1994 Volume 44 Pages 87-91
We studied the usefullness of the newly developed slim ultrasonic probe for the colorectal lesions comparison with the ultrasonic scope in the diagnosis of endoscopic ultrasonography (EUS) . From May 1993 to October 1993, 54 lesions (50 cases) were examined by EUS using slim ultrasonic probe[UM-2R (12MHz), UM-3R (20MHz) developed by Olympus Optical Co]. These result were compared with those of ultrasonic scope [CF-UM3 (12MHz), CF-UM20 (12MHz)]and ultrasonic probe〔UM-1W (7.5MHz)].
These slim ultrasonic probe were easily inserted into the ordinary scope instrument channel diameter of 2.8mm or more because of slim 2.4mm diameter. These probe was easily contact to the purpose lesions. Only 1 case located in the cecum bottom were failed to insert the probe into the instrument channel because of over scope bending. But other lesions were approached to the lesion completely.
Visualizing rate were almost well or fair, but 2 cases located in the cecum and transeverse colon were not well visualized because of the lesion was located on the intestinal fold. Concerning to the diagnostic ability, diagnostic accuracy of the depth of the cancer invasion was 94% (early cancer : 86%, advanced cancer : 100%) . These result was same as the data of UM-1W and better than those of ultrasonic scope. Concerning to the lymph node swelling detectability, only 1 case out of 6 cases was visualized because of echo dumping using slim ultrasonic probe.
From the relation to the thickness of the cancer lesion and the EUS visualization, superficial lesions were obtained diagnosable image using high ultrasonic frequency probe (20MHz) . But thick lesions were obtained inadequate image because of echo dumping. So concerning to the thickness of the lesion, under 15mm lesions would be better to use slim ultrasonic probe and over 15mm lesions should be used ultrasonic scope except stenotic sections.
In conclusion, these equipments provided advancement of operational and ultrasonic imaging capabilities and seemed to be much useful in the ultrasonic diagnosis of colorectal lesions because of greater sonographic definition.
