1. Running head: RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 1
Radiation Safety for Adults in Medical Imaging
Craig S. Peters
Boise State University

2. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 2
Radiation Safety for Adults in Medical Imaging
Craig S. Peters
This paper examines the topic, “Radiation Safety for Adults in Medical Imaging”, by
discussing different findings from several studies. Different people have varying sensitivity to
radiation than others. At present, there is no definitive way to determine one’s sensitivity to
radiation. Doudenkova & Bélisle (2016) researched that as much as 50% of radiological
examinations potentially were unnecessary and surmised that regulation of radiological practices
would be highly impacted by information and patient consent. Consensus regarding the nature
and need of patient consent prior to ionizing radiation exposure is absent.
This paper will first provide a brief background on how radiation is an essential part of
our lives. Next, a “General Conclusions from Research” section will highlight what causes
overutilization of imaging, what happens within the health delivery system that leads to this
overutilization of imaging, and the efficacy of programs aimed at reducing unnecessary imaging.
Finally, this paper proposes a study to compare the benefits of, versus the hazards of, radiation
exposure to older adults in medical imaging. Radiation exposure is unavoidable in medical
imaging for diagnostic purposes. A significant gap exists regarding agreement on what is, and is
not, an acceptable level of radiation exposure to patients in this environment.
Background on Research on Topic
The study designs and study methods referenced in this paper include a Phase-I trial, a
prospective cohort study, an epidemiologic study data review, an aggregated billing data review,
and a prospective, interdisciplinary study. Radiation is all around us. Gamma radiation is a
naturally occurring source of radiation produced by the Sun, known as sunlight. Sunlight is
composed of electromagnetic waves ranging from infrared (IR) to ultraviolet rays (UV), and

3. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 3
includes visible light waves, which are between IR and UV in the electromagnetic spectrum.
The Sun produces other forms of radiation.
As a comparison, an accumulation dose level of 0.2 Gy takes approximately two
centuries of exposure to naturally occurring gamma radiation. Numerous studies have been
conducted on patients in the 65-years-old and older age group. Several studies have been
conducted on pediatric patients. As this research was conducted, an overwhelming gap between
the pediatric age group and the geriatric age group was evident.
Accumulated radiation dose levels found in the human body received during diagnostic
medical imaging has been studied in populations of adults, generally aged 65 years and older.
On the opposite end of that scale, accumulated radiation dose levels found in the human body
received during diagnostic medical imaging has been studied in pediatrics. Studies of radiation
dose levels in “Middle-aged” adults, (45 – 64 years of age), are lacking. Radiation safety
concerns gained popularity in recent years due to an increase in cancer-related cases among
adults and children. These concerns fall into categories related to General Radiation Safety,
Computed Tomography (CT), Nuclear Medicine, and Fluoroscopy (Imaging Modalities, 2016).
According to Schauer and Linton (2009), a large source of radiation exposure to
American patients, which almost equals the radiation amount received from background
radiation sources, is radiation from medical imaging procedures. Computed tomography is the
largest source of medical radiation exposure (Schauer and Linton, 2009). Computed tomography
benefits are many and far exceed the risks when appropriately ordered with the lowest radiation
dosage utilized to obtain the best image quality (Schauer and Linton, 2009).
The top three sources of medical radiation exposure are, computed tomography, nuclear
medicine and fluoroscopy. Computed tomography is the largest source of medical radiation

4. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 4
exposure (Computed Tomography, 2016). Nuclear medicine is the second largest source of
medical radiation exposure after computed tomography (Nuclear Medicine, 2016). Fluoroscopy
is the third largest source of medical radiation exposure behind computed tomography and
nuclear medicine (Fluoroscopy, 2016).
Computed tomography (CT) is used, in part, when cranial images are needed. Nuclear
medicine is used in targeting specific areas, or groups, of tissues (Imaging Modalities, 2016).
For example, radioactive “seeds” can be implanted in patients for targeting prostatic cancer
tissue. Peters (2013) observed approximately 20 fluoroscopy procedures. Peters (2013)
surmised fluoroscopy was used in “active” examinations where the patient swallows a contrast
material while the fluoroscope monitors, in real time, the patient’s ability to move the contrast
material from the mouth to the stomach. The entire path is visible and the muscles used to
swallow the contrast material are monitored for proper function, possible herniation, and other
damage that would cause the patient difficulty during swallowing (C. Peters, personal
communication, 2013).
General Conclusions from Research
Numerous studies confirm lower tube current settings reduce the radiation dose level a
patient receives during a diagnostic medical imaging encounter. According to Linet, et al.,
(2012), technological improvements, including automatic tube current modulation (which
modifies the dose depending on the thickness of the anatomic site to be examined) and noise
reduction filters, further reduces the radiation doses from CT. Generally, this does not affect the
quality and clarity of the diagnostic image.
Variables that do affect the use of a reduced tube setting, and that are outside the control
of radiologists and radiology technicians, have been previously identified in numerous studies,

5. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 5
include a patient’s age, pregnancy status in females, and a patient’s physical size or anatomical
part thickness (Linet, et al., 2012). The further the emitted diagnostic medical imaging radiation,
or incident photons, needs to travel, the greater the intensity of radiation is required to penetrate
the additional tissue in order for one photon to reach the image intensifier (Duncan and
Panahipour, 2014).
Synthesized Finding #1: Reducing Tube Current Reduces Radiation Dose
Reducing the tube current setting is a primary method to reducing the accumulated
radiation dose level received by a patient during a diagnostic medical imaging encounter.
Manssor, et al., (2015) determined reducing the tube current value setting is the best method for
reducing radiation dose levels received by the patient. For example, changing the tube current
setting from 140 kVp to 120 kVp equates to, for a majority of abdominal CT scan patients, a
reduction of 20% – 40% in radiation dose levels.
Linet, et al., (2012), identified referring medical practitioners needed guidance to
determine whether an imaging study was needed. If an imaging study was required, determining
which imaging study type, in order to obtain the necessary clinical information at the lowest
achievable radiation dose, was paramount. An inappropriate imaging study, conducted at too
high a setting, produces useless diagnostic images, while increasing the accumulated radiation
dose level in the patient. Moloney, et al., (2016) identified one strategy available for radiation
dose optimization included reducing the amount of phases acquired. Another strategy identified
used automated exposure control processes rather than fixed tube current processes. Poor patient
centering, which significantly increases radiation dose levels, was also noted. As such, centering
the patient accurately reduces the overall radiation dose level received during the diagnostic
medical imaging process.

6. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 6
Linet, et al., (2012) recommended using as few phases as possible, with one phase being
preferred, during each medical imaging run, whether or not contrast was used, as well as
including some technological improvements now available. Two of the available technological
improvements include: 1) noise reduction filters, and 2) automatic tube current modulation. This
automatically modifies the tube current setting according to the thickness of the anatomic site
examined.
Synthesized Finding # 2: Patient Thickness Impacts Patient Radiation Dose
As patient thickness increases, higher radiation energies are needed for one photon to
reach the image detector (Duncan and Panahipour, 2014). This seems counter-intuitive to the
previous finding; however, it is a necessary compromise in order to obtain a viable image for
diagnostic purposes. Accumulated radiation dose levels increase with each medical imaging
event. Multiple images at lower tube current settings increase a patient’s accumulated radiation
dose level faster than a single image taken at a slightly higher tube current setting. Huang and
Jones, (2012) noted that with a tube current setting of 60 kV, a 3.5 cm increase in patient
thickness effectively doubles the number of X-rays required to penetrate the patient and reach the
image intensifier.
Linet, et al., (2012) noted that some technological improvements, including automatic
tube current modulation and noise reduction filters, improves images and further reduces the
doses from CT. Duncan and Panahipour (2014) formulated a tissue thickness of five centimeters
required three incident photons to ensure one photon reached the image detector; 66% of these
incident photons were absorbed or scattered by the patient’s tissue. Five centimeters in thickness
is comparable to the diameter of a participant’s wrist. In comparison, Duncan and Panahipour
(2014) formulated a tissue thickness of 30 centimeters required 1,000 incident photons to ensure

7. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 7
one photon reached the image detector; 99.9% of these incident photons were absorbed or
scattered by the patient’s tissue. Thirty centimeters in thickness is comparable to the diameter of
an obese participant’s waist.
Synthesized Finding # 3: Cardiac CTA use Dramatically Increased
During the previous ten years or more, cardiac computed tomographic angiography
(CTA) use has increased dramatically and is used to manage numerous cardiac conditions.
Nguyen, et al., (2015) determined that, in this procedure and due to cardiac motion, gating was
required to compensate for this motion, and the procedure’s resultant radiation exposure from
cardiac CTA was significant. A single cardiac CTA exposed patients to radiation dose levels
equivalent to receiving 150 or more chest x-rays (Nguyen, et al., 2015).
Aparicio, et al., (2014) observed that patients with biopsy-proven, unresectable pancreatic
adenocarcinoma, (based on vascular invasion detected by computed tomography), were treated
with gemcitabine, (300 mg/m2 i.v. weekly x5 weeks), concurrently with radiation therapy, (45
Gy in 25 fractions), and sorafenib, (escalated doses in a 3+3 design, from 200 to 800 mg/day).
At this stage of the study, patient thickness was not a primary consideration. Following
standard protocols and procedures for radiation therapy currently in use today, tube current levels
would require proper adjustments due to patient thickness in order to properly acquire medical
images for diagnostic and study-related evaluation purposes. Treatments were palliative due to
the twelve patients included in this study, all greater than 18 years of age, having a diagnosis of
pancreatic adenocarcinoma (Aparicio, et al., 2014).
Arasu, et al., (2015) identified that, in the emergency department, imaging usage had
increased significantly as the primary method for acute illness and trauma diagnosis. Helical
multidetector computed tomography is the preferred technology for imaging in emergency

8. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 8
departments today due to its speed, image resolution, and prevalence in emergency departments.
Arasu, et al., (2015) found the increase in emergency department radiology usage was criticized
as a replacement for the physical and other, less costly diagnostic examinations. Another
criticism was due to increased radiation exposure, and enabling defensive medicine practices,
despite the data supporting the improved diagnostic accuracy of these imaging procedures
(Arasu, et al., 2015). To help curb overutilization, evidenced-based practice guidelines and
increased awareness of radiation risk was introduced through the Image Wisely campaign
(Arasu, et al., 2015).
Need for Further Research
Nguyen, et al., (2015) determined that, to date, no human studies conducted have
measured the radiation exposure effects from medical imaging on changes in in vivo gene
expression. This gene expression change is significantly up-regulated after radiation therapy
(Nguyen, et al., 2015). A single cardiac CTA exposes patients to radiation levels equal to 150 or
more chest x-rays (Nguyen, et al., 2015). Expansive utilization of this procedure raises
significant concern between physicians and patients regarding the harmful effects related to
cardiac CTA radiation exposure (Nguyen, et al., 2015).
One can infer healthcare professionals and researchers agree, to some extent, that
research data and information is severely lacking on the subject of an acceptable, safe radiation
dose level for adults in diagnostic medical imaging. By measuring, as accurately as possible
with current and developing technologies, and monitoring radiation dose levels earlier in life, as
one ages, a reduction in accumulated radiation dose level-induced cancers could be seen. Rather
than waiting until age 65 to become concerned with an individuals accumulated radiation dose

9. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 9
level from diagnostic medical imaging, closely monitoring those same individuals’ radiation
dose levels prior to middle-age could lead to a better quality of life.
This study is feasible and realistic due to the current age range of patients currently
involved in similar studies. To identify possible participants, a request for volunteers could be
made at the time a diagnostic medical imaging procedure is conducted. A prospective cohort
study of these middle-aged patients who received diagnostic medical imaging procedures in
medical centers in the United States would close the gap that currently exists. The estimated
median blood radiation exposure is determined by using the ImPACT Computed Tomography
Patient Dosimetry Calculator spreadsheet currently available and used in London, England.
Biomarkers of deoxynucleic acid damage and apoptosis would be measured by flow
cytometry, whole genome sequencing, and single cell polymerase chain reaction from whole-
blood samples taken from participants to establish their baseline values. Additional whole-blood
samples would be taken multiple times throughout the study period. These participants would
then be asked to provide additional data at the time the blood sample was given. Medical
professionals would obtain biometrics from the participants to include weight, height, age, race,
procedure performed, body mass index (BMI), and blood type using standard protocols. Privacy
concerns of the participants would be addressed by fully complying with all HIPAA privacy
rules and guidelines in place at the time of the study commencement.
I propose a longitudinal study of 15 to 20 years on accumulated radiation dose level study
be conducted on 500,000 middle-aged adult males and 500,000 middle-aged adult females in the
United States. This study of middle-aged, (45-years-old to 64-years-old), females and males,
would close the gap between pediatric and geriatric studies currently in existence. This study
would establish a currently unknown baseline radiation dose level currently experienced by, but

10. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 10
unknown to, residents of all U.S. states. The total number of participants from each State could
be based upon a percentage of the current State population, as determined by the most recent
U.S. Census data on file.
This study would include several limitations. First, the technology available at this time
is not advanced enough to accurately measure and monitor the continual accumulation of
radiation dose levels associated with diagnostic medical imaging when future imaging
procedures are received. Second, current technologies can only measure and monitor the
additional damage to blood cells and DNA. Third, the rate of DNA decay and damage is not
measurable on a microcellular level. Fourth, use of an electron microscope could potentially
allow measurement and monitoring of DNA decay and damage, but the cost per patient per use
would be astronomical and is not fiscally feasible at this stage of the study. Fifth, x-ray image
intensifiers convert transmitted x-rays into an image. This occurs within the input phosphor of
the image intensifier by converting the x-ray photons to light photons. Once these light photons
reach the photocathode, they are converted to photoelectrons. Image intensifiers currently
available cannot be modified to use less radiation. Research into a new technology device that
can accept lower emissions from reduced tube settings is needed. This new technology device
would replace, or possibly augment, the image intensifiers currently available.
In closing, healthcare professionals and researchers agree a reduction in accumulated
radiation dose levels from diagnostic medical imaging is necessary. Conducting studies of
patients exposed to diagnostic medical imaging helps monitor their accumulated radiation dose
levels. The majority of studies of this type currently available do not occur until an individual
reaches a minimum of 65 years of age.

11. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 11
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13. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 13
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(2016). Cumulative radiation exposure from diagnostic imaging in intensive care unit
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14. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 14
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15. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 15
Appendix A – Study Analysis Table
Citation
Information
Aparicio, J., García-Mora, C.,
Martín, M., Petriz, M., Feliu, J.,
Sánchez-Santos, M., … Maurel,
J. (2014). A Phase I, Dose-
Finding Study of Sorafenib in
Combination with Gemcitabine
and Radiation Therapy in
Patients with Unresectable
Pancreatic Adenocarcinoma: A
Grupo Español
Multidisciplinario en Cáncer
Digestivo (GEMCAD) Study.
PLoS ONE, 9(1), e82209.
http://doi.org/10.1371/journal.po
ne.0082209
Arasu, V., Abujudeh, H.,
Biddinger, P., Noble, V.,
Halpern, E., Thrall, J., &
Novelline, R. (2015). Diagnostic
Emergency Imaging Utilization
at an Academic Trauma Center
From 1996 to 2012. Journal of
the American College of
Radiology, 12, 5, 467-474.
Linet, M., Slovis, T., Miller, D.,
Kleinerman, R., Lee, C.,
Rajaraman, P., & Berrington de
Gonzalez, A. (2012). Cancer
risks associated with external
radiation from diagnostic
imaging procedures. CA: A
Cancer Journal for Clinicians,
62(2), 75.
Permalink https://www-ncbi-nlm-nih-
gov.libproxy.boisestate.edu/pmc/
articles/PMC3886976/
http://www.sciencedirect.com.lib
proxy.boisestate.edu/science/arti
cle/pii/S1546144014007881
http://onlinelibrary.wiley.com.lib
proxy.boisestate.edu/doi/10.3322
/caac.21132/full
Purpose Evaluate the safety profileand
recommended dose of these
medications used with
concomitant radiation therapy.
Review emergency radiology
volume growth rate at an urban
academic trauma center, 1996
to 2012.
Reduce future projected cancers
from diagnostic procedures and
develop electronic lifetime
records of imaging procedures.
Study
Design
A phaseI–II multicenter, non-
randomized clinical trial.
Aggregated billing data collected
from 1996 to 2012 were
reviewed.
An analysis of patient records
from multiple studies were
reviewed.
Participants Patients’ proven diagnosis of
pancreatic adenocarcinoma were
included in thestudy if they
presented a locally advanced
disease, or metastaticdisease, or
unresectable local relapse. Other
inclusion criteria were age >18
years, written informed consent,
measurable disease.
Human subjects research.
Aggregated billing data from
1,458,230 diagnostic radiologic
examinations were reviewed in
this study.
Patient records from
epidemiologic studies of medical
and other radiation sources and
cancer risks, and dose trends
from diagnostic procedures.
Experimental studies records
were reviewed to project risks
from current imaging procedures.
Data
Collection
Pretreatment evaluation
comprised symptomassessment,
physicalexamination,
hematology, serum biochemistry,
CA 19.9 levels, coagulation tests,
EKG, tumor measurements by
means of multidetector or spiral
computed tomography (CT)
scans, endoscopic ultrasound
(EUS), and other symptom-
guided explorations when
needed.
Aggregated billing data from
diagnostic radiologic
examinations ordered in a
tertiary care, academic teaching
hospitalwith approximately 900
beds in an urban setting at a
Level I adult, pediatric, and burn
trauma center emergency
department (ED) were reviewed.
Records review of approximately
2500 atomic bomb survivors who
were in utero at the time of the
bombings. Morethan 105,000
records from The Life Span Study
of atomic bomb survivors
(including 30,000 children), were
reviewed.
Results Twelve patients with
unresectable, locally advanced or
metastatic pancreatic
adenocarcinoma were included
between 12/07 and 09/09,
median patient age was 59 years,
with the age range of 39 – 69
years, seven female patients. All
patients were evaluable for
response.
ED patient visits grew annually.
ED visit imaging increased from
1996 to 2003. ED physician
ultrasound data showed growth
from 2002 to 2011. CT and MRI
decreased from 2004 to 2012. No
change in ultrasound and x-ray
use during the study period.
Totalsolid cancer risk shows
linear dose response. Significant
radiation–associated excesses
seen for most solid tumors.
Dose-responseexcess persisted
for several decades for ALL and
CML, but peaked at 10 years
after the bombings for AML.

16. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 16
Weaknesses There are no previous published
clinical data of the combination
of sorafenib, radiotherapy and
gemcitabine in pancreatic ductal
adenocarcinoma (PDAC).
Individual patient cumulative
radiation dosages were not
calculated during this study.
ACR Appropriateness Criteria
have been criticized for not
utilizing the rigorous
methodology of the evidence-
based medicine approach for
radiology.
Strengths Preliminary clinical data shows
responserate activity by RECIST
criteria (16%), by PERCIST
criteria (100%), and local control
(75%).
The amount of patient data
analyzed during this study is
huge when compared to other
studies of this type.
Patient data analyzed in this
study exceeded 105,000 records.
Data from multiple studies were
reviewed and analyzed during
this study.
Relevance
to Topic
Radiation therapy and drug
therapy werecombined to treat
patients with pancreatic cancer.
ED patient visit data was
analyzed showing how prevalent
medical imaging use is in an
emergent situation and
environment.
Radiation exposure amounts and
dosing levels in adults and
children were identified, tracked,
and documented during this
study.
Citation
Information
Moloney, F., Fama, D., Twomey,
M., O’Leary, R., Houlihane, C.,
Murphy, K., … Maher, M.
(2016). Cumulative radiation
exposure from diagnostic imaging
in intensive care unit patients.
World Journal of Radiology, 8(4),
419–427.
http://doi.org/10.4329/wjr.v8.i4.4
19
Nguyen, P., Lee, W., Li, Y.,
Hong, W., Hu, S., Chan, C., & ...
Wu, J. (2015). Assessment of the
Radiation Effects of Cardiac CT
Angiography Using Protein and
Genetic Biomarkers. JACC.
Cardiovascular Imaging, 8(8),
873-884.
doi:10.1016/j.jcmg.2015.04.016
Manssor, E., Abuderman, A.,
Osman, S., Alenezi, S.,
Almehemeid, S., Babikir, E., &
... Sulieman, A. (2015).
Radiation doses in chest,
abdomen and pelvis CT
procedures. Radiation
Protection Dosimetry, 165(1-4),
194-198.
doi:10.1093/rpd/ncv107
Permalink https://www-ncbi-nlm-nih-
gov.libproxy.boisestate.edu/pmc/a
rticles/PMC4840200/
http://www.sciencedirect.com.li
bproxy.boisestate.edu/science/art
icle/pii/S1936878X15003770?np
=y
https://rpd-oxfordjournals-
org.libproxy.boisestate.edu/cont
ent/165/1-4/194
Purpose To quantify cumulative effective
dose of intensive care unit (ICU)
patients attributableto diagnostic
imaging.
Evaluate whether radiation
exposure from cardiac computed
tomographic angiography (CTA)
damages deoxyribonucleic acid
(DNA).
Determine patient optimaldoses
required to reduce radiation risk
due to unnecessary radiation
exposure.
Study
Design
A prospective, interdisciplinary
study.
Prospectivecohort study in
patients undergoing cardiac
computed tomographic
angiography.
A retrospective analysis was
done on the CT dose reports.
Participants Human subjects research.
Of patients admitted to a general
Intensive Care Unit over a one-
year period, a totalof 2737
studies were performed on 421
adult patients and a totalof 23
pediatric patients were selected
for subgroup analysis.
Sixty-seven adult patients, aged
18 years and older, who
underwent a clinically indicated
cardiac CTA between January
2012 and December 2013 were
recruited from Stanford Hospital
(Stanford, California) and the
Veterans Affairs Palo Alto
Health Care System(Palo Alto,
California).
Fifty-onepatients (24 men, 47 %
and 27 women, 53 %), aged 16-
85, had CT scans of thechest,
abdomen and pelvis (trunk) with
contrast media in one exam to
rule out metastasis after
confirmed primary tumor.
Data
Collection
Age, gender, date of ICU
admission, primary reason for
ICU admission, APACHEII
score, length of stay, number of
days intubated, date of death or
discharge, and re-admission data
was collected on all patients
admitted over a 1-year period.
Methods utilized in this study
include: Patients and Diagnostic
Imaging Studies, Estimation of
Radiation Dose, Sample
Collection for in Vivo Studies,
Proteomic Biomarker Assays,
Genomic Biomarker Assays, and
Statistical Analysis during the
two-year study period.
Patients’ weight, height and
body mass index (BMI) were
analyzed. Exposure parameters
were collected using a patient
dose survey form prepared for
collecting kVp, mAs, CTDIvol,
DLP, scan pitch, slice thickness,
number of slices and field of
view (FOV) values.

17. RADIATION SAFETY FOR ADULTS IN MEDICAL IMAGING 17
Results Cumulative effective radiation
dose (CED) was 1704
millisieverts (mSv) with a median
CED of 1.5 mSv (IQR 0.04-6.6
mSv). TotalCED in pediatric
patients was 74.6 mSv with a
median CED of 0.07 mSv (IQR
0.01-4.7 mSv) IQR=Interquartile
range.
Of the82 eligible patients, 67
underwent biomarker analysis
before and after exposure to
cardiac CTA. Seventy-percent of
patients (36 of 57) had ≥ 2%
increase in phosphorylation of at
least 1 DNA damage marker
post-radiation exposure.
The mean and standard deviation
of patients’ age, weight, height
and BMI were 48.0+18.6 y,
73.8+16.1 kg, 162.5+10.7 cm,
28.1+6.2 kg m-2
, respectively.
The mean effective dose was
21.2+5.7 mSv per procedure.
Weaknesses The study only measured ionizing
radiation exposure while patients
were in theICU. Patients were
studied in a single center.
DNA damage was not directly
measured during the study. The
risk of cancer from radiation
exposure from cardiac CTA
measured.
Study consisted of a small
number of patients for data
comparison. Data collected from
one location, (Siemens
healthcare, Forchheim,
Germany).
Strengths A large sample sizecompared to
previous studies assessing
radiation dose. Requesting
physicians were unaware of the
study.
Exposure to CTA radiation
activates biological pathways
and genes, increases
transcription factors in cell
repair, cell cycle progression,
and apoptosis.
Each category included wide
ranges in which values were
collected. The data is more
relevant for wider ranges of
individuals.
Relevance
to Topic
This study included 421 adult
patients and 23 pediatric patients
in a general Intensive Care Unit.
This study analyzed the amount
of damage to human cells at the
lowest level possiblewith the
techniques available today.
Cumulative radiation exposure
dosage values were calculated
for individual patients with wide
ranges in age, weight, height,
and BMI.