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Endosonographic staging of rectal carcinoma.

Transrectal ultrasonography (US) scanning facilitates the ultrastructural differentiation of the various histologic layers of the rectal wall. In particular, the muscularis propria is represented by the 4th sonographic layer. Rectal carcinoma appears on US as a low echogenic area that suddenly interrupts the regular sequence of parietal layers.Sixty-five patients suffering with carcinoma of the lower two-thirds of the rectum underwent pre-operative linear endosonography for staging. The reliability of such a method in assessing the extra-rectal spread was evaluated in our study, at the end of which 55 sonographic/histologic correlations were obtained. Four false-negative and 1 false-positive determinations of the presence or absence of extrarectal spread proved that sonography has a sensitivity and specificity of 91%, with a positive predictive value of 97% and a negative predictive value of 71%. Lower results are obtained in lymph node staging: enlarged lymph nodes are seen in only 11/22 C1/C2 patients (11 false negatives) while we were aware of 3 false positives.

Role of Ultrasound in Renal Transplantation

Ultrasound examination of a renal transplant was performed in 27 patients over a period of 28 months; there were kidneys from 12 living and 15 cadaveric donors. The ultrasonic scans were performed over a period ranging from 2 days to 12 years following transplantation. We were able to observe and describe the echographic findings of the normal evolution of a well functioning renal transplant, acute tubular necrosis, acute and chronic rejection, perirenal fluid collection, and obstructive uropathy. Ultrasound evaluation of renal transplant was accurate in the diagnosis of postoperative complications together with clinical and laboratory findings. Ultrasound imaging is independent of renal function and can be performed quickly as often as necessary. Percutaneous procedures, including fine needle aspiration, biopsy, aspiration of fluid collection, and positioning of the pyelostomy catheter can be performed under ultrasonic guidance.