Semi-quantitative grading and extended semi-quantitative grading for osteoporotic vertebral deformity: a radiographic image database for education and calibration

The Genant's semi- quantitative (GSQ) criteria is currently the most used approach in epidemiology studies and clinical trials for osteoporotic vertebral deformity (OVD) evaluation with radiograph. The qualitative diagnosis with radiological knowledge helps to minimize false positive readings. However, unless there is a face-to-face training with experienced readers, it can be difficult to apply GSQ criteria by only reading the text description of Genant et al. (in 1993), even for a musculoskeletal radiologist. We propose an expanded semi-quantitative (eSQ) OVD classification with the following features: (I) GSQ grade-0.5 is noted as minimal grade (eSQ grade-1) for OVDs with height loss <20%; (II) GSQ mild grade (grade-1) is the same as eSQ mild grade (grade-2); (III) GSQ moderate grade (grade-2) is subdivided into eSQ grade-3 (moderate, >25%-1/3 height loss) and eSQ grade-4 (moderately-severe, >1/3-40% height loss); (IV) GSQ severe grade is subdivided into eSQ grade-5 (severe, >40%-2/3 height loss) and eSQ grade-6 (collapsed, with >2/3 height loss). We advocate to estimate vertebral height loss with adjacent vertebral heights as the reference (rather than using individual vertebra's posterior height as the reference). This article presents radiographs of 36 cases with OVD, together with gradings using GSQ criteria and eSQ criteria. The examples in this article can serve as teaching material or calibration database for readers who will use GSQ criteria or eSQ criteria. Our approach for quantitative measurement is explained graphically.