Pulmonary nodules: dosimetric and clinical studies at low dose multidetector CT

Purpose. To measure breast radiation dose from multidetector CT using three different low dose protocols and compare it to a standard two view chest examination. To compare the number of pulmonary nodules detected at low and standard dose. Materials and methods. Thermoluminescent dosimetry was used to measure the absorbed dose on a phantom (Rando) and 10 patients. Then, we compared the standard dose to the low dose examinations. The Wilcoxon rank test and the kappa test were used to assess differences in the detection of nodules. Results. The absorbed dose of these low dose protocols correspond to the radiation dose for the acquisition of two to ten chest radiographs (two views). This study suggests that only the 30 mA protocol is sufficient for the detection of all pulmonary nodules; nodules smaller than 5 mm were overlooked at 10 mA. Conclusion. A good image quality can be obtained with low dose protocols at multidetector CT (correspond to 2 to 10 chest radiographs).