Magnetic Resonance in Medicine最新文献

{"title":"Minimally invasive measurement of carotid artery and brain temperature in the mouse","authors":"Lisa M. Gazdzinski,&nbsp;Luke Chung,&nbsp;Shoshana Spring,&nbsp;Owen Botelho,&nbsp;Bojana Stefanovic,&nbsp;Brian J. Nieman,&nbsp;Chinthaka C. Heyn,&nbsp;John G. Sled","doi":"10.1002/mrm.30405","DOIUrl":"10.1002/mrm.30405","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Brain temperature is tightly regulated and reflects a balance between cerebral metabolic heat production and heat transfer between the brain, blood, and external environment. Blood temperature and flow are critical to the regulation of brain temperature. Current methods for measuring in vivo brain and blood temperature are invasive and impractical for use in small animals. This work presents a methodology to measure both brain and arterial blood temperature in anesthetized mice by MRI using a paramagnetic lanthanide complex: thulium tetramethyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (TmDOTMA^-).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A phase-based imaging approach using a multi-TE gradient echo sequence was used to measure the temperature-dependent chemical shift difference between thulium tetramethyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid methyl protons and water, and from this calculate absolute temperature using calibration data.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In a series of mice in which core body temperature was held stable but at different values within the range of 33° to 37°C, brain temperature away from the midline was independent of carotid artery blood temperature. In contrast, midline voxels correlated with carotid artery blood temperature, likely reflecting the preponderance of larger arteries and veins in this region.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>These results are consistent with brain temperature being actively regulated. A limitation of the present implementation is that the spatial resolution in the brain is coarse relative to the size of the mouse brain, and further optimization is required for this method to be applied for finer spatial scale mapping or to characterize focal pathology.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 5","pages":"2049-2058"},"PeriodicalIF":3.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30405","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Noninvasive blood–brain barrier integrity mapping in patients with high-grade glioma and metastasis by multi–echo time–encoded arterial spin labeling","authors":"Gabriel Hoffmann,&nbsp;Christine Preibisch,&nbsp;Matthias Günther,&nbsp;Amnah Mahroo,&nbsp;Matthias J. P. van Osch,&nbsp;Lena Václavů,&nbsp;Marie-Christin Metz,&nbsp;Kirsten Jung,&nbsp;Claus Zimmer,&nbsp;Benedikt Wiestler,&nbsp;Stephan Kaczmarz","doi":"10.1002/mrm.30415","DOIUrl":"10.1002/mrm.30415","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;In brain tumors, disruption of the blood–brain barrier (BBB) indicates malignancy. Clinical assessment is qualitative; quantitative evaluation is feasible using the &lt;i&gt;K&lt;/i&gt;&lt;sub&gt;2&lt;/sub&gt; leakage parameter from dynamic susceptibility contrast MRI. However, contrast agent–based techniques are limited in patients with renal dysfunction and insensitive to subtle impairments. Assessing water transport times across the BBB (&lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt;) by multi-echo arterial spin labeling promises to detect BBB impairments noninvasively and potentially more sensitively.&lt;/p&gt;\u0000 \u0000 &lt;p&gt;We hypothesized that reduced &lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt; indicates impaired BBB. Furthermore, we assumed higher sensitivity for &lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt; than dynamic susceptibility contrast–based &lt;i&gt;K&lt;/i&gt;&lt;sub&gt;2&lt;/sub&gt;, because arterial spin labeling uses water as a freely diffusible tracer.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;We acquired 3T MRI data from 28 patients with intraparenchymal brain tumors (World Health Organization Grade 3 &amp; 4 gliomas [&lt;i&gt;n&lt;/i&gt; = 17] or metastases [&lt;i&gt;n&lt;/i&gt; = 11]) and 17 age-matched healthy controls. The protocol included multi-echo and single-echo Hadamard-encoded arterial spin labeling, dynamic susceptibility contrast, and conventional clinical imaging. &lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt; was calculated using a T&lt;sub&gt;2&lt;/sub&gt;-dependent multi-compartment model.&lt;/p&gt;\u0000 \u0000 &lt;p&gt;Areas of contrast-enhancing tissue, edema, and normal-appearing tissue were automatically segmented, and parameter values were compared across volumes of interest and between patients and healthy controls.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Results&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;&lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt; was significantly reduced (−20.3%) in contrast-enhancing tissue compared with normal-appearing gray matter and correlated well with |&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;2&lt;/sub&gt;| (&lt;i&gt;r&lt;/i&gt; = −0.347). Compared with healthy controls, &lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt; was significantly lower in tumor patients' normal-appearing gray matter (&lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex,tumor&lt;/sub&gt; = 0.141 ± 0.032 s vs. &lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex,HC&lt;/sub&gt; = 0.172 ± 0.036 s) and normal-appearing white matter (&lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex,tumor&lt;/sub&gt; = 0.116 ± 0.015 vs. &lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex,HC&lt;/sub&gt; = 0.127 ± 0.017 s), whereas |&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;2&lt;/sub&gt;| did not differ significantly. Receiver operating characteristic analysis showed a larger area under the curve for &lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt; (0.784) than &lt;i&gt;K&lt;/i&gt;&lt;sub&gt;2&lt;/sub&gt; (0.604).&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Conclusion&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;&lt;i&gt;T&lt;/i&gt;&lt;sub&gt;ex&lt;/sub&gt; is sensitive to pathophysiologically impaired BBB. It a","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 5","pages":"2086-2098"},"PeriodicalIF":3.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30415","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of particle size on \u0000 \u0000 \u0000 R\u0000 2\u0000 *\u0000 \u0000 and fat fraction estimation for accurate assessment of hepatic iron overload and steatosis using MRI","authors":"Utsav Shrestha,&nbsp;Sarah Brasher,&nbsp;Zachary Abramson,&nbsp;Cara E. Morin,&nbsp;Aaryani Tipirneni-Sajja","doi":"10.1002/mrm.30419","DOIUrl":"10.1002/mrm.30419","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;To investigate the impact of iron particle size on &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mo&gt;*&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {R}_2^{ast } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and fat fraction (FF) estimations for coexisting hepatic iron overload and steatosis condition using Monte Carlo simulations and phantoms.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Three iron particle sizes (0.38, 0.52, and 0.71 μm) were studied using simulations and phantoms. Virtual liver models mimicking in vivo spatial distribution of fat droplets and iron deposits were created, and MRI signals were synthesized using Monte Carlo simulations for FF 1%–30% and liver iron concentration (LIC) 1–20 mg/g. Seventy-five fat-iron phantoms with varying iron (0–8 μg/mL) and fat (0%–40%) concentrations and particle sizes were constructed. Three-way analysis of variance was used to assess the effect of iron particle size on &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mo&gt;*&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {R}_2^{ast } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and FF estimations.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Results&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;In simulations, estimated and true FF were in excellent agreement (slope: 0.93–1.09) for liver iron concentration ≤ 13 mg/g. For both simulations and phantoms, FF estimation bias increased as iron concentration increased and particle size decreased, with 0.71μm iron particle having the lowest bias (≤ 20%), and 0.52 μm and 0.38 μm iron particles producing higher bias (≥ 20%) for higher iron concentrations and lower FFs. Additionally, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;mo&gt;*&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {R}_2^{ast } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; increased linearly with increasing iron concentration (&lt;i&gt;r&lt;/i&gt; ≥ 0.87) and decreasing particle size. Iron particle size significantly influenced the estimated versus true FF (simulations: &lt;i&gt;p&lt;/i&gt; = 0.04; phantoms: &lt;i&gt;p&lt;/i&gt; = 0.03) and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 ","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 5","pages":"2176-2185"},"PeriodicalIF":3.0,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142922044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"T2* relaxometry of fetal brain structures using low-field (0.55T) MRI","authors":"Kelly Payette,&nbsp;Alena U. Uus,&nbsp;Ella Kollstad,&nbsp;Jordina Aviles Verdera,&nbsp;Dario Gallo,&nbsp;Megan Hall,&nbsp;Joseph V. Hajnal,&nbsp;Mary A. Rutherford,&nbsp;Lisa Story,&nbsp;Jana Hutter","doi":"10.1002/mrm.30409","DOIUrl":"10.1002/mrm.30409","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>Human brain development during gestation is complex, as both structure and function are rapidly forming. Structural imaging methods using MRI are well developed to explore these changes, but functional imaging tools are lacking. Low-field MRI is a promising modality to bridge this gap. The longer intrinsic T₂* values at low field strengths increase the dynamic range and enable the quantification of individual brain regions with low T₂* values, such as deep gray matter. This study investigates regional brain T₂* quantification throughout the second half of gestation on low-field 0.55T MRI.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Dynamic multi-echo gradient-echo sequences were acquired in 135 cases at 0.55 T between 20 and 40 weeks' gestation. Automatic high-resolution reconstruction and segmentation tools were developed, resulting in T₂* values of seven individual anatomical brain structures for each subject. These regional brain T₂* values were analyzed throughout gestation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>All regional fetal brain T₂* values decreased throughout gestation (<i>p</i> &lt; 0.01). Each anatomical brain structure had varying ranges and decay rates, with the cerebellum and white matter displaying the highest (nonfluid structure) values, with the maximum values between 350 and 400 ms at about 20 weeks. The brainstem and deep gray matter had the lowest range of T₂* values, reaching values of 250 ms early in gestation. The matched volumetric assessment of the different structures demonstrated expected growth, matching current literature.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Low-field MRI allows for a detailed, regional T₂* analysis of the fetal brain, with more inclusive norms to be developed due to its wider bore.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 5","pages":"1942-1953"},"PeriodicalIF":3.0,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30409","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142906531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of elevated succinate in brain during circulatory arrest in a piglet model: A 3T 1H MR spectroscopy study","authors":"Ralph E. Hurd,&nbsp;Meng Gu,&nbsp;Kenichi Okamura,&nbsp;Masafumi Shibata,&nbsp;Yoshikazu Ono,&nbsp;Moussa Haidar,&nbsp;R. Kirk Riemer,&nbsp;Frank L. Hanley,&nbsp;Daniel M. Spielman","doi":"10.1002/mrm.30414","DOIUrl":"10.1002/mrm.30414","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To measure and validate elevated succinate in brain during circulatory arrest in a piglet model of cardiopulmonary bypass.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using data from an archive of 3T ¹H MR spectra acquired in previous in-magnet studies, dynamic plots of succinate, spectral simulations and difference spectra were generated for analysis and validation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Elevation of succinate during circulatory arrest was observed and validated. Fitting bias was evaluated as a function of the line-widths and signal-to-noise ratios of the archived data. Succinate increases were independent of bypass temperature. Succinate elevation was also not observed with antegrade cerebral perfusion.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Although spectrally overlapped and at sub-millimolar levels, elevated brain succinate can be reliably measured by dynamic MR spectroscopy at 3T. Noise dependent bias of the stronger overlapping signals did not impact the succinate measurement. Elevated succinate during circulatory arrest and its recovery after reperfusion was observed. This finding is consistent with earlier reports that correlate elevated succinate with ischemic-reperfusion injury.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 5","pages":"1874-1885"},"PeriodicalIF":3.0,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142907370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"WALINET: A water and lipid identification convolutional neural network for nuisance signal removal in \u0000 \u0000 \u0000 \u0000  \u0000 \u0000 1\u0000 \u0000 \u0000 H\u0000 \u0000 $$ {}^1mathrm{H} $$\u0000 MR spectroscopic imaging","authors":"Paul J. Weiser,&nbsp;Georg Langs,&nbsp;Stanislav Motyka,&nbsp;Wolfgang Bogner,&nbsp;Sébastien Courvoisier,&nbsp;Malte Hoffmann,&nbsp;Antoine Klauser,&nbsp;Ovidiu C. Andronesi","doi":"10.1002/mrm.30402","DOIUrl":"10.1002/mrm.30402","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;Proton magnetic resonance spectroscopic imaging (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mo&gt; &lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {}^1mathrm{H} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;-MRSI) provides noninvasive spectral-spatial mapping of metabolism. However, long-standing problems in whole-brain &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mo&gt; &lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {}^1mathrm{H} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;-MRSI are spectral overlap of metabolite peaks with large lipid signal from scalp, and overwhelming water signal that distorts spectra. Fast and effective methods are needed for high-resolution &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mo&gt; &lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {}^1mathrm{H} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;-MRSI to accurately remove lipid and water signals while preserving the metabolite signal. The potential of supervised neural networks for this task remains unexplored, despite their success for other MRSI processing.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;We introduce a deep learning method based on a modified Y-NET network for water and lipid removal in whole-brain &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mo&gt; &lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mi&gt;H&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {}^1mathrm{H} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;-MRSI. The WALINET (WAter and LIpid neural NETwork) was compa","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 4","pages":"1430-1442"},"PeriodicalIF":3.0,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11782715/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142907369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MVP-VSASL: measuring MicroVascular Pulsatility using velocity-selective arterial spin labeling","authors":"Conan Chen,&nbsp;Ryan A. Barnes,&nbsp;Katherine J. Bangen,&nbsp;Fei Han,&nbsp;Josef Pfeuffer,&nbsp;Eric C. Wong,&nbsp;Thomas T. Liu,&nbsp;Divya S. Bolar","doi":"10.1002/mrm.30370","DOIUrl":"10.1002/mrm.30370","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Purpose&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;By leveraging the small-vessel specificity of velocity-selective arterial spin labeling (VSASL), we present a novel technique for measuring cerebral MicroVascular Pulsatility named MVP-VSASL.&lt;/p&gt;\u0000 &lt;/section&gt;\u0000 \u0000 &lt;section&gt;\u0000 \u0000 &lt;h3&gt; Theory and Methods&lt;/h3&gt;\u0000 \u0000 &lt;p&gt;We present a theoretical model relating the pulsatile, cerebral blood flow-driven VSASL signal to the microvascular pulsatility index (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;PI&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ mathrm{PI} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;), a widely used metric for quantifying cardiac-dependent fluctuations. The model describes the dependence of the &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;PI&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ mathrm{PI} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; of VSASL signal (denoted &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;PI&lt;/mi&gt;\u0000 &lt;mi&gt;VS&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{PI}}_{mathrm{VS}} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) on bolus duration &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ tau $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; (an adjustable VSASL sequence parameter) and provides guidance for selecting a value of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ tau $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; that maximizes the SNR of the &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;PI&lt;/mi&gt;\u0000 &lt;mi&gt;VS&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {mathrm{PI}}_{mathrm{VS}} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; measurement. The model predictions were assessed in humans using data acquired with retrospectively cardiac-gated VSASL sequences over a broad range of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 ","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 4","pages":"1516-1534"},"PeriodicalIF":3.0,"publicationDate":"2024-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11782735/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultra-high temporal resolution 4D angiography using arterial spin labeling with subspace reconstruction","authors":"Qijia Shen,&nbsp;Wenchuan Wu,&nbsp;Mark Chiew,&nbsp;Yang Ji,&nbsp;Joseph G. Woods,&nbsp;Thomas W. Okell","doi":"10.1002/mrm.30407","DOIUrl":"https://doi.org/10.1002/mrm.30407","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>To achieve ultra-high temporal resolution non-contrast 4D angiography with improved spatiotemporal fidelity.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Continuous data acquisition using 3D golden-angle sampling following an arterial spin labeling preparation allows for flexibly reconstructing 4D dynamic angiograms at arbitrary temporal resolutions. However, k-space data is often temporally “binned” before image reconstruction, negatively affecting spatiotemporal fidelity and limiting temporal resolution. In this work, a subspace was extracted by linearly compressing a dictionary constructed from simulated curves of an angiographic kinetic model. The subspace was used to represent and reconstruct the voxelwise signal timecourse at the same temporal resolution as the data acquisition without temporal binning. Physiological parameters were estimated from the resulting images using a Bayesian fitting approach. A group of eight healthy subjects were scanned and the in vivo results reconstructed by different methods were compared. Because of the difficulty of obtaining ground truth 4D angiograms with ultra-high temporal resolution, the in vivo results were cross-validated with numerical simulations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The proposed method enables 4D time-resolved angiography with much higher temporal resolution (14.7 ms) than previously reported (˜50 ms) while maintaining high spatial resolution (1.1 mm isotropic). Blood flow dynamics were depicted in greater detail, thin vessel visibility was improved, and the estimated physiological parameters also exhibited more realistic spatial patterns with the proposed method.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Incorporating a subspace compressed kinetic model into the reconstruction of 4D ASL angiograms notably improved the temporal resolution and spatiotemporal fidelity, which was subsequently beneficial for accurate physiological modeling.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 5","pages":"1924-1941"},"PeriodicalIF":3.0,"publicationDate":"2024-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30407","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diffusion time effects over the adult lifespan indicates persistent zone-specific microstructural alterations in the human prostate with aging","authors":"Xiao Ma,&nbsp;Peter Seres,&nbsp;Adam Kinnaird,&nbsp;Christopher Fung,&nbsp;Thorsten Feiweier,&nbsp;Christian Beaulieu","doi":"10.1002/mrm.30408","DOIUrl":"10.1002/mrm.30408","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Purpose</h3>\u0000 \u0000 <p>The purpose of this study was to investigate microstructural changes in the aging adult prostate by comparing the effects of varying diffusion times using diffusion MRI, and to provide an age-related benchmark for future prostate cancer studies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The prostates of normal male volunteers (<i>n</i> = 70, 19–69 years) were scanned at 3 T with an oscillating gradient spin echo (OGSE: 6 ms), pulsed gradient spin echo (PGSE: 40 ms) and pulsed gradient stimulated echo (PGSTE: 100 ms), and anatomical T₂-weighted image. Volume and mean diffusivity (MD) were measured in the peripheral (PZ) and transition zones (TZ), which were assessed versus age.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>PZ and TZ showed quadratic age trajectories for all diffusion scans, with MD decreasing from 19 years to a minimum ˜30–40 years followed by a greater increase at older ages. Short (OGSE) and medium (PGSE) diffusion time MD had similar age trajectories, whereas long diffusion time (PGSTE) MD was significantly lower, particularly in PZ (22%). MD difference (∆MD) of OGSE-PGSTE and PGSE-PGSTE showed significant positive linear correlations with age for both PZ (larger slope) and TZ, resulting in ˜3.3x (PZ) and 1.8x (TZ) greater ∆MD from 19 to 69 years. MD and ∆MD versus age relationships differed from volume, which conversely had greater proportional growth in TZ than PZ.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The diffusion time effects suggest age-related microstructural changes consistent with development of persistently larger cell dimensions mainly in the prostate peripheral zone over the adult lifespan. This normative data can be used for comparison to prostate cancer factoring in age.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 5","pages":"2059-2069"},"PeriodicalIF":3.0,"publicationDate":"2024-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30408","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142903328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"129Xe Image Processing Pipeline: An open-source, graphical user interface application for the analysis of hyperpolarized 129Xe MRI","authors":"","doi":"10.1002/mrm.30417","DOIUrl":"https://doi.org/10.1002/mrm.30417","url":null,"abstract":"","PeriodicalId":18065,"journal":{"name":"Magnetic Resonance in Medicine","volume":"93 3","pages":"C1"},"PeriodicalIF":3.0,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mrm.30417","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143110476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}