Patient Exposures with Imaging
Patient Radiation Exposure Tracking with an
Automated Database
William Pavlicek PhD
Dept of Radiology
Mayo Clinic Arizona
AAPM /COMP Meeting Vancover, BC
July-Aug 2011
©2011 MFMER | slide-1
©2011 MFMER | slide-2
Options Exist: Tracking Patient Exposure
• Siemens
• Philips
• General Electric
• Toshiba
• Radiance
• others
©2011 MFMER | slide-3
©2011 MFMER | slide-4
1
System Architecture
Tracking Medical Radiation Exposure
• As a Quality Control Tool (Six Sigma)
• Establish Reference Levels for routinely
DICOM
DICOM, HL7 Gateway
performed exams and procedures
DICOM SR
HL7
Exam
Information Database
Dose
Tracking
System
WAN
• Source of patient summary of exposures
• Recognize outliers (DMAIC)
• Provide Immediate Alerts for QA directed
Knowledge Base
Dosimetry Analyzer
Reporting &
Alerting Module
Emails
occurances (Level II Reference Levels)
Texts
©2011 MFMER | slide-5
©2011 MFMER | slide-6
DICOM tags and DICOM RDSR
Fluoroscopically Guided Procedures
Common tags, e.g.
(0010, 0010) Patient's Name
(0008, 1030) Study Description
(0008, 0060) Modality
(0008, 0032) Acquisition Time
Application-related tags
Peak Skin Dose, e.g.
(0018,115E) Area Kerma Product (KAP)
(0018,1510) Positioner Primary Angle
Mammography, e.g.
(0040, 0316) Organ Dose
(0018,7060) Exposure Control Mode
©2011 MFMER | slide-7
©2011 MFMER | slide-8
2
Peak Skin Dose not related to Fluoroscopy Time
Fluoroscopy: DICOM RD SR
Patient having 287 separate ‘events’
©2011 MFMER | slide-9
FLUORO
USE
Table
Table
Secondary
Longitudinal Lateral
angle
Position Position
Table
Height
PERP
(mGy)
672
130
1.3
-28.2
612
130
3.4
4.4
-23.1
583
130
6.3
32.7
4.8
-23.1
576
130
13.3
Acquisition
Event 1
-0.2
4.6
-9.6
640
130
179.7
Acquisition
Event 2
0.9
4.4
-0.6
702
130
78.7
0.9
4.4
-27.9
568
130
312.0
32.7
4.8
-23.1
576
130
358.5
DICOM & Info
Primary angle
Fluoroscopy
Event 1
-17
4.5
-21.8
Fluoroscopy
Event 2
-0.2
4.6
Fluoroscopy
Event 3
0.9
Fluoroscopy
Event 4
Local dose
mGy @ skin
©2011 MFMER | slide-10
Example – Simple Geometry
Ka,r = 5 Gy
Machine correction = 0.85
BSF = 1.4
Tissue/Air = 1.06
Ref Pt/Skin = ‘0’
Table/Pad = 0.7
PSD = 4.4 Gy
DSA
USE
Acquisition
Event 3
Acquisition
Event 4
Both Fluoro AND
Acquistions needed!
©2011 MFMER | slide-11
©2011 MFMER | slide-12
3
Define Virtual Equipment
PSD using Informatics: Virtual (reference)
Patients
©2011 MFMER | slide-13
©2011 MFMER | slide-14
Clinical Example
Table attenuation factor: 0.8; Machine correction factor: 0.8; Backscatter factor: 1.4.
ID
Gend
er
Procedure
KAP/air kerma
(cm2)
Number of
the scans
Number of
Fluoro
Peak
skin
dose
area>=0.95 peak skin
dose (cm2)
Total area
radiated
(cm2)
Lateral
inc (cm)
Long
inc (cm)
1234567890
f
IR Emobalization
(non-Neuro)
245.7
180
162
4.3 Gy
18
1068
6
25
15
©2011 MFMER | slide-15
©2011 MFMER | slide-16
4
General Search: PSD Exceeding 2Gy
PATIENT_NAME
PATIENT_ID
M/F
AGE
ACCESSION
DICOM_EXAM_UID
PSD
EXAM_DATE
TESTING^JOE
55505479
M
73
555063793-1
1.2.124.113532…
2.12
2001.01.03
TESTY^SMITH
55500348
M
84
555028234-1
1.2.124.113532…
2.06
2001.01.04
PHANTOM^JANE
55503229
M
76
555075490-1
1.2.124.113532…
2.24
2001.01.05
TESTT^JOE
55502419
M
71
555051025-1
1.2.124.113532…
2.77
2001.01.06
PHANTOMS^SMITH
55509381
M
68
555069339-1
1.2.124.113532…
3.71
2001.01.07
TESTS^TEST
55507826
M
82
555085478-1
1.2.124.113532…
2.16
2001.01.08
TESTIE^JOE
55509396
F
89
555048986-1
1.2.124.113532…
5.63
2001.01.09
REFER_DOC
RADIOLOGIST
EXAM_DESCRIP
CAMPUS
OPERATOR
STUDY_TIME
BLUE^DOC
GRAY^DOC
Vas Aorta
MCS
TECH
20:19.0
GREEN^DOC
GRAY^DOC
Vas Aorta
MCH
TECH
21:13.0
BLUE^DOC
GRAY^DOC
Aorta
MCH
TECH
00:51.0
ORANGE^DOC
GRAY^DOC
Vas Aorta
MCH
TECH
18:29.0
WHITE^DOC
GRAY^DOC
Vas Aorta
MCH
TECH
26:00.0
WHITE^DOC
GRAY^DOC
Mesenteric
MCH
TECH
22:55.0
ORANGE^DOC
GRAY^DOC
Vas Aorta
MCH
TECH
17:20.0
©2011 MFMER | slide-17
Mammography
©2011 MFMER | slide-18
Average Glandular Dose
Distribution of Average Glandular Dose
1.27 mGy for GE FFDM
Number of Exposures
1200
1000
800
600
400
~2.4 mGy for previous Analog
~2.4 mGy for previous Analog
200
0
0.6 - 0.8
0.9 - 1.1
1.2 - 1.4
1.5 - 1.7
1.8 - 2.0
2.1 - 2.3
2.4 - 2.6
> 2.6
Average Glandular Dose (mGy)
Mean = 1.27 mGy
Min = 0.48 mGy / Max = 7.04 mGy
* radiation concentration delivered to the breast tissue (“glandular tissue”) *
©2011 MFMER | slide-19
©2011 MFMER | slide-20
5
Anode – Filter Section
Computed Tomography
T/F
% of Total
# Exposures
Mo/Mo
Mo/Rh
Rh/Rh
1.19%
14.04%
84.78%
Most Common Most Common kVp as
kVp for T/F
% of Exposures with
Selection
Selected T/F
26
27
29
85.71%
72.21%
80.39%
 FFDM unit selected Rh/Rh Target/Filter combination for vast majority of phototimed
exposures (surprising selection was so lop-sided)
 What does this tell us about our study population?
 FFDM unit designed to optimize SNR for detector (explains frequent use of Rh/Rh)
 Mo/Mo: ~86% of exposures used 26 kVp
Mo/Rh: ~72% of exposures used 27 kVp
Rh/Rh: ~80% of exposures used 29 kVp
©2011 MFMER | slide-21
©2011 MFMER | slide-22
CT Protocol: 6110 Abd liv tri Pel
Exam Description (RIS)
Protocol Description(Scanner)
©2011 MFMER | slide-23
©2011 MFMER | slide-24
6
Alert: CT Perfusion
Trigger:
Perfusion
Alerts
Rule: CT time greater than 30 seconds
or: kVp(0018,060) higher than 80kV
or: Exposure (0018,1152) higher than 320 mAs.
Alert:
Email to QA@mayo.edu, DL Rad Trac
©2011 MFMER | slide-25
One Mayo
Implementation
©2011 MFMER | slide-26
Source of Nuclear Data HL7
Nuclear and PET and PET/CT
PATIENT
REGISTER
PATIENT
LIST
©2011 MFMER | slide-27
mCi admin
EXAMS
(HL7)
©2011 MFMER | slide-28
7
Nuclear/PET HL7 Data stream
Nuclear – PET Dosimetry
Diagnostic
Procedure
......
MSH|^~\&|HL7|Nuclear Medicine
Lab|||20110714122909||ORU^R01|201107141229094|P|2.3|||||||
PID|||075630111||TestyPerson,Martha||19290420000000|M|||^^^^^||||||||||
|||||||||
OBR|||542533466-1|NM PET/CT Whole Body^NM PET/CT Whole
Body||||||||||||||||||||||||||||||||20110714122209|||||||
ZDD|F-18 BULK
VIAL|DoseDrawnActivity^10.0|DoseDrawnActivityUnits^mCi|Whole
Body^700.00^mRads^361,490.0^kBq||| 7.0^mSv|||||||||||||||||||||||||
Mayo Dosage
MBq
Chemical Name
mCi
Common Name
Capromab Pendetide
Prostascint
Brain Death
740
20
Heart First Pass Only
370
10
Tc 99m Penteate
DTPA
Lung Ventilation
1480
40
Liver Scan
240.5
6.5
Cystogram
1
Package Insert37
First Organ
Dose
RADAR
Esophageal Transit
7.4 3 doses 200uCi 3 doses
Normal Dose
mSV
Organ 1
Rad
mGy mSV
mSV/MBq
Gastric Emptying
37
Liver Scan
6.5
2.7 (rads/5mCi)240.5
Tc 99m Sulfur Colloid
Sulfur Colloid
Peritoneal Distribution
74
2
Skeletal Bone Marrow
370
10
.03 (rads/5mCi)
Bladder Wall
2.99
2.99
1.81
0.0049
Breast Sentinel Lymph Node
37
1
Lymphedema Scan
18.5 2 doses 500uCi 2 doses
Melanoma Lymph Node
74 or 148
2 or 4
Hepatobiliary
148
4
Tc 99m Mebrofenin
Chloletec
Kidney
370
10
Tc 99m Mertiatide
TechneScan MAG3
Hepatic Artery
148
0.15 (rads/8mCi)
Spleen 4
2.22
21
2.78
0.0094
Tc 99m Albumin Aggregated
MAA Albumin Aggregated
Lung Perfusion
222
6
Portal Venous Shunt
148
4
Tc 99m Exametazime
Ceretec
Brain Spect Scan
925
25
0.2 (rads/10mCi)
Tc 99m Bicisate
Neurolite
Brain Death
740
20
0.666
Bladder
Wall
6.14
10.4
4.51
0.007
SISCOM Protocol
555-1295
15-35
0.060 (rad/4mCi)
0.26 (rads/20mCi)
Lungs
0.977
2.37
1.63
0.011
Kidneys
2.52
19.2
6.88
0.0093
Bladder Wall
5.4
20
8.14
0.011
Stabin, M "Adults-Doses per Unit Activity." Radiation Dose Assessment Resource. 2001.
Web. 9 June 2011. http://www.doseinfo-Radar.com/NMdoses.xls .
©2011 MFMER | slide-29
©2011 MFMER | slide-30
Challenges and Goal
• Different data types
• Different modalities
• Different medical imaging vendor content
• Huge amount of data
• Value
©2011 MFMER | slide-31
©2011 MFMER | slide-32
8
Team Members and I ‘Thank you’!
Yasaman
Khodadadegan
Dr. Steve
Langer, MCR
Dr. Brian Chong,
MCA
Dr. Beth
Schueler, MCR
Dr. Eric Huettl,
MCA
Dr. Richard Morin,
MCJ
Gene Paden, MS., Stephen Sabyan,
MCA
R.T. (R), MCA
Dr. Kevin
Nelson, MCJ
Dr. Teresa Wu,
ASU
Dr. Kenneth
Fetterly, MCR
Dr. Muhong Zhang,
ASU
©2011 MFMER | slide-33
9