The Journal of the Arkansas Medical Society Issue 3 Vol 115 | Page 10

SCIENTIFIC ARTICLE
Radiation Exposure in Children Undergoing
Abdomen-computed Tomography:
Experience in Arkansas Community Hospitals Differs from the Children’s Hospital
Robert F. Buchmann, DO; 2 Shilpa Hegde, MD; 1 Leann E. Linam, MD; 1 S. Bruce Greenberg, MD
1
Arkansas Children’s Hospital, 2 Children’s Hospital of Pittsburgh
1
Abstract
R
adiation exposure to children as-
sociated with computed tomog-
raphy (CT) is a public health con-
cern. Our purpose was to compare radiation ex-
posure of children who underwent abdomen and
pelvis CT exams at Arkansas community hospitals
with Arkansas Children’s Hospital. A total of 178
community hospital and 111 children’s hospital
CT abdomen and pelvis exams were compared.
Radiation exposure was calculated for all exams
and techniques compared. The mean effective
dose of the community hospital group was nearly
double that of the children’s hospital group. High-
er energy (kVp 120 or greater) and multiphase
imaging accounted for the large difference and
can be easily corrected by community hospitals.
Introduction
Computed tomography (CT) accounts for a
large portion of medically administered ionizing
radiation. The “Image Gently” campaign was in-
augurated in 2008 to address concerns about ex-
cessive patient radiation exposure, particularly in
children. 1 The primary objective of the campaign
was to raise awareness in the imaging communi-
ty of the need to reduce radiation dose to children
by establishing pediatric specific CT protocols. 2
The campaign targeted radiologists and technolo-
gists who perform CT primarily in adults who, in
aggregate, perform a significant number of CT
scans in children.
We were concerned that many community
hospitals in Arkansas continue to use adult pro-
tocols in children and that additional education
might be necessary to alter practice patterns in
hospitals that are primarily focused on adult care
but perform pediatric CT examinations. Our
purpose was to compare radiation exposure of
children who underwent abdomen and pelvis
CT exams at community hospitals with that of
children who received the exams at Arkansas
Children’s Hospital. A secondary purpose was to
analyze technique differences that could result
in specific recommendations to reduce radiation
exposure in community hospitals independent of
available equipment.
Materials and Methods
The study was approved by the hospital
institutional review board. The study included
all 178 abdomen and pelvis CT examinations
performed at community hospitals in children
that were subsequently referred to Arkansas
Children’s Hospital during the first six months of
2013. Inclusion criteria included age less than
19 years and a dose page that included phantom
size, computed tomography dose index (CTDI)
volume, and dose length product (DLP). The con-
trol group included 111 CT examinations per-
formed at the children’s hospital between April
and June, 2013. Patient age, number of imag-
ing phases, peak kilovoltage (kVp), CTDI volume,
and DLP were recorded for each examination.
The size-specific dose estimate (SSDE) was
calculated for each study. 3 The anteroposterior
and lateral patient diameters were summed on
the middle slice of each study to determine the
conversion factor, which was multiplied by the
scanner-recorded CTDI volume to calculate the
SSDE. 3,4 The effective dose was calculated for
each study using the conversion factors pub-
lished by Deak. 5 The conversion factors were
based on phantom size, patient age, kVp and
body location. 5 T tests compared differences
in patient group ages, kVp, effective dose and
SSDE. Fischer’s exact test was used to assess
the frequency of single and multiphase studies
in the two groups.
Results
The results are summarized in Table 1. The
mean ages of the community hospital group,
10.0 years (SD 4.8 years), and the children’s
hospital group, 10.7 years (5.1 years), were not
significantly different (p = 0.25).  The mean en-
ergy for the community hospital group was 116
kVp (SD 9.8 kVp) and for the children’s hospital
was 101.5 kVp (SD 11.1 kVp). The difference in
energy was highly significant (P < 0.0001). 120
kVp or greater was used in 83% of the com-
munity hospital examinations. By contrast, the
children’s hospital used 100 kVp or less in 85%
of their CT examinations. The mean SSDE for
the community hospital group was 26.4 mGy
Table 1. Comparison of radiation with CT abdomen and pelvis examinations
between community hospitals and Arkansas Children’s Hospital.
Community
Hospitals Arkansas Children’s
Hospital Significance (P)
10.0 (SD 4.8) 10.7 (SD 5.1) 0.2533
116 (9.8) 101.5 (11.1) < 0.0001
SSDE (mGy) 26.4 (51.3) 9.7 (SD 6.9) 0.0007
Effective Dose (mSv) 13.0 (12.4) 6.6 (SD 5.9) < 0.0001
Patient Age (years)
kVp
58 • THE JOURNAL OF THE ARKANSAS MEDICAL SOCIETY
VOLUME 115