title: Endosonographic diagnosis of early colorectal tumour invasion using ultrasound miniature probe.
abstract: OBJECTIVE
  We sought to determine the accuracy of differentiating between mucosal and submucosal colorectal tumour invasion using a high-frequency ultrasound miniature probe.
  
  
  METHODS
  We analysed 43 lesions sonographically interpreted as T1 colorectal tumours, and evaluated the accuracy of detecting mucosal neoplasia (true-positive and true-negative mucosal neoplasias divided by all lesions).
  
  
  RESULTS
  The overall accuracy of detecting mucosal neoplasia was 74%. Sonographic images were easily obtained under direct visualization, even for small and non-polypoid lesions anywhere in the colon and rectum. However, diagnostic accuracy tended to be low in polypoid lesions >20 mm in width, and pure carcinoma with submucosal invasion. The submucosal layer in 16 lesions was visualized as a more detailed laminar structure, whereas the remaining 27 lesions showed a single hyperechoic submucosal layer. However, there were no significant differences in accuracy between the two.
  
  
  CONCLUSIONS
  The high-frequency ultrasound miniature probe system may be useful for evaluating small non-polypoid colorectal tumours because of easy manipulation rather than high resolution visualization.
authors.affiliation: Second Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan, Second Department of Pathology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.lastname: Hizawa
authors.lastname: Kawasaki
authors.lastname: Hirakawa
authors.lastname: Aoyagi
authors.lastname: Yao
authors.lastname: Fujishima