Imaging characteristics and CT sensitivity for pyogenic spinal infections

Area of Science:

• Radiology
• Infectious Diseases
• Emergency Medicine

Background:

• Contrast-enhanced MRI is the gold standard for diagnosing pyogenic spinal infections (PSI).
• MRI may not always be accessible in community emergency departments.
• This study evaluates PSI imaging characteristics on CT in an emergency department setting.

Purpose of the Study:

• To describe imaging characteristics of pyogenic spinal infections (PSI) in patients presenting to an emergency department.
• To estimate the sensitivity of computed tomography (CT) for diagnosing various types of PSI.

Main Methods:

• Retrospective analysis of MRI reports from 88 PSI patients.
• Prevalence of PSI types (SEA, VO/D, SF, PVA) reported.
• Post hoc blinded CT overread in a 14-patient subcohort to determine CT sensitivity for PSI.

Main Results:

• Common PSI types include spinal epidural abscess (SEA) (69%), vertebral osteomyelitis/discitis (VO/D) (61%), and paravertebral abscess (PVA) (60%).
• SEA frequently co-occurred with VO/D, SF, and PVA.
• Overall CT sensitivity was 79% for any PSI, 83% for infections outside the spinal canal, and only 18% for SEA.

Conclusions:

• CT has moderate sensitivity for diagnosing infections outside the spinal canal.
• CT has low sensitivity for detecting spinal epidural abscess (SEA).
• SEA is often a coinfection and may be missed by CT, highlighting the need for careful interpretation or alternative imaging.