Digital radiographic scanning installation with multiwire proportional chamber

Babichev, E.A.; Baru, S.E.; Khabakhpashev, A.G.; Kolachev, G. M.; Savinov, G.A.; Shekhtman, K.I.; Sidorov, V.; Volobuev, A I

doi:10.1016/0168-9002(91)91078-a

Cited by 11 publications

(1 citation statement)

References 2 publications

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“…Skeletal exams are particularly good targets for this technology, especially for sensitive patients like scoliotic children and young adults for whom the risk of developing radiation-induced breast cancer is non-negligible. 9 Some studies have shown that dose reduction factors of up to two orders of magnitude can be achieved with scanning slit devices [10][11][12] in typical radiological exams. As a matter of fact, a fan-beam coupled with a collimation slit is optimal in terms of effective scatter rejection, 13 surpassed only by the pencil-beam pinhole geometry which is unlikely to become a clinical imaging solution because of acquisition time considerations.…”

Section: Introductionmentioning

confidence: 99%

Physical characteristics of a low‐dose gas microstrip detector for orthopedic x‐ray imaging

et al. 2005

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A new scanning slit gas detector dedicated to orthopedic x-ray imaging is presented and evaluated in terms of its fundamental imaging characteristics. The system is based on the micromesh gaseous structure detector and achieves primary signal amplification through electronic avalanche in the gas. This feature, together with high quantum detection efficiency and fan-beam geometry, allows for imaging at low radiation levels. The system is composed of 1764 channels spanning a width of 44.8 cm and is capable of imaging an entire patient at speeds of up to 15 cm/s. The resolution was found to be anisotropic and significantly affected by the beam quality in the horizontal direction, but otherwise sufficient for orthopedic studies. As a consequence of line-by-line acquisition, the images contain some ripple components due to mechanical vibrations combined with variations in the x-ray tube output power. The reported detective quantum efficiency (DQE) values are relatively low (0.14 to 0.20 at 0.5 mm(-1)) as a consequence of a suboptimal collimation geometry. The DQE values were found to be unaffected by the exposure down to 7 microGy, suggesting that the system is quantum limited even for low radiation levels. A system composed of two orthogonal detectors is already in use and can produce dual-view full body scans at low doses. This device could contribute to reduce the risk of radiation induced cancer in sensitive clientele undergoing intensive x-ray procedures, like young scoliotic women.

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Section: Introductionmentioning

confidence: 99%

Physical characteristics of a low‐dose gas microstrip detector for orthopedic x‐ray imaging

et al. 2005

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A digital x-ray system for diagnostic data collection, processing, storage, and transmission

Antonov¹,

Antonov²,

Lytkin³

1995

Biomed Eng

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A system for collecting, processing, archiving, and transmitting X-ray images

Alekseev¹,

Antonov²,

Antonov³

et al. 1997

Biomed Eng

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The possibility of collection, processing, archiving, and transmission of X-ray images is based on the methods of sampling of X-ray profile and its transformation into a set of digital data. Being entered to a computer, digital information provides a basis for repeated imaging, processing, etc. [7]. The main stages of this process are: 1) sampling of X-ray images [1]; 2) sampling of video signal from image intensifier [12]; 3) direct X-ray digital imaging by special X-ray detectors [2] or a scanning laser-induced system of luminescence (SLSL) [7]. The first and the second stages are very common in practical roentgenology.Schlossman [16] suggested the classification of digital roentgenography by the types of X-ray detectors (matrix and scanning systems). If an X-ray image is converted into a digital array via an intermediate carrier (X-ray film, video signal, etc.), such conversion is called secondary. Direct methods allow digital diagnostic information to be obtained without intermediate carriers. In Russia, direct digital X-ray images were first recorded at the Institute of Nuclear Physics, Siberian Division, Russian Academy of Sciences, Novosibirsk [3, 4, 6].The problem of resolving power of digital X-ray diagnostic devices was thoroughly investigated from the viewpoints of image quality and information storage [8, 10]. The optimum pixel size should simultaneously meet the requirement of high spatial resolution and reasonable information volume. According to Wong [18], as much as 10 I5 Bytes of information are annually stored in the medical information systems in the USA, and this volume is rising continuously. Lares [14] showed that septal lines are resolved at resolution of 0.4 ram. MacMahon [15] showed that resolution of more than 0.1 mm would require enormous computer memory, whereas resolution of 0.4 man is sufficient to resolve intersticial infiltrates and pneumothorax. Sclalossman [16] emphasized that resolution of 0.4 man is sufficient for most clinical purposes.Although resolution of digital X-ray imaging is a very important parameter, computer processing is able to improve the image quality to such an extent that the effect of spatial resolution on diagnostic efficiency could be regarded as minor. For example, electronic contrast between air and a pleural cavity may give correct diagnosis of pneumothorax even without imaging of the pleural line [13]. Fraser [9] and Ikezoe [11] believe that methods of image processing are of particular importance.The method of floating dynamic scale of gray is the most common electronic method of image processing. Methods of quantitative and qualitative evaluation of image contrast and brightness are also very promising for diagnostic purpose [1, 2].We developed a diagnostic system based on a solid-state detector and tested this system in clinics. The system has the following specifications: number of pixels per line, 1024; resolution, 1.2 lines/ram (0.4 ram); exposure time per line, 10-20 msec; X-ray radiation range, 25-125 kV; dynamic range, no less than 80 riB...

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Digital radiographic scanning installation with multiwire proportional chamber

Cited by 11 publications

References 2 publications

Physical characteristics of a low‐dose gas microstrip detector for orthopedic x‐ray imaging

Physical characteristics of a low‐dose gas microstrip detector for orthopedic x‐ray imaging

A digital x-ray system for diagnostic data collection, processing, storage, and transmission

A system for collecting, processing, archiving, and transmitting X-ray images

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