Quantitative Susceptibility Mapping: Basic Methods and Clinical Applications. July-August 2022-RG210054-2022-Kudo-SG

RG210054-2022-Kudo-SG

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The document provides a study guide for a test on "Quantitative Susceptibility Mapping: Basic Methods and Clinical Applications," which is part of the RadioGraphics Online SA-CME program. It includes a series of questions related to imaging findings and conditions as detected by quantitative susceptibility mapping (QSM), a technique used in MRI to measure magnetic susceptibility variations in tissues. <br /><br />1. The first question inquires about diamagnetic imaging findings in QSM, with options including deep gray matter, calcification, microbleeds, and iron deposition. The correct answer is typically calcification, which is generally diamagnetic and shows low contrast in QSM.<br /><br />2. The next question discusses intracranial entities that are hard to differentiate using conventional MRI but can be distinguished through varying magnetic susceptibilities in QSM, listing options like cortex and deep gray matter, myelin and choroid plexus, hemorrhage and calcification, and amyotrophic lateral sclerosis and normal aging. Hemorrhage and calcification are often difficult to distinguish due to their nonspecific low signal intensity on conventional MRI.<br /><br />3. The document asks about a condition shown in Figure 6C, which displays mixed areas of high and low contrast on QSM, indicative of both calcification and hemorrhage. The options provided are oligodendroglioma, neurodegeneration with brain iron accumulation, Parkinson disease, and meningioma, with oligodendroglioma often presenting such characteristics.<br /><br />4. It also questions the association of a specific substance with increased brain iron in regions like the hippocampus among individuals with Alzheimer's or mild cognitive impairment. The potential answers include β-amyloid, hemosiderin, calcification, and hemoglobin, with β-amyloid commonly linked to these conditions.<br /><br />5. Lastly, it queries which MRI sequence is employed to differentiate between neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis. The options are T2*-weighted sequence, FLAIR sequence, proton-density–weighted sequence, and T1-weighted sequence. The T2*-weighted sequence is often used for this purpose.<br /><br />This study guide is part of a continuing medical education activity that requires accessing the RSNA’s learning center online for full participation and credit.

Keywords

Quantitative Susceptibility Mapping

QSM

MRI

magnetic susceptibility

diamagnetic imaging

hemorrhage

calcification

brain iron

Alzheimer's

T2*-weighted sequence