SECTION 1: SKULL AND BRAIN SCALP, SKULL ANATOMICALLY BASED DIFFERENTIALS 4 Skull Normal Variants Miral D. Jhaveri, MD, MBA 6 Scalp Mass, Child Luke L. Linscott, MD and Chang Yueh Ho, MD 10 Scalp Mass, Adult Miral D. Jhaveri, MD, MBA 12 Congenital Anomalies of Skull Base Luke L. Linscott, MD and Chang Yueh Ho, MD GENERIC IMAGING PATTERNS 18 "Hair on End" Miral D. Jhaveri, MD, MBA 20 Thick Skull, Generalized Miral D. Jhaveri, MD, MBA 24 Thick Skull, Localized Miral D. Jhaveri, MD, MBA 26 Thin Skull, Generalized Miral D. Jhaveri, MD, MBA 28 Thin Skull, Localized Miral D. Jhaveri, MD, MBA 30 Lytic Skull Lesion, Solitary Miral D. Jhaveri, MD, MBA 34 Multiple Lucent Skull Lesions Miral D. Jhaveri, MD, MBA 38 Sclerotic Skull Lesion, Solitary Miral D. Jhaveri, MD, MBA 42 Sclerotic Skull Lesions, Multiple Miral D. Jhaveri, MD, MBA CLINICALLY BASED DIFFERENTIALS 44 Macrocrania/Macrocephaly Luke L. Linscott, MD 50 Microcephaly Luke L. Linscott, MD MENINGES ANATOMICALLY BASED DIFFERENTIALS 56 Dural Calcification(s) Miral D. Jhaveri, MD, MBA 58 Dural-Based Mass, Solitary Miral D. Jhaveri, MD, MBA 62 Dural-Based Masses, Multiple Miral D. Jhaveri, MD, MBA 66 Falx Lesions Miral D. Jhaveri, MD, MBA GENERIC IMAGING PATTERNS 68 Thick Dura/Arachnoid, Generalized Miral D. Jhaveri, MD, MBA and Yoshimi Anzai, MD, MPH 70 Pial Enhancement Miral D. Jhaveri, MD, MBA and Yoshimi Anzai, MD, MPH 74 Dural Tail Sign Miral D. Jhaveri, MD, MBA VENTRICLES, PERIVENTRICULAR REGIONS ANATOMICALLY BASED DIFFERENTIALS 76 Ventricles, Normal Variants Bernadette L. Koch, MD and Chang Yueh Ho, MD 80 Choroid Plexus Lesions, Child Chang Yueh Ho, MD and Karen L. Salzman, MD 82 Choroid Plexus Lesions, Adult Kalen Riley, MD, MBA, Chang Yueh Ho, MD, and Karen L. Salzman, MD 84 Ependymal/Subependymal Lesions Miral D. Jhaveri, MD, MBA 90 Lateral Ventricle Mass Karen L. Salzman, MD 94 Thick Septum Pellucidum Blair A. Winegar, MD and Karen L. Salzman, MD 96 Foramen of Monro Mass Troy A. Hutchins, MD 100 3rd Ventricle Mass, Anterior Karen L. Salzman, MD 104 3rd Ventricle Mass, Body/Posterior Karen L. Salzman, MD 106 Cerebral Aqueduct/Periaqueductal Lesion Nancy J. Fischbein, MD 112 4th Ventricle Mass, Child Chang Yueh Ho, MD and Karen L. Salzman, MD 116 4th Ventricle Mass, Adult Karen L. Salzman, MD GENERIC IMAGING PATTERNS 118 Bubbly-Appearing Intraventricular Mass Chang Yueh Ho, MD and Karen L. Salzman, MD 122 Ependymal Enhancement Blair A. Winegar, MD and Miral D. Jhaveri, MD, MBA 126 Ventriculomegaly Luke L. Linscott, MD 132 Small Ventricles Bernadette L. Koch, MD and Chang Yueh Ho, MD 134 Asymmetric Lateral Ventricles Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 138 Irregular Lateral Ventricles Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 142 Periventricular Enhancing Lesions Santhosh Gaddikeri, MD and Marinos Kontzialis, MD MODALITY-SPECIFIC IMAGING FINDINGS 146 Intraventricular Calcification(s) Blair A. Winegar, MD and Karen L. Salzman, MD 150 Periventricular Calcification(s) Luke L. Linscott, MD, Chang Yueh Ho, MD, and Susan I. Blaser, MD, FRCPC 154 Periventricular T2-/FLAIR-Hyperintense Lesions Troy A. Hutchins, MD and Karen L. Salzman, MD EXTRAAXIAL SPACES AND SUBARACHNOID CISTERNS ANATOMICALLY BASED DIFFERENTIALS 158 Subarachnoid Space Normal Variants Luke L. Linscott, MD and Karen L. Salzman, MD 160 Epidural Mass Miral D. Jhaveri, MD, MBA and Sheri L. Harder, MD, FRCPC 164 Enlarged Sulci, Generalized Troy A. Hutchins, MD and Chang Yueh Ho, MD 168 Effaced Sulci, Generalized Troy A. Hutchins, MD and Anne G. Osborn, MD, FACR 172 Interhemispheric Fissure Cysts Bernadette L. Koch, MD, Chang Yueh Ho, MD, and Anne G. Osborn, MD, FACR 176 CPA Mass, Adult Blair A. Winegar, MD and Karen L. Salzman, MD 180 Cystic CPA Mass Karen L. Salzman, MD and H. Ric Harnsberger, MD 184 Prepontine Cistern Mass Kalen Riley, MD, MBA, Gregory L. Katzman, MD, MBA, and Miral D. Jhaveri, MD, MBA 190 Ventral Foramen Magnum Mass Miral D. Jhaveri, MD, MBA and Karen L. Salzman, MD 194 Dorsal Foramen Magnum Mass Miral D. Jhaveri, MD, MBA and Karen L. Salzman, MD GENERIC IMAGING PATTERNS 198 Solitary Enhancing Cranial Nerve Miral D. Jhaveri, MD, MBA and Anne G. Osborn, MD, FACR 200 Multiple Enhancing Cranial Nerves Miral D. Jhaveri, MD, MBA and Anne G. Osborn, MD, FACR 204 CSF-Like Extraaxial Fluid Collection Miral D. Jhaveri, MD, MBA and Yoshimi Anzai, MD, MPH 206 Convexal Subarachnoid Hemorrhage Miral D. Jhaveri, MD, MBA 210 CSF-Like Extraaxial Mass Miral D. Jhaveri, MD, MBA and Yoshimi Anzai, MD, MPH 212 Sulcal/Cisternal Enhancement Miral D. Jhaveri, MD, MBA and Sheri L. Harder, MD, FRCPC 216 Fat in Sulci/Cisterns/Ventricles Miral D. Jhaveri, MD, MBA and Yoshimi Anzai, MD, MPH 218 Pneumocephalus Miral D. Jhaveri, MD, MBA MODALITY-SPECIFIC IMAGING FINDINGS 220 Extraaxial Flow Voids Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 222 T1-Hyperintense CSF Miral D. Jhaveri, MD, MBA and Bronwyn E. Hamilton, MD 224 FLAIR-Hyperintense Sulci Miral D. Jhaveri, MD, MBA and Bronwyn E. Hamilton, MD 228 T2-Hypointense Extraaxial Lesions Miral D. Jhaveri, MD, MBA and Bronwyn E. Hamilton, MD 232 Hyperdense CSF Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 234 Hyperdense Extraaxial Mass(es) Miral D. Jhaveri, MD, MBA 236 Hypodense Extraaxial Mass(es) Miral D. Jhaveri, MD, MBA and Bronwyn E. Hamilton, MD BRAIN PARENCHYMA, GENERAL GENERIC IMAGING PATTERNS 240 Multiple Enhancing Lesions, General Karen L. Salzman, MD and Miral D. Jhaveri, MD, MBA 244 Ring-Enhancing Lesion, Solitary Miral D. Jhaveri, MD, MBA and Yoshimi Anzai, MD, MPH 250 Ring-Enhancing Lesion, Multiple Miral D. Jhaveri, MD, MBA and Yoshimi Anzai, MD, MPH 254 Solitary Cystic Parenchymal Mass, General Nancy J. Fischbein, MD and Anne G. Osborn, MD, FACR 260 CSF-Like Parenchymal Lesion(s) Troy A. Hutchins, MD and Anne G. Osborn, MD, FACR 266 Cyst With Nodule Troy A. Hutchins, MD and Karen L. Salzman, MD 270 Fat and Fat-Like Lesion(s) Miral D. Jhaveri, MD, MBA and Sheri L. Harder, MD, FRCPC MODALITY-SPECIFIC IMAGING FINDINGS 272 Solitary Parenchymal Calcification Miral D. Jhaveri, MD, MBA 276 Multiple Parenchymal Calcifications Blair A. Winegar, MD, Anne G. Osborn, MD, FACR, and Miral D. Jhaveri, MD, MBA 280 Solitary Hyperdense Parenchymal Lesion Miral D. Jhaveri, MD, MBA and Anne G. Osborn, MD, FACR 286 Multiple Hyperdense Parenchymal Lesions Troy A. Hutchins, MD, Anne G. Osborn, MD, FACR, and Miral D. Jhaveri, MD, MBA 292 Solitary Hypodense Parenchymal Lesion Miral D. Jhaveri, MD, MBA and Anne G. Osborn, MD, FACR 296 Multiple Hypodense Parenchymal Lesions Troy A. Hutchins, MD and Chang Yueh Ho, MD 300 Multiple Brain Hyperintensities (T2/FLAIR), Common Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 306 Multiple Brain Hyperintensities (T2/FLAIR), Less Common Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 312 Multiple Brain Hyperintensities (T2/FLAIR), Rare but Important Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 318 Multiple Hypointense Foci on T2 Nancy J. Fischbein, MD 320 Multiple Hypointense Foci on GRE/SWI Nancy J. Fischbein, MD 324 T1-/T2-Hyperintense Parenchymal Lesions Santhosh Gaddikeri, MD and Anne G. Osborn, MD, FACR 328 T1-Hypointense, T2-Hyperintense Parenchymal Lesions Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 332 T1-/T2-Isointense Parenchymal Lesions Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 336 Restricted Diffusion, General Miral D. Jhaveri, MD, MBA and Bronwyn E. Hamilton, MD 342 Restricted Diffusion, Cortex Miral D. Jhaveri, MD, MBA 344 Restricted Diffusion, Basal Ganglia Miral D. Jhaveri, MD, MBA 348 T1-Hyperintense Parenchymal Lesion(s) Santhosh Gaddikeri, MD and Anne G. Osborn, MD, FACR CLINICALLY BASED DIFFERENTIALS 352 Brain Tumor in Newborn/Infant Chang Yueh Ho, MD 358 Brain Tumor in Child > 1 Year Chang Yueh Ho, MD 364 Epilepsy, Child Luke L. Linscott, MD 370 Epilepsy, Adult Chang Yueh Ho, MD and Bronwyn E. Hamilton, MD SUPRATENTORIAL BRAIN PARENCHYMA ANATOMICALLY BASED DIFFERENTIALS 372 Asymmetric Cerebral Hemispheres Santhosh Gaddikeri, MD and Gregory L. Katzman, MD, MBA 378 Thick Cerebral Cortex Luke L. Linscott, MD 384 Thin Cortex Karen L. Salzman, MD, Anne G. Osborn, MD, FACR, and Chang Yueh Ho, MD 390 Focal Cortical Mass Chang Yueh Ho, MD and James D. Eastwood, MD 396 Cortical Hyperintensity T2/FLAIR Karen L. Salzman, MD 400 Cortical Enhancement Karen L. Salzman, MD 402 Solitary White Matter Lesion Santhosh Gaddikeri, MD and Marinos Kontzialis, MD 406 Confluent White Matter Lesions Karen L. Salzman, MD 412 Abnormal Shape/Configuration of Corpus Callosum Luke L. Linscott, MD 418 Corpus Callosum Holes Troy A. Hutchins, MD and Karen L. Salzman, MD 420 Corpus Callosum Lesion Without Mass Effect Karen L. Salzman, MD 422 Corpus Callosum Mass Karen L. Salzman, MD 424 Corpus Callosum Splenium Lesion Troy A. Hutchins, MD 428 Medial Temporal Lobe Lesion Chang Yueh Ho, MD 434 Hippocampal Lesion Chang Yueh Ho, MD 438 Basal Ganglia Calcification Karen L. Salzman, MD 442 Hyperdense Basal Ganglia Karen L. Salzman, MD 444 Hypodense Basal Ganglia Karen L. Salzman, MD 448 T1-Hyperintense Basal Ganglia Karen L. Salzman, MD 452 T2-Hyperintense Basal Ganglia Karen L. Salzman, MD 456 Enlarged Perivascular Spaces Karen L. Salzman, MD 458 Perivascular Space Enhancing Lesions Karen L. Salzman, MD 462 Bilateral Basal Ganglia Lesions Nancy J. Fischbein, MD 466 Putamen Lesion(s) Karen L. Salzman, MD 468 Globus Pallidus Lesion(s) Karen L. Salzman, MD 472 Unilateral Thalamic Lesion Karen L. Salzman, MD 474 Bithalamic Lesions Nancy J. Fischbein, MD and Karen L. Salzman, MD 478 Pulvinar Sign Karen L. Salzman, MD 480 Tectal (Quadrigeminal Plate) Lesion Karen L. Salzman, MD INFRATENTORIAL BRAIN PARENCHYMA ANATOMICALLY BASED DIFFERENTIALS