Diseases once believed to be confined to the tropics, such as parasitic, mycobacterial, fungal, bacterial, and viral infections are still a major cause of mortality and moribidity in the tropics, yet can affect the developed world in an era of increased global travel and migration. Neuroimaging technique developments over the last several decades have helped clinicians better understand and diagnose these conditions. Experts from tropical countries share their experiences regarding tropical disorders, some of which are rare in the western world, but possible to appear in patients and not readily recognized by specialists not familiar with these diseases. Topics in this issue include: Relevance of neuroimaging in the diagnosis and management of tropical neurologic disorders; Pathology of Tropical Diseases; Viral Infections of the Central Nervous System; Central Nervous System Tuberculosis; Parasitic diseases of nervous system; Neuroimaging in Post-infectious Demyelination and Nutritional Disorders of the Central Nervous System; CNS Fungal Infections in the Tropics; Neuroimaging Epilepsy in the Tropics; Neuroimaging in Cranio-Vertebral Anomalies as seen in Tropics; Vascular Brain Pathologies; Neurobrucellosis; Hirayama Disease; Transverse Myelitis; and Pyomyositis.

An especially important issue during these uncertain times, this collection of articles examines Neuroimaging from an economic perspective, with articles that discuss leadership, “turf battles , strategic planning in the face of declining reimbursement, and the impact of teleradiology and telemedicine in cutting costs and improving access. Medicolegal issues are addressed, as is evidence-based medicine and effective utilization. Performance measures and conflict of interest are reviewed, among many other topics.

With each passing year neuroimaging becomes more and more central in the diagnosis of neurologic disease, as its capacity to detect subtle changes in nervous system tissue increases. This issue of Neurologic Clinics features twelve articles that address the key clinical applications of the several radiologic modalities. Topics include: Neuro-Imaging of Infectious Disease; Neuro-Imaging of Dementia; Imaging of Traumatic Brain Injury; 3. MR Guided Focused Ultrasound: A New Technology for Clinical Neurosciences; Novel Multi- Modality Imaging Techniques for the Diagnosis and Evaluation of Arteriovenous Malformations; Neuroimaging in the Critical Care Environment; Imaging of Cerebral Ischemia: From Acute Stroke to Chronic Disorders; Imaging of Cancer-Related Neurotoxicity; Neurocutaneous Syndromes; Imaging of Chiari Malformation and Hydrocephalus; and others.

In this issue of Neuroimaging Clinics, guest editor Dr. Tchoyoson Lim Choie Cheio brings his considerable expertise to the topic of Central Nervous System Infections. Infections can involve any part of the CNS and often, multiple parts of the CNS are involved at the same time. The imaging surrounding them is constantly evolving, and in this issue, key international experts provide a thorough update of the imaging of these common and pervasive infections. - Contains 13 practice-oriented topics including emerging public health, multidisciplinary teams and pitfalls in CNS infection imaging; acute neurological complications of COVID-19; subacute to chronic neuroimaging findings in SARS-CoV-2/COVID-19 infection; imaging of opportunistic infections and HIV/AIDS; imaging of head and neck infections; and more. - Provides in-depth clinical reviews on central nervous system infections, offering actionable insights for clinical practice. - Presents the latest information on this timely, focused topic under the leadership of experienced editors in the field. Authors synthesize and distill the latest research and practice guidelines to create clinically significant, topic-based reviews.

Spinal Infections is explored in this important Neuroimaging Clinics issue. Articles include: Pathologic approach to spinal cord infections; Pediatric spinal infection and inflammation; Pediatric and adult spinal Tb: imaging and pathophysiology; Pyogenic spinal infections; Spinal brucellosis; Viral infection of the spinal cord and roots; Parasitic and rare spinal infections; Overview of complications and sequeala in spinal infections; Neurosurgical approach to spinal infections; Image guided interventions in spinal infections; Pathological basis of pyogenic, nonpyogenic, and other spondylitis and discitis, and more!

CT, contrast CT, MRI, functional MRI, SPECT, CTA, and x-ray as tools to identify pathogens and diagnose intracranial infections are presented. Topics include: Epidemiology of Central Nervous System Infections; Imaging of Cranial Meningitis and Ventriculitis; Encephalitis, Cerebritis and Brain Abscess; Imaging of Central Nervous System Tuberculosis; Imaging of Rickettsial, Spirochetal, and Parasitic Infections; Imaging of Neurocysticercosis; Fungal Infections of the Central Nervous System; Central Nervous System Infections in the Pediatric Population; Imaging of Infectious Diseases of Spine; Neuropathological Findings in Intracranial Infections; Neurosurgical Approach to Infectious Disease of the Brain; Head and Neck Infections.

Dementia is a massive and increasing global problem, with the current prevalence anticipated to double every 20 years as people live longer. Neuroimaging in dementia is recommended by most clinical guidelines and its role has traditionally been to exclude a mass lesion, rather than to support a specific diagnosis. All radiologists will be aware of a steady rise in the number of requests for brain imaging in old people, but what can imaging reliably tell us and what kind of imaging should we use? In affluent societies we now have a range of structural and molecular brain imaging techniques at our disposal, with specific ligands and sophisticated image analysis techniques now available for clinical use. However, we have difficulty justifying which patients to scan, using which modality and when. We know that Alzheimer's disease is the most common neuropathology contributing to a diagnosis of Alzheimer's disease but we also know from large post-mortem studies that most brain pathology in those who have died with a diagnosis of dementia is mixed. Thus understanding different diseases that can cause dementia, how these co-exist or interact and appreciating that not all dementia is Alzheimer's disease is important. Equally important is awareness of individual differences in response to a neuropathological burden and what factors provide resilience against dementia that might be maximized to reduce or postpone its impact. This issue draws together contributions from experts in their fields to provide clarity to the topic in a comprehensive collection of articles.