Editorials Donald
R. Kirks,
MD
#{149} Kathleen
CT ofBlunt An Anatomic
H. Caron,
INCE the initial study by Berger and Kuhn in i98i (i), computed tomography (CT) has been increasingly used for evaluation of blunt abdominal trauma in infants and children. Prospective studies (2) and reviews (3) have documented the utility of CT in determining the presence and extent of injury in children with suspected abdominal injury after blunt trauma. The patterns of hepatic and splenic injury (4,5), bowel injury (6), and associated thoracic injuries (7) have been described in detail. Taylor et al (8) initially described the “hypoperfusion complex” secondary to hypovolemic shock in three patients less than 2 years of age. In this issue of Radiology, Sivit et al (9) further define the hypoperfusion cornin a total
of 27 children;
CT find-
ings were associated with both profound hernodynamic instability and poor prognosis. CT has become critical in the assessment and management of pediatric trauma; more than 2,000 patients at Children’s National Medical Center, Washington, DC, and Children’s Hospital Medical Center, Cincinnati (CHMC), have been evaluated with CT for blunt abdominal trauma. It should be stressed that not every child with blunt abdominal trauma should undergo imaging evaluation (iO). There are three general groups of pediatric trauma patients. Clinically stable patients with minor or trivial trauma require only careful clinical evaluation and observation. Clinically unstable children with severe head
Index
terms:
Abdomen,
men, injuries, 70.41 puted tomography children #{149}Editorials
Radiology
From
in infants #{149}Trauma
Corn-
#{149}
and
1992; 182:631-632
the
Department
Hospital
Medical
thesda
Ayes,
of Radiology, Center,
Cincinnati,
Departments
University Cincinnati.
Abdo-
#{149}
injuries
(CT),
dren’s
the
CT, 70.1211
Children,
#{149}
OH
of Radiology
of Cincinnati Received
cepted November to D.R.K. ( RSNA, 1992 See also the article in this issue.
College November
22. Address
by
Sivit
Chil-
Elland 45229-2899;
and
and and
Pediatrics,
Be-
S. Bisset
#{149} George
Abdominal “Snapshot
S
plex
MD
III, MD
Trauma in Children: in Time”
injury
and/or blunt abdominal trauma require immediate surgery. Finally, some pediatric patients have severe blunt abdominal trauma yet are cmically stable; CT has proved extremely valuable in this third group of patients (2,3,10). Because of recent advances in trauma support and improved patient survival, more seriously injured children are evaluated with CT (9). An increasing number of these patients with severe abdominal trauma have been resuscitated after hypovolemic shock and may demonstrate typical CT findings.
Pediatric
abdominal
CT in general
and CT of blunt abdominal trauma in particular require meticulous attention to technique (10,11). Our techniques at
CHMC
differ
slightly
from
those
scribed by Taylor and Federle (12);
et at (3,8) however,
mental
are similar.
principles
de-
and Jeffrey the funda-
Intrave-
graphy quent
require with
not only physielectrocardio-
and pulse oximetry clinical evaluation
but also frefor early signs
of shock. Unless the patient is comatose and at risk to aspirate, we give orally administered usual dose
contrast material for nonemergency
nal CT examination) tube
(half the abdomi-
via a nasogastric
approximately
10-15
fore the study. Although tion is rarely identified
minutes
be-
bowel perforaby means of
demonstration of extravasation of contrast material (3,6), we believe that orally administered contrast material provides optimal evaluation of the pancreas and bowel wall. A digital scout radiograph and three to four scout CT sections are obtained before intravenous administration of contrast material. This permits removal of tubes that might produce artifacts, assessment of adequacy of oral contrast material administration, verification of appropriate technique, accurate centering of the pa-
tient,
and
selection
of the appropriate
reprint
requests
field of view. Intravenously administered contrast material is given by means of rapid bolus hand injection; we routinely use nonionic contrast material
et al (pp
723-726)
in all patients.
of Medicine, 20, i99i; ac-
performed
Our with
examinations
a GE 9800
are
CT scanner
Systems,
table
with
Milwaukee), with sections obtained
through dynamic
incrementation
the lower scanning
is usually
performed. Contiguous scans of the lower abdomen and pelvis are obtained if pelvic injury is strongly suspected. Select, delayed images of the pelvis may be obtained to assess bladder integrity. A post-CT radiograph of the abdomen (“poor
man’s”
excretory
urogram)
is
frequently obtained to assess both upper and lower urinary tracts (10). CT shows the anatomy of the liver, spleen, kidneys, pancreas, peritoneal cavity, mesentery, and bowel. Despite the critical role of CT in evaluating blunt abdominal trauma in children, several potential pitfalls of the technique must be emphasized. Small traumatic
nous sedation is administered as necessary in consultation with pediatric trauma physicians. Patients who are comatose or who have been in shock
and resuscitated ologic monitoring
(GE Medical
contiguous i-cm-thick from the lung bases poles of the kidneys;
lesions
resolved.
of solid
creatic
injury,
bowel
perforation
difficult
may
diagnosis
intestinal
injury,
may
not
be
of panand
be extremely
(3,6,10).
In addition also
organs
Moreover,
allows
to depicting assessment
anatomy, of vascular
CT integ-
rity and inferring of the function of certam organs such as the liver, spleen, and kidneys. Described findings in the hypoperfusion complex (8,9) include small
size
cava,
presumably
of the
(12), and abnormal gans, presumably fusion.
aorta
and
due
inferior
vena
to hypovolemia
enhancement due to decreased
of orper-
It must be stressed that an abdominal CT study obtained after blunt abdominal trauma is an anatomic display at that point in time. Sivit et al (9) note that children may rapidly progress along
a continuum
from
compensated
to uncompensated to irreversible shock. Moreover, we have noted that there is also a spectrum traumatic shock
of CT findings and resuscitation
after in
children; not all of the defined findings are necessarily present at any given time. If hypovolemia is corrected during resuscitation, only abnormalities of endorgan perfusion are observed (Figure). We strongly agree with the previously published statement that “operafive or nonoperative approaches should
not be based on the extent of injury shown at CT, but on the physiologic condition
of the
child”
(5). This
is also 631
true of the hypoperfusion complex demonstrated at CT, which is merely a pictorial confirmation of what would be expected with a low Trauma Score and a low Glasgow Coma Score. These clinical tests allow accurate assessment of physiologic derangement and neurologic function on admission; they also provide prognostic information (9). In summary, Sivit et al should be congratulated on their ongoing clinical research that reconfirms the critical role of abdominal CT in children with suspected injury after blunt abdominal trauma. It is apparent that a number of
CT findings may be seen patient after resuscitation However,
tioned
radiologists
that
these
olemia and/or ing more than hemodynamic cance of these
in the pediatric for shock.
must
CT findings
also
References 1.
nal
of hypov-
PE, Kuhn
trauma
JP.
CT ofblunt
abdomi-
AJR
136:
in childhood.
1981;
105-110. 2.
3.
4.
Kaufman
RA,
7.
8.
role
of CT
et a!.
Potter BM, Eicheland splenic injury in the
decision
for
in lap-
arotomy. Radiology 1987; 165:643-646. Bulas DI, Taylor GA, Eichelberger MR. The value of CT in detecting bowel perforation in children after blunt abdominal trauma. AIR 1989; 153:561-564. Sivit CJ, Taylor GA, Eichelberger MR. Chest injury in children with blunt abdomma! trauma: evaluation with CT. Radiology 1989; 171:815-818. Taylor
GA,
Fallat
ME,
Eichelberger
shock
CT manifestations. 479-481. CJ,
Potter matic
BM, Eichelberger shock in children: with hernodynamic
ogy
1992;
Taylor
in children:
Radiology
Sivit
ated 10.
DS,
i986; 147:1199-1205.
Hypovolemic
9.
R, Babcock
Brick SH, Taylor GA, berger MR. Hepatic children:
6.
Towbin
Upper abdominal trauma in children: imaging evaluation. AJR 1984; 142:449-460. Taylor GA, Guion CJ, Potter BM, Eichelberger MR. CT of blunt abdominal trauma in children. AJR 1989; 153:555-559. Stalker HP, Kaufman RA, Towbin R. Patterns ofliver injury in childhood: CT analysis. AJR
5.
be cau-
hypoperfusion are nothan anatomic display of instability; the signififindings must be assessed in the context of the patient’s clinical status. It should not be assumed that significant visceral or bowel injuries are not also present. The decision for laparotomy is currently still based on the physiologic condition of the child rather than on the presence of any or all of the constellation of CT findings of the hypoperfusion complex. a
Berger
GA,
Bulas
MR.
after
DC,
MR. PosttrauCT findings associinstability. Radio!-
#{149} Radiology
posttraumatic
Blood pressure was normal at the time of the CT examination. There is marked stasis of contrast material in mesenteric vessels, indicating decreased bowel perfusion. Note normal
size
of the
aorta,
mesenteric
inferior
vein
due
tensive ischemic
central bowel
vena
and
artery,
nervous necrosis.
cava,
superior
to correction
volemia. The patient died CT examination. Autopsy
DR, Caron Ml. Gastrointestinal tract. In: Kirks DR. ed. Practical pediatric imaging: diagnostic radiology of infants and children. 2nd ed. Boston: Little, 1991;
823-828.
ii.
Kaufman dominal
of hypo-
18 hours after demonstrated
system
12.
RA.
Technical
CT in infants
injury
MP.
inferior
CT
vena
AJR
cava:
aspects and
1989; 153:549-554. Jeffrey RB, Federle volemia.
632
experiencing
CT scan and
the ex-
and
182:723-726.
Kirks
Brown,
resuscitated
complex; by automobile
shock
mesenteric
164:
DI, Kushner
of hypoperfusion of 9-year-old girl struck
superior
abdominal
1987;
Example
of ab-
children.
The evidence
AJR
collapsed of hypo-
1988; 150:431-432.
March
1992