Radiology Key

  CHOANAL NARROWING   KEY FACTS    Can be of two types: stenosis and atresia (note: severe stenosis behaves clinically like atresia), further subdivided into bony or soft tissue (plugs); for…

  MENINGIOMA   KEY FACTS     Most common extra-axial adult tumor; most common intracranial tumors (15% to 20%) in adults.     Occurs mainly in middle-aged women (possibly because of increased sensitivity…

  TEMPORAL BONE FRACTURES   KEY FACTS   Longitudinal type     Most common (70% to 80%) type of temporal bone fractures; results from blows to the temporoparietal region.     Results in…

  NEUROFIBROMATOSIS TYPE 1, ASTROCYTOMAS AND NEUROFIBROMAS   KEY FACTS     Autosomal dominant (chromosome 17) or sporadic (50%) disorder, ten times more common than NF-2; prominent cutaneous lesions, plexiform neurofibromas, and…

  OCCIPITOATLANTO SEPARATION   KEYFACTS     Commonly a fatal injury caused by rupture of craniocervical ligaments (tectorial membrane, cruciate, apical, and alar ligaments) due to rapid deceleration with hyperflexion or hyperextension…

  SKULL FRACTURES   KEY FACTS     Linear fractures or sutural diastases with no underlying brain injury are generally not clinically significant; formation of leptomeningeal cysts and/or herniated brain (“growing fracture”)…

  ANTERIOR COMMUNICATING (ACOMM) ARTERY ANEURYSMS   KEY FACTS     Represent 30% to 35% of intracranial aneurysms.     Overall incidence of intracranial aneurysms is 2% to 8% of population; risk of…

  ARTERIOVENOUS MALFORMATIONS   KEY FACTS     Congenital in nature, generally present in middle age (65% in patients >40 years of age).     Very rare, incidence of 1:100,000 individuals. Arteriovenous malformations…

  ANKYLOSING SPONDYLITIS (SERONEGATIVE SPONDYLOARTHROPATHY)   KEYFACTS    This disease occurs predominantly in young men and is associated with histocompatibility antigen B27.    Ankylosing spondylitis is found in 1.4% of the…

  TRAUMA: AVULSION AND STRETCH INJURIES   KEY FACTS    Nerve root avulsions are generally caused by traction injuries of the extremities (in the lower cervical spine, they are related to…