On the non-contrast study, there is hyperdense material centrally within the left kidney. What is this due to?
This is residual contrast from the first CT scan performed prior to transport. As the right kidney is devascularised, it is not producing urine and therefore no contrast is present with its collecting system.
What is the usual treatment for these injuries?
When complete occlusion of the renal artery is present, attempts to revascularise the kidney can be made, although the results are disappointing, even in patients with short ischaemic times. As such unless patients have a solitary kidney or are pre-morbidly on the brink of renal failure, most renal artery occlusions are treated conservatively. If there is significant bleeding and haemodynamic instability then surgery with emergency nephrectomy or endovascular coilling of the renal artery may be life saving.
Non enhancing right kidney (blue dotted line) with a only a short stump of the right renal artery visible (red arrow). A small amount of tissue at the inferior pole of the kidney demonstrates some enhancement, as a result of it being supplied by a very small accessory branch (yellow arrow) arising either form the aorta, or proximal renal artery, prior to occlusion.
The combination of this small accessort artery and some capsular supply (not visualised) contributes to contrast opacification of the right renal vein (orange arrow).