Reliability of vertebral fracture assessment using multidetector CT lateral scout views: the Framingham Osteoporosis Study.

UNLABELLED: Two radiologists evaluated images of the spine from computed tomography (CT) scans on two occasions to diagnose vertebral fracture in 100 individuals. Agreement was fair to good for mild fractures, and agreement was good to excellent for more severe fractures. CT scout views are useful to assess vertebral fracture.

INTRODUCTION: We investigated inter-reader agreement between two radiologists and intra-reader agreement between duplicate readings for each radiologist, in assessment of vertebral fracture using a semi-quantitative method from lateral scout views obtained by CT.

METHODS: Participants included 50 women and 50 men (age 50-87 years, mean 70 years) in the Framingham Study. T4-L4 vertebrae were assessed independently by two radiologists on two occasions using a semi-quantitative scale as normal, mild, moderate, or severe fracture.

RESULTS: Vertebra-specific prevalence of grade ≥ 1 (mild) fracture ranged from 3% to 5%. We found fair (κ = 56-59%) inter-reader agreement for grade ≥ 1 vertebral fractures and good (κ = 68-72%) inter-reader agreement for grade ≥ 2 fractures. Intra-reader agreement for grade ≥ 1 vertebral fracture was fair (κ = 55%) for one reader and excellent for another reader (κ = 77%), whereas intra-reader agreement for grade ≥ 2 vertebral fracture was excellent for both readers (κ = 76% and 98%). Thoracic vertebrae were more difficult to evaluate than the lumbar region, and agreement was lowest (inter-reader κ = 43%) for fracture at the upper (T4-T9) thoracic levels and highest (inter-reader κ = 76-78%) for the lumbar spine (L1-L4).

CONCLUSIONS: Based on a semi-quantitative method to classify vertebral fractures using CT scout views, agreement within and between readers was fair to good, with the greatest source of variation occurring for fractures of mild severity and for the upper thoracic region. Agreement was good to excellent for fractures of at least moderate severity. Lateral CT scout views can be useful in clinical research settings to assess vertebral fracture.