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PubMed1996

Endorectal color Doppler imaging of primary and recurrent rectal wall tumors: preliminary experience.

OBJECTIVE: The purpose of our study was to assess whether color Doppler imaging is a useful adjunct to endorectal sonography in evaluating rectal wall neoplasms and in distinguishing recurrent or residual tumor from postoperative changes. MATERIALS AND METHODS: Thirty-two patients underwent endorectal sonography with color Doppler imaging for one of two indications: evaluation and staging of a suspected primary rectal wall cancer, or distinguishing tumor recurrence from postoperative scarring in patients with previously resected lesions. Rectal wall lesions were evaluated for hypervascularity, and their corresponding flow patterns were graded from 0 to 4. Local tumor staging with endorectal sonography and color Doppler imaging was performed before the results of pathological staging were available. RESULTS: Ninety-five percent of patients with malignant rectal wall tumors demonstrated hypervascularity during color Doppler imaging. In 61% of patients with rectal cancers, prominent perirectal vessels were identified supplying the tumor and were never identified in patients with benign lesions. Endorectal sonography alone correctly identified perirectal fat invasion with a 100% sensitivity and an 83% specificity. Color Doppler imaging during endorectal sonography correctly identified perirectal fat invasion with a sensitivity of 91% and a specificity of 83%. Of the 8 patients with previously resected lesions (five adenomas and three cancers), two patients had recurrent tumor, and both of these demonstrated grade 3 abnormality. Six patients with biopsy-proven fibrosis only had grades of 0 or 1. CONCLUSIONS: Both benign and malignant rectal wall tumors demonstrate abnormal intratumoral hypervascularity when seen with color Doppler imaging. Advanced rectal cancers (T3 or greater) are also associated with abnormal perirectal vascularity. Color Doppler imaging during endorectal sonography does not appear to improve discrimination of benign from T2 (or less) rectal wall cancers, nor does it appear to improve the ability to locally stage rectal wall cancers during endorectal sonography. However, endorectal sonography with color Doppler imaging may add significant information in distinguishing recurrent tumor from postsurgical scarring.

Female↗

PubMed1998

Color velocity imaging and power Doppler sonography of the gallbladder wall: a new look at sonographic diagnosis of acute cholecystitis.

OBJECTIVE: Color velocity imaging is a color sonographic technique that uses data contained in gray-scale B-mode image scan lines to determine blood flow velocity. We prospectively determined if color velocity imaging and power Doppler sonography can be used to differentiate acute from chronic cholecystitis. We analyzed the potential role of using these two color imaging techniques as an adjunct to conventional gray-scale sonography to differentiate acute from chronic cholecystitis. SUBJECTS AND METHODS: One hundred twenty-nine patients with acute right upper quadrant pain or clinically suspected cholecystitis underwent color velocity imaging and power Doppler sonography of the gallbladder as an adjunct to gray-scale sonography. Morphologic criteria were analyzed on gray-scale sonography, and the presence of flow within the gallbladder wall was assessed with color velocity imaging and power Doppler sonography. Imaging findings were compared with pathologic findings in the 50 patients who underwent cholecystectomy and with clinical and biologic findings in the 79 patients who did not undergo cholecystectomy. RESULTS: Twenty-two patients had surgically proven acute cholecystitis, 28 patients had surgically proven chronic cholecystitis, and 79 patients had no gallbladder disease. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of gray-scale sonography for revealing acute cholecystitis were 86%, 99%, 92%, 87%, and 97%, respectively. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of color velocity imaging and power Doppler sonography for revealing acute cholecystitis were 95%, 100%, 99%, 100%, and 99%, respectively. CONCLUSION: The accuracy of color velocity imaging and power Doppler sonography in revealing acute cholecystitis is significantly greater than the accuracy of gray-scale sonography.

Acute Disease↗

PubMed1998

The effect of accelerated aging on color stability of denture liners.

The objective of the present study was to determine the color changes resulting from the aging process in two cold and three hot curing soft liners and two hard liners. Seven samples were fabricated for each material. The initial color measurements were made with a UV-Visible Recording Spectrophotometer. The samples were then placed in an accelerated aging chamber to simulate the aging process. The color of the samples was then measured again with a colorimeter, and the color changes (delta E) were calculated. The critical mark of color change (delta E) has been quantified by the NBS. It was concluded that cold curing soft liners were not color-stable, and that hot curing soft liners and hard liners had similar color durability. These results suggest that colorants used in cold curing soft liners must be reinforced.

Biocompatible Materials↗

PubMed1995

Effects of color on children's naming of pictures.

Two experiments assessed possible effects of memory for the typical colors of objects on children's naming of pictures. Children, 5 to 10 yr. old (N = 54 per experiment), named pictures of familiar objects in uncolored, typically colored (red for apple), and atypically colored (blue for apple) versions. Presentation of the three types of pictures was mixed in Exp. 1 and blocked in Exp. 2. With mixed presentation, reaction times for naming were unaffected by typical colors but slowed by atypical colors. With blocked presentation, naming was speeded by typical colors, but only for younger children, and was unaffected by atypical colors. Implications are discussed for understanding the processes by which objects are identified and named and the development of knowledge regarding the color of objects.

Association Learning↗

PubMed1998

Effect of viewed color on hand-grip strength.

Published reports on the effects of viewed color on physical strength are compromised by failure to specify each of the three dimensions of the color stimuli used. The present study investigated the relationship between color and grip strength by independently measuring the effects of the three dimensions of color. 80 students with normal color vision were tested for hand-grip strength while viewing color-stimuli sets which differed only in hue, saturation, or lightness. A two-way analysis of variance with two repeated measures showed no significant difference in hand-grip strength with changes in any dimension of color. Formal equivalence testing indicated that these results were not due to low statistical power but rather to an actual similarity in grip strength across different viewing conditions. The findings give clear support to those studies that have found no relationship between viewed color and strength.

Color Perception↗

PubMed1983

Factors affecting the color stability of restorative resins.

The color change resulting from storage in water was measured on a number of experimental and proprietary complex resins. The experimental resins contained varying amounts of amine (DEPT or DEBA), benzoyl-peroxide (BPO) and inhibitor (MHQ). The proprietary resins had earlier been analyzed as regards the composition of the monomer and the content of amine and peroxide. The color change of DEPT-containing resins was positively correlated with the DEPT/BPO ratio, and negatively correlated with the monomer content of BISGMA. DEBA-containing resins were more color stable than resins containing equimolar concentrations of DEPT. The color change was independent of MHQ up to a certain concentration; above this the color change increased with the amount of MHQ. In general, the light activated materials were more color stable than the chemically activated materials. The color change was not affected by pH, but decreased when the oxygen had been removed from the storage water. The test for color stability using UV-light irradiation gave results for proprietary resins that were not correlated with the results obtained by water storage.

Chemical Phenomena↗

PubMed2002

[Analysis of lac color in diets and feces of rats for toxicity studies].

An analytical method was developed for lac color in diets fed to rats and in the feces, and the contents of lac color were determined. After lac color was extracted with 0.05% sodium carbonate and 50% ethanol containing 0.02% sodium lauryl sulfate from the diets and feces, the extracted color solutions were analyzed by HPLC. The recoveries of lac color from diets spiked at 1.25, 5.00% and that from feces spiked at 5.00% were 85.6, 93.4% and 69.5%, respectively. Contents of lac color in diets prepared to contain 1.25 and 5.00% were 1.1 and 5.2%, and dose levels were confirmed by these results. Contents of lac color in feces of male and female rats given lac color were 127.8 mg/g and 138.6 mg/g, respectively. By comparing the HPLC chromatograms of laccaic acids in the diet with those in feces of rats, laccaic acid A, B, C and E were detected in both, and their content ratios were approximately determined.

Animal Feed↗

PubMed2005

Stimulus-driven attentional capture by equiluminant color change.

The aim of this research was to investigate the mechanisms underlying stimulus-driven attentional capture by feature changes in basic dimensions, and we chose color for the present investigation. In Experiment 1, participants searched for a target letter among colored disks containing distractor letters while a disk underwent color change. Although color change was irrelevant to the task and uninformative about the target position, we found a strong form of stimulus-driven attentional capture. Experiment 2 demonstrated that salient color discontinuity per se could not capture attention, ruling out the possibility that the capture effect we observed might be due to color discontinuity. In Experiment 3, we observed the capture effect by color change again in a more optimized experimental design. The present findings show that color change captures attention, supporting our view that dynamic feature changes can capture attention in a stimulus-driven manner.

Attention↗

PubMed1994

Text-contingent color aftereffects: a reexamination.

Five experiments reexamined color aftereffects contingent on the semantic properties of text (Allan, Siegel, Collins, & MacQueen, 1989). The influence of different assessment techniques and the effect of eye movements and overlapping contour information on the induction of color aftereffects by word and nonword letter strings were determined. Experiment 1 showed that no aftereffect was found when a traditional method of assessing color aftereffects was used. Experiments 2 and 4 demonstrated color aftereffects for both words and nonwords, but only when subjects fixated the same locus during induction and testing and only when assessed with the technique described by Allan et al. (1989). If, however, eye movements were made during induction, no color aftereffect was obtained (Experiment 3). Induction to nontext patterns with properties similar to those of text but with fewer overlapping contours resulted in a strong color aftereffect (Experiment 5). These results suggest that the color aftereffect contingent on text is very weak and is not dependent on semantic factors, but that it is a product of induction to local color and orientation information.

Adult↗

PubMed1991

Contingent aftereffects: lateral interactions between color and motion.

A randomly dotted yellow disk was rotated at a speed of 5 rpm, alternating in direction every 10 sec. Its change in direction of rotation was paired with a change in surround color, which was either red or green. After 15 min of exposure, observers reported vivid motion aftereffects contingent on the color of both the stationary disk and the surround, even though during adaptation only motion or color was associated with either alone. In further experiments, it was established that a change in color (or direction of motion) of the disk could be associated with a change in direction of motion (or color) of the surround. Such lateral effects were found even when a wide (5 degree) annulus was introduced between the disk and the surround during adaptation and testing. Furthermore, the aftereffects generalized to the annulus, which was not associated with either color or motion during adaptation. However, when the disk alone was adapted to color and motion, no generalization to the surround was found (and vice versa), suggesting that the effects are not produced by adaptation of large receptive fields or by scatter of light within the eye. The results appear to conflict with the ideas that contingent aftereffects are confined to the adapted area of the retina and that they are built up by links between single-duty neurones, and with an extreme view of the segregation of color and motion early in human vision.

Adult↗

PubMed1996

The representation of color and form in long-term memory.

Color and form are elementary stimulus encoding dimensions that have effects on the representation of visual stimuli at early processing stages. Little is known, however, about their effects on visual long-term memory. In three experiments we investigated whether color is part of the memory representation, whether color and form are bound in the memory representation, and the effect of color context on memory performance. Experimental results suggest that color is part of the memory representation and that color and form can be represented separately in memory and accessed independently. We suggest that the binding of color and form is a deliberate strategic act that requires focal attention, not a natural consequence of processing visual stimuli. We compare our results with the predictions of two computational memory models regarding feature binding. The effect of color context was not straightforward; however, results are consistent with the encoding specificity principle.

Color Perception↗

PubMed1979

[Superimpose of images by appending two simple video amplifier circuits to color television (author's transl)].

Images are very useful to obtain diagnostic informations in medical fields. Also by superimposing two or three images obtained from the same patient, various informations, for example a degree of overlapping and anatomical land mark, which can not be found in only one image, can be often found. In this paper characteristics of our trial color television system for the purpose of superimposing X-ray images and/or radionuclide images are described. This color television system, superimposing two images in each different color consists of two monochromatic vidicon cameras and 20 inches conventional color television in which only two simple video amplifier circuits are added. Signals from vidicon cameras are amplified about 40 dB and are directly applied to cathode terminals of color CRT in the television. This system is very simple and economical color displays, and enhance a degree of overlapping and displacement between images. As one of typical clinical applications, pancreas images were superimposed in color by this method. As a result, size and position of pancreas was enhanced. Also X-ray image and radionuclide image were superimposed to find exactly the position of tumors. Furthermore this system was very useful for color display of multinuclides scintigraphy.

Amplifiers, Electronic↗

PubMed1985

[Interference in the Stroop color-naming task].

To clarify the four processing stages in the Stroop task (input, decision, response selection, and output), and to examine on which stage or stages the interference occurs, seven undergraduates were used as subjects in a color-naming task with color names, words strongly associated with color, words weakly associated with color, a neutral word, and "X X X" as control stimulus. Color-patch pieces were also used to measure the operant level of reaction time. Main results were as follows: 1. On the congruent trials, the response time was shorter for color names than for the neutral word, control word, and words with weak association. 2. On the incongruent trials, the response time was longer for color names than for the neutral word, control word, and words with weak and strong association. Moreover, the interaction between pre-exposure duration and word conditions was significant; the difference of response time due to word conditions as significant when the pre-exposure duration was short, while it was not significant when the duration was long. 3. The neutral word and the control word gave similar response time, which was longer than that for color-patch pieces. From these results it is concluded that the interference in the Stroop task is most likely to occur on the decision and the output stages.

Adult↗

PubMed1998

[The role of local conjunction in the integration process of shape and color].

It is an open question how simple features are integrated in the attention spotlight. In this paper, we examined two opposing models for the integration process of shape and color. One is a local conjunction model in which simple features of shape and color are combined directly. The other is a whole conjunction model in which simple features of shape are integrated into the whole shape and then it is combined with color. In Experiment 1, we measured the time required to search for a target defined by a conjunction of shape and color for five subjects with changing coloring of the figures. The slope of the search function was gentler when corners of figures were colored (p < 0.01). In Experiment 2, we measured the time required to integrate shape and color of figures presented in rapid serial visual presentation (RSVP) for five subjects. The presentation time required to answer the correct combination was shorter when corners were colored (p < 0.01). These results support the local conjunction model.

Adult↗

PubMed1997

Color Doppler ultrasonography in the diagnosis of portal vein invasion in patients with pancreatic cancer.

We retrospectively evaluated the diagnostic usefulness of color Doppler ultrasonography for detecting portal vein invasion in 21 patients with pancreatic cancer who underwent surgical exploration (14 resection, seven inspection). Real-time gray scale ultrasonography, color Doppler ultrasonography, computed tomography, and angiography were performed in all patients to evaluate portal vein invasion, and the images were compared with the histopathologic or surgical inspection findings. On comparison between gray scale ultrasonographic and color Doppler ultrasonographic images, the tumor-vessel relations were visualized more clearly on color Doppler ultrasonography than on gray scale ultrasonography in 14 (22.2%) of 63 vessels. The sensitivity of color Doppler ultrasonography, computed tomography, and angiography for diagnosing portal invasion was 73.7%, 73.7%, and 73.6%, and the specificity was 95.1%, 95.5%, and 90.9%, respectively; the overall accuracy was 84.1%, 88.9% and 85.7%, respectively. A mosaic signal pattern was observed in 12 vessels and showed an accuracy of 86.4% for diagnosing portal vein invasion. In conclusion, compared with gray scale ultrasonography, color Doppler ultrasonography provided improved images of the tumor and portal vein. Furthermore, the accuracy of color Doppler evaluation of portal vein invasion appears to be equal to that of computed tomography and angiography. Therefore, color Doppler ultrasonography may play an important role as an initial examination for evaluating portal vein invasion.

Adult↗

PubMed2002

Twinkling artifact in color Doppler imaging of the orbit.

OBJECTIVE: To show an artifact related to color Doppler flow imaging of the orbit. METHODS: Three patients with strongly reflective structures in the orbit were selected from those routinely referred by clinicians for color Doppler ultrasonography of the orbit. Gray scale and color flow images were obtained with a 7.5-MHz linear array probe for a region with strongly reflective structures. A spectral display was acquired to confirm the presence of blood flow. RESULTS: One patient had a metallic foreign body just behind the bulb; another had calcification within the irregular mass of phthisis bulbi; and the third had hyperechoic drusen in the periphery of the intraocular melanoma. The color mosaic, suggesting the presence of blood flow, was detected beyond all hyperechoic structures. Close vertical bands with no outer wrapping were detected in the spectrum display, obtained by placing the sample volume on the region of color flow. The artificial color flow was recognized as a color Doppler twinkling artifact. CONCLUSIONS: The color flow beyond the strongly reflecting structures in the orbit might be mistakenly interpreted as real blood flow if an examiner is not familiar with the artifact. It should prompt further imaging with spectral Doppler ultrasonography.

Adult↗

PubMed2003

Color Doppler sonographic mapping of pulmonary lesions: evidence of dual arterial supply by spectral analysis.

OBJECTIVE: Within pulmonary lesions, flow signals of pulmonary arteries can be discriminated from flow signals of central bronchial and peripheral bronchial arteries on color Doppler sonography. Our aim was to evaluate the evidence and frequency of different arterial supplies of pleural-based pulmonary lesions using qualitative and quantitative color Doppler sonography. METHODS: Forty-one patients with roentgenologically confirmed pleural-based pulmonary lesions were investigated by color Doppler sonography. The following parameters were investigated: (1) qualitative color Doppler sonographic evidence of vascularization, (2) quantitative color Doppler sonographic evidence of arterial flow signals (resistive index and pulsatility index), and (3) number of different arterial flow signals in 1 lesion by color Doppler sonographic mapping. RESULTS: We found no vascularization in 5 patients, sparse vascularization in 21, and pronounced vascularization in 15. Quantitative color Doppler sonographic parameters were as follows: mean pulmonary artery resistive index, 1.2; mean central bronchial artery resistive index, 0.5; mean peripheral bronchial artery resistive index, 0.7; mean pulmonary artery pulsatility index, 7.8; mean central bronchial artery pulsatility index, 0.7; and mean peripheral bronchial artery pulsatility index, 1.6. There was a significant difference between all types of flow signals for resistive and pulsatility index values but not between pulmonary and peripheral bronchial arteries (P = .068). In 41 patients, 57 different arterial flow signals were determined; 19 (46%) of these patients had 2 or more different arterial flow signals in a lesion. There was no significant difference between benign and malignant lesions regarding the number of flow signals. CONCLUSIONS: Evidence of at least a dual arterial supply can be found on quantitative color Doppler sonography in almost 50% of pulmonary lesions. A single spectral analysis is not suitable for characterization of the arterial supply of pulmonary lesions.

Adolescent↗

PubMedDate not supplied

Color stability of visible light-cured, hard direct denture reliners: an in vitro investigation.

PURPOSE: Previous studies have disclosed the unsatisfactory color stability of autopolymerizing, hard direct denture reliners (HDDR). The present study investigated the color stability of the newly introduced visible light-cured and dual-cured HDDRs. MATERIALS AND METHODS: Five HDDRs were evaluated after 1 hour, 1 day, 7 days, and 30 days of immersion in coffee, tea, and water. Color measurements were obtained with a tristimulus colorimeter, and color differences (delta E*) were calculated. RESULTS: After 30 days of immersion one visible light-cured material exhibited the highest delta E* value (17.8). The other materials showed acceptable color stability in water and coffee. However, tea strongly affected their color. CONCLUSION: Reliners, staining solutions, and immersion time are significant factors that affect color stability. After 7 days of immersion, all of the materials showed perceptible color differences. Tea exhibited higher staining capacity than coffee.

Analysis of Variance↗