The spleen is the most commonly injured organ in the abdomen. Injury ranges from partial tears of the splenic capsule to complete disruption necessitating surgical intervention in hemodynamically unstable patients. Lacerations may also be caused by penetrating and surgical trauma.
IV contrast-enhanced CT remains the optimal method of imaging for detection of splenic injury. Radiographic findings associated with splenic trauma include irregular low-attenuation defects with grossly appreciable disruption of the splenic profile. Also found are splenic hematomas, assuming either a "wedge-shaped" appearance or multiple low-attenuation defects. The case above also shows active extravasation, a critical observation that will require embolization or laparotomy and splenectomy.
By comparison, non-contrast CT and ultrasound are less sensitive for the detection of splenic injury and the grading of parenchymal disruption.
In evaluation of the CT study, it is also important to avoid misdiagnosis due to study artifacts. Mimicking splenic injury and laceration are congenital splenic clefts. In addition, artifacts from ribs may suggest splenic laceration. For this reason, additional evidence of trauma, in correlation with plain film radiographic findings, can serve as points of differentiation.
Plain films are neither sensitive nor specific for detection of splenic injuries. However, certain findings can suggest the possiblity of splenic laceration. Radiographic evidence of abdomenal trauma include:
Plain Film Abdomen Trauma
A. rib fractures
B. pneumothorax
C. elevation of the left hemidiaphragm
D. enlargement of the splenic shadows
E. medial displacement of bowel
F. signs of intraperitoneal bleed
The abdominal plain film displayed illustrates rightward displacement of bowel, associated with LUQ haziness. This findiing is suggestive of splenic rupture. CT imaging with IV contrast is, however, required for a definitive diagnosis.
Displayed below is the appearance of a subcapsular splenic hematoma on CT (top row) and a comparison of the same subcapsular hematoma on US.
