Table-I.
Detected stones in different grades of hydronephrosis.
| Grade | SFU grading system of Hydronephrosis (Now it is used in adults as well) | Detection rate of stones as the cause of hydronephrosis N (%) | Nondetermined +Other causes N (%) | Total N (%) |
|---|---|---|---|---|
| Grade 1 | Dilated only renal pelvis | 13 (50) | 13 (50) | 26 (12.38) |
| Grade 2 | 1 + dilated few calyces | 75 (61) | 48 (39) | 123 (58.57) |
| Grade 3 | 2 + dilated all calyces | 30 (71.4) | 12 (28.6) | 42 (20) |
| Grade 4 | 3 + thinning of the renal Parenchyma | 8 (42.1) | 11 (57.9) | 19 (9.1) |
| 126 (60%) | 84 (40%) | 210 (100%) |
The rate of the detection of urinary stones increases with increasing the grade of hydronephrosis from grade 1 up to grade 3 then drops in grade 4.