比較緩瀉劑及對比劑應用在FDG-PET/CT檢查腸道病變

Application of Laxative and Contrast Medium in Detection of Colon Lesion by 18F-FDG-PET/CT

周宣宏(Hsuan-Hung Chou) ； 陳遠光(Yen-Kung Chen) ； 王素貞(Su-Chen Wang) ； 柴發順(Fa-Shun Tsai) ； 江泰林(Tai-Lin Jiang) ； 沈業有(Yeh-You Shen) ； 蘇誠道(Chen-Tau Su)

《核子醫學雜誌》 18卷4期 (2005/12) Pp. 203-208

https://doi.org/10.6332/ANMS.1804.003

摘要

背景：FDG PET是一種對於大腸癌有極高敏感度的檢查方法，但容易發生偽陽性之情形。此時可以讓受檢者服用緩瀉劑加速腸胃蠕動，以排除其可疑病灶僞陽性之可能。口服稀釋對比劑可以增加電腦斷層掃描判讀之解剖性資訊，提升影像判讀信心。本研究將針對服用緩瀉劑與否之兩組受檢者在服用稀釋對比劑後進行影像比對，受檢者的篩選條件爲無腸胃方面疾病也未經過手術處置，評估服用緩瀉劑與否，對比劑到達大腸等各解剖位置所需時間之差異。
方法：將執行FDG正子斷層造影檢查後在大腸部位發現可疑病灶之受檢者分爲兩組，每組各80人。一組受檢者只喝500 c.c稀釋對比劑，此爲對照組；另一組受檢者除喝下500 c.c。稀釋對比劑，另加喝125c.c之緩瀉劑，此爲實驗組，比對兩組受檢者對比劑到達大腸各解剖位置所需時間。
結果：服用緩瀉劑之80位受檢者中，造影時對比劑到達小腸有17位，平均時間爲78.8±14.7分鐘；升結腸有18位，平均時間爲81.9±12.7分鐘；橫結腸有21位，平均時間爲102.4±18.5分鐘；降結腸有24位，平均時間爲113.8±14.7分鐘。只服用稀釋對比劑之80位受檢者，造影時對比劑到達小腸有43位，平均時間爲83.2±19.2分鐘；升結腸有25位，平均時間爲98.0±23.6分鐘；橫結腸有8位，平均時間爲101.9±20.9分鐘；降結腸有4位，平均時間爲123.8±12.5 分鐘。
結論：經過影像比較之後，服用對比劑加緩瀉劑之受檢者其電腦斷層掃描影像顯示，對比劑到達大腸各解剖位置之平均時間比只服用對比劑之受檢者來得短。所以服用緩瀉劑除可排除大腸可疑病灶之僞陽性，亦有助於縮短對比劑到達大腸所需時間。也就是說服用緩瀉劑與稀釋對比劑對正子斷層掃描影像與電腦斷層掃描之判讀有所助益，可降低僞陽性及增加專一性。

關鍵字

PET/CT ； 緩瀉劑 ； 對比劑 ； FDG

並列摘要

Background: FDG PET is known as a very sensitive tool in detecting colon cancer. In order to avoid false positivity in suspicious lesions, laxatives, such as magnesium citrate, is used in this study to increase bowel activity. The use of oral diluted contrast medium offers anatomical information in the interpretation of CT scan hence improves physician's interpretation confidence. Therefore, in those examinees who have no GI disorders and GI surgery, this study aims to compare the activity time of oral diluted contrast medium to various parts of bowel in examinees with or without drinking magnesium citrate.
Methods: Using PET scan, examinees with suspicious lesions in the bowel were divided into two groups and each group contained 80 patients. Examinees in the control group drank 500 c.c. oral contrast medium alone whereas in the experimental group, examinees drank 500 c.c. diluted contrast medium with 125 c.c. laxatives. Timing of both contrast media to various parts of bowel was thus compared.
Results: In the 80 examinees who had diluted contrast medium with magnesium citrate, the contrast arriving time to the intestine, ascending colon, transverse colon, and descending colon were 78.8±14.7 min (17 persons), 81.9±12.7 min (18 persons), 102.4±18.5 min (21 persons), and 113.8±14.7 min (24 persons), respectively. In the 80 examinees who had diluted contrast medium only, the contrast arriving time to the intestine, ascending colon, transverse colon, and descending colon were 83.2±19.2 min (43 persons), 98.0±23.6 min (25 persons), 101.9±20.9 min (8 persons), and 123.8±12.5 min (4 persons), respectively.
Conclusion: After the comparisons of FDG PET images, the contrast medium arriving time to the various parts in the bowel was significantly shorter in the group with laxatives when compared to the group without laxatives. Therefore, the use of laxatives is helpful to rule out false positivity of suspicious lesions in the bowel and can significantly shorten the contrast medium arriving time to the colon. In other words, the use of diluted contrast medium with laxatives is very helpful in interpreting PET and PET/CT images and hence can decrease the false positive rate and increase the specificity of PET scan.

並列關鍵字

PET/CT ； laxatives ； contrast medium ； FDG