2004 Fiscal Year Final Research Report Summary
Optimum scanning protocol for the assessnert of cervicallymph metastases in patients with oral cancer using helical computed tomography
| Project/Area Number |
13671965
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
病態科学系歯学(含放射線系歯学)
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| Research Institution | Niigata University |
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Principal Investigator |
HAYASHI Takafimi Niigata University, Graduate School of Medical and Dental Sciences, Professor, 大学院・医歯学総合研究科, 教授 (80198845)
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| Co-Investigator(Kenkyū-buntansha) |
KATSURA Kouji Niigata University, Medical and Dental Hospital, Lecturer, 医歯学総合病院, 講師 (30283021)
TAIRA Shuhzou Niigata University, Graduate School of Medical and Dental Sciences, Assistant, 大学院・医歯学総合研究科, 助手 (70313525)
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| Project Period (FY) |
2001 – 2004
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| Keywords | oral cancer / cervical lymph node metastases / helical CT / intravenous contrast enhancement / optimum scanning protocol / keratinization / high density area / superior cervical ganglion |
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| Research Abstract |
1.Optimum scanning protocol :
Non-contrast 3 mm thickness conventional scans are taken parallel to Reid's base line (the anthropologic base line) followed by contrast helical scans. Using a power injector, contrast material (300mgI/mL) is administered at a rate of 1-1.5 mL/s. Helical scanning of a primary lesion and cervical lymph nodes is started 45 seconds after the initiation of contrast infusion. The scan data are acquired using a collimation of 3 mm and a table speed of 3 mm/s (pitch 1/s), and reformatted into 1 mm interval axial images. Delayed 3 mm thickness non-helical scan in also performed 3 minutes after the initiation of contrast infusion.
2.Additional interpretation :
1)In order to demonstrate the utility of the three-dimensional volumetric visualization of subsequent cervical lymph node metastases in patients with tongue carcinoma, a volume rendering visualization system was used. Ten metastatic nodes of 10 patients were found with repeated ultrasonography performed at an in
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terval of at least one month and, if possible, every two weeks. All of the metastatic nodes were detected on CT taken after sonographic examination and were distinctly demonstrated on the volume rendering three-dimensional images obtained with CT data. It is suggested that three-dimensional images reconstructed with CT data provide the accurate anatomical location of non-palpable metastatic nodes detected with repeated ultrasonography.
2)We presented the high density area(HDA) within the metastatic regional lymph nodes observed on non-contrast CT in two patients with stage I or II tongue carcinoma during a follow-up period. The density of HDAs was an attenuation value of more than approximately 70 Hounsfield units or more. One patient had a level I node and the other had a level II node. Contest CT failed to detect the HDAs within the nodes. Histopathological examination revealed that HDAs were strongly correlated with the area of marked keratinization of metastatic foci. HDAs might be overlooked if only contrast CT was used. The clinician should be aware of non-contrast CT as well as contrast CT on investigating lymph node metastases at an early stage in patients with stage I or II tongue carcinoma during the follow-up period.
3)In older to distinguish benign from malignant nodules within the dissected neck area in patients with oral cancer during a follow-up period, we retrospectively evaluate the frequency and the characteristic findings of fusiform-shaped nodule along the internal carotid artery observed on the follow-up sonography. Fifty-two patients with oral cancer, who underwent radical neck dissections, were enrolled in this study. After neck dissection, every patient was examined repeatedly with sonography during a follow-up period at an interval of one month. CT and/or MRI were performed when clinically required. Any patient with recurrent neck mass was excluded from this study. In the 52 patients, fusiform-shaped nodule was observed in 10 patients (19%) on the follow-up sonography. The nodule was homogenously hypoechoic and the margin of the nodule was well-demarcated except for the upper end. Hyperechoic core was clearly observed in every nodule, which showed a fatty density on post-contrast CT. On post-contrast MRI, the nodule enhanced markedly and the core showed hypointensity on fat saturated images. In conclusion, it was suggested that the fusiform-shaped nodule observed on the follow-up sonography within the dissected neck area might be the superior cervical ganglion of sympathetic trunk. However, further studies were needed to disclose the true character of the nodule. Less
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Research Products
(6 results)
