Sonographic features of horseshoe kidney: Review of 34 patients

Horseshoe kidney is a difficult sonographic diagnosis, especially if the is thmus is not seen. The purposes of this report are to review the sonographi c images in 34 patients with proven horseshoe kidney, to discuss the limita tions of ultrasonography in demonstrating the anomaly, and to identify feat ures that would alert the examiner to the possibility of a horseshoe kidney . Among 34 patients, the isthmus was noted in 27. Of the 67 kidneys studied , 52 (78%) were judged to be low-lying, and in 24 (36%) the sonographic ima ges suggested malrotation with anteriorly pointing pelvis. Additional sonog raphic features seen in the 67 kidneys included a bent or curved configurat ion of the kidney in the long axis (58%), tapering and elongation of the lo wer pole (60%), and a poorly defined inferior border of the kidney (84%). T hese features should suggest the presence of a horseshoe kidney and direct the examiner to search for the isthmus.