Hitachi, Ltd.

Tomoyuki Seino

Takafumi Ishitsu

Yuichiro Ueno

Yuuichirou Ueno

Kensuke Amemiya

Norihito Yanagita

Isao Takahashi

Kazuma Yokoi

Katsutoshi Tsuchiya

Shinya Kominami

Takashi Matsumoto

Keiji Kobashi

Naoki Matsushima

Tsutomu Imai

Toshiaki Takai

Chiko Yorita

Shinobu Irikura

A radiation measuring device includes: a detector that detects radiation; a preamplifier that amplifies a signal outputted from the detector; a shaping amplifier that shapes the waveform of the signal outputted from the preamplifier; an A/D converter that converts the analog signal output from the shaping amplifier to a digital signal; and a digital data processing unit that calculates digital signal output from the A/D converter, wherein energy information of the radiation inputted to the detector is obtained from a pulse height of the pulse signal processed by the preamplifier and the shaping amplifier, and the pulse height of the current pulse is corrected in the digital data processing unit by performing an arithmetic operation using the pulse height information of the current pulse digitalized by the A/D converter, the generation time information of the preceding pulse, and the pulse height information of the preceding pulse.

Radiation measuring device

The purpose of the present invention is to improve energy resolving power and prevent energy resolving power from deteriorating when a thick semiconductor detection element with a wide energy range is used, in a radiation measuring device using a semiconductor detector and a nuclear medicine diagnostic device. With the present invention, the purpose is achieved by pulsed wave value correction employing the difference of (Hs&#x2212;Hf) between the pulsed wave height value Hs obtained from the slow speed shaping circuit, and the pulsed wave height value Hf obtained from the fast speed shaping circuit and normalized with respect to Hs. An even more desirable result may be obtained by employing either (Hs&#x2212;Hf)/Hf or exp(k(Hs&#x2212;Hf)/Hf), wherein k is a coefficient to be optimized, said optimization being dependent on the measurement assembly.

Radiation measurement apparatus and nuclear medicine diagnosis apparatus

The present invention provides a radiation measurement device, which shortens periodic interruption periods in the radiation measurements and prevents damage to the amplifier, and a nuclear medicine diagnosis system using such measurement device. The radiation measurement device comprises a semiconductor radiation detector detecting a radiation, a capacitor, which applies voltage to the semiconductor radiation detector, one or more direct current power supplies each capable of making either of positive and negative electric charge collect on one of the electrodes of the capacitor, a constant-current device, which conducts an electric current from the direct current power supplies to the one of the electrodes of the capacitor, and two or more switching devices installed in the wiring connecting the direct current power supplies and the one of the electrodes of the capacitor. Further disclosed is a nuclear medicine diagnosis system equipped with such radiation measurement device.

Radiation measurement device and nuclear medicine diagnosis system

Provided between a bias power supply and a radiation detector are a noise filter and a bias voltage transmitting circuit. In a state where the bias voltage is applied, the noise filter circuit operates. In a state where the bias voltage is switched on and off, the bias voltage transmitting circuit and the noise filter circuit operate. In a state where the bias voltage is switched on and off, the bias voltage transmitting circuit operates.

Radiation measuring circuit, nuclear medicine diagnosing apparatus, and method of measuring radiation

A PET apparatus comprises a plurality of detector units in the circumferential direction, wherein the detector unit includes a plurality of unit substrates therein, and wherein the unit substrate includes: a plurality of detectors upon which a &#x3b3;-ray is incident; and an analog ASIC and digital ASIC for processing a &#x3b3;-ray detection signal outputted by each of the detectors. The analog ASIC includes two slow systems having mutually different time constants, each of which outputs a pulseheight value. A noise determination part of the digital ASIC determines whether a relevant detection signal is an intended &#x3b3;-ray detection signal or a noise based on a correlation between the pulseheight values, and a noise counting part counts the number of times of noise determination, and a detector output signal processing control part controls the signal processing with respect to an output signal from a relevant detector based on the count.

Nuclear medical diagnosis apparatus

A radiological imaging apparatus using a semiconductor radiation detector to make it possible to reduce a radiation measurement off time that may result from an attempt to avoid polarization, the radiological imaging apparatus comprising a capacitor that applies a voltage to a semiconductor radiation detector that detects a radiation from a subject, first current regulated means for conducting a charge current to the capacitor, and second current regulated means for conducting a discharge current from the capacitor, or comprising a capacitor that applies a voltage to the semiconductor radiation detector, a first resistor that conducts a charge current to and a discharge current from the capacitor, and a second resistor connected in parallel with the first resistor to subject the capacitor to charging and discharging.

Radiological imaging apparatus

A radiological measurement system protecting an amplifier from damage caused by a surge current, ensuring temporal continuity of measurement with a minimum dead time, and including a high voltage DC supply for applying a bias voltage to a radiation detector formed of semiconductor crystal, a controller for exercising on-off control on the bias voltage supplied from the high voltage DC supply, an amplifier, a protection circuit for protecting the amplifier from a surge current generated when the bias voltage is subjected to the on-off control, a control unit for preventing the surge current from flowing to the amplifier, and a switch provided in parallel with the protection circuit and controlled in operation state by the control unit, wherein the control unit controls the operation state of the switch in synchronism with the on-off control exercised by the control unit to prevent the surge current from flowing to the amplifier.

Radiological measurement system and radiological imaging system

A positron emission tomography apparatus installs a plurality of detector units in the circumference of a bed. The detector unit installs a plurality of combined substrates including detectors, analogue ASICs, and a digital ASIC and a voltage adjustment device inside a housing. A partition plate installed inside the housing separates the region inside the housing into a first region installed with the combined substrates and a second region installed with the voltage adjustment device. The partition plate blocks noise generated in the voltage adjustment device so as not to affect &#x3b3;-ray detection signals outputted from the detectors, thereby preventing the effect of the noise generated in the voltage adjustment device toward &#x3b3;-ray detection signals and shortening the examination time.

Radiological imaging apparatus and positron emission tomographic apparatus

The present invention provides a semiconductor radioactive ray detector having the excellent energy resolution or time precision, a radioactive detection module, and a nuclear medicine diagnosis apparatus. The semiconductor radioactive ray detector has a structure in which plate-like elements made of cadmium telluride and conductive members are alternately laminated and the plate-like element made of cadmium telluride and the conductive member are adhered to each other with a conductive adhesive agent, and the Young's modulus of the conductive adhesive agent is in the range from 350 MPa to 1000 MPa, while the conductive members are made from a material with the linear expansion coefficient of the conductive members in the range from 5&#xd7;10/&#xb0; C. to 7&#xd7;10/&#xb0; C.

Semiconductor radioactive ray detector, radioactive ray detection module, and nuclear medicine diagnosis apparatus

The energy calibration method detects irradiation of radiation with predetermined energy from a calibration radiation source using a plurality of radiation detectors having a peak value distribution whose mode and mean value are different and performs calibration so that mean values become identical within the peak value distributions of the respective radiation detectors obtained through irradiation of radiation with predetermined energy from the calibration radiation source.

Energy calibration method and radiation detecting and radiological imaging apparatus

Radiological imaging apparatus with current regulated units, imaging apparatus with bed, imaging apparatus with opening and closing units, and power supply unit

A radiological imaging apparatus including a bed which supports an object to be examined and an imaging apparatus, wherein the imaging apparatus has a unit substrate including a first substrate including a radiation detector and a second substrate including a signal processing apparatus to which detection signals of the radiation detector are inputted and the first substrate is connected through a connector, and is provided with a heat insulating member of separating mutually a first area where the radiation detector is disposed from a second area where the signal processing apparatus is disposed, both of which are formed inside the imaging apparatus.

Radiological imaging apparatus and its cooling system

A radiological imaging apparatus which can keep detectors at a low temperature, improve a time resolution and an energy resolution and perform an accurate diagnosis is provided. In the radiological imaging apparatus, an imaging apparatus imaging a testing subject supported by a bed couples a detector board having placed thereon radiation detectors detecting radiations emitted from the testing subject and a signal processing board having placed thereon a signal processing circuit processing detection signals of the radiation detectors via an intermediate board by connectors, and separates a detector space including the radiation detectors and a signal processing circuit space including the signal processing circuit.

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Hitachi, Japan

Tomoyuki Seino