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Sample records for previous functional imaging

  1. Executive Function in Previously Institutionalized Children.

    Science.gov (United States)

    Merz, Emily C; Harlé, Katia M; Noble, Kimberly G; McCall, Robert B

    2016-06-01

    In studies of children adopted from institutions, being raised in an institution has been associated consistently with an increased risk of persistent cognitive, academic, and social-emotional problems. These findings raise questions about the neurocognitive mechanisms that contribute to these negative outcomes. Theory and models based on studies of animals indicate that development of the prefrontal cortex (PFC) and executive function (EF) may be particularly susceptible to environmental influences during early childhood. In this article, we review recent studies of postinstitutionalized children that examined EF components such as inhibitory control, working memory, shifting, and planning. We then describe emerging research on the structure and function of the PFC. Converging evidence suggests both EF difficulties and alterations in development of the PFC following early institutionalization. We conclude by discussing possible explanations for these findings and implications for prevention and intervention, and by offering suggestions for ongoing research.

  2. Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Voos, Avery; Pelphrey, Kevin

    2013-01-01

    Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

  3. Functional brain imaging

    International Nuclear Information System (INIS)

    Frackowiak, R.S.J.

    1996-01-01

    Major advances in computing and mathematics, especially the back-projection algorithms introduced for reconstructing tomographic data obtained by non-invasive imaging, have led to new opportunities for the study of the structure, function and structure-function relationships of the human brain. Functional neuro-imaging methods fall, broadly, into two classes. Those methods that provide information about synaptic activity and those that provide information of a chemical or neurochemical nature. The former methods usually depend on some form of perfusion mapping because of the tight coupling between local glucose metabolism and blood flow in the brain at rest and at times of altered synaptic activity. The latter methods depend on identification of a chemical species of interest by using an appropriate radioligand, or by using the intrinsic magnetic properties of a compound. (author)

  4. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...... a reduced blood oxygenation level dependent (BOLD) signal increase and a greater asymmetry in the visual cortex, compared with controls. The volume of visual cortical activation was significantly correlated to the result of the contrast sensitivity test. The BOLD signal increase correlated significantly......The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...

  5. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...... to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input......The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...

  6. Low-dose computed tomography image restoration using previous normal-dose scan

    Science.gov (United States)

    Ma, Jianhua; Huang, Jing; Feng, Qianjin; Zhang, Hua; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan

    2011-01-01

    Purpose: In current computed tomography (CT) examinations, the associated x-ray radiation dose is of a significant concern to patients and operators. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) or kVp parameter (or delivering less x-ray energy to the body) as low as reasonably achievable in data acquisition. However, lowering the mAs parameter will unavoidably increase data noise and the noise would propagate into the CT image if no adequate noise control is applied during image reconstruction. Since a normal-dose high diagnostic CT image scanned previously may be available in some clinical applications, such as CT perfusion imaging and CT angiography (CTA), this paper presents an innovative way to utilize the normal-dose scan as a priori information to induce signal restoration of the current low-dose CT image series.Methods: Unlike conventional local operations on neighboring image voxels, nonlocal means (NLM) algorithm utilizes the redundancy of information across the whole image. This paper adapts the NLM to utilize the redundancy of information in the previous normal-dose scan and further exploits ways to optimize the nonlocal weights for low-dose image restoration in the NLM framework. The resulting algorithm is called the previous normal-dose scan induced nonlocal means (ndiNLM). Because of the optimized nature of nonlocal weights calculation, the ndiNLM algorithm does not depend heavily on image registration between the current low-dose and the previous normal-dose CT scans. Furthermore, the smoothing parameter involved in the ndiNLM algorithm can be adaptively estimated based on the image noise relationship between the current low-dose and the previous normal-dose scanning protocols.Results: Qualitative and quantitative evaluations were carried out on a physical phantom as well as clinical abdominal and brain perfusion CT scans in terms of accuracy and resolution properties. The gain by the use of

  7. Neurophysiology of functional imaging.

    Science.gov (United States)

    van Eijsden, Pieter; Hyder, Fahmeed; Rothman, Douglas L; Shulman, Robert G

    2009-05-01

    The successes of PET and fMRI in non-invasively localizing sensory functions had encouraged efforts to transform the subjective concepts of cognitive psychology into objective physical measures. The assumption was that mental functions could be decomposed into non-overlapping, context-independent modules that are operated on by separable areas of a computer-like brain. The failures of cognitive modularity and of a very localized phrenology are generally, but not universally, accepted; but in their place, and usually not distinguished from the original revolutionary hopes of clarification, experimental results are being interpreted in terms of rather flexible definitions of both cognitive concepts and the degree of localization. In an alternative approach, we have connected fMRI, (13)C MRS, and electrophysiology measurements of brain energy to connect with observable properties of mental life (i.e., awareness). We illustrate this approach with a sensory stimulation experiment; the degree of localization found in BOLD signals was related to the global energy of the brain which, when manipulated by anesthetics, affected the degree of awareness. The influence of brain energy upon functional imaging maps is changing the interpretations of neuroimaging experiments, from psychological concepts generating computer-like responses to empirical responses dominated by the high brain energy and signaling at rest. In our view "baseline" is an operational term, an adjective that defines a property of a state of the system before it is perturbed by a stimulus. Given the dependence of observable psychological properties upon the "baseline" energy, we believe that it is unnecessarily limiting to define a particular state as the baseline.

  8. [Functional imaging of pain].

    Science.gov (United States)

    Peyron, Roland

    2014-01-01

    In this review, we summarize the contribution of functional imaging to the question of nociception in humans. In the beginning of the 90's, brain areas supposed to be involved in physiological pain processes essentially concerned the primary somatosensory area (SI), thalamus, and anterior cingulate cortex. In spite of these a priori hypotheses, the first imaging studies revealed that the main brain areas and those providing the most consistent activations in pain conditions were the insular and the SII cortices, bilaterally. This has been checked with other techniques such as intracerebral recordings of evoked potentials after nociceptive stimulations with laser showing a consistent response in the operculo-insular area whose amplitude correlates with pain intensity. In spite of electrode implantations in other areas of the brain, only rare and inconsistent responses have been found outside the operculo-insular cortices. With electrical stimulation delivered directly in the brain, it has also been shown that stimulation in this area only - and not in other brain areas - was able to elicit a painful sensation. Thus, over the last 15 years, the operculo-insular cortex has been re-discovered as a main area of pain integration, mainly in its sensory and intensity aspects. In neuropathic pain also, these areas have been demonstrated as being abnormally recruited, bilaterally, in response to innocuous stimuli. These results suggest that plastic changes may occur in brain areas that were pre-defined for generating pain sensations. Conversely, when the brain activations concomitant to pain relief were taken in account, a large number of studies pointed out medial prefrontal and rostral cingulate areas as being associated with pain controls. Interestingly, these activations may correlate with the magnitude of pain relief, with the activation of the peri-acqueductal grey (PAG) and, at least in some instances, with the involvement of endogenous opioids. © Société de

  9. Functional imaging of the pancreas

    International Nuclear Information System (INIS)

    Nakanishi, Fumiko

    1984-01-01

    An image processing technique for functional imaging of the pancreas was developed and is here reported. In this paper, clinical efficacy of the technique for detecting pancreatic abnormality is evaluated in comparison with conventional pancreatic scintigraphy and CT. For quantitative evaluation, functional rate, i.e. the rate of normal functioning pancreatic area, was calculated from the functional image and subtraction image. Two hundred and ninety-five cases were studied using this technique. Conventional image had a sensitivity of 65 % and a specificity of 78 %, while the use of functional imaging improved sensitivity to 88 % and specificity to 88 %. The mean functional rate in patients with pancreatic disease was significantly lower (33.3+-24.5 in patients with chronic pancreatitis, 28.1+-26.9 in patients with acute pancreatitis, 43.4+-22.3 in patients with diabetes mellitus, 20.4+-23.4 in patients with pancreatic cancer) than the mean functional rate in cases without pancreatic disease (86.4+-14.2). It is suggested that functional image of the pancreas reflecting pancreatic exocrine function and functional rate is a useful indicator of pancreatic exocrine function. (author)

  10. Brain imaging and brain function

    International Nuclear Information System (INIS)

    Sokoloff, L.

    1985-01-01

    This book is a survey of the applications of imaging studies of regional cerebral blood flow and metabolism to the investigation of neurological and psychiatric disorders. Contributors review imaging techniques and strategies for measuring regional cerebral blood flow and metabolism, for mapping functional neural systems, and for imaging normal brain functions. They then examine the applications of brain imaging techniques to the study of such neurological and psychiatric disorders as: cerebral ischemia; convulsive disorders; cerebral tumors; Huntington's disease; Alzheimer's disease; depression and other mood disorders. A state-of-the-art report on magnetic resonance imaging of the brain and central nervous system rounds out the book's coverage

  11. Study of functional-performance deficits in athletes with previous ankle sprains

    Directory of Open Access Journals (Sweden)

    hamid Babaee

    2008-04-01

    Full Text Available Abstract Background: Despite the importance of functional-performance deficits in athletes with history of ankle sprain few, studies have been carried out in this area. The aim of this research was to study relationship between previous ankle sprains and functional-performance deficits in athletes. Materials and methods: The subjects were 40 professional athletes selected through random sampling among volunteer participants in soccer, basketball, volleyball and handball teams of Lorestan province. The subjects were divided into 2 groups: Injured group (athletes with previous ankle sprains and healthy group (athletes without previous ankle sprains. In this descriptive study we used Functional-performance tests (figure 8 hop test and side hop test to determine ankle deficits and limitations. They participated in figure 8 hop test including hopping in 8 shape course with the length of 5 meters and side hop test including 10 side hop repetitions in course with the length of 30 centimeters. Time were recorded via stopwatch. Results: After data gathering and assessing information distributions, Pearson correlation was used to assess relationships, and independent T test to assess differences between variables. Finally the results showed that there is a significant relationship between previous ankle sprains and functional-performance deficits in the athletes. Conclusion: The athletes who had previous ankle sprains indicated functional-performance deficits more than healthy athletes in completion of mentioned functional-performance tests. The functional-performance tests (figure 8 hop test and side hop test are sensitive and suitable to assess and detect functional-performance deficits in athletes. Therefore we can use the figure 8 hop and side hop tests for goals such as prevention, assessment and rehabilitation of ankle sprains without spending too much money and time.

  12. Neurophysiology of functional imaging

    NARCIS (Netherlands)

    van Eijsden, Pieter; Hyder, Fahmeed; Rothman, Douglas L.; Shulman, Robert G.

    2009-01-01

    The successes of PET and fMRI in non-invasively localizing sensory functions had encouraged efforts to transform the subjective concepts of cognitive psychology into objective physical measures. The assumption was that mental functions could be decomposed into non-overlapping, context-independent

  13. Functional imaging in Huntington disease.

    Science.gov (United States)

    Niethammer, Martin; Eidelberg, David

    2017-01-01

    Functional imaging has been increasingly used in the study of neurodegenerative diseases as such techniques can elucidate neurochemical and functional changes that cannot be captured with structural imaging. Unlike other neurodegenerative diseases, in Huntington disease (HD) genetic testing allows for diagnostic certainty. Thus, the focus has been on understanding the pathophysiogic processes underlying the development of the disease, as well as the identification of potential biomarkers to monitor disease progression, particularly during the presymptomatic stage. These imaging methods have expanded our understanding of HD beyond dopaminergic deficits and striatal cell loss, and have described alteration in widespread networks relating to motor and cognitive symptoms. In this chapter, we review the current literature on radiotracer and functional magnetic resonance imaging relating to HD. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Successful coronary revascularization improves prognosis in patients with previous myocardial infarction and evidence of viable myocardium at thallium-201 imaging

    International Nuclear Information System (INIS)

    Cuocolo, A.; Petretta, M.; Nicolai, E.; Pace, L.; Bonaduce, D.; Salvatore, M.; Trimarco, B.

    1998-01-01

    This study was designed to evaluate the effects of successful revascularization on survival and left ventricular (LV) function in patients with previous myocardial infarction and evidence of dysfunctional but still viable myocardium at rest-redistribution 201 Tl imaging. Seventy-six consecutive patients with LV dysfunction related to previous myocardial infarction and evidence of viable myocardium at rest-redistribution 201 Tl tomography were followed for 17±8 months. LV ejection fraction (EF) was assessed by radionuclide angiography at baseline and after 13±2 months. Thirty-nine patients were revascularized (group A) and 37 treated medically (group B). During the follow-up there were nine cardiac deaths. Survival rate was 97% in group A and 66% in group B (P 2 of the model from 14.1 to 21.9. At follow-up, EF had improved by ≥5% in 16 patients. By multivariate logistic analysis, the extent of viable myocardium was the best predictor of EF improvement and provided additional information to clinical and functional data. The inclusion of revascularization as a variable improved the global χ 2 of the model from 16.8 to 22.5 (P 201 Tl uptake is the strongest predictor of cardiac death in patients after myocardial infarction. Successful revascularization of dysfunctional but viable myocardium improves survival and LVEF in such patients.(orig./MG) (orig.)

  15. The Relationship Between Functional Movement, Balance Deficits, and Previous Injury History in Deploying Marine Warfighters.

    Science.gov (United States)

    de la Motte, Sarah J; Lisman, Peter; Sabatino, Marc; Beutler, Anthony I; OʼConnor, Francis G; Deuster, Patricia A

    2016-06-01

    Screening for primary musculoskeletal injury (MSK-I) is costly and time-consuming. Both the Functional Movement Screen (FMS) and the Y-Balance Test (YBT) have been shown to predict future MSK-I. With a goal of optimizing the efficiency of primary MSK-I screening, we studied associations between performance on the FMS and YBT and whether history of MSK-I influenced FMS and YBT scores. In total, 365 deploying Marines performed the FMS and YBT as prescribed. Composite and individual scores were each categorized as high risk or low risk using published injury thresholds: High-risk FMS included composite scores ≤14 and right-to-left (R/L) asymmetry for Shoulder Mobility, In-Line Lunge, Straight Leg Raise, Hurdle Step, or Rotary Stability. High-risk YBT consisted of anterior, posteromedial, and/or posterolateral R/L differences >4 cm and/or composite differences ≥12 cm. Pearson's χ tests evaluated associations between: (a) all FMS and YBT risk groups and (b) previous MSK-I and all FMS and YBT risk groups. Marines with high-risk FMS were twice as likely to have high-risk YBT posteromedial scores (χ = 10.2, p = 0.001; odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.3-3.2). History of any MSK-I was not associated with high-risk FMS or high-risk YBT. However, previous lower extremity MSK-I was associated with In-Line Lunge asymmetries (χ = 9.8, p = 0.002, OR = 2.2, 95% CI = 1.3-3.6). Overall, we found limited overlap in FMS and YBT risk. Because both methods seem to assess different risk factors for injury, we recommend FMS and YBT continue to be used together in combination with a thorough injury history until their predictive capacities are further established.

  16. Hemosiderin detected by T2*-weighted magnetic resonance imaging in patients with unruptured cerebral aneurysms: indication of previous bleeding?

    Science.gov (United States)

    Takada, Shihomi; Inoue, Takashi; Niizuma, Kuniyasu; Shimizu, Hiroaki; Tominaga, Teiji

    2011-01-01

    Previous bleeding from a cerebral aneurysm indicates a higher risk of rupture. Hemosiderin may be detected during aneurysm surgery or by preoperative imaging sensitive to hemosiderin. The detection of hemosiderin deposits by T(2)*-weighted magnetic resonance (MR) imaging was evaluated in 49 patients with unruptured cerebral aneurysms who underwent open surgery. MR imaging was performed using 3.0 tesla MR scanner. Two sequences of T(2)*-weighted imaging, and proton density images were obtained. Preliminary study in patients with old subarachnoid hemorrhage provided the definitions of likely pathological findings during surgery and on T(2)*-weighted imaging due to previous hemorrhage. Hemosiderin deposits in the subarachnoid space were observed during surgery in 9 of the 49 patients, although no obvious rupture site was detected around the aneurysm wall. Size, presence of bleb, location, and number of aneurysms showed no significant difference between patients with and without hemosiderin deposition. Hypointense areas on T(2)*-weighted imaging were recognized in four patients. The mean size of the aneurysms in these patients was 9.8 mm, significantly larger than those in other patients (p = 0.029). Hemosiderin deposits were observed during surgery in sites close to the lesions on T(2)*-weighted imaging in two of these four patients. Hemosiderin deposits are not rare in patients with unruptured aneurysms, and preoperative T(2)*-weighted imaging can detect such deposits.

  17. Magnetic resonance imaging detection of prostate cancer in men with previous negative prostate biopsy.

    Science.gov (United States)

    Truong, Matthew; Frye, Thomas P

    2017-06-01

    Use of transrectal ultrasound guided systematic prostate biopsy has poor diagnostic accuracy for prostate cancer (PCa) detection. Recently multiparametric MRI (mpMRI) of the prostate and MR/US fusion biopsy has been gaining popularity for men who have previously undergone a negative biopsy. We performed PubMed ® and Web of Science ® searches to identify studies on this subject, particularly focusing on studies consisting of patients who have had at least one previously negative biopsy. Across the literature, when a suspicious lesion is found on mpMRI, MR/US fusion biopsy has consistently demonstrated higher detection rate for any PCa and clinically significant PCa (csPCa) compared to the traditional repeat systematic biopsy (SB) approach. Furthermore, anteriorly located tumors are frequently identified using MR targeted biopsy (TB), suggesting that an MR guided approach allows for increased accuracy for detecting tumors commonly missed by systematic biopsies. We conclude that men with a prior negative biopsy and continued suspicion of PCa should strongly be encouraged to get a prostate mpMRI prior to a repeat biopsy.

  18. Functional brain imaging; Funktionelle Hirnbildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Gizewski, E.R. [Medizinische Universitaet Innsbruck, Universitaetsklinik fuer Neuroradiologie, Innsbruck (Austria)

    2016-02-15

    Functional magnetic resonance imaging (fMRI) is a non-invasive method that has become one of the major tools for understanding human brain function and in recent years has also been developed for clinical applications. Changes in hemodynamic signals correspond to changes in neuronal activity with good spatial and temporal resolution in fMRI. Using high-field MR systems and increasingly dedicated statistics and postprocessing, activated brain areas can be detected and superimposed on anatomical images. Currently, fMRI data are often combined in multimodal imaging, e. g. with diffusion tensor imaging (DTI) sequences. This method is helping to further understand the physiology of cognitive brain processes and is also being used in a number of clinical applications. In addition to the blood oxygenation level-dependent (BOLD) signals, this article deals with the construction of fMRI investigations, selection of paradigms and evaluation in the clinical routine. Clinically, this method is mainly used in the planning of brain surgery, analyzing the location of brain tumors in relation to eloquent brain areas and the lateralization of language processing. As the BOLD signal is dependent on the strength of the magnetic field as well as other limitations, an overview of recent developments is given. Increases of magnetic field strength (7 T), available head coils and advances in MRI analytical methods have led to constant improvement in fMRI signals and experimental design. Especially the depiction of eloquent brain regions can be done easily and quickly and has become an essential part of presurgical planning. (orig.) [German] Mittlerweile ist die funktionelle MRT (fMRT) eine Methode, die nicht mehr nur in der neurowissenschaftlichen Routine verwendet wird. Die fMRT ermoeglicht die nichtinvasive Darstellung der Hirnaktivitaet in guter raeumlicher und zeitlicher Aufloesung unter Ausnutzung der Durchblutungsaenderung aufgrund der erhoehten Nervenzellaktivitaet. Unter

  19. Physiology for the pulmonary functional imager

    International Nuclear Information System (INIS)

    Levin, David L.; Schiebler, Mark L.; Hopkins, Susan R.

    2017-01-01

    Highlights: • An understanding of the relevant pulmonary physiology is crucial to functional lung imaging. • Spatial resolution for pulmonary functional imaging can be substantially less than that used for anatomic/clinical imaging. • Regional deformation of the lung under the influence of gravity significantly affects the measurement of pulmonary perfusion. • Large vessels identified on perfusion imaging do not represent local blood flow. • Pulmonary diseases are typically characterized by a change in the matching of ventilation and perfusion. - Abstract: As pulmonary functional imaging moves beyond the realm of the radiologist and physicist, it is important that imagers have a common language and understanding of the relevant physiology of the lung. This review will focus on key physiological concepts and pitfalls relevant to functional lung imaging.

  20. Clinical application of functional magnetic resonance imaging

    CERN Document Server

    Alwatban, A Z W

    2002-01-01

    The work described in this thesis was carried out at the Magnetic Resonance Centre of the University of Nottingham during the time from May 1998 to April 2001, and is the work of the except where indicated by reference. The main source of signal changes in functional magnetic resonance imaging (fMRJ) is the fluctuation of paramagnetic deoxyhaemoglobin in the venous blood during different states of functional performance. For the work of this thesis, fMRI studies were carried out using a 3 T MR system with an echo planar imaging (EPI) pulse sequence. Hearing research utilising fMRI has been previously reported in normal subjects. Hearing fMRI is normally performed by stimulating the auditory cortex via an acoustic task presentation such as music, tone, etc. However, performing the same research on deaf subjects requires special equipment to be designed to allow direct stimulation of the auditory nerve. In this thesis, a new method of direct electrical stimulation of the auditory nerve is described that uses a ...

  1. Stereotactic imaging in functional neurosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Hirabayashi, Hidehiro

    2012-07-01

    Background: The birth of stereotactic functional neurosurgery in 1947 was to a great extent dependent on the development of ventriculography. The last decades have witnessed a renaissance of functional stereotactic neurosurgery in the treatment of patients with movement disorders. Initially, these procedures were largely based on the same imaging technique that had been used since the birth of this technique, and that is still used in some centers. The introduction of new imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) provided new potentials, but also new challenges for accurate identification and visualisation of the targets in the basal ganglia and the thalamus with an urge to thoroughly evaluate and optimize the stereotactic targeting technique, as well as evaluate accurately in stereotactic space the location and extent of stereotactic Radiofrequency (RF) lesions and the position of deep brain stimulation (DBS) electrodes. Aims: To study the differences between CT and MRI regarding indirect atlas coordinates in thalamic and pallidal procedures and to evaluate and validate visualisation of the pallidum and the subthalamic nucleus in view of direct targeting irrespective of atlas-derived coordinates. Furthermore, to evaluate the contribution of RF parameters on the size of stereotactic lesions, as well as the impact of size and location on clinical outcome. Method: The coordinates in relation to the landmarks of the 3{sup rd} ventricle of the targets in the pallidum and ventrolateral thalamus were compared between CT and MRI in 34 patients. In another 48 patients direct visualization of the pallidum was evaluated and compared to indirect atlas based targeting. The possibility and versatility of visualizing the Subthalamic Nucleus (STN) on short acquisition MRI were evaluated in a multicentre study, and the use of alternative landmarks in identification of the STN was demonstrated in another study. In 46 patients CT and

  2. Stereotactic imaging in functional neurosurgery

    International Nuclear Information System (INIS)

    Hirabayashi, Hidehiro

    2012-01-01

    Background: The birth of stereotactic functional neurosurgery in 1947 was to a great extent dependent on the development of ventriculography. The last decades have witnessed a renaissance of functional stereotactic neurosurgery in the treatment of patients with movement disorders. Initially, these procedures were largely based on the same imaging technique that had been used since the birth of this technique, and that is still used in some centers. The introduction of new imaging modalities such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) provided new potentials, but also new challenges for accurate identification and visualisation of the targets in the basal ganglia and the thalamus with an urge to thoroughly evaluate and optimize the stereotactic targeting technique, as well as evaluate accurately in stereotactic space the location and extent of stereotactic Radiofrequency (RF) lesions and the position of deep brain stimulation (DBS) electrodes. Aims: To study the differences between CT and MRI regarding indirect atlas coordinates in thalamic and pallidal procedures and to evaluate and validate visualisation of the pallidum and the subthalamic nucleus in view of direct targeting irrespective of atlas-derived coordinates. Furthermore, to evaluate the contribution of RF parameters on the size of stereotactic lesions, as well as the impact of size and location on clinical outcome. Method: The coordinates in relation to the landmarks of the 3 rd ventricle of the targets in the pallidum and ventrolateral thalamus were compared between CT and MRI in 34 patients. In another 48 patients direct visualization of the pallidum was evaluated and compared to indirect atlas based targeting. The possibility and versatility of visualizing the Subthalamic Nucleus (STN) on short acquisition MRI were evaluated in a multicentre study, and the use of alternative landmarks in identification of the STN was demonstrated in another study. In 46 patients CT and MRI

  3. Assessment of platelet function in acute ischemic stroke patients previously treated with aspirin.

    Science.gov (United States)

    Lago, Aida; Parkhutik, Vera; Tembl, Jose Ignacio; Vallés, Juana; Santos, Maria Teresa; Moscardó, Antonio

    2014-01-01

    Platelet inhibition measured by platelet function tests could be critical to understand the reasons for early recurrence and to guide therapeutic recommendations. We assess the platelet function during the acute phase of ischemic stroke in patients pretreated with aspirin who continue their treatment with aspirin only, are started on clopidogrel only, or add clopidogrel to aspirin. Sixty-four patients were taking aspirin before the stroke. Depending on the administered antiplatelet, 3 groups were defined: ASA: patients who continued on aspirin orally or intravenous acetylsalicylate of lysine, n = 30; CLO: patients who discontinued aspirin and were started on clopidogrel, n = 16; and ASA + CLO: patients who were prescribed both aspirin and clopidogrel, n = 10. Collagen-induced thromboxane A2 (TXA2) synthesis, ADP (adenosine diphosphate)-induced aggregation, and occlusion time (PF-100) were measured. CLO group only had a marked elevation of TXA2 (17.44 ± 15.62 ng/mL, P = .000) and a shortening of the platelet function analyzer (PFA)-100 closure time (157.13 ± 88 seconds, P = .047) compared with the other 2 groups (ASA: TXA2, .62 ± 1.59 ng/mL; ASA + CLO: TXA2 1.79 ± 4.59 ng/mL). They achieved a small (13%) but significant reduction of ADP-induced aggregation (87.00 ± 23.06 mm, P = .008) compared with the ASA group (102.82 ± 22.38 seconds). Stopping aspirin intake within the first 72 hours of the acute stroke drastically increases TXA2 synthesis. During the same time window, the freshly prescribed clopidogrel manages to reduce the ADP-induced aggregation only slightly (13%). This study offers analytic proof that the common practice of replacing aspirin with clopidogrel does not leave stroke patients fully protected during the first days after an ischemic stroke. Possible solutions could be to preserve aspirin during a few days or to use loading doses of clopidogrel at hospital admission. Copyright © 2014 National Stroke Association. Published by Elsevier Inc

  4. Infrared Imaging System for Studying Brain Function

    Science.gov (United States)

    Mintz, Frederick; Mintz, Frederick; Gunapala, Sarath

    2007-01-01

    A proposed special-purpose infrared imaging system would be a compact, portable, less-expensive alternative to functional magnetic resonance imaging (fMRI) systems heretofore used to study brain function. Whereas a typical fMRI system fills a large room, and must be magnetically isolated, this system would fit into a bicycle helmet. The system would include an assembly that would be mounted inside the padding in a modified bicycle helmet or other suitable headgear. The assembly would include newly designed infrared photodetectors and data-acquisition circuits on integrated-circuit chips on low-thermal-conductivity supports in evacuated housings (see figure) arranged in multiple rows and columns that would define image coordinates. Each housing would be spring-loaded against the wearer s head. The chips would be cooled by a small Stirling Engine mounted contiguous to, but thermally isolated from, the portions of the assembly in thermal contact with the wearer s head. Flexible wires or cables for transmitting data from the aforementioned chips would be routed to an integrated, multichannel transmitter and thence through the top of the assembly to a patch antenna on the outside of the helmet. The multiple streams of data from the infrared-detector chips would be sent to a remote site, where they would be processed, by software, into a three-dimensional display of evoked potentials that would represent firing neuronal bundles and thereby indicate locations of neuronal activity associated with mental or physical activity. The 3D images will be analogous to current fMRI images. The data would also be made available, in real-time, for comparison with data in local or internationally accessible relational databases that already exist in universities and research centers. Hence, this system could be used in research on, and for the diagnosis of response from the wearer s brain to physiological, psychological, and environmental changes in real time. The images would also be

  5. MR imaging of the heart: functional imaging

    International Nuclear Information System (INIS)

    Croisille, P.; Revel, D.

    2000-01-01

    To date, most applications of cardiovascular MRI relate to the evaluation of major vessels rather than the heart itself. However, MRI plays a major role in the evaluation of specific types of cardiovascular pathology, namely intracardiac and paracardiac masses, pericardial disease, and congenital heart disease. In addition, because the visualization of cardiovascular anatomy with MR is non-invasive and permits three-dimensional analysis but also allows functional assessment of the cardiac pump, it is clear that MRI will have a growing and significant impact over the next years. We review some of the technical aspect of cardiac MRI and describe the current and potential clinical and investigative applications of this new methodology. (orig.)

  6. Risk of behavioral and adaptive functioning difficulties in youth with previous and current sleep disordered breathing.

    Science.gov (United States)

    Perfect, Michelle M; Archbold, Kristen; Goodwin, James L; Levine-Donnerstein, Deborah; Quan, Stuart F

    2013-04-01

    To examine the rates of behavioral and adaptive functioning difficulties among youth who never had sleep disordered breathing (SDB), had remitted SDB, had incident SDB, or had persistent SDB; and to determine if there were increased odds of behavioral difficulties among youth with varying SDB histories relative to those who never had SDB. 263 youth had valid polysomnography and neurobehavioral data at two time points approximately 5 years apart from the prospective Tucson Children's Assessment of Sleep Apnea study. Primary outcomes were the behavior assessment scale for children-2(nd) Edition parent report form (BASC-PRF) and Self-Report of Personality (SRP), and the Adaptive Behavior Assessment System-2(nd) Edition (ABAS-2). Compared to those who never had SDB, individuals with persistent SDB had significant odds and met more cutoff scores on the BASC-2-PRF externalizing problems composite (odds ratio [OR] 3.29; 8.92% vs. 35.3%), behavioral symptoms index (OR 6.82; 7.4% vs. 35.3%) and Hyperactivity subscale (OR 6.82; 11.1% vs. 41.2%). Similarly, greater difficulties was seen for the group with persistent SDB (relative to never) on the ABAS-2 social domain (OR 3.39; 22% vs. 50%), and Communication (OR 4.26; 15% vs. 42.9%) and Self-Care subscales (OR = 2.97; 25.2% vs. 50%). Relative to youth who never had SDB, youth who developed SDB at Time 2 had compromised adaptive skills as evidenced by the BASC-2 PRF adaptive behavior composite (OR 3.34; 15.6% vs. 38.1%) and the ABAS-2 general adaptive composite (OR 2.83; 20.5% vs. 42.1%). Youth with current SDB exhibited hyperactivity, attention problems, aggressivity, lower social competency, poorer communication, and/or diminished adaptive skills.

  7. Functional Store Image and Corporate Social Responsibility Image: A Congruity Analysis on Store Loyalty

    OpenAIRE

    Jamaliah Mohd. Yusof; Rosidah Musa; Sofiah Abd. Rahman

    2011-01-01

    With previous studies that examined the importance of functional store image and CSR, this study is aimed at examining their effects in the self-congruity model in influencing store loyalty. In particular, this study developed and tested a structural model in the context of retailing industry on the self-congruity theory. Whilst much of the self-congruity studies have incorporated functional store image, there has been lack of studies that examined social responsibility i...

  8. Previous exercise training has a beneficial effect on renal and cardiovascular function in a model of diabetes.

    Directory of Open Access Journals (Sweden)

    Kleiton Augusto dos Santos Silva

    Full Text Available Exercise training (ET is an important intervention for chronic diseases such as diabetes mellitus (DM. However, it is not known whether previous exercise training intervention alters the physiological and medical complications of these diseases. We investigated the effects of previous ET on the progression of renal disease and cardiovascular autonomic control in rats with streptozotocin (STZ-induced DM. Male Wistar rats were divided into five groups. All groups were followed for 15 weeks. Trained control and trained diabetic rats underwent 10 weeks of exercise training, whereas previously trained diabetic rats underwent 14 weeks of exercise training. Renal function, proteinuria, renal sympathetic nerve activity (RSNA and the echocardiographic parameters autonomic modulation and baroreflex sensitivity (BRS were evaluated. In the previously trained group, the urinary albumin/creatinine ratio was reduced compared with the sedentary diabetic and trained diabetic groups (p<0.05. Additionally, RSNA was normalized in the trained diabetic and previously trained diabetic animals (p<0.05. The ejection fraction was increased in the previously trained diabetic animals compared with the diabetic and trained diabetic groups (p<0.05, and the myocardial performance index was improved in the previously trained diabetic group compared with the diabetic and trained diabetic groups (p<0.05. In addition, the previously trained rats had improved heart rate variability and BRS in the tachycardic response and bradycardic response in relation to the diabetic group (p<0.05. This study demonstrates that previous ET improves the functional damage that affects DM. Additionally, our findings suggest that the development of renal and cardiac dysfunction can be minimized by 4 weeks of ET before the induction of DM by STZ.

  9. Magnetic resonance imaging based functional imaging in paediatric oncology.

    Science.gov (United States)

    Manias, Karen A; Gill, Simrandip K; MacPherson, Lesley; Foster, Katharine; Oates, Adam; Peet, Andrew C

    2017-02-01

    Imaging is central to management of solid tumours in children. Conventional magnetic resonance imaging (MRI) is the standard imaging modality for tumours of the central nervous system (CNS) and limbs and is increasingly used in the abdomen. It provides excellent structural detail, but imparts limited information about tumour type, aggressiveness, metastatic potential or early treatment response. MRI based functional imaging techniques, such as magnetic resonance spectroscopy, diffusion and perfusion weighted imaging, probe tissue properties to provide clinically important information about metabolites, structure and blood flow. This review describes the role of and evidence behind these functional imaging techniques in paediatric oncology and implications for integrating them into routine clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Previous exercise training has a beneficial effect on renal and cardiovascular function in a model of diabetes.

    Science.gov (United States)

    Silva, Kleiton Augusto dos Santos; Luiz, Rafael da Silva; Rampaso, Rodolfo Rosseto; de Abreu, Nayda Parísio; Moreira, Édson Dias; Mostarda, Cristiano Teixeira; De Angelis, Kátia; de Paulo Castro Teixeira, Vicente; Irigoyen, Maria Cláudia; Schor, Nestor

    2012-01-01

    Exercise training (ET) is an important intervention for chronic diseases such as diabetes mellitus (DM). However, it is not known whether previous exercise training intervention alters the physiological and medical complications of these diseases. We investigated the effects of previous ET on the progression of renal disease and cardiovascular autonomic control in rats with streptozotocin (STZ)-induced DM. Male Wistar rats were divided into five groups. All groups were followed for 15 weeks. Trained control and trained diabetic rats underwent 10 weeks of exercise training, whereas previously trained diabetic rats underwent 14 weeks of exercise training. Renal function, proteinuria, renal sympathetic nerve activity (RSNA) and the echocardiographic parameters autonomic modulation and baroreflex sensitivity (BRS) were evaluated. In the previously trained group, the urinary albumin/creatinine ratio was reduced compared with the sedentary diabetic and trained diabetic groups (ptrained diabetic and previously trained diabetic animals (ptrained diabetic animals compared with the diabetic and trained diabetic groups (ptrained diabetic group compared with the diabetic and trained diabetic groups (ptrained rats had improved heart rate variability and BRS in the tachycardic response and bradycardic response in relation to the diabetic group (p<0.05). This study demonstrates that previous ET improves the functional damage that affects DM. Additionally, our findings suggest that the development of renal and cardiac dysfunction can be minimized by 4 weeks of ET before the induction of DM by STZ.

  11. [Functional and molecular imaging of breast tumors].

    Science.gov (United States)

    Pinker, K; Brader, P; Karanikas, G; El-Rabadi, K; Bogner, W; Gruber, S; Reisegger, M; Trattnig, S; Helbich, T H

    2010-11-01

    Molecular imaging is concerned with the presentation, description and quantification of biological and physiological processes at the cellular and molecular level. Most recently molecular imaging has started to become established in breast diagnostics. This review article will give an overview of procedures which are either in the preclinical development stage or which have already become clinically established. Molecular nuclear medicine breast imaging (breast-specific gamma imaging [BSGI] and positron emission mammography [PEM]) together with specific radiotracers and contrast media will be discussed. The possibilities for magnetic resonance imaging in functional (DWI) and metabolic (MRSI) imaging of breast lesions and the combined application of nuclear medicine and magnetic resonance imaging (PET/MRI) will be explained. Furthermore, an overview on the preclinical procedure and the possible clinical applications of optical and photoacoustic imaging will be given.

  12. Tutte polynomial in functional magnetic resonance imaging

    Science.gov (United States)

    García-Castillón, Marlly V.

    2015-09-01

    Methods of graph theory are applied to the processing of functional magnetic resonance images. Specifically the Tutte polynomial is used to analyze such kind of images. Functional Magnetic Resonance Imaging provide us connectivity networks in the brain which are represented by graphs and the Tutte polynomial will be applied. The problem of computing the Tutte polynomial for a given graph is #P-hard even for planar graphs. For a practical application the maple packages "GraphTheory" and "SpecialGraphs" will be used. We will consider certain diagram which is depicting functional connectivity, specifically between frontal and posterior areas, in autism during an inferential text comprehension task. The Tutte polynomial for the resulting neural networks will be computed and some numerical invariants for such network will be obtained. Our results show that the Tutte polynomial is a powerful tool to analyze and characterize the networks obtained from functional magnetic resonance imaging.

  13. Pulmonary functional MR imaging for COPD

    International Nuclear Information System (INIS)

    Ohno, Yoshiharu

    2008-01-01

    Chronic obstructive pulmonary disease (COPD) is a slowly progressive disease characterized by airflow limitation, cough, sputum production, and, at later stages, dyspnea. COPD is currently the fourth-leading cause of mortality and the twelfth-leading cause of disability, and by the year 2020 it is expected to be the third-leading cause of death and the fifth-leading cause of disability worldwide. The diagnosis of COPD largely relies on a history of exposure to noxious stimuli and abnormal lung function test results. Since the pathology of COPD varies and the molecular mechanisms are only slightly understood, the diagnosis and stage assessment of COPD have relied on the results of pulmonary function test. In addition, CT and nuclear medicine study are utilized for assessment of regional morphological and functional abnormalities. Recently, pulmonary functional MR imaging is suggested as a new technique for assessment of regional physiopathologic information in various pulmonary diseases including COPD, pulmonary thromboembolism, lung cancer and interstitial lung diseases. This review article covers the brief description of theory and clinical application of contrast-enhanced perfusion MR imaging; hyperpolarized noble gas MR imaging and oxygen-enhanced MR imaging in COPD subjects. We believe that further basic studies as well as clinical applications of this new technique will define the real significance of pulmonary functional MR imaging for the future of pulmonary functional imaging and its usefulness for diagnosis and patients' management in COPD. (author)

  14. Subband/transform functions for image processing

    Science.gov (United States)

    Glover, Daniel

    1993-01-01

    Functions for image data processing written for use with the MATLAB(TM) software package are presented. These functions provide the capability to transform image data with block transformations (such as the Walsh Hadamard) and to produce spatial frequency subbands of the transformed data. Block transforms are equivalent to simple subband systems. The transform coefficients are reordered using a simple permutation to give subbands. The low frequency subband is a low resolution version of the original image, while the higher frequency subbands contain edge information. The transform functions can be cascaded to provide further decomposition into more subbands. If the cascade is applied to all four of the first stage subbands (in the case of a four band decomposition), then a uniform structure of sixteen bands is obtained. If the cascade is applied only to the low frequency subband, an octave structure of seven bands results. Functions for the inverse transforms are also given. These functions can be used for image data compression systems. The transforms do not in themselves produce data compression, but prepare the data for quantization and compression. Sample quantization functions for subbands are also given. A typical compression approach is to subband the image data, quantize it, then use statistical coding (e.g., run-length coding followed by Huffman coding) for compression. Contour plots of image data and subbanded data are shown.

  15. Changes in the functional binocular status of older children and adults with previously untreated infantile esotropia following late surgical realignment.

    Science.gov (United States)

    Murray, Anthony David Neil; Orpen, Jane; Calcutt, Carolyn

    2007-04-01

    Most studies of infantile esotropia concern patients diagnosed in infancy and treated throughout childhood. This prospective study addresses changes in the functional binocular status of older children and adults with previously untreated infantile esotropia, following late surgical realignment. Seventeen patients aged 8 years or more with a history of untreated esotropia occurring within the first 6 months of life were included in this study. All had monocular optokinetic asymmetry, a visual acuity of 20/30 or better in the worse eye, and binocular function assesment preoperatively and postoperatively. All were surgically aligned within 8(Delta) of orthotropia. None had neurologic disease. Preoperatively, all 17 patients demonstrated a monocular response to Bagolini lenses, while postoperatively 15 (88%) of the 17 demonstrated binocular function with Bagolini lenses (in that they could constantly perceive the major part of both arms of the X generated by the Bagolini lenses) and 13/17 (76%) demonstrated an increase in the binocular field. All 17 had no sensory fusion, either preoperatively or postoperatively, when tested with the Worth 4-Dot test or synoptophore, and no stereopsis with the Titmus stereo test. Older children and adults with previously untreated infantile esotropia derive some functional benefits following late surgical realignment. The degree of binocular function may be lower than that achieved in patients aligned before 24 months of age.

  16. Olfactometer for functional resonance imaging

    International Nuclear Information System (INIS)

    Andrieu, Patrice

    2013-01-01

    The Magnetic Resonance Imaging (fMRI) has been developing for twenty years. Indeed, the marketing of high-resolution MRI (5 Tesla and 7 Tesla recently) allowed the study of brain mechanisms. The research work of this PHD was to develop instrumentation for objective studies of brain behavior during a sensory stimulation. We are interested in the study of olfaction. We have designed and built a six-channel olfactometer, synchronized with breathing and controlled by computer. The originality of our work lies in the modularity of our device, which makes it adaptable to a wide range of studies. We also propose a new method to change the intensity of stimulation delivered: the Pulse Width Modulation (PWM). This device has been used in several studies in fMRI. The effectiveness of the PWM is highlighted in a psychophysical study described in this manuscript. (author)

  17. Structural basis for pulmonary functional imaging

    International Nuclear Information System (INIS)

    Itoh, Harumi; Nakatsu, Masashi; Yoxtheimer, Lorene M.; Uematsu, Hidemasa; Ohno, Yoshiharu; Hatabu, Hiroto

    2001-01-01

    An understanding of fine normal lung morphology is important for effective pulmonary functional imaging. The lung specimens must be inflated. These include (a) unfixed, inflated lung specimen, (b) formaldehyde fixed lung specimen, (c) fixed, inflated dry lung specimen, and (d) histology specimen. Photography, magnified view, radiograph, computed tomography, and histology of these specimens are demonstrated. From a standpoint of diagnostic imaging, the main normal lung structures consist of airways (bronchi and bronchioles), alveoli, pulmonary vessels, secondary pulmonary lobules, and subpleural pulmonary lymphatic channels. This review summarizes fine radiologic normal lung morphology as an aid to effective pulmonary functional imaging

  18. Executive Functioning and Visuospatial Abilities in Bulimia Nervosa with or without a Previous History of Anorexia Nervosa.

    Science.gov (United States)

    Degortes, Daniela; Tenconi, Elena; Santonastaso, Paolo; Favaro, Angela

    2016-03-01

    The aim of the present study was to investigate executive functioning and visuospatial abilities in patients with bulimia nervosa (BN), with a particular interest in exploring the impact of a previous diagnosis of anorexia nervosa (AN). Several neuropsychological tasks were administered to 89 BN patients (52 with a previous history of AN and 37 without previous AN) and 160 healthy women. A poorer performance on set-shifting measures (Wisconsin Card Sorting Test) was found only in BN patients with a previous history of AN. Decision-making abilities (Iowa Gambling Task) were significantly impaired in the whole sample of BN patients, but difficulties were more pronounced in the subgroup with previous AN. Finally, we did not find any differences in response inhibition and visuospatial abilities between the two samples of BN patients and healthy women. Our findings support the idea that cognitive abilities in patients with BN are more impaired in the presence of a prior history of AN. The clinical and treatment implications of our findings should be explored in future studies. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

  19. Functional cardiac imaging: positron emission tomography

    International Nuclear Information System (INIS)

    Mullani, N.A.; Gould, K.L.

    1984-01-01

    Dynamic cardiovascular imaging plays a vital role in the diagnosis and treatment of cardiac disease by providing information about the function of the heart. During the past 30 years, cardiovascular imaging has evolved from the simple chest x-ray and fluoroscopy to such sophisticated techniques as invasive cardiac angiography and cinearteriography and, more recently, to noninvasive cardiac CT scanning, nuclear magnetic resonance, and positron emission tomography, which reflect more complex physiologic functions. As research tools, CT, NMR, and PET provide quantitative information on global as well as regional ventricular function, coronary artery stenosis, myocardial perfusion, glucose and fatty acid metabolism, or oxygen utilization, with little discomfort or risk to the patient. As imaging modalities become more sophisticated and more oriented toward clinical application, the prospect of routinely obtaining such functional information about the heart is becoming realistic. However, these advances are double-edged in that the interpretation of functional data is more complex than that of the anatomic imaging familiar to most physicians. They will require an enhanced understanding of the physiologic and biochemical processes, as well as of the instrumentation and techniques for analyzing the data. Of the new imaging modalities that provide functional information about the heart, PET is the most useful because it quantitates the regional distribution of radionuclides in vivo. Clinical applications, interpretation of data, and the impact of PET on our understanding of cardiac pathophysiology are discussed. 5 figures

  20. Clinical application of functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Alwatban, Adnan Z.W

    2002-07-01

    The work described in this thesis was carried out at the Magnetic Resonance Centre of the University of Nottingham during the time from May 1998 to April 2001, and is the work of the author except where indicated by reference. The main source of signal changes in functional magnetic resonance imaging (fMRJ) is the fluctuation of paramagnetic deoxyhaemoglobin in the venous blood during different states of functional performance. For the work of this thesis, fMRI studies were carried out using a 3 T MR system with an echo planar imaging (EPI) pulse sequence. Hearing research utilising fMRI has been previously reported in normal subjects. Hearing fMRI is normally performed by stimulating the auditory cortex via an acoustic task presentation such as music, tone, etc. However, performing the same research on deaf subjects requires special equipment to be designed to allow direct stimulation of the auditory nerve. In this thesis, a new method of direct electrical stimulation of the auditory nerve is described that uses a transtympanic electrode implanted onto the surface of the cochlea. This approach would however, result in electromotive forces (EMFs) being induced by the time varying magnetic field, which would lead to current flow and heating, as well as deflection of the metallic electrode within the static magnetic field, and image distortion due to the magnetic susceptibility difference. A gold-plated tungsten electrode with a zero magnetic susceptibility was developed to avoid image distortion. Used with carbon leads and a carbon reference pad, it enabled safe, distortion-free fMRI studies of deaf subjects. The study revealed activation of the primary auditory cortex. This fMRI procedure can be used to demonstrate whether the auditory pathway is fully intact, and may provide a useful method for pre-operative assessment of candidates for cochlear implantation. Glucose is the energy source on which the function of the human brain is entirely dependent. Failure to

  1. Clinical application of functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Alwatban, Adnan Z.W.

    2002-01-01

    The work described in this thesis was carried out at the Magnetic Resonance Centre of the University of Nottingham during the time from May 1998 to April 2001, and is the work of the author except where indicated by reference. The main source of signal changes in functional magnetic resonance imaging (fMRJ) is the fluctuation of paramagnetic deoxyhaemoglobin in the venous blood during different states of functional performance. For the work of this thesis, fMRI studies were carried out using a 3 T MR system with an echo planar imaging (EPI) pulse sequence. Hearing research utilising fMRI has been previously reported in normal subjects. Hearing fMRI is normally performed by stimulating the auditory cortex via an acoustic task presentation such as music, tone, etc. However, performing the same research on deaf subjects requires special equipment to be designed to allow direct stimulation of the auditory nerve. In this thesis, a new method of direct electrical stimulation of the auditory nerve is described that uses a transtympanic electrode implanted onto the surface of the cochlea. This approach would however, result in electromotive forces (EMFs) being induced by the time varying magnetic field, which would lead to current flow and heating, as well as deflection of the metallic electrode within the static magnetic field, and image distortion due to the magnetic susceptibility difference. A gold-plated tungsten electrode with a zero magnetic susceptibility was developed to avoid image distortion. Used with carbon leads and a carbon reference pad, it enabled safe, distortion-free fMRI studies of deaf subjects. The study revealed activation of the primary auditory cortex. This fMRI procedure can be used to demonstrate whether the auditory pathway is fully intact, and may provide a useful method for pre-operative assessment of candidates for cochlear implantation. Glucose is the energy source on which the function of the human brain is entirely dependent. Failure to

  2. The association between subjective memory complaint and objective cognitive function in older people with previous major depression.

    Directory of Open Access Journals (Sweden)

    Chung-Shiang Chu

    Full Text Available The goal of this study is to investigate associations between subjective memory complaint and objective cognitive performance in older people with previous major depression-a high-risk sample for cognitive impairment and later dementia. A cross-sectional study was carried out in people aged 60 or over with previous major depression but not fulfilling current major depression criteria according to DSM-IV-TR. People with dementia or Mini-Mental State Examination score less than 17 were excluded. Subjective memory complaint was defined on the basis of a score ≧4 on the subscale of Geriatric Mental State schedule, a maximum score of 8. Older people aged equal or over 60 without any psychiatric diagnosis were enrolled as healthy controls. Cognitive function was evaluated using a series of cognitive tests assessing verbal memory, attention/speed, visuospatial function, verbal fluency, and cognitive flexibility in all participants. One hundred and thirteen older people with previous major depression and forty-six healthy controls were enrolled. Subjective memory complaint was present in more than half of the participants with depression history (55.8%. Among those with major depression history, subjective memory complaint was associated with lower total immediate recall and delayed verbal recall scores after adjustment. The associations between subjective memory complaint and worse memory performance were stronger in participants with lower depressive symptoms (Hamilton Depression Rating Scale score<7. The results suggest subjective memory complaint may be a valid appraisal of memory performance in older people with previous major depression and consideration should be given to more proactive assessment and follow-up in these clinical samples.

  3. What is feasible with imaging human brain function and connectivity using functional magnetic resonance imaging.

    Science.gov (United States)

    Ugurbil, Kamil

    2016-10-05

    When we consider all of the methods we employ to detect brain function, from electrophysiology to optical techniques to functional magnetic resonance imaging (fMRI), we do not really have a 'golden technique' that meets all of the needs for studying the brain. We have methods, each of which has significant limitations but provide often complimentary information. Clearly, there are many questions that need to be answered about fMRI, which unlike other methods, allows us to study the human brain. However, there are also extraordinary accomplishments or demonstration of the feasibility of reaching new and previously unexpected scales of function in the human brain. This article reviews some of the work we have pursued, often with extensive collaborations with other co-workers, towards understanding the underlying mechanisms of the methodology, defining its limitations, and developing solutions to advance it. No doubt, our knowledge of human brain function has vastly expanded since the introduction of fMRI. However, methods and instrumentation in this dynamic field have evolved to a state that discoveries about the human brain based on fMRI principles, together with information garnered at a much finer spatial and temporal scale through other methods, are poised to significantly accelerate in the next decade.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. © 2016 The Author(s).

  4. Functional imaging of epileptic activity in humans

    OpenAIRE

    Vulliemoz, Serge

    2012-01-01

    Around 20% of patients suffering from epilepsy have medically refractory seizures and epilepsy surgery can offer a cure or at least a significant improvement of their seizures. in well selected patients. A comprehensive work-up combining different imaging techniques is necessary to localise brain regions involved in the epileptic network. Simultaneous ElectroEncephaloGraphy and functional Magnetic Resonance Imaging (EEG-fMRI) is a new technique that allows mapping epileptic networks at a whol...

  5. Imaging cellular and molecular biological functions

    Energy Technology Data Exchange (ETDEWEB)

    Shorte, S.L. [Institut Pasteur, 75 - Paris (France). Plateforme d' Imagerie Dynamique PFID-Imagopole; Frischknecht, F. (eds.) [Heidelberg Univ. Medical School (Germany). Dept. of Parasitology

    2007-07-01

    'Imaging cellular and molecular biological function' provides a unique selection of essays by leading experts, aiming at scientist and student alike who are interested in all aspects of modern imaging, from its application and up-scaling to its development. Indeed the philosophy of this volume is to provide student, researcher, PI, professional or provost the means to enter this applications field with confidence, and to construct the means to answer their own specific questions. (orig.)

  6. Alteration of distortion product otoacoustic emission input/output functions in subjects with a previous history of middle ear dysfunction.

    Science.gov (United States)

    De P Campos, Ualace; Sanches, Seisse G; Hatzopoulos, Stavros; Carvallo, Renata M M; Kochanek, Krzysztof; Skarżyński, Henryk

    2012-04-01

    The aim of this study was to investigate the effects of sub-clinical alterations on the amplitudes and slopes of the DPOAE input-output responses from subjects with previous history of middle ear dysfunction. The study included 15 subjects with and 15 subjects without a history of otitis media in the last 10 years. All participants were assessed with acoustic immittance, pure-tone audiometry, and DPOAEs. For the later, I/O functions and I/O slopes were estimated at 1501, 2002, 3174, 4004 and 6384 Hz. No statistically significant differences were found between the 2 groups in terms of behavioral thresholds. The group with a previous history of middle ear dysfunction presented significantly lower mean DPOAE amplitudes at 2002, 3174 and 4004 Hz. In terms of DPOAE slopes, no statistically significant differences were observed at the tested frequencies, except at 3174 Hz. Middle ear pathologies can produce subclinical alterations that are undetectable with traditional pure-tone audiometry. The data from the present study show that reduced amplitude DPOAEs are associated with a previous history of middle ear complications. The corresponding DPOAE slopes were affected at only 1 tested frequency, suggesting that the cochlear non-linearity is preserved. Considering these results, it remains to be elucidated to what degree the DPOAE amplitude attenuation interferes with higher-order auditory tasks.

  7. Functional brain imaging - baric and clinical questions

    International Nuclear Information System (INIS)

    Mager, T.; Moeller, H.J.

    1997-01-01

    The advancing biological knowledge of disease processes plays a central part in the progress of modern psychiatry. An essential contribution comes from the functional and structural brain imaging techniques (CT, MRI, SPECT, PET). Their application is important for biological oriented research in psychiatry and there is also a growing relevance in clinical aspects. This development is taken into account by recent diagnostic classification systems in psychiatry. The capabilities and limitations of functional brain imaging in the context of research and clinic will be presented and discussed by examples and own investigations. (orig.) [de

  8. Structural and functional imaging: Particularities in children

    Energy Technology Data Exchange (ETDEWEB)

    Chiron, C.; Hertz-Pannier, L. [Hop Necker Enfants Malad, INSERM, Serv Neuropediat, U663, F-75015 Paris (France); Chiron, C.; Hertz-Pannier, L. [UnivParis 05, F-75005 Paris (France); Chiron, C.; Hertz-Pannier, L. [CEA, I2BM, Neurospin, SHFJ, F-91191 Orsay (France)

    2008-07-01

    Surgery of partial epilepsies in childhood has largely benefited from the recent advances of imaging techniques, which carry a triple goal: (1) to contribute to the localization of the epilepsy onset zone, (2) to detect and delineate an underlying lesion, and (3) to study the spatial relationship between the epileptogenic zone and the neighboring functional cortex, in order to select patients and plan the resection. This noninvasive pre-surgical imaging workup must be compared to clinical and electrical data to estimate the postoperative prognosis, while invasive techniques such as SEEG, cortical stimulations, and IAT often remain indispensable in difficult cases, i.e., in cryptogenic epilepsies. As in adults, advances in MRI allow us to detect more and more subtle underlying lesions, but this requires repeating MR studies during early childhood and using adapted sequence parameters to account for ongoing myelination. Ictal SPECT and PET imaging prove especially useful in planning depth electrode placement when video-EEG is not contributive, when MRI looks normal or shows multiple abnormalities, or in cases of discrepant findings. Multimodal imaging greatly enhances the sensitivity of all of these techniques. Finally, functional MRI of motor and language functions provide noninvasive cortical mapping of essential functions, using age-adapted paradigms, in cooperating children from age five to six and from IQs around 60. (authors)

  9. Seeing double: combined modalities in functional imaging

    Energy Technology Data Exchange (ETDEWEB)

    Del Guerra, A. E-mail: delguerra@pi.infn.it; Damiani, C.; Di Domenico, G.; Gambaccini, M.; Motta, A.; Sabba, N.; Zavattini, G

    2001-09-21

    Various dedicated instruments for combined modalities in functional imaging are being developed by our group: a small animal PET/SPECT scanner, two scintimammography apparatus for breast cancer diagnosis, one with RX/PEM and the other with RX/SPECT capability. The performance and the status of development of these devices will be reported.

  10. Visceral Afferent Pathways and Functional Brain Imaging

    Directory of Open Access Journals (Sweden)

    Stuart W.G. Derbyshire

    2003-01-01

    Full Text Available The application of functional imaging to study painful sensations has generated considerable interest regarding insight into brain dysfunction that may be responsible for functional pain such as that suffered in patients with irritable bowel syndrome (IBS. This review provides a brief introduction to the development of brain science as it relates to pain processing and a snapshot of recent functional imaging results with somatic and visceral pain. Particular emphasis is placed on current hypotheses regarding dysfunction of the brain-gut axis in IBS patients. There are clear and interpretable differences in brain activation following somatic as compared with visceral noxious sensation. Noxious visceral distension, particularly of the lower gastrointestinal tract, activates regions associated with unpleasant affect and autonomic responses. Noxious somatic sensation, in contrast, activates regions associated with cognition and skeletomotor responses. Differences between IBS patients and control subjects, however, were far less clear and interpretable. While this is in part due to the newness of this field, it also reflects weaknesses inherent within the current understanding of IBS. Future use of functional imaging to examine IBS and other functional disorders will be more likely to succeed by describing clear theoretical and clinical endpoints.

  11. Functional imaging of the pelvic floor

    Energy Technology Data Exchange (ETDEWEB)

    Lienemann, Andreas E-mail: andreaslienemann@web.de; Fischer, Tanja

    2003-08-01

    Introduction/Objective: Pelvic floor dysfunction and associated pelvic organ prolapse represent a major problem in our present-day society, mostly afflicting parous women. Magnetic resonance imaging (MRI) is assuming an increasingly important role in the more accurate delineation of the extent of the problem. This article briefly reviews one of the main radiological methods for the dynamic evaluation of the pelvic floor: functional cine MRI. Methods and Material: Out of the literature the smallest common denominator for functional cine MRI can be defined as follows: high field system; patient either in supine or sitting position; fast gradient echo sequence; midsagittal slice orientation; either a stack of slices or repeated measurements at the same slice position with the patient at rest or straining; image analysis using the pubococcygeal reference line. Results: All except two publications stress the usefulness of functional cine MRI in the evaluation of patients with organ descent and prolapse. This well accepted method allows for the visualization of all relevant structures in the anterior, middle and posterior compartment. It is especially useful in the detection of enteroceles, and provides a reliable postoperative follow-up tool. Isolated urinary or stool incontinence are not an indication for functional cine MRI, as is the case in patients with equivocal clinical findings. To date it does not allow for real 3D imaging of the pelvic floor or sufficient determination of fascial defects. Discussion: Functional cine MRI of the pelvic floor is a promising new imaging method for the detection of organ descent and prolapse in patients with equivocal clinical findings. The combination of function and morphology allows for an innovative view of the pelvic floor, and thus adds to our understanding of the various interactions of the structures.

  12. Cognitive functioning in children and adolescents in their first episode of psychosis: differences between previous cannabis users and nonusers.

    Science.gov (United States)

    de la Serna, Elena; Mayoral, María; Baeza, Inmaculada; Arango, Celso; Andrés, Patricia; Bombin, Igor; González, Cristina; Rapado, Marta; Robles, Olalla; Rodríguez-Sánchez, Jose Manuel; Zabala, Arantzazu; Castro-Fornieles, Josefina

    2010-02-01

    To investigate the relationship between cognition and prior cannabis use in children and adolescents presenting a first episode of psychosis. A total of 107 patients with first episode of psychosis and 96 healthy controls, aged 9 to 17 years, were interviewed about their previous substance use and to assess their cognitive functions. Patients were assessed while not using cannabis by means of a comprehensive neuropsychological battery. They were divided into 2 groups depending on the history of prior cannabis use: cannabis users (CU) and cannabis nonusers (CNU). Significant differences were found in all areas evaluated between the 3 groups. Both CU and CNU patients obtained lower scores than controls on verbal learning and memory and working memory. Patients with prior cannabis use performed better on some tests of attention (Continuous performance test (CPT) number of correct responses, p = 0.002; CPT average reaction time, p < 0.001) and executive functions (Trail Making Test, part B (TMT-B) number of mistakes, p < 0.001; Wisconsin Card Sorting Test (WCST) number of categories completed, p < 0.001) than CNU patients. CU patients performed better than CNU subjects on some cognitive measures. This may indicate lower individual vulnerability for psychosis in CU patients in whom cannabis use can be a precipitating factor of psychotic episodes.

  13. Functional MR imaging study of the shoulder

    International Nuclear Information System (INIS)

    Minami, M.; Yoshikawa, K.; Shibuta, H.; Kokubo, T.; Itai, Y.; Iio, M.

    1989-01-01

    This paper presents a functional MR study of the shoulder performed with the positioning in which patients were about to complain of shoulder pain. A 0.064-T permanent MR system was used. The effectiveness of this study was evaluated in the diagnosis of rotator cuff impingement syndrome. Thirteen patients (11 males and two female) were examined prospectively. Three-dimensional Fourier transformation coronal images were obtained with patients' arms at the maximal abduction. They were compared with images obtained while patients' arms were at their sides, chiefly from the viewpoint of severity of impingement and intensity change of the supraspinatus muscle

  14. Exploring brain function with magnetic resonance imaging

    International Nuclear Information System (INIS)

    Di Salle, F.; Formisano, E.; Linden, D.E.J.; Goebel, R.; Bonavita, S.; Pepino, A.; Smaltino, F.; Tedeschi, G.

    1999-01-01

    Since its invention in the early 1990s, functional magnetic resonance imaging (fMRI) has rapidly assumed a leading role among the techniques used to localize brain activity. The spatial and temporal resolution provided by state-of-the-art MR technology and its non-invasive character, which allows multiple studies of the same subject, are some of the main advantages of fMRI over the other functional neuroimaging modalities that are based on changes in blood flow and cortical metabolism. This paper describes the basic principles and methodology of fMRI and some aspects of its application to functional activation studies. Attention is focused on the physiology of the blood oxygenation level-dependent (BOLD) contrast mechanism and on the acquisition of functional time-series with echo planar imaging (EPI). We also provide an introduction to the current strategies for the correction of signal artefacts and other image processing techniques. In order to convey an idea of the numerous applications of fMRI, we will review some of the recent results in the fields of cognitive and sensorimotor psychology and physiology

  15. High resolution multiplexed functional imaging in live embryos (Conference Presentation)

    Science.gov (United States)

    Xu, Dongli; Zhou, Weibin; Peng, Leilei

    2017-02-01

    Fourier multiplexed fluorescence lifetime imaging (FmFLIM) scanning laser optical tomography (FmFLIM-SLOT) combines FmFLIM and Scanning laser optical tomography (SLOT) to perform multiplexed 3D FLIM imaging of live embryos. The system had demonstrate multiplexed functional imaging of zebrafish embryos genetically express Foster Resonant Energy Transfer (FRET) sensors. However, previous system has a 20 micron resolution because the focused Gaussian beam diverges quickly from the focused plane, makes it difficult to achieve high resolution imaging over a long projection depth. Here, we present a high-resolution FmFLIM-SLOT system with achromatic Bessel beam, which achieves 3 micron resolution in 3D deep tissue imaging. In Bessel-FmFLIM-SLOT, multiple laser excitation lines are firstly intensity modulated by a Michelson interferometer with a spinning polygon mirror optical delay line, which enables Fourier multiplexed multi-channel lifetime measurements. Then, a spatial light modulator and a prism are used to transform the modulated Gaussian laser beam to an achromatic Bessel beam. The achromatic Bessel beam scans across the whole specimen with equal angular intervals as sample rotated. After tomography reconstruction and the frequency domain lifetime analysis method, both the 3D intensity and lifetime image of multiple excitation-emission can be obtained. Using Bessel-FmFLIM-SLOT system, we performed cellular-resolution FLIM tomography imaging of live zebrafish embryo. Genetically expressed FRET sensors in these embryo will allow non-invasive observation of multiple biochemical processes in vivo.

  16. Changes in nonhuman primate brain function following chronic alcohol consumption in previously naïve animals.

    Science.gov (United States)

    Rowland, Jared A; Stapleton-Kotloski, Jennifer R; Alberto, Greg E; Davenport, April T; Kotloski, Robert J; Friedman, David P; Godwin, Dwayne W; Daunais, James B

    2017-08-01

    Chronic alcohol abuse is associated with neurophysiological changes in brain activity; however, these changes are not well localized in humans. Non-human primate models of alcohol abuse enable control over many potential confounding variables associated with human studies. The present study utilized high-resolution magnetoencephalography (MEG) to quantify the effects of chronic EtOH self-administration on resting state (RS) brain function in vervet monkeys. Adolescent male vervet monkeys were trained to self-administer ethanol (n=7) or an isocaloric malto-dextrin solution (n=3). Following training, animals received 12 months of free access to ethanol. Animals then underwent RS magnetoencephalography (MEG) and subsequent power spectral analysis of brain activity at 32 bilateral regions of interest associated with the chronic effects of alcohol use. demonstrate localized changes in brain activity in chronic heavy drinkers, including reduced power in the anterior cingulate cortex, hippocampus, and amygdala as well as increased power in the right medial orbital and parietal areas. The current study is the first demonstration of whole-head MEG acquisition in vervet monkeys. Changes in brain activity were consistent with human electroencephalographic studies; however, MEG was able to extend these findings by localizing the observed changes in power to specific brain regions. These regions are consistent with those previously found to exhibit volume loss following chronic heavy alcohol use. The ability to use MEG to evaluate changes in brain activity following chronic ethanol exposure provides a potentially powerful tool to better understand both the acute and chronic effects of alcohol on brain function. Published by Elsevier B.V.

  17. Imaging visual function of the human brain

    International Nuclear Information System (INIS)

    Marg, E.

    1988-01-01

    Imaging of human brain structure and activity with particular reference to visual function is reviewed along with methods of obtaining the data including computed tomographic (CT) scan, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET). The literature is reviewed and the potential for a new understanding of brain visual function is discussed. PET is reviewed from basic physical principles to the most recent visual brain findings with oxygen-15. It is shown that there is a potential for submillimeter localization of visual functions with sequentially different visual stimuli designed for the temporal separation of the responses. Single photon emission computed tomography (SPECT), a less expensive substitute for PET, is also discussed. MRS is covered from basic physical principles to the current state of the art of in vivo biochemical analysis. Future possible clinical applications are discussed. Improved understanding of the functional neural organization of vision and brain will open a window to maps and circuits of human brain function.119 references

  18. Electroencephalographic imaging of higher brain function

    Science.gov (United States)

    Gevins, A.; Smith, M. E.; McEvoy, L. K.; Leong, H.; Le, J.

    1999-01-01

    High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. Electroencephalography (EEG) provides temporal resolution in the millisecond range. However, traditional EEG technology and practice provide insufficient spatial detail to identify relationships between brain electrical events and structures and functions visualized by magnetic resonance imaging or positron emission tomography. Recent advances help to overcome this problem by recording EEGs from more electrodes, by registering EEG data with anatomical images, and by correcting the distortion caused by volume conduction of EEG signals through the skull and scalp. In addition, statistical measurements of sub-second interdependences between EEG time-series recorded from different locations can help to generate hypotheses about the instantaneous functional networks that form between different cortical regions during perception, thought and action. Example applications are presented from studies of language, attention and working memory. Along with its unique ability to monitor brain function as people perform everyday activities in the real world, these advances make modern EEG an invaluable complement to other functional neuroimaging modalities.

  19. Retinal functional imager (RFI): non-invasive functional imaging of the retina.

    Science.gov (United States)

    Ganekal, S

    2013-01-01

    Retinal functional imager (RFI) is a unique non-invasive functional imaging system with novel capabilities for visualizing the retina. The objective of this review was to show the utility of non-invasive functional imaging in various disorders. Electronic literature search was carried out using the websites www.pubmed.gov and www.google.com. The search words were retinal functional imager and non-invasive retinal imaging used in combination. The articles published or translated into English were studied. The RFI directly measures hemodynamic parameters such as retinal blood-flow velocity, oximetric state, metabolic responses to photic activation and generates capillary perfusion maps (CPM) that provides retinal vasculature detail similar to flourescein angiography. All of these parameters stand in a direct relationship to the function and therefore the health of the retina, and are known to be degraded in the course of retinal diseases. Detecting changes in retinal function aid early diagnosis and treatment as functional changes often precede structural changes in many retinal disorders. © NEPjOPH.

  20. An automated patient recognition method based on an image-matching technique using previous chest radiographs in the picture archiving and communication system environment

    International Nuclear Information System (INIS)

    Morishita, Junji; Katsuragawa, Shigehiko; Kondo, Keisuke; Doi, Kunio

    2001-01-01

    An automated patient recognition method for correcting 'wrong' chest radiographs being stored in a picture archiving and communication system (PACS) environment has been developed. The method is based on an image-matching technique that uses previous chest radiographs. For identification of a 'wrong' patient, the correlation value was determined for a previous image of a patient and a new, current image of the presumed corresponding patient. The current image was shifted horizontally and vertically and rotated, so that we could determine the best match between the two images. The results indicated that the correlation values between the current and previous images for the same, 'correct' patients were generally greater than those for different, 'wrong' patients. Although the two histograms for the same patient and for different patients overlapped at correlation values greater than 0.80, most parts of the histograms were separated. The correlation value was compared with a threshold value that was determined based on an analysis of the histograms of correlation values obtained for the same patient and for different patients. If the current image is considered potentially to belong to a 'wrong' patient, then a warning sign with the probability for a 'wrong' patient is provided to alert radiology personnel. Our results indicate that at least half of the 'wrong' images in our database can be identified correctly with the method described in this study. The overall performance in terms of a receiver operating characteristic curve showed a high performance of the system. The results also indicate that some readings of 'wrong' images for a given patient in the PACS environment can be prevented by use of the method we developed. Therefore an automated warning system for patient recognition would be useful in correcting 'wrong' images being stored in the PACS environment

  1. The Structure of Treponema pallidum Tp0624 Reveals a Modular Assembly of Divergently Functionalized and Previously Uncharacterized Domains.

    Science.gov (United States)

    Parker, Michelle L; Houston, Simon; Wetherell, Charmaine; Cameron, Caroline E; Boulanger, Martin J

    2016-01-01

    Treponema pallidum subspecies pallidum is the causative agent of syphilis, a chronic, multistage, systemic infection that remains a major global health concern. The molecular mechanisms underlying T. pallidum pathogenesis are incompletely understood, partially due to the phylogenetic divergence of T. pallidum. One aspect of T. pallidum that differentiates it from conventional Gram-negative bacteria, and is believed to play an important role in pathogenesis, is its unusual cell envelope ultrastructure; in particular, the T. pallidum peptidoglycan layer is chemically distinct, thinner and more distal to the outer membrane. Established functional roles for peptidoglycan include contributing to the structural integrity of the cell envelope and stabilization of the flagellar motor complex, which are typically mediated by the OmpA domain-containing family of proteins. To gain insight into the molecular mechanisms that govern peptidoglycan binding and cell envelope biogenesis in T. pallidum we report here the structural characterization of the putative OmpA-like domain-containing protein, Tp0624. Analysis of the 1.70 Å resolution Tp0624 crystal structure reveals a multi-modular architecture comprised of three distinct domains including a C-terminal divergent OmpA-like domain, which we show is unable to bind the conventional peptidoglycan component diaminopimelic acid, and a previously uncharacterized tandem domain unit. Intriguingly, bioinformatic analysis indicates that the three domains together are found in all orthologs from pathogenic treponemes, but are not observed together in genera outside Treponema. These findings provide the first structural insight into a multi-modular treponemal protein containing an OmpA-like domain and its potential role in peptidoglycan coordination and stabilization of the T. pallidum cell envelope.

  2. Functional MRI using regularized parallel imaging acquisition.

    Science.gov (United States)

    Lin, Fa-Hsuan; Huang, Teng-Yi; Chen, Nan-Kuei; Wang, Fu-Nien; Stufflebeam, Steven M; Belliveau, John W; Wald, Lawrence L; Kwong, Kenneth K

    2005-08-01

    Parallel MRI techniques reconstruct full-FOV images from undersampled k-space data by using the uncorrelated information from RF array coil elements. One disadvantage of parallel MRI is that the image signal-to-noise ratio (SNR) is degraded because of the reduced data samples and the spatially correlated nature of multiple RF receivers. Regularization has been proposed to mitigate the SNR loss originating due to the latter reason. Since it is necessary to utilize static prior to regularization, the dynamic contrast-to-noise ratio (CNR) in parallel MRI will be affected. In this paper we investigate the CNR of regularized sensitivity encoding (SENSE) acquisitions. We propose to implement regularized parallel MRI acquisitions in functional MRI (fMRI) experiments by incorporating the prior from combined segmented echo-planar imaging (EPI) acquisition into SENSE reconstructions. We investigated the impact of regularization on the CNR by performing parametric simulations at various BOLD contrasts, acceleration rates, and sizes of the active brain areas. As quantified by receiver operating characteristic (ROC) analysis, the simulations suggest that the detection power of SENSE fMRI can be improved by regularized reconstructions, compared to unregularized reconstructions. Human motor and visual fMRI data acquired at different field strengths and array coils also demonstrate that regularized SENSE improves the detection of functionally active brain regions. 2005 Wiley-Liss, Inc

  3. Multiple image x-radiography for functional lung imaging

    Science.gov (United States)

    Aulakh, G. K.; Mann, A.; Belev, G.; Wiebe, S.; Kuebler, W. M.; Singh, B.; Chapman, D.

    2018-01-01

    Detection and visualization of lung tissue structures is impaired by predominance of air. However, by using synchrotron x-rays, refraction of x-rays at the interface of tissue and air can be utilized to generate contrast which may in turn enable quantification of lung optical properties. We utilized multiple image radiography, a variant of diffraction enhanced imaging, at the Canadian light source to quantify changes in unique x-ray optical properties of lungs, namely attenuation, refraction and ultra small-angle scatter (USAXS or width) contrast ratios as a function of lung orientation in free-breathing or respiratory-gated mice before and after intra-nasal bacterial endotoxin (lipopolysaccharide) instillation. The lung ultra small-angle scatter and attenuation contrast ratios were significantly higher 9 h post lipopolysaccharide instillation compared to saline treatment whereas the refraction contrast decreased in magnitude. In ventilated mice, end-expiratory pressures result in an increase in ultra small-angle scatter contrast ratio when compared to end-inspiratory pressures. There were no detectable changes in lung attenuation or refraction contrast ratio with change in lung pressure alone. In effect, multiple image radiography can be applied towards following optical properties of lung air-tissue barrier over time during pathologies such as acute lung injury.

  4. Self-reported previous knee injury and low knee function increase knee injury risk in adolescent female football

    DEFF Research Database (Denmark)

    Clausen, M B; Tang, L; Zebis, M K

    2015-01-01

    as independent variables in the risk factor analyses. The study showed that self-reported previous knee injury significantly increased the risk of time-loss knee injury [relative risk (RR): 3.65, 95% confidence (CI) 1.73-7.68; P 

  5. Automated assessment of heart chamber volumes and function in patients with previous myocardial infarction using multidetector computed tomography

    DEFF Research Database (Denmark)

    Fuchs, Andreas; Kühl, Jørgen Tobias; Lønborg, Jacob

    2013-01-01

    Left ventricular (LV), right ventricular (RV), and left atrial (LA) volumes and functions contain important prognostic information in ischemic heart disease. Because multidetector computed tomography (MDCT) has high spatial resolution, this method may be optimal to obtain this information....

  6. Long-term effects of amlodipine and lisinopril on left ventricular mass and diastolic function in elderly, previously untreated hypertensive patients : the ELVERA trial

    NARCIS (Netherlands)

    Terpstra, WF; May, JF; Smit, AJ; De Graeff, PA; Havinga, TK; van den Veur, E; Schuurman, FH; Meyboom-de Jong, B; Crijns, HJGM

    Objective To compare the effects of a calcium antagonist (amlodipine) and an angiotensin converting enzyme inhibitor (lisinopril) on left Ventricular mass and diastolic function in elderly, previously untreated hypertensives. Design A double-blind randomized parallel group trial. Effects of

  7. Teleseismic receiver functions imaging of Siberia

    DEFF Research Database (Denmark)

    Soliman, Mohammad Youssof Ahmad; Thybo, Hans; Artemieva, Irina

    2014-01-01

    We map the lithosphere in Siberia by using the available broadband seismic data for calculation of Ps- and Sp-wave receiver functions (RF). RFs show converted waves from discontinuities in the vicinity of the seismic stations. The main objective is to image the Moho and upper mantle discontinuities......, including the lithosphere-asthenosphere boundary (LAB) beneath the study area. We construct the RF using the LQT method (Vinnik, 1977; Kind et al. 1995) in the version by Yuan et al. (1997). Rotation of ray coordinates uses the incidence angles predicted by the AK135 velocity model. This decomposes the wave...... by high-frequency S-RFs. Teleseismic converted Ps waves have higher frequency content (0.5–2 Hz) than Sp, which have an upper frequency of 0.1–0.2 Hz, and therefore Ps have about an order of magnitude better resolving power than Sp. The converted Sp-wave rarely resolve intracrustal structure, but can...

  8. Functional Magnetic Resonance Imaging in Consumer Research

    DEFF Research Database (Denmark)

    Reimann, Martin; Schilke, Oliver; Weber, Bernd

    2011-01-01

    of prior fMRI research related to consumer behavior and highlights the features that make fMRI an attractive method for consumer and marketing research. The authors discuss advantages and limitations and illustrate the proposed procedures with an applied study, which investigates loss aversion when buying......Although the field of psychology is undergoing an immense shift toward the use of functional magnetic resonance imaging (fMRI), the application of this methodology to consumer research is relatively new. To assist consumer researchers in understanding fMRI, this paper elaborates on the findings...... and selling a common product. Results reveal a significantly stronger activation in the amygdala while consumers estimate selling prices versus buying prices, suggesting that loss aversion is associated with the processing of negative emotion. © 2011 Wiley Periodicals, Inc....

  9. Left ventricular function improves after pulmonary valve replacement in patients with previous right ventricular outflow tract reconstruction and biventricular dysfunction.

    Science.gov (United States)

    Kane, Colin; Kogon, Brian; Pernetz, Maria; McConnell, Michael; Kirshbom, Paul; Rodby, Katherine; Book, Wendy M

    2011-01-01

    Congenital heart defects that have a component of right ventricular outflow tract obstruction, such as tetralogy of Fallot, are frequently palliated in childhood by disruption of the pulmonary valve. Although this can provide an initial improvement in quality of life, these patients are often left with severe pulmonary valve insufficiency. Over time, this insufficiency can lead to enlargement of the right ventricle and to the deterioration of right ventricular systolic and diastolic function. Pulmonary valve replacement in these patients decreases right ventricular volume overload and improves right ventricular performance. To date, few studies have examined the effects of pulmonary valve replacement on left ventricular function in patients with biventricular dysfunction. We sought to perform such an evaluation.Records of adult patients who had undergone pulmonary valve replacement from January 2003 through November 2006 were analyzed retrospectively. We reviewed preoperative and postoperative echocardiograms and calculated left ventricular function in 38 patients.In the entire cohort, the mean left ventricular ejection fraction increased by a mean of 0.07 after pulmonary valve replacement, which was a statistically significant change (P < 0.01). In patients with preoperative ejection fractions of less than 0.50, mean ejection fractions increased by 0.10.We conclude that pulmonary valve replacement in patients with biventricular dysfunction arising from severe pulmonary insufficiency and right ventricular enlargement can improve left ventricular function. Prospective studies are needed to verify this finding.

  10. Left Ventricular Function Improves after Pulmonary Valve Replacement in Patients with Previous Right Ventricular Outflow Tract Reconstruction and Biventricular Dysfunction

    Science.gov (United States)

    Kane, Colin; Kogon, Brian; Pernetz, Maria; McConnell, Michael; Kirshbom, Paul; Rodby, Katherine; Book, Wendy M.

    2011-01-01

    Congenital heart defects that have a component of right ventricular outflow tract obstruction, such as tetralogy of Fallot, are frequently palliated in childhood by disruption of the pulmonary valve. Although this can provide an initial improvement in quality of life, these patients are often left with severe pulmonary valve insufficiency. Over time, this insufficiency can lead to enlargement of the right ventricle and to the deterioration of right ventricular systolic and diastolic function. Pulmonary valve replacement in these patients decreases right ventricular volume overload and improves right ventricular performance. To date, few studies have examined the effects of pulmonary valve replacement on left ventricular function in patients with biventricular dysfunction. We sought to perform such an evaluation. Records of adult patients who had undergone pulmonary valve replacement from January 2003 through November 2006 were analyzed retrospectively. We reviewed preoperative and postoperative echocardiograms and calculated left ventricular function in 38 patients. In the entire cohort, the mean left ventricular ejection fraction increased by a mean of 0.07 after pulmonary valve replacement, which was a statistically significant change (P < 0.01). In patients with preoperative ejection fractions of less than 0.50, mean ejection fractions increased by 0.10. We conclude that pulmonary valve replacement in patients with biventricular dysfunction arising from severe pulmonary insufficiency and right ventricular enlargement can improve left ventricular function. Prospective studies are needed to verify this finding. PMID:21720459

  11. A brush stimulator for functional brain imaging.

    Science.gov (United States)

    Jousmäki, V; Nishitani, N; Hari, R

    2007-12-01

    To describe a novel non-magnetic hand-held device to stimulate various parts of the skin and to evaluate its performance in magnetoencephalographic (MEG) recordings. The hand-held part of the device consists of an optic fiber bundle that forms a small brush. Half of the fibers emit modulated red light and the other half detect the reflected light from the skin so that the brush-to-skin contact is detected by means of reflectance. Light tapping of the back of the hand at the innervation area of the radial nerve elicited clear responses in all 10 subjects studied, with the main deflections peaking 40-70 ms after the stimulus. The earliest responses, obtained with a higher number of averaged trials, peaked 27-28 ms after the tap to the left hand dorsum. Source analysis of the MEG signals indicated neuronal sources at the primary somatosensory (SI) cortex, with a clear somatotopical order for face vs. hand. The device seems feasible for both MEG and functional magnetic resonance imaging experiments to address functional anatomy of the human somatosensory system with a real-life like stimulation. Non-magnetic and artefact-free tactile stimulator with a selective stimulus offers new possibilities for experimental designs to study the human mechanoreceptor system.

  12. Functional hepatobiliary MR imaging in children

    Energy Technology Data Exchange (ETDEWEB)

    Tamrazi, Anobel; Vasanawala, Shreyas S. [Stanford University, Department of Radiology, Stanford, CA (United States)

    2011-10-15

    Clinical application efforts for the hepatocyte-specific MRI contrast agent gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) have mainly been directed toward detection and characterization of various hepatic masses in the adult population. Here we report our initial experience with Gd-EOB-DTPA for evaluating congenital and acquired hepatobiliary pathologies in the pediatric population. Twenty-one consecutive children receiving Gd-EOB-DTPA for functional hepatobiliary evaluation at our institution were retrospectively identified with IRB approval. The use of Gd-EOB-DTPA was classified in each case as definite, potential, or no clinical utility, focusing on the clinical value gained beyond traditional noncontrast fluid-sensitive MR cholangiopancreatography (FS-MRCP) and other imaging modalities. Definite added value of Gd-EOB-DTPA was found in 12 patients, with potential value in 4 patients, and no value in 5 patients. Benefit was seen in cases of iatrogenic and non-iatrogenic biliary strictures, perihepatic fluid collections for biliary leak, hepatobiliary dysfunction in the absence of hyperbilirubinemia, and in the functional exclusion of cystic duct occlusion that can be seen in acute cholecystitis. This is the first reported series of children with Gd-EOB-DTPA and this early work suggests potential pediatric applications. (orig.)

  13. Three-dimensional reconstruction of functional brain images

    International Nuclear Information System (INIS)

    Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao

    1999-01-01

    We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: routine images by SPM, three-dimensional static images, and three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface

  14. Familial Essential Tremor Studied With Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Hernandez, A.; Salgado, P.; Gil, A.; Barrios, F. A.

    2003-09-01

    Functional Magnetic Resonance Imaging has become an important analytical tool to study neurodegenerative diseases. We applied the EPI-BOLD functional Magnetic Resonance Imaging technique to acquire functional images of patients with familial essential tremor (FET) disorder and healthy control volunteers, during a motor task activity. Functional and anatomic images were used to produce the brain activation maps of the patients and volunteers. These functional maps of the primary somatosensorial and motor cortexes of patients and control subjects were compared for functional differences per subject. The averaged functional brain images of eight of each case were acquired were, it can be clearly observed the differences in active zones. The results presented in this work show that there are differences in the functional maps during motor task activation between control subjects and FET patients suggesting a cerebral functional reorganization that can be mapped with BOLD-fMRI.

  15. Application platform 'ICX' designed for computer assisted functional image analyzer

    International Nuclear Information System (INIS)

    Kinosada, Yasutomi; Hattori, Takao; Yonezawa, Kazuo; Tojo, Shigenori.

    1994-01-01

    Recent clinical imaging modalities such as X-CT, MRI, SPECT and so on make it easy to obtain various functional images of the human body because of the rapid technical progress of modalities. But the technical progress such as fast imaging technique and 3D volume scanning technique have brought new problems for both medical doctors and technical staffs. They are the increase of both number of images and opportunities of the image processing for 3D presentations. Furthermore, it has been left difficult and troublesome to analyze these functional images. In this study, we have developed the application platform ICX (Independent Console based on X-window system) designed for a computer assisted functional image analyzer under the different concept from the conventional medical image processing workstations. ICX can manage clinical images from various modalities of imaging systems via Ethernet LAN and assist users to analyze or process these images easily with ICX's application programs or some commercial applications. ICX works as a diagnostic console, a personal PACS and a functional image analyzer, but independently works with imaging modalities. Many object-oriented image analysis and processing tools are available and they can be driven in any situations by users. ICX is a new type of the workstation and seems useful in the recent medical fields. (author)

  16. Functional cardiac imaging by random access microscopy

    Directory of Open Access Journals (Sweden)

    Claudia eCrocini

    2014-10-01

    Full Text Available Advances in the development of voltage sensitive dyes and Ca2+ sensors in combination with innovative microscopy techniques allowed researchers to perform functional measurements with an unprecedented spatial and temporal resolution. At the moment, one of the shortcomings of available technologies is their incapability of imaging multiple fast phenomena while controlling the biological determinants involved. In the near future, ultrafast deflectors can be used to rapidly scan laser beams across the sample, performing optical measurements of action potential and Ca2+ release from multiple sites within cardiac cells and tissues. The same scanning modality could also be used to control local Ca2+ release and membrane electrical activity by activation of caged compounds and light-gated ion channels. With this approach, local Ca2+ or voltage perturbations could be induced, simulating arrhythmogenic events, and their impact on physiological cell activity could be explored. The development of this optical methodology will provide fundamental insights in cardiac disease, boosting new therapeutic strategies, and, more generally, it will represent a new approach for the investigation of the physiology of excitable cells.

  17. Vision research with functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Nakadomari, Satoshi

    1999-01-01

    Present state of functional magnetic resonance imaging (fMRI), which is based on changes of MR signals produced by blood circulation changes due to the nerve activity, in vision research was reviewed. In this field, there are international associations of Human Brain Mapping and for Research in Vision and Ophthalmology (ARVO) and reports presented in ARVO in 1998 and 1999 were firstly described. Next, the comparison between two conditions was defined as the experimental paradigm of fMRI and analyses with the event related fMRI and with classification into visual central regions were explained. Major findings obtained by stimulation of visual central regions were discussed on the lateral corpus geniculatum, areas of V1, V2, V3 (VP), V3A, V4A (V8), V5 and LO (lateral occipital complex), and others. In practice of actual fMRI, the noise is often attributable to the examinee factor and notification for speculating the result is important. The value of fMRI in the clinical ophthalmological diagnosis was discussed and thought to be further investigated. (K.H.)

  18. The "Complex Restrictive" Pulmonary Function Pattern: Clinical and Radiologic Analysis of a Common but Previously Undescribed Restrictive Pattern.

    Science.gov (United States)

    Clay, Ryan D; Iyer, Vivek N; Reddy, Dereddi Raja; Siontis, Brittany; Scanlon, Paul D

    2017-12-01

    Most patients with restriction have a pulmonary function test (PFT) pattern in which total lung capacity (TLC), FVC, and FEV 1 are reduced to a similar degree. This pattern is called "simple restriction" (SR). In contrast, we commonly observe a pattern in which FVC percent predicted ( pp ) is disproportionately reduced relative to TLC pp . This pattern is termed "complex restriction" (CR), and we attempted to characterize its clinical, radiologic, and physiologic features. This study reviewed PFT results of patients tested between November 2009 and June 2013 who had restriction (TLC less than the lower limit of normal). SR was defined as TLC pp -FVC pp  ≤ 10%, and CR was stratified into four classes based on TLC pp -FVC pp discrepancy: Class 1 CR, TLC pp -FVC pp > 10% and ≤ 15%; Class 2 CR, TLC pp -FVC pp > 15% and ≤20%; Class 3 CR, TLC pp -FVC pp > 20% and ≤ 25%; and Class 4 CR, TLC pp -FVC pp > 25%. The medical records of 150 randomly selected patients with SR and 50 patients from each CR class were reviewed. Of 39,277 PFTs completed, we identified 4,532 patients (11.5%) with restriction: 2,407 (6.1%) with SR, 1,614 (4.1%) with CR, and 511 (1.3%) with a mixed pattern. Patients with CR were younger, were more often women, and had a higher prevalence of neuromuscular disease, BMI > 40 kg/m 2 or pattern with distinct clinical features. The associated clinical entities share impaired lung emptying (eg, neuromuscular disease, occult obstruction, chest wall limitation). Clinicians should be aware of this novel PFT pattern and how it shapes the differential diagnosis. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  19. Optical imaging of fast, dynamic neurophysiological function.

    Energy Technology Data Exchange (ETDEWEB)

    Rector, D. M. (David M.); Carter, K. M. (Kathleen M.); Yao, X. (Xincheng); George, J. S. (John S.)

    2002-01-01

    Fast evoked responses were imaged from rat dorsal medulla and whisker barrel cortex. To investigate the biophysical mechanisms involved, fast optical responses associated with isolated crustacean nerve stimulation were recorded using birefringence and scattered light. Such studies allow optimization of non-invasive imaging techniques being developed for use in humans.

  20. Imaging tools to study pharmacology: functional MRI on small rodents

    Directory of Open Access Journals (Sweden)

    Elisabeth eJonckers

    2015-10-01

    Full Text Available Functional Magnetic Resonance Imaging (fMRI is an excellent tool to study the effect of pharmacological modulations on brain function in a non-invasive and longitudinal manner. We introduce several blood oxygenation level dependent (BOLD fMRI techniques, including resting state (rsfMRI, stimulus-evoked (st-fMRI, and pharmacological MRI (phMRI. Respectively, these techniques permit the assessment of functional connectivity during rest as well as brain activation triggered by sensory stimulation and/or a pharmacological challenge. The first part of this review describes the physiological basis of BOLD fMRI and the hemodynamic response on which the MRI contrast is based. Specific emphasis goes to possible effects of anaesthesia and the animal’s physiological conditions on neural activity and the hemodynamic response. The second part of this review describes applications of the aforementioned techniques in pharmacologically-induced, as well as in traumatic and transgenic disease models and illustrates how multiple fMRI methods can be applied successfully to evaluate different aspects of a specific disorder. For example, fMRI techniques can be used to pinpoint the neural substrate of a disease beyond previously defined hypothesis-driven regions-of-interest (ROIs. In addition, fMRI techniques allow one to dissect how specific modifications (e.g. treatment, lesion etc. modulate the functioning of specific brain areas (st-fMRI, phMRI and how functional connectivity (rsfMRI between several brain regions is affected, both in acute and extended time frames. Furthermore, fMRI techniques can be used to assess/explore the efficacy of novel treatments in depth, both in fundamental research as well as in preclinical settings. In conclusion, by describing several exemplary studies, we aim to highlight the advantages of functional MRI in exploring the acute and long-term effects of pharmacological substances and/or pathology on brain functioning along with

  1. Functional magnetic resonance imaging of the primary motor cortex ...

    Indian Academy of Sciences (India)

    Unknown

    Abbreviations used: BOLD, Blood oxygenation level dependent; CBF, cerebral blood flow; fMRI, functional magnetic resonance imaging; EPI, eco-planar imaging; FOV, field of view; MRI, Magnetic resonance imaging; MRS, magnetic resonance spectroscopy;. PET, position emission tomography; rCBF, regional cerebral ...

  2. Color image coding based on recurrent iterated function systems

    Science.gov (United States)

    Kim, Kwon; Park, Rae-Hong

    1998-02-01

    This paper proposes a color image coding method based on recurrent iterated function systems (RIFSs). To encode a set of multispectral images, we apply a RIFS to multiset data consisting of three images. In the proposed method, the mappings not only between blocks within an individual spectral image but also between blocks of different spectral images are performed with contraction constraint. Simulation results show that the fractal coding based on the RIFS is useful for encoding concurrently a set of images by describing the similarity existing between a pair of images. In addition, the proposed color coding method can be applied to subband images and moving image sequences consisting of a set of images having similar gray patterns.

  3. Subband/Transform MATLAB Functions For Processing Images

    Science.gov (United States)

    Glover, D.

    1995-01-01

    SUBTRANS software is package of routines implementing image-data-processing functions for use with MATLAB*(TM) software. Provides capability to transform image data with block transforms and to produce spatial-frequency subbands of transformed data. Functions cascaded to provide further decomposition into more subbands. Also used in image-data-compression systems. For example, transforms used to prepare data for lossy compression. Written for use in MATLAB mathematical-analysis environment.

  4. Three-dimensional functional images of myocardial oxygen consumption from positron tomography

    International Nuclear Information System (INIS)

    Miller, T.R.; Wallis, J.W.; Geltman, E.M.; Bergmann, S.R.

    1990-01-01

    Images from positron emission tomography (PET) are usually presented as transaxial slices portraying tissue radioactivity. Studies can be difficult to interpret from transaxial images, and the temporal changes in tissue tracer concentrations which permit quantitative determinations of metabolism and perfusion are not displayed. We have developed a method to give quantitatively accurate three-dimensional images of myocardial oxygen consumption from serial images of the myocardial washout of carbon-11-acetate. Following i.v. bolus injection, data are collected for 20-30 min. The time-activity curves for each pixel in the transaxial slices are fit to a monoexponential function to determine the washout rate, which is directly related to the rate of myocardial oxygen utilization. Thus, functional images of myocardial oxygen consumption are produced for all seven slices of PET data. A previously developed method is then used to generate realistic and quantitatively accurate three-dimensional images

  5. Comparison of lingual tonsil size as depicted on MR imaging between children with obstructive sleep apnea despite previous tonsillectomy and adenoidectomy and normal controls

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Bradley L. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Emory University School of Medicine, Department of Radiology, Atlanta, GA (United States); Donnelly, Lane F. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Cincinnati, OH (United States); Shott, Sally R. [Cincinnati Children' s Hospital Medical Center, Division of Otolaryngology, Cincinnati, OH (United States); Kalra, Maninder; Poe, Stacy A.; Chini, Barbara A.; Amin, Raouf S. [Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Cincinnati, OH (United States)

    2006-06-15

    Cine MRI has become a useful tool in the evaluation of patients with persistent obstructive sleep apnea (OSA) despite previous surgical intervention and in patients with underlying conditions that render them susceptible to multilevel airway obstruction. Findings on cine MRI studies have also increased our understanding of the mechanisms and anatomic causes of OSA in children. To compare lingual tonsil size between children with OSA and a group of normal controls. In addition, a subanalysis was made of the group of children with OSA comparing lingual tonsils between children with and without underlying Down syndrome. Children with persistent OSA despite previous palatine tonsillectomy and adenoidectomy and controls without OSA underwent MR imaging with sagittal fast spin echo inversion-recovery images, and lingual tonsils were categorized as nonperceptible at imaging or present and measurable. When present, lingual tonsils were measured in the maximum anterior-posterior diameter. If lingual tonsils were greater than 10 mm in diameter and abutting both the posterior border of the tongue and the posterior pharyngeal wall, they were considered markedly enlarged. There were statistically significant differences between the OSA and control groups for the presence vs. nonvisualization of lingual tonsils (OSA 33% vs. control 0%, P=0.0001) and mean diameter of the lingual tonsils (OSA 9.50 mm vs. control 0.0 mm, P=0.00001). Within the OSA group, there were statistically significant differences between children with and without Down syndrome for the three lingual tonsil width categories (P=0.0070) and occurrence of markedly enlarged lingual tonsils (with Down syndrome 35% vs. without Down syndrome 3%, P=0.0035). Enlargement of the lingual tonsils is relatively common in children with persistent obstructive sleep apnea after palatine tonsillectomy and adenoidectomy. This is particularly true in patients with Down syndrome. (orig.)

  6. Comparison of lingual tonsil size as depicted on MR imaging between children with obstructive sleep apnea despite previous tonsillectomy and adenoidectomy and normal controls

    International Nuclear Information System (INIS)

    Fricke, Bradley L.; Donnelly, Lane F.; Shott, Sally R.; Kalra, Maninder; Poe, Stacy A.; Chini, Barbara A.; Amin, Raouf S.

    2006-01-01

    Cine MRI has become a useful tool in the evaluation of patients with persistent obstructive sleep apnea (OSA) despite previous surgical intervention and in patients with underlying conditions that render them susceptible to multilevel airway obstruction. Findings on cine MRI studies have also increased our understanding of the mechanisms and anatomic causes of OSA in children. To compare lingual tonsil size between children with OSA and a group of normal controls. In addition, a subanalysis was made of the group of children with OSA comparing lingual tonsils between children with and without underlying Down syndrome. Children with persistent OSA despite previous palatine tonsillectomy and adenoidectomy and controls without OSA underwent MR imaging with sagittal fast spin echo inversion-recovery images, and lingual tonsils were categorized as nonperceptible at imaging or present and measurable. When present, lingual tonsils were measured in the maximum anterior-posterior diameter. If lingual tonsils were greater than 10 mm in diameter and abutting both the posterior border of the tongue and the posterior pharyngeal wall, they were considered markedly enlarged. There were statistically significant differences between the OSA and control groups for the presence vs. nonvisualization of lingual tonsils (OSA 33% vs. control 0%, P=0.0001) and mean diameter of the lingual tonsils (OSA 9.50 mm vs. control 0.0 mm, P=0.00001). Within the OSA group, there were statistically significant differences between children with and without Down syndrome for the three lingual tonsil width categories (P=0.0070) and occurrence of markedly enlarged lingual tonsils (with Down syndrome 35% vs. without Down syndrome 3%, P=0.0035). Enlargement of the lingual tonsils is relatively common in children with persistent obstructive sleep apnea after palatine tonsillectomy and adenoidectomy. This is particularly true in patients with Down syndrome. (orig.)

  7. Functional MR Imaging in Gynecologic Cancer.

    Science.gov (United States)

    deSouza, Nandita M; Rockall, Andrea; Freeman, Susan

    2016-02-01

    Dynamic-contrast enhanced (DCE) and diffusion-weighted (DW) MR imaging are invaluable in the detection, staging, and characterization of uterine and ovarian malignancies, for monitoring treatment response, and for identifying disease recurrence. When used as adjuncts to morphologic T2-weighted (T2-W) MR imaging, these techniques improve accuracy of disease detection and staging. DW-MR imaging is preferred because of its ease of implementation and lack of need for an extrinsic contrast agent. MR spectroscopy is difficult to implement in the clinical workflow and lacks both sensitivity and specificity. If used quantitatively in multicenter clinical trials, standardization of DCE- and DW-MR imaging techniques and rigorous quality assurance is mandatory. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Functional imaging of hepatic masses using computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fujikawa, K.; Yamane, K.; Nakanishi, T.; Katsuta, S.

    1987-03-01

    In order to assess the usefulness of CT functional images, twenty one cases with liver masses were studied. We tried to minimize the motion artifacts by immobilizing the patients with a girdle in performing dynamic CT scans, and by discarding some of the segmented images with serious artifacts before constructing functional images. The qualities of images obtained were considered satisfactory. Of the several transit parameters obtained from the dynamic CT scans, we found the first moment (M1) to be most useful and the effectiveness of M1-functional images were studied. In all cases with hepatocellular carcinomas (12 cases) and intrahepatic cholangiocarcinomas (2 cases), the M1-functional images showed the viable portions of tumors as accumulations of dark pixels reflecting rapid transit times due to arterial blood supply. In three cases with hepatic cavernous hemangiomas, the lesions were represented as bright areas with a well-defined border. In two cases with hepatic abscesses, the M1-functional images suggested the presence of hyperemia in the surrounding tissue as demonstrated by bright pixels around the lesions. CT functional imaging was proved to be useful for evaluating the circulatory dynamics of contrast material and the differential diagnosis of liver tumors when conventional or dynamic CT studies failed to provide enough information. This technique enabled overall analysis of time-density curves for the entire plane of an image semiautomatically and without the subjective maneuver of setting ROI's (regions of interest).

  9. Generating text from functional brain images.

    Science.gov (United States)

    Pereira, Francisco; Detre, Greg; Botvinick, Matthew

    2011-01-01

    Recent work has shown that it is possible to take brain images acquired during viewing of a scene and reconstruct an approximation of the scene from those images. Here we show that it is also possible to generate text about the mental content reflected in brain images. We began with images collected as participants read names of concrete items (e.g., "Apartment'') while also seeing line drawings of the item named. We built a model of the mental semantic representation of concrete concepts from text data and learned to map aspects of such representation to patterns of activation in the corresponding brain image. In order to validate this mapping, without accessing information about the items viewed for left-out individual brain images, we were able to generate from each one a collection of semantically pertinent words (e.g., "door," "window" for "Apartment''). Furthermore, we show that the ability to generate such words allows us to perform a classification task and thus validate our method quantitatively.

  10. Estimating variability in functional images using a synthetic resampling approach

    International Nuclear Information System (INIS)

    Maitra, R.; O'Sullivan, F.

    1996-01-01

    Functional imaging of biologic parameters like in vivo tissue metabolism is made possible by Positron Emission Tomography (PET). Many techniques, such as mixture analysis, have been suggested for extracting such images from dynamic sequences of reconstructed PET scans. Methods for assessing the variability in these functional images are of scientific interest. The nonlinearity of the methods used in the mixture analysis approach makes analytic formulae for estimating variability intractable. The usual resampling approach is infeasible because of the prohibitive computational effort in simulating a number of sinogram. datasets, applying image reconstruction, and generating parametric images for each replication. Here we introduce an approach that approximates the distribution of the reconstructed PET images by a Gaussian random field and generates synthetic realizations in the imaging domain. This eliminates the reconstruction steps in generating each simulated functional image and is therefore practical. Results of experiments done to evaluate the approach on a model one-dimensional problem are very encouraging. Post-processing of the estimated variances is seen to improve the accuracy of the estimation method. Mixture analysis is used to estimate functional images; however, the suggested approach is general enough to extend to other parametric imaging methods

  11. Mediastinal goiter diagnosed by functional imaging | Michels ...

    African Journals Online (AJOL)

    In the next step, we initiated radionuclide imaging with technetium-99m pertechnetate (Tc-99m) and radioiodine (I-123). Low uptake of Tc-99m and intense accumulation of I-123 after 2 and 24 h to the mediastinal mass suggested that the mass was a mediastinal goiter. Based on iodine uptake and the fact that our patient ...

  12. Imaging of brain function based on the analysis of functional ...

    African Journals Online (AJOL)

    Results: The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA 37), inferior parietal lobule compared by before vs. after ...

  13. Nuclear transverse sectional brain function imager

    International Nuclear Information System (INIS)

    Stoddart, H.F.

    1982-01-01

    A transverse radionuclide scan field imaging apparatus comprises a plurality of highly focused closely laterally adjacent collimators arranged inwardly focused in an array that surrounds a scan field of interest. Each collimator is moveable relative to its adjacent collimator. Means are provided for imparting travel to the collimators such that the focal point of each uniformly samples at least one half of the scan field

  14. Single image super-resolution based on approximated Heaviside functions and iterative refinement.

    Science.gov (United States)

    Wang, Xin-Yu; Huang, Ting-Zhu; Deng, Liang-Jian

    2018-01-01

    One method of solving the single-image super-resolution problem is to use Heaviside functions. This has been done previously by making a binary classification of image components as "smooth" and "non-smooth", describing these with approximated Heaviside functions (AHFs), and iteration including l1 regularization. We now introduce a new method in which the binary classification of image components is extended to different degrees of smoothness and non-smoothness, these components being represented by various classes of AHFs. Taking into account the sparsity of the non-smooth components, their coefficients are l1 regularized. In addition, to pick up more image details, the new method uses an iterative refinement for the residuals between the original low-resolution input and the downsampled resulting image. Experimental results showed that the new method is superior to the original AHF method and to four other published methods.

  15. Single image super-resolution based on approximated Heaviside functions and iterative refinement.

    Directory of Open Access Journals (Sweden)

    Xin-Yu Wang

    Full Text Available One method of solving the single-image super-resolution problem is to use Heaviside functions. This has been done previously by making a binary classification of image components as "smooth" and "non-smooth", describing these with approximated Heaviside functions (AHFs, and iteration including l1 regularization. We now introduce a new method in which the binary classification of image components is extended to different degrees of smoothness and non-smoothness, these components being represented by various classes of AHFs. Taking into account the sparsity of the non-smooth components, their coefficients are l1 regularized. In addition, to pick up more image details, the new method uses an iterative refinement for the residuals between the original low-resolution input and the downsampled resulting image. Experimental results showed that the new method is superior to the original AHF method and to four other published methods.

  16. Pediatric applications of functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Altman, Nolan R. [Miami Children' s Hospital, Department of Radiology, Miami, FL (United States); Bernal, Byron [Miami Children' s Hospital, Pediatric Neuroradiology, Miami, FL (United States)

    2015-09-15

    Pediatric functional MRI has been used for the last 2 decades but is now gaining wide acceptance in the preoperative workup of children with brain tumors and medically refractory epilepsy. This review covers pediatrics-specific difficulties such as sedation and task paradigm selection according to the child's age and cognitive level. We also illustrate the increasing uses of functional MRI in the depiction of cognitive function, neuropsychiatric disorders and response to pharmacological agents. Finally, we review the uses of resting-state fMRI in the evaluation of children and in the detection of epileptogenic regions. (orig.)

  17. Establishment of frame image in dynamic function renal studies

    International Nuclear Information System (INIS)

    Guedes, Germano P.; Brunetto, Sergio Q.

    1996-01-01

    Statistical procedures applied to a set of images of renal function study are described to define a region of interest (ROI) on the kidneys's contours. The kidneys geometry is considered to adapt to the emitting area in every frames

  18. Functional Imaging of Dolphin Brain Metabolism and Blood Flow

    National Research Council Canada - National Science Library

    Ridgway, Sam; Finneran, James; Carder, Don; Keogh, Mandy; Van Bonn, William; Smith, Cynthia; Scadeng, Miriam; Dubowitz, David; Mattrey, Robert; Hoh, Carl

    2006-01-01

    .... Diazepam has been shown to induce unihemispheric slow waves (USW), therefore we used functional imaging of dolphins with and without diazepam to observe hemispheric differences in brain metabolism and blood flow...

  19. Functional Imaging of Dolphin Brain Metabolism and Blood Flow

    National Research Council Canada - National Science Library

    Ridgway, Sam; Finneran, James; Carder, Don; Keogh, Mandy; Van Bonn, William; Smith, Cynthia; Scadeng, Miriam; Dubowitz, David; Mattrey, Robert; Hoh, Carl

    2006-01-01

    This report documents the first use of magnetic resonance images (MRls) of living dolphins to register functional brain scans, allowing for the exploration of potential mechanisms of unihemispheric sleep...

  20. Functional magnetic resonance imaging of the primary motor cortex

    Indian Academy of Sciences (India)

    Functional magnetic resonance imaging (fMRI) studies have been performed on 20 right handed volunteers at 1.5 Tesla using echo planar imaging (EPI) protocol. Index finger tapping invoked localized activation in the primary motor area. Consistent and highly reproducible activation in the primary motor area was observed ...

  1. Cocaine: from addiction to functional imaging

    International Nuclear Information System (INIS)

    Tamgac, F.; Baillet, G.; Moretti, J.L.; Tikofski, R.

    1997-01-01

    Cocaine is wrongly held as a benign recreative drug whereas it is a highly addictive substance with possible dreadful cardiac a neurologic complications. Cocaine abuse results in patchy cerebral hypoperfusion and hypo-metabolism, clearly demonstrated by PET and SPECT imaging. Improvement after drug withdrawal is still unclear. Cocaine binds with a very high affinity to the dopamine reuptake transporter. Labelled cocaine congeners can be used to assess dopaminergic pathways, especially nigrostriatal neurons that play a key role in movement control. 123 I labelled beta-CIT can reproducibly be used to measure dopamine transporter density in the striatum, in one day. This approach seems very promising. (authors)

  2. Brain atlas for functional imaging. Clinical and research applications

    Energy Technology Data Exchange (ETDEWEB)

    Nowinski, W.L.; Thirunavuukarasuu, A.; Kennedy, D.N

    2001-07-01

    This CD-ROM: Allows anatomical and functional images to be loaded and registered. Enables interactive placement of the Talairach landmarks in 3D Space. Provides automatic data-to-atlas warping based on the Talairaich proportional gridsystem transformation. Real-time interactive warping for fine tuning is also available. Allows the user to place marks on the activation loci in the warped functional images, display these marks with the atlas, and edit them in three planes. Mark placement is assisted by image thresholding. Provides simultaneous display of the atlas, anatomical image and functional image within one interactively blended image. Atlas-data blending and anatomical-functional image blending are controlled independently. Labels the data by means of the atlas. The atlas can be flipped left/right so that Brodmann's areas and gyri can be labeled on both hemispheres. Provides additional functions such as friendly navigation, cross-referenced display, readout of the Talairach coordinates and intensities, load coordinates, save, on-line help. (orig.)

  3. Brain atlas for functional imaging. Clinical and research applications

    International Nuclear Information System (INIS)

    Nowinski, W.L.; Thirunavuukarasuu, A.; Kennedy, D.N

    2001-01-01

    This CD-ROM: Allows anatomical and functional images to be loaded and registered. Enables interactive placement of the Talairach landmarks in 3D Space. Provides automatic data-to-atlas warping based on the Talairaich proportional gridsystem transformation. Real-time interactive warping for fine tuning is also available. Allows the user to place marks on the activation loci in the warped functional images, display these marks with the atlas, and edit them in three planes. Mark placement is assisted by image thresholding. Provides simultaneous display of the atlas, anatomical image and functional image within one interactively blended image. Atlas-data blending and anatomical-functional image blending are controlled independently. Labels the data by means of the atlas. The atlas can be flipped left/right so that Brodmann's areas and gyri can be labeled on both hemispheres. Provides additional functions such as friendly navigation, cross-referenced display, readout of the Talairach coordinates and intensities, load coordinates, save, on-line help. (orig.)

  4. Supplementary value of functional imaging in forensic medicine.

    Science.gov (United States)

    Mirzaei, Siroos; Sonneck-Koenne, Charlotte; Bruecke, Thomas; Aryana, Kamran; Knoll, Peter; Zakavi, Rasoul

    2012-01-01

    The aim of this study is to evaluate the role of functional imaging for forensic purposes. We reviewed a few outpatient cases that were sent to our department for examination after traumatic events and one case with neuropsychic disturbances. Functional imaging showed signs of traumatic lesions in the skeletal system, of brain metabolism and of renal failure. Functional disturbances following traumatic events are in some cases more important than morphological abnormalities. Targeted scintigraphic examinations could be applied for visualisation of traumatic lesions or evaluation of functional disturbances caused by traumatic events. These examinations can be used as evidence in the courtroom.

  5. Imaging and functional assessment of bioresorbable scaffolds.

    Science.gov (United States)

    Pighi, Michele; Tanguay, Jean F; L'allier, Philippe L

    2016-08-01

    Bioresorbable vascular scaffolds (BRS) are novel devices designed to provide transient vessel support to drug-delivery capability without the potential long-term limitations of metallic drug-eluting stents. The technology, heralded as the latest revolution in the field of percutaneous coronary intervention, could overcome many of the long-term safety concerns associated with metallic stents and possibly even convey a further clinical benefit. However, despite its theoretical advantages, the safety and efficacy of the first generation BRS remain unclear in all-comer patient populations. Invasive imaging modalities and methodologies were developed to guide BRS implantation and monitor the interaction between the scaffold and the vessel at long-term follow-up. These tools are helpful to avoid some of the pitfalls associated with BRS implantation and may improve the clinical outcome of these devices. The present review aims to report the most recent data regarding multi-imaging modalities as guidance and follow-up of coronary interventions involving the use of BRS.

  6. Functional MR imaging of the patellofemoral joint

    International Nuclear Information System (INIS)

    Muhle, C.; Brossmann, J.; Heller, M.

    1995-01-01

    Conventional X-ray examinations of the patellofemoral joint in 30 , 60 and 90 of knee flexion demonstrate the position of the patella. On the other hand, they have been shown to be insufficient for the diagnosis of patellofemoral maltracking in the critical range between 30 of flexion and full extension. Motion-triggered and ultrafast MRI offer new possibilities for functional diagnosis of the patellofemoral joint under active knee motion. Functional MRI of the patellofemoral joint is suggested as an alternative to arthroscopy, particularly in patients with anterior knee pain or suspected patellar maltracking. (orig.) [de

  7. Imaging and assessment of placental function.

    LENUS (Irish Health Repository)

    Moran, Mary

    2011-09-01

    The placenta is the vital support organ for the developing fetus. This article reviews current ultrasound (US) methods of assessing placental function. The ability of ultrasound to detect placental pathology is discussed. Doppler technology to investigate the fetal, placental, and maternal circulations in both high-risk and uncomplicated pregnancies is discussed and the current literature on the value of three-dimensional power Doppler studies to assess placental volume and vascularization is also evaluated. The article highlights the need for further research into three-dimensional ultrasound and alternative methods of placental evaluation if progress is to be made in optimizing placental function assessment.

  8. Multicentre evaluation of targeted and systematic biopsies using magnetic resonance and ultrasound image-fusion guided transperineal prostate biopsy in patients with a previous negative biopsy.

    Science.gov (United States)

    Hansen, Nienke L; Kesch, Claudia; Barrett, Tristan; Koo, Brendan; Radtke, Jan P; Bonekamp, David; Schlemmer, Heinz-Peter; Warren, Anne Y; Wieczorek, Kathrin; Hohenfellner, Markus; Kastner, Christof; Hadaschik, Boris

    2017-11-01

    To evaluate the detection rates of targeted and systematic biopsies in magnetic resonance imaging (MRI) and ultrasound (US) image-fusion transperineal prostate biopsy for patients with previous benign transrectal biopsies in two high-volume centres. A two centre prospective outcome study of 487 patients with previous benign biopsies that underwent transperineal MRI/US fusion-guided targeted and systematic saturation biopsy from 2012 to 2015. Multiparametric MRI (mpMRI) was reported according to Prostate Imaging Reporting and Data System (PI-RADS) Version 1. Detection of Gleason score 7-10 prostate cancer on biopsy was the primary outcome. Positive (PPV) and negative (NPV) predictive values including 95% confidence intervals (95% CIs) were calculated. Detection rates of targeted and systematic biopsies were compared using McNemar's test. The median (interquartile range) PSA level was 9.0 (6.7-13.4) ng/mL. PI-RADS 3-5 mpMRI lesions were reported in 343 (70%) patients and Gleason score 7-10 prostate cancer was detected in 149 (31%). The PPV (95% CI) for detecting Gleason score 7-10 prostate cancer was 0.20 (±0.07) for PI-RADS 3, 0.32 (±0.09) for PI-RADS 4, and 0.70 (±0.08) for PI-RADS 5. The NPV (95% CI) of PI-RADS 1-2 was 0.92 (±0.04) for Gleason score 7-10 and 0.99 (±0.02) for Gleason score ≥4 + 3 cancer. Systematic biopsies alone found 125/138 (91%) Gleason score 7-10 cancers. In patients with suspicious lesions (PI-RADS 4-5) on mpMRI, systematic biopsies would not have detected 12/113 significant prostate cancers (11%), while targeted biopsies alone would have failed to diagnose 10/113 (9%). In equivocal lesions (PI-RADS 3), targeted biopsy alone would not have diagnosed 14/25 (56%) of Gleason score 7-10 cancers, whereas systematic biopsies alone would have missed 1/25 (4%). Combination with PSA density improved the area under the curve of PI-RADS from 0.822 to 0.846. In patients with high probability mpMRI lesions, the highest detection rates of Gleason

  9. Rehabilitative ultrasound imaging of pelvic floor muscle function.

    Science.gov (United States)

    Whittaker, Jackie L; Thompson, Judith A; Teyhen, Deydre S; Hodges, Paul

    2007-08-01

    This commentary provides an overview of the current concepts and evidence related to rehabilitative ultrasound imaging of pelvic floor (levator ani) function. As this is an emerging topic, the goal is to provide a basic understanding of ultrasound imaging applications related to levator ani function: the available quantitative and qualitative information, the limitations, as well as how ultrasound imaging can be incorporated as a form of biofeedback during rehabilitation. Furthermore, as the ability to compile and compare existing evidence depends on the degree of similarity in methodology by investigators, this commentary highlights points of consideration and provides guidelines, as well as an agenda, for future investigation.

  10. Image segmentation based on scaled fuzzy membership functions

    DEFF Research Database (Denmark)

    Jantzen, Jan; Ring,, P.; Christiansen, Pernille

    1993-01-01

    As a basis for an automated interpretation of magnetic resonance images, the authors propose a fuzzy segmentation method. The method uses five standard fuzzy membership functions: small, small medium, medium, large medium, and large. The method fits these membership functions to the modes...... of interest in the image histogram by means of a piecewise-linear transformation. A test example is given concerning a human head image, including a sensitivity analysis based on the fuzzy area measure. The method provides a rule-based interface to the physician...

  11. Image of the state in social constructivism and structural functionalism

    Directory of Open Access Journals (Sweden)

    A. O. Pocelujko

    2015-05-01

    In structural functionalism state image viewed through the prism of symbolic codes as hidden or deep structure of the social system that has a four­layer structure and follows the four levels of the social order. These levels are chotyryma tsinisno­semantic centers (central zone, the focus of institutionalization, Historical, Cultural­Political and geopolitical concepts, social and cultural identity. These four components of the image corresponds to four levels of society social order, forming a hierarchy of images, including the image of the state as part of the political agenda occupies a subordinate position on religious and cosmological, cultural and social order. Each of these components correspond symbolic codes as tools in establishing the identity of its borders, helping to establish its cultural and physical boundaries, the formation of the registry needs kordonoutvorennya other societies (states and the range of possible responses to pressure environment. Symbolic codes perform on the formation of social representations of the state and therefore the image of the state, programmable function because the logic of structural functionalism Eisenstadt, four levels correspond to the order of four types of images that can be played funktsionuvaty and as social representations, including: religious, cultural, social and political. The idea of the state and the image of the state, therefore, can not act on something autonomous value­semantic, focal­institutional, geopolitical and ethno­political and social images and, last can also remain or blurry.

  12. Treatment response in psychotic patients classified according to social and clinical needs, drug side effects, and previous treatment; a method to identify functional remission

    DEFF Research Database (Denmark)

    Alenius, Malin; Hammarlund-Udenaes, Margareta; Honoré, Per Gustaf Hartvig

    2009-01-01

    ; underestimating residual symptoms, negative symptoms, and side effects; or being to open for individual interpretation. The aim of this study was to present and evaluate a new method of classification according to treatment response and, thus, to identify patients in functional remission. METHOD: A naturalistic......, cross-sectional study was performed using patient interviews and information from patient files. The new classification method CANSEPT, which combines the Camberwell Assessment of Need rating scale, the Udvalg for Kliniske Undersøgelser side effect rating scale (SE), and the patient's previous treatment...... history (PT), was used to group the patients according to treatment response. CANSEPT was evaluated by comparison of expected and observed results. RESULTS: In the patient population (n = 123), the patients in functional remission, as defined by CANSEPT, had higher quality of life, fewer hospitalizations...

  13. Functional magnetic resonance imaging of the primary motor cortex ...

    Indian Academy of Sciences (India)

    Unknown

    cerebral pathophysiology, characterization and distinct regional mapping of human cognitive functions such as vision, motor, language, memory, etc. ..... Rosen B R 1991 Functional mapping of the human visual cortex by magnetic resonance imaging; Science 254 716–. 719. Blinkenberg M, Bonde C, Holm S, Svarer C, ...

  14. [Functional magnetic resonance imaging and dynamic neuroanatomy of addictive disorders].

    Science.gov (United States)

    Mel'nikov, M E; Shtark, M B

    2014-01-01

    Research into the cerebral patterns that govern the formation and development of addictive behavior is one of the most interesting goals of neurophysiology. Authors of contemporary papers on the matter define a number of symptoms that are all part of substance or non-substance dependence, each one of them leading to abnormalities in the corresponding system of the brain. During the last twenty years the functional magnetic resonance imaging (fMR1) technology has been instrumental in locating such abnormalities, identifying specific parts of the brain that, when dysfunctional, may enhance addiction and cause its positive or negative symptoms. This article reviews fMRI studies aimed toward locating areas in the brain that are responsible for cognitive, emotional, and motivational dysfunction. Cerebral correlatives of impulsiveness, behavior control, and drug cravings are reviewed separately. The article also contains an overview of possibilities to further investigate the Selves of those dependent on substances, identify previously unknown diagnostic markers of substance dependence, and evaluate the effectiveness of therapy. The research under review in this article provides data that points to a special role of the nucleus caudatus as well as the nucleus accumbens, the thalamus, the insular cortex (IC), the anterior cingulate, prefrontal and orbitofrontal areas in psychological disorders that are part of substance dependence. General findings of the article are in accordance with contemporary models of addictive pattern.

  15. Functional imaging of sympathetic activation during mental stress.

    Science.gov (United States)

    Fechir, M; Gamer, M; Blasius, I; Bauermann, T; Breimhorst, M; Schlindwein, P; Schlereth, T; Birklein, F

    2010-04-01

    Activation of the sympathetic nervous system (SNS) is essential in adapting to environmental stressors and in maintaining homeostasis. This reaction can also turn into maladaptation, associated with a wide spectrum of stress-related diseases. Up to now, the cortical mechanisms of sympathetic activation in acute mental stress have not been sufficiently characterized. We therefore investigated cerebral activation applying functional magnetic resonance imaging (fMRI) during performance of a mental stress task with graded levels of difficulty, i.e. four versions of a Stroop task (Colour Word Interference Test, CWT) in healthy subjects. To analyze stress-associated sympathetic activation, skin conductance and heart rate were continuously recorded. The results show that sympathetic activation through mental stress is associated with distinct cerebral regions being immediately involved in task performance (visual, motor, and premotor areas). Other activated regions (right insula, dorsolateral superior frontal gyrus, cerebellar regions) are unrelated to task performance. These latter regions have previously been considered to be involved in mediating different stress responses. The results might furthermore serve as a basis for future investigations of the connection between these cortical regions in the generation of stress-related diseases. Copyright 2009 Elsevier Inc. All rights reserved.

  16. Venous refocusing for volume estimation: VERVE functional magnetic resonance imaging.

    Science.gov (United States)

    Stefanovic, Bojana; Pike, G Bruce

    2005-02-01

    A novel, noninvasive magnetic resonance imaging-based method for measuring changes in venous cerebral blood volume (CBV(v)) is presented. Venous refocusing for volume estimation (VERVE) exploits the dependency of the spin-spin relaxation rate of deoxygenated blood on the refocusing interval. Interleaved CPMG EPI acquisitions following a train of either tightly or sparsely spaced hard refocusing pulses (every 3.7 or 30 msec, respectively) at matched echo time were used to isolate the blood signal while minimizing the intravascular blood oxygenation level dependent (BOLD) signal contribution. The technique was employed to determine the steady-state increase in the CBV(v) in the visual cortex (VC) in seven healthy adult volunteers during flickering checkerboard photic stimulation. A functional activation model and a set of previously collected in vitro human whole blood relaxometry data were used to evaluate the intravascular BOLD effect on the VERVE signal. The average VC venous blood volume change was estimated to be 16 +/- 2%. This method has the potential to provide efficient and continuous monitoring of venous cerebral blood volume, thereby enabling further exploration of the mechanism underlying BOLD signal changes upon physiologic, pathophysiologic, and pharmacologic perturbations.

  17. Software Tools for the Analysis of Functional Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Mehdi Behroozi

    2012-09-01

    Full Text Available Functional magnetic resonance imaging (fMRI has become the most popular method for imaging of brain functions. Currently, there is a large variety of software packages for the analysis of fMRI data, each providing many features for users. Since there is no single package that can provide all the necessary analyses for the fMRI data, it is helpful to know the features of each software package. In this paper, several software tools have been introduced and they have been evaluated for comparison of their functionality and their features. The description of each program has been discussed and summarized.

  18. Software Tools for the Analysis of functional Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Mehdi Behroozi

    2012-12-01

    Full Text Available Functional magnetic resonance imaging (fMRI has become the most popular method for imaging of brain functions. Currently, there is a large variety of software packages for the analysis of fMRI data, each providing many features for users. Since there is no single package that can provide all the necessary analyses for the fMRI data, it is helpful to know the features of each software package. In this paper, several software tools have been introduced and they have been evaluated for comparison of their functionality and their features. The description of each program has been discussed and summarized

  19. Robot-assisted radical prostatectomy in the setting of previous abdominal surgery: Perioperative results, oncological and functional outcomes, and complications in a single surgeon's series.

    Science.gov (United States)

    Di Pierro, Giovanni Battista; Grande, Pietro; Mordasini, Livio; Danuser, Hansjörg; Mattei, Agostino

    2016-12-01

    Data on safety and efficacy of robot-assisted radical prostatectomy (RARP) after previous abdominal surgery are scarce. Hence, we assessed perioperative, oncological and functional outcomes, and complications of RARP in patients with previous abdominal surgery after 1-year minimum follow-up. Prospectively collected data from 339 consecutive patients undergoing transperitoneal RARP by a single surgeon (AM) between November 2008 and May 2014 were analysed. Complications were classified according to Modified Clavien System. Biochemical recurrence (BCR) was defined as two consecutive PSA values ≥ 0.2 ng/ml. Functional outcomes were assessed using validated, self-administered questionnaires. In particular, only patients undergoing nerve-sparing RARP with no erectile dysfunction (baseline IIEF-5 score >21) and no use of phosphodiesterase-5 inhibitors preoperatively who were interested in erections and required no adjuvant therapy (radiation, orchiectomy and androgen-deprivation therapy) were evaluated concerning potency recovery. Patients without and with previous abdominal surgery were compared using Mann-Whitney and chi-square tests (or Fisher exact test). On 339 patients, 247 (71.6%) had not undergone previous abdominal surgery (Group 1) and 92 (28.4%) were pre-operated (Group 2). There were no statistically significant differences between Groups 1 and 2 regarding mean operative time (260 vs. 257 min; p = 0.597), median number of resected nodes (16 vs. 17; p = 0.484), mean length of stay (7.2 vs. 7.1 d; p = 0.151), positive surgical margin (12.5% vs. 16.3%; p = 0.233) and complication rates (26.7% vs. 31.5%; p = 0.187). Median (IQR) follow-up was 36 (12-48) months. For Groups 1 and 2, BCR-free survival rates were 78.5% and 79.8% (p = 0.467); continence rates were 97.9% and 100% (p = 0.329), whereas a potency recovery was achieved in 69.5% and 62.2% of patients (p = 0.460), respectively. Transperitoneal RARP is a safe and efficient treatment for

  20. EANM/ESC guidelines for radionuclide imaging of cardiac function

    DEFF Research Database (Denmark)

    Hesse, B.; Lindhardt, T.B.; Acampa, W.

    2008-01-01

    Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibrium...... radionuclide ventriculography, gated myocardial perfusion scintigraphy, gated PET, and studies with non-imaging devices for the evaluation of cardiac function. The items covered are presented in 11 sections: clinical indications, radiopharmaceuticals and dosimetry, study acquisition, RV EF, LV EF, LV volumes......, LV regional function, LV diastolic function, reports and image display and reference values from the literature of RVEF, LVEF and LV volumes. If specific recommendations given cannot be based on evidence from original, scientific studies, referral is given to "prevailing or general consensus...

  1. Development of contrast-enhanced rodent imaging using functional CT

    Science.gov (United States)

    Liang, Yun; Stantz, Keith M.; Krishnamurthi, Ganapathy; Steinmetz, Rosemary; Hutchins, Gary D.

    2003-05-01

    Micro-computed tomography (microCT) is capable of obtaining high-resolution images of skeletal tissues. However its image contrast among soft tissues remains inadequate for tumor detection. High speed functional computed tomography will be needed to image tumors by employing x-ray contrast medium. The functional microCT development will not only facilitate the image contrast enhancement among different tissues but also provide information of tumor physiology. To demonstrate the feasibility of functional CT in mouse imaging, sequential computed tomography is performed in mice after contrast material administration using a high-speed clinical CT scanner. Although the resolution of the clinical scanner is not sufficient to dissolve the anatomic details of rodents, bulky physiological parameters in major organs such as liver, kidney, pancreas, and ovaries (testicular) can be examined. For data analysis, a two-compartmental model is employed and implemented to characterize the tissue physiological parameters (regional blood flow, capillary permeability, and relative compartment volumes.) The measured contrast dynamics in kidneys are fitted with the compartmental model to derive the kidney tissue physiology. The study result suggests that it is feasible to extract mouse tissue physiology using functional CT imaging technology.

  2. Functional magnetic resonance imaging (FMRI) and expert testimony.

    Science.gov (United States)

    Kulich, Ronald; Maciewicz, Raymond; Scrivani, Steven J

    2009-03-01

    Medical experts frequently use imaging studies to illustrate points in their court testimony. This article reviews how these studies impact the credibility of expert testimony with judges and juries. The apparent "objective" evidence provided by such imaging studies can lend strong credence to a judge's or jury's appraisal of medical expert's testimony. However, as the court usually has no specialized scientific expertise, the use of complex images as part of courtroom testimony also has the potential to mislead or at least inappropriately bias the weight given to expert evidence. Recent advances in brain imaging may profoundly impact forensic expert testimony. Functional magnetic resonance imaging and other physiologic imaging techniques currently allow visualization of the activation pattern of brain regions associated with a wide variety of cognitive and behavioral tasks, and more recently, pain. While functional imaging technology has a valuable role in brain research and clinical investigation, it is important to emphasize that the use of imaging studies in forensic matters requires a careful scientific foundation and a rigorous legal assessment.

  3. The value of attenuation correction by hybrid SPECT/CT imaging on infarct size quantification in male patients with previous inferior myocardial infarct.

    Science.gov (United States)

    Giubbini, Raffaele Mario Tarquinio; Gabanelli, Sara; Lucchini, Silvia; Merli, Giuseppe; Puta, Erinda; Rodella, Carlo; Motta, Federica; Paghera, Barbara; Rossini, Pierluigi; Terzi, Arturo; Bertagna, Francesco

    2011-11-01

    Attenuation correction (AC) has been shown to improve the accuracy of myocardial perfusion single photon emission computed tomography (SPECT) for the detection and evaluation of patients with coronary artery disease. Attenuation artifacts, because of diaphragmatic attenuation, frequently affect the evaluation of the inferior wall, especially in male patients. The aim of this study was to evaluate the value of AC for the assessment of infarct size in coronary artery disease patients after inferior myocardial infarction. Gated-SPECT with Tc-labeled compounds with AC by hybrid SPECT/computed tomography (CT) was performed in 56 male patients with documented previous inferior myocardial infarction. Both corrected and uncorrected SPECT images were processed after motion and scatter correction by ordered-subset expectation maximization iterative reconstruction. When needed, a manual realignment between SPECT and computed tomography (CT) sections was performed. Uncorrected and corrected SPECT images were analyzed for perfusion using a 5-point segmental scoring scale from 0 (normal) to 4 (absent). Summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) of the inferior left ventricle wall (inferoseptal, inferior, infero-apical and infero-lateral segments) were determined and compared with the regional wall motion score as determined by uncorrected gated-SPECT. The SSS, SRS, SDS for attenuation-uncorrected and attenuation-corrected studies were 14.02 ± 7.9, 9.51 ± 7, 4.5 ± 3.2 and 9.39 ± 7.1, 5.6 ± 6.1, 3.8 ± 2.8, respectively. Differences were statistically significant (P<0.0001) for SSS and SRS but not for SDS. The regional summed rest score of the inferior wall (SRS of inferior segments) showed a better correlation with the regional summed wall motion score of the same segments: R²=0.50 in comparison to uncorrected SRS, R²=0.46. The combination of diaphragmatic attenuation and inferior myocardial infarction determines an artifactual

  4. Functional imaging - a new tool for X-ray functional diagnostics

    International Nuclear Information System (INIS)

    Boehm, M.; Erbe, W.; Sonne, B.; Hoehne, K.H.; Nicolae, G.C.; Pfeiffer, G.

    1978-05-01

    The method of functional imaging is applied to X-ray angiograms. Functional images are generated by inserting at each point of an X-ray image a computed grey value proportional to a dynamic parameter (such as blood velocity) instead of the recorded X-ray absorption value. For this purpose a new system for angiographic image processing has been developed. First results show that the method is a tool to extract more information about the blood dynamics in organs in an easier and faster way than with the conventional angiographic technique. (orig.)

  5. Current Status of Functional Imaging in Eating Disorders

    OpenAIRE

    Frank, Guido K.W.; Kaye, Walter H.

    2012-01-01

    Eating Disorders are complex psychiatric problems that involve biologic and psychological factors. Brain imaging studies provide insights how functionally connected brain networks may contribute to disturbed eating behavior, resulting in food refusal and altered body weight, but also body preoccupations and heightened anxiety. In this article we review the current state of brain imaging in eating disorders, and how such techniques may help identify pathways that could be important in the trea...

  6. Structural and functional imaging for vascular targeted photodynamic therapy

    Science.gov (United States)

    Li, Buhong; Gu, Ying; Wilson, Brian C.

    2017-02-01

    Vascular targeted photodynamic therapy (V-PDT) has been widely used for the prevention or treatment of vascular-related diseases, such as localized prostate cancer, wet age-related macular degeneration, port wine stains, esophageal varices and bleeding gastrointestinal mucosal lesions. In this study, the fundamental mechanisms of vascular responses during and after V-PDT will be introduced. Based on the V-PDT treatment of blood vessels in dorsal skinfold window chamber model, the structural and functional imaging, which including white light microscopy, laser speckle imaging, singlet oxygen luminescence imaging, and fluorescence imaging for evaluating vascular damage will be presented, respectively. The results indicate that vessel constriction and blood flow dynamics could be considered as the crucial biomarkers for quantitative evaluation of vascular damage. In addition, future perspectives of non-invasive optical imaging for evaluating vascular damage of V-PDT will be discussed.

  7. Epistemic Function and Ontology of Analog and Digital Images

    Directory of Open Access Journals (Sweden)

    Aleksandra Łukaszewicz Alcaraz

    2016-01-01

    Full Text Available The important epistemic function of photographic images is their active role in construction and reconstruction of our beliefs concerning the world and human identity, since we often consider photographs as presenting reality or even the Real itself. Because photography can convince people of how different social and ethnic groups and even they themselves look, documentary projects and the dissemination of photographic practices supported the transition from disciplinary society to the present-day society of control. While both analog and digital images are formed from the same basic materia, the ways in which this matter appears are distinctive. In the case of analog photography, we deal with physical and chemical matter, whereas with digital images we face electronic matter. Because digital photography allows endless modification of the image, we can no longer believe in the truthfulness of digital images.

  8. Functional MRI studies of human vision on a clinical imager

    International Nuclear Information System (INIS)

    George, J.S.; Lewine, J.D.; Aine, C.J.; van Hulsteyn, D.; Wood, C.C.; Sanders, J.; Maclin, E.; Belliveau, J.W.; Caprihan, A.

    1992-01-01

    During the past decade, Magnetic Resonance Imaging (MRI) has become the method of choice for imaging the anatomy of the human brain. Recently, Belliveau and colleagues have reported the use of echo planar magnetic resonance imaging (EPI) to image patterns of neural activity. Here, we report functional MR imaging in response to visual stimulation without the use of contrast agents, and without the extensive hardware modifications required for EPI. Regions of activity were observed near the expected locations of V1, V2 and possibly V3 and another active region was observed near the parietal-occipital sulcus on the superior surface of the cerebrum. These locations are consistent with sources observed in neuromagnetic studies of the human visual response

  9. Challenges of functional imaging research of pain in children

    Directory of Open Access Journals (Sweden)

    Sava Simona

    2009-06-01

    Full Text Available Abstract 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 in patients with chronic pain. However, most studies have been performed in adults. Because functional imaging is non-invasive and can be performed in awake individuals, applications in children have become more prevalent, but only recently in the pain field. Measures of changes in the brains of children have important implications in understanding neural plasticity in response to acute and chronic pain in the developing brain. Such findings may have implications for treatments in children affected by chronic pain and provide novel insights into chronic pain syndromes in adults. In this review we summarize this potential and discuss specific concerns related to the imaging of pain in children.

  10. Functional requirements for a central research imaging data repository.

    Science.gov (United States)

    Franke, Thomas; Gruetz, Romanus; Dickmann, Frank

    2013-01-01

    The current situation at many university medical centers regarding the management of biomedical research imaging data leaves much to be desired. In contrast to the recommendations of the German Research Foundation (DFG) and the German Council of Sciences and Humanities regarding the professional management of research data, there are commonly many individual data pools for research data in each institute and the management remains the responsibility of the researcher. A possible solution for this situation would be to install local central repositories for biomedical research imaging data. In this paper, we developed a scenario based on abstracted use-cases for institutional research undertakings as well as collaborative biomedical research projects and analyzed the functional requirements that a local repository would have to fulfill. We determined eight generic categories of functional requirements, which can be viewed as a basic guideline for the minimum functionality of a central repository for biomedical research imaging data.

  11. Imaging Brain Function with Functional Near-Infrared Spectroscopy in Unconstrained Environments

    Directory of Open Access Journals (Sweden)

    Joana B. Balardin

    2017-05-01

    Full Text Available Assessing the neural correlates of motor and cognitive processes under naturalistic experimentation is challenging due to the movement constraints of traditional brain imaging technologies. The recent advent of portable technologies that are less sensitive to motion artifacts such as Functional Near Infrared Spectroscopy (fNIRS have been made possible the study of brain function in freely-moving participants. In this paper, we describe a series of proof-of-concept experiments examining the potential of fNIRS in assessing the neural correlates of cognitive and motor processes in unconstrained environments. We show illustrative applications for practicing a sport (i.e., table tennis, playing a musical instrument (i.e., piano and violin alone or in duo and performing daily activities for many hours (i.e., continuous monitoring. Our results expand upon previous research on the feasibility and robustness of fNIRS to monitor brain hemodynamic changes in different real life settings. We believe that these preliminary results showing the flexibility and robustness of fNIRS measurements may contribute by inspiring future work in the field of applied neuroscience.

  12. Expression patterns of platypus defensin and related venom genes across a range of tissue types reveal the possibility of broader functions for OvDLPs than previously suspected.

    Science.gov (United States)

    Whittington, Camilla M; Papenfuss, Anthony T; Kuchel, Philip W; Belov, Katherine

    2008-09-15

    The platypus, as an egg-laying mammal, displays an unusual mixture of reptilian and mammalian characteristics. It is also venomous, and further investigations into its little-studied venom may lead to the development of novel pharmaceuticals and drug targets and provide insights into the origins of mammalian venom. Here we investigate the expression patterns of antimicrobial genes called defensins, and also the venom peptides called defensin-like peptides (OvDLPs). We show, in the first expression study on any platypus venom gene, that the OvDLPs are expressed in a greater range of tissues than would be expected for genes with specific venom function, and thus that they may have a wider role than previously suspected.

  13. Imaging insights into basal ganglia function, Parkinson's disease, and dystonia.

    Science.gov (United States)

    Stoessl, A Jon; Lehericy, Stephane; Strafella, Antonio P

    2014-08-09

    Recent advances in structural and functional imaging have greatly improved our ability to assess normal functions of the basal ganglia, diagnose parkinsonian syndromes, understand the pathophysiology of parkinsonism and other movement disorders, and detect and monitor disease progression. Radionuclide imaging is the best way to detect and monitor dopamine deficiency, and will probably continue to be the best biomarker for assessment of the effects of disease-modifying therapies. However, advances in magnetic resonance enable the separation of patients with Parkinson's disease from healthy controls, and show great promise for differentiation between Parkinson's disease and other akinetic-rigid syndromes. Radionuclide imaging is useful to show the dopaminergic basis for both motor and behavioural complications of Parkinson's disease and its treatment, and alterations in non-dopaminergic systems. Both PET and MRI can be used to study patterns of functional connectivity in the brain, which is disrupted in Parkinson's disease and in association with its complications, and in other basal-ganglia disorders such as dystonia, in which an anatomical substrate is not otherwise apparent. Functional imaging is increasingly used to assess underlying pathological processes such as neuroinflammation and abnormal protein deposition. This imaging is another promising approach to assess the effects of treatments designed to slow disease progression. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Interpreting "Personality" Taxonomies: Why Previous Models Cannot Capture Individual-Specific Experiencing, Behaviour, Functioning and Development. Major Taxonomic Tasks Still Lay Ahead.

    Science.gov (United States)

    Uher, Jana

    2015-12-01

    As science seeks to make generalisations, a science of individual peculiarities encounters intricate challenges. This article explores these challenges by applying the Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals (TPS-Paradigm) and by exploring taxonomic "personality" research as an example. Analyses of researchers' interpretations of the taxonomic "personality" models, constructs and data that have been generated in the field reveal widespread erroneous assumptions about the abilities of previous methodologies to appropriately represent individual-specificity in the targeted phenomena. These assumptions, rooted in everyday thinking, fail to consider that individual-specificity and others' minds cannot be directly perceived, that abstract descriptions cannot serve as causal explanations, that between-individual structures cannot be isomorphic to within-individual structures, and that knowledge of compositional structures cannot explain the process structures of their functioning and development. These erroneous assumptions and serious methodological deficiencies in widely used standardised questionnaires have effectively prevented psychologists from establishing taxonomies that can comprehensively model individual-specificity in most of the kinds of phenomena explored as "personality", especially in experiencing and behaviour and in individuals' functioning and development. Contrary to previous assumptions, it is not universal models but rather different kinds of taxonomic models that are required for each of the different kinds of phenomena, variations and structures that are commonly conceived of as "personality". Consequently, to comprehensively explore individual-specificity, researchers have to apply a portfolio of complementary methodologies and develop different kinds of taxonomies, most of which have yet to be developed. Closing, the article derives some meta-desiderata for future research on individuals' "personality".

  15. The study of CT pulmonary functional imaging technique

    International Nuclear Information System (INIS)

    Zhang Weihong; Liu Yuqing; Mou Weibin

    2001-01-01

    Objective: To evaluate the feasibility of CT pulmonary function imaging with emphasis on the results of the correlation between CT functional imaging parameters and that of pulmonary functional tests. Methods: The study population was 69 cases. According to the results of pulmonary functional tests (PFT), 21 persons with normal lung function, 37 patients with obstructive lung function abnormality, 9 with restrictive lung function abnormality, and 2 with mixed lung function abnormality were included. The CT scanning and pulmonary function tests were performed within one week for all of the cases. Spiral CT scans were obtained during breath hold at full inspiration and full expiration from the lung bases to the lung apices. The scanning parameters were as fellows: 120 kV, 175 mA, one revolution per second; 10 mm slice thickness; 20 mm/s table speed (pitch 2). The images were reconstructed by 10 mm slice thickness and standard algorithm, and then were archived and transferred digitally to personal computer for analysis. A CT pulmonary functional quantitative software designed by the authors was used to analysis all images. Results: Using full inspiratory and expirator spiral CT, total lung capacity (Vin) and residual capacity (Vex) were revealed, which had a good correlation with results obtained by pulmonary function tests (r = 0.866, P < 0.001; r = 0.833, P < 0.001). Vex/Vin showed correlation with RV/TLC (r = 0.590, P < 0.001). The mean lung CT value obtained at full inspiratory phase showed correlation with FEV 1%, FEV1/FVC (r = 0.382, P < 0.05; r = 0.682, P < 0.01). PI = -910- -950 HU were found to correlate with FEV1, FEV1%, FVC%, FEV1/FVC, especially to have good correlation with FEV1/FVC (r = 0.747 - 0.772, P < 0.01). The mean lung CT value obtained at full expiratory phase also showed correlation with FEV1, FEV1%, FVC%, FEV1/FVC (r = 0.624, P < 0.01; r = 0.654, P < 0.01; r = 0.452, P < 0.01; r = 0.758, P < 0.01); Several pixel index (PI) at expiratory also

  16. EANM/ESC guidelines for radionuclide imaging of cardiac function

    DEFF Research Database (Denmark)

    Hesse, B.; Lindhardt, T.B.; Acampa, W.

    2008-01-01

    Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibrium...... radionuclide ventriculography, gated myocardial perfusion scintigraphy, gated PET, and studies with non-imaging devices for the evaluation of cardiac function. The items covered are presented in 11 sections: clinical indications, radiopharmaceuticals and dosimetry, study acquisition, RV EF, LV EF, LV volumes...

  17. Fast undersampled functional magnetic resonance imaging using nonlinear regularized parallel image reconstruction.

    Directory of Open Access Journals (Sweden)

    Thimo Hugger

    Full Text Available In this article we aim at improving the performance of whole brain functional imaging at very high temporal resolution (100 ms or less. This is achieved by utilizing a nonlinear regularized parallel image reconstruction scheme, where the penalty term of the cost function is set to the L(1-norm measured in some transform domain. This type of image reconstruction has gained much attention recently due to its application in compressed sensing and has proven to yield superior spatial resolution and image quality over e.g. Tikhonov regularized image reconstruction. We demonstrate that by using nonlinear regularization it is possible to more accurately localize brain activation from highly undersampled k-space data at the expense of an increase in computation time.

  18. A simultaneous multimodal imaging system for tissue functional parameters

    Science.gov (United States)

    Ren, Wenqi; Zhang, Zhiwu; Wu, Qiang; Zhang, Shiwu; Xu, Ronald

    2014-02-01

    Simultaneous and quantitative assessment of skin functional characteristics in different modalities will facilitate diagnosis and therapy in many clinical applications such as wound healing. However, many existing clinical practices and multimodal imaging systems are subjective, qualitative, sequential for multimodal data collection, and need co-registration between different modalities. To overcome these limitations, we developed a multimodal imaging system for quantitative, non-invasive, and simultaneous imaging of cutaneous tissue oxygenation and blood perfusion parameters. The imaging system integrated multispectral and laser speckle imaging technologies into one experimental setup. A Labview interface was developed for equipment control, synchronization, and image acquisition. Advanced algorithms based on a wide gap second derivative reflectometry and laser speckle contrast analysis (LASCA) were developed for accurate reconstruction of tissue oxygenation and blood perfusion respectively. Quantitative calibration experiments and a new style of skinsimulating phantom were designed to verify the accuracy and reliability of the imaging system. The experimental results were compared with a Moor tissue oxygenation and perfusion monitor. For In vivo testing, a post-occlusion reactive hyperemia (PORH) procedure in human subject and an ongoing wound healing monitoring experiment using dorsal skinfold chamber models were conducted to validate the usability of our system for dynamic detection of oxygenation and perfusion parameters. In this study, we have not only setup an advanced multimodal imaging system for cutaneous tissue oxygenation and perfusion parameters but also elucidated its potential for wound healing assessment in clinical practice.

  19. New developments in paediatric cardiac functional ultrasound imaging.

    Science.gov (United States)

    de Korte, Chris L; Nillesen, Maartje M; Saris, Anne E C M; Lopata, Richard G P; Thijssen, Johan M; Kapusta, Livia

    2014-07-01

    Ultrasound imaging can be used to estimate the morphology as well as the motion and deformation of tissues. If the interrogated tissue is actively deforming, this deformation is directly related to its function and quantification of this deformation is normally referred as 'strain imaging'. Tissue can also be deformed by applying an internal or external force and the resulting, induced deformation is a function of the mechanical tissue characteristics. In combination with the load applied, these strain maps can be used to estimate or reconstruct the mechanical properties of tissue. This technique was named 'elastography' by Ophir et al. in 1991. Elastography can be used for atherosclerotic plaque characterisation, while the contractility of the heart or skeletal muscles can be assessed with strain imaging. Rather than using the conventional video format (DICOM) image information, radio frequency (RF)-based ultrasound methods enable estimation of the deformation at higher resolution and with higher precision than commercial methods using Doppler (tissue Doppler imaging) or video image data (2D speckle tracking methods). However, the improvement in accuracy is mainly achieved when measuring strain along the ultrasound beam direction, so it has to be considered a 1D technique. Recently, this method has been extended to multiple directions and precision further improved by using spatial compounding of data acquired at multiple beam steered angles. Using similar techniques, the blood velocity and flow can be determined. RF-based techniques are also beneficial for automated segmentation of the ventricular cavities. In this paper, new developments in different techniques of quantifying cardiac function by strain imaging, automated segmentation, and methods of performing blood flow imaging are reviewed and their application in paediatric cardiology is discussed.

  20. Integrating magnetic resonance imaging postprocessing results into neuronavigation for electrode implantation and resection of subtle focal cortical dysplasia in previously cryptogenic epilepsy.

    Science.gov (United States)

    Wellmer, Jörg; Parpaley, Yaroslav; von Lehe, Marec; Huppertz, Hans-Jürgen

    2010-01-01

    Focal cortical dysplasias (FCDs) are highly epileptogenic lesions. Surgical removal is frequently the best treatment option for pharmacoresistant epilepsy. However, subtle FCDs may remain undetected even after high-resolution magnetic resonance imaging (MRI). Morphometric MRI analysis, which compares the individual brain with a normal database, can facilitate the detection of FCDs. We describe how the results of normal database-based MRI postprocessing can be used to guide stereotactic electrode implantation and subsequent resection of lesions that are suspected to be FCDs. A presurgical evaluation was conducted on a 19-year-old woman with pharmacoresistant hypermotor seizures. Conventional high-resolution MRI was classified as negative for epileptogenic lesions. However, morphometric analysis of the spatially normalized MRI revealed abnormal gyration and blurring of the gray-white matter junction, which was suggestive of a small and deeply seated FCD in the left frontal lobe. The brain region highlighted by morphometric analysis was marked as a region of interest, transferred back to the original dimension of the individual MRI, and imported into a neuronavigation system. This allowed the region of interest-targeted stereotactic implantation of 2 depth electrodes, by which seizure onset was confirmed in the lesion. The electrodes also guided the final resection, which rendered the patient seizure-free. The lesion was histologically classified as FCD Palmini and Lüders IIB. Transferring normal database-based MRI postprocessing results into a neuronavigation system is a new and worthwhile extension of multimodal neuronavigation. The combination of resulting regions of interest with functional and anatomic data may facilitate planning of electrode implantation for invasive electroencephalographic recordings and the final resection of small or deeply seated FCDs.

  1. Signal and image processing techniques for functional near-infrared imaging of the human brain

    Science.gov (United States)

    Toronov, Vladislav Y.; Zhang, Xiaofeng; Fabiani, Monica; Gratton, Gabriele; Webb, Andrew G.

    2011-01-01

    Near-infrared spectro-imaging (NIRSI) is a quickly developing method for the in-vivo imaging of biological tissues. In particular, it is now extensively employed for imaging the human brain. In this non-invasive technique, the information about the brain is obtained from the analysis of spatial light bundles formed by the photons traveling from light sources to detectors placed on the surface of the head. Most significant problems in the functional brain NIRSI are the separation of the brain information from the physiological noise in non-cerebral tissues, and the localization of functional signals. In this paper we describe signal and image processing techniques we developed in order to measure two types of functional cerebral signals: the hemodynamic responses, and neuronal responses. PMID:21738383

  2. Treatment response in psychotic patients classified according to social and clinical needs, drug side effects, and previous treatment; a method to identify functional remission.

    Science.gov (United States)

    Alenius, Malin; Hammarlund-Udenaes, Margareta; Hartvig, Per; Sundquist, Staffan; Lindström, Leif

    2009-01-01

    Various approaches have been made over the years to classify psychotic patients according to inadequate treatment response, using terms such as treatment resistant or treatment refractory. Existing classifications have been criticized for overestimating positive symptoms; underestimating residual symptoms, negative symptoms, and side effects; or being to open for individual interpretation. The aim of this study was to present and evaluate a new method of classification according to treatment response and, thus, to identify patients in functional remission. A naturalistic, cross-sectional study was performed using patient interviews and information from patient files. The new classification method CANSEPT, which combines the Camberwell Assessment of Need rating scale, the Udvalg for Kliniske Undersøgelser side effect rating scale (SE), and the patient's previous treatment history (PT), was used to group the patients according to treatment response. CANSEPT was evaluated by comparison of expected and observed results. In the patient population (n = 123), the patients in functional remission, as defined by CANSEPT, had higher quality of life, fewer hospitalizations, fewer psychotic symptoms, and higher rate of workers than those with the worst treatment outcome. In the evaluation, CANSEPT showed validity in discriminating the patients of interest and was well tolerated by the patients. CANSEPT could secure inclusion of correct patients in the clinic or in research.

  3. Adaptive sigmoid function bihistogram equalization for image contrast enhancement

    Science.gov (United States)

    Arriaga-Garcia, Edgar F.; Sanchez-Yanez, Raul E.; Ruiz-Pinales, Jose; Garcia-Hernandez, Ma. de Guadalupe

    2015-09-01

    Contrast enhancement plays a key role in a wide range of applications including consumer electronic applications, such as video surveillance, digital cameras, and televisions. The main goal of contrast enhancement is to increase the quality of images. However, most state-of-the-art methods induce different types of distortion such as intensity shift, wash-out, noise, intensity burn-out, and intensity saturation. In addition, in consumer electronics, simple and fast methods are required in order to be implemented in real time. A bihistogram equalization method based on adaptive sigmoid functions is proposed. It consists of splitting the image histogram into two parts that are equalized independently by using adaptive sigmoid functions. In order to preserve the mean brightness of the input image, the parameter of the sigmoid functions is chosen to minimize the absolute mean brightness metric. Experiments on the Berkeley database have shown that the proposed method improves the quality of images and preserves their mean brightness. An application to improve the colorfulness of images is also presented.

  4. Extending Ripley's K-Function to Quantify Aggregation in 2-D Grayscale Images.

    Directory of Open Access Journals (Sweden)

    Mohamed Amgad

    Full Text Available In this work, we describe the extension of Ripley's K-function to allow for overlapping events at very high event densities. We show that problematic edge effects introduce significant bias to the function at very high densities and small radii, and propose a simple correction method that successfully restores the function's centralization. Using simulations of homogeneous Poisson distributions of events, as well as simulations of event clustering under different conditions, we investigate various aspects of the function, including its shape-dependence and correspondence between true cluster radius and radius at which the K-function is maximized. Furthermore, we validate the utility of the function in quantifying clustering in 2-D grayscale images using three modalities: (i Simulations of particle clustering; (ii Experimental co-expression of soluble and diffuse protein at varying ratios; (iii Quantifying chromatin clustering in the nuclei of wt and crwn1 crwn2 mutant Arabidopsis plant cells, using a previously-published image dataset. Overall, our work shows that Ripley's K-function is a valid abstract statistical measure whose utility extends beyond the quantification of clustering of non-overlapping events. Potential benefits of this work include the quantification of protein and chromatin aggregation in fluorescent microscopic images. Furthermore, this function has the potential to become one of various abstract texture descriptors that are utilized in computer-assisted diagnostics in anatomic pathology and diagnostic radiology.

  5. Functional magnetic resonance imaging in oncology: state of the art

    Directory of Open Access Journals (Sweden)

    Marcos Duarte Guimaraes

    2014-04-01

    Full Text Available In the investigation of tumors with conventional magnetic resonance imaging, both quantitative characteristics, such as size, edema, necrosis, and presence of metastases, and qualitative characteristics, such as contrast enhancement degree, are taken into consideration. However, changes in cell metabolism and tissue physiology which precede morphological changes cannot be detected by the conventional technique. The development of new magnetic resonance imaging techniques has enabled the functional assessment of the structures in order to obtain information on the different physiological processes of the tumor microenvironment, such as oxygenation levels, cellularity and vascularity. The detailed morphological study in association with the new functional imaging techniques allows for an appropriate approach to cancer patients, including the phases of diagnosis, staging, response evaluation and follow-up, with a positive impact on their quality of life and survival rate.

  6. Magnetic resonance imaging of respiratory movement and lung function

    International Nuclear Information System (INIS)

    Tetzlaff, R.; Eichinger, M.

    2009-01-01

    Lung function measurements are the domain of spirometry or plethysmography. These methods have proven their value in clinical practice, nevertheless, being global measurements the functional indices only describe the sum of all functional units of the lung. Impairment of only a single component of the respiratory pump or of a small part of lung parenchyma can be compensated by unaffected lung tissue. Dynamic imaging can help to detect such local changes and lead to earlier adapted therapy. Magnetic resonance imaging (MRI) seems to be perfect for this application as it is not hampered by image distortion as is projection radiography and it does not expose the patient to potentially harmful radiation like computed tomography. Unfortunately, lung parenchyma is not easy to image using MRI due to its low signal intensity. For this reason first applications of MRI in lung function measurements concentrated on the movement of the thoracic wall and the diaphragm. Recent technical advances in MRI however might allow measurements of regional dynamics of the lungs. (orig.) [de

  7. Functional Connectivity Magnetic Resonance Imaging Classification of Autism

    Science.gov (United States)

    Anderson, Jeffrey S.; Nielsen, Jared A.; Froehlich, Alyson L.; DuBray, Molly B.; Druzgal, T. Jason; Cariello, Annahir N.; Cooperrider, Jason R.; Zielinski, Brandon A.; Ravichandran, Caitlin; Fletcher, P. Thomas; Alexander, Andrew L.; Bigler, Erin D.; Lange, Nicholas; Lainhart, Janet E.

    2011-01-01

    Group differences in resting state functional magnetic resonance imaging connectivity between individuals with autism and typically developing controls have been widely replicated for a small number of discrete brain regions, yet the whole-brain distribution of connectivity abnormalities in autism is not well characterized. It is also unclear…

  8. Receiver Function Imaging of Dipping Structures - Technique and Applications

    Science.gov (United States)

    Liu, H.; Niu, F.

    2010-12-01

    CCP Stacking is probably the most common technique in receiver function imaging. In this technique, the conversion points are calculated and binned by assuming horizontal interfaces. However, for dipping structures such as tilted Moho or subducting slab, the horizontal interface assumption breaks down so that the image quality is low and the interfaces are misplaced. In these cases, the CCP stacking is not effective because the true conversion points do not necessarily lie in the vertical planes defined by sources and receivers and the delay time of conversion signals are varying with back azimuth. Although pre-stack time migration is an ideal technique to make correct images, the amount of qualified data it requires is often not available. An alternative way is to gather receiver functions based on conversion points and conversion times calculated from 3D velocity models with dipping structures. A dipping interface is defined by depth (d0) at a fixed geographic location, strike (Φ) and dipping angle (α). For an assumed (d0, Φ, α), we computed the conversion locations and conversion times by 3D ray tracing. We varied the depth (d0) and the dipping geometry (Φ, α) in certain range and determined the optimum value that gives the best coherent stacking signals. Note based on different tectonic setting, one or both of the dipping parameters can be fixed in the grid searching. We applied this technique to the imaging of two different geologic structures. One is a subducting slab case in western Mexico where the Rivera plate is subducting under the North American plate. Receiver functions recorded by fifty broadband seismic stations deployed under the MARS project were used to image the subducting Rivera slab. The second case is a tilted Moho lying underneath the GSN station SDV located at the southern flank of the central Venezuelan Andes. In both cases, we found substantial improvements in the receiver function images using our 3D ray tracing technique.

  9. Distinctions between manipulation and function knowledge of objects: evidence from functional magnetic resonance imaging.

    Science.gov (United States)

    Boronat, Consuelo B; Buxbaum, Laurel J; Coslett, H Branch; Tang, Kathy; Saffran, Eleanor M; Kimberg, Daniel Y; Detre, John A

    2005-05-01

    A prominent account of conceptual knowledge proposes that information is distributed over visual, tactile, auditory, motor and verbal-declarative attribute domains to the degree to which these features were activated when the knowledge was acquired [D.A. Allport, Distributed memory, modular subsystems and dysphagia, In: S.K. Newman, R. Epstein (Eds.), Current perspectives in dysphagia, Churchill Livingstone, Edinburgh, 1985, pp. 32-60]. A corollary is that when drawing upon this knowledge (e.g., to answer questions), particular aspects of this distributed information is re-activated as a function of the requirements of the task at hand [L.J. Buxbaum, E.M. Saffran, Knowledge of object manipulation and object function: dissociations in apraxic and non-apraxic subjects. Brain and Language, 82 (2002) 179-199; L.J. Buxbaum, T. Veramonti, M.F. Schwartz, Function and manipulation tool knowledge in apraxia: knowing 'what for' but not 'how', Neurocase, 6 (2000) 83-97; W. Simmons, L. Barsalou, The similarity-in-topography principle: Reconciling theories of conceptual deficits, Cognitive Neuropsychology, 20 (2003) 451-486]. This account predicts that answering questions about object manipulation should activate brain regions previously identified as components of the distributed sensory-motor system involved in object use, whereas answering questions about object function (that is, the purpose that it serves) should activate regions identified as components of the systems supporting verbal-declarative features. These predictions were tested in a functional magnetic resonance imaging (fMRI) study in which 15 participants viewed picture or word pairs denoting manipulable objects and determined whether the objects are manipulated similarly (M condition) or serve the same function (F condition). Significantly greater and more extensive activations in the left inferior parietal lobe bordering the intraparietal sulcus were seen in the M condition with pictures and, to a lesser

  10. Association of single nucleotide polymorphisms in candidate genes previously related to genetic variation in fertility with phenotypic measurements of reproductive function in Holstein cows.

    Science.gov (United States)

    Ortega, M Sofia; Denicol, Anna C; Cole, John B; Null, Daniel J; Taylor, Jeremy F; Schnabel, Robert D; Hansen, Peter J

    2017-05-01

    Many genetic markers related to health or production traits are not evaluated in populations independent of the discovery population or related to phenotype. Here we evaluated 68 single nucleotide polymorphisms (SNP) in candidate genes previously associated with genetic merit for fertility and production traits for association with phenotypic measurements of fertility in a population of Holstein cows that was selected based on predicted transmitting ability (PTA) for daughter pregnancy rate (DPR; high, ≥1, n = 989; low, ≤ -1.0, n = 1,285). Cows with a high PTA for DPR had higher pregnancy rate at first service, fewer services per conception, and fewer days open than cows with a low PTA for DPR. Of the 68 SNP, 11 were associated with pregnancy rate at first service, 16 with services per conception, and 19 with days open. Single nucleotide polymorphisms in 12 genes (BDH2, BSP3, CAST, CD2, CD14, FUT1, FYB, GCNT3, HSD17B7, IBSP, OCLN, and PCCB) had significant associations with 2 fertility traits, and SNP in 4 genes (CSPP1, FCER1G, PMM2, and TBC1D24) had significant associations with each of the 3 traits. Results from this experiment were compared with results from 2 earlier studies in which the SNP were associated with genetic estimates of fertility. One study involved the same animals as used here, and the other study was of an independent population of bulls. A total of 13 SNP associated with 1 or more phenotypic estimates of fertility were directionally associated with genetic estimates of fertility in the same cow population. Moreover, 14 SNP associated with reproductive phenotype were directionally associated with genetic estimates of fertility in the bull population. Nine SNP (located in BCAS, BSP3, CAST, FUT1, HSD17B7, OCLN, PCCB, PMM2, and TBC1D24) had a directional association with fertility in all 3 studies. Examination of the function of the genes with SNP associated with reproduction in more than one study indicates the importance of steroid hormones

  11. Bench to bedside molecular functional imaging in translational cancer medicine: to image or to imagine?

    Science.gov (United States)

    Mahajan, A; Goh, V; Basu, S; Vaish, R; Weeks, A J; Thakur, M H; Cook, G J

    2015-10-01

    Ongoing research on malignant and normal cell biology has substantially enhanced the understanding of the biology of cancer and carcinogenesis. This has led to the development of methods to image the evolution of cancer, target specific biological molecules, and study the anti-tumour effects of novel therapeutic agents. At the same time, there has been a paradigm shift in the field of oncological imaging from purely structural or functional imaging to combined multimodal structure-function approaches that enable the assessment of malignancy from all aspects (including molecular and functional level) in a single examination. The evolving molecular functional imaging using specific molecular targets (especially with combined positron-emission tomography [PET] computed tomography [CT] using 2- [(18)F]-fluoro-2-deoxy-D-glucose [FDG] and other novel PET tracers) has great potential in translational research, giving specific quantitative information with regard to tumour activity, and has been of pivotal importance in diagnoses and therapy tailoring. Furthermore, molecular functional imaging has taken a key place in the present era of translational cancer research, producing an important tool to study and evolve newer receptor-targeted therapies, gene therapies, and in cancer stem cell research, which could form the basis to translate these agents into clinical practice, popularly termed "theranostics". Targeted molecular imaging needs to be developed in close association with biotechnology, information technology, and basic translational scientists for its best utility. This article reviews the current role of molecular functional imaging as one of the main pillars of translational research. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  12. Lung function imaging methods in Cystic Fibrosis pulmonary disease.

    Science.gov (United States)

    Kołodziej, Magdalena; de Veer, Michael J; Cholewa, Marian; Egan, Gary F; Thompson, Bruce R

    2017-05-17

    Monitoring of pulmonary physiology is fundamental to the clinical management of patients with Cystic Fibrosis. The current standard clinical practise uses spirometry to assess lung function which delivers a clinically relevant functional readout of total lung function, however does not supply any visible or localised information. High Resolution Computed Tomography (HRCT) is a well-established current 'gold standard' method for monitoring lung anatomical changes in Cystic Fibrosis patients. HRCT provides excellent morphological information, however, the X-ray radiation dose can become significant if multiple scans are required to monitor chronic diseases such as cystic fibrosis. X-ray phase-contrast imaging is another emerging X-ray based methodology for Cystic Fibrosis lung assessment which provides dynamic morphological and functional information, albeit with even higher X-ray doses than HRCT. Magnetic Resonance Imaging (MRI) is a non-ionising radiation imaging method that is garnering growing interest among researchers and clinicians working with Cystic Fibrosis patients. Recent advances in MRI have opened up the possibilities to observe lung function in real time to potentially allow sensitive and accurate assessment of disease progression. The use of hyperpolarized gas or non-contrast enhanced MRI can be tailored to clinical needs. While MRI offers significant promise it still suffers from poor spatial resolution and the development of an objective scoring system especially for ventilation assessment.

  13. Functional and perfusion magnetic resonance imaging at 3 tesla

    CERN Document Server

    Klarhoefer, M

    2001-01-01

    This thesis deals with the development and optimization of fast magnetic resonance imaging (MRI) methods for non-invasive functional studies of the human brain and perfusion imaging on a 3 Tesla (T) whole body NMR system. The functional MRI (fMRI) experiments performed showed that single-shot multi-echo EPI and spiral imaging techniques provide fast tools to obtain information about T2* distributions during functional activation in the human brain. Both sequences were found to be useful in the separation of different sources contributing to the functional MR signal like inflow or susceptibility effects in the various vascular environments. An fMRI study dealing with the involvement of prefrontal brain regions in movement preparation lead to inconsistent results. It could not be clarified if these were caused by problems during a spatial normalization process of the individual brains or if the functional paradigm, using very short inter-stimulus intervals, was not suited for the problem investigated. Blood flo...

  14. Human brain activity with functional NIR optical imager

    Science.gov (United States)

    Luo, Qingming

    2001-08-01

    In this paper we reviewed the applications of functional near infrared optical imager in human brain activity. Optical imaging results of brain activity, including memory for new association, emotional thinking, mental arithmetic, pattern recognition ' where's Waldo?, occipital cortex in visual stimulation, and motor cortex in finger tapping, are demonstrated. It is shown that the NIR optical method opens up new fields of study of the human population, in adults under conditions of simulated or real stress that may have important effects upon functional performance. It makes practical and affordable for large populations the complex technology of measuring brain function. It is portable and low cost. In cognitive tasks subjects could report orally. The temporal resolution could be millisecond or less in theory. NIR method will have good prospects in exploring human brain secret.

  15. Physiological basis and image processing in functional magnetic resonance imaging: Neuronal and motor activity in brain

    Directory of Open Access Journals (Sweden)

    Sharma Rakesh

    2004-05-01

    Full Text Available Abstract Functional magnetic resonance imaging (fMRI is recently developing as imaging modality used for mapping hemodynamics of neuronal and motor event related tissue blood oxygen level dependence (BOLD in terms of brain activation. Image processing is performed by segmentation and registration methods. Segmentation algorithms provide brain surface-based analysis, automated anatomical labeling of cortical fields in magnetic resonance data sets based on oxygen metabolic state. Registration algorithms provide geometric features using two or more imaging modalities to assure clinically useful neuronal and motor information of brain activation. This review article summarizes the physiological basis of fMRI signal, its origin, contrast enhancement, physical factors, anatomical labeling by segmentation, registration approaches with examples of visual and motor activity in brain. Latest developments are reviewed for clinical applications of fMRI along with other different neurophysiological and imaging modalities.

  16. Functional imaging in oncology. Clinical applications. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Antonio [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Radiology; MRI Health Time Group, Jaen (Spain); Vilanova, Joan C. [Girona Univ. (Spain). Clinica Girona - Hospital Sta. Caterina; Hygino da Cruz, L. Celso Jr. (ed.) [CDPI and IRM, Rio de Janeiro (Brazil). Dept. of Radiology; Rossi, Santiago E. [Centro de Diagnostico, Buenos Aires (Argentina)

    2014-06-01

    Easy-to-read manual on new functional imaging techniques in oncology. Explains current clinical applications and outlines future avenues. Includes numerous high-quality illustrations to highlight the major teaching points. In the new era of functional and molecular imaging, both currently available imaging biomarkers and biomarkers under development are expected to lead to major changes in the management of oncological patients. This two-volume book is a practical manual on the various imaging techniques capable of delivering functional information on cancer, including diffusion MRI, perfusion CT and MRI, dual-energy CT, spectroscopy, dynamic contrast-enhanced ultrasonography, PET, and hybrid modalities. This second volume considers the applications and benefits of these techniques in a wide range of tumor types, including their role in diagnosis, prediction of treatment outcome, and early evaluation of treatment response. Each chapter addresses a specific malignancy and is written by one or more acclaimed experts. The lucid text is complemented by numerous high-quality illustrations that highlight key features and major teaching points.

  17. Functional imaging in oncology. Clinical applications. Vol. 2

    International Nuclear Information System (INIS)

    Luna, Antonio; Vilanova, Joan C.

    2014-01-01

    Easy-to-read manual on new functional imaging techniques in oncology. Explains current clinical applications and outlines future avenues. Includes numerous high-quality illustrations to highlight the major teaching points. In the new era of functional and molecular imaging, both currently available imaging biomarkers and biomarkers under development are expected to lead to major changes in the management of oncological patients. This two-volume book is a practical manual on the various imaging techniques capable of delivering functional information on cancer, including diffusion MRI, perfusion CT and MRI, dual-energy CT, spectroscopy, dynamic contrast-enhanced ultrasonography, PET, and hybrid modalities. This second volume considers the applications and benefits of these techniques in a wide range of tumor types, including their role in diagnosis, prediction of treatment outcome, and early evaluation of treatment response. Each chapter addresses a specific malignancy and is written by one or more acclaimed experts. The lucid text is complemented by numerous high-quality illustrations that highlight key features and major teaching points.

  18. Splenic concentration of bone imaging agents in functional asplenia

    International Nuclear Information System (INIS)

    Dhekne, R.D.

    1981-01-01

    Three cases of sickle cell disease associated with functional asplenia are described. The spleen was not visualized on routine Tc-99m-sulfur colloid scan. The bone scan performed with Tc-99m-phosphate compounds revealed abnormal splenic activity in all three cases. The previous case reports and the literature on this subject are reviewed

  19. NMR imaging of the head-neck region. Topography of function - clinical findings - imaging and spectroscopy

    International Nuclear Information System (INIS)

    Vogl, T.J.

    1991-01-01

    The book on nmr imaging in the head-neck region offers, on a total of 221 pages, 344 detailed representations with 141 figures and 44 tables. It provides information as to the relevant topography of function, presents clinical findings, explains imaging characteristics and also takes account of spectroscopic procedures. The multifarious methods of investigation are described and discussed in connection with the differential diagnoses. A score of suitable diagnostic measures is assigned to each region of examination. The method's value is assessed against that of other imaging techniques. (orig.) [de

  20. Point spread functions and deconvolution of ultrasonic images.

    Science.gov (United States)

    Dalitz, Christoph; Pohle-Fröhlich, Regina; Michalk, Thorsten

    2015-03-01

    This article investigates the restoration of ultrasonic pulse-echo C-scan images by means of deconvolution with a point spread function (PSF). The deconvolution concept from linear system theory (LST) is linked to the wave equation formulation of the imaging process, and an analytic formula for the PSF of planar transducers is derived. For this analytic expression, different numerical and analytic approximation schemes for evaluating the PSF are presented. By comparing simulated images with measured C-scan images, we demonstrate that the assumptions of LST in combination with our formula for the PSF are a good model for the pulse-echo imaging process. To reconstruct the object from a C-scan image, we compare different deconvolution schemes: the Wiener filter, the ForWaRD algorithm, and the Richardson-Lucy algorithm. The best results are obtained with the Richardson-Lucy algorithm with total variation regularization. For distances greater or equal twice the near field distance, our experiments show that the numerically computed PSF can be replaced with a simple closed analytic term based on a far field approximation.

  1. Utilizing Minkowski functionals for image analysis: a marching square algorithm

    International Nuclear Information System (INIS)

    Mantz, Hubert; Jacobs, Karin; Mecke, Klaus

    2008-01-01

    Comparing noisy experimental image data with statistical models requires a quantitative analysis of grey-scale images beyond mean values and two-point correlations. A real-space image analysis technique is introduced for digitized grey-scale images, based on Minkowski functionals of thresholded patterns. A novel feature of this marching square algorithm is the use of weighted side lengths for pixels, so that boundary lengths are captured accurately. As examples to illustrate the technique we study surface topologies emerging during the dewetting process of thin films and analyse spinodal decomposition as well as turbulent patterns in chemical reaction–diffusion systems. The grey-scale value corresponds to the height of the film or to the concentration of chemicals, respectively. Comparison with analytic calculations in stochastic geometry models reveals a remarkable agreement of the examples with a Gaussian random field. Thus, a statistical test for non-Gaussian features in experimental data becomes possible with this image analysis technique—even for small image sizes. Implementations of the software used for the analysis are offered for download

  2. Imaging regional renal function parameters using radionuclide tracers

    Science.gov (United States)

    Qiao, Yi

    A compartmental model is given for evaluating kidney function accurately and noninvasively. This model is cast into a parallel multi-compartment structure and each pixel region (picture element) of kidneys is considered as a single kidney compartment. The loss of radionuclide tracers from the blood to the kidney and from the kidney to the bladder are modelled in great detail. Both the uptake function and the excretion function of the kidneys can be evaluated pixel by pixel, and regional diagnostic information on renal function is obtained. Gamma Camera image data are required by this model and a screening test based renal function measurement is provided. The regional blood background is subtracted from the kidney region of interest (ROI) and the kidney regional rate constants are estimated analytically using the Kuhn-Pucker multiplier method in convex programming by considering the input/output behavior of the kidney compartments. The detailed physiological model of the peripheral compartments of the system, which is not available for most radionuclide tracers, is not required in the determination of the kidney regional rate constants and the regional blood background factors within the kidney ROI. Moreover, the statistical significance of measurements is considered to assure the improved statistical properties of the estimated kidney rate constants. The relations between various renal function parameters and the kidney rate constants are established. Multiple renal function measurements can be found from the renal compartmental model. The blood radioactivity curve and the regional (or total) radiorenogram determining the regional (or total) summed behavior of the kidneys are obtained analytically with the consideration of the statistical significance of measurements using convex programming methods for a single peripheral compartment system. In addition, a new technique for the determination of 'initial conditions' in both the blood compartment and the kidney

  3. Development of a liquid xenon Compton telescope dedicated to functional medical imaging

    International Nuclear Information System (INIS)

    Grignon, C.

    2007-12-01

    Functional imaging is a technique used to locate in three dimensions the position of a radiotracer previously injected in a patient. The two main modalities used for a clinical application to detect tumors, the SPECT and the PET, use solid scintillators as a detection medium. The objective of this thesis was to investigate the possibility of using liquid xenon in order to benefit from the intrinsic properties of this medium in functional imaging. The feasibility study of such a device has been performed by taking into account the technical difficulties specific to the liquid xenon. First of all, simulations of a liquid xenon PET has been performed using Monte-Carlo methods. The results obtained with a large liquid xenon volume are promising : we can expect a reduction of the injected activity of radiotracer, an improvement of the spatial resolution of the image and a parallax free camera. The second part of the thesis was focused on the development of a new concept of medical imaging, the three gamma imaging, based on the use of a new emitter: the 44 scandium. Associated to a classical PET camera, the Compton telescope is used to infer the incoming direction of the third gamma ray by triangulation. Therefore, it is possible to reconstruct the position of each emitter in three dimensions. This work convinced the scientific community to support the construction and characterization of a liquid xenon Compton telescope. The first camera dedicated to small animal imaging should then be operational in 2009. (author)

  4. 3-Tesla functional magnetic resonance imaging-guided tumor resection

    International Nuclear Information System (INIS)

    Hall, W.A.; Truwit, C.L.; Univ. of Minnesota Medical School, Minneapolis, MN; Univ. of Minnesota Medical School, Minneapolis, MN; Hennepin Country Medical Center, Minneapolis, MN

    2006-01-01

    Objective: We sought to determine the safety and efficacy of using 3-tesla (T) functional magnetic resonance imaging (fMRI) to guide brain tumor resection. Material and methods: From February 2004 to March 2006, fMRI was performed on 13 patients before surgical resection. Functional imaging was used to identify eloquent cortices for motor (8), speech (3), and motor and speech (2) activation using two different 3-T magnetic resonance (MR) scanners. Surgical resection was accomplished using a 1.5-T intraoperative MR system. Appropriate MR scan sequences were performed intraoperatively to determine and maximize the extent of the surgical resection. Results: Tumors included six oligodendrogliomas, three meningiomas, two astrocytomas and two glioblastomas multiforme. The fMRI data was accurate in all cases. After surgery, two patients had hemiparesis, two had worsening of their speech, and one had worsening of speech and motor function. Neurological function returned to normal in all patients within 1 month. Complete resections were possible in 10 patients (77%). Two patients had incomplete resections because of the proximity of their tumors to functional areas. Biopsy was performed in another patient with an astrocytoma in the motor strip. Conclusion: 3-T fMRI was accurate for locating neurologic function before tumor resection near eloquent cortex. (orig.)

  5. The role of functional imaging techniques in the dementia

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Young Hoon [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2004-06-01

    Evaluation of dementia in patients with early symptoms of cognitive decline is clinically challenging, but the need for early, accurate diagnosis has become more crucial, since several medication for the treatment of mild to moderate Alzheimer' disease are available. Many neurodegenerative diseases produce significant brain function alteration even when structural imaging (CT of MRI) reveal no specific abnormalities. The role of PET and SPECT brain imaging in the initial assessment and differential diagnosis of dementia is beginning to evolve rapidly and growing evidence indicates that appropriate incorporation of PET into the clinical work up can improve diagnostic and prognostic accuracy with respect to Alzheimer's disease, the most common cause of dementia in the geriatric population. In the fast few years, studies comparing neuropathologic examination with PET have established reliable and consistent accuracy for diagnostic evaluations using PET - accuracies substantially exceeding those of comparable studies of diagnostic value of SPECT or of both modalities assessed side by side, or of clinical evaluations done without nuclear imaging. This review deals the role of functional brian imaging techniques in the evaluation of dementias and the role of nuclear neuroimaging in the early detection and diagnosis of Alzheimer's disease.

  6. Functional imaging of neurocognitive dysfunction in attention deficit hyperactivity disorder

    International Nuclear Information System (INIS)

    Wolf, I.; Tost, H.; Ruf, M.; Ende, G.

    2005-01-01

    Attention Deficit Hyperactivity Disorder (ADHD) is a neurobiological disorder of early childhood onset. Defining symptoms are chronic impairments of attention, impulse control and motor hyperactivity that frequently persist until adulthood. Miscellaneous causes of the disorder have been discussed. Accumulating evidence from imaging- and molecular genetic studies strengthened the theory of ADHS being a predominantly inherited disorder of neurobiological origin. In the last 15 years, non-invasive brain imaging methods were successfully implemented in pediatric research. Functional magnetic resonance imaging studies gave major insight into the neurobiological correlates of executive malfunction, inhibitory deficits and psychomotoric soft signs. These findings are in good accordance with brain morphometric data indicating a significant volumetric decrease of major components of striato-thalamo-cortical feedback loops, primarily influencing prefrontal executive functioning (e.g. basal ganglia). Empirical evidence points to a broad array of associated behavioral disturbances like deficient visuomotor abilities and oculomotor dysfunctions. This paper reviews the current empirical evidence derived from prior imaging studies. Special emphasis is given to the relevance of oculomotor dysfunctions in clinical and research settings, as well as their assessment in the MR environment. (orig.) [de

  7. Methods for processing and analysis functional and anatomical brain images: computerized tomography, emission tomography and nuclear resonance imaging

    International Nuclear Information System (INIS)

    Mazoyer, B.M.

    1988-01-01

    The various methods for brain image processing and analysis are presented and compared. The following topics are developed: the physical basis of brain image comparison (nature and formation of signals intrinsic performance of the methods image characteristics); mathematical methods for image processing and analysis (filtering, functional parameter extraction, morphological analysis, robotics and artificial intelligence); methods for anatomical localization (neuro-anatomy atlas, proportional stereotaxic atlas, numerized atlas); methodology of cerebral image superposition (normalization, retiming); image networks [fr

  8. 2D imaging of functional structures in perfused pig heart

    Science.gov (United States)

    Kessler, Manfred D.; Cristea, Paul D.; Hiller, Michael; Trinks, Tobias

    2002-06-01

    In 2000 by 2D-imaging we were able for the first time to visualize in subcellular space functional structures of myocardium. For these experiments we used hemoglobin-free perfused pig hearts in our lab. Step by step we learned to understand the meaning of subcellular structures. Principally, the experiment revealed that in subcellular space very fast changes of light scattering can occur. Furthermore, coefficients of different parameters were determined on the basis of multicomponent system theory.

  9. Functional magnetic resonance imaging of higher brain activity

    International Nuclear Information System (INIS)

    Cui He; Wang Yunjiu; Chen Runsheng; Tang Xiaowei.

    1996-01-01

    Functional magnetic resonance images (fMRIs) exhibit small differences in the magnetic resonance signal intensity in positions corresponding to focal areas of brain activation. These signal are caused by variation in the oxygenation state of the venous vasculature. Using this non-invasive and dynamic method, it is possible to localize functional brain activation, in vivo, in normal individuals, with an accuracy of millimeters and a temporal resolution of seconds. Though a series of technical difficulties remain, fMRI is increasingly becoming a key method for visualizing the working brain, and uncovering the topographical organization of the human brain, and understanding the relationship between brain and the mind

  10. Functional photoacoustic tomography for neonatal brain imaging: developments and challenges

    Science.gov (United States)

    Hariri, Ali; Tavakoli, Emytis; Adabi, Saba; Gelovani, Juri; Avanaki, Mohammad R. N.

    2017-03-01

    Transfontanelle ultrasound imaging (TFUSI) is a routine diagnostic brain imaging method in infants who are born prematurely, whose skull bones have not completely fused together and have openings between them, so-called fontanelles. Open fontanelles in neonates provide acoustic windows, allowing the ultrasound beam to freely pass through. TFUSI is used to rule out neurological complications of premature birth including subarachnoid hemorrhage (SAH), intraventricular (IVH), subependimal (SEPH), subdural (SDH) or intracerebral (ICH) hemorrhages, as well as hypoxic brain injuries. TFUSI is widely used in the clinic owing to its low cost, safety, accessibility, and noninvasive nature. Nevertheless, the accuracy of TFUSI is limited. To address several limitations of current clinical imaging modalities, we develop a novel transfontanelle photoacoustic imaging (TFPAI) probe, which, for the first time, should allow for non-invasive structural and functional imaging of the infant brain. In this study, we test the feasibility of TFPAI for detection of experimentally-induced intra ventricular and Intraparenchymal hemorrhage phantoms in a sheep model with a surgically-induced cranial window which will serve as a model of neonatal fontanelle. This study is towards using the probe we develop for bedside monitoring of neonates with various disease conditions and complications affecting brain perfusion and oxygenation, including apnea, asphyxia, as well as for detection of various types of intracranial hemorrhages (SAH, IVH, SEPH, SDH, ICH).

  11. New technology of functional infrared imaging and its clinical applications

    Science.gov (United States)

    Yang, Hongqin; Xie, Shusen; Lu, Zukang; Liu, Zhongqi

    2006-01-01

    With improvements in infrared camera technology, the promise of reduced costs and noninvasive character, infrared thermal imaging resurges in medicine. The paper introduces a new technology of functional infrared imaging, thermal texture maps (TTM), which is not only an apparatus for thermal radiation imaging but also a new method for revealing the relationship between the temperature distribution of the skin surface and the emission field inside body. The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Any disease in the body is associated with an alteration of the thermal distribution of human body. Infrared thermography is noninvasive, so it is the best choice for studying the physiology of thermoregulation and the thermal dysfunction associated with diseases. Reading and extracting information from the thermograms is a complex and subjective task that can be greatly facilitated by computerized techniques. Through image processing and measurement technology, surface or internal radiation sources can be non-invasively distinguished through extrapolation. We discuss the principle, the evaluation procedure and the effectiveness of TTM technology in the clinical detection and diagnosis of cancers, especially in their early stages and other diseases by comparing with other imaging technologies, such as ultrasound. Several study cases are given to show the effectiveness of this method. At last, we point out the applications of TTM technology in the research field of traditional medicine.

  12. Development of integrated semiconductor optical sensors for functional brain imaging

    Science.gov (United States)

    Lee, Thomas T.

    Optical imaging of neural activity is a widely accepted technique for imaging brain function in the field of neuroscience research, and has been used to study the cerebral cortex in vivo for over two decades. Maps of brain activity are obtained by monitoring intensity changes in back-scattered light, called Intrinsic Optical Signals (IOS), that correspond to fluctuations in blood oxygenation and volume associated with neural activity. Current imaging systems typically employ bench-top equipment including lamps and CCD cameras to study animals using visible light. Such systems require the use of anesthetized or immobilized subjects with craniotomies, which imposes limitations on the behavioral range and duration of studies. The ultimate goal of this work is to overcome these limitations by developing a single-chip semiconductor sensor using arrays of sources and detectors operating at near-infrared (NIR) wavelengths. A single-chip implementation, combined with wireless telemetry, will eliminate the need for immobilization or anesthesia of subjects and allow in vivo studies of free behavior. NIR light offers additional advantages because it experiences less absorption in animal tissue than visible light, which allows for imaging through superficial tissues. This, in turn, reduces or eliminates the need for traumatic surgery and enables long-term brain-mapping studies in freely-behaving animals. This dissertation concentrates on key engineering challenges of implementing the sensor. This work shows the feasibility of using a GaAs-based array of vertical-cavity surface emitting lasers (VCSELs) and PIN photodiodes for IOS imaging. I begin with in-vivo studies of IOS imaging through the skull in mice, and use these results along with computer simulations to establish minimum performance requirements for light sources and detectors. I also evaluate the performance of a current commercial VCSEL for IOS imaging, and conclude with a proposed prototype sensor.

  13. Functional imaging of dolphin brain metabolism and blood flow.

    Science.gov (United States)

    Ridgway, Sam; Houser, Dorian; Finneran, James; Carder, Don; Keogh, Mandy; Van Bonn, William; Smith, Cynthia; Scadeng, Miriam; Dubowitz, David; Mattrey, Robert; Hoh, Carl

    2006-08-01

    This report documents the first use of magnetic resonance images (MRIs) of living dolphins to register functional brain scans, allowing for the exploration of potential mechanisms of unihemispheric sleep. Diazepam has been shown to induce unihemispheric slow waves (USW), therefore we used functional imaging of dolphins with and without diazepam to observe hemispheric differences in brain metabolism and blood flow. MRIs were used to register functional brain scans with single photon emission computed tomography (SPECT) and positron emission tomography (PET) in trained dolphins. Scans using SPECT revealed unihemispheric blood flow reduction following diazepam doses greater than 0.55 mg kg(-1) for these 180-200 kg animals. Scans using PET revealed hemispheric differences in brain glucose consumption when scans with and without diazepam were compared. The findings suggest that unihemispheric reduction in blood flow and glucose metabolism in the hemisphere showing USW are important features of unihemispheric sleep. Functional scans may also help to elucidate the degree of hemispheric laterality of sensory and motor systems as well as in neurotransmitter or molecular mechanisms of unihemispheric sleep in delphinoid cetaceans. The findings also demonstrate the potential value of functional scans to explore other aspects of dolphin brain physiology as well as pathology.

  14. High temporal resolution functional MRI using parallel echo volumar imaging

    International Nuclear Information System (INIS)

    Rabrait, C.; Ciuciu, P.; Ribes, A.; Poupon, C.; Dehaine-Lambertz, G.; LeBihan, D.; Lethimonnier, F.; Le Roux, P.; Dehaine-Lambertz, G.

    2008-01-01

    Purpose: To combine parallel imaging with 3D single-shot acquisition (echo volumar imaging, EVI) in order to acquire high temporal resolution volumar functional MRI (fMRI) data. Materials and Methods: An improved EVI sequence was associated with parallel acquisition and field of view reduction in order to acquire a large brain volume in 200 msec. Temporal stability and functional sensitivity were increased through optimization of all imaging parameters and Tikhonov regularization of parallel reconstruction. Two human volunteers were scanned with parallel EVI in a 1.5 T whole-body MR system, while submitted to a slow event-related auditory paradigm. Results: Thanks to parallel acquisition, the EVI volumes display a low level of geometric distortions and signal losses. After removal of low-frequency drifts and physiological artifacts,activations were detected in the temporal lobes of both volunteers and voxel-wise hemodynamic response functions (HRF) could be computed. On these HRF different habituation behaviors in response to sentence repetition could be identified. Conclusion: This work demonstrates the feasibility of high temporal resolution 3D fMRI with parallel EVI. Combined with advanced estimation tools,this acquisition method should prove useful to measure neural activity timing differences or study the nonlinearities and non-stationarities of the BOLD response. (authors)

  15. Hypercholesterolemia and Myocardial function evaluated via Tissue Doppler Imaging

    Directory of Open Access Journals (Sweden)

    Kotaru Pavan

    2009-11-01

    Full Text Available Abstract Objective To establish a link between hypercholesterolemia and myocardial dysfunction. Background Heart failure is a complex disease involving changes in systolic and diastolic function. Newer echocardiographic imaging modalities may be able to detect discreet changes in myocardial function associated with hypercholesterolemia. Therefore we sought to establish a link between hypercholesterolemia and myocardial dysfunction with tissue Doppler imaging (TDI. Methods Twenty-seven rabbits were studied: 7 were fed normal chow (group 1 and 20 a high cholesterol diet (10 with ezetimibe, 1 mg/kg/day; group 2 and 10 without, group 3. Echocardiographic images were obtained under general anesthesia. Serum cholesterol levels were obtained at baseline, 3 and 6 months and myocardial cholesterol levels measured following euthanasia. Results Doppler measurements, including E/A, E'/A' and S' were significantly lower in group 3 compared to both groups 1 and 2 but no significant differences were noted in chamber sizes or ejection fraction among the groups. Average serum cholesterol was higher in group 3 compared to groups 1 and 2 respectively (495 ± 305 mg/dl vs. 114 ± 95 mg/dl and 87 ± 37 mg/dl; p 2 = 0.17 p = 0.04, r2 = 0.37 p = 0.001 and r2 = 0.24 p = 0.01. Conclusion Cholesterol load in the serum and myocardium was significantly associated with decreased systolic and diastolic function by TDI. Moreover, lipid lowering was protective.

  16. Functional imaging of the sensorimotor cortex using an ultra-fast MR imaging method

    International Nuclear Information System (INIS)

    Tsunoda, Akira; Nakajima, Yasoichi; Sato, Kiyoshi; Katayama, Jin; Machida, Yoshio; Nozaki, Seiji; Makita, Jun-ichi.

    1996-01-01

    The aim of this study was to assess changes in brain activity during a motor task and variable sensory stimulation using echo planar imaging, which represents the fastest clinically useful imaging technique available. The subjects of this study were 11 healthy volunteers, 4 males and 11 females, with an average of 26.4 years. The subjects were instructed to tap the fingers of one hand as the motor task. Compressed air was applied 5 times a second as 'simple' sensory stimulation. Simple figures were drawn on the subjects palm as 'complex' sensory stimulation. In all cases, functional imaging was performed by T 2 * -weighted echo planar imaging (TE=53 msec, TR=3000 msec, flip angle=90 degrees, matrix 64 x 64, FOV=205 mm, slice thickness=8 mm) alternately at rest and during the task (intervals: 30 sec). A total of 60 images was collected in 3 minutes. Images obtained by subtracting images at rest and during the task were analyzed. Almost all subjects showed a transient signal increase in the contralateral paracentral region during simple sensory stimulation. Continuous signal increases in the contra- and/or ipsi-lateral para-central region were observed durirg complex sensory stimulation. Some exhibited signal increases in the parietal or frontal association cortex, but they disappeared when subject's attention was distracted during stimulation. All subjects displayed signal increases in the contralateral para-central region during the motor task. Some of them exhibited signal increases in the medial frontal area (supplementary motor area) and ipsilateral para-central region. These results suggest that the signal increases of functional MRI reflect not only simple reactions to stimulation but higher cerebral function as well. (J.P.N.)

  17. Functional Brain Imaging Synthesis Based on Image Decomposition and Kernel Modeling: Application to Neurodegenerative Diseases

    Science.gov (United States)

    Martinez-Murcia, Francisco J.; Górriz, Juan M.; Ramírez, Javier; Illán, Ignacio A.; Segovia, Fermín; Castillo-Barnes, Diego; Salas-Gonzalez, Diego

    2017-01-01

    The rise of neuroimaging in research and clinical practice, together with the development of new machine learning techniques has strongly encouraged the Computer Aided Diagnosis (CAD) of different diseases and disorders. However, these algorithms are often tested in proprietary datasets to which the access is limited and, therefore, a direct comparison between CAD procedures is not possible. Furthermore, the sample size is often small for developing accurate machine learning methods. Multi-center initiatives are currently a very useful, although limited, tool in the recruitment of large populations and standardization of CAD evaluation. Conversely, we propose a brain image synthesis procedure intended to generate a new image set that share characteristics with an original one. Our system focuses on nuclear imaging modalities such as PET or SPECT brain images. We analyze the dataset by applying PCA to the original dataset, and then model the distribution of samples in the projected eigenbrain space using a Probability Density Function (PDF) estimator. Once the model has been built, we can generate new coordinates on the eigenbrain space belonging to the same class, which can be then projected back to the image space. The system has been evaluated on different functional neuroimaging datasets assessing the: resemblance of the synthetic images with the original ones, the differences between them, their generalization ability and the independence of the synthetic dataset with respect to the original. The synthetic images maintain the differences between groups found at the original dataset, with no significant differences when comparing them to real-world samples. Furthermore, they featured a similar performance and generalization capability to that of the original dataset. These results prove that these images are suitable for standardizing the evaluation of CAD pipelines, and providing data augmentation in machine learning systems -e.g. in deep learning-, or even to

  18. Functional Brain Imaging Synthesis Based on Image Decomposition and Kernel Modeling: Application to Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Francisco J. Martinez-Murcia

    2017-11-01

    Full Text Available The rise of neuroimaging in research and clinical practice, together with the development of new machine learning techniques has strongly encouraged the Computer Aided Diagnosis (CAD of different diseases and disorders. However, these algorithms are often tested in proprietary datasets to which the access is limited and, therefore, a direct comparison between CAD procedures is not possible. Furthermore, the sample size is often small for developing accurate machine learning methods. Multi-center initiatives are currently a very useful, although limited, tool in the recruitment of large populations and standardization of CAD evaluation. Conversely, we propose a brain image synthesis procedure intended to generate a new image set that share characteristics with an original one. Our system focuses on nuclear imaging modalities such as PET or SPECT brain images. We analyze the dataset by applying PCA to the original dataset, and then model the distribution of samples in the projected eigenbrain space using a Probability Density Function (PDF estimator. Once the model has been built, we can generate new coordinates on the eigenbrain space belonging to the same class, which can be then projected back to the image space. The system has been evaluated on different functional neuroimaging datasets assessing the: resemblance of the synthetic images with the original ones, the differences between them, their generalization ability and the independence of the synthetic dataset with respect to the original. The synthetic images maintain the differences between groups found at the original dataset, with no significant differences when comparing them to real-world samples. Furthermore, they featured a similar performance and generalization capability to that of the original dataset. These results prove that these images are suitable for standardizing the evaluation of CAD pipelines, and providing data augmentation in machine learning systems -e.g. in deep

  19. A comprehensive neuropsychological mapping battery for functional magnetic resonance imaging.

    Science.gov (United States)

    Karakas, Sirel; Baran, Zeynel; Ceylan, Arzu Ozkan; Tileylioglu, Emre; Tali, Turgut; Karakas, Hakki Muammer

    2013-11-01

    Existing batteries for FMRI do not precisely meet the criteria for comprehensive mapping of cognitive functions within minimum data acquisition times using standard scanners and head coils. The goal was to develop a battery of neuropsychological paradigms for FMRI that can also be used in other brain imaging techniques and behavioural research. Participants were 61 healthy, young adult volunteers (48 females and 13 males, mean age: 22.25 ± 3.39 years) from the university community. The battery included 8 paradigms for basic (visual, auditory, sensory-motor, emotional arousal) and complex (language, working memory, inhibition/interference control, learning) cognitive functions. Imaging was performed using standard functional imaging capabilities (1.5-T MR scanner, standard head coil). Structural and functional data series were analysed using Brain Voyager QX2.9 and Statistical Parametric Mapping-8. For basic processes, activation centres for individuals were within a distance of 3-11 mm of the group centres of the target regions and for complex cognitive processes, between 7 mm and 15 mm. Based on fixed-effect and random-effects analyses, the distance between the activation centres was 0-4 mm. There was spatial variability between individual cases; however, as shown by the distances between the centres found with fixed-effect and random-effects analyses, the coordinates for individual cases can be used to represent those of the group. The findings show that the neuropsychological brain mapping battery described here can be used in basic science studies that investigate the relationship of the brain to the mind and also as functional localiser in clinical studies for diagnosis, follow-up and pre-surgical mapping. © 2013.

  20. Functional MR imaging of working memory in the human brain

    International Nuclear Information System (INIS)

    Na, Dong Gyu; Ryu, Jae Wook; Byun, Hong Sik; Lee, Eun Jeong; Chung, Woo In; Cho, Jae Min; Han, Boo Kyung; Choi, Dae Seob

    2000-01-01

    In order to investigate the functional brain anatomy associated with verbal and visual working memory, functional magnetic resonance imaging was performed. In ten normal right handed subjects, functional MR images were obtained using a 1.5-T MR scanner and the EPI BOLD technique. An item recognition task was used for stimulation, and during the activation period of the verbal working memory task, consonant letters were used. During the activation period of the visual working memory task, symbols or diagrams were employed instead of letters. For the post-processing of images, the SPM program was used, with the threshold of significance set at p < .001. We assessed activated brain areas during the two stimulation tasks and compared the activated regions between the two tasks. The prefrontal cortex and secondary visual cortex were activated bilaterally by both verbal and visual working memory tasks, and the patterns of activated signals were similar in both tasks. The superior parietal cortex was also activated by both tasks, with lateralization to the left in the verbal task, and bilaterally without lateralization in the visual task. The inferior frontal cortex, inferior parietal cortex and temporal gyrus were activated exclusively by the verbal working memory task, predominantly in the left hemisphere. The prefrontal cortex is activated by two stimulation tasks, and this is related to the function of the central executive. The language areas activated by the verbal working memory task may be a function of the phonological loop. Bilateral prefrontal and superior parietal cortices activated by the visual working memory task may be related to the visual maintenance of objects, representing visual working memory

  1. Functional brain imaging: an evidence-based analysis.

    Science.gov (United States)

    2006-01-01

    The objective of this analysis is to review a spectrum of functional brain imaging technologies to identify whether there are any imaging modalities that are more effective than others for various brain pathology conditions. This evidence-based analysis reviews magnetoencephalography (MEG), magnetic resonance spectroscopy (MRS), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI) for the diagnosis or surgical management of the following conditions: Alzheimer's disease (AD), brain tumours, epilepsy, multiple sclerosis (MS), and Parkinson's disease (PD). TARGET POPULATION AND CONDITION Alzheimer's disease is a progressive, degenerative, neurologic condition characterized by cognitive impairment and memory loss. The Canadian Study on Health and Aging estimated that there will be 97,000 incident cases (about 60,000 women) of dementia (including AD) in Canada in 2006. In Ontario, there will be an estimated 950 new cases and 580 deaths due to brain cancer in 2006. Treatments for brain tumours include surgery and radiation therapy. However, one of the limitations of radiation therapy is that it damages tissue though necrosis and scarring. Computed tomography (CT) and magnetic resonance imaging (MRI) may not distinguish between radiation effects and resistant tissue, creating a potential role for functional brain imaging. Epilepsy is a chronic disorder that provokes repetitive seizures. In Ontario, the rate of epilepsy is estimated to be 5 cases per 1,000 people. Most people with epilepsy are effectively managed with drug therapy; but about 50% do not respond to drug therapy. Surgical resection of the seizure foci may be considered in these patients, and functional brain imaging may play a role in localizing the seizure foci. Multiple sclerosis is a progressive, inflammatory, demyelinating disease of the central nervous system (CNS). The cause of MS is unknown; however, it is thought to be due to a combination of etiologies, including

  2. In vivo hepatocyte MR imaging using lactose functionalized magnetoliposomes.

    Science.gov (United States)

    Ketkar-Atre, Ashwini; Struys, Tom; Dresselaers, Tom; Hodenius, Michael; Mannaerts, Inge; Ni, Yicheng; Lambrichts, Ivo; Van Grunsven, Leo A; De Cuyper, Marcel; Himmelreich, Uwe

    2014-01-01

    The aim of this study was to assess a novel lactose functionalized magnetoliposomes (MLs) as an MR contrast agent to target hepatocytes as well as to evaluate the targeting ability of MLs for in vivo applications. In the present work, 17 nm sized iron oxide cores functionalized with anionic MLs bearing lactose moieties were used for targeting the asialoglycoprotein receptor (ASGP-r), which is highly expressed in hepatocytes. Non-functionalized anionic MLs were tested as negative controls. The size distribution of lactose and anionic MLs was determined by transmission electron microscopy (TEM) and dynamic light scattering (DLS). After intravenous administration of both MLs, contrast enhancement in the liver was observed by magnetic resonance imaging (MRI). Label retention was monitored non-invasively by MRI and validated with Prussian blue staining and TEM for up to eight days post MLs administration. Although the MRI signal intensity did not show significant differences between functionalized and non-functionalized particles, iron-specific Prussian blue staining and TEM analysis confirmed the uptake of lactose MLs mainly in hepatocytes. In contrast, non-functionalized anionic MLs were mainly taken up by Kupffer and sinusoidal cells. Target specificity was further confirmed by high-resolution MR imaging of phantoms containing isolated hepatocytes, Kupffer cell (KCs) and hepatic stellate cells (HSCs) fractions. Hypointense signal was observed for hepatocytes isolated from animals which received lactose MLs but not from animals which received anionic MLs. These data demonstrate that galactose-functionalized MLs can be used as a hepatocyte targeting MR contrast agent to potentially aid in the diagnosis of hepatic diseases if the non-specific uptake by KCs is taken into account. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Functional imaging of the multidrug resistance in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Tae [College of Medicine, Kyungpook National Univ., Taegu (Korea, Republic of)

    2001-07-01

    Although diverse mechanisms are involved in multidrug resistance for chemotherapeutic drugs, the development of cellular P-glycoprotein(Pgp) and multidrug-resistance associated protein (MRP) are improtant factors in the chemotherapy failure to cancer. Various detection assays provide information about the presence of drug efflux pumps at the mRNA and protein levels. However these methods do not yield information about dynamic function of Pgp and MRP in vivo. Single photon emission tomograpy (SPECT) and positron emission tomograpy (PET) are available for the detection of Pgp and MRP-mediated transport. {sup 99m}Tc-sestaMIBI and other {sup 99m}Tc-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies of tumor imaging, and to visualize blockade of Pgp-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with {sup 11}C have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and N-{sup (11}C]acetyl-leukotriene E4 provides an opportunity to study MRP function non-invasively in vivo. Results obtained from recent publications are reviewed to confirm the feasibility of using SPECT and PET to study the functionality of MDR transportes in vivo.

  4. Study of functional brain imaging for bilingual language cognition

    International Nuclear Information System (INIS)

    Sun Da

    2008-01-01

    Bilingual and multilingual brain studies of language recognition is an interdisciplinary subject which needs to identify different levels involved in the neural representation of languages, such as neuroanatomical, neurofunctional, biochemical, psychological and linguistic levels. Furthermore, specific factor's such as age, manner of acquisition and environmental factors seem to affect the neural representation. Functional brain imaging, such as PET, SPECT and functional MRI can explore the neurolinguistics representation of bilingualism in the brain in subjects, and elucidate the neuronal mechanisms of bilingual language processing. Functional imaging methods show differences in the pattern of cerebral activation associated with a second language compared with the subject's native language. It shows that verbal memory processing in two unrelated languages is mediated by a common neural system with some distinct cortical areas. The different patterns of activation differ according to the language used. It also could be ascribed either to age of acquisition or to proficiency level. And attained proficiency is more important than age of acquisition as a determinant of the cortical representation of the second language. The study used PET and SPECT shows that sign and spoken language seem to be localized in the same brain areas, and elicit similar regional cerebral blood flow patterns. But for sign language perception, the functional anatomy overlaps that of language processing contain both auditory and visual components. And the sign language is dependent on spatial information too. (authors)

  5. Assessment of cerebral perfusional and functional connectivity in schizophrenia using magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ícaro A. F.; Guimarães, Tiago M.; Souza, Roberto M.; Santos, Antônio C. dos; Leoni, Renata F.; Machado-Sousa, João Paulo; Hallak, Jaime E.C. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil)

    2017-07-01

    Schizophrenia is a significant mental disorder that compromises structural and functional aspects of the brain, with an extreme effect on the patient’s thoughts, feelings, and behavior. Physiologically, changes in neuronal activity are reported besides functional and structural abnormalities. Since the cerebral blood flow (CBF) is directly related to neuronal activity, the magnetic resonance imaging (MRI) technique called arterial spin labeling (ASL), which allows the quantification of CBF, is a useful tool in brain perfusional evaluation. In addition, ASL can be used to assess functional connectivity, which is efficient in investigating functional impairment between regions of the brain. Pseudo-continuous arterial spin labeling (pCASL) images were acquired from 28 schizophrenia patients in treatment and 28 age-matched healthy controls. Static CBF and connectivity patterns were assessed in both groups. Decreased CBF and functional connectivity were observed in regions that form two resting brain networks, default mode (DMN) and salience (SN), for schizophrenia patients. Previous studies related the features of this pathology with altered resting CBF and functional disconnections. Therefore, using a noninvasive technique, it was possible to find CBF deficits and altered functional organization of the brain in schizophrenia patients that are associated with the symptoms and characteristics of the disorder. (author)

  6. Assessment of cerebral perfusional and functional connectivity in schizophrenia using magnetic resonance imaging

    International Nuclear Information System (INIS)

    Oliveira, Ícaro A. F.; Guimarães, Tiago M.; Souza, Roberto M.; Santos, Antônio C. dos; Leoni, Renata F.; Machado-Sousa, João Paulo; Hallak, Jaime E.C.

    2017-01-01

    Schizophrenia is a significant mental disorder that compromises structural and functional aspects of the brain, with an extreme effect on the patient’s thoughts, feelings, and behavior. Physiologically, changes in neuronal activity are reported besides functional and structural abnormalities. Since the cerebral blood flow (CBF) is directly related to neuronal activity, the magnetic resonance imaging (MRI) technique called arterial spin labeling (ASL), which allows the quantification of CBF, is a useful tool in brain perfusional evaluation. In addition, ASL can be used to assess functional connectivity, which is efficient in investigating functional impairment between regions of the brain. Pseudo-continuous arterial spin labeling (pCASL) images were acquired from 28 schizophrenia patients in treatment and 28 age-matched healthy controls. Static CBF and connectivity patterns were assessed in both groups. Decreased CBF and functional connectivity were observed in regions that form two resting brain networks, default mode (DMN) and salience (SN), for schizophrenia patients. Previous studies related the features of this pathology with altered resting CBF and functional disconnections. Therefore, using a noninvasive technique, it was possible to find CBF deficits and altered functional organization of the brain in schizophrenia patients that are associated with the symptoms and characteristics of the disorder. (author)

  7. Methods for modeling and quantification in functional imaging by positron emissions tomography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Costes, Nicolas

    2017-01-01

    This report presents experiences and researches in the field of in vivo medical imaging by positron emission tomography (PET) and magnetic resonance imaging (MRI). In particular, advances in terms of reconstruction, quantification and modeling in PET are described. The validation of processing and analysis methods is supported by the creation of data by simulation of the imaging process in PET. The recent advances of combined PET/MRI clinical cameras, allowing simultaneous acquisition of molecular/metabolic PET information, and functional/structural MRI information opens the door to unique methodological innovations, exploiting spatial alignment and simultaneity of the PET and MRI signals. It will lead to an increase in accuracy and sensitivity in the measurement of biological phenomena. In this context, the developed projects address new methodological issues related to quantification, and to the respective contributions of MRI or PET information for a reciprocal improvement of the signals of the two modalities. They open perspectives for combined analysis of the two imaging techniques, allowing optimal use of synchronous, anatomical, molecular and functional information for brain imaging. These innovative concepts, as well as data correction and analysis methods, will be easily translated into other areas of investigation using combined PET/MRI. (author) [fr

  8. Follow-up of patients with previous treatment for coarctation of the thoracic aorta: comparison between contrast-enhanced MR angiography and fast spin-echo MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bogaert, J.; Kuzo, R.; Dymarkowski, S.; Janssen, L.; Celis, I. [University Hospital, Leuven (Belgium). Dept. of Radiology; Budts, W. [Dept. of Cardiology, University Hospital Gasthuisberg, Leuven (Belgium); Gewillig, M. [Dept. of Pediatric Cardiology, University Hospital Gasthuisberg, Leuven (Belgium)

    2000-12-01

    Regular follow-up is required in patients with previous intervention for coarctation of the aorta to detect recoarctation or aneurysm formation. In this study we describe the findings encountered on routine follow-up exams and we compare the use of contrast-enhanced 3D MR angiography (CE MRA) with fast spin-echo MRI (FSE) to study the thoracic aorta after previous intervention. In 51 consecutive patients previously treated for aortic coarctation, 74 MR studies of the thoracic aorta were performed during a 2-year period using CE MRA and FSE MRI. The thoracic aorta was evaluated for abnormalities of course, caliber, shape, and pathology of side branches. The CE MRA and FSE MRI studies were evaluated side by side by consensus of two reviewers evaluating which MR technique depicted the abnormalities of the thoracic aorta the best. Of 74 exams, six clinically important abnormalities were found: four aneurysms and two restenoses. Two small pseudoaneurysms were missed on the FSE studies. Contrast-enhanced MRA was judged to visualize aortic abnormalities better than FSE (47 of 74 MR studies) especially for the transverse aortic arch, coarctation site, left subclavian artery, and aortic arch configuration. For the ascending aorta and distal descending aorta, CE MRA and FSE performed equally well. Aortic diameters measured at four levels in the first 18 MRI studies showed no significant differences in diameter when measured by FSE or CE MRA (p = not significant). Clinically important abnormalities, such as aneurysm formation and restenosis, can be present years after treatment for aortic coarctation. In the regular follow-up of these patients, CE MRA may provide additional diagnostic information compared with FSE and should be included as part of the routine exam. (orig.)

  9. Functional Nonlinear Mixed Effects Models For Longitudinal Image Data

    Science.gov (United States)

    Luo, Xinchao; Zhu, Lixing; Kong, Linglong; Zhu, Hongtu

    2015-01-01

    Motivated by studying large-scale longitudinal image data, we propose a novel functional nonlinear mixed effects modeling (FN-MEM) framework to model the nonlinear spatial-temporal growth patterns of brain structure and function and their association with covariates of interest (e.g., time or diagnostic status). Our FNMEM explicitly quantifies a random nonlinear association map of individual trajectories. We develop an efficient estimation method to estimate the nonlinear growth function and the covariance operator of the spatial-temporal process. We propose a global test and a simultaneous confidence band for some specific growth patterns. We conduct Monte Carlo simulation to examine the finite-sample performance of the proposed procedures. We apply FNMEM to investigate the spatial-temporal dynamics of white-matter fiber skeletons in a national database for autism research. Our FNMEM may provide a valuable tool for charting the developmental trajectories of various neuropsychiatric and neurodegenerative disorders. PMID:26213453

  10. Functional magnetic resonance imaging of the human motor cortex

    Energy Technology Data Exchange (ETDEWEB)

    Sasahira, Masahiro; Asakura, Tetsuhiko; Niiro, Masaki; Haruzono, Akihiro; Hirakawa, Wataru [Kagoshima Univ. (Japan). Faculty of Medicine; Matsumoto, Tetsuro; Fujimoto, Toshiro

    1995-05-01

    Functional magnetic resonance (MR) imaging of the brain was performed during motor task activation in five normal subjects and a patient with meningioma using conventional fast low-angle shot sequences and a 2.0 T system. A high intensity area in the motor cortex was observed in all normal subjects. Single-slice studies showed the right-sided finger task produced an increase of 1.9-23.5% (6.67{+-}4.36%) in the signal intensity of the left motor cortex, while the left-sided finger task increased the signal by 1.5-18.2% (6.09{+-}3.34%) in the right motor cortex. There was no significant difference between the sides. Multiple-slice studies also showed the activated motor cortex as a high intensity area. The maximum signal intensity increase in the activated motor area was 11.0% for the left motor cortex and 8.8% for the right motor cortex. There was no significant difference between the sides. Preoperative mapping of the patient with meningioma showed that the motor cortex was displaced posteriorly by the tumor. Functional MR imaging is possible with a standard MR imaging system and conventional gradient echo sequences. Useful clinical information can be obtained by preoperative mapping of the motor cortex. (author).

  11. Modelling human musculoskeletal functional movements using ultrasound imaging

    Directory of Open Access Journals (Sweden)

    Stenlund Hans

    2010-05-01

    Full Text Available Abstract Background A widespread and fundamental assumption in the health sciences is that muscle functions are related to a wide variety of conditions, for example pain, ischemic and neurological disorder, exercise and injury. It is therefore highly desirable to study musculoskeletal contributions in clinical applications such as the treatment of muscle injuries, post-surgery evaluations, monitoring of progressive degeneration in neuromuscular disorders, and so on. The spatial image resolution in ultrasound systems has improved tremendously in the last few years and nowadays provides detailed information about tissue characteristics. It is now possible to study skeletal muscles in real-time during activity. Methods The ultrasound images are transformed to be congruent and are effectively compressed and stacked in order to be analysed with multivariate techniques. The method is applied to a relevant clinical orthopaedic research field, namely to describe the dynamics in the Achilles tendon and the calf during real-time movements. Results This study introduces a novel method to medical applications that can be used to examine ultrasound image sequences and to detect, visualise and quantify skeletal muscle dynamics and functions. Conclusions This new objective method is a powerful tool to use when visualising tissue activity and dynamics of musculoskeletal ultrasound registrations.

  12. Cardiac Function After Multimodal Breast Cancer Therapy Assessed With Functional Magnetic Resonance Imaging and Echocardiography Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Heggemann, Felix, E-mail: felix.heggemann@umm.de [First Medical Department, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); German Center for Cardiovascular Research, Mannheim (Germany); Grotz, Hanna; Welzel, Grit [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); Dösch, Christina [First Medical Department, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); German Center for Cardiovascular Research, Mannheim (Germany); Hansmann, Jan [Institute of Diagnostic Radiology and Nuclear Medicine, University Medical Center Mannheim University of Heidelberg, Mannheim (Germany); Kraus-Tiefenbacher, Uta [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); Attenberger, Ulrike; Schönberg, Stephan Oswald [German Center for Cardiovascular Research, Mannheim (Germany); Institute of Diagnostic Radiology and Nuclear Medicine, University Medical Center Mannheim University of Heidelberg, Mannheim (Germany); Borggrefe, Martin [First Medical Department, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); German Center for Cardiovascular Research, Mannheim (Germany); Wenz, Frederik [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); Papavassiliu, Theano [First Medical Department, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany); German Center for Cardiovascular Research, Mannheim (Germany); Lohr, Frank [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim (Germany)

    2015-11-15

    Purpose: Breast intensity modulated radiation therapy (IMRT) reduces high-dose heart volumes but increases low-dose volumes. We prospectively assessed heart changes after 3D conformal RT (3DCRT) and IMRT for left-sided breast cancer. Heart dose was analyzed individually, 3DCRT patients were moderately exposed, and IMRT was performed only in patients with unacceptably high heart doses upon 3DCRT planning. Methods and Materials: In 49 patients (38 patients received 3DCRT; 11 patients received IMRT; and 20 patients received neoadjuvant or adjuvant chemotherapy) magnetic resonance imaging (MRI) and echocardiography were performed before and at 6, 12, and 24 months after treatment. Results: Mean heart dose for IMRT was 12.9 ± 3.9 Gy versus 4.5 ± 2.4 Gy for 3DCRT. Heart volumes receiving >40 Gy were 2.6% (3DCRT) versus 1.3% (IMRT); doses were >50 Gy only with 3DCRT. Temporary ejection fraction (EF) decrease was observed on MRI after 6 months (63%-59%, P=.005) resolving at 24 months. Only 3 patients had pronounced largely transient changes of EF and left ventricular enddiastolic diameter (LVEDD). Mitral (M) and tricuspid (T) annular plane systolic excursion (MAPSE and TAPSE) were reduced over the whole cohort (still within normal range). After 24 months left ventricular remodeling index decreased in patients receiving chemotherapy (0.80 vs 0.70, P=.028). Neither wall motion abnormalities nor late enhancements were found. On echocardiography, in addition to EF findings that were similar to those on MRI, global strain was unchanged over the whole cohort at 24 months after a transient decrease at 6 and 12 months. Longitudinal strain decreased in the whole cohort after 24 months in some segments, whereas it increased in others. Conclusions: Until 24 months after risk-adapted modern multimodal adjuvant therapy, only subclinical cardiac changes were observed in both 3DCRT patients with inclusion of small to moderate amounts of heart volume in RT tangents and

  13. Functional imaging of cortical feedback projections to the olfactory bulb

    Directory of Open Access Journals (Sweden)

    Markus eRothermel

    2014-07-01

    Full Text Available Processing of sensory information is substantially shaped by centrifugal, or feedback, projections from higher cortical areas, yet the functional properties of these projections are poorly characterized. Here, we used genetically-encoded calcium sensors (GCaMPs to functionally image activation of centrifugal projections targeting the olfactory bulb (OB. The OB receives massive centrifugal input from cortical areas but there has been as yet no characterization of their activity in vivo. We focused on projections to the OB from the anterior olfactory nucleus (AON, a major source of cortical feedback to the OB. We expressed GCaMP selectively in AON projection neurons using a mouse line expressing Cre recombinase (Cre in these neurons and Cre-dependent viral vectors injected into AON, allowing us to image GCaMP fluorescence signals from their axon terminals in the OB. Electrical stimulation of AON evoked large fluorescence signals that could be imaged from the dorsal OB surface in vivo. Surprisingly, odorants also evoked large signals that were transient and coupled to odorant inhalation both in the anesthetized and awake mouse, suggesting that feedback from AON to the OB is rapid and robust across different brain states. The strength of AON feedback signals increased during wakefulness, suggesting a state-dependent modulation of cortical feedback to the OB. Two-photon GCaMP imaging revealed that different odorants activated different subsets of centrifugal AON axons and could elicit both excitation and suppression in different axons, indicating a surprising richness in the representation of odor information by cortical feedback to the OB. Finally, we found that activating neuromodulatory centers such as basal forebrain drove AON inputs to the OB independent of odorant stimulation. Our results point to the AON as a multifunctional cortical area that provides ongoing feedback to the OB and also serves as a descending relay for other neuromodulatory

  14. PREVIOUS SECOND TRIMESTER ABORTION

    African Journals Online (AJOL)

    PNLC

    PREVIOUS SECOND TRIMESTER ABORTION: A risk factor for third trimester uterine rupture in three ... for accurate diagnosis of uterine rupture. KEY WORDS: Induced second trimester abortion - Previous uterine surgery - Uterine rupture. ..... scarred uterus during second trimester misoprostol- induced labour for a missed ...

  15. Morphological and functional MR imaging of the pharyngotympanic tube

    International Nuclear Information System (INIS)

    Krombach, G.A.; Nolte-Ernsting, C.; Schmitz-Rode, T.; Guenther, R.W.; Di Martino, E.; Westhofen, M.; Prescher, A.

    2000-01-01

    Purpose: To develop and evaluate a protocol for the anatomic depiction and functional testing of the auditory tube with the use of MR imaging. Methods: Eleven volunteers were included into this study. For the morphological assessment, the imaging protocol included axial and coronal T 2 -weighted turbo-spin echo sequences (T R /T E =3194/100 ms) and a T 1 -weighted gradient echo sequence (T R /T E =42/4.6 ms). For the functional test a dynamic turbo-gradient echo sequence (TFE) with spectral fat suppression (T R /T E =15/6,2 ms; 4 sec) was obtained using the single slice technique before and during the Valsalva manoeuvre. Results: With multi-slice sequences, the osseous part of the auditory tube, the tubal cartilage (middle and lateral lamina), the ciliated epithelium, Ostmann's adipose body and the levator and tensor veli palatini muscles were delineated in all cases. During the Valsalva test, opening of the auditory tube was demonstrated in 20 of the 22 investigated sides using the dynamic TFE single slice sequence. Conclusions: The introduced MRI protocol allow visualization of the opening of the auditory tube and provides detailed anatomical information of the nasopharynx. Comprehensive morphological and functional evaluation of the auditory tube becomes possible within a single examination. (orig.) [de

  16. A Functional Approach to Hyperspectral Image Analysis in the Cloud

    Science.gov (United States)

    Wilson, A.; Lindholm, D. M.; Coddington, O.; Pilewskie, P.

    2017-12-01

    Hyperspectral image volumes are very large. A hyperspectral image analysis (HIA) may use 100TB of data, a huge barrier to their use. Hylatis is a new NASA project to create a toolset for HIA. Through web notebook and cloud technology, Hylatis will provide a more interactive experience for HIA by defining and implementing concepts and operations for HIA, identified and vetted by subject matter experts, and callable within a general purpose language, particularly Python. Hylatis leverages LaTiS, a data access framework developed at LASP. With an OPeNDAP compliant interface plus additional server side capabilities, the LaTiS API provides a uniform interface to virtually any data source, and has been applied to various storage systems, including: file systems, databases, remote servers, and in various domains including: space science, systems administration and stock quotes. In the LaTiS architecture, data `adapters' read data into a data model, where server-side computations occur. Data `writers' write data from the data model into the desired format. The Hylatis difference is the data model. In LaTiS, data are represented as mathematical functions of independent and dependent variables. Domain semantics are not present at this level, but are instead present in higher software layers. The benefit of a domain agnostic, mathematical representation is having the power of math, particularly functional algebra, unconstrained by domain semantics. This agnosticism supports reusable server side functionality applicable in any domain, such as statistical, filtering, or projection operations. Algorithms to aggregate or fuse data can be simpler because domain semantics are separated from the math. Hylatis will map the functional model onto the Spark relational interface, thereby adding a functional interface to that big data engine.This presentation will discuss Hylatis goals, strategies, and current state.

  17. Functional imaging in pre-motor Parkinson’s disease

    International Nuclear Information System (INIS)

    Arnaldi, D.; Picco, A.; Ferrara, M.; Nobili, F.; Famà, F.; Buschiazzo, A.; Morbelli, S.; De Carli, F.

    2014-01-01

    Several non motor symptoms (NMS) can precede the onset of the classical motor Parkinson’s disease (PD) syndrome. The existence of pre-motor and even pre-clinical PD stages has been proposed but the best target population to be screened to disclose PD patients in a pre-clinical, thus asymptomatic, stage is still matter of debate. The REM sleep behavior disorder (RBD) often affects PD patients at different stages of the disease and could precede the onset of motor symptoms by several years. However, RBD could also precede other synucleinopathies (namely, dementia with Lewy bodies and multisystem atrophy), and less frequently could be related to other neurological conditions or remain idiopathic. Moreover, not all PD patients exhibit RBD. Despite these caveats, RBD probably represents the best feature to disclose pre-motor PD patients given its high-risk of developing a full motor syndrome. Other clinical clues in the premotor stages of PD undergoing active investigation include hyposmia, depression, and autonomic dysfunction. Effective biomarkers are needed in order to improve the diagnostic accuracy in the pre-motor stage of PD, to monitor disease progression and to plan both pharmacological and non-pharmacological intervention. Functional imaging, in particular radionuclide methodologies, has been often used to investigate dopaminergic and non-dopaminergic features as well as cortical functioning in patients with RBD in its idiopathic form (iRBD) and/or associated with PD. Recently, new tracers to image α-synuclein pathologies are under development. Functional imaging in pre-motor PD, and in particular in iRBD, could improve our knowledge about the underlying mechanisms and the neurodegenerative progress of PD

  18. Function's evaluation, perfusion and metabolism by positron emission tomography associated with multislice tomography (PET/CT) in patient with previous diagnosis to myocardial necrosis

    International Nuclear Information System (INIS)

    Campisi, Roxana; Aramayo, Natalia; Osorio, Amilcar

    2010-01-01

    A 64-years-old male patient with previous diagnosis of myocardial necrosis as assessed by myocardial perfusion gated single photon emission computed tomography (gSPECT) with 3-vessel-disease, left ventricular dysfunction and symptomatic by epigastric pain. The patient was referred for myocardial viability assessment by positron emission tomography (PET) to define clinical management decision. (authors) [es

  19. Image Inpainting Based on Coherence Transport with Adapted Distance Functions

    KAUST Repository

    März, Thomas

    2011-01-01

    We discuss an extension of our method image inpainting based on coherence transport. For the latter method the pixels of the inpainting domain have to be serialized into an ordered list. Until now, to induce the serialization we have used the distance to boundary map. But there are inpainting problems where the distance to boundary serialization causes unsatisfactory inpainting results. In the present work we demonstrate cases where we can resolve the difficulties by employing other distance functions which better suit the problem at hand. © 2011 Society for Industrial and Applied Mathematics.

  20. Whiplash Injuries Can be Visible by Functional Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Bengt H Johansson

    2006-01-01

    Full Text Available Whiplash trauma can result in injuries that are difficult to diagnose. Diagnosis is particularly difficult in injuries to the upper segments of the cervical spine (craniocervical joint [CCJ] complex. Studies indicate that injuries in that region may be responsible for the cervicoencephalic syndrome, as evidenced by headache, balance problems, vertigo, dizziness, eye problems, tinnitus, poor concentration, sensitivity to light and pronounced fatigue. Consequently, diagnosis of lesions in the CCJ region is important. Functional magnetic resonance imaging is a radiological technique that can visualize injuries of the ligaments and the joint capsules, and accompanying pathological movement patterns.

  1. Special Considerations for Functional Magnetic Resonance Imaging of Pediatric Populations

    Science.gov (United States)

    Kotsoni, Eleni; Byrd, Dana; Casey, BJ

    2010-01-01

    Functional MRI (fMRI) provides a non-invasive means of studying both typical and atypical brain development in vivo. However, the developmental and clinical status of the populations of interest impact how neuroimaging data should be collected, analyzed, and interpreted. In the present paper, we review methodological and theoretical issues relevant to developmental and clinical neuroimaging research and provide possible approaches for addressing each. These issues include accounting for differences in biological noise, neuroanatomy, motion, and task performance. Finally, we emphasize the importance of a converging methods approach in constraining and supporting interpretations of pediatric imaging results. PMID:16649204

  2. Functional MR imaging of psychogenic amnesia: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jong Chul; Jeong, Gwang Woo; Lee, Moo Suk; Kang, Heoung Keun; Eun, Sung Jong; Lee, Yo Han [Chonnam National Univeristy Hospital, Chonnam National University Medical School, Kwangju (Korea, Republic of); Kim, Yong Ku [Korea University Ansan Hospital, Ansan (Korea, Republic of)

    2005-09-15

    We present here a case in which functional MR imaging (fMRI) was done for a patient who developed retrograde psychogenic amnesia for a four year period of her life history after a severe stressful event. We performed the fMRI study for a face recognition task using stimulation with three kinds of face photographs: recognizable familiar faces, unrecognizable friends' faces due to the psychogenic amnesia, and unfamiliar control faces. Different activation patterns between the recognizable faces and unrecognizable faces were found in the limbic area, and especially in the amygdala and hippocampus.

  3. Functional MR imaging of psychogenic amnesia: a case report

    International Nuclear Information System (INIS)

    Yang, Jong Chul; Jeong, Gwang Woo; Lee, Moo Suk; Kang, Heoung Keun; Eun, Sung Jong; Lee, Yo Han; Kim, Yong Ku

    2005-01-01

    We present here a case in which functional MR imaging (fMRI) was done for a patient who developed retrograde psychogenic amnesia for a four year period of her life history after a severe stressful event. We performed the fMRI study for a face recognition task using stimulation with three kinds of face photographs: recognizable familiar faces, unrecognizable friends' faces due to the psychogenic amnesia, and unfamiliar control faces. Different activation patterns between the recognizable faces and unrecognizable faces were found in the limbic area, and especially in the amygdala and hippocampus

  4. Measurement of spatial correlation functions using image processing techniques

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1985-01-01

    A procedure for using digital image processing techniques to measure the spatial correlation functions of composite heterogeneous materials is presented. Methods for eliminating undesirable biases and warping in digitized photographs are discussed. Fourier transform methods and array processor techniques for calculating the spatial correlation functions are treated. By introducing a minimal set of lattice-commensurate triangles, a method of sorting and storing the values of three-point correlation functions in a compact one-dimensional array is developed. Examples are presented at each stage of the analysis using synthetic photographs of cross sections of a model random material (the penetrable sphere model) for which the analytical form of the spatial correlations functions is known. Although results depend somewhat on magnification and on relative volume fraction, it is found that photographs digitized with 512 x 512 pixels generally have sufficiently good statistics for most practical purposes. To illustrate the use of the correlation functions, bounds on conductivity for the penetrable sphere model are calculated with a general numerical scheme developed for treating the singular three-dimensional integrals which must be evaluated

  5. Influence of PET/CT 68Ga somatostatin receptor imaging on proceeding with patients, who were previously diagnosed with 99mTc-EDDA/HYNIC-TOC SPECT.

    Science.gov (United States)

    Madrzak, Dorota; Mikołajczak, Renata; Kamiński, Grzegorz

    2016-01-01

    The aim of this study was the assessment of utility of somatostatin receptor scintigraphy (SRS) by SPECT imaging using 99mTc-EDDA/HYNIC-Tyr3-octreotide (99mTc-EDDA/HYNIC-TOC) in patients with neuroendocrine neoplasm (NEN) or suspected NEN, referred to Nuclear Medicine Dept. of Voivodship Specialty Center in Rzeszow. The selected group of patients was referred also to 68Ga PET/CT. The posed question was the ratio of patients for whom PET/CT with 68Ga would change their management. The distribution of somatostatin receptors was imaged using 99mTc-EDDA/HYNIC-TOC in 61 planar and SPECT studies between 13/05/2010 and 04/02/2013 in Nuclear Medicine Dept. of Voivodship Specialty Center in Rzeszow. The patient age was within a range of 17-80, with the average age of 57.6. The average age of women (65% of patients over-all) was 55.6 and the average age of men (35% of patients overall) was 61.4. In 46 participants (75% of the study group), that underwent SRS, NEN was documented using pathology tests. Selected patients were referred to PET/CT with 68Ga labeled somatostatin analogs, DOTATATE or DOTANOC. This study group consisted of 14 female and 10 male participants with age range of 35-77 and average age of 55.5 years. Patients were classified into 3 groups, as follows: detection - referral due to clinical symptoms and/or biochemical markers (CgA-Chromogranin A, IAA-indoleacetic acid) with the aim of primary diagnosis, staging - referral with the aim of assessment of tumor spread, and follow-up - assessment of the therapy. Out of 61 patients, 24 underwent both 99mTc-EDDA/HYNIC-Tyr3-octreotide SPECT and 68Ga PET/CT. The result of PET/CT was used as a basis for further evaluation. Therefore, the patients were divided into groups; true positive TP (confirmed presence of tissue somatostatin receptors with 68Ga PET/CT) and TN (68Ga PET/CT did not detect any changes and the results were comparable and had the same influence on treatment protocol). In case of SPECT, the results

  6. An imaging system for intraoperative functional imaging of optical intrinsic signals

    Science.gov (United States)

    Wong, Gregory Kai

    This dissertation focuses on the research, design, and implementation of a Neurosurgical Imaging System (NIS), having the principle characteristics of modularity, mobility, multispectral imaging capabilities, and an open software architecture. The NIS will enable functional imaging of humans and animals by implementing innovative hardware and software enhancements. The NIS is tightly integrated with data acquisition hardware and software for simultaneous measurements of real-time, physiological parameters and Optical Intrinsic Signals (OIS). The NIS provides a portable, versatile imaging system. High speed ``off the shelf'' hardware has been implemented and refined to reduce overall cost and maintenance of the NIS. Implementation of new, enhanced charge coupled device technology, such as, Electron Bombardment Charge Coupled Devices (EBCCD) dramatically increases sensitivity and multi-spectral image acquisition capabilities. Utilization of efficient calibration and testing protocols provides advanced trouble shooting and standard performance metrics for the NIS. The NIS was experimentally tested and validated on LED ``phantoms'' and a variety of mammalian brain models throughout its design phases. Implementation of an innovative imaging system such as the NIS provides a powerful research and clinical diagnostic tool that will enhance our current understanding of the various physiologic underpinnings of neurovascular coupling in normal and diseased brains. The development of this type of portable imaging instrumentation controlled by a robust software architecture that provides command and control, real time data acquisition, data analysis, auto calibration, and performance metrics lay the foundations for a comprehensive neurosurgical guidance tool, as well as, a powerful experimental research tool for mapping activity-related changes in cerebral perfusion and neuronal activity.

  7. A Cellular Perspective on Brain Energy Metabolism and Functional Imaging

    KAUST Repository

    Magistretti, Pierre J.

    2015-05-01

    The energy demands of the brain are high: they account for at least 20% of the body\\'s energy consumption. Evolutionary studies indicate that the emergence of higher cognitive functions in humans is associated with an increased glucose utilization and expression of energy metabolism genes. Functional brain imaging techniques such as fMRI and PET, which are widely used in human neuroscience studies, detect signals that monitor energy delivery and use in register with neuronal activity. Recent technological advances in metabolic studies with cellular resolution have afforded decisive insights into the understanding of the cellular and molecular bases of the coupling between neuronal activity and energy metabolism and pointat a key role of neuron-astrocyte metabolic interactions. This article reviews some of the most salient features emerging from recent studies and aims at providing an integration of brain energy metabolism across resolution scales. © 2015 Elsevier Inc.

  8. Meshfree Local Radial Basis Function Collocation Method with Image Nodes

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Seung Ki; Kim, Minjae [Pukyong National University, Busan (Korea, Republic of)

    2017-07-15

    We numerically solve two-dimensional heat diffusion problems by using a simple variant of the meshfree local radial-basis function (RBF) collocation method. The main idea is to include an additional set of sample nodes outside the problem domain, similarly to the method of images in electrostatics, to perform collocation on the domain boundaries. We can thereby take into account the temperature profile as well as its gradients specified by boundary conditions at the same time, which holds true even for a node where two or more boundaries meet with different boundary conditions. We argue that the image method is computationally efficient when combined with the local RBF collocation method, whereas the addition of image nodes becomes very costly in case of the global collocation. We apply our modified method to a benchmark test of a boundary value problem, and find that this simple modification reduces the maximum error from the analytic solution significantly. The reduction is small for an initial value problem with simpler boundary conditions. We observe increased numerical instability, which has to be compensated for by a sufficient number of sample nodes and/or more careful parameter choices for time integration.

  9. Functional magnetic resonance imaging of the frontal eye fields during saccadic eye movements

    International Nuclear Information System (INIS)

    Miki, Atsushi; Takagi, Mineo; Abe, Haruki; Nakajima, Takashi; Miyauchi, Satoru.

    1996-01-01

    We evaluated activity-induced signal intensity changes in the human cerebral cortex during horizontal saccadic eye movements using functional magnetic resonance imaging (fMRI) based on the blood-oxygenation-level-dependent (BOLD) contrast method. Compared with central fixation, significant signal increases were observed bilaterally in the middle frontal gyrus (Brodmann area 8) during saccadic conditions. The location of the activated area was consistent with that of previously reported frontal eye fields (FEF). These results suggest that fMRI has potential merit for the study of cortical control of eye movements in humans. (author)

  10. Investigating the emotional response to room acoustics: A functional magnetic resonance imaging study.

    Science.gov (United States)

    Lawless, M S; Vigeant, M C

    2015-10-01

    While previous research has demonstrated the powerful influence of pleasant and unpleasant music on emotions, the present study utilizes functional magnetic resonance imaging (fMRI) to assess the positive and negative emotional responses as demonstrated in the brain when listening to music convolved with varying room acoustic conditions. During fMRI scans, subjects rated auralizations created in a simulated concert hall with varying reverberation times. The analysis detected activations in the dorsal striatum, a region associated with anticipation of reward, for two individuals for the highest rated stimulus, though no activations were found for regions associated with negative emotions in any subject.

  11. SU-G-IeP3-08: Image Reconstruction for Scanning Imaging System Based On Shape-Modulated Point Spreading Function

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ruixing; Yang, LV [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha, Hunan (China); Xu, Kele [College of Electronical Science and Engineering, National University of Defense Technology, Changsha, Hunan (China); Zhu, Li [Institute of Electrostatic and Electromagnetic Protection, Mechanical Engineering College, Shijiazhuang, Hebei (China)

    2016-06-15

    Purpose: Deconvolution is a widely used tool in the field of image reconstruction algorithm when the linear imaging system has been blurred by the imperfect system transfer function. However, due to the nature of Gaussian-liked distribution for point spread function (PSF), the components with coherent high frequency in the image are hard to restored in most of the previous scanning imaging system, even the relatively accurate PSF is acquired. We propose a novel method for deconvolution of images which are obtained by using shape-modulated PSF. Methods: We use two different types of PSF - Gaussian shape and donut shape - to convolute the original image in order to simulate the process of scanning imaging. By employing deconvolution of the two images with corresponding given priors, the image quality of the deblurred images are compared. Then we find the critical size of the donut shape compared with the Gaussian shape which has similar deconvolution results. Through calculation of tightened focusing process using radially polarized beam, such size of donut is achievable under same conditions. Results: The effects of different relative size of donut and Gaussian shapes are investigated. When the full width at half maximum (FWHM) ratio of donut and Gaussian shape is set about 1.83, similar resolution results are obtained through our deconvolution method. Decreasing the size of donut will favor the deconvolution method. A mask with both amplitude and phase modulation is used to create a donut-shaped PSF compared with the non-modulated Gaussian PSF. Donut with size smaller than our critical value is obtained. Conclusion: The utility of donutshaped PSF are proved useful and achievable in the imaging and deconvolution processing, which is expected to have potential practical applications in high resolution imaging for biological samples.

  12. IMAGING OF BRAIN FUNCTION BASED ON THE ANALYSIS OF FUNCTIONAL CONNECTIVITY - IMAGING ANALYSIS OF BRAIN FUNCTION BY FMRI AFTER ACUPUNCTURE AT LR3 IN HEALTHY INDIVIDUALS

    OpenAIRE

    Zheng, Yu; Wang, Yuying; Lan, Yujun; Qu, Xiaodong; Lin, Kelin; Zhang, Jiping; Qu, Shanshan; Wang, Yanjie; Tang, Chunzhi; Huang, Yong

    2016-01-01

    Objective: This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint specificity of the Taichong acupoint. Methods: A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham acupoint group. Subjects received resting state fMRI before acupuncture, a...

  13. Functional imaging of the human placenta with magnetic resonance.

    Science.gov (United States)

    Siauve, Nathalie; Chalouhi, Gihad E; Deloison, Benjamin; Alison, Marianne; Clement, Olivier; Ville, Yves; Salomon, Laurent J

    2015-10-01

    Abnormal placentation is responsible for most failures in pregnancy; however, an understanding of placental functions remains largely concealed from noninvasive, in vivo investigations. Magnetic resonance imaging (MRI) is safe in pregnancy for magnetic fields of up to 3 Tesla and is being used increasingly to improve the accuracy of prenatal imaging. Functional MRI (fMRI) of the placenta has not yet been validated in a clinical setting, and most data are derived from animal studies. FMRI could be used to further explore placental functions that are related to vascularization, oxygenation, and metabolism in human pregnancies by the use of various enhancement processes. Dynamic contrast-enhanced MRI is best able to quantify placental perfusion, permeability, and blood volume fractions. However, the transplacental passage of Gadolinium-based contrast agents represents a significant safety concern for this procedure in humans. There are alternative contrast agents that may be safer in pregnancy or that do not cross the placenta. Arterial spin labeling MRI relies on magnetically labeled water to quantify the blood flows within the placenta. A disadvantage of this technique is a poorer signal-to-noise ratio. Based on arterial spin labeling, placental perfusion in normal pregnancy is 176 ± 91 mL × min(-1) × 100 g(-1) and decreases in cases with intrauterine growth restriction. Blood oxygen level-dependent and oxygen-enhanced MRIs do not assess perfusion but measure the response of the placenta to changes in oxygen levels with the use of hemoglobin as an endogenous contrast agent. Diffusion-weighted imaging and intravoxel incoherent motion MRI do not require exogenous contrast agents, instead they use the movement of water molecules within tissues. The apparent diffusion coefficient and perfusion fraction are significantly lower in placentas of growth-restricted fetuses when compared with normal pregnancies. Magnetic resonance spectroscopy has the ability to extract

  14. Evaluation of renal transplant perfusion by functional imaging

    International Nuclear Information System (INIS)

    Nicoletti, R.

    1990-01-01

    Radionuclide angiography (RNA) is used as a noninvasive method for the evaluation of renal transplant perfusion. The computer processing method generally used, based on regions of interest, is unsatisfactory because it does not permit the regional differentiation of perfusion defects. Furthermore, the subjective delineation of the regions of interest introduces considerable inter-observer variation of results. We developed a processing method which is less operator-dependent and permits the evaluation of local defects; it is based on the concept of functional imaging. The method was evaluated in 62 patient examinations, which were subdivided into four groups: Normal transplant perfusion (23 examinations), acute tubular necrose (ATN) (16), cellular rejection (13), and vascular rejection (10). Quantitative results derived from profile curves were combined with visual estimation of the functional images and yielded a synoptic graph which allowed differentiation into three groups: Normal transplant perfusion (sensitivity 0.78, specificity 0.97), ATN or cellular rejection (sens. 0.83, spec. 0.82), and vascular rejection (sens. 0.90, spec. 0.92). (orig.)

  15. Functional MR imaging of working memory before neurosurgery

    International Nuclear Information System (INIS)

    Wunderlich, A.P.; Groen, G.; Braun, V.

    2007-01-01

    Information concerning the tissue adjacent to a brain tumour is crucial for planning and performing a neurosurgical intervention. In this study, we evaluated the usefulness of functional imaging of working memory in terms of working memory preservation. Working memory performance of 14 patients with prefrontal tumours was tested preoperatively by means of a standardized neuropsychological test battery. Also, functional magnetic resonance imaging (fMRI) using a so-called two-back paradigm was performed to visualize brain areas related to that task. Working memory areas were reliably detected in all patients. Surgery was then planned on the basis of this information, and the data were used for intra-operative cranial neuronavigation. Three to twelve months after surgery, patients were tested again with the test battery in order to detect possible changes in working memory performance. In 13 cases the memory performance was unchanged, only one female patient had a slight impairment of working memory compared to the pre-operative status. (orig.)

  16. Correlating Function and Imaging Measures of the Medial Longitudinal Fasciculus.

    Directory of Open Access Journals (Sweden)

    Ken Sakaie

    Full Text Available To test the validity of diffusion tensor imaging (DTI measures of tissue injury by examining such measures in a white matter structure with well-defined function, the medial longitudinal fasciculus (MLF. Injury to the MLF underlies internuclear ophthalmoparesis (INO.40 MS patients with chronic INO and 15 healthy controls were examined under an IRB-approved protocol. Tissue integrity of the MLF was characterized by DTI parameters: longitudinal diffusivity (LD, transverse diffusivity (TD, mean diffusivity (MD and fractional anisotropy (FA. Severity of INO was quantified by infrared oculography to measure versional disconjugacy index (VDI.LD was significantly lower in patients than in controls in the medulla-pons region of the MLF (p < 0.03. FA was also lower in patients in the same region (p < 0.0004. LD of the medulla-pons region correlated with VDI (R = -0.28, p < 0.05 as did FA in the midbrain section (R = 0.31, p < 0.02.This study demonstrates that DTI measures of brain tissue injury can detect injury to a functionally relevant white matter pathway, and that such measures correlate with clinically accepted evaluation indices for INO. The results validate DTI as a useful imaging measure of tissue integrity.

  17. A hitchhiker’s guide to functional Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Jose Soares

    2016-11-01

    Full Text Available Functional Magnetic Resonance Imaging (fMRI studies have become increasingly popular both with clinicians and researchers as they are capable of providing unique insights into brain function. However, multiple technical considerations (ranging from specifics of paradigm design to imaging artifacts, complex protocol definition, and multitude of processing and methods of analysis, as well as intrinsic methodological limitations must be considered and addressed in order to optimize fMRI analysis and to arrive at the most accurate and grounded interpretation of the data. In practice, the researcher/clinician must choose, from many available options, the most suitable software tool for each stage of the fMRI analysis pipeline. Herein we provide a straightforward guide designed to address, for each of the major stages, the techniques and tools involved in the process. We have developed this guide both to help those new to the technique to overcome the most critical difficulties in its use, as well as to serve as a resource for the neuroimaging community.

  18. Effects of electroconvulsive therapy on amygdala function in major depression - a longitudinal functional magnetic resonance imaging study.

    Science.gov (United States)

    Redlich, R; Bürger, C; Dohm, K; Grotegerd, D; Opel, N; Zaremba, D; Meinert, S; Förster, K; Repple, J; Schnelle, R; Wagenknecht, C; Zavorotnyy, M; Heindel, W; Kugel, H; Gerbaulet, M; Alferink, J; Arolt, V; Zwanzger, P; Dannlowski, U

    2017-09-01

    Electroconvulsive therapy (ECT) is one of the most effective treatments for severe depression. However, little is known regarding brain functional processes mediating ECT effects. In a non-randomized prospective study, functional magnetic resonance imaging data during the automatic processing of subliminally presented emotional faces were obtained twice, about 6 weeks apart, in patients with major depressive disorder (MDD) before and after treatment with ECT (ECT, n = 24). Additionally, a control sample of MDD patients treated solely with pharmacotherapy (MED, n = 23) and a healthy control sample (HC, n = 22) were obtained. Before therapy, both patient groups equally showed elevated amygdala reactivity to sad faces compared with HC. After treatment, a decrease in amygdala activity to negative stimuli was discerned in both patient samples indicating a normalization of amygdala function, suggesting mechanisms potentially unspecific for ECT. Moreover, a decrease in amygdala activity to sad faces was associated with symptomatic improvements in the ECT sample (r spearman = -0.48, p = 0.044), and by tendency also for the MED sample (r spearman = -0.38, p = 0.098). However, we did not find any significant association between pre-treatment amygdala function to emotional stimuli and individual symptom improvement, neither for the ECT sample, nor for the MED sample. In sum, the present study provides first results regarding functional changes in emotion processing due to ECT treatment using a longitudinal design, thus validating and extending our knowledge gained from previous treatment studies. A limitation was that ECT patients received concurrent medication treatment.

  19. Developments in 99Tcm complexes for functional imaging

    International Nuclear Information System (INIS)

    Ramamoorthy, N.

    1998-01-01

    Technetium-99m coordination complexes constitute the backbone of diagnostic nuclear medicine. Early exciting advances in products for excretory organs / pathways were followed by arduous research efforts to design and optimise 99 Tc m compounds for imaging renal tubular function and mapping blood flow to myocardium and brain. A variety of neutral, cationic and anionic complexes of technetium, mostly in +5 or +3 oxidation states and usually involving N, S. P, O as coordinating atoms, have dominated the field. Blending the well-known versatile coordination chemistry of technetium with biochemical principles and pharmacology of some functional groups has helped achieve desirable properties in at least some of the resultant 99 Tc m complexes. Fascinating developments to tap the merits of 99 Tc m tracer for more sophisticated targeting approach involving biological substrates have yielded promising results. Use of appropriate ligands as bifunctional chelating agents (BCA) to form 99 Tc m labelled radiopharmaceuticals has also led to development of several new 99 Tc m complexes. Although 99 Tc m complexes for metabolism or receptor imaging may still be far from a clinical reality, many useful efficacious clinical applications have become feasible with the advent of some new 99 Tc m complexes, e.g. imaging infection / inflammation, certain tumours and even hypoxia. A strong synergism between academic universities and industries has evolved, amidst the rush for patenting all products and processes, despite low chances of success in developing a clinically useful product. The enormous research costs have made the new products very expensive and, in turn, driven many developing countries and large hospital radiopharmacies to seek alternate means of formulating equivalent products in-house or evolve modified protocols with commercial products for better economy. This review covers the major investigations of the last decade (but by no means exhaustive) after touching upon the

  20. ASSESSMENT OF LEFT VENTRICULAR FUNCTION USING TISSUE DOPPLER IMAGING

    Directory of Open Access Journals (Sweden)

    Martin Tretjak

    2004-09-01

    Full Text Available Background. Objective evidence of cardiac dysfunction is one of the diagnostic criteria for heart failure. It is often hard to assess systolic function and assessing diastolic dysfunction is even harder because there are no generally accepted echocardiographic criteria. Tissue Doppler imaging (TDI enables analysis of the mitral annular descent velocity for detection of left ventricular diastolic dysfunction along the longitudinal axis.Methods. 30 patients with heart failure and 30 healthy participants were enrolled in the study. Pulsed wave tissue Doppler imaging velocities of septal and lateral mitral annulus borders were recorded in systole (Sm and early diastole (Em. Velocities in both groups were compared. The correlations between Sm velocity and LVEF and Em velocity and age were studied.Results. Patients with heart failure had significantly decreased Sm and Em velocities compared with healthy participants (5.3 ± 1.6 cm/s vs. 8.4 ± 1 cm/s, P < 0.001, for Sm velocity and 5 ± 1.4 cm/s vs. 8.7 ± 1.6 cm/s, P < 0.001, for Em velocity. The correlation between Sm velocity and LVEF in all participants was very good and highly significant (r = 0.91, P < 0.001. The Sm velocity ≥ 6.4 cm/s was 91% sensitive and 95% specific for LVEF ≥ 0.45. There was a good correlation between age and Em velocity (r = -0.84, P < 0.001. The Em velocity < 7 cm/s had a sensitivity of 90% and specificity of 97% for diagnosing heart failure.Conclusions. Pulsed wave tissue Doppler imaging of mitral annulus enables simple, fast and precise assessment of systolic and diastolic left ventricular function. It can replace some other more time consuming echocardiographic measurements.

  1. Pheochromocytoma and Paraganglioma: Current Functional and Future Molecular Imaging

    International Nuclear Information System (INIS)

    Blanchet, Elise M.; Martucci, Victoria; Pacak, Karel

    2012-01-01

    Paragangliomas are neural crest-derived tumors, arising either from chromaffin sympathetic tissue (in adrenal, abdominal, intra-pelvic, or thoracic paraganglia) or from parasympathetic tissue (in head and neck paraganglia). They have a specific cellular metabolism, with the ability to synthesize, store, and secrete catecholamines (although most head and neck paragangliomas do not secrete any catecholamines). This disease is rare and also very heterogeneous, with various presentations (e.g., in regards to localization, multifocality, potential to metastasize, biochemical phenotype, and genetic background). With growing knowledge, notably about the pathophysiology and genetic background, guidelines are evolving rapidly. In this context, functional imaging is a challenge for the management of paragangliomas. Nuclear imaging has been used for exploring paragangliomas for the last three decades, with MIBG historically as the first-line exam. Tracers used in paragangliomas can be grouped in three different categories. Agents that specifically target catecholamine synthesis, storage, and secretion pathways include: 123 and 131I-metaiodobenzylguanidine (123/131I-MIBG), 18F-fluorodopamine (18F-FDA), and 18F-fluorodihydroxyphenylalanine (18F-FDOPA). Agents that bind somatostatin receptors include 111In-pentetreotide and 68Ga-labeled somatostatin analog peptides (68Ga-DOTA-TOC, 68Ga-DOTA-NOC, 68Ga-DOTA-TATE). The non-specific agent most commonly used in paragangliomas is 18F-fluorodeoxyglucose (18F-FDG). This review will first describe conventional scintigraphic exams that are used for imaging paragangliomas. In the second part we will emphasize the interest in new PET approaches (specific and non-specific), considering the growing knowledge about genetic background and pathophysiology, with the aim of understanding how tumors behave, and optimally adjusting imaging technique for each tumor type.

  2. Measurement of abdominal muscle thickness using M-mode ultrasound imaging during functional activities.

    Science.gov (United States)

    Bunce, Steve M; Hough, Alan D; Moore, Ann P

    2004-02-01

    Ultrasound imaging has been previously utilized in the measurement of muscle thickness and cross-sectional area in research studies, and advocated as a clinical biofeedback tool in the rehabilitation of transversus abdominis function following episodes of low back pain. This paper describes how the thickness of the abdominal muscles can be quantified with a new measurement technique using M-mode ultrasound. The technique uses a custom-made transducer holder that facilitates measurement of muscle thickness changes during functional activity. Limitations of the technique and potential future applications are discussed. The M-mode ultrasound technique may provide an effective method for the non-invasive measurement of abdominal muscle thickness during functional activities.

  3. Functional validation and comparison framework for EIT lung imaging.

    Directory of Open Access Journals (Sweden)

    Bartłomiej Grychtol

    Full Text Available INTRODUCTION: Electrical impedance tomography (EIT is an emerging clinical tool for monitoring ventilation distribution in mechanically ventilated patients, for which many image reconstruction algorithms have been suggested. We propose an experimental framework to assess such algorithms with respect to their ability to correctly represent well-defined physiological changes. We defined a set of clinically relevant ventilation conditions and induced them experimentally in 8 pigs by controlling three ventilator settings (tidal volume, positive end-expiratory pressure and the fraction of inspired oxygen. In this way, large and discrete shifts in global and regional lung air content were elicited. METHODS: We use the framework to compare twelve 2D EIT reconstruction algorithms, including backprojection (the original and still most frequently used algorithm, GREIT (a more recent consensus algorithm for lung imaging, truncated singular value decomposition (TSVD, several variants of the one-step Gauss-Newton approach and two iterative algorithms. We consider the effects of using a 3D finite element model, assuming non-uniform background conductivity, noise modeling, reconstructing for electrode movement, total variation (TV reconstruction, robust error norms, smoothing priors, and using difference vs. normalized difference data. RESULTS AND CONCLUSIONS: Our results indicate that, while variation in appearance of images reconstructed from the same data is not negligible, clinically relevant parameters do not vary considerably among the advanced algorithms. Among the analysed algorithms, several advanced algorithms perform well, while some others are significantly worse. Given its vintage and ad-hoc formulation backprojection works surprisingly well, supporting the validity of previous studies in lung EIT.

  4. Functional imaging in the assessment of myocardial infarction: MR imaging vs. MDCT vs. SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Mahnken, Andreas H. [Department of Diagnostic Radiology, RWTH Aachen University (Germany); Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University (Germany)], E-mail: mahnken@rad.rwth-aachen.de; Bruners, Philipp [Department of Diagnostic Radiology, RWTH Aachen University (Germany); Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University (Germany); Stanzel, Sven [Institute of Medical Statistics, RWTH Aachen University (Germany); Koos, Ralf [Medical Clinic I, RWTH Aachen University (Germany); Muehlenbruch, Georg; Guenther, Rolf W. [Department of Diagnostic Radiology, RWTH Aachen University (Germany); Reinartz, Patrick [Department of Nuclear Medicine, RWTH Aachen University (Germany); Radios Center of Diagnostic Radiology and Nuclear Medicine, Duesseldorf (Germany)

    2009-09-15

    Purpose: To intraindividually compare magnetic resonance (MR) imaging, ECG-gated multi-detector spiral computed tomography (MDCT) and gated single photon emission computed tomography (SPECT) for the evaluation of global and regional myocardial function and the identification of myocardial perfusion abnormalities. Materials and methods: Nine patients (8 men; 55.1 {+-} 8.9 years) with a history of myocardial infarction (MI) were included in this retrospective study. All patients had undergone segmented k-space steady state free precession MR imaging, {sup 99m}Tc-MIBI gated myocardial perfusion SPECT and contrast enhanced ECG-gated 16-MDCT. Ventricular volumes and ejection fraction (EF) were calculated. Left ventricular (LV) wall motion at rest was analyzed. For SPECT and arterial phase MDCT perfusion abnormalities were assessed. Data was compared with Lin's concordance-correlation coefficient ({rho}{sub c}), Bland-Altman plots and kappa statistics. Results: For EF, there was an excellent concordance and correlation ({rho}{sub c} = 0.99) between SPECT (EF = 41.7 {+-} 10.4%), MDCT (EF = 42.2 {+-} 11.1%), and MR imaging (EF = 41.9 {+-} 11.4%). Considering MR imaging as standard of reference, MDCT ({kappa} = 0.86) is superior to SPECT ({kappa} = 0.51) for the assessment of the regional wall motion at rest. There was a good agreement between SPECT and MDCT regarding the detection of perfusion abnormalities ({kappa} = 0.62). Conclusion: MDCT, MR imaging, and SPECT allow for the reliable assessment of global and regional left ventricular function in patients with a history of MI. MDCT also allows to some extent for the detection of perfusion abnormalities. With its potential to assess both, the coronary arteries as well as the myocardium, MDCT a promising modality for the comprehensive diagnostic work-up in patients with suspected myocardial ischemia.

  5. Motor system hyperconnectivity in juvenile myoclonic epilepsy: a cognitive functional magnetic resonance imaging study.

    Science.gov (United States)

    Vollmar, Christian; O'Muircheartaigh, Jonathan; Barker, Gareth J; Symms, Mark R; Thompson, Pamela; Kumari, Veena; Duncan, John S; Janz, Dieter; Richardson, Mark P; Koepp, Matthias J

    2011-06-01

    Juvenile myoclonic epilepsy is the most frequent idiopathic generalized epilepsy syndrome. It is characterized by predominant myoclonic jerks of upper limbs, often provoked by cognitive activities, and typically responsive to treatment with sodium valproate. Neurophysiological, neuropsychological and imaging studies in juvenile myoclonic epilepsy have consistently pointed towards subtle abnormalities in the medial frontal lobes. Using functional magnetic resonance imaging with an executive frontal lobe paradigm, we investigated cortical activation patterns and interaction between cortical regions in 30 patients with juvenile myoclonic epilepsy and 26 healthy controls. With increasing cognitive demand, patients showed increasing coactivation of the primary motor cortex and supplementary motor area. This effect was stronger in patients still suffering from seizures, and was not seen in healthy controls. Patients with juvenile myoclonic epilepsy showed increased functional connectivity between the motor system and frontoparietal cognitive networks. Furthermore, we found impaired deactivation of the default mode network during cognitive tasks with persistent activation in medial frontal and central regions in patients. Coactivation in the motor cortex and supplementary motor area with increasing cognitive load and increased functional coupling between the motor system and cognitive networks provide an explanation how cognitive effort can cause myoclonic jerks in juvenile myoclonic epilepsy. The supplementary motor area represents the anatomical link between these two functional systems, and our findings may be the functional correlate of previously described structural abnormalities in the medial frontal lobe in juvenile myoclonic epilepsy.

  6. Functional imaging of the kidneys with fast MRI techniques

    International Nuclear Information System (INIS)

    Prasad, P.V.; Priatna, A.

    1999-01-01

    Availability of faster and stronger gradient systems have given rise to a multitude of fast MRI data acquisition strategies which have tremendously increased the scope of MRI applications. These have led to the realization of long desired comprehensive approaches to evaluate anatomy and function using a single modality. In this work, we describe some of our own experiences with functional evaluation of the kidneys using MRI. Examples that suggest the feasibility of comprehensive approaches for evaluation of renal disease are also provided. We also introduce BOLD renal MRI, a method that may allow basic understanding of human renal physiology and pathophysiology in a way that has not been previously possible. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Tracking Regional Tissue Volume and Function Change in Lung Using Image Registration

    Directory of Open Access Journals (Sweden)

    Kunlin Cao

    2012-01-01

    Full Text Available We have previously demonstrated the 24-hour redistribution and reabsorption of bronchoalveolar lavage (BAL fluid delivered to the lung during a bronchoscopic procedure in normal volunteers. In this work we utilize image-matching procedures to correlate fluid redistribution and reabsorption to changes in regional lung function. Lung CT datasets from six human subjects were used in this study. Each subject was scanned at four time points before and after BAL procedure. Image registration was performed to align images at different time points and different inflation levels. The resulting dense displacement fields were utilized to track tissue volume changes and reveal deformation patterns of local parenchymal tissue quantitatively. The registration accuracy was assessed by measuring landmark matching errors, which were on the order of 1 mm. The results show that quantitative-assessed fluid volume agreed well with bronchoscopist-reported unretrieved BAL volume in the whole lungs (squared linear correlation coefficient was 0.81. The average difference of lung tissue volume at baseline and after 24 hours was around 2%, which indicates that BAL fluid in the lungs was almost absorbed after 24 hours. Regional lung-function changes correlated with the presence of BAL fluid, and regional function returned to baseline as the fluid was reabsorbed.

  8. Recommendations for Conducting Differential Item Functioning (DIF) Analyses for Students with Disabilities Based on Previous DIF Studies. Research Report. ETS RR-11-34

    Science.gov (United States)

    Buzick, Heather; Stone, Elizabeth

    2011-01-01

    The purpose of this study is to help ensure that strategies for differential item functioning (DIF) detection for students with disabilities are appropriate and lead to meaningful results. We surveyed existing DIF studies for students with disabilities and describe them in terms of study design, statistical approach, sample characteristics, and…

  9. Functional MR imaging on an open 1T MR imaging system: exploiting the advantages of an open MR imaging system for functional MR imaging

    NARCIS (Netherlands)

    van de Giessen, E.; Groot, P. F. C.; Booij, J.; van den Brink, W.; Veltman, D. J.; Nederveen, A. J.

    2011-01-01

    Open MR imaging scanners are designed for imaging of specific patient groups that cannot be routinely scanned with conventional MR imaging scanners (eg, patients with obesity and claustrophobia). This study aims to determine whether BOLD sensitivity on an open 1T scanner is adequate for fMRI for

  10. Independent Component Analysis of Resting-State Functional Magnetic Resonance Imaging in Pedophiles.

    Science.gov (United States)

    Cantor, J M; Lafaille, S J; Hannah, J; Kucyi, A; Soh, D W; Girard, T A; Mikulis, D J

    2016-10-01

    Neuroimaging and other studies have changed the common view that pedophilia is a result of childhood sexual abuse and instead is a neurologic phenomenon with prenatal origins. Previous research has identified differences in the structural connectivity of the brain in pedophilia. To identify analogous differences in functional connectivity. Functional magnetic resonance images were recorded from three groups of participants while they were at rest: pedophilic men with a history of sexual offenses against children (n = 37) and two control groups: non-pedophilic men who committed non-sexual offenses (n = 28) and non-pedophilic men with no criminal history (n = 39). Functional magnetic resonance imaging data were subjected to independent component analysis to identify known functional networks of the brain, and groups were compared to identify differences in connectivity with those networks (or "components"). The pedophilic group demonstrated wide-ranging increases in functional connectivity with the default mode network compared with controls and regional differences (increases and decreases) with the frontoparietal network. Of these brain regions (total = 23), 20 have been identified by meta-analytic studies to respond to sexually relevant stimuli. Conversely, of the brain areas known to be those that respond to sexual stimuli, nearly all emerged in the present data as significantly different in pedophiles. This study confirms the presence of significant differences in the functional connectivity of the brain in pedophilia consistent with previously reported differences in structural connectivity. The connectivity differences detected here and elsewhere are opposite in direction from those associated with anti-sociality, arguing against anti-sociality and for pedophilia as the source of the neuroanatomic differences detected. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  11. Myocardial adaption to HI(RT in previously untrained men with a randomized, longitudinal cardiac MR imaging study (Physical adaptions in Untrained on Strength and Heart trial, PUSH-trial.

    Directory of Open Access Journals (Sweden)

    Michael Scharf

    Full Text Available Although musculoskeletal effects in resistance training are well described, little is known about structural and functional cardiac adaption in formerly untrained subjects. We prospectively evaluated whether short term high intensity (resistance training (HI(RT induces detectable morphologic cardiac changes in previously untrained men in a randomized controlled magnetic resonance imaging (MRI study.80 untrained middle-aged men were randomly assigned to a HI(RT-group (n = 40; 43.5±5.9 years or an inactive control group (n = 40; 42.0±6.3 years. HI(RT comprised 22 weeks of training focusing on a single-set to failure protocol in 2-3 sessions/week, each with 10-13 exercises addressing main muscle groups. Repetitions were decreased from 8-10 to 3-5 during study period. Before and after HI(RT all subjects underwent physiologic examination and cardiac MRI (cine imaging, tagging.Indexed left (LV and right ventricular (RV volume (LV: 76.8±15.6 to 78.7±14.8 ml/m2; RV: 77.0±15.5 to 78.7±15.1 ml/m2 and mass (LV: 55.5±9.7 to 57.0±8.8 g/m2; RV: 14.6±3.0 to 15.0±2.9 g/m2 significantly increased with HI(RT (all p<0.001. Mean LV and RV remodeling indices of HI(RT-group did not alter with training (0.73g/mL and 0.19g/mL, respectively [p = 0.96 and p = 0.87], indicating balanced cardiac adaption. Indexed LV (48.4±11.1 to 50.8±11.0 ml/m2 and RV (48.5±11.0 to 50.6±10.7 ml/m2 stroke volume significantly increased with HI(RT (p<0.001. Myocardial strain and strain rates did not change following resistance exercise. Left atrial volume at end systole slightly increased after HI(RT (36.2±7.9 to 37.0±8.4 ml/m2, p = 0.411, the ratio to end-diastolic LV volume at baseline and post-training was unchanged (0.47 vs. 0.47, p = 0.79.22 weeks of HI(RT lead to measurable, physiological changes in cardiac atrial and ventricular morphologic characteristics and function in previously untrained men.The PUSH-trial is registered at the US National Institutes of Health

  12. Magnetic resonance imaging research progress on brain functional reorganization after peripheral nerve injury

    International Nuclear Information System (INIS)

    Wang Weiwei; Liu Hanqiu

    2013-01-01

    In the recent years, with the development of functional magnetic resonance imaging technology the brain plasticity and functional reorganization are hot topics in the central nervous system imaging studies. Brain functional reorganization and rehabilitation after peripheral nerve injury may have certain regularity. In this paper, the progress of brain functional magnetic resonance imaging technology and its applications in the world wide clinical and experimental researches of the brain functional reorganization after peripheral nerve injury is are reviewed. (authors)

  13. Development of New Contrast Agents for Imaging Function and Metabolism by Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Alexandra Carvalho

    2017-07-01

    Full Text Available Liposomes are interesting nanosystems with a wide range of medical application. One particular application is their ability to enhance contrast in magnetic resonance images; when properly loaded with magnetic/superparamagnetic nanoparticles, this means to act as contrast agents. The design of liposomes loaded with magnetic particles, magnetoliposomes, presents a large number of possibilities depending on the application from image function to metabolism. More interesting is its double function application as theranostics (diagnostics and therapy. The synthesis, characterization, and possible medical applications of two types of magnetoliposomes are reviewed. Their performance will be compared, in particular, their efficiency as contrast agents for magnetic resonance imaging, measured by their relaxivities r 1 and r 2 relating to their particular composition. One of the magnetoliposomes had 1,2-diacyl-sn-glycero-3-phosphocholine (soy as the main phospholipid component, with and without cholesterol, varying its phospholipid to cholesterol molar ratios. The other formulation is a long-circulating liposome composed of 1,2-diacyl-sn-glycero-3-phosphocholine (egg, cholesterol, and 1,2-distearoyl-sn-glycerol-3-phosphoethanolamine- N -[methoxy(polyethylene glycol-2000]. Both nanosystems were loaded with superparamagnetic iron oxide nanoparticles with different sizes and coatings.

  14. Functional magnetic resonance imaging of autism spectrum disorders

    Science.gov (United States)

    Dichter, Gabriel S.

    2012-01-01

    This review presents an overview of functional magnetic resonance imaging findings in autism spectrum disorders (ASDs), Although there is considerable heterogeneity with respect to results across studies, common themes have emerged, including: (i) hypoactivation in nodes of the “social brain” during social processing tasks, including regions within the prefrontal cortex, the posterior superior temporal sulcus, the amygdala, and the fusiform gyrus; (ii) aberrant frontostriatal activation during cognitive control tasks relevant to restricted and repetitive behaviors and interests, including regions within the dorsal prefrontal cortex and the basal ganglia; (iii) differential lateralization and activation of language processing and production regions during communication tasks; (iv) anomalous mesolimbic responses to social and nonsocial rewards; (v) task-based long-range functional hypoconnectivity and short-range hyper-connectivity; and (vi) decreased anterior-posterior functional connectivity during resting states. These findings provide mechanistic accounts of ASD pathophysiology and suggest directions for future research aimed at elucidating etiologic models and developing rationally derived and targeted treatments. PMID:23226956

  15. Testicular function in boys previously treated with recombinant-human growth hormone for non-growth hormone-deficient short stature.

    Science.gov (United States)

    Radicioni, A F; Paris, E; De Marco, E; Anzuini, A; Gandini, L; Lenzi, A

    2007-12-01

    Data on the effects of recombinant human GH (hGH) therapy during male puberty on future testis function are still inconclusive. The aim of this study was to investigate the long-term effects of recombinant hGH treatment on reproductive function in non-GH-deficient short stature boys. Eight boys with non-GH-deficient short stature, affected by constitutional delay of puberty or idiopathic short stature, were retrospectively studied after recombinant-hGH treatment to verify gonadal development, hormone production and semen quality. Auxological data, endocrinological/ andrological parameters and laboratory evaluation (GH, IGF-I, FSH, LH, testosterone, inhibin B) were assessed before treatment; after completion of pubertal development, the same parameters plus SHBG levels were evaluated and a seminal fluid examination was conducted (ejaculate volume, pH, sperm concentration, total sperm count, forward and total motility, morphology). All patients showed normal testicular volume at the final pubertal stage, with regular androgenization. Hormonal levels were within the normal adult range in all boys. Considering the immature reproductive system of these patients in comparison with adults, semen parameters (sperm count, motility, and morphology) were within almost normal limits, except in one patient. Although patients showed the wide fluctuation of semen values frequently observed at the end of puberty, the hypophysis-gonadal axis hormones were in the normal range in all adolescents. Pathological measurements of some seminal parameters were found in one patient only. This study suggests that recombinant hGH treatment has no detrimental effects on the development and maturation of male gonadal function in non- GH deficient short stature young patients.

  16. Magnetic resonance imaging as predictor of functional outcome in craniopharyngiomas.

    Science.gov (United States)

    Mortini, Pietro; Gagliardi, Filippo; Bailo, Michele; Spina, Alfio; Parlangeli, Andrea; Falini, Andrea; Losa, Marco

    2016-01-01

    Quality of life of craniopharyngioma patients can be severely impaired by derangement of hypothalamic function. A classification, taking into account preoperative hypothalamic damage, evaluated by magnetic resonance imaging (MRI), and correlating it with postoperative weight change is still missing in the literature. The aim of our study is to identify objective radiological criteria as preoperative prognostic factors for hypothalamic damage. Pre- and post-operative MRI and clinical data of 47 patients, treated at our Institution for craniopharyngioma, were retrospectively analyzed, based on radiological variables, identified as prognostic factor for hypothalamic involvement. Main factors associated with postoperative obesity were hypothalamic hyperintensity in T2-weighted/FLAIR imaging (p < 0.033), mammillary body involvement according to Müller classification (p < 0.020), unidentifiable pituitary stalk (p < 0.001), dislocated chiasm (p < 0.038), either not visible infundibular recess (p < 0.019) or unrecognizable supra-optic recess (p < 0.004), and retrochiasmatic tumor extension (p < 0.019). Accordingly, postoperative hypothalamic syndrome was associated with peritumoral edema in T2-weighted/FLAIR images (p < 0.003), unidentifiable hypothalamus (p < 0.024), hypothalamic compression (p < 0.006), fornix displacement (p < 0.032), and unrecognizable supra-optic recess (p < 0.031). Ultimately, variables identified as predictive factors of postoperative hypothalamic syndrome were the degree of hypothalamic involvement according to the classification described by Sainte-Rose and Puget (p < 0.002; grade 0 vs 2 p < 0.001), Van Gompel (p < 0.002; grade 0 vs 1, p < 0.027; and grade 0 vs 2, p < 0.002), and Muller (p < 0.006; grade 0 vs 1, p < 0.05; and grade 0 vs 2, p < 0.004). The identification of these predictive factors will help to define and score the preoperative hypothalamic involvement in craniopharyngioma patients.

  17. Functional Connectivity MR Imaging Reveals Cortical Functional Connectivity in the Developing Brain

    Science.gov (United States)

    Lin, W.; Zhu, Q.; Gao, W.; Chen, Y.; Toh, C.-H.; Styner, M.; Gerig, G.; Smith, J.K.; Biswal, B.; Gilmore, J.H.

    2008-01-01

    BACKGROUND AND PURPOSE: Unlike conventional functional MR imaging where external sensory/cognitive paradigms are needed to specifically activate different regions of the brain, resting functional connectivity MR imaging acquires images in the absence of cognitive demands (a resting condition) and detects brain regions, which are highly temporally correlated. Therefore, resting functional MR imaging is highly suited for the study of brain functional development in pediatric subjects. This study aimed to determine the temporal and spatial patterns of rfc in healthy pediatric subjects between 2 weeks and 2 years of age. MATERIALS AND METHODS: Rfc studies were performed on 85 children: 38 neonates (2–4 weeks of age), 26 one-year-olds, and 21 two-year-olds. All subjects were imaged while asleep; no sedation was used. Six regions of interest were chosen, including the primary motor, sensory, and visual cortices in each hemisphere. Mean signal intensity of each region of interest was used to perform correlation analysis pixel by pixel throughout the entire brain, identifying regions with high temporal correlation. RESULTS: Functional connectivity was observed in all subjects in the sensorimotor and visual areas. The percent brain volume exhibiting rfc and the strength of rfc continued to increase from 2 weeks to 2 years. The growth trajectories of the percent brain volume of rfc appeared to differ between the sensorimotor and visual areas, whereas the z-score was similar. The percent brain volume of rfc in the sensorimotor area was significantly larger than that in the visual area for subjects 2 weeks of age (P = .008) and 1-year-olds (P = .017) but not for the 2-year-olds. CONCLUSIONS: These findings suggest that rfc in the sensorimotor precedes that in the visual area from 2 weeks to 1 year but becomes comparable at 2 years. In contrast, the comparable z-score values between the sensorimotor and visual areas for all age groups suggest a disassociation between percent

  18. Functional magnetic resonance imaging in the activation of working memory

    International Nuclear Information System (INIS)

    Spitzer, M.; Kammer, T.; Bellemann, M.E.; Gueckel, F.; Georgi, M.; Gass, A.; Brix, G.

    1996-01-01

    Functional magnetic resonance imaging was used in conjunction with a letter detection task for the study of working memory in 16 normal subjects. Because of movement artifacts, data from only 9 subjects were analysed. In the activation taks, subjects responded by pressing a button whenever any presented letter was the same as the second last in the sequence. In the control condition, the subjects had to respond to a fixed letter. Hence, the activation condition and the control condition differend only subjectively, i.e., regarding the task demand, whereas the stimuli and the type and frequency of response were identical. The activation condition produced significant activation in the dorsolateral prefrontal cortex (Brodmann's areas 10, 46, and 9). In contrast to experimental tasks previsouly used rather extensively to study the prefrontal cortex, the present paradigm is characterized by its simplicity, interpretability, and its ties to known neurophysiology of the frontal cortex. (orig.) [de

  19. Semiotic aspects of human nonverbal vocalizations: a functional imaging study.

    Science.gov (United States)

    Dietrich, Susanne; Hertrich, Ingo; Alter, Kai; Ischebeck, Anja; Ackermann, Hermann

    2007-12-03

    Humans produce a variety of distinct nonverbal vocalizations. Whereas affective bursts, for example, laughter, have an intrinsic communicative role bound to social behavior, vegetative sounds, for example, snoring, just signal autonomic-physiological states. However, the latter events, for example, belching, may also be used as intentional communicative actions (vocal gestures), characterized by an arbitrary culture-dependent sound-to-meaning (semiotic) relationship, comparable to verbal utterances. Using a decision task, hemodynamic responses to affective bursts, vegetative sounds, and vocal gestures were measured by means of functional magnetic resonance imaging. Affective bursts elicited activation of anterior left superior temporal gyrus. In contrast, arbitrary vocal gestures yielded hemodynamic reactions of the left temporo-parietal junction. Conceivably, a listener's interpretation of nonverbal utterances as intentional events depends upon a left-hemisphere temporo-parietal 'auditory-to-meaning interface' related to our mechanisms of speech processing.

  20. Functional lung imaging during HFV in preterm rabbits.

    Directory of Open Access Journals (Sweden)

    Jordan Thurgood

    Full Text Available Although high frequency ventilation (HFV is an effective mode of ventilation, there is limited information available in regard to lung dynamics during HFV. To improve the knowledge of lung function during HFV we have developed a novel lung imaging and analysis technique. The technique can determine complex lung motion information in vivo with a temporal resolution capable of observing HFV dynamics. Using high-speed synchrotron based phase contrast X-ray imaging and cross-correlation analysis, this method is capable of recording data in more than 60 independent regions across a preterm rabbit lung in excess of 300 frames per second (fps. This technique is utilised to determine regional intra-breath lung mechanics of preterm rabbit pups during HFV. Whilst ventilated at fixed pressures, each animal was ventilated at frequencies of 1, 3, 5 and 10 Hz. A 50% decrease in delivered tidal volume was measured at 10 Hz compared to 1 Hz, yet at the higher frequency a 500% increase in minute activity was measured. Additionally, HFV induced greater homogeneity of lung expansion activity suggesting this ventilation strategy potentially minimizes tissue damage and improves gas mixing. The development of this technique permits greater insight and further research into lung mechanics and may have implications for the improvement of ventilation strategies used to support severe pulmonary trauma and disease.

  1. Aircraft path planning for optimal imaging using dynamic cost functions

    Science.gov (United States)

    Christie, Gordon; Chaudhry, Haseeb; Kochersberger, Kevin

    2015-05-01

    Unmanned aircraft development has accelerated with recent technological improvements in sensing and communications, which has resulted in an "applications lag" for how these aircraft can best be utilized. The aircraft are becoming smaller, more maneuverable and have longer endurance to perform sensing and sampling missions, but operating them aggressively to exploit these capabilities has not been a primary focus in unmanned systems development. This paper addresses a means of aerial vehicle path planning to provide a realistic optimal path in acquiring imagery for structure from motion (SfM) reconstructions and performing radiation surveys. This method will allow SfM reconstructions to occur accurately and with minimal flight time so that the reconstructions can be executed efficiently. An assumption is made that we have 3D point cloud data available prior to the flight. A discrete set of scan lines are proposed for the given area that are scored based on visibility of the scene. Our approach finds a time-efficient path and calculates trajectories between scan lines and over obstacles encountered along those scan lines. Aircraft dynamics are incorporated into the path planning algorithm as dynamic cost functions to create optimal imaging paths in minimum time. Simulations of the path planning algorithm are shown for an urban environment. We also present our approach for image-based terrain mapping, which is able to efficiently perform a 3D reconstruction of a large area without the use of GPS data.

  2. Laparoscopy After Previous Laparotomy

    Directory of Open Access Journals (Sweden)

    Zulfo Godinjak

    2006-11-01

    Full Text Available Following the abdominal surgery, extensive adhesions often occur and they can cause difficulties during laparoscopic operations. However, previous laparotomy is not considered to be a contraindication for laparoscopy. The aim of this study is to present that an insertion of Veres needle in the region of umbilicus is a safe method for creating a pneumoperitoneum for laparoscopic operations after previous laparotomy. In the last three years, we have performed 144 laparoscopic operations in patients that previously underwent one or two laparotomies. Pathology of digestive system, genital organs, Cesarean Section or abdominal war injuries were the most common causes of previouslaparotomy. During those operations or during entering into abdominal cavity we have not experienced any complications, while in 7 patients we performed conversion to laparotomy following the diagnostic laparoscopy. In all patients an insertion of Veres needle and trocar insertion in the umbilical region was performed, namely a technique of closed laparoscopy. Not even in one patient adhesions in the region of umbilicus were found, and no abdominal organs were injured.

  3. Effect of subsequent vaginal delivery on bowel symptoms and anorectal function in women who sustained a previous obstetric anal sphincter injury.

    Science.gov (United States)

    Jordan, Polly A; Naidu, Madhu; Thakar, Ranee; Sultan, Abdul H

    2018-03-29

    Our primary objective was to prospectively evaluate anorectal symptoms, anal manometry and endoanal ultrasound (EAUS) in women who followed the recommended mode of subsequent delivery following index obstetric anal sphincter injuries (OASIs) using our unit's standardised protocol. Our secondary objectives were to evaluate the role of internal anal sphincter defects and also to compare outcomes in a subgroup of symptomatic women with normal anorectal physiology. This is a prospective follow-up study of pregnant women with previous OASIs who were counselled regarding subsequent mode of delivery between January 2003 and December 2014. Assessment involved the St Mark's Incontinence Score (SMIS), anal manometry and EAUS at both antepartum and 3-month postpartum visits. Data were analysed using Wilcoxon and Mann-Whitney U tests. Three hundred and fifty women attended the perineal clinic over the study period, of whom 122 met the inclusion criteria (99 vaginal delivery [VD], 23 caesarean section). No significant worsening of anorectal symptoms was observed following subsequent delivery in the VD group (p = 0.896), although a reduced squeeze pressure was observed at 3 months postpartum (p delivery. In the absence of a randomised study, use of this protocol can aid clinicians in their decision-making.

  4. PET imaging reveals brain functional changes in internet gaming disorder

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Mei; Zhang, Ying; Du, Fenglei; Hou, Haifeng; Chao, Fangfang; Zhang, Hong [The Second Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou (China); Chen, Qiaozhen [The Second Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); The Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Psychiatry, Hangzhou (China)

    2014-07-15

    Internet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D{sub 2} (D{sub 2})/Serotonin 2A (5-HT{sub 2A}) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D{sub 2} receptor and glucose metabolism. Twelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and {sup 11}C-N-methylspiperone ({sup 11}C-NMSP) to assess the availability of D{sub 2}/5-HT{sub 2A} receptors and with {sup 18}F-fluoro-D-glucose ({sup 18}F-FDG) to assess regional brain glucose metabolism, a marker of brain function. {sup 11}C-NMSP and {sup 18}F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states. In internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D{sub 2} receptors was observed in the striatum, and was correlated to years of overuse. A low level of D{sub 2} receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex. For the first time, we report the evidence that D{sub 2} receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D{sub 2}/5-HT{sub 2A} receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects. (orig.)

  5. PET imaging reveals brain functional changes in internet gaming disorder

    International Nuclear Information System (INIS)

    Tian, Mei; Zhang, Ying; Du, Fenglei; Hou, Haifeng; Chao, Fangfang; Zhang, Hong; Chen, Qiaozhen

    2014-01-01

    Internet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D 2 (D 2 )/Serotonin 2A (5-HT 2A ) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D 2 receptor and glucose metabolism. Twelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and 11 C-N-methylspiperone ( 11 C-NMSP) to assess the availability of D 2 /5-HT 2A receptors and with 18 F-fluoro-D-glucose ( 18 F-FDG) to assess regional brain glucose metabolism, a marker of brain function. 11 C-NMSP and 18 F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states. In internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D 2 receptors was observed in the striatum, and was correlated to years of overuse. A low level of D 2 receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex. For the first time, we report the evidence that D 2 receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D 2 /5-HT 2A receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects. (orig.)

  6. Functional brain imaging of episodic memory decline in ageing.

    Science.gov (United States)

    Nyberg, L

    2017-01-01

    The episodic long-term memory system supports remembering of events. It is considered to be the most age-sensitive system, with an average onset of decline around 60 years of age. However, there is marked interindividual variability, such that some individuals show faster than average change and others show no or very little change. This variability may be related to the risk of developing dementia, with elevated risk for individuals with accelerated episodic memory decline. Brain imaging with functional magnetic resonance imaging (MRI) of blood oxygen level-dependent (BOLD) signalling or positron emission tomography (PET) has been used to reveal the brain bases of declining episodic memory in ageing. Several studies have demonstrated a link between age-related episodic memory decline and the hippocampus during active mnemonic processing, which is further supported by studies of hippocampal functional connectivity in the resting state. The hippocampus interacts with anterior and posterior neocortical regions to support episodic memory, and alterations in hippocampus-neocortex connectivity have been shown to contribute to impaired episodic memory. Multimodal MRI studies and more recently hybrid MRI/PET studies allow consideration of various factors that can influence the association between the hippocampal BOLD signal and memory performance. These include neurovascular factors, grey and white matter structural alterations, dopaminergic neurotransmission, amyloid-Β and glucose metabolism. Knowledge about the brain bases of episodic memory decline can guide interventions to strengthen memory in older adults, particularly in those with an elevated risk of developing dementia, with promising results for combinations of cognitive and physical stimulation. © 2016 The Association for the Publication of the Journal of Internal Medicine.

  7. Functional magnetic resonance imaging of internet addiction in young adults.

    Science.gov (United States)

    Sepede, Gianna; Tavino, Margherita; Santacroce, Rita; Fiori, Federica; Salerno, Rosa Maria; Di Giannantonio, Massimo

    2016-02-28

    To report the results of functional magnetic resonance imaging (fMRI) studies pertaining internet addiction disorder (IAD) in young adults. We conducted a systematic review on PubMed, focusing our attention on fMRI studies involving adult IAD patients, free from any comorbid psychiatric condition. The following search words were used, both alone and in combination: fMRI, internet addiction, internet dependence, functional neuroimaging. The search was conducted on April 20(th), 2015 and yielded 58 records. Inclusion criteria were the following: Articles written in English, patients' age ≥ 18 years, patients affected by IAD, studies providing fMRI results during resting state or cognitive/emotional paradigms. Structural MRI studies, functional imaging techniques other than fMRI, studies involving adolescents, patients with comorbid psychiatric, neurological or medical conditions were excluded. By reading titles and abstracts, we excluded 30 records. By reading the full texts of the 28 remaining articles, we identified 18 papers meeting our inclusion criteria and therefore included in the qualitative synthesis. We found 18 studies fulfilling our inclusion criteria, 17 of them conducted in Asia, and including a total number of 666 tested subjects. The included studies reported data acquired during resting state or different paradigms, such as cue-reactivity, guessing or cognitive control tasks. The enrolled patients were usually males (95.4%) and very young (21-25 years). The most represented IAD subtype, reported in more than 85% of patients, was the internet gaming disorder, or videogame addiction. In the resting state studies, the more relevant abnormalities were localized in the superior temporal gyrus, limbic, medial frontal and parietal regions. When analyzing the task related fmri studies, we found that less than half of the papers reported behavioral differences between patients and normal controls, but all of them found significant differences in cortical

  8. A study on quantifying COPD severity by combining pulmonary function tests and CT image analysis

    Science.gov (United States)

    Nimura, Yukitaka; Kitasaka, Takayuki; Honma, Hirotoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi; Mori, Kensaku

    2011-03-01

    This paper describes a novel method that can evaluate chronic obstructive pulmonary disease (COPD) severity by combining measurements of pulmonary function tests and measurements obtained from CT image analysis. There is no cure for COPD. However, with regular medical care and consistent patient compliance with treatments and lifestyle changes, the symptoms of COPD can be minimized and progression of the disease can be slowed. Therefore, many diagnosis methods based on CT image analysis have been proposed for quantifying COPD. Most of diagnosis methods for COPD extract the lesions as low-attenuation areas (LAA) by thresholding and evaluate the COPD severity by calculating the LAA in the lung (LAA%). However, COPD is usually the result of a combination of two conditions, emphysema and chronic obstructive bronchitis. Therefore, the previous methods based on only LAA% do not work well. The proposed method utilizes both of information including the measurements of pulmonary function tests and the results of the chest CT image analysis to evaluate the COPD severity. In this paper, we utilize a multi-class AdaBoost to combine both of information and classify the COPD severity into five stages automatically. The experimental results revealed that the accuracy rate of the proposed method was 88.9% (resubstitution scheme) and 64.4% (leave-one-out scheme).

  9. [Functional imaging insights into the pathophysiology of apraxia].

    Science.gov (United States)

    Weiss-Blankenhorn, P H; Fink, G R

    2008-07-01

    Apraxias are disorders of motor cognition that cannot be explained by basic sensorimotor deficits or aphasia. The relatively high frequency of apraxia (approximately half of all patients with left-hemispheric stroke suffer from apraxia during the acute phase) as well as its prognostic value for determining the outcome of rehabilitative therapy clearly convey the necessity of more comprehensive research into the pathophysiology of apraxia in order to develop new therapeutic strategies. In recent years, functional imaging (PET and fMRI) has helped to provide important new insights into the pathophysiology of ideomotor apraxia (defective movement plan) and ideational apraxia (defective action concept). In this review, the neural bases for the clinically observed dissociations between the imitation of abstract and symbolic movements (as in ideomotor apraxia) and for the object-trigger system (which is disturbed in ideational apraxia) will be exemplified. Furthermore, we will recapitulate recent studies that provide evidence for the complementary functions of the right and left parietal cortices in the spatial and temporal organization of complex, object-related actions. The particular importance of the left parietal cortex for motor cognition is further supported by studies examining the integration of spatial and temporal movement information during the generation of a movement plan as well as by the generation of such movement plans in the left parietal cortex independent from the hand that executes the movement.

  10. A compatible electrocutaneous display for functional magnetic resonance imaging application.

    Science.gov (United States)

    Hartwig, V; Cappelli, C; Vanello, N; Ricciardi, E; Scilingo, E P; Giovannetti, G; Santarelli, M F; Positano, V; Pietrini, P; Landini, L; Bicchi, A

    2006-01-01

    In this paper we propose an MR (magnetic resonance) compatible electrocutaneous stimulator able to inject an electric current, variable in amplitude and frequency, into the fingertips in order to elicit tactile skin receptors (mechanoreceptors). The desired goal is to evoke specific tactile sensations selectively stimulating skin receptors by means of an electric current in place of mechanical stimuli. The field of application ranges from functional magnetic resonance imaging (fMRI) tactile studies to augmented reality technology. The device here proposed is designed using safety criteria in order to comply with the threshold of voltage and current permitted by regulations. Moreover, MR safety and compatibility criteria were considered in order to perform experiments inside the MR scanner during an fMRI acquisition for functional brain activation analysis. Psychophysical laboratory tests are performed in order to define the different evoked tactile sensation. After verifying the device MR safety and compatibility on a phantom, a test on a human subject during fMRI acquisition is performed to visualize the brain areas activated by the simulated tactile sensation.

  11. Impact of SQUIDs on functional imaging in neuroscience

    Science.gov (United States)

    Della Penna, Stefania; Pizzella, Vittorio; Romani, Gian Luca

    2014-04-01

    This paper provides an overview on the basic principles and applications of magnetoencephalography (MEG), a technique that requires the use of many SQUIDs and thus represents one of the most important applications of superconducting electronics. Since the development of the first SQUID magnetometers, it was clear that these devices could be used to measure the ultra-low magnetic signals associated with the bioelectric activity of the neurons of the human brain. Forty years on from the first measurement of magnetic alpha rhythm by David Cohen, MEG has become a fundamental tool for the investigation of brain functions. The simple localization of cerebral sources activated by sensory stimulation performed in the early years has been successively expanded to the identification of the sequence of neuronal pool activations, thus decrypting information of the hierarchy underlying cerebral processing. This goal has been achieved thanks to the development of complex instrumentation, namely whole head MEG systems, allowing simultaneous measurement of magnetic fields all over the scalp with an exquisite time resolution. The latest trends in MEG, such as the study of brain networks, i.e. how the brain organizes itself in a coherent and stable way, are discussed. These sound applications together with the latest technological developments aimed at implementing systems able to record MEG signals and magnetic resonance imaging (MRI) of the head with the same set-up pave the way to high performance systems for brain functional investigation in the healthy and the sick population.

  12. Impact of SQUIDs on functional imaging in neuroscience

    International Nuclear Information System (INIS)

    Penna, Stefania Della; Pizzella, Vittorio; Romani, Gian Luca

    2014-01-01

    This paper provides an overview on the basic principles and applications of magnetoencephalography (MEG), a technique that requires the use of many SQUIDs and thus represents one of the most important applications of superconducting electronics. Since the development of the first SQUID magnetometers, it was clear that these devices could be used to measure the ultra-low magnetic signals associated with the bioelectric activity of the neurons of the human brain. Forty years on from the first measurement of magnetic alpha rhythm by David Cohen, MEG has become a fundamental tool for the investigation of brain functions. The simple localization of cerebral sources activated by sensory stimulation performed in the early years has been successively expanded to the identification of the sequence of neuronal pool activations, thus decrypting information of the hierarchy underlying cerebral processing. This goal has been achieved thanks to the development of complex instrumentation, namely whole head MEG systems, allowing simultaneous measurement of magnetic fields all over the scalp with an exquisite time resolution. The latest trends in MEG, such as the study of brain networks, i.e. how the brain organizes itself in a coherent and stable way, are discussed. These sound applications together with the latest technological developments aimed at implementing systems able to record MEG signals and magnetic resonance imaging (MRI) of the head with the same set-up pave the way to high performance systems for brain functional investigation in the healthy and the sick population. (paper)

  13. Low-Functioning Autism and Nonsyndromic Intellectual Disability: Magnetic Resonance Imaging (MRI) Findings.

    Science.gov (United States)

    Erbetta, Alessandra; Bulgheroni, Sara; Contarino, Valeria Elisa; Chiapparini, Luisa; Esposito, Silvia; Annunziata, Silvia; Riva, Daria

    2015-10-01

    Previous neuroradiologic studies reported a high incidence of abnormalities in low-functioning autistic children. In this population, it is difficult to know which abnormality depends on autism itself and which is related to intellectual disability associated with autism. The aim of this study was to evaluate the frequency of neuroradiologic abnormalities in low-functioning autistic children compared to Intellectual Quotient and age-matched nonsyndromic children, using the same set of magnetic resonance imaging (MRI) sequences. MRI was rated as abnormal in 44% of autistic and 54% of children with intellectual disability. The main results were mega cisterna magna in autism and hypoplastic corpus callosum in intellectual disability. These abnormalities are morphologically visible signs of altered brain development. These findings, more frequent than expected, are not specific to the 2 conditions. Although MRI cannot be considered mandatory, it allows an in-depth clinical assessment in nonsyndromic intellectual-disabled and autistic children. © The Author(s) 2015.

  14. Functional magnetic resonance imaging of the brain - a link between brain morphology and function, imaging of the functional status of the brain on a detailed anatomic background

    International Nuclear Information System (INIS)

    Obenberger, J.; Seidl, Z.; Ruzicka, E.; Jech, R.; Krasensky, J.

    1998-01-01

    The basic principles of functional magnetic resonance imaging are outlined. The current status of knowledge and ideas for a future development are highlighted. The application fields of this technique include neurosurgery, neurology, psychiatry. The method also serves as a research tool, where it may prove helpful in solving problems of sleep disorder and the generation and perception of speech. A brief overview of the requirements and the necessary background is given for those wishing to start their own activity in this field

  15. Using Anatomic Magnetic Resonance Image Information to Enhance Visualization and Interpretation of Functional Images: A Comparison of Methods Applied to Clinical Arterial Spin Labeling Images.

    Science.gov (United States)

    Zhao, Li; Dai, Weiying; Soman, Salil; Hackney, David B; Wong, Eric T; Robson, Philip M; Alsop, David C

    2017-02-01

    Functional imaging provides hemodynamic and metabolic information and is increasingly being incorporated into clinical diagnostic and research studies. Typically functional images have reduced signal-to-noise ratio and spatial resolution compared to other non-functional cross sectional images obtained as part of a routine clinical protocol. We hypothesized that enhancing visualization and interpretation of functional images with anatomic information could provide preferable quality and superior diagnostic value. In this work, we implemented five methods (frequency addition, frequency multiplication, wavelet transform, nonsubsampled contourlet transform and intensity-hue-saturation) and a newly proposed ShArpening by Local Similarity with Anatomic images (SALSA) method to enhance the visualization of functional images, while preserving the original functional contrast and quantitative signal intensity characteristics over larger spatial scales. Arterial spin labeling blood flow MR images of the brain were visualization enhanced using anatomic images with multiple contrasts. The algorithms were validated on a numerical phantom and their performance on images of brain tumor patients were assessed by quantitative metrics and neuroradiologist subjective ratings. The frequency multiplication method had the lowest residual error for preserving the original functional image contrast at larger spatial scales (55%-98% of the other methods with simulated data and 64%-86% with experimental data). It was also significantly more highly graded by the radiologists (p<0.005 for clear brain anatomy around the tumor). Compared to other methods, the SALSA provided 11%-133% higher similarity with ground truth images in the simulation and showed just slightly lower neuroradiologist grading score. Most of these monochrome methods do not require any prior knowledge about the functional and anatomic image characteristics, except the acquired resolution. Hence, automatic implementation on

  16. Shift & Mean algorithm for functional imaging with high spatio-temporal resolution

    Directory of Open Access Journals (Sweden)

    Sylvain eRama

    2015-11-01

    Full Text Available Understanding neuronal physiology requires to record electrical activity in many small and remote compartments such as dendrites, axon or dendritic spines. To do so, electrophysiology has long been the tool of choice, as it allows recording very subtle and fast changes in electrical activity. However, electrophysiological measurements are limited to large neuronal compartments such as the neuronal soma. To overcome these limitations, optical methods have been developed, allowing the monitoring of changes in fluorescence of fluorescent reporter dyes inserted into the neuron, with a spatial resolution theoretically only limited by the dye wavelength and optical devices. However, the temporal and spatial resolutive power of functional fluorescence imaging of live neurons is often limited by a necessary trade-off between image resolution, signal to noise ratio (SNR and speed of acquisition. Here, we propose to use a Super-Resolution Shift & Mean algorithm previously used in image computing to improve the SNR, time sampling and spatial resolution of acquired fluorescent signals. We demonstrate the benefits of this methodology using two examples: voltage imaging of action potentials (APs in soma and dendrites of CA3 pyramidal cells and calcium imaging in the dendritic shaft and spines of CA3 pyramidal cells. We show that this algorithm allows the recording of a broad area at low speed in order to achieve a high SNR, and then pick the signal in any small compartment and resample it at high speed. This method allows preserving both the SNR and the temporal resolution of the signal, while acquiring the original images at high spatial resolution.

  17. Functional imaging reveals movement preparatory activity in the vegetative state

    Directory of Open Access Journals (Sweden)

    Tristan A Bekinschtein

    2011-01-01

    Full Text Available The Vegetative State (VS is characterized by the absence of awareness of self or the environment and preserved autonomic functions. The diagnosis relies critically on the lack of consistent signs of purposeful behavior in response to external stimulation. Yet, given that patients with disorders of consciousness often exhibit fragmented movement patterns, voluntary actions may go unnoticed. Here we designed a simple motor paradigm that could potentially detect residual conscious awareness in VS patients with mild to severe brain damage by examining the neural correlates of motor preparation in response to verbal commands. Twenty-four patients who met the diagnostic criteria for VS were recruited for this study. Eleven of these patients showing preserved auditory evoked potentials underwent functional magnetic resonance imaging (fMRI to test for basic speech processing. Five of these patients, who showed word related activity, were included in a second fMRI study aimed at detecting functional changes in premotor cortex elicited by specific verbal instructions to move either their left or their right hand. Despite the lack of overt muscle activity, two patients out of five activated the dorsal premotor cortex contralateral to the instructed hand, consistent with movement preparation. Given that movement preparation in response to a motor command is a sign of purposeful behavior, our results are consistent with residual conscious awareness in these patients. We believe that the identification of positive results with fMRI using this simple task, may complement the clinical assessment by helping attain a more precise diagnosis in patients with disorders of consciousness.

  18. Functional Imaging of Autonomic Regulation: Methods and Key Findings

    Directory of Open Access Journals (Sweden)

    Paul M Macey

    2016-01-01

    Full Text Available Central nervous system processing of autonomic function involves a network of regions throughout the brain which can be visualized and measured with neuroimaging techniques, notably functional magnetic resonance imaging (fMRI. The development of fMRI procedures has both confirmed and extended earlier findings from animal models, and human stroke and lesion studies. Assessments with fMRI can elucidate interactions between different central sites in regulating normal autonomic patterning, and demonstrate how disturbed systems can interact to produce aberrant regulation during autonomic challenges. Understanding autonomic dysfunction in various illnesses reveals mechanisms that potentially lead to interventions in the impairments. The objectives here are to: 1 describe the fMRI neuroimaging methodology for assessment of autonomic neural control, 2 outline the widespread, lateralized distribution of function in autonomic sites in the normal brain which includes structures from the neocortex through the medulla and cerebellum, 3 illustrate the importance of the time course of neural changes when coordinating responses, and how those patterns are impacted in conditions of sleep-disordered breathing, and 4 highlight opportunities for future research studies with emerging methodologies. Methodological considerations specific to autonomic testing include timing of challenges relative to the underlying fMRI signal, spatial resolution sufficient to identify autonomic brainstem nuclei, blood pressure and blood oxygenation influences on the fMRI signal, and the sustained timing, often measured in minutes of challenge periods and recovery. Key findings include the lateralized nature of autonomic organization, which is reminiscent of asymmetric motor, sensory and language pathways. Testing brain function during autonomic challenges demonstrate closely-integrated timing of responses in connected brain areas during autonomic challenges, and the involvement with

  19. Imaging memory and predicting postoperative memory decline in temporal lobe epilepsy: Insights from functional imaging.

    Science.gov (United States)

    Dupont, S

    2015-03-01

    After medial temporal lobe epilepsy (MTLE) surgery, there is considerable individual variation in the extent, nature and direction of postoperative memory change. Before surgery, epileptic patients who are surgery candidates need precise information about the potential cognitive after effects, and particularly in temporal lobe epilepsy, postoperative memory changes. Clinical and neuropsychological data may bring useful information to predict the postoperative memory outcome, but, these data are not always sufficient to replace the Wada test, considered for a long time, as the gold standard to predict postoperative decline following surgery. In any case, numerous studies demonstrate that the Wada procedure can be nowadays reliably replaced by functional MRI (fMRI) activation studies. A vast majority of fMRI studies suggest that it is the functional adequacy of the resected hippocampus rather than the functional reserve of the contralateral hippocampus that determines the extent of postoperative memory decline. In addition, new functional neuroimaging procedures that explore more widespread network disruptions commonly found in MTLE such as diffusion-tensor imaging (DTI) or connectivity studies could in the future constitute a reliable approach combined with fMRI activation studies to significantly improve the prediction of postsurgical memory decline. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. Contributions of structural connectivity and cerebrovascular parameters to functional magnetic resonance imaging signals in mice at rest and during sensory paw stimulation.

    Science.gov (United States)

    Schroeter, Aileen; Grandjean, Joanes; Schlegel, Felix; Saab, Bechara J; Rudin, Markus

    2017-07-01

    Previously, we reported widespread bilateral increases in stimulus-evoked functional magnetic resonance imaging signals in mouse brain to unilateral sensory paw stimulation. We attributed the pattern to arousal-related cardiovascular changes overruling cerebral autoregulation thereby masking specific signal changes elicited by local neuronal activity. To rule out the possibility that interhemispheric neuronal communication might contribute to bilateral functional magnetic resonance imaging responses, we compared stimulus-evoked functional magnetic resonance imaging responses to unilateral hindpaw stimulation in acallosal I/LnJ, C57BL/6, and BALB/c mice. We found bilateral blood-oxygenation-level dependent signal changes in all three strains, ruling out a dominant contribution of transcallosal communication as reason for bilaterality. Analysis of functional connectivity derived from resting-state functional magnetic resonance imaging, revealed that bilateral cortical functional connectivity is largely abolished in I/LnJ animals. Cortical functional connectivity in all strains correlated with structural connectivity in corpus callosum as revealed by diffusion tensor imaging. Given the profound influence of systemic hemodynamics on stimulus-evoked functional magnetic resonance imaging outcomes, we evaluated whether functional connectivity data might be affected by cerebrovascular parameters, i.e. baseline cerebral blood volume, vascular reactivity, and reserve. We found that effects of cerebral hemodynamics on functional connectivity are largely outweighed by dominating contributions of structural connectivity. In contrast, contributions of transcallosal interhemispheric communication to the occurrence of ipsilateral functional magnetic resonance imaging response of equal amplitude to unilateral stimuli seem negligible.

  1. Convergent approaches for defining functional imaging endophenotypes in schizophrenia

    Directory of Open Access Journals (Sweden)

    Godfrey Pearlson

    2009-11-01

    Full Text Available In complex genetic disorders such as schizophrenia, endophenotypes have potential utility both in identifying risk genes and in illuminating pathophysiology. This is due to their presumed status as closer in the etiopathological pathway to the causative genes than is the currently defining clinical phenomenology of the illness and thus their simpler genetic architecture than that of the full syndrome. There, many genes conferring slight individual risk are additive or epistatic (interactive with regard to cumulative schizophrenia risk. In addition the use of endophenotypes has encouraged a conceptual shift away from the exclusive study of categorical diagnoses in manifestly ill patients, towards the study of quantitative traits in patients, unaffected relatives and healthy controls. A more recently employed strategy is thus to study unaffected first degree relatives of schizophrenia patients, who share some of the genetic diathesis without illness-related confounds that may themselves impact fMRI task performance. Consistent with the multiple biological abnormalities associated with the disorder, many candidate endophenotypes have been advanced for schizophrenia, including measures derived from structural brain imaging, EEG, sensorimotor integration, eye movements and cognitive performance (Allen 2009, but recent data derived from quantitative functional brain imaging measures present additional attractive putative endophenotypes. We will review two major, conceptually different approaches that use fMRI in this context. One, the dominant paradigm, employs defined cognitive tasks on which schizophrenia patients perform poorly as “cognitive stress tests”. The second uses very simple probes or “task-free” approaches where performance in patients and controls is equal. We explore the potential advantages and disadvantages of each method, the associated data analytic approaches and recent studies exploring their interface with the genetic

  2. The Relationship Between Body Image and Domains of Sexual Functioning Among Heterosexual, Emerging Adult Women

    Directory of Open Access Journals (Sweden)

    Christopher Quinn-Nilas, MA

    2016-09-01

    Conclusion: Findings from this study suggest important linkages between body image and sexual functioning constructs and indicates that interventions to improve body image could have concomitant benefits related to sexual experience.

  3. Image Super-Resolution Using Adaptive 2-D Gaussian Basis Function Interpolation

    National Research Council Canada - National Science Library

    Hunt, Terence

    2004-01-01

    ... characteristics to be more effectively represented. The interpolation is constrained to reproduce the original image mean gray level, and the mean basis function variance is determined using the expected image smoothness for the increased resolution...

  4. Structural and functional small animal imaging using hybrid-focus optoacoustic biomicroscopy

    Science.gov (United States)

    Rebling, Johannes; Estrada, Héctor; Gottschalk, Sven; Razansky, Daniel

    2017-07-01

    We present an optoacoustic microscope, combining structural and functional opticalresolution optoacoustic and ultrasound pulse-echo imaging. The system was applied to image Zebrafish larvae and complex vascular networks in the murine brain and ear.

  5. Direct Imaging of Space-Charge Accumulation and Work Function Characteristics of Functional Organic Interfaces.

    Science.gov (United States)

    Siles, Pablo F; Devarajulu, Mirunalini; Zhu, Feng; Schmidt, Oliver G

    2018-02-16

    The tailoring of organic systems is crucial to further extend the efficiency of charge transfer mechanisms and represents a cornerstone for molecular device technologies. However, this demands control of electrical properties and understanding of the physics behind organic interfaces. Here, a quantitative spatial overview of work function characteristics for phthalocyanine architectures on Au substrates is provided via kelvin probe microscopy. While macroscopic investigations are very informative, the current approach offers a nanoscale spatial rendering of electrical characteristics which is not possible to attain via conventional techniques. Interface dipole is observed due to the formation of charge accumulation layers in thin F 16 CuPc, F 16 CoPc, and MnPc films, displaying work functions of 5.7, 6.1, and 5.0 eV, respectively. The imaging and quantification of interface locations with significant surface potential and work function response (work function mapping suggests space-charge carrier regions of about 4 nm at the organic interface. This reveals rich spatial electric parameters and ambipolar characteristics that may drive electrical performance at device scales, opening a realm of possibilities toward the development of functional organic architectures and its applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Complex Subduction Imaged by Diffractional Tomography of USArray Receiver Functions

    Science.gov (United States)

    Zhou, Y.

    2016-12-01

    Subduction of a large oceanic plate beneath a continental plate is a complex process. In the Western United States, fragmentation of the Farallon slab has been reported in recent tomographic models. In this study, we measure finite-frequency travel times of P410s and P660s receiver functions recorded at USArray Transportable Array (TA) stations for teleseismic events occurred between 2015 and 2011. We calculate the finite-frequency sensitivities of receiver functions to depth perturbations of the 410-km and 660-km discontinuities to obtain high resolution mantle transition zone models based on diffractional tomography. The high-resolution discontinuity models reveal several interesting anomalies associated with complex subduction of the Farallon plate. In particular, we observe a linear feature in both the 410-km and 660-km discontinuity models. This mantle transition zone anomaly is roughly located in the western Snake River Plain and aligns with a major slab gap imaged in an earlier finite-frequency S-wave velocity model. We show that non-stationary upwellings generated by eastward propagation of a slab tearing event, together with a westward motion of the North American plate at a rate of about 1 to 1.5 centimeters per year (comparable to the half spreading rate of the Mid-Atlantic Ridge) in the past 16 million years can explain the age-progressive Snake River Plain / Yellowstone volcanic track. The slab to the west of the anomaly shows a near vertical subduction, it is heavily fragmented and the 410-km and 660-km discontinuity topography indicates that the southern fragment north of the Mendocino triple junction has subducted down to the mantle transition zone.

  7. Meta-analysis of functional brain imaging in specific phobia.

    Science.gov (United States)

    Ipser, Jonathan C; Singh, Leesha; Stein, Dan J

    2013-07-01

    Although specific phobia is a prevalent anxiety disorder, evidence regarding its underlying functional neuroanatomy is inconsistent. A meta-analysis was undertaken to identify brain regions that were consistently responsive to phobic stimuli, and to characterize changes in brain activation following cognitive behavioral therapy (CBT). We searched the PubMed, SCOPUS and PsycINFO databases to identify positron emission tomography and functional magnetic resonance imaging studies comparing brain activation in specific phobia patients and healthy controls. Two raters independently extracted study data from all the eligible studies, and pooled coordinates from these studies using activation likelihood estimation, a quantitative meta-analytic technique. Resulting statistical parametric maps were compared between patients and healthy controls, in response to phobic versus fear-evoking stimuli, and before and after therapy. Thirteen studies were included, comprising 327 participants. Regions that were consistently activated in response to phobic stimuli included the left insula, amygdala, and globus pallidus. Compared to healthy controls, phobic subjects had increased activation in response to phobic stimuli in the left amygdala/globus pallidus, left insula, right thalamus (pulvinar), and cerebellum. Following exposure-based therapy widespread deactivation was observed in the right frontal cortex, limbic cortex, basal ganglia and cerebellum, with increased activation detected in the thalamus. Exposure to phobia-specific stimuli elicits brain activation that is consistent with current understandings of the neuroanatomy of fear conditioning and extinction. There is evidence that the effects of CBT in specific phobia may be mediated through the same underlying neurocircuitry. © 2013 The Authors. Psychiatry and Clinical Neurosciences © 2013 Japanese Society of Psychiatry and Neurology.

  8. Functional imaging of neurotransmitter systems in movement disorders

    International Nuclear Information System (INIS)

    Ilgin, N.

    1998-01-01

    PET and SPECT enable the direct measurement of components of the dopaminergic and other systems in the living human brain and offer unique opportunity for the in vivo quantification on the dopaminergic function in PD and other movement disorders. The need to establish the early and differential diagnosis of PD is increasingly important given the recent evidence that early pharmacologic intervention may slow progression of this progressive degenerative disease. Accordingly, imaging with PET and SPECT using specific neuro markers has been increasingly important to biochemically identify the loss of specific neurotransmitters, their synthesizing enzymes and their receptors in movement disorders. Through the parallel development of new radiotracers, kinetic models and better instruments, PET and SPECT technology is enabling investigation of increasingly more complex aspects of the human brain neurotransmitter systems. This paper summarizes the results of different PET-SPECT studies used to evaluate the various elements of the dopamine system in the human brain with PET and intends to introduce the newly emerging specific tracers and their applications to clinical research in movement disorders

  9. [Nuclear medicine in vivo and functional imaging. Historical perspective].

    Science.gov (United States)

    Syrota, A

    1996-01-01

    Nuclear Medicine is the application of radioactive materials to the diagnosis and treatment of patients and the study of human disease. The field had its beginning with the discovery of radioactivity by H. Becquerel in 1896 and the tracer principle proposed in 1913 by G. de Hevesy who used a naturally occurring radioactive isotope of lead to obtain information regarding certain aspects of calcium metabolism in plants. The actual development is more recent. F. and I. Joliot-Curie just after the discovery of the artificial radioactivity predicted in their visionary Nobel conference in 1935 the future applications of radioisotopes in biology and medicine. The development of Nuclear Medicine was made possible by the possibility of producing routinely the radioisotopes after World War II and by the development of suitable detectors: moving detector devices (scanners) then gamma cameras after 1957. Nuclear Imaging is today a unique tool for the in vivo investigation of the biochemical functioning of an organ. Two techniques are in rapid development, SPECT (single photon emission computed tomography) and PET (positron emission tomography).

  10. Intravital imaging of CD8+ T cell function in cancer.

    Science.gov (United States)

    Mempel, Thorsten R; Bauer, Christian A

    2009-01-01

    Recent technological advances in photonics are making intravital microscopy (IVM) an increasingly powerful approach for the mechanistic exploration of biological processes in the physiological context of complex native tissue environments. Direct, dynamic and multiparametric visualization of immune cell behavior in living animals at cellular and subcellular resolution has already proved its utility in auditing basic immunological concepts established through conventional approaches and has also generated new hypotheses that can conversely be complemented and refined by traditional experimental methods. The insight that outgrowing tumors must not necessarily have evaded recognition by the adaptive immune system, but can escape rejection by actively inducing a state of immunological tolerance calls for a detailed investigation of the cellular and molecular mechanisms by which the anti-cancer response is subverted. Along with molecular imaging techniques that provide dynamic information at the population level, IVM can be expected to make a critical contribution to this effort by allowing the observation of immune cell behavior in vivo at single cell-resolution. We review here how IVM-based investigation can help to clarify the role of cytotoxic T lymphocytes (CTL) in the immune response against cancer and identify the ways by which their function might be impaired through tolerogenic mechanisms.

  11. Memory networks in tinnitus: a functional brain image study.

    Directory of Open Access Journals (Sweden)

    Maura Regina Laureano

    Full Text Available Tinnitus is characterized by the perception of sound in the absence of an external auditory stimulus. The network connectivity of auditory and non-auditory brain structures associated with emotion, memory and attention are functionally altered in debilitating tinnitus. Current studies suggest that tinnitus results from neuroplastic changes in the frontal and limbic temporal regions. The objective of this study was to use Single-Photon Emission Computed Tomography (SPECT to evaluate changes in the cerebral blood flow in tinnitus patients with normal hearing compared with healthy controls.Twenty tinnitus patients with normal hearing and 17 healthy controls, matched for sex, age and years of education, were subjected to Single Photon Emission Computed Tomography using the radiotracer ethylenedicysteine diethyl ester, labeled with Technetium 99 m (99 mTc-ECD SPECT. The severity of tinnitus was assessed using the "Tinnitus Handicap Inventory" (THI. The images were processed and analyzed using "Statistical Parametric Mapping" (SPM8.A significant increase in cerebral perfusion in the left parahippocampal gyrus (pFWE <0.05 was observed in patients with tinnitus compared with healthy controls. The average total THI score was 50.8+18.24, classified as moderate tinnitus.It was possible to identify significant changes in the limbic system of the brain perfusion in tinnitus patients with normal hearing, suggesting that central mechanisms, not specific to the auditory pathway, are involved in the pathophysiology of symptoms, even in the absence of clinically diagnosed peripheral changes.

  12. The Relationship Between Body Image and Domains of Sexual Functioning Among Heterosexual, Emerging Adult Women

    OpenAIRE

    Quinn-Nilas, Christopher; Benson, Lindsay; Milhausen, Robin R.; Buchholz, Andrea C.; Goncalves, Melissa

    2016-01-01

    Introduction: Research suggests that body image affects sexual functioning, but the relationship between specific types of body image (evaluative, affective, and behavioral) and domains of sexual functioning (desire, arousal, and orgasm) has not been investigated. Aim: To determine whether, and to what degree, body image concerns (evaluative, affective, and behavioral) influence aspects of women’s sexual functioning (desire, arousal, and orgasm). Methods: Eighty-eight sexually active wo...

  13. Chronic antiepileptic drug use and functional network efficiency: A functional magnetic resonance imaging study.

    Science.gov (United States)

    van Veenendaal, Tamar M; IJff, Dominique M; Aldenkamp, Albert P; Lazeron, Richard H C; Hofman, Paul A M; de Louw, Anton J A; Backes, Walter H; Jansen, Jacobus F A

    2017-06-28

    To increase our insight in the neuronal mechanisms underlying cognitive side-effects of antiepileptic drug (AED) treatment. The relation between functional magnetic resonance-acquired brain network measures, AED use, and cognitive function was investigated. Three groups of patients with epilepsy with a different risk profile for developing cognitive side effects were included: A "low risk" category (lamotrigine or levetiracetam, n = 16), an "intermediate risk" category (carbamazepine, oxcarbazepine, phenytoin, or valproate, n = 34) and a "high risk" category (topiramate, n = 5). Brain connectivity was assessed using resting state functional magnetic resonance imaging and graph theoretical network analysis. The Computerized Visual Searching Task was used to measure central information processing speed, a common cognitive side effect of AED treatment. Central information processing speed was lower in patients taking AEDs from the intermediate and high risk categories, compared with patients from the low risk category. The effect of risk category on global efficiency was significant ( P effect on the clustering coefficient (ANCOVA, P > 0.2). Also no significant associations between information processing speed and global efficiency or the clustering coefficient (linear regression analysis, P > 0.15) were observed. Only the four patients taking topiramate show aberrant network measures, suggesting that alterations in functional brain network organization may be only subtle and measureable in patients with more severe cognitive side effects.

  14. Form or function: Does focusing on body functionality protect women from body dissatisfaction when viewing media images?

    Science.gov (United States)

    Mulgrew, Kate E; Tiggemann, Marika

    2018-01-01

    We examined whether shifting young women's ( N =322) attention toward functionality components of media-portrayed idealized images would protect against body dissatisfaction. Image type was manipulated via images of models in either an objectified body-as-object form or active body-as-process form; viewing focus was manipulated via questions about the appearance or functionality of the models. Social comparison was examined as a moderator. Negative outcomes were most pronounced within the process-related conditions (body-as-process images or functionality viewing focus) and for women who reported greater functionality comparison. Results suggest that functionality-based depictions, reflections, and comparisons may actually produce worse outcomes than those based on appearance.

  15. Audiovisual functional magnetic resonance imaging adaptation reveals multisensory integration effects in object-related sensory cortices.

    Science.gov (United States)

    Doehrmann, Oliver; Weigelt, Sarah; Altmann, Christian F; Kaiser, Jochen; Naumer, Marcus J

    2010-03-03

    Information integration across different sensory modalities contributes to object recognition, the generation of associations and long-term memory representations. Here, we used functional magnetic resonance imaging adaptation to investigate the presence of sensory integrative effects at cortical levels as early as nonprimary auditory and extrastriate visual cortices, which are implicated in intermediate stages of object processing. Stimulation consisted of an adapting audiovisual stimulus S(1) and a subsequent stimulus S(2) from the same basic-level category (e.g., cat). The stimuli were carefully balanced with respect to stimulus complexity and semantic congruency and presented in four experimental conditions: (1) the same image and vocalization for S(1) and S(2), (2) the same image and a different vocalization, (3) different images and the same vocalization, or (4) different images and vocalizations. This two-by-two factorial design allowed us to assess the contributions of auditory and visual stimulus repetitions and changes in a statistically orthogonal manner. Responses in visual regions of right fusiform gyrus and right lateral occipital cortex were reduced for repeated visual stimuli (repetition suppression). Surprisingly, left lateral occipital cortex showed stronger responses to repeated auditory stimuli (repetition enhancement). Similarly, auditory regions of interest of the right middle superior temporal gyrus and sulcus exhibited repetition suppression to auditory repetitions and repetition enhancement to visual repetitions. Our findings of crossmodal repetition-related effects in cortices of the respective other sensory modality add to the emerging view that in human subjects sensory integrative mechanisms operate on earlier cortical processing levels than previously assumed.

  16. IMAGING OF BRAIN FUNCTION BASED ON THE ANALYSIS OF FUNCTIONAL CONNECTIVITY - IMAGING ANALYSIS OF BRAIN FUNCTION BY FMRI AFTER ACUPUNCTURE AT LR3 IN HEALTHY INDIVIDUALS.

    Science.gov (United States)

    Zheng, Yu; Wang, Yuying; Lan, Yujun; Qu, Xiaodong; Lin, Kelin; Zhang, Jiping; Qu, Shanshan; Wang, Yanjie; Tang, Chunzhi; Huang, Yong

    2016-01-01

    This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint specificity of the Taichong acupoint. A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham acupoint group. Subjects received resting state fMRI before acupuncture, after true (sham) acupuncture in each group. Analysis of changes in connectivity among the brain areas was performed using the brain functional connectivity method. The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA 37), inferior parietal lobule compared by before vs. after acupuncture at LR3, and right cerebrum sub-lobar insula and left cerebrum middle frontal gyrus, medial frontal gyrus compared by true vs. sham acupuncture at LR3, and right cerebrum occipital lobe cuneus, occipital lobe sub-gyral, parietal lobe precuneus and left cerebellum anterior lobe culmen by acupuncture at LR3 vs. sham acupoint. Acupuncture at LR3 mainly specifically activated the brain functional network that participates in visual function, associative function, and emotion cognition, which are similar to the features on LR3 in tradition Chinese medicine. These brain areas constituted a neural network structure with specific functions that had specific reference values for the interpretation of the acupoint specificity of the Taichong acupoint.

  17. The Relationship Between Body Image and Domains of Sexual Functioning Among Heterosexual, Emerging Adult Women.

    Science.gov (United States)

    Quinn-Nilas, Christopher; Benson, Lindsay; Milhausen, Robin R; Buchholz, Andrea C; Goncalves, Melissa

    2016-09-01

    Research suggests that body image affects sexual functioning, but the relationship between specific types of body image (evaluative, affective, and behavioral) and domains of sexual functioning (desire, arousal, and orgasm) has not been investigated. To determine whether, and to what degree, body image concerns (evaluative, affective, and behavioral) influence aspects of women's sexual functioning (desire, arousal, and orgasm). Eighty-eight sexually active women in heterosexual romantic relationships completed surveys assessing evaluative, affective, and behavioral body image and sexual functioning. Body composition data also were collected using dual energy x-ray absorptiometry. Sexual functioning was assessed using the desire, arousal, and orgasm subscales of the Female Sexual Functioning Index. Hierarchical multiple regression analysis indicated that poor evaluative, affective, and behavioral body image were detrimental to women's sexual functioning. Specifically, dissatisfaction with one's body predicted decrements in desire (β = -0.31, P benefits related to sexual experience. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Diffusion Weighted/Tensor Imaging, Functional MRI and Perfusion Weighted Imaging in Glioblastoma—Foundations and Future

    Directory of Open Access Journals (Sweden)

    Gayle R. Salama

    2018-01-01

    Full Text Available In this article, we review the basics of diffusion tensor imaging and functional MRI, their current utility in preoperative neurosurgical mapping, and their limitations. We also discuss potential future applications, including implementation of resting state functional MRI. We then discuss perfusion and diffusion-weighted imaging and their application in advanced neuro-oncologic practice. We explain how these modalities can be helpful in guiding surgical biopsies and differentiating recurrent tumor from treatment related changes.

  19. Discrete imaging models for three-dimensional optoacoustic tomography using radially symmetric expansion functions.

    Science.gov (United States)

    Wang, Kun; Schoonover, Robert W; Su, Richard; Oraevsky, Alexander; Anastasio, Mark A

    2014-05-01

    Optoacoustic tomography (OAT), also known as photoacoustic tomography, is an emerging computed biomedical imaging modality that exploits optical contrast and ultrasonic detection principles. Iterative image reconstruction algorithms that are based on discrete imaging models are actively being developed for OAT due to their ability to improve image quality by incorporating accurate models of the imaging physics, instrument response, and measurement noise. In this work, we investigate the use of discrete imaging models based on Kaiser-Bessel window functions for iterative image reconstruction in OAT. A closed-form expression for the pressure produced by a Kaiser-Bessel function is calculated, which facilitates accurate computation of the system matrix. Computer-simulation and experimental studies are employed to demonstrate the potential advantages of Kaiser-Bessel function-based iterative image reconstruction in OAT.

  20. Imaging the functional connectivity of the Periaqueductal Gray during genuine and sham electroacupuncture treatment

    Directory of Open Access Journals (Sweden)

    Tu Peichi

    2010-11-01

    Full Text Available Abstract Background Electroacupuncture (EA is currently one of the most popular acupuncture modalities. However, the continuous stimulation characteristic of EA treatment presents challenges to the use of conventional functional Magnetic Resonance Imaging (fMRI approaches for the investigation of neural mechanisms mediating treatment response because of the requirement for brief and intermittent stimuli in event related or block designed task paradigms. A relatively new analysis method, functional connectivity fMRI (fcMRI, has great potential for studying continuous treatment modalities such as EA. In a previous study, we found that, compared with sham acupuncture, EA can significantly reduce Periaqueductal Gray (PAG activity when subsequently evoked by experimental pain. Given the PAG's important role in mediating acupuncture analgesia, in this study we investigated functional connectivity with the area of the PAG we previously identified and how that connectivity was affected by genuine and sham EA. Results Forty-eight subjects, who were randomly assigned to receive either genuine or sham EA paired with either a high or low expectancy manipulation, completed the study. Direct comparison of each treatment mode's functional connectivity revealed: significantly greater connectivity between the PAG, left posterior cingulate cortex (PCC, and precuneus for the contrast of genuine minus sham; significantly greater connectivity between the PAG and right anterior insula for the contrast of sham minus genuine; no significant differences in connectivity between different contrasts of the two expectancy levels. Conclusions Our findings indicate the intrinsic functional connectivity changes among key brain regions in the pain matrix and default mode network during genuine EA compared with sham EA. We speculate that continuous genuine EA stimulation can modify the coupling of spontaneous activity in brain regions that play a role in modulating pain

  1. Functional magnetic resonance imaging of the heart and large vessels

    International Nuclear Information System (INIS)

    Coupland, R.E.; Mansfield, P.

    1987-01-01

    Imaging times using planar imaging techniques including projection reconstruction and two-dimensional Fourier transformation methods are comparatively long, typically 2-5 min: in consequence patient throughput is reduced. Problems also arise with regard to involuntary movements, e.g. of viscera, which degrade images. Gating procedures, especially in the heart, can to some extent overcome the problems of movements that would otherwise blur or degrade the image. Since 1976-1977 a new approach to the problem of imaging of moving organs has been developed. This allows the encoding and observing of all regions in a cross-sectional slice in a single experiment that lasts only a few tens of milliseconds. The technique is commonly referred to as echo planar imaging

  2. Point-spread function in ghost imaging system with thermal light.

    Science.gov (United States)

    Gao, Yang; Bai, Yanfeng; Fu, Xiquan

    2016-10-31

    The point-spread function (PSF) is fundamental importance in estimating the imaging resolution in optical imaging systems. By using the Collins formula, a analytical imaging formula for ghost imaging system is obtained. The intensity fluctuation correlation function can be viewed as the convolution of the original object and a PSF. The imaging resolution is determined by the width of PSF. Based on the optical transfer matrix theory, we present the analytical formula describing the width of the PSF, by which one can estimate imaging resolution of a new-designed imaging scheme when compared with that of the existing imaging system. Several typical ghost imaging systems are chosen to verify experimentally our theoretical results.

  3. User-Generated Contents in Facebook, Functional and Hedonic Brand Image and Purchase Intention

    Directory of Open Access Journals (Sweden)

    Adetunji Raji Ridwan

    2017-01-01

    Full Text Available User-Generated Contents is a type of brand-related communications on social media platforms. User-Generated Contents (UGC offers consumers the opportunity of sharing their experiences, contribute their opinion and communicate with other. This implies that brand managers no longer have solitary control in managing the brand images of their brands. Therefore, this study set out to examine the effect of user-generated contents on hedonic brand image and functional brand. Also, the study determines how hedonic and functional brand image influence brand purchase intention. 114 followers of fan pages of Malaysian automotive brands were surveyed. The hypotheses formulated were tested using PLS-SEM. The findings revealed that, UGC have significant and positive impact on both functional and hedonic brand image. Furthermore, functional and hedonic brand image have significant impact on purchase intention. This study provides insight on the importance of UGC, functional and hedonic brand image to brand managers.

  4. Functional cine MR imaging for the detection and mapping of intraabdominal adhesions: method and surgical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Buhmann-Kirchhoff, Sonja; Reiser, Maximilian; Lienemann, Andreas [University Hospital Grosshadern, Ludwig-Maximilians-University Munich, Department of Clinical Radiology, Munich (Germany); Lang, Reinhold; Steitz, Heinrich O.; Jauch, Karl W. [University Hospital Munich-Grosshadern, Department of Surgery, Munich (Germany); Kirchhoff, Chlodwig [University Hospital Munich-Innenstadt, Department of Surgery, Munich (Germany)

    2008-06-15

    The purpose of this study was to evaluate the presence and localization of intraabdominal adhesions using functional cine magnetic resonance imaging (MRI) and to correlate the MR findings with intraoperative results. In a retrospective study, patients who had undergone previous abdominal surgery with suspected intraabdominal adhesions were examined. A true fast imaging with steady state precession sequence in transverse/sagittal orientation was used for a section-by-section dynamic depiction of visceral slide on a 1.5-Tesla system. After MRI, all patients underwent anew surgery. A nine-segment abdominal map was used to document the location and type of the adhesions. The intraoperative results were taken as standard of reference. Ninety patients were enrolled. During surgery 71 adhesions were detected, MRI depicted 68 intraabdominal adhesions. The most common type of adhesion in MRI was found between the anterior abdominal wall and small bowel loops (n = 22, 32.5%) and between small bowel loops and pelvic organs (n = 14, 20.6%). Comparing MRI with the intraoperative findings, sensitivity varied between 31 and 75% with a varying specificity between 65 and 92% in the different segments leading to an overall MRI accuracy of 89%. Functional cine MRI proved to be a useful examination technique for the identification of intraabdominal adhesions in patients with acute or chronic pain and corresponding clinical findings providing accurate results. However, no differentiation for symptomatic versus asymptomatic adhesions is possible. (orig.)

  5. Prediction of memory rehabilitation outcomes in traumatic brain injury by using functional magnetic resonance imaging.

    Science.gov (United States)

    Strangman, Gary E; O'Neil-Pirozzi, Therese M; Goldstein, Richard; Kelkar, Kalika; Katz, Douglas I; Burke, David; Rauch, Scott L; Savage, Cary R; Glenn, Mel B

    2008-05-01

    To evaluate the ability of functional magnetic resonance imaging (fMRI) measures collected from people with traumatic brain injury (TBI) to provide predictive value for rehabilitation outcomes over and above standard predictors. Prospective study. Academic medical center. Persons (N=54) with TBI greater than 1 year postinjury. A novel 12-session group rehabilitation program focusing on internal strategies to improve memory. The Hopkins Verbal Learning Test-Revised (HVLT-R) delayed recall score. fMRI measures were collected while participants performed a strategically directed word memorization task. Prediction models were multiple linear regressions with the following primary predictors of outcome: age, education, injury severity, preintervention HVLT-R, and task-related fMRI activation of the left dorsolateral and left ventrolateral prefrontal cortex (VLPFC). Baseline HVLT-R was a significant predictor of outcome (P=.007), as was injury severity (for severe vs mild, P=.049). We also found a significant quadratic (inverted-U) effect of fMRI in the VLPFC (P=.007). This study supports previous evidence that left prefrontal activity is related to strategic verbal learning, and the magnitude of this activation predicted success in response to cognitive memory rehabilitation strategies. Extreme under- or overactivation of VLPFC was associated with less successful learning after rehabilitation. Further study is necessary to clarify this relationship and to expand and optimize the possible uses of functional imaging to guide rehabilitation therapies.

  6. Functional imaging: monitoring heme oxygenase-1 gene expression in vivo

    Science.gov (United States)

    Zhang, Weisheng; Reilly-Contag, Pamela; Stevenson, David K.; Contag, Christopher H.

    1999-07-01

    The regulation of genetic elements can be monitored in living animals using photoproteins as reporters. Heme oxygenase (HO) is the key catabolic enzyme in the heme degradation pathway. Here, HO expression serves as a model for in vivo functional imaging of transcriptional regulation of a clinically relevant gene. HO enzymatic activity is inhibited by heme analogs, metalloporphyrins, but many members of this family of compounds also activate transcription of the HO-1 promoter. The degree of transcriptional activation by twelve metalloporphyrins, differing at the central metal and porphyrin ring substituents, was evaluated in both NIH 3T3 stable lines and transgenic animals containing HO-1 promoter-luciferase gene fusions. In the correlative cell culture assays, the metalloporphyrins increased transcription form the full length HO promoter fusion to varying degrees, but none increased transcription from a truncated HO-1 promoter. These results suggested that one or both of the two distal enhancer elements located at -4 and -10 Kb upstream from transcriptional start are required for HO-1 induction by heme and its analogs. The full-length HO-1-luc fusion was then evaluated as a transgene in mice. It was possible to monitor the effects of the metalloporphyrins, SnMP and ZnPP, in living animals over time. This spatiotemporal analyses of gene expression in vivo implied that alterations in porphyrin ring substituents and the central metal may affect the extent of gene activation. These data further indicate that using photoprotein reporters, subtle differences in gene expression can be monitored in living animals.

  7. A NEW TOOL FOR IMAGE ANALYSIS BASED ON CHEBYSHEV RATIONAL FUNCTIONS: CHEF FUNCTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Teja, Y.; Benitez, N., E-mail: yojite@iaa.es [Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia s/n, Granada E-18008 (Spain)

    2012-02-01

    We introduce a new approach to the modeling of the light distribution of galaxies, an orthonormal polar basis formed by a combination of Chebyshev rational functions and Fourier polynomials that we call CHEF functions, or CHEFs. We have developed an orthonormalization process to apply this basis to pixelized images, and implemented the method as a Python pipeline. The new basis displays remarkable flexibility, being able to accurately fit all kinds of galaxy shapes, including irregulars, spirals, ellipticals, highly compact, and highly elongated galaxies. It does this while using fewer components than similar methods, as shapelets, and without producing artifacts, due to the efficiency of the rational Chebyshev polynomials to fit quickly decaying functions like galaxy profiles. The method is linear and very stable, and therefore is capable of processing large numbers of galaxies in a fast and automated way. Due to the high quality of the fits in the central parts of the galaxies, and the efficiency of the CHEF basis modeling galaxy profiles up to very large distances, the method provides highly accurate estimates of total galaxy fluxes and ellipticities. Future papers will explore in more detail the application of the method to perform multiband photometry, morphological classification, and weak shear measurements.

  8. Multidimensional digital image representations using generalized Kaiser-Bessel window functions.

    Science.gov (United States)

    Lewitt, R M

    1990-10-01

    Inverse problems that require the solution of integral equations are inherent in a number of indirect imaging applications, such as computerized tomography. Numerical solutions based on discretization of the mathematical model of the imaging process, or on discretization of analytic formulas for iterative inversion of the integral equations, require a discrete representation of an underlying continuous image. This paper describes discrete image representations, in n-dimensional space, that are constructed by the superposition of shifted copies of a rotationally symmetric basis function. The basis function is constructed using a generalization of the Kaiser-Bessel window function of digital signal processing. The generalization of the window function involves going from one dimension to a rotationally symmetric function in n dimensions and going from the zero-order modified Bessel function of the standard window to a function involving the modified Bessel function of order m. Three methods are given for the construction, in n-dimensional space, of basis functions having a specified (finite) number of continuous derivatives, and formulas are derived for the Fourier transform, the x-ray transform, the gradient, and the Laplacian of these basis functions. Properties of the new image representations using these basis functions are discussed, primarily in the context of two-dimensional and three-dimensional image reconstruction from line-integral data by iterative inversion of the x-ray transform. Potential applications to three-dimensional image display are also mentioned.

  9. The Relationships among Body Image, Body Mass Index, Exercise, and Sexual Functioning in Heterosexual Women

    Science.gov (United States)

    Weaver, Angela D.; Byers, E. Sandra

    2006-01-01

    Problems related to negative body image are very common among young women. In this study, we examined the relationship between women's body image and their sexual functioning over and above the effects of physical exercise and body mass index (BMI) in a sample of 214 university women. Low situational body image dysphoria and low body…

  10. Functional cardiac MR imaging with true fast imaging with steady-state free precession before and after intravenous injection of contrast medium: comparison of image quality and accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Krombach, Gabriele A. [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); University Hospital Giessen, Department of Radiology, Justus-Liebig University Giessen, Giessen (Germany); Plum, Thorsten; Kraemer, Nils A.; Guenther, Rolf W.; Schoth, Felix [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Koos, Ralf; Hoffmann, Rainer; Altiok, Ertunc [University Hospital, RWTH Aachen, Department of Cardiology, Aachen (Germany)

    2011-04-15

    To compare image quality and accuracy of left ventricular function of cine SSFP (steady-state free precession) images before and after injection of Gd-DTPA. In 30 patients T1 times of LV blood and myocardium were measured before and after injection of 0.2 mmol/kg body weight Gd-DTPA. Signal intensity of myocardium and left ventricular blood were measured on SSFP images and the contrast calculated. In 20 additional patients short axis images completely covering the left ventricle were acquired before and after injection of Gd-DTPA and parameters of left ventricular function compared. Image quality and regional function were assessed using the 17-segment model. Image quality after injection of contrast medium did not significantly change compared with unenhanced images. Contrast between myocardium and LV blood decreased from 0.6 {+-} 0.01 to 0.4 {+-} 0.03 after injection while the T1 value of myocardium decreased from 1121 {+-} 21 ms to 389 {+-} 14 ms (blood 1413 {+-} 48 ms to 222 {+-} 8 ms). Assessment of regional and global left ventricular function revealed similar results before and after the injection of contrast medium. Cine SSFP can be obtained after injection of contrast medium without loss of accuracy for regional and global LV ventricular function. This protocol can be used to decrease imaging time for thorough cardiac examination. (orig.)

  11. Functional MR imaging in the patients with complex partial seizures

    International Nuclear Information System (INIS)

    Chung, Jin Il; Chang, Kee Hyun; Song, In Chan; Goo, Jin Mo; Chung, Chun Kee; Lee, Sang Kun; Kim, Hong Dae; Han, Moon Hee; Kim, Sam Soo

    1999-01-01

    To evaluate the clinical usefulness of functional MR imaging (fMRI) for localization of the cerebral motor and sensory cortices and language center in patients with complex partial seizure. A total of 47 fMRIs were obtained in 14 patients (M:F = 9:5; age 15-50 years; 13 right handed and 1 ambidextrous) with complex partial seizure (6 temporal lobe epilepsy, 6 frontal lobe epilepsy, 1 occipitotemporal lobe epilepsy, 1 hemispheric epilepsy). Conventional MR imaging revealed no abnormality in four patients, localized cerebral atrophy in one, hippocampal sclerosis in four, and benign neoplasm in the remaining five. fMRI was performed on a 1.5 T MR scanner (GE Signa Horizon) using gradient-echo singleshot EPI. Nineteen fMRIs were obtained in eight patients who performed the language task, 16 fMRIs in ten who performed the motor task and 12 fMRIs in ten who performed the somatosensory task. The activation task consisted of three language tasks (silent picture naming , word generation from a character, categorical word generation), motor tasks (opposition of thumb and index finger for hand/dorsifexion or extension for foot), and sensory tasks (passive tactile stimulation of hand or foot using a toothbrush). The data were analyzed using z-score (p<0.05), clustering, and cross-correlation analysis based upon homemade software, IDL 5.1. The success rate for obtaining meaningful fMRI was evaluated and activated regions were assessed on the basis of each fMRI obtained during, language, motor, and somatosensory tasks. fMRI findings were compared with those of the Wada test (n = 7) for language lateralization and with invasive cortical mapping (n = 3) for the localization of eloquent cerebral cortex, especially around the central sulcus. The overall success rate of fMRI was 79 % (37/47); success rates of fMRI with language, sensory, and motor task were 89% (17/19), 83 % (10/12), and 63 % (10/16), respectively. Areas activated during language tasks (n=17) included the

  12. Functional MR imaging in the patients with complex partial seizures

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin Il; Chang, Kee Hyun; Song, In Chan; Goo, Jin Mo; Chung, Chun Kee; Lee, Sang Kun; Kim, Hong Dae; Han, Moon Hee [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Kim, Sam Soo [Boramae City Hospital, Seoul (Korea, Republic of)

    1999-09-01

    To evaluate the clinical usefulness of functional MR imaging (fMRI) for localization of the cerebral motor and sensory cortices and language center in patients with complex partial seizure. A total of 47 fMRIs were obtained in 14 patients (M:F = 9:5; age 15-50 years; 13 right handed and 1 ambidextrous) with complex partial seizure (6 temporal lobe epilepsy, 6 frontal lobe epilepsy, 1 occipitotemporal lobe epilepsy, 1 hemispheric epilepsy). Conventional MR imaging revealed no abnormality in four patients, localized cerebral atrophy in one, hippocampal sclerosis in four, and benign neoplasm in the remaining five. fMRI was performed on a 1.5 T MR scanner (GE Signa Horizon) using gradient-echo singleshot EPI. Nineteen fMRIs were obtained in eight patients who performed the language task, 16 fMRIs in ten who performed the motor task and 12 fMRIs in ten who performed the somatosensory task. The activation task consisted of three language tasks (silent picture naming , word generation from a character, categorical word generation), motor tasks (opposition of thumb and index finger for hand/dorsifexion or extension for foot), and sensory tasks (passive tactile stimulation of hand or foot using a toothbrush). The data were analyzed using z-score (p<0.05), clustering, and cross-correlation analysis based upon homemade software, IDL 5.1. The success rate for obtaining meaningful fMRI was evaluated and activated regions were assessed on the basis of each fMRI obtained during, language, motor, and somatosensory tasks. fMRI findings were compared with those of the Wada test (n = 7) for language lateralization and with invasive cortical mapping (n = 3) for the localization of eloquent cerebral cortex, especially around the central sulcus. The overall success rate of fMRI was 79 % (37/47); success rates of fMRI with language, sensory, and motor task were 89% (17/19), 83 % (10/12), and 63 % (10/16), respectively. Areas activated during language tasks (n=17) included the

  13. In Vivo Imaging of Tissue Physiological Function using EPR Spectroscopy | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    Electron paramagnetic resonance (EPR) is a technique for studying chemical species that have one or more unpaired electrons.  The current invention describes Echo-based Single Point Imaging (ESPI), a novel EPR image formation strategy that allows in vivo imaging of physiological function.  The National Cancer Institute's Radiation Biology Branch is seeking statements of capability or interest from parties interested in in-licensing an in vivo imaging using Electron paramagnetic resonance (EPR) to measure active oxygen species.

  14. Role of intensity transformation function for enhancement of bone scintigraphic images.

    Science.gov (United States)

    Pandey, Anil Kumar; Dhiman, Vishali; Sharma, Akshima; ArunRaj, Sreedharan Thankarajan; Baghel, Vivek; Patel, Chetan; Sharma, Param Dev; Bal, Chandrasekhar; Kumar, Rakesh

    2018-03-29

    The bone scintigraphic image might exceed the dynamic range (the ratio between the highest and the lowest brightness a monitor is capable of displaying) of display monitor. In this case, a high intensity area, and loss of the details of other structures in the displayed image makes the clinical interpretation a challenging task. We have investigated the role of intensity transformation function for enhancement of these types of images. Methods: Forty high dynamic range bone scintigraphic images were processed using intensity transformation (IT) function. The IT function has two parameters: threshold and slope. Keeping the threshold equal to mean counts of the image, the value of slope was varied from 1 to 20. In-house application program written in MATLAB R2013b was used to process images. Twenty output images corresponding to one input image were visually inspected by two experienced nuclear medicine (NM) physicians to select diagnostic quality images, and from their selection the standardized slope (value of slope parameter) that produced maximum numbers of diagnostic images was determined. They also rated the image quality of input and output images (at standardized slope) on scale 1 to 5 [where 1 is for poor and 5 if for the excellent diagnostic quality]. Student's t-test was used to test the significance of difference between the mean image quality score assigned to input and processed images at significance level α = 0.05. Results: The application of IT functions with standardized parameters significantly improved the quality of high dynamic range bone scintigraphic images ( P enhancement. Copyright © 2018 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  15. Refining Functional Optical Imaging of the Breast with Quantum Dots

    National Research Council Canada - National Science Library

    2006-01-01

    ... cancer marker Her2 on the surface of live cancer cells. This report documents a set of lab experiments on gelatin phantoms that were designed to look at the potential for enhanced imaging of QDs...

  16. Cardiovascular risks and brain function: a functional magnetic resonance imaging study of executive function in older adults.

    Science.gov (United States)

    Chuang, Yi-Fang; Eldreth, Dana; Erickson, Kirk I; Varma, Vijay; Harris, Gregory; Fried, Linda P; Rebok, George W; Tanner, Elizabeth K; Carlson, Michelle C

    2014-06-01

    Cardiovascular (CV) risk factors, such as hypertension, diabetes, and hyperlipidemia are associated with cognitive impairment and risk of dementia in older adults. However, the mechanisms linking them are not clear. This study aims to investigate the association between aggregate CV risk, assessed by the Framingham general cardiovascular risk profile, and functional brain activation in a group of community-dwelling older adults. Sixty participants (mean age: 64.6 years) from the Brain Health Study, a nested study of the Baltimore Experience Corps Trial, underwent functional magnetic resonance imaging using the Flanker task. We found that participants with higher CV risk had greater task-related activation in the left inferior parietal region, and this increased activation was associated with poorer task performance. Our results provide insights into the neural systems underlying the relationship between CV risk and executive function. Increased activation of the inferior parietal region may offer a pathway through which CV risk increases risk for cognitive impairment. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Functional neuroanatomy in depressed patients with sexual dysfunction: blood oxygenation level dependent functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jong Chul [Chonnam National Univ. Hospital, Kwangju (Korea, Republic of)

    2004-06-15

    To demonstrate the functional neuroanatomy associated with sexual arousal visually evoked in depressed males who have underlying sexual dysfunction using Blood Oxygenation Level Dependent-based fMRI. Ten healthy volunteers (age range 21-55: mean 32.5 years), and 10 depressed subjects (age range 23-51: mean 34.4 years, mean Beck Depression Inventory score of 39.6 {+-} 5.9, mean Hamilton Rating Scale Depression (HAMD)-17 score of 33.5 {+-} 6.0) with sexual arousal dysfunction viewed erotic and neutral video films during functional magnetic resonance imaging (fMRI) with 1.5 T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 oblique planes using gradient-echo EPI (flip angle/TR/TE=90 .deg. /6000 ms/50 ms). The visual stimulation paradigm began with 60 sec of black screen, 150 sec of neutral stimulation with a documentary video film, 30 sec of black screen, 150 sec of sexual stimulation with an erotic video film followed by 30 sec of black screen. The brain activation maps and their quantification were analyzed by SPM99 program. There was a significant difference of brain activation between two groups during visual sexual stimulation. In depressed subjects, the level of activation during the visually evoked sexual arousal was significantly less than that of healthy volunteers, especially in the cerebrocortical areas of the hypothalamus, thalamus, caudate nucleus, and inferior and superior temporal gyri. On the other hand, the cerebral activation patterns during the neutral condition in both groups showed no significant differences ({rho} < 0.01). This study is the first demonstration of the functional neuroanatomy of the brain associated with sexual dysfunction in depressed patients using fMRI. In order to validate our physiological neuroscience results, further studies that would include patients with other disorders and sexual dysfunction, and depressed patients without sexual dysfunction and their treatment response are needed.

  18. Functional neuroanatomy in depressed patients with sexual dysfunction: blood oxygenation level dependent functional MR imaging

    International Nuclear Information System (INIS)

    Yang, Jong Chul

    2004-01-01

    To demonstrate the functional neuroanatomy associated with sexual arousal visually evoked in depressed males who have underlying sexual dysfunction using Blood Oxygenation Level Dependent-based fMRI. Ten healthy volunteers (age range 21-55: mean 32.5 years), and 10 depressed subjects (age range 23-51: mean 34.4 years, mean Beck Depression Inventory score of 39.6 ± 5.9, mean Hamilton Rating Scale Depression (HAMD)-17 score of 33.5 ± 6.0) with sexual arousal dysfunction viewed erotic and neutral video films during functional magnetic resonance imaging (fMRI) with 1.5 T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 oblique planes using gradient-echo EPI (flip angle/TR/TE=90 .deg. /6000 ms/50 ms). The visual stimulation paradigm began with 60 sec of black screen, 150 sec of neutral stimulation with a documentary video film, 30 sec of black screen, 150 sec of sexual stimulation with an erotic video film followed by 30 sec of black screen. The brain activation maps and their quantification were analyzed by SPM99 program. There was a significant difference of brain activation between two groups during visual sexual stimulation. In depressed subjects, the level of activation during the visually evoked sexual arousal was significantly less than that of healthy volunteers, especially in the cerebrocortical areas of the hypothalamus, thalamus, caudate nucleus, and inferior and superior temporal gyri. On the other hand, the cerebral activation patterns during the neutral condition in both groups showed no significant differences (ρ < 0.01). This study is the first demonstration of the functional neuroanatomy of the brain associated with sexual dysfunction in depressed patients using fMRI. In order to validate our physiological neuroscience results, further studies that would include patients with other disorders and sexual dysfunction, and depressed patients without sexual dysfunction and their treatment response are needed

  19. The functional micro-organization of grid cells revealed by cellular-resolution imaging.

    Science.gov (United States)

    Heys, James G; Rangarajan, Krsna V; Dombeck, Daniel A

    2014-12-03

    Establishing how grid cells are anatomically arranged, on a microscopic scale, in relation to their firing patterns in the environment would facilitate a greater microcircuit-level understanding of the brain's representation of space. However, all previous grid cell recordings used electrode techniques that provide limited descriptions of fine-scale organization. We therefore developed a technique for cellular-resolution functional imaging of medial entorhinal cortex (MEC) neurons in mice navigating a virtual linear track, enabling a new experimental approach to study MEC. Using these methods, we show that grid cells are physically clustered in MEC compared to nongrid cells. Additionally, we demonstrate that grid cells are functionally micro-organized: the similarity between the environment firing locations of grid cell pairs varies as a function of the distance between them according to a "Mexican hat"-shaped profile. This suggests that, on average, nearby grid cells have more similar spatial firing phases than those further apart. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Cognitive impairment after traumatic brain injury: a functional magnetic resonance imaging study using the Stroop task

    International Nuclear Information System (INIS)

    Soeda, Akio; Iwama, Toru; Nakashima, Toshihiko; Okumura, Ayumi; Shinoda, Jun; Kuwata, Kazuo

    2005-01-01

    The anterior cingulate cortex (ACC) plays a key role in cognition, motor function, and emotion processing. However, little is known about how traumatic brain injury (TBI) affects the ACC system. Our purpose was to compare, by functional magnetic resonance imaging (fMRI) studies, the patterns of cortical activation in patients with cognitive impairment after TBI and those of normal subjects. Cortical activation maps of 11 right-handed healthy control subjects and five TBI patients with cognitive impairment were recorded in response to a Stroop task during a block-designed fMRI experiment. Statistical parametric mapping (SPM99) was used for individual subjects and group analysis. In TBI patients and controls, cortical activation, found in similar regions of the frontal, occipital, and parietal lobes, resembled patterns of activation documented in previous neuroimaging studies of the Stroop task in healthy controls. However, the TBI patients showed a relative decrease in ACC activity compared with the controls. Cognitive impairment in TBI patients seems to be associated with alterations in functional cerebral activity, especially less activation of the ACC. These changes are probably the result of destruction of neural networks after diffuse axonal injury and may reflect cortical disinhibition attributable to disconnection or compensation for an inefficient cognitive process. (orig.)

  1. Cognitive impairment after traumatic brain injury: a functional magnetic resonance imaging study using the Stroop task

    Energy Technology Data Exchange (ETDEWEB)

    Soeda, Akio; Iwama, Toru [Gifu University School of Medicine, Department of Neurosurgery, Gifu City (Japan); Nakashima, Toshihiko; Okumura, Ayumi; Shinoda, Jun [Kizawa Memorial Hospital, Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Department of Neurosurgery, Minokamo (Japan); Kuwata, Kazuo [Gifu University School of Medicine, Department of Biochemistry and Biophysics, Gifu (Japan)

    2005-07-01

    The anterior cingulate cortex (ACC) plays a key role in cognition, motor function, and emotion processing. However, little is known about how traumatic brain injury (TBI) affects the ACC system. Our purpose was to compare, by functional magnetic resonance imaging (fMRI) studies, the patterns of cortical activation in patients with cognitive impairment after TBI and those of normal subjects. Cortical activation maps of 11 right-handed healthy control subjects and five TBI patients with cognitive impairment were recorded in response to a Stroop task during a block-designed fMRI experiment. Statistical parametric mapping (SPM99) was used for individual subjects and group analysis. In TBI patients and controls, cortical activation, found in similar regions of the frontal, occipital, and parietal lobes, resembled patterns of activation documented in previous neuroimaging studies of the Stroop task in healthy controls. However, the TBI patients showed a relative decrease in ACC activity compared with the controls. Cognitive impairment in TBI patients seems to be associated with alterations in functional cerebral activity, especially less activation of the ACC. These changes are probably the result of destruction of neural networks after diffuse axonal injury and may reflect cortical disinhibition attributable to disconnection or compensation for an inefficient cognitive process. (orig.)

  2. A Computerized Tablet with Visual Feedback of Hand Position for Functional Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Mahta eKarimpoor

    2015-03-01

    Full Text Available Neuropsychological tests - behavioral tasks that very commonly involve handwriting and drawing - are widely used in the clinic to detect abnormal brain function. Functional magnetic resonance imaging (fMRI may be useful in increasing the specificity of such tests. However, performing complex pen-and-paper tests during fMRI involves engineering challenges. Previously, we developed an fMRI-compatible, computerized tablet system to address this issue. However, the tablet did not include visual feedback of hand position (VFHP, a human factors component that may be important for fMRI of certain patient populations. A real-time system was thus developed to provide VFHP and integrated with the tablet in an augmented reality display. The effectiveness of the system was initially tested in young healthy adults who performed various handwriting tasks in front of a computer display with and without VFHP. Pilot fMRI of writing tasks were performed by two representative individuals with and without VFHP. Quantitative analysis of the behavioral results indicated improved writing performance with VFHP. The pilot fMRI results suggest that writing with VFHP requires less neural resources compared to the without VFHP condition, to maintain similar behavior. Thus, the tablet system with VFHP is recommended for future fMRI studies involving patients with impaired brain function and where ecologically valid behavior is important.

  3. Selecting wavelet basis function for denoising of planar nuclear images using mutual information metric

    International Nuclear Information System (INIS)

    Matsuyama, Eri; Tsai, Du-Yih; Lee, Yongbum; Fuse, Masashi; Kojima, Katsuyuki

    2010-01-01

    Noise reduction in nuclear medicine images can be achieved by increasing the counts or by filtering the images. In this paper, we employed an image filtering technique, a wavelet-based method, for reducing image noise. We selected eight various wavelet basis functions for our study. Wavelet transforms were applied to planar images using the universal soft-thresholding method. We used mutual information (MI) as an image-quality metric to conduct quantitative image analysis and comparison on the processed images obtained from the eight selected, wavelet basis functions. To validate the usefulness of the proposed metric, standard deviation rate and edge slope ratio of the processed images were calculated and compared. In this study, a computer-generated 2-D grid-pattern image and phantom images acquired with a standard inkjet printer, were served as original images. Simulation experiments and phantom experiments demonstrate that MI value can be used as a criterion to select an appropriate wavelet basis for image denoising. (author)

  4. Feasibility of one-eighth time gated myocardial perfusion SPECT functional imaging using IQ-SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Caobelli, Federico; Thackeray, James T.; Bengel, Frank M. [Medizinische Hochschule Hannover, Klinik fuer Nuklearmedizin, Hannover (Germany); Soffientini, Alberto; Pizzocaro, Claudio; Guerra, Ugo Paolo [Fondazione Poliambulanza, Department of Nuclear Medicine, Brescia (Italy)

    2015-11-15

    LV functional parameters obtained with a one-eighth acquisition time were statistically comparable to the previously validated one-fourth time protocol using IQ-SPECT. Shorter acquisition times without loss of diagnostic accuracy provide improved patient comfort and streamlined departmental efficiency. (orig.)

  5. Implementation of digital image encryption algorithm using logistic function and DNA encoding

    Science.gov (United States)

    Suryadi, MT; Satria, Yudi; Fauzi, Muhammad

    2018-03-01

    Cryptography is a method to secure information that might be in form of digital image. Based on past research, in order to increase security level of chaos based encryption algorithm and DNA based encryption algorithm, encryption algorithm using logistic function and DNA encoding was proposed. Digital image encryption algorithm using logistic function and DNA encoding use DNA encoding to scramble the pixel values into DNA base and scramble it in DNA addition, DNA complement, and XOR operation. The logistic function in this algorithm used as random number generator needed in DNA complement and XOR operation. The result of the test show that the PSNR values of cipher images are 7.98-7.99 bits, the entropy values are close to 8, the histogram of cipher images are uniformly distributed and the correlation coefficient of cipher images are near 0. Thus, the cipher image can be decrypted perfectly and the encryption algorithm has good resistance to entropy attack and statistical attack.

  6. Efficient nonlinear registration of 3D images using high order co-ordinate transfer functions.

    Science.gov (United States)

    Barber, D C

    1999-01-01

    There is an increasing interest in image registration for a variety of medical imaging applications. Image registration is achieved through the use of a co-ordinate transfer function (CTF) which maps voxels in one image to voxels in the other image, including in the general case changes in mapped voxel intensity. If images of the same subject are to be registered the co-ordinate transfer function needs to implement a spatial transformation consisting of a displacement and a rigid rotation. In order to achieve registration a common approach is to choose a suitable quality-of-registration measure and devise a method for the efficient generation of the parameters of the CTF which minimize this measure. For registration of images from different subjects more complex transforms are required. In general function minimization is too slow to allow the use of CTFs with more than a small number of parameters. However, provided the images are from the same modality and the CTF can be expanded in terms of an appropriate set of basis functions this paper will show how relatively complex CTFs can be used for registration. The use of increasingly complex CTFs to minimize the within group standard deviation of a set of normal single photon emission tomography brain images is used to demonstrate the improved registration of images from different subjects using CTFs of increasing complexity.

  7. Tumor functional and molecular imaging utilizing ultrasound and ultrasound-mediated optical techniques.

    Science.gov (United States)

    Yuan, Baohong; Rychak, Joshua

    2013-02-01

    Tumor functional and molecular imaging has significantly contributed to cancer preclinical research and clinical applications. Among typical imaging modalities, ultrasonic and optical techniques are two commonly used methods; both share several common features such as cost efficiency, absence of ionizing radiation, relatively inexpensive contrast agents, and comparable maximum-imaging depth. Ultrasonic and optical techniques are also complementary in imaging resolution, molecular sensitivity, and imaging space (vascular and extravascular). The marriage between ultrasonic and optical techniques takes advantages of both techniques. This review introduces tumor functional and molecular imaging using microbubble-based ultrasound and ultrasound-mediated optical imaging techniques. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  8. Cross-sectional imaging of functional activation in the rat somatosensory cortex with optical coherence tomography

    Science.gov (United States)

    Aguirre, A. D.; Chen, Y.; Ruvinskaya, L.; Devor, A.; Boas, D. A.; Fujimoto, J. G.

    2005-08-01

    Simultaneous optical coherence tomography (OCT) and video microscopy were performed on the rat somatosensory cortex through a thinned skull during forepaw stimulation. Fractional change measurements in OCT images reveal a functional signal timecourse similar to well understood hemodynamic signal timecourses measured with video microscopy. The precise etiology of the observed OCT functional signal is still under investigation, but these results suggest that OCT can provide high-resolution cross-sectional images of functional neuro-vascular activation.

  9. Modified Sigmoid Function Based Gray Scale Image Contrast Enhancement Using Particle Swarm Optimization

    Science.gov (United States)

    Verma, Harish Kumar; Pal, Sandeep

    2016-06-01

    The main objective of an image enhancement is to improve eminence by maximizing the information content in the test image. Conventional contrast enhancement techniques either often fails to produce reasonable results for a broad variety of low-contrast and high contrast images, or cannot be automatically applied to different images, because they are parameters dependent. Hence this paper introduces a novel hybrid image enhancement approach by taking both the local and global information of an image. In the present work, sigmoid function is being modified on the basis of contrast of the images. The gray image enhancement problem is treated as nonlinear optimization problem with several constraints and solved by particle swarm optimization. The entropy and edge information is included in the objective function as quality measure of an image. The effectiveness of modified sigmoid function based enhancement over conventional methods namely linear contrast stretching, histogram equalization, and adaptive histogram equalization are better revealed by the enhanced images and further validated by statistical analysis of these images.

  10. Functional brain response to food images in successful adolescent weight losers compared with normal-weight and overweight controls.

    Science.gov (United States)

    Jensen, Chad D; Kirwan, C Brock

    2015-03-01

    Research conducted with adults suggests that successful weight losers demonstrate greater activation in brain regions associated with executive control in response to viewing high-energy foods. No previous studies have examined these associations in adolescents. Functional neuroimaging was used to assess brain response to food images among groups of overweight (OW), normal-weight (NW), and successful weight-losing (SWL) adolescents. Eleven SWL, 12 NW, and 11 OW participants underwent functional magnetic resonance imaging while viewing images of high- and low-energy foods. When viewing high-energy food images, SWLs demonstrated greater activation in the dorsolateral prefrontal cortex (DLPFC) compared with OW and NW controls. Compared with NW and SWL groups, OW individuals demonstrated greater activation in the ventral striatum and anterior cingulate in response to food images. Adolescent SWLs demonstrated greater neural activation in the DLPFC compared with OW/NW controls when viewing high-energy food stimuli, which may indicate enhanced executive control. OW individuals' brain responses to food stimuli may indicate greater reward incentive processes than either SWL or NW groups. © 2015 The Obesity Society.

  11. Functional Classification of the Gut Microbiota: The Key to Cracking the Microbiota Composition Code: Functional classifications of the gut microbiota reveal previously hidden contributions of indigenous gut bacteria to human health and disease.

    Science.gov (United States)

    Rosen, Connor E; Palm, Noah W

    2017-12-01

    The last decade has seen an explosion of research on the gut microbiota-the trillions of microorganisms that colonize the human gut. It is now clear that interindividual diversity in microbiota composition plays an important role in determining susceptibility to a wide variety of diseases. However, identifying the precise changes in microbiota composition that play causal roles has remained a largely unrealized goal. Here, we propose that functional classifications of microbes based on their interactions with and effects on the host-particularly the host immune system-will illuminate the role of the microbiota in shaping human physiology. We outline the benefits of "functional" classification compared to phylogenetic classifications, and review current efforts at functional classification of the microbiota. Finally, we outline a theoretical framework for classifying host-microbiota interactions. Future advances enabling broader functional classifications of the microbiota promise to revolutionize our understanding of the role of gut microbes in health and disease. © 2017 WILEY Periodicals, Inc.

  12. Drawing cartoon faces--a functional imaging study of the cognitive neuroscience of drawing.

    Science.gov (United States)

    Miall, R Chris; Gowen, Emma; Tchalenko, John

    2009-03-01

    We report a functional imaging study of drawing cartoon faces. Normal, untrained participants were scanned while viewing simple black and white cartoon line drawings of human faces, retaining them for a short memory interval, and then drawing them without vision of their hand or the paper. Specific encoding and retention of information about the faces were tested for by contrasting these two stages (with display of cartoon faces) against the exploration and retention of random dot stimuli. Drawing was contrasted between conditions in which only memory of a previously viewed face was available versus a condition in which both memory and simultaneous viewing of the cartoon were possible, and versus drawing of a new, previously unseen, face. We show that the encoding of cartoon faces powerfully activates the face-sensitive areas of the lateral occipital cortex and the fusiform gyrus, but there is no significant activation in these areas during the retention interval. Activity in both areas was also high when drawing the displayed cartoons. Drawing from memory activates areas in posterior parietal cortex and frontal areas. This activity is consistent with the encoding and retention of the spatial information about the face to be drawn as a visuo-motor action plan, either representing a series of targets for ocular fixation or as spatial targets for the drawing action.

  13. Intraoperative Functional Ultrasound Imaging of Human Brain Activity

    OpenAIRE

    Imbault, Marion; Chauvet, Dorian; Gennisson, Jean-Luc; Capelle, Laurent; Tanter, Mickael

    2017-01-01

    International audience; The functional mapping of brain activity is essential to perform optimal glioma surgery and to minimize the risk of postoperative deficits. We introduce a new, portable neuroimaging modality of the human brain based on functional ultrasound (fUS) for deep functional cortical mapping. Using plane-wave transmissions at an ultrafast frame rate (1 kHz), fUS is performed during surgery to measure transient changes in cerebral blood volume with a high spatiotemporal resoluti...

  14. Functional brain imaging in neuropsychology over the past 25 years.

    Science.gov (United States)

    Roalf, David R; Gur, Ruben C

    2017-11-01

    Outline effects of functional neuroimaging on neuropsychology over the past 25 years. Functional neuroimaging methods and studies will be described that provide a historical context, offer examples of the utility of neuroimaging in specific domains, and discuss the limitations and future directions of neuroimaging in neuropsychology. Tracking the history of publications on functional neuroimaging related to neuropsychology indicates early involvement of neuropsychologists in the development of these methodologies. Initial progress in neuropsychological application of functional neuroimaging has been hampered by costs and the exposure to ionizing radiation. With rapid evolution of functional methods-in particular functional MRI (fMRI)-neuroimaging has profoundly transformed our knowledge of the brain. Its current applications span the spectrum of normative development to clinical applications. The field is moving toward applying sophisticated statistical approaches that will help elucidate distinct neural activation networks associated with specific behavioral domains. The impact of functional neuroimaging on clinical neuropsychology is more circumscribed, but the prospects remain enticing. The theoretical insights and empirical findings of functional neuroimaging have been led by many neuropsychologists and have transformed the field of behavioral neuroscience. Thus far they have had limited effects on the clinical practices of neuropsychologists. Perhaps it is time to add training in functional neuroimaging to the clinical neuropsychologist's toolkit and from there to the clinic or bedside. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  15. Functional imaging equivalence and proof of concept for image-guided adaptive radiotherapy with fixed gantry and rotating couch.

    Science.gov (United States)

    Feain, Ilana; Shieh, Chun-Chien; White, Paul; O'Brien, Ricky; Fisher, Sandra; Counter, William; Lazarakis, Peter; Stewart, David; Downes, Simon; Jackson, Michael; Baxi, Siddhartha; Whelan, Brendan; Makhija, Kuldeep; Huang, Chen-Yu; Barton, Michael; Keall, Paul

    2016-01-01

    The purpose of this article is to present the first imaging experiments to demonstrate the functional equivalence between a conventional rotational gantry and a fixed-beam imaging geometry, and the feasibility of an iterative image-reconstruction technique under gravitational deformation. Experiments were performed using an Elekta Axesse with Agility MLC and XVI, a custom-built rotating phantom stage, a Catphan QA phantom, and a porcine heart. For the imaging equivalence, a conventional cone beam computed tomography (CBCT) of the Catphan was acquired, as well as a set of 660 x-ray projections with a static gantry and rotating Catphan. Both datasets were reconstructed with the Feldkamp-Davis-Kress (FDK) algorithm, and the resultant volumetric images were compared using standard metrics. For imaging under gravitational deformation, a conventional CBCT of the Catphan and a set of 660 x-ray projections with a static gantry and rotating Catphan were also acquired with a porcine heart. The conventional CBCT was reconstructed using FDK. The projections that were acquired with the heart rotating were sorted into angular bins and reconstructed with prior image constrained compressed sensing using a deformation-blurred FDK prior. Deformation was quantified with B-spline transformation-based deformable image registration. For imaging equivalence, the difference between the two Catphan images was consistent with Poisson noise. For imaging under gravitational deformation, the conventional CBCT porcine heart image (ground truth at 0 degrees) matched the static gantry, rotating heart reconstruction with a mean magnitude of <3 mm and maximum magnitude of <5 mm of the deformation vector field. The mean deformation of the rotating heart was 3.0 to 8.9 mm, up to 16.1 mm maximum deformation. Deformation was mainly observed in the direction of gravity. We have demonstrated imaging equivalence in cone beam CT reconstructions between rigid phantom images acquired with a conventional

  16. One decade of functional imaging in schizophrenia research. From visualisation of basic information processing steps to molecular brain imaging

    International Nuclear Information System (INIS)

    Tost, H.; Meyer-Lindenberg, A.; Ruf, M.; Demirakca, T.; Grimm, O.; Henn, F.A.; Ende, G.

    2005-01-01

    Modern neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) have contributed tremendously to our current understanding of psychiatric disorders in the context of functional, biochemical and microstructural alterations of the brain. Since the mid-nineties, functional MRI has provided major insights into the neurobiological correlates of signs and symptoms in schizophrenia. The current paper reviews important fMRI studies of the past decade in the domains of motor, visual, auditory, attentional and working memory function. Special emphasis is given to new methodological approaches, such as the visualisation of medication effects and the functional characterisation of risk genes. (orig.) [de

  17. Functional imaging of the central auditory system using PET

    NARCIS (Netherlands)

    Ruytjens, L.; Willemsen, A. T. M.; Van Dijk, P.; Wit, H. P.; Albers, F. W. J.

    2006-01-01

    In the last few decades functional neuroimaging tools have emerged to study the function of the human brain in vivo. These techniques have increased the knowledge of how the brain processes stimuli of different sensory modalities, including auditory processing. Positron emission tomography (PET) has

  18. Splenic imaging in a patient with functional asplenia

    Energy Technology Data Exchange (ETDEWEB)

    Wagman, P.G.; Dworkin, H.J.

    1989-04-01

    A 65-year-old woman presented with right upper extremity paralysis and left cerebrovascular accident. A routine complete blood count (CBC) demonstrated Howell-Jolly bodies on peripheral smear, and a liver-spleen scan showed absent splenic sulfur colloid uptake suggesting functional asplenia. A subsequent heat damaged red blood cell study demonstrated a normal sized spleen with preserved sequestering function, thereby excluding anatomic asplenia, vascular alterations, or congenital anomalies in the differential diagnosis of functional asplenia. This case illustrates the use of Tc-99m heat damaged red blood cells as a unique and useful diagnostic aid in identifying the presence and size of a spleen in patients with functional asplenia. It also demonstrates an apparent qualitative separation of splenic functions in processing sulfur colloid and heat damaged red blood cells.

  19. Brain Activity in Patients With Adductor Spasmodic Dysphonia Detected by Functional Magnetic Resonance Imaging.

    Science.gov (United States)

    Kiyuna, Asanori; Kise, Norimoto; Hiratsuka, Munehisa; Kondo, Shunsuke; Uehara, Takayuki; Maeda, Hiroyuki; Ganaha, Akira; Suzuki, Mikio

    2017-05-01

    Spasmodic dysphonia (SD) is considered a focal dystonia. However, the detailed pathophysiology of SD remains unclear, despite the detection of abnormal activity in several brain regions. The aim of this study was to clarify the pathophysiological background of SD. This is a case-control study. Both task-related brain activity measured by functional magnetic resonance imaging by reading the five-digit numbers and resting-state functional connectivity (FC) measured by 150 T2-weighted echo planar images acquired without any task were investigated in 12 patients with adductor SD and in 16 healthy controls. The patients with SD showed significantly higher task-related brain activation in the left middle temporal gyrus, left thalamus, bilateral primary motor area, bilateral premotor area, bilateral cerebellum, bilateral somatosensory area, right insula, and right putamen compared with the controls. Region of interest voxel FC analysis revealed many FC changes within the cerebellum-basal ganglia-thalamus-cortex loop in the patients with SD. Of the significant connectivity changes between the patients with SD and the controls, the FC between the left thalamus and the left caudate nucleus was significantly correlated with clinical parameters in SD. The higher task-related brain activity in the insula and cerebellum was consistent with previous neuroimaging studies, suggesting that these areas are one of the unique characteristics of phonation-induced brain activity in SD. Based on FC analysis and their significant correlations with clinical parameters, the basal ganglia network plays an important role in the pathogenesis of SD. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  20. Functional histology of tumors as a basis of molecular imaging

    International Nuclear Information System (INIS)

    Ljungkvist, A.S.; Bussink, J.; Rijken, P.F.; Van Der Kogel, A.; Kaanders, J.H.

    2003-01-01

    The aim of this study was to characterize the various elements of the microenvironment and their interrelationships by quantitative image analysis. Tumor cell proliferation, hypoxia, and apoptosis are detected by immunohistochemical methods, and mapped in relation to the vasculature. This allows quantitative relationships to be measured in the context of tissue structure. Guided by e.g., gene expression profiles for hypoxia induced-genes, several molecular markers of tumor hypoxia were identified and are immunohistochemically detectable. We have thus far concentrated on the glucose transporters glut-1 and glut-3, as well as a pH-regulating enzyme, carbonic anhydrase IX. The extent and distribution of hypoxia is assessed by administering nitroimidazole-based markers such as pimonidazole, that can be detected immunohistochemically. Multiple hypoxia markers (CCI-103F, pimonidazole) can be used to study the effects of modifiers of perfusion or oxygenation on the distribution and dynamics of hypoxic cells in the same tumor. Proliferating cells are detected by thymidine analogues. Apoptotic cells are imaged by TUNEL and caspase-3 detection. In xenografted human tumors, examples of the use of quantitative imaging of hypoxia and proliferation are the study of reoxygenation after irradiation, or the investigation of the lifespan and dynamics of hypoxic cell populations over time. Perturbation of the microenvironment after cytotoxic treatments has been investigated by co-registration of the various markers, e.g. after treatment with the hypoxic cytotoxin tirapazamine. The combination of well-timed administration of external markers of hypoxia and proliferation with the detection of intrinsic molecular markers followed by quantitative image-registration yields a comprehensive view of the dynamics of the microenvironment in individual tumors

  1. Neural mechanisms of subclinical depressive symptoms in women: a pilot functional brain imaging study

    Directory of Open Access Journals (Sweden)

    Felder Jennifer N

    2012-09-01

    Full Text Available Abstract Background Studies of individuals who do not meet criteria for major depressive disorder (MDD but with subclinical levels of depressive symptoms may aid in the identification of neurofunctional abnormalities that possibly precede and predict the development of MDD. The purpose of this study was to evaluate relations between subclinical levels of depressive symptoms and neural activation patterns during tasks previously shown to differentiate individuals with and without MDD. Methods Functional magnetic resonance imaging (fMRI was used to assess neural activations during active emotion regulation, a resting state scan, and reward processing. Participants were twelve females with a range of depressive symptoms who did not meet criteria for MDD. Results Increased depressive symptom severity predicted (1 decreased left midfrontal gyrus activation during reappraisal of sad stimuli; (2 increased right midfrontal gyrus activation during distraction from sad stimuli; (3 increased functional connectivity between a precuneus seed region and left orbitofrontal cortex during a resting state scan; and (4 increased paracingulate activation during non-win outcomes during a reward-processing task. Conclusions These pilot data shed light on relations between subclinical levels of depressive symptoms in the absence of a formal MDD diagnosis and neural activation patterns. Future studies will be needed to test the utility of these activation patterns for predicting MDD onset in at-risk samples.

  2. Functionality of veterinary identification microchips following low- (0.5 tesla) and high-field (3 tesla) magnetic resonance imaging.

    Science.gov (United States)

    Piesnack, Susann; Frame, Mairi E; Oechtering, Gerhard; Ludewig, Eberhard

    2013-01-01

    The ability to read patient identification microchips relies on the use of radiofrequency pulses. Since radiofrequency pulses also form an integral part of the magnetic resonance imaging (MRI) process, the possibility of loss of microchip function during MRI scanning is of concern. Previous clinical trials have shown microchip function to be unaffected by MR imaging using a field strength of 1 Tesla and 1.5. As veterinary MRI scanners range widely in field strength, this study was devised to determine whether exposure to lower or higher field strengths than 1 Tesla would affect the function of different types of microchip. In a phantom study, a total of 300 International Standards Organisation (ISO)-approved microchips (100 each of three different types: ISO FDX-B 1.4 × 9 mm, ISO FDX-B 2.12 × 12 mm, ISO HDX 3.8 × 23 mm) were tested in a low field (0.5) and a high field scanner (3.0 Tesla). A total of 50 microchips of each type were tested in each scanner. The phantom was composed of a fluid-filled freezer pack onto which a plastic pillow and a cardboard strip with affixed microchips were positioned. Following an MRI scan protocol simulating a head study, all of the microchips were accurately readable. Neither 0.5 nor 3 Tesla imaging affected microchip function in this study. © 2013 Veterinary Radiology & Ultrasound.

  3. Neural correlates of emotional personality: a structural and functional magnetic resonance imaging study.

    Science.gov (United States)

    Koelsch, Stefan; Skouras, Stavros; Jentschke, Sebastian

    2013-01-01

    Studies addressing brain correlates of emotional personality have remained sparse, despite the involvement of emotional personality in health and well-being. This study investigates structural and functional brain correlates of psychological and physiological measures related to emotional personality. Psychological measures included neuroticism, extraversion, and agreeableness scores, as assessed using a standard personality questionnaire. As a physiological measure we used a cardiac amplitude signature, the so-called E κ value (computed from the electrocardiogram) which has previously been related to tender emotionality. Questionnaire scores and E κ values were related to both functional (eigenvector centrality mapping, ECM) and structural (voxel-based morphometry, VBM) neuroimaging data. Functional magnetic resonance imaging (fMRI) data were obtained from 22 individuals (12 females) while listening to music (joy, fear, or neutral music). ECM results showed that agreeableness scores correlated with centrality values in the dorsolateral prefrontal cortex, the anterior cingulate cortex, and the ventral striatum (nucleus accumbens). Individuals with higher E κ values (indexing higher tender emotionality) showed higher centrality values in the subiculum of the right hippocampal formation. Structural MRI data from an independent sample of 59 individuals (34 females) showed that neuroticism scores correlated with volume of the left amygdaloid complex. In addition, individuals with higher E κ showed larger gray matter volume in the same portion of the subiculum in which individuals with higher E κ showed higher centrality values. Our results highlight a role of the amygdala in neuroticism. Moreover, they indicate that a cardiac signature related to emotionality (E κ) correlates with both function (increased network centrality) and structure (grey matter volume) of the subiculum of the hippocampal formation, suggesting a role of the hippocampal formation for

  4. Neural correlates of emotional personality: a structural and functional magnetic resonance imaging study.

    Directory of Open Access Journals (Sweden)

    Stefan Koelsch

    Full Text Available Studies addressing brain correlates of emotional personality have remained sparse, despite the involvement of emotional personality in health and well-being. This study investigates structural and functional brain correlates of psychological and physiological measures related to emotional personality. Psychological measures included neuroticism, extraversion, and agreeableness scores, as assessed using a standard personality questionnaire. As a physiological measure we used a cardiac amplitude signature, the so-called E κ value (computed from the electrocardiogram which has previously been related to tender emotionality. Questionnaire scores and E κ values were related to both functional (eigenvector centrality mapping, ECM and structural (voxel-based morphometry, VBM neuroimaging data. Functional magnetic resonance imaging (fMRI data were obtained from 22 individuals (12 females while listening to music (joy, fear, or neutral music. ECM results showed that agreeableness scores correlated with centrality values in the dorsolateral prefrontal cortex, the anterior cingulate cortex, and the ventral striatum (nucleus accumbens. Individuals with higher E κ values (indexing higher tender emotionality showed higher centrality values in the subiculum of the right hippocampal formation. Structural MRI data from an independent sample of 59 individuals (34 females showed that neuroticism scores correlated with volume of the left amygdaloid complex. In addition, individuals with higher E κ showed larger gray matter volume in the same portion of the subiculum in which individuals with higher E κ showed higher centrality values. Our results highlight a role of the amygdala in neuroticism. Moreover, they indicate that a cardiac signature related to emotionality (E κ correlates with both function (increased network centrality and structure (grey matter volume of the subiculum of the hippocampal formation, suggesting a role of the hippocampal formation for

  5. Imaging functional and structural brain connectomics in attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Cao, Miao; Shu, Ni; Cao, Qingjiu; Wang, Yufeng; He, Yong

    2014-12-01

    Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopment disorders in childhood. Clinically, the core symptoms of this disorder include inattention, hyperactivity, and impulsivity. Previous studies have documented that these behavior deficits in ADHD children are associated with not only regional brain abnormalities but also changes in functional and structural connectivity among regions. In the past several years, our understanding of how ADHD affects the brain's connectivity has been greatly advanced by mapping topological alterations of large-scale brain networks (i.e., connectomes) using noninvasive neurophysiological and neuroimaging techniques (e.g., electroencephalograph, functional MRI, and diffusion MRI) in combination with graph theoretical approaches. In this review, we summarize the recent progresses of functional and structural brain connectomics in ADHD, focusing on graphic analysis of large-scale brain systems. Convergent evidence suggests that children with ADHD had abnormal small-world properties in both functional and structural brain networks characterized by higher local clustering and lower global integrity, suggesting a disorder-related shift of network topology toward regular configurations. Moreover, ADHD children showed the redistribution of regional nodes and connectivity involving the default-mode, attention, and sensorimotor systems. Importantly, these ADHD-associated alterations significantly correlated with behavior disturbances (e.g., inattention and hyperactivity/impulsivity symptoms) and exhibited differential patterns between clinical subtypes. Together, these connectome-based studies highlight brain network dysfunction in ADHD, thus opening up a new window into our understanding of the pathophysiological mechanisms of this disorder. These works might also have important implications on the development of imaging-based biomarkers for clinical diagnosis and treatment evaluation in ADHD.

  6. Functional connectivity in the mouse brain imaged by B-mode photoacoustic microscopy

    Science.gov (United States)

    Nasiriavanaki, Mohammadreza; Xing, Wenxin; Xia, Jun; Wang, Lihong V.

    2014-03-01

    The increasing use of mouse models for human brain disease studies, coupled with the fact that existing functional imaging modalities cannot be easily applied to mice, presents an emerging need for a new functional imaging modality. Utilizing acoustic-resolution photoacoustic microscopy (AR-PAM), we imaged spontaneous cerebral hemodynamic fluctuations and their associated functional connections in the mouse brain. The images were acquired noninvasively in B-scan mode with a fast frame rate, a large field of view, and a high spatial resolution. At a location relative to the bregma 0, correlations were investigated inter-hemispherically between bilaterally homologous regions, as well as intra-hemispherically within the same functional regions. The functional connectivity in different functional regions was studied. The locations of these regions agreed well with the Paxinos mouse brain atlas. The functional connectivity map obtained in this study can then be used in the investigation of brain disorders such as stroke, Alzheimer's, schizophrenia, multiple sclerosis, autism, and epilepsy. Our experiments show that photoacoustic microscopy is capable to detect connectivities between different functional regions in B-scan mode, promising a powerful functional imaging modality for future brain research.

  7. Recommendations for breast imaging follow-up of women with a previous history of breast cancer: position paper from the Italian Group for Mammography Screening (GISMa) and the Italian College of Breast Radiologists (ICBR) by SIRM.

    Science.gov (United States)

    Bucchi, Lauro; Belli, Paolo; Benelli, Eva; Bernardi, Daniela; Brancato, Beniamino; Calabrese, Massimo; Carbonaro, Luca A; Caumo, Francesca; Cavallo-Marincola, Beatrice; Clauser, Paola; Fedato, Chiara; Frigerio, Alfonso; Galli, Vania; Giordano, Livia; Golinelli, Paola; Mariscotti, Giovanna; Martincich, Laura; Montemezzi, Stefania; Morrone, Doralba; Naldoni, Carlo; Paduos, Adriana; Panizza, Pietro; Pediconi, Federica; Querci, Fiammetta; Rizzo, Antonio; Saguatti, Gianni; Tagliafico, Alberto; Trimboli, Rubina M; Zuiani, Chiara; Sardanelli, Francesco

    2016-12-01

    Women who were previously treated for breast cancer (BC) are an important particular subgroup of women at intermediate BC risk. Their breast follow-up should be planned taking in consideration a 1.0-1.5 % annual rate of loco-regional recurrences and new ipsilateral or contralateral BCs during 15-20 years, and be based on a regional/district invitation system. This activity should be carried out by a Department of Radiology integrating screening and diagnostics in the context of a Breast Unit. We recommend the adoption of protocols dedicated to women previously treated for BC, with a clear definition of responsibilities, methods for invitation, site(s) of visits, methods for clinical and radiological evaluation, follow-up duration, role and function of family doctors and specialists. These women will be invited to get a mammogram in dedicated sessions starting from the year after the end of treatment. The planned follow-up duration will be at least 10 years and will be defined on the basis of patient's age and preferences, taking into consideration organizational matters. Special agreements can be defined in the case of women who have their follow-up planned at other qualified centers. Dedicated screening sessions should include: evaluation of familial/personal history (if previously not done) for identifying high-risk conditions which could indicate a different screening strategy; immediate evaluation of mammograms by one or, when possible, two breast radiologists with possible addition of supplemental mammographic views, digital breast tomosynthesis, clinical breast examination, breast ultrasound; and prompt planning of possible further workup. Results of these screening sessions should be set apart from those of general female population screening and presented in dedicated reports. The following research issues are suggested: further risk stratification and effectiveness of follow-up protocols differentiated also for BC pathologic subtype and molecular

  8. Target localization on standard axial images in computed tomography (CT) stereotaxis for functional neurosurgery - a technical note

    International Nuclear Information System (INIS)

    Patil, A.-A.

    1986-01-01

    A simple technique for marking functional neurosurgery target on computed tomography (CT) axial image is described. This permits the use of standard axial image for computed tomography (CT) stereotaxis in functional neurosurgery. (Author)

  9. Brain functional magnetic resonance imaging response to glucose and fructose infusions in humans

    Science.gov (United States)

    Objective: In animals, intracerebroventricular glucose and fructose have opposing effects on appetite and weight regulation. In humans, functional brain magnetic resonance imaging (fMRI) studies during carbohydrate ingestion suggest that glucose may regulate HT signaling but are potentially confoun...

  10. Introduction to the feature section on functional imaging of the pelvic floor.

    Science.gov (United States)

    Maccioni, Francesca

    2013-10-01

    This is the introduction to the feature section of functional imaging of the pelvic floor, which includes 6 articles, two focused on clinical issues, while four on radiological aspects, mostly on dynamic pelvic floor MRI.

  11. Declarative memory consolidation in humans: a prospective functional magnetic resonance imaging study.

    NARCIS (Netherlands)

    Takashima, A.; Petersson, K.M.; Rutters, F.; Tendolkar, I.; Jensen, O.; Zwarts, M.J.; McNaughton, B.L.; Fernandez, G.S.E.

    2006-01-01

    Retrieval of recently acquired declarative memories depends on the hippocampus, but with time, retrieval is increasingly sustainable by neocortical representations alone. This process has been conceptualized as system-level consolidation. Using functional magnetic resonance imaging, we assessed over

  12. Denoising functional MR images : A comparison of wavelet denoising and Gaussian smoothing

    NARCIS (Netherlands)

    Wink, Alle Meije; Roerdink, Jos B.T.M.

    We present a general wavelet-based denoising scheme for functional magnetic resonance imaging (fMRI) data and compare it to Gaussian smoothing, the traditional denoising method used in fMRI analysis. One-dimensional WaveLab thresholding routines were adapted to two-dimensional images, and applied to

  13. Print and Image Integration of Science Texts and Reading Comprehension: A Systemic Functional Linguistics Perspective

    Science.gov (United States)

    Hsu, Pei-Ling; Yang, Wen-Gin

    2007-01-01

    Systemic functional linguistics (SFL) was the foundation for this study that explored the effect of science text and image integration on grade 9 students' reading comprehension. Two texts in Chinese on the moon phase with different print and image integration were compared--a traditional textbook (TT) used in Taiwanese junior high schools and a…

  14. Decoding post-stroke motor function from structural brain imaging

    Directory of Open Access Journals (Sweden)

    Jane M. Rondina

    2016-01-01

    Full Text Available Clinical research based on neuroimaging data has benefited from machine learning methods, which have the ability to provide individualized predictions and to account for the interaction among units of information in the brain. Application of machine learning in structural imaging to investigate diseases that involve brain injury presents an additional challenge, especially in conditions like stroke, due to the high variability across patients regarding characteristics of the lesions. Extracting data from anatomical images in a way that translates brain damage information into features to be used as input to learning algorithms is still an open question. One of the most common approaches to capture regional information from brain injury is to obtain the lesion load per region (i.e. the proportion of voxels in anatomical structures that are considered to be damaged. However, no systematic evaluation has yet been performed to compare this approach with using patterns of voxels (i.e. considering each voxel as a single feature. In this paper we compared both approaches applying Gaussian Process Regression to decode motor scores in 50 chronic stroke patients based solely on data derived from structural MRI. For both approaches we compared different ways to delimit anatomical areas: regions of interest from an anatomical atlas, the corticospinal tract, a mask obtained from fMRI analysis with a motor task in healthy controls and regions selected using lesion-symptom mapping. Our analysis showed that extracting features through patterns of voxels that represent lesion probability produced better results than quantifying the lesion load per region. In particular, from the different ways to delimit anatomical areas compared, the best performance was obtained with a combination of a range of cortical and subcortical motor areas as well as the corticospinal tract. These results will inform the appropriate methodology for predicting long term motor outcomes

  15. Morphologic and functional imaging of malignant pleural mesothelioma

    Energy Technology Data Exchange (ETDEWEB)

    Yamamuro, Masaki; Gerbaudo, Victor H.; Gill, Ritu R.; Jacobson, Francine L.; Sugarbaker, David J. [Department of Radiology and Surgery, Brigham and Women' s Hospital and Harvard Medical School, 75 Francis Street, Boston, MA 02115 (United States); Hatabu, Hiroto [Department of Radiology and Surgery, Brigham and Women' s Hospital and Harvard Medical School, 75 Francis Street, Boston, MA 02115 (United States)], E-mail: hhatabu@partners.org

    2007-12-15

    Malignant pleural mesothelioma (MPM) is an aggressive tumor that arises from the pleura and frequently extends to adjacent structures. MPM cells produce and respond to many angiogenic factors, such as vascular endothelial growth factor (VEGF). VEGF expression in MPM is correlated with microvascular density, which is associated with poor survival. CT has been widely used as the primary imaging modality for the clinical evaluation of MPM. Major findings include nodular pleural thickening, unilateral pleural effusion, and tumor invasion of adjacent structures. CT tends to underestimate early chest wall invasion and peritoneal involvement and has well-known limitations in the evaluation of lymph node metastases. Perfusion CT can evaluate the microvasculature of tumors, while its disadvantages, such as high radiation exposure or side effects from iodinated contrast, limit its use in both research and clinical settings. MRI can provide additional information to CT. Because of its excellent contrast resolution, MRI is superior to CT, both in the differentiation of malignant from benign pleural disease, and in the assessment of chest wall and diaphragmatic involvement. Perfusion MRI is the most promising technique for the assessment of the tumor microvasculature. In MPM, therapeutic effects of chemotherapy can be monitored with perfusion MRI. It has been shown that FDG-PET is useful for the differentiation of benign from malignant lesions, for staging and monitoring metabolic response to therapy against MPM, and that it has prognostic value. An initial report on PET/CT imaging of MPM has shown increased accuracy of overall staging, improving the assessment of tumor resectability. PET/CT seems to be superior to other imaging modalities in detecting more extensive disease involvement, and identifying unsuspected occult distant metastases.

  16. Ultrasound in Radiology: from Anatomic, Functional, Molecular Imaging to Drug Delivery and Image-Guided Therapy

    Science.gov (United States)

    Klibanov, Alexander L.; Hossack, John A.

    2015-01-01

    During the past decade, ultrasound has expanded medical imaging well beyond the “traditional” radiology setting - a combination of portability, low cost and ease of use makes ultrasound imaging an indispensable tool for radiologists as well as for other medical professionals who need to obtain imaging diagnosis or guide a therapeutic intervention quickly and efficiently. Ultrasound combines excellent ability for deep penetration into soft tissues with very good spatial resolution, with only a few exceptions (i.e. those involving overlying bone or gas). Real-time imaging (up to hundreds and thousands frames per second) enables guidance of therapeutic procedures and biopsies; characterization of the mechanical properties of the tissues greatly aids with the accuracy of the procedures. The ability of ultrasound to deposit energy locally brings about the potential for localized intervention encompassing: tissue ablation, enhancing penetration through the natural barriers to drug delivery in the body and triggering drug release from carrier micro- and nanoparticles. The use of microbubble contrast agents brings the ability to monitor and quantify tissue perfusion, and microbubble targeting with ligand-decorated microbubbles brings the ability to obtain molecular biomarker information, i.e., ultrasound molecular imaging. Overall, ultrasound has become the most widely used imaging modality in modern medicine; it will continue to grow and expand. PMID:26200224

  17. Non-suicidal self-injury in patients with eating disorders: prevalence, forms, functions, and body image correlates.

    Science.gov (United States)

    Pérez, Sandra; Marco, Jos H; Cañabate, Montse

    2018-04-12

    More than one third of patients with eating disorders report NSSI. Moreover, negative attitudes and feelings toward the body, body dissatisfaction, and body image disturbances have been linked to NSSI in community and clinical samples. However, there is a lack of studies exploring NSSI frequency and functions and the specific relationship between multidimensional body image dimensions and NSSI in eating disorder patients. First, we explored the frequency, types, and functions of NSSI in a sample of 226 Spanish female participants with eating disorders (ED). Second, we explored differences in NSSI and body image depending on the ED restrictive-purgative subtype; and third, we explored differences in body dissatisfaction, body image orientation, and body investment in eating disorder patients without NSSI (n = 144), with NSSI in their lifetime (n = 19), and (b) with NSSI in the previous year (n = 63). Of the overall sample, 37.1% (n = 89) had a history of self-injury during their lifetime, and 27.1% (n = 65) had self-injured in the previous year. Among the types of ongoing NSSI, the most frequent were banging (64.6%) and cutting (56.9%). Restrictive vs purgative patients differed on NSSI lifetime, Appearance Evaluation, Body Areas Satisfaction, Body Protection and Feelings and Attitudes toward the Body. Moreover, significant differences were found on Appearance Evaluation, Body Areas Satisfaction, Positive Feelings and Attitudes towards the Body, Body Protection, and Comfort with physical contact, between participants without a history of self-injury and both NSSI groups. Body dissatisfaction and body investment have been found to be variables related to NSSI. Thus, the present study highlights the importance of working on body image in ED patients to reduce the frequency of NSSI. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Image contrast enhancement through regional application of partitioned iterated function systems

    Science.gov (United States)

    Koutsouri, Georgia D.; Economopoulos, Theodore L.; Matsopoulos, George K.

    2013-01-01

    A new technique is presented for enhancing the contrast in digital images, combining the theory of partitioned iterated function system (PIFS) and image segmentation. The image is first segmented through the region growing segmentation technique, and the PIFS enhancement algorithm is applied separately to each image segment. The defined PIFS of each section is modeled by a contractive transformation, which consists of an affine spatial transform, as well as the linear transform of the graylevels of image segment pixels. The transformation of the graylevels is determined by two parameters that adjust the brightness and contrast of the transformed image segment. After the PIFS algorithm is applied to each extracted image segment, a lowpass version of the original image is created. The contrast-enhanced image is obtained by suitably combining the original image with its lowpass version. The proposed regional PIFS approach was applied to numerous test images, ranging from medical data of various modalities to standard images. The obtained quantitative and qualitative results showed superior performance on behalf of the proposed method when compared with three other widely used contrast enhancement methods, namely, contrast stretching, unsharp masking, and contrast-limited adaptive histogram equalization.

  19. Impaired emotion processing in functional (psychogenic tremor: A functional magnetic resonance imaging study

    Directory of Open Access Journals (Sweden)

    Alberto J. Espay

    2018-01-01

    Conclusions: In response to emotional stimuli, functional tremor is associated with alterations in activation and functional connectivity in networks involved in emotion processing and theory of mind. These findings may be relevant to the pathophysiology of functional movement disorders.

  20. Imaging insights into basal ganglia function, Parkinson’s disease, and dystonia

    OpenAIRE

    Stoessl, A. Jon; Lehericy, Stephane; Strafella, Antonio P.

    2014-01-01

    Recent advances in structural and functional imaging have greatly improved our ability to assess normal functions of the basal ganglia, diagnose parkinsonian syndromes, understand the pathophysiology of parkinsonism and other movement disorders, and detect and monitor disease progression. Radionuclide imaging is the best way to detect and monitor dopamine deficiency, and will probably continue to be the best biomarker for assessment of the effects of disease-modifying therapies. However, adva...

  1. Preoperative functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS)

    DEFF Research Database (Denmark)

    Hartwigsen, G.; Siebner, Hartwig R.; Stippich, C.

    2010-01-01

    of essential cortex, it cannot provide information preoperatively for surgical planning.Brain imaging techniques such as functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS) are increasingly being used to localize functionally critical cortical......, if the stimulated cortex makes a critical contribution to the brain functions subserving the task. While the relationship between task and functional activation as revealed by fMRI is correlative in nature, the neurodisruptive effect of TMS reflects a causal effect on brain activity.The use of preoperative f...

  2. Intraoperative Functional Ultrasound Imaging of Human Brain Activity.

    Science.gov (United States)

    Imbault, Marion; Chauvet, Dorian; Gennisson, Jean-Luc; Capelle, Laurent; Tanter, Mickael

    2017-08-04

    The functional mapping of brain activity is essential to perform optimal glioma surgery and to minimize the risk of postoperative deficits. We introduce a new, portable neuroimaging modality of the human brain based on functional ultrasound (fUS) for deep functional cortical mapping. Using plane-wave transmissions at an ultrafast frame rate (1 kHz), fUS is performed during surgery to measure transient changes in cerebral blood volume with a high spatiotemporal resolution (250 µm, 1 ms). fUS identifies, maps and differentiates regions of brain activation during task-evoked cortical responses within the depth of a sulcus in both awake and anaesthetized patients.

  3. Image Restoration Using Functional and Anatomical Information Fusion with Application to SPECT-MRI Images

    Directory of Open Access Journals (Sweden)

    S. Benameur

    2009-01-01

    Full Text Available Image restoration is usually viewed as an ill-posed problem in image processing, since there is no unique solution associated with it. The quality of restored image closely depends on the constraints imposed of the characteristics of the solution. In this paper, we propose an original extension of the NAS-RIF restoration technique by using information fusion as prior information with application in SPECT medical imaging. That extension allows the restoration process to be constrained by efficiently incorporating, within the NAS-RIF method, a regularization term which stabilizes the inverse solution. Our restoration method is constrained by anatomical information extracted from a high resolution anatomical procedure such as magnetic resonance imaging (MRI. This structural anatomy-based regularization term uses the result of an unsupervised Markovian segmentation obtained after a preliminary registration step between the MRI and SPECT data volumes from each patient. This method was successfully tested on 30 pairs of brain MRI and SPECT acquisitions from different subjects and on Hoffman and Jaszczak SPECT phantoms. The experiments demonstrated that the method performs better, in terms of signal-to-noise ratio, than a classical supervised restoration approach using a Metz filter.

  4. Resting-state functional magnetic resonance imaging for surgical planning in pediatric patients: a preliminary experience.

    Science.gov (United States)

    Roland, Jarod L; Griffin, Natalie; Hacker, Carl D; Vellimana, Ananth K; Akbari, S Hassan; Shimony, Joshua S; Smyth, Matthew D; Leuthardt, Eric C; Limbrick, David D

    2017-12-01

    OBJECTIVE Cerebral mapping for surgical planning and operative guidance is a challenging task in neurosurgery. Pediatric patients are often poor candidates for many modern mapping techniques because of inability to cooperate due to their immature age, cognitive deficits, or other factors. Resting-state functional MRI (rs-fMRI) is uniquely suited to benefit pediatric patients because it is inherently noninvasive and does not require task performance or significant cooperation. Recent advances in the field have made mapping cerebral networks possible on an individual basis for use in clinical decision making. The authors present their initial experience translating rs-fMRI into clinical practice for surgical planning in pediatric patients. METHODS The authors retrospectively reviewed cases in which the rs-fMRI analysis technique was used prior to craniotomy in pediatric patients undergoing surgery in their institution. Resting-state analysis was performed using a previously trained machine-learning algorithm for identification of resting-state networks on an individual basis. Network maps were uploaded to the clinical imaging and surgical navigation systems. Patient demographic and clinical characteristics, including need for sedation during imaging and use of task-based fMRI, were also recorded. RESULTS Twenty patients underwent rs-fMRI prior to craniotomy between December 2013 and June 2016. Their ages ranged from 1.9 to 18.4 years, and 12 were male. Five of the 20 patients also underwent task-based fMRI and one underwent awake craniotomy. Six patients required sedation to tolerate MRI acquisition, including resting-state sequences. Exemplar cases are presented including anatomical and resting-state functional imaging. CONCLUSIONS Resting-state fMRI is a rapidly advancing field of study allowing for whole brain analysis by a noninvasive modality. It is applicable to a wide range of patients and effective even under general anesthesia. The nature of resting

  5. Elemental and isotopic imaging to study biogeochemical functioning of intact soil micro-environments

    Science.gov (United States)

    Mueller, Carsten W.

    2017-04-01

    The complexity of soils extends from the ecosystem-scale to individual micro-aggregates, where nano-scale interactions between biota, organic matter (OM) and mineral particles are thought to control the long-term fate of soil carbon and nitrogen. It is known that such biogeochemical processes show disproportionally high reaction rates within nano- to micro-meter sized isolated zones ('hot spots') in comparison to surrounding areas. However, the majority of soil research is conducted on large bulk (> 1 g) samples, which are often significantly altered prior to analysis and analysed destructively. Thus it has previously been impossible to study elemental flows (e.g. C and N) between plants, microbes and soil in complex environments at the necessary spatial resolution within an intact soil system. By using nano-scale secondary ion mass spectrometry (NanoSIMS) in concert with other imaging techniques (e.g. scanning electron microscopy (SEM) and micro computed tomography (µCT)), classic analyses (isotopic and elemental analysis) and biochemical methods (e.g. GC-MS) it is possible to exhibit a more complete picture of soil processes at the micro-scale. I will present exemplarily results about the fate and distribution of organic C and N in complex micro-scale soil structures for a range of intact soil systems. Elemental imaging was used to study initial soil formation as an increase in the structural connectivity of micro-aggregates. Element distribution will be presented as a key to detect functional spatial patterns and biogeochemical hot spots in macro-aggregate functioning and development. In addition isotopic imaging will be demonstrated as a key to trace the fate of plant derived OM in the intact rhizosphere from the root to microbiota and mineral soil particles. Especially the use of stable isotope enrichment (e.g. 13CO2, 15NH4+) in conjunction with NanoSIMS allows to directly trace the fate of OM or nutrients in soils at the relevant scale (e.g. assimilate C

  6. Null functions in three-dimensional imaging of alpha and beta particles.

    Science.gov (United States)

    Ding, Yijun; Caucci, Luca; Barrett, Harrison H

    2017-11-17

    Null functions of an imaging system are functions in the object space that give exactly zero data. Hence, they represent the intrinsic limitations of the imaging system. Null functions exist in all digital imaging systems, because these systems map continuous objects to discrete data. However, the emergence of detectors that measure continuous data, e.g. particle-processing (PP) detectors, has the potential to eliminate null functions. PP detectors process signals produced by each particle and estimate particle attributes, which include two position coordinates and three components of momentum, as continuous variables. We consider Charged-Particle Emission Tomography (CPET), which relies on data collected by a PP detector to reconstruct the 3D distribution of a radioisotope that emits alpha or beta particles, and show empirically that the null functions are significantly reduced for alpha particles if ≥3 attributes are measured or for beta particles with five attributes measured.

  7. Imaging vascular function for early stage clinical trials using dynamic contrast-enhanced magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Leach, M.O.; Orton, M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Cancer Research UK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Morgan, B. [Univ. of Leicester, College of Medicine, Biological Sciences and Psychology, Leicester (United Kingdom); Tofts, P.S. [Brighton and Sussex Medical School, Univ. of Sussex, Clinical Imaging Sciences Centre, Sussex (United Kingdom); Buckley, D.L. [University of Leeds, Division of Medical Physics, Leeds (United Kingdom); Huang, W. [Oregon Health and Science Univ., Advanced Imaging Research Centre, Portland, OR (United States); Horsfield, M.A. [Medical Physics Section, Leicester Royal Infirmary, Dept. of Cardiovascular Sciences, Leicester (United Kingdom); Chenevert, T.L. [Univ. of Michigan Health System, Ann Arbor, MI (United States); Collins, D.J. [Royal Marsden Hospital NHS Foundation Trust, Cancer Research UK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Jackson, A. [Univ. of Manchester, Wolfson Molecular Imaging Centre, Withington, Manchester, M20 3LJ (United Kingdom); Lomas, D. [Univ. of Cambridge, Dept. of Radiology, Cambridge (United Kingdom); Whitcher, B. [Unit 2 Greenways Business Park, Mango Solutions, Chippenham (United Kingdom); Clarke, L. [Cancer Imaging Program, Imaging Technology Development Branch, Rockville, MD (United States); Plummer, R. [Univ. of Newcastle Upon Tyne, The Medical School, Medical Oncology, Northern Inst. for Cancer Research, Newcastle Upon Tyne (United Kingdom); Judson, I. [Royal Marsden Hospital, Sutton, Surrey (United Kingdom); Jones, R. [Beatson West of Scotland Cancer Centre, Glasgow (United Kingdom); Alonzi, R. [Mount Vernon Cancer Centre, Northwood (United Kingdom); Brunner, T. [Gray Inst. for Radiation, Oncology and Biology, Oxford (United Kingdom); Koh, D.M. [Royal Marsden NHS Foundation Trust, Diagnostic Radiology, Sutton, Surrey (United Kingdom)] [and others

    2012-07-15

    Many therapeutic approaches to cancer affect the tumour vasculature, either indirectly or as a direct target. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important means of investigating this action, both pre-clinically and in early stage clinical trials. For such trials, it is essential that the measurement process (i.e. image acquisition and analysis) can be performed effectively and with consistency among contributing centres. As the technique continues to develop in order to provide potential improvements in sensitivity and physiological relevance, there is considerable scope for between-centre variation in techniques. A workshop was convened by the Imaging Committee of the Experimental Cancer Medicine Centres (ECMC) to review the current status of DCE-MRI and to provide recommendations on how the technique can best be used for early stage trials. This review and the consequent recommendations are summarised here. (orig.)

  8. A multicentre year-long randomised controlled trial of exercise training targeting physical functioning in men with prostate cancer previously treated with androgen suppression and radiation from TROG 03.04 RADAR.

    Science.gov (United States)

    Galvão, Daniel A; Spry, Nigel; Denham, James; Taaffe, Dennis R; Cormie, Prue; Joseph, David; Lamb, David S; Chambers, Suzanne K; Newton, Robert U

    2014-05-01

    Long-term prostate cancer (PCa) survivors are at increased risk for comorbidities and physical deconditioning. To determine the effectiveness of a year-long randomised controlled trial of exercise training in PCa survivors >5 yr postdiagnosis on physical functioning. Between 2010 and 2011, 100 long-term PCa survivors from Trans-Tasman Radiation Oncology Group 03.04 Randomised Androgen Deprivation and Radiotherapy previously treated with androgen-deprivation therapy and radiation therapy were randomly assigned to 6 mo of supervised exercise followed by 6 mo of a home-based maintenance programme (n=50) or printed educational material about physical activity (n=50) for 12 mo across 13 university-affiliated exercise clinics in Australia and New Zealand. Supervised resistance and aerobic exercise or printed educational material about physical activity. The primary end point was a 400-m walk as a measure of cardiovascular fitness. Secondary end points were physical function, patient-reported outcomes, muscle strength, body composition, and biomarkers. Analysis of covariance was used to compare outcomes for groups at 6 and 12 mo adjusted for baseline values. Participants undergoing supervised exercise showed improvement in cardiorespiratory fitness performance at 6 mo (-19 s [p=0.029]) and 12 mo (-13 s [p=0.028]) and better lower-body physical function across the 12-mo period (pphysical functioning at 6 (p=.006) and 12 mo (p=0.002), appendicular skeletal muscle at 6 mo (p=0.019), and objective measures of muscle strength at 6 and 12 mo (pphysical functioning measures, and inclusion of well-functioning individuals. Supervised exercise training in long-term PCa survivors is more effective than physical activity educational material for increasing cardiorespiratory fitness, physical function, muscle strength, and self-reported physical functioning at 6 mo. Importantly, these benefits were maintained in the long term with a home-based programme with follow-up at 12 mo. The

  9. [Effect of spectrum distortion on modulation transfer function in imaging fiber-optic spectrometer].

    Science.gov (United States)

    Cheng, Xin; Wang, Jing; Zhang, Bao; Hong, Yong-Feng

    2011-10-01

    Imaging fiber bundles were introduced to dispersion imaging spectrometer and substituted for slit, connecting the telescope and spectrometer to yield the imaging fiber-optic spectrometer. It is a double sampling system, the misalignment between image of optical fiber and detector pixel has arisen because of the spectrum distortion of spectrometer, which affected the second sampling process, and the modulation transfer function (MTF) therefore degraded. Optical transfer function of sampling process was derived from line spread function. The effect of spectrum distortion on system MTF was analyzed, and a model evaluating the MTF of imaging fiber-optic spectrometer was developed. Compared to the computation model of MTF of slit imaging spectrometer, a MTF item of sampling by optical fiber and a MTF item of misalignment arising from spectrum distortion were added in this model. Employing this, the MTF of an airborne imaging fiber-optic spectrometer for visible near infrared band was evaluated. The approach ro deriving and developing the MTF model has a reference signification for the computation of MTF of double sampling system, which can direct the design of imaging fiber-optic spectrometer also.

  10. Non-invasive imaging in detecting myocardial viability: Myocardial function versus perfusion

    Directory of Open Access Journals (Sweden)

    Iqbal A. Elfigih

    2014-12-01

    Full Text Available Coronary artery disease (CAD is the most prevalent and single most common cause of morbidity and mortality [1] with the resulting left ventricular (LV dysfunction an important complication. The distinction between viable and non-viable myocardium in patients with LV dysfunction is a clinically important issue among possible candidates for myocardial revascularization. Several available non-invasive techniques are used to detect and assess ischemia and myocardial viability. These techniques include echocardiography, radionuclide images, cardiac magnetic resonance imaging and recently myocardial computed tomography perfusion imaging. This review aims to distinguish between the available non-invasive imaging techniques in detecting signs of functional and perfusion viability and identify those which have the most clinical relevance in detecting myocardial viability in patients with CAD and chronic ischemic LV dysfunction. The most current available studies showed that both myocardial perfusion and function based on non-invasive imaging have high sensitivity with however wide range of specificity for detecting myocardial viability. Both perfusion and function imaging modalities provide complementary information about myocardial viability and no optimum single imaging technique exists that can provide very accurate diagnostic and prognostic viability assessment. The weight of the body of evidence suggested that non-invasive imaging can help in guiding therapeutic decision making in patients with LV dysfunction.

  11. Caffeine and cognition in functional magnetic resonance imaging.

    Science.gov (United States)

    Koppelstaetter, Florian; Poeppel, Thorsten D; Siedentopf, Christian M; Ischebeck, Anja; Kolbitsch, Christian; Mottaghy, Felix M; Felber, Stephan R; Jaschke, Werner R; Krause, Bernd J

    2010-01-01

    Caffeine has been consumed since ancient times due to its beneficial effects on attention, psychomotor function, and memory. Caffeine exerts its action mainly through an antagonism of cerebral adenosine receptors, although there are important secondary effects on other neurotransmitter systems. Recently, functional MRI (fMRI) entered the field of neuropharmacology to explore the intracerebral sites and mechanisms of action of pharmacological agents. However, as caffeine possesses vasoconstrictive properties it may interfere with the mechanisms underlying the functional contrast in fMRI. Yet, only a limited number of studies dealt with the effect of caffeine on measures in fMRI. Even fewer neuroimaging studies examined the effects that caffeine exerts on cognition: Portas and colleagues used fMRI in an attentional task under different levels of arousal (sleep deprivation or caffeine administration), concluding that the thalamus is involved in mediating the interaction of attention and arousal. Bendlin and colleagues found caffeine to stabilize the extent of neuronal activation in repetitive word stem completion, counteracting the general task practice effect. Recently, Koppelstaetter and colleagues assessed the effect of caffeine on verbal working memory demonstrating a modulatory effect of caffeine on brain regions (medial frontopolar and anterior cingulate cortex) that have been associated with attentional and executive functions. This review surveys and discusses neuroimaging findings on 1) how caffeine affects the contrast underlying fMRI techniques, particularly the blood oxygen level dependent contrast (BOLD fMRI), and 2) how caffeine operates on neuronal activity underlying cognition, to understand the effect of caffeine on behavior and its neurobiological underpinnings.

  12. Transfer function analysis of positron-emitting tracer imaging system (PETIS) data

    International Nuclear Information System (INIS)

    Keutgen, N.; Matsuhashi, S.; Mizuniwa, C.; Ito, T.; Fujimura, T.; Ishioka, N.S.; Watanabe, S.; Sekine, T.; Uchida, H.; Hashimoto, S.

    2002-01-01

    Quantitative analysis of the two-dimensional image data obtained with the positron-emitting tracer imaging system (PETIS) for plant physiology has been carried out using a transfer function analysis method. While a cut leaf base of Chinese chive (Allium tuberosum Rottler) or a cut stem of soybean (Glycine max L.) was immersed in an aqueous solution containing the [ 18 F] F - ion or [ 13 N]NO 3 - ion, tracer images of the leaf of Chinese chive and the trifoliate of soybean were recorded with PETIS. From the time sequence of images, the tracer transfer function was estimated from which the speed of tracer transport and the fraction moved between specified image positions were deduced

  13. Towards factor analysis exploration applied to positron emission tomography functional imaging for breast cancer characterization

    International Nuclear Information System (INIS)

    Rekik, W.; Ketata, I.; Sellami, L.; Ben slima, M.; Ben Hamida, A.; Chtourou, K.; Ruan, S.

    2011-01-01

    This paper aims to explore the factor analysis when applied to a dynamic sequence of medical images obtained using nuclear imaging modality, Positron Emission Tomography (PET). This latter modality allows obtaining information on physiological phenomena, through the examination of radiotracer evolution during time. Factor analysis of dynamic medical images sequence (FADMIS) estimates the underlying fundamental spatial distributions by factor images and the associated so-called fundamental functions (describing the signal variations) by factors. This method is based on an orthogonal analysis followed by an oblique analysis. The results of the FADMIS are physiological curves showing the evolution during time of radiotracer within homogeneous tissues distributions. This functional analysis of dynamic nuclear medical images is considered to be very efficient for cancer diagnostics. In fact, it could be applied for cancer characterization, vascularization as well as possible evaluation of response to therapy.

  14. MR imaging of non-functioning endocrine tumors of the pancreas

    International Nuclear Information System (INIS)

    Irie, Hiroyuki; Honda, Hiroshi; Kuroiwa, Toshiro

    2002-01-01

    The purpose of this study was to clarify the MR imaging characteristics of patients with non-functioning endocrine tumors of the pancreas. Fourteen patients with these tumors underwent MR imaging. The signal characteristics of the tumor on T 1 -, T 2 -, and contrast-enhanced T 1 -weighted images were evaluated. The enhancement pattern of the tumor on dynamic study was also examined. The degree of stromal fibrosis was evaluated on the pathologic specimen, and was then classified as mild, moderate, or marked fibrosis. On T 1 -weighted images, the tumors were hypointense in 12 of 14 cases. The signals of the tumors on T 2 -weighted images were varied. The tumors were hypointense in 1 case, isointense in 2 cases, hyperintense in 6 cases, and very hyperintense in the other 5 cases. On contrast-enhanced T 1 -weighted images, the tumors were hyperintense in 8 cases and very hyperintense in 5 cases. On T 2 - and contrast-enhanced T 1 -weighted images, 4 of 5 malignant tumors were very hyperintense. Dynamic study revealed prolonged enhancement in 10 of 11 cases. Pathologic analysis revealed moderate or marked fibrosis in 10 of 14 cases, and prolonged enhancement was considered to be related stromal fibrosis. In conclusion, MR imaging findings of non-functioning endocrine tumors of the pancreas vary in relation to pathological variety. Prolonged enhancement of the tumor on dynamic study is considered to be one of the characteristic MR imaging findings that corresponds to stromal fibrosis of the tumor. (author)

  15. Spectral contrast-enhanced optical coherence tomography for improved detection of tumor microvasculature and functional imaging of lymphatic drainage

    Science.gov (United States)

    SoRelle, Elliott D.; Liba, Orly; Sen, Debasish; de la Zerda, Adam

    2017-03-01

    Optical Coherence Tomography (OCT) is well-suited to study in vivo dynamics of blood circulation and lymphatic flow because of the technique's combination of rapid image acquisition, micron spatial resolution, and penetration depth in turbid tissues. However, OCT has been historically constrained by a dearth of contrast agents that are readily distinguished from the strong scattering intrinsic to biological tissues. In this study, we demonstrate large gold nanorods (LGNRs) as optimized contrast agents for OCT. LGNRs produce 32-fold greater backscattering than GNRs previously tested for contrast-enhanced OCT. Furthermore, LGNRs exhibit 110-fold stronger spectral signal than conventional GNRs when coupled with custom spectral detection algorithms. This signal enhancement enables picomolar OCT detection sensitivity in vivo and single-particle detection against optically-clear backgrounds. Moreover, the ability to synthesize LGNRs with tunable spectral peaks provides a viable platform for multiplexed imaging studies. To explore the advantages of LGNRs as OCT contrast agents, we implemented them for noninvasive 3D imaging of tumor blood supply and active lymphatic drainage in mice. Spectral detection of LGNRs enabled 100% improvement in imaging depth for detecting microvasculature (vessels 20 μm in diameter) in U87MG glioblastoma xenografts in mice pinnae. We also demonstrated our approach's ability to map the spatial dependence of lymph drainage and flow directionality within lymphatic capillaries. Using LGNRs with distinct spectra, we further identified the functional states of individual lymphatic valves in vivo. Thus, this approach provides a powerful new platform for functional imaging that may be extended for future molecular imaging studies with OCT.

  16. B-Spline potential function for maximum a-posteriori image reconstruction in fluorescence microscopy

    Directory of Open Access Journals (Sweden)

    Shilpa Dilipkumar

    2015-03-01

    Full Text Available An iterative image reconstruction technique employing B-Spline potential function in a Bayesian framework is proposed for fluorescence microscopy images. B-splines are piecewise polynomials with smooth transition, compact support and are the shortest polynomial splines. Incorporation of the B-spline potential function in the maximum-a-posteriori reconstruction technique resulted in improved contrast, enhanced resolution and substantial background reduction. The proposed technique is validated on simulated data as well as on the images acquired from fluorescence microscopes (widefield, confocal laser scanning fluorescence and super-resolution 4Pi microscopy. A comparative study of the proposed technique with the state-of-art maximum likelihood (ML and maximum-a-posteriori (MAP with quadratic potential function shows its superiority over the others. B-Spline MAP technique can find applications in several imaging modalities of fluorescence microscopy like selective plane illumination microscopy, localization microscopy and STED.

  17. Multimodality Cardiac Imaging for the Assessment of Left Atrial Function and the Association With Atrial Arrhythmias

    DEFF Research Database (Denmark)

    Olsen, Flemming Javier; Bertelsen, Litten; de Knegt, Martina Chantal

    2016-01-01

    Several cardiac imaging modalities are able to visualize the left atrium (LA) and, therefore, allow for quantification of both structural and functional properties of this cardiac chamber. In echocardiography, only the maximal LA volume is included in the assessment of diastolic function at the c......Several cardiac imaging modalities are able to visualize the left atrium (LA) and, therefore, allow for quantification of both structural and functional properties of this cardiac chamber. In echocardiography, only the maximal LA volume is included in the assessment of diastolic function...... atrial fibrillation, which will be a point of focus in this review. Pivotal cardiac magnetic resonance imaging studies have revealed high correlation between LA fibrosis and risk of atrial fibrillation recurrence after catheter ablation, and subsequent multimodality imaging studies have uncovered...... an inverse relationship between LA reservoir function and degree of LA fibrosis. This has sparked an increased interest into the application of advanced imaging modalities, including both speckle tracking echocardiography and tissue tracking by cardiac magnetic resonance imaging. Even though increasing...

  18. Brand Image as a Function of Self-Image and Self-Brand Connection

    Directory of Open Access Journals (Sweden)

    Rares MOCANU

    2014-02-01

    Full Text Available This study investigates how brand image relates to self-image and how brand consumption contributes to the construction of self. Most of the research on brand image refers to brand attitudes. Day (1970 considers attitudes "a central integrating feature” in marketing theory and advertising evaluation. Gardner (1985, p.197 studied differences in brand attitudes as they relate to advertisements, finding attitude toward an advertisement affects attitude toward the advertised brand as much under a brand evaluation set as under a non-brand evaluation set. The present study goes beyond Gardner's research to show why such attitudes exist as they relate to brand consumption and self-image. Erickson and Johansson (1985 also investigated product evaluations, with an analysis of surveyed beliefs, attitudes, and intentions regarding fashion brands. They concluded that price is not a significant determinant of overall attitude. This study inquires whether brand attitudes and beliefs correlate with purchase behavior in the form of self-brand connection.

  19. Quantitative functional optical imaging of the human skin using multi-spectral imaging

    International Nuclear Information System (INIS)

    Kainerstorfer, J. M.

    2010-01-01

    Light tissue interactions can be described by the physical principles of absorption and scattering. Based on those parameters, different tissue types and analytes can be distinguished. Extracting blood volume and oxygenation is of particular interest in clinical routines for tumor diagnostics and treatment follow up, since they are parameters of angiogenic processes. The quantification of those analytes in tissue can be done by physical modeling of light tissue interaction. The physical model used here is the random walk theory. However, for quantification and clinical usefulness, one has to account for multiple challenges. First, one must consider the effect of topology of the sample on measured physical parameters. Second, diffusion of light inside the tissue is dependent on the structure of the sample imaged. Thus, the structural conformation has to be taken into account. Third, clinical translation of imaging modalities is often hindered due to the complicated post-processing of data, not providing results in real-time. In this thesis, two imaging modalities are being utilized, where the first one, diffuse multi-spectral imaging, is based on absorption contrast and spectral characteristics and the second one, Optical Coherence Tomography (OCT), is based on scattering changes within the tissue. Multi-spectral imaging can provide spatial distributions of blood volume and blood oxygenation and OCT yields 3D structural images with micrometer resolution. In order to address the challenges mentioned above, a curvature correction algorithm for taking the topology into account was developed. Without taking curvature of the object into account, reconstruction of optical properties is not accurate. The method developed removes this artifact and recovers the underlying data, without the necessity of measuring the object's shape. The next step was to recover blood volume and oxygenation values in real time. Principal Component Analysis (PCA) on multi spectral images is

  20. Resolution enhancement in active underwater polarization imaging with modulation transfer function analysis.

    Science.gov (United States)

    Han, Jiefei; Yang, Kecheng; Xia, Min; Sun, Liying; Cheng, Zao; Liu, Hao; Ye, Junwei

    2015-04-10

    Active polarization imaging technology is a convenient and promising method for imaging in a scattering medium such as fog and turbid water. However, few studies have investigated the influence of polarization on the resolution in underwater imaging. This paper reports on the effects of polarization detection on the resolution of underwater imaging by using active polarization imaging technology. An experimental system is designed to determine the influence under various polarization and water conditions. The modulation transfer function is introduced to estimate the resolution variations at different spatial frequencies. Results show that orthogonal detection supplies the best resolution compared with other polarization directions in the turbid water. The performance of the circular polarization method is better than the linear process. However, if the light propagates under low scattering conditions, such as imaging in clean water or at small optical thickness, the resolution enhancement is not sensitive to the polarization angles.

  1. Atomic Resolution Imaging and Quantification of Chemical Functionality of Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Udo D. [Yale Univ., New Haven, CT (United States). Dept. of Mechanical Engineering and Materials Science; Altman, Eric I. [Yale Univ., New Haven, CT (United States). Dept. of Chemical and Environmental Engineering

    2014-12-10

    The work carried out from 2006-2014 under DoE support was targeted at developing new approaches to the atomic-scale characterization of surfaces that include species-selective imaging and an ability to quantify chemical surface interactions with site-specific accuracy. The newly established methods were subsequently applied to gain insight into the local chemical interactions that govern the catalytic properties of model catalysts of interest to DoE. The foundation of our work was the development of three-dimensional atomic force microscopy (3DAFM), a new measurement mode that allows the mapping of the complete surface force and energy fields with picometer resolution in space (x, y, and z) and piconewton/millielectron volts in force/energy. From this experimental platform, we further expanded by adding the simultaneous recording of tunneling current (3D-AFM/STM) using chemically well-defined tips. Through comparison with simulations, we were able to achieve precise quantification and assignment of local chemical interactions to exact positions within the lattice. During the course of the project, the novel techniques were applied to surface-oxidized copper, titanium dioxide, and silicon oxide. On these materials, defect-induced changes to the chemical surface reactivity and electronic charge density were characterized with site-specific accuracy.

  2. Comparison of magnetoencephalography with other functional imaging techniques.

    Science.gov (United States)

    Ioannides, A A

    1991-01-01

    Recent advances in instrumentation and analysis in biomagnetism offer a unique tool for studying the spatiotemporal evolution of spontaneous brain activity as well as activity evoked by a stimulus. The overall performance characteristics of this and other techniques used to study the dynamics of brain function are compared. Particular emphasis is placed on defining the general spatiotemporal window of brain activity that each technique makes accessible. Similarities and differences associated with diverse modelling schemes for extracting source current density properties from electrographic recordings are stated.

  3. Functional imaging of the brain with18F-fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Reivich, M.; Greenberg, J.; Alavi, A.; Hand, P.; Rintelmann, W.; Rosenquist, A.; Christman, D.; Fowler, J.; MacGregor, R.; Wolf, A.

    1980-01-01

    A techniques is reported by which it is possible to determine which regions of the human brain become functionally active in response to a specific stimulus. The method utilizes 18 F-2-fluoro-2-deoxyglucose ([ 18 F]-FDG) administered as a bolus. [ 18 F]-FDG is used as a tracer for the exchange of glucose between plasma and brain and its phosphorylation. The subject is then scanned during administration of a physiologic stimulus by position emission tomography and the three-dimensional distribution of 18 F activity in the brain determined

  4. Functional magnetic resonance imaging and dementia; Funktionelle Magnetresonanztomographie und Demenz

    Energy Technology Data Exchange (ETDEWEB)

    Giesel, F.L. [Abteilung fuer onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum (dkfz) Heidelberg (Germany); Abteilung fuer onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum (dkfz), Im Neuenheimer Feld 280, 69120, Heidelberg (Germany); Hempel, A.; Schoenknecht, P.; Schroeder, J. [Sektion Gerontopsychiatrie, Psychiatrische Universitaetsklinik Heidelberg (Germany); Wuestenberg, T. [Neurologische Klinik der Charite, Humboldt-Universitaet Berlin (Germany); Weber, M.A.; Essig, M. [Abteilung fuer onkologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum (dkfz) Heidelberg (Germany)

    2003-07-01

    Currently, different cerebral neuroimaging methods are being applied to varying questions in the diagnosis of dementia. In patients with manifest Alzheimer's disease a reduction of cortical perfusion and metabolism in temporal and temporoparietal regions has been demonstrated when compared to healthy controls on a diversity of memory tasks. Since differing levels of performance and varying degrees of cortical atrophy may influence functional results considerably, an understanding of the processes associated with normal ageing is perceived as prerequisite for studies applying functional neuroimaging. The integration of knowledge concerning neuropsychological and neurobiological alterations associated with healthy ageing allows hypotheses for the differentiation of pathological ageing processes to be phrased. In this connection non-invasive methods such as fMRI and ASL are of increasing importance. (orig.) [German] In der zerebralen Bildgebung werden heute verschiedene Methoden zu einzelnen Fragestellungen in der Demenzdiagnostik mit unterschiedlichem Stellenwert eingesetzt. Bei Patienten mit manifester Alzheimer-Demenz wurde eine Verminderung der kortikalen Durchblutung bzw. des zerebralen Glukoseumsatzes in temporalen Strukturen und im temporoparietalen Uebergang im Vergleich zu Gesunden unter verschiedenen Gedaechtnisaufgaben nachgewiesen. Da unterschiedliche Testleistungen und unterschiedliche Auspraegungen der kortikalen Atrophie die funktionellen Befunde wesentlich beeinflussen, wird das Verstaendnis der normalen Alterungsprozesse als Voraussetzung fuer neuere Studien mittels funktioneller Bildgebung angesehen. Die Integration der Kenntnisse ueber neuropsychologische und neurobiologische Veraenderungen gesunden Alterns erlaubt Hypothesen zur Differenzierung pathologischer Alterungsprozesse. Dabei nehmen heute die nichtinvasiven Verfahren wie fMRT und ASL einen zunehmenden Stellenwert ein. (orig.)

  5. Measurement of the presampled two-dimensional modulation transfer function of digital imaging systems

    International Nuclear Information System (INIS)

    Fetterly, Kenneth A.; Hangiandreou, Nicholas J.; Schueler, Beth A.; Ritenour, E. Russell

    2002-01-01

    The purpose of this work was to develop methods to measure the presampled two-dimensional modulation transfer function (2D MTF) of digital imaging systems. A custom x-ray 'point source' phantom was created by machining 256 holes with diameter 0.107 mm through a 0.5-mm-thick copper plate. The phantom was imaged several times, resulting in many images of individual x-ray 'spots'. The center of each spot (with respect to the pixel matrix) was determined to subpixel accuracy by fitting each spot to a 2D Gaussian function. The subpixel spot center locations were used to create a 5x oversampled system point spread function (PSF), which characterizes the optical and electrical properties of the system and is independent of the pixel sampling of the original image. The modulus of the Fourier transform of the PSF was calculated. Next, the Fourier function was normalized to the zero frequency value. Finally, the Fourier transform function was divided by the first-order Bessel function that defined the frequency content of the holes, resulting in the presampled 2D MTF. The presampled 2D MTF of a 0.1 mm pixel pitch computed radiography system and 0.2 mm pixel pitch flat panel digital imaging system that utilized a cesium iodide scintillator was measured. Comparison of the axial components of the 2D MTF to one-dimensional MTF measurements acquired using an edge device method demonstrated that the two methods produced consistent results

  6. Resting-state functional connectivity imaging of the mouse brain using photoacoustic tomography

    Science.gov (United States)

    Nasiriavanaki, Mohammadreza; Xia, Jun; Wan, Hanlin; Bauer, Adam Q.; Culver, Joseph P.; Wang, Lihong V.

    2014-03-01

    Resting-state functional connectivity (RSFC) imaging is an emerging neuroimaging approach that aims to identify spontaneous cerebral hemodynamic fluctuations and their associated functional connections. Clinical studies have demonstrated that RSFC is altered in brain disorders such as stroke, Alzheimer's, autism, and epilepsy. However, conventional neuroimaging modalities cannot easily be applied to mice, the most widely used model species for human brain disease studies. For instance, functional magnetic resonance imaging (fMRI) of mice requires a very high magnetic field to obtain a sufficient signal-to-noise ratio and spatial resolution. Functional connectivity mapping with optical intrinsic signal imaging (fcOIS) is an alternative method. Due to the diffusion of light in tissue, the spatial resolution of fcOIS is limited, and experiments have been performed using an exposed skull preparation. In this study, we show for the first time, the use of photoacoustic computed tomography (PACT) to noninvasively image resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight regions, as well as several subregions. These findings agreed well with the Paxinos mouse brain atlas. This study showed that PACT is a promising, non-invasive modality for small-animal functional brain imaging.

  7. Neural correlates of simple unimanual discrete and continuous movements: a functional imaging study at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Habas, Christophe; Cabanis, Emmanuel A. [Hopital des Quinze-Vingts, UPMC Paris 6, Service de NeuroImagerie, Paris (France)

    2008-04-15

    The cerebral and cerebellar network involved in unimanual continuous and discrete movements was studied in blood oxygenation level-dependent functional magnetic resonance imaging (fMRI) at 3 T. Seven healthy right-handed volunteers were scanned (1) while drawing a circle with the tip of the right index finger (continuous motor task), and (2) while drawing a triangle with the tip of the right index finger (discrete motor task). In both motor tasks, extensive activations were observed in the sensorimotor (M1/S1), parietal, prefrontal, insular, lateral occipital (LOC) and anterior cerebellar cortices. Subcortical activations within red, thalamic and lentiform nuclei were also detected. However, discrete movements were specifically followed by the recruitment of the left orbitofrontal cortex, right dentate nucleus and the second cerebellar homunculus (HVIII), and bilateral and stronger activation of the sensorimotor cortical areas, whereas continuous movements specifically activated the right prefrontal cortex and the lateral hemispherical part of the neocerebellum (crus 1). We confirm the findings of previous studies showing partly distinct neural networks involved in monitoring continuous and discrete movements, but we found new differential neural relays within the prefrontal, insular and neocerebellar cortices. (orig.)

  8. In the mind’s eye: Provider and patient attitudes on functional brain imaging

    Science.gov (United States)

    Illes, J.; Lombera, S.; Rosenberg, J.; Arnow, B.

    2008-01-01

    Success in functional neuroimaging has brought the promise of quantitative data in the form of brain images to the diagnosis of disorders of the central nervous system for which only qualitative clinical criteria have previously existed. Even though the translation of research to clinical neuroimaging for conditions such as major depression may not be available yet, rapid innovation along this trajectory of discovery to implementation compels exploration of how such information will eventually affect providers and patients. Clinical neuroethics is devoted to elucidating ethical challenges prior to and during the transfer of new research capabilities to the bedside. Through a model of proactive ethics, clinical neuroethics promotes the development of responsible social and public policies in response to new diagnostic and prognostic capabilities for the benefit of patients and their families, and for providers within the health care systems in which they practice. To examine views about the potential interaction of clinical neuroimaging and depression, we surveyed both mental health providers and outpatients and inpatients diagnosed with major depressive disorder. From responses of 52 providers and 72 patients, we found high receptivity to brain scans for treatment tailoring and choice, for improving understanding of and coping with disease, and for mitigating the effects of stigma and self-blame. Our results suggest that, once ready, roll out of the fully validated technology has significant potential to reduce social burden associated with highly stigmatized illnesses like depression. PMID:18423669

  9. An agent harms a victim: A functional magnetic resonance imaging study on specific moral emotions

    International Nuclear Information System (INIS)

    Kedia, G.; Kedia, G.; Martinot, J.L.; Kedia, G.; Martinot, J.L.; Kedia, G.; Hilton, D.; Berthoz, S.; Wessa, M.

    2008-01-01

    The statement 'An agent harms a victim' depicts a situation that triggers moral emotions. Depending on whether the agent and the victim are the self or someone else, it can lead to four different moral emotions: self-anger ('I harm myself'), guilt ('I harm someone'), other-anger ('someone harms me'), and compassion ('someone harms someone'). In order to investigate the neural correlates of these emotions, we examined brain activation patterns elicited by variations in the agent (self vs. other) and the victim (self vs. other) of a harmful action. Twenty-nine healthy participants underwent functional magnetic resonance imaging while imagining being in situations in which they or someone else harmed themselves or someone else. Results indicated that the three emotional conditions associated with the involvement of other, either as agent or victim (guilt, other-anger, and compassion conditions), all activated structures that have been previously associated with the Theory of Mind (ToM, the attribution of mental states to others), namely, the dorsal medial prefrontal cortex, the precuneus, and the bilateral temporo-parietal junction. Moreover, the two conditions in which both the self and other were concerned by the harmful action (guilt and other-anger conditions) recruited emotional structures (i. e., the bilateral amygdala, anterior cingulate, and basal ganglia). These results suggest that specific moral emotions induce different neural activity depending on the extent to which they involve the self and other. (authors)

  10. EVALUATION OF RATIONAL FUNCTION MODEL FOR GEOMETRIC MODELING OF CHANG'E-1 CCD IMAGES

    Directory of Open Access Journals (Sweden)

    Y. Liu

    2012-08-01

    Full Text Available Rational Function Model (RFM is a generic geometric model that has been widely used in geometric processing of high-resolution earth-observation satellite images, due to its generality and excellent capability of fitting complex rigorous sensor models. In this paper, the feasibility and precision of RFM for geometric modeling of China's Chang'E-1 (CE-1 lunar orbiter images is presented. The RFM parameters of forward-, nadir- and backward-looking CE-1 images are generated though least squares solution using virtual control points derived from the rigorous sensor model. The precision of the RFM is evaluated by comparing with the rigorous sensor model in both image space and object space. Experimental results using nine images from three orbits show that RFM can precisely fit the rigorous sensor model of CE-1 CCD images with a RMS residual error of 1/100 pixel level in image space and less than 5 meters in object space. This indicates that it is feasible to use RFM to describe the imaging geometry of CE-1 CCD images and spacecraft position and orientation. RFM will enable planetary data centers to have an option to supply RFM parameters of orbital images while keeping the original orbit trajectory data confidential.

  11. Comparing Fourier optics and contrast transfer function modeling of image formation in low energy electron microscopy.

    Science.gov (United States)

    Yu, K M; Locatelli, A; Altman, M S

    2017-12-01

    A theoretical understanding of image formation in cathode lens microscopy can facilitate image interpretation. We compare Fourier Optics (FO) and Contrast Transfer Function (CTF) approaches that were recently adapted from other realms of microscopy to model image formation in low energy electron microscopy (LEEM). Although these two approaches incorporate imaging errors from several sources similarly, they differ in the way that the image intensity is calculated. The simplification that is used in the CTF calculation advantageously leads to its computational efficiency. However, we find that lens aberrations, and spatial and temporal coherence may affect the validity of the CTF approach to model LEEM image formation under certain conditions. In particular, these effects depend strongly on the nature of the object being imaged and also become more pronounced with increasing defocus. While the use of the CTF approach appears to be justified for objects that are routinely imaged with LEEM, comparison of theory to experimental observations of a focal image series for rippled, suspended graphene reveals one example where FO works, but CTF does not. This work alerts us to potential pitfalls and guides the effective use of FO and CTF approaches. It also lays the foundation for quantitative image evaluation using these methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. An image enhancement technique using nonlinear transfer function and unsharp masking in multispectral endoscope

    Science.gov (United States)

    Zhang, Kejian; Wang, Huan; Yuan, Bo; Wang, Liqiang

    2017-01-01

    This paper studies the realization of image processing algorithm of multispectral endoscope. The research contents include: local brightness enhancement and adaptive contrast enhancement. Firstly, this paper transforms the image from the RGB space to the HSV space, and then carries on the image enhancement processing to the V space, finally transforms to the RGB space. Local brightness enhancement algorithm divides V space image into smaller windows, and then calculates the nonlinear transfer function of each window, which enhances the pixels in the window, and finally the contrast of brightness enhanced image is restored. The adaptive contrast enhancement adopts the unsharp mask technique based on the guided filter. First of all, this paper uses guided filter to the RGB channel of the original image and gets the unsharp mask of each channel, then plus a scaled image which is the result of the original image subtracts the unsharp mask. So the enhancement of the image is achieved. This paper uses subjective evaluation criteria and enhance factor α to evaluate the effect of enhancement. And this paper compares the enhancement effect of the proposed image enhancement algorithm and the traditional algorithm. The results show that the α of histogram equalization is smallest and AINDANE method is better than histogram equalization. The proposed method has the best α. The subjective evaluation also shows that the effect of HE is not satisfactory and the proposed method enhances the detail information tremendously. The subjective and objective criteria shows that the proposed method produces better enhancement effect.

  13. Diversity of radioprobes targeted to tumor angiogenesis on molecular functional imaging

    International Nuclear Information System (INIS)

    Lu Xia; Zhang Huabei

    2013-01-01

    Molecular functional imaging could visualize, characterize, and measure the bio- logical processes including tumor angiogenesis at the molecular and cellular levels in humans and other living systems. The molecular probes labeled by a variety of radionuclide used in the field of the nuclear medicine play pivotal roles in molecular imaging of tumor angiogenesis. However, the regulatory role of different probes in tumor angiogenesis has not been systematically illustrated. The current status of tumor angiogenesis imaging with radiolabeled probes of peptide, monoclonal antibody as well as its fragment, especially nanoparticle-based probes to gain insights into the robust tumor angiogenesis development were summarized. It was recognized that only the probes such as nanoparticle-based probes, which truly target the tumor vasculature rather than tumor cells because of poor extravasation, are really tumor angiogenesis imaging agent. The research of molecular probe targeted to angiogenesis would meet its flourish just after the outstanding improvements in the in vivo stability and biocompatibility, tumor-targeting efficacy, and pharmacokinetics of tumor angiogenesis imaging probes are made. Translation to clinical applications will also be critical for the maximize benefits of these novel agents. The future of tumor angiogenesis imaging lies in liable imaging probes and multiple imaging modalities, imaging of protein-protein interactions, and quantitative molecular imaging. (authors)

  14. Functional imaging in the Neuroscience. The role of PET, MR and SPECT

    International Nuclear Information System (INIS)

    Fulham, M.J.

    1998-01-01

    Full text: Functional imaging is commonly used to describe imaging techniques that provide data about aspects of tissue metabolism, such as glucose / protein metabolism, metabolite concentrations, neuro receptor density and blood flow / perfusion / diffusion when compared with the depiction of anatomy obtained with Computed Tomography (CT) and clinical Magnetic Resonance (MR) imaging. In the neuroscience this is a rapidly evolving area and unlike in the past where imaging of the nervous system was carried out by neuroradiologists participants in this dynamic field now come from diverse backgrounds and include basic scientists, clinicians, psychologists, physicists and chemists. PET and SPECT combine the principles of the tracer kinetic method and tomographic (as in CT) image reconstruction. A mathematical model can be derived to describe the biochemical process (in picomolar concentrations) under study and the raw counts of radioactivity that are detected by the scanner can be converted into units of physiological function in-vivo e.g. cerebral metabolic rate for glucose and receptor density. These techniques, using a variety of ligands, have been employed for evaluation of cerebral blood flow / volume, oxygen utilization / metabolism, glucose metabolism, amino acid transport / metabolism, protein synthesis, the dopaminergic, opiate, benzodiazepine, cholinergic and serotonergic systems and for brain mapping in humans. Meanwhile, the term 'functional MR imaging' encompasses MR spectroscopy, echoplanar imaging, diffusion tensor imaging and techniques that rely on the change in blood oxygenation levels to provide an indirect image of neuronal activity (referred to as fMRI). Unlike PET and SPECT, however, these data are obtained without using ionising radiation. In MRS, signals are obtained from nuclei (in mM concentrations) that are constituents of molecules other than water that provide the signal in clinical MR imaging; fibre tract directions have been depicted with

  15. Effective fuzzy c-means based kernel function in segmenting medical images.

    Science.gov (United States)

    Kannan, S R; Ramathilagam, S; Sathya, A; Pandiyarajan, R

    2010-06-01

    The objective of this paper is to develop an effective robust fuzzy c-means for a segmentation of breast and brain magnetic resonance images. The widely used conventional fuzzy c-means for medical image segmentations has limitations because of its squared-norm distance measure to measure the similarity between centers and data objects of medical images which are corrupted by heavy noise, outliers, and other imaging artifacts. To overcome the limitations this paper develops a novel objective function based standard objective function of fuzzy c-means that incorporates the robust kernel-induced distance for clustering the corrupted dataset of breast and brain medical images. By minimizing the novel objective function this paper obtains effective equation for optimal cluster centers and equation to achieve optimal membership grades for partitioning the given dataset. In order to solve the problems of clustering performance affected by initial centers of clusters, this paper introduces a specialized center initialization method for executing the proposed algorithm in segmenting medical images. Experiments are performed with synthetic, real breast and brain images to assess the performance of the proposed method. Further the validity of clustering results is obtained using silhouette method and this paper compares the results with the results of other recent reported fuzzy c-means methods. The experimental results show the superiority of the proposed clustering results. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Functional Principal Component Analysis and Randomized Sparse Clustering Algorithm for Medical Image Analysis

    Science.gov (United States)

    Lin, Nan; Jiang, Junhai; Guo, Shicheng; Xiong, Momiao

    2015-01-01

    Due to the advancement in sensor technology, the growing large medical image data have the ability to visualize the anatomical changes in biological tissues. As a consequence, the medical images have the potential to enhance the diagnosis of disease, the prediction of clinical outcomes and the characterization of disease progression. But in the meantime, the growing data dimensions pose great methodological and computational challenges for the representation and selection of features in image cluster analysis. To address these challenges, we first extend the functional principal component analysis (FPCA) from one dimension to two dimensions to fully capture the space variation of image the signals. The image signals contain a large number of redundant features which provide no additional information for clustering analysis. The widely used methods for removing the irrelevant features are sparse clustering algorithms using a lasso-type penalty to select the features. However, the accuracy of clustering using a lasso-type penalty depends on the selection of the penalty parameters and the threshold value. In practice, they are difficult to determine. Recently, randomized algorithms have received a great deal of attentions in big data analysis. This paper presents a randomized algorithm for accurate feature selection in image clustering analysis. The proposed method is applied to both the liver and kidney cancer histology image data from the TCGA database. The results demonstrate that the randomized feature selection method coupled with functional principal component analysis substantially outperforms the current sparse clustering algorithms in image cluster analysis. PMID:26196383

  17. Convex composite wavelet frame and total variation-based image deblurring using nonconvex penalty functions

    Science.gov (United States)

    Shen, Zhengwei; Cheng, Lishuang

    2017-09-01

    Total variation (TV)-based image deblurring method can bring on staircase artifacts in the homogenous region of the latent images recovered from the degraded images while a wavelet/frame-based image deblurring method will lead to spurious noise spikes and pseudo-Gibbs artifacts in the vicinity of discontinuities of the latent images. To suppress these artifacts efficiently, we propose a nonconvex composite wavelet/frame and TV-based image deblurring model. In this model, the wavelet/frame and the TV-based methods may complement each other, which are verified by theoretical analysis and experimental results. To further improve the quality of the latent images, nonconvex penalty function is used to be the regularization terms of the model, which may induce a stronger sparse solution and will more accurately estimate the relative large gradient or wavelet/frame coefficients of the latent images. In addition, by choosing a suitable parameter to the nonconvex penalty function, the subproblem that splits by the alternative direction method of multipliers algorithm from the proposed model can be guaranteed to be a convex optimization problem; hence, each subproblem can converge to a global optimum. The mean doubly augmented Lagrangian and the isotropic split Bregman algorithms are used to solve these convex subproblems where the designed proximal operator is used to reduce the computational complexity of the algorithms. Extensive numerical experiments indicate that the proposed model and algorithms are comparable to other state-of-the-art model and methods.

  18. Analysis of functional MR imaging patterns in adrenoleukodystrophy

    International Nuclear Information System (INIS)

    Lou Haiyan; Qi Jianpin; Xia Liming; Wei Hong; Wang Chengyuan; Luo Xiaoping

    2005-01-01

    Objective: To discuss the parallelism of signals in MR diffusion-weighted imaging (DWI) and metabolic abnormity in proton MR spectroscopy ( 1 HMRS) with pathologic and biochemical changes in adrenoleukodystrophy (ALD). Methods: DWI and 1 HMRS examination were performed in 6 cases with ALD proven by serum VLCFA, comparing ADC and relative ratio values of each metabolite in different regions of lesion with normal white matter. Results: Initial lesions in occipital-parietal lobes showed very low signals on DWI and the highest ADC values (2.400 x 10 -3 mm 2 /s, F=7.31, P=0.003), the ratios of NAA/Cr and NAA/Cho were lower (0.62 ±0.24, F=4.00, P=0.02; 0.32±0.16, F=6.75, P=0.02), and Cho/Cr and Lac/Cr were higher than normal white matter (1.96±0.53, F=3.53, P=0.03; 0.28±0.24, F=3.22, P=0.04). On expanding regions to frontal lobe, the signal became highest and ADC values was lowest [(0.749- 0.752) x 10 -3 mm 2 /s, F=7.31, P=0.003]. The depressed tendency of NAA/Cr and NAA/Cho in adjacent lesion was distinct than that of remote lesion (q 2 =-0.23, P 2 =0.047; q 2 =-0.23, P 2 =0.02). There was no significant difference in the increase of Cho/Cr and Lac/Cr ratios (q 2 =0.34, P 2 =0.19; q 2 =0.11, P 2 =0.17). Conclusion: MRS offers a useful method for dynamic observation of spatio-temporal changes in ALD. ADC values and choline, lactic acid levels increase in obsolete lesions whereas NAA levels decrease distinctly. In expanding lesion, ADC values decrease markedly, while the elevation of Choline and Lactic acid is not significant in adjacent region. NAA levels decrease moderately because of remnant neuron and axon. (authors)

  19. Automated Adaptive Brightness in Wireless Capsule Endoscopy Using Image Segmentation and Sigmoid Function.

    Science.gov (United States)

    Shrestha, Ravi; Mohammed, Shahed K; Hasan, Md Mehedi; Zhang, Xuechao; Wahid, Khan A

    2016-08-01

    Wireless capsule endoscopy (WCE) plays an important role in the diagnosis of gastrointestinal (GI) diseases by capturing images of human small intestine. Accurate diagnosis of endoscopic images depends heavily on the quality of captured images. Along with image and frame rate, brightness of the image is an important parameter that influences the image quality which leads to the design of an efficient illumination system. Such design involves the choice and placement of proper light source and its ability to illuminate GI surface with proper brightness. Light emitting diodes (LEDs) are normally used as sources where modulated pulses are used to control LED's brightness. In practice, instances like under- and over-illumination are very common in WCE, where the former provides dark images and the later provides bright images with high power consumption. In this paper, we propose a low-power and efficient illumination system that is based on an automated brightness algorithm. The scheme is adaptive in nature, i.e., the brightness level is controlled automatically in real-time while the images are being captured. The captured images are segmented into four equal regions and the brightness level of each region is calculated. Then an adaptive sigmoid function is used to find the optimized brightness level and accordingly a new value of duty cycle of the modulated pulse is generated to capture future images. The algorithm is fully implemented in a capsule prototype and tested with endoscopic images. Commercial capsules like Pillcam and Mirocam were also used in the experiment. The results show that the proposed algorithm works well in controlling the brightness level accordingly to the environmental condition, and as a result, good quality images are captured with an average of 40% brightness level that saves power consumption of the capsule.

  20. Classifying adolescent attention-deficit/hyperactivity disorder (ADHD) based on functional and structural imaging.

    Science.gov (United States)

    Iannaccone, Reto; Hauser, Tobias U; Ball, Juliane; Brandeis, Daniel; Walitza, Susanne; Brem, Silvia

    2015-10-01

    Attention-deficit/hyperactivity disorder (ADHD) is a common disabling psychiatric disorder associated with consistent deficits in error processing, inhibition and regionally decreased grey matter volumes. The diagnosis is based on clinical presentation, interviews and questionnaires, which are to some degree subjective and would benefit from verification through biomarkers. Here, pattern recognition of multiple discriminative functional and structural brain patterns was applied to classify adolescents with ADHD and controls. Functional activation features in a Flanker/NoGo task probing error processing and inhibition along with structural magnetic resonance imaging data served to predict group membership using support vector machines (SVMs). The SVM pattern recognition algorithm correctly classified 77.78% of the subjects with a sensitivity and specificity of 77.78% based on error processing. Predictive regions for controls were mainly detected in core areas for error processing and attention such as the medial and dorsolateral frontal areas reflecting deficient processing in ADHD (Hart et al., in Hum Brain Mapp 35:3083-3094, 2014), and overlapped with decreased activations in patients in conventional group comparisons. Regions more predictive for ADHD patients were identified in the posterior cingulate, temporal and occipital cortex. Interestingly despite pronounced univariate group differences in inhibition-related activation and grey matter volumes the corresponding classifiers failed or only yielded a poor discrimination. The present study corroborates the potential of task-related brain activation for classification shown in previous studies. It remains to be clarified whether error processing, which performed best here, also contributes to the discrimination of useful dimensions and subtypes, different psychiatric disorders, and prediction of treatment success across studies and sites.

  1. Method for recycling radioactive noble gases for functional pulmonary imaging

    International Nuclear Information System (INIS)

    Forouzan-Rad, M.

    1976-05-01

    A theoretical treatment of the dynamic adsorption and desorption processes in the adsorption column is developed. The results of this analysis are compared with the space-time measurements of 133 Xe activity distribution in a charcoal column, when trace amounts of this gas in exponentially decreasing concentrations are fed into the column. Based on these investigations, a recycling apparatus is designed for use with xenon isotopes, especially 127 Xe, in studies of pulmonary function. The apparatus takes advantage of the high adsorbability of activated coconut charcoal for xenon a low temperature (-78 0 C) in order to trap the radioactive xenon gas that is exhaled during each ventilation-perfusion study. The trapped xenon is then recovered by passing low-pressure steam through the charcoal column. It is found that steam removes xenon from the surface of the charcoal more effectively than does heating and evacuation of the charcoal bed. As a result, an average xenon recovery of 96 percent has been achieved. Improved design parameters are discussed

  2. Time domain functional NIRS imaging for human brain mapping.

    Science.gov (United States)

    Torricelli, Alessandro; Contini, Davide; Pifferi, Antonio; Caffini, Matteo; Re, Rebecca; Zucchelli, Lucia; Spinelli, Lorenzo

    2014-01-15

    This review is aimed at presenting the state-of-the-art of time domain (TD) functional near-infrared spectroscopy (fNIRS). We first introduce the physical principles, the basics of modeling and data analysis. Basic instrumentation components (light sources, detection techniques, and delivery and collection systems) of a TD fNIRS system are described. A survey of past, existing and next generation TD fNIRS systems used for research and clinical studies is presented. Performance assessment of TD fNIRS systems and standardization issues are also discussed. Main strengths and weakness of TD fNIRS are highlighted, also in comparison with continuous wave (CW) fNIRS. Issues like quantification of the hemodynamic response, penetration depth, depth selectivity, spatial resolution and contrast-to-noise ratio are critically examined, with the help of experimental results performed on phantoms or in vivo. Finally we give an account on the technological developments that would pave the way for a broader use of TD fNIRS in the neuroimaging community. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Method for recycling radioactive noble gases for functional pulmonary imaging

    Energy Technology Data Exchange (ETDEWEB)

    Forouzan-Rad, M.

    1976-05-01

    A theoretical treatment of the dynamic adsorption and desorption processes in the adsorption column is developed. The results of this analysis are compared with the space-time measurements of /sup 133/Xe activity distribution in a charcoal column, when trace amounts of this gas in exponentially decreasing concentrations are fed into the column. Based on these investigations, a recycling apparatus is designed for use with xenon isotopes, especially /sup 127/Xe, in studies of pulmonary function. The apparatus takes advantage of the high adsorbability of activated coconut charcoal for xenon a low temperature (-78/sup 0/C) in order to trap the radioactive xenon gas that is exhaled during each ventilation-perfusion study. The trapped xenon is then recovered by passing low-pressure steam through the charcoal column. It is found that steam removes xenon from the surface of the charcoal more effectively than does heating and evacuation of the charcoal bed. As a result, an average xenon recovery of 96 percent has been achieved. Improved design parameters are discussed. (auth)

  4. Functional Magnetic Resonance Imaging in Patients with the Wet Form of Age-Related Macular Degeneration

    Science.gov (United States)

    Lešták, Jan; Tintěra, Jaroslav; Karel, Ivan; Svatá, Zuzana; Rozsíval, Pavel

    2013-01-01

    Abstract The study is designed to determine the relationship between the progress of the wet form of age-related macular degeneration and the activity of the visual cortex examined using functional magnetic resonance imaging. Ten patients with the wet form of age-related macular degeneration (9 female and 1 male) with a mean age of 74.7 years (58–85 years) at various stages of bilateral involvement of the disease were included. Patients did not suffer from any other ocular nor neurological disease. All the patients underwent functional magnetic resonance imaging examinations with stimulation of both eyes using a black-and-white checkerboard of size 25.8 × 16.2 degrees. The group was compared with a group of healthy subjects with an average age of 54.1 years (45–65 years). For statistical evaluation, the Mann-Whitney U test was used. Comparing the extent of visual cortex activations we found a statistically significant difference between both the groups (p = 0.0247). However, the dependence of functional magnetic resonance imaging activity on visual acuity was not statistically significant (p = 0.223). We conclude that in patients with the wet form of age-related macular degeneration, lower functional magnetic resonance imaging activity of the visual cortex was found compared with the control group of healthy subjects. Dependence of functional magnetic resonance imaging activity on visual acuity was not statistically significant. PMID:28167987

  5. [The effect of permanent ostomy on body image, self-esteem, marital adjustment, and sexual functioning].

    Science.gov (United States)

    Kiliç, Esra; Taycan, Okan; Belli, Ahmet Korkut; Ozmen, Mine

    2007-01-01

    The aim of this study was to investigate the effects of permanent ostomy on body image, sexual functioning, self-esteem, and marital adjustment. SCID-I outpatient forms were administered to 52 subsequent patients that underwent permanent colostomy or ileostomy operations, and 40 of them that did not fit any of the diagnostic criteria for psychiatric disorders were then administered a sociodemographic data questionnaire, and the Body Image Scale, Rosenberg Self-Esteem Scale, Dyadic Adjustment Scale, and Golombok Rust Sexual Functions scale. The control group consisted of 20 age- and gender-matched healthy volunteers. Body Image, Rosenberg Self-Esteem, and Dyadic Adjustment Scale scores were higher in permanent ostomy patients compared to controls, indicating more ostomy-related disturbance. Sexual functions were found to be impaired as well, except impotence and rapid ejaculation parameters. Complaints of anorgasmia were more frequent among female colostomy patients. Body image, and the touch, communication, and frequency parameters of sexual functioning were less disturbed in male patients than in females. Female patients with a psychiatric history experienced vaginismus problems more frequently. Patients with a history early childhood separation from parents had lower self-esteem scores and more frequently avoided sexual activity. Following ostomy surgery, the frequency of male impotence decreased over time. Permanent ostomy causes impairment in perceived body image, dyadic adjustment, and sexual functioning.

  6. Alterations in Spontaneous Brain Activity and Functional Network Reorganization following Surgery in Children with Medically Refractory Epilepsy: A Resting-State Functional Magnetic Resonance Imaging Study

    Directory of Open Access Journals (Sweden)

    Yongxin Li

    2017-08-01

    Full Text Available For some patients with medically refractory epilepsy (MRE, surgery is a safe and effective treatment for controlling epilepsy. However, the functional consequences of such surgery on brain activity and connectivity in children remain unknown. In the present study, we carried out a longitudinal study using resting-state functional magnetic resonance imaging in 10 children with MRE before and again at a mean of 79 days after surgery, as well as in a group of 28 healthy controls. Compared with the controls, children with epilepsy exhibited abnormalities in intrinsic activity in the thalamus, putamen, pallidum, insula, hippocampus, cerebellum, and cingulate gyrus both before and after surgery. Longitudinal analyses showed that the amplitude of low frequency fluctuations (ALFF increased in the parietal–frontal cortex and decreased in the deep nuclei from pre- to post-surgery. The percentage changes in ALFF values in the deep nuclei were positively correlated with the age of epilepsy onset. Functional connectivity (FC analyses demonstrated a reorganization of FC architecture after surgery. These changes in brain activity and FC after surgery might indicate that the previously disrupted functional interactions were reorganized after surgery. All these results provide preliminary evidence that the age of epilepsy onset may have some potential to predict the outcome of brain functional reorganization after surgery in children with MRE.

  7. Point spread function modeling and image restoration for cone-beam CT

    International Nuclear Information System (INIS)

    Zhang Hua; Shi Yikai; Huang Kuidong; Xu Zhe

    2015-01-01

    X-ray cone-beam computed tomography (CT) has such notable features as high efficiency and precision, and is widely used in the fields of medical imaging and industrial non-destructive testing, but the inherent imaging degradation reduces the quality of CT images. Aimed at the problems of projection image degradation and restoration in cone-beam CT, a point spread function (PSF) modeling method is proposed first. The general PSF model of cone-beam CT is established, and based on it, the PSF under arbitrary scanning conditions can be calculated directly for projection image restoration without the additional measurement, which greatly improved the application convenience of cone-beam CT. Secondly, a projection image restoration algorithm based on pre-filtering and pre-segmentation is proposed, which can make the edge contours in projection images and slice images clearer after restoration, and control the noise in the equivalent level to the original images. Finally, the experiments verified the feasibility and effectiveness of the proposed methods. (authors)

  8. Functional Imaging of Human Vestibular Cortex Activity Elicited by Skull Tap and Auditory Tone Burst

    Science.gov (United States)

    Noohi, F.; Kinnaird, C.; Wood, S.; Bloomberg, J.; Mulavara, A.; Seidler, R.

    2016-01-01

    The current study characterizes brain activation in response to two modes of vestibular stimulation: skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit either the vestibulo-spinal reflex (saccular-mediated colic Vestibular Evoked Myogenic Potentials (cVEMP)), or the ocular muscle response (utricle-mediated ocular VEMP (oVEMP)). Some researchers have reported that air-conducted skull tap elicits both saccular and utricle-mediated VEMPs, while being faster and less irritating for the subjects. However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of cortical activity. Both forms of stimulation target the otolith response, which provides a measurement of vestibular function independent from semicircular canals. This is of high importance for studying otolith-specific deficits, including gait and balance problems that astronauts experience upon returning to earth. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation. Here we hypothesized that skull taps elicit similar patterns of cortical activity as the auditory tone bursts, and previous vestibular imaging studies. Subjects wore bilateral MR compatible skull tappers and headphones inside the 3T GE scanner, while lying in the supine position, with eyes closed. Subjects received both forms of the stimulation in a counterbalanced fashion. Pneumatically powered skull tappers were placed bilaterally on the cheekbones. The vibration of the cheekbone was transmitted to the vestibular system, resulting in the vestibular cortical response. Auditory tone bursts were also delivered for comparison. To validate our stimulation method, we measured the ocular VEMP outside of the scanner. This measurement showed that both skull tap and auditory

  9. SU-D-17A-04: The Impact of Audiovisual Biofeedback On Image Quality During 4D Functional and Anatomic Imaging: Results of a Prospective Clinical Trial

    Energy Technology Data Exchange (ETDEWEB)

    Keall, P; Pollock, S [University of Sydney, Sydney (Australia); Yang, J; Diehn, M; Berger, J; Graves, E; Loo, B [Stanford University, Stanford, CA (United States); Yamamoto, T [UC Davis School of Medicine, Sacramento, CA (United States)

    2014-06-01

    Purpose: The ability of audiovisual (AV) biofeedback to improve breathing regularity has not previously been investigated for functional imaging studies. The purpose of this study was to investigate the impact of AV biofeedback on 4D-PET and 4D-CT image quality in a prospective clinical trial. We hypothesized that motion blurring in 4D-PET images and the number of artifacts in 4D-CT images are reduced using AV biofeedback. Methods: AV biofeedback is a real-time, interactive and personalized system designed to help a patient self-regulate his/her breathing using a patient-specific representative waveform and musical guides. In an IRB-approved prospective clinical trial, 4D-PET and 4D-CT images of 10 lung cancer patients were acquired with AV biofeedback (AV) and free breathing (FB). The 4D-PET images in 6 respiratory bins were analyzed for motion blurring by: (1) decrease of GTVPET and (2) increase of SUVmax in 4-DPET compared to 3D-PET. The 4D-CT images were analyzed for artifacts by: (1) comparing normalized cross correlation-based scores (NCCS); and (2) quantifying a visual assessment score (VAS). A two-tailed paired t-test was used to test the hypotheses. Results: The impact of AV biofeedback on 4D-PET and 4D-CT images varied widely between patients, suggesting inconsistent patient comprehension and capability. Overall, the 4D-PET decrease of GTVPET was 2.0±3.0cm3 with AV and 2.3±3.9cm{sup 3} for FB (p=0.61). The 4D-PET increase of SUVmax was 1.6±1.0 with AV and 1.1±0.8 with FB (p=0.002). The 4D-CT NCCS were 0.65±0.27 with AV and 0.60±0.32 for FB (p=0.32). The 4D-CT VAS was 0.0±2.7 (p=ns). Conclusion: A 10-patient study demonstrated a statistically significant reduction of motion blurring of AV over FB for 1/2 functional 4D-PET imaging metrics. No difference between AV and FB was found for 2 anatomic 4D-CT imaging metrics. Future studies will focus on optimizing the human-computer interface and including patient training sessions for improved

  10. SU-D-17A-04: The Impact of Audiovisual Biofeedback On Image Quality During 4D Functional and Anatomic Imaging: Results of a Prospective Clinical Trial

    International Nuclear Information System (INIS)

    Keall, P; Pollock, S; Yang, J; Diehn, M; Berger, J; Graves, E; Loo, B; Yamamoto, T

    2014-01-01

    Purpose: The ability of audiovisual (AV) biofeedback to improve breathing regularity has not previously been investigated for functional imaging studies. The purpose of this study was to investigate the impact of AV biofeedback on 4D-PET and 4D-CT image quality in a prospective clinical trial. We hypothesized that motion blurring in 4D-PET images and the number of artifacts in 4D-CT images are reduced using AV biofeedback. Methods: AV biofeedback is a real-time, interactive and personalized system designed to help a patient self-regulate his/her breathing using a patient-specific representative waveform and musical guides. In an IRB-approved prospective clinical trial, 4D-PET and 4D-CT images of 10 lung cancer patients were acquired with AV biofeedback (AV) and free breathing (FB). The 4D-PET images in 6 respiratory bins were analyzed for motion blurring by: (1) decrease of GTVPET and (2) increase of SUVmax in 4-DPET compared to 3D-PET. The 4D-CT images were analyzed for artifacts by: (1) comparing normalized cross correlation-based scores (NCCS); and (2) quantifying a visual assessment score (VAS). A two-tailed paired t-test was used to test the hypotheses. Results: The impact of AV biofeedback on 4D-PET and 4D-CT images varied widely between patients, suggesting inconsistent patient comprehension and capability. Overall, the 4D-PET decrease of GTVPET was 2.0±3.0cm3 with AV and 2.3±3.9cm 3 for FB (p=0.61). The 4D-PET increase of SUVmax was 1.6±1.0 with AV and 1.1±0.8 with FB (p=0.002). The 4D-CT NCCS were 0.65±0.27 with AV and 0.60±0.32 for FB (p=0.32). The 4D-CT VAS was 0.0±2.7 (p=ns). Conclusion: A 10-patient study demonstrated a statistically significant reduction of motion blurring of AV over FB for 1/2 functional 4D-PET imaging metrics. No difference between AV and FB was found for 2 anatomic 4D-CT imaging metrics. Future studies will focus on optimizing the human-computer interface and including patient training sessions for improved comprehension and

  11. Functional Photoacoustic Imaging of Gastric Acid Secretion Using pH-Responsive Polyaniline Nanoprobes.

    Science.gov (United States)

    Li, Junwei; Xiao, Hong; Yoon, Soon Joon; Liu, Chengbo; Matsuura, Drew; Tai, Wanyi; Song, Liang; O'Donnell, Matthew; Cheng, Du; Gao, Xiaohu

    2016-09-01

    A stomach functional imaging technique based on photoacoustics achieves noninvasive gastric acid secretory assessment utilizing pH-responsive polyaniline nanoprobes. A testing protocol mimicking clinical practice is established using a mouse model. After imaging, the nanoprobes are excreted outside the body without inducing systematic toxicity. Further optimization and translation of this technology can help alleviate patients' suffering and side effects. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Localization of focal epileptic discharges using functional connectivity magnetic resonance imaging.

    Science.gov (United States)

    Stufflebeam, Steven M; Liu, Hesheng; Sepulcre, Jorge; Tanaka, Naoaki; Buckner, Randy L; Madsen, Joseph R

    2011-06-01

    In patients with medically refractory epilepsy the accurate localization of the seizure onset zone is critical for successful surgical treatment. The object of this study was to investigate whether the degree of coupling of spontaneous brain activity as measured with functional connectivity MR imaging (fcMR imaging) can accurately identify and localize epileptic discharges. The authors studied 6 patients who underwent fcMR imaging presurgical mapping and subsequently underwent invasive electroencephalography. Focal regions of statistically significant increases in connectivity were identified in 5 patients when compared with an ad hoc normative sample of 300 controls. The foci identified by fcMR imaging overlapped the epileptogenic areas identified by invasive encephalography in all 5 patients. These results suggest that fcMR imaging may provide an effective high-spatial resolution and noninvasive method of localizing epileptic discharges in patients with refractory epilepsy.

  13. Neuroendocrine tumours of the head and neck: anatomical, functional and molecular imaging and contemporary management

    Science.gov (United States)

    Subedi, Navaraj; Prestwich, Robin; Chowdhury, Fahmid; Patel, Chirag

    2013-01-01

    Abstract Neuroendocrine tumours (NETs) of the head and neck are rare neoplasms and can be of epithelial or non-epithelial differentiation. Although the natural history of NETs is variable, it is crucial to establish an early diagnosis of these tumours as they can be potentially curable. Conventional anatomical imaging and functional imaging using radionuclide scintigraphy and positron emission tomography/computed tomography can be complementary for the diagnosis, staging and monitoring of treatment response. This article describes and illustrates the imaging features of head and neck NETs, discusses the potential future role of novel positron-emitting tracers that are emerging into clinical practice and reviews contemporary management of these tumours. Familiarity with the choice of imaging techniques and the variety of imaging patterns and treatment options should help guide radiologists in the management of this rare but important subgroup of head and neck neoplasms. PMID:24240099

  14. A Novel Gradient Vector Flow Snake Model Based on Convex Function for Infrared Image Segmentation.

    Science.gov (United States)

    Zhang, Rui; Zhu, Shiping; Zhou, Qin

    2016-10-21

    Infrared image segmentation is a challenging topic because infrared images are characterized by high noise, low contrast, and weak edges. Active contour models, especially gradient vector flow, have several advantages in terms of infrared image segmentation. However, the GVF (Gradient Vector Flow) model also has some drawbacks including a dilemma between noise smoothing and weak edge protection, which decrease the effect of infrared image segmentation significantly. In order to solve this problem, we propose a novel generalized gradient vector flow snakes model combining GGVF (Generic Gradient Vector Flow) and NBGVF (Normally Biased Gradient Vector Flow) models. We also adopt a new type of coefficients setting in the form of convex function to improve the ability of protecting weak edges while smoothing noises. Experimental results and comparisons against other methods indicate that our proposed snakes model owns better ability in terms of infrared image segmentation than other snakes models.

  15. Structural-functional relationships between eye orbital imaging biomarkers and clinical visual assessments

    Science.gov (United States)

    Yao, Xiuya; Chaganti, Shikha; Nabar, Kunal P.; Nelson, Katrina; Plassard, Andrew; Harrigan, Rob L.; Mawn, Louise A.; Landman, Bennett A.

    2017-02-01

    Eye diseases and visual impairment affect millions of Americans and induce billions of dollars in annual economic burdens. Expounding upon existing knowledge of eye diseases could lead to improved treatment and disease prevention. This research investigated the relationship between structural metrics of the eye orbit and visual function measurements in a cohort of 470 patients from a retrospective study of ophthalmology records for patients (with thyroid eye disease, orbital inflammation, optic nerve edema, glaucoma, intrinsic optic nerve disease), clinical imaging, and visual function assessments. Orbital magnetic resonance imaging (MRI) and computed tomography (CT) images were retrieved and labeled in 3D using multi-atlas label fusion. Based on the 3D structures, both traditional radiology measures (e.g., Barrett index, volumetric crowding index, optic nerve length) and novel volumetric metrics were computed. Using stepwise regression, the associations between structural metrics and visual field scores (visual acuity, functional acuity, visual field, functional field, and functional vision) were assessed. Across all models, the explained variance was reasonable (R2 0.1-0.2) but highly significant (p pathology, this study aimed to analyze data across a variety of pathologies. This approach yielded a general model for the connection between orbital structural imaging biomarkers and visual function.

  16. Attentional and physiological processing of food images in functional dyspepsia patients: A pilot study.

    Science.gov (United States)

    Lee, In-Seon; Preissl, Hubert; Giel, Katrin; Schag, Kathrin; Enck, Paul

    2018-01-23

    The food-related behavior of functional dyspepsia has been attracting more interest of late. This pilot study aims to provide evidence of the physiological, emotional, and attentional aspects of food processing in functional dyspepsia patients. The study was performed in 15 functional dyspepsia patients and 17 healthy controls after a standard breakfast. We measured autonomic nervous system activity using skin conductance response and heart rate variability, emotional response using facial electromyography, and visual attention using eyetracking during the visual stimuli of food/non-food images. In comparison to healthy controls, functional dyspepsia patients showed a greater craving for food, a decreased intake of food, more dyspeptic symptoms, lower pleasantness rating of food images (particularly of high fat), decreased low frequency/high frequency ratio of heart rate variability, and suppressed total processing time of food images. There were no significant differences of skin conductance response and facial electromyography data between groups. The results suggest that high level cognitive functions rather than autonomic and emotional mechanisms are more liable to function differently in functional dyspepsia patients. Abnormal dietary behavior, reduced subjective rating of pleasantness and visual attention to food should be considered as important pathophysiological characteristics in functional dyspepsia.

  17. Development of dual-function SPECT and CT probe for small animal imaging

    International Nuclear Information System (INIS)

    Gambhir, Sanjay; Dube, Veeresh; Kheruka, Subash; Kumar, Uttam; Ahmad, Absar

    2010-01-01

    Full text: Different biological queries require different imaging strategies. In imaging this is more dependent not so much on the instruments but on the properties of the imaging agents.The development of dual-function probes for both fluorescence imaging and MRI was recently reported. Nano SPECT-CT, Bioscan system for animal imaging recently procured by our institute motivated us to explore and standardize a dual function probe for such a system. The study has been planned with a view develop a dual capability CT and radiopharmaceutical contrast to facilitate an anatomical and functional images thus combining the good resolution abilities of CT and high sensitivity functional images of SPECT. Method: Radiolabeling, of Bismuth nanocolloid with Technetium-99m was done and confirmation of good binding by instant thin layer chromatography (ITLC) confirmed more than 90% binding. This was injected into male Sprauge Dawley rats and biodistribution image and clearance time from blood was calculated. Confirmation, of Bismuth nano-colloid to act as CT contrast agent was done by performing phantom study at various concentrations in saline, 50 mg/ml, 100 mg/ml, 200 mg/ml and 500 mg/ml at CT tube current of 2.5mA and tube voltage of 140 KVp. Results: As compared to commercial Iodine contrast (375 mg/ml iodine) which was used as standard the average clearance time Bismuth colloid was longer. Its biodistribution was seen in heart, Liver, spleen and kidney. The iodine comparable CT contrast was achieved by 500 mg/ml of Bismuth colloid. 99m Tc-Bismuth colloid imaging on a dedicated animal SPECT-CT (Nano-SPECT, Bioscan) revealed similar biodistribution and in-vivo-stability of labeling. Conclusion: Successful radiolabeling, in-vivo stability and SPECT imaging of 99m Tc-Bismuth colloid along with its potential to impart iodine equivalent contrast raises the possibility of converting 99m-Tc-Bismuth as dual SPECT-CT probe for obtaining functional and anatomical image in pre

  18. Usefulness of true FISP cine MR imaging in patients with poor cardiac function

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, Toshiharu; Yamada, Naoaki; Motooka, Makoto; Enomoto, Naoyuki; Maeshima, Isamu; Matsuda, Kazuhide; Urayama, Shinichi; Ikeo, Miki [National Cardiovascular Center, Suita, Osaka (Japan)

    2002-01-01

    This study was done to assess the value of True FISP cine in patients with poor cardiac function. True FISP cine and FLASH cine imaging were performed on a 1.5 T machine. Both short axis and horizontal long axis imaging sections were used. The imaging sections used a Matrix (120 x 128), FOV (24 x 32 cm), and had a slice thickness of 8 mm. The imaging time for True FISP cine was 8 heart beats and 17 heart beats for FLASH cine. The contrast-to-noise ratio between the blood and myocardium (CNR) was measured at enddiastole and endsystole. The subjects in the study were 10 healty volunteers (average age 26.5{+-}3.2 years) and 12 patients with hypofunction (average age 53.9{+-}13.2 years). In the volunteers, the CNR of the short axis imaging was similar in both True FISP (24.6{+-}3.7) and FLASH (23.4{+-}5.9). In the patients with poor cardiac function however, the CNR of True FISP was larger than FLASH in both the short and long axis. In the short axis (22.7{+-}6.1 vs. 17.9{+-}5.3, P<0.01) and in the long axis (17.4{+-}4.3 vs. 9.3{+-}4.0, P<0.01). We conclude that True FISP cine has a higher contrast in a shorter imaging time than FLASH cine. True FISP cine is especially useful in patients with poor cardiac function. (author)

  19. The role of hyperpolarized 129xenon in MR imaging of pulmonary function

    International Nuclear Information System (INIS)

    Ebner, Lukas; Kammerman, Jeff; Driehuys, Bastiaan; Schiebler, Mark L.; Cadman, Robert V.; Fain, Sean B.

    2017-01-01

    Highlights: • Recent advances in hyperpolarized 129Xe MRI are reviewed. • Xenon MRI allows for functional imaging of ventilation, diffusion, and gas exchange. • Xenon’s unique gas exchange imaging capabilities are highlighted. • Applications to obstructive and restrictive lung diseases are presented. • These advances are ready for translation to clinical applications. - Abstract: In the last two decades, functional imaging of the lungs using hyperpolarized noble gases has entered the clinical stage. Both helium ( 3 He) and xenon ( 129 Xe) gas have been thoroughly investigated for their ability to assess both the global and regional patterns of lung ventilation. With advances in polarizer technology and the current transition towards the widely available 129 Xe gas, this method is ready for translation to the clinic. Currently, hyperpolarized (HP) noble gas lung MRI is limited to selected academic institutions; yet, the promising results from initial clinical trials have drawn the attention of the pulmonary medicine community. HP 129 Xe MRI provides not only 3-dimensional ventilation imaging, but also unique capabilities for probing regional lung physiology. In this review article, we aim to (1) provide a brief overview of current ventilation MR imaging techniques, (2) emphasize the role of HP 129 Xe MRI within the array of different imaging strategies, (3) discuss the unique imaging possibilities with HP 129 Xe MRI, and (4) propose clinical applications.

  20. Post-operative imaging assessment of non-functioning pituitary adenomas.

    Science.gov (United States)

    Patel, Kunal S; Dhawan, Sanjay; Wang, Renzhi; Carter, Bob S; Chen, James Y; Chen, Clark C

    2018-02-16

    Non-functioning pituitary adenomas (NFAs) are the most common pituitary tumors. There is significant variability in clinical practice in terms of post-operative imaging evaluation. The objective of this manuscript is to provide an exhaustive review of published articles pertaining to the post-operative imaging evaluation of NFAs. The MEDLINE database was queried for studies investigating imaging for the post-operative evaluation of pituitary adenomas. From an initial search of 5589 articles, 37 articles were evaluated in detail and included in this review. Magnetic resonance imaging (MRI) is the gold standard for post-operative monitoring of NFAs, although functional imaging modalities may improve identification of residual tumor in conjunction with MRI. The residual tumor can be distinguished from post-operative changes by experienced practitioners using high-resolution MRI in the immediate post-operative setting (within 1 week of surgery). However, continued imaging evolution in the appearance of residual tumor or resection cavity is expected up to 3 months post-operatively. Post-operative imaging appearance of the pituitary gland, optic apparatus, and pneumocephalus patterns, correlated with the clinical outcomes. Long-term, lifetime follow-up is warranted for NFA patients who underwent surgical resection.

  1. Study of human brain functions by functional magnetic resonance imaging (fMRI) and spectroscopy (fMRS)

    International Nuclear Information System (INIS)

    Jagannathan, N.R.

    1998-01-01

    Functional magnetic resonance imaging (fMRI) has become a powerful tool in the detection and assessment of cerebral pathophysiology and the regional mapping and characterization of cognitive processes such as motor skills, vision, language and memory. The results of the effect of motor cortex stimulation during repetitive hand squeezing task activation using in-vivo single voxel NMR spectroscopy carried out on normal volunteer subjects are presented

  2. Highlights from the previous volumes

    Science.gov (United States)

    Jacopo, Iacovacci; Takahiro, Kohsokabe; Kunihiko, Kaneko; al., Lange Steffen et; al., Helden Laurent et; et al.

    2017-04-01

    Functional Multiplex PageRank: The centrality is a functionPattern formation induced by fixed boundary conditionPower-law distributed Poincaré recurrences in higher-dimensional systemsMeasurement of second-order response without perturbation

  3. Imaging insights into basal ganglia function, Parkinson’s disease, and dystonia

    Science.gov (United States)

    Stoessl, A. Jon; Lehericy, Stephane; Strafella, Antonio P.

    2015-01-01

    Recent advances in structural and functional imaging have greatly improved our ability to assess normal functions of the basal ganglia, diagnose parkinsonian syndromes, understand the pathophysiology of parkinsonism and other movement disorders, and detect and monitor disease progression. Radionuclide imaging is the best way to detect and monitor dopamine deficiency, and will probably continue to be the best biomarker for assessment of the effects of disease-modifying therapies. However, advances in magnetic resonance enable the separation of patients with Parkinson’s disease from healthy controls, and show great promise for differentiation between Parkinson’s disease and other akinetic-rigid syndromes. Radionuclide imaging is useful to show the dopaminergic basis for both motor and behavioural complications of Parkinson’s disease and its treatment, and alterations in non-dopaminergic systems. Both PET and MRI can be used to study patterns of functional connectivity in the brain, which is disrupted in Parkinson’s disease and in association with its complications, and in other basal-ganglia disorders such as dystonia, in which an anatomical substrate is not otherwise apparent. Functional imaging is increasingly used to assess underlying pathological processes such as neuroinflammation and abnormal protein deposition. This imaging is another promising approach to assess the effects of treatments designed to slow disease progression. PMID:24954673

  4. Imaging of lung function using synchrotron radiation computed tomography: What's new?

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, Sam [Universite de Picardie Jules Verne, Departement de Physiologie, DMAG EA 3901, 3 Rue des Louvels, 80036 Amiens Cedex 1 (France)], E-mail: Bayat.Sam@chu-amiens.fr; Porra, Liisa [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Department of Physics, POB 64, FIN-00014 University of Helsinki, Helsinki (Finland)], E-mail: porra@esrf.fr; Suhonen, Heikki [Department of Physics, POB 64, FIN-00014 University of Helsinki, Helsinki (Finland)], E-mail: heikki.suhonen@helsinki.fi; Janosi, Tibor [Geneva Children' s Hospital, University Hospitals of Geneva and University of Geneva, Geneva (Switzerland)], E-mail: janosit@dmi.u-szeged.hu; Strengell, Satu [Department of Physics, POB 64, FIN-00014 University of Helsinki, Helsinki (Finland)], E-mail: skstreng@mappi.helsinki.fi; Habre, Walid [Geneva Children' s Hospital, University Hospitals of Geneva and University of Geneva, Geneva (Switzerland)], E-mail: Walid.Habre@hcuge.ch; Petak, Ferenc [Department of Department of Medical Informatics and Engineering, University of Szeged, 6720 Szeged, Koranyi fasor 9 (Hungary)], E-mail: petak@dmi.szote.u-szeged.hu; Hantos, Zoltan [Department of Department of Medical Informatics and Engineering, University of Szeged, 6720 Szeged, Koranyi fasor 9 (Hungary)], E-mail: hantos@dmi.u-szeged.hu; Suortti, Pekka [Department of Physics, POB 64, FIN-00014 University of Helsinki, Helsinki (Finland)], E-mail: Pekka.Suortti@helsinki.fi; Sovijaervi, Anssi [Departments of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, POB 340, FIN-00029 HUS, Helsinki (Finland)], E-mail: anssi.sovijarvi@hus.fi

    2008-12-15

    There is a growing interest in imaging techniques as non-invasive means of quantitatively measuring regional lung structure and function. Abnormalities in lung ventilation due to alterations in airway function such as those observed in asthma and COPD are highly heterogeneous, and experimental methods to study this heterogeneity are crucial for better understanding of disease mechanisms and drug targeting strategies. In severe obstructive diseases requiring mechanical ventilation, the optimal ventilatory strategy to achieve recruitment of poorly ventilated lung zones remains a matter of considerable debate. We have used synchrotron radiation computed tomography (SRCT) for the in vivo study of regional lung ventilation and airway function. This imaging technique allows direct quantification of stable Xenon (Xe) gas used as an inhaled contrast agent using K-edge subtraction imaging. Dynamics of Xe wash-in can be used to calculate quantitative maps of regional specific lung ventilation. More recently, the development of Spiral-CT has allowed the acquisition of 3D images of the pulmonary bronchial tree and airspaces. This technique gives access to quantitative measurements of regional lung volume, ventilation, and mechanical properties. Examples of application in an experimental model of allergic asthma and in imaging lung recruitment as a function of mechanical ventilation parameters will be presented. The future orientations of this tecnique will be discussed.

  5. [Functional connectivity of temporal parietal junction in online game addicts:a resting-state functional magnetic resonance imaging study].

    Science.gov (United States)

    Yuan, Ji; Qian, Ruobing; Lin, Bin; Fu, Xianming; Wei, Xiangpin; Weng, Chuanbo; Niu, Chaoshi; Wang, Yehan

    2014-02-11

    To explore the functions of temporal parietal junction (TPJ) as parts of attention networks in the pathogenesis of online game addiction using resting-state functional magnetic resonance imaging (fMRI). A total of 17 online game addicts (OGA) were recruited as OGA group and 17 healthy controls during the same period were recruited as CON group. The neuropsychological tests were performed for all of them to compare the inter-group differences in the results of Internet Addiction Test (IAT) and attention functions. All fMRI data were preprocessed after resting-state fMRI scanning. Then left and right TPJ were selected as regions of interest (ROIs) to calculate the linear correlation between TPJ and entire brain to compare the inter-group differences. Obvious differences existed between OGA group (71 ± 5 scores) and CON group (19 ± 7 scores) in the IAT results and attention function (P online game addicts showed decreased functional connectivity with bilateral ventromedial prefrontal cortex (VMPFC), bilateral hippocampal gyrus and bilateral amygdaloid nucleus, but increased functional connectivity with right cuneus.However, left TPJ demonstrated decreased functional connectivity with bilateral superior frontal gyrus and bilateral middle frontal gyrus, but increased functional connectivity with bilateral cuneus (P online game addicts.It suggests that TPJ is an important component of attention networks participating in the generation of online game addiction.

  6. Functionalized silica nanoparticles: a platform for fluorescence imaging at the cell and small animal levels.

    Science.gov (United States)

    Wang, Kemin; He, Xiaoxiao; Yang, XiaoHai; Shi, Hui

    2013-07-16

    Going in vivo, including living cells and the whole body, is very important for gaining a better understanding of the mystery of life and requires specialized imaging techniques. The diversity, composition, and temporal-spatial variation of life activities from cells to the whole body require the analysis techniques to be fast-response, noninvasive, highly sensitive, and stable, in situ and in real-time. Functionalized nanoparticle-based fluorescence imaging techniques have the potential to meet such needs through real-time and noninvasive visualization of biological events in vivo. Functionalized silica nanoparticles (SiNPs) doped with fluorescent dyes appear to be an ideal and flexible platform for developing fluorescence imaging techniques used in living cells and the whole body. We can select and incorporate different dyes inside the silica matrix either noncovalently or covalently. These form the functionalized hybrid SiNPs, which support multiplex labeling and ratiometric sensing in living systems. Since the silica matrix protects dyes from outside quenching and degrading factors, this enhances the photostability and biocompatibility of the SiNP-based probes. This makes them ideal for real-time and long-time tracking. One nanoparticle can encapsulate large numbers of dye molecules, which amplifies their optical signal and temporal-spatial resolution response. Integrating fluorescent dye-doped SiNPs with targeting ligands using various surface modification techniques can greatly improve selective recognition. Along with the endocytosis, functionalized SiNPs can be efficiently internalized into cells for noninvasive localization, assessment, and monitoring. These unique characteristics of functionalized SiNPs substantially support their applications in fluorescence imaging in vivo. In this Account, we summarize our efforts to develop functionalized dye-doped SiNPs for fluorescence imaging at the cell and small animal levels. We first discuss how to design and

  7. Evaluation of coronary artery disease by functional imaging from equilibrium radionuclide ventriculography

    International Nuclear Information System (INIS)

    He Zuoxiang

    1992-01-01

    Functional imagings were performed in 10 normals, 9 subjects with Non coronary Artery disease (NCAD), 33 CAD patients with documented MI (CAD-WMI) and 20 without MI (CAD-NMI). The sensitivity of LVGEF, LVREF and phase analysis at rest for detecting CAD-WMI was 66.7%, 78.8%, 93.9% respectively. LVGEF, LVREF during exercise for assessing CAD-NMI had the sensitivity of 90%, 80%, respectively, while specificity 90%. Early LVEF decrease, > 10% LVEF decrease and abnormal response at > 7 sectors during exercise were observed in 2 patients with 3 vessel. In conclusion, functional imaging were very useful for detecting CAD and evaluating its extent

  8. Functional magnetic resonance imaging of the kidneys; Funktionelle Magnetresonanztomographie der Nieren

    Energy Technology Data Exchange (ETDEWEB)

    Lanzman, R.S.; Wittsack, H.J. [Universitaetsklinik Duesseldorf, Institut fuer Diagnostische und Interventionelle Radiologie, Duesseldorf (Germany); Notohamiprodjo, M. [Universitaetsklinik Tuebingen, Abteilung fuer Diagnostische und Interventionelle Radiologie, Tuebingen (Germany)

    2015-12-15

    Interest in functional renal magnetic resonance imaging (MRI) has significantly increased in recent years. This review article provides an overview of the most important functional imaging techniques and their potential clinical applications for assessment of native and transplanted kidneys, with special emphasis on the clarification of renal tumors. (orig.) [German] Die funktionelle MRT der Nieren hat in den letzten Jahren zunehmend an Bedeutung gewonnen. In diesem Uebersichtsartikel werden die wichtigsten funktionellen Untersuchungstechniken vorgestellt und deren potenzielle klinische Bedeutung zur Evaluation von Nieren und Transplantatnieren hervorgehoben, wobei ein besonderes Augenmerk auf die Abklaerung von Nierentumoren gelegt wird. (orig.)

  9. Towards risk stratification in systemic atherosclerosis: value of myocardial function and viability imaging as an adjunct to MR angiography

    International Nuclear Information System (INIS)

    Seeger, Achim; Fenchel, Michael; Kramer, Ulrich; Bretschneider, Christiane; Grimm, Florian; Klumpp, Bernhard; Claussen, Claus D.; Miller, Stephan; Scheule, Albertus; Balletshofer, Bernd

    2010-01-01

    To longitudinally assess the value of cardiac functional and viability imaging as a supplement to MR angiography in patients with atherosclerotic disease. Cardiac MRI was performed in 195 consecutive patients with symptomatic peripheral arterial disease. Of these, 186 patients were followed for 22 ± 5 months for the presence of cardiac events (cardiac death, acute coronary syndrome and hospitalisation as a result of congestive heart failure). Myocardial viability imaging showed a high prevalence of known (n = 31) and occult myocardial infarctions (MI) (n = 26). Cardiac events occurred more often in patients with reduced ventricular function (ejection fraction (EF) less than 40%, cardiac event in 4/8 patients; EF 40-55%, cardiac event in 10/40 patients; EF greater than 55%, cardiac event in 15/138 patients) as well as in patients with occult MI (8/25 patients) and known MI (11/30 patients). In patients with normal function, the detection of a previous MI was of high relevance to prognosis. Both reduced EF and the presence of MI influence patients' prognoses. Performing cardiac MRI in this patient population may influence further patient management including intensified risk factor intervention. (orig.)

  10. Imaging strategies using focusing functions with applications to a North Sea field

    Science.gov (United States)

    da Costa Filho, C. A.; Meles, G. A.; Curtis, A.; Ravasi, M.; Kritski, A.

    2018-04-01

    Seismic methods are used in a wide variety of contexts to investigate subsurface Earth structures, and to explore and monitor resources and waste-storage reservoirs in the upper ˜100 km of the Earth's subsurface. Reverse-time migration (RTM) is one widely used seismic method which constructs high-frequency images of subsurface structures. Unfortunately, RTM has certain disadvantages shared with other conventional single-scattering-based methods, such as not being able to correctly migrate multiply scattered arrivals. In principle, the recently developed Marchenko methods can be used to migrate all orders of multiples correctly. In practice however, using Marchenko methods are costlier to compute than RTM—for a single imaging location, the cost of performing the Marchenko method is several times that of standard RTM, and performing RTM itself requires dedicated use of some of the largest computers in the world for individual data sets. A different imaging strategy is therefore required. We propose a new set of imaging methods which use so-called focusing functions to obtain images with few artifacts from multiply scattered waves, while greatly reducing the number of points across the image at which the Marchenko method need be applied. Focusing functions are outputs of the Marchenko scheme: they are solutions of wave equations that focus in time and space at particular surface or subsurface locations. However, they are mathematical rather than physical entities, being defined only in reference media that equal to the true Earth above their focusing depths but are homogeneous below. Here, we use these focusing functions as virtual source/receiver surface seismic surveys, the upgoing focusing function being the virtual received wavefield that is created when the downgoing focusing function acts as a spatially distributed source. These source/receiver wavefields are used in three imaging schemes: one allows specific individual reflectors to be selected and imaged

  11. Simultaneous morphological and functional imaging of the honeybee's brain by two-photon microscopy

    International Nuclear Information System (INIS)

    Haase, A.

    2011-01-01

    Thanks to its rather simply structured but highly performing brain, the honeybee (Apis mellifera) is an important model for neurobiological studies. Therefore there is a great need for new functional imaging modalities adapted to this species. Herein we give a detailed report on the development and performance of a platform for in vivo functional and morphological imaging of the honeybee's brain, focusing on its primary olfactory centres, the antennal lobes (ALs). The experimental setup consists of a two-photon microscope combined with a synchronized odour stimulus generator. Our imaging platform allows to simultaneously obtain both morphological measurements of the ALs functional units, the glomeruli, and in vivo calcium recording of their neural activity. We were able to record the characteristic glomerular response maps to odour stimuli applied to the bee's antennae. Our approach offers several advantages over the commonly used conventional fluorescence microscopy. Two-photon microscopy provides substantial enhancement in both spatial and temporal resolutions, while minimizing photo damage. Calcium recordings show a more than fourfold improvement in the functional signal with respect to the techniques available up to now. Finally, the extended penetration depth, thanks to the infrared excitation, allows the functional imaging of profound glomeruli which have not been optically accessible up to now.

  12. The impact of genital self-image on sexual function in women with pelvic floor disorders.

    Science.gov (United States)

    Handelzalts, Jonathan E; Yaakobi, Tal; Levy, Sigal; Peled, Yoav; Wiznitzer, Arnon; Krissi, Haim

    2017-04-01

    There is conflicting evidence regarding the impact of urinary incontinence and pelvic organ prolapse on overall sexual function. However, psychological variables thought to be associated with sexual function, have not been fully explored. We assessed the sexual functioning of women with pelvic floor disorders while measuring for psychological factors such as distress and genital self-image. In a cross-sectional study, 155 women in an urogynecology outpatient clinic of a tertiary health center completed a demographic questionnaire, the Brief Symptom Index-18 (BSI-18), Pelvic Floor Distress Inventory-20 (PFDI-20), Genital Self-Image Scale-20 (GSIS-20) and the Female Sexual Function Index (FSFI). Linear regression showed that when controlling for age and depression, GSIS significantly predicted FSFI total score (Beta=0.38, pself-image. This variable is more important than self-reported symptoms, type of specific disorder or other demographic variables. Older women tended not to complete the scales concerning more intimate matters. We suggest that urogynecologists should inquire about genital self-image as well as sexual function in this population. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Visualizing rotational wave functions of electronically excited nitric oxide molecules by using an ion imaging technique.

    Science.gov (United States)

    Mizuse, Kenta; Chizuwa, Nao; Ikeda, Dai; Imajo, Takashi; Ohshima, Yasuhiro

    2018-01-31

    Here we report the dissociative ionization imaging of electronically excited nitric oxide (NO) molecules to visualize rotational wave functions in the electronic excited state (A 2 Σ + ). The NO molecules were excited to a single rotational energy eigenstate in the first electronic excited state by a resonant nanosecond ultraviolet pulse. The molecules were then irradiated by a strong, circularly polarized femtosecond imaging pulse. Spatial distribution of the ejected N + and O + fragment ions from the dissociative NO 2+ was recorded as a direct measure of the molecular axis distribution using a high-resolution slice ion imaging apparatus. The circularly polarized probe pulse realizes the isotropic ionization and thus undistorted shapes of the functions can be visualized. Due to the higher ionization efficiency of the excited molecules relative to the ground state ones, signals from the excited NO were enhanced. We can, therefore, extract shapes of the square of rotational wave functions in the electronic excited state although the unexcited ground state molecules are the majority in an ensemble. The observed images show s-function-like and p-function-like shapes depending on the excitation wavelengths. These shapes well reflect the rotational (angular momentum) character of the prepared states. The present approach directly leads to the evaluation method of the molecular axis alignment in photo-excited ensembles, and it could also lead to a visualization method for excited state molecular dynamics.

  14. Pulmonary function-morphologic relationships assessed by SPECT-CT fusion images

    International Nuclear Information System (INIS)

    Suga, Kazuyoshi

    2012-01-01

    Pulmonary single photon emission computed tomography-computed tomography (SPECT-CT) fusion images provide objective and comprehensive assessment of pulmonary function and morphology relationships at cross-sectional lungs. This article reviewed the noteworthy findings of lung pathophysiology in wide-spectral lung disorders, which have been revealed on SPECT-CT fusion images in 8 years of experience. The fusion images confirmed the fundamental pathophysiologic appearance of lung low CT attenuation caused by airway obstruction-induced hypoxic vasoconstriction and that caused by direct pulmonary arterial obstruction as in acute pulmonary thromboembolism (PTE). The fusion images showed better correlation of lung perfusion distribution with lung CT attenuation changes at lung mosaic CT attenuation (MCA) compared with regional ventilation in the wide-spectral lung disorders, indicating that lung heterogeneous perfusion distribution may be a dominant mechanism of MCA on CT. SPECT-CT angiography fusion images revealed occasional dissociation between lung perfusion defects and intravascular clots in acute PTE, indicating the importance of assessment of actual effect of intravascular colts on peripheral lung perfusion. Perfusion SPECT-CT fusion images revealed the characteristic and preferential location of pulmonary infarction in acute PTE. The fusion images showed occasional unexpected perfusion defects in normal lung areas on CT in chronic obstructive pulmonary diseases and interstitial lung diseases, indicating the ability of perfusion SPECT superior to CT for detection of mild lesions in these disorders. The fusion images showed frequent ''steal phenomenon''-induced perfusion defects extending to the surrounding normal lung of arteriovenous fistulas and those at normal lungs on CT in hepatopulmonary syndrome. Comprehensive assessment of lung function-CT morphology on fusion images will lead to more profound understanding of lung pathophysiology in wide-spectral lung

  15. Functional image guided radiation therapy planning in volumetric modulated arc therapy for patients with malignant pleural mesothelioma

    Directory of Open Access Journals (Sweden)

    Yoshiko Doi, MD

    2017-04-01

    Conclusions: Significant reductions in fV5, fV10, fMLD, V5, and MLD were achieved with the functional image guided VMAT plan without negative effects on other factors. LAA-based functional image guided radiation therapy planning in VMAT is a feasible method to spare the functional lung in patients with MPM.

  16. Functional imaging of interleukin 1 beta expression in inflammatory process using bioluminescence imaging in transgenic mice

    Directory of Open Access Journals (Sweden)

    Liu Zhihui

    2008-08-01

    Full Text Available Abstract Background Interleukin 1 beta (IL-1β plays an important role in a number of chronic and acute inflammatory diseases. To understand the role of IL-1β in disease processes and develop an in vivo screening system for anti-inflammatory drugs, a transgenic mouse line was generated which incorporated the transgene firefly luciferase gene driven by a 4.5-kb fragment of the human IL-1β gene promoter. Luciferase gene expression was monitored in live mice under anesthesia using bioluminescence imaging in a number of inflammatory disease models. Results In a LPS-induced sepsis model, dramatic increase in luciferase activity was observed in the mice. This transgene induction was time dependent and correlated with an increase of endogenous IL-1β mRNA and pro-IL-1β protein levels in the mice. In a zymosan-induced arthritis model and an oxazolone-induced skin hypersensitivity reaction model, luciferase expression was locally induced in the zymosan injected knee joint and in the ear with oxazolone application, respectively. Dexamethasone suppressed the expression of luciferase gene both in the acute sepsis model and in the acute arthritis model. Conclusion Our data suggest that the transgenic mice model could be used to study transcriptional regulation of the IL-1β gene expression in the inflammatory process and evaluation the effect of anti-inflammatory drug in vivo.

  17. Appling a Novel Cost Function to Hopfield Neural Network for Defects Boundaries Detection of Wood Image

    Directory of Open Access Journals (Sweden)

    Qi Dawei

    2010-01-01

    Full Text Available A modified Hopfield neural network with a novel cost function was presented for detecting wood defects boundary in the image. Different from traditional methods, the boundary detection problem in this paper was formulated as an optimization process that sought the boundary points to minimize a cost function. An initial boundary was estimated by Canny algorithm first. The pixel gray value was described as a neuron state of Hopfield neural network. The state updated till the cost function touches the minimum value. The designed cost function ensured that few neurons were activated except the neurons corresponding to actual boundary points and ensured that the activated neurons are positioned in the points which had greatest change in gray value. The tools of Matlab were used to implement the experiment. The results show that the noises of the image are effectively removed, and our method obtains more noiseless and vivid boundary than those of the traditional methods.

  18. Effect of heroin use on changes of brain functions as measured by functional magnetic resonance imaging, a systematic review.

    Science.gov (United States)

    Fareed, Ayman; Kim, Jungjin; Ketchen, Bethany; Kwak, Woo Jin; Wang, Danzhao; Shongo-Hiango, Hilaire; Drexler, Karen

    2017-01-01

    In this study the authors focus on reviewing imaging studies that used resting state functional magnetic resonance imaging for individuals with a history of heroin use. This review study compiled existing research addressing the effect of heroin use on decision making by reviewing available functional neuroimaging data. Systematic review of the literatures using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Eligible articles were retrieved through a computer-based MEDLINE and PsycINFO search from 1960 to December 2015 using the major medical subject headings "heroin, fMRI" (all fields). Only English language was included. Thirty-seven articles were initially included in the review. Sixteen were excluded because they did not meet the inclusion criteria. The results of 21 articles that met all the inclusion criteria were presented. Based on the 21 studies included in the current review, there is evidence that heroin use may have a direct and damaging effect on certain brain functions and that these changes may be associated with impulsive and unhealthy decision making. From the review of these studies, the authors understand that a longer duration of heroin use may be associated with more damaging effects on brain functions. The authors also understand that these brain changes could last long after abstinence, which may increase the risk of relapse to heroin use. More research is needed to create a biomarker map for patients with heroin use disorder that can be used to guide and assess response to treatment.

  19. A novel passive paradigm for functional magnetic resonance imaging (fMRI) to localize brain functions

    International Nuclear Information System (INIS)

    Gasser, T.; Sandalcioglu, I.E.; Skwarek, V.; Gizewski, E.; Stolke, D.; Hans, V.

    2003-01-01

    The design of a shielded stimulation-device for electrical stimulation of peripheral nerves in the MRI-environment as passive fMRI-paradigm is content of this study. Especially the technical aspects and selection criteria of the stimulation-parameters are discussed. The clinical value for neurosurgical patients is outlined by supplying data from clinical studies, evaluating this novel paradigm. Thus neurosurgeons are supplied with superior information about functional anatomy, therefore being able to preserve functionally relevant brain-structures. (orig.) [de

  20. Love-related changes in the brain: a resting-state functional magnetic resonance imaging study

    OpenAIRE

    Song, Hongwen; Zou, Zhiling; Kou, Juan; Liu, Yang; Yang, Lizhuang; Zilverstand, Anna; d?Oleire Uquillas, Federico; Zhang, Xiaochu

    2015-01-01

    Romantic love is a motivational state associated with a desire to enter or maintain a close relationship with a specific other person. Functional magnetic resonance imaging (fMRI) studies have found activation increases in brain regions involved in the processing of reward, motivation and emotion regulation, when romantic lovers view photographs of their partners. However, not much is known about whether romantic love affects the brain’s functional architecture during rest. In the present stu...

  1. Improvement in cognitive and psychosocial functioning and self image among adolescent inpatient suicide attempters

    OpenAIRE

    Hintikka, Ulla; Marttunen, Mauri; Pelkonen, Mirjami; Laukkanen, Eila; Viinamäki, Heimo; Lehtonen, Johannes

    2006-01-01

    Abstract Background Psychiatric treatment of suicidal youths is often difficult and non-compliance in treatment is a significant problem. This prospective study compared characteristics and changes in cognitive functioning, self image and psychosocial functioning among 13 to 18 year-old adolescent psychiatric inpatients with suicide attempts (n = 16) and with no suicidality (n = 39) Methods The two-group pre-post test prospective study design included assessments by a psychiatrist, a psycholo...

  2. Variability in functional magnetic resonance imaging : influence of the baseline vascular state and physiological fluctuations

    OpenAIRE

    Behzadi, Yashar

    2006-01-01

    In recent years, functional magnetic resonance imaging (fMRI) has become an increasingly important tool for studying the working human brain. The blood oxygenation level dependent signal signal used in most fMRI experiments is an indirect measure of neural activity and reflects local changes in deoxyhemoglobin content, which is a complex function of dynamic changes in cerebral blood flow, cerebral blood volume, and the cerebral metabolic rate of oxygen. Although significant progress has been ...

  3. Optimizing top precision performance measure of content-based image retrieval by learning similarity function

    KAUST Repository

    Liang, Ru-Ze

    2017-04-24

    In this paper we study the problem of content-based image retrieval. In this problem, the most popular performance measure is the top precision measure, and the most important component of a retrieval system is the similarity function used to compare a query image against a database image. However, up to now, there is no existing similarity learning method proposed to optimize the top precision measure. To fill this gap, in this paper, we propose a novel similarity learning method to maximize the top precision measure. We model this problem as a minimization problem with an objective function as the combination of the losses of the relevant images ranked behind the top-ranked irrelevant image, and the squared Frobenius norm of the similarity function parameter. This minimization problem is solved as a quadratic programming problem. The experiments over two benchmark data sets show the advantages of the proposed method over other similarity learning methods when the top precision is used as the performance measure.

  4. In Vivo Voltage-Sensitive Dye Imaging of Subcortical Brain Function

    Science.gov (United States)

    Tang, Qinggong; Tsytsarev, Vassiliy; Liang, Chia-Pin; Akkentli, Fatih; Erzurumlu, Reha S.; Chen, Yu

    2015-11-01

    The whisker system of rodents is an excellent model to study peripherally evoked neural activity in the brain. Discrete neural modules represent each whisker in the somatosensory cortex (“barrels”), thalamus (“barreloids”), and brain stem (“barrelettes”). Stimulation of a single whisker evokes neural activity sequentially in its corresponding barrelette, barreloid, and barrel. Conventional optical imaging of functional activation in the brain is limited to surface structures such as the cerebral cortex. To access subcortical structures and image sensory-evoked neural activity, we designed a needle-based optical system using gradient-index (GRIN) rod lens. We performed voltage-sensitive dye imaging (VSDi) with GRIN rod lens to visualize neural activity evoked in the thalamic barreloids by deflection of whiskers in vivo. We stimulated several whiskers together to determine the sensitivity of our approach in differentiating between different barreloid responses. We also carried out stimulation of different whiskers at different times. Finally, we used muscimol in the barrel cortex to silence the corticothalamic inputs while imaging in the thalamus. Our results show that it is possible to obtain functional maps of the sensory periphery in deep brain structures such as the thalamic barreloids. Our approach can be broadly applicable to functional imaging of other core brain structures.

  5. Functional Ultrasound Imaging for Assessment of Extracellular Matrix Scaffolds Used for Liver Organoid Formation

    Science.gov (United States)

    Gessner, Ryan C.; Hanson, Ariel D.; Feingold, Steven; Cashion, Avery T.; Corcimaru, Ana; Wu, Bryant T.; Mullins, Christopher R.; Aylward, Stephen R.; Reid, Lola M.; Dayton, Paul A.

    2015-01-01

    A method of 3D functional ultrasound imaging has been developed to enable non-destructive assessment of extracellular matrix scaffolds that have been prepared by decellularization protocols and are intended for recellularization to create organoids. A major challenge in organ decellularization is retaining patent micro-vascular structures crucial for nutrient access and functionality of organoids. The imaging method described here provides statistical distributions of flow rates throughout the tissue volumes, 3D vessel network architecture visualization, characterization of microvessel volumes and sizes, and delineation of matrix from vascular circuits. The imaging protocol was tested on matrix scaffolds that are tissue-specific, but not species-specific, matrix extracts, prepared by a process that preserved >98% of the collagens, collagen-associated matrix components, and matrix-bound growth factors and cytokines. Image-derived data are discussed with respect to assessment of scaffolds followed by proof-of-concept studies in organoid establishment using Hep3B, human hepatoblast-like cells. Histology showed that the cells attached to scaffolds with patent vasculature within minutes, achieved engraftment at near 100%, expressed liver-specific functions within 24h, and yielded evidence of proliferation and increasing differentiation of cells throughout the two weeks of culture studies. This imaging method should prove valuable in analyses of such matrix scaffolds. PMID:24011714

  6. Dynamic chest radiography: flat-panel detector (FPD) based functional X-ray imaging.

    Science.gov (United States)

    Tanaka, Rie

    2016-07-01

    Dynamic chest radiography is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view (FOV) of FPDs permits real-time observation of the entire lungs and simultaneous right-and-left evaluation of diaphragm kinetics. Most importantly, dynamic chest radiography provides pulmonary ventilation and circulation findings as slight changes in pixel value even without the use of contrast media; the interpretation is challenging and crucial for a better understanding of pulmonary function. The basic concept was proposed in the 1980s; however, it was not realized until the 2010s because of technical limitations. Dynamic FPDs and advanced digital image processing played a key role for clinical application of dynamic chest radiography. Pulmonary ventilation and circulation can be quantified and visualized for the diagnosis of pulmonary diseases. Dynamic chest radiography can be deployed as a simple and rapid means of functional imaging in both routine and emergency medicine. Here, we focus on the evaluation of pulmonary ventilation and circulation. This review article describes the basic mechanism of imaging findings according to pulmonary/circulation physiology, followed by imaging procedures, analysis method, and diagnostic performance of dynamic chest radiography.

  7. Multiscale Geoscene Segmentation for Extracting Urban Functional Zones from VHR Satellite Images

    Directory of Open Access Journals (Sweden)

    Xiuyuan Zhang

    2018-02-01

    Full Text Available Urban functional zones, such as commercial, residential, and industrial zones, are basic units of urban planning, and play an important role in monitoring urbanization. However, historical functional-zone maps are rarely available for cities in developing countries, as traditional urban investigations focus on geographic objects rather than functional zones. Recent studies have sought to extract functional zones automatically from very-high-resolution (VHR satellite images, and they mainly concentrate on classification techniques, but ignore zone segmentation which delineates functional-zone boundaries and is fundamental to functional-zone analysis. To resolve the issue, this study presents a novel segmentation method, geoscene segmentation, which can identify functional zones at multiple scales by aggregating diverse urban objects considering their features and spatial patterns. In experiments, we applied this method to three Chinese cities—Beijing, Putian, and Zhuhai—and generated detailed functional-zone maps with diverse functional categories. These experimental results indicate our method effectively delineates urban functional zones with VHR imagery; different categories of functional zones extracted by using different scale parameters; and spatial patterns that are more important than the features of individual objects in extracting functional zones. Accordingly, the presented multiscale geoscene segmentation method is important for urban-functional-zone analysis, and can provide valuable data for city planners.

  8. Behaviors of cost functions in image registration between 201Tl brain tumor single-photon emission computed tomography and magnetic resonance images

    International Nuclear Information System (INIS)

    Soma, Tsutomu; Takaki, Akihiro; Teraoka, Satomi; Ishikawa, Yasushi; Murase, Kenya; Koizumi, Kiyoshi

    2008-01-01

    We studied the behaviors of cost functions in the registration of thallium-201 ( 201 Tl) brain tumor single-photon emission computed tomography (SPECT) and magnetic resonance (MR) images, as the similarity index of image positioning. A marker for image registration [technetium-99m ( 99m Tc) point source] was attached at three sites on the heads of 13 patients with brain tumor, from whom 42 sets of 99m Tc- 201 Tl SPECT (the dual-isotope acquisition) and MR images were obtained. The 201 Tl SPECT and MR images were manually registered according to the markers. From the positions where the two images were registered, the position of the 201 Tl SPECT was moved to examine the behaviors of the three cost functions, i.e., ratio image uniformity (RIU), mutual information (MI), and normalized MI (NMI). The cost functions MI and NMI reached the maximum at positions adjacent to those where the SPECT and MR images were manually registered. As for the accuracy of image registration in terms of the cost functions MI and NMI, on average, the images were accurately registered within 3 deg of rotation around the X-, Y-, and Z-axes, and within 1.5 mm (within 2 pixels), 3 mm (within 3 pixels), and 4 mm (within 1 slice) of translation to the X-, Y-, and Z-axes, respectively. In terms of rotation around the Z-axis, the cost function RIU reached the minimum at positions where the manual registration of the two images was substantially inadequate. The MI and NMI were suitable cost functions in the registration of 201 Tl SPECT and MR images. The behavior of the RIU, in contrast, was unstable, being unsuitable as an index of image registration. (author)

  9. Writing affects the brain network of reading in Chinese: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Cao, Fan; Vu, Marianne; Chan, Derek Ho Lung; Lawrence, Jason M; Harris, Lindsay N; Guan, Qun; Xu, Yi; Perfetti, Charles A

    2013-07-01

    We examined the hypothesis that learning to write Chinese characters influences the brain's reading network for characters. Students from a college Chinese class learned 30 characters in a character-writing condition and 30 characters in a pinyin-writing condition. After learning, functional magnetic resonance imaging collected during passive viewing showed different networks for reading Chinese characters and English words, suggesting accommodation to the demands of the new writing system through short-term learning. Beyond these expected differences, we found specific effects of character writing in greater activation (relative to pinyin writing) in bilateral superior parietal lobules and bilateral lingual gyri in both a lexical decision and an implicit writing task. These findings suggest that character writing establishes a higher quality representation of the visual-spatial structure of the character and its orthography. We found a greater involvement of bilateral sensori-motor cortex (SMC) for character-writing trained characters than pinyin-writing trained characters in the lexical decision task, suggesting that learning by doing invokes greater interaction with sensori-motor information during character recognition. Furthermore, we found a correlation of recognition accuracy with activation in right superior parietal lobule, right lingual gyrus, and left SMC, suggesting that these areas support the facilitative effect character writing has on reading. Finally, consistent with previous behavioral studies, we found character-writing training facilitates connections with semantics by producing greater activation in bilateral middle temporal gyri, whereas pinyin-writing training facilitates connections with phonology by producing greater activation in right inferior frontal gyrus. Copyright © 2012 Wiley Periodicals, Inc.

  10. An agent harms a victim: A functional magnetic resonance imaging study on specific moral emotions

    Energy Technology Data Exchange (ETDEWEB)

    Kedia, G. [INSERM, Inst Hlth et Med Res, U797, Res Unit Neuroimaging Psychiat, F-91401 Orsay (France); Kedia, G.; Martinot, J.L. [CEA, DSV, I2BM, SHFJ, Orsay (France); Kedia, G.; Martinot, J.L. [Univ Paris Sud, U797, Paris (France); Kedia, G.; Hilton, D. [Univ Toulouse, Toulouse (France); Berthoz, S. [Paris Descartes Univ, U797, Paris (France); Wessa, M. [Univ Heidelber, Cent Inst Mental Hlth, D-6800 Mannheim (Germany)

    2008-07-01

    The statement 'An agent harms a victim' depicts a situation that triggers moral emotions. Depending on whether the agent and the victim are the self or someone else, it can lead to four different moral emotions: self-anger ('I harm myself'), guilt ('I harm someone'), other-anger ('someone harms me'), and compassion ('someone harms someone'). In order to investigate the neural correlates of these emotions, we examined brain activation patterns elicited by variations in the agent (self vs. other) and the victim (self vs. other) of a harmful action. Twenty-nine healthy participants underwent functional magnetic resonance imaging while imagining being in situations in which they or someone else harmed themselves or someone else. Results indicated that the three emotional conditions associated with the involvement of other, either as agent or victim (guilt, other-anger, and compassion conditions), all activated structures that have been previously associated with the Theory of Mind (ToM, the attribution of mental states to others), namely, the dorsal medial prefrontal cortex, the precuneus, and the bilateral temporo-parietal junction. Moreover, the two conditions in which both the self and other were concerned by the harmful action (guilt and other-anger conditions) recruited emotional structures (i. e., the bilateral amygdala, anterior cingulate, and basal ganglia). These results suggest that specific moral emotions induce different neural activity depending on the extent to which they involve the self and other. (authors)

  11. Functional luminal imaging probe topography: an improved method for characterizing esophageal distensibility in eosinophilic esophagitis.

    Science.gov (United States)

    Lin, Zhiyue; Kahrilas, Peter J; Xiao, Yinglian; Nicodème, Frédéric; Gonsalves, Nirmala; Hirano, Ikuo; Pandolfino, John E

    2013-03-01

    The aims of this study were to develop a new method for analysis and presentation of esophageal distensibility data using high-resolution impedance planimetry recordings during a volume-controlled distention. Two control subjects and six patients with eosinophilic esophagitis (EoE) with stricture, narrow caliber or normal endoscopy according to EndoFLIP studies were included for analysis. Median filtering and pulse detection techniques were applied to the pressure signal and a wavelet decomposition technique was applied to the 16 channels of raw esophageal diameter data to reduce vascular artifact, respiratory effect and remove esophageal contraction interference. These data were used to generate a functional luminal imaging probe (FLIP) topography plot that describes regional variation of cross-sectional area (CSA). A previously developed computer program was used to calculate and model the CSA-pressure data to derive the slope of line fitting and distension plateau for each individual subject. The results were compared among the four endoscopic phenotypes. Patients with EoE and normal endoscopy had similar esophageal distensibility parameters to those of normal controls whereas patients with EoE and stricture or narrow caliber had much lower distensibility than patients with EoE and normal endoscopy. The FLIP topography plots provided a global assessment of the esophageal distensibility along the axial plane of measurement that differentiated patients with varying degrees of endoscopic abnormality. New techniques can be leveraged to improve data analysis and presentation using EndoFLIP assessment of the esophageal body in EoE. These techniques may be helpful in defining clinically relevant phenotypes and guiding treatment strategies and should be helpful in structuring future outcome trials.

  12. Functional and magnetic resonance imaging evaluation after single-tendon rotator cuff reconstruction

    DEFF Research Database (Denmark)

    Knudsen, H B; Gelineck, J; Søjbjerg, Jens Ole

    1999-01-01

    The aim of this study was to investigate tendon integrity after surgical repair of single-tendon rotator cuff lesions. In 31 patients, 31 single-tendon repairs were evaluated. Thirty-one patients were available for clinical assessment and magnetic resonance imaging (MRI) at follow-up. A standard...... series of MR images was obtained for each. The results of functional assessment were scored according to the system of Constant. According to MRI evaluation, 21 (68%) patients had an intact or thinned rotator cuff and 10 (32%) had recurrence of a full-thickness cuff defect at follow-up. Patients...... with an intact or thinned rotator cuff had a median Constant score of 75.5 points; patients with a full-thickness cuff defect had a median score of 62 points. There was no correlation between tendon integrity on postoperative MR images and functional outcome. Patients with intact or thinned cuffs did not have...

  13. Self-consistent density functional calculation of the image potential at a metal surface

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J [Departamento de Fisica Fundamental, Universidad Nacional de Educacion a Distancia, Apartado 60141, 28080 Madrid (Spain); Alvarellos, J E [Departamento de Fisica Fundamental, Universidad Nacional de Educacion a Distancia, Apartado 60141, 28080 Madrid (Spain); Chacon, E [Instituto de Ciencias de Materiales de Madrid, Consejo Superior de Investigaciones CientIficas, E-28049 Madrid (Spain); GarcIa-Gonzalez, P [Departamento de Fisica Fundamental, Universidad Nacional de Educacion a Distancia, Apartado 60141, 28080 Madrid (Spain)

    2007-07-04

    It is well known that the exchange-correlation (XC) potential at a metal surface has an image-like asymptotic behaviour given by -1/4(z-z{sub 0}), where z is the coordinate perpendicular to the surface. Using a suitable fully non-local functional prescription, we evaluate self-consistently the XC potential with the correct image behaviour for simple jellium surfaces in the range of metallic densities. This allows a proper comparison between the corresponding image-plane position, z{sub 0}, and other related quantities such as the centroid of an induced charge by an external perturbation. As a by-product, we assess the routinely used local density approximation when evaluating electron density profiles, work functions, and surface energies by focusing on the XC effects included in the fully non-local description.

  14. Self-consistent density functional calculation of the image potential at a metal surface

    International Nuclear Information System (INIS)

    Jung, J; Alvarellos, J E; Chacon, E; GarcIa-Gonzalez, P

    2007-01-01

    It is well known that the exchange-correlation (XC) potential at a metal surface has an image-like asymptotic behaviour given by -1/4(z-z 0 ), where z is the coordinate perpendicular to the surface. Using a suitable fully non-local functional prescription, we evaluate self-consistently the XC potential with the correct image behaviour for simple jellium surfaces in the range of metallic densities. This allows a proper comparison between the corresponding image-plane position, z 0 , and other related quantities such as the centroid of an induced charge by an external perturbation. As a by-product, we assess the routinely used local density approximation when evaluating electron density profiles, work functions, and surface energies by focusing on the XC effects included in the fully non-local description

  15. Influence of environmental tobacco smoke on morphology and functions of cardiovascular system assessed using diagnostic imaging.

    Science.gov (United States)

    Gać, Paweł; Poręba, Małgorzata; Pawlas, Krystyna; Sobieszczańska, Małgorzata; Poręba, Rafał

    Exposure to tobacco smoke is a significant problem of environmental medicine. Tobacco smoke contains over one thousand identified chemicals including numerous toxicants. Cardiovascular system diseases are the major cause of general mortality. The recent development of diagnostic imaging provided methods which enable faster and more precise diagnosis of numerous diseases, also those of cardiovascular system. This paper reviews the most significant scientific research concerning relationship between environmental exposure to tobacco smoke and the morphology and function of cardiovascular system carried out using diagnostic imaging methods, i.e. ultrasonography, angiography, computed tomography and magnetic resonance imaging. In the forthcoming future, the studies using current diagnostic imaging methods should contribute to the reliable documentation, followed by the wide-spreading knowledge of the harmful impact of the environmental tobacco smoke exposure on the cardiovascular system.

  16. Application of gastric emptying imaging in the therapy of functional dyspepsia

    International Nuclear Information System (INIS)

    Wen Qingxiang; Shi Jin; Rong Rong; Wang Hongbing

    2012-01-01

    Objective: To investigate the application of gastric emptying imaging in the therapy of functional dyspepsia (FD) of Spleen deficiency and qi stagnation. Methods: 78 cases of patients with FD were divide into Chinese herbal medicine group (40 cases treated with Chinese herbal medicine of Decoction of invigorating spleen) and Western medicine group (38 cases treated with regulating qi and Domperidone). The gastric emptying imagings were carried out before and after treatment. Results: The gastric emptying imaging results showed that both traditional Chinese Medicine and Western medicine treatments had good curative effects (P<0.01), and the traditional Chinese Medicine was better than that of Wester medicine (P<0.05). Conclusion: Gastric emptying imaging is very useful in observation curative effect of FD treatment. (authors)

  17. Are Imaging and Lesioning Convergent Methods for Assessing Functional Specialisation? Investigations Using an Artificial Neural Network

    Science.gov (United States)

    Thomas, Michael S. C.; Purser, Harry R. M.; Tomlinson, Simon; Mareschal, Denis

    2012-01-01

    This article presents an investigation of the relationship between lesioning and neuroimaging methods of assessing functional specialisation, using synthetic brain imaging (SBI) and lesioning of a connectionist network of past-tense formation. The model comprised two processing "routes": one was a direct route between layers of input and output…

  18. Functional magnetic resonance imaging of the normal and abnormal visual system in early life

    DEFF Research Database (Denmark)

    Born, A.P.; Miranda Gimenez-Ricco, Maria Jo; Rostrup, Egill

    2000-01-01

    Functional magnetic resonance imaging (fMRI) in young children may provide information about the development of the visual cortex, and may have predictive value for later visual performance. The purpose of this study was to evaluate the usefulness of fMRI for examining cerebral processing of visi...

  19. Time of acquisition and network stability in pediatric resting-state functional magnetic resonance imaging

    NARCIS (Netherlands)

    T.J.H. White (Tonya); R.L. Muetzel (Ryan); M. Schmidt (Marcus); S.J.E. Langeslag (Sandra); V.W.V. Jaddoe (Vincent); A. Hofman (Albert); V.D. Calhoun Vince D. (V.); F.C. Verhulst (Frank); H.W. Tiemeier (Henning)

    2014-01-01

    textabstractResting-state functional magnetic resonance imaging (rs-fMRI) has been shown to elucidate reliable patterns of brain networks in both children and adults. Studies in adults have shown that rs-fMRI acquisition times of ∼5 to 6 min provide adequate sampling to produce stable spatial maps

  20. Functional Magnetic Resonance Imaging Connectivity Analyses Reveal Efference-Copy to Primary Somatosensory Area, BA2

    NARCIS (Netherlands)

    Cui, Fang; Arnstein, Dan; Thomas, Rajat Mani; Maurits, Natasha M.; Keysers, Christian; Gazzola, Valeria

    2014-01-01

    Some theories of motor control suggest efference-copies of motor commands reach somatosensory cortices. Here we used functional magnetic resonance imaging to test these models. We varied the amount of efference-copy signal by making participants squeeze a soft material either actively or passively.

  1. Functional magnetic resonance imaging connectivity analyses reveal efference-copy to primary somatosensory area, BA2

    NARCIS (Netherlands)

    Cui, Fang; Arnstein, Dan; Thomas, Rajat Mani; Maurits, Natasha M; Keysers, C.; Gazzola, Valeria

    2014-01-01

    Some theories of motor control suggest efference-copies of motor commands reach somatosensory cortices. Here we used functional magnetic resonance imaging to test these models. We varied the amount of efference-copy signal by making participants squeeze a soft material either actively or passively.

  2. Functional Magnetic Resonance Imaging of Cognitive Processing in Young Adults with Down Syndrome

    Science.gov (United States)

    Jacola, Lisa M.; Byars, Anna W.; Chalfonte-Evans, Melinda; Schmithorst, Vincent J.; Hickey, Fran; Patterson, Bonnie; Hotze, Stephanie; Vannest, Jennifer; Chiu, Chung-Yiu; Holland, Scott K.; Schapiro, Mark B.

    2011-01-01

    The authors used functional magnetic resonance imaging (fMRI) to investigate neural activation during a semantic-classification/object-recognition task in 13 persons with Down syndrome and 12 typically developing control participants (age range = 12-26 years). A comparison between groups suggested atypical patterns of brain activation for the…

  3. Students' Images of Two-Variable Functions and Their Graphs

    Science.gov (United States)

    Weber, Eric; Thompson, Patrick W.

    2014-01-01

    This paper presents a conceptual analysis for students' images of graphs and their extension to graphs of two-variable functions. We use the conceptual analysis, based on quantitative and covariational reasoning, to construct a hypothetical learning trajectory (HLT) for how students might generalize their understanding of graphs of…

  4. Substance Use and Its Relationship to Family Functioning and Self-Image in Adolescents

    Science.gov (United States)

    Weiss, Jie Wu; Merrill, Vincent; Akagha, Kathy

    2011-01-01

    This study examined associations between substance use, family functioning, and self-image among four ethnic adolescent groups. Three thousand three hundred and fifteen 8th and 9th grade students were recruited from 10 schools in Los Angeles County. Participants completed a paper-and-pencil survey regarding their alcohol and marijuana use, along…

  5. Micro-seismic imaging using a source function independent full waveform inversion method

    Science.gov (United States)

    Wang, Hanchen; Alkhalifah, Tariq

    2018-03-01

    At the heart of micro-seismic event measurements is the task to estimate the location of the source micro-seismic events, as well as their ignition times. The accuracy of locating the sources is highly dependent on the velocity model. On the other hand, the conventional micro-seismic source locating methods require, in many cases manual picking of traveltime arrivals, which do not only lead to manual effort and human interaction, but also prone to errors. Using full waveform inversion (FWI) to locate and image micro-seismic events allows for an automatic process (free of picking) that utilizes the full wavefield. However, full waveform inversion of micro-seismic events faces incredible nonlinearity due to the unknown source locations (space) and functions (time). We developed a source function independent full waveform inversion of micro-seismic events to invert for the source image, source function and the velocity model. It is based on convolving reference traces with these observed and modeled to mitigate the effect of an unknown source ignition time. The adjoint-state method is used to derive the gradient for the source image, source function and velocity updates. The extended image for the source wavelet in Z axis is extracted to check the accuracy of the inverted source image and velocity model. Also, angle gathers is calculated to assess the quality of the long wavelength component of the velocity model. By inverting for the source image, source wavelet and the velocity model simultaneously, the proposed method produces good estimates of the source location, ignition time and the background velocity for synthetic examples used here, like those corresponding to the Marmousi model and the SEG/EAGE overthrust model.

  6. Micro-seismic imaging using a source function independent full waveform inversion method

    KAUST Repository

    Wang, Hanchen

    2018-03-26

    At the heart of micro-seismic event measurements is the task to estimate the location of the source micro-seismic events, as well as their ignition times. The accuracy of locating the sources is highly dependent on the velocity model. On the other hand, the conventional micro-seismic source locating methods require, in many cases manual picking of traveltime arrivals, which do not only lead to manual effort and human interaction, but also prone to errors. Using full waveform inversion (FWI) to locate and image micro-seismic events allows for an automatic process (free of picking) that utilizes the full wavefield. However, full waveform inversion of micro-seismic events faces incredible nonlinearity due to the unknown source locations (space) and functions (time). We developed a source function independent full waveform inversion of micro-seismic events to invert for the source image, source function and the velocity model. It is based on convolving reference traces with these observed and modeled to mitigate the effect of an unknown source ignition time. The adjoint-state method is used to derive the gradient for the source image, source function and velocity updates. The extended image for the source wavelet in Z axis is extracted to check the accuracy of the inverted source image and velocity model. Also, angle gathers is calculated to assess the quality of the long wavelength component of the velocity model. By inverting for the source image, source wavelet and the velocity model simultaneously, the proposed method produces good estimates of the source location, ignition time and the background velocity for synthetic examples used here, like those corresponding to the Marmousi model and the SEG/EAGE overthrust model.

  7. Quantitative functional lung imaging with synchrotron radiation using inhaled xenon as contrast agent.

    Science.gov (United States)

    Bayat, S; Le Duc, G; Porra, L; Berruyer, G; Nemoz, C; Monfraix, S; Fiedler, S; Thomlinson, W; Suortti, P; Standertskjöld-Nordenstam, C G; Sovijärvi, A R

    2001-12-01

    Small airways play a key role in the distribution of ventilation and in the matching of ventilation to perfusion. The purpose of this study was to introduce an imaging method that allows measurement of regional lung ventilation and evaluation of the function of airways with a small diameter. The experiments were performed at the Medical Beamline of the European Synchrotron Radiation Facility. Monochromatic synchrotron radiation beams were used to obtain quantitative respiration-gated images of lungs and airways in two anaesthetized and mechanically ventilated rabbits using inhaled stable xenon (Xe) gas as a contrast agent. Two simultaneous images were acquired at two different energies, above and below the K-edge of Xe. Logarithmic subtraction of the two images yields absolute Xe concentrations. This technique is known as K-edge subtraction (KES) radiography. Two-dimensional planar and CT images were obtained showing spatial distribution of Xe concentrations within the airspaces, as well as the dynamics of filling with Xe. Bronchi down to 1 mm in diameter were visible both in the subtraction radiographs and in tomographic images. Absolute concentrations of Xe gas were calculated within the tube carrying the inhaled gas mixture, small and large bronchi, and lung tissue. Local time constants of ventilation with Xe were obtained by following the evolution of gas concentration in sequential computed tomography images. The results of this first animal study indicate that KES imaging of lungs with Xe gas as a contrast agent has great potential in studies of the distribution of ventilation within the lungs and of airway function, including airways with a small diameter.

  8. Structural and Functional Characterization of Human Stem-Cell-Derived Retinal Organoids by Live Imaging.

    Science.gov (United States)

    Browne, Andrew W; Arnesano, Cosimo; Harutyunyan, Narine; Khuu, Thien; Martinez, Juan Carlos; Pollack, Harvey A; Koos, David S; Lee, Thomas C; Fraser, Scott E; Moats, Rex A; Aparicio, Jennifer G; Cobrinik, David

    2017-07-01

    Human pluripotent stem cell (hPSC)-derived retinal organoids are a platform for investigating retinal development, pathophysiology, and cellular therapies. In contrast to histologic analysis in which multiple specimens fixed at different times are used to reconstruct developmental processes, repeated analysis of the same living organoids provides a more direct means to characterize changes. New live imaging modalities can provide insights into retinal organoid structure and metabolic function during in vitro growth. This study employed live tissue imaging to characterize retinal organoid development, including metabolic changes accompanying photoreceptor differentiation. Live hPSC-derived retinal organoids at different developmental stages were examined for microanatomic organization and metabolic function by phase contrast microscopy, optical coherence tomography (OCT), fluorescence lifetime imaging microscopy (FLIM), and hyperspectral imaging (HSpec). Features were compared to those revealed by histologic staining, immunostaining, and microcomputed tomography (micro-CT) of fixed organoid tissue. We used FLIM and HSpec to detect changes in metabolic activity as organoids differentiated into organized lamellae. FLIM detected increased glycolytic activity and HSpec detected retinol and retinoic acid accumulation in the organoid outer layer, coinciding with photoreceptor genesis. OCT enabled imaging of lamellae formed during organoid maturation. Micro-CT revealed three-dimensional structure, but failed to detect lamellae. Live imaging modalities facilitate real-time and nondestructive imaging of retinal organoids as they organize into lamellar structures. FLIM and HSpec enable rapid detection of lamellar structure and photoreceptor metabolism. Live imaging techniques may aid in the continuous evaluation of retinal organoid development in diverse experimental and cell therapy settings.

  9. Diffusion tensor imaging (DTI) predicts functional impairment in mild to moderate cervical spondylotic myelopathy

    Science.gov (United States)

    Ellingson, Benjamin M.; Salamon, Noriko; Grinstead, John W.; Holly, Langston T.

    2014-01-01

    Background Context MRI is the standard imaging modality for the assessment of the cervical spinal cord; however, MRI assessment of the spinal cord in cervical spondylotic myelopathy (CSM) patients has not demonstrated a consistent association with neurological function or outcome after surgical or medical intervention. Thus, there is a need for sensitive imaging biomarkers that can predict functional impairment in patients with advanced cervical spondylosis. Purpose The purpose of this study was to implement diffusion tensor imaging (DTI) as an imaging biomarker for microstructural integrity and functional impairment in patients with cervical spondylosis. Study Design/Setting Non-randomized, single institution study. Patient Sample Forty-eight cervical spondylosis patients with or without spinal cord signal change underwent DTI of the spinal cord along with functional assessment. Outcome Measures Functional measures of neurological function via mJOA score Methods This study was supported by the NIH and there are no perceived conflicts of interest. A zoomed-EPI technique and 2D spatially selective RF excitation pulse were used for DTI measurement. Fractional anisotropy (FA), mean diffusivity (MD), radial and axial diffusion coefficient (RD and AD), axial diffusion anisotropy, ψ, defined as AD-MD, and the standard deviation of primary eigenvector orientation were evaluated at the site of compression. Results Results suggest average FA, tADC, ψ, and standard deviation of primary eigenvector orientation at the spinal level of highest compression were linearly correlated with modified Japanese Orthopedic Association (mJOA) score. Receiver-operator characteristic (ROC) analysis suggested FA and ψ could identify stenosis patients with mild to moderate symptoms with a relatively high sensitivity and specificity. Conclusion The results of this study support the potential use of DTI as a biomarker for predicting functional impairment in patients with cervical spondylosis

  10. Scattering images from autocorrelation functions of P-wave seismic velocity images: the case of Tenerife Island (Canary Islands, Spain)

    Science.gov (United States)

    García-Yeguas, A.; Sánchez-Alzola, A.; De Siena, L.; Prudencio, J.; Díaz-Moreno, A.; Ibáñez, J. M.

    2018-03-01

    We present a P-wave scattering image of the volcanic structures under Tenerife Island using the autocorrelation functions of P-wave vertical velocity fluctuations. We have applied a cluster analysis to total quality factor attenuation ( {Q}_t^{-1} ) and scattering quality factor attenuation ( {Q}_{PSc}^{-1} ) images to interpret the structures in terms of intrinsic and scattering attenuation variations on a 2D plane, corresponding to a depth of 2000 m, and check the robustness of the scattering imaging. The results show that scattering patterns are similar to total attenuation patterns in the south of the island. There are two main areas where patterns differ: at Cañadas-Teide-Pico Viejo Complex, high total attenuation and average-to-low scattering values are observed. We interpret the difference as induced by intrinsic attenuation. In the Santiago Ridge Zone (SRZ) region, high scattering values correspond to average total attenuation. In our interpretation, the anomaly is induced by an extended scatterer, geometrically related to the surficial traces of Garachico and El Chinyero historical eruptions and the area of highest seismic activity during the 2004-2008 seismic crises.

  11. Resting-State Functional MR Imaging for Determining Language Laterality in Intractable Epilepsy.

    Science.gov (United States)

    DeSalvo, Matthew N; Tanaka, Naoaki; Douw, Linda; Leveroni, Catherine L; Buchbinder, Bradley R; Greve, Douglas N; Stufflebeam, Steven M

    2016-10-01

    Purpose To measure the accuracy of resting-state functional magnetic resonance (MR) imaging in determining hemispheric language dominance in patients with medically intractable focal epilepsies against the results of an intracarotid amobarbital procedure (IAP). Materials and Methods This study was approved by the institutional review board, and all subjects gave signed informed consent. Data in 23 patients with medically intractable focal epilepsy were retrospectively analyzed. All 23 patients were candidates for epilepsy surgery and underwent both IAP and resting-state functional MR imaging as part of presurgical evaluation. Language dominance was determined from functional MR imaging data by calculating a laterality index (LI) after using independent component analysis. The accuracy of this method was assessed against that of IAP by using a variety of thresholds. Sensitivity and specificity were calculated by using leave-one-out cross validation. Spatial maps of language components were qualitatively compared among each hemispheric language dominance group. Results Measurement of hemispheric language dominance with resting-state functional MR imaging was highly concordant with IAP results, with up to 96% (22 of 23) accuracy, 96% (22 of 23) sensitivity, and 96% (22 of 23) specificity. Composite language component maps in patients with typical language laterality consistently included classic language areas such as the inferior frontal gyrus, the posterior superior temporal gyrus, and the inferior parietal lobule, while those of patients with atypical language laterality also included non-classical language areas such as the superior and middle frontal gyri, the insula, and the occipital cortex. Conclusion Resting-state functional MR imaging can be used to measure language laterality in patients with medically intractable focal epilepsy. (©) RSNA, 2016 Online supplemental material is available for this article.

  12. Improvement in cognitive and psychosocial functioning and self image among adolescent inpatient suicide attempters.

    Science.gov (United States)

    Hintikka, Ulla; Marttunen, Mauri; Pelkonen, Mirjami; Laukkanen, Eila; Viinamäki, Heimo; Lehtonen, Johannes

    2006-12-29

    Psychiatric treatment of suicidal youths is often difficult and non-compliance in treatment is a significant problem. This prospective study compared characteristics and changes in cognitive functioning, self image and psychosocial functioning among 13 to 18 year-old adolescent psychiatric inpatients with suicide attempts (n = 16) and with no suicidality (n = 39) The two-group pre-post test prospective study design included assessments by a psychiatrist, a psychologist and medical staff members as well as self-rated measures. DSM-III-R diagnoses were assigned using the SCID and thereafter transformed to DSM-IV diagnoses. Staff members assessed psychosocial functioning using the Global Assessment Scale (GAS). Cognitive performance was assessed using the Wechsler Adult Intelligence Scale, while the Offer Self-Image Questionnaire (OSIQ) was used to assess the subjects' self-image. ANCOVA with repeated measures was used to test changes from entry to discharge among the suicide attempters and non suicidal patients. Logistic regression modeling was used to assess variables associated with an improvement of 10 points or more in the GAS score. Among suicide attempter patients, psychosocial functioning, cognitive performance and both the psychological self and body-image improved during treatment and their treatment compliance and outcome were as good as that of the non-suicidal patients. Suicidal ideation and hopelessness declined, and psychosocial functioning improved. Changes in verbal cognitive performance were more pronounced among the suicide attempters. Having an improved body-image associated with a higher probability of improvement in psychosocial functioning while higher GAS score at entry was associated with lower probability of functional improvement in both patient groups. These findings illustrate that a multimodal treatment program seems to improve psychosocial functioning and self-image among severely disordered suicidal adolescent inpatients. There were no

  13. Improvement in cognitive and psychosocial functioning and self image among adolescent inpatient suicide attempters

    Directory of Open Access Journals (Sweden)

    Laukkanen Eila

    2006-12-01

    Full Text Available Abstract Background Psychiatric treatment of suicidal youths is often difficult and non-compliance in treatment is a significant problem. This prospective study compared characteristics and changes in cognitive functioning, self image and psychosocial functioning among 13 to 18 year-old adolescent psychiatric inpatients with suicide attempts (n = 16 and with no suicidality (n = 39 Methods The two-group pre-post test prospective study design included assessments by a psychiatrist, a psychologist and medical staff members as well as self-rated measures. DSM-III-R diagnoses were assigned using the SCID and thereafter transformed to DSM-IV diagnoses. Staff members assessed psychosocial functioning using the Global Assessment Scale (GAS. Cognitive performance was assessed using the Wechsler Adult Intelligence Scale, while the Offer Self-Image Questionnaire (OSIQ was used to assess the subjects' self-image. ANCOVA with repeated measures was used to test changes from entry to discharge among the suicide attempters and non suicidal patients. Logistic regression modeling was used to assess variables associated with an improvement of 10 points or more in the GAS score. Results Among suicide attempter patients, psychosocial functioning, cognitive performance and both the psychological self and body-image improved during treatment and their treatment compliance and outcome were as good as that of the non-suicidal patients. Suicidal ideation and hopelessness declined, and psychosocial functioning improved. Changes in verbal cognitive performance were more pronounced among the suicide attempters. Having an improved body-image associated with a higher probability of improvement in psychosocial functioning while higher GAS score at entry was associated with lower probability of functional improvement in both patient groups. Conclusion These findings illustrate that a multimodal treatment program seems to improve psychosocial functioning and self-image among

  14. Measurement of human advanced brain function in calculation processing using functional magnetic resonance imaging (fMRI)

    International Nuclear Information System (INIS)

    Hashida, Masahiro; Yamauchi, Syuichi; Wu, Jing-Long

    2001-01-01

    Using functional magnetic resonance imaging (fMRI), we investigated the activated areas of the human brain related with calculation processing as an advanced function of the human brain. Furthermore, we investigated differences in activation between visual and auditory calculation processing. The eight subjects (all healthy men) were examined on a clinical MR unit (1.5 tesla) with a gradient echo-type EPI sequence. SPM99 software was used for data processing. Arithmetic problems were used for the visual stimulus (visual image) as well as for the auditory stimulus (audible voice). The stimuli were presented to the subjects as follows: no stimulation, presentation of random figures, and presentation of arithmetic problems. Activated areas of the human brain related with calculation processing were the inferior parietal lobule, middle frontal gyrus, and inferior frontal gyrus. Comparing the arithmetic problems with the presentation of random figures, we found that the activated areas of the human brain were not differently affected by visual and auditory systems. The areas activated in the visual and auditory experiments were observed at nearly the same place in the brain. It is possible to study advanced functions of the human brain such as calculation processing in a general clinical hospital when adequate tasks and methods of presentation are used. (author)

  15. Calibrated image-derived input functions for the determination of the metabolic uptake rate of glucose with [18F]-FDG PET

    DEFF Research Database (Denmark)

    Christensen, Anders N; Reichkendler, Michala H; Larsen, Rasmus

    2014-01-01

    PURPOSE: We investigated the use of a simple calibration method to remove bias in previously proposed approaches to image-derived input functions (IDIFs) when used to calculate the metabolic uptake rate of glucose (K(m)) from dynamic [(18)F]-FDG PET scans of the thigh. Our objective was to obtain...... nonbiased, low-variance K(m) values without blood sampling. MATERIALS AND METHODS: We evaluated eight previously proposed IDIF methods. K(m) values derived from these IDIFs were compared with Km values calculated from the arterial blood samples (gold standard). We used linear regression to extract...

  16. Imaging human reward processing with positron emission tomography and functional magnetic resonance imaging.

    Science.gov (United States)

    Urban, Nina B L; Slifstein, Mark; Meda, Shashwath; Xu, Xiaoyan; Ayoub, Rawad; Medina, Olga; Pearlson, Godfrey D; Krystal, John H; Abi-Dargham, Anissa

    2012-05-01

    Functional neuroimaging (fMRI) studies show activation in mesolimbic circuitry in tasks involving reward processing, like the Monetary Incentive Delay Task (MIDT). In voltammetry studies in animals, mesolimbic dopamine release is associated with reward salience. This study examined the relationship between fMRI activation and magnitude of dopamine release measured with Positron emission tomography study (PET) in the same subjects using MIDT in both modalities to test if fMRI activation is related to dopamine release. Eighteen healthy subjects were scanned with [¹¹C]raclopride PET at baseline and after MIDT. Binding potential (BP(ND)) was derived by equilibrium analysis in striatal subregions and percent change across conditions (∆BP(ND)) was measured. Blood oxygen level dependence (BOLD) signal changes with MIDT were measured during fMRI using voxelwise analysis and ROI analysis and correlated with ∆BP(ND). ∆BP(ND) was not significant in the ventral striatum (VST) but reached significance in the posterior caudate. The fMRI BOLD activation was highest in VST. No significant associations between ∆BP(ND) and change in fMRI BOLD were observed with VST using ROI analysis. Voxelwise analysis showed positive correlation between BOLD activation in anticipation of the highest reward and ∆BP(ND) in VST and precommissural putamen. Our study indicates that endogenous dopamine release in VST is of small magnitude and is related to BOLD signal change during performance of the MIDT in only a few voxels when rewarding and nonrewarding conditions are interspersed. The lack of correlation at the ROI level may be due to the small magnitude of release or to the particular dependence of BOLD on glutamatergic signaling.

  17. Effect of hyoscine butylbromide on prostate multiparametric MRI anatomical and functional image quality.

    Science.gov (United States)

    Slough, R A; Caglic, I; Hansen, N L; Patterson, A J; Barrett, T

    2018-02-01

    To evaluate the effect of the spasmolytic agent hyoscine butylbromide (HBB) on the quality of anatomical and functional imaging of the prostate. One hundred and seventy-three patients were included in this retrospective study. Eighty-seven patients received intravenous HBB prior to scanning (HBB group) and 86 patients did not (non-HBB group). Multiparametric (mp) 3 T magnetic resonance imaging (MRI) was performed using a 32-channel body coil. Two radiologists independently evaluated the image quality of T2-weighted imaging (WI), diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps, using a five-point Likert scale. DWI was further assessed for distortion and artefact (four-point Likert scale), and T2WI for the presence of motion artefact or blurring. Dynamic contrast-enhanced (DCE) image quality was assessed by recording the number of corrupt contrast curve data points. T2W image quality in the HBB group was significantly higher than in the non-HBB group (3.63±1.11 versus 2.84±0.899); ppoints from the contrast curve (2.47±2.44 versus 3.68±2.64), but this did not reach significance (p=0.052). Administration of HBB significantly improves the image quality of T2WI images. These results provide evidence for the use of HBB in routine patient preparation prior to prostate mpMRI. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  18. Psychophysiology and Imaging of Visual Cortical Functions in the Blind: A Review

    Directory of Open Access Journals (Sweden)

    Stephanie L. Simon-Dack

    2008-01-01

    Full Text Available Imaging, transcranial magnetic stimulation, and psychophysiological recordings of the congenitally blind have confirmed functional activation of the visual cortex but have not extensively explained the functional significance of these activation patterns in detail. This review systematically examines research on the role of the visual cortex in processing spatial and non-visual information, highlighting research on individuals with early and late onset blindness. Here, we concentrate on the methods utilized in studying visual cortical activation in early blind participants, including positron emissions tomography (PET, functional magnetic resonance imaging (fMRI, transcranial magnetic stimulation (TMS, and electrophysiological data, specifically event-related potentials (ERPs. This paper summarizes and discusses findings of these studies. We hypothesize how mechanisms of cortical plasticity are expressed in congenitally in comparison to adventitiously blind and short-term visually deprived sighted participants and discuss potential approaches for further investigation of these mechanisms in future research.

  19. Functional imaging of numerical processing in adults and 4-y-old children.

    Directory of Open Access Journals (Sweden)

    Jessica F Cantlon

    2006-05-01

    Full Text Available Adult humans, infants, pre-school children, and non-human animals appear to share a system of approximate numerical processing for non-symbolic stimuli such as arrays of dots or sequences of tones. Behavioral studies of adult humans implicate a link between these non-symbolic numerical abilities and symbolic numerical processing (e.g., similar distance effects in accuracy and reaction-time for arrays of dots and Arabic numerals. However, neuroimaging studies have remained inconclusive on the neural basis of this link. The intraparietal sulcus (IPS is known to respond selectively to symbolic numerical stimuli such as Arabic numerals. Recent studies, however, have arrived at conflicting conclusions regarding the role of the IPS in processing non-symbolic, numerosity arrays in adulthood, and very little is known about the brain basis of numerical processing early in development. Addressing the question of whether there is an early-developing neural basis for abstract numerical processing is essential for understanding the cognitive origins of our uniquely human capacity for math and science. Using functional magnetic resonance imaging (fMRI at 4-Tesla and an event-related fMRI adaptation paradigm, we found that adults showed a greater IPS response to visual arrays that deviated from standard stimuli in their number of elements, than to stimuli that deviated in local element shape. These results support previous claims that there is a neurophysiological link between non-symbolic and symbolic numerical processing in adulthood. In parallel, we tested 4-y-old children with the same fMRI adaptation paradigm as adults to determine whether the neural locus of non-symbolic numerical activity in adults shows continuity in function over development. We found that the IPS responded to numerical deviants similarly in 4-y-old children and adults. To our knowledge, this is the first evidence that the neural locus of adult numerical cognition takes form early in

  20. Magnetic resonance imaging assessment of regional abdominal muscle function in elite AFL players with and without low back pain.

    Science.gov (United States)

    Hides, Julie; Hughes, Brita; Stanton, Warren

    2011-06-01

    Changes in the motor control of trunk muscles have been identified in people with low back pain (LBP) including elite football players. Previous research has found functional differences in the anatomical regions of abdominal muscles; however, this has not been examined in football players with LBP. The aim of this study was to investigate if the ability to draw-in the abdominal wall is altered among football players with LBP, and to determine if there are functional differences between the middle and lower abdominal regions in participants with and without LBP. Forty-three elite Australian Football League players were imaged using magnetic resonance imaging (MRI) as they drew in their abdominal walls, and the trunk cross-sectional area (CSA) was measured in relaxed and contracted states. At the lower region, participants with LBP (1.1%) reduced their trunk CSA to a lesser extent than those without LBP (3.2%) (P = 0.018). The results also showed that the draw-in of the abdominal wall was smaller in Region 1 (8.8%) compared to Region 2 (16.0%) and Region 3 (19.7%) (P < 0.001). This study provides evidence of regional differences in motor control and altered control of the lower region in participants with LBP. This may direct physiotherapists, especially those treating athletes, to focus on the lower abdominal region in those with LBP. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Evaluation of factor analysis and other functional images in exercise gated blood-pool study

    International Nuclear Information System (INIS)

    Matsunari, Ichiro; Bunko, Hisashi; Nakajima, Kenichi; Taki, Junichi; Shiire, Yasushi; Hisada, Kinichi

    1990-01-01

    Factor analysis, a new method of functional imaging, has been applied to cardiovascular nuclear medicine. Because of the difficulty of its interpretation, it has not been popular as a method for detecting abnormal wall motion. The purpose of this study was to evaluate the usefulness of factor analysis in exercise gated blood-pool study in patients with ischemic heart disease. In our factor analysis, left ventricular region of interest (LVROI) was extracted to exclude the surrounding radioactivities. The new method was compared with the conventional factor analysis using whole region (whole ROI method), and the other functional images, i.e. stroke volume, ejection fraction and phase images. At first we tried 3-factor analysis of the LVROI method, which resulted in many uninterpretable factors. Whereas in 2-factor analysis no uninterpretable factors were extracted. In comparison with cine-mode display, the LVROI method with 2-factor analysis showed the best sensitivity (85%) and specificity (100%). In exercise gated blood-pool study, it became easier to detect abnormal wall motion by comparing the factor image at exercise with resting image. In conclusion, the 2-factor analysis using the LVROI method greatly improved the limitation of conventional factor analysis, and will be useful in detecting wall motion abnormality in patients with ischemic heart disase. (author)

  2. Imaging of the Eustachian tube and its function: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.E.; Tysome, J.R. [Cambridge University Hospitals NHS Foundation Trust, Department of ENT Surgery, Addenbrooke' s Hospital, Cambridge (United Kingdom); Scoffings, D.J. [Cambridge University Hospitals NHS Foundation Trust, Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2016-06-15

    The Eustachian tube is a complex and inaccessible structure, which maintains middle ear ventilation to facilitate transmission of sound from the tympanic membrane to the cochlea. A renewed interest in treatments for eustachian tube dysfunction has led to a demand for methods of imaging the Eustachian tube, and assessing tube opening non-invasively. This review aims to summarise the use of imaging in the anatomical assessment of the Eustachian tube, and to explore how radiological techniques can be used to assess tube function. A systematic review o