A shattered kidney: a pitfall in imaging of renal trauma.

To cite: Fang C, Husainy MA, Huang D. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2015211496 DESCRIPTION A young man fell off a bike and landed on his right side, resulting in severe right flank tenderness. A dipstick test revealed the presence of blood (++), protein (++) and ketones (++) in his urine. Contrast-enhanced CT imaging revealed a complex right renal injury. On axial images, the devascularised lower renal pole fragment could not be easily appreciated as it was surrounded by a haematoma/urinoma; but this was better appreciated on reformatted images. CT is the primary modality for assessing renal trauma as the severity of the haematuria is poorly correlated with the severity of the renal injury. On CT scan, the devascularised, non-enhancing renal segments in this case were not readily identified as they were surrounded and displaced by haematoma/ urinoma (figures 1 and 2). Multiplanar reformatted images improved demonstration of the unenhanced polar segments of the injured kidney (figures 3 and 4). In addition, presence of the renal sinus fat within the urinoma/haematoma aided in the identification of unenhanced renal tissue (figure 4). Together they helped alleviate the potential pitfall in this under-staging renal trauma. The use of multiplanar CT scan often facilitates the decision between conservative and surgical management. In grade V injuries, where renal laceration extends through the renal cortex, medulla and collecting system, or where it involves the renal vascular pedicles, nephrectomy is often required. However, importantly, therapeutic strategies should also be guided by the clinical picture in conjunction with functional imaging such as renal scintigraphy. This patient was successfully managed conservatively with eventual reduced, but valuable, right renal function (split function of 34%) and a normal estimated glomerular filtration rate.