Computed Radiographic Evaluation of Simulated Pulmonary Nodules

Jd, Newell; Seeley, George W.; Rm, Hagaman; Nishikawa, Makiko; Nakagawa, K.; M, Kakegawa; Tw, Ovitt; Gd, Pond; Mp, Capp

doi:10.1097/00004424-198804000-00005

Cited by 11 publications

(1 citation statement)

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“…Studies have shown that 30% of all lung nodules can be missed on the first reading of a chest radiogram, even though the same nodules were clearly present on prior radiograms of the same patient [3], [33]. Reasons proposed for these false negatives include factors relating to the image such as the location of nodules within the chest [29], the size and number of nodules present [35], and the diagnostic quality of the images [27], [36]; as well as factors relating to the diagnostician, such as level of training [4], search versus nonsearch protocols [38], premature termination of the search [8]- [10], [31], and conservative decision criteria [26].…”

Section: B Computer-aided Diagnosismentioning

confidence: 99%

Modeling human eye behavior during mammographic scanning: preliminary results

White

Hutson²,

Hutchinson³

1997

IEEE Trans. Syst., Man, Cybern. A

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Understanding how people acquire information from pictures-radiographs, maps, charts, photographs, drawings, and other static images-can be an important component in understanding, aiding, and eventually automating a wide range of diagnostic tasks. In the experiment reported here, we investigate the use of an inexpensive and unobtrusive eye-tracking system to explore relationships between visual scanning patterns, pupillary response, and the clinical diagnoses of mammographic experts. One radiologist and three radiological technicians each examined a series of 14 mammograms for indications of abnormalities associated with breast cancer. The status of each mammogram was verified by biopsy. The eye-tracking system was used to measure and record eye position and pupil diameter as a function of time as the subjects scanned the mammograms. Three treatments were applied to the scan data to model the experts' eye behaviors. These included quantification of dwell time and pupil diameter as a function diagnostic accuracy in regions of the mammogram where abnormalities existed or were perceived; independent clustering of lookpoints without respect to abnormalities; and analysis of scan transitions between lookpoint clusters. Results of the analysis were consistent with extensive prior studies of eyescan measures recorded during the diagnosis of abnormalities on chest radiograms. This preliminary investigation provides a proof of concept for use of the eye-tracking technology, experimental protocols, and analysis methodologies as the basis for expanded mammographic studies, with the promise of eventual adaptation as a source of diagnostic information in clinical practice.

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Section: B Computer-aided Diagnosismentioning

confidence: 99%

Modeling human eye behavior during mammographic scanning: preliminary results

White

Hutson²,

Hutchinson³

1997

IEEE Trans. Syst., Man, Cybern. A

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Phenols as Diamagnetic T₂‐Exchange Magnetic Resonance Imaging Contrast Agents

Zhang

Slania

et al. 2018

Chemistry A European J

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Although T -exchange (T ) NMR phenomena have been known for decades, there has been a resurgence of interest to develop T MRI contrast agents. One indispensable advantage of T MR agents is the possibility of using non-toxic and/or bio-compatible diamagnetic compounds with intermediate exchangeable protons. Herein a library of phenol-based compounds is screened and their T contrast (exchange relaxivity, r ) at 9.4 T determined. The T contrast of phenol protons allows direct detection by MRI at a millimolar concentration level. The effect of chemical modification of the phenol on the T MRI contrast through modulation of exchange rate and chemical shift was also studied and provides a guideline for use of endogenous and exogenous phenols for T MRI contrast. As a proof-of-principle application, phenol T contrast can be used to detect enzyme activity in a tyrosinase-catalyzed catechol oxidation reaction.

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Triazoles as T₂‐Exchange Magnetic Resonance Imaging Contrast Agents for the Detection of Nitrilase Activity

Zhang

Zheng

et al. 2018

Chemistry A European J

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We characterized the T -exchange (T ) magnetic resonance imaging (MRI) contrast of azole protons that have large chemical shifts from the water proton resonance as a function of pH, temperature, and chemical modification. Our results showed that 1,2,4-triazoles could be tuned into excellent diamagnetic T contrast agents, with an optimal exchange-based relaxivity r of 0.10 s mm at physiological pH and B =9.4 T. A fit of r data to the Swift-Connick equation indicated that imino proton exchange of triazoles is dominated by a base-catalyzed process at higher pH values and an acid-catalyzed process at lower pH. The magnitude of r was also found to be heavily dependent on chemical modifications, that is, enhanced by electron-donating groups, such as amines and methyls, or by intramolecular hydrogen bonding between the imino proton and the carboxyl, and weakened by electron-withdrawing groups like bromo, cyano, and nitro. In light of these findings, we applied T MRI to assess the activity of nitrilase, an enzyme catalyzing the hydrolysis of 1,2,4-triazole-3-carbonitrile to 1,2,4-triazole-3-carboxylic acid, resulting in the enhancement of R . Our findings suggest that 1,2,4-triazoles have potential to provide sensitive and tunable diagnostic probes for MRI.

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Computed Radiographic Evaluation of Simulated Pulmonary Nodules

Cited by 11 publications

References 0 publications

Modeling human eye behavior during mammographic scanning: preliminary results

Modeling human eye behavior during mammographic scanning: preliminary results

Phenols as Diamagnetic T₂‐Exchange Magnetic Resonance Imaging Contrast Agents

Triazoles as T₂‐Exchange Magnetic Resonance Imaging Contrast Agents for the Detection of Nitrilase Activity

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Computed Radiographic Evaluation of Simulated Pulmonary Nodules

Cited by 11 publications

References 0 publications

Modeling human eye behavior during mammographic scanning: preliminary results

Modeling human eye behavior during mammographic scanning: preliminary results

Phenols as Diamagnetic T2‐Exchange Magnetic Resonance Imaging Contrast Agents

Triazoles as T2‐Exchange Magnetic Resonance Imaging Contrast Agents for the Detection of Nitrilase Activity

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Product

Resources

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Phenols as Diamagnetic T₂‐Exchange Magnetic Resonance Imaging Contrast Agents

Triazoles as T₂‐Exchange Magnetic Resonance Imaging Contrast Agents for the Detection of Nitrilase Activity