Download - Impact of Optimization in Newer Technologies
International Atomic Energy Agency
Impact of Optimization in Impact of Optimization in Newer TechnologiesNewer Technologies
L 8.2
Lecture 8.2: Impact of optimization in newer technologies 2Radiation Protection in Cardiology
Educational ObjectivesEducational Objectives
1. What benefit of digital flat panel technology be expected on patient dose
2. How to translate this into practice3. Experience with optimisation
Lecture 8.2: Impact of optimization in newer technologies 3Radiation Protection in Cardiology
Anticipated per-frame dose reduction with Digital Flat Panel technology is 30%
Lecture 8.2: Impact of optimization in newer technologies 4Radiation Protection in Cardiology
Motorized Iris
Video Camera
Image Intensifier
DE
TE
CT
OR
DE
TE
CT
OR
Photons
Cesium Iodide (CsI)
Light
Amorphous Silicon Panel(Photodiode/Transistor Array)
Digital DataDigital Data
Electrons
Read Out Electronics
Photons
Cesium Iodide (CsI)
Light
Photo-cathode
Video SignalVideo Signal
Electrons
Output screen
Light
CCD or PUT
Electrons
Readout Electronics
1
3,000
400
400,000
2,400
Particles #
Lecture 8.2: Impact of optimization in newer technologies 5Radiation Protection in Cardiology
diagnostic and interventional activitydiagnostic and interventional activityUdine,Udine, years 1990-2002years 1990-2002
0
500
1000
1500
2000
'90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03
diagnostic
PCI
Philips OM 200 (1983)
Philips Integris 3000 (1995)
performed by 3 interventionalists except in 1998
Lecture 8.2: Impact of optimization in newer technologies 6Radiation Protection in Cardiology
Innova 2000 at Udine CenterInnova 2000 at Udine Center
• activity started
• 04/12/2002
• Jan.-Oct. 2003
• 1421 procedures (79% of total)
• 1019 diagnostic
• 402 PCI
Lecture 8.2: Impact of optimization in newer technologies 7Radiation Protection in Cardiology
• Dose in a plane (or exposure, or air-KERMA) decreases as the inverse square of the distance between this plane and the source (focal spot)
• The area of the intersection of the beam with a plane increases as the square of the distance between this plane and the source (focal spot)
• The product of Dose times Area is therefore independent from the distance to the source;
• This Dose.Area product (DAP) can be measured by an ionization chamber, provided the beam is fully contained by the chamber
d1
d2
d3
S3
S2
S1
D1
D2
D3
1000
1000
1000
Dose Area Product
Lecture 8.2: Impact of optimization in newer technologies 8Radiation Protection in Cardiology
comparison of Philips H 3000 and Innova 2000 in PCI comparison of Philips H 3000 and Innova 2000 in PCI characteristics of patientscharacteristics of patients
66
77
1,9
56
31,2 33,4 35,4
66
78
1,9
53
30,8
38,5
30,8
0
10
20
30
40
50
60
70
80
90
age
(y)
male sex
(%)
BSA
(sqm)
EF
(%)
1 2 3
H 3000: 588 pts, 90% of tot. treated in the year 2002
Innova: 274 pts, 67% of tot. treated between Jan-Oct 2003
diseased vessels (%)
Lecture 8.2: Impact of optimization in newer technologies 9Radiation Protection in Cardiology
65,9
22,9
11,314,8
6,12,6 3,2
56,5
25,5
15,3
10,2
3,6 2,96,6
0
10
20
30
40
50
60
70
H 3000
Innova
%
comparison of Philips H 3000 and Innova 2000 in PCI characteristics of procedures & lesions (1)
Lecture 8.2: Impact of optimization in newer technologies 10Radiation Protection in Cardiology
29
22,2
6,2
18,1
4,8
12,8
37,2
22,3
4,7
16,1
3,6 3,3
0
5
10
15
20
25
30
35
40
H 3000
Innova
%
comparison of Philips H 3000 and Innova 2000 in PCI characteristics of procedures & lesions (2)
Lecture 8.2: Impact of optimization in newer technologies 11Radiation Protection in Cardiology
0
10
20
30
40
50
60
70
(m’)
comparison of Philips H 3000 and Innova 2000 in PCI performance & complexity indexes
1,37
1
1,47
0,93
0
0,2
0,4
0,6
0,8
1
1,2
1,4
1,6
1,8
2
Com
p. In
dex
GIS
E In
dex
r (with fluoro time)
0.30 0.29 0.34 0.26
11,6
11,5
40
48
59
84
24,1 21,
6
H 3000
Innova
Lecture 8.2: Impact of optimization in newer technologies 12Radiation Protection in Cardiology
comparison of Philips H 3000 and Innova 2000 in diagnostic comparison of Philips H 3000 and Innova 2000 in diagnostic proceduresprocedurescharacteristics of patients & procedurescharacteristics of patients & procedures
67
1,9
72
99
71
20 1812 9
67
1,9
74
98
69
2024
19
9
0
20
40
60
80
100
120 H 3000: 1401 pts, 92% of tot. studied in the year 2002
Innova: 702 pt, 69% of tot. studied between Jan-Oct 2003
(%)
Lecture 8.2: Impact of optimization in newer technologies 13Radiation Protection in Cardiologym’ Gy * cm2
measured
comparison of Philips H 3000 and Innova 2000 in diagnostic procedures performance indexes and exposure parameters
calculated
4.2
24
54
15.6
20.39
10.67
31.06
4.4
28
54
15.8
27.05
18.83
45.88
35.32
0
10
20
30
40
50
60
Fluoro T
proced. T
room occ.
contrast
(dl)
cine DAP
fluoro DAP
tot. DAP
1,3
H 3000
Innova
Lecture 8.2: Impact of optimization in newer technologies 14Radiation Protection in Cardiology
why why the anticipated 30% per-frame dose the anticipated 30% per-frame dose reduction of DFP technology does not reduction of DFP technology does not
translates into an effective dose reduction translates into an effective dose reduction to patientsto patients
Lecture 8.2: Impact of optimization in newer technologies 15Radiation Protection in Cardiology
differences in operating conditions of the two systemsdifferences in operating conditions of the two systems
H 3000• field of view (cm)
23/18/14
• cine mode
12,5/25 fps
• fluoro mode
low/medium/high
• filter
automatic
Innova• field of view (cm)
20/17/15/12
• cine mode
15/30 fpspref 1/pref 2 (lower dose)
• fluoro mode
low/normal
• filter
manual
Lecture 8.2: Impact of optimization in newer technologies 16Radiation Protection in Cardiology
Exact framing (underframing) maximum intensifier output used the smallest image
Total overframing intensifier output underused the largest image
Maximum horizontal framing compromise in intensifier output compromise in image size
Maximum square framing compromise in intensifier output compromise in image size
Modified from Green, Lippincott - Raven 1996
Lecture 8.2: Impact of optimization in newer technologies 17Radiation Protection in Cardiology
20 cm23
cm
400 cm2
375 cm2
Lecture 8.2: Impact of optimization in newer technologies 18Radiation Protection in Cardiology
other possibilities……other possibilities……
patients may not be the same
procedures may not be the same
operators’ behavior
filters/collimation
use of “difficult” projections (fluoro/cine)
focus-detector mean distances
………
Lecture 8.2: Impact of optimization in newer technologies 19Radiation Protection in Cardiology
collimators use in INNOVA to reduce exposure
FOV 15
dose reduction 25%
Lecture 8.2: Impact of optimization in newer technologies 20Radiation Protection in Cardiology
FOV 20
collimators use in INNOVA to reduce exposure
Lecture 8.2: Impact of optimization in newer technologies 21Radiation Protection in Cardiology
proper filtering
improper filtering causes image deterioration
H 3000
Lecture 8.2: Impact of optimization in newer technologies 22Radiation Protection in Cardiology
INNOVAimproper filtering does not cause image deterioration
Lecture 8.2: Impact of optimization in newer technologies 23Radiation Protection in Cardiology
variation in exposure rate with projectionanthropomorphic phantom (average-sized) measurements
Cusma JACC 1999
Lecture 8.2: Impact of optimization in newer technologies 24Radiation Protection in Cardiology
Distance between patient and detector
Lecture 8.2: Impact of optimization in newer technologies 25Radiation Protection in Cardiology
d
2d
Because the same energy is spread over a surface 4 times larger at a doubled distance, the same object will receive only a fourth of the dose when moved away from “d” to “2d”
Source
Doubling the distance from the source divides the dose by a factor of 4
The inverse square law
Lecture 8.2: Impact of optimization in newer technologies 26Radiation Protection in Cardiology
The inverse square law
Lecture 8.2: Impact of optimization in newer technologies 27Radiation Protection in Cardiology
Collimation
Lecture 8.2: Impact of optimization in newer technologies 28Radiation Protection in Cardiology
Anti-scatter grid
Lecture 8.2: Impact of optimization in newer technologies 29Radiation Protection in Cardiology
MD
nurse
technician 1
staff position in the cath. lab.
mobile screens
ceiling bed
technician 2
Lecture 8.2: Impact of optimization in newer technologies 30Radiation Protection in Cardiology
staff neck dose in the cath. lab.staff neck dose in the cath. lab.57 procedures57 procedures
0
50
100
150
200
250
300
350
procedure
G
y/p
roce
du
ra
MD
nurse
Technician 1
Cathet Cardiovasc Diagn 1997Cardiologia & Fisica Sanitaria - Udine
MD
nurse
technician 1
staff position in the cath. lab.
mobile screens
ceiling bed
technician 2
Lecture 8.2: Impact of optimization in newer technologies 31Radiation Protection in Cardiology
Example of the optimization processExample of the optimization process
• Data collection
• procedures, DAP, fluoro time
• Data analysis
• reliability of data
• Discussion & processes review
• collimators/filters use, FOV, projections
• Implementation of changes
• more precise data collection, collimators/filters use,
FOV 17 whenever possible, avoiding LAO projections
• Data verification
Lecture 8.2: Impact of optimization in newer technologies 32Radiation Protection in Cardiology
Innova 2000. Changes in exposure parameters over time Innova 2000. Changes in exposure parameters over time diagnostic procedures Jul. diagnostic procedures Jul. 2003 - Feb. 20042003 - Feb. 2004
0
1
2
3
4
5
J ul-
Aug
Sept-
Oct
Nov-
Dec
J an-
Feb
Fluoro T (m')
25
26
27
28
29
30
31
32
33
34
J ul-
Aug
Sept-
Oct
Nov-
Dec
J an-
Feb
Tot DAP(Gy*cm2)
Lecture 8.2: Impact of optimization in newer technologies 33Radiation Protection in Cardiology
procedure optimization in the cath. lab.procedure optimization in the cath. lab.patients and staff share a lot……patients and staff share a lot……
• correct indications
• fluoro time reduction
• frame rate reduction (25 12,5/sec)
• collimation/filtering
• LAO cranial projection limitation
• distance from X rays source
• protective screen use
• protective glasses and gloves
(staff)
(patient)
Lecture 8.2: Impact of optimization in newer technologies 34Radiation Protection in Cardiology
PCI optimization PCI optimization comparison of two periodscomparison of two periods
0
200
400
600
800
1000
1200
giu 96-nov 96 n 100 ott 97-mag 98 n 100
fluoro t = sec
DAP=cGy*cm2715
± 462652
± 458
1021± 600
640± 393
-37% p<0.0001
p=ns
CI=0.65 CI=0.58p=ns
Cardiologia & Fisica Sanitaria - Udine
Lecture 8.2: Impact of optimization in newer technologies 35Radiation Protection in Cardiology
procedure optimizationprocedure optimizationannual hand dose (cardiologist)annual hand dose (cardiologist)
0
10
20
30
40
50
60
1994 1995 1996 1997 1998
n. procedurex10
dose mSv- 27%
+ 2%
- 49% - 23%
Cardiologia & Fisica Sanitaria - Udinem
Sv
1994-1998 - 71%
Lecture 8.2: Impact of optimization in newer technologies 36Radiation Protection in Cardiology
0
10
20
30
40
50
60
70
1998 1999 2000 2001 2002
DAP cine
DAP fluoro
DAP totGy*c
m2
procedure optimization procedure optimization DAP measurements at Udine Hospital (aDAP measurements at Udine Hospital (all proceduresll procedures))
Lecture 8.2: Impact of optimization in newer technologies 37Radiation Protection in Cardiology
Gy*c
m2
0
5
10
15
20
25
30
35
40
45
1998 1999 2000 2001 2002
0
1
2
DAP cine
DAP fl uoro
DAP tot
complexity score
PCI optimization over time
Lecture 8.2: Impact of optimization in newer technologies 38Radiation Protection in Cardiology
closing remarksclosing remarks
angiographic procedure optimization is a continuous process of research and audit
this must involve Scientific Societies and single operators
must be based on co-operation of all professionals involved (cardiologists, physicists, radiologists, technicians)