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   The Division of Environmental Health licenses, certifications, and permits

Learn more about the Division of Environmental Health

Inspections

Instruments Used During Inspections

Our inspectors utilize instruments made by RADCAL in Monrovia, CA; these instruments are the MDH models 1015, 9010 and 3036 ionization chamber survey meters and Unfors Mult-O-Meter model 436.  These meters are primarily used for measuring patient exposures from radiographic exams and fluoroscopic entrance exposure rates. The instruments provide readings in Roentgens per minute for fluoroscopy, and pulse measurements of milliRoentgens for radiographic exams, along with the duration of each exposure in seconds (or milliseconds).

In addition to this survey meter for patient exposure, we use Keithley model 36100 and Victoreen model 450P ratemeters for assessing operator exposure and public exposure at points of concern throughout the x-ray facility. These instruments provide readings of milliRoentgens per hour.  In order to determine a weekly exposure rate at a point near the x-ray control panel and exposure switch, for example, one would have to collect 3 data items: one, the rate of exposure measured by the meter at that point; two, the number of x-ray exposures typically taken in one week; and three, the average duration of each exposure.  Multiplying these figures gives one a rough idea of the levels of exposure, so that compliance with the regulations can be determined and the need for further protection or personnel monitoring can be evaluated.

Another meter that we use is a kVp meter (RTI Mini-X, UNFORS 9002, and Keithley 35075), which is a non-invasive way of evaluating the accuracy of the indicated kilovoltage selected on the x-ray machine.  Normally, an x-ray machine operator will select 3 factors which determine the amount or intensity of the radiation: time (or duration) of exposure, milliamperage ("quantity"), and kilovoltage (energy or "penetration").  If the kilovoltage is not accurate, there can be problems with image quality and/or unnecessarily high patient exposure.  A new multipurpose instrument we are also currently using is the ultra-small UNFORS 436, sold by Radwest in Covina, CA.

Finally, we use X-Rite sensitometers and densitometers to evaluate density and contrast on film that was flashed and fed through a facility's film processor. This procedure is an FDA-developed one called S.T.E.P.  (Sensitometric Technique for the Evaluation of Processing).  The test enables us to determine if a facility has set up and maintained the film processing in accordance with optimal conditions and state standards.  Also we check for light leaks and safelight conditions in the darkroom.  Fog on x-ray film could adversely affect the image and cause mis-diagnosis (i.e., a false negative finding).

Facilities

Here is a list (updated as of September 15, 2003) of the types and numbers of facilities using x- ray machines in Washington State:

• Hospitals: 94 facilities with 1508 tubes
• Medical Private Practice: 865 facilities, 1729 tubes
• Chiropractic: 934 facilities, 939 tubes
• Dental: 2758 facilities, 10,199 tubes
• Veterinary: 554 facilities, 747 tubes
• Podiatry: 132 facilities, 142 tubes
• Industry and Research: 188 facilities, 603 tubes

X-Ray Machines

This is a general outline of the types of x-ray machines used:

     1.   Radiographic systems (dental, podiatry, veterinary, medical, chiropractic)

o       Chest Radiography

o       Panoramic Dental

o       Intraoral Dental

o       Cephalometric Dental

o       Portable and mobile

     2.   Fluoroscopic systems (hospitals, radiologists)

o       Heart catheterization and other Special Procedures

o       C-arms in surgery

o       Upper GIs and Barium Studies

o       Mini-C-arms (e.g., Fluoroscan, OEC and XiScan)

     3.   Mammographic (special purpose machines---about 200 facilities)

     4.   Linear accelerators (used for cancer therapy)

     5.   Computer Tomography (CAT or CT)

     6.   Cabinet X-ray Systems (e.g., airport baggage x-ray)

     7.   Diffractometers (research)

     8.   Industrial radiography (pipe welds, circuit board analysis)

     9.   Cyclotrons (industry and research)

   10.   Bone Densitometers (x-ray absorptiometry) for detection of osteoporosis

Violations by X-Ray Facility Type

Inspections in Washington State Between 9/1/02 And 8/31/03

(source: Department of Health inspection data)

Medical

        Total Inspections for Period: 327               Total Violations for Period: 43

Dental

      Total Inspections for Period:  672               Total Violations for Period: 226

        Total Inspections for Period: 290              Total Violations for Period: 60

        Total Inspections for Period: 74               Total Violations for Period: 15

                               (special update -- July 1, 2003 - June 30, 2004)

Suggested steps for correcting violations at hospitals:

     1.    Inadequate Technique Charts:  Follow the standards of WAC 246-225-020(2)(c)

which lists all the items necessary for a complete chart, including gonad shielding,

film size, phototimer settings, etc.

     2.    kVp not accurate:  Have routine preventative maintenance done on each x-ray

machine; many hospitals have annual calibration checks done by a hired medical

physicist.  Ensure that discrepancies in kVp accuracy found by such visits are

corrected by the machine vendor representative.

     3.    X-ray beam filtration (HVL) too low:  Same procedure as (2) above.

     4.    Inadequate x-ray exposure switch placement:  Ensure that x-ray operators are

completely protected by barriers and that the exposure switches are permanently

mounted in shielded areas.  Make sure radiation barriers are in place and used,

especially in fluoroscopic procedures.

     5.    Technique factors not indicated:  All x-ray machines are required to have dials,

meters or labels showing what factors (kVp, mA, time, etc) the machine operates at, or

what factors are chosen.  If these are missing, they need to be provided.  In the case of

fixed technique factors, a label will do.

     6.    Other violations related to Mammography:  These vary from Level 1 to Level 3,

            and can be corrected by referring to the MQSA Inspector's report left with the

            Hospital's Mammography Director.

For more information email Ellen G. Haars, or you may also reach her by telephone at 360-236-3237.

Veterinary

        Total Inspections for Period: 113             Total Violations for Period: 29

        Total Inspections for Period: 58               Total Violations for Period: 25

Contact Information

X-Ray Control Section
P.O. Box 47827
Olympia, WA 98504-7827

Phone (360) 236-3231
FAX (360) 236-2266

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Washington State Department of Health

Office of Radiation Protection                                       Physical Address:
P.O. Box 47827                                                            111 Israel Road SE, TC2
Olympia, Washington 98504-7827                                  Tumwater, Washington 98501
(360) 236-3300

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Last Update : 02/02/2007 08:58 AM