Lawrence Livermore Realistic Phantom was developed under the direction
of the U.S. Department of Energy, primarily as a reference standard for
the in-vivo counting of emissions from low-energy transuranic nuclides.
The organs of
interest are the lungs, liver and lymph nodes. Each of these may be radioactive
or inert. These organs are accommodated in a male thorax generally similar
to average adult males.
phantom contains a synthetic bone skeleton molded within a
material. The organs are located in an internal cavity with a separate
torso cover that closes the phantom. Anterior sections of ribs and the
sternum are molded into this cover.
blocks are used to position the organs and fill significant air spaces,
providing continuity of the soft-tissues throughout the phantom. The phantom
is shipped assembled with inert organs. Any or all of these organs can
be replaced with radioactive organs, which are shipped in separate packages.
All organs are made of soft-tissue
equivalent materials. Lungs are available with the nuclides uniformly dispersed
throughout the lung molding material. Optional organs (developed by RSD
and not part of the original DOE specifications) are inert, but have holes
in 2 cm2 grids. These either can be filled with inert plugs
or with active capsules to establish any desired distribution within the
The liver has the same loading flexibility,
but another option is available, designed for use with solutions having
relatively short half-lives. This liver is a hollow shell with a fill/drain
If the liver is not required, it may
be replaced with the Abdominal Contents, which is available solid, with
a hole matrix, or active.
Lymph nodes are available as hollow
shells or as active packets. Two are 8 mm in diameter by 17 mm long. A
third is 13 mm in diameter by 25 mm long. They are
positioned in recesses molded in a
lymph node block.
Transuranic emissions from individuals
with varying amounts of muscle and/or adipose tissue may be so attenuated
as to be undetectable. Chest overlay plates were developed to ensure the
validity of in-vivo counting of such individuals.
There are three sets of plates, each
in four graded thicknesses. One set is equivalent to 87% adipose and 13%
muscle, another is equivalent to 50% adipose and 50% muscle, and the third
is equivalent to 100% muscle. Plates of each material and/or each thickness
are available separately.