SEARCH · PubMed Health

Results for “Projection”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

PubMed1991

Retinal projections in the freshwater butterfly fish, Pantodon buchholzi (Osteoglossoidei). II. Differential projections of the dorsal and ventral hemiretinas.

Pantodon buchholzi, the freshwater butterfly fish, is a member of the Osteoglossomorpha, the most primitive of the four major teleost radiations. The projections of fibers originating in the dorsal and ventral hemiretinas in Pantodon, as determined with autoradiography, are reported here. Fibers originating in the ventral hemiretina reach their targets through the axial, medial and dorsal optic tracts. Fibers that originate in the dorsal hemiretina reach their points of termination by way of the axial, medial and ventral optic tracts. Projections of the various tracts to preoptic, thalamic, tubercular, pretectal and tectal regions, as described in the previous study of total retinal projections, were verified. The retinal projections to the preoptic, thalamic and tubercular nuclei do not map topographically. Ventral hemiretinal fibers are mapped, however, onto the dorsal part of the nucleus pretectalis superficialis pars parvocellularis, the rostral part of the dorsal accessory optic nucleus, the entire nucleus pretectalis periventricularis pars ventralis and the dorsomedial portion of the optic tectum. Ventral hemiretinal fibers also supply most if not all the retinal innervation to the central pretectal nucleus. In contrast, dorsal hemiretinal fibers are mapped onto the ventral part of nucleus pretectalis superficialis pars parvocellularis, the entire dorsal accessory optic nucleus and the ventrolateral portion of the optic tectum. The dorsal and ventral hemiretinal projections to the tectum about at a cytoarchitectonically recognizable point, indicating that no discontinuity is present in the retinal connectivity with the tectum. The pars parvocellularis of nucleus pretectalis superficialis is a simple, unfolded, and nonlaminar structure in Pantodon. This structure contrasts markedly with the more complex, folded structure of the nucleus in the majority of other examined teleosts. The orientation of the projections from the dorsal and ventral hemiretinas onto this nucleus in Pantodon is congruent with that seen in other fishes only after a schematic unfolding of the nucleus in these fishes.

Animals↗

PubMed1999

Notice of availability of funding for alternative projects, known as Wilson/Fish Projects, to implement alternative means of providing interim financial assistance, medical assistance, social services, and case management to refugees and Cuban and Haitian entrants. Office of Refugee Resettlement (ORR), ACF, DHHS.

The Office of Refugee Resettlement (ORR) announces that competing applications will be accepted from public and private non-profit organizations under a standing announcement for Wilson/Fish projects which propose alternative approaches to serving refugees. The purpose of an alternative project is to provide integrated services and cash assistance to refugees in order to increase refugees' prospects for early employment and self-sufficiency, reduce their level of welfare dependence, enhance acculturation, and promote coordination among voluntary resettlement agencies and service providers. Projects will be accepted under either of two categories: (1) Projects to establish or maintain a refugee program in a State where the State is not participating in the refugee program or is dropping out of the refugee program or a portion of the program; and (2) projects to provide an alternative to the existing system of assistance and services to refugees. Funding is available to these projects under the "Wilson/Fish" authority.

Cuba↗

PubMed1995

A portable communicative architecture for electronic healthcare records: the Good European Healthcare Record project (Aim project A2014).

The European Union is supporting research into medical informatics via its Advanced Informatics in Medicine (AIM) program. One of the current AIM projects is the Good European Healthcare Record (GEHR) project. Its objective is to devise an architecture for electronic healthcare records that will enable them to be comprehensive, communicative, and portable to different systems. The work was funded from January 1992 to December 1994. The project team consisted of over 50 personnel representing clinicians, computer scientists, and computer programmers in eight European countries. The partner organizations are Health Data Management Partners (Belgium), Croix Rouge Francaise (France), France Telecom, Association des Medecins et Medicins Dentistes (Luxembourg), Instituto Clinica Geral Zona Norte (Portugal), Medical College of St Bartholomew's Hospital (UK), and SmithKline Beecham (UK). The work of the project has been carried out by three subgroups covering clinical, architecture, and systems aspects. One of the strengths of the project has been that most of the work has been done as collaborations between members of different groups. This has meant that there has been very close contact between clinicians and computer experts. The GEHR project is providing important input into the standardization process in Europe via, for example, PT011 of Working Group 1 of CEN TC/251 (the developing standards for the architecture of healthcare records).

Computer Communication Networks↗

PubMed1998

A project to reduce the burden of diabetes in the African-American Community: Project DIRECT.

Project DIRECT (Diabetes Interventions Reaching and Educating Communities Together) is the first comprehensive community diabetes demonstration project in the United States in an African-American community. This article describes its intervention components and evaluation design. The development and implementation of Project DIRECT has included the community since the project's beginning. Interventions are targeted in three areas: health promotion (improving diet and physical activity levels), outreach (improving diabetes awareness, detection of undiagnosed diabetes, and ensuring that persons with diabetes who are not receiving continuing diabetes care are integrated into the health-care system), and diabetes care (improving self-care, increasing access, and improving the quality of diabetes preventive care received within the health-care system). Evaluation will be internal (conducted by Project DIRECT staff to assess process outcomes in persons directly exposed to each specific intervention) and external (review of outcomes to assess the impact of the multi-intervention program at the level of the entire community). Because diabetes exacts a disproportionate toll among African Americans, the findings from this project should aid in developing strategies to lessen the burden of this disorder, particularly among minority populations.

Black or African American↗

PubMed1998

Timing and origin of the first cortical axons to project through the corpus callosum and the subsequent emergence of callosal projection cells in mouse.

A precise knowledge of the timing and origin of the first cortical axons to project through the corpus callosum (CC) and of the subsequent emergence of callosal projection cells is essential for understanding the early ontogeny of this commissure. By using a series of mouse embryos and fetuses of the hybrid cross B6D2F2/J weighing from 0.36 g to 1.0 g (embryonic day E15.75-E17.25), we examined the spatial and temporal distribution of callosal projection cells by inserting crystals of the lipophilic dye (DiI: 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate) into the contralateral white matter just lateral to the midsagittal plane. Around 0.4 g or E15.8, retrogradely labeled cells were found restricted to a discrete cluster continuously distributed from the most ventral part of presumptive cingulate cortex to the hippocampus. During subsequent development, however, the tangential distribution of these labeled cells in ventromedial cortex did not extend further dorsally, and in fetuses where the CC became distinct from the hippocampal commissure (HC), labeled axons of cells in the ventral cingulate cortex were observed to intersect the callosal pathway and merge with labeled axons of the HC derived from cells in the hippocampus. The first cortical axons through the CC crossed the midline at about 0.64 g or E16.4, and these axons originated from a scattered neuronal population in the dorsal to lateral part of the presumptive frontal cortex. The earliest callosal cells were consistently located in the cortical plate and showed an immature bipolar appearance, displaying an ovoid- or pearl-shaped perikaryon with an apical dendrite coursing in a zig-zagging manner toward the pial surface and a slender axon directed toward the underlying white matter. Callosal projection cells spread progressively with development across the tangential extent of the cerebral cortex in both lateral-to-medial and rostral-to-caudal directions. In any cortical region, the first labeled cells appeared in the cortical plate and their number in the subplate was insignificant compared to that in the cortical plate. Thus, these results clarify that the CC is pioneered by frontal cortical plate cells, and the subsequent ontogeny of callosal projection cells proceeds according to the gradient of cortical maturation.

Animals↗

PubMed1999

Descending auditory pathways: projections from the inferior colliculus contact superior olivary cells that project bilaterally to the cochlear nuclei.

Multiple retrograde and anterograde tracers were used to characterize a pathway that extends from the inferior colliculus to both the left and right cochlear nuclei via a synaptic relay in the superior olivary complex. Different fluorescent tracers were injected into the left and right cochlear nuclei to identify cells in the superior olivary complex that project bilaterally. Double-labeled cells were present in almost all periolivary nuclei; the majority were located in the ventral nucleus of the trapezoid body and the anteroventral periolivary nucleus. Because these two nuclei are targets of descending projections from the inferior colliculus, triple-labeling experiments were performed to determine whether collicular axons contact the periolivary cells that project to the cochlear nuclei. The results demonstrate that descending axons from the inferior colliculus contact periolivary cells that project to the cochlear nuclei, including periolivary cells that project bilaterally. This pathway could provide an opportunity for higher levels of the auditory system to influence activity bilaterally in the cochlear nuclei and thus to modulate the initial processing of acoustic information by the brain.

Animals↗

PubMed1987

Noradrenergic projections to brainstem nuclei: evidence for differential projections from noradrenergic subgroups.

Retrograde transport of the fluorescent tracer True Blue was used in combination with immunohistochemical staining of dopamine-beta-hydroxylase (a marker protein for noradrenergic neurons) to determine the origin of noradrenergic projections to three cranial nerve nuclei: 1) the motor nucleus of the trigeminal nerve, 2) the motor nucleus of the facial nerve, and 3) the spinal trigeminal nucleus pars interpolaris. Noradrenergic cells in the rat brainstem were divided into subgroups and their numbers were determined in serial sections stained with an antiserum to rat dopamine-beta-hydroxylase. Following tracer injections into the three brainstem nuclei, retrogradely labeled noradrenergic neurons were counted and the percentage of True Blue-labeled noradrenergic cells in each subgroup was calculated. Injections of tracer into the three cranial nerve nuclei resulted in distinctly different labeling patterns of noradrenergic cells. Of the total number of norepinephrine neurons projecting to the motor nucleus of the trigeminal nerve, 68% were observed within the A7 cell group; 75% of those innervating the motor nucleus of the facial nerve were found in the A5 cell group, and 65% of those projecting to the spinal trigeminal nucleus pars interpolaris were present in the locus ceruleus and subceruleus. These findings indicate that norepinephrine cells in the rat brainstem do not constitute a homogeneous population of cells but that several discrete systems can be identified that differ not only in topography but also in the terminal distribution of their axons. This combined retrograde transport-immunohistochemical study reveals a much higher degree of topographic order in the projections of norepinephrine neurons than has previously been recognized. The observation of differential projections of noradrenergic subgroups argues against the notion of a global influence of these cells over functionally diverse areas of the brainstem.

Animals↗

PubMed1990

Extrinsic projections from area CA1 of the rat hippocampus: olfactory, cortical, subcortical, and bilateral hippocampal formation projections.

Hippocampal area CA1 provides the major cortical output of the hippocampus, but only its projections to the subiculum and lateral septal nucleus are well characterized. The present study reexamines these extrinsic projections by using anterograde and retrograde tracing techniques. Injections of the anterograde tracer Phaseolus vulgaris leucoagglutinin (PHA-L) in the septal one-third of CA1 label axons and terminals in subicular, postsubicular, retrosplenial, perirhinal, and entorhinal cortices, lateral septal nucleus, and diagonal band of Broca. The septal CA1 injections also label terminal fields in contralateral CA1, and in contralateral subicular, postsubicular, perirhinal, and entorhinal cortices. Injections into the splenial one-third of CA1 label axons and terminals in subiculum, postsubiculum, ventral area infraradiata, and lateral septal nucleus, but they do not label axons and terminals on the contralateral side of the brain. Injections in the temporal one-third of CA1 label axons and terminals in subicular, parasubicular, entorhinal, and infraradiata cortices, anterior olfactory nucleus, olfactory bulb, lateral septal nucleus, nucleus accumbens, amygdala, and hypothalamus. The temporal CA1 injections label no axons on the contralateral side of the brain. These data demonstrate that CA1 has more widespread projections than previously appreciated, and they provide the first clear evidence that CA1 projects to the contralateral cortex and to the ipsilateral olfactory bulb, amygdala, and hypothalamus. The results also demonstrate a heterogeneity in the efferent projections originating in different septotemporal levels of CA1.

Afferent Pathways↗

PubMed1993

Specificity in the efferent projections of the nucleus accumbens in the rat: comparison of the rostral pole projection patterns with those of the core and shell.

The efferent connections of the rostral pole of the rat accumbens, where distinct core and shell subterritories can not be identified, were examined with the aid of the anterogradely transported plant lectin, Phaseolus vulgaris-leucoagglutinin (PHA-L), for comparison with the previously reported projection patterns of the accumbal core and shell. Injection sites and transported PHA-L were evaluated with the aid of reference to adjacent sections processed to display substance P or calbindin 28 kD immunoreactivities, i.e., markers that demonstrate the core and shell. Lateral parts of the rostral pole gave rise to a "core-like" projection system that involved the rostroventral globus pallidus, subcommissural ventral pallidum, entopeduncular nucleus and an adjacent part of the lateral hypothalamus, lateral ventral tegmental area, dorsal pars compacta, and structures in the lateral mesencephalic tegmentum and central grey. The medial part of the rostral pole gave rise to a "shell-like" innervation of the subcommissural ventral pallidum, lateral preoptic region, lateral hypothalamus, ventral tegmental area, dorsalmost pars compacta, retrorubral field, lateral midbrain tegmentum, and central grey. In contrast to the large numbers of axon varicosities observed through the entire length of lateral hypothalamus following shell injections, dense accumulations of axon collaterals and varicosities in hypothalamus were limited to the levels of origin of the stria medullaris bundle and entopeduncular nucleus and to the posterlateral region following medial injections. The medial part of the rostral pole contributed some projections to preoptic and sublenticular regions, but not to the bed nucleus of the stria terminalis. Noteworthy concentrations of calbindin immunoreactive cells observed in the lateral rostral pole correlate with the origin of the "basal ganglia-like" projection system, provoking the speculation that ventral striatal calbindin immunoreactive cells contribute principally to basal ganglia-like projections while cells lacking calbindin immunoreactivity contribute to the innervation of hypothalamus and midbrain tegmentum.

Animals↗

PubMed1997

Three-dimensional projection imaging with half the number of projections.

This study demonstrates a sampling scheme for three-dimensional projection imaging with half the number of projections. The angular distribution of projections is designed so that the oversampling of the low spatial frequencies, in tandem with a partial Fourier algorithm, can be used to recreate purposely missing projections. The performance of the sampling scheme and its associated reconstruction algorithm are illustrated with computer-simulated as well as experimental data sets. We find that this technique produces images of comparable quality to the conventional projection imaging scheme. Although a 30% loss of signal-to-noise ratio (SNR) results from its use, the algorithm should prove useful for applications where robustness against motion artifacts and reduced T2* signal loss are desired.

Algorithms↗

PubMed1995

A breast and cervical cancer project in a native Hawaiian community: Wai'anae cancer research project.

BACKGROUND: This article describes a breast and cervical cancer control project in a Native Hawaiian community and presents preliminary findings from its first year. The project is community driven, with Native Hawaiian community investigators and advisors involved in all phases of the research project. Its purpose is to test the effectiveness of a culturally appropriate intervention as a means of increasing breast and cervical cancer screening practices among Native Hawaiian women. METHODS: This article discusses the process of community participation in the development of a baseline survey as well as selected findings from that survey. A baseline telephone survey was conducted to obtain an initial assessment of community knowledge, attitudes, and behavior related to cancer. Community representatives were an integral part of the research team that planned and implemented the survey. RESULTS: A total of 1,260 women drawn equally from the study and the control communities participated in the survey. A majority of those surveyed in both communities indicated adherence to cancer screening recommendations. Seventy-three percent of the women reported having obtained a Pap test during the past 2 years. Fifty-nine percent of women over 40 years of age reported having had a mammogram during the past 2 years. Twenty-eight percent reported having used Hawaiian remedies within the past year. Thirty-six percent of the women reported encouraging others to obtain cancer screening services. DISCUSSION: Though a majority of the target population are following cancer screening guidelines, a significant minority are not. While the project intervention aims to change the screening behavior of women not currently getting cancer screening, it plans to do so by enlisting the women already in compliance to reach others in their social networks who are currently not getting cancer screening. The involvement of community representatives, working alongside researchers, in baseline survey planning helped assure the survey was acceptable to the participants and the community as a whole. This process is illustrative of a participatory research commitment which underlies success in the early phase of this Native Hawaiian research project.

Adult↗

PubMed1987

The cerebellar corticonuclear projection from lobule Vb/c of the cat anterior lobe: a combined electrophysiological and autoradiographic study. I. Projections from the intermediate region.

The present study examines the projection to the cerebellar nuclei of Purkinje cells in particular sagittal zones within the intermediate region of the cerebellar cortex. The boundaries between the zones were delimited electrophysiologically on the basis of their climbing fibre input so that a small volume (10-120 nl) of 3H-leucine could be injected into the centre of a chosen zone. The subsequent uptake and orthograde transport of labelled material by the Purkinje cells was studied autoradiographically. It was found that the smallest injections resulted in injection sites restricted to a single cortical zone and extremely reproducible results could be obtained using such a combined electrophysiological/autoradiographic technique. Larger injections sometimes spread to a neighbouring zone but the resultant terminal labelling within the deep nuclei was invariably consistent with the results obtained from smaller injections. The c1 and c3 olivocerebellar zones, which are known to receive climbing fibre input transmitted from the ipsilateral forelimb via a dorsal funiculus spino-olivo-cerebellar pathway (DF-SOCP), were found to project to partially overlapping regions within nucleus interpositus anterior (NIA). No projection to nucleus interpositus posterior (NIP) was demonstrated for either zone. No distinction could be seen between the terminal fields for the medial and lateral halves of the c1 zone which are, however, known to receive their climbing fibre input from quite separate regions within the inferior olive. The c2 zone, which was delimited on the basis of its climbing fibre input which is transmitted from both forelimbs via a lateral funiculus SOCP, was found to project exclusively to interpositus posterior. The hemispheral d1 zone was found to project to the transitional region where interpositus anterior and the dentate nucleus adjoin.

Animals↗

PubMed1982

An autoradiographic study of the cerebellopontine projections in the rat. I. Projections from the medial cerebellar nucleus.

The medial cerebellar nucleus of the rat is shown by the autoradiographic technique to project to both the contralateral nucleus reticularis tegmenti pontis and the pontine nuclei proper. The former projection is more concentrated in the medial--parvocellular --region. In the pontine gray, the bulk of the projection concerns the dorsal aspect of the medial nucleus. Rostral parts of the medial cerebellar nucleus project to caudal pontine levels whereas caudal parts seem to project throughout the rostrocaudal extent of the basilar pons.

Animals↗

PubMedDate not supplied

Distribution and origins of substance P-immunoreactive projections to the paraventricular and supraoptic nuclei: partial overlap with ascending catecholaminergic projections.

Anatomical and pharmacological evidence suggests a role for substance P (SP) in the control of vasopressin secretion, but the origins of SP-immunoreactive (IR) projections to the paraventricular (PVH) and supraoptic (SO) nuclei of the hypothalamus have not yet been identified. Combined axonal transport, immunohistochemical, and ablation approaches were used to characterize the organization of SP-IR projections to the PVH. The results may be summarized as follows: (1) SP-IR projections are broadly and prominently distributed throughout the SO and both the magnocellular and parvicellular divisions of the PVH. The distribution within the PVH is quite uniform. (2) Combined retrograde transport-immunohistochemical analyses identified multiple potential sources of SP-IR inputs to the PVH. These included a number of hypothalamic cell groups, the laterodorsal and peduculopontine tegmental nuclei, and the rostral and caudal aspects of the ventrolateral medulla. Portions of the tegmental and medullary SP-IR neurons that were retrogradely labelled following tracer deposits in the PVH also stained positively for choline acetyltransferase or tyrosine hydroxylase, respectively. (3) To evaluate the distribution and prominence of medullary SP-IR projections to the PVH and SO, staining for SP and catecholamine-synthesizing enzymes was carried out in animals that had previously received knife cuts at the level of the pontomedullary border. Pronounced, and roughly parallel decrements in staining for peptide and amines were seen in the magnocellular division of the PVH and in the SO; less marked reductions in SP-IR varicosities are in a position to influence multiple visceral regulatory cell types in the PVH and SO. Inputs to the magnocellular neurosecretory system arise in large measure from medullary neurons in which SP coexists with catecholamines. SP-IR projections to the parvicellular division of the PVH appear to originate from a number of sources.

Amino Acid Sequence↗

PubMed1988

Axon extension and retraction by leech neurons: severing early projections to peripheral targets prevents normal retraction of other projections.

During leech embryogenesis, interactions between homologous neurons in neighboring segments lead to the selective retraction of longitudinal axonal projections by midbody AP and AE neurons, which maintain lateral axonal projections to the periphery. Results of experiments reported here show that disconnecting the lateral projections from the periphery rescues the projections normally fated to retract. We propose that these neurons normally progress through two states during early development, one in which they are insensitive to interactions with their homologs (state A) and a second in which they are sensitive (state B). Establishment of lateral connections with their targets triggers the switch from state A to state B; cutting these projections puts neurons back to state A.

Animals↗

PubMed1998

Effects of projection geometry and number of projections on accuracy of depth discrimination with tuned-aperture computed tomography in dentistry.

OBJECTIVE: The purpose of this study was to determine the degree to which the number and angular disparity of component projections influence depth discrimination with tuned-aperture computed tomography. STUDY DESIGN: Groups of three tiny steel spheres served as fiducial references on and in four partially edentulous mandibles. Two spheres were attached to the facial and lingual surfaces of each mandible, and the third was fixed in the apical region of an open tooth socket. Errors in estimates of the depth of the apically positioned sphere relative to the other two spheres were determined from three-dimensional tuned-aperture computed tomography reconstructions. These data were compared with actual measurements produced independently with an optical micrometer. Multiple projections required by the tuned-aperture computed tomography reconstruction algorithm were produced from radially symmetric exposures bearing angular disparities of 5, 15, 30, and 45 degrees. The number of symmetrically dispersed projections per tuned-aperture computed tomography reconstruction likewise was varied systematically (2, 4, 8, 12, and 16 projections). These variables were manipulated through the use of a balanced factorial design. Depth estimates were performed by trained observers; the estimates were based on the determination of tuned-aperture computed tomography slices perceived as imaging the respective apical spheres in sharpest focus. Specimen and observer effects were also considered as independent variables. Resulting data were normalized by logarithmic transformation and analyzed statistically by analysis of variance. RESULTS: Significant differences (p < 0.005) were demonstrated for angular disparity and specimen effects, but the number of projections and the effect of the observer were not found to be statistically significant. CONCLUSIONS: In dentistry, angular disparities of 15 degrees or greater should be used when tuned-aperture computed tomography is being applied to diagnostic tasks requiring maximal depth discrimination accuracy.

Algorithms↗

PubMed1999

A comparison of pre-Project 2000 and Project 2000 nurses' perceptions of their research training, research needs and of their use of research in clinical areas.

Most of the literature on the research training and education of nurses has focused on teaching strategies. Only a few authors have assessed systematically the impact of research modules or courses on the knowledge and attitudes of nurses. There is a lack of research on nurses' use of research following their preparation. This paper reports on some of the data from a large-scale survey of the utilization of research among nurses in Northern Ireland. In particular, a comparison is made of the perceptions of pre-Project 2000 and Project 2000 qualified nurses of their research training, research needs, and use of research in clinical areas. A questionnaire was distributed to a convenience sample of 2600 nurses from 23 hospitals in 14 Trusts in Northern Ireland. The response rate was 52.6% (n = 1368). The findings show, among others, a shortfall in research preparation of pre-Project 2000 nurses in important aspects of research. While Project 2000 nurses reported receiving more training, they did not report higher rates of research utilization than pre-Project 2000 nurses. Registered mental nurses (RMNs) and registered nurses mental handicap (RNMHs) also reported lower rates of research utilization than registered general nurses (RGNs), despite reporting the same amount of research preparation as RGNs. The implications of these findings are discussed.

Curriculum↗

PubMed2000

EPR imaging from projections: errors due to misalignment of projection centres and their rectification by a novel acquisition modality.

Continuous wave and pulsed wave electron paramagnetic resonance imaging (EPRI) makes use of classical methods of acquisition of projections. Acquisition/reconstruction techniques, such as spin-echo, gradient-echo, etc, cannot be applied to EPRI because they would require very short switching times for the gradient coils. Due to the use of the polar acquisition technique, it is necessary to define a centre of rotation about which the measured projections are rotated during the reconstruction process. This centre represents the point at which the field gradient coils must produce zero magnetic field. Due to the presence of a magnetic field control system that serves to compensate for field variations, principally due to heating, some interference can occur in the control system between the main magnetic field and the magnetic field produced by the gradient coils. The effect changes as the orientation changes. This results in a shift of the centres of the projections as a function of the variation of magnetic field produced by the gradient coils on the control Hall probe. If this condition is present, some artefacts can appear on the reconstructed image. This effect is irrelevant when EPR is used for imaging of paramagnetic probes whose linewidths are of the order of 10(-4) T, while it can be significant in the case of linewidths of the order of 10(-5) T or lower or when EPR is used in microimaging applications (i.e. for high values of magnetic field gradient). We describe the effects that misalignments of the projections have on the reconstructed images. We present a useful method for estimating the real position of the centre and correcting the measured projections before the application of the reconstruction algorithm. Moreover, we demonstrate the functioning of our technique by presenting some examples of EPR reconstruction collected by an X-band EPR imaging apparatus.

Algorithms↗