急診肺栓塞病患在高低劑量電腦斷層曝露的差別影響

Differences of the Radiation Exposure from Computed Tomography for Diagnostic of Pulmonary Embolism in the Emergency Department

陳祥元(Hsiang-Yuan Chen) ； 郭宗德(Tsung-Ter Kuo) ； 陳建誠(Chien-Cheng Chen) ； 陳煥武(Huan-Wu Chen) ； 吳茂昌(Mao-Chang Wu) ； 姜義成(Yi-Cheng Chiang) ； 蔡辰昊(Chen-Hao Tsai)

《中華放射線技術學雜誌》 45卷1期 (2021/03) Pp. 41-47

摘要

對於現代醫療而言，急性肺栓塞仍然為致命性的疾病，多切面電腦斷層為最佳醫療影像診斷工具。然而電腦斷層給予病患者的輻射曝露為一般X光檢查的數倍，應當加以重視。電腦斷層肺動脈血管攝影掃描（CTPA）的檢查中肺栓塞的血栓往往小於公分之內，必須使用窄的射束、小的螺距技術，在快速的掃描中為了維持影像品質，需要有恆定或是較高的輻射曝露。在不影響正確診斷的前提下，本研究探討降低CTPA不必要的輻射劑量方法與成效。本研究回溯性分析使用高與低劑量（120 kV/100 kV）於各15位急診肺栓塞病患，其中男性18例、女性12例，平均年齡48.6歲，身體質量指數（BMI）平均為22.3±1.77 kg/m^2，量化影像品質分析為計算影像的訊號雜訊比（SNR）與對比雜訊比（CNR）。兩個族群在身高、體重與BMI及影像SNR及CNR，皆無顯著差異。在電腦斷層劑量指數（CTDI）和劑量長度乘積（DLP）的p值皆小於0.05，有顯著性差異，顯示在常規使用肺栓塞掃描檢查時，使用低劑量進行掃描的方式是可以有效降低輻射曝露，且不影響影像的診斷價值。

關鍵字

急性肺栓塞 ； 電腦斷層劑量指標 ； 劑量長度乘積 ； 身體質量指數

並列摘要

With modern medical science, Acute pulmonary embolism (PE) is still a fetal disease. The development of MDCT becomes the best medical imaging tool. However, radiation exposure of MDCT is far more than routine X-ray. It should be placed the first consideration. In order to view the thrombus which is less than a centimeter in CT pulmonary angiography, narrower beam, lower pitch and faster scanning techniques are applied. However, the better image quality is compatible with the higher radiation exposure. This study performed the techniques without misinterpreting acute PE to lowering unnecessary radiation exposure and its outcomes in CTPA. The study retrospectively reviewed 30 acute PE patients in emergency room. Instrument setup with two different tube kilovoltage settings (120kVp and 100kVp) were given to each 15 patients. 18 males and 12 females were included, average age: 48.6, body mass index (BMI): 22.3 ± 1.77kg/m2. Quantitative analysis of image quality was analyzed by calculating SNR and CNR. Height, weight, BMI, SNR and CNR did not differ significantly between the two different tube kilovoltage parameters. Furthermore, there was no significance difference in CT dose index (CTDI) and dose-length product (DLP) between 2 groups with p-value less than 0.05. It demonstrated that the lower tube kilovoltage settings for patients in the routine CTPA procedure lowers the radiation exposure effectively and not affects image quality and diagnostic value.

並列關鍵字

Acute pulmonary embolism ； Computed tomography dose index (CTDI) ； dose length product (DLP) ； Body Mass Index (BMI)