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Quality Improvement Tools

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…

Quality Improvement : Definition and Limitations

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…

Key Concepts in Quality Improvement

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…

History and Current Status of Quality Improvement in Radiology

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…

Single Voxel MR Spectroscopy in the Spinal Cord: Technical Challenges and Clinical Applications

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…

Mapping the Vasculature of the Spinal Cord

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…

Physiological Noise Modeling and Analysis for Spinal Cord fMRI

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…

Spinal Cord fMRI

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…

Atrophy

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.…

T 2 Relaxation

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

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…

Advanced Methods to Study White Matter Microstructure

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…

Q -Space Imaging: A Model-Free Approach

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…

Diffusion-Weighted Imaging of the Spinal Cord

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…

Ultra-High Field Spinal Cord Imaging

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…

Susceptibility Artifacts

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”,…

B 0 Inhomogeneity and Shimming

Acknowledgments The author is very grateful to Susann Boretius, Martin Busch, Yasar Goedecke, Martin Koch, Joost Kuijer, Marco Lawrenz, and Petra Pouwels for helpful discussions and to Joachim Graessner (Siemens Healthcare) and Jürgen Bunke (Philips Healthcare) for providing information about the shim techniques of their companies' MR systems. In the context of magnetic resonance (MR) experiments, “shimming” describes the procedures performed to provide a sufficiently homogeneous…

Array Coils

2.1.1 Introduction Essential parts of a magnetic resonance imaging (MRI) system, radiofrequency (RF) coils or antennas are used to transmit and/or receive signal. Phased-array coils combine multiple small coil elements to transmit or receive signal using independent channels. Array coils were first described in a seminal paper by Roemer et al., and proof-of-concept was demonstrated in the spine. Since then, array coils have become the standard for…

Traumatic Spinal Cord Injury: Chronic Spinal Cord Injury and Recovery

1.3B.1 Introduction The introduction of magnetic resonance imaging (MRI) to the field of spine trauma has vastly improved the clinical diagnosis of spinal cord injury (SCI). MRI has advantages over conventional X-ray and computer tomography (CT) as it more precisely details posttraumatic compression of the spinal cord, either due to soft tissue (i.e., traumatic disc herniation or bleeding within the spinal canal) or spinal canal encroachment…