Open Journal of Radiology, 2013, 3, 124-129
http://dx.doi.org/10.4236/ojrad.2013.33020 Published Online September 2013 (http://www.scirp.org/journal/ojrad)
Three-Dimensional Rotational Angiography in Congenital
Heart Disease: Estimation of Radiation Exposure
Gloria Reinke1, Julia Halbfaß1, Sven Dittrich1, Rosemarie Banckwitz2, Christoph Köhler2,
Stephan Achenbach3, Oliver Rompel4, Martin Glöckler1*
1Department of Pediatric Cardiology, University Hospital Erlangen, Erlangen, Germany
2Siemens Medical Solutions, Forchheim, Germany
3Department of Cardiology, University Hospital Erlangen, Erlangen, Germany
4Division of Pediatric Radiology, Department of Radiology, University Hospital Erlangen, Erlangen, Germany
Received June 1, 2013; revised July 1, 2013; accepted July 9, 2013
Copyright © 2013 Gloria Reinke et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Objectives: There is an increasing use of three-dimensional rotational angiography (3D-RA) during catheterization of
congenital heart disease. Dose-area-product (DAP) measured by the angiography system and computed-tomography
dose index (CTDI) do not appear practical for dose assessment. Hence, we performed real dose measurements in an-
thropomorphic phantoms. Methods: Three different anthropomorphic phantoms (10 kg, 19 kg and 73 kg bodyweight)
equipped with thermoluminescent dosimeters (TLD) were used. We used a typical standard diagnostic program and a
low-dose program. The effective dose (ED) was calculated according to the International Commission on Radiological
Protection (ICRP) 103. The 3D distribution of radiation in the body was assessed. Results: ED for the male 10 kg
phantom was 0.192 mSv in the diagnostic program and 0.050 mSv (male) in the low-dose program. The 19 kg phantom
received an ED of 0.205 mSv (male) in the diagnostic program. In the low-dose program the ED reached 0.058 mSv
(male). The male adult 73 kg phantom was exposed with an ED of 0.730 mSv in the diagnostic program and 0.282 mSv
in the low-dose program. ED for the female phantoms was slightly higher for both acquisition-programs. Dose distribu-
tion was inhomogeneous with a dose maximum in the esophageal region behind the heart, whereas in the brain, intes-
tine and gonads we found nearly no radiation. Conclusions: 3D-RA imaging in the interventional catheter laboratory is
possible with an effective dose lower than 1 mSv. With its potential to reduce fluoroscopic time and the number of con-
trol angiographies in catheterization and intervention in complex anatomy, it can decrease the radiation dose.
Keywords: Effective Dose; Radiation Exposure; Anthropomorphic Phantom; Rotational Angiography
1. Introduction
The emerging technique of three-dimensional rotational
angiography (3D-RA) in congenital heart disease has a
high impact on the workflow of pediatric cardiologists.
The 3D-RA is a flat-detector computer tomography (FD-
CT) with continuous contrast admission in the volume of
interest (VOI) during a typical acquisition time of 5 sec.
The flat-detector is mounted on the c-arm of the angio-
graphy-system and moves once over 180˚ plus fan angle
around the patient. It provides accurate diagnostic infor-
mation exceeding conventional biplane angiography. The
main advantages of this new imaging modality include
the unlimited views on the high resolution three dimen-
sional (3D) vascular models for surgical planning and the
use of 3D models in interventions. These 3D models can
be used for 3D navigation in catheter interventions. There-
fore, models from high resolution 3D-RA as well as im-
ages from former magnetic resonance imaging (MRI) or
computed tomography (CT) studies are acquired. MRI
and CT images can be implemented by merging them
with an actual low-dose 3D-RA dataset [1-4].
Image acquisition for 3D-RA is performed by a single
run of the c-arm equipped with a flat detector around the
patient. These FD-CT scanners provide an irradiation
field in cranio-caudal z-direction of typically up to 200
mm. Consequently, resulting radiation doses should be
determinable in a reliable way. In standard CT, dosi-
metry is based upon the concept of the computed to-
mography dose index (CTDI) as a dose descriptor. In its
current definition it is characterized by an integration
*Corresponding author.
C
opyright © 2013 SciRes. OJRad

G. REINKE ET AL. 125
length of 100 mm. Therefore CTDI100 is inadequate for
dose assessment in wide beam CT-scanners such as C-
arm FD-CT [5]. Moreover, these scanners utilize the
so-called partial scanning (angular range < 360˚), which
is expected to cause inhomogeneous dose distribution
within the patient and consequently makes the use of
CTDI even more questionable. Kyriakou et al. emphasize
that the use of CTDI100 may strongly underestimate pa-
tient’s dose acquired during FD-CT examination. As a
practical solution they recommend Monte Carlo simula-
tion-based radiation dose calculations [5]. On the other
hand, dose estimations solely based on the dose-area pro-
duct (DAP) also have to be scrutinized critically, be-
cause the used conversion factors derive from single in-
cidence imaging and have never been validated for FD-
CT. This clearly leads to underestimation of dose asses-
sment, too [6]. To estimate the organ and the total dose
phantom measurements have to be performed in large
phantoms with respect to the large z-coverage. Therefore,
humanlike anthropomorphic phantoms equipped with
multiple thermoluminescent dosimeters (TLD) seem to
be a reliable method to estimate the effective dose (ED).
2. Methods
In our catheterization laboratory we exposed the phan-
toms to a biplane angiography system equipped with two
20 × 20 cm2 flat panel detectors (Axiom Artis, syn-
goDynaCT, Siemens Healthcare, Forchheim, Germany).
Two different imaging protocols were used: First, a di-
agnostic program (5sDRc) with 30 images per second,
scanning time 5 sec, a fixed tube voltage of 90 kV and
automatically adapted tube current. Second, a low-dose
program which is in use for registration of prior high
resolution datasets from MRI or CT. The low-dose pro-
gram (5sDR-L) also uses 30 images per second and a 5
second-scanning time but 0.2 mm copper filtration and a
tube voltage of 70 kV. To achieve enough radiation ex-
posure for the TLDs we always exposed the phantom
three times with the same program in the same position.
Three different anthropomorphic phantoms were exa-
mined:
1. A 10 kg model “Clifford” representing children with
an age of 0.5 - 3 years.
2. A 19 kg model “Braden” representing children with
an age of 3 - 7 years.
3. A 73 kg model “Alderson” representing an adult
person.
We exposed the Clifford- and the Braden-model se-
parately with the two different programs and in addition
separately with and without anti scatter grid in the diag-
nostic program. The adult Alderson model also under-
went both programs, always using the anti-scatter grid.
The models are composed of transversal slices with
2.5 cm thickness including drilled holes in which the
lithium fluoride TLDs were placed (TLD-100 rods, 1 × 1
× 6 mm; The Harshaw Chemical Company, Chrystal and
Electronics Products Department, Solon, Ohio, USA).
There are always 3 TLDs for one anatomic structure to
get an averaged dose value. For the male gonads we used
sachets.
Before starting the irradiation the TLDs were cali-
brated. The TLDs of one series were always used to-
gether for a measuring cycle to guarantee equal quality.
Thus, they were irradiated, read and regenerated. There-
fore, they were divided in two fractions: fraction 1 was
used for the calibration and for the determination of the
calibration factor. It was irradiated by a definitive dose of
1Gy. Fraction 2 then underwent the real examination
after the calibration factor had been transferred to the
TLDs.
The readout was performed according to a standard
procedure [7]. The organ doses result from the mean value
of 3 TLDs. To estimate the organ equivalent dose the di-
rectly and indirectly weighted organ dose were added.
The effective dose was calculated by summarizing the
weighted organ doses according to the guidelines of the
International Commission on Radiological Protection
(ICRP) 103 [8].
To illustrate the measured organ doses, we created de-
lineations with slices in frontal, sagittal and transversal
direction. To visualize the amount and the distribution of
the organ doses a color scale represented in spectral col-
ors was designed with the dimension of 0 mSv to 8.5
mSv. Then the organs and tissues were dyed referring to
the dose values on the scale (image editing software
GIMP 2.1.11; GNU imaging manipulation program; Free
Software Foundation, Boston, MA USA).
3. Results
We found an inhomogeneous dose distribution. The
highest dose was registered anterior the spine behind the
heart, measured by TLDs in the esophagus (Alderson:
8.43 mSv). In all three phantoms the maximal organ dose
is located in the thorax (Alderson: esophagus, Braden:
left lung, Clifford: right lung). Concerning the head and
abdominal region, especially the brain (≤0.06 mSv), the
intestine (≤0.04 mSv), the urinary bladder (≤0.01 mSv)
and the gonads (≤0.02 mSv), we detected only little ra-
diation. No radiation measured by the testis sachets. We
noticed higher dose values in the posterior part of the
body than in the front (lung, esophagus > thymus, ster-
num). There was a slightly higher dose registered on the
patient’s left side compared to the right in the Alderson
phantom. Figure 1 illustrates the organ doses and their
distribution in the phantom bodies.
The effective gender-specific dose of the different pro-
grams and phantoms are represented in Table 1. De-
pending on the acquisition-program, the phantom and

G. REINKE ET AL. 126
(a) (b) (c)
Figure 1. (a) “Clifford”, 10 kg bodyweight anthropomorphic model representing children with an age of 0.5 - 3 years. (b)
“Braden”, 19 kg bodyweight anthr opomorphic model representing children with an age of 3 - 7 years. (c) “Alderson”, 73 kg
bodyweight anthropomorphic model representing an adult. Slices in frontal (A), sagittal (B) and transversal direction(C) are
shown to visualize the amount and the distribution of the organ doses. The color scale on the left side (D) represents the di-
mension of 0 mSv to 8.5 mSv in spectral colors. The organs and tissues are dyed referring to the dose values on the scale.
Table 1. Effective dose.
the gender the effective whole-body dose ranged from
0.05 mSv (male Clifford phantom; Low dose program) to
0.73 mSv (adult Alderson phantom; diagnostic program
with grid). The effective dose values of the female phan-
toms were higher for all acquisition-programs.
Programs
5sDRc without
grid 5sDRc with grid
Low Dose
5sDR-L 0.2Cu
(with grid)
male femalemale female male female
Clifford 0.1920.2720.219 0.326 0.0500.072
Braden 0.2050.2720.315 0.392 0.0580.068
Alderson 0.730 0.282
Table 2 shows the organ equivalent doses (ICRP103)
of the different programs for all three models in mSv.
4. Discussion
Since there is a special responsibility towards children’s
health, radiation dose in pediatric radiology has to be
reduced to a minimum. Therefore the technical progress
developing new X-ray systems are one of the major cri-
teria. As far as we know only few studies exist which
examined radiation exposure using 3D-RA in pediatric
catheter laboratories [1,2]. Because CTDI and DAP are
neither practicable nor reliable to estimate effective dose
[5,6,9] we equipped three different anthropomorphic
phantoms with several TLDs to determine organ and
effective dose as well as dose distribution in their bodies
depending on program, phantom and gender.
a. The effective dose according to ICRP103 separate for each program,
phantom and gender. The values are given in milli Sievert (mSv). Clifford
and Braden are hermaphrodite, Alderson is a male phantom. Alderson did
not undergo the 5sDRc diagnostic program without grid.
of 6.6 ± 1.8 mSv according to ICRP103 using 3D-RA
[10,11]. However, we did not include patient individual
factors, especially the use of contrast dye, which could
increase radiation dose. However, Wielandts et al. (2010)
only examined adult computer-simulated models whereas
we performed real dose measurement in different sized
phantoms. This is a more reliable method to evaluate
radiation dose and leads to more exact results than simu-
lated calculations. Moreover, Wielandts et al. (2010)
performed image acquisition with a dose of 0.54 μGy per
frame (60 frames per second) which is a higher mean
dose compared to ours (0.36 μGy per image in the diag-
nostic programs, 0.1 μGy in the low dose program; al-
ways 30 images per second). The higher dose and frame
rate could possibly explain the elevated EDs measured
y Wielandts et al. Another publication by Glatz et al.
The lowest effective dose was achieved using the low
dose program for all phantoms, followed by the diagnos-
tic program without grid. The highest effective dose
emerged using the diagnostic program with grid. Our
calculated effective doses ranged from 0.05 mSv up to
0.73 mSv. Compared to Wielandts et al. (2010) our re-
sults show lower doses [10]. They estimated a mean ef-
fective dose in computer-simulated phantoms (PCXMC) b

G. REINKE ET AL. 127
Table 2. Organ equivalent doses.
Clifford Braden Alderson
organ/
5sDRc
without grid
5sDRc with
Low Dose
5sDRc
without grid
5sDRc with
Low Dose
5sDRc with
Dose
tissue grid
5sDR-L
0.2Cu (with
grid)
grid
5sDR-L
0.2Cu (with
grid)
grid
Low
5sDR-L
0.2Cu (with
grid)
brain 0.04 0.03 0.01 0.02 0.00 0.00 0.00 0.01
thyroid 0.75 0.33 0.19 0.06 0.08 0.03 0.08 0.01
lung 0.87 1.19 0.23 0.89 1.28 0.23 2.87 1.21
red bone rrow
0 0.
s
adrd
s
urinder
remairgans
ma0.09 0.12 0.02 0.31 0.47 0.09 1.29 0.51
esophagus 0.78 0.60 0.20 1.06 1.50 0.32 3.86 1.24
thymus 0.87 1.10 0.22 0.90 1.25 0.25 1.03 0.45
breast 0.65 0.88 0.19 0.64 0.83 0.15 - -
liver 0.03 0.03 0.01 0.03 0.08 0.00 .1706
tomach0.03 0.04 0.01 0.02 0.08 0.00 0.18 0.07
spleen 0.06 0.10 0.02 0.02 0.06 0.00 0.11 0.02
enal glan0.07 0.09 0.02 0.03 0.06 0.00 0.19 0.07
pancreas 0.05 0.12 0.02 0.01 0.08 0.00 0.16 0.05
left kidney0.03 0.06 0.00 0.02 0.03 0.00 0.09 0.05
mall intestine0.02 0.03 0.01 0.00 0.02 0.00 0.00 0.00
colon 0.01 0.02 0.00 0.00 0.04 0.00 0.01 0.00
ovary 002 0.02 0.00 0.00 0.00 0.00 0.00 0.00
testis 0.00 0.00 0.00 0.00 0.00 0.07 0.00 0.00
uterus 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00
ary blad0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00
bone surface 0.05 0.17 0.02 0.00 0.01 0.00 0.99 0.38
skin 0.05 0.17 0.02 0.00 0.00 0.00 0.98 0.38
nder o0.15 0.20 0.04 0.12 0.19 0.03 0.20 0.07
a.the len. The we organ equt dose is giilli Sievor the rogramch phantomrson
.5 mSv program) than in the children phantoms Braden (EDmax
Organs are listed in ft columightedivalenven in mert (mSv) fdifferent ps of ea. Alde
has no values for the breast because it represents a male phantom.
0) reported effective doses <0.1 mSv to 3(201
using 3D-RA [1]. They also used phantom testing with a
dose of 0.17 μGy per frame (60 frames per second), but
calculated the radiation dose leading to less correct val-
ues than measured in our direct dose assessment.
With the use of the anti-scatter grid the dose increases
according to Partridge et al. (2006) and Justino et al.
(2006) [12,13]. Indeed, we also registered higher radia-
tion doses when using the program with grid. Neverthe-
less, we found the difference in radiation doses between
the diagnostic program with and without grid is minimal.
Studies examining the relation between phantom size
(age) and radiation dose for 3D-RA are scarce. Increased
ED with decreasing age of the patients is reported for
biplane catheterization units [14]. Our results are com-
parable to those published by Glatz et al. (2010): total
effective dose increased with older age [1]. We detected
higher ED in the adult phantom (0.730 mSv in the diag-
nostic program with grid, 0.282 mSv in the low dose
0.392 mSv) and Clifford (EDmax 0.326 mSv) both in the
diagnostic program with grid. We also observed a higher
radiation dose in the adult phantom (organ dose maxi-
mum 8.43 mSv in the esophagus) than in the children
phantoms (organ dose maximum Braden: 1.86 mSv left
lung; Clifford: 1.69 mSv right lung) for all acquisi-
tion-programs. Comparing our organ doses to those es-
timated by Wielandts et al. (2010), most of the organ
doses are stated to be a lot higher in their study [10]. Or-
gans such as the lungs, the esophagus, the breasts and the
thymus show higher radiation doses (up to 23.35 mGy)
in their study [10], whereas organs such as the brain, the
urinary bladder and the gonads are evaluated as low
(<0.03 mGy) as our organ dose values (<0.04 mSv, Al-
derson even <0.01 mSv). The advantage of our dose as-
sessment based on real phantom measurement compared
to the computer-simulated method has already been men-
tioned. Moreover, our phantoms were equipped with an

G. REINKE ET AL. 128
extraordinarily large number of accurately calibrated
TLDs (up to 141 TLDs). In addition, we always used
three TLDs for one anatomic structure to guarantee a
high quality of our measurements and to get an averaged
dose value.
In our current study we demonstrated an inhomoge-
neous dose distribution. The highest doses were meas-
ured in the thorax region and the posterior parts of the
body where the X-ray tube rotates. This is similar to the
re
0.04 mSv) compared t
ad
erable to
dergoing one of the exam-
factors, such as the BMI, t
onal pediatric catheter laboratory can be per-
formed with an effective dose less than 1 mSv. The tech-
is imaging method leads to a reduce-
c CT Imaging in the Cardiac
Catheterization Laboratory for Congenital Heart Di-
sease,” JACC g, Vol. 3, No. 11,
2010, pp. 1149g.2010.09.011
sults shown by Kalender and Kyriakou et al. (2007)
and Kyriakou et al. (2008) [5,6]. In the evaluation of our
organ doses visualized by the phantom drawings, some
dose values seem to differ from the expected distribution:
In the fourth transversal section of phantom Clifford we
measured a higher dose in both lungs than in the eso-
phagus. In the third transversal section of the Alderson
phantom a higher dose was registered in the thymus than
in the lungs. Reasons for these aberrations could be the
attenuation of the radiation by bones and the spine, the
particular wave angle and the radiation sensitivity of the
organ, respectively. These observations can not be found
in computer-simulated phantom studies. Therefore, an-
thropomorphic phantoms as we used are necessary to
notice scattered radiation. The female phantoms received
a slightly higher radiation dose compared to the male
ones which is due to the breast tissue and its high con-
version factor [10,15,16].
Nearly no radiation was measured in the brain with all
programs in each phantom. However, the children phan-
toms, especially the smallest, received a slightly in-
creased brain dose (up too the
ult phantom. This observation may be important since
small children still have a weak skullcap. Consequently,
it could be assumed that there is even more radiation
exposure to the brain than was measured in our study.
3D-RA leads to an increase of the skin dose due to its
rotation around the patient compared to fixed tubes. Even
though the region of interest is still the heart, the skin
dose is no longer concentrated on the thoracic skin region
but evenly spread over the whole skin surface. In conse-
quence, less radiation injuries can be observed.
5. Study Limitations
Since we exposed anthropomorphic phantoms of normal
weight in this study, the results are only transf
normal weighted persons un
ined programs. Individual he
application of contrast dye, the radiation sensitivity and
the DNA repair capacity were not taken into account
[17-20].
6. Conclusion
In our study we showed that 3D-RA imaging in the
interventi
nical progress in th
tion of fluoroscopic time resulting in a reduced radiation
dose due to high image quality and decreasing number of
control angiographies. However, due to our responsibil-
ity towards children’s health, further methods to reduce
radiation in children during diagnostic and interventional
procedures need to be found. Further studies, especially
biological dose assessments are necessary to consider
individual factors and to receive more information about
the direct effects of irradiation in children’s bodies dur-
ing diagnostic procedures and interventions in the pediat-
ric catheterization laboratory.
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