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Your search keyword '"Haacke, E.M."' showing total 101 results
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101 results on '"Haacke, E.M."'

8. Temporal averaging of phase measurements in the presence of spurious phase drift: application to phase-stepped real-time holographic interferometry

Author

Ovryn, B. and Haacke, E.M.

Subjects
Holographic interferometry -- Research, Interference (Light) -- Analysis, Optical measurements -- Research, Astronomy, Physics
Abstract

A technique that compensates for low spatial frequency spurious phase changes during an interference experiment is developed; it permits temporal averaging of multiple phase measurements, made before and after object displacement. The method is tested with phase-stepped real-time holographic interferometry applied to cantilever bending of a piezoelectric bimorph ceramic. Results indicate that temporal averaging of the corrected data significantly reduces the white noise in a phase measurement without incurring systematic errors or sacrificing spatial resolution. White noise is reduced from 3 degrees to less than 1 degree (lambda/360) using these methods.

Published
1993

9. Conformal mapping analyses of microstrips with circular and elliptical cross-sections

Author

Martens, M.A., Brown, R.W., and Haacke, E.M.

Subjects
Conformal mapping -- Research, Microwave wiring -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

A new conformal transformation is derived in terms of a Schwarz-Christoffel transformation involving elliptic integrals of the first and third kind. This mapping function is used to give exact solutions for TEM excitations of microstrips and coupled microstrips with circular and elliptical cross-sections. Using these maps, the uniformity of the TEM mode magnetic field inside an elliptical slotted tube transmission line is investigated.

Published
1992

13. Increased iron deposition of deep cerebral gray matter structures in hemodialysis patients: A longitudinal study using quantitative susceptibility mapping.

Author

Chai, Chao, Wang, Huiying, Liu, Saifeng, Chu, Zhi‐Qiang, Li, Jinping, Qian, Tianyi, Haacke, E.M., Xia, Shuang, Shen, Wen, and Chu, Zhi-Qiang

Abstract

Background: The cerebral iron overload in hemodialysis patients has been reported in a previous study, in which the evaluation of the changes in iron content could be affected by the cross-sectional analysis.Purpose: To investigate the longitudinal changes of iron deposition in hemodialysis patients using quantitative susceptibility mapping (QSM) and correlate these findings with the longitudinal changes of neurocognitive function and clinical factors.Study Type: Prospective; longitudinal.Population: In all, 34 patients and 30 healthy controls (HCs); the mean follow-up interval was 22 ± 7 months.Field Strength/sequence: 3.0T, susceptibility-weighted imaging (SWI).Assessment: QSM reconstructed from original phase data of SWI was used to measure the susceptibility of gray matter structures including bilateral caudate nucleus (CN), globus pallidus (GP), putmen (PUT), red nucleus (RN), substantia nigra (SN), dentate nucleus (DN), thalamus (THA), pulvinar of thalamus (PT). The Mini-Mental State Examination (MMSE) test and clinical factors were recorded.Statistical Testing: Analysis of covariance adjusting for age and gender as covariates or a paired t-test for the differences in susceptibility, MMSE scores, and clinical factors among baseline, follow-up patients, and HCs. Correlation and stepwise regression analysis for the relationship between susceptibility, MMSE scores, and clinical factors.Results: The susceptibility of bilateral CN, GP, PUT, RN, SN, DN, THA, PT in follow-up patients was significantly higher than that in baseline between patients and HCs except for left THA (all P < 0.05; Bonferroni corrected). MMSE scores significantly negatively correlated with the susceptibility of bilateral CN, PUT, and RRN in the baseline examination and bilateral CN, PUT, RN, and DN in the follow-up examination (all P < 0.05; false discovery rate [FDR] corrected). The follow-up interval, creatinine, phosphorus, and calcium were independent factors for the increased susceptibility of some nuclei (all P < 0.05).Data Conclusion: The iron deposition of gray matter nuclei in hemodialysis patients increased over roughly a 2-year period and may be a risk factor for neurocognitive impairment. Creatinine and abnormal calcium-phosphorus metabolism were independent risk factors for abnormal iron deposition.Level Of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:786-799. [ABSTRACT FROM AUTHOR]

Published
2019
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16. Multimodality Imaging of Cortical and White Matter Abnormalities in Sturge-Weber Syndrome

Author

Juhász, C., Haacke, E.M., Hu, J., Xuan, Y., Makki, M., Behen, M.E., Maqbool, M., Muzik, O., Chugani, D.C., and Chugani, H.T.

Subjects
Male, Collateral Circulation, Infant, Water, Neuropsychological Tests, Pediatrics, Cerebral Veins, Nerve Fibers, Myelinated, Diffusion Magnetic Resonance Imaging, Glucose, Sturge-Weber Syndrome, Child, Preschool, Positron-Emission Tomography, Humans, Female, Prospective Studies, Child, Cognition Disorders
Abstract

BACKGROUND AND PURPOSE: Impaired cortical venous outflow and abnormal deep venous collaterals are common in Sturge-Weber syndrome (SWS), but their relation to brain metabolism and function is poorly understood. In this study, advanced MR imaging techniques, such as susceptibility-weighted imaging (SWI) and diffusion tensor imaging (DTI), were applied in conjunction with positron-emission tomography (PET), to assess cortical and white matter structural abnormalities and their relation to cortical glucose metabolism and cognitive functions in children with unilateral SWS. MATERIALS AND METHODS: Thirteen children (age, 1.5–10.3 years) with unilateral SWS underwent MR imaging with SWI and DTI, glucose metabolism PET, and comprehensive neuropsychologic assessment prospectively. The MR imaging and PET images were coregistered and cortical regions showing decreased glucose metabolism were compared with locations of SWI signal intensity abnormalities, changes in white matter water diffusion, and cognitive functions. RESULTS: SWI detected both cortical abnormalities (n = 8) and deep transmedullary veins (n = 9), including those in young children with no cortical SWI signal intensity changes. These veins were often located under cortex adjacent to hypometabolic regions. DTI showed abnormal water diffusion both under hypometabolic cortex and in adjacent white matter with collateral veins. Cognitive dysfunction was associated with abnormal water diffusion in the posterior white matter. CONCLUSIONS: Transmedullary venous collaterals can be detected early by SWI and persist in white matter adjacent to damaged cortex in children with SWS. Microstructural white matter damage extends beyond cortical abnormalities and may contribute to cognitive impairment. SWI and DTI can be incorporated into clinical MR imaging acquisitions to objectively assess microstructural abnormalities at different stages of SWS.

Published
2007

17. Imaging Cerebral Amyloid Angiopathy with Susceptibility-Weighted Imaging

Author

Haacke, E.M., DelProposto, Z.S., Chaturvedi, S., Sehgal, V., Tenzer, M., Neelavalli, J., and Kido, D.

Subjects
Male, Cerebral Amyloid Angiopathy, Cerebrovascular Circulation, Microcirculation, mental disorders, nutritional and metabolic diseases, Brain, Humans, cardiovascular diseases, Cerebral Infarction, Magnetic Resonance Imaging, Aged
Abstract

SUMMARY: Gradient-echo (GE) imaging is recognized as a means to detect hemorrhagic changes in cerebral amyloid angiopathy (CAA). However, almost 25% of patients with CAA do not show microhemorrhages on T2* GE imaging. We applied a new imaging method, susceptibility weighted imaging (SWI), to evaluate the presence of microhemorrhages. In a suspected case of CAA, where cognitive effects are also present, we show that SWI is much more sensitive in detecting microhemorrhages than conventional methods.

Published
2007

48. The FUTURE PRESENT.

Author

Stone, Jennifer, Rubel, Edwin, Hillman, Robert E., Cutter, Matthew, Mauszycki, Shannon C., Shannon, Robert V., Fridriksson, Julius, Murray Law, Bridget, Shuster, Linda I., Dronkers, Nina F., Patel, Rupal, and Haacke, E.M.

Subjects
COMMUNICATIVE disorders, HEARING disorder diagnosis, TINNITUS treatment, VOICE disorders, BRAIN injury diagnosis, STEM cell transplantation, HAIR cells, PHYSIOLOGICAL control systems, BRAIN, BRAIN injuries, COMMUNICATION devices for people with disabilities, DIAGNOSTIC imaging, ELECTRIC stimulation, ELECTRODIAGNOSIS, FACILITATED communication, HEARING aids, HEARING impaired, MAGNETIC resonance imaging, MAGNETOTHERAPY, COMPUTERS in medicine, PALATE, REHABILITATION, SPEECH therapy, THERAPEUTICS, WIRELESS communications, REHABILITATION of aphasic persons, SPEECH apraxia, AUDITORY brain stem implants, COMPUTER-aided diagnosis, DIAGNOSIS, TRANSPLANTATION of organs, tissues, etc.
Abstract

The article describes 11 new technologies that could revolutionize diagnosis and treatment of speech, language, and hearing disorders. Research is being conducted on hair cell transplantation and auditory brain stem implants to treat hearing loss. Advanced forms of laryngeal imaging to diagnose problems with the vocal cords are being investigated by scientists. Research is underway on diffusion magnetic resonance imaging to better diagnose traumatic brain injury.

Published
2013
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