Vertebral fracture assessment: between experts and young physicians

Purpose: The aim of our study was to determine the diagnostic accuracy of new dual-energy x-ray absorptiometry technologies in the detection of vertebral fractures and to analyse intra- and inter-observer variability and time consumption of densitometric methods (MXA) compared with radiographic ones (MRX) in two groups of readers: experts and residents. Methods and Materials: Forty-five patients were submitted to both MRX and MXA (Lunar-iDXATM, GE-Healthcare, USA) on the same day. Lateral images of the spine were independently evaluated by 3 expert radiologists (group-1) and by 3 radiology residents (group-2) in two sessions with 7 days between evaluations of the same anonymous images. “True” fractures were defined by an independent expert radiologist on MRX evaluation. Cohen test was used to analyse interpretation agreement. Results: Forty-eight “true” fractures were detected (48/585 vertebrae, 8.2% - 28 mild, 16 moderate, 4 severe) in 45 analysed patients (61.2±11.1years, BMI=25.3±3.0Kg/m2). MXA accuracy was 97 % and 80 % on a lesion-based and patient-based analysis, respectively. Inter-observer agreement on presence/absence of vertebral fracture (lesion-based) was 67 % for MXA versus 65 % for MRX in group-1, 65 % versus 58 % in group-2. The average intra-observer agreement in the two groups was equally 98 % for both methods. The mean time spent for a single examination was 1.35 (min.sec) for MXA versus 2.10 for MRX in group-1 and 2.11 for MXA versus 3.36 for MRX in group-2. Conclusions: Nowadays technical improvements make MXA comparable with traditional radiographic gold standard, providing consistent advantages and attractions even for less-experienced physicians.