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Object: To develop and evaluate a 2D modified Look-Locker (MOLLI) for high-resolution T1 mapping in mice using a 3T MRI scanner., Materials and Methods: To allow high-resolution T1 mapping in mice at high heart rates a multi-shot ECG-triggered 2D MOLLI sequence was developed. In the proposed T1 mapping sequence the optimal number of sampling points and pause cardiac cycles following an initial adiabatic inversion pulse was investigated in a phantom. Seven native control and eight mice, 3 days post myocardial infarction (MI) after administration of gadolinium were scanned. Two experienced readers graded the visual T1 map quality., Results: In T1 phantoms, there were no significant differences (<0.4% error) between 12, 15 and 20 pause cardiac cycles (p = 0.1, 0.2 and 0.6 respectively) for 8 acquisition cardiac cycles for 600bpm in comparison to the conventional inversion recovery spin echo T1 mapping sequence for short T1's (<600 ms). Subsequently, all in-vivo scans were performed with 8 data acquisitions and 12 pause cardiac cycles to minimize scan time. The mean native T1 value of myocardium in control animal was 820.5±52 ms. The post-contrast T1 measured 3 days after MI in scar was 264±59 ms and in healthy myocardium was 512±62 ms. The Bland-Altman analysis revealed mean difference of only -1.06% of infarct size percentage between T1 maps and LGE., Conclusions: A multi-shot 2D MOLLI sequence has been presented that allows reliable measurement of high spatial resolution T1 maps in mice for heart rates up to 600bpm.

Magnetic resonance imaging (MRI) has rapidly become an essential diagnostic tool in modern medicine. Understanding the objectives, perception and expectations of the different medical specialties towards MRI is therefore important to improve the quality of the examinations. Our aim was to better comprehend the reasons and expectations of neurologists, neurosurgeons and psychiatrists when requesting brain MRI scans for their patients, and also to perceive the degree of confidence of these specialists in the images and respective reports. Sixty-three specialists were recruited from two tertiary hospitals and answered a tailored questionnaire. Neurosurgeons were more concerned with the images themselves; neurologists lacked confidence in both MRI images and reports, and one third of the psychiatrists only read the report and were the most confident of the specialties in MRI findings. These results possibly reflect the idiosyncrasies of each of these medical specialties. This knowledge, driven by efficient communication between neuroradiologists and neurosurgeons, neurologists and psychiatrists, may contribute to improve the quality of MRI examinations and consequently patient care and management of health resources.

We present the case of an 84-year-old woman admitted for Takotsubo cardiomyopathy complicated by congestive heart failure. Cardiovascular magnetic resonance (CMR) imaging was performed on day five and confirmed severely depressed left ventricular systolic function with typical apical ballooning. In steady-state free precession long-axis cine imaging, a basal inferior myocardial cleft was also observed, with no signs of myocardial noncompaction or regional wall motion abnormalities involving this segment. The pre-discharge CMR study confirmed the presence of a basal inferior myocardial cleft and significant improvement in left ventricular systolic function. Myocardial clefts are congenital abnormalities that have been described in healthy individuals as well as in the setting of hypertrophic cardiomyopathy, but it is not clear whether it is a benign structural variant or a distinct cardiomyopathy phenotype. To our knowledge this is the first reported case of this abnormality in a patient with Takotsubo cardiomyopathy., (Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.)

This article reviews the current role of magnetic resonance imaging in the study of the pelvic floor anatomy and pelvic floor dysfunction. The application of static and dynamic magnetic resonance imaging in the clinical context and for biomechanical simulation modeling is assessed, and the main findings are summarized. Additionally, magnetic resonance-based diffusion tensor imaging is presented as a potential tool to evaluate muscle fiber morphology. In this article, focus is set on pelvic floor muscle damage related to urinary incontinence and pelvic organ prolapse, sometimes as a consequence of vaginal delivery. Modeling applications that evaluate anatomical and physiological properties of pelvic floor are presented to further illustrate their particular characteristics. Finally, finite element method is described as a method for modeling and analyzing pelvic floor structures' biomechanical performance, based on material and behavioral properties of the tissues, and considering pressure loads that mimic real-life conditions such as active contraction or Valsalva maneuver.

Unlabelled: The processes that take place during singing and acting are complex. However, morphologic and dynamic studies of the vocal tracts during speech have been gaining greater attention, mainly because of the rapid technical advances being made with magnetic resonance imaging (MRI) and image analysis and processing techniques. OBJECTIVES/HYPOTHESIS AND METHODS: Our aim was to describe the morphologic differences in the vocal tract resonance cavities among voice professionals using MRI, and with the three-dimensional models built from the MRI data, compare the volumes calculated for the whole vocal tract and its major resonance cavities., Study Design: Prospective study., Results: The images acquired during the spoken and singing tasks provided morphologic information about the whole vocal tract cavity and also its two major resonance cavities: the oral and the pharynx cavities; differences were observed in the volumes measured during the production of some vowels., Conclusions: The morphologic differences found in the singing voices indicated an increase in the oral cavity volume, resulting in an increase in the overall volumes measured. In the acting voices, both the resonance cavities of the vocal tract contributed to the differences measured., (Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.)

In the evaluation of patients with chest pain it is crucial to differentiate between cardiac and non-cardiac etiology. In turn, acute chest pain of cardiac origin includes many clinical entities. The combination of elevated cardiac serum markers, particularly troponin, with typical clinical presentation and electrocardiographic abnormalities most frequently establishes a diagnosis of acute coronary syndrome. However, when coronary angiography reveals only non-significant lesions, this may present a diagnostic dilemma. The authors present the case of a patient admitted with chest pain, initially interpreted as an acute coronary syndrome, based on laboratory parameters and electrocardiographic abnormalities. Coronary angiography showed normal coronary arteries. This result, combined with the findings of subsequent cardiovascular magnetic resonance (myocardial edema and subepicardial delayed enhancement), established a diagnosis of myocarditis. The case illustrates the application of this noninvasive imaging technique in the diagnostic work-up of patients with acute chest pain.

Nuclear Magnetic Ressonance applied to the cardiovascular area has nowadays a wide range of utilization, in the morphologic and functional assessment of the heart, pericardium, aorta and its major branches. The structure and function of myocardium and its contractility, the anatomy and function of cardiac valves and coronary artery blood flow can be easily and precisely estimated, as well as the diverse pericardial and aortic diseases. Further developments of NMR in cardiovascular area sound promising, mainly in the field of tissue characterization of atherosclerotic plaques, in the intravascular evaluation and endovascular intervention and it is expected that the technique will play a major role in the cardiovascular intervention of the near future.

Object: To develop and evaluate a 2D modified Look-Locker (MOLLI) for high-resolution T1 mapping in mice using a 3T MRI scanner. Materials and methods: To allow high-resolution T1 mapping in mice at high heart rates a multi-shot ECG-triggered 2D MOLLI sequence was developed. In the proposed T1 mapping sequence the optimal number of sampling points and pause cardiac cycles following an initial adiabatic inversion pulse was investigated in a phantom. Seven native control and eight mice, 3 days post myocardial infarction (MI) after administration of gadolinium were scanned. Two experienced readers graded the visual T1 map quality. Results: In T1 phantoms, there were no significant differences (<0.4% error) between 12, 15 and 20 pause cardiac cycles (p = 0.1, 0.2 and 0.6 respectively) for 8 acquisition cardiac cycles for 600bpm in comparison to the conventional inversion recovery spin echo T1 mapping sequence for short T1’s (<600 ms). Subsequently, all in-vivo scans were performed with 8 data acquisitions and 12 pause cardiac cycles to minimize scan time. The mean native T1 value of myocardium in control animal was 820.5±52 ms. The post-contrast T1 measured 3 days after MI in scar was 264±59 ms and in healthy myocardium was 512±62 ms. The Bland-Altman analysis revealed mean difference of only -1.06% of infarct size percentage between T1 maps and LGE. Conclusions: A multi-shot 2D MOLLI sequence has been presented that allows reliable measurement of high spatial resolution T1 maps in mice for heart rates up to 600bpm. [ABSTRACT FROM AUTHOR]

We performed numerical simulation of voluntary contraction of the pelvic floor muscles to evaluate the resulting displacements of the organs and muscles. Structures were segmented in Magnetic Resonance (MR) images. Different material properties and constitutive models were attributed. The Finite Element Method was applied, and displacements were compared with dynamic MRI findings. Numerical simulation showed muscle magnitude displacement ranging from 0 to 7.9 mm, more evident in the posterior area. Accordingly, the anorectum moved more than the uterus and bladder. Dynamic MRI showed less 0.2 mm and 4.1 mm muscle dislocation in the anterior and cranial directions, respectively. Applications of this model include evaluating muscle impairment, subject-specific mesh implant planning, or effectiveness of rehabilitation. [ABSTRACT FROM PUBLISHER]

The development of two and three-dimensional magnetic resonance imaging (MRJ) opened new options for a better understanding of speech production; in particular, for the articulation process, comparing with other imagmg techniques, such as x-rays. Several MRI studies have been carried out considering different languages, but concerning European Portuguese the available information is far from being completely achieved. Recently, the knowledge gained with the application of deformable models in magnetic resonance images towards the automatic study of the vocal tract, has allowed an enhanced identification and description of the articulatory mechanism and its organs. Our aim is to extract and evaluate the main characteristics of the movements of vocal tract during European Portuguese speech production to achieve speaker-specific articulatory assessment from MRI. For this, we used active shape and active appearance models to identify, i.e. to segment, and simulate the vocal tract's shape in MR images and concluded that both are suitable for such tasks being the later more proficient. Thefindings obtained are believed to be useful for speech rehabilitation and simulation purposes, namely to recognize and simulate the compensatory movements of the articulators during speech production. Therefore, this chapter gains particular interest within the communities of speech study and rehabilitation, medical imaging and bioengineering. It is organized as follows: the introduction section starts with a literature review concerning the use, application and challenges of MRI in speech production study, in particular for speech articulation. In addition, image analysis techniques based on deformable templates, more specifically by using geometrical shapes driven by parameterized functions, are introduced. In the second section, the adopted methodology of MRI acquisition and data assessment are described. Based on this image analysis approach, in the results section the key aspects of articulatory movements during the production of relevant European Portuguese speech sounds are addressed. In the final section of this chapter, conclusions are presented and further suggestions for future work are indicated. [ABSTRACT FROM AUTHOR]

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Supplemental Digital Content is available in the text. Background: Optimal healing of the myocardium after myocardial infarction (MI) requires a suitable degree of inflammation and its timely resolution, together with a well-orchestrated deposition and degradation of ECM (extracellular matrix) proteins. Methods and Results: MI and SHAM-operated animals were imaged at 3, 7, 14, and 21 days with 3T magnetic resonance imaging using a 19F/1H surface coil. Mice were injected with 19F-perfluorocarbon nanoparticles to study inflammatory cell recruitment, and with a gadolinium-based elastin-binding contrast agent to evaluate elastin content. 19F magnetic resonance imaging signal colocalized with infarction areas, as confirmed by late gadolinium enhancement, and was highest 7 days post-MI, correlating with macrophage content (MAC-3 immunohistochemistry; ρ=0.89, P <0.0001). 19F quantification with in vivo (magnetic resonance imaging) and ex vivo nuclear magnetic resonance spectroscopy correlated linearly (ρ=0.58, P =0.020). T1 mapping after gadolinium-based elastin-binding contrast agent injection showed increased relaxation rate (R1) in the infarcted regions and was significantly higher at 21 days compared with 7 days post-MI (R1 [s−1]: 21 days=2.8 [interquartile range, 2.69–3.30] versus 7 days=2.3 [interquartile range, 2.12–2.5], P <0.05), which agreed with an increased tropoelastin content (ρ=0.89, P <0.0001). The predictive value of each contrast agent for beneficial remodeling was evaluated in a longitudinal proof-of-principle study. Neither R1 nor 19F at day 7 were significant predictors for beneficial remodeling (P =0.68; P =0.062). However, the combination of both measurements (R1<2.34 Hz and 0.55≤19F≤1.85) resulted in an odds ratio of 30.0 (CI 95%, 1.41–638.15; P =0.029) for favorable post-MI remodeling. Conclusions: Multinuclear 1H/19F magnetic resonance imaging allows the simultaneous assessment of inflammation and elastin remodeling in a murine MI model. The interplay of these biological processes affects cardiac outcome and may have potential for improved diagnosis and personalized treatment. [ABSTRACT FROM AUTHOR]