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In recent years there have been several initiatives dedicated to improving radiologic standards of practice. Many of these programs, such as “Image Gently,” “Image Wisely,” “Step Lightly,” and the Dose Index Registry, address growing concerns over patient exposure to high levels of ionizing radiation from radiologic exams and raise awareness in both the medical community and public to these trends while taking steps to curtail radiation…

Introduction In 2012, the American Board of Radiology (ABR) implemented a new Maintenance of Certification (MOC) process, known as Continuous Certification, for all participating diplomates. Every year on March 15, the ABR looks back at the previous 3 years for each diplomate to consider if he or she is meeting the MOC requirements. All diplomates who hold continuous certificates issued in 2012 or after or time-limited…

Safety in radiology is expected by our patients, colleagues, administrators, providers, national organizations, oversight organizations, and the government. It is no longer enough to provide accurate reports of findings on imaging studies. Radiologists and their coworkers in the radiology department are also expected to provide patient-centered care and safe experiences prior to, during, and after imaging and procedures in radiology. To meet this need, considerable educational…

Introduction The challenge of a changing economy and increasing pressure in healthcare for optimal performance while dealing with limited resources and maintaining the high quality levels of medicine is becoming increasingly difficult. There is increasing demand for quality improvement to drive improved outcomes and reduce costs. The primary methodology used to deliver improved quality with lower costs is a process improvement methodology known as Lean Six…

Current and Traditional Definitions of Quality in Healthcare How do we best define quality in healthcare? The quality literature includes several definitions. The Institute of Medicine (IOM) defines quality of care as the degree to which health services for individuals and populations increase the likelihood of desired health outcomes and are consistent with current professional knowledge. How care is administered should demonstrate appropriate use of the…

Concepts for Quality Improvement Quality improvement (QI) methods are not new; they are just relatively new to the healthcare industry and the field of radiology. As a result, there is currently a gap between the high desire and need to apply QI methods in daily practice and a lack of radiologists who are sufficiently trained in the proper use of these methods. In response to this…

To Err is Human When the Institute of Medicine (IOM, now the Academy of Medicine) first released its report, To Err Is Human , in 1999, headlines were made throughout the world. The notion that our healthcare delivery system was not only not achieving the positive exceptionalism that one might expect from the most expensive system in the world, but also guilty of contributing to the…

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5.1.1 Magnetic Resonance Spectroscopy 5.1.1.1 Introduction In the large majority of applications MRI focuses on detecting proton signal, in particular the signal from water protons. It therefore provides information about anatomical structure and the biophysical state of tissue water. Magnetic resonance spectroscopy (MRS) can be seen as an alternative or complementary technique to MRI as it provides chemical and biophysical information that can be extracted from…

4.3.1 Rationale Spinal cord blood vessels are millimeter- to submillimeter-sized blood vessels that are hard to visualize in the human body. In vivo imaging of spinal cord arteries and veins was until recently only possible using invasive catheter-based angiography, which involves a radiation burden and needs to be performed by experienced specialists. Noninvasive imaging of spinal cord blood vessels had only recently become available in a…

4.2.1 What is Physiological Noise? Physiological noise can be defined as any signal change occurring in an image that is due to the subject and that is of no interest. Equally, movement of the subject (e.g., bulk movement of the cord) and indirect movement of structures of interest (e.g., caused by arterial pulsation or cerebrospinal fluid (CSF) flow) could also be included in this heading. For the…

4.1.1 Blood Oxygenation Level Dependent 4.1.1.1 Basic Principles Functional magnetic resonance imaging (fMRI) allows noninvasive detection of neuronal activity. fMRI based on the blood oxygenation level dependent (BOLD) contrast mechanism was first introduced in 1990. The basic principle behind the BOLD effect is that following neuronal activation, metabolic demand for oxygen induces a local increase in blood flow and blood volume. However, this blood supply far…

3.6.1 Historical Perspective Since the early days of X-ray computerized tomography (CT) in the late 1970s, it has been possible to visualize the spinal cord in cross-section in vivo, and to make quantitative measurements of the cord diameter. Early studies required the introduction of an iodinated contrast agent into the cerebrospinal fluid (CSF) by means of a lumbar puncture, in a procedure known as computed myelography.…

3.5.1 Overview T 2 -weighted imaging plays a key role in clinical MR imaging of spinal cord. While T 2 weighting is highly sensitive, it is notoriously unspecific as very different pathological conditions can lead to similar increases in water content that result in similar T 2 increases. Therefore, T 2 -weighted imaging should be considered a qualitative clinical tool; however, if the full T 2…

Magnetization transfer (MT), first demonstrated in vivo by Wolff and Balaban, is a contrast mechanism based on the exchange of magnetization occurring between groups of spins characterized by different molecular environments. MT produces a source of contrast alternative to T 1 and T 2 , which has become widely used in clinical imaging to improve the suppression of static tissue in MR angiography and to increase…

3.3.1 Introduction: Diffusion Imaging and Tissue Microstructure Diffusion imaging and particularly diffusion tensor imaging (DTI) have become standard tools for assessment of white matter in the brain. Although somewhat more technically challenging to implement in the spinal cord, these methods are now also commonplace in studies of the spinal cord. DTI provides two unique pieces of information over any preceding method. First, it provides an estimate…

In Chapter 3.1 , the diffusion of water molecules was described according to the diffusion tensor model, which assumes a Gaussian probability of displacement associated to the diffusion of water molecules. This assumption is true in free systems, but it is also applied for water in complex biological structures. In this chapter, the q -space theory is explored as a model free from assumptions, and we…

3.1.1 Principles of Diffusion-Weighted Magnetic Resonance Imaging 3.1.1.1 Basic Concept of Diffusion Weighting Water molecules in tissue undergo Brownian motion, which means that molecules are not perfectly static over time but experience random microscopic displacements due to thermal agitation. This effect can be characterized by a diffusion coefficient. Compared to free water, where this effect is equal whatever the direction of observation is (i.e., it is…

2.4.1 Background 2.4.1.1 Importance of High Field In the early 1980s, magnetic resonance imaging (MRI) was introduced into clinical practice and has subsequently undergone technical advancements that have resulted in improvements in image quality. For nearly 20 years, 1.5 T has been the most common field strength in use for clinical MRI of the human spinal cord. In fact, according to current European Union regulations, scanners…

2.3.1 Introduction: Sources of Susceptibility Artifacts The uniformity of the B 0 main field in magnetic resonance imaging (MRI) is critical for artifact-free image formation. MRI scanners are manufactured with a stringent requirement of less than one part-per-million (ppm) a a In MRI, the variations in B 0 field or the differences in resonant frequencies are so small that they are expressed in “parts per million”,…