Evaluation of Computed Tomography Scan Ability in Detecting Chest Nodules Using Tissue Equivalent Phantom

Aim of Study: The lung cancer is noted at the end stages of disease, the morbidity and mortality rate related to is higher than others. To minimize this rate, early diagnosis of lung solitary nodules before spreading metastases to lymph nodes and other organs is of consideration. At the moment, Computerized Tomography is one of the most important modalities in diagnosing lung solitary nodules, however the CT exposure rates are much higher than diagnostic radiology field. Therefore it is necessary to do evaluation of CT. Scan ability in detecting chest nodules for preventing unnecessary radiation dose to patient. Materials and Methods: In this study, a chest phantom including different nodules of sizes and types was designed. Imaging of phantom was performed by TOSHIBA spiral CT of Imam Khomaini medical complex and GE spiral CT of Fayyazbakhsh hospital with 5,3,1 mm slices and 80, 120 kVp and 50,60,80,100 mA. Results: This study revealed, 4 mm width nodules were noted both in slices with 120 kV and 50, 100 mA and 3, 5 mm thickness and in 80 kV and 60 mA with 3 mm thickness. The calcium carbonated particles were noted in 6, 8, and 10 mm whitish but not in smaller nodules; however a low density of carbonated calcium was noted just in 10 mm width nodules. Conclusion: CT.scan is a useful technique for detection of lung tumor with sizes more than 4mm.