lung nodules are reliably detectable on ultralowdose ct utilising modelbased iterative reconstruction with radiation equivalent to plain radiography aim to determine if ultralowdose uld computed tomography ct utilising modelbased iterative reconstruction mbir with radiation equivalent to plain radiography allows the detection of lung nodulesmaterials and methods ninetynine individuals undergoing surveillance of solid pulmonary nodules undertook a lowdose ld and uld ct during the same sitting image pairs were read blinded in random order and independently by two experienced thoracic radiologists with ldct as the reference standard the number size and location of nodules was compared and interrater agreement was establishedresults there was very good interrater agreement with regards nodules 4mm for both the ld k0931 and uldct k0869 one hundred and ninetynine nodules were reported on the ldct by both radiologists and 196 reported on the uldct with no nodules reported only on the uldct this gives a sensitivity of 985 and specificity of 100 for uldct with mbir the effective dose of radiation was significantly different between the two scans p00001 167 msv for the ldct and 013 msv for the uldctconclusion uldct utilising mbir and delivering radiation equivalent to plain radiography allows detection of lung nodules with high sensitivity the attendant 10fold reduction in radiation may allow for dramatic reductions in cumulative radiation exposure