Zernike-type X-ray imaging microscopy at 25 keV with Fresnel zone plate optics.

A Zernike-type imaging microscope using a sputtered-sliced Fresnel zone plate (SS-FZP) has been developed and tested at an X-ray energy of 25 keV. The SS-FZP was used as an objective. A copper (Cu) phase plate was placed at the back focal plane of the SS-FZP in order to produce phase contrast. The performance of the Zernike-type imaging microscope was tested with a gold (Au) mesh and a resolution test pattern at undulator beamline 47 of SPring-8. The Au mesh and the resolution test pattern could be imaged in transmission with a magnification of x10.2. Owing to the Cu phase plate, different image contrast was observed compared with the bright-field image contrast. Tantalum microstructures down to 0.5 microm line-and-space have been observed on spatial resolution test patterns.

Development of a multilayer Fresnel zone plate for high-energy synchrotron radiation X-rays by DC sputtering deposition.

Hard X-ray microscopy with high spatial resolution (or=20 keV) because a large thickness (aspect ratio) can be available. Various types of multilayer FZPs have been fabricated by DC sputtering deposition. Their focusing characteristics have been evaluated at the high-brilliance undulator beamline BL47XU of SPring-8. An optical system using a Cu/Al multilayer FZP (with an outermost zone width of 0.25 microm) as the focusing optics fabricated by the optimum deposition condition with precise film (zone) thickness control has attained an almost diffraction-limited microbeam of 0.3-0.35 microm at 8.9 keV. A line-and-space resolution test pattern has been observed: fine structures up to 0.2 microm were clearly observed in the measured image. This FZP has been working since 1995, keeping good focusing characteristics. It can be said from these results that a spatial resolution better than 0.1 microm in the high-energy X-ray region is in prospect by the development of a multilayer FZP with a narrower outermost zone width in the near future.

Hard X-ray microbeam experiments with a sputtered-sliced Fresnel zone plate and its applications.

Hard X-ray microbeam experiments with sputtered-sliced Fresnel zone plates have been performed. Zone plates with an outermost zone width of 0.25 microm (#FZP1) and 0.1 microm (#FZP2) were fabricated and evaluated. In a scanning X-ray microscopy experiment, a line-and-space pattern with structure as fine as 0.1 microm was resolved using #FZP2 at an X-ray wavelength of 1 A. As an application of the microbeam technique, a two-dimensional distribution of constituent elements in forensic samples has been obtained (e.g. section view of human and elephant hairs) using fluorescent scanning microscopy.

Does stool collection method affect outcomes in immunochemical fecal occult blood testing?

PURPOSE: This paper compares the positive predictive value of an immunochemical fecal occult blood test for colorectal neoplasms between the stool specimens obtained during the digital rectal examination and those obtained during the routine screening. METHODS: In a medical check-up, 1,688 subjects received both an immunochemical fecal occult blood test and a colonoscopy. Fecal occult blood was tested by two methods: digital rectal examination and routine screening. The positivity rate of an immunochemical fecal occult blood test and the positive predictive value for colorectal cancer and large adenomatous polyp were determined by these two methods. RESULTS: The positivity rate and the positive predictive value were 5.4 percent and 19.8 percent (4.4 percent for cancer and 15.4 percent for adenomatous polyp) in the digital rectal examination method and 3.5 percent and 27.1 percent (6.8 percent for cancer and 20.3 percent for adenomatous polyp) in the routine screening method, respectively. These figures indicate a significant difference in the positivity rate (P < 0.01) and the positive predictive value (P < 0.05) between these two methods. CONCLUSIONS: These findings indicate that the stool obtained by routine screening has a better positive predictive value than stool collected during the digital rectal examination.

Characteristics of colorectal cancer that produce positive immunochemical occult blood test results on stool obtained by digital rectal examination.

OBJECTIVE: To clarify the clinicopathological features of colorectal cancer that show positive results on an immunochemical fecal occult blood test of stool obtained by digital rectal examination. METHODS: In a cross-sectional study, 9952 subjects received both an immunochemical fecal occult blood test of stool obtained by digital rectal examination and colonoscopy annually over a nine-year period of medical checkups; 64 patients with colorectal cancer were identified. The study subjects comprised 39 patients with colorectal cancer who had positive results (positive group) and 25 patients with colorectal cancer who had negative results (negative group) on an immunochemical fecal occult blood test of stool obtained by digital rectal examination. The positive and negative groups were compared in terms of their individual factors, such as site, size, Dukes classification and histological type of the cancer lesions. RESULTS: The prevalence of rectal cancers was higher in the positive group than in the negative group (P<0.05), but there were no differences between the two groups with respect to any other factors. CONCLUSIONS: These findings indicate that stool obtained during the digital rectal examination is unsuitable for detecting fecal occult blood, especially for the detection of proximal colon neoplasms.

Association of diverticulosis coli and vascular ectasias and the results of fecal occult blood test.

BACKGROUND/AIMS: This study was conducted to clarify the diagnostic value of an immunochemical fecal occult blood test for diverticulosis coli and vascular ectasias of the colon, and to assess the association of these diseases to the results of fecal occult blood test. METHODOLOGY: An immunochemical fecal occult blood test over 2 consecutive days was carried out on 72 patients with diverticulosis coli, on 36 patients with vascular ectasias of the colon, on 36 patients with colon cancer, and on 144 healthy subjects. RESULTS: The test was positive in 13.8% patients with diverticulosis coli, in 11.1% patients with vascular ectasias, in 83.3% patients with colon cancer, and in 6.2% healthy subjects, respectively, showing a significant difference in the detection rate between colonic diverticulosis and colon cancer, between vascular ectasias and colon cancer (P < 0.001). However, there was no significant difference in the detection rate between diverticulosis coli and healthy subjects, and between vascular ectasias and healthy subjects. In addition, there was no significant association between the degrees of diverticulosis coli and vascular ectasias to the results of immunochemical fecal occult blood test. CONCLUSIONS: These findings indicate that the immunochemical fecal occult blood is unsuitable for the diagnosis of the patients with colonic diverticulosis and patients with vascular ectasias, and these disorders have little influence on the results of fecal occult blood test.

Digital rectal examination sampling of stool is less predictive of significant colorectal pathology than stool passed spontaneously.

OBJECTIVES: To compare the positivity rate and the positive predictive value of an immunochemical faecal occult blood test (FOBT) carried out by using stool samples obtained during a routine screening method and those obtained during digital rectal examination. DESIGN: Screening programme-based, cross-sectional study. METHODS: In a screening programme-based, cross-sectional study, 1,044 subjects who received both an immunochemical FOBT and colonoscopy were divided into two groups according to stool collection techniques--the routine screening method and the digital rectal examination method. The positivity rate of the immunochemical FOBT, as well as the positive predictive value for colorectal cancer and large adenomatous polyp, were determined in the two groups. RESULTS: The positivity rate and positive predictive value were 3.8% and 60.0% (10.0% for cancer and 50.0% for adenomatous polyp) in the routine screening group, and 9.4% and 26.5% (4.1% for cancer and 22.4% for adenomatous polyp) in the digital rectal examination group, respectively, indicating a significant difference in the positivity rate (P < 0.01) as well as the positive predictive value (P< 0.05) between the two groups. CONCLUSIONS: These results show that digital rectal examination sampling of stool is less predictive of significant colorectal pathology than stool passed spontaneously, and therefore the latter is the preferred method for stool sampling.

Relationships between a sign of rectal bleeding and the results of an immunochemical occult blood test, and colorectal cancer.

A cross-sectional study based on medical check-up was carried out to investigate the association between signs of rectal bleeding and colorectal cancer, and the results of an immunochemical faecal occult blood test. The 9625 patients received both an immunochemical faecal occult blood test using a two-consecutive-day method and colonoscopy. They were then divided into two groups, according to the results of a self-completed questionnaire on the signs of rectal bleeding. The positivity rate of the immunochemical faecal occult blood test as well as the positive predictive value for colorectal cancer were determined in these two groups. The faecal occult blood test was positive in 9.3% of patients with rectal bleeding and in 4.4% of patients without rectal bleeding, and the positive predictive value for colorectal cancer was 0.79 and 0.27 in patients with and without rectal bleeding, respectively. This indicates a significant difference in the positivity rate (P < 0.001) as well as the positive predictive value (P < 0.05) between these two groups. The results suggest that there are positive associations between the signs of rectal bleeding and the results of immunochemical faecal occult blood test, and between the patients presenting with rectal bleeding and colorectal cancer.

Comparison of predictive value for colorectal cancer in subjects with and without rectal bleeding.

BACKGROUND/AIMS: To clarify the association between a sign of rectal bleeding and colorectal cancer, and to reveal the relationship of rectal bleeding to the results of an immunochemical fecal occult blood test. METHODOLOGY: In a population-based cross sectional study, 30,138 subjects who received immunochemical fecal occult blood screening with a 2-day method were divided into two groups, according to the results of a questionnaire on a sign of rectal bleeding, and the positivity rate of an immunochemical occult blood test as well as the predictive value for colorectal cancer were compared in the two groups. RESULTS: The fecal occult blood test was positive in 8.8% of subjects with rectal bleeding and in 6.0% of subjects without rectal bleeding, and the predictive value was 6.4% and 3.3% in subjects with and without rectal bleeding, respectively, showing a significant difference in the positivity rate (p<0.001) as well as the predictive value (p<0.05) between these two groups. CONCLUSIONS: These findings indicate that there are positive relations between the subjects with rectal bleeding presentation and colorectal cancer, and a sign of rectal bleeding and the results of an immunochemical fecal occult blood test.

Colonoscopic evaluation of immunochemical fecal occult blood test for detection of colorectal neoplasia.

BACKGROUND/AIMS: This study was carried out to assess the validity of three testing methods of immunochemical occult blood according to the number of collection times as a means for colorectal cancer screening. METHODOLOGY: Four thousand six hundred and eleven asymptomatic individuals, who received both an immunochemical occult blood test with a three-day method and colonoscopy during a medical checkup, served as subjects for this study. For evaluation of the desirable number of sampling times, we used the results of the first day for the 1-day method, the results of the first and second days for the 2-day method, and the results of three-consecutive days for the 3-day method. Sensitivities and specificities of these three testing methods were evaluated. RESULTS: Sensitivities and specificities for colorectal cancer were calculated to be 56% and 97% for the 1-day method, 83% and 96% for the 2-day method, and 89% and 94% for the 3-day method, respectively, showing a significant difference in sensitivity between the 1-day and the 2-day methods, as well as the 3-day method (p < 0.01), and in specificity between the 1-day as well as the 2-day and 3-day methods (p < 0.05). CONCLUSIONS: These findings indicate that the immunochemical fecal occult blood test is useful for the diagnosis of colorectal cancer, and that 2-day testing is recommended as a means of screening for colorectal cancer.

Sensitivity and specificity of several immunochemical tests for colorectal cancer.

BACKGROUND/AIM: The purpose of this study was to evaluate the diagnostic accuracy of new different immunochemical fecal occult blood tests for colorectal cancer, including Iatro Hemcheck, Immudia-Hem Sp, LA Hemochaser, Monohaem and OC-Hemodia. METHODOLOGY: Ninety-six patients with colorectal cancer and the same number of healthy controls served as subjects for the study. In this study, each subject received a set of five immunochemical tests over three consecutive days; and sensitivities and specificity of these tests were evaluated. RESULTS: Mean sensitivity and specificity in a set of five immunochemical tests were 91.0% and 95.2%, respectively. Sensitivities and specificity of five different immunochemical tests were calculated as 92.7% and 92.7% for Iatro-Hemcheck, 90.6% and 96.9% for Immudia-Hem Sp, 88.5% and 96.9% for LA Hemochaser, 91.7% and 95.8% for Monohaem, and 91.7% and 93.8% for OC-Hemodia, respectively, showing no significant difference in sensitivity and specificity among five tests. CONCLUSIONS: These results suggest that immunochemical tests for fecal occult blood tests has high diagnostic validity for colorectal cancer. In addition, there is no significant difference in the degree of accuracy among the several types of immunochemical tests.

Colorectal adenomatous polyps detected by immunochemical occult blood screening.

BACKGROUND/AIMS: This study aimed to evaluate the validity of immuno-chemical occult blood screening for colorectal adenomas and to clarify the characteristics of this disease which are detected. METHODOLOGY: We studied 140 colorectal adenomas and 140 healthy controls in a hospital based case control study, in which three-day testing was conducted to assess the accuracy of the immuno-chemical occult blood screening test (total 280 patients). A further 80 colorectal adenomas 1 cm or larger, which were detected by a screening program, were compared with matched cases detected by the outpatient clinics (total 160 patients). A comparison of characteristics including tumor location, shape and histology was made between the two groups. RESULTS: Sensitivity and specificity were calculated to be 46% (61% for tumors larger than 1 cm, 30% for those less than 1 cm), and 96% respectively, showing a significant difference in sensitivity between large and small adenomas (p < 0.01). The proportion of rectal adenomas was significantly higher in the outpatient clinics (41%) than in the screening program (21%) (p < 0.05), whereas no differences were noted in the other measures. CONCLUSIONS: These results suggest that immuno-chemical occult blood is inadequate as a screening test for detecting small adenomas, as t can not differentiate between the detection of rectal adenomas from large adenomatous polyps.

Immunologic detection of fecal occult blood from upper digestive tract diseases.

BACKGROUND/AIMS: This study was conducted to evaluate the accuracy of the immunochemical occult blood test for upper digestive tract diseases. METHODOLOGY: The test was performed on 226 subjects, including 124 upper digestive tract diseases (12 ulcerative esophagitis cases, 10 esophageal cancer cases, 33 gastric ulcer cases, 33 gastric cancer cases, and 36 duodenal ulcer cases), 34 colorectal cancer cases, and 68 healthy subjects, after which, the accuracy of this test was evaluated. RESULTS: The test was positive 23 in upper digestive tract diseases (2 in ulcerative esophagitis, 2 in esophageal cancer, 5 in gastric ulcer, 8 in gastric cancer, 6 in duodenal ulcer), 31 in colorectal cancer, and 3 in healthy subjects, respectively. Thus, the sensitivity was 19% for upper digestive tract diseases (16.7% for ulcerative esophagitis, 20% for esophageal cancer, 15% for gastric ulcer, 24% for gastric cancer, 20% for duodenal ulcer) and 91% for colorectal cancer, and the specificity was 96%. Significant difference was noted in the sensitivity between upper digestive tract diseases and colorectal cancers (p0.001), whereas there was no difference among 5 upper digestive tract diseases. CONCLUSIONS: These results indicate that the immunochemical occult blood is inadequate as means for detection of upper digestive tract diseases, and that an examination of upper digestive tract is unnecessary in cases where the immunochemical occult blood test is positive, but there is no evidence of diseases in colon and rectum.

Clinico-pathological features of colorectal adenomatous polyps with negative results on immunochemical fecal occult blood test.

BACKGROUND: This study was carried out to clarify the clinico-pathological features of colorectal adenomatous polyps showing negative results on an immunochemical fecal occult blood test. METHODS: Four hundred sixty patients with colorectal adenoma 1.0 cm or larger in diameter served as subjects of this study. They were divided into two groups based on the results of an immunochemical fecal occult blood test with a 3-day method: two hundred twenty four patients with positive results (positive group) and two hundred thirty six patients with negative results (negative group). The above two groups were compared in terms of their individual factors such as lesion site, lesion size, lesion shape, and histological type. RESULTS: In negative group, the frequencies of rectal adenomatous polyps (p<0.01) and colorectal adenomatous polyps 1.0-1.5 cm in size (p<0.001) were higher, and also pedunculated type (p<0.05) were lower than in positive group, but there was no difference in histological type between the two groups. CONCLUSIONS: These findings suggest that immunochemical fecal occult blood testing is relatively inferior for the detection of colorectal adenomatous polyps in rectum, smaller size, and non-pedunculated type.

Detection rate of immunochemical fecal occult blood test for colorectal adenomatous polyps with severe dysplasia.

This study was conducted to assess the accuracy of an immunochemical occult blood test for detecting colorectal adenomas with severe dysplasia, and to determine the relationship between the grading of adenomatous dysplasia and the results of this test. Sixteen colorectal adenomas under 1 cm with severe dysplasia, 65 adenomas under 1 cm with mild-to-moderate dysplasia, 65 adenomas 1 cm or larger with mild-to-moderate dysplasia, 65 colorectal cancers and 130 healthy controls were investigated. Each subject was tested with an immunochemical fecal occult blood test on 3 consecutive days, and the accuracy of the test was evaluated. The detection rate of this test was 13% for severe dysplasia under 1 cm, 45% for severe dysplasia 1 cm or more, 17% for mild-to-moderate dysplasia under 1 cm, 40% for mild-to-moderate dysplasia 1 cm or more, and 89% for colorectal cancers, and the false positive rate was 5%, showing a significant difference in the detection rate between severe dysplasias 1 cm or more and those under 1 cm (P < 0.05) as well as significant difference between severe dysplasias 1 cm or more and mild-to-moderate dysplasia under 1 cm (P < 0.01), and between cancers and adenomas (P < 0.001), whereas there was no significant difference between the detection rates for severe dysplasia 1 cm or more and mild-to-moderate dysplasia 1 cm or more. These results indicate that there is no association between the detection rate of this immunochemical occult blood test for adenomas and the grade of adenomatous dysplasia.

Relationship between fecal sampling times and sensitivity and specificity of immunochemical fecal occult blood tests for colorectal cancer: a comparative study.

PURPOSE: The present study was conducted to assess the accuracy of three testing methods using an immunochemical fecal occult blood test based on the number of samples as the optimum means for screening of colorectal cancer. METHOD: One hundred eighty-four patients with colorectal cancer and 368 healthy controls served as the subjects for this study. Each subject was tested by an immunochemical fecal occult blood test for three consecutive days. For evaluation of the most desirable number of sampling times, we used the results of the first day for the one-day method, results of the first and second days for the two-day method, and results of three consecutive days for the three-day method. Sensitivities and specificities of the three testing methods were evaluated. RESULTS: Sensitivities of an immunochemical fecal occult blood test were calculated as 67.9 percent for the one-day method, 88 percent for the two-day method, and 90.8 percent for the three-day method; specificity was as follows: 97.5 percent for the one-day method, 95.6 percent for the two-day method, and 92.1 percent for the three-day method. A significant difference in sensitivity was shown between the one-day and two-day and the one-day and three-day methods (P < 0.01); also, a significant difference in specificity was shown between one-day and three-day and two-day and three-day methods (P <0.05). CONCLUSIONS: These results indicate that the two-day method is recommended for immunochemical fecal occult blood testing as a means of screening for colorectal cancer.

Immunochemical fecal occult blood test is not suitable for diagnosis of hemorrhoids.

PURPOSE: This study was conducted to clarify the diagnostic value of an immunochemical fecal occult blood test for hemorrhoids. PATIENTS AND METHODS: In a case-control study, an immunochemical fecal occult blood test with a 2-day method was carried out on 82 subjects with hemorrhoids, on 82 subjects with colorectal cancer, and on 82 healthy subjects. In a population-based cross-sectional study, 29,714 subjects who received an immunochemical occult blood screening with a 2-day method were divided into two groups, according to the results of a questionnaire on hemorrhoids, and the positivity rate of an immunochemical test as well as the predictive value for colorectal cancer were compared in the two groups. Moreover, both an immunochemical occult blood test with a 2-day method and colonoscopy were conducted at the same time on asymptomatic subjects during a medical checkup. RESULTS: In the case-control study, the test was positive in 13.4% subjects with hemorrhoids, in 84.1% subjects with colorectal cancer, and in 4.9% healthy subjects, respectively, showing a significant difference in the detection rate between the two diseases (P < 0.001). In the population screening program, the test was positive in 6.9% subjects with hemorrhoids and in 6.5% subjects without hemorrhoids, and the predictive value was 3.2% in subjects with and without hemorrhoids, respectively, indicating no significant difference in the positivity rate as well as the predictive value between the two groups. Among 232 subjects in a medical checkup, 28 patients with hemorrhoids and 21 patients with colorectal polyp 1 cm or larger were diagnosed by colonoscopy, and the occult blood test was positive in 16.7% patients with hemorrhoids and in 52.4% patients with colorectal polyp, respectively. There was a significant difference in the sensitivity between the two disease groups (P < 0.05). CONCLUSIONS: These findings indicate that the immunochemical fecal occult blood is unsuitable for the diagnosis of the patients with hemorrhoids and an examination of the colorectum is necessary in cases where the occult blood test is positive but there is a sign of hemorrhoids.

Diagnostic value of immunochemical fecal occult blood test for small colorectal neoplasms.

This study was designed to assess the diagnostic value of an immunochemical fecal occult blood test for small colorectal adenomas. In a screening program based comparative study, 60 colorectal adenomas under 1 cm (small polyp group), 60 colorectal adenomas 1 cm or larger (large polyp group) and 60 colorectal cancers (cancer group) detected by occult blood screening, and 120 healthy controls (control group), served as subjects. Moreover, 50 small adenomas, 50 large adenomas and 50 cancers detected in out-patient clinics, and 100 controls, served as subjects of a hospital based comparative study. Each of these subjects was tested by an immunochemical occult blood with 3 consecutive days, after removal of these colorectal neoplasms in a screening program based study and before as well as after removal in a hospital based study, and the positivity rate of this test was evaluated among these four groups in the two comparative studies. The positivity rate in a screening program based study was 23% for small polyp group, 8% for large polyp group, 5% for cancer group and 6% for control group, respectively. Significant difference was noted between small polyp and cancer as well as control groups (p <0.01), and between small polyp and large polyp groups (p <0.05). In a hospital based study, however, there was no significant difference in the positivity rate among four groups. These results suggest that high proportion of small polyps detected by fecal occult blood test screening may not be associated with bleeding from adenomas but probably from another gastrointestinal pathology.