE: To evaluate the effect of exposure time and image resolution on fractal dimension calculations for determining the optimal range of these two variances. MATERIALS AND METHODS: Thirty-one radiographs of the mandibular angle area of sixteen human dry mandibles were taken at different exposure times (0.01, 0.08, 0.16, 0.25, 0.40, 0.64, and 0.80 s). Each radiograph was digitized at 1200 dpi, 8 bit, 256 gray level using a film scanner. We selected an Region of Interest (ROI) that corresponded to the same region as in each radiograph, but the resolution of ROI was degraded to 1000, 800, 600, 500, 400, 300, 200, and 100 dpi. The fractal dimension was calculated by using the tile-counting method for each image, and the calculated values were then compared statistically. RESULTS: As the exposure time and the image resolution increased, the mean value of the fractal dimension decreased, except the case where exposure time was set at 0.01 seconds (alpha = 0.05). The exposure time and image resolution affected the fractal dimension by interaction (p<0.001). When the exposure time was set to either 0.64 seconds or 0.80 seconds, the resulting fractal dimensions were lower, irrespective of image resolution, than at shorter exposure times (alpha = 0.05). The optimal range for exposure time and resolution was determined to be 0.08-0.40 seconds and from 400-1000 dpi, respectively. CONCLUSION: Adequate exposure time and image resolution is essential for acquiring the fractal dimension using tile-counting method for evaluation of the mandible.

Squamous cell carcinoma in the submandibular space / 대한구강악안면방사선학회지

A 66-year-old man visited author's institute complaining of the swelling on the submandibular gland area. Clinically, the exophytic mass penetrated the skin of the submandibular area. On MRI, the lesion occupied the left submandibular space and extended downward, protruding exterior to the subcutaneous fat layer, but the center of the lesion was located on the side of the skin and the growth exterior to the skin was prominent. Demarcation of the lesion and the submandibular gland was unclear. Histopathologically the epithelial nests and keratin production were seen, then the biopsy result was squamous cell carcinoma. The stroma of lesion showed a myxoid characteristic and some ducts showed metaplasia of the ductal cells, which suggested the gland-origin carcinoma. However, lots of keratin production and carcinomatous change of cells continuous to the normal epithelium of the skin, the skin-origin carcinoma invading into the submandibular gland area could not be excluded.

Squamous cell carcinoma in the submandibular space / 대한구강악안면방사선학회지

A 66-year-old man visited author's institute complaining of the swelling on the submandibular gland area. Clinically, the exophytic mass penetrated the skin of the submandibular area. On MRI, the lesion occupied the left submandibular space and extended downward, protruding exterior to the subcutaneous fat layer, but the center of the lesion was located on the side of the skin and the growth exterior to the skin was prominent. Demarcation of the lesion and the submandibular gland was unclear. Histopathologically the epithelial nests and keratin production were seen, then the biopsy result was squamous cell carcinoma. The stroma of lesion showed a myxoid characteristic and some ducts showed metaplasia of the ductal cells, which suggested the gland-origin carcinoma. However, lots of keratin production and carcinomatous change of cells continuous to the normal epithelium of the skin, the skin-origin carcinoma invading into the submandibular gland area could not be excluded.