應用田口方法評估頸部固定之外傷患者顴骨弓攝影的最佳參數

Optimizing theCassette-fixed Tool for Emergency Patient Radiographing Zygomatic Arches via Taguchi Analysis

蘇柏華(Po-Hua Su)；黃耀慶(Yao-Ching Hung)；蔡松伯(Po-Sung Tsai)；何昭霆(Ting-Chao Ho)；潘榕光(Lung-Kwang Pan)

骸下頭頂投射法 ； 顴骨弓 ； 田口實驗設計法 ； 變異數分析 ； 驗證實驗 ； Skull Submentovertex (SMV) projection ； zygomatic arch ； Taguchi ； ANOVA

中華放射線技術學雜誌

39卷3期（2015 / 09 / 01）

144 - 152

繁體中文

本研究探討運用自製輔具改變急診外傷患者，因頸部固定無法維持常規骸下頭頂投射攝影技術(SMV Projection)，以取得顴骨弓X光影像的方法，並減少檢查時的不舒服，避免頸椎因過度伸展所造成二次傷害且降低重照率。研究使用人體模型及應用田口實驗設計法，採用L_8(2^7)直交表，歸納出四項控制因子進行評量SMV投射中，對清晰影像呈現的最佳化參數組合及最重要控制因子且探求最重要因子的極大值，並進行單因子實驗。結果顯示最佳影像品質水準組合為(A)光片匣和檢查檯的角度為60度(B)管電壓為80kVp(C)管電流為5.6mAs(D)射源到受體中心的距離為85cm，並得知A為最重要控制因子。將此結果進行臨床確認驗證，收集自2013年5月至2014年5月共60位疑有顴骨弓骨折伴有(或)頸椎骨折、脫位而用頸圈固定的急診外傷患者，在自製輔具協助下，進行顴骨弓攝影。將最佳化影像與「放射線攝影擺位與相關解剖學」中的標準影像比較，得知在平均值及信號/雜訊比各為4.38±0.27、4.36±0.25及0.83dB、0.82dB其值相互接近且穩定，其影像重照率下降至5%並證實X光片匣和檢查檯的相對最佳角度為60度。藉由使用自製輔具，放射師可以依照病患所能配合的角度，選擇適當片匣放置角度，維持如傳統常規攝影技術中，X光入射角度與顴骨弓及片匣三者互為平行的關係，取得平行於病患下眼眶與耳洞連線X光入射角度，而不是要求病患配合片匣的角度來擺位，讓外傷患者在安全、快速且頸椎無過度伸展的情況下，也能獲得相同於傳統常規攝影方式一樣，具有臨床診斷價值的顴骨弓影像品質。

The optimization of the cassette-fixed tool for emergency patient radiographing zygomatic arches via Taguchi analysis was accomplished in this work. Radiographers in dealing of the patients delivered from urgently surgical accidents were strongly recommended for not removing the cervical collar, to suppress the secondary injury risk. Then, the conventional suggestion for acquiring optimal image quality of cervical vertebra became inappropriate in practical cases. A revised technique for fulfilling the critical case was proposed according to the Taguchi L_8(2^7) analysis. Four factors were assigned herein to optimize the exposed X-ray image quality of the cervical vertebra for urgent trauma patients, (A) projected angle degree between cassette and table, (B) kVp (C) mAs of X-ray, (D) SID. The optimized result was (A) 60 degree (B) 80kVp (C) 5.6mAs (D) 85cm SID and the dominant factor was A, the projected angle. To further verify the results, data of 60 urgent trauma patients were collected from 2013/05 to 2014/05. To further verify the optimized setting, the optimized images from the patients with cervical collar were compared to the regular patients without the cervical collar and exposed under the regular position; and the average, S/N is 4.38±0.27, 0.83dB and 4.36±0.25, 0.82dB, respectively. Furthermore, the retaking rate of the optimal setting also reduced to 5%indicating that the projection 60 degree is superior to 55 degree from clinical viewpoint. The patients with similar syndromes could have optimal X-ray exposed image quality from the auxiliary cassette-fix tool without causing hyperextension of cervical spine.