Relationship between divided-shaped kidney and collecting system duplication.

PURPOSE: We aimed to assess the incidence of divided-shaped kidney and the relationship between divided-shaped kidney and collecting system duplication.

SUBJECTS AND

METHODS

Between May 1 and June 30, 2012, 857 patients (men:women, 493:364; mean age 39.6 years; age range 2-98 years) with 1699 kidneys underwent enhanced computed tomography of the abdomen and pelvis at our institution. Sixty kidneys were excluded (tumor, 3; percutaneous nephrostomy, 9; polycystic kidney disease, 4; renal injury, 1; infarct, 1; hydronephrosis, 18; parapelvic cyst, 17; artifact, 5; horseshoe kidney, 2). Finally, 845 patients and 1639 kidneys were included. The number of cases of prominent column of Bertin (divided by grade of prominence as either divided-shaped kidney or hypertrophy) and collecting system duplication (bifid, partial, and complete) were evaluated. Fisher exact test was used to determine the relationship between divided-shaped kidney and collecting system duplication, and between hypertrophy and collecting system duplication.

RESULTS

Of 1639 kidneys, 66 (4%) were divided-shaped kidneys, and 88 (5%) had collecting system duplication (bifid, 69; partial, 19; complete, 0); among the 66 divided-shaped kidneys, 28 (42%) had collecting system duplication. Among the 429 cases of hypertrophy and 1144 normal kidneys, 51 (11.9%) and 9 (0.8%) had collecting system duplication, respectively.

CONCLUSIONS

The incidence of divided-shaped kidney was 4%, and there was a significant association between divided-shaped kidney and collecting system duplication.