Multidetector CT Evaluation of Active Extravasation in Blunt Abdominal and Pelvic Trauma Patients

Abstract

Timely localization of a bleeding source can improve the efficacy of trauma management, and improvements in the technology of computed tomography (CT) have expedited the work-up of the traumatized patient. The classic pattern of active extravasation (ie, administered contrast agent that has escaped from injured arteries, veins, or urinary tract) at dual phase CT is a jet or focal area of hyperattenuation within a hematoma that fades into an enlarged, enhanced hematoma on delayed images. This finding indicates significant bleeding and must be quickly communicated to the clinician, since potentially lifesaving surgical or endovascular repair may be necessary. Active extravasation can be associated with other injuries to arteries, such as a hematoma or a pseudoaneurysm. Both active extravasation and pseudoaneurysm (unlike bone fragments and dense foreign bodies) change in appearance on delayed images, compared with their characteristics on arterial images. Other clues to the location of vessel injury include lack of vascular enhancement (caused by occlusion or spasm), vessel irregularity, size change (such as occurs with pseudoaneurysm), and an intimal flap (which signifies dissection). The sentinel clot sign is an important clue for locating the bleeding source when other more localizing findings of vessel injury are not present. Timely diagnosis, differentiation of vascular injuries from other findings of trauma, signs of depleted intravascular volume, and localization of vascular injury are important to convey to interventional radiologists or surgeons to improve trauma management.

Optimizing Trauma Multidetector CT Protocol for Blunt Splenic Injury: Need for Arterial and Portal Venous Phase Scans

“…Active bleeding appears on CT images as areas of contrast agent extravasation typically larger and more irregular than contained injuries; more reliably, in active bleeding, extravasation volume typically increases on images from sequentially obtained sequences and does not exhibit the contrast agent washout of a contained injury (although apparent attenuation of extravasated blood may decrease because of dilution related to ongoing bleeding or mixing into a preexisting hematoma) (18,19). Thus multiphase CT is helpful, and in many cases necessary, for accurate characterization of intrasplenic vascular injury (3,18). Previous investigations have utilized portal venous phase imaging followed by delayed excretory phase imaging (3,4,6,8,11) for evaluation of the imaged spleen.…”

“…Intrasplenic arterial pseudoaneurysms appear on CT images as foci of contrast enhancement not conforming to intact vessels but closely matching the attenuation of intraarterial blood; the lesions do not increase in size on consecutive phase images obtained during a single examination, but do exhibit washout of enhancement synchronous with contrast agent clearance from intact arteries (11,18). CT features of EMERGENCY RADIOLOGY: Trauma CT Protocol for Blunt Splenic Injury Boscak et al management (20,21), the published literature is contradictory regarding the relationship between splenic injury grade and incidence of intrasplenic vascular injury.…”

Investigating of the Usefulness of Multidetector-row Computed Tomography for Diagnosing Abdominal Visceral Pseudoaneurysms

“…Based on the findings for these four patients, we expect that the bleeding source and possibility of endovascular treatment could be predicted during angiography for cases with a medical device inserted or in a poor general state, even if the bleeding source cannot be determined from MDCT findings. Vascular injury can be recognized by typical changes over time 15 , in particular, contrast medium extravasation, pseudoaneurysm, arteriovenous AV fistula, and vessel truncation 16,17 . These findings support our suggestion that for severe pathologies, such as vascular injury Fig.…”

Quando a fase de equilíbrio pode ser suprimida nos exames de tomografia computadorizada de abdome?

“…When such strategies are applied together, a significant reduction is observed in the radiation dose to which the patient is exposed (6) , in some specific clinical situations attaining equivalent doses lower than 2 mSv (23) , which correspond to three views of plain abdominal radiography or one cranial CT (25) . Besides the above mentioned strategies, suppression of one or more imaging phases has been showing to be a feasible and effective alternative (7,11) . In the present study, considering the evaluation of a wide range of clinical indications, frequently with four acquisition phases, the authors obtained an estimated mean effective dose of 41.2 mSv per scan, with an average of 12.5 mSv per phase.…”