Fluke 57-441 User Manual

Nuclear Associates 57-441

CLEAR-Pb® X-Ray Compensation Foot Filter

March 2005
Manual No. 57-441-1 Rev. 2
©2004, 2005 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies

Users Manual

Fluke Biomedical

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139

440.498.2564

www.flukebiomedical.com/rms

Table of Contents

Section 1: Introduction................................................................................................ 1-1

1.1 General Information ..................................................................................... 1-1

1.2 Applications and Specifications ................................................................... 1-2

Section 2: Filter Holder Mounting Instructions ......................................................... 2-1

2.1 Filter Holder Mounting Instructions .............................................................. 2-1

Section 3: Filter Positioning ....................................................................................... 3-1

3.1 AP Foot 40” F.F.D........................................................................................ 3-1

3.2 Oblique ........................................................................................................ 3-1

3.3 Lateral.......................................................................................................... 3-2

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Introduction

General Information

1

Section 1

Introduction

1.1 General Information

CLEAR-Pb Compensation X-Ray Filters are made of lead-plastic material that is 30% lead by
weight. Since lead is an efficient absorber of x-rays, the filters will attenuate the x-ray beam. By
varying the shape and thickness of the filters, many combinations of filtering action can be
achieved...from almost complete attenuation to full penetration.

CLEAR-Pb Foot Filters are transparent and lightweight. By means of our "Quick-Stik" system of
magnetic strips, the filters can be held firmly in place or repositioned instantly. You can see and/or
adjust the area of filter coverage as necessary by observing the light shadow projected on the region
being radiographed. Last minute positioning checks of the patient, x-ray collimator and filters are
possible. Selected beam shaping has never been so simple and effective.

CLEAR-Pb Filters may be used with all film/screen combinations and non-screen direct exposure film
packs.

Rare-earth intensifying screens are recommended in order to further reduce patient exposure, and to
provide the best image quality. Consult your film manufacturer for the proper film/screen combination.

1.2 Applications and Specifications

Foot Filter Filter Holder

Model #

Applications

Length x Width
Thickness

Configuration

57-441 57-426

PA Foot -

PA Foot

Weight-Bearing -

LAT Foot -

LAT Foot

Weight-Bearing

6-½“ L x 2” W

5/32”

5-½” L x 6-½” W

¼"

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Operators Manual

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Filter Holder Mounting Instructions

Filter Holder Mounting Instructions

2

Section 2

Filter Holder Mounting Instructions

2.1 Filter Holder Mounting Instructions

If the collimator housing has an accessory tray, the two 9" x 3" x 1/16" acrylic mounting plates (held
together by four screws) should be cut to fit the rails of the tray (Figure 2-1). If the tray channel is less
than 1/8" wide, only one of the mounting plates is required. The other should be removed and retained as
a spare.

If the collimator does not have an accessory tray, the filter holder can be mounted with self-stick Velcro®
tape. The Velcro attachment kit (57-426-1100) is available.

To separate the filter holder from the mounting plate(s), remove the four small screws holding them
together (Figure 2-2). Carefully measure the collimator’s accessory tray and mark one or both of the
mounting plates for cutting. A cardboard template is recommended as a cutting guide. Make a trial fitting
with the template before cutting the plastic to ensure that the filter holder will be in the proper position on
the mounting plate. If the final shape of the mounting plate is not square, be sure to check for proper
longitudinal orientation of the filter holder (Figure 2-1).

Cut Mounting Plates to Size

of Accessory Tray

Filter Holder, Cut to

Proper Fit

Filter Holder Slides Into
the Rails of Collimator’s

Accessory Tray

Beam Exit Window

Figure 2-1. Mounting the Filter Holder

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Operators Manual

Screws Attach
Mounting Plates
to Filter Holder

Figure 2-2. Filter Holder to Mounting Plate

To cut the plastic mounting plate(s), use a plastic scoring knife. Cut each plate separately. Score the
plastic at the desired locations, making sure each score runs the full length (width) of the plate. Make the
scores deep by going over each scratch several times.

Next, place the scored plate over the edge of a table, with the score mark on top and exactly above the
edge. Hold the plastic sheet flat to the table top with one hand. With the other hand, bend the
overhanging part of the plastic sheet down. If the score mark lines up exactly at the table edge, the
overhanging piece will break cleanly at the mark.

Check that the mounting plate slides easily into the accessory tray. To make any fine adjustments
needed for a proper fit, use a file or fine sandpaper.

Reattach the filter holder to the mounting plate(s), and insert the assembly into the collimator’s accessory
tray (Figure 2-1).

Turning the Steel
Rails Increases
Spacing Between
Them

Figure 2-3. Reversing the Guide Rails

If the steel rails on the filter holder intrude into the x-ray field of view, unscrew the rails and turn them
around (Figure 2-3). Since the screw holes in these rails are off center, turning the rails will set them ¾”
further apart.

If desired, the magnetic tape on some or all of the filters can be cut to match the new position of the
holder rails. Using a sharp knife, cut through the magnetic tape (on each side of the filter) in a line parallel
to, and 3/8" from the inner edge. Remove this 3/8" strip, leaving a 5/8" tape strip along the outer edge of
the filter, which matches the new position of the filter holder rails.

The use of the filters and holder is not changed by the above procedure.

2-2

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3.1 AP Foot 40” F.F.D.

Filter Positioning

AP Foot 40” F.F.D

3

Section 3

Filter Positioning

This section contains a detailed description of filter
positioning. Please read it thoroughly before
continuing.

When performing a single-exposure AP radiograph of the foot, the thin filtration portion of the filter should
begin at the proximal end of the metatarsal bones. The thick edge of the filter should extend beyond the
terminal phalanges. (See Figure 3-1)

Technique should be increased in order to image the tarsal bones; the attenuation of the filter will
compensate for the exposure in order to prevent the terminal phalanges from becoming overexposed.
The entire foot can be imaged with one exposure.

NOTE

3.2 Oblique

The position of the filter is the same for an oblique projection.

Thick Edge of Filter

Figure 3-1. AP Filter Orientation

NOTE: Thin Edge of Filter Over
Proximal Metatarsal Area

Shows Area of
Filter Covera

e

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Operators Manual

3.3 Lateral

When performing a single-exposure lateral radiograph of the foot, the thin filtration portion of the filter
should begin at the proximal end of the metatarsal bones. The thick edge of the filter should extend
beyond the terminal phalanges. (See Figure 3-2)

Technique should be increased in order to image the tarsal banes; the attenuation of the filter will
compensate for the less-dense terminal phalanges.

Shows Area of
Filter Coverage

Thick Ed

Figure 3-2. Lateral Filter Orientation

For AP and lateral weight-bearing views, the positioning is the same as for conventional views.

e of Filter

NOTE: Thin Edge of Filter Over
Proximal Metatarsal Area

3-2

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Fluke Corporation

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139

440.498.2564

www.flukebiomedical.com/rms