In these patients, dose comparison was
made to studies from the outside institutions. Data collection was performed
over a six month period, which was specified by the PQI template.
Advice was also solicited from the
manufacturers of the CT scanners for
low dose techniques. Because bismuth
shielding can reduce dose to the breast
by 26%, breast shields were used in all
female patients. 3 In addition, thyroid
shields were used in all patients to protect the thyroid gland. Data comparison
in February 2011 showed a significant
dose reduction as a result of the combination of the low dose techniques as well
as the use of breast and thyroid shields,
usually between 30–50%, sometimes as
high as 70%, especially in patients over
150 pounds. Between February 2011 and
July 2011, additional fine tuning modifications were made based on the patients’
body habitus and automatic tube current
modulation. The imaging quality and
diagnostic value of these low dose chest
CTs were monitored by the 20-plus radiologists of Lake Medical Imaging. It was
agreed among the radiologists that there
was no significant image quality degradation. In July 2011, final data collection was performed based on the “Chest
CT Radiation Exposure Reduction PQI
Template” timetable. This confirmed
that the new protocols reduced the radiation dose of routine chest CT. One
special note is that the data comparison
did not take into account the additional
protective effect of breast and thyroid
shields. In July 2011, the low dose chest
CT protocol was finalized.
After completing the “Low Dose
Chest CT” project, it was seen that sig-
nificant dose reduction on routine chest
CTs was achieved. Data analysis shows
that prior to the project, the dose of a
routine chest CT was already signifi-
cantly lower than the proposed reference
dose value by the Fleischner Society. At
the completion of the project, a standard
protocol was established. Comparison of
chest CT dose performed at Lake Medi-
cal Imaging also showed that the low
dose chest CT protocol resulted in sig-
nificantly less radiation exposure.
1Board on Radiation Effects Research.
“Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII, Phase
2.” Washington, DC: The National Acade-mies Press. 2006.
2Mayo JR, Aldrich J, Müller, NL. Radiation
exposure at chest CT: a statement of the
Fleishner Society. Radiology. 2003;228:
3Coursey C, Frush DP, Yoshizumi T, et al. Pediatric chest MDCT using tube current
modulation: effect on radiation dose with
breast shielding. AJR Am J Roentgenol.
Yi Liu, MD, PhD is a board certified radiologist with
Lake Medical Imaging & Vascular Institute in Leesburg
and The Villages, FL. He received his medical degree
from Capital University of Medical Sciences in Beijing
and a PhD in neuroscience from Hahnemann
University in Philadelphia.
Wendy Jordan, RT(R)(M)(MRI)(CT) is the C T/MRI
supervisor at Lake Medical Imaging & Vascular
Institute where she’s been part of the staff for more
than 25 years. She is an active member of ARRT.
Marcella “Chella” Volkmar, RT(R) is technical director
for Lake Medical Imaging’s two outpatient centers
located in The Villages, FL. She has been with the
practice for 14 years after serving 20 years at Leesburg
Regional Medical Center. She is an active member of
AHRA, ARRT, and BSSRT and serves on the Radiology
Advisory Board for Community Technical and Adult
Education in Ocala, FL.