Experiences with anorectal ultrasonography

Introduction: The newest development of transducer and software technology made possible to improve the efficacy of anorectal ultrasonography (US). It became possible to work with higher frequency, and 360 degrees field of view.

Material and methods: 21 patients were investigated after traditional endoscopy and biopsy. In cases of malignancy abdominal sonography was also done for exact staging. B&K Hawk EXL equipment was used with multifrequency rotating endosonic probe of 7,5 and 10MHz and 360 degrees field of view. For anal use a special accessory can be attached. In some cases of uncertain anal complaints anal US was made before traditional endoscopy.

Results: It was found that anorectal US with this probe was very sensitive. The depth of tumor invasion and peri-rectal lymph nodes were excellently detected. The diagnostic value of US was usually better than that of CT of the same patients. Anal US with the special accessory of the probe could detect small lesions causing uncertain pain of this region even in those cases when the lesions did not reach the visible surface of the anal canal.

Conclusion: Using high frequency US endosonic probe, perirectal lymph nodes can be detected with high sensitivity. After positive finding CT can be abandoned. Anal US could detect the cause of uncertain complaints of this region, even below the visible surface; therefore it can be applied as the first diagnostic modality.