NBI and pit pattern observation are the gold standard for tumor characterization [13, 14]. BLI magnification is also regularly used for tumor characterization. This enables us to clearly observe the surface and vessel patterns [6, 7]. Our previous study compared BLI and NBI. Endoscopic images of vessels and surface patterns obtained using BLI magnification were slightly different from those obtained with NBI magnification [6]. In detail, 104 colorectal neoplasms were examined with both BLI and NBI magnification. The Hiroshima classification, according to the surface and vessel patterns observed with NBI magnification, was used in the study [15]. The diagnostic accuracy of BLI magnification in the NBI classification was 74.0% (77/104), which was similar to that of NBI magnification (77.8%). The rate of consistency between BLI and NBI magnification in the NBI classification was 74.0%. Another study from our group showed the accuracy in differentiation between nonneoplastic lesions and neoplastic lesions was 99.3% (312/314), while that between adenomatous lesions and cancerous lesions was 85.0% (232/273). The diagnostic accuracy for polyps of <20 mm in diameter was better than that for polyps of ≥20 mm in diameter (92.1% vs. 72.5%; p < 0.001). The diagnostic accuracy with regard to the morphology was significantly lower for superficial polyps of ≥20 mm in diameter than for superficial polyps of <20 mm in diameter (70.0% vs. 82.9%; p = 0.03). In type C3 in Hiroshima classification, which is almost similar to JNET type 3, sensitivity and specificity for T1b cancers are 64.3% and 81.8%. In another study, the diagnostic accuracy of BLI magnification and pit pattern observation was compared [8]. It showed the diagnostic accuracy in the differentiation of neoplastic lesions from nonneoplastic lesions was 98.4% with BLI and 98.7% with pit pattern observation. In addition, the diagnostic accuracy of BLI magnification for T1b cancers was 89.5%, while that of pit pattern observation was 92.1%. The study also showed that pit pattern observation should be performed for lesions with severely irregular surface or vessel patterns on BLI in order to improve the diagnostic accuracy. Recently, the JNET (Japan NBI Expert Team) classification has been reported to differentiate between low-grade adenoma, high-grade dysplasia (Tis), and T1b cancer (Fig. 4.2) [13, 16]. Although it was originally performed with NBI, the JNET classification can be performed with BLI; we previously demonstrated the high consistency in the findings of NBI and BLI magnification [4]. Typical T1b cancers are diagnosed as JNET type 3 and show loose vascular area and amorphous surface pattern. In those tumors, surface structure seems destroyed (Fig. 4.3). However, some of T1b cancers and T1a cancers remain surface structures and show irregular vessel and surface pattern (Figs. 4.4 and 4.5). In JNET classification, a lesion which is diagnosed type 2B with low confidence is expected to be examined with pit pattern observation for more accurate diagnosis. In the lesions with poor pit dyeing with crystal violet, a unique method of observation with the combination of LCI observation and crystal violet dyeing was reported for achieving a detailed pit pattern observation [9]. This improved the contrast of the pit pattern, allowing the endoscopist to determine whether or not it was destroyed. It is expected to diagnose T1 cancers more accurately (Fig. 4.6).