| 特集名 | Helicobacter pylori感染の内視鏡診断 | |
|---|---|---|
| 題名 | Hemoglobin indexの診断への応用 (3) 粘膜ヘモグロビン値(IHb)によるH.pylori感染診断と新たな展開 | |
| 発刊年月 | 2001年 10月 | |
| 著者 | 浅木 茂 | 東北大学医学部消化器内科 |
| 著者 | 相田 重光 | 東北大学医学部消化器内科 |
| 【 要旨 】 | 胃粘膜の色調は粘膜ヘモグロビン(Hb)濃度と相関すると考えられている．胃粘膜Hbは，560nm付近のHbを吸収するG信号(Vg)とHbに影響されない650nm付近のR信号(Vr)の比を対数変換することで算出される．筆者らは胃体上部後壁の非萎縮性の胃底腺粘膜におけるHb値(IHb)からHelicobacter pylori(HP)感染診断能を検討した．当科におけるHP感染診断能はカット・オフ値を62にしたとき感度93.3％，特異度80.0％を示した．当科関連施設における検討では感度90.9％，特異度84.2％とほぼ同様の結果が得られた．IHb値には施設問で若干のバラツキがみられたが，その要因はまだ不明である．IHb測定は胃粘膜におけるHP感染診断に簡便で感度，特異度に優れた方法である． さらに，IHb値の最低36.5を青に，最高の90.0を赤に配色し，その間を16等分しカラー割付けをすることで，リアルタイムに胃粘膜微細病変とくに微小胃癌やその側方浸潤の診断が容易となる．この粘膜擬似カラー化の試みは今後内視鏡診断の向上，とりわけ超微小胃癌の診断に寄与すると考える． |
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| Theme | Endoscopic Diagnosis of Helicobater pylori Infection | |
|---|---|---|
| Title | Significance of Hemoglobin Index in Diagnosis of Helicobacter pylori Infection and Future Developments in Color Imaging to Detect Super Minute Cancers | |
| Author | Shigeru Asaki | Department of Internal Medicine, Division of Gastroenterology, Tohoku University School of Medicine |
| Author | Shigemitsu Aida | Department of Internal Medicine, Division of Gastroenterology, Tohoku University School of Medicine |
| [ Summary ] | Color images of gastric mucosa are thought to display the level of mucosal hemoglobin density. Gastric mucosal hemoglobin indicates the correlation between extracted G-signal (Vg) and R-signal (Vr). Vg reflects around 560nm rays from absorbed hemoglobin and Vr reflects around 650nm rays from unmodified hemoglobin. Extracting Vg and Vr to transform the logarithm for the ratio of Vr to Vg makes it possible to evaluate the hemoglobin index (IHb). We studied the diagnostic value of the mucosal IHb for Helicobacter pylori (HP) infection in the non atrophic fundic gland area of the upper body posterior wall of the stomach, which is about 1cm in size. We determined the cut-off index is 62 for the diagnosis of HP infection in our university trials. These showed a sensitivity of 93.3% and a specificity of 80%. About the same results were obtained in our related institution, with sensitivity of 90.9% and specificity of 84.2%. The index of IHb showed some differences in each institution, but the cause of this difference is uncertain. IHb may be a simple, sensitive and highly specific method to diagnose HP infected gastric mucosa. Moreover, we conducted tests to using colors divided 16 equal parts, ranging between 36.5 IHb value at the lowest being blue, with a 90.0 IHb value and the highest being red. The real time coloring method is very useful in diagnosing minute mucosal lesions, especially minute gastric cancer and its lateral invasion. A trial to determing mucosal hemoglobin values by routine endoscopic observation or coloring, according to IHb levels, might allow us in the near future to improve G-I endoscopic diagnosis, especially in the diagnosis of super minute gastric cancers. |
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