The purpose of this project was to design, build, and characterize the performance of a volume breast ultrasound (VBUS) scanner that images the pendant breast. VBUS scanner design includes a: 1) clinical ultrasound scanner and transducer; 2) scanning table with a hole for the pendant breast; 3) rotational gantry; 4) probe mounting assembly; 5) compressionless breast stabilization device; 6) acquisition, control, reconstruction, and display software. Performance assessment characterized a variety of parameters including: spatial resolution, uniformity, and distortion using high and low contrast test objects in both horizontal and vertical scanning modes. The VBUS scanner modules have been constructed and initial performance evaluated. Approximately 300 scans are acquired over 360 degrees in 18 seconds. Reconstruction requires 25 ms per slice. Test object images depicted hyper- and ...
Although ultrasound arrays were exploited in photoacoustic imaging to improve imaging speed, ultrasound-array-based optical-resolution photoacoustic microscopy (OR-PAM) has never been achieved...Full Text Available
Previous ultrasound elasticity imaging experiments supported a generally accepted concept that the hardness of deep venous thrombi increases with thrombus aging. Results also showed that this...Full Text Available
We present two cases of fetal neck masses that were initially diagnosed by ultrasound and further evaluated with prenatal MRI. MRI findings aided in further delineating the neck masses, increasing confidence in the final diagnosis (cervical teratoma and cystic hygroma). With the fetal airway typically filled with fluid that is of high signal on T2-weighted sequences, MRI images in three planes could identify whether the fetal larynx and trachea were partially or completely compressed by the neck tumor. This information was particularly useful in determining if a controlled delivery such as ex utero intrapartum treatment (EXIT) was necessary and aided the surgeons in planning their approach to establishing airway control in the delivery room. (orig.)
ObjectiveAngiography remains a critical component for diagnostic imaging and therapeutic intervention in peripheral arterial disease (PAD). The goal of this study...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
OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare...Full Text Available
Ultrasound examinations for foetal brain abnormalities have been a part of the routine antenatal screening programme in the UK for many years. In utero brain magnetic resonance imaging (MRI) is now being used increasingly successfully to clarify abnormal ultrasound findings, often resulting in a change of diagnosis or treatment plan. Interpretation requires an understanding of foetal brain development, malformations and acquired diseases. In this paper we will outline the technique of foetal MRI, relevant aspects of brain development and provide illustrated examples of foetal brain pathology.
Percutaneous coronary intervention can be associated with distal embolization of thrombotic material causing myocardial necrosis and infarction.We discuss the role of intravascular imaging to...Full Text Available
A prospective comparative study with pathology was performed to assess the clinical value of Computed Tomography (CT) and endoscopic ultrasound (EUS) for nodal staging in lung cancer. A total of 329 nodal stations were dissected or sampled and 755 lymph nodes were examined at histology. On a pre-station basis, CT had greater sensitivity (74%) than EUS (56%), but EUS was more specific (83% versus 93%). The accuracy rates of the two techniques were similar. In conclusion, endoscopic ultrasound should be part of a routine preoperative diagnostic approach to non-small-cell lung cancer., because of its high specificity. Results can be improved when EUS and CT are combined., which suggests that these imaging modalities should be used together in selected patients for the noninvasive staging of non-small-cell lung cancer to identify local lymphatic spread.
In this paper, we put forward a systematic method to analyze, control and evaluate the safety issues of medical robotics. We created a safety model that consists of three axes to analyze safety factors. Software and hardware are the two material axes. The third axis is the policy that controls all phases of design, production, testing and application of the robot system. The policy was defined as hazard identification and safety insurance control (HISIC) that includes seven principles: definitions and requirements, hazard identification, safety insurance control, safety critical limits, monitoring and control, verification and validation, system log and documentation. HISIC was implemented in the development of a robot for urological applications that was known as URObot. The URObot is a universal robot with different modules adaptable for 3D ultrasoundimage-guided interstitial laser coagulation, radiation seed implantation, laser resection, ...
To study the utility of ultrasound and computed tomography (CT) in case of suspected appendicitis. To determine the diagnostic yield in terms of different clinical contexts and patient characteristics. to assess the costs and benefits of introducing these techniques and propose a protocol for their use. Negative appendectomies, complications and length of hospital stay in a group of 152 patients with suspected appendicitis who underwent ultrasound and CT were compared with those of 180 patients who underwent appendectomy during the same time period, but had not been selected for the first group: these patients costs for each group were calculated. In the first group, the diagnostic value of the clinical signs was also evaluated. The reliability of the clinical signs was limited, while the results with ultrasound and CT were excellent. The incidence of negative appendectomy was 9.6% in the study group and 12.2% in the ...
Intramuscular hermorrhage was induced by injecting autologous blood into the paraspinal muscle of 8 rabbits. In order to evaluate the time-dependent changes of hemorrhage observed on MRI, the animals were imaged at different stages of blood resolution at 0.02 tesla (T), and control examined with ultrasound using a 7.5 MHz linear transducer. Six inversion recovery sequences (TR=1 000 ms. TE=30 ms, and TI=18, 48, 148, 201, 302, and 398 ms) were used for the invivo calculation of T1 relaxation times. IR 1 000 (398)/30 imaging was performed before and after the Gd-DOTA administration. The hemorrhage was evident on MR images throughout the study, especially on the T2 weighted (SE 1 000/100) images. MRI showed the healing lesion longer than ultrasound. The T1 relaxation time increased during the time of resolution. Lesions on days 4 to 7 enhanced in intensity after ...
Ultrasound tomography is an attractive imaging method for the detection of breast cancer. The complex anatomy of the breast with its different spatial scales and material property contrasts make accurate reconstructions very challenging. This paper proposes a hybrid approach whereby Travel-of-Flight and Diffraction Tomography are combined together to achieve high-resolution and high-accuracy sound-speed reconstructions. The method is validated with several numerical phantoms.
Background: Mechanisms underlying the association between myocardial bridge (MB)-stenting and in-stent restenosis (ISR) are still unclear. Objective: To assess the impact of MB on ISR using intravascular ultrasound (IVUS). Methods: In the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial, 100 left anterior descending artery (LAD) culprit lesions (79 treated with paclitaxel-eluting stents [PES] and 21 treated with bare metal stents) were imaged with serial IVUS immediately postprocedure and at 13 months. Results: At baseline the LAD stent extended into the MB segment beyond the culprit lesion in seven patients (MB-stent group). In the remaining 93 patients the LAD stent was implanted only in the culprit lesion without extending into t...
17 patients with chronic aortic dissection were examined by MRI. In 12 patients, comparison between gradient echo sequences and SE sequences was possible. Gradient echo sequences, unlike SE sequences, permitted evaluation of flow in the true and false lumen, reliable differentiation between thrombus and flowing blood and clear delination of the intimal flap. An additional comparison between transoesophageal ultrasound and MRT in 15 patients showed significant advantages in favour of MRI. In three patients MRI was able to detect more proximal origins of the dissection. Moreover, MRI allowed evaluation of the major aortic branches and their relation to the dissection; this was not possible with ultrasound. MRI plays an important role in the follow-up of chronic aortic dissections. (orig.).
High-intensity contact ultrasound (HICU) under MRI guidance may provide minimally invasive treatment of endocavitary digestive tumors in the esophagus, colon or rectum. In this study, a miniature receive-only coil was integrated into an endoscopic ultrasound applicator to offer high-resolution MRI guidance of thermotherapy. A cylindrical plastic support with an incorporated single element flat transducer (9.45 MHz, water cooling tip) was made and equipped with a rectangular RF loop coil surrounding the active element. The integrated coil provided significantly higher sensitivity than a four-element extracorporeal phased array coil, and the standard deviation of the MR thermometry (SDT) improved up to a factor of 7 at 10 mm depth in tissue. High-resolution morphological images (T1w-TFE and IR-T1w-TSE with a voxel size of 0.25 x 0.25 x 3 mm3) and accurate thermometry data (the PRFS method with a voxel size of 0.5 x 0.5 x 5 ...
For the evaluation of diseases of salivary origin, ultrasound and/or sialography is recommended instead of MRI. In cases of salivary tumor, ultrasound may be helpful in delineating superficial tumors. For small tumors no further imaging is needed. When dealing with a large tumor or a tumor in the deep lobe of the parotid gland, MRI is the preferred imaging method. Not only does MRI provide a large variety of soft tissue signal differences, but also the multiplanar facilities are helpful in delineating the extent of the tumor, whether located in the submandibular, sublingual, or parotid gland. Skull base invasion is often well seen by MRI. Subtle changes may be missed and in those cases CT is recommended to exclude or prove destruction of the skull base. For the evaluation of patients presenting with a recurrent pleomorphic adenoma, MRI is recommended in all patients. MRI delineates the extent and number ...
For good image quality using ultrasound inverse scattering, one alternately solves the well-posed forward scattering equation for an estimated total field and the ill-posed inverse scattering equation for the desired object property function. In estimating the total field, error or noise contaminates the coefficients of both matrix and data of the inverse scattering equation. Previous work on ill-posed inverse ultrasonic scattering commonly used Tikhonov regularization, which considers error only in the data. The solution so obtained is not precise enough to reconstruct the quantitative internal structure of a large or high-contrast object. This paper adopts the truncated total least squares method, simultaneously considering error and noise on both sides of the inverse scattering equation, and compares it with the classical Tikhonov regularization. We show that it can substantially improve reconstruction fit and image ...
Purpose: The purpose of this research was to identify the extent and scope of changes to radiography practice. Method: Questionnaires were sent to radiology managers at acute National Health Service (NHS) hospitals in 2000 as a follow-up to an initial survey conducted in 1998. Information was sought on region, teaching/non-teaching status, the nature of extended role tasks undertaken and the year in which these tasks were first undertaken. Results: Some 172 questionnaires were returned from a total of 253 dispatched (68%). In 161 hospitals radiographers administered intravenous injections and performed barium enemas in 119 hospitals, while a red-dot system was in operation in 141 hospitals. Reporting by radiographers had increased since 1998. Replies indicated that, at 124 hospitals, radiographers were reporting in ultrasound. Skeletal reporting was the second most-frequently-reported activity, with 63 hospitals indicating that radiographers ...
Objective To report the clinical response to image-guided percutaneous cryotherapy (IPC) for the palliative management of localized metastases in patients with gynecologic malignancies. Methods Institutional review board approval and patient consent were obtained. Gynecologic oncology patients were identified from our institution's cryotherapy database from August 2003 to August 2007. Cryotherapy was performed with 2.4?mm diameter probes (Endocare, Irvine, CA) with ultrasound or computerized tomography (CT) guidance under conscious sedation and local anesthesia. Follow-up was conducted by imaging studies and clinical encounters, using Response Evaluation Criteria in Solid Tumors (RECIST criteria). Results Twenty-eight ablation sessions were performed for 41 metastatic foci in 15 patients w...
Fetal MRI examines non-invasively the unborn fetus. Ultrafast MRI sequences effectively suppress fetal motion. Multiple case reports and studies have shown that fetal MRI is particularly helpful in the evaluation of the central nervous system. The high contrast-to-noise ratio, the high spatial resolution, the multiplanar capabilities, the large field of view and the simultaneous visualisation of fetal and maternal structures have proven to be advantageous. Fetal MRI is particularly helpful in the evaluation of the normal and pathological development of the brain. Despite the fact that no side effects have been reported or are to be expected, the use of MRI during pregnancy is still limited to the second and third trimester of pregnancy. Magnetic resonance imaging contrast media are not to be used as it passes the placenta. Ultrasound remains the primary screening modality for fetal pathology; fetal MRI can serve as an adjunct or second-line ...
Minimally invasive thermotherapies for focal tissue destruction on the basis of laser-, microwave-, focused ultrasound-, or cryogeninduced changes of tissue temperature represent an alternative to surgical tissue ablation, particularly in the treatment of tumors. The thermotherapy modalities listed necessitate indirect guidance and monitoring, since they often do not lend themselves to immediate visual control. In the brain, in head and neck tumors, in the liver, and in the prostate, MRI reliably and accurately delineates both the positions of interstitial thermotherapy applicators and - in contrast-enhanced, T1-weighted images - the perfusion defects in tissue necrosis induced by thermotherapy. The transfer of results of in-vitro and in-vivo model studies to assess interstitial temperature and lesion development during thermotherapy to the actual treatment of patients, however, is still in an initial phase. Further ...
This paper presents a new approach to improve the in silico modeling of ultrasound transducer arrays. While current simulation tools accurately predict the theoretical element...Full Text Available
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 ...
Two cases of focal nodular hyperplasia (FNH), in which ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MR) studies detected an atypical hemorrhagic pattern associated with an intrahepatic arterio venous malformation (AVM) around the growths, are presented. In both cases, histology demonstrated a very early regenerative stage and necrotic-hemorrhagic areas within the lesions. In these cases, the analysis of radiological findings, surgical specimens and histology seemed to confirm the pathogenetic hypothesis suggested by Wanless: in normal liver parenchyma, a ``blood steal`` phenomenon due to congenital or acquired intrahepatic AVM could cause ischemic damage, appearing as a hemorrhagic necrotic area, the extent of which depends on the degree of residual portal supply. (orig.)
Objective To demonstrate clinical features of a patient subgroup presenting with polycystic ovary syndrome (PCOS) without polycystic ovary morphology. Design Retrospective study. Setting Hospital-based IVF center. Patient(s) In the present study, 876 PCOS patients were selected from women who visited the Reproductive Medicine Center at Shandong Provincial Hospital, Shandong University, between September 2004 and October 2006. Women with PCOS were divided into two groups based on ultrasoundimage: group A, PCOS patients with classic polycystic ovary (n = 800); group B, PCOS patients without polycystic ovary morphology (n = 76). The following available data were analyzed in the large cohort of women: body height, weight, waistline, hip circumference, hirsutism scores, family history, serum s...
Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with GD-DTPA enhancement. ...
The effect of ultrasound waves, airflow and combined ultrasound with the airflow on the thermal instability suppression of a hollow needle-to-plate electrical discharge was studied experimentally. To evaluate the thermal instability suppression we used the V-A characteristics of the discharge in stationary air, with ultrasound applied in stationary air, and finally when the airflow was supplied into the discharge through the needle without and with ultrasound application. To illustrate the effect of ultrasound, airflow and combined ultrasound with airflow on the discharge thermal instability suppression we also studied the discharge ozone production. We found that in stationary air the application of ultrasound only slightly suppresses thermal instability. A substantial increase of ozone generation was not detected. Application of the ...
Opinion statement Because a minority of patients with D-transposition of the great arteries are diagnosed in utero by ultrasound, most present after delivery with cyanosis. In the absence of apparent lung disease, cyanotic neonates suspected of having a cardiac lesion should be immediately transferred to an intensive care unit at a pediatric tertiary care center for monitoring, resuscitation, and to define the cardiac anatomy and physiology. A prostaglandin E-1 infusion is usually initiated to maintain ductal patency and promote intra-cardiac mixing. In the past, balloon atrial septostomy (BAS) was routinely performed to enlarge the atrial septal defect and improve intra-cardiac mixing while the infants awaited surgery. Recent literature has reported an increase risk of stroke in neonates ...
Background: Pleural biopsy and cytology are standard procedures for the investigation of pleural disease. Recent medical literature has suggested that image-guided pleural biopsy shows improved sensitivity for the diagnosis of pleural malignancy, when compared with the more commonly performed reverse bevel needle biopsy such as Abrams' needle. In our centre there has been an increasing trend towards performing image-guided pleural biopsies, and to our knowledge there is no large published series documenting the complication rate and diagnostic yield. Methods: The radiology and pathology databases were searched for all image-guided [computed tomography (CT) and ultrasound (US)] pleural biopsies from January 2001 to December 2004. All imaging and histology were reviewed, and final diagnostic information about patients was obtained from the respiratory multidisciplinary team database ...
The solid-pseudopapillary tumor (SPT) of the pancreas is a rare type of exocrine pancreatic neoplasm. SPT predominantly affects young women and female children, and is usually discovered incidentally. This tumor is generally benign with a low incidence of malignancy. A 13-year-old girl was admitted to the hospital with a few weeks' history of mild abdominal pain and jaundice. On physical examination, there was no palpable mass. The laboratory tests showed increased SR, CRP, high bilirubin, amylase and lipase serum levels. Ultrasoundimaging revealed a solid lesion in the region of the pancreatic head. On MRI, precise tumor localization in the head of the pancreas with pancreatic duct dilatation and compression of the common bile duct were visualized. Pancreaticoduodenectomy and cholecystectomy was performed with good clinical outcome. Microscopic and immunohistochemical studies indicated that tumor cells were typical of SPT without any signs of ...
SommarioScopo Valutare limpatto clinico negli anni dellecografia intraoperatoria (IOUS) nella identificazione delle metastasi epatiche rispetto alle altre metodiche di imaging. Materiali e metodi risultati delle ecografie intraoperatorie effettuate per lidentificazione delle metastasi epatiche in un periodo compreso tra gli anni 2000 e 2006 sono stati retrospettivamente revisionati e comparati con le metodiche di imaging preoperatorio: Ecografia (US), Tomografia Computerizzata (TC) e/o Risonanza Magnetica (RM). Tutti i casi sono stati patologicamente provati. Sono stati calcolati per anno i casi discordanti in termini di presenza/assenza di lesione focale epatica. Il confronto statistico e stato effettuato con il test di McNemar. Un valore del p<0,05 e stato considerato statisticamente sig...
The diagnostic imaging findings in hepatic amoebiasis and the capabilities of percutaneous drainage have already been described but some debate is open on both diagnosis and treatment. It is reported the experience with the ultrasound (US) and Computed Tomography (CT) studies of the hepatic amoebic abscess and its management. [Italian] I reperti con diagnostica per immagini nell'amebiasi epatica e le possibilita' del drenaggio percutaneo sono stati gia' illustrati; esistono tuttavia controversie sul piano sia diagnostico che terapeutico. Obiettivo di questo lavoro e' quello di riportare l'esperienza personale nella diagnostica con ecografia e tomografia computerizzata (TC) e nel trattamento degli ascessi amebici del fegato.
Materials and methods: 12 patients with 22 coronary bypass grafts underwent intraoperative flow quantification using the transit time ultrasound method. These values were compared to postoperative MR phase shift measurements. Flow measurements were performed preoperatively in 28 coronary arteries of 20 patients. For flow measurement, we used a velocity-encoded k-space segmented gradient echo sequence with a temporal resolution of 110 or 125 ms, respectively. 6-8 pase shift images could be acquired during one cardiac cycle. Results: There was a significant correlation between intraoperative and flow measurements using velocity-encoded MR imaging (r=0.76, p<0.0001, t-test). Flow volumes determined by MR imaging were systematically larger than those determined by the transit time ultrasound method. Mean flow in coronary arteries was reduced in severely stenosed vessels ...
The authors report a case of a cephalopagus conjoined twin that was diagnosed at 29 weeks of gestation despite the mother having had two ultrasounds done previously. The fetus had one head and face,...Full Text Available
We investigate a method for gene delivery to vascular smooth muscle cells using ultrasound triggered delivery of plasmid DNA from electrostatically coupled cationic microbubbles. Microbubbles...Full Text Available
A bladder neck obstruction was suspected after ultrasound investigation at 16 weeks' gestation. Evaluation of protein content in the amniotic fluid, fetal ascites, and fluid from the overdistended bladder...Full Text Available
Although previous intravascular ultrasound (IVUS) radiofrequency-based analysis data showed acceptable reproducibility for plaque composition, measurements are not easily obtained, particularly that...Full Text Available
Previous investigations have shown promising results in using the directional cross-correlation method to estimate velocity vectors. The velocity vector estimate provides information on both velocity direction and magnitude. The direction is estimated by beamforming signals along directions in the range $[0^{\\circ}; 180^{\\circ}[$ and identifying the direction that produces the largest correlation across emissions. An estimate of the velocity magnitude is obtained from the spatial shift between signals beamformed along the estimated direction. This paper expands these investigations to include estimations of the vector velocities of a larger region by combining the estimations along several scan lines. In combination with a B-mode image, the vector velocities are displayed as an image of the investigated region with a color indicating the magnitude, and arrows showing the direction of the flow. Using the RASMUS experimental ...
The mortality in undrained abdominal abscesses is high with a mortality rate ranging between 45 and 100%. The outcome in abdominal abscesses, however, has improved due to advances in image guided percutaneous interventional techniques. The main indications for the catheter drainage include treatment or palliation of sepsis associated with an infected fluid collection, and alleviation of the symptoms that may be caused by fluid collections by virtue of their size, like pancreatic pseudocele or lymphocele. The single liver abscesses may be drained with ultrasound guidance only, whereas the multiple abscesses usually require computed tomography (CT) guidance and placement of multiple catheters. The pancreatic abscesses are generally drained routinely and urgently. Non-infected pancreatic pseudocysts may be simply observed unless they are symptomatic or cause problems such as pain or obstruction of the biliary or the gastrointestinal tract. ...
Positron-emission tomography (PET) and PET/CT (computed tomography) are becoming increasingly important for diagnosis and treatment of cancer. Clinically relevant changes can sometimes be seen on PET that are not seen on other imaging modalities. However, PET is not suitable for guiding biopsy as the images are not obtained in real-time. Therefore, our research group has begun developing a concept for PET/CT-guided interventional procedures. This paper presents the rationale for this concept, outlines our research plan, and includes an initial study to evaluate the relative sensitivity of CT and PET/CT in detecting suspicious lesions. (orig.)
A method and apparatus is provided for detecting explosives by thermal imaging. The explosive material is subjected to a high energy wave which can be either a sound wave or an electromagnetic wave which will initiate a chemical reaction in the explosive material which chemical reaction will produce heat. The heat is then sensed by a thermal imaging device which will provide a signal to a computing device which will alert a user of the apparatus to the possibility of an explosive device being present.
Initial clinical experience in gastrointestinal radiography using Fuji Computed Radiography(FCR) system was reported. Image quality of conventional film/screen radiography and FCR system on upper GI series and barium enema was compared. Reflecting wide dynamic range of the system, improved image quality was confirmed, particularity in visibility of fine mucosal pattern(area gastricae), folds and overall contour. High sensor sensitivity of the system could reduce radiation dose requirement significantly. Diagnostically acceptable images were obtained with approximately 1/5 of routine dose for conventional radiography except in cases of lateral view of the rectum. (author).
Quantitative structure activity relationship (QSAR) analysis of the correlations between initial brain uptake and structure parameters, for example lipophilicity F_r, molar refractivity MR and electronic parameters #sigma#_1 of the "9"9Tc"m-N_2S_2 complexes have been studied with multiple regression analysis method. The main structural factors which affect the initial brain uptake of this kind of brain imaging agents have been discussed. The results may give some theoretical information for designing new brain imaging agents
Sep 19, 2011 ... (The whispering voice, on the other hand, was the latest in ultrasound directed audio technology from the firm Audio Spotlight.) The NASA ...
... mammography or on ultrasound but not found on physical examination, we consider them non-palpable or not ... lot of this. We send every patient for physical therapy, no matter what type of reconstruction we ...
In diabetic patients with autonomic neuropathy, it is suggested that there is a reduced uptake of [sup 123]I-metaiodobenzylguanidine (MIBG) in the heart. We compared the difference of myocardial [sup 123]I-MIBG accumulation between 4 diabetic patients with triopathy and 6 patients without it. In all 10 patients, coronary angiography and [sup 201]Tl imaging (rest and 4 hours later) were performed. [sup 123]I-MIBG (111 MBq) was administered intravenously and its imaging was recorded on 15 minutes and 4 hours after injection. In all 4 cases with triopathy, [sup 123]I-MIBG imaging showed defect in apical and inferior region. In 2 out of 6 cases without triopathy, rapid clearance was noticed in apical and inferior region. There was no significant stenosis in right coronary artery and no defect in initial and delayed [sup 201]Tl images in all cases. We concluded that diabetic autonomic ...
Heterogeneous gasless reactive systems, including high-energy density metal-nonmetal compositions, have seen increasing study due to their various applications. However, owing to their high reaction temperature, short reaction time, and small scale of heterogeneity, investigation of their reaction mechanisms and kinetics is very difficult. In this study, microstructural changes and the kinetics of product layer growth in the W-Si system was investigated using a high-speed x-ray phase-contrast imaging technique. Using the Advanced Photon Source of Argonne National Laboratory, this method allowed direct imaging of irreversible reactions in the W-Si reactive system at frame rates up to 36 000 frames per second with 4 {mu}s exposure and spatial resolution of 10 {mu}m. Details of the Si melt and reactions between W and Si, that are unable to be viewed with visible-light imaging, were revealed. These include processes such as the ...
Heterogeneous gasless reactive systems, including high-energy density metal-nonmetal compositions, have seen increasing study due to their various applications. However, owing to their high reaction temperature, short reaction time, and small scale of heterogeneity, investigation of their reaction mechanisms and kinetics is very difficult. In this study, microstructural changes and the kinetics of product layer growth in the W-Si system was investigated using a high-speed x-ray phase-contrast imaging technique. Using the Advanced Photon Source of Argonne National Laboratory, this method allowed direct imaging of irreversible reactions in the W-Si reactive system at frame rates up to 36 000 frames per second with 4 #mu#s exposure and spatial resolution of 10 #mu#m. Details of the Si melt and reactions between W and Si, that are unable to be viewed with visible-light imaging, were revealed. These include processes such as the ...
Background/AimsAlthough endoscopic ultrasound guided fine needle aspiration (EUS-FNA) has been introduced and its use has been increasing in Korea, there have not been many reports...Full Text Available
BackgroundCardiovascular magnetic resonance (CMR) allows volumetric carotid plaque measurement that has advantage over 2-dimensional ultrasound (US) intima-media thickness (IMT)...Full Text Available
Purpose: To visualise the vessel wall of the descending thoracic aorta using magnetic resonance imaging. To evaluate the diagnostic potential of tailored T{sub 1}-weighted sequences with contrast enhancement to assess systemic atherosclerotic disease. Methods: This study was performed on a clinical 1.5 Tesla scanner using a gradient strength of 30 mT/m and the phased array spine coil. A cadaver was examined to optimise a magnetic resonance imaging (MRI) protocol to evaluate atherosclerotic aortic wall disease. The acquired MR images were compared to gross specimens and histology. Subsequently seven patients who had undergone transesophageal ultrasound (TEU) with detailed assessment of the descending thoracic aorta were examined with MRI. The optimised protocol included untriggered and fat suppressed T{sub 2}-weighted turbo spin echo sequences and ECG-triggered and fat suppressed T{sub 1}-weighted spin ...
Purpose/Objective: At present, treatment verification between portal and reference images is performed based on manually-identified features by radiation oncologist, which is both time-consuming and potentially error-prone. There is a demand for the computerized verification procedure in clinical application. The purpose of this study is to develop a computerized portal verification scheme for pelvic treatment fields. Materials/Methods: The automated verification system involves image acquisition, image feature extraction, feature matching between reference and portal images and quantitative evaluation of patient setup. Electronic portal images with a matrix size of 256 x 256 and 12 bit gray levels were acquired using a liquid matrix electronic portal imaging device. Simulation images were acquired by digitizing simulation films using a TV ...
Four /sup 125/I labeled mono- and diamines were prepared and evaluated as potential brain-imaging agents. The diamines are analogues of the previously reported /sup 75/Se labeled diamines, which show high brain uptake and retention. All of the radioiodinated amines display high initial brain uptake in rats after intravenous injection (1.7-2.4% dose/organ). The xylylenediamines show prolonged brain retention (t1/2 approximately 18 h), which is desirable for brain imaging. In contrast, the benzylamine is rapidly cleared from brain tissue (t1/2 approximately 15 min).
In developing new brain imaging agents for single photon emission computed tomography (SPECT), we synthesized eleven radioiodinated phenoxyacetic acid derivatives and investigated the relationship between the chemical structure and in vivo characteristics. Biodistribution studies in mice revealed high initial brain uptake for all the compounds. Blood radioactivity level depended markedly upon the chemical stability of the compound. The alpha,alpha-dimethylester derivative, amide derivatives and diamine derivatives, which were stable to hydrolysis, showed low blood activity levels following intravenous administration. Disappearance of the ester and amide compounds from the brain was rapid. However, the diamine derivatives displayed improved retention in the brain. Compounds 3a and 4 possessed the best combination of high brain uptake and sufficient retention to be useful as potential brain imaging radiopharmaceuticals with ...
Purpose: Three-dimensional rotational angiography (3DRA) is a new technique based on a rotational angiographic acquisition able to display arterial vessels in a 3D rendering mode. The system was mainly developed for neuroradiological evaluations but preliminary extracranial experiences have also been reported. The aim of our work was to compare the results of three-dimensional angiography of the carotid arteries done with high-flow injection of contrast medium from the aortic arch with the results of selective angiography. Materials and methods: Twenty patients underwent digital angiography of the supra-aortic vessels in order to quantify a stenosis of the carotid bifurcations previously detected at Doppler Ultrasound. Examinations were performed with the Philips Integris Allura system provided with the rotational angiography (RA) tool connected to a workstation for three-dimensional reconstruction able to display vessels in a 3D fashion (Volume Rendering, Shaded ...
In a prospective study 102 patients with malignant tumors of the tongue, oropharynx, hypopharynx, and larynx were staged by means of MRI. Special attention was directed at those tumour extensions that could influence the treatment strategy. The MR findings were correlated with the results of palpation, endoscopy, ultrasound, computerised tomography and histopathological findings. MRI showed a good delineation of pT{sub 2} to pT{sub 4} tumours. However, visualisation of small tumours in the soft palate, the tonsils, the pyriform sinuses and vocal cords was difficult. In conclusion our results suggest that in addition to endoscopy MRI is a valuable tool for the examination of tumours of tongue, oropharynx, hypopharynx and larynx. (orig.) [Deutsch] In einer prospektiven Studie wurden 102 Patienten mit malignen Tumoren der Mundhoehle, des Oro- und Hypopharynx sowie des Larynx mit der Mgnetresonanztomographie (MRT) untersucht, wobei besonders Wert auf die Bestimmung ...
As an alternative to surgery, endovascular therapy with stent grafts has become the second main treatment option for infrarenal abdominal aortic aneurysms. Unlike surgery, endovascular treatment with stent grafts is also applicable in patients unfit for open repair. Despite current improvements in endovascular repair devices, significant anatomic barriers still exclude this technique for a large number of patients. Computed tomography, magnetic resonance imaging, and ultrasound are essential for diagnostics, preintervention planning, and postintervention follow-up of abdominal aneurysms treated with stent grafts. This review covers etiology, pathology, and diagnostic aspects. Materials and methods for endovascular treatment of abdominal aortic aneurysms are presented in detail, and clinical results and complications are discussed. (orig.) [German] Die endovaskulaere Therapie des infrarenalen Bauchaortenaneurysmas hat sich als Alternative zur ...
Targeted studies completed include the evaluation of tritiated N-0437, evaluation of "3"5S-cysteamine, evaluation of "1"8F-FDG and initiation of synthetic efforts towards the synthesis of iodinated N-0437 and pergolide analogs. The direction of the project has been changed due to several factors which include the decided lack of favorable experimental results, the excellence of results using muscarinic receptor ligands in pituitary, brain and heart and the contention of the DOE review panel that the original grant proposal was based on flawed assumptions together with their perceived lack of importance to pituitary imaging. In the final year of this grant, three studies will be completed. The first study is the continuation of synthetic efforts to prepare iodinated N-0437 and pergolide analogs for possible use as brain imaging agents. The second study is directed towards completion of biochemical evaluation of various ...
Targeted studies completed include the evaluation of tritiated N-0437, evaluation of /sup 35/S-cysteamine, evaluation of /sup 18/F-FDG and initiation of synthetic efforts towards the synthesis of iodinated N-0437 and pergolide analogs. The direction of the project has been changed due to several factors which include the decided lack of favorable experimental results, the excellence of results using muscarinic receptor ligands in pituitary, brain and heart and the contention of the DOE review panel that the original grant proposal was based on flawed assumptions together with their perceived lack of importance to pituitary imaging. In the final year of this grant, three studies will be completed. The first study is the continuation of synthetic efforts to prepare iodinated N-0437 and pergolide analogs for possible use as brain imaging agents. The second study is directed towards completion of biochemical evaluation of ...
Purpose Skilled placement of peripherally inserted central catheters (PICC) has a profound impact on patient well-being and costs of care. The use of ultrasound-guided methods and prescribed training for cannulation skills are evidence-based practice recommendations. The purpose of this study was to compare two methods of PICC instruction on the acquisition of applied skills. Methods Residents were randomly assigned to one of two groups (N?=?16/16) of this blind-rater study and were trained to perform ultrasound-guided PICC cannulation using either simulation or apprenticeship methods. All residents were assessed placing a PICC in applied clinical patient care. Results Residents who completed simulation training had significantly better transfer of skills to applied clinical practice than ...
The growth of silver chloride nanoparticles on ancient textile was achieved by sequential dipping steps in alternating bath of potassium chloride and silver nitrate under ultrasound irradiation. The effect of ultrasound irradiation and sequential dipping steps in growth of the AgCl nanoparticles has been studied. These systems depicted a decrease in the particles size accompanying a decrease in the sequential dipping steps. The samples were characterized with powder X-ray diffraction (XRD) and scanning electron microscopy. XRD analyses indicated that the prepared AgCl nanoparticles on fiber were crystalline. The textile samples containing AgCl nanoparticles were tested for their antibacterial efficacy against Escherichia coli and were found to possess significant antibacterial activity.
Objectives To investigate the feasibility and reproducibility of measurements of nasal bone length using a three-dimensional (3D) ultrasound in the first trimester. Methods In a prospective study, 118 consecutive pregnant women attending for Down syndrome screening at 11-13 + 6 weeks were recruited. They had successful fetal nasal bone measurement by two-dimensional (2D) ultrasound by four operators. Three-dimensional volumes were recorded in the mid-sagittal plane of fetal profile by the fifth operator and examined using multiplanar techniques. Another independent investigator randomly compared his measurements with one of the four operators. Results In the subsequent 3D examination, the nasal bone length could be examined in 94 cases (79.7%). The mean difference between the 2D and 3D mea...
Helical tomotherapy presented many unique dosimetric challenges and solutions during the initial commissioning process, and some of them are presented. The dose calculation algorithm is convolution/superposition based. This requires that the energy fluence spectrum and magnitude be quantified. The methodology for doing so is described. Aspects of the energy fluence characterization that are unique to tomotherapy are highlighted. Many beam characteristics can be measured automatically by an included megavoltage computed tomography imaging system. This greatly improves data collection efficiency.
In earliest works devoted to proton computed tomography it was shown that the advantage of pCT image reconstruction appears when the energy is close to the Bragg peak region, since the proton passes the object. This effect provided by the Bragg peak makes the computerized tomography with protons possible. However, when decreasing the initial proton energy, with the increase of the irradiation dose, there are two effects that work simultaneously in opposite ways. First, the energy loss of a proton in an object becomes bigger at small initial energy. At the same time decreasing of the proton energy results in the increase of the energy straggling, requiring a larger number of protons. In this work the radiation dose dependence on the proton initial energy was studied using analytical formulas and computer simulations. The investigation determined that the radiation dose practically does not depend on the ...
Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with ...
Femur fractures typically affect elderly patients with multiple co-morbidities. Pain control can be difficult, requiring intensive nursing and physician care as elderly patients may manifest cardiovascular...Full Text Available
A novel method for non-destructive intramuscular fat (IMF) estimation via spectral ultrasound backscatter analysis of signals obtained from pig carcasses early post mortem is described. A commercial hand-held ultrasound device (center frequency: 2.7MHz) was modified to focus the sound beam to the longissimus muscle at the 2nd/3rd last rib. Time-resolved ultrasound backscatter signals of loin muscle were recorded 45minp.m. on 82 pig carcass sides. Backfat width (d"B"F=18.9+/-3.8mm) and muscle attenuation (@a"m"u"s"c"l"e=.77+/-.15dBMHz^-^1cm^-^1) were assessed from the measured pulse echo data. Other propagation properties of skin, backfat and muscle tissue obtained in a previous investigation were incorporated into the signal pre-processing to minimize parameter estimation artifacts. Spectr...
Advances in neuroscience have resulted in the development of new diagnostic and therapeutic agents for potential use in the central nervous system (CNS). However, the ability to deliver the...Full Text Available
BackgroundThe aim of the present article was to evaluate whether angiogenic parameters as assessed by transvaginal color Doppler ultrasound (TVCD) may predict those prognostic factors...Full Text Available
A 30-year-old man with acquired immune deficiency syndrome (AIDS) and Kaposi's sarcoma had a palpable thyroid mass and cervical lymphadenopathy. Nuclear medicine and ultrasound scans revealed multiple thyroid nodules. Results of biopsy showed Kaposi's sarcoma metastatic to the thyroid.
Endovascular surgery is a new multidisciplinary field that applies the recently innovated techniques of angioscopy, intraluminal ultrasound, balloon angioplasty, laser, mechanical atherectomy, and stents....Full Text Available
Background:During transurethral resection surgery (TUR), accidental stimulation of the obturator nerve can cause violent adductor contraction, leading to serious intraoperative...Full Text Available
BackgroundLifestyle, genetics and environmental factors are established determinants of bone density. We aimed to describe the bone characteristics of competitive top-ranked Nigerian...Full Text Available
An 11-year-old mare presented 36 hours after foaling with a ruptured bladder. Uroperitoneum was diagnosed on ultrasound and from the creatinine concentration of the peritoneal fluid. Bladder endoscopy...Full Text Available
In developing new Tc-99m brain perfusion imaging agents for SPECT, a series of BAT (bis-aminoethanethiol) derivatives was prepared. These N/sub 2/S/sub 2/ ligands formed stable and neutral complexes with reduced Tc-99m, either by Sn(II)-PPi or sodium borohydride reduction. The purity of the Tc-99m complexes was >95% (HPLC reverse-phase column, acetonitrile: pH 7.0 buffer, 85:15). The biodistribution in rats was evaluated using I-125 iodoantipyrine (IAP), a free diffusible tracer, as the internal reference. Compounds with a free hydroxyl group (I and IV) showed lower brain uptake, inspite of high P.C.; this may be related to in vivo instability of the complexes. High initial brain uptake was observed for three compounds (II, III and V), however, only compound V (P.C.=384) showed significant brain retention. Planar imaging with compound V in a monkey demonstrated that the compound localized in brain and the retention time ...
In developing new Tc-99m brain perfusion imaging agents for SPECT, a series of BAT (bis-aminoethanethiol) derivatives was prepared. These N/sub 2/S/sub 2/ ligands formed stable and neutral complexes with reduced Tc-99m, either by Sn(II)-PPi or sodium borohydride reduction. The purity of the Tc-99m complexes was >95% (HPLC reverse-phase column, acetonitrile: pH 7.0 buffer, 85:15). The biodistribution in rats was evaluated using I-125 iodoantipyrine (IAP), a free diffusible tracer, as the internal reference. Compounds with a free hydroxyl group (I and IV) showed lower brain uptake, inspite of high P.C.; this may be related to in vivo instability of the complexes. High initial brain uptake was observed for three compounds (II, III and V), however, only compound V (P.C.=384) showed significant brain retention. Planar imaging with compound V in a monkey demonstrated that the compound localized in brain and the retention time ...
A Langmuir film is a molecularly thin film on the surface of a fluid; we study the evolution of a Langmuir film with two co-existing fluid phases driven by an inter-phase line tension and damped by the viscous drag of the underlying subfluid. Experimentally, we study an 8CB Langmuir film via digitally-imaged Brewster Angle Microscopy (BAM) in a four-roll mill setup which applies a transient strain and images the response. When a compact domain is stretched by the imposed strain, it first assumes a bola shape with two tear-drop shaped reservoirs connected by a thin tether which then slowly relaxes to a circular domain which minimizes the interfacial energy of the system. We process the digital images of the experiment to extract the domain shapes. We then use one of these shapes as an initial condition for the numerical solution of a boundary-integral model of the underlying hydrodynamics and compare the ...
Purpose: To describe the technique of DE MDCT colonoscopy and to assess its feasibility. Materials and Methods: 8 patients were scanned with DSCT with a DE scan protocol and dose modulation software. Analysis was performed using dedicated DE software. Prone non-contrast images and DE supine images after contrast injection were obtained. Results: DE colonoscopic images were successfully obtained in 7 patients, but the FOV did not cover all colonic segments in 1 patient, thus resulting in a technical success rate was 87.5%. Streak artifacts were present in the pelvic region in 2 patients. Virtual unenhanced images and iodine map images were obtained for all patients. In 1 patient a polypoid non-enhancing structure was noted on the iodine map, and conventional colonoscopy revealed impacted stool. Enhancing rectal cancer in 1 patient was correctly shown on the iodine map. Iodine maps ...
The purpose of this study was to compare a double freeze-thaw protocol to a triple freeze-thaw protocol for pulmonary cryoablation utilizing an in vivo porcine lung model. A total of 18 cryoablations were performed in normal porcine lung utilizing percutaneous technique with 9 each in a double- (10-5-10) and triple-freeze (3-3-7-7-5) protocol. Serial noncontrast CT images were obtained during the ablation. CT imaging findings and pathology were reviewed. No imaging changes were identified during the initial freeze cycle with either protocol. However, during the first thaw cycle, a region of ground glass opacity developed around the probe with both protocols. Because the initial freeze was shorter with the triple freeze-thaw protocol, the imaging findings were apparent sooner with this protocol (6 vs. 13 min). Also, despite a shorter total freeze time (15 vs. 20 ...
Four "1"2"5I labeled mono- and diamines were prepared and evaluated as potential brain-imaging agents. The diamines are analogues of the previously reported "7"5Se labeled diamines, which show high brain uptake and retention. All of the radioiodinated amines display high initial brain uptake in rats after intravenous injection (1.7-2.4% dose/organ). The xylylenediamines show prolonged brain retention (t1/2 approximately 18 h), which is desirable for brain imaging. In contrast, the benzylamine is rapidly cleared from brain tissue (t1/2 approximately 15 min).
We describe a position sensitive photon counting microchannel plate based detector with an improved quadrant anode (QA) readout system. The technique relies on a combination of the four planar elements pattern and an additional fifth electrode. The charge cloud induced by single particle detection is split between the electrodes. The measured charge values uniquely define the position of the initial event. QA has been first published in 1976 by Lampton and Malina. This anode configuration was undeservedly forgotten and its potential has been hardly underestimated. The presented approach extends the operating spatial range to the whole sensitive area of the microchannel plate surface and demonstrates good linearity over the field of view. Therefore, the novel image sensor results in spatial resolution better then 50?m and count rates up to one million events per second.
We describe a position sensitive photon counting microchannel plate based detector with an improved quadrant anode (QA) readout system. The technique relies on a combination of the four planar elements pattern and an additional fifth electrode. The charge cloud induced by single particle detection is split between the electrodes. The measured charge values uniquely define the position of the initial event. QA has been first published in 1976 by Lampton and Malina. This anode configuration was undeservedly forgotten and its potential has been hardly underestimated. The presented approach extends the operating spatial range to the whole sensitive area of the microchannel plate surface and demonstrates good linearity over the field of view. Therefore, the novel image sensor results in spatial...
The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest...
The Full Aperture Backscatter System (FABS) provides a measure of the spectral power, and integrated energy scattered by stimulated Brillouin (348-354 nm) and Raman (400 - 700 nm) scattering into the final focusing lens of the first four beams of the NIF laser. The system was designed to provide measurements at the highest expected fluences with: (1) spectral and temporal resolution, (2) beam aperture averaging, and (3) near-field imaging. This is accomplished with a strongly attenuating diffusive fiber coupler and streaked spectrometer and separate calibrated time integrated spectrometers, and imaging cameras. Measurement of the wavelength dependent sensitivity of the complete system is accomplished with a calibrated Xe lamp. Data from the calibration system is combined with experimental data to produce the power and energy measurements. Examples of measurements will be discussed.
The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with prototype animal PET/MRI ...
Positron emission tomography (PET) imaging of {beta}-amyloid (A{beta}) plaques in the brain is a potentially valuable tool for studying the pathophysiology of Alzheimer's disease (AD). It may also be applicable for measuring the effectiveness of therapeutic drugs aimed at lowering A{beta} plaques in the brain. We have successfully reported a series of {sup 18}F-labeled fluoropegylated stilbenes for PET imaging studies. Encouraging results clearly demonstrated the usefulness of {sup 18}F-labeled stilbenes as potential A{beta} plaque-imaging agents. In the present study, we applied a similar approach to a styrylpyridine backbone structure. Among all derivatives examined (E)-2-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)-5-(4-dimethylaminostyryl) -pyridine (2) displayed high binding affinity in postmortem AD brain homogenates (K {sub i}=2.5{+-}0.4 nM, with [{sup 125}I]IMPY as radioligand). No-carrier-added [{sup 18}F]2 was ...
Of the radionuclides with physical properties most suited for use with monoclonal antibody for tumor imaging or therapy, few are more available or desirable than Pb-203, 212 and Bi-212. Yet no clinical studies have as yet been possible solely due to the lability in vivo of known complexes. We now report that bismuth complexes of the ligands p-SCN-Bz-DOTA and p-SCN-Bz-trans-cyclohexylDTPA are effective at protecting Bi-206 from release when linked to immunoproteins. Practicable, efficient ligand syntheses will be reported. Initial studies reveal that antibody is labeled efficiently with radiolead DOTA complexes. Preliminary studies indicate stability in vivo.
Periureteral or subtrigonal injection of dextranomer/hyaluronic acid (Dx/HA) copolymer (Deflux, Q-Med, Uppsala, Sweden) is an increasingly common endoscopic treatment for vesicoureteral reflux. We report a confusing radiographic finding of bilateral calcified Dx/HA injections initially thought to represent bilateral distal ureteral stones in a boy who presented with intermittent periumbilical pain. Urologists, radiologists, and emergency room physicians should be aware of the potential for calcification of ureteral implants of Dx/HA, and of the potentially confusing radiographic images that may result. (orig.)
The goals of this paper are to describe the fabrication and complete evaluation of a dihydropyridine <- -> pyridinium salt type redox system for the delivery of radioiodinated agents to the brain. Tissue distribution studies of "1"2"5I-labeled 4-iodoaniline and the redox agents were performed in rats. ["1"2"5I]Iodoaniline initially showed moderate brain uptake with subsequent release of the radioactivity from the brain. ["1"2"5I]Iodoaniline, however, when coupled to a dihydropyridine carrier showed significantly higher uptake and retention in the brain. (author).
BAE Systems is the leading producer of uncooled microbolometer based thermal imaging engines in the world. Initial investments to develop and produce uncooled infrared (IR) technology were primarily driven by military applications, but it was the commercial market with the potential for large product volumes which provided BAE Systems with the business model required for investment in uncooled IR technology. This paper reviews the heritage of BAE Systems technology and current products and is an example of the success of a Dual-Use technology area which DARPA invested in during the 1990s.
Acquired cystic kidney disease (ACKD), also known as acquired renal cystic disease (ARCD,) occurs in patients who are on dialysis for end-stage renal disease. It is generally accepted that ACKD develops as a consequence of sustained uremia and can first manifest even before dialysis is initiated while the patient is still in chronic renal failure. The role of immune suppression, particularly in transplant recipients, in the development of ACKD, is still under investigation. The prevalence of ACKD is directly related to the duration of dialysis and the risk of cancer is directly related to the presence of cysts. Herein we review the current understanding of the pathophysiology and imaging implications of ACKD. (orig.)
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)
OBJECTIVE: To evaluate the interobserver agreement of ultrasonographic assessment of finger and toe joints in patients with rheumatoid arthritis (RA) by 2 investigators with different medical backgrounds. METHODS: Ultrasonography and clinical examination were performed on 150 small joints of 30 patients with active RA. A General Electric LOGIQ 500 ultrasound unit with a 7-13-MHz linear array transducer was used. In each patient, 5 preselected small joints (second and third metacarpophalangeal, second proximal interphalangeal, first and second metatarsophalangeal) were examined independently on the same day by 2 ultrasound investigators (an experienced musculoskeletal radiologist and a rheumatologist with limited ultrasound training). Joint effusion, synovial thickening, bone erosions, and power Doppler signal were evaluated in accordance with an introduced 4-grade semiquantitative scoring system, on which the investigators ...
The near infrared (NIR) upgrade to the Robert Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT), RSS/NIR, extends the spectral coverage of all modes of the visible arm. The RSS/NIR is a low to medium resolution spectrograph with broadband imaging, spectropolarimetric, and Fabry-Perot imaging capabilities. The visible and NIR arms can be used simultaneously to extend spectral coverage from approximately 3200 A to 1.6 um. Both arms utilize high efficiency volume phase holographic gratings via articulating gratings and cameras. The NIR camera is designed around a 2048x2048 HAWAII-2RG detector housed in a cryogenic dewar. The Epps optical design of the camera consists of 6 spherical elements, providing sub-pixel rms image sizes of 7.5 +/- 1.0 um over all wavelengths and field angles. The exact long wavelength cutoff is yet to be determined in a detailed thermal analysis and will depend on the semi-warm ...
In developing new brain imaging agents for single photon emission computed tomography (SPECT), we synthesized eleven radioiodinated phenoxyacetic acid derivatives and investigated the relationship between the chemical structure and in vivo characteristics. Biodistribution studies in mice revealed high initial brain uptake for all the compounds. Blood radioactivity level depended markedly upon the chemical stability of the compound. The #alpha#,#alpha#-dimethylester derivative (1e), amide derivatives (2a-c) and diamine derivatives (3a, b, 4), which were stable to hydrolysis, showed low blood activity levels following i.v. administration. Disappearance of the ester and amide compounds from the brain was rapid. However, the diamine derivatives displayed improved retention in the brain. Compounds 3a and 4 possessed the best combination of high brain uptake and sufficient retention to be useful as potential brain imaging ...
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 ...
Purpose: To evaluate the outcome of repeat stereotactic radiosurgery (SRS) for acoustic neuromas, we assessed tumor control, clinical outcomes, and the risk of adverse radiation effects in patients whose tumors progressed after initial management. Methods and Materials: During a 21-year experience at our center, 1,352 patients underwent SRS as management for their acoustic neuromas. We retrospectively identified 6 patients who underwent SRS twice for the same tumor. The median patient age was 47 years (range, 35-71 years). All patients had imaging evidence of tumor progression despite initial SRS. One patient also had incomplete surgical resection after initial SRS. All patients were deaf at the time of the second SRS. The median radiosurgery target volume at the time of the initial SRS was 0.5 cc and was 2.1 cc at the time of the second SRS. The median margin dose at the time of ...
In principle four different methods (ultrasound, microwaves, {gamma}-radiation and x-rays) are available for the non-destructive testing of refractories. Three of these methods, i.e. ultrasound, microwaves and {gamma}-radiation, are in use by different producers of AZS materials to carry out the quality control of their products. This paper will compare the three methods on the basis of the physical properties, present the existing devices, and show the advantages as well as the limits of the different methods. {gamma}-radiography, the oldest method in use, has one main disadvantage, which is the requirement of protection against radioactive radiation. Furthermore, while cracks and cavities can be detected with this method, structural changes can not be monitored. Therefore, the ultrasonic method was developed that allows to detect variations of porosity and grain size as well as cracks and voids when the ultrasonic parameters are tuned as well ...
In this work, the antibacterial effect of fluoroquinolones (FQs) upon Escherichia coli (E.coli) was measured with and without application of 40kHz ultrasound (US) stimulation. The research results demonstrated that simultaneous application of 40kHz US apparently enhanced the antibacterial effectiveness of FQs. That is, the synergistic effect was observed and the bacterial viability was reduced when FQs and US were combined. In addition, various influencing factors, such as FQs drug concentration, US irradiation time and solution temperature, on the inhibition of E.coli were also investigated. The antibacterial activity was enhanced apparently with increasing of FQs drug concentration, US irradiation time and solution temperature. Furthermore, we discussed preliminarily the mechanism of US ...
Background This study aimed to evaluate the feasibility, safety, and follow-up results of endoscopic papilletomy (ESP) with pancreatic and biliary duct stent placement for ampullary tumors. The therapeutic approach to benign ampullary tumors remains unsettled. The ESP procedure is a curative treatment option for benign papillary tumors, but ESP raises concerns about a relatively high risk for procedure-related complications such as pancreatitis. A pancreatic stent may protect against complications. Methods Between September 2000 and June 2008, 36 patients with ampullary tumors confined to the mucosa and no intraductal tumor growth underwent ESP. The preprocedural diagnostic tools included endoscopic ultrasound, transpapillary intraductal ultrasound, and endoscopic retrograde cholangiopancr...
Calcaneus quantitative ultrasound (QUS) assessment is a safe and reliable method for evaluating skeletal status. Until now, considerable data have been accumulated on the distribution of QUS in Caucasian populations, whereas such data are still insufficient in Asian populations, especially in Chinese mainland. The present study aimed to obtain the distribution characteristic of calcaneus QUS in healthy Chinese women, and to further investigate the distribution of low bone mass by QUS stiffness index (SI). This study included 2,498 healthy Chinese females aged 10-87 yr. The QUS exhibited a characteristic mild rise and then fall pattern with increasing age. Age, body height, and weight were significant influencing factors on SI, especially age and weight. The prevalence of osteoporosis detec...
The high spatial resolution of state-of-the-art commercial satellite imagery provides a good basis for recognising and monitoring even small-scale structural changes within nuclear facilities and for planning of routine and/or challenge inspections of nuclear sites. Despite the advantages of the improved spatial resolution some problems exist that may make the interpretation of the changes more difficult: Firstly, the results of the change analysis can be very complex and unclear at a glance. Secondly, shadow formation and off-nadir images due to different sensor and solar conditions at the acquisition times can cause false signals or overlap real changes. In view to the fast-growing amount of data from different sensor types there are then some requirements of an effective change detection procedure for safeguards purposes: i. The techniques involved should possess a certain amount of robustness in terms of small misregistration errors, different atmospheric ...
... Title : Optical Images Due to Lenses and Mirrors. ... Abstract : The properties of real and virtual images formed by lenses and mirrors are reviewed. ...
We attempt to image the rupture propagation of the 2004 M6.0 Parkfield earthquake by analyzing records from the USGS Parkfield seismic array (UPSAR) and other strong-motion stations. The UPSAR array consists of 12 stations distributed over about one square kilometer at a distance of 10~km from the San Andreas fault near Parkfield, California. We employ a method that uses reverse time migration to stack the seismograms at back-projected locations along the fault. We use waveform cross-correlation to align the initial P-wave arrivals and correct for small static time shifts in the records. This forces a coherent image at the hypocenter at the quake origin time. Initial results at later time steps show some evidence of the expected rupture propagation to the north. However, the resolution of the back-projection is limited by the small aperture of the UPSAR array. Records from other strong-motion stations ...
Full text: Certain groups of patients have been excluded from ventilation lung scanning due to their inability to comply with instruction. Tetley Manufacturing have recently developed a Positive Ventilation Delivery System (PVDS) which assists in delivering Technegas to patients who are unable to cooperate fully. The aim of this study is to evaluate the PVDS in the clinical setting. Fifteen frail aged and psychogeriatric patients (n=l 5), mean age 78 years (range 60-93), were ventilated with Technegas using the PVDS. The decision to ventilate the patient with the PVDS was based on an initial assessment of the patients ability to comply with instructions, or failure of the conventional ventilation method, to produce an adequate count rate. Technegas was prepared in the usual manner and then delivered to the patients lungs by squeezing a black anesthetic bag synchronously with the patients breathing, until a count rate of approximately 1000 counts/second was ...
This case report presents the prenatal diagnosis of conjoined twins at 7 weeks and 6 days’ gestation according to the last menstrual period and 6 weeks and 4 days’ gestation according...Full Text Available
Success in improving treatment outcomes in childhood cancer has been achieved almost exclusively through multicenter and multidisciplinary clinical and applied research over several decades. While biologically rational as well as empirical approaches have led to combination chemotherapy and multimodality approaches to therapy, which have given rise to evidence-based practice standards, similar scientific rigor has not always been as evidently applied to modalities utilized to assess initial disease burden and, more important, response to investigational approaches to therapy. As the empirical approach to therapeutic advances has likely maximized its benefit, future progress will require translation of biologic discovery most notably from the areas of genomics and proteomics. Hence, attempts to improve efficacy of therapy will require a parallel effort to minimize collateral damage of future therapeutic approaches, and such a parallel approach will mandate the ...
Authors obtained T1-weighted MRI images of the femoral head after fracture of the femoral neck and classified the signals into four patterns to investigate the sequential changes of the femoral head. The T1-weighted MRI images obtained initially after femoral neck fracture showed a normal pattern in 10 of the 15 hip joints studied. MRI images obtained subsequently still showed the normal signal pattern in eight of the 10 hip joints which had shown the normal pattern in the first MRI, while two of the 10 joints subsequently showed a band pattern. The joint with the homogeneous pattern in the first MRI subsequently showed a band pattern. Of the three joints with an inhomogeneous pattern in the first MRI, two joints showed a subsequent band pattern, and the other a normal pattern. The joints which showed a band pattern continued to show a similar band pattern. Eventually, all hip joints studied showed a ...
Concerning the transient phenomenon of solid-gas two-phase flow, an attempt was made to visualize and measure a flow phenomenon in which three-dimensional bubbles occurred, grew and collapsed in the vicinity of a gas injection nozzle while solid particles were circulating. Such a phenomenon could not or hardly be visualized and measured by conventional methods. Such two-phase flow was visualized using neutron radiography, its characteristics measured and the usefulness of the visualization by neutron radiography confirmed. For this purpose, three-dimensional fluidized bed vessels, rectangular or cylindrical-shaped, made of steel or aluminum sheet, were prepared. Polyethylene or glass beads were used as solid particles and activated carbon particles as the tracer. In the experiment, nitrogen gas was blown into the vessel from one nozzle and distributors provided at the bottom of the vessel and exhausted from the top via the exhaust valve, by which the pressure in the vessel was ...
The microstructure of the secondary deformation zone (SDZ) near the cutting surface in metal chips of Ti-6Al-4V formed during machining was investigated using focused ion beam (FIB) specimen preparation and transmission electron microscopy (TEM) imaging. Use of the FIB allowed precise extraction of the specimen across this region to reveal its inhomogeneous microstructure resulting from the non-uniform distribution of strain, strain rate, and temperature generated during the cutting process. Initialimaging from conventional TEM foil preparation revealed microstructures ranging from heavily textured to regions of fine grains. Using FIB preparation, the transverse microstructure could be interpreted as fine grains near the cutting surface which transitioned to coarse grains toward the free surface. At the cutting surface a 10 nm thick recrystallized layer was observed capping a 20 nm thick amorphous layer.
The shell integrity near peak compression of spherical implosions using the 60-beam, 30-kJ UV OMEGA laser system [Opt. Commun. 133, 495 (1997)] has been measured. Hot core emission backlights a shell with a thin titanium-doped layer that is imaged at x-ray photon energies above and below the titanium K edge. The x-ray intensity ratio between the two images is related to perturbations in the cold, or absorbing, part of the shell. The measured cold-shell areal-density modulations, integrated over the time of peak compression, are of the order of 25% to 50% with nonuniformity spectra peaked at spatial wavelengths of 30 to 50 #mu#m and with the smallest detectable nonuniformity features extending down to spatial wavelengths of 12 to 15 #mu#m. Hot-shell areal-density modulations of the emitting part of the shell (inner edge) are of the order of 13% to 20%. The measured shell modulations are in agreement with the results of two-dimensional ...
Initial CT grading of renal injury was correlated with the frequency of complications and the time course of healing in 35 children. All renal contusions (grade 1, 8) and small parenchymal lacerations (grade 2, 8) healed without complications. All lacerations extending to the collecting system (grade 3, 9) resulted in mild to severe loss of renal function with progressive healing over 4 months. One of four segmental infarcts (grade 4 A), and five of six vascular pedicle injuries (grade 4 B) resulted in severe loss of renal function. Complications, including urinoma (2), sepsis (1), hydronephrosis (1), and persistent hypertension (2), were limited to grade 3 and 4 injuries. Our results suggest that mild renal injuries do not require follow-up imaging. Major renal lacerations and vascular pedicle injuries, however, often result in loss of renal function and should be followed up closely due to the risk of delayed complications. Follow-up ...
In the search for new brain imaging agents for use with single photon emission computed tomography (SPECT), quantitative structure activity relationship (QSAR) analysis of the correlations between initial brain uptake and physicochemical parameters like lipophilicity, log P, molecular weight, log MW and log U/D (undissociated/dissociated), of the {sup 99m}Tc-DADT (diaminedithiol) complexes and {sup 99m}Tc-PAO (propyleneaminoxime) complexes have been analyzed. High correlations are found for both the {sup 99m}Tc-DADT complexes (r = 0.94) and for the {sup 99m}Tc-PAO complexes (r = 0.83) which are significant at 99.9 and 99.5 percentile level, respectively. These results will help the further design of better ligands for {sup 99m}Tc in brain imaging. (author).
We compare experimental measurements of inhomogeneous plastic deformation in a Ni bicrystal with crystal-plasticity simulations. Polychromatic X-ray microdiffraction, orientation imaging microscopy and scanning electron microscopy, were used to characterize the geometrically necessary dislocation distribution of the bicrystal after uniaxial tensile deformation. Changes in the local crystallographic orientations within the sample reflect its plastic response during the tensile test. Elastic strain in both grains increases near the grain boundary. Finite element simulations were used to understand the influence of initial grain orientation and structural inhomogeneities on the geometrically-necessary dislocations arrangement and distribution and to understand the underlying materials physics.
There is evidence that aged normal subjects have more difficulty in achieving automaticity than young subjects. The underlying central neural mechanism for this phenomenon is unclear. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the effect of normal ageing on automaticity. Aged healthy subjects were asked to practice self-initiated, self-paced, memorized sequential finger movements with different complexity until they could perform the tasks automatically. Automaticity was evaluated by having subjects perform a secondary task simultaneously with the sequential movements. Although it took more time, most aged subjects eventually performed the tasks automatically at the same level as the young subjects. Functional MRI results showed that, for bot...
On November fourth and fifth 2010 a group of more than 100 international investigators gathered in Atlanta for the second Osteoarthritis (OA) Biomarkers Global Initiative workshop titled ''Genetics and Genomics: New Targets in OA''. The first workshop took place in April 2009 and focused on in vitro (soluble) biomarkers whilst the third and final workshop will take place in 2012 and will focus on imaging biomarkers. The OA Research Society International (OARSI) has organized the workshops. In addition to OARSI, the National Institute of Arthritis, Musculoskeletal and Skin Diseases, the Arthritis Foundation, Amgen, Genzyme, the American Orthopaedic Society for Sports Medicine and Pfizer sponsored the second meeting. It was clear from this meeting that experiments in the genetics, epigenetic...
Smoothing of laser beam non-uniformities using gas jets has been studied. The experiment has been performed with the PALS (Prague Asterix Laser System) laser working at 0.44 ?m with an intensity of about 1015 W/cm2. The laser beam has been split in two by a prism thus creating an artificial large-scale non-uniformity (? 90 ?m). We recorded time resolved and static images of laser-gas jet interaction with and without an Al target. Multi 1-dimensional and 2-dimensional simulations show that such interaction acts redistributing the over-intensities over larger surface. This effect has to be attributed to ionization processes with consequent laser beam refraction. Results show that Argon gas jet produces a strong refraction of the laser beam thus strongly reducing the initial two spots separation. (authors)
The X-ray storage phosphor CsBr:Eu2+ in form of needle image plates is believed to be a promising alternative to the granular BaFBr:Eu2+ with regard to PSL yield and spatial resolution. Unfortunately, CsBr:Eu2+ exhibits poor radiation hardness, which is caused by a migration of europium ions initiated by naturally existing defect centers like (Eu2+-VCs)-centers and X-ray generated MEu-centers. It will be shown that the formation of (Eu2+-O2?)-dipoles at the expense of (Eu2+-VCs)-dipoles, incorporated by thermal annealing in O2-containing and humid atmosphere, does not improve the radiation stability. There is, however, a strong improvement in the radiation hardness by codoping of CsBr:Eu2+ with lithium ions, which is accompanied by a complete suppression of the previously observed MEu-cent...
Aim To determine the fate and clinical implication of large (?2cm), non-hypervascular nodules depicted on magnetic resonance imaging (MRI) in the cirrhotic liver. Materials and methods In 21 patients with cirrhosis (14 hepatitis B, two ethanol abuse, four cryptogenic, one Wilson's disease), 25 large (?2cm in the longest dimension) non-hypervascular nodules were identified on dynamic MRI. The implications for diagnosis of the initial size, contour, and signal characteristics on MRI in addition to patients' age and cause of cirrhosis were assessed in our analysis. Results Twelve (75%) out of 16 lesions were malignant or potentially-malignant from 14 hepatitis B patients, while seven (78%) of the nine lesions from other patients were benign (p=0.016). The mean age of the patients who ha...
Strong gravitational lensing of an extended object is described by a mapping from source to image coordinates that is nonlinear and cannot generally be inverted analytically. Determining the structure of the source intensity distribution also requires a description of the blurring effect due to a point spread function. This initial study uses an iterative gravitational lens modeling scheme based on the semilinear method to determine the linear parameters (source intensity profile) of a strongly lensed system. Our 'matrix-free' approach avoids construction of the lens and blurring operators while retaining the least squares formulation of the problem. The parameters of an analytical lens model are found through nonlinear optimization by an advanced genetic algorithm (GA) and particle swarm optimizer (PSO). These global optimization routines are designed to explore the parameter space thoroughly, mapping model degeneracies in detail. We develop a ...
Flame propagating through zirconium particle cloud in a small-scale vertical rectangle chamber was investigated experimentally. In the experiments, the zirconium quoted 99% purity was used and the diameter of particles was distributed 1?22 ?m. The zirconium dust was dispersed into the chamber by air flow and ignited by an electrode spark. A high-speed video camera was used to record the images of the propagating flame. Micro-thermocouples, schlieren optical system and microscopic lens were used to obtain temperature profiles and flame structure, respectively. Based on the experimental results, flame propagation characteristics and flame structure of zirconium particle cloud were analyzed. The propagation velocity of the flame is quite slow in the initial 14 ms and then accelerates to maxim...
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 ...
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
Computed Tomography (CT) and, more recently, ultrasound (US), have proved excellent tools for quantifying adipose tissue distribution. Body fat distribution is an important factor in the treatment of obesity and its complications. In this work it is investigated the correlation between CT and US measurements in pediatric obesity. Forty obese children and adolescents aged 4.1-14.8 years were submitted to CT and US. Intra-abdominal, subcutaneous and total body fat were calculated (in cm{sup 2}), with the CT image analysis software. The rectus muscle-spine and rectus muscle-aorta distances, as indicative of visceral fat thickness, were measured on US images with(out) compression. The distance between skin fat and fat-rectus muscle interfaces was measured as subcutaneous fat thickness. US-CT findings have been compared with other morphometric variables-i.e., patient's (ideal) body weight and skin fold measures. A ...
Magnetic resonance imaging (MRI) in stroke makes it possible to visualize the initial infarct in cases of acute cerebral ischemia. Perfusion MRI serves to determine which tissues are additionally at risk of infarction due to persistent hypoperfusion. MRI also allows those examiners with limited experience to reliably confirm an infarct. The most important differential diagnosis of cerebral ischemia, intracerebral hemorrhage, can likewise be recognized with certainty using MRI. Although diffusion and perfusion MRI only demonstrate the pathophysiology of cerebral ischemia approximately, the method is suited for identifying those patients who would profit from reperfusion therapy. Whether MRI is also appropriate as an aid to reaching a prognosis on the risk of secondary hemorrhage has not yet been resolved. (orig.) [German] Die Schlaganfall-MRT ermoeglicht es, bei akuter zerebraler Ischaemie den bereits initial entstandenen ...
This paper introduces examples of satellite imageries analysis and utilizations for safeguards activities. Recently, many kinds of satellite imageries are available in the world i.e., high-spatial resolution, multi- and hyper-spectral, multi-function, and multi-polarization radars. The problem is that how to obtain the required information from these digital images. The Japan Aerospace Exploration Agency (JAXA) has successfully launched the Advanced Land Observing Satellite (ALOS, the nickname is 'Daichi') on 24th January, 2006. The mission objectives are cartography, regional observation, disaster monitoring etc. ALOS has three instruments, PRISM, AVNIR-2, and PALSAR, to achieve these objectives. An overview of ALOS is provided. ALOS follows the Japanese Earth Resources Satellite- 1 (JERS-1) and the Advanced Earth Observing Satellite (ADEOS) and utilizes advanced land-observing technology. ALOS is fling in a Sun-synchronous orbit with an inclination angle of 98.16 ...
AIM: To assess the impact of the introduction of a computed tomography (CT) imaging protocol for multi-trauma patients on the workload, overall diagnostic yield, and effect on detection of cervical spine injury and pneumothorax. METHOD: Between February 1997 and April 2004, all patients presenting acutely to the Emergency Department (ED) with haemodynamically stable trauma (Abbreviated Injury Scale 3 or more) involving more than two body systems were imaged with a comprehensive pre-set helical CT protocol (including non-contrast head, cervical spine: cranio-cervical and cervico-thoracic junctions; and oral and intravenous contrast-enhanced thoracic, abdomen and pelvis) after initial triage and a standard trauma series of radiographs (chest, lateral C-spine and pelvis). Diagnosis of cervical spine fracture and pneumothorax was noted before and after the CT protocol was carried out and findings from all studies were recorded ...
The objective of this study was to compare contrast-enhanced magnetic resonance angiography (CE MRA) and multislice computed tomographic angiography (MS CTA) in the follow-up of thoracic stent-graft placement. The CE MRA and MS CTA were performed following nitinol stent-graft treatment due to thoracic aneurysm (n=4), intramural bleeding (n=2) and type-B aortic dissection (n=5). Corresponding evaluation of arterial-phase imaging characteristics focused on the stent-graft morphology and leakage assessment. Stent-graft and aneurysm extensions were comparable between both techniques. Complete exclusion (aneurysm, n=4; dissection, n=2) was assessed with high confidence with CE MRA and MS CTA. Incomplete exclusion (intramural bleeding, n=2; dissection, n=3) was assigned to lower confidence scores on CE MRA compared with MS CTA. On CE MRA the stent-graft lumen demonstrated an inhomogeneous signal, the stent struts could not be assessed. The CE MRA can be used as ...
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 den letzten Jahren ...
Initial major applications of neutron radiography (NR) to nuclear engineering were nondestructive inspections of nuclear fuel, control rods, reactor materials and some other components. Increase in the available neutron flux over 10{sup 8} n/cm{sup 2}s at the JRR-3M thermal neutron radiography facility (TNRF) in 1991 has expanded the application field to the dynamic but clear imaging of moving objects and fluid phenomena. The JRR-3M TNRF is facilitated with three major imaging systems, being characterized by spatial and/or temporal resolutions: 1. Static neutron radiography (SNR), 2. real-time neutron radiography (RNR) with an imaging rate of 30 frames/s and 3. High-frame-rate neutron radiography (HFRNR). SNR has been used for three-dimensional visualization of air-water two-phase flows in a simulated rod bundle. Three-dimensional computed tomography clearly illustrated average void fraction ...
We present an image of the rupture propagation of the 2004 M6.0 Parkfield earthquake using records from a dense network of local strong motion stations. We back-propagate high-frequency waveforms in 3D with a method, similar to reverse time migration, to obtain an estimate of the distribution of radiated high-frequency seismic energy in space and time. The image is forced to be coherent at the known hypocenter location and the quake origin time by applying small static time shifts obtained using waveform cross-correlation. We observe that the Parkfield earthquake radiated a distinct secondary high-frequency phase, which is located about 12.5~km northwest of the hypocenter with an onset of seismic radiation about 5~s after the rupture initiation. The time history of the back-projection suggests a rupture velocity of 2.5~km/s between hypocenter and subevent. The back-projection result is confirmed by inversion of picked ...
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)
A 1.5-year-old male Belgian Malinosis Military Working Dog presented with a 1-month history of intermittent hematuria. Diagnostic ultrasound and contrast radiography demonstrated large blood clots in the urinary bladder and a filling defect in the right renal pelvis. At surgery, clotted blood was present in the right ureter and bladder. Following right nephrectomy, the dog returned to training. One month later, elevations in urea nitrogen and creatinine were noted. Hematuria recurred at 3 months and the dog was found dead in its kennel. Necropsy showed a blood-filled left renal pelvis and ureter. PMID:1454185
Purpose: Efficacy and safety of the own single-center experience with moderately dosed radiosurgery (SRS) for limited (one to four) brain metastases were analyzed and correlated with patient- and treatment-related variables. Patients and Methods: Between 05/1998 and 10/2006, 93 patients received SRS for a total of 142 brain metastases. The median number of brain metastases treated per patient was one (range, one to four). 46 patients (49%) received initial SRS alone, 13 patients (14%) SRS with up-front whole-brain radiotherapy (WBRT), and 34 patients (37%) SRS for recurrent metastases after WBRT. Median dose was 16 Gy (range, 10-20 Gy). Results: Median overall survival (OS) was 7.5 months. The actuarial 6- and 12-month data for OS were 60% and 35%, for local brain control (LBC) 87% and 79%, and for distant brain control (DBC) 48% and 37%, respectively. Only ten of 46 patients (22%) with initial SRS alone ultimately received WBRT. Ten patients ...
Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ...
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 ...
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.
TiO{sub 2} is a vital material in several technologies including, photocatalysis, gas sensing, biomaterials and optical coatings. Among the several crystal structures of this oxide, rutile has the highest density and microhardness, the highest index of refraction and the highest temperature stability. The processing of dense polycrystalline materials often includes the addition of a liquid-forming phase at higher temperatures. This technique is known as liquid-phase sintering and has been studied extensively. Rutile boundaries containing an amorphous phase have been used to study boundary migration and grain-boundary grooving. Visible-light (VLM), scanning electron (SEM) and transmission electron microscopy (TEM) in addition to electron-backscatter diffraction (EBSD) and a focused-ion beam (FIB) tool were used to characterize boundary migration in rutile. EBSD analysis was carried out on a Philips XL30 FEG SEM equipped with a DigiView 1612 high-resolution, high-speed CCD camera. A 2.5 ...
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.
Superparamagnetic MFe{sub 2}{sup 3+}O{sub 4} (M=Mn{sup 2+}, Fe{sup 2+} and Co{sup 2+}) inverse spinel ferrite (ISF) nanoparticles with narrow size distribution having average diameters of 6-8 nm were synthesized by a diol reduction of organic metals and the surface was modified to be hydrophilic by coating with succimer. Magnetic resonance imaging (MRI) contrast enhancement by dipolar coupling defined interactions between the synthesized ISFs and protons in the bulk water was investigated with initial susceptibility, magnetization and anisotropy of the succimer-coated ISFs. The relaxivity ratios, r{sub 2}/r{sub 1}, for MnFe{sub 2}O{sub 4}, Fe{sub 3}O{sub 4} and CoFe{sub 2}O{sub 4} were measured to be 12.2, 23.1 and 62.3, respectively, which demonstrate the potential usefulness of these magnetic nanoparticles as T{sub 2} contrast agents for MRI.
Heating during frictional sliding is a major component of the energy budget of earthquakes and represents a potential weakening mechanism. It is therefore important to investigate how heat dissipates during sliding on simulated faults. We present results from laboratory friction experiments where a halite (NaCl) slider held under constant load is dragged across a coarse substrate. Surface evolution and frictional resistance are recorded. Heat emission at the sliding surface is monitored using an infra-red camera. We demonstrate a link between plastic deformations of halite and enhanced heating characterized by transient localized heat spots. When sand 'gouge' is added to the interface, heating is more diffuse. Importantly, when strong asperities concentrate deformation, significantly more heat is produced locally. In natural faults such regions could be nucleation patches for melt production and hence potentially initiate weakening during earthquakes at much ...
Six species having characteristics of plants with the C4 dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon L. (Bermuda grass), Kyllinga brevifolia Rottb., Amaranthus tricolor L. cv. Early splendour, Kochia childsii Hort., and Portulaca grandiflora Hook (rose moss), responded decisively to 0.1 milliequivalent per liter NaCl supplied to their culture solutions initially containing less than 0.08 microequivalent per liter Na. Chlorosis and necrosis occurred in leaves of plants not receiving sodium. Portulaca failed to set flower in the sodium-deficient cultures. Under similar conditions Poa pratensis L. (Kentucky blue grass) having characteristics of the C3 photosynthetic pathway made normal growth and did not respond to the addition of sodium. It is concluded from these results and previously reported work that sodium is generally essential for species having the C4 pathway but not for species with the C3 ...
Superparamagnetic MFe23+O4 (M=Mn2+, Fe2+ and Co2+) inverse spinel ferrite (ISF) nanoparticles with narrow size distribution having average diameters of 6-8 nm were synthesized by a diol reduction of organic metals and the surface was modified to be hydrophilic by coating with succimer. Magnetic resonance imaging (MRI) contrast enhancement by dipolar coupling defined interactions between the synthesized ISFs and protons in the bulk water was investigated with initial susceptibility, magnetization and anisotropy of the succimer-coated ISFs. The relaxivity ratios, r2/r1, for MnFe2O4, Fe3O4 and CoFe2O4 were measured to be 12.2, 23.1 and 62.3, respectively, which demonstrate the potential usefulness of these magnetic nanoparticles as T2 contrast agents for MRI.
For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO{sub 4}. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge-discharge test is carried out in the range of 3.0-5.0 V at 0.2 mA cm{sup -2}. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g{sup -1}, respectively. The better electrochemical property should be ascribed to the better crystallized ...
For the first time, rheological phase method, a simple and effective route, is applied to synthesize novel cathode material LiCoPO4. X-ray diffraction spectrometer (XRD), X-ray photoelectron spectrometer (XPS), transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) are taken to investigate this material, respectively. XRD figure shows that the rheological sample is better crystallized than the solid-state one. XPS result of the rheological sample exhibits that the valence of Co is 2+. TEM images show that better dispersed particles with smaller size can be formed by rheological method comparing to the solid-state route. Charge-discharge test is carried out in the range of 3.0-5.0 V at 0.2 mA cm-2. The initial discharge capacity for rheological phase and solid-state powder is 71.5 and 30.9 mAh g-1, respectively. The better electrochemical property should be ascribed to the better crystallized rheological phase ...
We have used a cell-free polymerase I transcription system derived from HeLa cells to study the regulation of human rRNA synthesis. Analysis of deletion mutants spanning the start site of transcription at nucleotide +1 indicates that the control region affecting initiation of human rRNA synthesis is contained within sequences from nucleotides -158 to +18. This promoter region can be subdivided into (i) a central segment of approximately 40 base pair that is required for transcription and (ii) flanking sequences that influence the efficiency of transcription in vitro. We have examined the in vitro transcriptional activity of the human extract under various conditions that are thought to modulate rRNA synthesis in vivo. Cell-free extracts prepared from HeLa cells infected with adenovirus 2 synthesize human rRNA at levels greatly decreased relative to uninfected cell extracts. By contrast, in vitro transcription of human rRNA is stimulated 2- to 3-fold by the addition ...
We present the initial results of an observational study into the variation of the dominant length-scale of quiet solar emission: supergranulation. This length-scale reflects the radiative energy in the plasma of the upper solar chromosphere and transition region at the magnetic network boundaries forming as a result of the relentless interaction of magnetic fields and convective motions of the Sun's interior. We demonstrate that a net difference of ~0.5Mm in the supergranular emission length-scale occurs when comparing observations cycle 22/23 and cycle 23/24 minima. This variation in scale is reproduced in the datasets of multiple space- and ground-based instruments and using different diagnostic measures. By means of extension, we consider the variation of the supergranular length-scale over multiple solar minima by analyzing a subset of the Mt Wilson Solar Observatory (MWO) Ca II K image record. The observations and analysis presented ...
A novel method to detect and correct inaccuracies in a set of unconstrained dense correspondences between two images is presented. Starting with a robust, general-purpose dense correspondence algorithm, an initial pose estimate and dense 3D scene reconstruction are obtained and bundle-adjusted. Reprojection errors are then computed for each correspondence pair, which is used as a metric to distinguish high and low-error correspondences. An affine neighborhood-based coarse-to-fine iterative search algorithm is then applied only on the high-error correspondences to correct their positions. Such an error detection and correction mechanism is novel for unconstrained dense correspondences, for example not obtained through epipolar geometry-based guided matching. Results indicate that correspondences in regions with issues such as occlusions, repetitive patterns and moving objects can be identified and corrected, such that a more accurate set of ...
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, possible presence of a bile leak and ...
Tantalum and tantalum-based thin films have gained precedence as the diffusion barrier for copper interconnects used in the latest generation of integrated circuits (ICs). The paper presents insight and observations on the covariance of texture and grain size of wrought tantalum sputtering targets and their influence on sputtering performance. Previous studies involving deposition trials of tantalum targets of varying metallurgical character had demonstrated that both grain size and textural homogeneity is critical for assuring reliable sputtering performance of tantalum. Subsequently, a model had been proposed to prescribe how localized texture bands and orientation clusters in tantalum are effectively resistant to sputter erosion. In this paper, results of atomic force microscopy (AFM) and orientation imaging microscopy (OIM{sup TM}) analyses on the eroded surface of a tantalum sputtering target are presented. Initial findings support the ...
U3Si2 Al fuel plate is one of the dispersion fuel structure materials recently developed and widely used in research reactors. The mechanical properties of this structural material, especially the fatigue performance, are strongly dependent on its fabrication process. To investigate the effects of these processing technologies, the fatigue tests for the different specimens were carried out. The S N curves indicate that the fabrication processing technologies of U3Si2 fuel plate, such as the addition of U3Si2 particles into aluminum powder to form the fuel meat, holding and rolling the processes of meat and cladding of 6061-Al alloy, plays an important role in improving the mechanical properties and fatigue performance of this fuel plate. In addition, some factors that influence the crack initiation and propagation are summarized based on the fatigue images that are in situ observations with SEM. The critical criterion for fatigue damage is ...
Through analysis of archival images and photometry from the Spitzer GLIMPSE and MIPSGAL surveys combined with Two Micron All Sky Survey and MSX data, we have identified 488 candidate young stellar objects (YSOs) in the giant molecular cloud M17 SWex, which extends #approx#50 pc southwest from the prominent Galactic H II region M17. Our sample includes >200 YSOs with masses >3 M _s_u_n that will become B-type stars on the main sequence. Extrapolating over the stellar initial mass function (IMF), we find that M17 SWex contains >1.3 x 10"4 young stars, representing a proto-OB association. The YSO mass function is significantly steeper than the Salpeter IMF, and early O stars are conspicuously absent from M17 SWex. Assuming M17 SWex will form an OB association with a Salpeter IMF, these results reveal the combined effects of (1) more rapid circumstellar disk evolution in more massive YSOs and (2) delayed onset of massive star formation.
The fabrication and complete evaluation are described of a dihydropyridine in equilibrium pyridinium salt type redox system for the delivery of radioiodinated agents to the brain. The pivotal intermediate, N-succinimidyl (1-methylpyridinium iodide)-3-carboxylate was prepared by condensation of nicotinic acid and N-hydroxysuccinimide in the presence of dicyclohexylcarbodimide, followed by quaternization of III with methyl iodide. Tissue distribution studies of "1"2"5I-labeled 4-iodoaniline and the redox agents were performed in rats. ["1"2"5I]Iodoaniline initially showed moderate (0.58% dose/gm) brain uptake with subsequent release of the radioactivity from the brain. ["1"2"5I]Iodoaniline, when coupled to a dihydropyridine carrier showed higher uptake and retention in the brain. The ["1"2"5I]iodophenylethyl analogue showed uptake and retention in the brain to be very similar. Apparently the lipophilic agents cross the blood-brain barrier and are oxidized ...
Regulation of transcription initiation by RNA polymerase II requires TFIID, a multisubunit complex composed of the TATA binding protein (TBP) and at least seven tightly associated factors (TAFs). Some TAFs act as direct targets or coactivators for promoter-specific activators while others serve as interfaces for TAF-TAF interactions. Here, we report the molecular cloning, expression and characterization of Drosophila dTAFII60 and its human homolog, hTAFII70. Recombinant TAFII60/70 binds weakly to TBP and tightly to the largest subunit of TFIID, TAFII250. In the presence of TAFII60/70, TBP and TAFII250, a stable ternary complex is formed. Both the human and Drosophila proteins directly interact with another TFIID subunit, dTAFII40. Our findings reveal that Drosophila TAFII60 and human TAFII70 share a high degree of structural similarity and that their interactions with other subunits of TFIID are conserved.Images
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 ...
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 energetic tracers and large series of ...
This paper presents the results of the Spatial Signature Analysis (SSA) Electrical-test (e-test) validation study that was conducted between February and June, 1998. SSA is an automated procedure developed by researchers at the Oak Ridge National Laboratory to address the issue of intelligent data reduction while providing feedback on current manufacturing processes. SSA was initially developed to automate the analysis of optical defect data. Optical defects can form groups, or clusters, which may have a distinct shape. These patterns can reveal information about the manufacturing process. Optical defect SSA uses image processing algorithms and a classifier system to interpret and identify these patterns, or signatures. SSA has been extended to analyze and interpret electrical test data. The algorithms used for optical defect SSA have been adapted and applied to e-test binmaps. An image of the binmap is created, and ...
In situ scanning tunneling microscopy has been used to study the nucleation and growth mechanisms and the structure of passive films formed on Cu(111) surfaces in 0.1 M borate buffer solution (pH 9.3). A surface topography characterized by terraces with monoatomic steps is obtained after potentiodynamic reduction down to {minus}1.12 V/standard hydrogen electrode (SHE), of the electropolished surface exposed to air. The formation of a single Cu{sub 2}O passive layer at 0.03 V/SHE proceeds first by a roughening of the steps assigned to a locally blocked step flow process due to a competition between dissolution and preferential nucleation of the oxide at the steps. The observed oxide nuclei are 2--3 nm wide and about one atomic plane high. This process leads to the complete coverage of the terraces by a grain-like structure of the oxide film. The initial terrace topography is completely altered. Thickening of this oxide layer leads to unstable scanning tunneling ...
During the last decade, new radiopharmaceutical have been introduced for brain imaging. The marked differences of these tracers in tissue specificity within the brain and their increasing use for diagnostic studies support the need for a more anthropomorphic model of the human brain and head. Brain and head models developed in the past have been only simplistic representations of this anatomic region. For example, the brain within the phantom of MIRD Pamphlet No. 5 Revised is modeled simply as a single ellipsoid of tissue With no differentiation of its internal structures. To address this need, the MIRD Committee established a Task Group in 1992 to construct a more detailed brain model to include the cerebral cortex, the white matter, the cerebellum, the thalamus, the caudate nucleus, the lentiform nucleus, the cerebral spinal fluid, the lateral ventricles, and the third ventricle. This brain model has been included within a slightly modified version of the head ...
During the last decade, new radiopharmaceutical have been introduced for brain imaging. The marked differences of these tracers in tissue specificity within the brain and their increasing use for diagnostic studies support the need for a more anthropomorphic model of the human brain and head. Brain and head models developed in the past have been only simplistic representations of this anatomic region. For example, the brain within the phantom of MIRD Pamphlet No. 5 Revised is modeled simply as a single ellipsoid of tissue With no differentiation of its internal structures. To address this need, the MIRD Committee established a Task Group in 1992 to construct a more detailed brain model to include the cerebral cortex, the white matter, the cerebellum, the thalamus, the caudate nucleus, the lentiform nucleus, the cerebral spinal fluid, the lateral ventricles, and the third ventricle. This brain model has been included within a slightly modified version of the head ...
The authors have examined the pyrolysis of Argonne samples of Wyodak and Illinois No. 6 coal in argon, undecane, Tetralin, and water. The effects of the pyrolysis on individual particles of coal were monitored visually in a cell with diamond windows capable of operation to temperature and pressures in excess of 500{degrees}C and 3000 psi. The changes in the particles from ambient to 460{degrees}C were recorded in real time on video tape, and images were then taken from the tape record and analyzed. The study showed that in argon both coals developed tars at 350{degrees}-370{degrees}C. The tars then quickly evaporated, leaving core particles remarkably similar in size and shape to the initial particles. These observations suggest that coal does not melt nor become fully liquid when heated. Nor does the softened coal undergo crosslinking to generate coke. Rather the simple loss of volatiles leaves behind the core residue as coke. Contrary to the ...
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 ...
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).
AIM: The purpose of the study was to evaluate the percutaneous use of the new nitinol SMARTeR stents in patients with biliary obstruction. MATERIALS AND METHODS: Four stents were placed in three patients percutaneously under ultrasound and fluoroscopic guidance. RESULTS: The deployment of the stents was successful in all three patients. All stents maintained their patency and position after short-term follow-up. CONCLUSION: The nitinol SMARTeR stent is useful in the management of patients with biliary obstruction although accurate placement across the ampulla was found to be technically more difficult than with the Wallstent. Larger, long-term follow-up studies are required to evaluate the long-term patency of these new devices.
In previous work, on cooling from 300 K to 10 K the elastic moduli for both #alpha#- and #delta#-Pu dropped 30%. This large change may reflect effects of 5f-electron localization. In this work, the elastic moduli at ambient temperature of several Pu-Ga alloys were measured using resonant ultrasound spectroscopy (RUS). The strong temperature dependence of the bulk and shear modulus and the temperature independence of Poisson's ratio was confirmed and the upper temperature limit for #alpha#-Pu was extended to 360 K. Measurements of the time dependence of the shear moduli of Pu and Pu-2.36 at.% Ga were determined with high precision as a function of time and temperature. Using a model for time dependence of point defects, we determined the exponential time constant at ambient temperature for such variations. The low temperature results are consistent with Fluss .
Abstract Suspension of solids in stirred reactor is widely used for catalytic reactions, dissolution, etc. Quality of solid suspension is an important parameter required for the reliable design, optimum performance, and scale up of the system. Quality of suspension depends on local characteristics of solid velocity and hold up profiles. The present work was focused on investigating quality of solid suspension using ultrasound velocity profiler (UVP) measurements and CFD simulations. The slip velocity measurements carried out with UVP were used to evaluate different drag correlations used in CFD simulations. Results discussed in this work would be useful for extending the applications of CFD models for simulating large stirred slurry reactors.
This paper is concerned with the real time automatic discriminating of flaws from two categories; i. cracks (planar defect) and ii. Non-cracks (volumetric defect such as cluster porosity and slag) using pulse-echo ultrasound. The raw ultrasonic flaws signal were collected from a computerized robotic plane scanning system over the whole of each reflector as the primary source of data. The signal is then filtered and the analysis in both time and frequency domain were executed to obtain the selected feature. The real time feature analysis techniques measured the number of peaks, maximum index, pulse duration, rise time and fall time. The obtained features could be used to distinguish between quantitatively classified flaws by using various tools in artificial intelligence such as neural networks. The proposed algorithm and complete system were implemented in a computer software developed using Microsoft Visual BASIC 6.0 (author)
Abstract In this brief report, we have described the fine-needle aspiration cytology (FNAC) of a hepatosplenic T-cell lymphoma (HSTCL) in a 60-year-old female patient. The patient complained of fever and heaviness of left upper abdomen. Ultrasound-guided FNAC of the spleen showed immature lymphoid cells, and a diagnosis of primary non-Hodgkin lymphoma of spleen was offered. Subsequently, the patient underwent splenectomy and wedge biopsy of liver that confirmed the cytological diagnosis. The lymphoma cells were positive for CD3 immunostain. Primary hepatosplenic T-cell lymphoma is a rare entity and may often pose diagnostic problems on FNAC. Diagn. Cytopathol. 2010. 2010 Wiley-Liss, Inc.
Background: Superficial inferior epigastric artery (SIEA) flap has a great advantage over other flaps of the area, that is, readily non-existent donor-site problems. The main reason why the SIEA flap has never been extensively used in breast reconstruction is the small diameter and variable anatomy of its donor artery. This study presents a possibility of enlarging the SIEA diameter using the delay-phenomenon mechanism. Methods: A prospective clinical study of 26 patients was undertaken. Prior to surgery, ultrasound examinations were performed, measuring the diameter of SIEA and the velocity of blood flow in SIEA. The ipsilateral deep inferior epigastric artery (DIEA) was then ligated in all patients who had a measurable SIEA preoperatively. Two weeks later, measurements were repeated. The...
The techniques in order to measure the depth of defect in weldment and structure accurately have been developed. Many researches have made efforts to develop the methods for the accurate depth sizing of defect. TOFD is known as the most accurate method of various methods for measuring depth sizing. However, there is a possibility to miss defects because of the limitation of beam coverage for the ultrasound incident angle. In this study, the results for detectability and depth sizing using phased array ultrasonic technique for thick body were compared with those of conventional TOFD technique. It was experimentally confirmed that the phased array ultrasonic TOFD technique gives good detectability and accurate depth measurement for the various types of defects. The phased array ultrasonic TOFD technique developed in this study will contribute to increase the inspection reliability in thick component such as the pressure vessel of power generation industry
This document - IAEA Safeguards: Implementation Blueprint of Commercial Satellite Imagery - constitutes the second report from SSC Satellitbild giving a structured view and solid guidelines on how to proceed with a conceivable implementation of satellite imagery to support Safeguards activities of the Agency. This Phase 2 report presents a large number of concrete recommendations regarding suggested management issues, work organisation, imagery purchasing and team building. The study has also resulted in several lists of actions and preliminary project plans with GANT schedules concerning training, hardware and software, as well as for the initial pilot studies. In both the Phase 1 and Phase 2 studies it is confirmed that the proposed concept of a relatively small Imagery Unit using high-resolution data will be a sound and feasible undertaking. Such a unit capable of performing advanced image processing as a tool for various safeguard tasks ...
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
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
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)
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
To assess the efficacy and resulting complications of tetracycline sclerotherapy in renal, hepatic, ovarian, and perivesical cysts. We retrospectively reviewed 23 cases of benign cysts (16 renal, 4 hepatic, 2 ovarian, and 1 perivesical) in 22 patients in whom the condition was diagnosed or confirmed by either ultrasound, CT, or cytology, and who underwent percutaneous tetracycline sclerotherapy. Using a 21-gauge Chiba needle, the target cyst was punctured under ultrasound guidance. Prior to the injection of 1500 mg of tetracycline diluted in 5 ml of normal saline, almost all the cystic content was aspirated, and at the end of the procedure the tetracycline was left in the cyst. During a period of between 3 and 22 months, 18 of the 23 cases were followed up. In six of the 18 cases followed up, the cysts either decreased in size by 10%, or collapsed completely. In seven cases a collapse of over 50% was noted, and in the remaining five the cyst ...
The aim of this work is to investigate the acoustic wave generation by pulsed and periodically modulated ion beams in different solid materials depending on the beam parameters and to demonstrate the possibility to apply an intensity modulated focused ion beam (FIB) for acoustic emission and for nondestructive investigation of the internal structure of materials on a microscopic scale. The combination of a FIB and an ultrasound microscope in one device can provide the opportunity of nondestructive investigation, production and modification of micro- and nanostructures simultaneously. This work consists of the two main experimental parts. In the first part the process of elastic wave generation during the irradiation of metallic samples by a pulsed beam of energetic ions was investigated in an energy range from 1.5 to 10 MeV and pulse durations of 0.5-5 #mu#s, applying ions with different masses, e.g. oxygen, silicon and gold, in charge states from 1"+ to 4"+. The ...
Purpose To investigate the sensitivity and accuracy of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for restaging the mediastinum after induction chemotherapy in patients with non-small-cell lung cancer (NSCLC). Patients and Methods One hundred twenty-four consecutive patients with tissue-proven stage IIIA-N2 disease who were treated with induction chemotherapy and who had undergone mediastinal restaging by EBUS-TBNA were reviewed. On the basis of computed tomography, 58 patients were classified as having stable disease and 66 were judged to have had a partial response. All patients subsequently underwent thoracotomy with attempted curative resection and a lymph node dissection regardless of EBUS-TBNA findings. Results Persistent nodal metastases were detected by using EBUS-TBNA in 89 patients (72%). Of the 35 patients in whom no metastases were assessed by EBUS-TBNA, 28 were found to have residual stage IIIA-N2 disease at ...
Carpal tunnel syndrome (CTS) is a common disorder, for which various conservative treatment options are available. The objective of this study is to determine the efficacy of the various conservative treatment options for relieving the symptoms of CTS. Computer-aided searches of MEDLINE (1/1966 to 3/2000), EMBASE (1/1988 to 2/2000) and the Cochrane Controlled Trials Register (2000, issue 1) were conducted, together with reference checking. Included were randomised controlled trials evaluating the efficacy of conservative treatment options in a study population of CTS patients, with a full report published in English, German, French or Dutch. Two reviewers independently selected the studies. Fourteen randomised controlled trials were included in the review. Assessment of methodological quality and data-extraction was independently performed by two reviewers. A rating system, based on the number of studies and their methodological quality and findings, was used to determine the strength ...
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 ...
In this work, we use lasers to enhance possibilities of laser desorption methods and to optimize coating procedure for capillary electrophoresis (CE). We use several different instrumental arrangements to characterize matrix-assisted laser desorption (MALD) at atmospheric pressure and in vacuum. In imaging mode, 488-nm argon-ion laser beam is deflected by two acousto-optic deflectors to scan plumes desorbed at atmospheric pressure via absorption. All absorbing species, including neutral molecules, are monitored. Interesting features, e.g. differences between the initial plume and subsequent plumes desorbed from the same spot, or the formation of two plumes from one laser shot are observed. Total plume absorbance can be correlated with the acoustic signal generated by the desorption event. A model equation for the plume velocity as a function of time is proposed. Alternatively, the use of a static laser beam for observation enables reliable ...
In this review, we demonstrate the developmental appearance, structural features, and reorganization of transient cerebral zones and structures in the human fetal brain using a correlative histological and MRI analysis. The analysis of postmortem aldehyde-fixed specimens (age range: 10 postovulatory weeks to term) revealed that, at 10 postovulatory weeks, the cerebral wall already has a trilaminar appearance and consists of: (1) a ventricular zone of high cell-packing density; (2) an intermediate zone; (3) the cortical plate (in a stage of primary consolidation) with high MRI signal intensity. The anlage of the hippocampus is present as a prominent bulging in the thin limbic telencephalon. The early fetal telencephalon impar also contains the first commissural fibers and fornix bundles in the septal area. The ganglionic eminence is clearly visible as an expanded continuation of the proliferative ventricular zone. The basal ganglia showed an initial aggregation of ...
Development of selective serotonin transporter (SERT) tracers for single-photon emission tomography (SPET) is important for studying the underlying pharmacology and interaction of specific serotonin reuptake site inhibitors, commonly used antidepressants, at the SERT sites in the human brain. In search of a new tracer for imaging SERT, IDAM (5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio]benzyl alcohol) was developed. In vitro characterization of IDAM was carried out with binding studies in cell lines and rat tissue homogenates. In vivo binding of [[sup 125]I]IDAM was evaluated in rats by comparing the uptakes in different brain regions through tissue dissections and ex vivo autoradiography. In vitro binding study showed that IDAM displayed an excellent affinity to SERT sites (K[sub i]=0.097 nM, using membrane preparations of LLC-PK[sub 1] cells expressing the specific transporter) and showed more than 1000-fold of selectivity for SERT over norepinehrine and ...
To evaluate the role of positron emission tomography-computed tomography (PET-CT) in staging and determining early treatment response to chemotherapy in children with neuroblastoma (NB) and its correlation with the final outcome. Patients and Methods: Seventeen patients of NB with mean age of 51.5 months (age range 2-132 months; 14 males, 3 females) underwent serial "1"8F-fluorodeoxyglucose (FDG) PET-CT imaging. All 17 patients were for staging before any treatment. Twelve of 17 patients underwent "1"3"1I meta-iodobezylguanidine (MIBG) scan and bone scan. MIBG uptake was seen in the primary lesion in 11/12 patients. MIBG uptake in bones was seen in 3/12 patients. All bone lesions were concordant on MIBG and bone scan. Early response to chemotherapy was evaluated after two cycles using PET-CT. A 30% reduction in longest diameter was taken as cut-off value for response on CT based on the response evaluation criteria in solid tumors criteria. Response on PET-CT was ...
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.
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.
In a study of initiations caused by reflected shock from a high-impedance boundary, attempts to establish sufficient conditions for initiative are described. Shock polar analysis is used to discover the ranges of various flow regimes, general shock structures and pressure estimates of states behind the reflected wave. Using this knowledge, wave structure growth rates from hydrocode simulations are estimated and standard-shock initiation criteria are used; experiments are designed in which the initiation from a reflected-shock wave structure appears likely. Two experiments are described in which a reflected-shock wave from a uranium surface initiated PBX 9502. The experimental evidence is in good agreement with the assumptions and results of the analysis.
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 ...
OBJECTIVE AND DESIGNThis study used qualitative and quantitative methods to examine the reasons primary care physicians and nurses offered for their inability to initiate guideline-concordant...Full Text Available
Monte Carlo (MC) dose calculations can be accurate but are also computationally intensive. In contrast, convolution superposition (CS) offers faster and smoother results but by making approximations. We investigated MC denoising techniques, which use available convolution superposition results and new noise filtering methods to guide and accelerate MC calculations. Two main approaches were developed to combine CS information with MC denoising. In the first approach, the denoising result is iteratively updated by adding the denoised residual difference between the result and the MC image. Multi-scale methods were used (wavelets or contourlets) for denoising the residual. The iterations are initialized by the CS data. In the second approach, we used a frequency splitting technique by quadrature filtering to combine low frequency components derived from MC simulations with high frequency components derived from CS components. The rationale is to ...
The synthesis and brain uptake in mice of the radioidinated derivatives of N,N-dimethyl-N'-(idodimethoxyphenyl)-1,3-propanediamine, as well as the N-substituted derivatives of (iodoalkylphenyl)isopropyl, iodoalkylphenylethylamine and 3,4-(methylenedioxy)phenyl-amphetamine (MDA) are described. These compounds contain structural features of both IMP and HIPDM, the cerebral perfusion agents currently in clinical use. The radiolabeled analogs were obtained via the [{sup 125}I]I exchange method, or by [{sup 125}I]NaI treatment of the iodo-free precursor in the presence of an oxidant. Following intravenous injection in mice, all compounds showed important radioactivity concentrations in the lungs and kidneys. The N-substituted (iodoalkylphenyl)isopropyl and iodoalkylphenyl-ethylamine derivatives displayed a high initial brain uptake (>10%IDg{sup -1}) followed by a rapid clearance phase, resulting in lower brain-to-blood ratios as those reported for IMP ...
The synthesis and brain uptake in mice of the radioidinated derivatives of N,N-dimethyl-N'-(idodimethoxyphenyl)-1,3-propanediamine, as well as the N-substituted derivatives of (iodoalkylphenyl)isopropyl, iodoalkylphenylethylamine and 3,4-(methylenedioxy)phenyl-amphetamine (MDA) are described. These compounds contain structural features of both IMP and HIPDM, the cerebral perfusion agents currently in clinical use. The radiolabeled analogs were obtained via the ["1"2"5I]I exchange method, or by ["1"2"5I]NaI treatment of the iodo-free precursor in the presence of an oxidant. Following intravenous injection in mice, all compounds showed important radioactivity concentrations in the lungs and kidneys. The N-substituted (iodoalkylphenyl)isopropyl and iodoalkylphenyl-ethylamine derivatives displayed a high initial brain uptake (>10%IDg"-"1) followed by a rapid clearance phase, resulting in lower brain-to-blood ratios as those reported for IMP and HIPDM. In contrast, ...
Polycyclic aromatic hydrocarbons (PAHs) are combustion products of organic materials, mixtures of which contain multiple known and probable human carcinogens. PAHs occur in indoor and outdoor air, as well as in char-broiled meats and fish. Human exposure to PAHs occurs by inhalation, ingestion and topical absorption, and subsequently formed metabolites are either rendered hydrophilic and excreted, or bioactivated and bound to cellular macromolecules. The formation of PAH-DNA adducts (DNA binding products), considered a necessary step in PAH-initiated carcinogenesis, has been widely studied in experimental models and has been documented in human tissues. This review describes immunohistochemistry (IHC) studies, which reveal localization of PAH-DNA adducts in human tissues, and semi-quantify PAH-DNA adduct levels using the Automated Cellular Imaging System (ACIS). These studies have shown that PAH-DNA adducts concentrate in: basal and supra-basal ...
The implementation of a three-dimensional conformal radiotherapy facility in the radiotherapy department of the Heinrich Heine University is described. Complex radiotherapy techniques with commercially available networked systems are introduced to improve clinical work. Over 18 month we have gained clinical experience with a PHILIPS Multileaf Collimator (MLC) mounted on a SL 25 linear accelerator. For a limited period the MLC was used as a conventional blocking device. The standard MLC-shapes are controlled with a stand-alone computer system. In addition, a three-dimensional treatment planning system (3-D-TPS / TMS-Radix, Helax AB) based on convolution/superposition algorithms was recently installed. Treatment optimization is achieved using static field arrangements with complete volumetric computerized tomographic patient data for 3-D-TPS. Conformal adaptation of the 95%-isodose to the Planning Target Volume (PTV, ICRU 50) results in MLC-field-shaping concerning size, position and ...
The in-situ measurement of a crystallographic texture is a special type of a non-destructive measurement, which need special equipments. Due to the high photon flux and the excellent brilliance high energetic synchrotron radiations are a fantastic tool particular in fast experimentation. Moreover, a high penetration power allows the investigation of standard tensile sample of the DIN-norm. A loading device with a power up to 20 kN was installed at the hard wiggler beamline BW5 (HASYLAB-DESY) to perform in-situ strain and in-situ texture analysis. Using 100keV X-rays one gets short wavelength so that a 2D image-plate detector offers a wide range of diffraction pattern within the first 10 degree in 2 theta. Thermal neutron is another radiation with a high penetration power, which is the standard method for global texture analysis of bulk samples. As an example rectangular extruded Mg- Az31 was investigated by an in-situ. tensile experiment. Samples with 0 degree, 45 ...
The biological literature is huge and increasingly moving to electronic form. By developing a variety of new techniques, it should be possible to take advantage of this huge and growing electronic store. Computers should allow one to use the literature with greater efficiency and insight to disseminate information and to advance scientific understanding. Though there is a great deal of research and development effort focused on electronic text, e.g., the Digital Libraries initiative, little attention has been paid to the diagrammatic content of documents. However, it is common knowledge among biologists, and scientists in general, that the figures in documents are of critical importance. Little work has been done to develop principles and systems for analyzing, representing, and indexing and searching the diagrammatic content of electronic documents. This has been the main thrust of this research project. The primary work in the world on the analysis of graphics in ...
This paper describes the design of a test rig, which is used to apply a representative pressure load to a full-scale composite sandwich secondary aircraft structure. A generic panel was designed with features to represent those in the composite sandwich secondary aircraft structure. To provide full-field strain data from the panels, the test rig was designed for use with optical measurement techniques such as thermoelastic stress analysis (TSA) and digital image correlation (DIC). TSA requires a cyclic load to be applied to a structure for the measurement of the strain state; therefore, the test rig has been designed to be mounted on a standard servo-hydraulic test machine. As both TSA and DIC require an uninterrupted view of the surface of the test panel, an important consideration in the design is facilitating the optical access for the two techniques. To aid the test rig design a finite element (FE) model was produced. The model provides information on the ...
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 ...
Purpose: An inverse treatment planning algorithm for tomotherapy is described. Methods and Materials: The algorithm iteratively computes a set of nonnegative beam intensity profiles that minimizes the least-squares residual dose defined in the target and selected normal tissue regions of interest. At each iteration the residual dose distribution is transformed into a set of residual beam profiles using an inversion method derived from filtered backprojection image reconstruction theory. These 'residual' profiles are used to correct the current beam profile estimates resulting in new profile estimates. Adaptive filtering is incorporated into the inversion model so that the gross structure of the dose distribution is optimized during initial iterations of the algorithm, and the fine structure corresponding to edges is obtained at later iterations. A three dimensional, kernel based, convolution/superposition dose model is used to compute dose ...
Amyloid aggregation starts with the initial misfolding of peptide/protein precursors, with subsequent structural rearrangement into oligomers and protofibrils; the latter eventually organize into fibrils with shared basic structural features, found deposited in amyloid diseases. Mounting evidence indicates early oligomers as the most toxic amyloid species; accordingly, the search of inhibitors of their growth is considered a promising target to prevent amyloid toxicity. We recently showed that oleuropein aglycon, a polyphenol abundant in the extra virgin olive oil, interferes with the aggregation of amylin (involved in type-2 diabetes), eliminating its cytotoxicity. Here we report that oleuropein aglycon also hinders amyloid aggregation of A?(1-42) and its cytotoxicity, suggesting a general effect of such polyphenol. In particular, by using a wide panel of different spectroscopic, immunologic, cell viability and imaging techniques we provide a ...
This paper discusses the structural and compositional changes at the nanometer scale associated with the nucleation and growth of #alpha# precipitates in the #beta# titanium alloy Ti-5553 (Ti-5Al-5Mo-5 V-3Cr-0.5Fe) with #omega# precipitates acting as heterogeneous nucleation sites. The microstructural evolution in this alloy, during #beta#-solutionizing, quenching and aging type heat-treatments, has been investigated by combining results from scanning electron microscopy, orientation imaging microscopy, transmission electron microscopy, high-resolution TEM and three-dimensional atom probe (3DAP) tomography. Athermal #omega# precipitates form in this alloy on quenching from above the #beta# transus temperature. On isothermal annealing at low temperatures, these #omega# precipitates coarsen to form chemically ordered #omega# precipitates, accompanied by the nucleation of the stable #alpha# phase. Annealing at higher temperatures leads to dissolution of #omega# and ...
Subtractive imaging in confocal fluorescence light microscopy is based on the subtraction of a suitably weighted widefield image from a confocal image. An approximation to a widefield image can be obtained by detection with an opened confocal pinhole. The subtraction of images enhances the resolution in-plane as well as along the optic axis. Due to the linearity of the approach, the effect of subtractive imaging in Fourier-space corresponds to a reduction of low spatial frequency contributions leading to a relative enhancement of the high frequencies. Along the direction of the optic axis this also results in an improved sectioning. Image processing can achieve a similar effect. However, a 3D volume dataset must be acquired and processed, yielding a result essentially identical to subtractive imaging but superior in ...
X-ray imaging using asymmetric Bragg reflection in the hard x-ray regime opens the way to improve the spatial resolution limit below 1 #mu#m by magnifying the image before detection, simultaneously providing a strong phase contrast. A theoretical formalism of the imaging process is established. Based on this algorithm, numerical simulations are performed and demonstrate that both Fresnel propagation and Bragg diffraction contribute to contrast formation. The achievable resolution of this technique is investigated theoretically; the results obtained can be used to improve future experimental setups. Furthermore, the minimum detectable phase gradient is estimated, for comparison with other phase sensitive imaging techniques. Results from biological objects demonstrate that the technique is viable for imaging both in two and three dimensions. Refraction contrast ...
Based on a recently introduced phase X-ray imaging approach, a dual-detector prototype was developed for in-line X-ray phase imaging and phase retrieval utilizing a micro-focus X-ray source and two computed radiography (CR) cassette detectors. The system was built on a horizontal optical rail to facilitate manual adjustment of the positions of the X-ray source, the sample and the detectors. The novel design of the detector-1 is essential, it detects a portion of radiation to form an attenuation image; allows the rest of radiation to reach the detector-2 to form a phase contrast image, and the two images are used to retrieve a phase map. The two detectors are balanced for optimal phase-retrieval with reasonable radiation dose to the object to be imaged. The system was examined in terms of the linearity, the fractions of the X-ray photons detected by the two ...
In our evaluation we utilized the Asahi Mark-J NMR-CT system, with a resistive vertical quadrupolar electromagnet (0.1 Tesla) and a proton resonance frequency of 4.5 MHz. Our main imaging methods are the inversion-recovery or IR, saturation-recovery, or SR, and calculated T/sub 1/. Difference, or D images, constructed by subtracting the data of the IR signal from that of the SR signal, have also been obtained in some cases. The system allows averaging of raw data. Hybrid images were constructed from two or more images to obtain clear definition of areas of interest. By using the hybrid image, several tissues of different relaxation times can be shown in the same image. Application in our study of the newly developed hybrid image indicates its importance in the detection and diagnosis of lesion, especially the detection of the differentiation ...
Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and ...
Objective: An evaluation of the application of DR in thoracic spine and a comparative study of the DR with the conventional radiography. Methods: DR images and the conventional radiogram of 89 cases respectively were evaluated by 3 vice-consultant doctors and 2 chief technicians. Statistics was processed with 2 categories: (1) images were classified into grade A, B, C and condemned according to the image quality; and (2) thoracic spine are divided into upper, middle and lower portions, in which the rate of successful imaging were compared respectively. Results: The image quality of DR: 74. 1% images in grade A, 20.2% in grade B, 5.7% in grade C, and no image condemned. Conventional radiogram: 45% images in grade A, 41.6% in grade B, 11.2% in grade C, and 2.2% images condemned. The successful ...
Phase-contrast imaging with a practical cone-beam X-ray tube has been realized for clinical use in digital mammography using computed radiography (CR). To perform phase-contrast imaging, the X-ray detector must be distanced from an object so that the phase-contrast image achieves magnification; in a mammography unit dedicated to phase-contrast imaging, the magnification ratio is 1.75. When using an X-ray tube with a 0.1-mm focal spot, it appears that the penumbra in magnification blurs both projected images and the phase contrast, which generates an edge effect. However, where the sampling pitch of the CR plate is 43.75 {mu}m, the blur stretches the width of the phase contrast so that unit pixels in the detector can capture it. Note that the width of an ideal phase contrast using an X-ray point source results in a phase contrast too narrow for detection with CR. In addition to phase ...
Of 1850 patients with cholelithiasis diagnosed in the past 17 years, 1116 female and 734 male, 598 patients (32.3%) presented with one or more of three major symptoms, i.e., abdominal pain, fever and jaundice, whereas the remainder (67.7%) had none of these symptoms. The proportion of the asymptomatic patients was similar in all age groups, being around 70%. Only 20 per cent of 680 asymptomatic patients, followed for 10 to 17 years (median 13.3 years), developed biliary symptoms. Older patients over 70 years of age had a higher rate of change to the symptomatic group, as compared with younger patients under 70, 29.5% vs. 19.3%, respectively. During this period, carcinoma of the gallbladder developed in one of the asymptomatic patients (0.1%). Oral dissolution therapy was successful in only 4.2 per cent of attempted cases and associated with a recurrence rate of as high as 20%. We conclude that asymptomatic gallstone patients should only be followed up by ultrasound ...
Fiber delivered laser pulses emulsify thrombus by mechanical stresses that include a combination of pressure, tension and shear stress. Laser radiation is delivered to the locality of a thrombus and the radiation is absorbed by blood, blood dot, or other present materials. The combination of a leading pressure wave and subsequent vapor bubble cause efficient, emulsification of thrombus. Operating the laser in a low average power mode alleviates potential thermal complications. The laser is operated in a high repetition rate mode to take advantage of ultrasound frequency effects of thrombus dissolution as well as to decrease the total procedure time. Specific parameter ranges for operation are described. The device includes optical fibers surrounding a lumen intended for flow of a cooling agent. The fibers may be arranged concentrically around the lumen to deliver radiation and heat over as large an area as possible. An alternative design approach incorporates the ...
We report on a hard X-ray phase imaging microscopy (a phase-difference microscopy) that consists of an objective and a transmission grating. The simple optical system provides a quantitative phase image, and does not need a wave field mostly coherent on the objective. Our method has a spatial resolution almost same as that of the absorption contrast microscope image obtained by removing the grating. We demonstrate how our approach provides a phase image from experimentally obtained images. Our approach is attractive for easily appending a quantitative phase-sensitive mode to normal X-ray microscopes, and has potentially broad applications in biology and material sciences.
Twenty patients with lesions in the trachea or bronchus underwent energy subtraction Fuji computed radiography (FCR). Images obtained were compared with those from conventional FCR (plain FCR). ''Very clear'' images (in which the contour of the trachea and bronchus could be clearly defined) were obtained in 12/22 (55 %) by energy subtraction FCR and in 3/22 (14 %) by plain FCR; ''clear'' images (in which the contour could be defined) in 9/22 (41 %) by energy subtraction FCR and in 18/22 (82 %) by plain FCR; and ''unclear'' images (in which the contour could not be defined) in 1/22 (5 %) by both methods. Energy subtraction FCR, as well as plain FCR, yielded high image quality for the trachea. Energy subtraction FCR was superior to plain films when tumors existed within the trachea. (Namekawa, K.).
Background Computed tomography (CT) and magnetic resonance (MR) imaging can help diagnose benign adrenal adenomas, but prior studies rely on nonoperative follow-up as proof of a lesion?s benign nature. We examined adrenalectomy tissues to determine if imaging characteristics correlate with histopathologic findings. Methods We retrieved data for 196 consecutive adrenalectomies in 192 patients from 2000 to 2008. Imaging results were considered to signify benign adrenal adenoma if one or more of the following was present: Hounsfield units 60% or relative contrast washout of >40%, or MR with chemical-shift imaging demonstrating loss of signal intensity on out-of-phase images. Results The sensitivity and specif...
Real Time Radiography (RTR) finds extensive applications for inspection of objects on assembly lines for rapid inspection. A typical RTR widely used includes a image intensifier, CCD camera, image processor and high resolution TV monitor in addition to radiographic source. Image intensifiers used in X-radiography employ CsI as the input detector. With the increased use of neutrons as radiation source, real time neutron radiography is also being practised widely. Image intensifiers used in neutron radiography employ gadolinium as the input screen. The neutron image intensifier system at the authors laboratory essentially consists of a 9 inch Trifield image intensifier tube, motorised zoom lens, CCD camera and a high resolution TV monitor
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. (orig.).
A multiprocessor architecture inspired by the Disney multiplane camera is proposed. For many applications, this approach produces a natural mapping of processors to objects in a scene. Such a mapping promotes parallelism and reduces the hidden-surface work with minimal interprocessor communication and low-overhead cost. Existing graphics architectures store the final picture as a monolithic entity. The architecture here stores each object's image separately. It assembles the final composite picture from component images only when the video display needs to be refreshed. This organization simplifies the work required to animate moving objects that occlude other objects. In addition, the architecture has multiple processors that generate the component images in parallel. This further shortens the time needed to create a composite picture. In addition to generating images for animation, the ...
A neutron imaging system (NIS) has been recently installed at the University of Texas TRIGA reactor facility. The imaging system establishes new capabilities for beam diagnostics at the Texas Cold Neutron Source (TCNS) for real-time neutron radiography (RTNR) and for neutron computed tomography (NCT) research. The NIS will also be used for other research projects. The system consists of two subsystems as follows: (1) Thomson 9-in. neutron image intensifier (NII) tube sensitive to cold, thermal, and epithermal neutrons, (2) image-processing unit consisting of vidicon camera, two high-resolution monitors, image enhancement and measurement processor, and video printer. The NIS is installed at the cold neutron beam of the TCNS for testing and cold neutron beam diagnostics.
Magnetization transfer contrast (MTC) on fast spin echo (FSE) images was evaluated in normal brain tissue as well as in brain tumors to better understand contrast of FSE images. On multislice FSE images, attenuation of the signal intensity of brain tissue due to MTC is observed. The rate of MTC (MTR) is obtained by comparing with additional single slice images. The effect of signal attenuation is greater on images with smaller interslice gap, larger number of slices, and longer echo train length. MTR of brain tumors is less than that of normal brain tissue. Among them, meningiomas have relatively high MTR, and cavernous malformation has relatively low MTR. Determination of MTC can be easily specified by obtaining multislice and single slice FSE images, and it may help differentiate brain tumors. (author).
This paper introduces a parallel measurement approach for fast infrared-based human temperature screening suitable for use in a large public area. Our key idea is based on the combination of simple image processing algorithms, infrared technology, and human flow management. With this multidisciplinary concept, we arrange as many people as possible in a two-dimensional space in front of a thermal imaging camera and then highlight all human facial areas through simple image filtering, image morphological, and particle analysis processes. In this way, an individual's face in live thermal image can be located and the maximum facial skin temperature can be monitored and displayed. Our experiment shows a measured 1ms processing time in highlighting all human face areas. With a thermal imaging ca...
An iterative phase retrieval algorithm was previously investigated for in-line x-ray phase imaging. Through detailed theoretical analysis and computer simulations, we now discuss the limitations, robustness, and efficiency of the algorithm. The iterative algorithm was proved robust against imaging noise but sensitive to the variations of several system parameters. It is also efficient in terms of calculation time. It was shown that the algorithm can be applied to phase retrieval based on one phase-contrast image and one attenuation image, or two phase-contrast images; in both cases, the two images can be obtained either by one detector in two exposures, or by two detectors in only one exposure as in the dual-detector scheme.
X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more ...
X-ray diffraction enhanced imaging (DEI) is one of X-ray phase-contrast imaging methods, which is applied to inspect internal structures of weakly absorbing low-Z samples. The key problem of the DEI is how to extract phase information which is expressed by refraction-angle images from a series of DEI images measured in different positions of the rocking curve of the analyzer. Three effective extraction methods are presented in this paper: the statistical geometric-optics-approximation method, the maximum refraction-angle method and the Gaussian curve fitting method. They are compared with the existing methods, such as the D. Chapman's geometric optics approximation method and the multiple-images statistical method. A 2D computer simulation experiment is performed to draw comparisons of these methods. The experimental results prove that the above three methods have more precision of ...
Fuji computed radiography (FCR) utilizing imaging plates stimulated by a scanning lazer has been developed in Japan and come to be widely available in diagnostic radiology. This system is advantageous because many processed images can be obtained with a single exposure. However, no reports have been published on the exact conditions necessary under which the FCR image processing method will produce improved visibility of pulmonary abnormal shadows on chest radiographs. In this report, chest FCR images obtained from 50 patients were analyzed, and the best practical image processing conditions were determined for each pathological state. Fundamental analysis was also performed for spatial and contrast resolution with FUNK chart and Burger's phantom using various thickness of acryl plate. Ninety processing images per exposure were analyzed, and the best ...
Fuji computed radiography (FCR) utilizing imaging plates stimulated by a scanning lazer has been developed in Japan and come to be widely available in diagnostic radiology. This system is advantageous because many processed images can be obtained with a single exposure. However, no reports have been published on the exact conditions necessary under which the FCR image processing method will produce improved visibility of pulmonary abnormal shadows on chest radiographs. In this report, chest FCR images obtained from 50 patients were analyzed, and the best practical image processing conditions were determined for each pathological state. Fundamental analysis was also performed for spatial and contrast resolution with FUNK chart and Burger's phantom using various thickness of acryl plate. Ninety processing images per exposure were analyzed, and the best practical ...
The authors have developed a high-sensitivity real-time neutron radiography (NR) system by the use of the low power reactor of Kinki University. The system was constructed with a high efficiency neutron-photon converter, an image intensifier and a SIT TELEVISION camera. Some digital image processing techniques were applied for improving the quality of the real-time neutron images. By the use of this system, dynamic neutron imaging was performed successfully under the condition of a weak neutron field that was about two orders of magnitude lower than that of the standard NR system. The neutron flux, calculated from the fluctuation of the neutron response of the images, was nearly equal to the value measured by the foil activation method. From this fact, the efficiency for the neutron detection of the imaging system was estimated to be almost 100%. For the purpose ...
The authors have developed a high-sensitivity real-time neutron radiography (NR) system by the use of the low power reactor of Kinki University. The system was constructed with a high efficiency neutron-photon converter, an image intensifier and a SIT TELEVISION camera. Some digital image processing techniques were applied for improving the quality of the real-time neutron images. By the use of this system, dynamic neutron imaging was performed successfully under the condition of a weak neutron field that was about two orders of magnitude lower than that of the standard NR system. The neutron flux, calculated from the fluctuation of the neutron response of the images, was nearly equal to the value measured by the foil activation method. From this fact, the efficiency for the neutron detection of the imaging system was estimated to be almost 100%. For the purpose ...
Summary Solid state nuclear track detectors are used to determine the concentration of a particles in the environment. The standard method for assessing exposed detectors involves 2D image analysis. However 3D imaging has the potential to provide additional information relating to angle as well as to differentiate clustered hit sequences and possibly energy of a particles but this could be time consuming. Here we describe a new method for rapid high-resolution 3D imaging of solid state nuclear track detectors. A `LEXT' OLS3100 confocal laser scanning microscope (Olympus Corporation, Tokyo, Japan) was used in confocal mode to successfully obtain 3D image data on four CR-39 plastic detectors. Three-dimensional visualization and image analysis enabled characterization of track features. This ...
Exploding bridgewire (EBW) initiation of high explosives (HE) has been used for many years without a clear understanding of the mechanisms involved. Evidence indicates that the shock pressures produced by the EBW may be insufficient for direct initiation and that the electric field about the wire at the time of burst ionizes the surface of the HE. We hypothesize that the ionization pre-sensitizes the HE so that a weak shock can then initiate a detonation wave. 13 refs., 7 figs.
A generic insensitive fuze train to initiate insensitive high explosives, such as PBXW-124. The insensitive fuze train uses a slapper foil to initiate sub-gram quantities of an explosive, such as HNS-IV or PETN. This small amount of explosive drives a larger metal slapper onto a booster charge of an insensitive explosive, such as UF-TATB. The booster charge initiates a larger charge of an explosive, such as LX-17, which in turn, initiates the insensitive high explosive, such as PBXW-124.
Conventional Radiography, Fuji Computed Radiography (FCR) hardcopy and CRT images were evaluated about the detectability of pulmonary nodule using the chest phantom. Conventional and digitized chest radiographs (FCR) were used, including 45 normal cases and 45 abnormal cases with a variety pulmonary nodule. Observer performance tests were conducted to compare the effects on diagnostic accuracy of Conventional Radiography, FCR hardcopy and CRT images, and diagnostic accuracy was determined with receiver operating characteristic (ROC) analysis. ROC study was performed in which six radiologists were asked to locate nodule on three modalities. Two CRT monitors were used to observed CRT images. The left side CRT monitor was divided into two parts and displayed two images which were done as same image processing as FCR hardcopy. The right side CRT monitor was divided into four parts and ...
Conventional Radiography, Fuji Computed Radiography (FCR) hardcopy and CRT images were evaluated about the detectability of pulmonary nodule using the chest phantom. Conventional and digitized chest radiographs (FCR) were used, including 45 normal cases and 45 abnormal cases with a variety pulmonary nodule. Observer performance tests were conducted to compare the effects on diagnostic accuracy of Conventional Radiography, FCR hardcopy and CRT images, and diagnostic accuracy was determined with receiver operating characteristic (ROC) analysis. ROC study was performed in which six radiologists were asked to locate nodule on three modalities. Two CRT monitors were used to observed CRT images. The left side CRT monitor was divided into two parts and displayed two images which were done as same image processing as FCR hardcopy. The right side CRT monitor was divided into four parts and ...
Power system analysis shows the output from the solar arrays varies as a function .... Each array corresponds to a raw image browse product, which is generated by .... low outgassing, ability to withstand long-term exposure to the space ...
Purpose: The authors have developed a novel technique using an electronic portal imaging device (EPID) to verify the geometrical accuracy of delivery of dose-rate-regulated tracking (DRRT)....Full Text Available
The purpose of this study was to investigate the feasibility of a simple deformable phantom as a QA tool for testing and validation of deformable image registration algorithms. A diagnostic thoracic imaging phantom with a deformable foam insert was used in this study. Small plastic markers were distributed through the foam to create a lattice with a measurable deformation as the ground truth data for all comparisons. The foam was compressed in the superior-inferior direction using a one-dimensional drive stage pushing a flat 'diaphragm' to create deformations similar to those from inhale and exhale states. Images were acquired at different compressions of the foam and the location of every marker was manually identified on each image volume to establish a known deformation field with a known accuracy. The markers were removed digitally from corresponding images prior to ...
Advances in laboratory animal imaging have provided new resources for noninvasive biomedical research. Among these technologies is microcomputed tomography (microCT) which is widely used to obtain high...Full Text Available
Many simulation studies in biomedicine are based on a similar sequence of processing steps, starting from images and running through geometric model generation, assignment of tissue properties, numerical...Full Text Available
To treat or prevent some of the 795,000 annual strokes in the U.S., self-expanding endo-vascular stents deployed under fluoroscopic image guidance are often used. Neuro-interventionalists need...Full Text Available
A single exposure energy subtraction technique with a metal filter and an imaging plate for the Fuji Computed Radiography (FCR) system was developed for dual-energy subtraction radiography (DES) of the chest. By the use of this technique, 206 patients with suspected lung cancer were scanned in the clinical settings. The subtracted images in 200 patients, excluding six with poor image quality, were examined. Soft-tissue images (bone cancelled images) were useful in visualizing abnormality of the airway and nodules lying under the ribs; and bone images (soft-tissue cancelled images) in detecting rib metastases and the presence or absence of calcification in nodules. Additional information was acquired in 21 % (42/200). A single exposure is capable of neglecting motion artifacts. In addition, this technique may be of value in DES, which is ...
A single exposure energy subtraction technique with a metal filter and an imaging plate for the Fuji Computed Radiography (FCR) system was developed for dual-energy subtraction radiography (DES) of the chest. By the use of this technique, 206 patients with suspected lung cancer were scanned in the clinical settings. The subtracted images in 200 patients, excluding six with poor image quality, were examined. Soft-tissue images (bone cancelled images) were useful in visualizing abnormality of the airway and nodules lying under the ribs; and bone images (soft-tissue cancelled images) in detecting rib metastases and the presence or absence of calcification in nodules. Additional information was acquired in 21 % (42/200). A single exposure is capable of neglecting motion artifacts. In addition, this technique may be of value in DES, which is ...
The simple device for scanning image is described. It has much in common with usual TV camera, with an electron beam replaced by an optical one. After the general description of the device, we present a simple experimental illustration.
Papers are presented in the areas of: Medical Technologies; Non-Destructive Evaluation; Applications of Signal/Image Processing; Laser Guide Star and Adaptive Optics; Computational Electromagnetic, Acoustics and Optics; Micro-Impulse Radar Processing; Optical Applications; TANGO Space Shuttle.
This paper presents a new deformable model using both population and patient-specific statistics to segment the prostate from CT images. There are two novelties in the proposed method. First,...Full Text Available
This review presents a summary of existing knowledge regarding the impact of testicular cancer along four broad domains, including romantic and sexual relationships, body image, and fertility....Full Text Available
Motivated by the observation that a retinal fundus image may contain some unique geometric structures within its vascular trees which can be utilized for feature matching, in this paper, we proposed...Full Text Available
ObjectivesWe have developed an image-guided surgery system based on invisible near-infrared (NIR) fluorescent light. Presently, the only clinically-available NIR...Full Text Available
Currently several groups are actively researching the integration of a megavoltage teletherapy unit with magnetic resonance (MR) imaging for real-time image-guided radiotherapy. The use of a...Full Text Available
Voxel-based prescriptions of deliberately non-uniform dose distributions based on molecular imaging, so-called dose painting or theragnostic radiation therapy, require specification of a transformation...Full Text Available
An examination of the noise of polycrystalline silicon thin film transistors, in the context of flat panel x-ray imager development, is reported. The study was conducted in the spirit of exploring...Full Text Available
To investigate the usefulness of a newly developed magnetic resonance (MR) image-guided surgical robotic system for minimally invasive laparoscopic surgery. The system consists of MR image guidance [interactive scan control (ISC) imaging, three-dimensional (3-D) navigation, and preoperative planning], an MR-compatible operating table, and an MR-compatible master-slave surgical manipulator that can enter the MR gantry. Using this system, we performed in vivo experiments with MR image-guided laparoscopic puncture on three pigs. We used a mimic tumor made of agarose gel and with a diameter of approximately 2 cm. All procedures were successfully performed. The operator only advanced the probe along the guidance device of the manipulator, which was adjusted on the basis of the preoperative plan, and punctured the target while maintaining the operative field using robotic forceps. The position of the probe ...
Adaptive radiation therapy (ART) is the incorporation of daily images in the radiotherapy treatment process so that the treatment plan can be evaluated and modified to maximize the amount of radiation...Full Text Available
Cancer immunotherapies can be guided by cellular imaging techniques, which can identify the presence or absence of immune-cell accumulation in the tumor tissue in-vivo and in real time. This...Full Text Available
BackgroundMany three-dimensional (3D) images are routinely collected in biomedical research and a number of digital atlases with associated anatomical and other information have...Full Text Available
This volume contains the proceedings of a symposium entitled In Vivo Imaging of Neurotransmitter Function in Brain, Heart, and Tumors'' held August 24--25, 1990 in Montreal Canada. The six individual papers contained herein are separately abstracted and indexed for the database.
BACKGROUND: Although the importance of lymphatic function is well recognized, the lack of real-time imaging modalities limits our understanding of its role in many diseases. In a phase...Full Text Available
Background and Objectives:Sound enamel manifests peak transparency in the near-IR (NIR) at 1310-nm, therefore the near-IR is ideally suited for high contrast imaging...Full Text Available
Objective: To investigate the relationship between exposure dose and image quality for a direct digital radiography system and to determine the optimum exposure parameters for pelvic examination. Methods: A contrast-detail phantom CDRAD2.0 was exposed to different doses and the IQF of phantom images were calculated. The optimum exposure parameters were determined by ANOVA and SNK analysis. The image of an anthropomorphic phantom taken with optimized exposure parameters was verified using CEC image criteria. Results: The IQF of the images of CDRAD2.0 phantom was significantly different for different doses, as the exposure dose was greater than 0.61 mGy. The IQFs have no difference for different dose groups. The image quality between this optimized exposure dose and conventional exposure dose not was significantly different. Conclusion: The ...
RATIONALE AND OBJECTIVESNon-invasive longitudinal imaging of tumor vasculature could provide new insights into the development of solid tumors, facilitating efficient...Full Text Available
Bone metastases of an Ewing's sarcoma were detected by magnetic resonance imaging (MRI), when bone scan, CT and plain films were still normal. This is due to the ability of MRI to detect intramedullary metastases before involvement of the cortex. (Auth.).
The performance of the Lung Imaging Fluorescence Endoscope (LIFE) system was compared with conventional bronchoscopy in 158 patients: 68 patients with invasive cancer, 42 patients with abnormal sputum...Full Text Available
A two-channel optical system has been developed to provide spatially resolved simultaneous imaging of singlet molecular oxygen (1O2) phosphorescence and photosensitizer (PS) fluorescence...Full Text Available
The capability to image tissue motion such as blood flow through an endoscope could have many applications in medicine. Spectrally encoded endoscopy (SEE) is a recently introduced technique...Full Text Available
The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the ...
The real-time neutron radiography system of the Kyoto University Reactor (KUR) has been practically applied to penetrating the side plates containing boron burnable poison to test MTR type reactor fuels and to investigation of moving objects. Compared with the image obtained by the direct film method, however, the image from the TV system is in low-contrast and poor-resolution. This paper presents some digital processing approaches to improve the image quality and the neutron TV system is successfully applied to neutron computed tomography (NCT). The frame summing technique is effective to increase the quality of the radiographic image. By using the NTV system in NCT, the projection data are able to be acquired in a single measurement as observing the projection image on a CRT monitor. Two weighting functions based on the Fourier-convolution algorithm are employed to obtain the ...
This paper hopes to share the insights we experienced during designing, building, and running an indexing solution for a large set of radiological reports and images in a production environment for...Full Text Available
We describe a closed-loop brain-computer interface that re-ranks an image database by iterating between user generated 'interest' scores and computer vision generated visual similarity measures. The interest scores are based on decoding the electroencephalographic (EEG) correlates of target detection, attentional shifts and self-monitoring processes, which result from the user paying attention to target images interspersed in rapid serial visual presentation (RSVP) sequences. The highest scored images are passed to a semi-supervised computer vision system that reorganizes the image database accordingly, using a graph-based representation that captures visual similarity between images. The system can either query the user for more information, by adaptively resampling the database to create additional RSVP sequences, or it can converge to a 'done' state. The done state includes a ...
Due to the widespread clinical use of imaging modalities such as ultrasonography, computed tomography and magnetic resonance imaging (MRI), previously unsuspected liver masses are increasingly being...Full Text Available
Functional imaging has revolutionized the neurosciences. In the pain field it has dramatically altered our understanding of how the brain undergoes significant functional, anatomical and chemical changes...Full Text Available
The 3-D spectral-domain optical coherence tomography (SD-OCT) images of the retina often do not reflect the true shape of the retina and are distorted differently along the x and y...Full Text Available
Antisense radiopharmaceuticals could be used to image gene expression in the brain in vivo, should these polar molecules be made transportable through the blood–brain barrier....Full Text Available
A high-speed fiber-based network for the transmission and display of digitized full-motion cardiac images has been developed. Based on Asynchronous Transfer Mode (ATM), the network is scaleable, meaning...Full Text Available
We studied 64 ADHD children patients group (4 {approx} 15 ys, mean age: 8 {+-} 2.6 ys. M/F: 52/12) and 12 normal group (6 {approx} 7 ys, mean age: 9.4 {+-} 3.4 ys, M/F: 8/4) of the brain had been used to analysis of blood flow between normal and ADHD group. For analysis of Children ADHD, we used 12 children's mean brain images and made Template image of SPM99 program. In crease of blood flow (P-value 0.05), the result of normalized images to Template image to offer from SPM99 program, showed significant cluster in inter-Hemispheric and occipital Lobe, in the case of normalized images to children template image, showed inter-hemispheric and parietal lobe.
Software for gel image analysis and base-calling in fluorescence-based sequencing consisting of two primary programs, BaseFinder and GelImager, is described. BaseFinder is a framework for trace processing,...Full Text Available
BackgroundThis in vitro study was conducted to compare the accuracy of two digital image receptors in identifying the location of tip of a fine endodontic file and radiographic apex...Full Text Available
Evaluation of the tolerance limits of X-ray image density accepted by the radiologist shows that for different kinds of examinations, deviations of more than 50% from optimal density lead to images which cannot be used diagnostically. Within this range diagnostic accuracy shows a distinct maximum and diminishes to the limits by 20%. These figures are related to differences in the intensifying factor of screens, sensitivity of films, sensitometric parameters of film processing as well as the doses employed with automatic exposure control devices, measured in clinical conditions. Maximum permissible tolerance limits of the whole imaging system and of its constituents are discussed using the Gaussian law of error addition. (author).
The patch and voxel methods are representative examples of the ways in which multi-slice images may be displayed three-dimensionally by means of computer-graphics. Each of them have advantages and disadvantages and they are mutually complementary. We have developed algorithms for a modified voxel method which incorporates the advantages of the patch methods. We have applied this to the three-dimensional image display of brain tumor with excellent results. The three-dimensional reconstructions used for clinical application in this study were derived from X-ray CT images.
The authors present a guide to the imaging of facial fractures. It is illustrated with conventional radiographs and computed tomograms; the magnetic resonance images primarily suggest the potential applications of this technique. This book provides a source of imaging information on facial trauma. A section on pertinent anatomy is followed by a systematic discussion of the common isolated and complex facial fractures. Perspectives are offered on some commonly seen but infrequently described relationships, such as the tripod-LeFort II association. Consideration is also given to related soft-tissue injuries. The book includes a brief chapter on the type and utility of supplementary imaging studies in the evaluation of those intracranial injuries that may occur concurrently.
Disaster impact modeling and analysis uses huge volumes of image data that are produced immediately following a natural or an anthropogenic disaster event. Rapid damage assessment is the key to time critical decision support in disaster management to better utilize available response resources and accelerate recovery and relief efforts. But exploiting huge volumes of high resolution image data for identifying damaged areas with robust consistency in near real time is a challenging task. In this paper, we present an automated image analysis technique to identify areas of structural damage from high resolution optical satellite data using features based on image content.
There is strong interest in lithium imaging, particularly because of its significance in battery materials. However, light atoms only scatter electrons weakly and atomic resolution direct imaging of lithium has proven difficult. This paper explores theoretically the conditions under which lithium columns can be expected to be directly visible using annular bright field scanning transmission electron microscopy. A detailed discussion is given of the controllable parameters and the conditions most favourable for lithium imaging.
A possible novel application of hard x-ray emitted during laser-plasma interaction was discussed. The authors established an Optical Transform Function to study the joint effect of the spectral distribution and temporal profile of the laser-produced x-ray on x-ray phase imaging. Though the laser-produced x-ray pulse duration is short and incoherent, the analysis confirms that the current x-ray phase imaging theory still holds for laser-produced x-ray phase imaging
Cross-sectional imaging has revolutionised the radiological diagnosis of pleural collections. Not only can the precise location and volume of a pleural effusion be established, but also features specific for the aetiology of the effusion can be demonstrated. Increasingly, radiologists are called upon to perform image-guided biopsies, aspirations and small bore chest drain placement, all of which have been shown to be safe and efficacious. Pneumothoraces occurring due to acute trauma and in an intensive care setting can also benefit from radiological input, both in terms of diagnosis and image-guided treatment. (orig.)
Multitemporal TM images are used to collect information about the extension and variation of water influx subsidence in coal district in order to provide a reference for the harnessing and utilization of water influx subsidence. The multitemporal TM images are used as a blended data group for the analysis of the principal components to reflect the expanding water influx subsidence in the past years. Because of the differences in the environment and imaging condition, 'unitary' order is used to enhance the 'coherence' and 'comparability' of the original TM images. 5 refs., 4 figs., 2 tabs.
/sup 99m/Tc biliary imaging was performed on a 34-year-old woman who was being investigated for suspected cholelithiasis. A left-sided liver was detected. On subsequent radionuclide imaging, partial visceral situs inversus and asplenia were demonstrated. Extensive roentgenographic investigation, ECG, echocardiogram, and laparotomy confirmed the radionuclide findings. Asplenia syndrome may exist without cardiovascular abnormalities and thus be undiscovered. Radionuclide imaging is important in the diagnosis of this syndrome.
We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes.
The aim of this work is the implantation and characterization of a neutron radiography system that uses an electronic device for attainment of images in real time, for its implementation in the nuclear research reactor Argonauta at IEN/CNEN (Nuclear Engineering Institute of the Brazilian Nuclear Energy Commission). The Electronic Imaging System in Real Time is composed by a scintillator screen for neutron, a video camera (CCD), a digital plate and a computer with specific computational programs for digital processing of the images. The System in installed real time is apt to carry through neutron radiography inspections of static and dynamic events of several types of samples. (author)
Peripheral primitive neuroectodermal tumors (peripheral PNETs) are rare in the abdomen. We report the imaging findings of four peripheral PNETs arising in the abdomen. Three were ill-demarcated tumors and one was a well-demarcated tumor, with extensive local invasion and lymph node metastasis in two cases, respectively. The tumors are of inhomogeneous attenuation and heterogeneous enhancement after intravenous administration of contrast materials. Although their imaging manifestations cannot distinguish them from other sarcomas, recognition of these imaging features may be helpful in suggesting the possibility of peripheral PNETs in some cases.
A carbon nanotube (CNT) tip, which assembled on the sharp end of a Si tip by dielectrophoresis, was structurally modified using focused ion beam (FIB). We described the imaging characterization of the FIB-modified CNT tip in noncontact AFM mode in terms of wear, deep trench accessibility, and imaging resolution. Compared to a conventional Si tip, the FIB-modified CNT tip was superior, especially for prolonged scanning over 10 h. We conclude that modified CNT tips have the potential to obtain high-quality images of nanoscale structures.
... is the sensor that converts incoming photons into a ... with CCD foundries to acquire such a sensor. ... 2007, Journal of Spacecraft and Rockets, 44, 910 ...
High (spatial) resolution imaging detectors for X-ray astronomy were developed. Several prototype detectors built and their feasibility and baseline performance were assessed. Two of these detector types are proposed for investigations on the advanced X-ray astrophysics facility (AXAF). The readiness of a new X-ray imaging system, the charge coupled device (CCD) imaging specctrometer is outlined, and state of the art performance parameters for microchannel plate (MCP) and CCD detectors are measured. Laboratory facilities and procedures for coating MCP are developed general high resolution imagery systems are analyzed.
High (spatial) resolution imaging detectors for X-ray astronomy were developed. Several prototype detectors built and their feasibility and baseline performance were assessed. Two of these detector types are proposed for investigations on the advanced X-ray astrophysics facility (AXAF). The readiness of a new X-ray imaging system, the charge coupled device (CCD) imaging specctrometer is outlined, and state of the art performance parameters for microchannel plate (MCP) and CCD detectors are measured. Laboratory facilities and procedures for coating MCP are developed general high resolution imagery systems are analyzed.
ARIES Baker-Nunn Schmidt telescope project is converting a Baker-Nunn satellite tracking camera for Astronomical research. Original Baker-Nunn camera produces an extremely large (5X30 degree) curved focal plane at the prime focus for photographic imaging. We present here the re-designing of the camera produces a wide (4 X 4 degree) flat field of view for CCD imaging observations, which have many scientific potentials in Astronomy. Imaging performance of the CCD camera is also estimated.
This book constitutes the thoroughly refereed post proceedings of the international workshop Computer Vision Approaches to Medical Image Analysis, CVAMIA 2006, held in Graz, Austria in May 2006 as a satellite event of the 9th European Conference on Computer Vision, EECV 2006. The 10 revised full papers and 11 revised poster papers presented together with 1 invited talk were carefully reviewed and selected from 38 submissions. The papers are organized in topical sections on clinical applications, image registration, image segmentation and analysis, and the poster session. (orig.)
Eighty-seven subtraction images of FCR were compared with subtraction images of conventional angiography. Although FCR images with reduced exposure dose (25 % of regular dose) and with diluted contrast material (150 mgI/ml, 50 % of usual concentration) were slightly inferior to the images of conventional angiography, most clinically important vessels were adequately visualized. As FCR has wider dynamic range and higher contrast resolution than conventional angiography, FCR may take over conventional angiography. (author).
The Digital Raster Graphic (DRG) is a raster image of a scanned USGS topographic map including the collar information, georeferenced to the UTM grid....
We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes. (orig.).
We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes.
... order probabilistic modelling, multisensor monitoring of ... object recognition, image registration and point ... of the Berkeley Continuous Media Toolkit. ...
Purpose: To determine if involved field radiation (IF) is equivalent to standard whole bone radiation (SF) in local tumor control; to establish patterns of failure following treatment; and to determine response, event-free survival (EFS), and overall survival rates from multidisciplinary therapy in Ewing's sarcoma. Methods and Materials: Between 1983 and 1988, 184 children with Ewing's sarcoma were enrolled onto Pediatric Oncology Group 8346 (POG 8346). A total of 178 (97%) met eligibility criteria; 6 had pathology other than Ewing's sarcoma. Induction chemotherapy of cyclophosphamide/doxorubicin (adriamycin )(C/A) x 12 weeks was followed by local treatment either surgery or radiation therapy and C/A, dactinomycin, and vincristine for 50 weeks. Resection was advised for patients with small primary tumors if accomplished without functional loss. Forty patients were randomized to receive SF, whole bone radiation to 39.6 Gy plus a 16.2 Gy boost (total 55.8 Gy) or IF to 55.8 Gy, and the ...
In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).
In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).
A series of real-time, neutron radiography, experiments are ongoing at the Texas A and M Nuclear Science Center Reactor (NSCR). These tests determine the resolving capabilities for radiographic imaging of two phase water and air flow regimes through small diameter flow channels. Though both film and video radiographic imaging is available, the real-time video imaging was selected to capture the dynamic flow patterns with results that continue to improve. (author)
Parathyroid imaging based on the principle of differential uptakes of Tc-99m and T1-201 in the anterior neck to localize parathyroid (PT) disease has been reported with widely varying results. To evaluate the usefulness of this method, we have performed PT imaging on 47 patients prior to exploratory surgery for PT disease. Using pinhole collimation and digital acquisition, a 50k count image of the thyroid was obtained 20 minutes after injection of 1mCi99m Tc-pertechnetate. Then a lmCi dose of Tl-201 chloride was injected and a series of images acquired for 30 minutes at 30 sec/image. Raw data was spatially filtered and normalized by summing sufficient T1-201 images to equal the Tc-99m image scale of maximum cts/pixel. Image subtraction (Tl-Tc) gave the final PT image. Of 10 pts who had previous neck ...
Results of the evaluation of the scattered radiation effect on the image of defects in examined products are given. The formula is suggested which characterizes the image of defects on a scintillation screen as well as accumulation factors are calculated by the Monte-Carlo method. Values of fluctuations of absorbed energy in the screen used for the evaluation of sensitivity are experimentally obtained. The effect of high-energy bremsstrahlung on the defect detection is analyzed.
For comparison of radiation exposure and risk in different diagnostic procedures for adults and children dose measurements and calculations of organs with special risk were carried out. Parameters of image formation influencing image quality as well as of exposure concerning infants and children are recorded and discussed as to radiation exposure and protection. Conclusions are drawn with respect to systems of image formation and to standards of examination and quality assurance.
The quantitative imaging of a phase object using 16 keV x-rays is reported. The theoretical basis of the techniques is presented along with its implementation using a synchrotron x-ray source. It is found that the phase image is in quantitative agreement with independent measurements of the object. 13 refs., 5 figs.
In this article, the authors recall the factors apt to influence image quality in NMR Imaging and present the european works that have been developed in MRIQA to set 5 quality assurance tests: EUROSPIN 1 to 5.
Sponsored by the Defense Advanced Research Projects Agency the Image Understanding Workshop is a forum for the presentation of new research in vision, image analysis, and geometric modeling. Leading scientists present overviews of projects underway at major universities and corporate research sites, as well as results of individual work. The 1987 volume contains 94 articles and technical reports in two volumes.
The characteristics of real-time neutron radiography are described briefly in this paper, and the acquirement of neutron flux, the selection of convertor and the structure of the twilight imaging system and the image-sampling and image-processing system in SPRR-300 reactor are also analyzed detailedly. The experimental result of real-time neutron radiograph is too analyzed in this paper
This manuscript reviews some of the more controversial dose-related issues in cardiac CT imaging. Discussion covers the relative merits of cardiac CT versus MR, advantages and concerns regarding gated versus nongated cardiac CT and advantages and concerns regarding the use of breast shields in girls undergoing cardiac CT imaging.
Positron emission tomography (PET) and magnetic resonance imaging (MRI) studies were performed on a case of neuro-Behcet's syndrome. In accordance with the clinical signs, FDG PET (using /sup 18/F-labeled 2-F-2'-desoxyglucose) revealed disseminated storage defects in the cerebrum and cerebellum. Focal regions of enhanced signal intensity were demonstrated in the parietal white matter of the cerebrum in T2-weighted images and in the brain stem by MRI. (orig.).
The image processing system for the dynamic neutron radiography has been developed. It is based on the hardware subset, composed by the method of the pipe-line and use of algorithm of local statistics. The processing speed per one pixel is shorter than 100 n sec and video-rate processing can be executed on it. Some image processes for improving the quality of the real-time neutron image, noise reduction and contrast stretching would be attempted by the use of this system. (author).
An analyzer-based X-ray phase-contrast imaging (ABI) setup has been mounted at the Brazilian Synchrotron Light Laboratory (LNLS) for multiple imaging radiography (MIR) purposes. The algorithm employed for treating the MIR data collected at LNLS is described, and its reliability in extracting the distinct types of contrast that can be obtained with MIR is demonstrated by analyzing a test sample (thin polyamide wire). As a practical application, the possibility of studying ophthalmic tissues, corneal sequestra in this case, via MIR is investigated.
A thermal neutron imaging facility for computed tomography and real-time neutron radiography is being developed at the University of Texas at Austin. The TRIGA reactor is a graphite-reflected Mark It pool-type research reactor. The neutron imaging facility will use beam port, which is at one end of a through part. Monte Carlo calculations were used to design the neutron collimator for this facility.
The "1"3"1I-labelled monoclonal antibodies 791T/36 and 79IT/36 Fab fragments have been evaluated in the imaging of patients with colorectal cancer, with benign colorectal tumours, and with malignant tumours of other parts of the gastrointestinal tract. The results of clinical imaging have been carefully correlated with clinical findings and direct measurement of the preferential uptake of antibody by the tumours. (UK).
A pulsed field gradient spin echo sequence has been incorporated in a nuclear magnetic resonance (NMR) imaging experiment to provide an image contrast dependent on local molecular self-diffusion. The...Full Text Available
We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.).
The clinical feasibility of using interventional examination techniques was tested with an equipment combining fluoroscopy and MR imaging. This hybrid system showed to be of advantage in a great number of interventional examinations. The 1.5 Tesla magnet proved to be superior to open MR scanning systems in terms of image quality and scanning times. (orig.).
The authors report an extension of the source imaging method for analyzing three-dimensional sources from three-dimensional correlations. The technique consists of expanding the correlation data and the underlying source function in spherical harmonics and inverting the resulting system of one-dimensional integral equations. With this strategy, they can image the source function quickly, even with the extremely large data sets common in three-dimensional analyses.
We have investigated the detection performance of GaAs detectors made with different thickness and contact geometries. A comparison is made between these detection capabilities and the imaging requirements for the following medical applications: digital mammography, digital chest radiography and nuclear medicine. Experimental results and preliminary images are presented and discussed. (author)
In this study, an apparatus suitable to photoacoustic (PA) imaging to measure blood-analysis and urinalysis is fabricated and its measurement scheme has been established for the first time. The PA imaging of urinalysis test strip, blood sugar test strip, and cholesterol test strip is performed. A calibration curve of PA measurement is obtained for a urine test strip. The detectivity is better than that obtained by an eye-measurement.
Our goal is to determine an optimized image-guided setup by comparing setup errors determined by two-dimensional (2D) and three-dimensional (3D) image guidance for head and neck cancer (HNC)...Full Text Available
A real-time two-dimensional void fraction distribution measurement of gas-liquid two-phase flow was carried out by real-time neutron radiography and real-time image processing. The JRR-3M real-time thermal neutron radiography system and a Musashi dynamic image processing system were used. Image processing methods to calculate two-dimensional and cross-sectional void fraction distributions were proposed. The void fraction distribution was calculated by non-linear processing of the neutron radiography image and displayed by pseudo-color in real-time. A simple gas-liquid two-phase flow induced by injecting gas through needles at the bottom of water pool in a rectangular vessel was tested. (orig.).
MR images of steady and pulsatile disturbed flow, obtained with use of flow-compensated spin-echo (SE) and cine pulse sequences, revealed excellent flow visualization in three dimensions. Phantoms, built from molds of actual blood vessels, reproduced laminar, disturbed, or turbulent flow. Video recording (VR), performed under conditions equivalent to those of the MR experiments, showed separation zones identical to those seen on SE images. Pulsatile flow studies showed complex patterns of vortical flow on cine images and VR. Varying pulse sequence details changed contrast but not flow patterns. The validation of MR observations by VR has implications for clinical cine imaging and low abnormal signals observed on MR angiograms.
VSP reverse-time migration is a well adaptable wave equation migration method. Its control equation not only describes all-direction propagation of seismic wave but also removes interbed multiples. Clearbout's image principle is generalized to determine image conditions, real VSP data are used to determine boundary condition, and two way reflection-free wave equation is solved by making reverse-time extrapolation. In each step of extrapolation, the migration value at relevant image point is obtained by using the image condition. The complete migration of a seismic section is achieved when reverse-time extrapolation reaches the minimum image time. In this paper it is proved theoretically and practically that this method is applicable to any velocity variation and makes the migrated section have both good resolution and high S/N ratio. Besides, this method results in high ...
The advent, in the near future, of compact X-ray sources like Thomson Back-Scattering (TBS) will allow the clinical application of advanced X-ray imaging techniques, such as phase contrast, with higher sensitivity and lower impact in terms of dose delivery. In this work, we theoretically investigated the possibility of using such sources for phase contrast imaging of micro-calcifications included in a breast tissue. In our study we analyzed the phase and amplitude distribution of the TBS source and we showed that this source can be used for phase contrast imaging since the source coherence at the sample position is sufficiently high for achieving good contrast and micrometer spatial resolution. Indeed the spatial coherence of a TBS source is closer to that of a synchrotron radiation source, and much better than that of a laboratory source. Moreover, we showed the advantages of phase imaging with respect ...
The auroras on Jupiter and Saturn can be studied with a high sensitivity and resolution by the Hubble Space Telescope (HST) ultraviolet (UV) and far-ultraviolet (FUV) Space Telescope spectrograph (STIS) and Advanced Camera for Surveys (ACS) instruments. We present results of automatic detection and segmentation of Jupiter's auroral emissions as observed by HST ACS instrument with VOronoi Image SEgmentation (VOISE). VOISE is a dynamic algorithm for partitioning the underlying pixel grid of an image into regions according to a prescribed homogeneity criterion. The algorithm consists of an iterative procedure that dynamically constructs a tessellation of the image plane based on a Voronoi Diagram, until the intensity of the underlying image within each region is classified as homogeneous. The computed tessellations allow the extraction of quantitative information about the auroral features such as mean ...
Two peptide ligands conjugated adenine, [9-N-(tritylmercapto acetyl diglycyl aminoethyl) adenine, Tr-MAG_2-Ade] and [9-N-(tritylmercapto acetyl triglycyl aminoethyl) adenine, Tr-MAG3-Ade], are synthesized and labeled with "9"9"mTc by directly labeling method. The stability of "9"9"mTc-MAG_2- adenine and "9"9"mTc-MAG_3-adenine in vitro is measured. The uptake radios of tumor to muscle at 3h post-injection are 5.70 and 4.92, respectively. The biodistribution and scintigraphic imaging studies show that the two complexes have high localization in tumor and high contrasted tumor images can be obtained, which suggest their potential utility as tumor imaging agents. But the high radioactivity of abdomen could prevent the tumor imaging in this area. (author)
In a fluoroscopic imaging system, image quality and patient dose are both affected by the optical system linking the image intensifier with the video camera. The effect on patient exposure of increasing the optical iris aperture size over that required for other procedures performed on the same imaging system was investigated for the air-contrast barium enema examination. Using a large-area transmission ionisation chamber to monitor the Roentgen-area-product of entrance exposure, a decrease in fluoroscopic radiation of greater than 50% was clinically documented for a fluoroscopic system utilising kVp and mA variable automatic brightness control. For this iris change, the video image was of acceptable quality for positioning and monitoring the patient, and no deleterious effect was detected in the conduct of the air-contrast exam. The availability of a variable-sized ...
A photoacoustic (PA) imaging system based on an ultrasonic Fresnel zone plate (FZP) transducer is developed for the purpose of imaging biological tissue. This FZP transducer has a two-zone negative zone plate piezoelectric material pattern, and an optical fibre is integrated with the transducer on the symmetric axis of the zone plates to deliver laser pulses to the sample. The focal characteristic of the FZP transducer is analysed by theoretical prediction and experimental measurement, and the measured results are in good agreement with the predicted results. The limited-field back-projection deconvolution algorithm combined with the coherence-factor weighting technique is used to reconstruct the optical absorption distribution. The experiments were performed with phantoms and the blood vessels of chicken embryo chorioallantoic membrane. The results demonstrate that PA imaging using the FZP transducer has the ability to ...
Positron emission tomography (PET) is the gold standard for non-invasive assessment of myocardial viability and allows accurate detection of coronary artery disease by assessment of myocardial perfusion. Magnetic resonance imaging (MRI) provides high resolution anatomical images that allow accurate evaluation of ventricular structure and function together with detection of myocardial infarction. Potential hybrid PET/MR tomography may potentially facilitate the combination of information from these imaging modalities in cardiology. Furthermore, the combination of anatomical MRI images with the high sensitivity of PET for detecting molecular targets may extent the application of these modalities to the characterization of atherosclerotic plaques and to the evaluation of angiogenetic or stem cell therapies, for example. This article reviews studies using MRI and PET in parallel to compare their performance ...
An algorithm for creating synthetic telescope images of Smoothed Particle Hydrodynamics (SPH) density fields is presented, which utilises the adaptive nature of the SPH formalism in full. The imaging process uses Monte Carlo Radiative Transfer (MCRT) methods to model the scattering and absorption of photon packets in the density field, which then exit the system and are captured on a pixelated image plane, creating a 2D image (or a 3D datacube, if the photons are also binned by their wavelength). The algorithm is implemented on the density field directly: no gridding of the field is required, allowing the density field to be described to an identical level of accuracy as the simulations that generated it. Some applications of the method to star and planet formation simulations are presented to illustrate the advantages of this new technique, and suggestions as to how this framework could support a ...
The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might ...
We propose a combined migration velocity analysis and imaging method based on Kirchhoff integral migration and reverse time migration, using the residual curvature analysis and layer stripping strategy to build the velocity model. This method improves the image resolution of Kirchhoff integral migration and reduces the computations of the reverse time migration. It combines the advantages of efficiency and accuracy of the two migration methods. Its application in tunnel seismic prediction shows good results. Numerical experiments show that the imaging results of reverse time migration are better than the imaging results of Kirchhoff integral migration in many aspects of tunnel prediction. Field data show that this method has efficient computations and can establish a reasonable velocity model and a high quality imaging section. Combination with geological information can make an ...
In the autonomous unmanned helicopter landing problem, the position of the unmanned helicopter relative to the landmark is very important. A camera carried on the unmanned helicopter can capture an image of the landmark. In earlier research, it was reported that the camera position could be estimated by features extracted from the landmark image. However, it is necessary that the landmark image should be complete, or with only slight deficiencies, in order for this estimation process to be possible. In this article, we report on an innovative design for an estimation made from a camera position giving an incomplete single image of the landmark. An adaptive neuro-fuzzy inference system (ANFIS) is used to construct the mapping relation between the features of complete and incomplete landmark...
We introduce a multi-layered image cache system that is designed to work with a pool of rendering engines to facilitate an interactive, frameless, asynchronous rendering environment. Our system decouples the rendering from the display of imagery. Therefore, it decouples render frequency and resolution from display frequency and resolution, and allows asynchronous transmission of imagery instead of the compute/send cycle of standard parallel systems. It also allows local, incremental refinement of imagery without requiring all imagery to be re-rendered. Images are placed in fixed position in camera (vs. world) space to eliminate occlusion artifacts. Display quality is improved by increasing the number of images. Interactivity is improved by decreasing the number of images.
The neutron transmutation doping (NTD) method was applied to the initially p-type silicon in order to extend the NTD applications at HANARO. The relationship between the irradiation neutron fluence and the final resistivity of the initially p-type silicon material was investigated. The proportional constant between the neutron fluence and the resistivity was determined to be 2.3473x10{sup 19} n {omega} cm{sup -1}. The deviation of the final resistivity from the target for almost all the irradiation results of the initially p-type silicon ingots was at a range from -5% to 2%. In addition, the burn-up effect of the boron impurities, the residual {sup 32}P activity and the effect of the compensation characteristics for the initially p-type silicon were studied. Conclusively, the practical methodology to perform the neutron transmutation doping of the initially p-type silicon ingot was ...
The neutron transmutation doping (NTD) method was applied to the initially p-type silicon in order to extend the NTD applications at HANARO. The relationship between the irradiation neutron fluence and the final resistivity of the initially p-type silicon material was investigated. The proportional constant between the neutron fluence and the resistivity was determined to be 2.3473x1019 n ? cm-1. The deviation of the final resistivity from the target for almost all the irradiation results of the initially p-type silicon ingots was at a range from -5% to 2%. In addition, the burn-up effect of the boron impurities, the residual 32P activity and the effect of the compensation characteristics for the initially p-type silicon were studied. Conclusively, the practical methodology to perform the neutron transmutation doping of the initially p-type silicon ingot was established.
Identification of factors that determine individual patient risk for recurrence and progression in superficial papillary carcinoma of the bladder is a subject of extensive research as it would be a major outcome in patient management. It has been well recognized that traditional prognostic markers as tumor grade and stage are not accurate enough in predicting biological behavior. A large number of markers have been investigated as potential prognostic factors and relatively few can help in predicting outcome. Material and Methods: Forty-nine cases undergoing complete transurethral resection for primary superficial papillary transitional cell carcinoma were subjected to clinicopathologic evaluation as well as immunohistochemical staining for p53, bcl-2, cytokeratin 20 and Ki-67. The CAS-200 image analyzer was used to estimate the Ki-67 labeling index. Results: Recurrence was observed in 19 cases (38.8%) and progression in 7 cases (14.3%) with a median followup of 49 ...