Dr. Sivit is in the Department of Radiology, University Hospitals Case Medical Center, Cleveland, OH.
Imaging is central to the evaluation of injured children following
abdominal trauma, and computed tomography (CT) is the imaging method of
choice to evaluate hemodynamically stable children sustaining
significant blunt abdominal trauma.
multidetector CT systems provide high image quality, owing to thinner
collimation, reduced partial volume and motion artifacts, and the
ability to perform multiplanar reformatted images. CT allows for the
accurate detection and quantification of injury to solid and hollow
viscera. CT also detects and quantifies intraperitoneal and
extraperitoneal fluid and blood. CT can help prioritize optimal
management by diagnosing life-threatening injury and active hemorrhage.
Additionally, CT demonstrates associated bony injury to the ribs, spine,
and pelvis. A normal CT also serves an important function in patient
management by excluding potential intra-abdominal or pelvic sources of
Solid viscus injury
The liver is either
the most commonly injured or second-most commonly injured solid viscera.
Hepatic injury is believed responsible for the most fatalities in which
abdominal trauma is the primary cause of death. Most hepatic injury
occurs in the posterior segment of the right lobe.1 The
effects of blunt force are maximized in this location because the
posterior right lobe is fixated by the coronary ligaments, which limit
its movement while the rest of the liver is free to move. Hepatic
lacerations may be simple or stellate (Figure 1). Stellate or complex
lacerations have a branching pattern. They may be associated with
parenchymal or subcapsular hematoma. Hepatic injury is associated with
hemoperitoneum in approximately two-thirds of cases.2-3
Hemoperitoneum associated with hepatic injury principally relates to
violation of the liver capsule at the site of injury. Hepatic injury may
not be associated with hemoperitoneum if the injury does not extend to
the surface of the liver, if the hepatic capsule is not disrupted, or if
there is extension to the liver surface in the bare area of the liver,
which is devoid of peritoneal reflection.4 Injury extending to the bare area may lead to associated retroperitoneal hemorrhage.
primary grading scale used to quantify hepatic injury was developed by
the American Association for the Surgery of Trauma (AAST).5
Attempts to develop CT classification systems have had limited success.
The AAST grading scale emphasizes the anatomic extent of the injury,
including capsular integrity, extent of subcapsular collection, extent
of parenchymal disruption, and state of the vascular pedicle. This
grading scale is universally utilized in children and adults. However,
in children this scale is not predictive of need for operative
management because most hepatic injuries can be successfully managed
nonoperatively regardless of severity. In various reports between 1% and
3% of children with hepatic injury required surgical hemostasis.6-7
The primary utility of the AAST grading scale in the pediatric age
group is in nonsurgical patient management decisions, including duration
and intensity of hospitalization and activity restriction.
injury is also common after blunt trauma. Splenic lacerations vary in
appearance, ranging from linear to branching patterns (Figure 2).
Because the spleen is much smaller than the liver, complex injury
typically results in shattering or fragmentation of the spleen (Figure
3). Associated parenchymal or subcapsular hematoma may be present as
seen with hepatic injury. Associated intraperitoneal hemorrhage is not
always present, relating to whether a laceration extends to the spleen
surface and whether the capsule remains intact. Absence of
hemoperitoneum is observed in approximately 25% of splenic injuries.2-3
AAST grading scale is also the primary grading scale for splenic
injury. As is true for hepatic injury, this scale is not a measure of
required surgical treatment, as nonoperative management is successful in
most children with splenic injury. The primary utility of the AAST
grading scale in pediatric patients is in nonsurgical patient management
decisions. The kidney is the third-most frequently injured abdominal
viscera in children. The most common renal injury is the parenchymal
contusion, manifested on CT by a focal or diffuse region of
delayed-contrast enhancement. Renal lacerations appear as linear,
low-attenuation areas in the parenchyma. Renal injury may be complicated
by subcapsular or perinephric hematoma. Deep lacerations may involve
the renal collecting system. Renal collecting system injury results in
urinary extravasation of IV contrast medium (Figure 4).8
Delayed imaging through the kidneys is useful in detecting
extravasation. Urine leakage typically remains encapsulated in the
perirenal space and may lead to urinoma. Conservative treatment is
successful in the management of most high-grade renal injury.9
infarction occurs after a main or segmental renal arterial branch is
lacerated. Injury to a segmental renal artery produces a segmental renal
infarct. The appearance at CT is that of a peripheral, wedged-shaped
area of nonenhancing parenchyma.10-11 These are typically
managed nonoperatively and result in a focal area of renal scarring.
Injury to the main renal artery results in devascularization of the
entire kidney. This is the most severe form of renal injury. Early
recognition is essential, as prompt vascular repair is crucial to
prevent permanent loss of renal function.12
injury is relatively uncommon in children. Approximately 2⁄3 of injuries
occur in the pancreatic body. Direct signs of injury may be difficult
to identify, owing to the small size of the gland, the paucity of
surrounding fat, and the minimal separation of fracture fragments.
Transection results in complete separation of pancreatic fragments
(Figure 5). Unless the two edges of a fracture are separated by
low-attenuation fluid or hematoma, the diagnosis may be difficult to
recognize at CT. The best indicator of pancreatic injury at CT is
unexplained peripancreatic fluid (fluid in the anterior pararenal space
or lesser sac) (Figure 6).13-14 This finding may be seen more
often than the actual laceration. When fluid collects in the anterior
pararenal space it may also dissect between the pancreas and splenic
vein.14-15 Additional CT signs of pancreatic injury are
typically due to associated pancreatitis. These include focal or diffuse
gland enlargement, stranding of peripancreatic and/or mesenteric fat,
thickening of the anterior renal fascia, and free peritoneal fluid.
of pancreatic duct disruption may impact patient management although
there are currently divergent opinions regarding the management of
ductal injury. The nonoperative management of most pancreatic injury has
been proven successful by some, even when there is involvement of the
pancreatic duct.16-17 Others feel that a distal
pancreatectomy for transection to the left of the spine is the treatment
of choice as it is definitive with decreased complications.18-19
Injury to the pancreatic duct can be predicted at CT by evaluating the
depth of laceration. More precise assessment of the pancreatic duct is
obtained with MRCP.
contribution of CT to the evaluation of abdominal trauma is the ability
to identify an active hemorrhage. The diagnosis of an active hemorrhage
at CT is predicated on the identification of a contrast “blush” or a
high-attenuation jet after IV contrast enhancement (Figure 7).20-21
An active hemorrhage results in attenuation values of > 90 HU. The
attenuation of extravasated contrast is usually similar to that seen in
adjacent blood vessels. The rate of active bleeding required for
detection at CT is unclear. Although identifying an active hemorrhage
during a CT scan denotes ongoing bleeding at the examination, it does
not predict continued bleeding, and most children with an active
hemorrhage detected during a CT scan do not require operative
intervention. This is particularly the case when the active hemorrhage
is contained within a solid viscus and thus surrounded by organ
parenchyma, which can tamponade the site of bleeding. In various
reports, 20% or fewer of children with hepatic or splenic injury and an
active hemorrhage required operative hemostasis.22-25
However, it is imperative that these children—particularly younger
children, who have a smaller circulating blood volume—be closely
Hollow viscus injury
Bowel injury is
uncommon after blunt trauma in children. However, partial thickness
injury resulting in intramural hematoma, or full-thickness injury
resulting in bowel rupture, can occur. Most bowel injuries in children
occur following motor vehicle crashes and are due to compression of
bowel and mesentery by the seat belt.26 These children typically display linear lap belt ecchymosis across the lower abdomen and/or flank.26
hematoma results from hemorrhage into the bowel wall following a
partial-thickness tear. The most common location is the duodenum. The
injury can usually be managed nonoperatively. Large hematomas can result
in a proximal small-bowel obstruction. The CT appearance is that of
focal bowel-wall thickening that is often eccentric. No extraluminal air
or extravasated contrast material should be present.
rupture in children most commonly occurs in the mid-to-distal small
intestine, usually the jejunum. Signs of bowel rupture may be subtle on a
CT scan. Extraluminal air is noted on CT in only approximately
one-third to one-half of cases.27-29 Review of the
examination at a wide window setting (> 500) helps to detect small
amounts of extraluminal air (Figure 8). Oral contrast extravasation is
rarely seen.30 The most frequent CT findings associated with
bowel rupture are “unexplained” peritoneal fluid (moderate to large
amounts of fluid in the absence of solid viscus injury or bony pelvic
fracture (Figure 9).27 Approximately 50% of children with
moderate to large amounts of peritoneal fluid as the only finding on CT
following blunt trauma have a bowel injury.2 Additional CT
findings associated with bowel rupture include abnormally intense
bowel-wall enhancement, focal bowel-wall discontinuity, bowel
dilatation, bowel-wall thickening, and streaky infiltration of
Bladder injury is also uncommon
in children. Bladder rupture can be intraperitoneal or extraperitoneal;
combined injuries may occur. Extraperitoneal bladder rupture occurs more
frequently than intraperitoneal rupture. Intraperitoneal rupture
typically results from shearing of the distended bladder by a lap belt,
whereas extraperitoneal rupture often results from laceration by a bony
spicule from a pelvic fracture.30
is essential in detecting bladder injury at CT in order to demonstrate
extravasation of IV contrast material (Figure 10). CT cystography is the
method of choice for the evaluation of suspected bladder rupture.31-33
CT cystography is performed by administering dilute iodinated contrast
into the bladder in a retrograde fashion until the flow stops followed
by clamping of the Foley catheter.31-32 Sagittal and coronal reformations help to localize the site of bladder rupture.32
has largely replaced peritoneal lavage in the assessment of unstable
patients following blunt abdominal trauma since it can be rapidly
performed at the bedside. Sonography has been primarily utilized to
detect free fluid indicative of hemoperitoneum. However, hemoperitoneum
in the hemodynamically stable child typically has limited impact on
management decisions. Sonography has important limitations in the
evaluation of the abdomen in injured children. First, it does not
provide any diagnostic information regarding injury to the bony pelvis
or lumbar spine. Additionally, sonography cannot be used in the
diagnosis of hollow viscus injury. Finally, sonography has been shown to
miss approximately 1⁄4 to 1⁄3 of solid viscus injuries.34-35 Therefore, sonography has a limited role in assessing hemodynamically stable children following blunt abdominal trauma.
Impact of CT on medical decision making
role of CT in evaluating injured children includes establishing the
presence or absence of visceral and bony injury, identifying injury
requiring close monitoring and operative intervention, detecting active
hemorrhage and estimating associated blood loss. The use of CT as the
primary screening modality in the assessment of injured children, along
with improvements in supportive care, has played a critical role in the
success of nonoperative management of solid viscus injuries. The rapid
evaluation of injured children with CT has also resulted in improved
triage and has contributed to reduced morbidity and mortality.
decision for operative intervention in the small percentage of children
who require surgical hemostasis is primarily made based on clinical
criteria, not CT findings.7 Therefore, CT primarily guides
nonoperative decisions, such as duration of hospitalization, intensity
of care, and length of activity restriction.
It has been shown that solid viscus injury grading at CT is useful for estimating the time course of healing.36-40
However, follow-up imaging of solid viscus injury is not indicated in
asymptomatic children for several reasons. First, no injury progression
or complication is noted in most cases of solid viscus injury. Second,
clinical management is rarely altered based on follow-up imaging.
a negative CT also serves an important function in excluding an
intra-abdominal or pelvic source of blood loss, thus enabling early
discharge of the child from the hospital without further observation.41
The high negative predictive value of CT indicates that hospital
admission or observation is not necessary for patients with suspected
blunt abdominal injury and a negative abdominal CT.41-42
CT is the exam of choice in the imaging evaluation of children
following abdominal trauma. CT is highly accurate in detecting and
quantifying solid and hollow viscus injuries. Sonography has a limited
role in the pediatric population for this clinical application, being
used primarily to detect free fluid in the unstable child. In addition,
CT can help prioritize optimal management by diagnosing life-threatening
injury and active hemorrhage. CT primarily guides nonoperative decision
making, such as intensity of care and duration of hospitalization.
- Stalker HP, Kaufman RA. Towbin R. Patterns of liver injury in childhood: CT analysis. AJR Am J Roentgenol. 1986;147:1199-1205.
- Sivit CJ, Taylor GA, Bulas DI, et al. Blunt trauma in children: Significance of peritoneal fluid. Radiology. 1991;178:185-188.
- Taylor GA, Sivit CJ. Posttraumatic peritoneal fluid: Is it a reliable indicator of intraabdominal injury in children? J Pediatr Surg. 1995;30:1644-1648.
- Patten RM, Spear RP, Vincent LM, et al. Traumatic laceration of the liver limited to the bare area: CT findings in 25 patients. AJR Am J Roentgenol. 1993;160:1019-1022.
- Moore EE, Cogbill TH, Jurkovitch J, et al. Organ injury scaling. spleen and liver (1994 revision). J Trauma. 1995;38:323-324.
- Stylianos S. Outcomes from pediatric solid organ injury: Role of standardized care guidelines. Curr Opin Pediatr. 2005;17:402-406.
- Ruess L, Sivit CJ, Eichelberger MR, et al: Blunt abdominal trauma in
children: Impact of CT on operative and nonoperative management. AJR Am J Roentgenol.1997;169:1011-1014.
- Harris AC, Zwirewich CV, Lyburn ID, et al. CT findings in blunt renal trauma. Radiographics. 2001;21:S201-S214.
- Salem HK, Morsi HA, Zakario A. Management of high-grade renal
injuries in children after blunt abdominal trauma: Experience of 40
cases. J Pediatr Urol. 2007;3:222-229.
- Kawahma A, Sandler CM, Carl FM, et al. Imaging of renal trauma: A comprehensive review. Radiographics. 2001;21:557-574.
- Lewis DR, Mirvis SE, Shanmuganathan K. Segmental renal infarction
after blunt abdominal trauma: Clinical significance and appropriate
management. Emerg Radiol. 1996;3:236-240.
- Carroll PR, McAninch JW, Klosterman P, Greenblatt M. Renovascular trauma: risk assessment, surgical management and outcome. J Trauma. 1990;30:547-552.
- Sivit CJ, Eichelberger MR, Taylor GA, et al. Blunt pancreatic trauma in children: CT diagnosis. AJR Am J Roentgenol. 1992;158:1097-1100.
- Sivit CJ, Eichelberger MR. CT diagnosis of pancreatic injury in
children: Significance of fluid separating the splenic vein and
pancreas. AJR Am J Roentgenol. 1995;165:921-924.
- Lane MJ, Mindelzun RE, Sandhu JS, et al. CT diagnosis of blunt
pancreatic trauma: importance of detecting fluid between the pancreas
and the splenic vein. AJR Am J Roentgenol. 1994;163:833-835.
- Wales PW, Shuckett B, Kim PC. Long-term outcome after nonoperative
management of complete traumatic pancreatic transaction in children. J Pediatr Surg. 2001;36:823-827.
- Cigdem MK, Senturk S, Onen A, et al. Nonoperative management of pancreatic injuries in pediatric patients. Surg Today. 2011;41:655-659.
- Canty TG, Weinman D. Management of major pancreatic duct injuries in children. J Trauma. 2001;50:1001-1007.
- Wood JH, Patrick DA, Bruny JL, et al. Operative vs nonoperative management of blunt pancreatic trauma in children. J Pediatr Surg. 2010;45:401-406.
- Sivit CJ, Peclet MH, Taylor GA. Life-threatening intraperitoneal bleeding: Demonstration with CT. Radiology. 1989;171:430.
- Taylor GA, Kaufman RA, Sivit CJ. Active hemorrhage in children after thoracoabdominal trauma: Clinical and CT features. AJR Am J Roentgenol. 1994;162:401-404.
- Cloutier DR, Baird TB, Gormley P, et al. Pediatric splenic injuries
with a contrast blush: Successful nonoperative management without
angiography and embolization. J Pediatr Surg 2004;39:969-971.
- Lutz N, Mahboubi S, Nance ML, Stafford PW. The significance of
contrast blush on computed tomography in children with splenic injuries.
J Pediatr Surg. 2004;39:491-494.
- Nwomeh BC, Nadler EP, Meza MP, et al. Contrast extravasation
predicts the need for operative intervention in children with blunt
splenic trauma. J Trauma. 2004;56:537-541.
- Davies DA, Ein SH, Pearl R, et al. What is the significance of contrast “blush” in pediatric blunt splenic trauma? J Pediatr Surg 2010;45:916-920.
- Sivit CJ, Taylor GA, Newman KD, et al. Safety-belt injuries in children with lap-belt ecchymosis: CT findings in 61 patients. AJR Am J Roentgenol. 1991;157:111-114.
- Sivit CJ, Eichelberger MR, Taylor GA. CT in children with rupture of
the bowel caused by blunt trauma: Diagnostic efficacy and comparison
with hypoperfusion complex. AJR Am J Roentgenol. 1994;163:1195-1198.
- Strouse PJ, Bradley JC, Marshall KW, Cywes R. CT of bowel and mesenteric trauma in children. Radiographics. 1999;19:1237-1250.
- Jamieson DH, Babyn PS, Pearl R. Imaging gastrointestinal perforation in pediatric blunt abdominal trauma. Pediatr Radiol. 1996;26:188-194.
- Sivit CJ, Cutting JP, Eichelberger MR. CT diagnosis and localization
of rupture of the bladder in children with blunt abdominal trauma:
Significance of contrast material in the pelvis. AJR Am J Roentgenol. 1995;164:1243-1246.
- Vaccaro JP, Brody JM. CT cystography in the evaluation of major bladder trauma. Radiographics. 2000;20:1373-1381.
- Chan DP, Abujudeh HH, Cushing GL, Novelline RA. CT cystography with
multiplanar reformation for suspected bladder rupture: experience in 234
cases. AJR Am J Roentgenol. 2006;187:1296-1302.
- Morgan DE, Nallamala LK, Kenny PJ, et al. CT cystography: Radiographic and clinical predictors of bladder rupture. AJR Am J Roentgenol. 2000;174:89-95.
- Poletti PA, Kinkel K, Vermeulen B, et al. Blunt abdominal trauma:
Should US be used to detect both free fluid and organ injuries? Radiology. 2003;227:97-103.
- Richards JR, Knopf NA, Wong L, McGahan JP. Blunt abdominal trauma in children: Evaluation at emergency US. Radiology. 2002;222:749-754.
- Bulas DI, Eichelberger MR, Sivit CJ, et al. Hepatic injury from blunt trauma in children: Follow-up examination with CT. AJR Am J Roentgenol. 1993;160:347-351.
- Benya EC, Bulas DI, Eichelberger MR, Sivit CJ. Splenic injury from
blunt abdominal trauma in children: Follow-up examination with CT. Radiology. 1995;195:685-688.
- Huebner S, Reed M. Analysis of the value of imaging as part of the follow-up of splenic injury in children. Pediatr Radiol. 2001;31:847-855.
- Yale-Loehr AJ, Kramer SS, Quinlan DM, et al. CT of severe renal
trauma in children: Evaluation and course of healing with conservative
therapy. AJR Am J Roentgenol. 1989;152:109-113.
- Abdalati H, Bulas DI, Sivit CJ. Blunt renal trauma in children:
Healing of renal injuries and recommendations for imaging follow-up. Pediatr Radiol. 1994;24:573-576.
- Livingston DH, Lavery RF, Passannante MR, et al. Admission or
observation is not necessary after a negative abdominal computed
tomographic scan in patients with suspected blunt abdominal trauma:
Results of a prospective, multi-institutional trial. J Trauma. 2008;44:273-280.
- Hom J. The risk of intra-abdominal injuries in pediatric patients
with stable blunt abdominal trauma and negative abdominal computed
tomography. Acad Emerg Med. 2010;17:469-475.