[Diagnosis and staging of blunt kidney trauma. A comparison of urinalysis, i.v. urography, sonography and computed tomography].

In a retrospective study of 1230 patients with blunt abdominal or flank trauma, the results of microscopic urinalysis, urography, sonography, and computed tomography in the diagnosis and staging of renal injuries were compared. Haematuria was present in 98% of renal lacerations and in all pedicle injuries, whereas among 1038 patients without haematuria only one small laceration was found. The degree of haematuria showed no correlation with the severity of renal injury. 92 renal injuries were diagnosed radiologically, including 58 lacerations, 31 contusions, and three pedicle injuries. Computed tomography was performed in 39 lacerations and six contusions, and allowed correct diagnosis and staging in all cases. Urography established the correct diagnosis in 72%, and sonography in 85%. Sensitivity in the diagnosis of clinically relevant injuries (lacerations and pedicle injuries) was 98% (specificity: 99%), when both modalities were combined. Based on the results of our study, we suggest the use of sonography as a screening modality in blunt abdominal or flank trauma, and additional urography in case of haematuria. Computed tomography is the method of choice for exact staging of suspected renal injury.