T-Spine Anatomy and CT Imaging

Flashcards about the T-Spine, its anatomy, relevant injuries, and diseases for CT imaging

What are four distinguishing features of thoracic vertebrae?

Heart-shaped vertebral body, demi- or partial facets (T2-T9) on vertebral bodies, costal facets on transverse processes (T1-T10), long spinous processes that slant inferiorly.

What is unique to the T1 vertebra?

Superior facet is not a demi-facet and articulates with the 1st rib.

What is unique to the T10 vertebra?

A single pair of whole facets are present, that articulate with the 10th rib; located across both vertebral body and pedicle.

What is unique to the T11 and T12 vertebra?

Each have a single pair of entire costal facets, which are located on the pedicles.

What are the two groups which divide T-Spine joints?

Between vertebral bodies and vertebral arches. Unique to the thoracic spine are costovertebral and costotransverse articulations.

What are the key characteristics of thoracic discs?

Thoracic discs are thinner, contributing to less mobility compared to the cervical and lumbar spine. All but the bottom two interface with ribs.

List indications for a CT of the T-Spine

Thoracic or thoracolumbar injury, implants and complications, congenital anomalies, spinal tumors/vertebral metastasis, interventions, degenerative diseases, CT myelography, spinal cord compression.

Describe a CT T-spine scanning protocol example.

Remove metal, head first, supine, arms above head, patient straight. Scout AP and lateral. Scan range as specified. Reconstructions include thin soft tissue and bone axials, soft and bone sagittals and coronals.

How should reformats be aligned for a CT T-spine?

Axials parallel to discs, sagittals parallel to spinal cord, perpendiculars parallel to spinal cord.

What are the window settings for soft tissue and bone in a CT T-spine?

Soft: WW 350-400, WL 40-50; Bone: WW 3000-3500, WL 500.

What types of injuries can be seen on a CT T-spine?

Compression (wedge) fracture, burst fracture, chance fracture, fracture-dislocations, translation-rotation injury, pathological fractures.

Describe a compression fracture of the T-Spine

Axial loading causing a wedge-shaped compression of the vertebral body, often due to falls or MVA (younger) or minor incidents secondary to osteoporosis (older).

Describe a Burst Fracture of the T-Spine

High energy axial loading causing the entire vertebra to be crushed; unstable with retropulsed bone fragments into the spinal canal.

Describe a Chance Fracture of the T-Spine

Flexion-distraction injury with separation of the fractured vertebra, often at the thoracolumbar junction, due to forced flexion anterior to the abdomen (i.e., seatbelt). Associated with intra-abdominal injuries.

Describe Thoracic spine fracture-dislocations.

Severe flexion force or object falling across the back causing unstable vertebral fracture with dislocation of facet joints and/or intervertebral disc space, often with neurological deficits.

Describe Thoracic spine translation-rotation injury

Displacement in the horizontal plane due to torsional and shear forces.

What are Pathological fractures?

Fractures resulting from an underlying disease process, such as osteoporosis, Paget's disease, neoplastic process, or spinal infections.

What is an Osteoblastic Metastatic tumours?

Characterized by deposition of new bone, associated with prostate, breast, carcinoid, lung, GI, bladder, nasopharynx, and pancreas cancers.

What is an Lytic Metastatic tumour?

Characterized by destruction of normal bone, associated with renal, lung, breast, thyroid, melanoma, chordoma, paraganglioma, GI tract, urothelial, ovarian cancers.

Describe Multiple Myeloma and changes seen on CT

Blood cancer that develops from plasma cells in the bone marrow, with purely lytic lesions; can be identified using whole-body low-dose CT.

What features are associated with degenerative thoracic disease that may be seen on CT?

Decreased height of vertebral bodies, disc degeneration, disc protrusion/herniation, spinal canal stenosis, facet joint arthrosis, bone spurs.

Describe Diffuse idiopathic skeletal hyperostosis (DISH) as it relates to the T-Spine

Bony proliferation at tendinous and ligamentous insertion, typically characterized by flowing ossification of the anterior longitudinal ligament; associated with older age, male sex, obesity, hypertension, atherosclerosis, and diabetes mellitus.