Ipshita Bhattacharya¹, Rajiv Ramasawmy¹, Joel Moss¹, Marcus Y Chen¹, Waqas Majeed², Thomas Benkert³, Robert S Balaban¹, and Adrienne Campbell-Washburn^1
1National Institutes of Health, Bethesda, MD, United States, ²Siemens Medical Solutions, Malvern, PA, United States, ³Siemens Healthcare GmbH, Erlangen, Germany

Lung imaging using conventional MRI has several limitations for clinical use. A contemporary low-field MRI (0.55T) system offers several advantages for structural and functional imaging of lung owing to low magnetic susceptibility and increased oxygen relaxivity. In this abstract we present an improved structural imaging method and  functional imaging method for patients with lymphangioleiomyomatosis (LAM) at low-field. Anatomical imaging offers improved delineation of cystic structures in the lung parenchyma. Oxygen-enhanced lung MRI is used to measure ventilation and regional texture in healthy volunteers and this patient group with abnormal pulmonary function.

Brandon Zanette¹, Samal Munidasa^1,2, Marcus J Couch¹, Elaine Stirrat¹, Eric Schrauben¹, Robert Grimm³, Andreas Voskrebenzev^4,5, Jens Vogel-Claussen^4,5, Ravi Seethamraju⁶, Christopher K Macgowan^1,2, Mary-Louise C Greer^7,8, Emily Tam^9,10, and Giles Santyr^1,2
1Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada, ²Medical Biophysics, University of Toronto, Toronto, ON, Canada, ³MR Predevelopment, Siemens Healthcare, Erlangen, Germany, ⁴Diagnostic and Intervetional Radiology, Hannover Medical School, Hannover, Germany, ⁵Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany, ⁶MR Collaborations North East, Siemens Healthineers, Boston, MA, United States, ⁷Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada, ⁸Medical Imaging, University of Toronto, Toronto, ON, Canada, ⁹Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada, ¹⁰Neurology, The Hospital for Sick Children, Toronto, ON, Canada

MRI of the neonatal pulmonary system can be a useful tool for the clinical evaluation of lung structure and function without ionizing radiation. Despite this, the inherent challenges associated with MRI of the lung make this difficult. This works demonstrates the feasibility of structural and functional imaging of the neonatal lung without exogenous contrast using a clinical whole-body 3T system with standard coils in neonates without any cardiorespiratory history. The imaging protocol includes T1-weighted, T2-weighted, and ultrashort echo time (UTE) imaging for structural imaging as well as novel free-breathing Phase-Resolved Function Lung (PREFUL) MRI for ventilation/perfusion imaging.

Corona Metz¹, David Böckle², Julius Frederik Heidenreich¹, Andreas Max Weng ¹, Thomas Benkert³, Götz Ulrich Grigoleit², Herbert Köstler¹, Thorsten Alexander Bley¹, and Simon Veldhoen^1
1Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany, ²Department of Internal Medicine II, University Hospital Würzburg, Würzburg, Germany, ³Application Development, Siemens Healthcare GmbH, Erlangen, Germany

Immunocompromised patients during HSCT procedure commonly need repeated MDCT examinations resulting in a high cumulative radiation dose. 3D-UTE MRI using a stack-of-spirals trajectory, enables contrast-free and radiation-free imaging of the lungs within a single breath-hold with increased signal yield due to echo times being well below parenchymal T2*. 3D-UTE MRI allows diagnostics of inflammatory consolidations and pleural effusions with high sensitivity, specificity and consistency when compared to MDCT. Moreover, 3D-UTE sequences improve detection rates of ground glass opacities in pulmonary MRI.

Ho-Fung Chan¹, Madeleine Petersson Sjögren², Paul J.C. Hughes¹, Oliver I Rodgers¹, Guilhem J Collier¹, Graham Norquay¹, Lars E Olsson³, Per Wollmer³, Jakob Löndahl², and Jim M Wild^1
1Academic Radiology, University of Sheffield, Sheffield, United Kingdom, ²Division of Ergonomics and Aerosol Technology, Lund University, Lund, Sweden, ³Department of Translational Medicine, Lund University, Malmö, Sweden

Airspace Dimension Assessment with inhaled nanoparticles (AiDA) and hyperpolarized ¹²⁹Xe diffusion-weighted (DW)-MRI was performed in twenty-three healthy volunteers to benchmark measurements from AiDA against those from ¹²⁹Xe DW-MRI. Significant correlations were observed between AiDA derived root mean square distal airspace radius, and ¹²⁹Xe apparent diffusion coefficient and diffusion model derived acinar airway dimensions. Furthermore, the AiDA recovery at zero-second breath-hold significantly correlated with ¹²⁹Xe alpha index from the stretched exponential model, a marker of acinar airspace heterogeneity. This benchmarking study demonstrates the potential of AiDA as an alternative method for the clinical evaluation of acinar airway microstructure changes.

Leith Rankine^1,2, Ziyi Wang¹, Elianna Bier¹, Christopher Kelsey³, Shiva Das², Lawrence Marks², and Bastiaan Driehuys^1
1Center for In Vivo Microscopy, Duke University, Durham, NC, United States, ²Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC, United States, ³Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States

Radiation therapy (RT) is widely used to treat lung cancer, but damage to surrounding healthy tissues can lead to compromised lung function. In this study, patients undergoing RT were imaged pre- and post-treatment using hyperpolarized ¹²⁹Xe gas exchange MRI to assess for RT-induced changes in regional lung function. At 3-months post-treatment, a dose-response was evident in ventilation and gas exchange. Lung regions receiving ≥20Gy exhibited significantly increased barrier uptake and decreased RBC transfer. This may help radiation oncologists further understand the dose-dependence of RT-induced lung injury, and design dose distributions with fewer treatment toxicities.

Peter James Niedbalski¹, Elianna A Bier^2,3, Ziyi Wang^2,3, Matthew M Willmering¹, Bastiaan Driehuys^2,3,4, and Zackary I Cleveland^1,5
1Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, ²Department of Biomedical Engineering, Duke University, Durham, NC, United States, ³Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, ⁴Department of Radiology, Duke University Medical Center, Durham, NC, United States, ⁵Department of Pediatrics, University of Cincinnati Medical Center, Cincinnati, OH, United States

Hyperpolarized ¹²⁹Xe MRI offers the ability to analyze pulmonary gas transfer by imaging ¹²⁹Xe dissolved in red blood cells (RBCs) separately from ¹²⁹Xe in other tissues. A notable feature of the dissolved ¹²⁹Xe signal is the presence of small cardiogenic oscillations in the ¹²⁹Xe RBC signal, which have been used to characterized global abnormalities in pulmonary microvascular hemodynamics. Here, we demonstrate that these cardiogenic oscillations can be mapped 3-dimensionally to image capillary bed hemodynamics. Our approach uses keyhole reconstruction of standard ¹²⁹Xe gas exchange MR acquisitions. Metrics obtained from these maps distinguished healthy from disease cohorts and predicted disease progression.

Yoshiharu Ohno^1,2, Masao Yui³, Daisuke Takenaka⁴, Yoshimori Kassai³, Kazuhiro Murayama¹, and Takeshi Yoshikawa^2
1Radiology, Fujita Health University School of Medicine, Toyoake, Japan, ²Radiology, Kobe University Graduate School of Medicine, Kobe, Japan, ³Canon Medical Systems Corporation, Otawara, Japan, ⁴Diagnostic Radiology, Hyogo Cancer Center, Akashi, Japan

No major papers that determined the utility of cDWI for diagnosis of lymph node metastasis have been reported.  We hypothesize that cDWI has a potential for improving diagnostic performance of N-stage in NSCLC patients as compared with aDWI and FDG-PET/CT, when set appropriate b value.  The purpose of this study is to determine the utility of cDWI for differentiating metastatic from non-metastatic lymph nodes in NSCLC patients as compared with aDWI and FDG-PET/CT.

Khin Khin Tha^1,2, Ulrich Katscher³, Eiki Kikuchi⁴, Yasuka Kikuchi¹, Yuki Yoshino¹, Kinya Ishizaka⁵, Noriko Manabe^1,2, Kohsuke Kudo^1,2, and Hiroki Shirato^2
1Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan, ²Global Station for Quantum Medical Science and Engineering, Hokkaido University, Sapporo, Japan, ³Philips Research Laboratories, Hamburg, Germany, ⁴First Department of Medicine, Hokkaido University Hospital, Sapporo, Japan, ⁵Department of Radiological Technology, Hokkaido University Hospital, Sapporo, Japan

We evaluated the feasibility of σ measurable by EPT in evaluating lung and mediastinal mass lesions. EPT was performed in 21 patients with lung or mediastinal mass lesions.  The lesion σ distribution, its relationship with histological findings, lesion size, location and the number of successful scans were evaluated. The malignant tumors had larger maximum σ and intralesional standard deviation and contrast. The larger the lesions, the greater were the intralesional contrast and entropy.  The number of possible dynamic scans for reconstruction appeared to be larger in the upper lobe tumors, but the findings need to be confirmed with larger samples. 

Grzegorz Bauman^1,2 and Oliver Bieri^1,2
1Radiological Physics, University of Basel Hospital, Basel, Switzerland, ²Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland

This work demonstrates the application of single-breathold thoracic MRI with balanced steaty-state free precession half-radial dual-echo readout technique (bSTAR) in human subjects. The proposed imaging technique combines a minimal-TR acquisition with a smoothly interleaved Archimedean spiral trajectory, which results in markedly improved signal intensity from low proton lung parenchyma tissue, improved visualization of the pulmonary vascular tree as well as a successful mitigation of eddy current and cardiac motion artifacts.

Arnd Jonathan Obert^1,2, Marcel Gutberlet^1,2, Agilo Luitger Kern^1,2, Frank Wacker^1,2, and Jens Vogel-Claussen^1,2
1Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany, ²Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany

Since Perfluoropropane is highly inert, and can be mixed with oxygen, patients can inhale up to 30 liters of gas during one examination without a significant physiological impact. This enables detailed measurements of gas wash-in dynamics using ¹⁹F magnetic resonance imaging. In this work, an experimental setup for volume-controlled imaging of multiple breath-holds is realized using a pneumotachometer and pneumatic valves as well as MR triggering. In three healthy volunteers, the stability of the breathing volumes and the positions of the diaphragm, as well as the standard deviation of wash-in times, were analyzed comparing volume-controlled to non-controlled scans.