X-ray Fluorescence Computed Tomography (XFCT) for High-Sensitivity Imaging of Cisplatin

AbstractThe design and performance of a high sensitivity monolithic X-ray detector array fabricated by depositing CdTe photodiodes on CdWO4 scintillators for computed tomography (CT) are presented. CdTe photodiodes offer improved sensitivity due to the better match to the CdWO4 scintillator emission spectrum than the Si photodiodes used in current CT scanners. A CdTe photodiode fabricated on glass mechanically stacked to a CdWO4 scintillator showed 30% improvement in signal strength over Si photodiodes stacked to CdWO4-. Monolithic X-ray detector arrays were fabricated by depositing a CdTe photodiode structure on CdWO4 using close-spaced sublimation technique. Preliminary results on the detector's X-ray response, signalto- noise ratio and the X-ray temporal response show that monolithic CdTe X-ray detectors are suitable for practical CT scanner applications.

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X-ray microtomography

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107058 ◽

1988 ◽

Vol 46 ◽

pp. 998-999

Author(s):

H.W. Deckman ◽

B.F. Flannery ◽

J.H. Dunsmuir ◽

K.D' Amico

Keyword(s):

Computed Tomography ◽

Internal Structure ◽

Imaging Technique ◽

Three Dimensional ◽

Tissue Structure ◽

Individual Element ◽

X Ray ◽

Non Invasive ◽

Panoramic Imaging ◽

Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

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An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100133424 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1758-1759

Author(s):

D. A. Carpenter ◽

M. A. Taylor

Keyword(s):

Imaging Techniques ◽

Fluorescence Analysis ◽

High Sensitivity ◽

Specimen Preparation ◽

X Rays ◽

Glass Capillary ◽

Close Coupling ◽

X Ray ◽

Point To Point ◽

Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

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X-Ray Computed Tomography of Ultralightweight Metals

Research in Nondestructive Evaluation ◽

10.1080/09349849908968156 ◽

1999 ◽

Vol 11 (1) ◽

pp. 199-211

Author(s):

J. M. Winter ◽

R. E. Green ◽

A. M. Waters ◽

W. H. Green

Keyword(s):

Computed Tomography ◽

X Ray ◽

X Ray Computed

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Identification of Fibrotic Thickening as Early Marker of Aortic Valve Stenosis Using X-Ray Micro Computed Tomography and Optical Coherence Tomography

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-0036-1571661 ◽

2016 ◽

Vol 64 (S 01) ◽

Author(s):

A. Jannasch ◽

C. Schnabel ◽

M. Santini ◽

S. Fest-Santini ◽

M. Lorenzi ◽

...

Keyword(s):

Computed Tomography ◽

Optical Coherence Tomography ◽

Aortic Valve ◽

Aortic Valve Stenosis ◽

Optical Coherence ◽

Micro Computed Tomography ◽

X Ray ◽

Early Marker

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Morphology and Affinities of Ampelocissites Seeds (Vitaceae: Ampelopsis clade) from the Paleogene of Texas, USA

Systematic Botany ◽

10.1600/036364420x15935294613400 ◽

2020 ◽

Vol 45 (3) ◽

pp. 478-482

Author(s):

Steven R. Manchester

Keyword(s):

Computed Tomography ◽

Cross Sections ◽

Seed Coat ◽

Ct Scanning ◽

Seed Morphology ◽

Early Eocene ◽

Micro Computed Tomography ◽

X Ray ◽

Fossil Seeds ◽

Fossil Genus

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.

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Requesting physicians’ knowledge of X-radiation exposure from computed tomography scan examinations: A case study of two Nigerian tertiary hospitals

Calabar Journal of Health Sciences ◽

10.25259/cjhs_9_2019 ◽

2020 ◽

Vol 3 ◽

pp. 36-39

Author(s):

Samson O. Paulinus ◽

Benjamin E. Udoh ◽

Bassey E. Archibong ◽

Akpama E. Egong ◽

Akwa E. Erim ◽

...

Keyword(s):

Computed Tomography ◽

Ionizing Radiation ◽

Ct Scan ◽

Radiation Exposure ◽

Work Experience ◽

Radiation Risk ◽

Radiological Protection ◽

X Ray ◽

Tertiary Hospitals ◽

Medical Exposure

Objective: Physicians who often request for computed tomography (CT) scan examinations are expected to have sound knowledge of radiation exposure (risks) to patients in line with the basic radiation protection principles according to the International Commission on Radiological Protection (ICRP), the Protection of Persons Undergoing Medical Exposure or Treatment (POPUMET), and the Ionizing Radiation (Medical Exposure) Regulations (IR(ME)R). The aim is to assess the level of requesting physicians’ knowledge of ionizing radiation from CT scan examinations in two Nigerian tertiary hospitals. Materials and Methods: An 18-item-based questionnaire was distributed to 141 practicing medical doctors, excluding radiologists with work experience from 0 to >16 years in two major teaching hospitals in Nigeria with a return rate of 69%, using a voluntary sampling technique. Results: The results showed that 25% of the respondents identified CT thorax, abdomen, and pelvis examination as having the highest radiation risk, while 22% said that it was a conventional chest X-ray. Furthermore, 14% concluded that CT head had the highest risk while 9% gave their answer to be conventional abdominal X-ray. In addition, 17% inferred that magnetic resonance imaging had the highest radiation risk while 11% had no idea. Furthermore, 25.5% of the respondents have had training on ionizing radiation from CT scan examinations while 74.5% had no training. Majority (90%) of the respondents were not aware of the ICRP guidelines for requesting investigations with very little (<3%) or no knowledge (0%) on the POPUMET and the IR(ME)R respectively. Conclusion: There is low level of knowledge of ionizing radiation from CT scan examinations among requesting physicians in the study locations.

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