Entity

Time filter

Source Type

Image, Netherlands

Van Der Aa N.E.,Ke Diet Inc. | Leemans A.,Image science Institute | Northington F.J.,Johns Hopkins Hospital | Van Straaten H.L.,Isala Clinics | And 4 more authors.
Stroke | Year: 2011

Background and Purpose: After perinatal arterial ischemic stroke, diffusion-weighted imaging (DWI) and early evaluation of spontaneous motor behavior can be used to predict the development of unilateral motor deficits. The aim of this study was to investigate whether diffusion tensor imaging-based tractography at 3 months of age contributes to this prediction. Methods: Twenty-two infants with unilateral perinatal arterial ischemic stroke were included and scanned during the neonatal period. DWI was used to assess restricted diffusion in the cerebral peduncle. At the age of 3 months, diffusion tensor imaging-based tractography of the corticospinal tracts was performed along with assessment of the movement repertoire. The role of DWI, diffusion tensor imaging, and motor assessment in predicting unilateral motor deficits were compared by calculating the positive and negative predictive values for each assessment. Results: Eleven infants (50%) showed abnormal motor behavior at 3 months with subsequent development of unilateral motor deficits in 8 as determined at follow-up (9-48 months, positive predictive value 73%). Diffusion tensor imaging-based tractography correctly predicted the development of unilateral motor deficits in all 8 infants (positive predictive value 100%). A diagnostic neonatal DWI was available in 20 of 22 (91%) infants. Seven infants showed an abnormal DWI, resulting in unilateral motor deficits in 6 infants (positive predictive value 86%). All assessments had a negative predictive value of 100%. Conclusions: Diffusion tensor imaging-based tractography at 3 months can be used to predict neurodevelopmental outcome after perinatal arterial ischemic stroke. It has a similar predictive value as DWI in the neonatal period and can especially be of additional value in case of an indecisive neonatal DWI or unexpected abnormal early motor development. © 2011 American Heart Association, Inc. Source


Turkbey B.,U.S. National Cancer Institute | Merino M.J.,U.S. National Institutes of Health | Gallardo E.C.,U.S. National Institutes of Health | Gallardo E.C.,Image science Institute | And 11 more authors.
Journal of Magnetic Resonance Imaging | Year: 2014

Purpose To compare utility of T2-weighted (T2W) MRI and diffusion-weighted MRI (DWI-MRI) obtained with and without an endorectal coil at 3 Tesla (T) for localizing prostate cancer. Materials and Methods This Institutional Review Board-approved study included 20 patients (median prostate-specific antigen, 8.4 ng/mL). Patients underwent consecutive prostate MRIs at 3T, first with a surface coil alone, then with combination of surface, endorectal coils (dual coil) followed by robotic assisted radical prostatectomy. Lesions were mapped at time of acquisition on dual-coil T2W, DWI-MRI. To avoid bias, 6 months later nonendorectal coil T2W, DWI-MRI were mapped. Both MRI evaluations were performed by two readers blinded to pathology with differences resolved by consensus. A lesion-based correlation with whole-mount histopathology was performed. Results At histopathology 51 cancer foci were present ranging in size from 2 to 60 mm the sensitivity of the endorectal dual-coil, nonendorectal coil MRIs were 0.76, 0.45, respectively. PPVs for endorectal dual-coil, nonendorectal coil MRI were 0.80, 0.64, respectively. Mean size of detected lesions with nonendorectal coil MRI were larger than those detected by dual-coil MRI (22 mm versus 17.4 mm). Conclusion Dual-coil prostate MRI detected more cancer foci than nonendorectal coil MRI. While nonendorectal coil MRI is an attractive alternative, physicians performing prostate MRI should be aware of its limitations. Copyright © 2013 Wiley Periodicals, Inc. Source


Wisse L.E.M.,Brain Center Rudolf Magnus | Wisse L.E.M.,Julius Center for Health science and Primary Care | Biessels G.J.,Brain Center Rudolf Magnus | Heringa S.M.,Brain Center Rudolf Magnus | And 4 more authors.
Neurobiology of Aging | Year: 2014

We compared hippocampal subfield and entorhinal cortex (ERC) volumes between patients with mild cognitive impairment (MCI), Alzheimer's disease (AD), and controls without cognitive impairment. Additionally, we investigated the relation between age and hippocampal subfields and ERC in controls. We performed ultra-high field 0.7 mm3 7Tesla magnetic resonance imaging in 16 patients with amnestic MCI, 9 with AD, and 29 controls. ERC, subiculum, cornu ammonis (CA)1, CA2, CA3, and dentate gyrus (DG)&CA4 were traced on T2-weighted images. Analyses of covariance, adjusted for age, sex, and intracranial volume showed that compared with controls and patients with MCI, patients with AD had significantly smaller ERC, subiculum, CA1, CA3, and DG&CA4 volumes. Trend analyses revealed similar associations between ERC and hippocampal subfields and diagnostic group. Older age was significantly associated with smaller CA1 and DG&CA4 volumes. In conclusion, almost all hippocampal subfields and ERC show volume reductions in patients with AD compared with controls and patients with MCI. Future, larger studies should determine which subfields are affected earliest in the disease process and what mechanisms underlie the volume loss. © 2014 Elsevier Inc. Source


Smeets P.A.M.,Image science Institute | Smeets P.A.M.,Wageningen University | Kroese F.M.,University Utrecht | Evers C.,University Utrecht | De Ridder D.T.D.,University Utrecht
Behavioural Brain Research | Year: 2013

Typically, it is believed that palatable, high caloric foods signal reward and trigger indulgent responses. However, Counteractive Control Theory suggests that, to the extent that people are concerned about their weight, a confrontation with palatable foods should also trigger 'alarm bell responses' which promote successful self-control. Our study is the first to investigate such counteractive control processes in the brain employing functional magnetic resonance imaging (fMRI) in a sample of successful self-regulators. Indeed, besides the traditional finding that foods elicit heightened attention as witnessed by greater activation of primary visual cortex, we found that viewing palatable foods elicited brain activation in areas associated with self-regulation. Crucially, brain activation in self-regulation areas was related to diet importance. Thus, our results are the first to show that food cues not only evoke hedonic brain responses; in successful self-regulators they also trigger alarm bell responses, which may reflect the neural processes underlying successful self-control. © 2013 Elsevier B.V. Source


Tiebosch I.A.C.W.,Image science Institute | Van Den Bergh W.M.,University Utrecht | Van Den Bergh W.M.,University of Groningen | Bouts M.J.R.J.,Image science Institute | And 3 more authors.
Cerebrovascular Diseases | Year: 2013

Background: The pathogenesis of delayed cerebral injury after aneurysmal subarachnoid hemorrhage (SAH) is largely unresolved. In particular, the progression and interplay of tissue and perfusion changes, which can significantly affect the outcome, remain unclear. Only a few studies have assessed pathophysiological developments between subacute and chronic time points after SAH, which may be ideally studied with noninvasive methods in standardized animal models. Therefore, our objective was to characterize the pattern and correlation of brain perfusion and lesion status with serial multiparametric magnetic resonance imaging (MRI) from subacute to chronical after experimental SAH in rats. Methods: SAH was induced by endovascular puncture of the intracranial bifurcation of the right internal carotid artery in adult male Wistar rats (n = 30). Diffusion-, T2-, perfusion- and contrast-enhanced T1-weighted MRI were performed on a 4.7-tesla animal MR system to measure cytotoxic and vasogenic edema, hemodynamic parameters and blood-brain barrier permeability, respectively, at days 2 and 7 after SAH. The neurological status was repeatedly monitored with different behavioral tests between days -1 and 7 after SAH. Lesioned tissue - identified by edema-associated T2 prolongation - and unaffected tissue were outlined on multislice images and further characterized based on tissue and perfusion indices. Correlation analyses were performed to evaluate relationships between different MRI-based parameters and between MRI-based parameters and neurological scores. Results: Similar to clinical SAH and previous studies in this experimental SAH model, mortality up to day 2 was high (43%). In surviving animals, neurological function was significantly impaired subacutely, and tissue damage (characterized by T2 prolongation and diffusion reduction) and blood-brain barrier leakage (characterized by contrast agent extravasation) were apparent in ipsilateral cortical and subcortical tissue as well as in contralateral cortical tissue. Notably, ipsilateral cortical areas revealed increased cerebral blood flow and volume. Animals that subsequently died between days 2 and 7 after SAH had markedly elevated ipsilateral perfusion levels at day 2. After a week, neurological function had improved in surviving animals, and brain edema was partially resolved, while blood-brain barrier permeability and hyperperfusion persisted. The degree of brain damage correlated significantly with the level of perfusion elevation (r = 0.78 and 0.85 at days 2 and 7, respectively; p < 0.05). Furthermore, chronic (day 7 after SAH) blood-brain barrier permeability and vasogenic edema formation were associated with subacute (day 2 after SAH) hyperperfusion (r = 0.53 and 0.66, respectively; p < 0.05). Conclusion: Our imaging findings indicate that SAH-induced brain injury at later stages is associated with progressive changes in tissue perfusion and that chronic hyperperfusion may contribute or point to delayed cerebral damage. Furthermore, multiparametric MRI may significantly aid in diagnosing the brain's status after SAH. Copyright © 2013 S. Karger AG, Basel. Source

Discover hidden collaborations