Neurologic and Musculoskeletal Imaging Studies دکترامیر هوشنگ واحدی متخصص طب فیزیکی و توانبخشی قسمت 1

IMAGING MODALITIES  Plain radiography and its variants (stress radiography, arthrography, myelography, diskography, fluoroscopy, and videofluoroscopy)  Computed tomography  CT myelography and postdiskography CT  CT with contrast agent enhancement  Magnetic resonance imaging  Nuclear medicine studies  Ultrasound

Imaging options  Radiography  CT Better for fine bone detail, arthritis As good as MRI for acute disc disease  MRI Very good for disc, Para spinal pathology, stenosis Infection Marrow disorders Contrast for infection, post-op, tumor  Bone scan Not for primary imaging in most cases

Plain radiography  Five different types of tissues can be imaged with plain radiography: gas, fat, soft tissue and water, bone, and metal (metals, barium, and iodinated contrast material).

 Inexpensive way to assess fractures or bony abnormalities  At least 2 orthogonal views perpendicular to each other are necessary

Plain radiography 1.stress radiography 2. arthrography 3. myelography 4. diskography 5. Tenography 6. videofluoroscopy 7.fluoroscopy

 advantages of myelography over MRI Myelography and postmyelography computed tomography (CT) : 1.better show bony detail and subtle impressions on the nerve roots. 2. Myelography also allows imaging of the lumbar spine in the upright weight- bearing position as well as in flexion and extension.

Plain radiography artifacts  a common artifact is the Mach line, which occurs when a bony edge overlaps another bone. A thin dark line appears just adjacent to the overlapping bone and can be mistaken for a fracture  Mach line simulating a dens fracture. (a) but this parallels the undersurface of the C1 ring and mastoid bones as well as extending past the margins of the dens. (b) Repeat extension lateral view of the same patient demonstrates no fracture line at the same site, and there is a fainter Mach line( arrows). Figure