Computerized tomography in normal abdomen: retrospective study of renal hila angles

To obtain mean angulation values for renal hila in relation to the horizontal plane traced over the right and left spinal erector muscles, considering the center of the lumbar vertebral spine as a parameter for measuring the renal hila angles. The authors have analyzed 250 abdominal computed tomography studies of both male and female healthy individuals (128 men with mean age 52.45 ± 17.42 years, and 122 women with mean age 54.39 ± 18.27 years), corresponding to 500 renal hila evaluated. The mean angulation of each hilum in relation to the horizontal plane was obtained taking acute angles into consideration. The comparative study have not found any statistically significant difference in acute angles of renal hila between male and female individuals. The statistical analysis demonstrated limits of 40.40 deg and 44.54 deg for mean right hilum angulation and 39.91 deg and 43.23 deg for mean left hilum angulation, with a confidence interval of 95% . Renal hila present similar angulation independently of sex. Higher angulation values correspond to hyper-rotation or excessive rotation, and lower angulation values, to incomplete or reverse rotation. (author)