Approach to Splenic Trauma on CT: A Systematic Framework
A structured approach to splenic injury on CT: what the AAST grade is really asking, and the vascular survey that drives management.
Last reviewed 2026-01
The spleen is the most commonly injured solid organ in blunt abdominal trauma, so this is the read you’ll do most often on a trauma service. Whether the patient goes to the OR, to angiography, or to a monitored bed hangs largely on the CT. The lacerations themselves are usually easy to see, and they’re rarely the problem. The trouble comes from missing the vascular findings, and from treating the grade as the whole answer.
Find It, Then Grade It#
On the portal venous phase the spleen enhances homogeneously, so lacerations, hematomas, and subcapsular collections stand out as defects against a uniform background. Often the perisplenic fluid is what pulls your eye to the quadrant first.
Grading comes next, and it helps to know what the AAST Organ Injury Scale is really asking: how much of the spleen has lost its blood supply. That’s what predicts whether the injury will heal or keep bleeding. The scale was built around operative findings, so imaging-based grades correlate imperfectly with what the surgeon sees, and the grade alone should not be the whole of what you communicate.
The Vascular Survey#
This is where management actually gets decided. Active extravasation appears as a focus of contrast that grows and brightens from the arterial to the portal venous phase, because blood is still leaving the circulation while the scanner runs. Say explicitly in the report whether it’s contained within the parenchyma or capsule, or free in the peritoneum. Contained bleeding under an intact capsule can often be watched, but free hemorrhage usually can’t.
A pseudoaneurysm can look similar on a single phase, but it follows blood pool on every phase instead of growing. It isn’t bleeding at the moment you scan it, and it still matters, because pseudoaneurysms are behind many of the delayed ruptures.
Then check the neighbors. The same blow that injures the spleen also loads the left lower ribs, the left hemidiaphragm, the left kidney, and the pancreatic tail. Check all four before you sign off.
The 48 to 72 Hour Problem#
Delayed splenic rupture is a real entity. A hematoma or pseudoaneurysm that looked stable on arrival can rupture on day two or three, which is why nonoperative management includes follow-up imaging at 48 to 72 hours. If the plan is observation, the initial report should recommend that follow-up explicitly.
Putting It Together#
No single imaging feature dictates management. The team integrates hemodynamic status, injury grade, and the vascular survey, and the decision to take a patient to the OR belongs entirely to the surgeon, not to you. What your report needs to give them is each piece stated plainly: the grade, any vascular finding by name, and contained versus free. That covers the two common mistakes, overcalling a low-grade laceration into an intervention it doesn’t need, and undercalling the pseudoaneurysm that needed angiography.