用氮分子激光（波长３３７ｎｍ）做为激发光源，光多道分析仪为光谱分析手段，对３９例正常结肠和大肠癌的激光诱发荧光（ＬＩＦ）光谱分析的结果发现，正常结肠和大肠癌各具其不同的光谱特征峰值。正常结肠有一主峰和一次峰，主峰相对强度较强，其近红光侧下降较快，Ｆ１（４００ｎｍ处强度／５３０ｎｍ处强度）平均为１．２９，Ｆ２（主峰强度）平均为１２０２８，Ｆ３（主峰波长）在４６０ｎｍ；大肠癌也有一主峰和一次峰，主峰相对强度较弱，其强度为正常结肠强度的１／３～１／５，主峰近红光侧下降迟缓，Ｆ１平均为０．４３，Ｆ２平均为３９７０，Ｆ３在４７０ｎｍ。以正常结肠光谱参数为标准，区分大肠癌的敏感性为７４％，特异性为９６％，阳性预示值９４％，阴性预示值７８．６％，诊断符合率８４％；以大肠癌光谱参数为标准，区分大肠癌的敏感性为９１．３％，特异性为７３．９％，阳性预示值７７．８％，阴性预示值８９．５％，诊断符合率８３％。上述结果说明ＬＩＦ可以用来区分正常结肠和大肠癌 Using a nitrogen molecular laser (wavelength of 337 nm) as the excitation light source, an optical multi-channel analyzer was used as a means of spectral analysis. The results of laser induced fluorescence (LIF) spectrum analysis of 39 cases of normal colon and large intestine cancer revealed normal colon and large intestine cancer. With different peak spectral characteristics. The normal colon has a main peak and a primary peak. The relative intensity of the main peak is relatively strong, and the near red light decreases rapidly. The average intensity of F1 (intensity at 400 nm/intensity at 530 nm) is 1.29, and the average intensity of F2 (main peak) is 12028, F3 ( The main peak wavelength is at 460 nm; colorectal cancer also has a main peak and a primary peak, the relative intensity of the main peak is weak, its intensity is 1/3 to 1/5 of the normal colon intensity, the main peak near the red side is slow and the F1 average is 0.43. The average F2 is 3970 and the F3 is 470 nm. Using the normal colon spectral parameters as criteria, the sensitivity of distinguishing colorectal cancer was 74%, specificity was 96%, positive predictive value was 94%, negative predictive value was 78.6%, diagnostic coincidence rate was 84%; and the colorectal cancer spectral parameter was The standard, distinguishing the sensitivity of colorectal cancer was 91.3%, the specificity was 73.9%, the positive predictive value was 77.8%, the negative predictive value was 89.5%, and the diagnostic coincidence rate was 83%. The above results show that LIF can be used to distinguish between normal colon and colorectal cancer