Objective:To explore the value of dual-layer spectral CT virtual monoenergetic images (VMI) in contrast-enhanced abdominal CT scans with reduced contrast medium volume in pediatric tumor patients.Methods:The study is a self-matched case-control study. From January to October 2024, pediatric patients admitted to Shandong Cancer Hospital with abdominal tumors who underwent low contrast dose spectral CT contrast-enhanced scans during follow-up were prospectively included. A total of 47 patients aged (6.2±2.2) years (4-14 years) were enrolled. Usual contrast dose enhanced CT served as the conventional-dose group, while the follow-up low-dose spectral CT scans employed a protocol with half the contrast agent dose (low-dose group). Images were reconstructed as conventional CT images and VMI at 45, 55, and 65 keV. Using muscle as the reference background, differences in CT values and contrast-to-noise ratio (CNR) in the aorta, kidneys, liver, and spleen were compared between the low-dose group and conventional-dose group. Multi-group comparisons were performed using the Friedman test. Post-hoc pairwise comparisons were conducted with Bonferroni correction for P-values. Results:CT values and CNRs for all measured regions progressively increased with decreasing keV levels in spectral CT VMI. Significant overall differences were found in CT values and CNRs for the aorta, kidneys, liver, and spleen among the low-dose group (all VMIs) and the conventional-dose group (all P<0.001). At 65 keV VMI in the low-dose group, both CT values and CNRs (except for the liver CNR) were significantly lower than those in the conventional-dose group (all adjusted P<0.05). At 55 keV VMI in the low-dose group, CT values and CNRs for all regions did not show statistically significant differences compared to the conventional-dose group (all adjusted P>0.05). At 45 keV VMI in the low-dose group, CT values for all structures and CNR for the spleen were significantly higher than those in the conventional-dose group (all adjusted P<0.05). However, no statistically significant difference was found in CNRs for the aorta, kidneys, and liver (adjusted P=1.000, 0.313, and 0.503, respectively). Conclusion:When the contrast dose is halved, spectral CT 45 keV VMI enhances CT attenuation values and CNR in the abdomen of pediatric tumor patients, while 55 keV VMI provides image quality comparable to that of conventional-dose CT.

Objective:To explore the value of dual-layer spectral CT virtual monoenergetic images (VMI) in contrast-enhanced abdominal CT scans with reduced contrast medium volume in pediatric tumor patients.Methods:The study is a self-matched case-control study. From January to October 2024, pediatric patients admitted to Shandong Cancer Hospital with abdominal tumors who underwent low contrast dose spectral CT contrast-enhanced scans during follow-up were prospectively included. A total of 47 patients aged (6.2±2.2) years (4-14 years) were enrolled. Usual contrast dose enhanced CT served as the conventional-dose group, while the follow-up low-dose spectral CT scans employed a protocol with half the contrast agent dose (low-dose group). Images were reconstructed as conventional CT images and VMI at 45, 55, and 65 keV. Using muscle as the reference background, differences in CT values and contrast-to-noise ratio (CNR) in the aorta, kidneys, liver, and spleen were compared between the low-dose group and conventional-dose group. Multi-group comparisons were performed using the Friedman test. Post-hoc pairwise comparisons were conducted with Bonferroni correction for P-values. Results:CT values and CNRs for all measured regions progressively increased with decreasing keV levels in spectral CT VMI. Significant overall differences were found in CT values and CNRs for the aorta, kidneys, liver, and spleen among the low-dose group (all VMIs) and the conventional-dose group (all P<0.001). At 65 keV VMI in the low-dose group, both CT values and CNRs (except for the liver CNR) were significantly lower than those in the conventional-dose group (all adjusted P<0.05). At 55 keV VMI in the low-dose group, CT values and CNRs for all regions did not show statistically significant differences compared to the conventional-dose group (all adjusted P>0.05). At 45 keV VMI in the low-dose group, CT values for all structures and CNR for the spleen were significantly higher than those in the conventional-dose group (all adjusted P<0.05). However, no statistically significant difference was found in CNRs for the aorta, kidneys, and liver (adjusted P=1.000, 0.313, and 0.503, respectively). Conclusion:When the contrast dose is halved, spectral CT 45 keV VMI enhances CT attenuation values and CNR in the abdomen of pediatric tumor patients, while 55 keV VMI provides image quality comparable to that of conventional-dose CT.

Objective To evaluate left ventricular(LV)global and regional systolic function by three-dimensional speckle tracking imaging (3D-STI)in patients with systemic lupus erythematosus (SLE). Methods Twenty-two patients with SLE were selected randomly as SLE group and twenty-two healthy people were included as control group.3D-STI was performed in all participants to get global and regional strain parameters,including global longitudinal peak systolic strain(GLS),global circular peak systolic strain (GCS ),global radial peak systolic strain (GRS ),global area peak systolic strain (GAS ),segmental longitudinal peak systolic strain (SLS),segmental circumferential peak systolic strain (SCS),segmental radial peak systolic strain (SRS),and segmental area peak systolic strain (SAS).The sensitivity and specificity of GCS and GAS reflecting LV systolic function in patients with SLE were analyzed under the receiver operating characteristic (ROC)curve.Results ①The global strain:compared with the control group,GCS and GAS decreased significantly in SLE group (P <0.01),there was no significant change in GLS and GRS(P >0.05).②The regional strain:compared with the control group,the SCS in segments of basal anteroseptal,basal inferoseptal,mid anterior,mid inferosptal,mid anterolateral,apical inferior,apical lateral decreased significantly in SLE group.The SAS of basal anterior,basal inferoseptal,mid inferosptal, mid anterolateral,apical anterioe,apical lateral decreased significantly in SLE group (P <0.01).The SCS in segments of apex and the SAS of mid anterior,apical septal,apex decreased in SLE group (P <0.05).③The ROC curve:the sensitivity and specificity of GCS on detecting the LV systolic dysfunction were 59.1%and 87.5%,and those of GAS were 77.3% and 83.3%,respectively.Conclusions 3D-STI is a convenient and accurate way to early detect LV global and regional systolic dysfunction in SLE patients.

Objective:To establish a real time dissolution determination method for furosemide tablets and compare the similarity of dissolution curves of furosemide tablets from 11 generic drug manufacturers and the original research drug manufacturer in four kinds of dissolution media to evaluate the overall situation of dissolution process of furosemide tablets in our country. Methods:A fiber-optic medicine dissolution process real time test system was used to monitor the dissolution process of furosemide tablets from 11 generic drug manufacturers and the original research drug manufacturer. A paddle method was applied and the rotation speed was 50 r·min-1 . The dissolution medium was pH 1. 2 hydrochloric acid solution, pH 4. 0 acetate buffer, pH 6. 8 phosphate buffer and water, respectively with volume of 900 ml. The absorbance wavelength was 277 nm. The dissolution profile was drawn and f 2 factor was used to evaluate the similarity. Results:The dissolution tests were not influenced by the excipients and the dissolution media. The liner range of furose-mide was 4. 44-26. 66 μg·ml-1(r=0. 9997). The average recovery of furosemide was 101. 26% and RSD was 1. 84%(n=9). Ee-spect to 11 manufactures, there was only one of the dissolution similarity can meet the requirements. Conclusion:A simple, fast and accurate fiber-optic method for medicine dissolution process real time test is established. The method can reflect the real dissolution and provide the information on how to improve the preparation technology and monitor the stability of the preparation technology.