Chiari 2 Malformation
KEY FACTS Terminology • Hindbrain compression with cerebellar herniation through foramen magnum • Open spina bifida present in almost every case Imaging • Posterior fossa compression is key finding ○…
KEY FACTS Terminology • Hindbrain compression with cerebellar herniation through foramen magnum • Open spina bifida present in almost every case Imaging • Posterior fossa compression is key finding ○…
KEY FACTS Imaging • Characterization of plaques ○ Uniformly echolucent or predominantly echolucent; fatty or fibrofatty; ↑ risk of embolization ○ Uniformly/mildly echogenic and predominantly echogenic; fibrous; ↓ risk of…
KEY FACTS Imaging • Congenital diaphragmatic hernias (CDH) are most commonly left sided (80-90% of cases) through posterior foramen of Bochdalek ○ Stomach usually in chest ○ Deviation of heart…
KEY FACTS Terminology • Inflammation of epididymis &/or testis Imaging • Grayscale US ○ Epididymis enlarged and hypoechoic ○ Testes mildly heterogeneous • Color Doppler US ○ Diffuse or focal…
KEY FACTS Terminology • Synonyms: Peritoneal pseudocyst, benign cystic mesothelioma • Not true cyst but peritoneal or ovarian fluid trapped by peritoneal adhesions Imaging • Unilocular or multilocular pelvic cystic…
KEY FACTS Imaging • Thin-walled, distended tube; tube wall < 3 mm • Convoluted or S-shaped, oval or pear-shaped, more dilated at fimbriated end • Separate from uterus and ovaries…
KEY FACTS Imaging • Location: Levels I-VI • Head and neck squamous cell cancers: Most common in upper neck, at level II • Thyroid cancers: Most common at levels VI,…
KEY FACTS Imaging • Ill-defined, hypoechoic tumor diffusely involving entire lobe or gland, often invading adjacent structures • Background of multinodular goiter or differentiated thyroid cancer • Typically > 5…
KEY FACTS Terminology • Mechanisms of injury ○ Overuse: Strenuous exercise results in diffuse muscular edema ○ Stretch: Causes torn muscle fibers + hematoma ○ Direct: Usually blunt trauma causes…
KEY FACTS Imaging • Plaque formation: Proximal vertebral artery (VA) > distal VA • Grayscale imaging ○ Chronic occlusion: Contracted vessel caliber; VA may be hard to demonstrate • Spectral…