Gamma - camera

developed for

Static scintigraphy: viewing two-dimensional image  (in plane of the detector) of three-dimensional distribution radionuclide inside static object.

GAMMA - CAMERA POSSIBLE FIELDS OF APPLICATION

Parallel collimator

·         Thyroid

·         Mammography

·         Lymph’s nuts

·         Post-transplantation investigation (e.g. kidney)

·         Static scintigraphy of lungs, liver, kidney for babies

·         Medico-biological trials with animals

Single slot collimator ( “pinhole” type)

·         Liver

·         Lungs

·         Bones (atomy)

·         Medico – biological trials with huge animals

Gamma - Camera "MiniScan" Principle of Operation

The activity this gamma - camera essentially differs from one of a classic gamma - cameras such as Anger’s. The principle of operation is based on measurement of a set of one-dimensional projections (sinogram) of required two-dimensional image. As against Anger’s gamma - camera the registration of radiation is made through a slot-hole collimator representing a set of flat plates arranged with a certain pitch. The inlet side of the collimator is oriented towards an object while there is a gamma radiation detector behind the outlet side. The “collimator – detector” system incrementally rotates around its axis (normal to the plane of  required image) to an angle 180 or 360 grades, capturing a set of projections of the required image of radionuclide distribution. The said set of projections goes to computer where  recovery of the required image from projections is performed. The specific feature of the described gamma-camera is that it does not have any coordinate-sensitive detector. The measurement of the image projections in this gamma - camera  is based on time-division multiplexing of a detector signal. For this purpose the system movable gamma-radiopaque  shield with slots is provided. The shield is placed between the collimator and the detector with its slits oriented in bridge to collimator slots. The shield movement results in an output detector signal presenting the cycle convolution of given distribution of slots with the required projection.  To obtain indispensable projection parameters back convolution operation is performed by the software. Thus, the data processing in this gamma - camera consists of two stages: (a) back cycle convolution; (b) image reconstruction from projections. As a result the two-dimensional image of a radionuclide inside an object is obtained.

The single-slot collimator (pinhole equivalent in present technology) may be used for decreasing and increasing  the object image, by changing the object-to-collimator distance. This allows inspecting both huge and tiny objects in this gamma - camera.

TECHNICAL ADVANTAGES OF THE GAMMA - CAMERA "MINISCAN"

·         High internal spatial resolution (1.6 mm) not dependent on scintillator depth.

·         High performance in gamma-quanta registration at the expense of usage of thick scintillator (current thickness is 10 mm and much more is possible).

·         Absence of geometrical distortion observed in Anger’s cameras and caused by  drift of electronic parameters.

·         Low  distortion caused by radiation absorption (at the expense of broad solid angle capturing of radiation through slots instead of small foramens).

·         Fast warm-up to operational mode.

·         Simple  accommodation to power range of registered  gamma-quanta.

·         Medical image format (DICOM 3.0) support.

·         Possibility of operation in medical data networks (during trials the device was working in a local network together with General Electric  - ENTEGRA work station).

·         Low consumed power (200 W).

·         Built-in UPS.

·         Mobility becaue of small overall dimensions and weight.

·         Control simplicity.

·         Possibility of using routine, convergent and divergent  collimators.

·         Potentiality of internal spatial resolution increase (2 to 4 times, that is up to 800 - 400 microns, at the expense of replacement of the shutter).

·         Low cost price of manufacturing resulting in low price.

TECHNICAL TRIALS OF THE GAMMA - CAMERA

·         All-Russia State Scientific Research Institute of Medical Engineering

CLINICAL TRIALS OF THE GAMMA - CAMERA

·         Russian Scientific Center of Roentgeno-Radiology (the Department of Health of Russia)

·         State Resarch Center – Institute of  Biophysics

ANALOGS

·          No analogs are found at the moment

MEDICO-BIOLOGICAL TRIALS and CLINNICAL TESTS OF THE GAMMA - CAMERA

1. Medico-biological trials with animals (mice and rats)

2. Matching with Anger gamma-camera Toshiba GCA-7200 A/DI (left in couple) for mice

3. Dynamic distribution activity in bones of living mouse (Perfotech, Tc-99m)

4. Thyroid images (data from observed patients) matched with Anger GE Millenium gamma-camera (upper in the couple). 50 mm long parallel collimator, about 10 cm distance to thyroid; more than 50 patients were observed

MAIN PARAMETERS OF THE GAMMA - CAMERA "MINISCAN"

DOWNLOAD

 MiniScan - print version ( 2,1 Mb )

 Institute of Biophysics - Clinical Trials ( 3,3 Mb )

 RCSCRR - Clinical Tests ( 2,9 Mb )

 Animal centigrams from MiniScan ( 0,7 Mb )

CONTACTS

Institute for Roentgen Optics
Russia, 125315, Moscow, Chasovaja 28, build 64/A, in NPP “Radij”
Тel       +7(499)1514956

Fax      +7(499)1512992
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