Quantitative bone scintigraphy was performed on 23 white females with post-menopausal osteoporosis and vertebral compression fractures. These patients were then entered into a randomized, double-blind clinical trial or sodium fluoride therapy (NaF=14, placebo=9) which included repeat bone scintigraphy every six months. Scintigraphic images were acquired for 500K counts per image over the total body with computer acquisition over the posterior thoracic and lumbar spine. Images were obtained on a wide field-of-view gamma camera two hours after injecting 15 mCi of Tc-99m MDP. Data analysis showed a significant reduction in the activity ratio of abnormal vertebral body to normal vertebral body in those patients treated with sodium fluoride (paired t-test p=0.0095). No significant change was observed in the control group of (p=0.142). These results suggest that ...
This paper reviews the development of cerebral scintigraphy from its early days of planar imaging with simple technetium-99m labelled compounds to the recent revival of the technique in the form of...Full Text Available
Colorectal carcinoma is a highly prevalent and common cause of cancer in Taiwan. There is still no available cure for this malignant disease. To address this issue, we applied the multimodality of molecular imaging to explore the efficacy of diagnostic and therapeutic nanoradiopharmaceuticals in an animal model of human colorectal adenocarcinoma [colorectal cancer (CRC)] that stably expresses luciferase (luc) as a reporter. In this study, an in vivo therapeutic efficacy evaluation of dual-nanoliposome (100 nm in diameter) encaged vinorelbine (VNB) and "1"1"1In-oxine on HT-29/luc mouse xenografts was carried out. HT-29/luc tumor cells were transplanted subcutaneously into male SCID mice. Multimodality of molecular imaging approaches including bioluminescence imaging (BLI), gammascintigraphy, whole-body autoradiography (WBAR) and in vivo tumor growth tracing, histopathology and ...
As compared with terrestrial circuits, the communication satellite possesses superior characteristics such as wide area coverage, broadcasting, high capacity, and robustness to disasters. Utilizing the narrow band channel (64 kbps) of the geostationary satellite JCSAT 1 located at the altitude of 36,000 km above the equator, the authors investigated satellite-relayed medical imagings by video signals, with bone scintigraphy as a model. Each bone scintigraphy was taken by a handy-video camera, digitalized and transmitted from faculty of technology located at 25 kilometers apart from our department. Clear bone scintigraphy was obtained via satellite, as seen on the view box. Eight nuclear physicians evaluated 20 cases of bone scintigraphy. ROC (Receiver Operating Characteristic) analysis was performed between the scintigraphies on view box and via satellite by the ...
Quantitative bone scintigraphy was performed in patients with prostatic carcinoma before orchiectomy as well as two weeks, two and six months after operation. The count rate was recorded as serial gamma camera images over the lower thoracic and all lumbar vertebrae from 1 to 240 min and at 24 h after injection of "9"9"Tc"m-MDP. In almost all abnormal vertebrae an increased count rate was observed within one hour after injection. Most of the vertebrae which were considered normal at 4 h after injection, but had an increased 24h/4h ratio developed into abnormal vertebrae later in the study. The patients with normal bone scintigrams showed no change in "9"9Tc"m-MDP uptake during the study. The reproducibility of quantitative bone scintigraphy was found to be #+-# 7% (1 SD). In response to therapy, most of the patients with abnormal bone scintigrams showed an increase in count rate two weeks after operation ...
Qualitative technetium Tc 99m bone scintigraphy using phosphate compounds and gallium 67 scintigraphy were described as a helpful means in diagnosing necrotizing external otitis (NEO). They were, however, claimed to be nonspecific. Quantitative Tc 99m methylene diphosphonate bone scintigraphy and gallium 67 scintigraphy were performed in eight patients with NEO and in 20 patients with severe external otitis, in order to prove usefulness of scintigraphy in the diagnosis of NEO. Ratios of lesion to nonlesion for bone scintigraphy were 1.67 {plus minus} 0.16 in patients with NEO and 1.08 {plus minus} 0.09 in patients with severe external otitis, and for gallium 67 scintigraphy they were 1.35 {plus minus} 0.24 in NEO patients and 1.05 {plus minus} 0.03 in patients with severe external otitis. There was no difference in uptake between diabetic ...
Qualitative technetium Tc 99m bone scintigraphy using phosphate compounds and gallium 67 scintigraphy were described as a helpful means in diagnosing necrotizing external otitis (NEO). They were, however, claimed to be nonspecific. Quantitative Tc 99m methylene diphosphonate bone scintigraphy and gallium 67 scintigraphy were performed in eight patients with NEO and in 20 patients with severe external otitis, in order to prove usefulness of scintigraphy in the diagnosis of NEO. Ratios of lesion to nonlesion for bone scintigraphy were 1.67 #+-# 0.16 in patients with NEO and 1.08 #+-# 0.09 in patients with severe external otitis, and for gallium 67 scintigraphy they were 1.35 #+-# 0.24 in NEO patients and 1.05 #+-# 0.03 in patients with severe external otitis. There was no difference in uptake between diabetic patients with severe external ...
The need for noninvasive sensitive techniques for the diagnosis and follow-up of metabolic bone disease in dialysis patients has stimulated the author's interest in the efficacy of more detailed quantitative bone scintigraphy. Using hemodialysis to reduce elevated soft-tissue activity at scintigraphy, an attempt was made to assess the diagnostic sensitivity of quantitative bone scintigraphy as compared to qualitative bone scintigraphic, biochemical, radiographic and bone histologic studies. The second aim of these studies was to determine if one of the two major components of renal osteodystrophy is a major determinant for skeletal radiotracer uptake. The clinical observations on the efficacy and possible specificity of quantitative bone scintigraphy in the diagnosis and follow-up during treatment of renal osteodystrophy are presented briefly in this chapter. Thus, the use of ...
Sonography, subtraction scintigraphy, computed tomography and MRI were compared in 100 patients who had surgery 105 times for hyperparathyroidism (HPT). Surgical and pathological data were available for all operations. A total of 105 MR, 77 CT, 84 sonograms and 70 subtraction scintigrams were performed. The ability of the imaging modalities, individually and in combination, to detect HPT, histology, size, concomitant thyroid disease and location of the diseased glands has been evaluated. For primary HPT, sensitivity ranged from 68% for MRI to 40% for scintigraphy but was much lower for tertiary HPT with all modalities. The ability to identify diseased glands was strongly size dependent for all methods. If patients had had previous neck surgery, the most sensitive methods were MRI and scintigraphy and this also held true for patients with concomitant thyroid disease and ectopically located glands. The ...
The purpose of work - to estimate opportunities of scintigraphy using "9"9"mTc-MIBI, her necessities and demerits in parathyroid glands adenoma, also to compare her results to conclusions of other radiological methods and results of research of an operational fabric. (author)
Quantitative assessment of bone scintigraphy was performed in fifty-six patients with hip joint disease including femoral neck fracture, aseptic necrosis of the femoral head, traumatic dislocation of the hip, Perthes disease, and transient synovitis of the hip. In the static study, bone scintigraphy was obtained 3 hours after injection of sup(99m)Tc-MDP by gamma camera equipped with a computer and uptake ratios were calculated. In the dynamic study, bone scintigraphy was performed in one, 3 and 5 hours after injection of radionuclide. Femoral head uptake ratio was markedly decreased in osteonecrosis following femoral neck fracture and characteristically increased in aseptic necrosis of the femoral head but prolonged retention of sup(99m)Tc-MDP could be observed. Uptake ratios of epiphysis were decreased in Perthes disease but normal in transient synovitis of the hip. Static and dynamic study of bone ...
Twenty-two out of 31 patients with chronic renal failure and secondary hyperparathyroidism who underwent parathyroidectomy before operation underwent non-invasive image diagnosis of parathyroid glands by computed tomography (CT), scintigraphy with /sup 201/TlCl and /sup 99m/TcO/sup 4 +/, and/or ultrasonography. CT visualized 39 of 45 parathyroid glands (86.7%), weighing more than 500 mg. Scintigraphy with a subtraction method using a computer performed the diagnosis in 19 of 27 glands (70.4%). Ultrasonography detected 21 of 27 glands (77.8%). Image diagnosis was also useful in the postoperative follow-up study. The non-invasive image diagnosis of parathyroid glands in patients with chronic renal failure is thus valuable for 1) definite diagnosis of secondary hyperparathyroidism, 2) localization, and 3) diagnosis for effectiveness of conservative treatment.
Purpose: To evaluate a simple method for quantification of focal activity in bone scintigraphy (BS). Material and methods: The gamma camera was calibrated using a phantom. Quantitative bone scintigraphy (QBS) was performed on 11 men recently diagnosed with prostate cancer (PCa), for whom routine BS showed involvement of the skeleton. Following endocrine therapy for 4 to 8 months, a second QBS was performed. Changes in QBS values were then compared to changes in serum levels of prostate-specific antigen (PSA). Results: PSA response indicating regression of PCa was accompanied by a decrease in the QBS value in 8 of the 11 patients. The overall mean error of the QBS values was 15%. conclusion: QBS according to this method is a relatively simple procedure that might contribute to objective evaluation of therapeutic effects in skeletal metastases, although its validity must be tested in a larger clinical material.
Purpose: To evaluate a simple method for quantification of focal activity in bone scintigraphy (BS). Material and methods: The gamma camera was calibrated using a phantom. Quantitative bone scintigraphy (QBS) was performed on 11 men recently diagnosed with prostate cancer (PCa), for whom routine BS showed involvement of the skeleton. Following endocrine therapy for 4 to 8 months, a second QBS was performed. Changes in QBS values were then compared to changes in serum levels of prostate-specific antigen (PSA). Results: PSA response indicating regression of PCa was accompanied by a decrease in the QBS value in 8 of the 11 patients. The overall mean error of the QBS values was 15%. conclusion: QBS according to this method is a relatively simple procedure that might contribute to objective evaluation of therapeutic effects in skeletal metastases, although its validity must be tested in a larger clinical material
Sentinel node (SN) scintigraphy for cervical and vulvar cancer guides the gynaecological oncologist in finding the metastatic lymph nodes during lymphadenectomy. The role of the surgical gamma probe in the sentinel node concept in gynaecological oncology is to localise (SN) both intra-operatively and transcutaneously. Intra-operative hand-held collimated gamma probes are increasingly used for detection of the sentinel lymph node. A comparative evaluation of handheld gamma probes: Neoprobe 1500, Europrobe, Gamma Finder, Gamma Ray Prospector GRP1 and GPR2 was performed using different detection methods. Laboratory tests were performed in which sensitivity, spatial resolution and angular sensitivity were evaluated. The results for each gamma probe were summarised and discussed. Awareness of a gamma probes capabilities and ...
The purpose of this study is to evaluate the therapeutic efficacy of the liposome encaged with vinorelbine (VNB) and "1"1"1In-oxine on human colorectal adenocarcinoma (HT-29) using HT-29/luc mouse xenografts. HT-29 cells stably transfected with plasmid vectors containing luciferase gene (luc) were transplanted subcutaneously into the male NOD/SCID mice. Biodistribution of the drug was performed when tumor size reached 500-600 mm"3. The uptakes of "1"1"1In-VNB-liposome in tumor and normal tissues/organs at various time points postinjection were assayed. Multimodalities, including gammascintigraphy, bioluminescence imaging (BLI) and whole-body autoradiography (WBAR), were applied for evaluating the therapeutic efficacy when tumor size was about 100 mm"3. The tumor/blood ratios of "1"1"1In-VNB-liposome were 0.044, 0.058, 2.690, 20.628 and 24.327, respectively, at 1, 4, 24, 48 and 72 h postinjection. Gamma ...
Thirty-four patients with prostatic carcinoma were studied with quantitative bone scintigraphy and whole-body counting (WBC) 1 and 24 h after injection of [sup 99m]Tc-MDP before as well as two weeks and two months after orchiectomy. Thirteen of the patients had normal bone scintigrams and WBR at the three different investigations; 21 had skeletal metastases. The latter showed throughout the study higher local gamma camera count rates as well as WBR values than the patiens with normal scintigrams. In these patients a ''flare phenomenon'', with an increase in count rate two weeks after orchiectomy followed by a decrease two months post-operatively, was seen with quantitative bone scintigraphy but not with WBC. However, WBC may be a valuable method indicating the total extent of skeletal metastases in the body, while quantitative bone scintigraphy is more accurate in the ...
Thirty-four patients with prostatic carcinoma were studied with quantitative bone scintigraphy and whole-body counting (WBC) 1 and 24 h after injection of "9"9"mTc-MDP before as well as two weeks and two months after orchiectomy. Thirteen of the patients had normal bone scintigrams and WBR at the three different investigations; 21 had skeletal metastases. The latter showed throughout the study higher local gamma camera count rates as well as WBR values than the patiens with normal scintigrams. In these patients a ''flare phenomenon'', with an increase in count rate two weeks after orchiectomy followed by a decrease two months post-operatively, was seen with quantitative bone scintigraphy but not with WBC. However, WBC may be a valuable method indicating the total extent of skeletal metastases in the body, while quantitative bone scintigraphy is more accurate in the interpretation of individual skeletal ...
Secondary ischemic necrosis of femoral head due to loss of blood supply following to femoral neck fracture is well known. The regional distribution of bone-seeking radiopharmaceuricals in the skeleton can depend on a number of factors, but bone blood flow is a major physiological determinant of regional skeletal uptake of Tc-99m polyphosphate and bone imaging may thus be used for the evaluation of vascularity of the femoral head. The authors made a comparative study of scintigraphic findings and operative findings of 28 cases of femoral neck fracture treated at Kyung Hee University Hospital from April 1980 to May 1984. The results were as follows: 1. In 16 cases of proven avascular necorsis of femoral head, scintigraphy showed absent or decreased activity in 14 cases (87.5%), while radiography showed increased density in 10 cases (62.5%). 2. In 12 cases of proven vital femoral head, scintigraphy showed increased activity in ...
Hepatobiliary scintigraphy is the only non-invasive technique providing real-time assessment of hepatocytes function and bile progression from the liver to the intestine; for this reason it is of great importance in the study of jaundice and many other disorders of the liver and the biliary tract in children. Ultrasonography is the initial method of evaluating the intra- and extrahepatic bile ducts dilatation: the differential diagnosis between biliary atresia and neonatal hepatitis cannot however be done without hepatobiliary scintigraphy. Cystic fibrosis patients also require hepatobiliary scintigraphy; liver and biliary tract disease can really occur independently of the underlying disease severity and the presence of steatorrhoea. Hepatobiliary imaging in children who have undergone liver transplantation is of major importance; it can assess vascularity, parenchymal function biliary drainage, ...
Image subtraction techniques, in conjunction with [75Se]selenomethionine (75Se) scintigraphy, have recently been suggested to be a potentially valuable tool for localization of parathyroid abnormalities. With use of these techniques, we prospectively studied 15 patients scheduled for parathyroid operations. Postoperatively, all were normocalcemic. Anterior scintiscans of the neck were divided into quadrants, and regions of enhanced uptake were assigned to one or more quadrants. On this basis, by chance alone a minimum of 25% of single-gland enlargements would be assigned to the correct quadrant of the neck. We found that by use of 75Se scanning only 8 of 22 abnormal glands (36%) were assigned to the quadrant of the neck in which they were found intraoperatively. In no case was a clearly visualized focus of parathyroid activity encountered. These results do not justify the continued use of 75Se scintigraphy with or without ...
Computed tomography (CT) of the neck and mediastinum was performed in 16 patients with renal osteodystrophy. Thirty out of 34 excised parathyroid glands weighing more than 500mg were diagnosed preoperatively (88.2%). Scintigraphy of the neck with _2_0_1TlCl and sup(99m)TcOsub(4-) was also performed in 15 patients. The introduction of subtraction method with a mini-computor in the scintigraphy has remarkably improved the visualization rate of parathyroid glands. Ultrasonic echography (US) of the neck which is able to obtain not only transverse butalso longitudinal imaging was done in 7 patients. It has about same detection rate of the glands with CT. The visualization of enlarged parathyroid glands is valuable not only for localization but also for undeniable evidence of hyperparathyroidism. Also, repeated follow-up examination can determine the effectiveness of conservative treatment. (author).
This study was performed to evaluate the diagnostic usefulness of double-phase Tc-99m MIBI parathyroid scintigraphy with single photon emission computed tomography (SPECT) in patients with hyperparathyroidism. We also evaluated the relationship between Tc-99m MIBI uptake and oxyphil cell contents in parathyroid glands. The subjects were 28 parathyroid glands of 10 patients who underwent Tc-99m MIBI parathyroid scintigraphy and parathyroidectomy for clinically suspected hyperparathyroidism. Early and delayed pinhole images were obtained at 15 minutes and 2 hours after injection of Tc-99m MIBI, and SPECT images were followed. The weight and oxyphil cell contents of parathyroid tissue were obtained from pathologic specimen, and the scintigraphic findings were compared with histopathology. In surgical histopathology, 6 parathyroid adenomas and 9 parathyroid hyperplasias were confirmed. The sensitivity, ...
A large inguino-scrotal hernia was detected in the early phase of a radionuclide bone scan performed for evaluation of a femoral neck fracture not visualized on plain x-rays. The patient was administered 1 GBq of Scrotal scintigraphy using "9"9"mTc-MDP and a regional three-phase bone scan of the pelvis, hips and proximal femora was obtained on the gamma camera. Copyright (1999) Blackwell Science Pty Ltd
Quantitative bone scans were evaluated in 16 patients with osteoporosis and in a control group of 7 healthy subjects. Along with a detailed biochemical analysis of calcium-phosphorus metabolism and standartized reongenographs, a quantitative dynamic bone scintigraphy was performed according to the method proposed by the authors. The bone-accumulating factor K_b was determined on the base of mathematical analysis of the graph reflecting activity changes in bone tissue unit during the investigation, the blood-elimination factor K_h and kidney-elimination factor K_k. In addition the accumulation index AI (in %) was calculated as a relation between the activity in bone tissue unit, registered in 20 min interval, and the activity in soft tissues for the same time. Whereas the static gamma camera scintigraphy, made 3-4 hrs after injecting of the osteotrope radiopharmaceuticals, showed no specific changes in the patients examined, ...
[sup 123]I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was performed in 20 diabetic patients (NIDDM) and 8 control subjects to investigate the association between clinical autonomic nerve dysfunction and myocardial accumulation of MIBG. We used coefficient variance of R-R interval (CV[sub R-R]) as a index of the autonomic neuropathy and categorized diabetes into two groups (CV[sub R-R][>=]2.0: non-autonomic neuropathy. CV[sub R-R]<2.0: autonomic neuropathy). In planar imaging studies, heart to mediastinum MIBG uptake ratio (H/M) was calculated on both early and delayed images. The washout ratio of [sup 123]I-MIBG in the heart (%WR) was also obtained using myocardial tracer activity on the both images. Mean value of these indices in diabetic group did not reveal any significant difference with the value in the control group. On the SPECT images, low uptake was ...
Adenosine triphosphate (ATP) is an alternative to dipyridamole or adenosine in thallium-201 myocardial scintigraphy. However, the optimal dose of ATP has not been determined. A Doppler guide wire study showed the coronary flow velocity at a dose of 0.15 mg/kg of ATP was equal or higher than that at 0.14 mg/kg of adenosine or 0.56 mg/kg of dipyridamole. ATP was given intravenously to 67 patients with coronary artery disease at 0.15 mg/kg/min for 6 min. Thallium-201 was injected at 3 min, followed by immediate and delayed (3 hrs) tomographic imaging. There was no serious side effect during examination, although chest pain (26%), dyspnea (17%), and flushing (33%) were common. The sensitivity and specificity to detect coronary artery disease were 98 and 100%, respectively. The sensitivity to detect left anterior descending artery, left circumflex artery, and right coronary artery lesions was 94, 59 and 77%, respectively. ATP loading thallium-201 ...
Somatostatin receptor scintigraphy (SRS) is a valuable method for the detection of somatostatin receptor-positive lesions. Most gastrinomas (over-)express the somatostatin receptor subtype 2 which can be targeted by In-111 labeled Octreotide. Different studies show a high sensitivity of SRS for the localization and staging of gastrinomas. SRS seems to be superior to other non-invasive imaging modalities and has been proven to significantly contribute to patient management. However, the sensitivity depends on the size and exact localization of the tumors. Smaller lesions and lesions located in the duodenum show a significantly lower sensitivity. In any case, SRS belongs to the routine imaging procedure for gastrinomas for localization and staging and can also be used for evaluation of the tumor progression. (author)
For many years, {beta} radioactivity has been used to label molecules and follow them in various biological processes. {beta} imaging is obtained by autoradiography. Classically made on films or on photographic emulsions, autoradiography is now supplanted by radio-imagers which are very performing. The phosphor-imager, {beta}-imager and {mu}-imager are the systems mainly used today and their operating principles and properties are compared. The great advantages of these imagers are: their rapidity to obtain results and their reliability for absolute quantification. All emitters ({beta}{sup -}, {beta}{sup -} -{gamma} and {beta}{sup +}) are detectable as well as the gamma emitters of nuclear medicine, by means of their low energy electrons ejected during y emission. Phosphor-imager is well suited to ...
Purpose: To clarify the characteristics of meningioma scintigraphy with multiple brain imaging agents and to evaluate their roles in diagnosis of meningiomas. Methods: Blood flow, "9"9"mTc-ECD, "9"9"mTc-DTPA, and/or "9"9"mTc-MIBI brain imagings were performed in 21 patients with meningiomas (3 malignant, 18 benign) proved by surgery and pathology. CT/MRI examinations were also made within one month. Characteristics of meningioma images were analyzed and uptake ratios were calculated. Results: In 16 of 20 patients, increased radioactivity during the arterial phase in the blood flow image was seen. Concave round or oval defects with smooth contour in the cerebral cortex were observed in 17 of 19 patients with "9"9"mTc-ECD, depression of frontoparietal cortex was found in one case and no abnormality in the other. A homogeneous accumulation of radioactivity in area corresponding to the ...
Quantitative bone scintigraphy was performed in 24 patients with prostatic carcinoma before orchiectomy and up to one to four years after operation. The gamma camera count rate was recorded over the lower thoracic and all lumbar vertebrae 4 h after injection of [sup 99m]Tc-MDP. Twelve patients has normal bone scintigrams throughout the study. They showed from two years after operation a slight increase in count rate values compared with the preoperative values, probability due to hormonal changes after orchiectomy and to age-related alterations in skeletal metabolism. Twelve patients had abnormal bone scintigrams. They showed as a response to treatment the flare phenomenon with an increase in count rate over the abnormal vertebrae when measured two weeks after operation followed by a decrease after two months. The lowest count rate values were obtained between six months and one year after operation. Thereafter the count rate seemed to remain ...
Quantitative bone scintigraphy was performed in 24 patients with prostatic carcinoma before orchiectomy and up to one to four years after operation. The gamma camera count rate was recorded over the lower thoracic and all lumbar vertebrae 4 h after injection of "9"9"mTc-MDP. Twelve patients has normal bone scintigrams throughout the study. They showed from two years after operation a slight increase in count rate values compared with the preoperative values, probability due to hormonal changes after orchiectomy and to age-related alterations in skeletal metabolism. Twelve patients had abnormal bone scintigrams. They showed as a response to treatment the flare phenomenon with an increase in count rate over the abnormal vertebrae when measured two weeks after operation followed by a decrease after two months. The lowest count rate values were obtained between six months and one year after operation. Thereafter the count rate seemed to remain on ...
The purpose of this study is to evaluate the radiologic findings of the extraosseous Ewing's sarcoma. Six patients with pathologically confirmed extraosseous Ewing's sarcoma were retrospectively reviewed. Patients included two men and four women with an average age of 21.5 years (age range 9-48 years). Plain radiographs (six patients), magnetic resonance (MR) images (five patients), computed tomographic (CT) scans (three patients) and whole body scintigraphy (two patients) were reviewed and analyzed. Images were evaluated with regard to lesion location, size, margin, muscle or bone involvement and intrinsic imaging characteristics on CT and MRI. The tumors were located in the thigh (three patients), back (two patients) and upper arm (one patient). The tumors ranged in size from 2.3 cm to 7.5 cm (mean, 5.2 cm), were mainly well circumscribed and showed no evidence of calcification prior to treatment. ...
Twenty-four patients were studied with both /sup 201/Tl-thallus chloride and /sup 99m/Tc-TBI scintigraphy following exercise. Comparison of the two agents in detecting segmental myocardial ischemia and scar was made in 18 patients with evidence of coronary artery disease on /sup 201/Tl-thallous chloride scintigraphy. Agreement between the two studies was observed in 77% (125 of 162) of left ventricular segments, suggesting that /sup 99m/Tc-TBI can be used as a myocardial perfusion agent. Limitations were related to early high background activity from lungs and liver. The high lung activity and early myocardial redistribution within the 1st hour contributed to the failure of /sup 99m/Tc-TBI to detect 16 segmental defects seen in the immediate post-exercise thallous chloride scan. Persistently high liver activity additionally affected accurate interpretation in the left ventricular segments close to the diaphragm. Improvement in the accuracy of ...
Dynamic quantitative bone scintigraphy was performed on 31 men with prostatic carcinoma before orchiectomy as well as 2 weeks, 2 and 6 months postoperatively. After injection of technetium methylene diphosphonate Tc 99m ("9"9"mTc-MDP) the count rate was recorded as serial images over the lower thoracic and all the lumbar vertebrae from 1 to 240 min post-injection. Thirteen men had normal bone scintigrams with no changes in "9"9"mTc-MDP content at the four different investigation times. Eighteen men had skeletal metastases. Throughout the study half of the abnormal vertebrae in these patients showed an abnormal count rate after only 6 min post-injection. After 1 h it was possible in almost all abnormal vertebrae to predict abnormal bone uptake. In response to therapy a 'flare phenomenon' with an increase in count rate was seen 2 weeks after orchiectomy followed by a decrease 2 months postoperatively in most of the abnormal vertebrae. The count ...
Ewing's sarcoma is a highly malignant neoplasm of the bone whose origin is still uncertain. A strong relationship exists between Ewing's sarcoma and tumors of neural origin (Ewing family of tumors). Ewing's sarcoma must be distinguished from other round-cell tumors like lymphoma and neuroblastoma and also must be differentiated from osteogenic sarcomas. On plain radiographs, Ewing's sarcoma appears as a lytic or mixed lytic-sclerotic, rarely as predominantly sclerotic lesion with margins Lodwick grade III. It is located primarily in the diaphyseal and metadiaphyseal regions of the long bones of the lower extremities. A large soft tissue tumor is usually present. Magnetic resonance imaging is the imaging modality of choice to evaluate the extent of the primary lesion, to monitor the response to neoadjuvant chemotherapy and to follow up non-resected Ewing's sarcomas. Bone scintigraphy is necessary to detect skeletal ...
An imaging detector for {gamma}-rays ({approx equal}1 MeV) based on minicell MWPCs with converters and a position resolution of {Delta}x=0.5 mm has been developed and tested. Very high rate capability (>10{sup 8}/cm{sup 2} s) and a special readout for suppression of scattered radiation are implemented allowing to enhance the measured contrast. The relevant physical processes are discussed and first pictures are presented. (orig.).
The purpose of this paper is to investigate the influence of diabetic myocardial damage (suspected myocardial damage; SMD) diagnosed by [sup 201]Tl-SPECT and diabetic cardiac autonomic neuropathy (AN) on myocardial MIBG uptake in patients with NIDDM. Eighty-seven diabetic patients divided into four subgroups: 23 with SMD (+) AN (+); 19 with SMD (+) AN (-); 27 with SMD (-) AN (+); 18 with SMD (-) AN (-), and 10 controls were studied. Both planar and SPECT images were taken at 30 minutes (early) and 3 hours (delayed) after [sup 123]I-MIBG injection. The heart to mediastinum uptake ratio (H/M) and washout ratio of [sup 123]I-MIBG (WR) were obtained from both planar images. Similarly, the difference between the [sup 201]Tl image and the [sup 123]I-MIBG image in the total uptake score (TUS) was taken as the difference in the total uptake score ([Delta]TUS) representing cardiac sympathetic denervation without ...
The objective of this study was to determine the usefulness of parathyroid scintigraphy in histological estimation for secondary hyperparathyroidism (2HPT) using Tc-99m sestamibi or Tc-99m tetrofosmin. Tc-99m sestamibi (MIBI) and Tc-99m tetrofosmin (Tetro) parathyroid imaging following double-phase study, magnetic resonance imaging (MRI), and ultrasound were performed on 14 patients with 2HPT. All patients underwent parathyroidectomy. The uptake of two tracers in parathyroid areas was compared with the histopathologic findings. Forty-nine parathyroid glands were surgically explored and histologically proven to be hyperplastic. Of these, 42 were diagnosed with nodular type (N-type) hyperplasia, and 7 with diffuse type (D-type) hyperplasia. MIBI and Tetro parathyroid imagings detected 34 and 35 parathyroid glands, respectively. The sensitivity of MIBI was determined to be 76.2% (32/42) for N-type, and ...
There are no specific diagnostic tests or a gold standard method for measuring disease activity and outcome in spondyloarthropathies (SpA). Many different methods have been developed to assess the signs and symptoms in SpA. The aim of this study was to evaluate the value of scintigraphy, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and Bath Ankilosing Spondylitis Disease Activity Index (BASDAI) in the evaluation of disease activity in early axial SpA diagnosed with magnetic resonance imaging (MRI). Thirty early MRI-positive axial SpA patients (23 males, 7 females) with a median age of 35 (18?55) years and a median duration of inflammatory low back pain of 24 (8?60) months were included in the study. In the patients with sacroiliitis, the sensitivity, specificity, and pos...
Direct radionuclide cystography is known to be sensitive and safe in children with suspected vesical-ureteral reflux. In this study we have investigated the utility of direct radionuclide cystography in renal transplant recipients with a recent history of pyelonephritis or recurrent urinary infections. Direct radionuclide cystography is a simple test, however it requires a rigorous methodology in order to obtain images during fill-in as well as during voiding in both men and women. The images must be interpreted using a rigorous image display methodology. Twenty-eight radionuclide cystographies were performed in 17 patients. Among the 17 tests performed for the initial diagnosis of reflux , 12 were positive. Four patients with positive results and four patients with negative results were also investigated by radiologic cystography. Similar results were obtained in those patients. Nine scintigraphies ...
The NIS-6 group at Los Alamos National Laboratory pioneered the development of Tomographic Gamma Scanning and continue to improve its utility in real measurement situations. Building on this experience we report the development of a state of the art TGS system suitable for industrial applications. The image reconstruction and visualization software has been integrated into the familiar Canberra NDA2000 software suite which also handles all other aspects of the data acquisition and management. In this paper we describe the salient design and performance parameters of the system. The application of gamma-ray tomography to safeguards for improved assay accuracy and knowledge confirmation is discussed. In particular we compare and contrast the relative merits of this TGS and a traditional Segmented Gamma Scanner and illustrate how the 3-D visualization of the TGS image can provide ...
To assess the contribution of adrenal-derived androgens in women with hirsutism, adrenal scintigrams under dexamethasone suppression (DS) were performed on 35 women with increasing facial or body hair and irregular or absent menses. Based upon the DS regimen chosen (8 mg/d for 2 days or 4 md/d for 7 days before the injection of 6..beta..-(/sup 131/I)iodomethylnorcholesterol), three imaging patterns were identified. The first was the absence of uptake before 3 days (8-mg DS) or before 5 days (4-mg DS) after injection. This imaging pattern was seen in 17 of the 35 patients studied and was considered normal. The second pattern was bilateral uptake earlier than 3 days (8-mg DS regimen) or 5 days (4-mg DS) after injection. This was seen in 13 of the 35 patients and was interpreted as bilateral early visualization. Adrenal-vein catheterization performed on six patients with this pattern showed increased adrenal-vein testosterone. The third pattern, ...
An imaging position sensitive detector for charged particles, neutrons, X-and gamma rays has been developed. The novel feature of this scintillation imaging radiation detector is its ability to detect individual nuclear particle scintillations with a h igh degree of spatial resolution. The key elements of this detector system are a high gain, low noise image intensifier tube, a CCD camera and commercially available image processing hardware and software. This detector system is highly effective for applications such as low fluence and real time neutron radiography, mapping of radioactive contamination in nuclear reactor fuel rods, X-ray diffraction imaging, high speed autoradiography and in general position sensitive detection of nuclear radiation. Results of some of the exploratory experiments carried out using this detector system are presented in this paper. ...
Fourteen patients with cervical hip fractures were treated with internal fixation using titanium screws. The femoral head vitality was evaluated with "9"9Tc"m-MDP scintigraphy and scintimetry within 2 weeks postoperatively and by serial low field magnetic resonance imaging (MR). Two patients with reduced radionuclide uptake (femoral head ratio =# 1.0), MR revealed a focal decrease of the signal intensity in the femoral head or neck at 2, 3 and 7 months after fracture, respectively. The radiographs in one of these patients were normal at 7 months after fracture. The second one showed signs of necrosis at 16 months and the last one developed delayed/non-union. With a non-ferromagnetic osteosynthesis the healing course after femoral neck fracture can be studied with low field MR equipment without disturbing artifacts. The time period between ischaemia and definite abnormalities on MR may embrace several months. (orig.).
There are many differences between industrial CT and industrial radiography, such as imaging principle, inspection time, radiation dose and the requirements for operators etc. The national standards for radiation protection of industrial detection are not applicable to the requirements of protection and safety for #gamma#-ray industrial CT to some extent now. In order to standardize the production and use for #gamma#-ray industrial CT, protect the safety of operators and the public, and to promote the popularization and application of #gamma#-ray industrial CT, it is significant to establish the national standards for radiation protection of #gamma#-ray industrial CT as soon as possible. The purpose of this paper is to introduce the contents of this standard, and specify some important terms. Then there is a brief discussion on the existing problems during establishing such ...
The paper describes an application of the tree classification method Random Forest (RF), as used in the analysis of data from the ground-based gamma telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to be discriminated against a dominating background of hadronic cosmic-ray particles. We describe the application of RF for this gamma/hadron separation. The RF method often shows superior performance in comparison with traditional semi-empirical techniques. Critical issues of the method and its implementation are discussed. An application of the RF method for estimation of a continuous parameter from related variables, rather than discrete classes, is also discussed.
It is shown that a cosmic gamma-ray telescope made of a multilayer silicon tracker and a imaging CsI calorimeter, is capable of identifying cosmic ray nuclei. The telescope charge resolution is estimated around 4% independently of charge. Simulation methods are used to determine the telescope properties for nuclei detection.
A computer controlled digital system, Fuji Computed Radiography (FCR) is capable of providing more stable output image than conventional screen/film system. So FCR would be an ideal system for the detection of pneumoconiosis due to the constant high quality of the output films. We tried to find the optimum image processing to compensate the small size (1/2 in length of a full-size radiograph) of the output image of digital radiography. The best result for FCR was given with gamma 0.85 and 0.30 enhancement of response at spatial frequency of 0.085 cycle/mm. On the other hand, the digitally processed FCR size ILO standard films, the characteristics of which is different from FCR output films, proved to be most preferable when the image processing is made with gamma 0.85 and 0.25 enhancement at spacial frequency of 0.17 cycle/mm. If the above mentioned ...
French ... Orig. Title Scintigraphie osseuse quantifiee chez l'enfant et l'adolescent - repartition selon l'age des taux de fixation de diverses pieces osseuses normales.
Medical imaging using single gamma-ray-emitting radionuclides typically makes use of parallel hole collimators or pinholes in order to achieve good spatial resolution. However, a tradeoff in sensitivity is inherent in the use of a collimator, and modern preclinical single photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma rays, often less than 0.1%. A system for small animal SPECT imaging which uses no collimators could potentially achieve very high sensitivity-several tens of percent-with reasonably sized detectors. This would allow two significant improvements in preclinical studies: images could be obtained more rapidly, allowing higher throughput for screening applications, or for dynamic processes to be observed with very good time resolution; and images could be obtained with less radioactive tracer, making ...
The tissue distribution of "1"3"1I-transferrin ("1"3"1I-Tf) was studied in athymic nude mice having s.c. human colonic adenocarcinoma HT-29 xenografts. Four days after "1"3"1I-Tf injection, the "1"3"1I specific activity measured in the HT-29 tumor, i.e. amount of radioactivity per gram of fresh tissue, represented 0.31 #+-# 0.09% of the injected radioactivity and was 1.90 fold more than that measured in the murine colon (P < 0.05). After correction for intravascular "1"3"1I-Tf as estimated by mean of "9"9"mTc-Sn in vivo labeling of red blood cells, the "1"3"1I specific activity observed in the HT-29 tumor was 7.21 fold more than that observed in the murine colon. This subtracting method enabled us to localize a HT-29 tumor xenograft by #gamma# scintigraphy of the entire animal and demonstrated that "1"3"1I-Tf could be a non-specific but potent marker for human colon cancer. (author).
The value of biliary scintigraphy was studied in 180 patients with suspected biliary tract disease. Most of the patients were investigated additionally by conventional techniques such as cholecystography, cholangiography and ultrasonography. It is concluded that biliary scintigraphy is a simple and safe technique for visualization of the biliary tract. It is particularly useful in the evaluation of acute cholecystitis, in patients with iodine sensitivity obstructive from nonobstructive jaundice.
A computer controlled digital system, Fuji Computed Radiography (FCR) is capable of providing more stable output image than conventional screen/film system. So FCR would be an ideal system for the detection of pneumoconiosis due to the constant high quality of the output films. We tried to find the optimum image processing to compensate the small size (1/2 in length of a full-size radiograph) of the output image of digital radiography. The best result for FCR was given with gamma 0.85 and 0.30 enhancement of response at spatial frequency of 0.085 cycle/mm. On the other hand, the digitally processed FCR size ILO standard films, the characteristics of which is different from FCR output films, proved to be most preferable when the image processing is made with gamma 0.85 and 0.25 enhancement at spacial frequency of 0.17 cycle/mm. If the above mentioned ...
The field of neutron imaging has a broad scope of applications and has played a pivotal role in visualizing and quantifying hydrogenous masses in metallic matrices. The field continues to expand into new applications with the installation of new neutron imaging facilities. In this scope, a neutron imaging facility for computed tomography and real-time neutron radiography is currently being developed around 2.0 MW TRIGA MARK-II Reactor at Maamora Nuclear Research Centre in Morocco (CENM). The neutron imaging facility consists of a neutron collimator, a real-time neutron imaging system and imaging process systems. In order to reduce the gamma-ray content in the neutron beam, the reactor tangential channel was selected. For power of 250 kW, the corresponding thermal neutron flux measured at the inlet of the tangential channel is around 3.10{sup ...
The field of neutron imaging has a broad scope of applications and has played a pivotal role in visualizing and quantifying hydrogenous masses in metallic matrices. The field continues to expand into new applications with the installation of new neutron imaging facilities. In this scope, a neutron imaging facility for computed tomography and real-time neutron radiography is currently being developed around 2.0 MW TRIGA MARK-II Reactor at Maamora Nuclear Research Centre in Morocco (CENM). The neutron imaging facility consists of a neutron collimator, a real-time neutron imaging system and imaging process systems. In order to reduce the gamma-ray content in the neutron beam, the reactor tangential channel was selected. For power of 250 kW, the corresponding thermal neutron flux measured at the inlet of the tangential channel is around 3.1011 ...
Osteonecrosis (ON) of the hip joint remains an unsolved therapeutical problem. Diagnosis of ON of the hip has been improved by the technical progress of imaging modalities and better understanding pathomorphology. Over a long period only plain radiographs have been available. Scintigraphy and computed tomography contributed to differential diagnosis and early detection of bone necrosis. Diagnosis in an early reversible stage is of importance. Understanding of pathophysiology, early diagnosis and therapeutical approach has been significantly improved by MR imaging. Using the ARCO system all imaging modalities and their diagnostic viability are described in the five ARCO stages. At the end a diagnostic algorithm will be proposed. (orig.) [German] Die Osteonekrose des Hueftgelenks (ON) stellt noch immer ein nicht geloestes therapeutisches Problem dar. Die diagnostischen Moeglichkeiten bei der ON wurden in ...
A neutron collimator system is being designed as part of a neutron imaging facility for computed tomography and real-time neutron radiography research at the through beam port of the University of Texas TRIGA reactor. Lack of sufficient information about collimator systems in a through port from the literature necessitated the use of Monte Carlo calculations using the MCNP code 3 to search for optimal design configuration and materials that maximize the thermal neutron intensity at the image plane while minimizing the fast neutrons and gamma radiation.
Globular clusters are quite compact (size {proportional_to}10 pc) objects distributed spherically around the galaxy. They contain about 10{sup 5}-10{sup 6} mostly old stars. The number of millisecond pulsars in typical globular cluster is expected to be large (of the order of 100). We investigate the possible mechanism of production of high energy gamma-rays in those objects. Part of the wind energy of pulsars (energy conversion factor) is converted into relativistic leptons. Those leptons can upscatter in inverse Compton process low energy starlight and CMB photons and produce gamma-rays. MAGIC is an Imaging Atmospheric Cerenkov Telescopes located at Canary island of La Palma. We present results and discussion of the MAGIC observations of globular cluster M13.
A thermal neutron imaging facility for real-time neutron radiography and computed tomography has recently been developed at the University of Texas TRIGA reactor. Extensive Monte Carlo design calculations were used to determine optimal design parameters of the neutron collimator system to avoid costly trial and error. Thermal neutron flux determined by gold foil activation is 5 {times} 10{sup 6} n/cm{sup 2}{center_dot}s at the primary imaging location with beam size of 22.5 cm in diameter. The collimation ratio can be varied from 125 to 235. The neutron-to-gamma ratio is 7.8 {times} 10{sup 6} n/cm{sup 2}{center_dot}mR. The facility has been tested for radiography and tomography applications and is now fully operational.
The ability of "9"9"mTc-IgG scintigraphy to predict the development of rheumatoid arthritis (RA) in 47 patients with arthralgia was investigated. "9"9"mTc-IgG scintigraphy and the serum test for rheumatoid factor (RF), measured at the beginning of a year long study, were compared for their ability to predict RA. During the study 8 patients developed RA. The specificity and positive predictive values of RF in predicting RA were 79% and 50% respectively, and for "9"9"mTc-IgG scintigraphy 97% and 88%. The sensitivity and negative predictive values of RF were 100% and of "9"9"mTc-IgG-scintigraphy 88% and 97%, respectively. In conclusion, "9"9"mTc-IgG scintigraphy has additional value to RF with respect to the prediction of the development of RA in patients with arthralgia. 27 refs.
For diagnosis of loosening or infection after implantation of a single-side or double-side total hip endoprosthesis 59 patients being in pain were investigated by a combination of bone scan (Technetium-99m DPD) and leucocyte scan (Indium-111 labelled leucocytes). The correlation between clinical results and scintigraphic findings revealed: bone scintigraphy detects loosening of prostheses with 95% sensitivity (45/47); bone scintigraphy excludes an instable prosthesis with 89% specificity (3/27). 45% of the loosened prostheses revealed an infection (21/47): leucocyte scintigraphy could detect 17 correct positive. Three leucocyte scans of 53 prostheses without clinical signs of infection were false positive. Therefore, leucocyte scintigraphy had a sensitivity of 91% and a specificity of 94% for detecting infection. Bone scintigraphy can detect loosening of prostheses with 93% ...
Surgical resection is the only curative treatment strategy for intrahepatic cholangiocarcinoma (CC). Therefore, accurate staging is essential for appropriate management of patients with CC. We assessed the usefulness of 2-["1"8F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in the staging of CC. We undertook a retrospective review of FDG PET images in 21 patients (10 female, 11 male; mean age 57 years) diagnosed with CC. Ten patients had hilar CC and 11, peripheral CC. Patients underwent abdominal magnetic resonance imaging (MRI) (n=20) and computed tomography (CT) (n=12) for the evaluation of primary tumours, and chest radiography and whole-body bone scintigraphy for work-up of distant metastases. For semi-quantitative analysis, the maximum voxel standardised uptake value (SUV_m_a_x) was obtained from the primary tumour. All peripheral CCs showed intensely increased FDG uptake, and some demonstrated ...
A phantom simulation imaging quality control device is described that effectively simulates one centimeter lesions, using steel ball bearings as gamma ray attenuators. The bearings are mounted in a synthetic resinous sheet in an orthogonal pattern. The phantom can provide uniformity, resolution, linearity, distortion and field size checks, all with a single exposure.
This study concerns our experiences with abdominal gammaimaging using Tc-99m colloid and with abdominal angiography using Tc-99m-pyrophosphate labelled erythrocytes ''in vivo'' based on the modified technique described by Callahan. The dynamic or perfusion phase was first performed, then the static phase during which for the first two hours scans were taken every 15 minutes and thereafter every 4-6 hours. The routine image corresponds to the first, although it was necessary at times to take oblique projections. The study was felt to be accomplished after 48 hours upon observing no extravasation of radioactive material in the abdominal region, or upon detecting a bleeding site. The investigation was performed on 11 patients, 8 having positive scans of abdominal extravasation, later confirmed in 6 by endoscopy and by surgery. In 2, the presence of salmonelosis was shown by laboratory analysis. Endoscopy and angiography XR ...
AGILE pointed observations performed from July 9, 2007 to October 30, 2009 are a recent, high quality gamma-ray data archive for monitoring studies of medium to high brightness gamma-ray sources in the 30 MeV -50 GeV energy range. We present a variability study of the 1AGL sources over the complete AGILE pointed Observation Blocks (OBs) dataset. The first AGILE Gamma-Ray Imaging Detector (GRID) catalog (Pittori et al. 2009) included a significance-limited (4 sigma) sample of 47 sources (1AGL), detected with a conservative analysis over a first-year non-uniform sky coverage dataset. In this analysis we used data of an improved full Field of View (FOV) event filter, on a much larger (about 27.5 months) observation dataset, analyzing each OB separatedly. This data processing resulted in an improved source list as compared to the 1AGL one. We present here some results on the variability of some of these ...
We report a new case of Lyme disease with cardiac manifestations, which has been possible to follow during the long period of 12 years. We have detected the usual ECG abnormalities, and concentric hypertrophic myocardiopathy, by echocardiography. The acute myocarditis was demonstrated by /sup 111/In-antimyosin scintigraphy, which showed global myocardial uptake of the tracer, constituting the first report, to our knowledge, of Lyme myocarditis diagnosed by this method.
Infections of aortoarterial prostheses are serious, difficult to detect, and difficult to treat. Scintigraphy with indium-111 labeled autologous leukocytes is an accurate noninvasive method of assessing the presence and extent of such an infection. In three cases of aorto-arterial bypass graft infections, the leukocyte study was successful in establishing the diagnosis and in assessing the extent of infection. Other noninvasive diagnostic techniques are useful, but all have serious limitations. The leukocyte study alone appears to be free of likely sources of error.
Gamma scanning measurements are used to determine the radioactive nuclides from an irradiated fuel rod in a hot cell which is a routine task in the Irradiated Materials Examination Facility (IMEF) of the Korea Atomic Energy Research Institute (KAERI), Total gamma spectra of radioactive nuclides and the atomic ratio of {sup 134}Cs to {sup 137}Cs in a few segments of a single fuel rod are measured by the present gamma scanning system. For the purpose of determining the radioactive nuclide's distribution in detail within a fuel rod quantitatively, we attempt to upgrade the present gamma scanning system in this paper, therefore, an investigation of the feasibility of the tomographic gamma scanning (TGS) technique, which is one of the promising nondestructive assay (NDA) methods is proposed. The TGS technique is an efficient method and it has an accurate precision for the ...
The possibility to transform the future linear e"+e"-colliders into the #gamma#e and #gamma##gamma# colliders with approximately the same energies and luminosities was shown earlier. Their properties are compared from the point of view of possible physical investigations on them. 10 refs.; 1 tab.
The development of a replacement to the conventional film based X-ray imaging technique is required for many reasons. One possible route for this is the use of a large area film of a suitable semiconductor overlaid on an amorphous silicon readout array. A suitable semiconductor exists in cadmium telluride and its tertiary alloy cadmium zinc telluride. In this thesis the spectroscopic characteristics of commercially available CZT X- and gamma-radiation detectors are established. The electronic, optical, electro-optic, structural and compositional properties of these detectors are then investigated. The attained data is used to infer a greater understanding for the carrier transport in a CZT radiation detector following the interaction of a high energy photon. Following this a method used to fabricate large area films of CdTe on a commercial scale is described. This is cathodic electrodeposition from an aqueous electrolyte. The theory and ...
Nuclear medicine and magnetic resonance imaging (MRI) are widely used in cardiac diagnostics. Both techniques have been carefully evaluated and are equivalent for the assessment of regional and global wall motion as well as the evaluation of ejection fraction and cardiac volumes, though MRI is herein currently seen as gold standard. For evaluation of myocardial perfusion, extensive data exist for nuclear imaging, that, next to high diagnostic accuracy for evaluation of coronary artery disease, show incremental prognostic information and allow for independent risk stratification. Because of rapid technical advance, myocardial perfusion imaging has also become feasible with cardiac MRI. Results of recent studies are promising, but the data are few compared to perfusion scintigraphy. For viability assessment in patients with ischemic cardiomyopathy, positron emission tomography (PET) with FDG is currently ...
The University of Virginia's real-time neutron radiography facility was characterized by measurement of the total neutron flux, gold/cadmium ratio, neutron/gamma ratio, and the effective collimar length-to-aperture diameter (L/D) ratio. The real-time neutron imaging system and collimator were further characterized by measuring the modulation transfer function (MTF) of the system. The collimator effectiveness was measured by using the MTF to determine the ''unparallelism'' of the neutron beam. The computer-based image processing system allowed rapid calculation of the MTF and the collimator effectiveness. The results of these measurements, using no collimator and a simple tube collimator, demonstrated the method's ability to determine the effective L/D ratio. The MTF measurement scheme provided a fast, reliable, and reproducible means of monitoring any changes in the ...
The University of Virginia's real-time neutron radiography facility was characterized by measurement of the total neutron flux, gold/cadmium ratio, neutron/gamma ratio, and the effective collimar length-to-aperture diameter (L/D) ratio. The real-time neutron imaging system and collimator were further characterized by measuring the modulation transfer function (MTF) of the system. The collimator effectiveness was measured by using the MTF to determine the ''unparallelism'' of the neutron beam. The computer-based image processing system allowed rapid calculation of the MTF and the collimator effectiveness. The results of these measurements, using no collimator and a simple tube collimator, demonstrated the method's ability to determine the effective L/D ratio. The MTF measurement scheme provided a fast, reliable, and reproducible means of monitoring any changes in the real-time system, including both the neutron beam and the ...
Indium-111 is currently the radionuclide of choice for colonic transit study. However, it is expensive and not available in many hospitals. Technetium-99m has been proposed for colonic transit study but the short half-life has limited its use. Gallium-67 citrate is inexpensive and available in most countries. Most importantly, it has a suitable half-life for colonic transit study. Attempts have been made in some studies to use {sup 67}Ga citrate to label activated charcoal, but the results have not been good because of poor stability. In this study, we successfully labelled activated charcoal with {sup 67}Ga citrate by adding alcohol and 5% glucose solution. To evaluate the in vitro stability, the {sup 67}Ga-activated charcoal was incubated in a milieu mimicking the intestinal content, containing lipase, trypsin and glycochenodeoxycholate at different pH values (6.0, 7.0, 7.4 and 8.0) and for different durations (0 h, 24 h, 48 h, 72 h and 96 h). For the in vivo study, the {sup ...
Until April 2007 the Major Atmospheric Gamma ray Imaging Cherenkov (MAGIC) telescope used a 300 MSamples/s flash analog-to-digital converter (FADC) system to sample the shaped photomultiplier tube (PMT) signals produced by the captured Cherenkov photons of air showers. Different algorithms to reconstruct the signal from the read-out samples (extractors) have been implemented and are described and compared. Criteria based on the obtained charge and time resolution/bias are defined and used to judge the different extractors, by applying them to calibration, cosmic and pedestal signals. The achievable charge and time resolution have been derived as functions of the number of incident photo-electrons.
Tumor-targeted monoclonal antibodies (mAb) might be useful as diagnostic or therapeutic agents when linked to cytotoxic or imaging reagents. Our group is working to test this hypothesis by linking cytocidal and image-producing isotopes to mAb and testing the utility of the radioimmunoconjugates formed in animal model systems. Radioiodines were first employed for these purposes,but unfavorable nuclear properties (half-lives, #gamma#-ray and #beta#-particle energies) and chemical reactivity (deiodination in vivo) limit their utility. Labeling immunoproteins with metallic radionuclides offers more versatility in that the selection of potentially useful radiometals spans the periodic table.Of the metallic radionuclides with physical properties most suited for use with mAb in nuclear medicine, few are more available or desirable than those of bismuth ("2"1"2Bi) and lead ("2"0"3Pb, "2"1"2Pb), as listed in Table 1. "2"1"2Bi or ...
We investigate monoenergetic gamma-ray signatures of Z^1 dark matter annihilations in a non-minimal Universal Extra Dimensions model. The self-interactions of the non-Abelian Z^1 gauge boson give rise to a large number of contributing Feynman diagrams that do not exist for annihilations of the Abelian gauge boson B^1, which is the standard Kaluza-Klein dark matter candidate. We find that the annihilation rate is indeed considerably larger for the Z^1 than for the B^1. Even though relic density calculations indicate that the mass of the Z^1 should be larger than the mass of the B^1, the predicted fluxes are of the same order of magnitude. We compare our results to existing experimental limits, as well as to future sensitivities, for image air Cherenkov telescopes, and we find that the limits are reached already with a moderately large boost factor. However, the realistic prospects for detection depend on the energy resolution, as well as on the ...
The full text follows. A thermal neutron imaging facility (TNIF) capable of real time neutron radiography and computed tomography was developed for the University of Texas TRIGA Mark II (UT-TRIGA) reactor from 1994-1998. The facility was developed with a through reactor beam port capable of producing a 5.2 x 10{sup 6} n/cm{sup 2}/s thermal neutron flux with a gamma dose rate of less than 1 mR/s after collimation. The original TNIF included the UT-TRIGA reactor, neutron collimation array, sample positioning system, neutron image intensifier tube, video camera, computerized image acquisition system, and a radiation shield. A 0.7 mm slit in cadmium was easily detectable using neutron radiography, and 1.4 mm diameter holes bored in an aluminum block were easily resolved using computed neutron tomography. Precise lower limits of the system resolution have hot been determined. The TNIF is currently being ...
Currently, x-ray mammography is the method of choice in breast cancer screening programmes. As the mammography technology moves from 2D imaging modalities to 3D, conventional computational phantoms do not have sufficient detail to support the studies of these advanced imaging systems. Studies of these 3D imaging systems call for a realistic and sophisticated computational model of the breast. DeBRa (Detailed Breast model for Radiological studies) is the most advanced, detailed, 3D computational model of the breast developed recently for breast imaging studies. A DeBRa phantom can be constructed to model a compressed breast, as in film/screen, digital mammography and digital breast tomosynthesis studies, or a non-compressed breast as in positron emission mammography and breast CT studies. Both the cranial-caudal and mediolateral oblique views can be modelled. The anatomical details inside the phantom ...
The main objective of the present thesis was develop and get operational a real-time neutron radiography system, at the IPEN-CNEN/SP. This system is installed inside the shielding of an old facility, designed in 1988, for film radiography, which is installed at the beam-hole 08 of the 5 MW, IEA-R1 Nuclear Research Reactor. The most important modifications at the such facility were the increase of the {gamma}-radiation filter thickness, increase of the inner area of the shielding, design of a neutron collimator and a light tight box. The main characteristics of the neutron beam at the irradiation position are: flux: 1 x 10{sup 6}n/cm{sup 2}s, collimation ratio 70, effective energy 7 meV, diameter 20 cm, neutron/{gamma} ratio {approx} 10{sup 6}n/cm{sup 2}mrem. The real-time images have been obtained by means of an imaging system that consists of a screen scintillator, a light intensifier, a video camera, ...
The main objective of the present thesis was develop and get operational a real-time neutron radiography system, at the IPEN-CNEN/SP. This system is installed inside the shielding of an old facility, designed in 1988, for film radiography, which is installed at the beam-hole 08 of the 5 MW, IEA-R1 Nuclear Research Reactor. The most important modifications at the such facility were the increase of the #gamma#-radiation filter thickness, increase of the inner area of the shielding, design of a neutron collimator and a light tight box. The main characteristics of the neutron beam at the irradiation position are: flux: 1 x 10"6n/cm"2s, collimation ratio 70, effective energy 7 meV, diameter 20 cm, neutron/#gamma# ratio #approx# 10"6n/cm"2mrem. The real-time images have been obtained by means of an imaging system that consists of a screen scintillator, a light intensifier, a video camera, a digitizing frame ...
WR 104 is the prototype for a small but growing group of stars that present the remarkably striking appearance of pinwheels. High resolution images of WR 104 show the (apparently) face-on spiral turning with an 8 month period. The pinwheel is assumed to be composed of dust produced via colliding winds in a low-inclination WR+OB binary. These assumptions have been very successful in modeling the imaging, but remain largely untested by spectroscopy. Strong motivation for further study of this system has emerged. Recent theory suggests that some gamma-ray bursts (GRB's) are core-collapse supernovae viewed nearly pole-on. The WC class Wolf-Rayet star in WR 104 is the type of star thought to be a possible GRB progenitor. If the orbit (and thus stellar rotation axes) are pole-on, the effects on Earth's biosphere could be significant. Confrontation of the face-on colliding-wind binary model with eight years of spectroscopy, ...
A LIXI (Light Intensifier X-ray Image) device has been employed in a real-time neutron radiography system. The LIXI is coupled to a video camera and the real-time images can be observed in a TV monitor, and processed in a computer. In order to get the real-time system operational, the neutron radiography facility installed at the IEA-R1 m nuclear research reactor of the IPEN-CNEN/S P has been optimized. The most important improvements were the neutron/gamma ratio, the effective energy of the neutron beam, decrease of the scattered radiation at the irradiation position, and the additional shielding of the video camera. Several one-frame as well as computer processed images are presented. The overall Modulation Transfer Function for the real-time system was obtained from the resolution parameter p = 0:44 +- 0:04 mm; the system sensitivity, evaluated for a Perspex step wedge, was determined and the average ...
We review results from general relativistic axisymmetric magnetohydrodynamic simulations of accretion in Sgr A*. We use general relativistic radiative transfer methods and to produce a broad band (from millimeter to gamma-rays) spectrum. Using a ray tracing scheme we also model images of Sgr A* and compare the size of image to the VLBI observations at 230 GHz. We perform a parameter survey and study radiative properties of the flow models for various black hole spins, ion to electron temperature ratios, and inclinations. We scale our models to reconstruct the flux and the spectral slope around 230 GHz. The combination of Monte Carlo spectral energy distribution calculations and 230 GHz image modeling constrains the parameter space of the numerical models. Our models suggest rather high black hole spin ($a_*\\approx 0.9$), electron temperatures close to the ion temperature ($T_i/T_e \\sim 3$) and high ...
This progress report covers period from Nov. 1, 1989 to Aug. 31, 1990. The long term objective was to develop receptor-binding radiotracers for SPECT or PET imaging of CNS or peripheral nervous system. The specific chemistry aims, as understood on the basis of past findings, were: to synthesize and develop a more polar analogs of 4IQNB, possessing similar binding characteristics but eliminated more rapidly from the surrounding tissues and the target organ, to design a method of introducing a technetium chelating group onto a molecule or cholinergic agent without drastic lowering of its apparent affinity, to synthesize and develop radiotracers based on m-AChR antagonists selective for one of the subtypes of the receptor. The chemistry service aims were to prepare and characterize (R,R)- and (R,S)-4IQNB and derivatives, to provide the triazene intermediate to other investigators, and to provide ({sup 123}I)4IQNB for in vivo imaging. The ...
Bone scintigraphy was performed in 16 men with newly diagnosed prostatic carcinoma before orchiectomy as well as 2 weeks and 2 months after operation. The uptake in the lower thoracic and lumbar vertebrae was registered up to 240 min after injection of /sup 99m/Tc-MDP and was then calculated for each patient and vertebra. The relative standard deviation in measured uptake due to measuring technique was estimated to be +-7%. In eight patients, who had normal bone scintigraphies before orchiectomy, there were no changes in the uptake values after operation. The remaining eight patients had widespread metastatic involvement prior to treatment, six of these patients showed a so-called 'flare phenomenon' in the abnormal vertebrae which means an initial increase in uptake after operation followed by a decreased uptake in response to therapy. One patient had a continuously increased uptake in all the abnormal vertebrae which ...
Bone scintigraphy was performed in 16 men with newly diagnosed prostatic carcinoma before orchiectomy as well as 2 weeks and 2 months after operation. The uptake in the lower thoracic and lumbar vertebrae was registered up to 240 min after injection of "9"9"mTc-MDP and was then calculated for each patient and vertebra. The relative standard deviation in measured uptake due to measuring technique was estimated to be #+-#7%. In eight patients, who had normal bone scintigraphies before orchiectomy, there were no changes in the uptake values after operation. The remaining eight patients had widespread metastatic involvement prior to treatment, six of these patients showed a so-called 'flare phenomenon' in the abnormal vertebrae which means an initial increase in uptake after operation followed by a decreased uptake in response to therapy. One patient had a continuously increased uptake in all the abnormal vertebrae which correlated well with the ...
{sup 99m}Tc-N-pyridoxyl-5-methyl-tryptophan (PMT) scintigraphy, which exhibits highly specific for the diagnosis of primary hepatocellular carcinoma (HCC), was performed for recurrent HCC following non-surgical treatment. Eighty-four patients (total 351 examinations) were selected for the study. The ability of PMT scintigraphy to diagnose recurrent HCC after treatment was compared with that of computed tomography, ultrasonography and angiography. The results showed that sixty-three (75%) of 84 cases demonstrated positive findings during our follow-up period, most of the tumors initially showing positive findings remained PMT positive when they recurred and PMT studies shortly after treatment demonstrated wider tracer uptake rather than the actual tumor area. In conclusion, PMT scintigraphy for patients with HCC after non-surgical treatment exhibited high accuracy in identifying viable HCC only for tumors indicating positive ...
In 576 patients quantitative scintigraphy of the sacroiliac joints and the spinal cord with "9"9"mTc-pyrophosphate was performed. 328 were patients with proven ankylosing spondylitis according to the New York criteria. 120 were patients with a clinically and roentgenologically suspected ankylosing spondylitis and 128 persons formed a healthy control group. The count rate in small regions of interest (ROI) in the sacroiliac joints, the spinal cord and the os sacrum were compared on the basis of indexes. The scintigraphic data of patients with ankylosing spondylitis were compared with the healthy control group and with the radiographic findings and radiologic staging of the disease. In a longitudinal follow-up study during 1 to 6 years these investigations were continued together with clinical and roentgenological checks. Quantitative bone scintigraphy provides characteristic indexes for ankylosing spondylitis, indicating the increased mineral ...
The atrial myocardium has been barely visible with thallium-201 myocardial scintigraphy. This is probably related to the difference in size, distance from anterior chest wall, and small coronary blood flow of the atrium, compared with the ventricle. We have encountered eight cases of visualization of the right atrial appendix (RAA). The RAA was identified from multiple projections in all cases and sometimes confirmed by radionuclide angiocardiography. Evidence derived from ECG, chest radiographs, and cardiac catheterization, indicated that the most important factor in the visualization might be the displacement of the RAA to a more anterior position.
While bone metastases producing photon deficient defects on bone scintigraphy have previously been reported, this finding has not been emphasized for hepatocellular carcinoma (HCC). Furthermore, ''filling-in'' of such photon deficient defects with 67Ga at skeletal sites of metastatic HCC has not been described. In this case report, the combination of a photon deficient defect on bone scintigraphy and avid accumulation of 67Ga in this same area was of value in confirming the diagnosis of metastatic HCC.
We treated 13 patients for femoral neck fracture. They consisted of 2 males and 11 females, and were classified according to Garden stage classification; Stage I, 3 cases; Stage II, 2 cases; Stage III, 2 cases; Stage IV, 4 cases. Two trochanteric fracture cases were used by control. We evaluated perfusion of the femoral head after femoral neck fracture using bone scintigraphy, which is considered useful for evaluation of perfusion of the femoral neck before operation. (author)
Sixteen patients with PAGET's disease of bone underwent quantitative bone scintigraphy with "9"9"mTc-MDP before and after a long-term treatment with carbocalcitonin, a synthetic analogue of eel calcitonin. The radionuclide study consisted in the blood pool and bone uptake measurement and in the bone avidity calculation (bone uptake - blood pool ratio). In our patients, a significant decrease in bone uptake and bone avidity was found, whereas the blood pool remained statistically unchanged. This behaviour could be accounted for the shift of the compact bone to a lamellar pattern. (orig.).
Sixteen patients with PAGET's disease of bone underwent quantitative bone scintigraphy with /sup 99m/Tc-MDP before and after a long-term treatment with carbocalcitonin, a synthetic analogue of eel calcitonin. The radionuclide study consisted in the blood pool and bone uptake measurement and in the bone avidity calculation (bone uptake - blood pool ratio). In our patients, a significant decrease in bone uptake and bone avidity was found, whereas the blood pool remained statistically unchanged. This behaviour could be accounted for the shift of the compact bone to a lamellar pattern.
sup(99m)Tc-MDP bone scintigraphy was performed on patients who received muscle-pedicle bone graft. In each of the bone head and the bone graft, a time-activity curve was obtained. In this muscle-pedicle bone graft, active revascularization and marked osteogenesis, which suggested rapid bone repairing, were observed. The bone scintigraphy was considered to be useful in observing the result of bone grafts, blood circulation, and time of bone fusion, and of value for early detection of secondary changes.
In the fields of medical imaging, geophysical well logging, and industrial radiography, it is often of interest to characterize the spatially distributed sensitivities of neutron and gamma-ray measurement devices to the physical properties of the materials being examined. For instance, one may wish to know how the count rate in a detector varies in response to small changes in the local density of the irradiated object as a function of position. Experimental determination of such sensitivity functions is often impractical. Consequently, we have developed a general three-dimensional Monte Carlo numerical technique that allows us to directly compute the differential sensitivity of an arbitrary integral response parameter, such as a time- or energy-discriminated count rate, with respect to the spatial distribution of macroscopic cross sections and sources in the irradiated medium. Sensitivities to object density, porosity, etc., can easily be ...
It is proposed to measure the spot sizes and polarization of #gamma# beams of future #gamma#e and #gamma##gamma# colliders detecting e"+e"- pairs produced as a result of interaction of high energy #gamma# quanta with density modulated and not modulated laser photons. The quantum electrodynamics cross sections, necessary numerical results as well as a short comparison of the proposed method with some other methods are given. (orig.).
We discuss the search of excited leptons and quarks with spin 1/2 at #gamma##gamma# and at #gamma#e colliders. We show that #gamma##gamma# colliders have important advantages for the observation of excited leptons and quarks in comparison with ee, ep, and pp colliders discussed in previous papers. These collisions give a simple test for the chirality of the l"*l#gamma# transition. The anomalous magnetic moment of excited leptons can be observed when its value is not too small. (orig.).
Aim: Compounds such "9"9"mTc-MDP and "9"9"mTc-HEDP are used regularly in bone scintigraphy for metastasis detection. The therapeutics properties of beta emitter radionuclides like "1"5"3Sm, "1"6"6Ho and "1"7"7Lu has been widely reported in literature being "1"7"7Lu the less developed for medical applications. With the purpose of study different radiopharmaceuticals alternatives, for metastasis bone palliation, we have evaluated, on a comparative basis, the labeling of "1"5"3Sm-MDP, "1"5"3Sm-HEDP, "1"6"6Ho-MDP, "1"6"6Ho-HEDP, "1"7"7Lu-MDP and "1"7"7Lu-HEDP from the exhibited radionuclidic purity and biological distribution point of view. Material and Methods: The radionuclides were produced at La Reina Research Reactor, Chilean Nuclear Energy Commission. The radionuclidic purity was determined by gamma-Ray spectrometry. The labeling was accomplished with MDP (Plenum) and HEDP synthesized in-house. The in-vitro affinity of labeled compounds to ...
The authors study the processes {gamma}e {r{underscore}arrow} {gamma}e and {gamma}{gamma} {r{underscore}arrow} {gamma}{gamma}, in the context of the proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. With an ultraviolet cutoff M{sub S} {approximately} 1 TeV for the effective gravity theory, the cross sections obtained for these processes at the Next Linear Collider (NLC), with the e{gamma} an {gamma}{gamma} options, deviate from the predictions of the Standard Model significantly. The results suggest that, for typical proposed NLC energies and luminosities, the predictions of WSQG can be tested in the range 1 TeV {approx{underscore}lt} M{sub S} {approx{underscore}lt} 10 TeV, making e{gamma} an {gamma}{gamma} colliders important tools for probing WSQG.
An exhaustive compendium of normal and abnormal imaging is presented. The following systems and procedures are illustrated by over 2800 captioned illustrations: liver, spleen, and hepatobiliary imaging; perfusion and ventilation lung imaging; thyroid imaging; salivary gland imaging; bone imaging; brain imaging; radionuclide cisternography; blood flow studies; gallium imaging; nuclear cardiology; and renal imaging. Not included in the atlas are adrenal imaging procedures and emission computed tomography. (ERB)
We summarize the predictions of different models for total #gamma##gamma# cross-sections. The experimentally observed rise of #sigma#_#gamma#_#gamma# with s radical _#gamma#_#gamma#, faster than that for #sigma#_p_-_b_a_r_p, #sigma#_#gamma#_p is in agreement with the predictions of the Eikonalized Minijet Models as opposed to those of the Regge-Pomeron models. We then show that a measurement of #sigma#_#gamma#_#gamma# with an accuracy of < or approx. 8-9% (6-7%) is necessary to distinguish among different Regge-Pomeron type models (the different parameterisations of the EMM models) and a precision of < or approx. 20% is required to distinguish the predictions of the EMMs and of those models which treat 'photon like a proton', for the energy range 300< s radical_#gamma#_#gamma# <500 GeV. We further show that the difference in model predictions for ...
Three possibilities to observe the Higgs-top interaction at future {gamma}{gamma}-colliders are discussed: (a) associated Higss production via the {gamma}{gamma}{yields}tanti tH reaction, (b) Higgs obliged radiative correction to the {gamma}{gamma}{yields}tanti t channel, (c) Higgs resonance production via {gamma}{gamma}{yields}H{yields}ZZ. The results obtained show windows of the Higss mass where the Yukawa interaction of the Higss with the top quark can be studied at {gamma}{gamma}-colliders. (orig.).
Three possibilities to observe the Higgs-top interaction at future #gamma##gamma#-colliders are discussed: a) associated Higss production via the #gamma##gamma##->#tanti tH reaction, b) Higgs obliged radiative correction to the #gamma##gamma##->#tanti t channel, c) Higgs resonance production via #gamma##gamma##->#H#->#ZZ. The results obtained show windows of the Higss mass where the Yukawa interaction of the Higss with the top quark can be studied at #gamma##gamma#-colliders. (orig.).
A recently developed neutron diagnostic probe system has the potential to satisfy a significant number of van-mobile and fixed- portal requirements for nondestructive verification of sealed munitions and detection of contraband explosives and drugs. The probe is based on a unique associated-particle sealed-tube neutron generator (APSTNG) that interrogates the object of interest with a low-intensity beam of 14-MeV neutrons generated from the deuterium-tritium reaction and that detects the alpha-particle associated with each neutron. Gamma-ray spectra of resulting neutron inelastic scattering and fission reactions identify nuclides associated with all major chemicals in chemical warfare agents, explosives, and drugs, as well as many pollutants and fissile and fertile special nuclear material. Flight times determined from determined from detection times of the gamma-rays and alpha-particles yield a separate tomographic image ...
The first meeting on e{gamma}/{gamma}{gamma} colliders was held on September 28 and 29, 1993, at the National Laboratory for High Energy Physics. After general remarks were delivered, lectures were given on QED in intense laser field, photon linear collider, laser focusing, luminosity distribution in the e{gamma}/{gamma}{gamma} colliders, QCD correction for {gamma}{gamma}{yields}H, radiation correction for e{gamma}/{nu}W process, SUSY particle production at the e{gamma} and {gamma} gamma colliders, formation of e{sup *} in e{gamma} collision, and general remarks on the theory. Discussion was carried out on `Where are we going from here?` In this book, the gists of the lectures are collected. (K.I.).
A 52-year-old woman had a history of left hearing loss for 5 years. An acoustic neurinoma with 3.2 cm in diameter was diagnosed and treated with gamma-knife radiosurgery (19 Gy of marginal dose) 1 year and 4 months ago. She developed headache, nausea, and visual disturbance 1 month prior to admission. Slight left facial palsy appeared after radiosurgery. Magnetic resonance imaging demonstrated the tumor with central necrosis in the left cerebellopontine angle cistern, increasing in size to 3.5 cm in diameter, and hydrocephalus. Tumor removal was performed incompletely, because of the fibrous appearance of the tumor and severe adherence with the surrounding cerebellar tissue. Facial palsy did not worsen after surgery. Since the hydrocephalus was not resolved, a right ventriculo-peritoneal shunt was inserted. The clinical course in this case suggests that tumor removal followed by radiosurgery was an approximately effective treatment for large ...
Cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) have been regarded as promising semiconductor materials for hard X-ray and Gamma-ray detection. The high atomic number of the materials (Z_{Cd} =48, Z_{Te} =52) gives a high quantum efficiency in comparison with Si. The large band-gap energy (Eg ~ 1.5 eV) allows us to operate the detector at room temperature. However, a considerable amount of charge loss in these detectors produces a reduced energy resolution. This problem arises due to the low mobility and short lifetime of holes. Recently, significant improvements have been achieved to improve the spectral properties based on the advances in the production of crystals and in the design of electrodes. In this overview talk, we summarize (1) advantages and disadvantages of CdTe and CdZnTe semiconductor detectors and (2) technique for improving energy resolution and photopeak efficiencies. Applications of these imaging detectors in ...
Full text: Based on experience with nuclear material confiscated in Hungary from illicit trafficking activities in the nineties it has been decided that traditional gamma-spectrometry should be complemented by destructive analytical techniques. The 17/1996 (I. 31.) Korm. Governmental Decree delegated the identification, categorization and characterization tasks to the Institute of Isotopes, Budapest. Routine gamma-spectrometric methods have been further developed aiming at the i) age (production date) determination of seized samples and complete (nondismountable) uranium-bearing items (such as fresh fuel bundles and fission chambers) by HRGS technique, ii) improvement of measurement accuracy and reliability. Starting in 2005 mass spectrometry (ICP-SFMS) and scanning electron microscopy have been implemented to characterize nuclear samples in more detail and to analyze environmental samples both for isotopic and elemental composition focusing on ...
The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm{sup -3} or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant ...
The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm"-"3 or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant applications. ...
The Gamma Physics (GaP) program of physical phenomena investigation is proposed on #gamma#p, #gamma#e and #gamma##gamma# colliders at TeV energies. The program contains specialized software (CompHEP system) created for automation of particle interaction processes calculations in the framework of various gauge models. Preliminary physical results are presented (heavy quark production, W, Z production, supersymmetry etc.), and further software development is suggested. (R.P.) 22 refs., 8 figs., 4 tabs.
Very high energy (VHE; >100 GeV) observations of a sample of selected active galactic nuclei (AGN) were performed between January 2005 and April 2007 with the High Energy Stereoscopic System (HESS), an array of imaging atmospheric-Cherenkov telescopes. Significant detections are reported elsewhere for many of these objects. Here, integral flux upper limits for twelve candidate very high energy (VHE; >100 GeV) gamma-ray emitters are presented. In addition, results from HESS observations of four known VHE-bright AGN are given although no significant signal is measured. For three of these AGN (1ES 1101-232, 1ES 1218+304, and Mkn 501) simultaneous data were taken with the Suzaku X-ray satellite.
Dusty primordial disks surrounding young low-mass stars are revealing tracers of stellar and planetary formation. The evolution and lifetime of these disks define the boundary conditions of the mechanisms of planet formation. Stellar companions, however, can significantly change this evolution through their tidal interactions. Stellar evolution and planet formation in binaries have to respond to an environment of truncated, quickly disappearing disks--very different compared to an isolated star environment. In order to investigate details of the influence of binarity on circumstellar disk evolution, we obtained adaptive optics supported near-infrared imaging and spectroscopy of the individual components of 22 low-mass binaries in the well-known Orion Nebula Cluster. Brackett gamma emission, which we detect in several systems, is used as a tracer for the presence of an active accretion disk around each binary component. We find a low fraction of ...
An apparatus for non-invasively inspecting an object, such as an item of luggage, for explosives material is described. It comprises a multi-channel thermal neutron inspection system having a plurality of neutron irradiation chambers. Simultaneous operation of several channels increases the maximum system throughput several times. Each chamber has a lithium neutron source which is stimulated to neutron production by a proton beam. Beam switching magnets are energised by pulsing to divert a common proton beam to each source in turn. The initial beam is generated by a radio frequency quadrupole accelerator. The advantages of this system are very low residual source activity and controllable neutron production thereby minimising safety hazards. The irradiation chamber may contain several different gamma ray detectors to identify the elements present in explosives material. In addition, a neutron radiography imaging means may be employed to ...
The authors are developing a high specificity detector for detecting the increased metabolic rate of breast tumors. Positron emission mammography (PEM) provides a highly efficient, high spatial resolution positron imaging system. PMT plays a very important role in PEM detectors, because most of the systems consist of scintillator arrays coupled with PMT. Our detector is composed of 20 x 20 arrays of 2 mm x 2 mm x 20 mm of Bi_4Ge_3O_1_2 (BGO) scintillators and a novel flat panel position-sensitive PMT (FP-PS-PMT)-Hamamatsu R8400-00-M256. Spatial resolutions of 2.0 mm FWHW and energy resolutions of 23% FWHM are achieved. (authors)
The diagnosis of dialysis-related amyloid (AB-amyloid) has been based usually on clinical and radiological criteria. Following the discovery that beta 2-microglobulin was the major protein of this amyloid, we isolated and radiolabelled uremic plasma beta 2-microglobulin. After intravenous injection, gamma-camera images of selected joint areas were obtained from 42 patients who were on regular hemodialysis therapy. Positive scans involving the shoulder, hip, knee and carpal regions were found in 13 of 14 patients treated for more than 10 years and 10 of 16 patients treated for 5 to 10 years. Patients treated for less time had negative scans. Specificity was indicated by negative scans in non-amyloid inflammatory lesions in control hemodialysis patients. Up to 48-fold tracer enrichment was detected in excised AB-amyloid containing tissue as compared to amyloid-free tissue. These findings suggest that circulating radiolabelled beta 2-microglobulin ...
Gemini North adaptive optics imaging spectroscopy is presented for the Galactic ultra-compact HII (UCHII) region K3-50A. Data were obtained in the K-band using the Near-infrared Integral Field Spectrograph (NIFS) behind the facility adaptive optics module ALTAIR in natural guide star mode. The NIFS data cube reveals a complex spatial morphology across the 0.1 pc scale of the 3'' UCHII region. Comparison of the nebular emission to Cloudy ionization models shows that the central source must have an effective temperature between about 37000 K and 45000 K with preferred values near 40000 K. Evidence is presented for sharp density variations in the nebula which are interpreted as a clearing of material nearest the central source. High excitation lines of FeIII and SeIV show that the ionization of the nebula clearly changes with distance from the central source. A double lobed kinematic signature (+/- 25 kms) is evident in the Br gamma line map which ...
Aim: Rheumatoid arthritis is a limiting disease having, among its pathological features, the inflammation of synovial tissue with progressive and later destruction of the articulation. This leads to joint deformation and loss of its function, generating pain and reducing the mobility of the affected articulation. The aim was to evaluate "1"6"6Ho-Hydroxyapatite ("1"6"6 Ho-HA) as potential radiopharmaceutical for the symptomatic treatment of chronic and acute arthritis. Materials and Methods: Holmiun-166 was produced by irradiation of Ho_2O_3 at La Reina Research Reactor, Nuclear Chilean Energy Commission. Hydroxyapatite was in-house synthesized. Its labelling and quality controls follows the internationally accepted procedures. An antigen's arthritis was induced to eight New Zealand rabbits with the "1"6"6 Ho-HA radiochemical being administered thereafter in two dosage modalities (single and double). The compound therapeutic efficiency was evaluated based upon clinical improvement and ...
The Subcommittee for Surveillance of Nuclear Medicine Practice has implemented a survey for actual nuclear medicine practice in Japan every 5 years. This article reports on the third survey implemented during a one-month period in June 1992. Questionnaires were sent to all 1256 facilities employing radiopharmaceuticals in routine practice, and 1162 (92.5%) answered. In vivo nuclear medicine examinations per day were performed in 6600 cases. SPECT accounted for 19.4%, as compared with 7.1% in the 1987 survey. According to organs, the frequency of examination for the cerebrospinal region was 3.2 and 2.2 times higher than that in the 1982 and 1987 surveys, respectively, whereas for the thyroid gland it was 0.6-fold and 0.7-fold that of these surveys. The proportion of bone scintigraphy was the highest (24.5%), followed by tumor scintigraphy (14.1%) and myocardial scintigraphy (11.9%). The frequency of myocardial and cerebral ...
The frequency of peripheral pulmonary artery stenosis in patients after surgical repair of tetralogy of Fallot (TOF) ranges from 20 to 40%. This can be either primary or secondary to the surgical intervention. The influence of resulting lung perfusion alterations on the life quality of patients is difficult to predict. The aim of this study was to compare the utility of the diagnostic procedures in this group of patients, with particular focus on lung perfusion scintigraphy. This study comprised 104 patients who underwent repair of TOF at ages from 5 months to 25 years. The patients have been followed up for from 4.2 to 25 years. On the basis of chest X-ray peripheral pulmonary artery stenosis was suspected in 11 patients, in 12 on the basis of echocardiography examination. Lung perfusion scintigraphy has been performed on 87 patients. The disturbances in lung perfusion (mostly in the left lung) were show by means of lung perfusion ...
In not infected knee prostheses bone scintigraphy is a possible method to diagnose mechanical loosening, and therefore, to affect treatment regimes in symptomatic patients. However, hitherto studies showed controversial results for the reliability of bone scintigraphy in diagnosing loosened knee prostheses by using asymptomatic control groups. Therefore, the aim of our study was to optimize the interpretation procedure and to evaluate the accuracy using results from revision surgery as standard. Methods: Retrospectively, we were able to examine the tibial component in 31 cemented prostheses. In this prostheses infection was excluded by histological or bacteriological examination during revision surgery. To quantify bone scintigraphy, we used medial and lateral tibial regions with a reference region from the contralateral femur. Results: to differentiate between loosened and intact prostheses we found a threshold of 5.0 for ...
In not infected knee prostheses bone scintigraphy is a possible method to diagnose mechanical loosening, and therefore, to affect treatment regimes in symptomatic patients. However, hitherto studies showed controversial results for the reliability of bone scintigraphy in diagnosing loosened knee prostheses by using asymptomatic control groups. Therefore, the aim of our study was to optimize the interpretation procedure and to evaluate the accuracy using results from revision surgery as standard. Methods: Retrospectively, we were able to examine the tibial component in 31 cemented prostheses. In this prostheses infection was excluded by histological or bacteriological examination during revision surgery. To quantify bone scintigraphy, we used medial and lateral tibial regions with a reference region from the contralateral femur. Results: to differentiate between loosened and intact prostheses we found a threshold of 5.0 for ...
Renal osteodystrophy is a metabolic bone disease and a common complication of end-stage chronic renal failure and maintenance dialysis treatment. In this study, we examined the correlation between quantifying bone scintigraphy and serum biochemical markers in hemodialysis patients. Bone scintigraphy with technetium-99m-hydroxy-methylene-diphosphonate ("9"9"mTc-HMDP) was performed on 28 patients on maintenance hemodialysis. Bone scintigraphy was performed using a standard protocol and was quantified by setting regions of interest (ROIs) over selected regions. The bone-to-soft-tissue ratio (B/ST ratio) at each region was calculated in all patients. The B/ST ratios were then compared with serum biochemical markers. The B/ST ratio for the skull correlated well with serum bone-specific alkaline phosphatase (BAP) (r=0.735, p<0.001), serum deoxypyridinoline (DPD) (r=0.806, p<0.001) and intact parathyroid hormone (intact PTH) ...
The cross sections of neutral tensor mesons T=a_2, f, f', ... production in the exclusive #gamma##gamma##->#TT' or semiexclusive #gamma##gamma##->#TX processes (three gluon exchange) in the semihard region s>>vertical stroketvertical stroke>1 GeV"2 are calculated. The relation of investigated processes to the problem of perturbative Odderon is discussed. The possibility of measurements at LEP and at a future #gamma##gamma#-colliders is discussed too. (orig.).
Future linear colliders offer unique opportunities to study {gamma}{gamma}, {gamma}e interactions. Using the laser backscattering method one can obtain {gamma}{gamma}, {gamma}e colliding beams with energy and luminosity comparable to the electron-position luminosity or even higher. In this review physical principles of photon colliders are described and various problems, concerning the accelerator, laser, interaction region and luminosity are discussed. Some examples of physical processes are given. ((orig.)).
We study the signals for composite vector leptoquarks in e"+e- colliders (CERN e"+e- collider LEP II, Next Linear Collider, and CERN Linear Collider) through their effects on the production of jet pairs, as well as their single and pair productions. We also analyze their production in #gamma#e and #gamma##gamma# collisions.
... Title : Optical Images Due to Lenses and Mirrors. ... Abstract : The properties of real and virtual images formed by lenses and mirrors are reviewed. ...
The angular ..gammagamma..-correlations for nuclei of Sr even-even isotopes with A=82, 84, 86, 88 were measured. Multipole structurs of ..gamma..-transtion series and th coefficients multipole mixing were determined.
The angular #gamma##gamma#-correlations for nuclei of Sr even-even isotopes with a=8 82, 84, 86, 88 were measured. Multipole structurs of #gamma#-transtion series and th coefficients multipole mixing were determined.
The gamma spectrum and gamma - gamma coincidences of /sup 177/W were measured with a Ge(Li) detector. A level scheme was proposed for /sup 177/Ta. (tr-auth)
There are several on-going projects of e"+e"- colliders. If they are constructed, we can convert them into photon-photon (#gamma#-#gamma#) colliders by converting electron beams into #gamma# beams, irradiating laser beams just before the interaction point. In this report we discuss the technical issues on the accelerator.
This is a report of 21 patients presenting with epigastric pain, bilious vomiting, upper gastrointestinal bleeding, iron-deficiency anemia, and weight loss, who had undergone Billroth II gastrectomy from 3 to 35 yr earlier. Eighteen of 21 patients were found to have significant enterogastric reflux indices varying from 60% to 95% demonstrated by /sup 99m/Tc HIDA scintigraphy. Thirteen patients had diversion antireflux surgery in the form of a Roux-en-Y procedure, and 1 patient had a Henley loop jejunal interposition. Postoperative /sup 99m/Tc HIDA scintigraphic studies showed the enterogastric reflux indices to have decreased significantly to a range of 2%-26% (p less than 0.00001). There was marked improvement of symptoms, including correction of anemia and weight gain in those patients who had been anemic or who had sustained earlier weight loss. The enterogastric reflux indices of 10 asymptomatic control patients after Billroth II gastrectomy ranged from 4% to ...
The effect of various forms of treatment of renal osteodystrophy was evaluated in 25 dialysis patients by quantitative bone scintigraphy, using 99m-Tc-HEDP. The results were compared with those of biochemical and bone morphometric studies. The total skeletal activity (TSA) decreased in 5 patients after transplantation, in 11 after parathyroidectomy and in 6 out of 9 treated conservatively, but did not normalize in any of the patients. Bone morphometric evaluation of treatment, which could be performed in 19 of the 20 patients who did not receive a transplant, demonstrated a reduction in the degree of hyperparathyroidism in 17 patients (89 percent). Osteoid excess was reduced in 13 patients (68 percent) but an evident reduction of osteomalacic osteoid, i.e. improvement of osteomalacia, occurred in only 4 patients (21 percent). Changes in the TSA correlated significantly with the changes in the biochemical and histological parameters of hyperparathyroidism, but not ...
The effect of various forms of treatment of renal osteodystrophy was evaluated in 25 dialysis patients by quantitative bone scintigraphy, using 99m-Tc-HEDP. The results were compared with those of biochemical and bone morphometric studies. The total skeletal activity (TSA) decreased in 5 patients after transplantation, in 11 after parathyroidectomy and in 6 out of 9 treated conservatively, but did not normalize in any of the patients. Bone morphometric evaluation of treatment, which could be performed in 19 of the 20 patients who did not receive a transplant, demonstrated a reduction in the degree of hyperparathyroidism in 17 patients (89 per cent). Osteoid excess was reduced in 13 patients (68 per cent) but an evident reduction of osteomalacic osteoid, i.e. improvement of osteomalacia, occurred in only 4 patients (21 per cent). Changes in the TSA correlated significantly with the changes in the biochemical and histological parameters of hyperparathyroidism, but ...
Thirty-six patients with acquired immunodeficiency syndrome (AIDS), who were febrile but without localizing signs, underwent indium-111 leukocyte scintigraphy 24 hours after injection of labeled white blood cells (WBCs) and were restudied 48 hours after injection of gallium-67 citrate. Fifty-six abnormalities were identified as possible sources of the fever; 27 were confirmed with biopsy. Of these 27, 15 were identified only on In-111 WBC scans (including colitis, sinusitis, and focal bacterial pneumonia); six, only on Ga-67 scans (predominantly Pneumocystis carinii pneumonia and lymphadenopathy); and six, on both studies (predominantly pulmonary lesions). In-111 WBC scanning revealed 21 of 27 abnormalities (78%) and gallium scanning, 12 of 27 (44%). If only one scintigraphic study has been performed, particularly with Ga-67, a significant number of lesions would not have been detected. The authors believe radionuclide evaluation of the febrile AIDS patient without ...
In 620 patients quantitative bone scintigraphy with "9"9"mTc pyrophosphate of the sacroiliac joints and of the spine was performed: 365 patients with confirmed ankylosing spondylitis, 125 patients with clinical radiological suspicion for ankylosing spondylitis (probable Bechterev) and control group of 130 healthy individuals. By comparison of the activity in zones of interest of the sacroiliac joints, the spine and sacrum, the following indices were determined: sacroiliac (separately for the left and right sacroiliac joints), index D_1_0/sacrum, index L_4/sacrum and index C_7/sacrum. The scintigraphic finding was compared to the X-ray one and to the radiological stage of the disease. A long-term follow-up of the patients was carried out during 1-6 years with scintigraphic, X-ray and clinical investigations. Emphasis was laid upon the posibilities for quantitative scintigraphy for early diagnostics of ankylosing spondylitis. The combination of ...
In this report we assessed retrospectively the usefulness of Thallium-201 chloride scintigraphy for diagnosing malignant tumors of the maxillofacial region. Thallium-201 chloride scintigraphy was performed on 74 patients with malignant tumors and 8 patients with benign tumors, and a retention index was calculated from the early and delayed scintigrams (delayed accumulation ratio/ early accumulation ratio). This retention index depended on the blood flow of tumors and the affinity of tumors with Thallium-201 chloride. The retention index was large for malignant tumors (avg.: 1.05) and small for benign tumors (avg.: 0.78). Concerning the degree of malignancy (the histological type and the degree of tumor involvement), the retention index was higher in highly malignant tumors (1.20 for poorly-differentiated tumors and 1.19 for aggressive-involvement-type tumors) and lower for tumors of low malignancy (1.02 for well-differentiated tumors and 0.98 ...
We present methods to measure the beam polarizations and the luminosity of [gamma][gamma] colliders at TeV energy scale. The beam polarizations of a [gamma][gamma] collider can easily be monitored by comparing the numbers of events of the processes [gamma][gamma] [yields] l[sup +]l[sup -] and [gamma][gamma] [yields] W[sup +] W[sup -], where l means e or [mu]. The luminosity of a [gamma][gamma] collider is also measurable by the event rate of W boson pair productions and the light lepton pair productions. (orig.)
We discuss the search of excited leptons and quarks with spin 1/2 at {gamma}{gamma} and at {gamma}e colliders. We show that {gamma}{gamma} colliders have important advantages for the observation of excited leptons and quarks in comparison with ee, ep, and pp colliders discussed in previous papers. These collisions give a simple test for the chirality of the l{sup *}l{gamma} transition. The anomalous magnetic moment of excited leptons can be observed when its value is not too small. (orig.).
Insulitis is considered the histopathological hallmark of type I diabetes. In the non-obese diabetic (NOD) mouse, diabetes has never been observed in the absence of insulitis. The in vivo detection of insulitis could be of relevance for early prediction of diabetes. As approximately 15% of islet-infiltrating lymphocytes express interleukin 2 receptors, the authors have labelled recombinant inter-leukin 2 with "1"2"3I and used this radiopharmaceutical to detect insulitis by gamma camera imaging. The authors studied 71 prediabetic NOD and 27 normal Balb/c mice. Labelled #alpha#-lactalbumin was used as the control protein. In the first set of experiments the tissue distribution of radiolabelled interleukin 2 in isolated organs from animals sacrificed at different time points was studied. Higher radioactivity was detected in the pancreas of NOD mice injected with labelled interleukin 2, as compared to NOD mice receiving labelled ...
Femoral head replacement was performed for femoral neck fracture or femoral head necrosis on 36 hips of 34 patients on whom Tc-99m MDP scintigraphy was done for analysis of radioisotope uptake around the prosthesis. In the cases with satisfactory clinical course after replacement surgery the uptake was high in the area between the prosthesis and the trochanter, in the area of the stem tip of the prosthesis and in the acetabular area. The high uptake decreased gradually and reached a normal level by 8 months after surgery. The cases with no decrease of high uptake by 8 months after surgery were considered to have had an eventful postoperative course associated with some complication such as infection, fracture, loosening etc. Tc-99m MDP scintigraphy was useful for early detection of complications and to evaluate progress of the operated patients. (author)
Fifteen quantitative bone scintigraphies were performed in an adolescent girl during the follow-up of a femoral osteogenic sarcoma treated by chemotherapy and massive allograft. Three hours after injection of the radiopharmaceutical (7.4 MBq/kg of 99mTc-MDP) bone activity was measured in the inferior limbs at several regions of interest centered on the hips, femurs (proximal, middle, distal) and proximal tibias. The variations of relative bone activities A/S (ratio of corresponding counting rates between two homologous regions in the affected A and in the healthy S limb) and of absolute bone activities (expressed in counts/pixel-second) are interpreted as a function of times during treatment. The quantitative results are discussed with regard to main phenomena influencing bone activity in this particular clinical case: bone growth, chemotherapy and neo-osteogenesis in allograft.
Evaporation of "9"9"mTc-pertechnetate at about 2500"0C on a carbon surface generates an ultrafine aerosol of labelled carbon clusters. Its particle size of about 2-5 nm enables the aerosol to behave similarly to a gas regarding the ability of penetration. After inhalation, the radioactive particles adhere to the walls of the respiratory bronchioli and alveoli. The high concentration of the radioactivity in the argon carrier gas makes it possible to record a scintigram after a single deep breath. We studied four healthy volunteers and 79 patients including 34 with a tentative diagnosis of pulmonary embolism, 20 with bronchus carcinoma, and 15 with various other lung diseases. Ten of these patients were infants, the youngest being nine months old. All patients also had a perfusion scintigraphy. (orig.).
In this talk I briefly summarize different models for #sigma#_2_#gamma#"t"o"t (e"+e"-#->##gamma##gamma##->#hadrons) and contrast model predictions with the data. I will then discuss the capability of the future e"+e"- and #gamma##gamma# colliders to distinguish between various models and end with an outlook for future work.
A #gamma##gamma# collider would extend and complement the physics capability of a linear collider; e.g. it would be suitable for direct measurement of the partial decay width of a Higgs boson into two gamma quanta. This paper discusses choice of laser parameters, luminosity optimization, electron and laser parameters for a gamma- gamma collider as a second interaction region for the Next Linear Collider, laser path, and the lasers. It is concluded that a gamma- gamma collider is technically feasible; however it will require a significant investment in preparatory R ampersand D.
We investigate the chargino production process {gamma}{gamma} {yields} (W-tilde){sup +}(W-tilde){sup -} at high energy {gamma}{gamma} colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy {gamma} beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV ee colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section to for us extract the signal from the dominant background {gamma}{gamma} {yields} W{sup +}W{sup -}. (author).
We investigate the chargino production process #gamma##gamma# #-># (W-tilde)"+(W-tilde)"- at high energy #gamma##gamma# colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy #gamma# beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV ee colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section to for us extract the signal from the dominant background #gamma##gamma# #-># W"+W"-. (author).
The symmetrical complexes [{sup 99m}Tc][TcN(R{sub 2}PS{sub 2}){sub 2}] [R = CH{sub 3}, CH{sub 2}CH{sub 3}, CH{sub 2}CH{sub 2}CH{sub 3}, CH{sub 2}(CH{sub 3}){sub 2}], and the unsymmetrical complex [{sup 99m}Tc][TcN(Me{sub 2}PS{sub 2})(Et{sub 2}PS{sub 2})] have been prepared, at tracer level, through a two-step procedure involving the preliminary formation of a prereduced technetium nitrido intermediate followed by substitution reaction onto this species by the appropriate dithiophosphinate ligand [R{sub 2}PS{sub 2}]Na. The chemical identity of the resulting complexes have been established by comparison with the corresponding {sup 99}Tc-analogs prepared, at macroscopic level, by reacting the complex [{sup 99}TcNCl{sub 4}] [n-Bu{sub 4}N] (n-Bu = n-butyl) with an excess of ligand in methanol, and characterized by elemental analyses and spectroscopic techniques. The complexes are neutral and lipophilic, and possess a square pyramidal geometry, with an apical Tc N group and two ...
The symmetrical complexes ["9"9"mTc][TcN(R_2PS_2)_2] [R = CH_3, CH_2CH_3, CH_2CH_2CH_3, CH_2(CH_3)_2], and the unsymmetrical complex ["9"9"mTc][TcN(Me_2PS_2)(Et_2PS_2)] have been prepared, at tracer level, through a two-step procedure involving the preliminary formation of a prereduced technetium nitrido intermediate followed by substitution reaction onto this species by the appropriate dithiophosphinate ligand [R_2PS_2]Na. The chemical identity of the resulting complexes have been established by comparison with the corresponding "9"9Tc-analogs prepared, at macroscopic level, by reacting the complex ["9"9TcNCl_4] [n-Bu_4N] (n-Bu = n-butyl) with an excess of ligand in methanol, and characterized by elemental analyses and spectroscopic techniques. The complexes are neutral and lipophilic, and possess a square pyramidal geometry, with an apical Tc N group and two dithiophosphinate ligands spanning the four positions on the basal plane through the four sulfur atoms of the >PS_2 group. ...
Image enhancement is of great importance in medical imaging where image resolution remains a crucial point in many image analysis algorithms. In this paper, we investigate brain hallucination...Full Text Available
By generalizing the algebra satisfied by the ..gamma../sub 5/ matrix, it is possible to give an extension of ..gamma../sub 5/ to d dimensions. We discuss the connection of this scheme to others.
Brain scintiscanning which was first carried out exclusively 'statical' and only with test substances of limited quality has been replaced nowadays by 'dynamical' camera-sequency-scintiscanning with technetium. This brought considerable progress not only for identifying but also for the differential diagnosis of cerebro-organic processes. Development, methods, and integration of brain scintiscanning in a diagnostical conception are described briefly. (orig.).
Coronary angiography provides anatomical information whereas thellium myocardial scintigraphy measures resistive tissue perfusion. Because of this fundamental difference. The authors question the validity of using coronary angiography as the gold standard to judge thellium myocardial scintigraphy. The authors studied 20 patients undergoing elective percutaneous coronary angioplasty who fulfilled the following criteria: (1) history of chest pain; (2) angiographically significant single vessel disease (>50% stenosis); (3) no prior myocardial infarction. All patients underwent maximal exercise thallium single photon emission computed tomography (T1-SPECT). Tl-SPECT was scored visually according to a 0 to 3 scale (0=absent uptake; 1=markedly decreased uptake; 2=minimally decreased uptake; 3=normal uptake). Translesional gradient and percent stenosis were measured before and after angioplasty. The authors found that significant linear ...
The author reports 10 studies concerning the diagnosis of renal osteodystrophy and extraskeletal calcification in patients on maintenance hemodialysis as well as some aspects of persistent hyperparathyroidism after renal transplantation. The majority of the studies focus on the value of bone scintigraphy with Tc-99m HEDP in the diagnosis of these disorders. (Auth.).
The pharmacokinetics of Tl/sup +/ were studied in 9 patients who underwent myocardial scintigraphy with /sup 201/Tl/sup +/. The time course of the /sup 201/Tl/sup +/ concentration fitted to an open two-compartment model. Using previously published dialysance values the influence of hemodialysis on Tl/sup +/ elimination was calculated. Hemodialysis in Tl/sup +/ intoxications should be moderately effective.
Bone radiotracer uptake in renal osteodystrophy was investigated in 35 dialysis patients by correlating the results of quantitative bone scintigraphy with those of biochemical and bone morphometric studies. There were highly significant correlations (P < 0.001) between the total skeletal activity and the biochemical (iPTH and alkaline phosphatase), and histologic parameters of hyperparathyroidism. These clinical results strongly suggest that increased bone turnover i.e. hyperparathyroidism, rather than osteomalacia is the major cause of increased skeletal uptake in renal osteodystrophy.
Eight patients with primary hyperparathyroidism were examined preoperative to locate the affected parathyroid glands. The localisation was done with technetium 99m and thallium 201. This new method seems to be of great value to locate preoperative the affected parathyroid glands. (R.B.).
A bone scan can be negative in Ewing's sarcoma. The bone scan during and after treatment can give prognostic information on the primary tumor site: A persisting hot spot strongly suggests the presence of local malignancy, while a hot spot becomming negative points to local cure of Ewing's sarcoma. (orig.).
Several computer assisted processing and display methods are evaluated using a series of 100 normal brain scintigrams, 50 of which have had single 'mathematical tumours' superimposed. Using a standard rating system, or in some cases quantitative estimation, LROC curves are generated for each method and compared. (author).
Serotonin is one of the neurotransmitters found in the brain and mediates brain functions. It is very well known that serotonin related brain abnormalities are exerted mainly via serotonin receptors in a similar manner to other neurotransmitters found in the brain. Recently, it has also been found that serotonin is involved in Alzheimer's disease either directly or indirectly by its actions on serotonergic neurons. To understand and treat the diseases caused by abnormalities in the serotonergic system in the brain, it is certain that its mechanism of function has to be well investigated. So far several 5-HT receptors and receptor subtypes have been well characterized. Moreover, serotonin agonists and antagonists acting on specific receptors are chemically synthesized and are now available for the prevention or treatment of serotonergic related diseases. In recent years, a great demand for developing neuroimaging agents has emerged for the diagnosis of abnormal brain functions in the ...
The collisions of high energy photons produced at an electron-positron collider provide a comprehensive laboratory for testing QCD, electroweak interactions, and extensions of the standard model. The luminosity and energy of the colliding photons produced by backscattering laser beams is expected to be comparable to that of the primary e"+e"- collisions. In this overview, we shall focus on tests of electroweak theory in photon-photon annihilation, particularly #gamma##gamma##->#W"+W"-, #gamma##gamma##->#Higgs bosons, and higher-order loop processes, such as #gamma##gamma##->##gamma##gamma#, Z#gamma# and ZZ. Since each photon can be resolved into a W"+W"- pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying WW collisions and annihilation. We also review high energy #gamma##gamma# tests of quantum chromodynamics, ...
The cross sections of neutral tensor mesons T=a{sub 2}, f, f', ... production in the exclusive {gamma}{gamma}{yields}TT' or semiexclusive {gamma}{gamma}{yields}TX processes (three gluon exchange) in the semihard region s>>vertical stroketvertical stroke>1 GeV{sup 2} are calculated. The relation of investigated processes to the problem of perturbative Odderon is discussed. The possibility of measurements at LEP and at a future {gamma}{gamma}-colliders is discussed too. (orig.).
We summarize the predictions of different models for total {gamma}{gamma} cross-sections. The experimentally observed rise of {sigma}{sub {gamma}}{sub {gamma}} with s radical {sub {gamma}}{sub {gamma}}, faster than that for {sigma}{sub p-barp}, {sigma}{sub {gamma}}{sub p} is in agreement with the predictions of the Eikonalized Minijet Models as opposed to those of the Regge-Pomeron models. We then show that a measurement of {sigma}{sub {gamma}}{sub {gamma}} with an accuracy of < or approx. 8-9% (6-7%) is necessary to distinguish among different Regge-Pomeron type models (the different parameterisations of the EMM models) and a precision of < or approx. 20% is required to distinguish the predictions of the EMMs and of those models which treat 'photon like a proton', for the energy range ...
The results that can be expected by e#gamma# and #gamma##gamma# colliders in future are summarized. e#gamma# and #gamma##gamma# colliders have many fine possibilities, and are the economical selection for utilizing future e"+e"- colliders more effectively. e#gamma# and #gamma##gamma# colliders were proposed by former USSR researchers at the beginning of 1980s, but recently, the prospect of realizing future e"+e"- collision type linear accelerator projects has become high, they have become to be considered seriously as the option of remodeling them. The high energy photon beam of e#gamma# and #gamma##gamma# colliders is obtained by causing Compton reverse scattering, irradiating laser beam to the electron beam of e"+e"- accelerators. The production of #gamma#-beam is explained. As for the physics ...
We analyze spin correlations between top quark and anti-top quark produced at polarized e{sup +} e{sup -} and {gamma}{gamma} colliders. We consider a generic spin basis to find a strong spin correlation. Optimal spin decompositions for top quark pair are presented for e{sup +}e{sup -} and {gamma}{gamma} colliders. We show the cross- section in these bases and discuss the characteristics of results.
In the framework of the equivalence theorem the one-loop helicity amplitudes and cross section for the double Higgs production process {gamma}{gamma}{yields}HH are calculated. It is shown that the cross section is measurable at TeV {gamma}{gamma} colliders and is marginally sensitive to the triple-Higgs variation. (orig.).
In the framework of the equivalence theorem the one-loop helicity amplitudes and cross section for the double Higgs production process #gamma##gamma##->#HH are calculated. It is shown that the cross section is measurable at TeV #gamma##gamma# colliders and is marginally sensitive to the triple-Higgs variation. (orig.).
The complementarity of e{sup +}e{sup -} and {gamma}{gamma} colliders to discover and explore new physics beyond the Standard Model (SM) is discussed. After briefly surveying a number of various new physics scenarios, we concentrate in detail on signatures for Large Extra Dimensions via the process {gamma}{gamma}{yields}WW.
The complementarity of e"+e"- and #gamma##gamma# colliders to discover and explore new physics beyond the Standard Model (SM) is discussed. After briefly surveying a number of various new physics scenarios, we concentrate in detail on signatures for Large Extra Dimensions via the process #gamma##gamma##->#WW.
The complementarity of e{sup +}e{sub {minus}} and gamma-gamma colliders to discover and explore new physics beyond the Standard Model (SM) is discussed. After briefly surveying a number of various new physics scenarios the authors concentrate in detail on signatures for Large Extra Dimensions via the process gamma-gamma --> WW.
Peroxisome proliferator activated receptor-{gamma} (PPAR{gamma}) regulates metabolic homeostasis and adipocyte differentiation, and it is activated by oxidized and nitrated fatty acids. Here we report the crystal structure of the PPAR{gamma} ligand binding domain bound to nitrated linoleic acid, a potent endogenous ligand of PPAR{gamma}. Structural and functional studies of receptor-ligand interactions reveal the molecular basis of PPAR{gamma} discrimination of various naturally occurring fatty acid derivatives.
The results that can be expected by e{gamma} and {gamma}{gamma} colliders in future are summarized. e{gamma} and {gamma}{gamma} colliders have many fine possibilities, and are the economical selection for utilizing future e{sup +}e{sup -} colliders more effectively. e{gamma} and {gamma}{gamma} colliders were proposed by former USSR researchers at the beginning of 1980s, but recently, the prospect of realizing future e{sup +}e{sup -} collision type linear accelerator projects has become high, they have become to be considered seriously as the option of remodeling them. The high energy photon beam of e{gamma} and {gamma}{gamma} colliders is obtained by causing Compton reverse scattering, irradiating laser beam to the electron beam of e{sup +}e{sup -} accelerators. The production of {gamma}-beam is ...
Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction ...
Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction ...
Background/Objectives:Imaging technology is an important part of the diagnosis and management of spinal trauma. Indications and findings in post-traumatic imaging of the vertebral...Full Text Available
performs Gaussian pyramid operation on an image performs expand pyramid operation on an image mosaic two images using 'reduce' and 'expand' pyramid ...
This report describes the design of, and image reconstruction capacity of a Hadamard Raman Microscopic imager. Microscopy of benzoic acid and graphite electrodes, as well as electrophoretic blotting, are described. (CBS)
We investigate the sparticle production processes e{gamma} {yields} e tilde(Z tilde){sub 1} and {gamma}{gamma} {yields} (f tilde)(f tilde and bar) at high energy e{gamma} and {gamma}{gamma} colliders in the framework of the minimal supersymmetric standard model (MSSM). It will be shown that the e{gamma} colliders would be more suitable in searching for the heavy selectrons than ee colliders because of the low mass threshold of the process e{gamma} {yields} (e tilde)(Z tilde){sub 1}. We show that the standard background processes e{gamma} {yields} {nu}W and eZ can be suppressed in terms of initial beam polarization as well as the kinematical cuts on the energy and angle of the final electron. Moreover, it will be argued that the experimental measurements of the cross sections for the processes e{gamma} {yields} (e ...
We investigate the sparticle production processes e#gamma# #-># e tilde(Z tilde)_1 and #gamma##gamma# #-># (f tilde)(f tilde and bar) at high energy e#gamma# and #gamma##gamma# colliders in the framework of the minimal supersymmetric standard model (MSSM). It will be shown that the e#gamma# colliders would be more suitable in searching for the heavy selectrons than ee colliders because of the low mass threshold of the process e#gamma# #-># (e tilde)(Z tilde)_1. We show that the standard background processes e#gamma# #-># #nu#W and eZ can be suppressed in terms of initial beam polarization as well as the kinematical cuts on the energy and angle of the final electron. Moreover, it will be argued that the experimental measurements of the cross sections for the processes e#gamma# #-># (e tilde)(Z tilde)_1 and ...
To determine the presence, prevalence, and clinical importance of /sup 99m/Tc pertechnetate uterine uptake, this retrospective analysis of 71 Meckel's scans was undertaken. Specifically, each study was evaluated for the presence of a focal accumulation of radiotracer cephalad to the bladder. Patients received an intravenous dose of 150 microCi/kg of /sup 99m/Tc pertechnetate. Each study consisted of 15 one minute anterior serial gamma camera images, and a 15, 30, and 60 minute anterior, right lateral and posterior scintiscan. Menstrual histories were obtained from all patients except two. No males (33/33), nor premenstrual (13/13), menopausal (4/4) or posthysterectomy (2/2) patients revealed a uterine blush. Eleven of 15 patients (73%) with regular menses demonstrated a uterine blush. They were in the menstrual or secretory phases of their cycle. Four demonstrated no uterine uptake, had regular periods, but were in the proliferative ...
We present a set of structural parameters for the central parts of 57 early-type galaxies observed with the Planetary Camera of the Hubble Space Telescope. These parameters are based on a new empirical law that successfully characterizes the centers of early type galaxies. This empirical law assumes that the surface brightness profile is a combination of two power laws with different slopes gamma and beta for the inner and outer regions. Conventional structural parameters such as core radius and central surface brightness are replaced by break radius r_b, where the transition between power-law slopes takes place, and surface brightness mu_b at that radius. An additional parameter alpha describes the sharpness of the break. The structural parameters are derived using a chi-squared minimization process applied to the mean surface brightness profiles. The resulting model profiles generally give very good agreement to the observed profiles out to the radius of 10 ...
EOS Technologies has been commissioned to design and build a unique 2.4m astronomical telescope for the Magdalena Ridge Observatory. This telescope utilizes a high quality primary mirror and cell from a now decommissioned military application. This paper describes the project and gives an overview of the telescope design. The Magdalena Ridge Observatory (MRO) 2.4 meter telescope will be primarily utilized to observe, track, and characterize solar system astronomical targets, Earth satellites, space vehicles, and terrestrial military targets. The telescope's rapid tracking (slew rates are 10o/sec) will allow it to move to any target and acquire data within one minute of receipt of notice. In this way, the telescope will be used to capitalize on targets of opportunity that occur in asteroid studies (e.g., Near Earth Objects) and in astrophysics, such as gamma ray bursts and other transient phenomena. Planned instrumentation includes a CCD imager, ...
We developed a new TLD array for precise dose measurement and verification of the spatial dose distribution in small radiation targets. It consists of a hemicylindrical, tissue-equivalent rod made of polystyrene with 17 parallel moulds for an exact positioning of each TLD. The spatial resolution of the TLD array was evaluated using the Leskell spherical phantom. Dose planning was performed with KULA 4.4 under stereotactic conditions on axial CT images. In the Leksell gamma unit the TLD array was irradiated with a maximal dose of 10 Gy with an unplugged 14 mm collimator. The doses delivered to the TLDs were rechecked by diode detector and film dosimetry and compared to the computer-generated dose profile. We found excellent agreement of our measured values, even at the critical penumbra decline. For the 14 mm and 18 mm collimator and for the 11 mm collimator combination we compared the measured and calculated data at full width at half maximum. ...
Context: The colliding-wind binary Eta Car exhibits soft X-ray thermal emission that varies strongly around periastron, and non-thermal emission seen in hard X-rays and gamma-rays. Aims: To definitively identify Eta Car as the source of the hard X-ray emission, to examine how changes in the 2-10 keV band influence changes in the hard X-ray band, and to understand more clearly the mechanisms producing the non-thermal emission using new INTEGRAL observations obtained close to periastron. Methods: A Chandra observation encompassing the ISGRI error circle was analysed, and all other soft X-ray sources (including the outer shell of Eta Car itself) were discarded as likely counter-parts. New hard X-ray images of Eta Car were studied close to periastron, and compared to previous observations far from periastron. Results: The INTEGRAL component, when represented by a power law (with a photon index of 1.8), would produce more emission in the Chandra ...
The principle and history of free-electron laser (FEL), first evidenced in 1977, the relationship between FEL wavelength and output power, the high-power FEL driven by the superconducting linac, the X-ray FEL by the linac, and the medical use are described. FEL is the vacuum oscillator tube and essentially composed from the high-energy linac, undulator and light-resonator. It utilizes free electrons in the vacuum to generate the beam with wavelength ranging from microwave to gamma ray. The first high-power FEL developed in Japanese Atomic Energy Research Institute (JAERI) is based on the development of superconducting linac for oscillating the highest power beam. In the medical field, applications to excise brain tumors (in US) and to reconstruct experimentally blood vessels in the pig heart (in Gunma University) by lasing and laser coagulator are in progress with examinations to remove intra-vascular cholesterol mass by irradiation of 5.7#mu#m FEL beam. Cancer ...
There is an increasing interest in using radioisotopes of rare earth elements for internal radiotherapy and for imaging in nuclear medicine. {sup 177}Lu is one of the promising radionuclides. This article reports on the first measurements of the excitation function for the production of {sup 177}Lu with proton-beam energies up to 17 MeV on natural hafnium targets. The experimental cross sections for the reaction {sup nat}Hf(p,x){sup 177}Lu were obtained by the activation of a stacked-foil target and subsequent gamma spectrometry. Theoretical cross sections were calculated up to 35 MeV with the EMPIRE nuclear reaction model code. The measured and calculated cross sections were used for deriving the thick-target yields and for estimating the production of other nuclides than {sup 177}Lu. Measured production cross sections of {sup 175,176,177,178}Ta on the same target are also presented.
There is an increasing interest in using radioisotopes of rare earth elements for internal radiotherapy and for imaging in nuclear medicine. "1"7"7Lu is one of the promising radionuclides. This article reports on the first measurements of the excitation function for the production of "1"7"7Lu with proton-beam energies up to 17 MeV on natural hafnium targets. The experimental cross sections for the reaction "n"a"tHf(p,x)"1"7"7Lu were obtained by the activation of a stacked-foil target and subsequent gamma spectrometry. Theoretical cross sections were calculated up to 35 MeV with the EMPIRE nuclear reaction model code. The measured and calculated cross sections were used for deriving the thick-target yields and for estimating the production of other nuclides than "1"7"7Lu. Measured production cross sections of "1"7"5","1"7"6","1"7"7","1"7"8Ta on the same target are also presented.
We analyze the potential of the e{sup +}e{sup -} linear colliders, operating in the e{gamma} and {gamma}{gamma} modes, to probe anomalous quartic vector-boson interactions through the multiple production of W's and Z's. We examine all SU(2){sub L}(circle times)U(1){sub Y} chiral operators of order p{sup 4} that lead to new four-gauge-boson interactions but do not alter trilinear vertices. We show that the e{gamma} and {gamma}{gamma} modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10{sup -2} at 90% C.L. Moreover, the information gathered in the e{gamma} mode can be used to reduce the ambiguities of the e{sup +}e{sup -} mode.
We analyze the potential of the e"+e"- linear colliders, operating in the e#gamma# and #gamma##gamma# modes, to probe anomalous quartic vector-boson interactions through the multiple production of W's and Z's. We examine all SU(2)_L(circle times)U(1)_Y chiral operators of order p"4 that lead to new four-gauge-boson interactions but do not alter trilinear vertices. We show that the e#gamma# and #gamma##gamma# modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10"-"2 at 90% C.L. Moreover, the information gathered in the e#gamma# mode can be used to reduce the ambiguities of the e"+e"- mode.
{sup 188}Re is a {beta}{sup -} (Emax=2.12 MeV) and {gamma} (155 keV) emitter. Since its chemistry is similar to that of the largely employed tracer, {sup 99m}Tc, molecules of hyaluronic acid (HA) have been labelled with {sup 188}Re to produce a target specific radiopharmaceutical. The radiolabeled compound, i.v. injected in healthy mice, is able to accumulate into the liver after a few minutes. To study the effect of metabolic radiotherapy in mice, we have built a small gamma camera based on a matrix of YAP:Ce crystals, with 0.6x0.6x10 mm{sup 3} pixels, read out by a R2486 Hamamatsu PSPMT. A high-sensitivity 20 mm thick lead parallel-hole collimator, with hole diameter 1.5 mm and septa of 0.18 mm, is placed in front of the YAP matrix. Preliminary results obtained with various phantoms containing a solution of {sup 188}Re and with C57 black mice injected with the {sup 188}Re-HA solution are presented. To increase the space resolution and to ...
The fine scale mechanical probing capability of NI-AFM was used to examine hydrogen interaction with plasticity. To realize this, an electrochemical three electrode setup was incorporated into the NI-AFM. The developed ECNI-AFM is capable of performing nanoindentation as well as imaging surfaces inside electrolytes. The developed ECNI-AFM setup was used to examine the effect of cathodically charged hydrogen on dislocation nucleation in pure metals and alloys. It was shown that hydrogen reduces the pop-in load in all of the tested materials except Cu. The reduced pop-in load can be interpreted as the HELP mechanism. Classical dislocation theory was used to model the homogeneous dislocation nucleation and it was shown that H reduces the activation energy for dislocation nucleation in H sensitive metals which are not undergoing a phase transformation. The activation energy for dislocation nucleation is related to the material specific parameters; shear modulus {mu}, ...
This paper describes estimation of a stress field in the earth`s crust in the Kakkonda geothermal field. Formation micro imager (FMI) logging known as a crack detecting logging was performed in the well WD-1. This FMI logging has made observation possible on cracks along well axis thought to indicate size and direction of the crust stress, and drilling-induced tensile fractures (DTF). It was verified that these DTFs are generated initially in an azimuth determined by in-situ stress (an angle up to the DTF as measured counterclockwise with due north as a starting point, expressed in {theta}) in the well`s circumferential direction. It was also confirmed that a large number of cracks incline at a certain angle to the well axis (an angle made by the well axis and the DTF, expressed in {gamma}). The DTF is a crack initially generated on well walls as a result of such tensile stresses as mud pressure and thermal stress acting on the well walls ...
In 2002 and again in 2003, an investigative journalist unit at ABC News transported a 6.8 kilogram metallic slug of depleted uranium (DU) via shipping container from Istanbul, Turkey to Brooklyn, NY and from Jakarta, Indonesia to Long Beach, CA. Targeted inspection of these shipping containers by Department of Homeland Security (DHS) personnel, included the use of gamma-ray imaging, portal monitors and hand-held radiation detectors, did not uncover the hidden DU. Monte Carlo analysis of the gamma-ray intensity and spectrum of a DU slug and one consisting of highly-enriched uranium (HEU) showed that DU was a proper surrogate for testing the ability of DHS to detect the illicit transport of HEU. Our analysis using MCNP-5 illustrated the ease of fully shielding an HEU sample to avoid detection. The assembly of an Improvised Nuclear Device (IND) -- a crude atomic bomb -- from sub-critical pieces of HEU metal was then examined ...
We propose new method of assessment of histological images for medical diagnostics. 2-D image is preprocessed to form 1-D landscapes or 1-D signature of the image contour and then their complexity is...Full Text Available
In vivo two-photon imaging through the pupil of the primate eye has the potential to become a useful tool for functional imaging of the retina. Two-photon excited fluorescence images...Full Text Available
This paper describes Image Engine, an object-oriented, microcomputer-based, multimedia database designed to facilitate the storage and retrieval of digitized biomedical still images, video, and text...Full Text Available
Adaptive image processing is one of the most important techniques in visual information processing, especially in early vision such as image restoration, filtering, enhancement, and segmentation. This work focuses on applications of advanced CI techniques in image processing applications
A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Illinois. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further enhanced or processed to obtain ...
A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Ill. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further enhanced or processed to obtain ...
Modeling artificial scanning electron microscope (SEM) and scanning ion microscope images has recently become important. This is because of the need to provide repeatable images with a priori determined parameters. Modeled artificial images are highly useful in the evaluation of new imaging and metrological techniques, like image-sharpness calculation, or drift-corrected image composition (DCIC). Originally, the NIST-developed artificial image generator was designed only to produce the SEM images of gold-on-carbon resolution sample for image-sharpness evaluation. Since then, the new improved version of the software was written in C++ programming language and is in the Public Domain. The current version of the software can generate arbitrary samples, any drift function, and many other features. This ...
The US DOE manages the safe storage of approximately 650,000 tons of depleted uranium hexafluoride remaining from the Cold War. This slightly radioactive, but chemically active, material is contained in more than 46,000 steel storage cylinders that are located at Oak Ridge, Tennessee; Paducah, Kentucky; and Portsmouth, Ohio. Some of the cylinders are more than 40 years old, and approximately 17,500 are considered problem cylinders because their physical integrity is questionable. These cylinders require an annual visual inspection. The remainder of the 46,000-plus cylinders must be visually inspected every four years. Currently, the cylinder inspection program is extremely labor intensive. Because these inspections are accomplished visually, they may not be effective in the early detection of leaking cylinders. The inspection program requires approximately 12--14 full-time-equivalent (FTE) employees. At the cost of approximately $125K per FTE, this translates to $1,500K per annum just ...
We study the production of three gauge bosons (W"+W"-Z"0 and W"+W"-#gamma#) at the next generation of linear e"+e"- colliders operating in the #gamma##gamma# mode. We analyze the total cross sections as well as several kinematical distributions of the final state particles. We find out that a linear e"+e"- machine operating in the #gamma##gamma# mode will produce 5--10 times more three-gauge-boson states compared to the standard e"+e"- mode at high energies.
An electroweak singlet scalar can couple to pairs of vector bosons through loop-induced dimension five operators. Compared to a Standard Model Higgs boson, the singlet decay widths in the diphotons and Z gamma channels are generically enhanced, while decays into massive final states like WW and ZZ are kinematically disfavored. The overall event rates into gammagamma and Z gamma can exceed the Standard Model expectations by orders of magnitude. Such a singlet may appear as a resonant signal in the gammagamma and Z gamma channels, even with a mass above the WW kinematic threshold.
Possible anomalous top-quark couplings induced by SU(2)xU(1) gauge-invariant dimension-6 effective operators were studied in the process of ttbar productions and decays at polarized #gamma##gamma# colliders. Two CP-violating asymmetries, a linear-polarization asymmetry and a circular-polarization asymmetry, were computed including both non-standard ttbar#gamma# and #gamma##gamma#H couplings. An optimal-observable analysis for the process #gamma##gamma##->#ttbar#->#l"#+-# was performed in order to estimate the precision for determination of all relevant non-standard couplings, including the anomalous tbW coupling.
Corrosion testings of model alloys, corresponding by chemical composition to simple and complex-alloyed #gamma#- and #gamma#'-phases of nickel heat-resistant alloys are conducted in sodium sulfate and chloride melts. It is ascertained that heat resistant nickel alloys containing over 50 % of hardening #gamma#'-phase, are subject to disastrous sulfide corrosion (SC). Resistance against SC alloys containing below 50 % of #gamma#'-phase is determined by the resistance of #gamma#-solid solution. 10 refs., 3 figs., 2 tabs.
Certain radioiodine containing amides useful as brain imaging agents are disclosed. The compounds of the subject invention are represented by the formula
Certain radioiodine containing amides useful as brain imaging agents are disclosed. The compounds of the subject invention are represented by the formula.
A diverse set of digital image-processing applications exists at the Lawrence Livermore National Laboratory. While many of these include some sort of image analysis or restoration, virtually all of them require image-enhancement procedures. In this paper we describe the principal image-processing facility at the Laboratory, followed by a discussion of several of the major image-processing application areas.
Somatostatin receptor expression has been demonstrated on a number of plasma cell lines. Therefore, we questioned whether somatostatin receptor scintigraphy (SRS) can be used to demonstrate in vivo multiple myeloma (MM) activity. SRS was performed in newly diagnosed (n = 9) or relapsing (n = 18) MM patients or in patients with localized plasmacytoma (n = 2). The results were compared with radiographic findings. A positive SRS was demonstrated in 44% of the newly diagnosed patients, in 83% of the relapsed patients and in both patients with plasmacytoma. The SRS findings corresponded with radiographic abnormalities in 40% of the patients. However, in relapsed patients 60% demonstrated increased SRS uptake in areas without new radiographic abnormalities. The positive SRS corresponded with histologically proven disease activity and responded upon treatment. Moreover, immunohistochemical staining of MM material demonstrated concordant somatostatin receptor sst3 staining ...
In 10 cases of femoral neck fracture treated with prosthetic replacement, the preoperative sup(99m)Tc-MDP scintigraphs were investigated and then compared with each histological findings of the extracted femoral head. The appearances of the scintigraphs were classified into following 3 patterns; increased activity pattern of sup(99m)Tc-MDP uptake in the overall femoral head (type I) in 4 cases, deficient activity pattern at the lateral side correspond to weight-bearing area (type II) in 2 cases and considerably deficient activity pattern in the whole femoral head (type III) in remaining 4 cases. Histological examination of the extracted femoral heads revealed the narrow part of ischemic necrosis in type I. However type II showed extensive necrosis in the portion of deficient activity by scintigraphs and in type III, the femoral heads except articular cartilage were entirely necrotic. This classification of sup(99m)Tc-MDP scintigraphy is correlated with the degree ...
In IO cases of femoral neck fracture treated with prosthetic replacement, the preopera tive sup(99m)Tc-MDP scintigraphs were investigated and then compared with each histological findings of the extracted femoral head. The appearances of the scintigraphs were classified into following 3 patterns; increased activity pattern of sup(99m)Tc-MDP uptake in the overall femoral head (type I) in 4 cases, deficient activity pattern at the lateral side correspond to weight-bearing area (type II) in 2 cases and considerably deficient activity pattern in the whole femoral head (type III) in remaining 4 cases. Histological examination of the extracted femoral heads revealed the narrow part of ischemic necrosis in type I. However type II showed extensive necrosis in the portion of deficient activity by scintigraphs and in type III, the femoral heads except articular cartilage were entirely necrotic. This classification of sup(99m)Tc-MDP scintigraphy is correlated with the degree ...
Skeletal radiotracer (sup(99m)Tc-HEDP) uptake was quantitated with and without the aid of a computer in 30 chronic dialysis patients with histologic evidence of renal osteodystrophy. Before scintigraphy, elevated soft-tissue activity due to the absence of renal radiotracer excretion was reduced by hemodialysis. The results were compared with those of a normal group and with the results of the biochemical and the bone morphometric studies of these patients. In all patients the radiotracer uptake was elevated, often markedly. In several patients with minimal histologic bone disease, however, soft-tissue activity could not be normalized by hemodialysis although its influence on the quantitative data could be further reduced (but not excluded) by computer evaluation of skeletal radiotracer uptake. Since the latter technique clearly distinguished the majority of the patients from the normals, it appears that computerized quantitative skeletal analysis is a potentially ...
Skeletal radiotracer (sup(99m)Tc-HEDP) uptake was quantitated with and without the aid of a computer in 30 chronic dialysis patients with histologic evidence of renal osteodystrophy. Before scintigraphy, elevated soft-tissue activity due to the absence of renal radiotracer excretion was reduced by hemodialysis. The results were compared with those of a normal group and with the results of the biochemical and the bone morphometric studies of these patients. In all patients the radiotracer uptake was elevated, often markedly. In several patients with minimal histologic bone disease, however, soft-tissue activity could not be normalized by hemodialysis although its influence on the quantitative data could be further reduced (but not excluded) by computer evaluation of skeletal radiotracer uptake. Since the latter technique clearly distinguished the majority of the patients from the normals, it appears that computerized quantitative skeletal analysis is a potentially ...
Ectopically located parathyroid adenomas may be difficult to find during initial neck exploration. They account for over 70 percent of missed adenomas found at reexploration. Preoperative localization of parathyroid adenomas would reduce unnecessary dissection and possibly reduce the number of negative results of initial neck exploration. Before reoperative parathyroid surgery is performed, some means of localization is mandatory to detect ectopic adenomas in the neck and mediastinum. Computed tomography and ultrasonography cannot effectively evaluate the mediastinum. Angiography and venous parathyroid hormone sampling are invasive, costly, and tedious to perform. We have shown that thallium-201 will accurately localize ectopic parathyroid adenomas. All 10 adenomas found in positions not immediately adjacent to the thyroid gland were detected by thallium-201 scintigraphy. One was a mediastinal adenoma resected with a median sternotomy. Our results suggest that ...
In the paper six cases of facial osteomyelitis as a complication of chronic sinusitis in hemophiliac-AIDS patients are reported. Osteomyelitis was suggested by an increasing of erythrocyte sedimentation rate. The diagnosis was confirmed by a positive {sup 99m} Tc MDP scintigraphy. The patients were submitted to clinical treatment. The erythrocyte sedimentation rate and 67-gallium citrate scans were used in the follow-up of the therapy. Three patients had negative gallium after three weeks of organism-specific antibiotic therapy; in two patients the gallium scintigraphy remained positive. One patient did not undergo the radionuclide scan for this clinical conditions. These results suggest that MDP scans showed higher sensitivity and specificity in detection of bone disease in chronic sinusitis. Gallium scans appeared to be valuable tool in the follow-up of the infection. There are no reports in the literature of osteomyelitis as a complication ...
Quantitative bone scintigraphy was performed at 4 and 24 h after injection of {sup 99m}Tc-MDP. The lower thoracic and all the lumbar vertebrae were recorded in 37 patients with prostatic carcinoma before orchiectomy as well as two weeks, two and six months postoperatively. Fourteen patients had normal bone scintigrams. By means of the measured variation in the count rate between normal vertebrae, the criterion for a vertebra to be considered as abnormal was determined using the 4 h-uptake values. For patients with normal scintigrams the count rate at 24 h was below the 4 h level and the mean 24 h/4 h ratio was determined to be 0.85 {+-} 0.09 (1 SD). Normal vertebrae in patients with skeletal metastases had only slightly lower count rate values at 24 h than at 4 h. Abnormal vertebrae showed a higher count rate at 24 h, especially two weeks postoperatively, while a tendency towards lower values than at 4 h was seen after 6 months. If the 24 h/4 h ratio is used as an ...
Quantitative bone scintigraphy was performed at 4 and 24 h after injection of "9"9"mTc-MDP. The lower thoracic and all the lumbar vertebrae were recorded in 37 patients with prostatic carcinoma before orchiectomy as well as two weeks, two and six months postoperatively. Fourteen patients had normal bone scintigrams. By means of the measured variation in the count rate between normal vertebrae, the criterion for a vertebra to be considered as abnormal was determined using the 4 h-uptake values. For patients with normal scintigrams the count rate at 24 h was below the 4 h level and the mean 24 h/4 h ratio was determined to be 0.85 #+-# 0.09 (1 SD). Normal vertebrae in patients with skeletal metastases had only slightly lower count rate values at 24 h than at 4 h. Abnormal vertebrae showed a higher count rate at 24 h, especially two weeks postoperatively, while a tendency towards lower values than at 4 h was seen after 6 months. If the 24 h/4 h ratio is used as an ...
The decay modes $\\jpsi\\ar\\gamma\\pi^0, \\gamma\\eta$ and $\\gamma\\etap$ are analyzed using a data sample of 58 million $\\jpsi$ decays collected with the BESII detector at BEPC. The branching fractions are determined to be: $Br(\\jpsi\\ar\\gamma\\pi^0)=(3.13^{+0.65}_{-0.44})\\times10^{-5}$, $Br(\\jpsi\\ar\\gamma\\eta)=(11.23\\pm0.89)\\times10^{-4}$, and $Br(\\jpsi\\ar\\gamma\\etap)=(5.55\\pm0.44)\\times10^{-3}$, where the errors are combined statistical and systematic errors. The ratio of partial widths $\\Gamma(\\jpsi\\ar\\gamma\\etap)/\\Gamma(\\jpsi\\ar\\gamma\\eta)$ is measured to be $4.94\\pm0.40$, and the singlet-octet pseudoscalar mixing angle of $\\eta-\\etap$ system is determined to be $\\theta_{P}=(-22.08\\pm0.81)^{\\circ}$.
We calculate the cross sections for the single production of doubly charged dileptons, both scalar and vector, at e"+e"-, e#gamma#, and #gamma##gamma# colliders at #sq root#s =500 GeV and 1 TeV. The e#gamma# mode is by far the most promising---dileptons whose coupling is as weak as #approx#10"-"4#alpha#_e_m can be observed, for masses virtually up to the kinematic limit. Dileptons of mass up to #sq root#s can also be seen in e"+e"- and #gamma##gamma# colliders, for couplings of order #alpha#_e_m. In all three colliders, most of the cross section comes from events in which the only particles detected are e"-e"- (or #mu#"-#mu#"- or #tau#"-#tau#"-), the decay products of the dilepton, yielding an unmistakable experimental signature.
The future e"+e"- linear colliders can also operate in the e#gamma# or #gamma##gamma# modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process #gamma##gamma# #-># tb-bar#PI#_t"-. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode #PI#_t"- #-># bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in #gamma##gamma# mode at the TeV energy scale
We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in {gamma}{gamma}{yields}t t-bar {yields}lX/bX for various beam polarizations in order to study possible anomalous t t-bar {gamma}, tbW and {gamma}{gamma}H couplings, which could be generated by SU(2) x U(1) gauge-invariant dimension-6 effective operators. We find optimal beam polarizations that will minimize the uncertainty in determination of those non-standard couplings. We also compare e e-bar and {gamma}{gamma} colliders from the viewpoint of the anomalous-top-quark-coupling determination.
We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in #gamma##gamma##->#t t-bar #->#lX/bX for various beam polarizations in order to study possible anomalous t t-bar #gamma#, tbW and #gamma##gamma#H couplings, which could be generated by SU(2) x U(1) gauge-invariant dimension-6 effective operators. We find optimal beam polarizations that will minimize the uncertainty in determination of those non-standard couplings. We also compare e e-bar and #gamma##gamma# colliders from the viewpoint of the anomalous-top-quark-coupling determination.
CMSX-4 superalloy laser beam welds were investigated by transmission electron microscopy and atom probe field-ion microscopy (APFIM). The weld microstructure consisted of fine (10- to 50-nm) irregularly shaped {gamma}` precipitates (0.65 to 0.75 volume fraction) within the {gamma} matrix. APFIM compositions of the {gamma} and {gamma}` phases were found to be different from those in the base metal. Concentration profiles across the {gamma} and {gamma}` phases showed extensive variations of Cr, Co and Al concentrations as a function of distance within the {gamma} phase. Calculated lattice misfits near the {gamma}/{gamma}` interface in the welds are positive values compared to the negative values for base metal. (orig.).
We study the constraints on the anomalous coupling g_5"Z that can be obtained from the analysis of the reaction #gamma##gamma##->#W"+W"-Z at future linear e"+e"- colliders. We find out that a 0.5 (1) TeV e"+e"- collider operating in the #gamma##gamma# mode can probe values of g_5"Z of the order of 0.15 (4.5x10"-"2) for an integrated luminosity of 10 fb"-"1. This shows that the ability to search for this anomalous interaction of the #gamma##gamma# mode is better than the one of the usual e"+e"- mode, and it is similar to the ability of the e#gamma# mode.
A technique for quantitative analysis of growth plates in varus or valgus deformity about the knee has been developed. Computer-generated regions of interest are placed on magnification scintigraphs to divide distal femoral and proximal tibial physes into four equal segments. The ratio of counts in the medial half to counts in the lateral half was studied in 31 children (22 normal, 9 with angular deformity). Normal ratios were 0.74 to 0.98 for femora and 0.98 to 1.20 for tibias. In eight of nine patients with deformity, the ratio was abnormal; in two patients the ratio returned to normal when the deformity ceased to progress.
Posttraumatic tibia valga is a well-recognized complication following fracture of the upper tibial metaphysis in young children. We present a case of a child who developed a valgus deformity following fracture of the proximal tibia and fibula in which quantitative bone scintigraphy at 5 months after injury demonstrated increased uptake at the proximal tibial growth plate with proportionally greater uptake on the medial side. This finding suggests that the valgus deformity in this patient was due to a relative increase in vascularity and consequent overgrowth of the medial portion of the proximal tibial physis.
Posttraumatic tibia valga is a well-recognized complication following fracture of the upper tibial metaphysis in young children. We present a case of a child who developed a valgus deformity following fracture of the proximal tibia and fibula in which quantitative bone scintigraphy at 5 months after injury demonstrated increased uptake at the proximal tibial growth plate with proportionally greater uptake on the medial side. This finding suggests that the valgus deformity in this patient was due to a relative increase in vascularity and consequent overgrowth of the medial portion of the proximal tibial physis.
Thirty-two patients with AIDS related complex (ARC) or acquired immunodeficiency syndrome (AIDS) underwent /sup 67/Ga scans as part of their evaluation. Three patterns of /sup 67/Ga biodistribution were found: lymph node uptake alone; diffuse pulmonary uptake; normal scan. Gallium-67 scans were useful in identifying clinically occult Pneumocystis carinii pneumonia in seven of 15 patients with ARC who were asymptomatic and had normal chest radiographs. Gallium scans are a useful ancillary procedure in the evaluation of patients with ARC or AIDS.
There are several on-going projects of e{sup +}e{sup -} colliders. If they are constructed, we can convert them into photon-photon ({gamma}-{gamma}) colliders by converting electron beams into {gamma} beams, irradiating laser beams just before the interaction point. In this report we discuss the technical issues on the accelerator.
The present investigation was aimed to assess the usefulness of biliary agents scintigraphy in the diagnosis of hepatocellular carcinoma (HCC) and to ascertain the relationship between the uptake of these agents and the degree of HCC differentiation. Forty-four patients with this hepatic cancer were included in the study. Liver scans were performed 20 min and 3 hr after the administration of 99mTc diisopropyliminodiacetic acid (DISIDA). DISIDA scintigraphy could not be assessed in six cases. In 16 (42%) out of the remaining 38 patients, the tumor exhibited equal or greater radioactivity uptake than the surrounding liver. In six out of these 16 patients, tumor uptake was apparent in the early and delayed hepatic scans, while in the other ten subjects radioactivity uptake by the HCC could only be detected in the 3-hr delayed scans. In the remaining 22 patients, HCC appeared as a cold area. Tumor location by this technique did not differ from that ...
The present research scholars are having keen interest in doing their research activities in the area of Data mining all over the world. Especially, [13]Mining Image data is the one of the essential features in this present scenario since image data plays vital role in every aspect of the system such as business for marketing, hospital for surgery, engineering for construction, Web for publication and so on. The other area in the Image mining system is the Content-Based Image Retrieval (CBIR) which performs retrieval based on the similarity defined in terms of extracted features with more objectiveness. The drawback in CBIR is the features of the query image alone are considered. Hence, a new technique called Image retrieval based on optimum clusters is proposed for improving user interaction with image retrieval systems by fully exploiting ...
Using $\\gamma \\gamma J/\\psi, J/\\psi \\ra e^+ e^-$ and $\\mu^+ \\mu^-$ events from a sample of $14.0\\times 10^6$ $\\psip$ decays collected with the BESII detector, the branching fractions for $\\psip\\ra \\pi^0\\J$, $\\eta\\J$, and $\\psi(2S)\\ar\\gamma\\chi_{c1},\\gamma\\chi_{c2}\\ar\\gamma\\gamma\\jpsi$ are measured to be $B(\\psip\\ra \\pi^0\\J) = (1.43\\pm0.14\\pm0.13)\\times 10^{-3}$, $B(\\psip\\ra \\eta\\J) = (2.98\\pm0.09\\pm0.23)%$, $B(\\psi(2S)\\ar\\gamma\\chi_{c1}\\ar\\gamma\\gamma\\jpsi) = (2.81\\pm0.05\\pm 0.23)%$, and $B(\\psi(2S)\\ar\\gamma\\chi_{c2}\\ar\\gamma\\gamma\\jpsi) = (1.62\\pm0.04\\pm 0.12)%$.
Interleukin 12 (IL-12) activates natural killer (NK) and T cells with the secondary synthesis and release of interferon-gamma (IFN-gamma) and other cytokines. IL-12-induced organ alterations are reported...Full Text Available
The phagocytic and killing abilities of heifer mammary gland macrophages (M phi) and neutrophils were evaluated after exposure to recombinant bovine interferon-gamma (rBoIFN-gamma) stimulation in vitro....Full Text Available
The radioactive decay of "2"0"3Bi is studied. A level scheme is proposed for "2"0"3Pb on the basis of #gamma#-ray and electron spectra and #gamma#-#gamma# coincidence measurements. The experimental data are compared with theoretical results obtained in a three quasiparticle approximation. (Auth.).
The CKM angle $\\gamma/\\phi_{3}$ had been measured by two B-factories, the PEPII collider for the BaBar experiment and the KEKB collider for the Belle experiments. The present paper reports recent progress in $\\gamma/\\phi_{3}$.
The natural biotic capacity of soils to degrade gamma-hexachlorocyclohexane (gamma-HCH, lindane) was estimated using an enrichment technique based on the ability of soil bacteria to develop on synthetic...Full Text Available
In Pseudomonas paucimobilis UT26, gamma-hexachlorocyclohexane (gamma-HCH) is converted by two steps of dehydrochlorination to a chemically unstable intermediate, 1,3,4,6-tetrachloro-1,4-cyclohexadiene...Full Text Available
The top-color assisted technicolor (TC2) mode predicts the existence of a pair of charged top-pions $\\pi^{\\pm}_t$. In this paper, we study the production of the charged top-pions pair $\\pi^{\\pm}_t$ at next generation $\\gamma\\gamma$ colliders. The results show that the production rates can reach the level of $10^2$ fb with reasonable parameter space. With a large number of events and the clean background, the charged top-pion should be observable at the $\\gamma\\gamma$ colliders. Therefore, our studies can help us to search for charged top-pion, and furthermore, to test the TC2 model.
We present the efficient technique to extract the signal of the intermediate mass Higgs boson from the backgrounds at future {gamma}{gamma} colliders. For a clear Higgs detection, it is important to fit the original electron accelerator energy depending on the Higgs mass, to set the polarization of the photon beams and to apply the efficient b quark tagging method. we demonstrate the extraction of information of Higgs parameters and the new physics from the observable physical quantities. It is clearly shown that a future {gamma}{gamma} collider will have a rich potential for study on the new physics, as well as the Higgs physics. (author).
We present the efficient technique to extract the signal of the intermediate mass Higgs boson from the backgrounds at future #gamma##gamma# colliders. For a clear Higgs detection, it is important to fit the original electron accelerator energy depending on the Higgs mass, to set the polarization of the photon beams and to apply the efficient b quark tagging method. we demonstrate the extraction of information of Higgs parameters and the new physics from the observable physical quantities. It is clearly shown that a future #gamma##gamma# collider will have a rich potential for study on the new physics, as well as the Higgs physics. (author).
Compton backscattering of laser photons near the interaction point of an e"+e"- or e"-e"- collider can be used to produce a #gamma#-#gamma# or #gamma#-e"- collider. This paper describes the laser requirements, including pulse duration, intensity, energy, and wavelength, for such a collider. For most of the proposed, next generation, e"+e"- colliders, the laser wavelength should be in the near-infrared, with a pulse duration of 1 ps or less and an energy of similar 1 J per pulse. Current chirped pulse amplification laser systems in solid state lasing materials are well suited to meet these requirements. These systems are described. ((orig.)).
Heavy quark production in $\\gamma\\gamma$ collisions is analyzed within the approach to hard collisions of photons recently proposed by the author. In this approach evaluating the cross section $\\sigma(\\gamma\\gamma\\to Q\\bar{Q})$ in the ``next-to-leading order of QCD'' requires the inclusion of direct photon contributions up to the order $\\alpha^2\\alpha_s^2$, whereas in the standard approach direct photon terms only up to the order $\\alpha^2\\alpha_s$ are taken into account. Phenomenological consequences of this difference are discussed.
We investigate the semihard production of neutral pseudoscalar and tensor mesons in high-energy [gamma][gamma] collisions (M=P=[pi][sup 0], [eta], [eta]' or M=T=a[sub 2], f[sub 2], f[sub 2]'). We deal with the exclusive [gamma][gamma][yields]MM' or semi-exclusive [gamma][gamma][yields]MX reactions (X is the hadron jet with not too large mass). The considered transfer momenta are small in comparison with the photon energies and they are large in comparison with the confinement scale. The amplitudes of these processes are determined by the odderon exchange, i.e. three-gluon exchange in the lowest order of perturbative QCD. The cross sections are calculated in this approximation. The possibility of measurements at LEP and at future [gamma][gamma] colliders is discussed. (orig.).
The fundamental product of tetracycline hydrochlorine gamma radiolysis was separated in its solid state. From the results of spectroscopic studies it has been established that it is des-N,N-dimethylaminotetracycline.
The production of pairs of doubly charged vector bileptons is studied at future #gamma##gamma# colliders. The unpolarized cross section for the #gamma##gamma##->#Y"-"-Y"+"+ subprocess is analytically calculated and convoluted to predict the number of events in the complete e"+e"-#->##gamma##gamma##->#Y"-"-Y"+"+ process. The gauge or nongauge character of the vector bilepton Y"#+-#"#+-# is discussed. It is found that, as a consequence of its spectacular signature, as it decays dominantly into two identical charged leptons, and also due to its charge contents, which significantly enhance the cross section, the detection of this class of particles with mass in the sub-TeV region can be at the reach of these colliders. The model-independent nature of our results is stressed.
The possibility of gamma-absorption identification of the analyzed substance is considered. the basic provisions of the proposed method are concentrated on the example of carbohydrates and hydrocarbons. The above method is tested experimentally on polyethylenes and polystyrene
The coupled neutron-gamma cross section libraries BUGLE-80 and SAILOR are compared, with focus on gamma production and transport and its sensitivity to the thermal component of the neutron flux. In addition, the importance of the prompt versus delayed components of the gamma source is addressed. Although BUGLE-80 shows some discrepancies in the core region, the two libraries demonstrate similar capability in the vicinity of the pressure vessel and beyond. The delayed fission product gammas from the core have little impact on the local gamma fluxes beyond the pressure vessel. Although thermal neutron capture is the dominant component of the gamma source, there is little sensitivity of the gamma source to uncertainties in the thermal neutron cross sections, due to compensating effects which tend to keep the thermal neutron capture rate ...
In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable for routine work. In ...
Two geriatic male rhesus monkeys were used for the radioisotope imaging in this research. Discussion of the radionuclide, materials, and method used to accomplish the neurologic examination and the results obtained, both during the procedure and confirmation of the results by necropsies were accompanied by color photos of scan images. Results were that the nuclear images provided accurate images of intracranial neoplasia.
Computed radiography (CR) systems use a photostimulable phosphor plate enclosed in a cassette. In CR, image acquisition is a two-stage process wherein image capture and image read out are done separately. Direct digital radiography (DR) systems, on the other hand, use detectors that have a combined image capture and image read out capability. DR systems are also called as DDR or ddR systems by some vendors. This article focuses on DR systems
This paper examines the seismic signatures of discrete, finite-length fractures, and outlines an approach for elastic, prestack reverse-time imaging of discrete fractures. The results of this study highlight the importance of incorporating fracture-generated P-S converted waves into the imaging method, and presents an alternate imaging condition that can be used in elastic reverse-time imaging when a direct wave is recorded (e.g., for crosswell and VSP acquisition geometries).
The purpose of this study is to investigate the possibility of verifying depleted uranium (DU), natural uranium (NU), low enriched uranium (LEU) and high enriched uranium (HEU) by a developed digital gamma-gamma coincidence spectroscopy. The spectroscopy consists of two NaI(Tl) scintillators and XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results demonstrate that the spectroscopy provides an effective method of "2"3"5U and "2"3"8U quantification based on the count rate of their gamma-gamma coincidence counting signatures. The main advantages of this approach over the conventional gamma spectrometry include the facts of low background continuum near coincident signatures of "2"3"5U and "2"3"8U, less interference from other radionuclides by the gamma-gamma coincidence counting, and region-of-interest (ROI) imagine analysis for uranium enrichment ...
State-of-the-art approaches for the calculation of gamma heating in LMFBR core, blanket and reflector regions have been evaluated, with particular emphasis on coupled neutron-gamma methods/cross section sets. The major source of calculational error was found to be the apparent failure to impose a mass-energy balance on total gamma energy yield from neutron capture and other interactions in the preparation of representative neutron-gamma cross section sets. The applicability of many simplifying assumptions was demonstrated, including: volume-weighted homogenization, insensitivity to the shape of the gamma-source-spectrum, gamma energy deposition equal to gamma energy source more than 10 cm inside large zones of uniform composition, and the negligible effect of bremsstrahlung. A simple one-group method was developed to permit rapid, accurate ...
Neutron Coded Aperture Imaging is a nondestructive imaging technique that utilizes neutrons scattered from an object through specially designed apertures. Coded Aperture Imaging is an alternative technique to Computed Tomography for three-dimensional imaging. Coded Aperture Imaging has the advantage that all of the three-dimensional information is contained in a single image, whereas Computed Tomography requires several images or projections. This technique has been implemented by other using photographic film as an image recording medium and optical reconstruction or decoding of the images. In this work, the possibility of using a real-time neutron video camera to record the images, followed by digital decoding methodology has been investigated. Because only a small fraction of ...
The aim of this study was to assess the possibility of digital image analysis of pit-and-fissure discoloration in order to diagnose caries. Digital images showing pit-and-fissure discoloration in 100...Full Text Available
The goal of ultrasonic molecular imaging is the detection of targeted contrast agents bound to receptors on endothelial cells. We propose imaging methods that can distinguish adherent microbubbles...Full Text Available
This paper discusses the clinical application and main objective of testicular imaging. The authors present cases that represent a spectrum of the abnormalities which might be detected by testicular imaging, with special attention given to testicular torsion and the acute diseases which may mimic it clinically. Accuracy of the test is noted.
Four-dimensional (4D) radiotherapy is the explicit inclusion of the temporal changes in anatomy during the imaging, planning, and delivery of radiotherapy. One key component of 4D radiotherapy planning...Full Text Available
PurposeAuto-propagation of anatomical region-of-interests (ROIs) from the planning CT to daily CT is an essential step in image-guided adaptive radiotherapy. The...Full Text Available
This paper proposes a novel method for computing linear basis images from tensor-valued image data. As a generalization of the nonnegative matrix factorization, the proposed method aims to approximate...Full Text Available
A new gadolinium chelating NIR fluorescent molecular probe increases T1 relaxivity of water protons, facilitating combined optical and magnetic resonance imaging.
Multimodality imaging with PET/CT and SPECT/CT has become commonplace in clinical practice and in preclinical and basic medical research. Do other combinations of imaging modalities have a similar...Full Text Available
Purpose: Small animal micro-CT imaging is being used increasingly in preclinical biomedical research to provide phenotypic descriptions of genomic models. Most of this imaging is coincident...Full Text Available
Epifluorescence images of Ca2+ transients elicited by electrical stimulation of single skeletal muscle fibers were studied with fast imaging techniques that take advantage of the large fluorescence...Full Text Available
Optical coherence microscopy (OCM) is a promising technique or high resolution cellular imaging in human tissues. An OCM system for high-speed en face cellular resolution imaging...Full Text Available
This multiauthored text is aimed particularly toward the resident or registrar training in diagnostic radiology. This is a text book on the entire scope of diagnostic imaging. It includes techniques and imaging modalities of all the systems, head, face and neck. The book covers the entire gamut of diagnostic radiology.
The use of digital wound images would allow remote consultation between patients, physicians, or other caregivers over the Internet. To evaluate the efficacy and validity of digital images for assessment...Full Text Available
Parallel imaging reconstructions result in spatially varying noise amplification characterized by the g-factor, precluding conventional measurements of noise from the final...Full Text Available
Image registrations that are based on similarity measures simply adjust the parameters of an appropriate spatial transformation model until the similarity measure reaches an optimum. The numerous similarity measures that have been proposed in the past are differently sensitive to imaging modality, image content and differences in the image content, selection of the floating and target image, partial image overlap, etc. In this paper, we evaluate and compare 12 similarity measures for the rigid registration. To study the impact of different imaging modalities on the behavior of similarity measures, we have used 16 CT/MR and 6 PET/MR image pairs with known 'gold standard' registrations. The results for the PET/MR registration and for the registration of CT to both rectified and unrectified MR ...
An image slicing spectrometer (ISS) for microscopy applications is presented. Its principle is based on the redirecting of image zones by specially organized thin mirrors within a custom fabricated...Full Text Available
In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable for routine work. In ...
ObjectiveThis study was conducted to evaluate a computer-imaging program called HAAIR (Help with Adjustment to Alopecia by Image Recovery) that was developed to provide...Full Text Available
Purpose: Reverse helical cone-beam computed tomography (CBCT) is a scanning configuration for potential applications in image-guided radiation therapy in which an accurate anatomic image...Full Text Available
The heavy Higgs bosons H,A of the minimal supersymmetric extension of the Standard Model can be produced as resonances in high-energy #gamma##gamma# colliders. Prospects of the search for these particles in bb-bar and neutralino-pair final states are studied in this report. Heavy Higgs bosons can be found with masses up to about 70-80% of the initial e"+e"- collider energy for moderate values of tan #beta#, i.e. in areas of the parameter space not accessible at other colliders.
Future #gamma##gamma# colliders allow the production of the heavy neutral MSSM Higgs bosons H and A as single resonances. The prospects of finding these particles in the bb-bar and the neutralino-pair final states have been analyzed. The H, A bosons can be discovered for medium values of tan #beta# with masses up to 70-80% of the initial e"#+-#e"- c.m. energy. This production mode thus covers parts of the supersymmetric parameter space that are not accessible at other colliders.
We study heavy physics effects on the Higgs production in #gamma##gamma# fusion using the effective Lagrangian approach. We find that the effects coming from new physics may enhance the standard model predictions for the number of events expected in the final states b-barb, WW, and ZZ up to one order of magnitude, whereas the corresponding number of events for the final state t-bart may be enhanced up to two orders of magnitude.
We investigate the scope of all relevant production modes of charged Higgs bosons in the MSSM, with mass larger than the one of the top quark, at future Linear Colliders operating in {gamma}{gamma} mode at the TeV energy scale. Final states with one or two H{sup {+-}} bosons are considered, as produced by both tree- and loop-level interactions. (orig.)
We investigate the scope of all relevant production modes of charged Higgs bosons in the MSSM, with mass larger than the one of the top quark, at future Linear Colliders operating in #gamma##gamma# mode at the TeV energy scale. Final states with one or two H"#+-# bosons are considered, as produced by both tree- and loop-level interactions. (orig.)
The gamma-ray spectrum following neutron capture on /sup 87/Sr was measured at 3 neutron energies: E/sub n/ = thermal, 2 keV, and 24 keV. Gamma rays were detected in a three-crystal Ge(Li)-NaI-NaI pair spectrometer. Gamma-ray intensities deduced from these spectra by spectral unfolding are presented.
This patent describes a {gamma}-ray detector. It comprises: a dislocation-free single crystal having an input surface and a transmission surface at opposite ends thereof; an active shield surrounding the crystal and functioning as an anticoincidence counter; and {gamma}-ray detector means disposed adjacent the transmission surface of the crystal for receiving and detecting {gamma}-rays of a predetermined wavelength incident on the input surface of the crystal at a specific Bragg angle and transmitted through the crystal.
We have constructed a Monte Carlo generator (the corresponding FORTRAN code can be obtained from the authors upon request) for lowest-order predictions for the processes {gamma}{gamma}{yields}4f and {gamma}{gamma}{yields}4f{gamma} in the standard model and extensions thereof by an effective {gamma}{gamma}H coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes {gamma}{gamma}{yields}4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic beam spectrum on cross sections and distributions is illustrated. Moreover, the size ...
We have constructed a Monte Carlo generator (the corresponding FORTRAN code can be obtained from the authors upon request) for lowest-order predictions for the processes #gamma##gamma##->#4f and #gamma##gamma##->#4f#gamma# in the standard model and extensions thereof by an effective #gamma##gamma#H coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes #gamma##gamma##->#4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic beam spectrum on cross sections and distributions is illustrated. Moreover, the size of ...
In 1998, research began at Idaho National Engineering and Environmental Laboratory to investigate the application of {sup 6}Li and {sup 7}Li isotopes to the measurement of neutron and gamma radiation. Various size pairs of {sup 6}Li and {sup 7}Li based detectors were exposed to mixed neutron and gamma radiation. Experiments demonstrated that these detectors could be used to measure low level neutron radiation in the presence of high level gamma radiation. (author)
In 1998, research began at Idaho National Engineering and Environmental Laboratory to investigate the application of "6Li and "7Li isotopes to the measurement of neutron and gamma radiation. Various size pairs of "6Li and "7Li based detectors were exposed to mixed neutron and gamma radiation. Experiments demonstrated that these detectors could be used to measure low level neutron radiation in the presence of high level gamma radiation. (author)
The working group reviewed the main difficulties foreseen in doing physics at a gamma-gamma collider. They discussed the requirements for the detector, calculated some of the signal and background rates, compared methods of measuring luminosity, looked at how to get the laser beams in, investigated ways of sweeping aside the electrons and considered ways of disposing of the used beams. No overwhelming obstacles were found but important questions still need to be answered. ((orig.)).
The working group reviewed the main difficulties foreseen in doing physics at a gamma-gamma collider. They discussed the requirements for the detector, calculated some of the signal and background rates, compared methods of measuring luminosity, looked at how to get the laser beams in, investigated ways of sweeping aside the electrons and considered ways of disposing of the used beams. No overwhelming obstacles were found but important questions still need to be answered. ((orig.)).
Carbide reactions occurring in a precipitation-hardening gamma/gamma-prime Ni-Cr alloy during prolonged high-temperature aging are investigated experimentally. It is found that the decomposition of primary MC carbides, which is accompanied by the precipitation of M23C6 particles, may lead to void nucleation and growth. The effect of carbide transformations on the residual properties of the material at temperatures above the equicohesion temperature is observed at the late stages of aging only. 6 references.
The Albedo Theory was applied in order to develop an one-group algorithm for coupled neutron-gamma shielding calculations. The configuration analyzed consists of multilayered plane systems, where a incident neutron current generates gamma radiation through neutron-gamma reactions. The results obtained by Albedo Method and ANISN code have shown excellent agreement. (author)
The Albedo Theory was applied in order to develop an one-group algorithm for coupled neutron-gamma shielding calculations. The configuration analyzed consists of multilayered plane systems, where a incident neutron current generates gamma radiation through neutron-gamma reactions. The results obtained by Albedo Method and ANISN code have shown excellent agreement. (author)
A multi-group neutron-gamma cross-section library in DTF-IV format is supplemented with electron production matrix to generate a coupled neutron-gamma-electron library. This is realized by estimating the contributions from Compton scattering, pair production and photoelectric effect to the electron production cross-sections. A novel application of this new library, which involves transport of neutrons, gammas and electrons, for estimating the Compton current due to a pulse of radiation in air is discussed.
A multi-group neutron-gamma cross-section library in DTF-IV format is supplemented with electron production matrix to generate a coupled neutron-gamma-electron library. This is realized by estimating the contributions from Compton scattering, pair production and photoelectric effect to the electron production cross-sections. A novel application of this new library, which involves transport of neutrons, gammas and electrons, for estimating the Compton current due to a pulse of radiation in air is discussed.
Post-mortem magnetic resonance (MR) imaging is of increasing interest not only as an alternative to autopsy but as a research tool to aid the interpretation and diagnosis of in utero MR images. The information from the post-mortem MR has allowed the development of imaging sequences applicable to in utero imaging and neonatal imaging. It has established brain development during gestation and has provided data on this to which in utero MR can be compared. The detail available from the post-mortem images is such that brain development can be studied in a non-invasive manner, a permanent record on the normal and abnormal areas is available and a greater understanding of developmental abnormalities is possible.
The central nervous system is involved in 10-20% of cases in Lyme disease. The neurological symptoms, time course of the disease and imaging findings are multifaceted. We report two patients with cervical radiculitis. Magnetic resonance imaging revealed strong enhancement of the cervical nerve roots on contrast-enhanced T1-weighted images. These imaging patterns of borrelia-associated radiculitis have not been reported before. Knowledge of these imaging features may help to diagnose neuroborreliosis, which presents with non-specific symptoms. (orig.)
Weakly absorbing materials, such as biological, soft tissues, can be imaged by generating contrast due to the phase shift of X-rays. In the past decade, several methods for X-ray phase imaging were proposed and demonstrated. The performance of X-ray phase imaging is attractive in the field of medical imaging technology, and its development for practical use is expected. Many methods, however, have been developed under the assumption of the use of synchrotron radiation, which is an obstacle to practical use. The method based on Talbot (-Lau) interferometry enables us to use a compact X-ray source, and its development is expected as a breakthrough for medical applications. (author)
Possible anomalous top-quark couplings induced by SU(2)xU(1) gauge-invariant dimension-6 effective operators were studied in the process of ttbar productions and decays at polarized {gamma}{gamma} colliders. Two CP-violating asymmetries, a linear-polarization asymmetry and a circular-polarization asymmetry, were computed including both non-standard ttbar{gamma} and {gamma}{gamma}H couplings. An optimal-observable analysis for the process {gamma}{gamma}{yields}ttbar{yields}l{sup {+-}} was performed in order to estimate the precision for determination of all relevant non-standard couplings, including the anomalous tbW coupling.
Physical processes in the region of laser conversion for the next Linear Colliders (NLC) are discussed. The main goal of this conversion is to obtain high-energy intense #gamma# beams for #gamma#e and #gamma##gamma# colliders. This conversion has important by-products: (i) one can observe here effect of nonlinear QED (in a strong external field)-production of e"+e"- pairs by a high-energy photon and emission of very high-energy photons by an electron; (ii) one can produce and observe here the invisible axion in colliding #gamma#_0e beams. The NQED effects also result in variation of the spectra of high-energy photons and an additional background. 12 refs., 12 figs., 1 tab.
Measurements of {gamma}-ray, {gamma}{gamma}-coincidence and internal conversion electron spectra from the {sup 106}Cd({alpha},n{gamma}){sup 109}Sn reaction were carried out at 15-20 MeV {alpha}-particle bombarding energies with Ge(HP) {gamma}-ray and superconducting magnetic lens plus Si(Li) electron spectrometers. The energies, relative intensities, internal conversion coefficients and coincidence relations of the {sup 109}Sn transitions were determined, and a more complete, consistent level scheme has been deduced. Spin and parity values have been determined from the internal conversion coefficients, the bombarding-energy dependence of the side-feeding intensities of the states and the available {gamma}-ray angular distribution data. The level scheme was interpreted in the framework of the quasi-particle shell model.
Aug 25, 2004 ... The Tropical Rainfall Measuring Mission or TRMM satellite provided this image of Typhoon Aere over the western Philippine Sea as it was ...
Selection of the appropriate radiation quality is an important aspect of optimisation for every clinical imaging task in radiology, since it affects both image quality and patient dose. Spreadsheet...Full Text Available
Abstract The authors provide a survey of how images are used in radiation therapy to improve the precision of radiation therapy plans, and delivery of radiation treatment. In contrast...Full Text Available
Portal localization images for high-energy electron beam therapy are necessary to confirm the treatment field by comparing them with a simulation image obtained before treatment or portal verification images after treatment. In this study, portal localization images were acquired using the computed radiography (CR) system and bremsstrahlung X-rays generated in the electron beam irradiations. All images obtained with phantom and the irradiations of in the electron energy of 8, 10, 12 and 15 MeV were feasible for clinical use. The CR system used in this study included general diagnostic imaging cassette and storage phosphor plate, but none of other special devices. The system can usually supply portal localization images, which maintains the quality assurance of high-energy electron beam therapy. (author)
A method of increasing information content for content-based image retrieval (CBIR) systems includes the steps of providing a CBIR database, the database having an index for a plurality of stored digital images using a plurality of feature vectors, the feature vectors corresponding to distinct descriptive characteristics of the images. A visual similarity parameter value is calculated based on a degree of visual similarity between features vectors of an incoming image being considered for entry into the database and feature vectors associated with a most similar of the stored images. Based on said visual similarity parameter value it is determined whether to store or how long to store the feature vectors associated with the incoming image in the database.
An image-analysis system, based on commercially available data visualization software (IDL [1]), allows convenient interaction with image data while still providing calculated beam parameters at a rate of up to 2 Hz. Image data are transferred from the IOC to the workstation via EPICS [2] channel access. A custom EPICS record was created in order to overcome the channel access limit of 16k bytes per array. The user can conveniently calibrate optical transition radiation (OTR) and fluorescent screens, capture background images, acquire and average a series of images, and specify several other filtering and viewing options. The images can be saved in either IDL format or APS-standard format (SDDS [3]), allowing for rapid postprocessing of image data by numerous other software tools.
This paper presents two imaging methods by using cross correlation. The one method images the subsurface by cross-correlation of the observed data and partial derivative seismograms calculated for a guessed model. The other method images the interface by use of cross-correlation of the virtual sources and the back propagated wave fields calculated from the observed data. Experimental tests show that both methods image subsurface interfaces well even if the guessed model is different from the true one. These imaging methods are reverse time migration that we perform cross-correlation as an imaging condition and have an advantage, as compared to conventional waveform inversion method, that images subsurface structure without iterative perturbation of the assumed model. (author). 18 refs., 15 figs.
Over the past decade, dramatic increases in computational power and improvement in image analysis algorithms have allowed the development of powerful computer-assisted analytical approaches...Full Text Available
The short review of complete tree level calculations for three particle final states production at the future e"+e"-, #gamma#e and #gamma##gamma# colliders is presented. The results obtained with the help of CompHEP system for total cross sections and other characteristics of processes in the energy range 0.1-2 TeV are summarized and their comparison with the results of different approaches is discussed. In particular we are interested in the processes of W, Z and H boson production. The reactions under consideration are especially interesting in connection with probing of new couplings, searching for new particle signals and as an important backgrounds to these experiments. The main subjects described are basic reactions rates (sections 2,3), Higgs production in #gamma#e collisions (section 4), the possibilities of testing some four vector bosons interaction vertices and Higgs-fermion coupling (section 5), the process of ...
We consider single production of leptoquarks (LQ's) at e"+e- and #gamma##gamma# colliders, for two values of the center-of-mass energy: #sq root#s =500 GeV and 1 TeV. We find that LQ's which couple within the first generation are observable for LQ masses almost up to the kinematic limit, both at e"+e- and #gamma##gamma# colliders, for an LQ coupling strength equal to #alpha#_e_m. The cross sections for single production of second- and third-generation LQ's at e"+e- colliders are too small to be observable. In #gamma##gamma# collisions, on the other hand, second-generation LQ's with masses much larger than #sq root#s /2 can be detected. However, third-generation LQ's can be seen at #gamma##gamma# colliders only for masses at most #approx# #sq root#s /2, making their observation more probable via the pair production mechanism.
1. Gamma globulin metabolism and distribution were studied employing rabbit gamma globulin (RGG)I(131) 24 times in 13 control rabbits. Similar studies were performed before and during the ananmestic response in 4 rabbits previously sensitized with a polyvalent pneumococcal vaccine. 2. During the ananmestic response, gamma-globulin levels increased from 1.0 to 6.0 gm/100 ml, and the gamma-globulin pool increased from 0.7 to 4.7 gm/kg. There was no change in the intravascular-extravascular partition of gamma globulin. 3. Gamma globulin degradation increased from 0.06 to 0.33 gm/kg/day during the 28 days of the immunization period while gamma globulin synthesis increased even further to average 0.47 gm/kg/day. Following the attainment of elevated gamma globulin levels the fractional rate of RGG-I(131) turnover increased ...
We consider the possibility of detecting a heavy Higgs boson (m_H>2m_Z) in proposed #gamma##gamma# colliders through the semileptonic mode #gamma##gamma##->#H#->#ZZ#->#q bar ql"+l-. We show that due to the nonmonochromatic nature of the photon beams produced by the laser-backscattering method, the resultant cross section for Higgs production is much smaller than the on-resonance cross section, and generally decreases with increasing collider energy. Although continuum ZZ production is expected to be negligible, we demonstrate the presence of, and calculate sizable backgrounds from, #gamma##gamma##->#l"+l-Z,q bar qZ, with Z#->#q bar q,l"+l-, respectively, and #gamma##gamma##->#t bar t#->#b bar bl"+l-#nu# bar #nu#. This channel may be used to detect a Higgs boson of mass m_H up to around 350 GeV at a 0.5 TeV e"+e- collider, assuming a nominal yearly luminosity of 10--20 fb"-"1.
We investigate the effect of anomalous gamma-W-W couplings in e-gamma --> nu W through the angular and energy spectrum of the secondary leptons. Within the narrow-width approximation, a semi-analytical study of the secondary lepton energy-angle double distribution is considered. Utility of observables derived from this is demonstrated by considering the anomalous coupling, delta-kappa-gamma. Results of our investigation for typical ILC machine considered at Ecm = 300-1000 GeV re-affirms potential of this collider as a precision machine.
A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.
With the development of an array of highly-segmented germanium detectors, it now becomes possible to perform in-flight #gamma#-ray spectroscopy experiments on intermediate energy beams with unprecedented #gamma#-ray energy resolution. Presented in this report are examples of two techniques in which SeGA, the most highly-segmented operational germanium array for in-flight spectroscopy with fast beams, was used for the detection of #gamma# rays. SeGA used in conjunction with a high-resolution magnetic spectrograph (S800) to detect the reaction residues in coincidence represents a powerful combination for in-beam #gamma#-ray studies.
A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.
The notion of intuitionistic fuzzy set was introduced by Atanassov as a generalization of the notion of fuzzy set. In this paper we apply this concept of Atanassov to ideals, prime ideals and semiprime ideals of gamma semigroups in order to obtain some characterization theorems. We also introduce the notion of Atanassov's intuitionistic fuzzy ideal extension in a gamma semigroup and investigate some of their important properties. A regular gamma semigroup has been characterized in terms of Atanasov's intutionistic fuzzy ideal. Characterization of prime ideal of a gamma semigroup has also been obtained in terms of Atanassov's intutionistic fuzzy ideal extension.
As a method to enhance the sensitivity (S) of an inorganic resist for focused-ion-beam (FIB), lithography, sub-0.1 #mu#m patterning properties of a columnar structural #alpha#-Se_7_5Ge_2_5 resist have been investigated using 30 keV low-energy Ga"+-FIB exposure and CF_4 reactive-ion etching (RIE). development. The Se_7_5Ge_2_5 thin films were 60 .deg. and 80 .deg. -obliquely deposited on Si substrate and parts of the films were annealed for several minutes at the glass transition temperature (T_g=#approx#220 .deg. C). Columnar structures with the angles of approximately 40 .deg. and 65 .deg. are observed in 60 .deg. and 80 .deg. -obliquely deposited films, respectively, and they disappear after annealing. Despite the disappearance of the columnar structures, a critical decrease in thickness is not observed. For the FIB exposures with a beam diameter of #approx#0.1#mu#m and around the threshold dose, the negative-type fine patterns with linewidth of about 0.06#approx#0.09 #mu#m are ...
Quantitative I-131 labelled Peanut lectin (I-131-PNA) renal clearance was determined in dogs before and after a 5 day single cycle cis-platinum chemotherapy regimen (0.5mg/Kg/day). Results were statistically compared with E.R.P.F. (I-131-Hippuran), G.F.R. (Tc-99m-DTPA), and serum biochemistry and correlated with histopathology. I-131-PNA clearance was significantly reduced in all dogs 5 days after cessation of cis-platinum treatment (mean #DELTA#S% = 71.3%) and similar reductions in the gamma camera derived renogram peak were demonstrated (mean #DELTA#S% = 65.8%). E.R.P.F. was noted to drop by a minor degree (mean #DELTA#S% = 20.9%) post treatment. G.F.R. was diminished (mean #DELTA#S% = 46.6%) and serum creatinine elevated (mean #DELTA#S% = 42.7%) in all dogs compared to their pretreatment values. Histopathology demonstrated variable degrees of tubular toxicity ranging from mild to severe. The degree of change of the I-131-PNA values was significantly greater than ...
US Department of Energy methods used for characterization of contact-handled transuranic (CH-TRU) waste prior to shipment to the Waste Isolation Pilot Plant (WIPP) are described and listed by contractor site. The methods described are part of the certification process. All CH-TRU waste must be assayed for determination of fissile material content and decay heat values prior to shipment and prior to storage on-site. Both nondestructive assay (NDA) and destructive assay methods are discussed, and new NDA developments such as passive-action neutron (PAN) crate counter improvements and neutron imaging are detailed. Specifically addressed are assay method physics; applicability to CH-TRU wastes; calibration standards and implementation; operator training requirements and practices; assay procedures; assay precision, bias, and limit of detection; and assay limitation. While PAN is a new technique and does not yet have established American Society for Testing and ...
US Department of Energy methods used for characterization of contact-handled transuranic (CH-TRU) waste prior to shipment to the Waste Isolation Pilot Plant (WIPP) are described and listed by contractor site. The methods described are part of the certification process. All CH-TRU waste must be assayed for determination of fissile material content and decay heat values prior to shipment and prior to storage on-site. Both nondestructive assay (NDA) and destructive assay methods are discussed, and new NDA developments such as passive-action neutron (PAN) crate counter improvements and neutron imaging are detailed. Specifically addressed are assay method physics; applicability to CH-TRU wastes; calibration standards and implementation; operator training requirements and practices; assay procedures; assay precision, bias, and limit of detection; and assay limitation. While PAN is a new technique and does not yet have established American Society for Testing and ...
Involvement of the dopaminergic system has been suggested in patients suffering from attention deficit hyperactivity disorder (ADHD) since the symptoms can be successfully treated with methylphenidate, a potent blocker of the dopamine transporter (DAT). This study reports the findings on the status of the DAT in adults with ADHD before and after commencement of treatment with methylphenidate, as measured using [{sup 99m}Tc]TRODAT-1. Seventeen patients (seven males, ten females, aged 21-64 years, mean 38 years) were examined before and after the initiation of methylphenidate treatment (3 x 5 mg/day). All subjects were injected with 800 MBq [{sup 99m}Tc]TRODAT-1 and imaged 3 h p.i. Single-photon emission tomography (SPET) scans were acquired using a triple-headed gamma camera. For semi-quantitative evaluation of the DAT, transverse slices corrected for attenuation were used to calculate specific binding in the striatum, with the cerebellum used ...
CNPT-3 is the laboratory designation of a strain of bacteria that reproduces best at deep-sea pressures. It was isolated from a sample collected at a 5800 m depth of the Pacific Ocean. This isolation was achieved from a sample that had been retrieved without warning. This year we demonstrated that there are similarly behaving bacteria that can be isolated from samples even when retrieved with decompression. The purpose of this project was to define the temperatures and pressures over which CNPT-3 can exist and function. (1) At 2"0C CNPT-3 is eurybathic from about 1000 to 6500 m, as judged from an only slightly pressure dependent generation time. (2) CNPT-3 is unquestionably barophilic at 2"0C, with doubling times of 9 hours at 580 bars and over 18 hours at 1 bar. (3) At 10"0C, reproduction is adversely affected at 1 bar to the extent that CNPT-3 becomes obligately barophilic at 10"0C. Yet reproduction is enhanced above 280 bars and occurs with a regeneration time of 4 hours at 690 bars ...
Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1 mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a ...
Ultra-high resolution radiographs can be obtained using synchrotron X-rays. A collaboration team consisting of K-JIST, POSTECH and YUMC has recently commissioned a new beamline (5C1) at Pohang Light Source (PLS) in Korea for medical applications using phase contrast radiology. Relatively simple image acquisition systems were set up on 5C1 beamline, and imaging studies were performed for resolution test patterns, mammographic phantom, and animals. Resolution test patterns and mammographic phantom images showed much better image resolution and quality with the 5C1 imaging system than the mammography system. Both fish and mouse images with 5C1 imaging system also showed much better image resolution with great details of organs and anatomy compared to those obtained with a conventional mammography system. A simple and ...
Modern imaging technologies visualize different aspects of disease in a non-invasive way. Considerable progress has been made in the fusion of images from different imaging modalities using software approaches. One goal of fusion software is to align anatomical and functional images and allow improved spatial localization of abnormalities. The resulting correlation of the anatomical and functional images may clarify the nature of the abnormality and help diagnose or stage the underlying disease. Whereas successful image fusion software has been developed for the brain, only limited success has been achieved for image alignment in other parts of the body. The development and current status of alternative approaches are presented. Dual-modality imaging is described with devices where two modalities are combined and mounted ...
The authors describe the application of an approximate fuzzy C-means (AFCM) clustering algorithm as a data dimension reduction approach to medical magnetic resonance images (MRI). Image data consisted of one T1-weighted, two T2-weighted, and one T2*-weighted (magnetic susceptibility) image for each cranial study and a matrix of 10 images generated from 10 combinations of TE and TR for each body lymphoma study. All images were obtained with a 1.5 Tesla imaging system (GE Signa). Analyses were performed on over 100 MR image sets with a variety of pathologies. The cluster analysis was operated in an unsupervised mode and computational overhead was minimized by utilizing a table look-up approach without adversely affecting accuracy. Image data were first segmented into 2 coarse clusters, each of which was then subdivided ...
Previous reports have stressed the importance of the nutrient blood supply in rib grafts transferred by microvascular anastomoses. In the present experimental study, we have demonstrated that a rib graft transferred by microvascular anastomoses based on periosteal vessels can survive; vascular clearing studies demonstrated that the vascularity of these grafts extends not only into the cortex but the medulla as well. The relative facility of harvesting these grafts (compared with those based on nutrient vessels) should make them the favored choice. Technetium bone scintigraphy proved accurate in the assessment of both vascular pattern and microanastomotic patency. Tetracycline labeling did not correlate well with the patency of a rib graft's pedicle blood supply.
To investigate the role of intravenously administered, radioiodinated peanut lectin ("1"3"1I-PNA) in the non-invasive detection of cancer, the pharmacokinetics and scintigraphic distribution of this novel tumor-seeking compound were studied in 8 patients with metastatic cancer of the colon, breast or lung. Scintigraphic localization of "1"3"1I-PNA was apparent at certain anatomical sites of known metastases in 2 patients and in a further 2 patients an adjacent malignant pleural effusion was visualized. The rapid clearance of radioactivity from the whole body and plasma with marked renal concentration and rapid urinary excretion of significant amounts of intact "1"3"1I-PNA (mol.wt. 107,000,pI 5.95) implied that this molecule was excreted selectively by the renal tubules. PNA or other lectins may find a role in the scintigraphic detection of selected types of cancer. (author).
Aim: This study was performed: 1) to assess the relationship between blood flow velocity in the internal carotid artery (CBFICA) and pial artery pulsation (cc-TQ) and 2) to evaluate flow-induced changes in pial artery compliance. Methods: Experiments were performed on 10 crossbred male rabbits. Heart rate (HR), blood pressure (BP), left ventricle ejection fraction (LVEF), CBFICA, the systolic-diastolic blood volume fraction in the brain circulation (CBFSDF) and cc-TQ were recorded after glucagon and acetazolamide administration. cc-TQ was measured with near-infrared transillumination back scattering sounding (NIR-T/BSS), LVEF and CBFSDF with gated scintigraphy and BP and CBFICA with electromagnetic pressure and flow transducers, respectively. Doses of drugs were chosen to exert a haemodyna...
This study evaluated the clinical efficacy of treatment with oral risedronate (17.5?mg once daily) for 8?weeks in 11 Japanese patients with Paget?s disease of bone (PDB). Risedronate suppressed the excessive bone turnover associated with PDB and improved several biochemical markers, including serum alkaline phosphatase (ALP), serum bone-specific ALP (BALP), urinary deoxypyridinoline (DPD), and urinary cross-linked N-telopeptide of type 1 collagen (NTX). These markers began to decrease within about 2?weeks after the initiation of treatment in most patients, and the response persisted for up to 40?weeks after the cessation of treatment. Risedronate reduced pain by week 24 in most patients. According to quantitative bone scintigraphy, the lesion with the highest radioisotope (RI) uptake showe...
The future e{sup +}e{sup -} linear colliders can also operate in the e{gamma} or {gamma}{gamma} modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process {gamma}{gamma} {yields} tb-bar{pi}{sub t}{sup -}. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode {pi}{sub t}{sup -} {yields} bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in {gamma}{gamma} mode at the TeV energy scale.
The O({alpha}) electroweak radiative corrections to {gamma}{gamma}{yields}WW{yields}4f within the electroweak standard model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into factorizable and non-factorizable contributions, and real-photonic corrections are based on complete lowest-order matrix elements for {gamma}{gamma}{yields}4f+{gamma}. Soft and collinear singularities appearing in the virtual and real corrections are combined alternatively in two different ways, namely by using the dipole subtraction method or by applying phase-space slicing. The radiative corrections are implemented in a Monte Carlo generator called Coffer {gamma}{gamma} - the computer code can be obtained from the authors upon request - which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over ...
The O(#alpha#) electroweak radiative corrections to #gamma##gamma##->#WW#->#4f within the electroweak standard model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into factorizable and non-factorizable contributions, and real-photonic corrections are based on complete lowest-order matrix elements for #gamma##gamma##->#4f+#gamma#. Soft and collinear singularities appearing in the virtual and real corrections are combined alternatively in two different ways, namely by using the dipole subtraction method or by applying phase-space slicing. The radiative corrections are implemented in a Monte Carlo generator called Coffer #gamma##gamma# - the computer code can be obtained from the authors upon request - which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over ...
We study the constraints on the anomalous coupling {ital g}{sub 5}{sup {ital Z}} that can be obtained from the analysis of the reaction {gamma}{gamma}{r_arrow}{ital W}{sup +}{ital W}{sup {minus}}{ital Z} at future linear {ital e}{sup +}{ital e}{sup {minus}} colliders. We find out that a 0.5 (1) TeV {ital e}{sup +}{ital e}{sup {minus}} collider operating in the {gamma}{gamma} mode can probe values of {ital g}{sub 5}{sup {ital Z}} of the order of 0.15 (4.5{times}10{sup {minus}2}) for an integrated luminosity of 10 fb{sup {minus}1}. This shows that the ability to search for this anomalous interaction of the {gamma}{gamma} mode is better than the one of the usual {ital e}{sup +}{ital e}{sup {minus}} mode, and it is similar to the ability of the {ital e}{gamma} mode.
In this report, I surveyed physics potential of the {gamma}{gamma} option of a linear e{sup +}e{sup -} collider with the following questions in mind: What new discovery can be expected at a {gamma}{gamma} collider in addition to what will be learned at its 'parent' e{sup +}e{sup -} linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e{sup -} beams, we find that a {gamma}{gamma} collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e{sup -}e{sup -} system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a {gamma}{gamma} collider. CP property ...
In this report, I surveyed physics potential of the #gamma##gamma# option of a linear e"+e"- collider with the following questions in mind: What new discovery can be expected at a #gamma##gamma# collider in addition to what will be learned at its 'parent' e"+e"- linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e"- beams, we find that a #gamma##gamma# collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e"-e"- system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a #gamma##gamma# collider. CP property of the scalar sector can be explored in detail by ...
We investigate theoretically subwavelength imaging by acoustic metamaterial slabs immersed in the liquid matrix. A near-field subwavelength image formed by evanescent waves is achieved by a designed metamaterial slab with negative mass density and positive modulus. A subwavelength real image is achieved by a designed metamaterial slab with simultaneously negative mass density and modulus. These results are expected to shed some lights on designing novel devices of acoustic metamaterials.
X-ray imaging is a very useful plasma diagnostic method. A theoretical analysis of the x-ray phase imaging in the method based on Fresnel diffraction is given. The authors show it is a linear band pass filter, a property suit for Rayleigh-Taylor (R-T) instability measurement. The evaluation permits the possibility of R-T instability measurement in x-ray phase imaging
Magnetic resonance imaging can be used in the trauma setting to detect fractures and associated soft tissue injuries of the musculoskeletal system. Magnetic resonance imaging complements plain radiography and CT for evaluating cancellous bone, cartilage and growth-plate injuries, and intra- and extraarticular supporting soft tissue structures. This review outlines typical applications and imaging consideration for injuries of the pelvis and lower extremity. (orig.) With 12 figs., 78 refs.
The computer vision approach to image analysis is discussed from two aspects. First, this approach is constrasted to the pattern recognition approach. Second, how external knowledge and information and models from other fields of science and engineering can be used for image and scene analysis is discussed. In particular, the connections between computer vision and computer graphics are pointed out.
The reconstruction of coronal and Sagittal Image of Brain C. T. is helpful to diagnosis of Brain. Three Dimensional Reconstruction software package allows to display three dimensional Image clerived from a series of Horizontal, Sagittal and Coronal Brain C. T. images. It useful in determine approach of operation, to define portals of deep radiation therapy.
Image representations have gained wide acceptance in displaying data collected during optical, ultrasonic, radiographic, and thermographic inspections. Applying imaging techniques to eddy current testing is explored in this article. The authors show that flaw interpretation and characterization are made considerably simpler when images are used to visualize the impedance changes in eddy current probes.
This report considers the use of a submillimeter wavelength space-based imaging radar. The main application envisioned is midcourse decoy discrimination for strategic defense, for which it would have the capability of producing a series of images, in real time, at strategic ranges, with less than meter scale resolution and with modest power requirements. Undoubtedly, there are other applications. The requirements for a SAR and ISAR imaging radar at submillimeter wavelength are determined, and the prospect for the development of RF sources to power the radar is examined.
The patient positioning and repositioning control in radiation therapy all along the treatment can be conducted using a variety of X-ray sources and imaging detector devices. The development of image guided radiation therapy techniques leads to more frequent use of this imaging control. In this article we summarize the current methods for measuring the dose delivered by X-ray imaging devices used in radiation therapy, as well as basic proposals to take account of these imaging doses for prescribing, recording and reporting radiation therapy treatment. (authors)
Constrained least-squares techniques have been used to produce a well known class of image restoration algorithms. These techniques typically involve minimizing a linear operator on a vector representation of an image, subject to a constraint. For cases where an equality constraint is appropriate the method of Lagrange multipliers can be used to produce a restored image. In this work a fractal textural model, fractional Brownian motion, is used to represent images of interest. Using a variance fractal dimension estimator a non-linear operator, that represents the squared difference between the fractal dimension of the restored image and on a priori value is minimized, subject to the constraint that the norm of the residual between the restored image and available measurement equal the norm of the additive noise.
Digital libraries need more than just a retrieval based on keywords, which can be inefficient for some applications. Thus, a document retrieval based on content of the digitized image version of the document can be a more appropriated approach. This paper discusses the retrieval of document images by means of identifying a variety of elements present in the document's image body. We propose a new strategy to identify and combine features extracted from a document image. We also consider the task of constructing an optimized feature set to improve the retrieval performance and to validate our experiments on an assorted database. Experimental results show that the proposed segmentation together with a wisely feature combination increase the overall retrieval performance. Moreover the retrieved images demonstrate the generality and effectiveness of our approach for an efficient ...
The brain imaging properties of /sup 99m/Tc glucoheptonate, /sup 99m/Tc pertechnetate, and /sup 99m/Tc DPTA are compared. Results demonstrate that optimum images are obtained at 90, 180, and 180 min., for /sup 99m/Tc GH, /sup 99m/Tc DTPA, and /sup 99m/Tc pertechnetate, respectively. The former two images are not affected by prior bone imaging with /sup 99m/Tc pyrophosphate, while /sup 99m/Tc pertechnetate images are adversely affected. /sup 99m/Tc glucoheptonate appears to be the superior agent for brain imaging, followed by /sup 99m/Tc DTPA and /sup 99m/Tc pertechnetate.
The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,..cap alpha..), E = thermal, reactions for which the residual nucleus mass number is greater than or equal to 45 are included. These correspond to evaluations published in Nuclear Data Sheets. The publication source data are contained in the Evaluated Nuclear Structure Data File (ENSDF). The data presented here do not involve any additional evaluation. Appendix I lists all the residual nuclides for which the data are included here. Appendix II gives a cumulated index to A-chain evaluations including the year of publication. The capture gamma ray data are given in two tables - the Table 1 is the list of all gamma rays seen in (n,..gamma..) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide.
We present the effects of heavy CP-even (H) and CP-odd (A) Higgs bosons on the production cross section of the process {gamma}{gamma}{yields}tt at the energy around the mass poles of the Higgs bosons. It is found that interference between H and A with small mass gap, as well as the ones between Higgs bosons and continuum, contributes to the cross section, if the photon beams are polarized and if we observe the helicity of the top quarks. It is demonstrated in the framework of the minimal supersymmetric extension of the standard model that the H and A contributions can be sizable at future {gamma}{gamma} colliders for small values of tan {beta}. The methods to measure the CP-parity of the Higgs boson are also presented. The statistical significance of detecting the Higgs signals and measuring the Higgs CP-parity is evaluated. (orig.)
We present the effects of heavy CP-even (H) and CP-odd (A) Higgs bosons on the production cross section of the process #gamma##gamma##->#tt at the energy around the mass poles of the Higgs bosons. It is found that interference between H and A with small mass gap, as well as the ones between Higgs bosons and continuum, contributes to the cross section, if the photon beams are polarized and if we observe the helicity of the top quarks. It is demonstrated in the framework of the minimal supersymmetric extension of the standard model that the H and A contributions can be sizable at future #gamma##gamma# colliders for small values of tan #beta#. The methods to measure the CP-parity of the Higgs boson are also presented. The statistical significance of detecting the Higgs signals and measuring the Higgs CP-parity is evaluated. (orig.)
"1"0"1Mo is one of the key nuclides in diagnosing fission burn-up. However, it's difficult to measure its nuclear decay data due to its short half-life. Present study concerns in the measurements of #gamma#-ray emission probabilities, P_#gamma#, of "1"0"1Mo and "1"0"1Tc using the balance of scheme method and the entire process recording. The P_#gamma# of "1"0"1Mo by the entire process recording is about 5% lower than that by using the balance of scheme method. The P_#gamma# of "1"0"1Tc using the two methods agree each other very well. So, it seems the #gamma#-ray emission probabilities as well as measurement method still need study further for "1"0"1Mo. (authors)
The resonant scattering of bremsstrahlung #gamma#-rays by a SrCO_3 target has been studied for #gamma#-ray energies of 5-11 MeV. Six #gamma#-transitions of energies between 6-8 MeV, which indicate six resonant states in "8"8Sr, were observed. The relative intensities of the resonantly scattered #gamma#-rays at 125 and 150"0 were found to be compatible only with the assignment of spin 1 to the six states. Radiative widths of the resonant states were deduced. The possibility that these states are components of the giant M1 resonance in "8"8Sr is discussed. (orig.).
The {rvec n} + p {yields} d + {gamma} experiment under construction at LANSCE studies the weak interaction between neutrons and protons. The experiments will measure the directional dependence of the parity-violating {gamma}-ray asymmetry, A{sub {gamma}}, in the polarized cold neutron capture by para-hydrogen. The goal is to measure A{sub {gamma}} with uncertainty of 0.5 x 10{sup -8}, 10% of its predicted value. A{sub {gamma}} primarily isolates the {Delta}I = 1 component of the hadronic weak interaction and thus will determine the long-range weak pion-nucleon coupling constant H{sub {pi}}{sup 1}. The experiment is carefully designed for the LANSCE pulsed spallation neutron source to achieve the proposed statistical precision and to control systematic errors. We discuss the experiment and its status.
One of the main challenges for a high energy {gamma}{gamma} collider is the high repetition rate required for the laser-electron-beam collisions to convert into high energy gamma beams. State-of-the-art, high power lasers have a much lower repetition rate than that of the electron pulses. It is therefore highly desirable that the same laser pulse can be reused. As an example, for NLC where beams collide at 120 Hz, within each collision cycle there are 90 electron bunches separated by 1.4 ns between successive bunches. We show, by invoking a recently invented laser optical box, that the laser pulses can be reused for the entire train of bunches within each collision cycle. ((orig.)).
One of the main challenges for a high energy #gamma##gamma# collider is the high repetition rate required for the laser-electron-beam collisions to convert into high energy gamma beams. State-of-the-art, high power lasers have a much lower repetition rate than that of the electron pulses. It is therefore highly desirable that the same laser pulse can be reused. As an example, for NLC where beams collide at 120 Hz, within each collision cycle there are 90 electron bunches separated by 1.4 ns between successive bunches. We show, by invoking a recently invented laser optical box, that the laser pulses can be reused for the entire train of bunches within each collision cycle. ((orig.)).
A subsurface imaging system is utilized to test the ability of the spectral polarization difference imaging technique for deep subsurface imaging in tissues. The illumination of the system is derived from compact class III lasers in the red and NIR spectral region and, alternatively, from a white light source and selection of the appropriate illumination wavelength using band-pass optical filters. The experimental results demonstrate detection and imaging of a high-scattering object located up to 1.5 cm underneath the surface of a host chicken tissue.
Gallium imaging is increasingly being used for the early detection of complications in patients with AIDS. A 26-year-old homosexual man who was HIV antibody positive underwent gallium imaging for investigation of possible Pneumocystis carinii pneumonia. Widespread cutaneous focal uptake was seen, which was subsequently shown to be due to mycobacterium avium-intracellulare (MAI) septicemia. This case demonstrates the importance of whole body imaging rather than imaging target areas only, the utility of gallium imaging in aiding the early detection of clinically unsuspected disease, and shows a new pattern of gallium uptake in disseminated MAI infection.
To establish test specific normal limits for quantitative analysis of uptake and washout of /sup 201/Tl after dipyridamole infusion combined with low level exercise, 20 healthy volunteers were studied with low likelihood of coronary artery disease (CAD) assessed by a stepwise probability analysis based on age, sex, symptoms, resting electrocardiogram, and exercise electrocardiography. Likelihood of CAD in these volunteers was calculated as less than or equal to 1%. After dipyridamole infusion combined with low level exercise, one volunteer complained of headache; no other side effects were observed. There were no chest pain complaints. Maximal hemodynamic changes were achieved during the 6th and 7th min of the test. No ST segment depression was recorded. Visual analysis of the /sup 201/Tl scintigrams was normal in all volunteers. Mean regional washout at 4 h was 44.37%+-2.11%. The regional washout in the 70/sup 0/ LAO view (46.65%+-1.10%) was significantly higher than in the anterior ...
7,959 patients were examined by radionuclide in-vivo methods within one year, 1,228 of them by application of "1"3"1I-iodide (radioiodine test and scintigraphy of the thyroid gland). In compliance with the ICRP publications 26 and 27 the somatically effective equivalent dose H/sub s,eff/ was ascertained for several examining methods, derived from it the collective dose S/sub s,eff/ and considering a part of manifestation resulting from the age distribution of patients, the somatic risk regarding radiation-induced malignoma with fatal termination. For the patients examined by "1"3"1I-iodide the collective dose was 79.9 man x Sv and the mean somatic risk 30 x 10"-"5 with a part of manifestation of 0.39 accordig to 0.37 radiation-induced malignomas with fatal termination. For all patients examined by other radiopharmaceuticals the collective dose was 14.07 man x Sv, the mean somatic risk 1.7 x 10"-"5 according to 0.11 malignomas. The average somatic risk of all ...
A selected series of 24 patients with displaced medial femoral neck fracture, treated with closed reduction and osteosynthesis with cancellous bone screws (ASIF), were investigated. During an observation period of 6 to 26 months, serial hip joint scintigraphies were performed and compared with serial X-ray examinations. At the first scintigraphic examination performed on average 5-6 weeks after the fracture, two separate investigators found a decreased amount of activity or no activity in the femoral head of 10 and 8 patients, respectively. At the second scintigraphic examination performed on average 11.1 weeks after the fracture both investigators found no activity or a decreased amount of activity in 8 patients. This figure declined to 7 during the following period, because one patient with decreased activity was recorded as having normal activity 15 months after the fracture. These 7 patients all developed radiological signs of femoral head collapse on average ...
Thallium-201 myocardial imaging was performed in 80 children with coronary arterial lesions due to Kawasaki disease in order to assess the value of serial and exercise myocardial imagings. In eight of these children, abnormalities of the image were noted. Twenty children had serial thallium studies with an interval of three to 18 months, and five of these showed changes in the image including appearance of a new perfusion defect in one patient and improvement of perfusion defects in four. These changes of the myocardial image were correlated well with coronary angiographic findings obtained within a few days of the isotope studies. It was noted that the changes of the myocardial image were more frequently observed at relatively recent period recovered from Kawasaki disease. Exercise myocardial imaging using a bicycle ergometer was performed ...
Higgs mediated flavor violating electromagnetic interactions, induced at the one-loop level by a nondiagonal Hf_if_j vertex, with f_i and f_j charged leptons or quarks, are studied within the context of a completely general effective Yukawa sector that comprises SU_L(2)xU_Y(1)-invariant operators of up to dimension-six. Exact formulae for the one-loop #gamma#f_if_j and #gamma##gamma#f_if_j couplings are presented and their related processes used to study the phenomena of Higgs mediated lepton flavor violation. The experimental limit on the #mu##->#e#gamma# decay is used to derive a bound on the branching ratio of the #mu##->#e#gamma##gamma# transition, which is 6 orders of magnitude stronger than the current experimental limit. Previous results on the #tau##->##mu##gamma# and #tau##->##mu##gamma##gamma# decays are reproduced. The possibility of ...
Given an invariant gauge potential and a periodic scalar potential \\tilde{V} on a Riemannian manifold \\tilde{M} with a discrete symmetry group \\Gamma, consider a \\Gamma-periodic quantum Hamiltonian \\tilde{H}=-\\tilde{\\Delta}_{B}+\\tilde{V} where \\tilde{\\Delta}_{B} is the Bochner Laplacian. Both the gauge group and the symmetry group \\Gamma can be noncommutative, and the gauge field need not vanish. On the other hand, \\Gamma is supposed to be of type I. To any unitary representation \\Lambda of \\Gamma one relates a Hamiltonian H^{\\Lambda}=-\\Delta_{B}^{\\Lambda}+V on M=\\tilde{M}/\\Gamma where V is the projection of \\tilde{V} to M. We describe a construction of the Bloch decomposition of \\tilde{H} into a direct integral whose components are H^{\\Lambda}, with \\Lambda running over the dual space \\hat{\\Gamma}. The evolution ...
The NS together with a gamma ray sensor make up the Gamma- Ray and ... A simplified view of the interactions between incoming cosmic rays and the .... held in Huntsville, Alabama, at the U.S. Space and Rocket Center on January 2830. ...
Evidence is presented for a distinctive type of hippocampal synaptic modification [previously described for a molluscan gamma-aminobutyric acid (GABA) synapse after paired pre- and postsynaptic excitation]:...Full Text Available
In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, Utah; Ely, Nevada; and Las Vegas, Nevada. Three events, HARRY (May 19, 1953), BEE (March 22, 1955), and SMOKY (August 31, 1957), accounted for over half of the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of ''infinite exposure,'' ...
We give a summary of the discussions in Working Group V of the CKM2010 workshop dealing with determinations of the angle gamma of the unitarity triangle of the Cabibbo-Kobayashi-Maskawa matrix from B-meson decays into charmed final states.
The dielectrical properties of organosilicon sealants have been studied in the wide range of temperatures in the low and radio frequencies range. The effect of thermal treatment and #gamma#-irradiation on these properties is discussed.
Massive particle candidates for dark matter provide a potentially observable signature by virtue of their annihilations in the galactic halo at a known but model-dependent rate. Possible signatures are described, including cosmic ray antiproton and gamma-ray production. (orig.).
Neutron diffraction was used to monitor elastic strains during in situ tension testing of a directionally solidified (DS) superalloy at 900 deg. C. Changes in misfit and thermal expansion coefficients of individual phases were obtained. In the {gamma} phase, it is demonstrated that elastic strains saturate at 350 MPa, which is well below the yield strength of the alloy. This is interpreted as the onset of dislocation glide through less stressed vertical channels. The critical resolved shear stress (CRSS) of {gamma} is found to be 143 {+-} 11 MPa, in agreement with a calculated CRSS that is dominated by Orowan bowing of dislocations through nanoscale-wide {gamma} channels. This provides confirmation of Orowan bowing in plasticity/creep of the {gamma} phase. Implications of CRSS and misfit in a 'threshold stress' for creep and rafting are discussed. The CRSS of ...
Gamma interferon (IFN-γ) and the cellular responses induced by it are essential for controlling mycobacterial infections. Most patients bearing an IFN-γ receptor ligand-binding chain...Full Text Available