Reducing Radiation Dose in CT Abdomen and Pelvis Studies

20 Pages·2014·0.38 MB·English

Reducing Radiation Dose in Abdominal CT
Studies: ACR Dose Index Registry Data as an
Imppetus for QQualityy Impprovement
Mark P. Supanich, Ph.D.1
Nicholas Bevins, Ph.D.2
DDaanniieell MMyyeerrss, MMDD22
1Rush University Medical Center - Chicago, IL
2Henry Ford Health System- Detroit, MI
Contact: [email protected]
Disclosures
• Nothing to disclose
Background
• The Radiology division of the Henry Ford Medical covers
imaging for 3 hospitals and a number of outpatient centers
• CT scanners include systems from 3 major vendors (n=13)
• Only data from scanners with the ability to reconstruct 64
slices were included in this study
▫ Vendor 1, n=1
▫ Vendor 2, n=2
▫ Vendor 3, n=5
• No scanners empployyed iterative reconstruction
Motivation
• Continuous quality improvement is a priority in
the Radiologgyy deppartment
• Matching radiation dose and image quality for
the same pprotocol across all scanners was
identified as a goal by the radiologists and
medical pphyysicists
Tools Used
• eXposureTM software from Bayer Healthcare used to
collect dose and protocol information
• IInsttiittuttiionall parttiiciipattiion iin AAmeriican CCollllege off
Radiology (ACR) CT Dose Index Registry (DIR)
▫ SSeemmii-aannnnuuaall rreeppoorrttss ooff iinnssttiittuuttiioonnaall ddoossee mmeettrriiccss
broken down by orderable
▫ Summary of dose metrics from 300+ participating
institutions included
Collection of Baseline Data
• Institutional dose metrics and scan information collected by
eXposureTM from 7/2011 through present including
▫ CTDI
vol
▫ SSDE
▫ Master Scan Protocol
• Participation in DIR from 1/2012 through present
• Protocols on scanners from same vendor all equivalent
• Image thickness within 0.25 mm on all scanners
• CT Abdomen Pelvis ((with or without contrast)) exams analyyzed
▫ Image quality reference parameter on multiphase exams are
equal
VVeennddoorr 11 BBaasseelliinnee DDaattaa
CTDI Values Vendor 1
vol
4400
y
c 30
n
e 20
u
q
10
e
rr
F 0
0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 e
1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 r
o
M
CCTTDDII MMeeaann:: 1199.77 mmGGyy Bin
voll
CTDI Median: 17.3 mGy
vol
SSDE Mean: 21.7 mGy
SSDE Median: 20.44 mGyy
N=389
VVeennddoorr 22 BBaasseelliinnee DDaattaa
CTDI Values Vendor 2
vol
300
y
c
n200
e
u
100
q
ee
r
0
F
0 3 6 9 2 5 8 1 4 7 0 3 6 9 2 5
1 1 1 2 2 2 3 3 3 3 4 4
Bin
CCTTDDII MMeeaann:: 1166.99 mmGGyy
voll
CTDI Median: 17.2 mGy
vol
SSDE Mean: 19.3 mGy
SSDE Median: 20.1 mGyy
N=2565
VVeennddoorr 33 BBaasseelliinnee DDaattaa
CTDI Values Vendor 3
vol
550000
y
c 400
n
300
e
u 200
q
e 100
rr
F 0
0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 e
1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 r
o
M
CCTTDDII MMeeaann:: 1188.99 mmGGyy Bin
voll
CTDI Median: 19.5 mGy
vol
SSDE Mean: 21.6 mGy
SSDE Median: 21.99 mGyy
N=2160
Notes on Histograms
• Vendor 2 offered a maximum tube current
settingg which was utilized resultingg in a
maximum CTDIvol of ~26 mGy for the standard
acqquisition
• The output of Vendor 3’s systems were tube
current limited to outpputs of ~255 mGyy for
standard acquisition technique