Precise differential diagnosis of acute bone marrow edema and hemorrhage and trabecular microfractures using naïve and gamma correction pinhole bone scans.

Objective To analyze the performance of sequential naive pinhole bone scan (nPBS) and gamma correction pinhole bone scan (GCPBS), reinforced by ImageJ densitometry and pixelized microfracture measurement, for making specific diagnoses of bone marrow edema (BME), bone marrow hemorrhage (BMH), and trabecular microfractures (TMF). Methods We prospectively examined BME, BMH, TMF, and normal trabeculae in 10 patients using sequential nPBS and GCPBS. The intensity of (99m)technetium-hydroxydiphosphonate (Tc-99m-HDP) uptake was measured using a pixelized method and calculated using ImageJ densitometry in terms of arbitrary units (AU). This overall method was termed a visuospatial-mathematic assay (VSMA). We analyzed the ability of the calculated AU values to discriminate between the four states using GraphPad Prism software, with reference to previous morphological data. Results The calculated values were categorized as <= 50 AU for normal trabecula, 51-100 AU for BME, 101-150 AU for BMH, and >= 151 AU for TMF. The difference in uptake between normal trabecula and BME was significant and the differences among BME, BMH, and TMF were highly significant. Conclusion VSMA is a useful technique for refining objective individual diagnoses and for differentiating and quantitating BME, BMH, and TMF.