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Objective To estimate the absorbed dose and effective dose to the examined adult patients during digital tomosynthesis and to provide reference data for radiation dosimetry.Methods The phantom experiments were grouped according to the examined site(main beam scanned site),and the data displayed in real time during digital tomosynthesis are used as conditions for the phantom experiments.The effective doses to the examined patients were estimated on the basis of phantom scanning and tissue-absorbed dose calculation.Results During digital tomosynthesis,the effective doses to the examined patients of various groups were 0.524 mSv for head,0.736 mSv for cervical spine,2.719 mSv for thoracic vertebra,1.810 mSv for chest,1.240 mSv for lumbar spine,2.317 mSv for abdomen and 2.316 mSv for pelvis,respectively.Conclusions During digital tomography,the highest value of effective doses was estimated to be 2.719 mSv in thoracic vertebra group,followed by abdominal group 2.317 mSv and pelvic group 2.316 mS,with the lowest 0.524 mSv in head group.The main factors influencing the effective dose include tube voltage,total mAs,irradiation field size,main beam irradiation range,and the number of tissues or organs in scanned range.
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Because X-ray digital tomosynthesis (DTS) imaging principle is different from that of CT, DTS has better spatial resolution than that of CT in sagittal and coronal planes, and since DTS is reconstructed to generate"layer" images, its power in the aspect of distinguishing 3D tissue structures is superior to that of general X-ray photography, so DTS can provide 3D information for clinical diagnosis; its radiation dose is markedly lower than that of CT. In recent years, DTS has made progress in the application of skeletal system imaging; the research progress and the possible direction of future application of DTS in bone fracture diagnosis, fracture healing estimation, vertebral bone quality assessment and fracture risk prediction, joint dislocation diagnosis, bone erosion evaluation and postoperative arthroplasty assessment were summarized.
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Objective To investigate the significance of digital tomosynthesis (DTS) for suspicions lesions in the physical examination of the chest.Methods Totally 1 000 physical examinees were divided into two groups,with 500 younger ones in one group and the remained 500 ones in the other.The examinees underwent examination with digital X-ray radiography,and then the suspicious cases went through DTS examination to analyze the detection rate of pulmonary positive results.Results There were 110 suspected cases found by digital X-ray radiography,including 8 young ones and 102 old ones.The suspected cases went through DTS examination,and totally 92 nodules were found including 4 ones in the young persons and 88 ones in old persons.CT examination found 89 carcinomatous nodules in the 92 ones.Conclusion DTS examination can detect the lesion of the physical examinee,and lays a foundation for early diagnosis and treatment.
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Objective To explore the digital tomosynthesis(DTS)technology application value in children with atlanto-axial joint subluxation inspection.Methods 30 children with torticollis after injury,head and neck activities obstacles or local pain were selected.The consent of patient and family was obtained.At the same time the atlanto-axial joint open mouth,cervical lateral radiographies and DTS scanning were performed,two imaging quality and the diagnosis were compared.Results In all 30 cases,excellent imaging rate was 90% (27/30)on DTS and 53% (1 6/30)on DR respectively.On DTS atlanto-axial sublution were found in 22 cases but on DR atlanto-axial sublution were diagnosed in only 12 cases,suspicious subluxation in 4 cases,and misdiagnosis in 6 cases.Conclusion For diagnosis of atlanto-axial joint subluxation in children,DTS can obtain high quality images,clearly display anatomic structures and pathological morphology of atlanto-axial joint.
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Objective:To discuss the X-ray digital tomosynthesis (Digital Tomosynthesis, DTS) application value in the occult fractures of the scaphoid. Methods: we selected 19 patients in our hospital in 2012 examined by DTS, who were negative or highly suspicious of occult fracture with X-ray examination, and spiral CT (SCT) three-dimensional (3D) reconstructions were applied in seven patients. Results:There were 17 patients with fracture by DTS.7 patients showed fracture by spiral CT(SCT) three-dimensional(3D) reconstructions. Conclusion:Compared with X-ray examination, the image quality of Digital Tomosynthesis (DTS) is higher, which can show occult fracture better. Compared with CT, DTS can show spatial location of bony anatomy more clearly and can obtain more detailed information. With the important extension and supplement of CT and MRI, the distal tomosynthesisis is worth to be generalized for lower radiation, lower price, higher positive rate and high quality of the pictures.
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Bronchial carcinosarcoma is a very rare malignant tumor that is composed of carcinomatous and sarcomatous elements. We describe the first case in which digital tomosynthesis was useful for the evaluation of airway obstruction by bronchial carcinosarcoma that was overlooked on initial chest radiography.
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Airway Obstruction , Carcinosarcoma , Radiography , ThoraxABSTRACT
Objective To explore the optimal dose ratio set in the hip digital tomosynthesis (DTS),and to reduce patient's examination dose as low as possible.Methods Ninety patients who received hip DTS examination were randomly divided into 3 groups,with the dose ratio as 6,7 and 8,respectively.One-way ANOVA test was used to compare.the image quality and radiation dose among 3 groups.Results The values of entrance surface dose (ESD),dose-area product (DAP) and image quality score of 3 groups were [(3.76 ± 1.89) mGy,(18.41 ± 11.71) dGy·cm2,3.03 ± 0.24],[(5.24±2.76)mGy,(26.99±13.34)dGy·cm2),3.60±0.11],and [(6.39±1.75)mGy,(36.96± 22.49) dGy· cm2,3.64 ± 0.09],respectively.The difference among three groups was statistically significant (F =10.94,9.45,139.26,P ＜ 0.05).The S-N-K test showed that both ESD values and DAP values in 6,7,and 8 time-dose ratio group was from small to large.The image quality score of 6 time-dose ratio group was lower than that of the other groups with no significant difference.Conclusions Dose ratio is one of the important parameters to result in the radiation dose of DTS.Dose ration 7 is optimal in hip DTS,which could match the image quality and radiation dose best and finally protect patients from unnecessary radiation damage.
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Objective To evaluate the value of digital tomosynthesis (TOMOS)in diagnosis of odontogenic cystic lesions of the jaws with oral fixed metal dentures, and compared with multi-slice spiral CT (MSCT). Methods The imaging findings of 40 cases with fixed metal dentures pathologically proved odontogenic cystic lesions of the jaws jn retrospective were retrospectively analyzed.All cases were performed by MSCT and TOMOS scanning,and 13 cases enhanced at the same time. The characteristics of the imaging findings in TOMOS and MSCT were compared. The diagnosis merits and disadvantages, especially their ability to detect the lesions and adjacent structures,were assessed. Results There were no significant difference (consistency check Kappa value>0.4) in evaluating the structure characteristics of the lesions, the relationgship between the lesions and cortex ,and the relationship between the lesions and surrounding organs. TOMOS is superior to MSCT in displaying apical change, the same in pure cystic and cystic-solid lesions interfered by artifacts.However, it is inferior to MSCT in detection of soft tissue invasion. Conclusion There is similar assessment value of TOMOS and MSCT in displaying odontogenic cystic lesions of the jaws. TOMOS can be chosen when the imaging findings of the lesions are interfered by metal artifacts.
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To generate on-board digital tomosynthesis (DTS) for three-dimensionalimage-guided radiation therapy (IGRT) as an alternative to conventional portal imaging or on-board cone-beam computed tomography (CBCT), two clinical cases (liver and bladder) were selected to illustrate the capabilities of on-board DTS for IGRT. DTS images were generated from subsets of CBCT projection data (45, 162 projections) using half-fan mode scanning with a Feldkamp-type reconstruction algorithm. Digital tomosynthesis slices appeared similar to coincident CBCT planes and yielded substantially more anatomic information. Improved bony and soft-tissue visibility in DTS images is likely to improve target localization compared with radiographic verification techniques and might allow for daily localization of a soft-tissue target. Digital tomosynthesis might allow targeting of the treatment volume on the basis of daily localization.