Scott J. Edwards¹, Jingting Yao², Marcos Coutinho Schechter¹, Maya Fayfman¹, Gabriel Santamarina¹, Paula Nesbeth¹, Vincent Giacalone¹, Gerado Blanco¹, Rabindra Tirouvanziam¹, Jessica Alvarez¹, Benjamin Risk¹, Ravi Rajani¹, and David A. Reiter^1
1Emory University, Atlanta, GA, United States, ²Department of Radiology, Massachusetts General Hospital, Boston, MA, United States

Diabetic foot ulcer (DFU) patients often face incomplete wound healing which leads to a long-term state of inflammation and risk of infection. Prolonged wound healing is thought to result in part from impaired tissue perfusion due to microvascular disease. This study applies dynamic blood-oxygenation-level-dependent (BOLD) imaging to quantify reperfusion of tissue after induced occlusion and ischemia in the foot. When compared to a healthy population, DFU patients show an increased ischemic state during cuff occlusion and decreased reperfusion after release. Quantification of cuff-occlusion parameters may assist in the classification of DFUs and be used to predict the prognosis and enhance treatment plan.

Irène Brumer¹, Simon Jonscher¹, Indre Gineitaite¹, Rebeca Echeverria-Chasco², Lothar R. Schad¹, María Asunción Fernández-Seara², and Frank G. Zöllner^1
1Computer Assisted Clinical Medicine, Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ²Department of Radiology, Clínica Universidad de Navarra, Pamplona, Spain

In this study, we investigated the influence of ECG-triggering and respiration strategy choice on renal perfusion. To this end, pCASL data of healthy volunteers was acquired at 3T. Acquisitions and processing followed the PARENCHIMA consensus. Processing consisted of groupwise registration, manual whole kidney segmentation and automated cortex/medulla segmentation. All calculated perfusion values were close to the expected range for healthy individuals. Preliminary results from four subjects suggest the influence of cardiac cycle is negligible and the choice of respiration strategy has little effect on renal perfusion values calculated from pCASL data, however additional data is necessary for more complete evaluation.

Mareike Alicja Buck^1,2, Simon Konstandin^1,3, Nora-Josefin Breutigam¹, and Matthias Günther^1,2,3
1Fraunhofer MEVIS, Bremen, Germany, ²University Bremen, Bremen, Germany, ³mediri GmbH, Heidelberg, Germany

In this work, the application of velocity-selective inversion ASL in healthy breast tissue is demonstrated for the first time. The measurements show a low measured signal in breast tissue. However, the prominent fat artifacts that appear in the images will need to be addressed in future work. The technique presented here has nonetheless been shown to hold promise in the field of non-invasive breast cancer diagnostics with further development, particularly the inclusion of background suppression to get clear perfusion signal.

Manuel Taso¹ and David C Alsop^1
1Division of MRI Research, department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States

Renal Arterial Spin Labeling (ASL) is becoming more widely used as a non-invasive technique for measuring renal perfusion and hence renal function. Free-breathing acquisitions with retrospective motion-correction are commonly used as it facilitates workflow and is robust against uncooperative patients. However, PCASL, especially the balanced implementation in which the same net gradient is used for both label and control, has been shown to be sensitive to off-resonance leading to a loss of labeling efficiency. We propose here a pilot study measuring B₀ shifts during free-breathing to simulate its impact on free-breathing renal PCASL perfusion imaging.  

Martin Segeroth¹, David Winkel¹, Shan Yang¹, Alexander Sauter¹, Jens Bremerich¹, Michael Zellweger², Christian Müller², and Philip Haaf^2
1Clinic for radiology and nuclear medicine, Universitätsspital Basel, Basel, Switzerland, ²Clinic for cardiology, Universitätsspital Basel, Basel, Switzerland

Pulmonary transit time (PTT) derived from routine cardiac magnetic resonance perfusion scans is a robust and easily obtainable noninvasive parameter of hemodynamics. PTT correlates with both LVEF, RVEF and NT-proBNP and could serve as a new global non-invasive parameter with a discriminative character for detecting cardiopulmonary dysfunction. We demonstrate that PTT has a high diagnostic accuracy in terms of exclusion and inclusion of heart failure as assessed by NT-proBNP, even in patients with preserved LVEF and RVEF.

Bo He¹ and Fabao Gao^1
1Department of Radiology, West China Hospital, Sichuan University, Chengdu, China

This study investigated the feasibility of a novel compact MRI-compatible ergometer to evaluate myocardial tissue characteristics and blood flow. The results showed a significant increase in heart rate, RPP, native T1 and MBF by using this ergometer in healthy controls. Our study has shown an excellent reproducibility in measuring free-breathing native myocardial T1, MBF and MPR during exercise. The pilot testing demonstrated that the novel compact MRI-compatible ergometer was successful at inducing a cardiac stress state and can able to characterise exercise physiology at every stage allowing high quality MR imaging during the stress. 

Sarah M Schwartz¹, Lexiaozi Fan¹, Bradley D Allen¹, Jeremy D Collins², Kyungpyo Hong¹, James C Carr¹, Brandon Benefield^1,3, Amit R Patel⁴, Daniel Kim¹, and Daniel C Lee^1,3
1Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, ²Department of Radiology, Mayo Clinic, Rochester, MN, United States, ³Department of Medicine, Division of Cardiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, ⁴Department of Radiology, University of Chicago, Chicago, IL, United States

This study evaluates visual scores of image quality (conspicuity, artifact, noise; Likert scale 1[worst]-5[best], 3 acceptable) produced by a wideband cardiac perfusion sequence in patients with CIED and a standard sequence in matching non-device patients in the setting of vasodilated stress perfusion imaging. The median conspicuity scores were not significantly different between wideband (4) and standard (4). While the median artifact score was significantly worse for wideband (4) than standard (5), it was above the acceptable cutoff. The median noise score was significantly better for wideband than standard. Our wideband perfusion sequence produces diagnostically acceptable image quality in CIED patients.

Matthew Van Houten¹, Xue Feng¹, Yang Yang², Patricia Rodriguez Lozano¹, Christopher Kramer¹, and Michael Salerno^3
1University of Virginia, Charlottesville, VA, United States, ²Icahn School of Medicine at Mount Sinai, New York, NY, United States, ³Stanford University, Stanford, CA, United States

We developed high resolution quantitative perfusion sequence, along with DCNN network to automatically segment the image sets for motion correction. We deployed the acquisition and post-processing on patients with suspected coronary artery disease and compared the results to their coronary angiography findings. Our sequence and processing successfully match the angiography results.

Stefanie Eriksson^1,2, Jonathan Arvidsson^1,2, Suhela Abubakar Mohammad¹, Edvin Johansson³, and Kerstin Lagerstrand^1,2
1Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden, ²Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden, ³Antaros Medical, Mölndal, Sweden

This study demonstrates the cuffing duration dependence of BOLD T2*-time curve parameters in peripheral skeletal muscle in the calf. This was made possible by the repeated measurements of healthy individuals using two different cuffing paradigms. The cuffing paradigms consisted of an ischemic period induced by cuffing of the thigh for 1.5 or 5 minutes, as well a 5 minute period of reactive hyperaemia. Systematic comparison of derived parameters was done from a descriptive representation of the T2* time curve. 

Deborah Hill¹, Alicja Molska¹, Trygve Andreassen¹, and Marius Widerøe^1
1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway

We designed an NMR-compatible bioreactor that allows real-time metabolic measurements of viable rat brain slices under normal conditions and under conditions mimicking hypoxic-ischemic (HI) brain injury. Special emphasis was put on providing physiological temperature in the system, a significant factor in the HI model. ¹H NMR spectra were acquired to assess changes in brain metabolites. Peaks of lactic acid, NAA, glutamate, aspartate, and creatine were detected. By acquiring a time series of proton spectra, we observed significantly increased lactate levels over time when switching from normoxia to hypoxia while other metabolites remained stable over the whole experiment.