Imaging Strategy for Preoperative Planning in Orthopedic Spinal Surgery

Primary Imaging Modalities

MRI without contrast is the initial imaging modality of choice for patients being evaluated for spinal surgery, providing essential soft‑tissue detail and delineating disc degeneration, thecal sac, neural structures, and compressive pathology. American College of Radiology recommendation. 1
In candidates for lumbar spine surgery, MRI identifies actionable pain generators that can be directly targeted during operative intervention. American College of Radiology. 2
For thoracic spine surgery, non‑contrast MRI evaluates compressive etiologies affecting the spinal cord (myelopathy) or nerve roots (radiculopathy). American College of Radiology. 4
Many MRI abnormalities are also present in asymptomatic individuals; therefore imaging findings must be correlated with the patient’s clinical presentation. American College of Radiology. 1

Upright radiographs supply functional information about axial loading that cannot be captured by MRI, essential for assessing spinal alignment under weight‑bearing conditions. American College of Radiology. 2
Flexion and extension radiographs are required to identify segmental motion and instability, a critical factor in the surgical management of spondylolisthesis. American College of Radiology. 3
Lateral bending views aid in planning deformity‑correction surgery by revealing coronal plane flexibility. American College of Radiology. 3
In pediatric scoliosis, postero‑anterior (PA) radiographs are preferred over anteroposterior (AP) views to reduce breast radiation exposure. American College of Radiology. 6
Post‑operative radiographs are used to assess hardware position, integrity, fusion status, and overall spinal alignment. American College of Radiology. 8

CT delineates osseous margins and supports trajectory planning for pedicle screws and other fixation hardware. American College of Radiology. 1
CT evaluation of facet joints and neural foramina is comparable to MRI for predicting clinically significant spinal stenosis. American College of Radiology. 2
For pediatric scoliosis, multiplanar and three‑dimensional CT reconstructions facilitate presurgical planning and can be integrated with navigation systems. American College of Radiology. 7
CT is especially valuable when metallic instrumentation creates substantial MRI artifact, allowing clear visualization of bony anatomy. American College of Radiology. 2

CT myelography is indicated when MRI is contraindicated (e.g., non‑MRI‑compatible implants) or when metallic artifact severely degrades MRI quality. American College of Radiology. 3
It provides detailed assessment of spinal canal and thecal sac patency, subarticular recesses, and neural foramina. American College of Radiology. 2
The technique requires lumbar puncture for intrathecal contrast administration, representing a major procedural disadvantage. American College of Radiology. 2
CT myelography may be appropriate for thoracic spine surgery when a compressive etiology is suspected. American College of Radiology. 5

Routine preoperative planning does not require contrast‑enhanced MRI; it should be reserved for specific clinical scenarios. American College of Radiology. 6
Indications for contrast MRI include suspected neoplasm, infection, postoperative complications (e.g., hematoma, abscess, fluid collections), or acute canal compromise. American College of Radiology. 8
In congenital scoliosis, preoperative MRI can detect neural‑axis anomalies (e.g., syringomyelia, Chiari malformation, tethered cord) present in more than 20 % of patients. American College of Radiology. 6

SPECT/CT has a limited role but may help identify pain generators related to facet arthropathy or sacroiliac joint dysfunction. American College of Radiology. 1
SPECT bone scan is the reference standard for detecting radiographically occult active spondylolysis in adolescents and young adults. American College of Radiology. 3
In pediatric painful scoliosis, bone scintigraphy is sensitive for primary bone tumors (e.g., osteoid osteoma, osteoblastoma), occult spondylolysis, and infection. American College of Radiology. 7

Patients with suspected osteoporosis should undergo pre‑operative bone‑density evaluation using DEXA, CT Hounsfield‑unit measurement, or serum vitamin D 3 level assessment. Neurosurgical community. 11
A DEXA T‑score < ‑2.5, CT Hounsfield units < 97.9, or vitamin D 3 < 20 ng/mL are predictive of increased risk for postoperative adverse events after spinal instrumentation. Neurosurgical community. 11
Confirmed osteoporosis warrants counseling regarding heightened risk of pseudarthrosis, instrumentation failure, and proximal junctional failure. Neurosurgical community. 11

Do not rely on radiography alone for surgical planning; MRI and/or CT are required for comprehensive assessment. American College of Radiology. 1
Do not obtain routine contrast‑enhanced MRI; reserve it for infection, tumor, or postoperative complication work‑up. American College of Radiology. 6
Do not omit flexion/extension radiographs, as they reveal segmental instability not seen on static images. American College of Radiology. 3
Do not assume all MRI abnormalities are clinically significant; correlation with patient symptoms is essential. American College of Radiology. 2
For pediatric imaging, use PA projection and low‑dose protocols to minimize radiation exposure. American College of Radiology. 7