Part I Imaging Applications in Current Clinical Practice
- 1 Clinical Evaluation of Dementia and When to Perform PET.
- 2 Clinical Interpretation of Brain PET Scans: Performing Visual Assessments, Providing Quantifying Data, and Generating Integrated Reports.
- 3 FDG PET in the Evaluation of Mild Cognitive Impairment and Early Dementia.
- 4 PET and SPECT in the Evaluation of Patients with Central Motor Disorders.
Part II Emerging Approaches Using PET.
- 5 Microstructural Imaging of Neurodegenerative Changes.
- 6 Amyloid Imaging with PET in Alzheimer’s Disease, Mild Cognitive Impairment, and Clinically Unimpaired Subjects.
Part III Atlas.
- 7 Interpretive Practice Atlas.
Index.
Among all the clinical indications for which radiologists, nuclear medicine physicians, neurologists, neurosurgeons, psychiatrists (and others examining disorders of the brain) order and read brain PET scans, demand is greatest for those pertaining to dementia and related disorders. This demand is driven by the sheer prevalence of those conditions, coupled with the fact that the differential diagnosis for causes of cognitive impairment is wide and often difficult to distinguish clinically. The conceptual framework by which evaluation and management of dementia is guided has evolved considerably during the last decade. Although we still are far from having ideal tests or dramatic cures for any of the established causes of dementia, our options have expanded with respect to both the diagnostic and therapeutic tools now available. In the first chapter of this book, the contribution and limitations of different elements of the clinical examination for diagnosis of cognitive symptoms are described, and the roles of structural and functional neuroimaging in the clinical workup are given context.
The clinical utility of brain positron emission tomography (PET), as with other imaging modalities, depends in part on how accurately and fully the information inherently represented in the scans is appreciated and relayed in the interpretation of the images. Even highly trained imaging specialists are challenged by this since, for example, neuroradiologists are generally far more familiar with computed tomography (CT) and magnetic resonance (MR) studies of the brain than with PET studies, and specialists in PET and PET/CT facilities tend to be much more experienced with oncology studies than with dedicated brain studies performed for the evaluation of neurologic disorders. To help meet this challenge, the second chapter offers practical instruction on adopting a systematic method for visual analysis of scans, describes how quantification with clinically available and friendly software tools can be employed to assist with analysis, and then illustrates a straightforward approach for integrating the qualitative and quantitative findings in meaningful interpretations. An Atlas in the final section of this book complements Chapter 2 by providing interpretive practice for many real (and clinically realistic) cases, to which the tools outlined in the second chapter can be directly applied.
The most frequent causes of dementia are neurodegenerative disorders, with Alzheimer’s disease being the most common. By the time patients are symptomatic with these disorders, they have undergone significant distinct alterations in brain metabolism. The increasing use of brain PET stems from the high sensitivity of this imaging tool in identifying those alterations. The third chapter looks at the full spectrum of changes in glucose metabolism detectable with PET in monitoring the course of cognitive decline, beginning before the emergence of the first neurologic symptoms, in people who are predisposed to developing problems, in some cases many years into the future. Progressive changes observed with PET in the brains of patients who experience very mild symptoms, to those who meet criteria for having mild cognitive impairment, to those suffering from full-blown dementia, are described, as is the role of PET in the differential diagnosis of the underlying cause for the dysfunction.
Neurodegenerative diseases often impact not only on cognitive function, but also on motor function. The two neurologic domains can be affected in isolation, but frequently a mixed presentation of symptoms occurs. For example, approximately one third of Alzheimer’s patients eventually experience parkinsonian symptoms and, conversely, a similar proportion of patients with Parkinson’s disease develop significant cognitive impairment. Other conditions, such as dementia with Lewy bodies, may be characterized at an early stage by both motor and cognitive problems. Chapter 4 examines neuronuclear imaging studies explicitly aimed at illuminating changes in the brain associated with movement disorders. Their potential utility with respect to drug development, as well as in direct clinical application, is explained.
Although the most commonly performed clinical PET studies by far are carried out with [18F]fluorodeoxyglucose (FDG) as the imaged radiotracer, substantial advances have occurred in the development of other radiotracers with which to probe brain processes associated with neurodegenerative disease. Chapter 5 describes work that is making it possible to observe and measure the molecular participants of such processes as they accumulate, or are lost from, living brain tissue. In the setting of Alzheimer-related changes, one molecular participant in particular, the ?-amyloid of extracellular plaques constituting one of the histopathologic hallmarks of Alzheimer’s disease, has attracted substantial attention in both industry and academic scientific settings. Following the introduction of this area of investigation in the fifth chapter, Chapter 6 is devoted to expanding on the scientific implications and clinical potential of radiotracers being developed to localize and measure ?-amyloid deposits occurring in the brain. In the latter chapter, particular attention is given to characterizing ?-amyloid deposition in older people who would not be considered cognitively impaired by standard clinical criteria.
PET scans, particularly with FDG, have demonstrated diagnostic and prognostic utility in evaluating patients with cognitive impairment and in distinguishing among primary neurodegenerative disorders and other etiologies for cognitive decline. Since the diagnostic capabilities of this medical technology have outpaced therapeutic advances, a look into the future of PET requires concomitant consideration of the future of therapeutic strategies for addressing the underlying conditions. As preventive and specific disease-modifying treatments are developed, early detection of accurately diagnosed neuropathologic processes, facilitated by appropriate use of PET and other neuroimaging technologies, can be expected to increasingly impact on the enormous human toll currently exacted by these disorders.
Book Details
- Hardcover: 229 pages
- Publisher: Springer; 1 edition (April 1, 2009)
- Language: English
- ISBN-10: 0387764194
- ISBN-13: 978-0387764191
- Product Dimensions: 9.4 x 6.2 x 0.6 inches
List Price: $149.00