Background and purpose:With the increasing use of medical imaging examinations,Computed tomography(CT)scans have become one of the primary sources of effective dose.This study analyzed the correlation between radiation dose,image quality and body composition in thyroid CT to provide a data foundation for better control of radiation dose and image quality in the future.Methods:A retrospective analysis was conducted on patients who underwent thyroid CT scans at Fudan University Shanghai Cancer Center from January 2015 to December 2019.CT values and standard deviations(SD)of the homogeneous parenchyma of the thyroid were collected,and CT values and SD values of adjacent subcutaneous fat tissue were measured with the same region of interest(ROI)size.All data were measured three times to obtain the average value,and the volume CT dose index(CTDIvol)and dose-length product(DLP)were recorded.Effective dose values and signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)for various parts were calculated.All patients underwent bone density examinations,and patient height,weight,body mass index(BMI),body surface area(BSA),and the percentage of muscle and fat in the spine and thighs were recorded.Results:A total of 104 patients were enrolled in this study.The SNR of thyroid CT images and the percentage of spinal muscle(r=0.284,P=0.004),CNR of thyroid CT images and the percentage of spinal fat(r=0.197,P=0.045),and the effective dose of thyroid CT images and age,weight,BMI,thigh fat percentage,and body surface area(r=0.221,0.247,0.260,0.262,and 0.222;P=0.024,0.011,0.008,0.007 and 0.024)were positively correlated.While,SNR and age,weight,BMI,and the percentage of spinal fat(r=-0.292,-0.198,-0.207,and-0.284;P=0.003,0.044,0.035,0.004),CNR and the percentage of spinal muscle(r=-0.197,P=0.045),and the effective dose and the percentage of thigh muscle(r=-0.262,P=0.007)were negatively correlated.Conclusion:The radiation dose in thyroid CT is correlated with female body composition.The image quality is related to female body composition,providing a data foundation for better control of radiation dose and image quality in the future.

Background and purpose:With the increasing use of medical imaging examinations,Computed tomography(CT)scans have become one of the primary sources of effective dose.This study analyzed the correlation between radiation dose,image quality and body composition in thyroid CT to provide a data foundation for better control of radiation dose and image quality in the future.Methods:A retrospective analysis was conducted on patients who underwent thyroid CT scans at Fudan University Shanghai Cancer Center from January 2015 to December 2019.CT values and standard deviations(SD)of the homogeneous parenchyma of the thyroid were collected,and CT values and SD values of adjacent subcutaneous fat tissue were measured with the same region of interest(ROI)size.All data were measured three times to obtain the average value,and the volume CT dose index(CTDIvol)and dose-length product(DLP)were recorded.Effective dose values and signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)for various parts were calculated.All patients underwent bone density examinations,and patient height,weight,body mass index(BMI),body surface area(BSA),and the percentage of muscle and fat in the spine and thighs were recorded.Results:A total of 104 patients were enrolled in this study.The SNR of thyroid CT images and the percentage of spinal muscle(r=0.284,P=0.004),CNR of thyroid CT images and the percentage of spinal fat(r=0.197,P=0.045),and the effective dose of thyroid CT images and age,weight,BMI,thigh fat percentage,and body surface area(r=0.221,0.247,0.260,0.262,and 0.222;P=0.024,0.011,0.008,0.007 and 0.024)were positively correlated.While,SNR and age,weight,BMI,and the percentage of spinal fat(r=-0.292,-0.198,-0.207,and-0.284;P=0.003,0.044,0.035,0.004),CNR and the percentage of spinal muscle(r=-0.197,P=0.045),and the effective dose and the percentage of thigh muscle(r=-0.262,P=0.007)were negatively correlated.Conclusion:The radiation dose in thyroid CT is correlated with female body composition.The image quality is related to female body composition,providing a data foundation for better control of radiation dose and image quality in the future.

Background and purpose:In the quality control of mammography,the signal-to-noise ratio(SNR)refers to the ratio of the useful signal intensity to the background noise in the image,which is one of the important indicators for measuring the quality of the image.The coefficient of variation(CoV)is a commonly used indicator to describe the consistency and repeatability of SNR.This study aimed to assess the stability and repeatability of mammographic device performance by analyzing the changes in SNR CoV in two-dimensional(2D)images and tomosynthesis images(referred to as Tomo images)under different exposure modes using three mammographic devices from different manufacturers.Methods:A polymethylmethacrylate(PMMA)phantom designed for mammography quality control was used to perform automatic exposure detection at PMMA thicknesses ranging from 20-80 mm,with actual compression thickness equivalent to the average density of the breast compressed to 21-103 mm under full-field digital mammography(FFDM),low-dose mammography and digital breast tomosynthesis(DBT)exposure modes.The CoV of SNR in 2D images and tomosynthesis images was calculated for different mammographic devices under different exposure modes and compression thicknesses.Results:Between the compression thicknesses equivalent to the average density of the breast from 21 mm to 103 mm under FFDM,low-dose mammography,and DBT exposure modes,the differences in SNR CoV of 2D images under different exposure modes among mammographic devices 1,2,and 3 were statistically significant only in the DBT exposure mode(P=0.003),with SNR CoV ranging from 0.188%to 0.720%,0.368%to 1.073%and 0.402%to 1.662%,respectively.There were no statistically significant differences in SNR CoV of 2D images among devices 1,2,and 3 under FFDM and low-dose exposure modes(P=0.060).Under the DBT exposure mode,there were no statistically significant differences in the SNR CoV of the first projection image and the 0° projection image of tomosynthesis among devices 1(2 angles),2,and 3(P=0.373,P=0.742,P=0.225,P=0.693,respectively).Conclusion:The SNR CoV in 2D images and tomosynthesis images varies under different mammographic devices and exposure modes,with no fixed or standard values,but all within the required range for mammographic device quality control.The stability and repeatability of 2D images of mammographic devices are better under FFDM and low-dose exposure modes;the SNR CoV values of the first projection image and the 0° projection image of tomosynthesis under the DBT exposure mode show no statistical differences,indicating good stability of the devices.

Background and purpose:In the quality control of mammography,the signal-to-noise ratio(SNR)refers to the ratio of the useful signal intensity to the background noise in the image,which is one of the important indicators for measuring the quality of the image.The coefficient of variation(CoV)is a commonly used indicator to describe the consistency and repeatability of SNR.This study aimed to assess the stability and repeatability of mammographic device performance by analyzing the changes in SNR CoV in two-dimensional(2D)images and tomosynthesis images(referred to as Tomo images)under different exposure modes using three mammographic devices from different manufacturers.Methods:A polymethylmethacrylate(PMMA)phantom designed for mammography quality control was used to perform automatic exposure detection at PMMA thicknesses ranging from 20-80 mm,with actual compression thickness equivalent to the average density of the breast compressed to 21-103 mm under full-field digital mammography(FFDM),low-dose mammography and digital breast tomosynthesis(DBT)exposure modes.The CoV of SNR in 2D images and tomosynthesis images was calculated for different mammographic devices under different exposure modes and compression thicknesses.Results:Between the compression thicknesses equivalent to the average density of the breast from 21 mm to 103 mm under FFDM,low-dose mammography,and DBT exposure modes,the differences in SNR CoV of 2D images under different exposure modes among mammographic devices 1,2,and 3 were statistically significant only in the DBT exposure mode(P=0.003),with SNR CoV ranging from 0.188%to 0.720%,0.368%to 1.073%and 0.402%to 1.662%,respectively.There were no statistically significant differences in SNR CoV of 2D images among devices 1,2,and 3 under FFDM and low-dose exposure modes(P=0.060).Under the DBT exposure mode,there were no statistically significant differences in the SNR CoV of the first projection image and the 0° projection image of tomosynthesis among devices 1(2 angles),2,and 3(P=0.373,P=0.742,P=0.225,P=0.693,respectively).Conclusion:The SNR CoV in 2D images and tomosynthesis images varies under different mammographic devices and exposure modes,with no fixed or standard values,but all within the required range for mammographic device quality control.The stability and repeatability of 2D images of mammographic devices are better under FFDM and low-dose exposure modes;the SNR CoV values of the first projection image and the 0° projection image of tomosynthesis under the DBT exposure mode show no statistical differences,indicating good stability of the devices.

Objective To investigate the diagnostic value and characteristics of breast lesion in digital breast tomosynthesis (DBT) in combination with synthesized two-dimensional (2D) images. Methods The prospective study enrolled women older than 18 years with clinically suspected breast lesion.One hundred and sixty seven patients with 177 lesions confirmed by biopsy or surgery were included. All the patients underwent full-field digital mammography(FFDM)and DBT examinations,and synthesized 2D images(V-preview)were reconstructed from DBT.The images of FFDM,V-preview images and DBT plus FFDM, V-preview images were analyzed. The breast imaging reporting and data system (BI-RADS) and characteristic for predicting benign and malignant lesion were also evaluated.The average glandular dose for a single mammographic view between FFDM and DBT was recorded.The Nonparametric Z test was used to compare the differences among four different mammographic images in BI-RADS.The differential diagnostic performance among different mammography was evaluated by ROC analysis.Independent t test was used to compare the average glandular dose between FFDM and DBT.Results One hundred three benign lesions and 74 malignant lesions were confirmed. Compared with FFDM images alone or plus DBT,the diagnostic values of V-preview images alone/or plus DBT were not significantly different(Z=0.187 and 0.226,P=0.851 and 0.821), but compared with V-preview, the diagnostic values of V-preview images plus DBT revealed significant difference(Z=3.546,P<0.01).The area under ROC for V-preview plus DBT were 0.899,and the sensitivity,specificity,and accuracy were 90.5%,89.3%,and 89.3%,separately.For the average glandular dose, there was no significant difference between FFDM (1.48 ± 0.52) mGy and DBT (1.56 ± 0.39) mGy examination(t=1.714,P=0.087).Conclusion Synthesized 2D images from DBT,which may eliminate the need for FFDM,in combination with DBT can improve the diagnostic efficiency.

Background and purpose: Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) can be used for magnetic resonance imaging systemic examination, especially in examing the metastatic lesions, lymph node and bone diseases, and the imaging result is similar with PET. This study aimed to evaluate the application value of magnetic resonance DWIBS and positron emission tomography with computed tomography (PET/CT) on malignant metastatic diseases. Methods: Thirty-six patients confirmed with malignant tumors accompanying metastasis by the pathology of operation or biopsy underwent both DWIBS imaging and PET/CT, chi-square test and Kappa test were used for comparing the detection results of metastasis by these 2 imaging methods. Results:Among the 36 malignant tumor patients with 238 metastatic lesions, 218 (91.6%, 218/238) lesions in DWIBS and 209 (87.8%, 209/238) lesions in PET/CT were detected, with 200 lesions detected by the two methods simultaneously, and the concordance rate was 88.7%(211/238);but there was no statistical signiifcance between this two methods (χ2=1.843, P=0.157). Kappa test showed a fair concordance rate between DWIBS and PET/CT (P=0.000).There were different significance between DWIBS and PET/CT in detecting metastatic lesions of brain and bone (P=0.005 and 0.031);But there was no signiifcant differences (P=0.309 and 1.000) in detecting metastatic lesions of lymph nodes and liver. Conclusion:DWIBS could detect metastatic lesions effectively, and there is ifne consistency with PET/CT. DWIBS is more sensitive than PET/CT in detecting metastatic lesions of brain and bone, so DWIBS could be chosed for screening metastatic lesions according to the characteristics of different primary tumors.

Background and purpose:Diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) can be used for MR imaging systemic examination, especially the lymph node and bone diseases can be clear, and the imaging result is similar with PET. The aim of this study was to compare the value of clinical application in the diagnosis of malignant metastatic osteopathic between DWIBS and bone scintigraphy mapping. Methods:Thirty-six specimens conifrmed with malignant tumors by the pathology of operation or biopsy underwent both DWIBS imaging and bone scintigraphy mapping, chi-square test was used for comparing the detection results of bone metastasis by this two imaging methods. Results:Thirty (165 positions in all) of 36 malignant tumor patients were conifrmed as having bone metastasis, compared that 26 patients (143 positions) with DWIBS method and 23 patients (132 positions) with bone scintigraphy mapping were detected, but there was no statistical signiifcance between this two imaging methods (χ2=1.002, P=0.506). The sensitivity, positive predictive value (PPV) and accuracy of the detection rate of bone metastasis were similar in DWIBS and bone scintigraphy, with 86.7%, 96.3%, 86.1%and 76.7%, 88.5%, 72.2%, respectively;but the speciifcity and negative predictive value (NPV) in DWIBS (83.3%and 55.6%) was higher than that of in bone scintigraphy (50.0%and 30.0%). The detection rates of different bone metastasis with DWIBS and bone scintigraphy were 86.7%(143/165) and 80.0%(132/165), and it was no signiifcant difference (χ2=2.640, P=0.104);DWIBS method was better than bone scintigraphy in the detection of osseous metastasis on pelvis and limbs long bone, and there was different signiifcant (χ2=6.783 and 7.636, P=0.023 and 0.016). Conclusion:DWIBS could detect bone metastatic lesions effectively, and there is ifne consistency with bone scintigraphy. Therefore, DWIBS is to hope to be extended and applicated clinically.

Objective To describe the radiological features of mastitis.Methods Imaging findings were retrospectively reviewed in 58 women with mastitis,which was confirmed by pathological results.The imaging features were described according to the BI-RADS (breast imaging reporting and data system).All 58 patients had preoperative MRI,while 49 of them were examined with sonograms and 30 with mammograms preoperatively.Results Overall,no remarkable findings were reported on 6 mammography and 2 sonography examinations,but all 58 lesions were identified on MRI in our study.Asymmetrical density (n =16,53.3％) on mammograms and solitary or multiple separated/contiguous hypoechoic mass-like lesions (n =34,69.4％) on ultrasound were the most common signs of mastitis.On enhanced MR images,82.8 ％ (48/58) patients showed non-mass-like enhanced lesions.Multiple,regional enhancement (66.7％,32/48) and separated or contiguous,clumped,rim-like enhancement (63.1％,31/48) were the most common manifestations in non-mass-like enhanced lesions.Of the 58 patients,type Ⅰ and type Ⅱ timesignal intensity curve were detected in 48.3％ and 50.0％ of the patients,respectively.BI-RADS 0 had the highest frequency in reports on mammography (33.3％,10/30),while category 4a was most frequent on sonography (36.7％,18/49) and also on MRI (56.9％,33/58).Conclusion The imaging findings from mammography and US are non-specific for mastitis,therefore,MR can be helpful in the diagnosis,especially in the presence of non-mass-like enhancement that are multiple,regional,separated,or contiguous,clumped,and tim-like.

Objective Analysis of myocardial microvascular perfusion in patients with chronic total coronary occlusion (CTO) who underwent a coronary artery bypass graft (CABG) use real-time myocardial contrast echocardiography (RTMCE),to provide an effective method of detecting viable myocardium and a reference for the choice of CABG indications.Methods Twenty-seven patients with CTO underwent RTMCE 1 week before CABG,they underwent follow-up echocardiography and coronary artery 256-slice multislice computed tomography aagiography 1 year after CABG.Myocardial viability was defined as a postoperative ultrasound wall motion significantly improved ≥ 1 point.Semi-quantitative analysis of contrast images,myocardial viability was defined as myocardial perfusion score ≤ 2 points.Viable myocardium by quantitative assessment of myocardial blood flow (MBF) was determined by analyses of receiver-operating characteristic (ROC) curves.Results Patients with LVEF increased significantly after CABG (P ＜ 0.01),Of 259 segments with wall motion abnormality,149 (58％) showed wall motion significantly improved ≥ 1 point after CABG,considered viable myocardium,110 (42％) were not observed in wall motion improved,considered to be non-viable.The viable myocardial segments were significantly greater than non-viable myocardial segments in A,β,A × β value (P ＜ 0.01).Compared with the semi-quantitative analysis,quantitative analysis of MBF increased the sensitivity and accuracy of RTMCE for detecting viable myocardium (P ＜ 0.05).Conclusion RTMCE could accurately assess myocardial viability and provide a strong reference for clinical decision making and judging prognosis.

ObjectiveTo evaluate the function of the salivary glands with gustatory stimulation by using MR DWI.MethodsA prospective study was conducted in 30 patients with nasopharyngeal carcinoma who had normal salivary function.A DWI sequence was performed on the salivary glands at resting state,and continually repeated on the parotid immediately after oral ascorbic acid stimulation over a period of 21 minutes (once every 18 seconds).The multiple b-values (0,400,600,800,1000 s/mm2) were used.ADC maps were evaluated with a manually placed region of interest including the entire salivary gland.The ADC of each gland was obtained by taking the mean of values on three contiguous sections containing the largest areas of the gland.The paired two-tailed Student t test was used to compare the ADC values of the parotid and the submandibular glands at rest,and of the parotid before and after stimulation.ResultsThe mean ADC value at rest was significantly lower in the parotid [ (1.23 ±0.12) × 10-3 mm2/s] than in the submandibular glands [(1.34 ± 0.07 ) × 10 -3 mm2/s,t =4.545,P ＜ 0.01 ].After acid stimulation,the ADC value increased from the baseline to (1.41 ±0.19) × 10-3 mm2/s firstly and then fluctuated at the following time,with a peak value of ( 1.49 ± 0.20 )× 10 -3 mm2/s and the average value of ( 1.36 ±0.17) × 10-3 mm2/s.The average value was significantly different from the baseline value (t =15.127,t =11.905,P ＜ 0.01 ).The minimum value [ ( 1.24 ± 0.14) × 10-3 mm2/s] was not significantly different compared to the baseline value (t =1.329,P ＞ 0.05 ).ConclusionMR DW1 can noninvasively evaluate the physiologic changes of salivary glands before and after acid stimulation.