Positional relations of colon and kidney determined by perirenal fat.

The anatomic relations of the colon in regard to the kidney at three levels were studied with CT in 70 male and 70 female patients in various age groups. The study was initiated when two patients with large left-kidney masses had an unusual posterior location of the colon. Considering the increase in percutaneous uroradiologic invasive procedures, it was believed that such a study was needed. It was shown that the colon has a tendency to be displaced anteriorly to the kidney in elderly men, whereas it is laterally located in females of all ages. An outstanding and unique finding was the excessive accumulation of perinephric fat in males and its quite total absence in females. It is suggested that this gender-related peculiar fat distribution might explain the anterior displacement of the colon in males.