MRA and ASL perfusion findings in pediatric reversible cerebral vasoconstriction syndrome

Arterial spin labeling (ASL) is a powerful noncontrast magnetic resonance imaging (MRI) technique that enables quantitative evaluation of brain perfusion. To optimize the clinical and research utilization of ASL, radiologists and physicists must understand the technical considerations and age-related variations in normal and disease states. We discuss advanced applications of ASL across the lifespan, with example cases from children and adults covering a wide variety of pathologies. Through literature review and illustrated clinical cases, we highlight the subtleties as well as pitfalls of ASL interpretation. First, we review basic physical principles, techniques, and artifacts. This is followed by a discussion of normal perfusion variants based on age and physiology. The three major categories of perfusion abnormalities-hypoperfusion, hyperperfusion, and mixed patterns-are covered with an emphasis on clinical interpretation and relationship to the disease process. Major etiologies of hypoperfusion include large artery, small artery, and venous disease; other vascular conditions; global hypoxic-ischemic injury; and neurodegeneration. Hyperperfusion is characteristic of vascular malformations and tumors. Mixed perfusion patterns can be seen with epilepsy, migraine, trauma, infection/inflammation, and toxicmetabolic encephalopathy. Level of Evidence: 4 Technical Efficacy Stage: 3

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“…6e). 70 Drug‐induced vasculopathies can also present with ASL abnormalities, depending on the mechanism and affected vessel size (Fig. 6f).…”

Section: Hypoperfusion Patternsmentioning

confidence: 99%

Arterial Spin Labeling Applications in Pediatric and Adult Neurologic Disorders

Bambach

Smith

Morris

et al. 2020

Magnetic Resonance Imaging

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“…Major etiologies include connective tissue disorders, blood dyscrasias, inflammatory/infectious conditions, and vascular dysautoregulation. [64][65][66][67][68][69][70][71][72] [Figure 6] Hypoxic-Ischemic injury Hypoxic-ischemic injury (HII) has different imaging manifestations, depending on the severity and duration of cerebral flow compromise, as well as the timing of imaging after injury. Age of is also very important: children experience higher flow to actively developing brain regions, thus makes these areas selectively vulnerable in the setting of profound HII.…”

Section: Vasculopathymentioning

confidence: 99%

Multidelay ASL of the pediatric brain

Golay

2022

The British Journal of Radiology

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Arterial spin labeling (ASL) is a powerful noncontrast MRI technique for evaluation of cerebral blood flow (CBF). A key parameter in single-delay ASL is the choice of postlabel delay (PLD), which refers to the timing between the labeling of arterial free water and measurement of flow into the brain. Multidelay ASL (MDASL) utilizes several PLDs to improve the accuracy of CBF calculations using arterial transit time (ATT) correction. This approach is particularly helpful in situations where ATT is unknown, including young subjects and slow-flow conditions. In this article, we discuss the technical considerations for MDASL, including labeling techniques, quantitative metrics, and technical artifacts. We then provide a practical summary of key clinical applications with real-life imaging examples in the pediatric brain, including stroke, vasculopathy, hypoxic-ischemic injury, epilepsy, migraine, tumor, infection, and metabolic disease.

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