Book contents
- Frontmatter
- Contents
- Contributors
- Case studies
- Preface to the second edition
- Preface to the first edition
- Abbreviations
- Introduction
- Section 1 Physiological MR techniques
- Chapter 1 Fundamentals of MR spectroscopy
- Chapter 2 Quantification and analysis in MR spectroscopy
- Chapter 3 Artifacts and pitfalls in MR spectroscopy
- Chapter 4 Fundamentals of diffusion MR imaging
- Chapter 5 Human white matter anatomical information revealed by diffusion tensor imaging and fiber tracking
- Chapter 6 Artifacts and pitfalls in diffusion MR imaging
- Chapter 7 Cerebral perfusion imaging by exogenous contrast agents
- Chapter 8 Detection of regional blood flow using arterial spin labeling
- Chapter 9 Imaging perfusion and blood–brain barrier permeability using T1-weighted dynamic contrast-enhanced MR imaging
- Chapter 10 Susceptibility-weighted imaging
- Chapter 11 Artifacts and pitfalls in perfusion MR imaging
- Chapter 12 Methodologies, practicalities and pitfalls in functional MR imaging
- Section 2 Cerebrovascular disease
- Section 3 Adult neoplasia
- Section 4 Infection, inflammation and demyelination
- Section 5 Seizure disorders
- Section 6 Psychiatric and neurodegenerative diseases
- Section 7 Trauma
- Section 8 Pediatrics
- Section 9 The spine
- Index
- References
Chapter 8 - Detection of regional blood flow using arterial spin labeling
from Section 1 - Physiological MR techniques
Published online by Cambridge University Press: 05 March 2013
- Frontmatter
- Contents
- Contributors
- Case studies
- Preface to the second edition
- Preface to the first edition
- Abbreviations
- Introduction
- Section 1 Physiological MR techniques
- Chapter 1 Fundamentals of MR spectroscopy
- Chapter 2 Quantification and analysis in MR spectroscopy
- Chapter 3 Artifacts and pitfalls in MR spectroscopy
- Chapter 4 Fundamentals of diffusion MR imaging
- Chapter 5 Human white matter anatomical information revealed by diffusion tensor imaging and fiber tracking
- Chapter 6 Artifacts and pitfalls in diffusion MR imaging
- Chapter 7 Cerebral perfusion imaging by exogenous contrast agents
- Chapter 8 Detection of regional blood flow using arterial spin labeling
- Chapter 9 Imaging perfusion and blood–brain barrier permeability using T1-weighted dynamic contrast-enhanced MR imaging
- Chapter 10 Susceptibility-weighted imaging
- Chapter 11 Artifacts and pitfalls in perfusion MR imaging
- Chapter 12 Methodologies, practicalities and pitfalls in functional MR imaging
- Section 2 Cerebrovascular disease
- Section 3 Adult neoplasia
- Section 4 Infection, inflammation and demyelination
- Section 5 Seizure disorders
- Section 6 Psychiatric and neurodegenerative diseases
- Section 7 Trauma
- Section 8 Pediatrics
- Section 9 The spine
- Index
- References
Summary
Introduction
The motivation to measure regional perfusion is well established in physiology and medicine. Techniques to measure regional blood flow in animal models such as using microspheres [1] and radiolabeled tracers [2] have had a major impact on our understanding of the regulation of microcirculation in normal tissue and changes that occur during a variety of disease processes. A major limitation of these techniques is that, for the most part, they require sacrificing the animal after only one or a few independent measurements of blood flow. Techniques to measure regional blood flow in humans have relied on the wash-in/wash-out kinetics of tracers that can be detected by radiological imaging techniques. Most important have been the use of radiolabeled water detected by positron emission tomography (PET) [3] and regional distribution of inhaled xenon detected by X-ray computed tomography (CT).[4] The results from these techniques show a wide range of problems that perfusion imaging can address, from functional mapping of active brain regions during cognitive task activation to attempts to detect the development of Alzheimer’s disease. These techniques are limited by low spatial resolution compared with MRI and the inability to make numerous serial measurements owing to radiation dose issues. All of these approaches have been inspirational, offering theoretical frameworks and practical motivation to develop MRI techniques to measure regional perfusion. The goal has been to take advantage of the non-invasive nature of MRI and the very high resolution that can be obtained to make maps of tissue blood flow.
Early approaches to measure regional blood flow by MR techniques relied on adapting the well-developed class of techniques that measure tissue-specific wash-in and wash-out of tracers. Tracers such as deuterium oxide [5,6] or fluorinated inhalants [7,8] were first detected using MR spectroscopy (MRS) from specified regions and later images were made that enabled estimates of cerebral blood flow (CBF),[9,10] and blood flow in tumors.[11] A major drawback with the MR techniques that relied on directly detecting tracers was the low spatial resolution that could be obtained compared with normal MRI. A solution to this problem was to follow the tracer kinetics of MRI contrast agents indirectly through their effects on tissue water relaxation.[12,13] After a rapid bolus of gadolinium chelates, the change in contrast in a tissue can be used to calculate regional blood volume and blood flow at the resolution of standard MRI. This approach has become an important technique for assessing hemodynamics during ischemia in heart and brain [14] and is described in detail in Ch. 7.
- Type
- Chapter
- Information
- Clinical MR NeuroimagingPhysiological and Functional Techniques, pp. 94 - 112Publisher: Cambridge University PressPrint publication year: 2009