(BQ) Part 2 book "Diagnostic imaging spine" presentation of content: Infections, inflammatory and autoimmune disorders, neoplasms, nonneoplastic cysts and tumor mimics, vascular and systemic disorders, plexus and peripheral nerve lesions, spine postprocedural imaging,.and other contents. | PART IV SECTION 1 Infections Pathways of Spread 564 Spinal Meningitis 568 Pyogenic Osteomyelitis 572 Tuberculous Osteomyelitis 578 Fungal and Miscellaneous Osteomyelitis 584 Osteomyelitis, C1-C2 586 Brucellar Spondylitis 590 Septic Facet Joint Arthritis 592 Paraspinal Abscess 598 Epidural Abscess 602 Subdural Abscess 608 Abscess, Spinal Cord 612 Viral Myelitis 616 HIV Myelitis 620 Syphilitic Myelitis 624 Opportunistic Infections 626 Echinococcosis 630 Schistosomiasis 634 Cysticercosis 638 Infection and Inflammatory Disorders: Infections Pathways of Spread Anatomy-Based Imaging Issues Spread of infection may occur along one of many different tracts, including direct extension, lymphatic spread, hematogenous spread, and along the cerebrospinal fluid pathways. Direct extension, as its name implies, occurs when bone or soft tissue comes into contact with a directly adjacent infection leading to a soft tissue abscess or osteomyelitis. For the spine, this route is typically seen adjacent to a decubitus ulcer where there is adjacent osteomyelitis. An infection of the disc space can extend into the adjacent paravertebral soft tissues and produce psoas muscle abscesses. Direct extension is also the mechanism for epidural abscess involvement cranial or caudal to the site of disc space infection. This route can also be seen for an intramedullary spinal cord abscess where the infection occurs through congenital dysraphism or a dermal sinus tract. Lymphatic spread is of limited importance in the spine relative to the much more commonly seen direct extension and hematogenous spread. Lymphatic spread may be seen in cases of retroperitoneal node enlargement from pelvic or abdominal primary neoplasms. Hematogenous Spread Hematogenous spread is the major pathway of infection spread to the axial skeleton. Which route is more important (arterial or venous) is controversial. The arterial route is classically more important for spread of spinal
