ABSTRACT
Objective To evaluate the feasibility of chest digital tomosynthesis(DTS)for lung lesion screening by comparing the effective dose of chest DTS with chest digital radiography(DR),low-dose MSCT and MSCT examinations.Methods The Fluke lung/chest phantom underwent posterior-anterior (PA),left lateral(LAT)chest DR and DTS with automatic exposure control technique.Using RTI DoseGuard and WinODS,the dose area product(DAP)and effective dose of PA,LAT and total DTS were calculated.CareDose technique was used for MSCT and low-dose MSCT scans,the dose length products (DLP)was acquired.According to the DLP to E(k)conversion coefficient in ICRP 103,the effective dose of low-dose MSCT and MSCT were calculated.Paired t test was used for comparison of the mean effective dose of DTS,DR and low-dose MSCT.Results The mean effective dose was 0.1 3 mSv for chest DR and 0.11 mSv for DTS examination.The mean effective dose of low-dose MSCT and MSCT scans were 1.13 mSv and 6.38 mSv.The effective dose of chest DTS was comparable to that of chest DR,and was approximately 1/10 and 1/60 times lower than that of low-dose MSCT and MSCT scans.There was no statistical difference between chest DTS and DR(t =3.514,P ＞0.01),and there was a significant difference between chest DTS and low-dose MSCT(t =178.769,P ＜0.01).Conclusion DTS is a new X-ray tomography which has the advantage of low radiation dosage in chest examination for lung lesion screening comparing with low-dose MSCT.
ABSTRACT
Objective To evaluate the digital tomosynthesis in the diagnosis of occult bone fracture. Methods Both DR and DTS were performed in 135 cases with traumatic-induced pain. All the cases were suspected of bone fractures but with no abnormal findings in DR images. Two radiologists reviewed all the images and diagnosed in consensus. All cases were followed up and the imaging diagnoses were reviewed. Results Bone fractures or joint dislocations of 61 cases were shown in DTS images but not in DR images, including atlanto-axial fracture and subluxation in 7 cases, articular fracture of limbs in 20 cases, bone fractures of wrist, hand and foot in 11 cases, fractures of cervical, thoracic and lumbar vertebra in 7 cases, fracture of sacrococcyx in 8 cases, fracture of nasal bone in 4 cases, fractures of Sternum ,rib ,orbit and mandible in 1 case. Thirty-four cases with bone fractures were determined by using DTS in suspected cases and 17 cases were denied. Both DR and DTS images showed normal findings in 23 cases. Imaging diagnoses of all cases were consistent with the results of follow up. Conclusion DTS can depict bone fractures especially in the deep and complex bony structures, which may improve the diagnostic accuracy of bone fracture.