Fluke 57-411 User Manual

Nuclear Associates

57-411, 57-412, 57-413
57-426, 57-431, 57-432
57-433, 57-435, 57-436

CLEAR-Pb Transparent X-Ray Compensation Filters

March 2005
Manual No. 57-XXX-1 Rev. 2
©2003, 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: General Information................................................................................... 1-1

1.1 Introduction .................................................................................................. 1-1

1.2 Applications & Specifications ....................................................................... 1-2

1.3 Accessories ................................................................................................. 1-3

1.4 Filter Holder Mounting Instructions .............................................................. 1-3

1.5 Long Leg Filter Mounting Instructions - Ceiling Mount (Model 57-435)........ 1-4

1.6 Tomography Trough Filter (Models 57-412 & 57-413)................................. 1-5

1.7 1” Wedge Filter (Model 57-431) ................................................................... 1-6

1.8 2” Wedge (Decubitus) Filter (Model 57-432)................................................ 1-6

1.9 3” Wedge Filter (Model 57-433) ................................................................... 1-6

1.10 Long-Leg Filter (Model 57-435) ................................................................... 1-6

1.11 Long-Leg Filter (Model 57-436) ................................................................... 1-7

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General Information

Introduction

1

Section 1

General Information

1.1 Introduction

CLEAR-Pb Compensation Filters are made of a 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. (See Figure 1-1.)

Figure 1-1 Filters attenuate x-ray beam to provide even exposure throughout image area.

CLEAR-Pb Filters improve image quality significantly and decrease patient radiation doses during
radiography. They compensate for differences in body thickness or density in full-spine exams, combined
mediastinum and lung-chest tomography, aortic arch angiography, full-length leg radiographs, among
others.

CLEAR-Pb 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 adjust the area
and/or degree of filter coverage as necessary. Last-minute positioning checks of the patient, x-ray
collimator and filters are possible, thanks to the filter transparency. Selected-beam shaping has never
been so simple and effective.

CLEAR-Pb Filters should be used with a rare-earth film/screen combination to improve the image quality.
Consult your film manufacturer for the proper combination.

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Operators Manual

1.2 Applications & Specifications

Filter 1” Wedge 2” Wedge 3” Wedge Long Leg

(Ceiling-mount machines)

Model No. 57-431 57-432 57-433 57-435 57-436
Applications Tangential

breast (for

therapy seed

location)

Angiography

of limbs (use

2 filters)
Length x Width
Max. Thickness

Configuration
Filter Materials

Plastic

Lead-Plastic
Magnetic

Tape

Trough

(Regular)

57-412 57-413

Chest

tomography

6.5” L x 5.5 “ W

0.187”

1.25”

6.5” L x 1 W 6.5” L x 2” W 6.5” L x 3” W 7” L x 4” w Filter

Trough
(Small)

Chest

tomography

Angiography

of neck and

head

6.5” L x 5.5”
W

01.”

0.75”

Lateral

decubitus at

40° FFD

Angiography

of neck and

head (use 2

filters)

This list of uses is by no means exhaustive. Applications are limited only
by the user’s imagination.

All filters on these pages, except the 57-435 Long-Leg Filter, require a 57­426 Filter Holder to make them compatible with collimator accessory trays.
One filter holder per machine is sufficient.

Lateral

decubitus at

40° FFD

(suggested

for children)

IVP

Orthopedic and

angiographic

on 7” x 8” mounting plate

0.25”

Mounting plate included.
Does not need 57-426
Filter Holder assembly

Long Leg

(Conventional

machines)

Full-leg
radiography
under body-

weight load

Orthopedic and

angiographic

6.5” L x 4.25” W

0.29”

1-2

General Information

Accessories

1

1.3 Accessories

Filter Holder & Mounting Plate Assembly

Model 57-426 consists of a transparent filter holder 6 ½” wide x 5 ½” long x 3/8” thick, fastened to 9” x 9”
mounting plates. Thin steel rails on both ends of the holder attract the filter’s magnetic strips. Weighs 18
oz.

Replacement Mounting Plates (2)

Model 57-411 clear plastic, 9” x 9” x 1/16” thick. attached to filter holder with four (4) screws. Can be cut
to fit the collimator’s accessory tray.

1.4 Filter Holder Mounting Instructions

If the collimator housing has an accessory tray, the two 9" x 9" X 1/16" acrylic mounting plates (held
together by four (4) screws) should be cut to fit the rails of the tray (Figure 1-3). 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.

To separate the filter holder from the mounting plate(s), remove the four (4) small screws holding them
together (Figure 1-2). 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 1-3).

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

To break the plastic, place it 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.

Re-attach the filter holder to the mounting
plate(s), and insert the assembly into the
collimator’s accessory tray (Figure 1-3).

Figure 1-3.
Cut mounting plates to size of

accessory tray.

Filter holder, cut to proper fit.

It slides into rails of collimator’s
accessory tray.

Beam exit window.

Figure 1-2.

Screws attach
mounting plates to
filter holder.

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Operators Manual

If the steel rails on the filter holder intrude into the x-ray field of view, unscrew the rails and turn them
around (Figure 1-4). 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 filers and holder is not changed by the above procedure.

Figure 1-4. Turning the steel rails increases spacing between them.

1.5 Long Leg Filter Mounting Instructions – Ceiling Mount
(Model 57-435)

This filter is mounted at the bottom of the beam-defining cone below ceiling mount x-ray tubes. The lower
beam opening of the cone is typically a 4" x 10" rectangle, and the location of the x-ray beam limits, at the
position of the patient, is known. The filter can be mounted by using double-sided tape, epoxy (or other
cement), screws or other convenient methods. The uniformly thick part of the filter attenuates the x-ray
beam from the patient’s feet to approximately the knees. The tapered part of the filter attenuates the
beam approximately 1/3 to 1/2 way up the thighs (See Figure 1-5).

1-4

Long Leg Filter Mounting Instructions-Ceiling Mount (Model 57-435)

Figure 1-5. Shows placement of ceiling mount Long-Leg Filter

Filter

General Information

1

1.6 Tomography Trough Filters (Models 57-412 & 57-413)

The regular trough filter (57-412) is used for adult linear tomography. Use the small filter (57-413) for
linear motion tomography of pediatric patients.

Position the filter with the collimator at the midpoint of its motion path so that the collimator, the patient's
chest and the film are lined up vertically (See Figure 1-6). Place the gap in the filter's center over the
patient's mediastinum. The width of the gap permits alignment during the motion.

Depending on the FFD used, the small filter (57-413) may be appropriate even for adult patients. Then,
the 57-412 would be used only for occasional cases of cardiomegaly.

Figure 1-6. Shows correct positioning of Tomography filters

Filter

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Operators Manual

1.7 1” Wedge Filter (Model 57-431)

The 1" wedge filter is used to prevent "burn out" or overexposure where parts of the body vary in
thickness over a short distance. It is appropriate when radiographing the breast in a tangential direction
(for example, when locating radioactive therapy "seeds").

Two such filters, with their thin edges placed together or at a slight separation, form a trough whose
spacing is adjustable. This positioning is particularly useful for angiography of the limbs, where
overexposure would make details near peripheral edges of the limb difficult to see.

1.8 2” Wedge (Decubitus) Filter (Model 57-432)

This filter is ideal for preventing over-exposure to the upper portion of the colon during double contrast
(Barium and Air) studies when the patient is in the Lateral Decubitus Position. With the patient lying on
one side, the viscera tend to drop, so that the upper side of the body has less attenuation to x-rays. The
decubitus filter is placed on the holder rails horizontally, with its thicker (more attenuating) side up, so that
it attenuates approximately the upper half of the field of view. Placement is facilitated by using the
collimator light.

A pair of these filters, with their thin edges (low attenuating edges) together or nearly together, forms a
trough filter that may be used for angiography of the head and neck. This makes the peripheral regions of
the subject more easily visible. In an emergency, 2” wedge filters can also be used for angiography of the
limbs when 1” wedges are not available.

1.9 3” Wedge Filter (Model 57-433)

The first two-thirds of this filter may be considered as a thinner or less attenuating decubitus filter.
Therefore it is useful for the decubitus view on children or adults who are particularly thin or small.

When used in pairs (as a trough) the 3” wedges are particularly suited for most films of the abdominal
region. This makes the peripheral parts more visible than in a non-filtered view. An I.V.P. film will benefit
in the same way.

1.10 Long-Leg Filter (Model 57-435)

This filter is intended for use with ceiling-mount x-ray generators. It is used in radiographing the whole leg,
from the ankle up to and including the lower abdomen. Such films, used in orthopedics as well as in
angiography, would otherwise require dividing the view into several sections. Each section would be
exposed with a technique appropriate to the thickness of that section of the leg.

The filter is mounted at the bottom of the beam-defining cone so that the thickest part of the filter covers
the lowest part of the foot and leg. The thinnest part reaches approximately 3/5 of the way up,
approximately half way up the thigh. Ceiling-mounted generators do not have a collimator light, and the
size of the x-ray beam can be located with a fluorescent target (e.g., Nuclear Associates' Beam-Size
Ruler, Model 07-606). Since these x-ray generators are usually used only for long-leg radiography,
permanent mounting of the filter on the cone is practical, and either a long (36”) cassette or two 14” x 17"
cassettes may be used.

1-6

General Information

Long-Leg Filter (Model 57-436)

1

1.11 Long-Leg Filter (Model 57-436)

Where a conventional x-ray generator is used, such as in long-leg radiography taken with the patient
standing, the 57-436 filter can be used. It is mounted on a standard 57-426 Filter Holder. The thick part
of the filter is placed so as to attenuate the lowest portion of the x-ray beam, and the tapered edge of the
filter is cephalad, reaching to the level of the patient's lesser trochanter. The filter is placed correctly with
the aid of the collimator light. Because the taper refracts light, the filter produces a dark band on the
patient where the tapered portion affects the x-ray beam. This facilitates filter placement.

Thin edge of filter

1-7

Fluke Biomedical

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139

440.498.2564

www.flukebiomedical.com/rms