Rosh Varghese Georgy¹, Elizabeth Joseph¹, Aparna Irodi¹, Binita Riya Chacko¹, Leena Vimala Robinson¹, and Roshan Samuel Livingstone^1
1Department of Radiology, Christian Medical College, Vellore, India

Parametric techniques like native T1 and T2 mapping showed a strong positive correlation with T2* in the non-invasive assessment of cardiac iron overload. T1 mapping was shown to be superior to T2 mapping in the diagnosis of cardiac iron overload. 30% of the study population had normal T2* values, but low T1 values. T1 mapping may be more sensitive in the detection of patients with early/mild cardiac iron overload, who are being missed by T2*.

Xiaoqing Wang^1,2, Sebastian Rosenzweig^1,2, Moritz Blumenthal¹, Zhengguo Tan^1,2, Nick Scholand^1,2, and Martin Uecker^1,2,3,4
1University Medical Center Göttingen, Göttingen, Germany, ²Partner Site Göttingen, German Centre for Cardiovascular Research (DZHK), Göttingen, Germany, ³Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany, ⁴Campus Institute Data Science (CIDAS), University of Göttingen, Göttingen, Germany

In this work, we develop a motion-resolved model-based reconstruction for free-breathing multi-phase myocardial T1 mapping using a free-running inversion-recovery radial FLASH sequence. Initial results on an experimental phantom and two healthy subjects have demonstrated that the proposed method could achieve motion-resolved T1 mapping at a spatial resolution of 1.33 × 1.33 × 6 mm³ with good accuracy, precision and reproducibility.

Andreia S Gaspar¹, Nuno A da Silva², and Rita G Nunes^1
1Institute for Systems and Robotics - Lisboa and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal, ²Hospital da Luz Learning Health, Lisboa, Portugal

T1 mapping is a crucial technique for myocardial tissue characterization. T1-mapping MOLLI sequences are widely used in the clinic but fast prototyping for concept testing and improvements is challenging and time consuming as it requires knowledge of the vendor specific programming environment. The use of an open-source framework would enable faster sequence prototyping, and facilitate reproducibility studies of new T1 mapping techniques. The aim of this work is to develop an open-source Prototype of Myocardial T1 mapping (ProMyoT1) using Pulseq to implement an inversion recovery T1 mapping sequence based on the MOLLI inversion/triggering scheme.

Yuta Endo¹, Haruna Shibo¹, Makoto Amanuma¹, Kuninori Kobayashi¹, and Shigehide Kuhara^1
1Faculty of Health Sciences, Kyorin University, Mitaka-shi, Tokyo, Japan

Myocardial T1 mapping using the modified Look-Locker inversion recovery (MOLLI) method shows good precision of T1 measurements, but their underestimation has long remained a problem in accurate T1 estimation. We developed a novel T1 analysis method by applying a data-matching strategy to the MOLLI method. The analysis method we propose estimates the T1 map by matching the MOLLI signals of a subject to dictionary data pixel-wise, which are the Look-Locker signals calculated in advance for various tissue parameters. The proposed method sufficiently reduces T1 underestimation of the MOLLI method and obtains more accurate T1 values.

Habib Rebbah¹, Anaîs Bernard¹, Julien Rouyer¹, and Timothé Boutelier^1
1Research & Innovation, Olea Medical, La Ciotat, France

The registration of pre- and post-injected T1 maps is a multimodal image registration problem. To employ algorithms based on intensity preservation assumption, one need to use image descriptor. By comparing six of them, we aim to choose the most adequate one to our issue. We conducted our analyzes using a STEMI-patients database. The Sobel filter emerge as the most accurate and precise descriptor. The study of the results shows that the position of the acquired slice has no effect on the performances of the algorithm, while the size of the lesion and the cross-slice motion are inversely correlated to them

Thomas Lottner¹, Joannes Fischer¹, Simon Reiss¹, Lars Bielak¹, Timo Heidt², Ali Caglar Özen^1,3, Julien Thielmann², Constantin von zur Mühlen², and Michael Bock^1
1Department of Radiology, Medical Physics, Faculty of Medicine, University Medical Center Freiburg, University of Freiburg, Freiburg, Germany, ²University Heart Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany, ³German Consortium for Translational Cancer Research Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany

Iron accumulation is a side effect from regular blood transfusions, which are a common treatment for diseases like hemochromatosis and sickle cell disease. T₂* mapping can be a useful tool in therapy planning as it allows for monitoring of the iron accumulation in the heart. Multi-echo-GRASP offers a method of T₂* mapping for all phases of the cardiac cycle. The acquisition can be performed in free breathing which is beneficial for patients with an impaired cardiac and/or respiratory capacity.

Isao Shiina¹, Michinobu Nagao², Masami Yoneyama³, Yasuhiro Goto⁴, Kazuo Kodaira⁴, takumi ogawa⁴, Mamoru Takeyama⁴, Isao Tanaka⁴, and Shuji Sakai^2
1Radiological Services, Tokyo Women's Medical University Hospital, tokyo, Japan, ²Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University Hospital, Tokyo, Japan, ³Philips Electronics Japan, Tokyo, Japan, ⁴Department of Radiological Services, Tokyo Women's Medical University Hospital, Tokyo, Japan

Myocardial T2 mapping using a multi-echo gradient-spin-echo (mGraSE) is widely used in clinical practice for quantitatively evaluating myocardial tissue properties with single breath-hold scan, but the limited scan time during the breath-hold period often results in poor signalto-noise ratio. Compressed SENSE has recently been developed to accelerate the acquisition time. Although C-SENSE is basically applied for non-EPI scans, mGraSE can also be applied the C-SENSE reconstruction framework. mGraSE myocardial T2 mapping with C-SENSE demonstrated improved image quality with higher image uniformity entire the shot-axis myocardium compared with conventional SENSE. 

Yurie Shirai¹, Michinobu Nagao¹, Noriko Kikuchi¹, Atsushi Yamamoto¹, Yuka Matsuo¹, Risako Nakao¹, Kiyoe Ando¹, Eri Watanabe¹, Shinichi Nunoda¹, Masami Yoneyama², and Syuji Sakai^1
1Tokyo Women’s Medical University, Tokyo, Japan, ²Philips Japan, Tokyo, Japan

We investigate the diagnostic performance of native T1 and T2 mapping cardiovascular magnetic resonance imaging (CMR) for cardiac allograft vasculopathy (CAV) after heart transplantation, using myocardial flow reserve (MFR) estimated by 13N-ammonia (NH3) positron emission tomography (PET) as reference. Non-contrast native T1 mapping is a minimally invasive and effective method for monitoring CAV. In contrast, the effectiveness of T2 mapping could not be demonstrated.

Seonghwan Yee¹, Lorna Browne¹, and Justin Honce^1
1Radiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States

The modified Look-Locker imaging (MOLLI) technique is widely used in cardiac imaging for T1 mapping. When the MOLLI technique is performed, the B1 field, perpendicular to the magnetization, is continually applied during the steady state imaging. Hence, the relaxation of the magnetization during this time may be linked to the T2rho (the T2 relaxation time constant in the rotating frame) contrast, sensitive to the iron content. Here, the theoretical background and a preliminary phantom imaging results are presented to explore the possibility of extracting T2rho contrast from the MOLLI sequence.

Malte Roehl^1,2, Peter D Gatehouse^1,2, Pedro F Ferreira^1,2, Sonya V Babu-Narayan^1,2, David N Firmin^1,2, Dudley J Pennell^1,2, Sonia Nielles-Vallespin^1,2, and Andrew D Scott^1,2
1National Heart and Lung Institute, Imperial College London, London, United Kingdom, ²Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, United Kingdom

Here we propose a new method to reduce the influence of blood and epicardial fat on right ventricular T1 mapping. This is achieved by leveraging the excellent blood and fat suppression provided by the stimulated echo acquisition mode (STEAM) EPI sequence in a novel saturation recovery based (SASHA) single-shot T1 mapping sequence. The novel (STEAM-SASHA) approach is evaluated and compared to a standard modified Look-Locker imaging sequence in both phantom and in vivo measurements in the septum and right ventricle.

Thibault Marin¹, Paul K. Han¹, Yue Zhuo¹, Yanis Djebra^1,2, Fang Liu¹, Georges El Fakhri¹, and Chao Ma^1
1Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, ²LTCI, Telecom Paris, Institut Polytechnique de Paris, Paris, France

Cardiac T1 mapping is a powerful MR imaging technique for quantitative assessment of microstructural changes in myocardial tissues. Existing methods are limited in terms of spatial coverage and through-plane resolution due to limitations in acquisition speed and the presence of cardiac and respiratory motion. This work presents a direct reconstruction framework, which allows estimation of 3D T1 maps from sparsely sampled k-space data using physical modeling through the Bloch equation, low-rank constraints on the dynamic images and sparsity constraints on the estimated T1 maps.

Constance J Mietus¹, Yue Gao¹, Mariano G Uberti², Nicholas G Lambert¹, Panagiotis Koutakis³, Evlampia Papoutsi³, Jonathan R Thompson¹, Holly K DeSpiegelaere⁴, Michael D Boska², Sara A Myers⁵, George P Casale¹, Iraklis I Pipinos^1,4, and Balasrinivasa R Sajja^2
1Department of Surgery, University of Nebraska Medical Center, Omaha, NE, United States, ²Department of Radiology, University of Nebraska Medical Center, Omaha, NE, United States, ³Department of Biology, Baylor University, Waco, TX, United States, ⁴Department of Surgery and VA Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE, United States, ⁵Department of Biomechanics, University of Nebraska Omaha, Omaha, NE, United States

Understanding the quantitative MRI features of the myopathy of Peripheral Artery Disease (PAD) may aid in grading disease severity, treatment response, and potentially predicting favorable response to exercise or revascularization surgery.  In this study we explored the relationship between T1 and T2 relaxation times and measurements of hemodynamic and ambulatory performance in patients with PAD.  T1 relaxation time positively correlated with ankle brachial index and peak plantar flexion and inversely correlated with claudication onset time.  T2 relaxation time correlated positively with peak plantar flexion and inversely correlated with ischemic window, claudication onset time, and peak walking time.

Huiyu Qiao¹, Shuo Chen¹, Zihan Ning¹, Hualu Han¹, Rui Shen¹, and Xihai Zhao^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine Tsinghua University, Beijing, China

Carotid T1 mapping calculated by variable flip angle imaging usually needs an additional B1 mapping to correct nominal flip angle. However, B1 mapping techniques are difficult to implement in clinical settings. This study proposed a muscle referenced B1 mapping for a more accurate carotid T1 mapping using variable flip angle imaging but without an additional B1 mapping scan. The proposed muscle referenced B1 mapping could effectively adjust the B1 inhomogeneity, particularly for the B1 inhomogeneity between left and right carotid vessel walls. Furthermore, the T1 mapping with muscle referenced B1 mapping correction showed the capability of identifying the intraplaque hemorrhage.

María A Iglesias¹, Daniel Lorenzatti², José T Ortiz², Susanna Prat², Adelina Doltra², Rosario J Perea², Teresa M Caralt², Oscar Camara¹, Gaspar Delso³, and Marta Sitges^2
1Universitat Pompeu Fabra, Barcelona, Spain, ²Hospital Clínic de Barcelona, Barcelona, Spain, ³GE Healthcare, Barcelona, Spain

In this study, an image processing pipeline based on Deep Learning is presented to identify myocardial tissue in MOLLI series. The main goal is to provide an automated tool to evaluate the impact of motion correction on cardiac T1 mapping.

Daniel A Herzka¹, Rajiv A Ramasawny¹, Chris G. Bruce¹, Delaney R. McGuirt¹, William H. Schenke¹, Jaffar M. Khan¹, Adrienne E. Campbell-Washburn^1,2, Aravindan A Kolandaivelu^1,3, Toby A Rogers^1,4, and Robert J. Lederman^1
1NHLBI, Division of Intramural Research, National Institutes of Health, Bethesda, MD, United States, ²Biophysics and Biochemistry Branch, Division of Intramural Research, NHLBI, NIH, Bethesda, MD, United States, ³Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁴Department of Cardiology, Medstar Washington Hospital Center, Washington, DC, United States

In this work, we visualize chemoablation lesions created by intracoronary injection as used in alcohol septal ablation for the treatment of hypertrophic obstructive cardiomyopathy. 3D native contrast and gadolinium-enhanced MRI were examined. Two chemoablation agents were used: standard ethanol and a potential alternative agent, glacial acetic acid. In swine, both 3D native contrast and gadolinium-enhanced imaging clearly delineated lesion extent acutely and up to two weeks post ablation. Acutely, chemoablation with ethanol induced a 22% increase in T1 within lesion cores and acetic acid yielded a 36% decrease.

Xianglun Mao¹, Hsu-Lei Lee¹, Sen Ma¹, Zhehao Hu^1,2, Fei Han³, Yibin Xie¹, Debiao Li^1,2, and Anthony G Christodoulou^1,2
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Department of Bioengineering, University of California in Los Angeles, Los Angeles, CA, United States, ³Siemens Medical Solutions Inc., Los Angeles, CA, United States

Cardiac MR Multitasking has been shown to acquire simultaneous T1 and T2 maps without ECG or breath-holds. Simultaneous multi-slice (SMS) acquisition has the potential to increase the clinical value of CMR by decreasing the exam time. In this work, we developed an SMS, non-ECG and free-breathing MR Multitasking technique and demonstrated that it had consistent T1, T2 measurements when compared with the overall-slower series of reference protocols (MOLLI, T2-prep FLASH).

Antonella Meloni¹, Nicola Martini¹, Rita Laura Borrello², Vincenzo Positano¹, Laura Pistoia¹, Calogera Gerardi³, Mauro Murgia⁴, Valentina Carrai⁵, Monica Benni⁶, Sara Gentili⁷, Roberto Pedrinelli², and Alessia Pepe^1
1MRI Unit, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy, ²Università degli Studi di Pisa, Pisa, Italy, ³Presidio Ospedaliero "Giovanni Paolo II" - Distretto AG2 di Sciacca, Sciacca (AG), Italy, ⁴Ospedale San Martino di Oristano, Oristano, Italy, ⁵Azienda Ospedaliero - Universitaria Careggi, Firenze, Italy, ⁶Policlinico S. Orsola "L. e A. Seragnoli", Bologna, Italy, ⁷Ospedale "San Donato", Arezzo, Italy

The T2 mapping does not offer any advantage over the T2* technique in terms of sensitivity for myocardial iron overload assessment. However, more than half of patients with thalassemia major had an increased T2 value, that may be caused by the presence of myocardial inflammation and/or edema.

Jingyuan Lyu¹, Qi Liu¹, Zhongqi Zhang², Jian Xu¹, and Weiguo Zhang^1
1UIH America, Inc., Houston, TX, United States, ²United Imaging Healthcare, Shanghai, China

This abstract presents a new approach to accelerated T1 mapping of the heart under free-breathing and without ECG. Compared with traditional radial sampling trajectory, spiral sampling offers the possibility to get ride of navigator data in the framework of “multitasking”, though at an extra cost of increased susceptibility to system imperfections such as gradient delay.

Gaspar Delso¹, Laura Farre², Daniel Lorenzatti³, Santi Sotes³, Adelina Doltra³, Susanna Prat³, Rosario J Perea³, Teresa M Caralt³, José T Ortiz³, and Marta Sitges^3
1GE Healthcare, Barcelona, Spain, ²Universitat de Barcelona, Barcelona, Spain, ³Hospital Clínic de Barcelona, Barcelona, Spain

Cardiac T1-mapping methods often require motion correction. The contrast changes intrinsic to the inversion recovery series often used for this purpose can occasionally cause registration errors, resulting in inaccurate T1 values. It has been shown, using a large database of clinical cases, that accounting for those contrast changes markedly increases the robustness of the correction. A new metric of cardiac anatomy alignment had to be defined, in order to automate the quantitative analysis of the database. This metric was shown to correlate with the visual scoring of misalignment in MOLLI series.

Habib Rebbah¹, Anaïs Bernard¹, Julien Rouyer¹, and Timothé Boutelier^1
1Department of Research & Innovation, Olea Medical, La Ciotat, France

The myocardial ECV involves manual segmentation on pre- and post-injection T1 maps, which is a time-consuming process. An initial registration of the two maps represents a suitable solution to reduce the analyze duration. Here, we propose to compare the ECV obtained after the registration against the manual computed one using a STEMI-patients database. If the difference between the two approaches was significant, the bias remained thin (less than 1% for the remote part and 3% for the infarct part). These results and the speed of the registration (1s per slice) tip the scales in favor of its use