SU1644009A1 - Nmr tomograph - Google Patents

Description

This invention relates to nuclear magnetic resonance computed tomography and can be used for introscopic examination and non-destructive testing in medicine and technology.

The purpose of the invention is to reduce the rotation of the processing of measurement results from

Figure 1 shows a block diagram of an NMR tomograph; FIG. 2 is a block diagram of a specialized analog computer.

A tomograph based on the phenomenon of nuclear magnetic resonance with an analog calculator (cbig.1) includes a 1 carrier frequency synthesizer, a central processor 2, a pulse shaper 3, a selective pulse formation block 4, a power amplifier 5, a receiving and transmitting coil 6, the contents of the object under study 7, as well as a gradient coil control device 8 connected to an x-gradient coil 9, a y-gradient coil 10, a z-gradient coil 11 and a scanning coil 12, a signal detection unit 13, a specialized processor S4, stroystvo 15 control and analog display information specialized calculator 16,

A specialized analog transmitter (Fig. 2) is made of a first analog switch 1 7 "analog Fourier processor 18, a second analog switch 19S interface 20 connecting to the central processor f DAC 21, buffer memory 22, ADC 23" first 24 and second 25 monitors of the unit 26 scans about

O5 44y

ABOUT

NMR imaging works as follows4

According to the selected method, the 1 carrier frequency synthesizer, at the command of the CPU 2, generates sinusoidal oscillations with a frequency equal to the core magnetic resonance frequency of the core being studied and received at the first pulse shaper 3 inputs, in which, according to commands from central processor 2, coming through the second input, the base and duration of the pulses are formed, as well as the distance between the pulses. A bath of pulses is fed to the first input of block 4 Formation of a selective pulse with two inputs, in which the amplitude is modulated according to the form specified by commands received at the second input from the central processor 2, the Formation of a selective pulse is carried out in order to obtain given spectral pulse shape. A fully formed sequence of pulses is amplified in the power amplifier 5 and transmitted to the receiving and transmitting coil 6, in which the object under study 7 is located. Simultaneously with the transfer of the command to the synthesizer 1 of the carrier frequency, the command is sent to the gradient control device 8, which gives control signals x-gradient 9, y-gradient 10, z-rpa-eleven 11 and scanning 12 rolls.

The excitation pulses and the gradients of the magnetic field are switched strictly synchronously by the commands of the central processor 2. After the action of the excitation pulses, a signal of nuclear magnetic resonance is induced in the receiving-transmitting coil, which in the detection unit 13 is subjected to amplification and quadrature detection. From the output of the detecting unit 13, the signal in the form of the components of the absorption signal 1 and the dis- pergy signal is received at the analog calculator f} t where it undergoes an analogue Urie transform in the Fourier processor 18 and enters the signal inputs of the monitors 24 and 25 where rendered (object line by line method). Scan the monitor line by line. The main processor 2 and the special processor 14 are not used in the processing. In order to archive the results, the data is digitized by the A / D converter 23 and, via the buffer memory 22, transferred to the central processor 2 via the interface 20 for storage. Archiving is not required.

Claims (1)

Invention Formula An NMR tomograph containing a magnetic system with a sensor located in it, including an x-gradient coil, a y-gradient coil, a z-gradient coil, a scanning coil and a receiving-transmitting coil, a gradient coil control device connected to the inputs of the corresponding gradient coils, a signal detection unit connected to the output of a receiving and transmitting coil, a central processor, a power amplifier connected to the input of a receiving and transmitting coil, a non-existent synthesizer, a specialized percentage a sysorer, a control and information display device, a pulse shaper, whose input is connected to a carrier frequency synthesizer, and an output to a central processor, also connected to a gradient coil control device, a carrier frequency synthesizer, a specialized processor and information control and display device, different By the fact that, in order to reduce the processing time of the measurement results, a specialized analog calculator containing an analog Fur was additionally introduced e-processor, first and second monitors, D / A converter, ADC, buffer memory, analog switches, a scanner and an interface connected to the central processor, while the output interface is connected to the control digital inputs of analog analog Fourier processor switches, the output buffer the memory, the DAC input and the control input of the scanner unit, the first input of the first switch is connected to the detection unit, the second input is I with the analog output of the DAC, and the output is connected to the input of the analog Fourier processor 516L40096 the output of which is connected to the input by the second input of the sweep unit, the second output of the ry switch, the first output of which of the second switch is connected to the first inputs through the ADC of the connected memory, and the output and second monitors, the second input the buffer memory is connected to the inputs of which are connected to each other and to the ZAN figure 1 To the central processor YU