The contribution of renal scanning in the evaluation of renal trauma

Renal trauma

Renal injuries are classified as minor, major, and critical/catastrophic for purposes of management. The radionuclide renal scintigram is a safe, simple, and extremely sensitive means of establishing the presence of an injury and monitoring kidney function during conservative management, which is utilized in the vast majority of cases. The information that may be obtained from radionuclide imaging is the state of overall and regional blood transit, overall and regional parenchymal function, and urinary extravasation.

Renal angiography and the management of severe closed renal trauma

The purpose of this study was to determine the place of selective renal angiography in the assessment of major renal trauma. Thirty-one cases of renal injury assessed by urography and angiography were reviewed, and the radiological features correlated with the subsequent clinical course. Based on the angiographic findings, a classification of these more severe injuries is proposed, and the prognostic significance of renal ischaemia demonstrated. Because conservative treatment in those cases with significant ischaemia is likely to fail, early elective surgery is recommended. In this selected group, viable renal tissue can be preserved, and the necessity for subsequent nephrectomy due to secondary haemorrhage, or continuing urine leakage, is avoided.

A unified concept of renal trauma

Of 115 cases of renal trauma 75 injuries were blunt and 40 were penetrating. Primary exploration was done in20 per cent of the patients with blunt injuries and in 100 per cent of those with penetrating injuries. A reparative procedure was done in 60 per cent of the patients operated on for blunt trauma and in 73 per cent of those operated upon for penetrating trauma. Only 3 per cent of the patients with blunt injury and 28 per cent of those with penetrating injury required a nephrectomy. We have concluded that renal injuries should be classified by type and extent rather than by etiology, that the extent of injury should be determined and not surmised, and that the management of renal trauma is a function of the extent of injury and the over-all status of the patient. In addition, the non-operative management of an inadequately defined renal injury cannot be considered conservative management.

Renal scintiscanning. A review

Renal scintiscanning is a simple investigation that does not require special preparation and is well tolerated by patients.

Radiopharmaceuticals used in linear scanning are accumulated in the renal cortex. This accumulation is diminished: (a) when the cortex is destroyed, e.g. by pyelonephritis, injury, etc.; and (b) when the amount available to the cortex is reduced, e.g. by ischaemia. The scintigram depicts the kidneys unimpeded by bowel contents, gives a qualitative assessment of renal function and shows the distribution of zones of normal function. Recent technical improvements show great promise in deriving a quantitative measure of renal function in some circumstances.

The location of normally functioning cortex is often important in the management of renal diseases and the value of scintiscanning is then considerable. It is occasionally useful in planning surgery.

The anatomy of the renal collecting system can be shown only by urography. High dose techniques achieve this even in the face of renal failure, and scintiscanning has few indications in investigating lesions that distort the renal anatomy, e.g. tumours and cysts.

Renal scintiscanning is a very valuable additional method to urography, arteriography and renography in investigation of renal disorders.