Traumatic injuries of the renal vasculature and parenchyma

Renal injuries may be classified according to their severity as minor, major, or massive. Roentgenographs and radionuclide investigation are indicated in all patients with gross or microscopic hematuria after trauma. Initial study should include high-dose infusion urography and static renal scintigraphy. If both examinations are within normal limits, no further workup may be necessary. When no contrast medium appears in the kidney during urography, a radiopertechnetate flow study is indicated. Absence of kidney activity during this study is compatible with major arterial occlusion, and prompt angiographic examination should be performed. Segmental areas of impaired visualization on the urogram or of diminished activity on the scintigram in the region of the kidney may represent minor contusion or major injury such as infarct. If the patient's condition is stable and if surgery is not contemplated, angiography may be delayed and possibly omitted. The differentiation between major and minor injury can be made by follow-up nuclide imaging studies. Infarcts remain with persistent defects in the renal image, while contusions demonstrate a return to normal pattern over a period of several weeks. If the patient is unstable, prompt angiographic study may be necessary for immediate definitive diagnosis. Angiography is particularly valuable in rapidly evaluating a patient with intra-abdominal injuries thought to involve more than one organ. Radionuclide and roentgenographic studies of renal trauma have correlated well in previous studies. When the radionuclide study has been normal, no significant injuries have been observed at subsequent angiographic examination. Because of their safety and ease of performance, radionuclide techniques are of great value in these cases, particularly for serial follow-up studies.