Zhaoxia Yang¹, Chunlin Xiang¹, Weiyin Vivian Liu², Haonan Wang³, Lu Huang¹, and Liming Xia^1
1Tongji Hospital,Huazhong University of Science and Technology, wuhan, China, ²MR Research, GE Healthcare, Beijing, China, ³MR Research, General Electric Healthcare, Chicago, IL, United States

Keywords: Quantitative Imaging, Ischemia, stress cardiac magnetic resonance imaging

Automated CMR perfusion maps enable quantification of MBF for detection of myocardial ischaemia rapidly within a clinical workflow. Stress perfusion CMR derived quantitative parameters had good to excellent reproducibility, as well as quantitative MPR was moderately correlated with semi-quantitative MPR. Quantitative myocardial perfusion CMR provides objective indices (MBF and MPR), which could better identify disease extent and detect coronary microvascular disease than visual interpretation.

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Dariya Malyarenko¹, Scott D Swanson¹, Ramesh Paudyal², Amaresh Konar², Eddy Solomon³, Eric E Sigmund⁴, Stephen E Russek⁵, Sungheon Gene Kim³, Amita Shukla-Dave^2,6, and Thomas L Chenevert^1
1Radiology, University of Michigan Health System, Ann Arbor, MI, United States, ²Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States, ³Radiology, MRI Research Institute, Weill Cornell Medical College, New York, NY, United States, ⁴Radiology, Center for Biomedical Imaging, NYU Langone Health, New York, NY, United States, ⁵National Institute of Standards and Technology, Boulder, CO, United States, ⁶Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States

Keywords: Quantitative Imaging, Diffusion/other diffusion imaging techniques, diffusion kurtosis, multi-system reproducibility, quantitative phantom

This work studied reproducibility of apparent diffusion (D_a) and kurtosis (K_a) coefficients for three families of lamellar-vesicle materials in a quantitative phantom scanned at ambient temperature in a multi-site setting. Inter-system reproducibility of K_a was improved by maximum b-value fit-constraints for phantom materials with higher solid concentration, while temperature calibration improved D_a parameter consistency predominantly for materials with low solid concentration and containing longer-chain alcohols. After correction for temperature-dependence, these materials exhibited apparent diffusion reproducibility comparable to that of standard Gaussian diffusion controls.

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Andreia S Gaspar¹, Nuno A Silva², António M Ferreira^3,4, and Rita G Nunes^1
1Institute for Systems and Robotics - Lisboa and Department of Bioengineering, Instituto Superior Técnico – Universidade de Lisboa, Lisbon, Portugal, ²Hospital da Luz Learning Health, Luz Saúde, Lisbon, Portugal, ³Serviço de Cardiologia, Hospital de Santa Cruz, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal, ⁴Unidade de Imagiologia Cardíaca Avançada, Hospital da Luz, Lisbon, Portugal

Keywords: Quantitative Imaging, Heart, T1 mapping

The open-source method Prototype of Myocardial T1 mapping (ProMyoT1) created with Pulseq was tested in vivo in healthy subjects to evaluate its repeatability and compare its performance with that of the clinical MOLLI method. ProMyoT1 provided myocardium T1 values similar to those obtained with MOLLI. The precision was better for MOLLI, but the repeatability measures (Coefficient of Variation and Repeatability Coefficient) were similar in both methods. The developed ProMyoT1 method was shown to be reliable and should improve the accessibility to T1 mapping, while also enabling fast sequence prototyping so that further improvements can easily be tested. 

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Scott D. Swanson¹, Ted Lynch², Shigeto Ono², and Dariya I. Malyarenko^1
1Department of Radiology, University of Michigan, Ann Arbor, MI, United States, ²CIRS/Mirion Inc., Norfolk, VA, United States

Keywords: Quantitative Imaging, Phantoms, Diffusion, Kurtosis, Transverse Relaxation

A set of materials with tunable T₂, diffusion, and kurtosis were assembled to create quantitative biomimetic MRI phantoms. T₂ is controlled with variable agarose concentration, mono-exponential diffusion by polyvinylpyrrolidone, and kurtosis by addition of lamellar vesicles. The phantoms are mechanically stabilized by polyacrylamide gels to allow biomimetic morphologies. These nanostructured systems provide an ideal platform for moldable multiparametric MRI phantoms that are useful for pulse sequence design and protocol standardization for multi-site multi-vendor imaging trials, as well as for refinement of emerging AI analysis methods.  

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Stella Heo¹, Christopher Rowley², Christine Tardif², and Nicholas Bock^1
1Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, ON, Canada, ²McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada

Keywords: Quantitative Imaging, Challenges, Reproducibility

The longitudinal relaxation rate (R₁) is deemed to be a suitable quantitative imaging metric for multi-site investigations as it describes a quantitative property of the tissue that can be measured, reproduced, and compared across sites when differences in hardware and acquisition settings are accounted for. Here, we present inter- and intra-vendor variability observed in whole-brain R₁ maps generated from two-point inversion-recovery MRI data after accounting for variations in pulse sequences and B₁⁺  field maps. We posit that this inter-site variability may be due to differential intensity scaling applied at acquisition and suggest a potential correction method using site-specific scaling factors.

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Kalina V Jordanova¹, Ye Tian², Sheng Shen³, Michele N Martin¹, Megan E Poorman⁴, Rui Pedro Teixeira⁴, Krishna S Nayak², Matthew S Rosen^3,5, and Kathryn E Keenan^1
1NIST: National Institute of Standards and Technology, Boulder, CO, United States, ²Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, United States, ³Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, ⁴Hyperfine, Inc., Guilford, CT, United States, ⁵Department of Physics, Harvard University, Cambridge, MA, United States

Keywords: Quantitative Imaging, Relaxometry

There is re-emerging interest in MRI fields ≤0.55T as well as quantitative MRI (qMRI) methods. Physiologically relevant reference objects are needed to adapt qMRI techniques to lower fields.

 

We investigate materials as tissue mimics for brain imaging at 0.0065T, 0.064T, 0.55T, for white matter, gray matter, fat, cerebrospinal fluid, and blood. We create samples composed of agarose and paramagnetic salts and measure relaxation across field strengths. Samples suitable to mimic each tissue are presented for each field strength. This work will facilitate qMRI development for fields ≤0.55T by providing accessible mimic compositions to the community.

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Prashant Prabhakaran Nair¹, Robin J.M. Navest², Rosie Goodburn¹, Bastien Lecoeur¹, Uwe Oelfke¹, and Andreas Wetscherek^1
1Radiotherapy and Imaging, The Institute of Cancer Research, London, United Kingdom, ²Netherlands Cancer Institute, Amsterdam, Netherlands

Keywords: Quantitative Imaging, Precision & Accuracy, MR-Linac

DW-acquisitions with high ADC accuracy, precision and low geometric distortion are necessary for using ADC maps for treatment planning and response assessment in MR-guided radiotherapy on MR-Linacs. We measured SNR, ADC bias, repeatability coefficient and marker distances on the NIST phantom for DW-EPI, DW-TSE and SPLICE protocols. Two volunteers were scanned in the head and neck region. The investigated TSE-based protocols showed ADC bias and DW-EPI demonstrated better repeatability. Spectral fat-suppression techniques led to higher SNR than using STIR. SPLICE DWI could be an alternative to diffusion EPI with reduced distortion and comparable SNR, if low-high profile order is used.

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Neville D Gai¹, Ruifeng Dong¹, Jeffrey Hopkins², and Carlo Pierpaoli^1
1Laboratory of Quantitative Imaging, National Institute of Biomedical Imaging and Bioengineering, Bethesda, MD, United States, ²MR Division, GE Healthcare, Waukesha, WI, United States

Keywords: Quantitative Imaging, Diffusion Tensor Imaging, PVP phantom, spectroscopy, temperature mapping

Clinical acceptance of quantitative diffusion MRI faces difficulties due to lack of standardization. Quality control across platforms and centers is vital for multicenter efforts. Polyvinylpyrrolidone(PVP) phantoms provide excellent properties suitable for cross-center validation. However, diffusion metrics vary with temperature. Measuring phantom temperature along with diffusion metrics is necessary. Spectroscopic temperature mapping of the PVP phantom and ADC values were investigated on two different vendor platforms. It is shown that the water peak moves relative to easily identifiable stable peaks in PVP allowing intrinsic temperature measurement. Excellent agreement for temperature and ADC mapping across both platforms should make cross-site standardization possible.

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Emile Clements Kadalie¹, Aurélien J Trotier¹, Nadège Corbin¹, Sylvain Miraux¹, and Emeline J Ribot^1
1Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536, CNRS / Université de Bordeaux, Bordeaux, France

Keywords: Quantitative Imaging, Brain, T2 mapping

While recent works have determined that the DESS sequence has the ability to produce 3D T₂ mapping of the brain, it remains sensitive to B₀-related variation due to respiration. Multiple encoding strategies, using cartesian-spiral trajectories with different lengths combined with a variable density Poisson undersampling mask and Compressed-Sensing reconstruction, were consequently employed and compared in order to suppress respiration artifacts as well as to establish accurate and repeatable 3D T₂ maps of the brain at 3T.

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Alistair Lamb¹, David Atkinson², Shonit Punwani², Hui Zhang³, and Anna Barnes^4
1Department of Medical Physics & Biomedical Engineering, University College London, London, United Kingdom, ²Centre for Medical Imaging, University College London, London, United Kingdom, ³Centre for Medical Image Computing, University College London, London, United Kingdom, ⁴King's Technology Evaluation Centre, King's College London, London, United Kingdom

Keywords: Quantitative Imaging, Whole Body, T1-mapping

We investigate the feasibility of whole-body (WB) variable flip angle (VFA) T1 mapping using linear least squares fitting with only two flip angles (FAs) in order to obtain WB T1 maps within a clinically viable timeframe. This could enable its use as an imaging biomarker in metastatic cancer. We assessed the agreement across eight subjects in a variety of abdominal tissues between T1 estimates fitted using eight FAs and just 2 FAs. We found that VFA T1 mapping can be achieved by acquiring only two FAs with minimal loss to precision, providing the lower FA is between 2.5° and 7.5°.

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Eric Y. Pierre¹, David N. Vaughan^1,2, Warda T. Syeda³, Bahman Tahayori¹, Heath R. Pardoe¹, David F. Abbott¹, and Graeme D. Jackson^1
1Imaging and Epilepsy, The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, ²Department of Neurology, Austin Health, Melbourne, Australia, ³Department of Psychiatry, The University of Melbourne, Melbourne, Australia

Keywords: Quantitative Imaging, Quantitative Susceptibility mapping, Reproducible Research

We propose the customization of a commercially-available phantom design to be used for QSM reproducibility research with long-term stability, allowing reproduction of the phantom itself commercially. The proposed phantom is based on master-dilution of Gadolinium in pure water vials, offering long-term stability, with theoretical susceptibility range chosen to match normal tissue and common pathologies in the brain. We evaluate the suitability of the phantom for QSM reproducible research for different sequences, orientation within the scanner and regularization algorithms.  

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Yuting Ling¹, Jianjun Zhang², Jiangwei Xiang², Yu Wang¹, Zhenzhuang Miao¹, Xingxing Zhang¹, Xiaoyun Liang¹, and Feng Huang^1
1Neusoft Medical Systems Co., Ltd., Shanghai, China, ²Department of Radiology, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, China

Keywords: Stroke, Screening

Smart BrainQuant, adapted from strategically acquired gradient echo (STAGE) method, is capable to provide 10 multi-contrast and multi-quantitative images with high image quality in 4:21 minutes at 1.5T. A preclinical validation work was introduced in this study with the aim to assess the test-retest repeatability of T1, proton spin density (PSD), susceptibility, and R2* by recruiting 18 healthy volunteers. Coefficient of variation of T1, PSD, and R2* ranged from 3.3% to 4.1%. Bland-Altman demonstrated that the line of equality is in the 95% confidence interval (CI) of the mean difference for the four maps.

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Anna Caroli¹, Siria Pasini¹, Tau Vandelboe², Anish Raj^3,4, Leyre Garcia-Ruiz⁵, Anika Strittmatter^3,4, Rebeca Echeverria-Chasco⁵, Giulia Villa¹, Paolo Brambilla⁶, Esben Søvsø Szocska Hansen², Steffen Ringgaard², Frank G Zoellner^3,4, Maria Fernandez-Seara⁵, Susan Francis⁷, and Christoffer Laustsen^2
1Bioengineering Department, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Ranica (BG), Italy, ²The MR Research Centre, Aarhus University, Aarhus, Denmark, ³Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ⁴Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ⁵Clínica Universidad de Navarra, Pamplona, Spain, ⁶Unit of Radiology, ASST Papa Giovanni XXIII, Bergamo, Italy, ⁷University of Nottingham, Nottingham, United Kingdom

Keywords: Quantitative Imaging, System Imperfections: Measurement & Correction

This multicentre study aimed at assessing multi-vendor accuracy and reproducibility of typical MR biomarkers on 3T and 1.5T scanners from 5 clinical centers. MRI acquisitions were performed using NIST protocols, on Essential System and Diffusion NIST phantoms. T1 was measured by 3-parameter fitting, while T2 and ADC by mono-exponential fitting, using PhantomViewer software. When compared with reference values, non-negligible discrepancies were found across vendors, especially for T1 and T2 measurements. Reproducibility was vendor-dependent, and higher on 3T than on 1.5T scanners. ADC and T1 showed highest reproducibility. Corrections are likely needed to account for possible temperature and scanner differences.

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Mathieu Boudreau¹, Agah Karakuzu¹, Arnaud Boré^2,3, Kiril Zelenkovski⁴, Basile Pinsard^2,3, Eva Alonso-Ortiz¹, Julie Boyle^2,3, Pierre Bellec^2,3,5, and Julien Cohen-Adad^1,3,6,7
1NeuroPoly, Polytechnique Montreal, Montreal, QC, Canada, ²Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montreal, QC, Canada, ³Unité de Neuroimagerie Fonctionnelle (UNF), Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montreal, QC, Canada, ⁴Faculty of Computer Science and Engineering (FINKI), Skopje, Macedonia, ⁵Psychology Department, Université de Montréal, Montreal, QC, Canada, ⁶Mila - Quebec AI Institute, Montreal, QC, Canada, ⁷Centre de recherche du CHU Sainte-Justine, Université de Montréal, Montreal, QC, Canada

Keywords: Quantitative Imaging, Quantitative Imaging

The stability of quantitative MRI measures of microstructure in the brain and spinal cord was quantified longitudinally over three years. Six healthy subjects were scanned approximately four times per year with an structural quantitative imaging protocol (T1w, T2w, T2*w, DWI, MP2RAGE, MTsat, and B1). The intra-subject COV indicated good stability of all quantitative metrics measured in the brain (< 2.3% in WM, < 3.1% in GM). The spinal cord resulted in slightly higher COVs (3.9% - 9.5%). This work is part of a larger project, the Courtois project on neural modelling (CNeuroMod).

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Michael Malmberg¹, Henrik L Odéen², and Dennis L Parker^2
1Biomedical Engineering, University of Utah, Salt Lake City, UT, United States, ²Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States

Keywords: Quantitative Imaging, Quantitative Imaging, T1 mapping

An innovative cylindrical phantom is used to mimic a dynamic acquisition with temperature-induced changes in T₁. Single reference (SR) variable flip angle (VFA) T₁ maps are acquired at several rotational positions of this phantom, and are compared to corresponding T₁ values acquired with the dual-angle variable flip angle and inversion recovery T₁ mapping methods. The SR-VFA method of T₁ mapping is shown to produce T₁ accuracy within 4-10% of both inversion recovery and dual-angle VFA T₁ measurements.

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Kathryn E Keenan¹, Bilal Tasdelen², Adrienne E Campbell-Washburn³, Harish Sharma⁴, Ahsan Javed³, Rajiv Ramasawmy³, Michele N Martin¹, Nicole Seiberlich⁴, and Krishna Nayak^2
1NIST, Boulder, CO, United States, ²Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, United States, ³Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States, ⁴Department of Radiology, University of Michigan, Ann Arbor, MI, United States

Keywords: Quantitative Imaging, Relaxometry

We compare T1 and T2 measurements between the Free.Max and ramped-down Aera using the ISMRM/NIST system phantom at multiple sites. All 0.55T systems had comparable, to each other, measurements of T1 and T2 on both the NiCl2 and MnCl2 arrays. The T1 measurement of the NiCl2 array by VFA-GRE with B1+correction was overestimated compared to the site-reference by 1% to 92%. The rest of the measurements – MnCl2 T1, NiCl2 T2, and MnCl2 T2 – were within +/-20% of the site-reference and NMR-reference values. As adoption of 0.55T platforms increases, it is important to characterize and compare systems across sites.

Xiaoxi Yu¹, Zhaoxi Liu², Jianxun Qu³, Fengdan Wang², Zhichao Lai¹, Xiaoyuan Fan², Luming Ye⁴, Jiang Shao¹, Yan Zhang², Bao Liu¹, Zhengyu Jin², and Feng Feng^2
1Vascular Surgery, Peking Union Medical College Hospital, Beijing, China, ²Radiology, Peking Union Medical College Hospital, Beijing, China, ³MR Collaboration, Siemens Healthineers Ltd., Beijing, China, ⁴Advanced Therapies Collaboration, Siemens Healthineers Ltd., Beijing, China

Keywords: Quantitative Imaging, Perfusion

This study used blood oxygen level-dependent (BOLD) imaging to assess the hemodynamics of the lower limbs among elder controls and patients with peripheral artery disease (PAD). The BOLD-derived perfusion parameters, such as time to peak and gradient during reactive hyperemia, showed good reproducibility and significantly differed between patients and controls. The results indicated decreased vasodilatation ability and perfusion levels in patients with PAD. Therefore, BOLD imaging can be a feasible perfusion assessment method for long-term noninvasive PAD monitoring.

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Jessica Lauren Asay¹, Krithika Balaji², Anthony A Gatti¹, Arjun D Desai¹, Michael Mendoza², Zimu Huo², Akshay S Chaudhari^1,3, Feliks Kogan¹, Peter J Lally^4,5, Neal K Bangerter², and Garry E Gold^1
1Radiology, Stanford University, Stanford, CA, United States, ²Bioengineering, Imperial College London, London, United Kingdom, ³Biomedical Data Science, Stanford University, Stanford, CA, United States, ⁴Brain Sciences, Imperial College London, London, United Kingdom, ⁵UK Dementia Research Institute Centre for Care Research and Technology, London, United Kingdom

Keywords: Quantitative Imaging, Data Processing, Repeatability, cartilage, knee

Cartilage T₂ relaxation times (T₂), used to detect early knee osteoarthritis, lack standardization in acquiring and processing data, making comparisons between studies difficult. Standardizing image post-processing could possibly control for biases. Here, we assess qDESS cartilage T₂ repeatability across two different sites and 7T scanner vendors with identical automatic segmentation and T₂ mapping software. Within-site repeatability was good (ICC≥ 0.75) for most cartilage regions, while cross-vendor repeatability was good for the tibial and femoral posterior cartilage. This preliminary study shows standardizing acquisition and post-processing can lead to repeatable T₂ values across different vendors.

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Yael Vainberg¹, Valentina Mazzoli¹, and Feliks Kogan^1
1Stanford University, Stanford, CA, United States

Keywords: Quantitative Imaging, Cartilage, Repeatability

T2 and T1rho repeatability is essential for evaluating the small changes that occur during early osteoarthritis disease progression. In this study, we acquired phantom data on T2 and T1rho relaxation times across 6 time points as well as 3 distinct locations along the scanner for T2/T1rho 3D MAPSS and 3D qDESS with varying resolution for T2 mapping. We observed repeatability of the 4 quantitative MRI sequences that were well within the QIBA benchmark for phantom scans of 4-5%. Further, our data suggests that phantom positioning within the scanner bore did not affect repeatability or quantitative values. 

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Hooman Hamedani¹, Stephen Kadlecek², Faraz Amzajerdian², Ryan Baron², Kai Ruppert², Mostafa Ismail², Luis Loza², Duncan Ian², and Rahim Rizi^2
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²University of Pennsylvania, Philadelphia, PA, United States

Keywords: Quantitative Imaging, Lung, Hyperpolarized MRI

In order to image function in the free breathing lung with high temporal and special resolution, we have developed a methodology that can be used in combination with a non-rigid image registration technique to generate comprehensive quantitative maps of lung ventilation and gas exchange. For these HP MRI-derived regional parameters to produce meaningful information that can be used to characterize lung disorders, a reproducibility study that systematically assesses the variability of these parameters is needed. Here, we assess the reproducibility of our previously reported dynamic hyperpolarized imaging measurements between two sessions separated by minutes.