# Use of Contrast-Enhanced Ultrasound in Suspected Traumatic or Spontaneous Renal Injury in Cats: A Case Series

## TL;DR

This study explores the use of contrast-enhanced ultrasound in diagnosing kidney injuries in cats, showing it can help identify traumatic or spontaneous renal damage.

## Contribution

The study is among the first to describe CEUS findings in feline renal trauma, offering insights into its diagnostic potential.

## Key findings

- CEUS identified focal disruptions and non-enhancing areas consistent with hematomas or lacerations in two cats.
- One cat showed active subcapsular hemorrhage with contrast extravasation, indicating active bleeding.
- CEUS was found to be a rapid, safe, and minimally invasive method for evaluating feline renal injuries.

## Abstract

Traumatic injuries caused by penetrating or blunt trauma account for approximately 10% of mortality in companion animals. In pediatric human patients, the kidney is the third most frequently injured abdominal organ during trauma. In human medicine, contrast-enhanced ultrasound (CEUS) is a well-established technique for assessing traumatic injuries involving parenchymal organs. While CEUS is increasingly utilized in veterinary medicine, its application in renal assessment remains underexplored, particularly in the context of trauma. This study describes CEUS findings in three cases of traumatic or spontaneous renal rupture in cats. Two cases presented ultrasonographic and CEUS features consistent with renal hematomas or lacerations, while one case showed active subcapsular renal hemorrhage. Hematomas appeared as focal disruptions of renal architecture, often with cystic, non-enhancing areas on CEUS. Active bleeding was characterized by contrast extravasation in subcapsular or retroperitoneal locations. Overall, CEUS appeared to be a rapid, safe, and minimally invasive method for evaluating traumatic and/or spontaneous renal injuries and may represent a useful complementary tool in the diagnostic approach to feline renal trauma. However, the findings of this study should be interpreted cautiously given the small number of cases.

Contrast-enhanced ultrasound (CEUS) is increasingly applied in veterinary medicine as a safe, rapid, and non-invasive imaging technique for assessing renal disorders. Despite its expanding use, the literature on its application in feline renal trauma remains scarce. This retrospective study aimed to describe CEUS findings in cats with suspected traumatic renal injuries. Medical records were reviewed for cats that underwent both B-mode ultrasonography and CEUS, with findings confirmed by follow-up, surgery, or cytology. Three cats met the inclusion criteria. Two presented focal or multifocal renal lesions ranging from 10 to 20 mm in diameter, with heterogeneous echotexture, distortion of renal contours, and non-enhancing areas on CEUS consistent with hematomas or lacerations. The third cat showed a circumferential subcapsular halo (approximately 3–5 mm thick) with evidence of contrast leakage, compatible with limited active hemorrhage. CEUS appeared effective in identifying and characterizing renal injuries, offering valuable information to support clinical decision-making and guide both conservative and surgical management. Nevertheless, due to the limited sample size and the absence of quantitative data, these results should be considered preliminary. Further prospective studies are warranted to confirm the diagnostic performance and clinical utility of CEUS in feline renal trauma.