Aurelien Bustin^1,2,3, Pauline Ferry³, Andrei Codreanu⁴, Anne Menini², and Freddy Odille^3,5,6
1Department of Computer Science, Technische Universität München, Munich, Germany, ²GE Global Research, Munich, Germany, ³Imagerie Adaptative Diagnostique et Interventionnelle, Universite de Lorraine, Nancy, France, ⁴Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg, ⁵CIC-IT 1433, INSERM, Nancy, France, ⁶U947, INSERM, Nancy, France

To improve precision and accuracy in myocardial T₁ mapping by combining saturation-recovery acquisitions with a joint denoising method. The proposed method is shown to improve mapping techniques by exploiting the spatiotemporal correlations in the native T₁-weighted images, thus providing a promising tool for the measurement of myocardial and blood T₁ times.

Joep van Oorschot¹, Fatih Guclu², Peter Luijten¹, Tim Leiner¹, and Jaco Zwanenburg^1
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, ²Cardiology, University Medical Center Utrecht, Utrecht, Netherlands

Native T1ρ-mapping is a promising non-contrast enhanced method for fibrosis detection, that would overcome problems associated with contrast agent use. In this work, we will evaluate the performance of T1ρ-mapping versus ECV-m and native T1 in DCM patients. Native T1, native T1ρ and Contrast enhanced T1-maps were acquired in twelve DCM patients, and 8 healthy volunteers. The T1ρ relaxation time was significantly higher in the DCM patients (55.6 ± 3.0 ms), compared to the healthy control subjects (51.5 ± 1.2 ms), p<0.005. A significant correlation was found between the T1ρ relaxation time and the Extracellular Volume fraction in patients.

Jiaxin Shao¹, Shams Rashid¹, Kim-Lien Nguyen^2,3, and Peng Hu^1,4
1UCLADepartment of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, United States, ²Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA, United States, ³Division of Cardiology, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, United States, ⁴Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, CA, United States

Current cardiac T1 mapping techniques, including the modified Look-Locker inversion-recovery (MOLLI), cannot be used effectively in patients with implanted cardiac devices due to large off-resonance induced by the device. To eliminate the device-induced image artefacts, we developed a technique by modifying the MOLLI sequence to use spoiled gradient echo readout and a wideband inversion pulse, with a new acquisition scheme and T1 estimation algorithm. The feasibility of our new technique was tested in phantom studies and validated in eight healthy volunteers and ten patients with implanted cardiac devices at 1.5 Tesla.

Dagmar Hartung^1,2, Rongjun Chen³, Marcel Gutberlet^1,2, Song Rong³, Mi-Sun Jang³, Jan Hinrich Braesen⁴, Martin Meier^2,5, Hermann Haller³, Frank Wacker^1,2, Faikah Gueler³, and Hueper Katja^1,2
1Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany, ²Rebirth, Hannover, Germany, ³Clinic for Nephrology, Hannover Medical School, Hannover, Germany,⁴Institute for Pathology, Hannover Medical School, Hannover, Germany, ⁵Imaging Center of the Central Animal Laboratory, Hannover Medical School, Hannover, Germany

Acute cardiac allograft rejection is a frequent and life-threatening complication during the first year after heart transplantation (HTx) and therefore early detection is most important. The standard of care for HTx recipients is periodic rejection surveillance by endomyocardial biopsy. We investigated whether T2 mapping allows non-invasive detection of acute cardiac allograft rejection in mice. We demonstrated that myocardial T2 is significantly increased in allogenic HTx compared to isogenic HTx mice on day 6 after transplantation likely reflecting myocardial edema and corresponds to the extent of T cell infiltration. Thus, non-invasive T2 mapping might enable early and non-invasive detection of acute cardiac allograft rejection. 

Mahesh Bharath Keerthivasan¹, Sagar Mandava¹, Kevin Johnson², Diego R Martin³, Ali Bilgin^1,3,4, and Maria I Altbach^3
1Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States, ²Siemens Healthcare, Tucson, AZ, United States, ³Medical Imaging, University of Arizona, Tucson, AZ, United States,⁴Biomedical Engineering, University of Arizona, Tucson, AZ, United States

A technique to increase slice coverage in dark blood fast spin echo sequences by a multi-band excitation is presented. The proposed technique can acquire multiple slices at the exact null point of blood. The radial version of the single slice sequence can generate black blood images, TE images and T2 maps within a single breath-hold. In this work we present a model based reconstruction to generate TE images and T2 maps for upto 4 slices in a single breath-hold.

Sophia Xinyuan Cui¹ and Frederick H. Epstein^1,2
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Radiology, University of Virginia, Charlottesville, VA, United States

Endothelial nitric oxide synthase (eNOS)-mediated production of NO is an important system regulating the microvasculature, controlling both vessel diameter and permeability.  We hypothesized that T1 mapping of the heart during NOS inhibition could detect increased water content resulting from increased microvascular permeability, providing a novel means to noninvasively probe eNOS regulation of the coronary microvasculature.  T1-mapping in mice after intravenous NOS inhibition detected an increase in myocardial T1 of 113±15 ms compared to baseline (p<0.05).  These methods are likely probing eNOS regulation of coronary microvascular permeability, which may represent a novel means of assessing the health of the coronary endothelium.    

Mu Zeng¹, Nan Zhang¹, Yi He¹, Jing An², Andreas Greiser³, and Zhanming Fan^1
1Radiology, Beijing Anzhen Hospital,Capital medical university, Beijing, China, People's Republic of, ²MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, Beijing, China, People's Republic of, ³Siemens AG Healthcare Sector MR, Erlangen, Germany

In recent years, use of the MRI T1 mapping technique to detect diffuse myocardial fibrosis has received increasing attention. Although previous studies have verified the relationship between T1 mapping and pathological findings, our study is the first to show continuity during the observation of a single disease while avoiding interference caused by other diseases. In addition, the pathology can be fully verified in real time using animal experiments. 

The main findings of this study were that (1) the ECV obtained from the MRI T1 mapping sequence was highly correlated with the CVF in terms of the degree of histologically diffuse interstitial fibrosis; (2) the correlation between the native T1 value and the CVF change was not strong; and (3) the rabbit is a suitable model for cardiac magnetic resonance research using clinical equipment.

Satoshi Kawanami¹, Michinobu Nagao¹, Yuzo Yamasaki², Takeshi Kamitani², Torahiko Yamanouchi², Tomomi Ide³, Ryohei Funatsu⁴, Hidetake Yabuuchi⁵, Yuji Watanabe¹, and Hiroshi Honda^2
1Molecular Imaging & Diagnosis, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Japan, ²Clinical Radiology, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Japan,³Cardiovascular Medicine, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Japan, ⁴Radiological Technology, Kyushu University Hospital, Fukuoka, Japan, ⁵Health Sciences, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Japan

In this study, we analyzed T2* value in the mid-left ventricular septum avid normoxia (T2*air) and hyperoxia (T2*oxy) in cases with normal, hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Oxygen-enhanced T2* cardiac magnetic resonance (CMR) showed the different delta T2* (T2*oxy – T2* air), reflecting myocardial blood-oxygen dependent (BOLD) effect. Oxygen-enhanced T2* CMR has potential to open up a new avenue for the study of the pathophysiology of cardiomyopathy. The ΔT2* was prolonged in DCM, stable in control and shortened in HCM, respectively. Oxygen-enhanced T2* CMR can assess the oxygen metabolism in the mid-left ventricular septum with various density of capillaries and myocardial cells. We also note the relationship between T2* value and late gadolinium enhancement (LGE) or left ventricular ejection fraction (LVEF).

Yoshiaki Morita¹, Naoaki Yamada¹, Emi Tateishi², Teruo Noguchi², Masahiro Higashi¹, and Hiroaki Naito^1
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, ²Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan

Diffuse interstitial fibrosis is frequently observed in dilated cardiomyopathy (DCM). A non-invasive method that could reliably quantify fibrosis would be preferable. In this study, we demonstrated that the T1-map-derived ECV reflects the myocardial collagen volume fraction in DCM. Therefore, the ECV could be a useful and practical biomarker for the detection of diffuse interstitial fibrosis that is difficult to evaluate using only conventional LGE images.

Damian J Tyler¹, Angus Lau¹, Ferdia Gallagher², and Marie A Schroeder^1
1DPAG, University of Oxford, Oxford, United Kingdom, ²Radiology, University of Cambridge, Cambridge, United Kingdom

The aim of this study was to evaluate the potential of hyperpolarised [1, 4-13C2]fumarate, coupled with MRS, to measure cardiac necrosis during ischemia and reperfusion. Hyperpolarised [1, 4-13C2]fumarate was infused into rat hearts at three time points, corresponding with the healthy heart, early reperfusion after a 20 min ischemic period, and late reperfusion. The amount of [1, 4-13C2]malate production was measured using MRS and quantified to reflect degree of cardiomyocyte necrosis. We observed a 3.8-fold increase in [1,4-13C2]malate during the late reperfusion period but no change in early reperfusion, suggesting that necrotic cell death takes place during reperfusion only. This technique shows potential to evaluate therapies targeting necrosis to prevent cardiac remodeling into failure.