Detection of choroidal calcium by computed tomography scan quantitative computerized tomography - A clinically useful diagnostic tool

Objective: Quantitative computerized tomography (QCT), a scanning method ro utinely 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-choroi dal osteoma (CO) and pseudoxanthoma elasticum (PXE) and five normal control subjects were assessed. Intervention: The CT scan of choroid, B-scan ultrasound, fluorescein angiog raphy. 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 bot h eyes of CO, although only one eye had a clinically noted lesion. No contr ol 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 ultrasono graphy and CT scan fine sectioning fail to identify calcium despite high cl inical suspicion.