Is peripheral cortication of intraosseous lesions accurately displayed on panoramic radiography?

The aim of this study was to calculate the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for the detection of the presence and continuity of peripheral cortication (PC) around benign intraosseous lesions on panoramic radiography (PR), with cone beam computed tomography (CBCT) as the reference standard.

The sample consisted of the mesial, distal, superior, and inferior borders of 40 bony lesions (n = 160) depicted on both PR and CBCT. Ten observers assessed the PRs. CBCT images were assessed by 2 radiologists. For each lesion, observers classified the 4 borders with regard to the presence of PC, and if present, its continuity. Sensitivity, specificity, PPV, and NPV were calculated for the presence and continuity of PC. Intra- and interobserver agreements were calculated.

PR had sensitivity, specificity, PPV, and NPV for PC detection of 0.844, 0.435, 0.435, and 0.844, respectively. With regard to PC continuity, those values were 0.750, 0.810, 0.577, and 0.904. Observer agreement was slight to fair.

The high sensitivity and low specificity for the presence of PC indicate a large false-positive rate. The high NPVs suggest greater validity for negative decisions. The findings corroborate the influence of the eggshell effect. Observer agreement rates indicate that interpretation of PC is substantially subjective.