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Titolo:
Effect of inherent location uncertainty on detection of stationary targetsin noisy image sequences
Autore:
Manjeshwar, RM; Wilson, DL;
Indirizzi:
Case Western Reserve Univ, Dept Biomed Engn, Cleveland, OH 44106 USA Case Western Reserve Univ Cleveland OH USA 44106 Cleveland, OH 44106 USA Univ Hosp Cleveland, Dept Radiol, Cleveland, OH 44106 USA Univ Hosp Cleveland Cleveland OH USA 44106 adiol, Cleveland, OH 44106 USA
Titolo Testata:
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
fascicolo: 1, volume: 18, anno: 2001,
pagine: 78 - 85
SICI:
1084-7529(200101)18:1<78:EOILUO>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
VISUAL SIGNAL-DETECTION; X-RAY FLUOROSCOPY; CONTRAST DISCRIMINATION; PHASE INFORMATION; SPATIAL-FREQUENCY; MOVING-OBJECTS; EFFICIENCY; BACKGROUNDS; PERCEPTION; KNOWLEDGE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Engineering, Computing & Technology
Citazioni:
37
Recensione:
Indirizzi per estratti:
Indirizzo: Wilson, DL Case Western Reserve Univ, Dept Biomed Engn, Cleveland, OH 44106 USA Case Western Reserve Univ Cleveland OH USA 44106 OH 44106 USA
Citazione:
R.M. Manjeshwar e D.L. Wilson, "Effect of inherent location uncertainty on detection of stationary targetsin noisy image sequences", J OPT SOC A, 18(1), 2001, pp. 78-85

Abstract

The effect of inherent location uncertainty on the detection of stationarytargets was determined in noisy image sequences. Targets were thick and thin projected cylinders mimicking arteries, catheters, and guide wires in medical imaging x-ray fluoroscopy. With the use of an adaptive forced-choice method, detection contrast sensitivity (the inverse of contrast) was measured both with and without marker cues that directed the attention of observers to the target location. With the probability correct clamped at 80%, contrast sensitivity increased an average of 77% when the marker was added to the thin-cylinder target. There was an insignificant effect on the thick cylinder. The large enhancement with the thin cylinder was obtained even though the target was located exactly in the center of a small panel, giving observers the impression that; it was well localized. Psychometric functions consisting of d' plotted as a function of the square root of the signal-energy-to-noise-ratio gave a positive x intercept for the case of the thin cylinder without a marker. This x intercept, characteristic of uncertainty in other types of detection experiments, disappeared when the marker was addedor when the thick cylinder was used. Inherent location uncertainty was further characterized by using four different markers with varying proximity to the target. Visual detection by human observers increased monotonically as the markers better localized the target. Human performance was modeled asa matched-filter detector with an uncertainty in the placement of the template. The removal of a location cue was modeled by introducing a location uncertainty of approximate to0.4 mm on the display device or only 7 mum on the retina, a size on the order of a single photoreceptor field. We concludethat detection is affected by target location uncertainty on the order of cellular dimensions, an observation with important implications for detection mechanisms in humans. In medical imaging, the results argue strongly forinclusion of high-contrast visualization markers on catheters and other interventional devices. (C) 2001 Optical Society of America.

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Documento generato il 01/04/20 alle ore 11:49:56