Radiology Key

Epidermoid Cyst KEY FACTS Terminology • Slow-growing subdermal cyst that contains keratin and is lined by stratified squamous epithelium  Cyst wall must not contain dermal elements Imaging • US appearances depend on…

Developmental Hip Dysplasia KEY FACTS Imaging • Shallow acetabulum ± subluxation of femoral head • US useful before 6 months of age • Normal hip  Capsular laxity: > 50% bony coverage femoral head…

Tarsus TERMINOLOGY Definitions • 3 major divisions  Hindfoot : Calcaneus and talus  Midfoot : Navicular, cuneiforms, and cuboid  Forefoot : Metatarsals and phalanges • 2 columns  Medial column : Talus, navicular, cuneiforms…

Hemarthrosis and Lipohemarthrosis KEY FACTS Terminology • Hemarthrosis: Blood in joint cavity • Lipohemarthrosis: Blood and fat in joint cavity Imaging • Layered joint effusion • Hemarthrosis initially seen as finely speckled echogenic joint…

Peritendinous Mass DIFFERENTIAL DIAGNOSIS Common • Ganglion Cyst • Giant Cell Tumor of Tendon Sheath • Tenosynovitis • Annular Pulley Thickening • Gouty Tophus Less Common • Nerve Sheath Tumor • Extensor Retinaculum Thickening • Bursitis • Synovial Sarcoma…

Tendon Hyperechogenicity DIFFERENTIAL DIAGNOSIS Common • Calcific Tendinitis • Calcification Within Tendinosis • Gout Less Common • Tendon Tear • Avulsion Injury of Tendon • Accessory Ossicle • Suture Material Within Tendon • Foreign Body Within Tendon ESSENTIAL…

Knee TERMINOLOGY Abbreviations • Origin (O), insertion (I), function (F) GROSS ANATOMY Overview • Largest and most complex joint  Hinge joint throughout its main range of motion  Stability is maintained by ligaments,…

Calcified Soft Tissue Mass DIFFERENTIAL DIAGNOSIS Common • Granuloma • Venous Vascular Malformation • Gout or Pseudogout Less Common • Fat Necrosis • Panniculitis • Pilomatricoma • Sarcoma • Soft Tissue Metastases • Nerve Sheath Tumor • Fibroma • Soft Tissue…

Gluteal Muscles TERMINOLOGY Abbreviations • Anterior superior iliac spine (ASIS) IMAGING ANATOMY Gluteal Muscles • Components: Gluteus maximus, gluteus medius, gluteus minimus, tensor fascia lata, piriformis, superior and inferior gemellus, obturator internus…

Ankle TERMINOLOGY Abbreviations • Artery (a.) • Ligament (l.) • Muscle (m.) • Tendon (t.) • Vein (v.) GROSS ANATOMY Osseous Anatomy • Ankle (talocrural) joint  Tibia, fibula, and talus form synovial joint  Supported by lateral…