| 1. ObjectiveThe radiation dose of chest imaging examination has attracted more and more attention. Patients and healthy physical examinees benefit from X-ray test as well as suffer its damage. So it is becoming research focus that how to obtain enough imaging information for diagnosis under a reasonably low dose. The digital tomosynthesis (DTS) is a new tomography method and it evolved from the conventional tomography. It is usually used in chest examine to overcome the influence of overlap of tissues. In this study we will evaluate the chest digital tomosynthesis (DTS) for lung lesion screening by comparing the effective dose of chest digital tomosynthesis (DTS) with chest digital X-ray radiography(posterior anterior position, left lateral position), low-dose MSCT and standard-dose MSCT examinations.2. Materials and MethodsThe Fluke lung/chest phantom underwent posterior anterior (PA), left lateral (LAT) chest digital X-ray radiography and digital tomosynthesis with automatic exposure control technique. Using RTI DoseGuard and WinODS, the dose area product (DAP) and effective dose (ED) of posterior anterior position, left lateral position chest digital X-ray radiography and total digital tomosynthesis were acquired. CareDose technique was required for standard-dose MSCT and low-dose MSCT scan, the dose length products (DLP) were acquired. According to the dose length products (DLP) to effective dose (k) conversion coefficient based on ICRP103, the effective dose of low-dose MSCT and standard-dose MSCT were acquired. Paired t test was used for the mean effective dose of digital tomosynthesis (DTS), chest digital X-ray radiography(P-A, left Lateral) and low-dose MSCT.3. ResultsThe mean effective dose was determined to be0.13mSv for the chest digital X-ray radiography(posterior anterior position, left lateral position) and0.11mSv for the digital tomosynthesis (DTS) examination, respectively. The mean effective dose of low-dose MSCT and standard-dose MSCT scans were determined to be1.13mSv and6.38mSv. The effective dose of chest digital tomosynthesis (DTS) was comparable to that of chest digital X-ray radiography(posterior anterior position, left lateral), and was approximately1/10and1/60times lower than that of low-dose MSCT and standard-dose MSCT scan. There was no statistical difference between chest digital tomosynthesis (DTS) and chest digital X-ray radiography(P-A, left Lateral)(t=3.514, P=0.025), and significant difference between chest digital tomosynthesis (DTS) and low-dose MSCT(t=178.769, P=0.000).4. ConclusionDigital tomosynthesis is a quick low-dose tomography method, and it can obtain the volume X-ray data during one continuous procedure. After reconstruction, it can obtain high resolution sectional images which overcome the influence of overlap of tissues. And comparing with low-dose MSCT, Digital tomosynthesis is a new X-ray tomography which has the advantage of low radiation dosage in chest examination for lung lesion screening. 1. ObjectiveDigital Tomosynthesis (DTS) is a new X-ray imaging technology developed from the traditional tomography along with the born of the big flat panel detectors and the development computer technology in recent years. High sectional quality coronary images parallel to the detector can be reconstructed using the3D volume data, which can be obtained by one breath-holding exposure. This technique used to the chest imaging to improve the sensitivity in detecting the pulmonary nodules, by decreasing the effect of tissue overlap on the emission direction of X-ray exposure. In his study, we will discuss the application value of digital tomosynthesis(DTS) for detection of pulmonary nodules, by comparing the sensitivity of digital tomosynthesis(DTS) for pulmonary nodules detecting with posterior anterior position chest digital X-ray radiography.2. Methods43cases with non-calcified pulmonary nodules confirmed by conventional MSCT underwent posterior-anterior digital X-ray radiography and digital tomosynthesis (DTS).43normal cases were considered as contrast group, who without nodules confirmed by conventional MSCT. MSCT served as reference method.4observers marked suspected pulmonary nodules by using a5-point rating scale for the confidence of presence.1score:definitely exist,2score:possible exist,3score:uncertain,4score:may not exist,5score: definitely does not exist. The results were statistically analyzed with ROC curve. The consistency of4radiologists was analyzed using Kappa. 3. ResultsFor the detection of pulmonary nodules, the area under ROC curve in posterior-anterior chest digital X-ray radiography group and in digital tomosynthesis (DTS) group was0.763±0.247(0.755,0.768,0.735,0.794) and0.941±0.209(0.946,0.910,0.951,0.956).4ROC curves analysis showed the pulmonary nodules detection capability of digital tomosynthesis (DTS) was significantly higher than chest digital X-ray radiography. The difference between the Az valves in the two group was significant (t=10.954, P=0.02, P<0.05). The measure of diagnosis agreement Kappa confirmed the agreement of4radiologists in detection of pulmonary nodules (Kappa>0.75).4. ConclusionsThe performance of digital tomosynthesis (DTS) is better than that of posterior-anterior chest digital X-ray radiography in the detection of pulmonary nodules. It can improve the sensitivity in detecting the pulmonary nodules, by decreasing the effect of tissue overlap on the emission direction of X-ray exposure. Digital tomosynthesis (DTS) may play an important role for the detection of pulmonary nodules. ObjectiveTo evaluate the chest digital tomosynthesis for lung lesion screening by comparing the effective dose of chest digital tomosynthesis with chest digital X-ray radiography, low-dose MSCT and conventional-dose MSCT examinations.Materials and MethodsThe Fluke lung/chest phantom underwent posterior anterior, left lateral chest digital X-ray radiography and digital tomosynthesis with automatic exposure control technique. Using RTI DoseGuard and WinODS, the dose area product (DAP) and effective dose of posterior anterior, left lateral and total digital tomosynthesis were acquired. CareDose technique was required for conventional-dose MSCT and low-dose MSCT scans, the dose length products (DLP) were acquired. According to the DLP to E (k) conversion coefficient based on ICRP103, the effective dose of low-dose MSCT and conventional-dose MSCT were acquired. Paired t test was used for the mean effective dose of digital tomosynthesis, digital X-ray radiography and low-dose MSCT.ResultsThe mean effective dose was determined to be0.13mSv for the chest digital X-ray radiography and0.11mSv for the digital tomosynthesis examination, respectively. The mean effective dose of low-dose MSCT and conventional-dose MSCT scans were determined to be1.13and6.38mSv. The effective dose of chest digital tomosynthesis was comparable to that of chest digital X-ray radiography, and was approximately1/10and1/60times lower than that of low-dose MSCT and conventional-dose MSCT scan. There was no statistical difference between chest digital tomosynthesis and digital X-ray radiography (t=3.514, P=0.025), and significant difference between chest digital tomosynthesis and low-dose MSCT (t=178.769, P=0.000).ConclusionsComparing with low-dose MSCT, digital tomosynthesis is a new X-ray tomography which has the advantage of low radiation dosage in chest examination for lung lesion screening. ObjectiveDigital Tomosynthesis (DTS) is a new X-ray imaging technology, which developed from the traditional tomography along with the born of the big flat panel detectors and the development computer technology in recent years. In this study, we will evaluate the application value of digital tomosynthesis (DTS) in detecting pulmonary nodules.Materials and Methods43patients with pulmonary nodules and43normal patients underwent conventional-dose thoracic MSCT, posterior-anterior digital X-ray radiography and digital tomosynthesis. Conventional-dose MSCT served as reference standard.4radiologists read and scored the images with suspected pulmonary nodules by using a5-point rating scale for the confidence of presence.1score:definitely exist,2score:possible exist,3score: uncertain,4score:may not exist,5score:definitely does not exist. The results were statistically analyzed with receiver operating characteristic curves.ResultsFor the detection of pulmonary nodules, the area under ROC curve of digital X-ray radiography (posterior anterior) group and digital tomosynthesis group were0.763±0.247(0.755,0.768,0.735,0.794) and0.941±0.209(0.946,0.910,0.95,0.956) respectively. The difference of the Az valves between the two groups was significant (t=10.954, P=0.02, P<0.05). Kappa analysis confirmed that there was good consistency for the4radiologists in the diagnosis of pulmonary nodules (Kappa>0.75).Conclusions The performance of digital tomosynthesis is better than that of digital X-ray radiography (posterior anterior) in the detection of pulmonary nodules. Digital tomosynthesis plays an important role in the detection of pulmonary nodules. |
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