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Society for Pediatric Radiology – Poster Archive


Alex Chan

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Showing 2 Abstracts.

The goal of this educational exhibit is to use a graphical and image heavy Powerpoint presentation to familiarize the reader with the background necessary to understand common clinical ASL-PWI imaging techniques along with displaying a pictorial assay of different normal and abnormal ASL perfusion findings within the field of Pediatric Neuroradiology. To introduce our topic, we will briefly discuss the physiology of cerebral blood flow and how it is measured with and without an exogenous tracer. Next, to serve as an overview, we will show the general ASL experiment, namely, labeling, post label delay, and readout. Following, we will discuss each of the above components, beginning with showing the different main labeling methods, CASL, PCASL, and PASL. Finally, the concept of post label delay will be illustrated respective to each of the main labeling methods. In the second section, we will discuss the image acquisition component by first describing and illustrating two common readout methods, such as 2D-EPI and 3D-GRASE methods along with their advantages and disadvantages. Additionally, we will illustrate the process of background suppression along with its significance. Finally, we will review the process of obtaining perfusion weighted images through the subtraction between tagged and control images. The third section will illustrate an assortment of clinical examples beginning with showing normal physiological hyper- and hypoperfusion and newborn perfusion characteristics. Following, we will highlight a spectrum of clinical cases including: moyamoya, HIE, medullary infarct with luxury perfusion, arteriovenous malformation, PRES, infections (intracerebral abscess, toxoplasmosis, cerebellitis), characteristics of headache, intracranial tumors (juvenile astrocytoma, hemangioblastoma, ATRT, and choroid plexus papilloma), cortical dysplasia, tuberous sclerosis with seizures, and variations presentations of methotrexate toxicity. Lastly, we will discuss cerebral blood reserve imaging utilizing acetazolamide challenge. All cases will contain pertinent clinical information and images from other sequences/modalities that aid in the diagnosis of disease. Read More

Meeting name: SPR 2019 Annual Meeting & Postgraduate Course , 2019

Authors: Chan Alex, Laughlin Brady, Abid Waqas, Latshaw Rachael, Iaia Alberto, Moftakhar Parham, Nikam Rahul, Kandula Vinay, Choudhary Arabinda

Keywords: Arterial Spin Labeling, Physics

PET/MRI has recently become a clinical realization after overcoming complex hardware and image reconstruction issues. The goal of this educational exhibit is to provide a comprehensive, yet understandable, introduction to these aspects of PET/MRI along with displaying a pictorial assay of different normal and abnormal metabolic findings within the field of Pediatric Neuroradiology. The first part of this presentation will begin by highlighting the basic hardware components of the PET/CT contrasting with the interactions between the main components of the PET/MRI scanner along with their associated solutions. In general, these issues include how MRI can affect PET in terms of their magnetic field and RF properties and how PET affect MRI due to the scintillator/electronic components. The second part will begin by discussing some soft tissue and hardware attenuation correction techniques that are currently in use, such as: Segmentation and atlas-based methods along with attenuation map generation and coil localization methods. Additionally, we will show the consequence of field-of-view (FOV) mismatch between the PET and MRI acquisitions and partial volume effects along with their solutions. The final part will showcase clinical applications of PET/MRI to Pediatric Neuroradiology, featuring imaging protocol details and a pictorial guide of normal distributions and pathologic conditions. Clinical examples range from seizure localization, cortical malformations, manifestations of Phakomatoses, perinatal stroke, tumor recurrence, and Flutriciclamide (<sup>18</sup>F-GE180) imaging in the setting of neuroinflammation. Read More

Meeting name: SPR 2019 Annual Meeting & Postgraduate Course , 2019

Authors: Chan Alex, Laughlin Brady, Latshaw Rachael, Abid Waqas, Iaia Alberto, Moftakhar Parham, Kandula Vinay, Nikam Rahul, Choudhary Arabinda

Keywords: PET/MRI, Physics