ACR Electronics L-32 FIELD MARKER LIGHTING SYSTEM Información técnica Pagina 1

AAPM REPORT NO. 25PROTOCOLS FOR THE RADIATIONSAFETY SURVEYS OFDIAGNOSTIC RADIOLOGICALEQUIPMENTPublished for theAmerican Association of Physicists in M

I-3. Beam on Controls and IndicatorsVerify the availability of a positive indicator ofx-ray production when the x-raytube is energized, suchas:(a) mA-

The surveyorshielding devices.should verify the presence and use ofThe surveyor should check or monitorthe checking ofprotectiveapparel. Theshieldinga

devices have been developed to expedite this. Hendee andRossi, for example,employ aplasticcylinder formeasuring SID (Reference #3).Localization of the

3)4)5)6)8)TheSet a standard x-ray field size, 18 x 24 cm(8 x 10"), using the appropriate numericalindicator scale on the collimator.Turn on the c

on the x-ray tube assembly.X-ray Field/Numerical Indicator Size:I-6(c)Measure the length and width of the x-ray field oneach film.These dimensionsshou

Three differenttestmethods which require nospecial instrumentation are described below.Test Method I1)Place the collimator in automatic mode.2)Center

Caution:Some PBL collimators do not have a key designedto-disable their automatic sizing as required in step 3of Method II.If this key is not provided

lock out exposuresuntilthe operator has manuallyadjusted the x-ray field to be smaller or equal to thesize of the image receptor.The function and sizi

the HVL measurement.The test protocolsof the following two sectionsdescribe methods to measurethe HVL todeterminecompliance with minimum filtration re

concerning compliance with minimumfiltrationrequirements. For example.if the actual kV is lowerthan indicated on the operator's console,the measu

AAPM REPORT NO. 25PROTOCOLS FOR THE RADIATIONSAFETY SURVEYS OFDIAGNOSTIC RADIOLOGICALEQUIPMENTA REPORT OF THE DIAGNOSTICX-RAY IMAGING COMMITTEETASKGRO

7) Compare the measured HVL against "Table I-Minimum HVL Requirement" to determinecompliance.Test Method II: Units With No Manual TimingPlac

filtration may be necessary as discussed in Section 1-7-A.This abbreviated test method can also be applied tostep #8 in Test Method II in section I-7-

(g) X-ray tube age.If the measured radiation output deviates more than40-50% from the appropriate value suggested in Table III,the generator may need

high voltage cables contributes to the actual output ofeach exposure (Reference #21).While this contributionto the measured mR/mAs is less than 5-10%

items should beincluded on the survey forms. Arecommendation or a suggestion should accompany each itemin an effort to bring the unit into full compli

Checklist Outline forRadiographic InstallationsI-2.SYSTEM INFORMATIONA.Installation2.1. Date of surveyRoom number3.Department/Building4.InstitutionUn

E.Other Specialized DevicesI-5.SOURCE-TO-IMAGE RECEPTOR DISTANCEA.Focal Spot Localization (when x-raytube is replaced)B.SID indicators2.1. Accuracy

(at least annually or as in I-7.A)I-8.RADIOGRAPHIC TECHNIQUE CHARTA.AvailabilityB.UseC.CompletenessI-9.IDENTIFICATION OF PERSON CONDUCTING EVALUATIONA

Part II. Medical Fluoroscopic InstallationsII-l. IntroductionPages 34-37 contain a checklist of the physicalparameters which require evaluation and th

the completion of the elapsed preset time. Re-initiationof the fluoroscopic exposure without resetting the timershall restart the audible warning (Ref

DISCLAIMER: This publication is based on sources andinformation believed to be reliable, but the AAPM and theeditors disclaim any warranty or liabilit

capabilities. The 38 cm SSD also applies to lateralplane x-ray tubes found in biplane fluoroscopic systems.Since automatic collimators required on cer

II-6. Radiation Beam Restriction and AlignmentThis sectiondescribestheevaluation of thecollimator's ability to automatically restrict the x-rayfi

3)4)5)6)7)8)9)10)11)12)During fluoroscopy, center the test tool.This process is normally easier if one ofthe two pair of collimator blades is closedto

19) If any question concerning alignment as afunction of SID exists, steps 13-18 shouldbe repeated with the tower positioned verticallyat the maximum

intersecting at the center of the field of view shall notexceed 4 percent of the SID (Reference #1).II-6-C. Evaluation of Spotfilm AlignmentSteps 13-1

II-6-E. Alternate Test MethodsThe test method briefly described in II-6-A is onlyone of many. While the test equipment required for thismethod is mini

HVLs for Units With Manual Exposure Rate ControlsFluoroscopic systemswith manual exposureratecontrols allow use of Test Method I in Section I-7-A with

7) Complete steps #8-#12 of Test Method IIfound in Section I-7-A.HVL Test Method II: Noninvasive, Maximum kVp Test Point1) Use identical geometry desc

for the high exposure rate mode.considered good practice to However, it islimit this mode to 10 R/min(2.6 mC/(kgmin)) unless a specific clinical need

assembly. When the maximumis measured, theentrance exposure of a unitlead plate protects theintensifier from excessiveimageentrance exposure rates.Als

ContentsIntroduction and General ClarificationsIntroduction ------------------------------- 1General Clarifications---------------------1Part I.Medica

II-l.II-2Checklist Outline forFluoroscopic InstallationSYSTEM INFORMATION (See Section I-2)A. Installation1. Date of survey2. Room number3. Department

II-3.FLUOROSCOPIC TIMERA. Five Minute Maximum SettingB. Audible Warning FunctionalC. Accuracy of Elapsed Exposure time (at leastannually or after repa

B. Fluoroscopic Mode Alignment and Sizing(Maximum SID, auto and/or manual mode)1. Large FOV (14", 13, 12", 11", 10", or 9")2.

C. Qualitative Evaluation of AERC Device (samefrequency as II-7.BII-8.IDENTIFICATION OF PERSON CONDUCTING EVALUATIONA. NameB. TitleC. Professional Cer

III. Dental Radiographic InstallationsIII-l. IntroductionMany items discussed in the Medical RadiographicInstallation Section, Section I, are applicab

SSD shall be 10 cm (4") (Reference #L). The distancebetween the end of the cone attached to the tube headassembly and focalspot usually can be me

an appropriate image receptor which is larger than the x-ray field placed at the distal end of the cone. The imagereceptor can be film, fluorescent sc

these interchangeable cones. or apertures shall havepermanent labels which indicate the image receptor sizeand SID for which the beam restrictor is de

for Devices and Radiological Health (CDRH) of the USDepartment of Health and Human Services (USDHHS), hasdocumented that dental film development is a

The general commentsof Section I-7-C on measuringradiation exposures apply to dental x-ray units. Theionization chamber and electrometer described in

Radiographic Installation Checklist -------- 19Part II.Medical Fluoroscopic InstallationsII-l. Introduction---------------------------- 22II-2. Exposu

The mechanical support of the x-ray tube on Cephalometricand Panoramic units shall be designedso that the x-raytube housing assembly remains stable du

Checklist Outline ForDental Radiographic InstallationsIII-1.SYSTEM INFORMATION (See Section I-2)A.Installation2.1. Date of surveyRoom number4.3. Dep

III-5.III-6.III-7.III-8.III-9.RADIATION BEAM RESTRICTORSA.Intraoral System (at least annually or afterremoval of cone)1.X-ray field diameter at SSDB.P

III-12. IDENTIFICATION OF PERSON CONDUCTING EVALUATION(See Section I-9)A.NameB.TitleC.Professional CertificationIII-13. RECOMMENDATIONS AND SUGGESTION

IV. Measurement of Area Radiation LevelsIV-l. IntroductionParts I,II, and III, have concentrated on equipmentrelated radiation safety matters.In addit

(b) The lowest tube current station availableon the control panel exceeds the maximumcontinuous rated current for the maximumrated tube potential, and

6) Select positions on the surface of animaginary sphere of 1 meter radius withits-center located at the focal spot.Include points at a height equal t

(b) Orientation of the x-ray beam in the room,(c) Workload of the x-ray unit,(d) Size of the room and the equipment layout, and(e) Degree of occupancy

following factors must be considered when quantitativemeasurements are completed:(a) Meter's energy response(b) Meter's directional response

Checklist OutlineMeasurement of Area Radiation LevelsIV-2.LEAKAGE RADIATION (prior to first patient use oranytime damage to the tube housing is suspec

III-2.Beam-on Controls and Indicators ------ 38III-3.Minimum Source-Skin Distance:Intraoral Unit----------------------- 38III-4.Source to Image Recept

1.2.3.4.5.6.7.8.9.10.11.12.REFERENCES"Part 1020-PerformancestandardsforRadiation Emitting Products", 21 Code ofIonizingFederal Regulations,

13.14.15.16.17.18.19.20.21.22.24.Personal Communication with Thomas Mosely concerningFDA Compliance Policy Guide issued to manufacturers,assemblers, a

Introduction and General ClarificationsIntroductionThe task group:"Protocols on The Radiation SafetySurvey of Diagnostic Radiological Equipment&q

2.Determine typical patient exposure levelsfor standard radiographic exams and fluoroscopy,3. Assess fluoroscopic contrast and spatialresolution,5.4.

Part I:Medical Radiographic InstallationsI-l. IntroductionPages 19-21 contain a checklist of the physicalparameters to be evaluated and the informatio