This App presents normal imaging variations of the brain, skull, and craniocervical vasculature. Magnetic resonance (MR) imaging and computed tomography (CT) have advanced dramatically in the past 10 years, particularly in regard to new techniques and 3D imaging. One of the major problems experienced by radiologists and clinicians is the interpretation of normal variants as compared with the abnormalities that the variants mimic. Through an extensive collection of images, this app offers a spectrum of appearances for each variant with accompanying 3D imaging for confirmation; explores common artifacts on MR and CT that simulate disease; discusses each variant in terms of the relevant anatomy; and presents comparison cases for the purpose of distinguishing normal findings from abnormalities. It includes both common variants as well as newly identified variants that are visualized by recently developed techniques such as diffusion-weighted imaging and multidetector/multislice CT. The app also highlights normal imaging variants in pediatric cases.


Atlas of Normal Imaging Variations of the Brain, Skull, and Craniocervical



Brain
Front Matter

Brain: Introduction

Cerebellar Tonsillar Ectopia

Cerebellar Flocculus Pseudomass

Mega Cisterna Magna and Retrocerebellar Arachnoid Cysts

Cranial Nerve VII: Normal Contrast Enhancement on Magnetic Resonance Imaging

Meckel Cave Prominence, Asymmetry, and Petrous Apex Cephaloceles

Cavernous Sinus Fat and Pseudomasses

Pituitary Variations, Artifacts, Primary Empty Sella, and Incidentalomas

Liliequist Membrane

Pineal Gland: Normal Size, Appearance, and Enhancement

Choroid Plexus: Normal Locations and Appearances

Hippocampi, Caudate Tail, and Ependymal Variants

Midline Variants of the Septum Pellucidum, Corpus Callosum, and Massa Intermedia

Dilated Perivascular Spaces

Enlargement or Asymmetry of the Lateral Ventricles Simulating Hydrocephalus

Cerebral or Cerebellar Volume Loss Simulating Subdural Hematomas, Hygromas, and Arachnoid Cysts

Dural Calcifications: Normal Locations and Appearances

Pseudo-leptomeningeal Contrast Enhancement

Basal Ganglia: Physiologic Calcifications

Susceptibility-Weighted Imaging: Concepts, Basal Ganglia Variation in Age-Related Iron Deposition, and Artifacts

Slow-Flow, Asymptomatic Vascular Malformations: Brain Capillary Telangiectasias and Developmental Venous Anomalies

Brain MRI Pseudolesions: 3.0 T Imaging, FLAIR, and Diffusion-Weighted Imaging

Pediatric Brain: Normal Variations in Development, Maturation, and Myelination

Skull
Front Matter

Skull: Introduction

Pediatric Skull: Normal Pediatric Sutures on Computed Tomography

Skull Base Foramina: Normal Variations and Developmental Defects

Normal Variations and Developmental Anatomy of the Calvarial Sutures and Fontanelles Above the Skull Base

Emissary Veins, Vascular-Containing Foramina, and Vascular Depressions of the Skull

Normal Variations in Calvarial Contour, Irregular Ossification/Aeration, and Inward/Outward Projections/Protuberances

Other “Don’t Touch” Skull Lesions: Arachnoid Granulations, Calvarial Depressions, Hemangiomas, and Intraosseous Lipomas

Craniocervical Vasculature

Craniocervical Vasculature: Introduction

Aortic Arch and Great Vessel Origin Arterial Variants

Cervical Carotid and Vertebral Arterial Variants

Tortuous Cervical and Intracranial Arteries and Basilar-Carotid Dolichoectasia

Miscellaneous Cervical Venous Variants

Intracranial Posterior Circulation Variants

Intracranial Anterior Circulation Variants

Infundibular Outpouchings of Intracranial Arteries

Persistent Carotid-Basilar and Carotid-Vertebral Anastomoses

Variations in the Intracranial Venous System

Arachnoid Granulations Within the Dural Sinuses

Artifacts of the Craniocervical Venous System on MRI

Artifacts of the Craniocervical Arterial System on MRI

Artifacts on Craniocervical CT Angiography

Dense Vessels Simulating Thrombosis on Non enhanced CT