Arterial phase in multidetector CT optimizes splenic injury detection

The arterial phase of image acquisition has been shown to improve the detection of traumatic contained splenic vascular injuries, according to a study published in the January 2014 issue of Radiology.

Multidetector CT enables speedy evaluation and detection of hollow and solid organ injuries from trauma, which include traumatic splenic injuries. Active splenic hemorrhage and contained vascular injuries must be detected in order to best determine the need for direct intervention or nonsurgical treatment.

“Multiphasic multidetector CT protocols enable imaging of the chest, abdomen, pelvis, and, when necessary, extremities with use of a single intravenous bolus of contrast material,” wrote the study’s lead author, Jennifer W. Uyeda, MD, of the Boston University School of Medicine, and colleagues. “Traditionally, the CT assessment of traumatic intraabdominal injuries, including splenic injuries, has relied on portal venous phase imaging, with the addition of delayed phase imaging as necessary.”

Though arterial phase imaging has recently demonstrated improved depiction of vascular injuries in the solid abdominal organs, the benefits of its clinical utility must be considered due to increased radiation exposure. Uyeda and colleagues thus designed a retrospective study to assess the addition of arterial phase CT to the ubiquitous combination of portal venous and delayed phase images and its impact on the sensitivity in diagnosis of active hemorrhage and/or contained vascular injuries in patients with splenic trauma.

The study’s population was comprised of all patients 15 years or older who had a splenic injury from trauma and underwent CT in the arterial and portal venous phases of image acquisition from September 2005 to November 2011. The CT scans were reviewed by three radiologists who came to consensus interpretations in order to classify the splenic injuries based on the American Association for the Surgery of Trauma splenic injury scale. Clinical outcomes were then assessed through the review of medical records and the relationship between the imaging findings and clinical management was evaluated with the Fisher exact test.

Results revealed that 32 of 147 patients had active hemorrhage and 22 had several contained vascular injuries. In 13 of the 22 patients with vascular injuries, the vascular lesion was solely visualized at the arterial phase of image acquisition. The other nine had vascular injuries seen at all phases of acquisition. Surgery or embolization was performed in 11 of the 22 patients.

"In conclusion, this study demonstrates that the use of arterial phase imaging markedly increases the sensitivity of CT in the detection of contained vascular injuries in splenic trauma,” wrote the study’s authors. “However, the effect of these gains in sensitivity on clinical management and patient outcomes remains uncertain and must be weighed against risks to the patient population, including additional radiation exposure. Nevertheless, the use of arterial phase imaging in abdominal trauma should be strongly considered and deserves further inquiry.”