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Utility of magnetic resonance spectroscopic imaging for human epilepsy

Jullie W Pan, Ruben I Kuzniecky
2015 Quantitative Imaging in Medicine and Surgery  
Recent data from Hetherington 2007 and Pan 2012 (29, 30) has also demonstrated that the decrements in NAA are not just localized to the ipsilateral hippocampus, but consistent with existing PET finding  ... 
doi:10.3978/j.issn.2223-4292.2015.01.03 pmid:25853088 pmcid:PMC4379323 fatcat:atvuvrdjkvcwnd5jzuiump2psy

Metabolic injury in a variable rat model of post-status epilepticus

Patrice S. Pearce, Yijen Wu, Amedeo Rapuano, Kevin M. Kelly, Nihal de Lanerolle, Jullie W. Pan
2016 Epilepsia  
Objective: In vivo studies of epilepsy typically use prolonged status epilepticus to generate recurrent seizures. However, reports on variable status duration have found discrete differences in injury after 40-50 min of seizures, suggesting a pathophysiologic sensitivity to seizure duration. In this report we take a multivariate cluster analysis to study a short duration status epilepticus model using in vivo 7T magnetic resonance spectroscopy (MRS) and histologic evaluation. Methods: The
more » ... r Dudek model was applied with 45 min of status epilepticus after which the animals were imaged twice, at 3 days and 3 weeks post-status epilepticus. Single voxel point resolved spectroscopy (PRESS) MRS was used to acquire data from the dentate gyrus and CA3 region of the hippocampus, assessing metabolite ratios to total creatine (tCr). In a subset of animals after the second imaging study, brains were analyzed histologically by Nissl staining. Results: A hierarchical cluster analysis performed on the 3-day data from 21 kainatetreated animals (dentate gyrus voxel) segregated into two clusters, denoted by KM (more injured, n = 6) and KL (less injured, n = 15). Although there was no difference in kainate dosing or seizure count between them, the metabolic pattern of injury was different. The KM group displayed the largest significant changes in neuronal and glial parameters; the KL group displayed milder but significant changes. At 3 weeks, the KL group returned to normal compared to controls, whereas the KM group persisted with depressed N-acetyl aspartate (NAA)/tCr, glutamate/tCr, and increased inositol/tCr and glutamine/tCr. The classification was also consistent with subsequent histologic patterns at 3 weeks. Significance: Although a short status period might be expected to generate a continuous distribution of metabolic injury, these data show that the short Hellier Dudek model appears to generate two levels of injury. The changes seen in segregated groups persisted into 3 weeks, and can be interpreted according to neuronal and glial biomarkers consistent with histology results.
doi:10.1111/epi.13588 pmid:27943308 pmcid:PMC5215597 fatcat:dht2zrphobforou7wpjm6vrebu

MRI- and MRS-derived hippocampal correlates of quantitative locomotor function in older adults

Molly E. Zimmerman, Richard B. Lipton, Jullie W. Pan, Hoby P. Hetherington, Joe Verghese
2009 Brain Research  
participant recruitment; Danielle Coyle, Betty Forro, Alicia Gomez, and Mary Joan Sebastian for assistance with neuropsychological assessment; Rebecca Gottlieb for quantitative gait assessments; Cynthia Pan  ... 
doi:10.1016/j.brainres.2009.07.043 pmid:19631621 pmcid:PMC2747520 fatcat:rzxyr3ilcbbnthwwymzgtjbdui

Cerebrospinal fluid-suppressed T2 -weighted MR imaging at 7 T for human brain

Jullie W. Pan, Chan Hong Moon, Hoby P. Hetherington
2018 Magnetic Resonance in Medicine  
| 2925 PAN et al. because of the increased power deposition and poor transmit homogeneity due to the need for multiple spin echoes.  ...  Based on the transceiver range of ±15% (dashed lines), the B 1 + sensitivity of GM and WM is within approximately 25% over a T 2 range of 60-160 ms F I G U R E 5 B | 2931 PAN et al.  ... 
doi:10.1002/mrm.27598 pmid:30450583 pmcid:PMC6590483 fatcat:hqho3pc2vrbebji6ikirfaucia

RF shimming for spectroscopic localization in the human brain at 7 T

Hoby P. Hetherington, Nikolai I. Avdievich, Andrey M. Kuznetsov, Jullie W. Pan
2009 Magnetic Resonance in Medicine  
Spectroscopic imaging of the human head at short TEs (≤15ms) typically requires suppression of signals from extracerebral tissues. However, at 7, decreasing efficiency in generation (Hz/Watt) and increasing spectral bandwidth result in dramatic increases in power deposition and increased chemical shift registration artifacts for conventional gradient based in-plane localization. In this work, we describe a novel method using RF shimming and an 8 element transceiver array to generate a field
more » ... ribution that excites a ring about the periphery of the head and leaves central brain regions largely unaffected. We have used this novel distribution to provide in-plane outer volume suppression (>98% suppression of extracerebral lipids) without the use of gradients. This novel distribution is used in conjunction with a double inversion recovery method to provide suppression of extracerebral resonances with T1s greater than 400ms, while having negligible effect on metabolite ratios of cerebral resonances with T1s >1000ms. Despite the use of two adiabatic pulses, the high efficiency of the ring distribution allows RF power deposition to be limited to 3-4W for a TR of 1.5s. The short TE enabled the acquisition of images of the human brain displaying glutamate, glutamine, macromolecules and other major cerebral metabolites.
doi:10.1002/mrm.22182 pmid:19918903 pmcid:PMC2811270 fatcat:h3pq7hh7breg7berk4vobpdg2m

[2,4-13C2]-β-Hydroxybutyrate Metabolism in Human Brain

Jullie W. Pan, Robin A. de Graaf, Kitt F. Petersen, Gerald I. Shulman, Hoby P. Hetherington, Douglas L. Rothman
2002 Journal of Cerebral Blood Flow and Metabolism  
After baseline MR data acquisition, the acute hyperketonemia was induced using a variant of the protocol earlier described (Pan et al., 2001) .  ...  Normalized to brain tissue only (excluding CSF), in healthy adults this region is approximately 67% gray matter, 33% white matter (Pan et al., 2000b) .  ... 
doi:10.1097/00004647-200207000-00014 pmid:12142574 pmcid:PMC2995543 fatcat:llavrnw77vfc3axc7arnugjjza

Concussive brain injury from explosive blast

Nihal C. de Lanerolle, Hamada Hamid, Joseph Kulas, Jullie W. Pan, Rebecca Czlapinski, Anthony Rinaldi, Geoffrey Ling, Faris A. Bandak, Hoby P. Hetherington
2014 Annals of Clinical and Translational Neurology  
Objective: Explosive blast mild traumatic brain injury (mTBI) is associated with a variety of symptoms including memory impairment and posttraumatic stress disorder (PTSD). Explosive shock waves can cause hippocampal injury in a large animal model. We recently reported a method for detecting brain injury in soldiers with explosive blast mTBI using magnetic resonance spectroscopic imaging (MRSI). This method is applied in the study of veterans exposed to blast. Methods: The hippocampus of 25
more » ... rans with explosive blast mTBI, 20 controls, and 12 subjects with PTSD but without exposure to explosive blast were studied using MRSI at 7 Tesla. Psychiatric and cognitive assessments were administered to characterize the neuropsychiatric deficits and compare with findings from MRSI. Results: Significant reductions in the ratio of N-acetyl aspartate to choline (NAA/Ch) and N-acetyl aspartate to creatine (NAA/Cr) (P < 0.05) were found in the anterior portions of the hippocampus with explosive blast mTBI in comparison to control subjects and were more pronounced in the right hippocampus, which was 15% smaller in volume (P < 0.05). Decreased NAA/Ch and NAA/Cr were not influenced by comorbidities -PTSD, depression, or anxiety. Subjects with PTSD without blast had lesser injury, which tended to be in the posterior hippocampus. Explosive blast mTBI subjects had a reduction in visual memory compared to PTSD without blast. Interpretation: The region of the hippocampus injured differentiates explosive blast mTBI from PTSD. MRSI is quite sensitive in detecting and localizing regions of neuronal injury from explosive blast associated with memory impairment. 692
doi:10.1002/acn3.98 pmid:25493283 pmcid:PMC4241796 fatcat:wc4azpyfljhizlr3ygwelkgveq

7T MR spectroscopic imaging in the localization of surgical epilepsy

Jullie W. Pan, Robert B. Duckrow, Jason Gerrard, Caroline Ong, Lawrence J. Hirsch, Stanley R. Resor, Yan Zhang, Ognen Petroff, Susan Spencer, Hoby P. Hetherington, Dennis D. Spencer
2013 Epilepsia  
., 1996; Pan & Takahashi, 2005) .  ...  this study made use of several advances in B0 shimming and radiofrequency (RF) technology to achieve consistent spectroscopic imaging performance (Avdievich et al., 2009; Hetherington et al., 2010; Pan  ... 
doi:10.1111/epi.12322 pmid:23895497 pmcid:PMC3938332 fatcat:pjd7vkt4azafjmigoddzqwfcdu

Role of very high order and degreeB0shimming for spectroscopic imaging of the human brain at 7 tesla

Jullie W. Pan, Kai-Ming Lo, Hoby P. Hetherington
2011 Magnetic Resonance in Medicine  
With the advent of ultrahigh field systems (7T), significant improvements in spectroscopic imaging (SI) studies of the human brain have been anticipated. These gains are dependent upon the achievable B 0 homogeneity, both globally (σB 0 Global , over the entire ROI or slice) and locally (σB 0 Local , influencing the linewidth of individual SI voxels within the ROI). Typically the B 0 homogeneity is adjusted using shim coils with spatial distributions modeled on spherical harmonics which can be
more » ... haracterized by a degree (radial dependence) and order (azimuthal symmetry). However, the role of very high order and degree shimming (e.g. 3 rd and 4 th degree) in MRSI studies has been controversial. Measurements of σB 0 Global and σB 0 Local were determined from B 0 field maps of 64×64 resolution. In a 10mm thick slice taken through the region of the subcortical nuclei, we find that in comparison to 1 st −2 nd degree shims, use of 1 st −3 rd and 1 st −4 th degree shims reduces σB 0 Global by 29% and 55% respectively. Using a spectroscopic imaging voxel size of ~1cc with an estimate of σB 0 Local from 3×3×3 B 0 map pixels in this subcortical region, the number of pixels with σB 0 Local of less than 5Hz increased from 24% to 59% with 1 st −3 rd and 1 st −4 th over 1 st −2 nd degree shims respectively.
doi:10.1002/mrm.24122 pmid:22213108 pmcid:PMC3323711 fatcat:a7g6uwhshzbuvmazlcet5c5kmi

Human Brain β-Hydroxybutyrate and Lactate Increase in Fasting-Induced Ketosis

Jullie W. Pan, Douglas L. Rothman, Kevin L. Behar, Daniel T. Stein, Hoby P. Hetherington
2000 Journal of Cerebral Blood Flow and Metabolism  
PAN ET AL. .l Cereb Blood Flow Metab. Vol. 20, No. 10. 2000  ...  Quantification of the BHB and lactate was performed using an internal reference of N-acetyl aspartate (NAA) at 10 mmollL (Pan et aI., 1998) .  ... 
doi:10.1097/00004647-200010000-00012 pmid:11043913 fatcat:jzznlkblzzeazfb5l2rguoulqq

Regional differences in intramyocellular lipids in humans observed by in vivo 1H-MR spectroscopic imaging

Jong-Hee Hwang, Jullie W. Pan, S. Heydari, Hoby P. Hetherington, Daniel T. Stein
2001 Journal of applied physiology  
However, T1 of TCr at 4.7 T by Pan et al. (22) in human muscle and that at 1.5 T by Schick et al. (27) were reported to be about the same (1.1 s).  ... 
doi:10.1152/jappl.2001.90.4.1267 pmid:11247923 fatcat:habmh3ppnzciji7zy2fqr4meyu

Metabolic Changes in Early Poststatus Epilepticus Measured by MR Spectroscopy in Rats

Yijen Wu, Patrice S Pearce, Amedeo Rapuano, T Kevin Hitchens, Nihal C de Lanerolle, Jullie W Pan
2015 Journal of Cerebral Blood Flow and Metabolism  
There is little experimental in vivo data on how differences in seizure duration in experimental status epilepticus influence metabolic injury. This is of interest given that in humans, status duration is a factor that influences the probability of subsequent development of epilepsy. This question is studied using 7-T magnetic resonance (MR) spectroscopy, T2 relaxometry in the incremented kainate rodent model of temporal lobe epilepsy, using two durations of status epilepticus, 1.5 and 3 hours.
more » ... Histologic evaluation was performed in a subset of animals. Three days after status, single-voxel (8 mm 3 ) point resolved spectroscopy (PRESS) MR spectroscopic measurements were acquired at 7 T to assess the cerebral metabolites measured as a ratio to total creatine (tCr). The status injury resulted in decreased N-acetylaspartate NAA/tCr, increased myo-inositol/tCr and glutamine/tCr, increased T2, and significant declines in NeuN-stained neuronal counts in both status groups. Regressions were identified in the status groups that provide evidence for neuronal injury and astrocytic reaction after status in both the short and long status duration groups. The long status group displays changes in glutathione/tCr that are not identified in the short status group, this difference possibly representing a maturation of injury and antioxidant response that occurs in synchrony with glutamatergic injury and glial activation.
doi:10.1038/jcbfm.2015.145 pmid:26104287 pmcid:PMC4635243 fatcat:lv4473g33jfpvi46kyrak4h6em

Gradient-echo EPI using a high-degree shim insert coil at 7 T: Implications for BOLD fMRI

Tae Kim, Yoojin Lee, Tiejun Zhao, Hoby P. Hetherington, Jullie W. Pan
2016 Magnetic Resonance in Medicine  
Purpose: To quantitatively assess the effects of high degree and order (1 st -4 thþ ) relative to 1 st -2 nd degree B 0 shimming at 7 Tesla (T) on gradient-echo echo planar imaging (GE-EPI) and blood-oxygen-level dependent (BOLD) activation. Methods: Simulations and GE-EPI were performed at (2mm) 3 and (3mm) 3 resolution, evaluating the temporal signal-to-noise ratio (tSNR), transverse relaxivity (R Ã 2 ), BOLD % signal change and activated pixel counts in a breath-hold task. Results: Comparing
more » ... the 1 st -4 thþ degree with 1 st -2 nd degree shimmed B 0 maps generated spatially varying regions of DjB 0 j ¼ jB 1À2 0 j À jB 1À4þ 0 j. As binned in 10-Hz intervals, the two center DjB 0 j (610 Hz) bins maintained the B 0 offset of 48.6% of gray-matter pixels. In the positive DjB 0 j bins greater than 10 Hz, the 1 st -4 thþ degree shimming improved the B 0 offset in 41.1%; in negative DjB 0 j bins less than À10 Hz, the offset worsened in 10.2% of the pixels. In the positive DjB 0 j bins, we found variable but significant increases in BOLD sensitivity; the negative DjB 0 j bins showed significant decreases. In the breath-hold studies, positive bins showed significantly increased activated pixel numbers (þ5-29%), whereas negative bins showed À18 to 0% decline. Conclusion: 1 st -4 thþ degree shimming maintained B 0 homogeneity over central brain regions while improving most of the other regions, including the inferior frontal lobe. Magn Reson Med 78:1734-1745,
doi:10.1002/mrm.26563 pmid:27910126 pmcid:PMC6084307 fatcat:w5azilj6gbhrlmmkns3x5hrnre

MRSI of the medial temporal lobe at 7 T in explosive blast mild traumatic brain injury

Hoby P. Hetherington, Hamada Hamid, Joseph Kulas, Geoffrey Ling, Faris Bandak, Nihal C. de Lanerolle, Jullie W. Pan
2013 Magnetic Resonance in Medicine  
Purpose-Up to 19% of veterans returning from the wars in Iraq and Afghanistan have a history of mild traumatic brain injury (mTBI) with 70% associated with blast exposure. Tragically, 20-50% of this group reports persistent symptoms, including memory loss. Unfortunately, routine clinical imaging is typically normal, making diagnosis and clinical management difficult. The goal of this work was to develop methods to acquire hippocampal MRSI at 7T and evaluate their sensitivity to detect injury in
more » ... veterans with mTBI. Methods-At 7T, hippocampal MRSI measurements are limited by: 1) poor B 0 homogeneity; 2) insufficient B 1 + strength and homogeneity; and 3) chemical shift dispersion artifacts. To overcome these limitations we: 1) used 3 rd degree B 0 shimming; 2) an inductively decoupled transceiver array with RF shimming and 3) a volume localized single slice sequence using RF shimming based outer volume suppression. Results-In 20 controls and 25 veterans with mTBI due to blast exposure with memory impairment, hippocampal NAA/Cho (P<0.001) and NAA/Cr (P<0.001) were decreased in comparison to control subjects.
doi:10.1002/mrm.24814 pmid:23918077 pmcid:PMC4117409 fatcat:wcwhcxgva5hbbpxp2ogixhays4

Intracranial monitoring contributes to seizure freedom for temporal lobectomy patients with non‐concordant pre‐operative data

Elisaveta Sokolov, Nathaniel D. Sisterson, Helweh Hussein, Cheryl Plummer, Danielle Corson, Arun R. Antony, Joseph M. Mettenburg, Gena R. Ghearing, Jullie W. Pan, Alexandra Urban, Anto Bagić, R. Mark Richardson (+1 others)
2021 Epilepsia Open  
The question of whether a patient with presumed temporal lobe seizures should proceed directly to temporal lobectomy surgery versus undergo intracranial monitoring arises commonly. We evaluate the effect of intracranial monitoring on seizure outcome in a retrospective cohort of consecutive subjects who specifically underwent an anterior temporal lobectomy (ATL) for refractory temporal lobe epilepsy (TLE). We performed a retrospective analysis of 85 patients with focal refractory TLE who
more » ... t ATL following: (a) intracranial monitoring via craniotomy and subdural/depth electrodes (SDE/DE), (b) intracranial monitoring via stereotactic electroencephalography (sEEG), or (c) no intracranial monitoring (direct ATL-dATL). For each subject, the presurgical primary hypothesis for epileptogenic zone localization was characterized as unilateral TLE, unilateral TLE plus (TLE+), or TLE with bilateral/poor lateralization. At one-year and most recent follow-up, Engel Class I and combined I/II outcomes did not differ significantly between the groups. Outcomes were better in the dATL group compared to the intracranial monitoring groups for lesional cases but were similar in nonlesional cases. Those requiring intracranial monitoring for a hypothesis of TLE+had similar outcomes with either intracranial monitoring approach. sEEG was the only approach used in patients with bilateral or poorly lateralized TLE, resulting in 77.8% of patients seizure-free at last follow-up. Importantly, for 85% of patients undergoing SEEG, recommendation for ATL resulted from modifying the primary hypothesis based on iEEG data. Our study highlights the value of intracranial monitoring in equalizing seizure outcomes in difficult-to-treat TLE patients undergoing ATL.
doi:10.1002/epi4.12483 pmid:34786887 pmcid:PMC8886064 fatcat:jbb63ix5ynexhlfek2gfhjhd6q
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