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102 citation(s) found for "In, Myung‐Ho".

INHIBITORS OF INORGANIC POLYPHOSPHATE AND NUCLEIC ACIDS ATTENUATE IN VITRO THROMBIN GENERATION IN PLASMA FROM TRAUMA PATIENTS
Goswami, Julie , Navarro, Sergio M. , Vappala, Sreeparna , La, Chanel C. , Yudin, Nikoli , Zietlow, John , Morrissey, James H. , Spears, Grant M. , Bailey, Kent R. , Dong, Jing‐fei , Kozar, Rosemary A. , Kizhakkedathu, Jayachandran N. , Park, Myung S., MacArthur, Taleen A. , Navarro, Sergio Michael , Smith, Stephanie A.

Mayo Clinic

Shock | April 25, 2024 | Volume: 61 | Issue: 6 | Pages: 848-854

10.1097/shk.0000000000002362 | PMID 38662595 Get It

ABSTRACT Background: Inorganic polyphosphate (polyP) is a procoagulant polyanion. We assessed the impact of polyP inhibition on thrombin generation after trauma using the novel polyP antagonists, macromolecular polyanion inhibitor 8 (MPI 8), and universal heparin reversal agent 8 (UHRA-8). Methods: Plasma thrombin generation (calibrated automated thrombogram, CAT), in 56 trauma patients and 39 controls +/− MPI 8 and UHRA-8 (50 μg/mL), was expressed as lag time (LT, minutes), peak height (PH, nM), and time to peak (ttPeak, minutes), with change in LT (ΔLT) and change in ttPeak (ΔttPeak) quantified. Results expressed in median and quartiles [Q1, Q3], Wilcoxon matched-pairs testing, P < 0.05 significant. Results: Trauma patients had greater baseline PH than controls (182.9 [121.0, 255.2]; 120.5 [62.1, 174.8], P < 0.001). MPI 8 treatment prolonged LT and ttPeak in trauma (7.20 [5.88, 8.75]; 6.46 [5.45, 8.93], P = 0.020; 11.28 [8.96, 13.14]; 11.00 [8.95, 12.94], P = 0.029) and controls (7.67 [6.67, 10.50]; 6.33 [5.33, 8.00], P < 0.001; 13.33 [11.67, 15.33]; 11.67 [10.33, 13.33], P < 0.001). UHRA-8 treatment prolonged LT and ttPeak and decreased PH in trauma (9.09 [7.45, 11.33]; 6.46 [5.45, 8.93]; 14.02 [11.78, 17.08]; 11.00 [8.95, 12.94]; 117.4 [74.5, 178.6]; 182.9 [121.0, 255.2]) and controls (9.83 [8.00, 12.33]; 6.33 [5.33, 8.00]; 16.67 [14.33, 20.00]; 11.67 [10.33, 13.33]; 55.3 [30.2, 95.9]; 120.5 [62.1, 174.8]), all P < 0.001. Inhibitor effects were greater for controls (greater ΔLT and ΔttPeak for both inhibitors, P < 0.001). Conclusion: PolyP inhibition attenuates thrombin generation, though to a lesser degree in trauma than in controls, suggesting that polyP contributes to accelerated thrombin generation after trauma.
SNOT‐22 subdomain outcomes following treatment for sinonasal malignancy: A prospective, multicenter study
Grimm, David R. , Beswick, Daniel M. , Maoz, Sabrina L. , Chan, Erik, Adappa, Nithin D. , Getz, Anne E., Humphreys, Ian M. , Chang, Eugene H. , Jafari, Aria , Kingdom, Todd T. , Kohanski, Michael A. , Lee, Jivianne K., Adappa, Nithin D. , Patel, Zara M. , Sim, Myung‐Shin , Smith, Timothy L. , Storm, Phillip B. , Wang, Marilene B. , Hwang, Peter H. , Wang, Eric W , Choby, Garret , Kuan, Edward C , Humphreys, Ian M , Jafari, Aria , Nayak, Jayakar V , Patel, Zara , Smith, Timothy L , Snyderman, Carl H , Hwang, Peter H , Beswick, Daniel , Grimm, David R , Maoz, Sabrina L , Choby, Garret , Adappa, Nithin D. , Geltzeiler, Mathew , Le, Christopher H. , Abuzeid, Waleed M. , Nayak, Jayakar V. , Pinheiro‐Neto, Carlos , Resnick, Adam , John, Maie A. St. , Suh, Jeffrey D.

Mayo Clinic

International Forum of Allergy & Rhinology | February 19, 2024 | Volume: 14 | Issue: 8 | Pages: 1314-1326

10.1002/alr.23338 | PMID 38372441 Get It

AbstractBackgroundPatients with sinonasal malignancy (SNM) present with significant sinonasal quality of life (QOL) impairment. Global sinonasal QOL as measured by the 22‐item Sinonasal Outcomes Test (SNOT‐22) has been shown to improve with treatment. This study aims to characterize SNOT‐22 subdomain outcomes in SNM.MethodsPatients diagnosed with SNM were prospectively enrolled in a multi‐center patient registry. SNOT‐22 scores were collected at the time of diagnosis and through the post‐treatment period for up to 5 years. Multivariable regression analysis was used to identify drivers of variation in SNOT‐22 subdomains.ResultsNote that 234 patients were reviewed, with a mean follow‐up of 22 months (3 months–64 months). Rhinologic, psychological, and sleep subdomains significantly improved versus baseline (all p < 0.05). Subanalysis of 40 patients with follow‐up at all timepoints showed statistically significant improvement in rhinologic, extra‐nasal, psychological, and sleep subdomains, with minimal clinically important difference met between 2 and 5 years in sleep and psychological subdomains. Adjuvant chemoradiation was associated with worse outcomes in rhinologic (adjusted odds ratio (5.22 [1.69–8.66])), extra‐nasal (2.21 [0.22–4.17]) and ear/facial (5.53 [2.10–8.91]) subdomains. Pterygopalatine fossa involvement was associated with worse outcomes in rhinologic (3.22 [0.54–5.93]) and ear/facial (2.97 [0.32–5.65]) subdomains. Positive margins (5.74 [2.17–9.29]) and surgical approach—combined versus endoscopic (3.41 [0.78–6.05])—were associated with worse psychological outcomes. Adjuvant radiation (2.28 [0.18–4.40]) was associated with worse sleep outcomes.ConclusionsSinonasal QOL improvements associated with treatment of SNM are driven by rhinologic, extra‐nasal, psychological, and sleep subdomains.
Hypertension treatment for patients receiving ibrutinib: a multicenter retrospective study
Samples, Laura , Fakhri, Bita , Khajavian, Sirin, Spurgeon, Stephen E. , Stephens, Deborah M. , Skarbnik, Alan P , Mato, Anthony R. , Broome, Catherine M. , Gopal, Ajay K. , Smith, Stephen D. , Lynch, Ryan C. , Rainey, Magdalena A., Barrett-Campbell, Odeth, Hemond, Emily, Malakhov, Nikita , Rao, Danielle, Shakib-Azar, Mehrdad, Morrigan, Beth, Chauhan, Ayushi , Plate, Thomas , Gooley, Ted, Ryan, Kellie, Hill, Brian T. , Pongas, Georgios , Allan, John N. , Cheng, Richard K. , Ujjani, Chaitra S. , Fakhri, Bita , Stephens, Deborah M , Gopal, Ajay , Smith, Stephen D , Rainey, Magdalena , Tsang, Mazie , Chauhan, Ayushi , Lansigan, Frederick , Parikh, Sameer A , Roeker, Lindsey , Allan, John N , Cheng, Richard , Ujjani, Chaitra , Voutsinas, Jenna M. , Kim, Myung Sun , Tsang, Mazie , Ermann, Daniel A. , Lansigan, Frederick , Parikh, Sameer A. , Roeker, Lindsey E. , Shadman, Mazyar

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Blood Advances | February 5, 2024 | Volume: 8 | Issue: 9 | Pages: 2085-2093

10.1182/bloodadvances.2023011569 | PMID 38315043 Get It

Abstract Although Bruton tyrosine kinase inhibitors (BTKis) are generally well tolerated and less toxic than chemotherapy alternatives used to treat lymphoid malignancies, BTKis like ibrutinib have the potential to cause new or worsening hypertension (HTN). Little is known about the optimal treatment of BTKi-associated HTN. Randomly selected patients with lymphoid malignancies on a BTKi and antihypertensive drug(s) and with at least 3 months of follow-up data were sorted into 2 groups: those diagnosed with HTN before BTKi initiation (prior-HTN), and those diagnosed with HTN after BTKi initiation (de novo HTN). Generalized estimating equations assessed associations between time varying mean arterial pressures (MAPs) and individual anti-HTN drug categories. Of 196 patients included in the study, 118 had prior-HTN, and 78 developed de novo HTN. Statistically significant mean MAP reductions were observed in patients with prior-HTN who took β blockers (BBs) with hydrochlorothiazide (HCTZ), (−5.05 mmHg; 95% confidence interval [CI], 10.0 to −0.0596; P = .047), and patients diagnosed with de novo HTN who took either an angiotensin converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) with HCTZ (−5.47 mmHg; 95% CI, 10.9 to −0.001; P = .05). These regimens also correlated with the greatest percentages of normotensive MAPs. Treatment of HTN in patients taking a BTKi is challenging and may require multiple antihypertensives. Patients with prior-HTN appear to benefit from combination regimens with BBs and HCTZ, whereas patients with de novo HTN appear to benefit from ACEi/ARBs with HCTZ. These results should be confirmed in prospective studies.
The impact of breathing patterns on CSF flow and global brain BOLD signal while awake: A study using real‐time phase‐contrast MRI and fast rsfMRI
Lee, Jeyeon , Shu, Yunhong , Ghatamaneni, Sujala, Núñez, Nicolás A. , Park, John G. , Maihle, Nita J. , Gunter, Jeffrey L. , Graff‐Radford, Jonathan , Petersen, Ronald C. , Lowe, Val J. , Kang, Daehun , Kang, Daehun , In, Myung‐Ho , Bernstein, Matt A. , Nedelská, Zuzana , Ganji, Sandeep K , Cogswell, Petrice M. , Huston, John , Botha, Hugo , Jones, David T. , Min, Hoon-Ki Paul

Mayo Clinic

Alzheimer's & Dementia | December 25, 2023 | Volume: 19 | Issue: S19 | Pages: No page available

10.1002/alz.079182 Get It

AbstractBackgroundThe cardiac and respiratory cycles have been suggested as major drivers of cerebrospinal fluid(CSF) flow. The glymphatic system, one of the mechanisms for the clearance of amyloid‐beta and tau proteins, relies heavily on the movement(flow) of the CSF, and thus, investigating the forces that modulate the CSF flow is essential for understanding the glymphatic flux. Because breathing is trainable through exercise and self‐directed methods, various breathing methods may enhance the CSF flow.MethodReal‐time phase‐contrast MRI(pc‐MRI) was used to measure the CSF flow at the foramen magnum on a 3T. Fast resting‐state fMRI(rsfMRI;TR400ms) was conducted on a compact 3T. Under an IRB‐approved protocol, participants were instructed to breathe slowly and deeply, and subsequently switch to their spontaneous breathing. For rsfMRI data preprocessing, we performed motion correction, skull stripping, spatial smoothing(4mm), temporal filtering(0.01 to 0.1Hz), and linear and quadratic temporal trends removal. fMRI time courses were then normalized to Z‐score at each voxel before being averaged. On the pcMRI, the phase was summed in a CSF region‐of‐interest and plotted vs time. Additionally, we confirmed for possible confounding effects such as head motion or motion‐induced susceptibility changes.ResultrsfMRI findings showed that deep breathing promoted large oscillations in the CSF flow in the ventricles, while spontaneous breathing did not(Figure 1). Additionally, deep breathing resulted in large oscillations in lobar cortical regions. Similar results were observed in the pcMRI, with larger CSF velocity through the foramen magnum during the deep breathing compared to the spontaneous breathing(Figure 2A‐B). The cumulative summation result showed that the volume of CSF flow was increased during deep breathing(Figure 2C).ConclusionThis study provides new evidence that slow and deep breathing promotes CSF flow and global brain BOLD signal, which may be useful in promoting circulation in the brain. The study’s findings also open new avenues for research in the field of neurovascular coupling and mechanisms associated with glymphatic clearance. As hampered CSF flow and/or worsen glymphatic clearance have been shown to associate with pathological aging and dementia, including Alzheimer’s disease and Parkinson’s disease, future research is needed explore the potential of breathing training methods as a non‐pharmacological intervention to support brain health.
Pralsetinib in Patients with Advanced/Metastatic Rearranged During Transfection (RET)-Altered Thyroid Cancer: Updated Efficacy and Safety Data from the ARROW Study
Subbiah, Vivek , Schüler, Martin , Zhu, Viola W. , Hadoux, Julien , Curigliano, Giuseppe , Wirth, Lori J. , Gainor, Justin F. , Alonso, Guzmán , Adkins, Douglas, Godbert, Yann , Ahn, Myung‐Ju , Cassier, Philippe A. , Cho, Byoung Chul , Zalutskaya, Alena , Barata, Teresa, Trask, Peter C., Scalori, Astrid, Bordogna, Walter, Heinzmann, Sebastian , Brose, Marcia S. , Hadoux, Julien , Curigliano, Giuseppe , Subbiah, Vivek , Hu, Mimi I. , Mansfield, Aaron S. , Taylor, Matthew H. , Adkins, Douglas, Lin, Chia‐Chi , Zalutskaya, Alena A. , Cho, B , Schuler, M.

Mayo Clinic

Thyroid® | November 27, 2023 | Volume: 34 | Issue: 1 | Pages: 26-40

10.1089/thy.2023.0363 | PMID 38009200 Get It

Background: Rearranged during transfection ( RET ) alterations are targetable oncogenic drivers in thyroid cancer. Primary data from the open-label, phase 1/2 ARROW study demonstrated clinical activity and manageable safety with pralsetinib, a selective RET inhibitor, in patients with advanced/metastatic RET -altered thyroid cancer. We present an updated analysis with more patients and longer follow-up. Methods: Adult patients with advanced/metastatic RET -mutant medullary thyroid cancer (MTC) or RET fusion-positive thyroid cancer who initiated oral pralsetinib at 400 mg once daily were included. Primary endpoints were overall response rate (ORR) by blinded independent central review (per RECIST v1.1) and safety. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), and overall survival. Responses were assessed in three cohorts of patients with baseline measurable disease: patients with RET -mutant MTC who had received prior cabozantinib and/or vandetanib (C/V), treatment-naïve patients with RET -mutant MTC, and patients with previously treated RET fusion-positive thyroid cancer. Patient-reported outcomes (PROs) were an exploratory endpoint. Results: As of October 18, 2021, the measurable disease population comprised of 61 patients with RET -mutant MTC and prior C/V, 62 treatment-naïve patients with RET -mutant MTC, and 22 patients with RET fusion-positive thyroid cancer who had received prior systemic therapy, including radioactive iodine. The ORR was 55.7% [confidence interval; 95% CI: 42.4–68.5] in patients with RET -mutant MTC and prior C/V, 77.4% [95% CI: 65.0–87.1] in treatment-naïve patients with RET -mutant MTC, and 90.9% [95% CI: 70.8–98.9] in patients with previously treated RET fusion-positive thyroid cancer. Median DoR and median PFS were both 25.8 months in patients with RET -mutant MTC and prior C/V, not reached in treatment-naïve patients with RET -mutant MTC, and 23.6 and 25.4 months, respectively, in patients with previously treated RET fusion-positive thyroid cancer. In the RET -altered thyroid cancer safety population ( N = 175), 97.1% of patients reported a treatment-related adverse event (TRAE); these led to discontinuation in 5.7% and dose reduction in 52.6% of patients. There was one death (0.6%) due to a TRAE. PROs improved or remained stable after pralsetinib treatment. Conclusions: In this updated analysis of the ARROW study, pralsetinib continued to show deep and durable clinical activity and a manageable safety profile in patients with advanced/metastatic RET- altered thyroid cancer. Clinical Trial Registration: NCT03037385
Locally Low-Rank Denoising of Multi-Echo Functional MRI Data With Application in Resting-State Analysis
Meyer, Nolan , Ahmed, Zaki , In, Myung‐Ho , Shu, Yunhong , Trzasko, Joshua D. , Meyer, Nolan K , In, Myung-Ho , Kang, Daehun , Huston, John , Bernstein, Matt A.

Mayo Clinic

Topics in Magnetic Resonance Imaging | October 5, 2023 | Volume: 32 | Issue: 5 | Pages: 37-49

10.1097/rmr.0000000000000307 | PMID 37796647 Get It

Abstract: Objectives: Locally low-rank (LLR) denoising of functional magnetic resonance imaging (fMRI) time series image data is extended to multi-echo (ME) data. The proposed method extends the capabilities of non-physiologic noise suppression beyond single-echo applications with a dedicated ME algorithm. Materials and Methods: Following an institutional review board (IRB) approved protocol, resting-state fMRI data were acquired in 7 healthy subjects. A compact 3T scanner enabled whole-brain acquisition of multiband ME fMRI data at high spatial resolution (1.4 × 1.4 × 2.8 mm3) with a 1810 ms repetition time (TR). Image data were denoised with ME-LLR preceding functional processing. The results of connectivity maps generated from denoised data were compared with maps generated with equivalent processing of non-denoised images. To assess ME-LLR as a method to reduce scan time, comparisons were made between maps computed from image data with full and retrospectively truncated durations. Assessments were completed with seed-based connectivity analyses using echo-combined image data. In a feasibility assessment, nondenoised and denoised full-duration echo-combined data were equivalently processed with independent component analysis (ICA) and compared. Results: ME-LLR denoising yielded strengthened resting-state network connectivity maps after nuisance regression and seed-based connectivity analysis. In assessing ME-LLR as a scan reduction mechanism, maps generated from denoised data at half scan time showed comparable quality with maps generated from full-duration, non-denoised data, at both single subject and group levels. ME-LLR substantially increased temporal signal-to-noise ratio (tSNR) for image data respective to each individual echo and for image data after nuisance regression. Among echo-specific image volumes, increases in tSNR yielded by ME-LLR were most pronounced for image data with the longest echo time and thereby lowest SNR. ICA showed resting-state networks consistently identified between non-denoised and denoised data, with clearer demarcation of networks for ME-LLR. Conclusions: ME-LLR is demonstrated to suppress non-physiologic noise, enhance functional connectivity map quality, and could potentially facilitate scan time reduction in ME-fMRI.
Pemigatinib For Previously Treated Central Nervous System Tumors With Activating FGFR Mutations or Translocations: Results From FIGHT-207 (S17.004)
Spanggaard, Iben , Matrana, Marc , Rocha‐Lima, Caio, Hervieu, Alice , Ahn, Myung‐Ju , Ahnert, Jordi Rodon, Véronèse, L., Oliveira, Natália , Schäffer, Michael, Mahipal, Amit , Vieito, María , Hervieu, Alice, Goyal, Lipika , Ahnert, Jordi Rodon, Li, Xin , Schaffer, Michael, Kesari, Santosh

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Neurology | April 28, 2023 | Volume: 100 | Issue: 17_supplement_2 | Pages: No page available

10.1212/wnl.0000000000203833 Get It

Improved Resting-State Functional MRI Using Multi-Echo Echo-Planar Imaging on a Compact 3T MRI Scanner with High-Performance Gradients
Kang, Daehun , In, Myung‐Ho , Halverson, Maria, Meyer, Nolan , Ahmed, Zaki , Gray, Erin M. , Fernandez, Brice , Black, David F. , Welker, Kirk M. , Trzasko, Joshua D. , Huston, John , Shu, Yunhong , Huston, John , Halverson, Maria A, Meyer, Nolan K , Ahmed, Zaki , Fernandez, Brice , Shu, Yunhong , Kang, Daehun , In, Myung-Ho , Jo, Hang Joon , Madhavan, Radhika , Foo, Thomas , Bernstein, Matt A.

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Sensors | April 28, 2023 | Volume: 23 | Issue: 9 | Pages: 4329

10.3390/s23094329 | PMID 37177534 Get It

In blood-oxygen-level-dependent (BOLD)-based resting-state functional (RS-fMRI) studies, usage of multi-echo echo-planar-imaging (ME-EPI) is limited due to unacceptable late echo times when high spatial resolution is used. Equipped with high-performance gradients, the compact 3T MRI system (C3T) enables a three-echo whole-brain ME-EPI protocol with smaller than 2.5 mm isotropic voxel and shorter than 1 s repetition time, as required in landmark fMRI studies. The performance of the ME-EPI was comprehensively evaluated with signal variance reduction and region-of-interest-, seed- and independent-component-analysis-based functional connectivity analyses and compared with a counterpart of single-echo EPI with the shortest TR possible. Through the multi-echo combination, the thermal noise level is reduced. Functional connectivity, as well as signal intensity, are recovered in the medial orbital sulcus and anterior transverse collateral sulcus in ME-EPI. It is demonstrated that ME-EPI provides superior sensitivity and accuracy for detecting functional connectivity and/or brain networks in comparison with single-echo EPI. In conclusion, the high-performance gradient enabled high-spatial-temporal resolution ME-EPI would be the method of choice for RS-fMRI study on the C3T.
Long‐term quality of life after treatment in sinonasal malignancy: A prospective, multicenter study
Maoz, Sabrina L. , Hwang, Peter H. , Fleseriu, Cara M. , Chan, Erik P., Adappa, Nithin D. , Getz, Anne E., Humphreys, Ian M. , Chang, Eugene H. , Jafari, Aria , Kingdom, Todd T. , Kohanski, Michael A. , Lee, Jivianne K., Lazor, Jillian W. , Nabavizadeh, Ali , Adappa, Nithin D. , Patel, Zara M. , Smith, Timothy L. , Storm, Phillip B. , Suh, Jeffrey D. , Wang, Marilene B. , Sim, Myung‐Shin , Wang, Eric W , Choby, Garret , Kuan, Edward C , Humphreys, Ian M , Jafari, Aria , Nayak, Jayakar V , Patel, Zara , Smith, Timothy L , Snyderman, Carl H , Beswick, Daniel , Hwang, Peter H , Maoz, Sabrina L , Choby, Garret , Chan, Erik, Adappa, Nithin D. , Geltzeiler, Mathew , Le, Christopher H. , Abuzeid, Waleed M. , Lee, Jivianne K., Nayak, Jayakar V. , Pinheiro‐Neto, Carlos , Resnick, Adam , John, Maie A. St. , Beswick, Daniel M.

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International Forum of Allergy & Rhinology | April 21, 2023 | Volume: 13 | Issue: 11 | Pages: 2030-2042

10.1002/alr.23171 | PMID 37082883 Get It

AbstractBackgroundQuality of life (QOL) for individuals with sinonasal malignancy (SNM) is significantly under‐studied, yet it is critical for counseling and may impact treatment. In this study we evaluated how patient, treatment, and disease factors impact sinonasal‐specific and generalized QOL using validated metrics in a large cohort over a 5‐year posttreatment time frame.MethodsPatients with SNM who underwent definitive treatment with curative intent were enrolled in a prospective, multisite, longitudinal observational study. QOL was assessed using the 22‐item Sino‐Nasal Outcome Test (SNOT‐22) and University of Washington Quality of Life Questionnaire (UWQOL) instruments at pretreatment baseline and multiple follow‐ups through 5 years posttreatment. Multivariable modeling was used to determine demographic, disease, and treatment factors associated with disease‐specific and generalized physical and social/emotional function QOL.ResultsOne hundred ninety‐four patients with SNM were analyzed. All QOL indices were impaired at pretreatment baseline and improved after treatment. SNOT‐22 scores improved 3 months and UWQOL scores improved 6 to 9 months posttreatment. Patients who underwent open compared with endoscopic tumor resection had worse generalized QOL (p < 0.001), adjusted for factors including T stage. Pterygopalatine fossa (PPF) involvement was associated with worse QOL (SNOT‐22, p < 0.001; UWQOL Physical dimension, p = 0.02). Adjuvant radiation was associated with worse disease‐specific QOL (p = 0.03). Neck dissection was associated with worse generalized physical function QOL (p = 0.01). Positive margins were associated with worse generalized social/emotional function QOL (p = 0.01).ConclusionDisease‐specific and generalized QOL is impaired at baseline in patients with SNM and improves after treatment. Endoscopic resection is associated with better QOL. PPF involvement, adjuvant radiation, neck dissection, and positive margins were associated with worse QOL posttreatment.
Minimizing susceptibility-induced BOLD sensitivity loss in multi-band accelerated fMRI using point spread function mapping and gradient reversal
In, Myung‐Ho , Yarach, Uten , Meyer, Nolan , Trzasko, Joshua D. , Shu, Yunhong , Meyer, Nolan K , Shu, Yunhong , In, Myung-Ho , Kang, Daehun , Jo, Hang Joon , Huston, John , Bernstein, Matt A.

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Physics in Medicine & Biology | December 22, 2022 | Volume: 68 | Issue: 2 | Pages: 025012

10.1088/1361-6560/acae14 | PMID 36549001 Get It

Abstract Objective . Interleaved reverse-gradient fMRI (RG-fMRI) with a point-spread-function (PSF) mapping-based distortion correction scheme has the potential to minimize signal loss in echo-planar-imaging (EPI). In this work, the RG-fMRI is further improved by imaging protocol optimization and application of reverse Fourier acquisition. Approach . Multi-band imaging was adapted for RG-fMRI to improve the temporal and spatial resolution. To better understand signal dropouts in forward and reverse EPIs, a simple theoretical relationship between echo shift and geometric distortion was derived and validated by the reliable measurements using PSF mapping method. After examining practical imaging protocols for RG-fMRI in three subjects on both a conventional whole-body and a high-performance compact 3 T, the results were compared and the feasibility to further improve the RG-fMRI scheme were explored. High-resolution breath-holding RG-fMRI was conducted with nine subjects on the compact 3 T and the fMRI reliability improvement in high susceptibility brain regions was demonstrated. Finally, reverse Fourier acquisition was applied to RG-fMRI, and its benefit was assessed by a simulation study based on the breath-holding RG-fMRI data. Main results . The temporal and spatial resolution of the multi-band RG-fMRI became feasible for whole-brain fMRI. Echo shift measurements from PSF mapping well estimated signal dropout effects in the EPI pair and were useful to further improve the RG-fMRI scheme. Breath-holding RG-fMRI demonstrated improved fMRI reliability in high susceptibility brain regions. Reverse partial Fourier acquisition omitting the late echoes could further improve the temporal or spatial resolution for RG-fMRI without noticeable signal degradation and spatial resolution loss. Significance . With the improved imaging scheme, RG-fMRI could reliably investigate the functional mechanisms of the human brain in the temporal and frontal areas suffering from susceptibility-induced functional sensitivity loss.