NIMG-50. INITIAL EXPERIENCE: DETECTION OF ABERRANT HYPERPOLARIZED [1-13C]PYRUVATE METABOLISM IN PATIENTS WITH GBM PRIOR TO RESECTION

Abstract INTRODUCTION Detecting radiological response or resistance to treatment in patients with GBM is difficult with conventional MRI. In response to this challenge, hyperpolarized carbon-13 (HP-13C) MRI techniques were developed to probe real-time [1-13C]pyruvate metabolism. METHODS Dynamic HP-13C MRI was acquired pre-operatively from 6 patientswith recurrent GBM following intravenous injection of HP [1-13C]pyruvate. Five were confirmed with tumor progression and one had treatment effects without progression. Frequency-selective echo-planar imaging (8 slices, 3s temporal resolution, 3.38 cm3 spatial resolution, 60s acquisition) captured [1-13C]pyruvate metabolism to [1-13C]lactate and [1-13C]bicarbonate in the brain. Proton imaging included 3-D FLAIR, T1-weighted post-Gd IRSPGR, and spectroscopy. Carbon-13 voxels with non-enhancing lesion (NEL) or contrast-enhancing lesion (CEL) were identified for subsequent analysis. Temporally-summed HP-13C metabolite data within the CEL and NEL were evaluated using the pyruvate-to-lactate ratio; a modified ratio that takes into account vascular contributions of pyruvate; and parameter percentile ranks over the entire brain. Proton spectroscopy data were processed to obtain choline-to-NAA index (CNI) maps, which provide z-scores of relative tissue abnormality. RESULTS All of the anatomic lesions displayed abnormal CNI with maximum values of 3.22-6.35. The 5 patients with CEL lesions demonstrated 87th– 98thpercentile levels of pyruvate in the brain; and 95th-100thpercentile levels of lactate in 4 progressed patients and 60thpercentile in the patient presenting with treatment effects. For the patient with an exclusively non-enhancing lesion, percentile levels of pyruvate and lactate were 66thand 88thin the brain, respectively. The mean+/-SD percentile of the lactate-to-pyruvate and modified ratios were 75+/-22, 86+/-23 and 60+/-3, 71+/-12 in the progressed and non-progressed patients, respectively. CONCLUSION These data importantly demonstrate aberrant [1-13C]pyruvate metabolism in patients with GBM in both contrast-enhancing and non-enhancing lesions. Ongoing studies will further characterize the utility of HP imaging markers.

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NIMG-43. ADVANCED MULTI-PARAMETRIC HYPERPOLARIZED 13C/1H IMAGING OF GBM

Neuro-Oncology ◽

10.1093/neuonc/noab196.542 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi138-vi138

Author(s):

Adam Autry ◽

Sana Vaziri ◽

Marisa LaFontaine ◽

Jeremy Gordon ◽

Hsin-Yu Chen ◽

...

Keyword(s):

Mixed Effects ◽

Planar Imaging ◽

Pyruvate Metabolism ◽

Metabolic Alterations ◽

Hyperpolarized 13C ◽

Imaging Parameters ◽

Normal Appearing White Matter ◽

Parametric Data ◽

Echo Planar ◽

The Brain

Abstract INTRODUCTION The goal of this study was to characterize progressive and pseudoprogressive GBM using multi-parametric hyperpolarized (HP)-13C / 1H MRI. METHODS Dynamic HP-13C MRI was acquired from 13 patients with progressive GBM [patients (scans): 2(3) IDH-mutant; 11(13) IDH-wildtype] and 2 IDH-wildtype patients (3 scans) demonstrating pseudo-progression following intravenous injection of HP [1-13C]pyruvate. Frequency-selective echo-planar imaging (3s temporal resolution, 3.38 cm3 spatial resolution) captured [1-13C]pyruvate metabolism to [1-13C]lactate and 13C-bicarbonate in the brain. Dynamic 13C data were kinetically modeled to obtain the pyruvate-to-lactate conversion rate constant k PL and temporally summed to calculate 13C-metabolite percentiles and ratios (linearly interpolated 2x in-plane). 1H imaging included T2, post-Gd T1, perfusion (nCBV, %recovery), diffusion (ADC), and lactate-edited spectroscopy (CNI, choline-to-NAA index; 1H-lactate). The normal-appearing white matter (NAWM), non-enhancing lesion (NEL), and contrast-enhancing lesion (CEL) were segmented from 1H images. 13C-resolution masks were iteratively applied on a voxel-wise basis to evaluate 1H imaging parameters within each ROI and multi-parametric data were collectively evaluated using a mixed effects model in R. RESULTS Progressive IDH-mutant GBM compared to wildtype counterparts displayed increased perfusion %recovery (p < 0.001) and k PL (p < 0.01), together with reduced 1H-lactate (p < 0.001) and pyruvate percentile (p < 0.01), in the T2 lesion. Among IDH-wildtype progressive GBM, the CEL was distinguished from NEL/NAWM by increased nCBV (p < 0.05/0.001), 1H-lactate (p < 0.05/0.001); and decreased bicarbonate / lactate (p < 0.05/0.001). The CEL and NEL were collectively distinguished from NAWM by elevated CNI (p < 0.001/0.001), ADC (p < 0.05/0.001), pyruvate percentile (p < 0.001/0.001), lactate percentile (p < 0.001/0.001), and relative lactate / pyruvate (p < 0.001/0.05). Psuedo-progressive IDH-wildtype GBM displayed lower k PL (T2 Lesion; p < 0.01) and nCBV (CEL; p < 0.01) compared to progressive GBM. CONCLUSION HP-13C parameters can potentially augment proton imaging and demonstrated Warburg-associated metabolic alterations.

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Reduced field of view echo-planar imaging diffusion tensor MRI for pediatric spinal tumors

Journal of Neurosurgery Spine ◽

10.3171/2019.4.spine19178 ◽

2019 ◽

Vol 31 (4) ◽

pp. 607-615 ◽

Cited By ~ 3

Author(s):

Lily H. Kim ◽

Edward H. Lee ◽

Michelle Galvez ◽

Murat Aksoy ◽

Stefan Skare ◽

...

Keyword(s):

Diffusion Tensor ◽

Field Of View ◽

Spinal Tumors ◽

Planar Imaging ◽

Diagnostic Confidence ◽

Conventional Mri ◽

The Mean ◽

Echo Planar ◽

Spine Mri ◽

Lesion Conspicuity

OBJECTIVESpine MRI is a diagnostic modality for evaluating pediatric CNS tumors. Applying diffusion-weighted MRI (DWI) or diffusion tensor imaging (DTI) to the spine poses challenges due to intrinsic spinal anatomy that exacerbates various image-related artifacts, such as signal dropouts or pileups, geometrical distortions, and incomplete fat suppression. The zonal oblique multislice (ZOOM)–echo-planar imaging (EPI) technique reduces geometric distortion and image blurring by reducing the field of view (FOV) without signal aliasing into the FOV. The authors hypothesized that the ZOOM-EPI method for spine DTI in concert with conventional spinal MRI is an efficient method for augmenting the evaluation of pediatric spinal tumors.METHODSThirty-eight consecutive patients (mean age 8 years) who underwent ZOOM-EPI spine DTI for CNS tumor workup were retrospectively identified. Patients underwent conventional spine MRI and ZOOM-EPI DTI spine MRI. Two blinded radiologists independently reviewed two sets of randomized images: conventional spine MRI without ZOOM-EPI DTI, and conventional spine MRI with ZOOM-EPI DTI. For both image sets, the reviewers scored the findings based on lesion conspicuity and diagnostic confidence using a 5-point Likert scale. The reviewers also recorded presence of tumors. Quantitative apparent diffusion coefficient (ADC) measurements of various spinal tumors were extracted. Tractography was performed in a subset of patients undergoing presurgical evaluation.RESULTSSixteen patients demonstrated spinal tumor lesions. The readers were in moderate agreement (kappa = 0.61, 95% CI 0.30–0.91). The mean scores for conventional MRI and combined conventional MRI and DTI were as follows, respectively: 3.0 and 4.0 for lesion conspicuity (p = 0.0039), and 2.8 and 3.9 for diagnostic confidence (p < 0.001). ZOOM-EPI DTI identified new lesions in 3 patients. In 3 patients, tractography used for neurosurgical planning showed characteristic fiber tract projections. The mean weighted ADCs of low- and high-grade tumors were 1201 × 10−6 and 865 × 10−6 mm2/sec (p = 0.002), respectively; the mean minimum weighted ADCs were 823 × 10−6 and 474 × 10−6 mm2/sec (p = 0.0003), respectively.CONCLUSIONSDiffusion MRI with ZOOM-EPI can improve the detection of spinal lesions while providing quantitative diffusion information that helps distinguish low- from high-grade tumors. By adding a 2-minute DTI scan, quantitative diffusion information and tract profiles can reliably be obtained and serve as a useful adjunct to presurgical planning for pediatric spinal tumors.

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Analysis of Apparent Diffusion Coefficients of the Brain in Healthy Controls: A Comparison Study between Single-Shot Echo-Planar Imaging and Read-out-Segmented Echo-Planar Imaging

Korean Journal of Radiology ◽

10.3348/kjr.2018.0899 ◽

2019 ◽

Vol 20 (7) ◽

pp. 1138 ◽

Cited By ~ 1

Author(s):

Yangsean Choi ◽

Eo-Jin Hwang ◽

Yoonho Nam ◽

Hyun Seok Choi ◽

Jinhee Jang ◽

...

Keyword(s):

Diffusion Coefficients ◽

Echo Planar Imaging ◽

Single Shot ◽

Healthy Controls ◽

Comparison Study ◽

Planar Imaging ◽

Apparent Diffusion Coefficients ◽

Apparent Diffusion ◽

Echo Planar ◽

The Brain

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Hemodynamic Changes Owing to Sensory Activation of the Brain Monitored by Echo-Planar Imaging

Encyclopedia of Magnetic Resonance ◽

10.1002/9780470034590.emrstm0201 ◽

1996 ◽

Author(s):

Peter A. Bandettini ◽

Jeffrey R. Binder ◽

Edgar E. DeYoe ◽

James S. Hyde

Keyword(s):

Echo Planar Imaging ◽

Planar Imaging ◽

Hemodynamic Changes ◽

Sensory Activation ◽

Echo Planar ◽

The Brain

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High-resolution echo-planar imaging of the brain: is it suitable for routine clinical imaging?

Neuroradiology ◽

10.1007/s002340050516 ◽

1997 ◽

Vol 39 (12) ◽

pp. 833-840 ◽

Cited By ~ 3

Author(s):

C. Ozdoba ◽

L. Remonda ◽

O. Heid ◽

K.-O. L�vblad ◽

G. Schroth

Keyword(s):

High Resolution ◽

Echo Planar Imaging ◽

Planar Imaging ◽

Clinical Imaging ◽

Routine Clinical Imaging ◽

Echo Planar ◽

The Brain

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Improved cortical boundary registration for locally distorted fMRI scans

10.1101/248120 ◽

2018 ◽

Cited By ~ 4

Author(s):

Tim van Mourik ◽

Peter J Koopmans ◽

David G Norris

Keyword(s):

Gold Standard ◽

Static Field ◽

Distortion Correction ◽

Cortical Surface ◽

Planar Imaging ◽

Cortical Layers ◽

Echo Planar ◽

Clear Increase ◽

The Brain

AbstractWith continuing advances in MRI techniques and the emergence of higher static field strengths, submillimetre spatial resolution is now possible in human functional imaging experiments. This has opened up the way for more specific types of analysis, for example investigation of the cortical layers of the brain. With this increased specificity, it is important to correct for the geometrical distortions that are inherent to echo planar imaging (EPI). Inconveniently, higher field strength also increases these distortions. The resulting displacements can easily amount to several millimetres and as such pose a serious problem for laminar analysis. We here present a method, Recursive Boundary Registration (RBR), that corrects distortions between an anatomical and an EPI volume. By recursively applying Boundary Based Registration (BBR) on progressively smaller subregions of the brain we generate an accurate whole-brain registration, based on the grey-white matter contrast. Explicit care is taken that the deformation does not break the topology of the cortical surface, which is an important requirement for several of the most common subsequent steps in laminar analysis. We show that RBR obtains submillimetre accuracy with respect to a manually distorted gold standard, and apply it to a set of human in vivo scans to show a clear increase in spacial specificity. RBR further automates the process of non-linear distortion correction. This is an important step towards routine human laminar fMRI. We provide the code for the RBR algorithm, as well as a variety of functions to better investigate registration performance in a public GitHub repository, https://github.com/TimVanMourik/OpenFmriAnalysis, under the GPL 3.0 license.

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Echo-Planar Imaging of the Brain at 3.0 T

Journal of Computer Assisted Tomography ◽

10.1097/00004728-199405000-00001 ◽

1994 ◽

Vol 18 (3) ◽

pp. 339-343 ◽

Cited By ~ 44

Author(s):

Peter Mansfield ◽

Ronald Coxon ◽

Paul Glover

Keyword(s):

Echo Planar Imaging ◽

Planar Imaging ◽

3.0 T ◽

Echo Planar ◽

The Brain

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Evaluation of the Contribution of Signals Originating from Large Blood Vessels to Signals of Functionally Specific Brain Areas

BioMed Research International ◽

10.1155/2015/234345 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

Jun-Young Chung ◽

Yul-Wan Sung ◽

Seiji Ogawa

Keyword(s):

Blood Vessels ◽

Group Analysis ◽

Target Area ◽

Fusiform Face Area ◽

Planar Imaging ◽

Ventral Region ◽

Face Area ◽

Echo Planar ◽

Dual Echo ◽

The Brain

The fusiform face area (FFA) is known to play a pivotal role in face processing. The FFA is located in the ventral region, at the base of the brain, through which large blood vessels run. The location of the FFA via functional MRI (fMRI) may be influenced by these large blood vessels. Responses of large blood vessels may not exactly correspond to neuronal activity in a target area, because they may be diluted and influenced by inflow effects. In this study, we investigated the effects of large blood vessels in the FFA, that is, whether the FFA includes large blood vessels and/or whether inflow signals contribute to fMRI signals of the FFA. For this purpose, we used susceptibility-weighted imaging (SWI) sequences to visualize large blood vessels and dual-echo gradient-echo echo-planar imaging (GE-EPI) to measure inflow effects. These results showed that the location and response signals of the FFA were not influenced by large blood vessels or inflow effects, although large blood vessels were located near the FFA. Therefore, the data from the FFA obtained by individual analysis were robust to large blood vessels but leaving a warning that the data obtained by group analysis may be prone to large blood vessels.

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