Wang T D, Crawford J M, Feld M S, Wang Y, Itzkan I, Van Dam J
G.R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
Gastrointest Endosc. 1999 Apr;49(4 Pt 1):447-55. doi: 10.1016/s0016-5107(99)70041-6.
Previous in vitro studies showed that autofluorescence images of colonic mucosa collected endoscopically can be used to detect dysplasia with high sensitivity. This method is extended to the collection of fluorescence images of adenomatous polyps in vivo.
Fluorescence images were collected during colonoscopy in 30 patients. A total of 12 adenomatous and 6 hyperplastic polyps were identified. A fiberoptic excitation probe, located in the instrument channel of the colonoscope, delivered 300 mW of near-ultraviolet light at lambdaex = 351 and 364 nm. Mucosal fluorescence in the spectral bandwidth between 400 and 700 nm was imaged, processed, and displayed with various likelihoods of associated dysplasia.
Adenomatous polyps exhibited decreased fluorescence intensity compared with adjacent mucosa with normal appearance. With the fluorescence threshold set to 80% of the average intensity of normal mucosa, a sensitivity of 83% for dysplasia identification was achieved. All hyperplastic polyps were correctly identified as being non-dysplastic. Optimal identification of dysplastic regions was obtained with the colonoscope oriented at a near-normal angle of incidence to the polyps. At higher angles of incidence, artifacts caused by illumination shadows were introduced.
The dysplasia associated with adenomatous polyps can be identified in vivo by fluorescence imaging with high sensitivity, thus demonstrating the potential to guide endoscopic procurement of biopsy specimens.
先前的体外研究表明，通过内镜收集的结肠黏膜自体荧光图像可用于高灵敏度地检测发育异常。该方法已扩展至体内腺瘤性息肉荧光图像的收集。
对30例患者进行结肠镜检查时收集荧光图像。共识别出12个腺瘤性息肉和6个增生性息肉。一个位于结肠镜器械通道内的光纤激发探头，在λex = 351和364 nm处提供300 mW的近紫外光。对400至700 nm光谱带宽内的黏膜荧光进行成像、处理，并以与相关发育异常的不同可能性进行显示。
与外观正常的相邻黏膜相比，腺瘤性息肉的荧光强度降低。将荧光阈值设定为正常黏膜平均强度的80%时，发育异常识别的灵敏度达到83%。所有增生性息肉均被正确识别为无发育异常。当结肠镜与息肉的入射角接近正常时，可获得发育异常区域的最佳识别效果。在较高入射角时，会引入由照明阴影引起的伪像。
通过荧光成像可在体内高灵敏度地识别与腺瘤性息肉相关的发育异常，从而证明了其指导内镜下活检标本获取的潜力。
