A Framework for Anemia Differential Diagnosis in Paleopathology Incorporating Metric Methods

OBJECTIVES: This paper explores metric manifestations of anemia in crania undergoing growth and development using micro-CT imaging. It proposes a framework for assigning a most-likely diagnostic option for anemia, based on evaluating the parameters proposed in this study. MATERIALS AND METHODS: Sixty-eight orbits/frontal bones of individuals aged birth to 15 years from Quebecois and Dutch archaeological collections dating to the 18th and 19th centuries underwent micro-CT analysis. Individuals were visually assessed for skeletal manifestations of marrow hyperplasia within the internal marrow space using a scoring rubric. Bone microarchitecture measurements were used to calculate T-scores and identify individuals who displayed potential manifestations of marrow hyperplasia. Relative cortical thickness ratios of the frontal bone were calculated for 16 individuals. Error testing was performed for all evaluations. RESULTS: Using the micro-CT analysis and our diagnostic framework, anemia was inferred in 16% (10/61) of the sample that was preserved well enough for the study. Trabecular separation T-scores were considered the most significant metric for evaluating anemia. Frontal bone ratios were regarded as less insightful due to the imaging technique used. Age had a significant effect on bone measurements, and high repeatability was seen across methods. DISCUSSION: In this study, recommendations for assigning a diagnostic option prioritize evaluating metric features strongly related to anemia through a biological approach that considers the etiology of marrow hyperplasia. Including a combination of metric and internal visual evaluation criteria provides clearer lines of evidence for the assessment of abnormal bone changes associated with anemia beyond the macroscopic evaluation of porous lesions.