錐形束電腦斷層用於評估翼管神經及相關解剖影像的適當性

Applicability of Cone-beam Computed Tomography in Evaluating Vidian Nerve and Related Structure

蕭舜仁(Shun-Jen Hsiao) ； 鍾從得(Tsung-Te Chung) ； 陳泰逸(Tai-Yi Chen)

《台灣耳鼻喉頭頸外科雜誌》 50卷2期 (2015/06) Pp. 90-98

https://doi.org/10.6286/2015.50.2.90

摘要

目的：錐形束電腦斷層cone-beam computed tomography（CBCT）的特點是以低放射劑量的攝影提供高空間解析度但低對比解析的影像。本研究評估CBCT是否可提供翼管神經切除術之術前攝影足夠的影像品質及資訊，並與多排螺旋電腦斷層multidetector computer tomography（MDCT）比較影像清晰度及放射計量。方法：回朔性截取2012年為牙齒矯正所做的22個全顱CBCT，排除掉5個有明顯的artifact，以間距0.3 mm做重組，由兩名耳鼻喉科醫師獨立閱片，評估翼管神經清晰度（主觀三級分級：良好，尚可，無法辨析），翼管與蝶竇的關係，翼槽氣化與否，計算觀測者間差異，尋找影響翼管清晰度的干擾因子。另擷取21個為鼻竇炎手術所做全顱低放射劑量MDCT影像，和另外16個高放射劑量MDCT影像，由第一位觀測者，依干擾因子分組，比較這三類CT翼管神經清晰度。結果：CBCT的翼管神經清晰度：於冠狀面84%良好，16%尚可，0%無法辨析。橫切面68%良好，12%尚可，20%無法辨析。（翼管與蝶竇的關係）及（翼槽氣化與否），可100%清楚辨別，且皆為翼管神清晰度的干擾因子。與MDCT相比，CBCT影像品質與高劑量MDCT差不多，除了翼管神經部分突入蝶竇內且有翼槽氣化這類，CBCT影像劣於高劑量MDCT。CBCT在部分分組影像優於低劑量MDCT。而放射線劑量以CBCT最低。結論：CBCT可以以較低放射劑量勝任翼管神經切除術的術前攝影。

關鍵字

錐形束電腦斷層 ； 電腦斷層 ； 翼管神經 ； 翼管 ； 翼管神經切除

並列摘要

PURPOSE: Cone-beam computed tomography (CBCT) can produce an image with a high spatial resolution (but low contrast resolution) at a low radiation dose. The objective of this study was to determine whether CBCT can produce an image quality suitable for preoperative planning for vidian neurectomy and to compare the image quality and radiation dose with those of images produced using multidetector computed tomography (MDCT). METHOD: A total of 23 full cranial CBCT images produced for orthodontic treatment planning were retrospectively collected in 2012. Five images were excluded because of artifact formation, and contiguous 0.3-mm sections were subsequently reconstructed. Two readers interpreted the images independently for determining the quality of the vidian nerve images (evaluated using a three-point grading scale: good, fair, and not discriminable) and the relationship of the vidian nerve and sphenoidal sinus; and pterygoid pneumatization. The interobserver variability was calculated and the confounding factor of vidian nerve image quality was identified. Furthermore, 21 low-radiation-dose full head MDCT images produced for sinus surgery and 16 high-radiation-dose MDCT images for other sinus surgery were collected. These images were classified according to the confounding factor, and the first reader compared the quality of the vidian nerve images in the three CT image groups and the radiation dosage among them. RESULTS: Of the vidian nerve CBCT images in the coronal section, 84% were classified as good, 16% were classified as fair, and 0% were classified as not discriminable; of the images in the axial section, 68% were considered good, 12% were considered fair, and 20% were classified as not discriminable. The relationship between the vidian nerve and sphenoid sinus and pterygoid pneumatization was clearly distinguished, and this relationship constituted the confounding factor of the vidian nerve image quality. The CBCT and high-dose MDCT images had no difference in quality, except for one subclass (vidian nerve partially protruding into the sphenoidal sinus with pterygoid pneumatization), in which the CBCT images exhibited lower quality compared with high-dose MDCT images. In some subclasses, the CBCT images exhibited higher quality levels compared with the low-dose MDCT images. Furthermore, CBCT provided the lowest radiation dose. CONCLUSION: CBCT can produce a preoperative image at a low radiation dose for vidian neurectomy.

並列關鍵字

cone-beam computed tomography ； computed tomography ； vidian nerve ； vidian canal/pterygoid canal ； Vidian Neurectomy