Table 2.

Strength and weaknesses of spinal imaging techniques in patients with AS

Imaging technique	Strengths	Weaknesses
Conventional radiography [3, 57]	Relatively less expensive and widely available Relatively rapid review	Unable to visualize the thoracic spine reliably Radiation exposure Long duration (≥2 years) required to detect structural progression, precluding placebo-controlled trials
MRI [3, 57]	Detects inflammatory changes in bone and soft tissue Does not use radiation Tomographic method Allows visualization of the thoracic spine	Long acquisition time Scoring of MR images can be time-consuming More expensive and less widely available than conventional radiography Value in detecting new bone formation is limited
CT [3, 57]	Rapid technique Tomographic method Excellent visualization of bone Allows visualization of thoracic spine Sensitive method for detection of new bone formation	Use of ionizing radiation More expensive and less widely available than conventional radiography