ABSTRACT
This study aimed to investigate body physical parameters as substitutes for water equivalent diameter (Dw) while calculating size-specific dose estimates (SSDEs) during adult chest computed tomography (CT). A retrospective analysis was conducted on 776 patients. Patients were divided into training set (542 patients) and validation set (234 patients) according to a ratio of 7:3. The correlations between physical parameters and Dw were analyzed. The differences between SSDEsubstitutes and the reference SSDE (SSDEreference) were compared. Strong positive correlations were observed between body mass index (BMI) and Dw as well as between weight and Dw in overall, male, and female patients (all p < 0.001). The correlations between BMI and Dw were stronger than those between weight and Dw in overall, male, and female subjects (all p < 0.001). SSDEweight and SSDEBMI were not significantly different from SSDEreference (p > 0.05). The RMSEs of overall patients between SSDEweight and SSDEreference as well as between SSDEBMI and SSDEreference were 0.237 and 0.2, respectively. The use of sex-specific regression equations for BMI caused a slightly reduction in RMSE. Weight and BMI can be used as surrogate parameters for Dw when calculating SSDE in adult chest CT exams, with BMI being the preferred substitute parameter.
Subject(s)
Body Mass Index , Radiation Dosage , Tomography, X-Ray Computed , Humans , Male , Female , Tomography, X-Ray Computed/methods , Middle Aged , Adult , Retrospective Studies , Aged , Body Weight , Radiography, Thoracic/methods , Aged, 80 and over , Water , Thorax/diagnostic imagingABSTRACT
This study aimed to evaluate the value of low-dose dual-input computed tomography perfusion (CTP) imaging in the differential diagnosis of benign and malignant pulmonary ground-glass opacity nodules (GGO). A retrospective study was conducted in patients with GGO who underwent CTP in our hospital from January 2021 to October 2023. All nodules were confirmed via pathological analysis or disappeared during follow-up. Postprocessing analysis was conducted using the dual-input perfusion mode (pulmonary artery and bronchial artery) of the body perfusion software to measure the perfusion parameters of the pulmonary GGOs. A total of 101 patients with pulmonary GGOs were enrolled in this study, including 43 benign and 58 malignant nodules. The dose length product of the CTP (348 mGy.cm) was < 75% of the diagnostic reference level of the unenhanced chest CT (470 mGy.cm). The effective radiation dose was 4.872 mSV. The blood flow (BF), blood volume (BV), mean transit time (MTT), and flow extraction product (FEP) of malignant nodules were higher than those of the benign nodules (p < 0.05). The FEP had the highest accuracy for the diagnosis of malignant nodules (area under the curve [AUC] = 0.821, 95% confidence interval [CI]: 0.735-0.908) followed by BV (AUV = 0.713, 95% CI 0.608-0.819), BF (AUC = 0.688, 95% CI 0.587-0.797), and MTT (AUC = 0.616, 95% CI 0.506-0.726). When the FEP was ≥ 19.12 mL/100 mL/min, the sensitivity was 91.5% and the specificity was 62.8%. To distinguish between benign nodules and malignant nodules, the AUC of the combination of BV and FEP was 0.816 (95% CI 0.728-0.903), whereas the AUC of the combination of BF, BV, MTT, and FEP was 0.814 (95% CI 0.729-0.900). Low-dose dual-input perfusion CT was extremely effective in distinguishing between benign from malignant pulmonary GGOs, with FEP exhibiting the highest diagnostic capability.
Subject(s)
Lung Neoplasms , Tomography, X-Ray Computed , Humans , Male , Female , Middle Aged , Diagnosis, Differential , Lung Neoplasms/diagnostic imaging , Lung Neoplasms/pathology , Lung Neoplasms/diagnosis , Retrospective Studies , Aged , Tomography, X-Ray Computed/methods , Adult , Solitary Pulmonary Nodule/diagnostic imaging , Solitary Pulmonary Nodule/pathology , Perfusion Imaging/methods , Multiple Pulmonary Nodules/diagnostic imaging , Multiple Pulmonary Nodules/pathology , Lung/diagnostic imaging , Lung/blood supply , Lung/pathology , ROC Curve , Radiation DosageABSTRACT
Combining a strong second-order nonlinear optical (NLO) effect (>1×KH2PO4 (KDP)), a large band gap (>4.2â eV), and a moderate birefringence in ultraviolet (UV) NLO crystals remains a formidable challenge. Herein, Cd(SCN)2(C4H6N2)2, the first example of a thiocyanate capable of realizing a phase-matched UV NLO crystal material, is obtained by reducing the sulfur (S) content in the centrosymmetric (CS) structure of Cd(SCN)2(CH4N2S)2. Compared to the "shoulder-to-shoulder" one-dimensional (1D) chain of Cd(SCN)2(CH4N2S)2, Cd(SCN)2(C4H6N2)2 has a different sawtooth 1D chain structure. Cd(SCN)2(CH4N2S)2 has second harmonic generation (SHG) inertia with a band gap of 3.90â eV and a UV cutoff edge of 342â nm, however, it possesses a large birefringence (0.35@546â nm). In contrast, the symmetry center breaking of Cd(SCN)2(C4H6N2)2 leads to remarkably strong SHG intensity (10â times that of KDP). Furthermore, it has a wide band gap (4.74â eV), short UV cutoff edge (234â nm), and moderate birefringence capable of phase matching (0.17@546â nm). This research indicates that thiocyanates are a promising class of UV NLO crystal materials, and that modulation of the sulfur content of CS thiocyanates is an effective strategy for the development of UV NLO crystals with excellent overall performances.
ABSTRACT
In the search for nonlinear optical (NLO) materials with excellent overall performance, we have devoted ourselves to organic-inorganic hybrids consisting of anionic groups containing stereochemically active lone-pair (SCALP) electron cations and organic planar π-conjugated group cations. Accordingly, in this paper, two novel organic-inorganic hybrid metal halides, C4H7N2Ge0.4Sn0.6Br3 (I) and C6H11N2Ge0.4Sn0.6Br3 (II), have been synthesized. The powder second-harmonic technique shows that both C4H7N2Ge0.4Sn0.6Br3 and C6H11N2Ge0.4Sn0.6Br3 have moderately strong second-order nonlinear optical effects, which are about 2.03 (I) and 1.16 (II) times that of KH2PO4 (KDP), respectively. They also have different optical band gaps of 2.75 (I) and 2.88 eV (II) due to the different sizes of the organic cations, and their photoluminescent and thermal properties were also investigated. This work provides new structural insights for the design and modulation of organic-inorganic hybrid halide materials with multiple excellent optical properties.
ABSTRACT
RATIONALE AND OBJECTIVES: This study aimed to compare the volume computed tomography dose index (CTDIvol), dose length product (DLP), and size-specific dose estimate (SSDE), with the China and updated 2017 American College of Radiology (ACR) diagnostic reference levels (DRLs) in chest CT examinations of adults based on the water-equivalent diameter (Dw). MATERIALS AND METHODS: All chest CT examinations conducted without contrast administration from January 2020 to July 2020 were retrospectively included in this study. The Dw and SSDE of all examinations were calculated automatically by "teamplay". The CTDIvol and DLP were displayed on the DICOM-structured dose report in the console based on a 32cm phantom.The differences in patient CTDIvol, DLP, and SSDE values between groups were examined by the one-way ANOVA. The differences in patient CTDIvol, DLP, and SSDE values between the updated 2017 ACR and the China DRLs were examined with one sample t-tests. RESULTS: In total 14666 chest examinations were conducted in our study. Patients were divided into four groups based on Dw:270 (1.84%) in 15-20 cm group, 10287 (70.14%) in the 21-25 cm group, 4097 (27.94%) in the 26-30 cm group, and 12 (0.08%) patients had sizes larger than 30 cm. CTDIvol, DLP, and SSDE increased as a function of Dw (p<0.05). CTDIvol was smaller than SSDE among groups (p<0.05). The mean CTDIvol and DLP values were lower than the 25th, 50th, and 75th percentile of the China DRLs (p <0.05). The CTDIvol, DLP, and SSDE were lower than the 50th and 75th percentiles of the updated 2017 ACR DRLs (p <0.05) among groups. CONCLUSIONS: SSDE takes into account the influence of the scanning parameters, patient size, and X-ray attenuation on the radiation dose, which can give a more realistic estimate of radiation exposure dose for patients undergoing CT examinations. Establishing hospital's own DRL according to CTDIvol and SSDE is very important even though the radiation dose is lower than the national DRLs.
Subject(s)
Tomography, X-Ray Computed/methods , Adult , China , Diagnostic Reference Levels , Female , Humans , Male , Middle Aged , Radiation Dosage , Reference Values , Retrospective Studies , Tomography, X-Ray Computed/standardsABSTRACT
OBJECTIVE: This study was designed to explore the diagnostic value of multi-slice spiral CT (MSCT) scanning in lung compression ratio of patients with pulmonary contusion complicated by pneumothorax or hydropneumothorax. METHODS: Seventy-eight patients with pulmonary contusions complicated by pneumothorax or hydropneumothorax treated in the Department of Emergency Surgery of our hospital were examined by CT and X-ray, and the diagnostic value of these two methods was observed. The correlation of lung compression ratio measured by multiplanar reconstruction (MPR) and volume rendering (VR) with W/D ratio was studied, and the formula between VR-measured lung compression ratio and W/D ratio was constructed using a one-variable linear regression equation. RESULTS: The diagnostic rate of pulmonary contusions complicated by pneumothorax or hydropneumothorax measured by CT was higher than that by X-ray (P<0.05). Among the patients with pulmonary contusion diagnosed by CT, 45 were localized and 33 were extensive, and there were statistically significant differences in the incidence of comorbid rib fractures (P<0.05). The correlation of lung compression ratio measured by VR with W/D ratio measured by CT was analyzed, and the regression equation of the two was obtained by one-variable linear regression equation analysis: lung compression ratio =1.159* W/D -1.034. VR-measured lung compression ratio measured was positively correlated with W/D ratio (r=0.936, P<0.001). CONCLUSION: CT is superior to X-ray in the diagnosis of pulmonary contusions complicated by pneumothorax or hydropneumothorax. The calculation of lung compression ratio using the formula of lung compression ratio =1.159* W/D -1.034 has certain clinical value and can improve clinical work efficiency.
ABSTRACT
Since December 2019, a new type of acute respiratory disease caused by the 2019 novel coronavirus (COVID-19) appeared to Wuhan, China. Currently, positive of virus nucleic acid in respiratory or blood samples is the gold standard for the diagnosis of the disease, but the nucleic acid test may be false negative. Chest CT examination plays an important role in diagnosis of COVID-19 pneumonia. The clinical manifestations, laboratory examination, and chest CT characteristics of 3 patients with COVID-19 pneumonia were reported. The mainly clinical manifestation of the 3 patients was fever. White blood cell, neutrophil cell, and lymphocyte cell count can be normal, only C-reactive protein slightly elevated. Real-time fluorescence polymerase chain reaction of throat swab detection can be negative. Chest CT showed multifocal ground-glass opacities in the peripheral of bilateral lungs. Ground-glass opacities with consolidation, air bronchogram, vascular enlargement, and halo sign were found. In the early stages of COVID-19 pneumonia, the laboratory parameters may be normal, the nucleic acid test may be false negative. Chest CT examination may be helpful for diagnosis of COVID-19 pneumonia.
ABSTRACT
Inulin (IN), as a classic diagnostic for determination of glomerular filtration rate, reached high concentration in kidney. Introducing drug into IN derivatives may be a new method to target kidney for drug delivery. To test the hypothesis, ferulic acid (FeA) was conjugated into IN by ester bond and amide bond (ethylenediamine as spacer), respectively, and the two FeA-IN conjugations, inulin ferulate (IN-FeA) and inulin ethylenediamine ferulate (IN-EDA-FeA) were obtained. NMR spectrum was involved to characterize the conjugations. The FeA in vitro release profiles were tested in mice plasma and renal homogenate. Finally, the biodistribution test was performed to evaluate their renal-targeting ability. Both IN-FeA and IN-EDA-FeA showed a higher release rate of FeA in renal homogenate than in mouse plasma suggesting the conjugates are relatively stable in plasma and more likely FeA release in kidney. The renal area under the curve (AUC) for IN-FeA and IN-EDA-FeA were 539.6 ± 107.9 and 558.5 ± 131.6 µg h/mL, respectively, which were 4.47 and 4.62 times of 120.8 ± 18.1 µg h/mL for free FeA. Meanwhile, significant smaller FeA accumulation in other organs was observed. These data indicated that IN-FeA and IN-EDA-FeA effectively targeted kidney for FeA delivery.