Toru Wakasa

Mandibular metastasis presenting as the initial maifestation of malignant pheochromocytoma

A case of 59-year-old male patient presenting with metastasis to the mandible from malignant pheochromocytoma is described. The conventional radiographs and CT images suggested that the lesion was malignant osteogenic tumors or metastatic tumors due to the existence of calcification and widespread periosteal sunburst spiculation. On MRI, an expansive mass was clearly depicted and the signal intensities of the lesion were low to intermediate on T1 weighted image with intermediate to high signal intensity on T2 weighted image. A strong enhancement of the lesion was also observed on contrast enhanced T1 weighted image. On maximum intensity projection image in the arterial phase, the mass showed exceedingly early enhancement and excessively dislocated adjacent vessels. The diagnosis of a pheochromcytoma was difficult on the basis of these imagings. The final diagnosis was based on a biopsy of the mandible and I-131 Meta-iodobenzylguanidine scintigraphy (MIBG) scintigraphy. A primary lesion of the right adrenal showed low uptake due to wide centric necrosis and metastatic lesions of liver, lumber vertebrae, ribs and sacroiliac joint showed high uptake on the I-131 MIBG scintigraphy. The final diagnosis was nonfunctioning malignant pheochromocytoma due to the absence of elevation of catecholamine or its metabolite.

Correlation of the near-infrared spectroscopy signals with signal intensity in T2-weighted magnetic resonance imaging of the human masseter muscle

The purpose of this study was to compare and contrast blood volume changes transcutaneously measured using near-infrared (NIR) spectroscopy against water signal intensity changes taken from a transverse T(2)-weighted MR image of the masseter muscle in healthy human subjects before, during and after contraction. Eight healthy non-smoking males with no history of chronic muscle pain or vascular headaches participated (mean age: 23.9+/-0.6 years). The MRI data were gathered using a turbo spin echo sequence (TR: 2300 ms; TE: 90 ms; FOV: 188x300 mm; scanning time: 30 s; slice thickness: 10 mm) and the slice level was set at the mid-point between the origin and insertion of the masseter. Intramuscular haemoglobin (Hb) levels and water content of the right masseter muscle were continuously monitored for 2 min before, 30 s during and 15 min after a maximum voluntary clenching (MVC) task. Both the near-infrared and MRI data were baseline-corrected and normalized and mean levels were established and plotted. Plots of the data showed that both near-infrared-based total Hb and T(2)-weighted MRI-based signal-intensity levels clearly decreased during contraction and a clear post-contraction rebound response was evident after the contraction. The near-infrared data were found to be highly correlated with MRI-based signal-intensity data (Pearsons r=0.909, P<0.0001). In conclusion, these data provide powerful evidence that near-infrared data (total Hb), transcutaneously taken from the masseter muscle in humans, will reflect the intramuscular water signal intensity changes seen using a T(2)-weighted MRI imaging method.

Application of dynamic CT for various diseases in the oral and maxillofacial region.

OBJECTIVE To investigate whether dynamic CT enables quantitative differentiation between inflammation, benign tumors, and malignant tumors in oral and maxillofacial regions. METHODS Sixteen malignant tumors (14 squamous cell Ca, one adenoid cystic Ca, one mucoepidermoid Ca), six benign tumors (one Warthin tumor, two pleomorphic adenomas, one lipoma, one Schwanoma, one hemangioma), and seven inflammation cases (three submandibular adenitis, two osteomyelitis, two perimandibular inflammations) were examined. Contrast agent (0.8 ml/kg) was injected intravenously at 5 ml/s. CT (Toshiba TCT 900S) scanning was performed at the time of the beginning of contrast medium injection. Parameters from the time-density curve were investigated: peak height (PH), relative CT value from the base CT value when the curve reached peak point; peak time (PT), the time when the curve reaches the peak point from contrast medium infusion; transit time (TT), time between two transit points on the time-density curve; and peak time ratio (PR), the ratio of peak time from the lesion to the artery and peak time from the vein to the artery. RESULTS PH was highest in inflammation, followed by malignant tumors and benign tumors. TT was significantly longer in benign tumor cases compared with malignant tumor and inflammation cases. PR for malignant tumor and inflammation were between the artery and vein phase, and that for benign tumor was beyond the vein phase. CONCLUSION Parametrical analysis of a contrast enhanced dynamic CT study may serve to differentiate the lesions in the oral and maxillofacial region.

Multiple bilateral calcifications of lymph nodes in the submandibular and cervical regions — Report of a case —

SummaryA case of tuberculous lymphadenitis with multiple bilateral calcifications in the submandibular and cervical regions has been reported. Radiographic findings revealed that multiple calcifications of various sizes and forms were arranged in rows bilaterally. A possible mode of calcification and infection ways in the lymph nodes was discussed.

A radiographic study on resorption of tooth root associated with malignant tumors

AbstractRoot resorption is a very important finding in the radiographic diagnosis of the oral and maxillofacial region. However, there are few reports about root resorption related to malignant tumors. It is a commonly accepted theory that a malignant tumor does not cause root resorption because its invasion is too rapid. However, we have encountered many unexpected cases of root resorption associated with malignant tumors. In this study, we investigated the frequency and shape of root resorption in malignant tumors and considered the relation between tumor extension and root resorption. The subjects were 72 patients with pathologically diagnosed malignant tumors. Radiography showed that the roots of their teeth were in contact or involved with the tumors. We observed the radiographs and classified the findings into 2 types as follows:(1)resorption of alveolar bone (site of tumor invasion): 1. alveolar-margin type 2. root-apex type.(2)resorption of tooth root: 1. spike type 2. knife-edge type. The root resorption rate for all cases was 43% (31/72). (There were 19 squamous cell carcinomas, 2 adenoid cystic carcinomas, 3 malignant lymphomas, 2 metastatic tumors, 1 poorly differentiated carcinoma, 3 undifferentiated carcinomas and 1 fibrosarcoma.) Root resorption rate of alveolar-margin-type tumors was 37% (19/51), and that of the root-apex-type tumors was 57% (12/21). All alveolar-margin-type tumors showed spike-type root resorption, and all root-apex-type tumors were of the knife-edge type except 1 case. Our study suggested that root resorption associated with malignant tumors is not rare and that the shape of root resorption may be related to the site of tumor invasion. In the case of root resorption with resorption of alveolar bone, it is important to take malignant tumors into consideration as well as other diseases.

Clinical evaluation of thermography in the diagnosis of malignant tumors in the oral and maxillo-facial region

Thermographic images of 48 cases of malignant tumors were analyzed and compared with those of other lesions: 93 cases of acute inflammation, 48 cases of chronic inflammation, 48 cases of benign tumors and 28 cases of cystic lesions. The majority of the cases with malignant tumors showed higher skin temperature over the affected area, but usually not so remarkable such as those of the cases with acute inflammation. The border of the thermal pattern of the tumors showed the tendency to be unclear. Both malignant tumors and acute inflammation appeared to cause an increase in skin temperature of the common carotid artery region on the affected side as compared with the opposite side. Malignant tumors showed the tendency that the temperature of the common carotid artery region of the affected side is equal or lower than the affected region in many cases. It is suggested that with further sophistication of the system suitable for the maxillofacial region, thermography may serve a role in the clinical diagnosis of malignant tumors.

Radiographic study of extension phase of chronic osteomyelitis of the mandible

It is thought that the phase of inflammatory extension in osteomyelitis of the mandible varies according to the primary site of infection, that is, the causative tooth. This study was conducted to analyze the relationship between the extension phase of inflammatory bone changes and the causative tooth in patients with radiographically diagnosised osteomyelitis of the mandible. Between 1983 and 1993, a total of 219 patients with osteomyelitis of the mandible were seen in our department. In the age distribution, 135 cases occurred in men and 98 cases in women. Osteomyelitis was most prevalent in patients in their sixties (39 cases) followed by patients in their forties and fifties (38 cases each). The causative tooth was identified in 97 cases of osteomyelitis in the mandible. In the 39 cases in which the primary infection was caused by the third mandibular molar, distal extension was most prevalent (30 cases). In the 58 cases in which a tooth other than the third mandibular molar was the cause (front tooth, premolar, deciduous tooth and other molars), equal extension in the mesio-distal direction was most prevalent (40 cases). In the upper-lower extension phase, lower extension beyond the mandibular canal was most prevalent in the first, second and third molar teeth. In the cases involving teeth other than the mandibular molars, the inflammatory bone changes were rather limited to the upper part of the mandibular canal.

Evaluation of several imaging techniques for a diagnosis of inflammation of jaw bones

Recent developments of various imaging techniques have resulted in a great improvement in the diagnostic capabilities of the diseases of the dento-maxillo-facial region. Therefore, a combination of the conventional radiograph and some of the new imaging techniques may provide the most valuable information in the diagnosis of inflammatory diseases. A retrospective study was conducted on 331 patients attending the Okayama University affiliated hospital between April, 1982 and January, 1987, that presented inflammation of the jaw bones. Inflammatory diseases were compared with the effectiveness of the various imaging systems i. e. conventional radiography, ultrasound sonography, RI scintigraphy, and thermography. Resul ts 1. Clinical and radiographic study Inflammation of the jaw bone area was classified as chronic osteomyelitis and acute perimaxillary (perimandibular) inflammation according to the clinical and radiographic features. The sex ratio was 1.8 to 1 in favor of males in osteomyelitis cases and 1.3 to 1 in favor of males in perimaxillary inflammation (Table 1). Osteomyelitis occurred most

Functional MRI Study of Cerebral Cortical Activation during Volitional Swallowing

ObjectivesTo investigate the somatotopic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging.MethodsNine healthy right-handed adult volunteers (6 men, 3 women; ages 22–38) were examined. Their cortical activities were evoked by having them swallow, five times, asmall bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; TR/TE=0.96/0.66, FA=90°). T1 weighted anatomical images were obtained for the same slices in each subject.ResultsCerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally.ConclusionsThis study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks.

Clinical and radiographical study of antro-oral fistula

Fifty-two patients who developed antro-oral fistula following tooth extraction were examined clinically and radiographically. Of these, 39 patients had only perforation of the antral floor and the other 13 had the tooth root pushed into the maxillary sinus. Maxillary sinusitis was present in 43 cases. The most frequent site of antro-oral fistula was the upper first molar, and the palatal root of the upper first molar was pushed into the antrum the most frequently. Our study suggested that most of the patients with antro-oral fistula had associated maxillary sinusitis before the extraction of the tooth. The highest risk of the occurrence of antro-oral fistula appeared to be at the time of extraction of the upper first molar associated with periapical and periodontal lesions.