Detection of choroidal calcium by computed tomography scan quantitative computerized tomography: a clinically useful diagnostic tool.

Objective: Quantitative computerized tomography (QCT), a scanning method routinely used to classify tissues based on their radio density, was used to detect choroidal calcification.

Design: Case reports.

Participants: Two patients with known or suspected choroidal calcium-choroidal osteoma (CO) and pseudoxanthoma elasticum (PXE) and five normal control subjects were assessed.

Intervention: The CT scan of choroid, B-scan ultrasound, fluorescein angiography.

Main Outcome Measures: The QCT scan used to detect the presence of calcium based on a readout greater than 90.

Results: Calcium was detected bilaterally, as predicted, in PXE, and in both eyes of CO, although only one eye had a clinically noted lesion. No control eye gave a scale readout consistent with calcium. No findings suggestive of calcium were noted with B-scan ultrasound or fluorescein angiography in PXE or CO.

Conclusion: The QCT can detect calcium in the choroid when B-scan ultrasonography and CT scan fine sectioning fail to identify calcium despite high clinical suspicion.