1993 Volume 42 Pages 81-85
Judgement of the depth of gastric cancer invasion by endoscopic ultrasonography (EUS) has become more important with the progress of the endoscopic treatment.
We applied a new radial scannig type ultrasound imaging catheter named“Ultrasonic Microprobe : UMP” (Toshiba Co) for estimation of the invasion depth in 6 cases of the gastric cancer. The new instrument UMP has a diameter of 2.4mm can be passaged down the forceps channel of a routine used endoscopes. There are three types of the tiny ultrasonic probe equipped with 10/15/20MHz high frequency transducer. Mainly 15 and 20MHz probes were used on this study.
The normal wall of stomach was imaged as 5 to 7 layers structure by the UMP. In superficial and small lesions (IIc and micro IIc type) which had mucosal invasion, the excellent capacity of the UMP was showed. The image obtained by the UMP clearly demonstrated the changes of mucosal structure reflected by these small lesions. As the depth penetration of ultrasound was limited in about 5mm because of high frequency and small caliber, in the cases of tall and wide-spreaded lesions (I and IIc like advance type) , it was difficult to judge of the invasion depth. Lesions (IIa and IIa+IIc type) with ulcer (Ul-IIs) which had mucosal invasion were overdiagnosed as submucosal invasion on account of the fibros tissue.
Intra-corporeal ultrasonography using the UMP, with some improvements, will develop the ability of EUS in estimation of the invasion depth in the early gastric cancer.
