Safety Code 35 Talk Rps Feb 200976109

8/12/2019 Safety Code 35 Talk Rps Feb 200976109

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ACR Phantom Phantom Images


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Overview Session 2

CT 20

Patient dose 15Equipment Purchase/ Acceptance Testing 15

Questions 10

Personnel qualifications 20Education and training 10

Questions 20


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Patient Dose (A 3.0)

It is recommended that Diagnostic Reference Levels(DRLs) be used as guidance in the optimization of patientdose

DRLs are values related to patient dose using DoseIndicatorswhich can be easily measured

dose-linear product (DLP) for CT or

dose-are product (DAP) for radiography/radioscopy.

Conversion factors are available to convert from DoseIndicator values to Effective Dose (E)


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Diagnostic Reference Levels

It is very difficult to optimize patient dose

However, it is relatively easy to decide those doses

which are clearly too high and unacceptable

DRLs are derived from large surveys of

examinations in a region or country; usually the

DRL is set at the 75% level of the distribution


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BC CT Dose Survey 2004

Hospitals around BC were asked to provide

data on routine head, chest, abdomen, pelvis

CT

Data collected from 18 hospitals


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BC Patient Dose - Head

0

500

1000

1500

2000

2500

1 2 3 4 5 6 7 8 9 10 11 1 2 13 14 1 5 16 17 18

Hospital #

DLP(mGy.cm) DRL


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BC Patient Dose - Chest

0

200

400

600

800

1000

1200

1400

1600

1800

1 2 3 4 5 6 7 8 9 10 11 1 2 13 14 1 5 16 17 18

Hospital #

DLP(mGy.cm)


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Reference Doses BC

* 75 percentile

Exam Reference

DLP

Reference Dose

mSv

mGy.cm

Head 1300 3

Chest 600 10.2

Abdomen 900 13.8

Pelvis 650 12.3

Abdomen-Pelvis 1100 18.7


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Reference Doses

For other imaging systems the dose-areaproduct (DAP) is the most convenient to use

to evaluate patient dose Should be a requirement on all new

radiographic and radioscopic systems


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Dose Area Product Meter

Dose Area Product detector

after collimator intercepts

all radiation used both forradiography and radioscopy

X-rayTube

Collimator

X-rayfield

5.2 Gy.cm2

DAP meter

PACS


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Patient Dose MonitoringIt is now technicallypossible to estimate patient

dose from most x-ray systems

Equipment Dose Indicator Status

CT Dose-length product

DLP

Available on all CTs

Radiographic/

Fluoroscopic/

Angiographic

Dose-area product

DAP

Available on all new

units- can be

retrofitted

CR Exposure Index (EI) of

detector

All CR

Both DLP and DAP values are directly related to

patient dose


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CT Patient Dose Monitoring

Patient ID: Exam No:

Exam Description: CABD2PCT Date:

Dose Report

Series Type Scan Range

(mm)

CTDIvol

(mGy)

DLP

(mGy.cm)

Phantom

cm

1 Scout - - - -

2 Helical S111-I319 12.77 577.08 Body 32

1/1


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Radiographic

Exam View DRL

Generalized Conversion

Coefficients DAP to Effective Dose

Gy.cm2 mSv per Gy.cm2

Skull PA 2 0.03

Lat 1.3 0.03

Chest PA 0.15 0.12

Lat 0.6 0.1

T Spine Lat 7 0.1

AP 4 0.2

L Spine Lat 11 0.1

AP 5 0.2

Abdomen PA 4 0.1

AP 4 0.2

Pelvis AP 4 0.3


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Complete

Exams DRL DAP to E

Fluoroscopy

Time

Gy.cm2 mSv per Gy.cm2 minutes

Barium Swallow 9 0.26 2.3

Barium Meal 14 0.26 2.7

Ba follow thru 12 0.26 2.2

Barium enema 24 0.26 2.8

IVP 14 0.2

MCU 12 0.2 1.9

Nephrostography 12 0.2 4.8

Retro Pyelogram 13 0.2 3

T tube cholangiogram 8 0.26 1.9

Sinography 9 2.1

Small bowel enema 40 9.2

Venography leg 7 2.2

Coronary angiography 29 0.2 4.5


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Complete Exam DRL DAP to E

Fluoroscopy

Time

Gy.cm2 mSv per Gy.cm2 minutes

Biliary Drainage 50 0.26 15

Facet joint injection 5 0.2 1.8

Hickman line 3 0.1 1.4

Nephrostomy 14 0.16 5.1

Esophageal stent 25 0.1 5.9

Esophageal dilation 11 0.1 2.8

Pacemaker 11 0.1 8.2

PTCA single stent 50 0.2 26


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Exam

EU DRL

Dose Area

Product

Gy cm2

VGH DR

Ave Dose

Area Product

Gy cm2

DAP to E

Conversion

Factor

mSv/Gy cm2

Skull AP 4 0.2 0.03

Chest PA 0.2 0.15 0.12

Abdomen AP 7 2.3 0.2

Pelvis AP 5 1.4 0.2

Barium enema 30 0.2IVP 14 0.1

Coronary

Angiography

35-75 120* 0.15

*diagnostic + angioplasty


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Overview Session 2

CT 20


Questions 10


Questions 20


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Acceptance Testing (C 1.0)

The following steps mustbe included for the

establishment of QC procedures

Clear performance specifications

Baseline performance

Reference images

QC Action Levels


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Quality Control

Baseline value determination

Device use period

Next constancy testing

Data evaluation

Within the

established criteria

Remedy

Acceptance testing

FAIL

PASS

Acceptance testing New equipment

Conformance to

manufacturers

specifications/RFP

Baseline performance


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Acceptance testing

Items for Acceptance Testing Film CR DR Radioscopic CT

1.0 Identification

1.1 Initial Inspection and Inventory X X X X X

1.2 Inspection of Documentation X X X X X

2.0 Visual and Functional Tests

2.1 Mechanical Properties X X X X X

2.2 Safety Systems X X X X X


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Acceptance testing


3.0 Performance Evaluation (X-ray Generator)

3.1 X-ray Tube Voltage X X X X X

3.2 Current Time Product X X X

3.3 Loading Time X X X

3.4 Radioscopic Timer and Chronometer X

3.5 Beam Limitation and Indication X X X X X

3.6 X-ray Beam Filtration X X X X

3.7 Automatic Exposure Control X X X

3.8 Automatic Intensity Control X X3.9 Radiation Output X X X X X

3.10 Maximum Air Kerma Rate X

3.11 Phantom (Entrance) Dose (Rate) X X X X X


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Acceptance testing


4.0 Performance Evaluation (Image Receptor)

4.1 Exposure Index X X

4.2 Dynamic Range X X X

4.3 Spatial Resolution X X X X X

4.4 Contrast Detectability X X X X X

4.5 Uniformity X X X

4.6 Artifacts X X X X X

4.7 Digital Detector Residual Image X X

4.8 Noise X X X4.9 Modulation Transfer Function X X

4.10 Mean CT Numbers (calibration and linearity) X

4.11 Tomographic Section Thickness X

4.12 Axial Patient Positioning Accuracy X

4.13 Positioning of Patient Support X


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Equipment Purchase

This new Code has implications for new equipment

Code 20A was usually a condition for RFPs

With Code 35 much more is involved Performance of the x-ray system

At acceptance

In routine operation

Performance of the image receptor At acceptance

In routine operation

Ability to determine patient dose indicators At control

For transfer to PACS


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Equipment Purchase

Will service contracts cover the increasedtesting?

For new units For existing equipment

At the moment radiation doses such as CTDIare not measured by any of the companies as

part of QC

What about equipment not on servicecontract?


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Overview Session 2

CT 20


Questions 20


Questions 20


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Personnel Qualifications

Responsible User

X-ray equipment Operator

RSO


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Responsible User

Possess qualifications required by applicableprovince or statute eg RCPSC, CAMRT

Acquire refresher training according to similarstandard

Ensure equipment functions correctly

Ensure equipment is used correctly

Establish safe operating procedures Promulgate radiation safety for staff

Ensure radiation levels are within regulatory limits


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X-ray Equipment Operator

Possess qualifications required by applicableprovince or statute eg RCPSC, CAMRT

Acquire refresher training according to similarstandard

Have documented training

Ensure equipment is used correctly

Establish safe operating procedures Promulgate radiation safety for staff

Ensure radiation levels are within regulatory limits


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Overview Session 2

CT 20

Equipment Purchase/ Acceptance Testing15

Patient dose 15

Questions 20


Questions 20


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Education and Training - Standards

Collation of Standards/Action Levels

Although frequency of tests is well covered

in SC 35 not all Action Levelsare defined.


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Education and Training - QC

PACS and image display systems QC

Visual

Measurements Image receptor quality tests and calibration

CR

DR

DF CT


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Education and Training - Dose

Patient dose measurement

Dose- area product (DAP) in radiography

and radioscopy. Calibration of meters.

CTDI in computed tomography


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The Future

The only perfect science

ishindsight

Documents

Safety Code 35 Talk Rps Feb 200976109