BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.Th...BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.This study aimed to assess the diagnostic value of dual-layer spectral computed tomography(CT)-derived VMIs,in combination with multiplanar reformation(MPR)and evaluation of peritumoral fat stranding(PFS),for improving the accuracy of T staging in CRC.AIM To assess the diagnostic performance of dual-layer spectral CT(DLSCT)VMIs,particularly at low energy levels,and their integration with personalized MPR for preoperative T staging of CRC.METHODS In this retrospective study,157 patients with pathologically confirmed CRC(mean age:63.5±12.1 years)underwent DLSCT within 1 week before surgery.VMIs ranging from 40 keV to 70 keV(at 10 keV intervals)and conventional polyenergetic images(PEIs)were reconstructed.Objective image quality parameters,including image noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR),were quantified,alongside subjective image quality scores using a 5-point Likert scale.Interobserver agreement was evaluated usingκstatistics.Taking histopathology as the reference standard,the diagnostic accuracy of T staging(T1-2 vs T3-4)was compared across PEIs and VMIs,both with and without MPR and PFS.RESULTS Low-keV VMIs(40-70 keV)demonstrated significantly higher SNR and CNR than PEIs(all P<0.001).Notably,40-keV VMIs achieved noise levels comparable to PEIs(8.17±3.63 vs 8.53±2.90;P=0.673).Subjective image quality peaked at 40-50 keV VMIs(Likert scores 4.85-4.88 vs 3.97 for PEIs;P<0.001),supported by excellent interobserver agreement(κ=0.812-0.913).The combination of 40-50 keV VMIs with MPR yielded the highest T staging accuracy(94.27%)compared to axial PEIs(70.7%),with a sensitivity and specificity of 83.87%and 96.83%,respectively(Youden index=0.81;P<0.05).While PFS enhanced staging accuracy on PEIs(up to 77.07%with MPR),it provided no significant additional benefit for VMIs.CONCLUSION DLSCT VMIs at 40-50 keV significantly enhanced image quality and improved preoperative T staging accuracy of CRC when combined with MPR.These findings underscored the clinical value of low-keV spectral imaging in tailoring individualized treatment strategies.展开更多
The formulation for the stress concentration matrix of multiplanar tubular joint with braces subjected to combined load is established in this paper. The formulations for SCF values of multiplanar tubular joints are c...The formulation for the stress concentration matrix of multiplanar tubular joint with braces subjected to combined load is established in this paper. The formulations for SCF values of multiplanar tubular joints are compared with those by Wordsworth and Efthymiou. The stiffening effect and load-interaction effect are discussed. A spatial offshore jacket with braces subjected to combined load is computed as a numerical example. The maximum stress of each multiplanar tubular joint and its location are found through SCF matrix. Finally, the difference between the maximum stresses of multiplanar tubular joints and their corresponding uniplanar tubular joints are discussed.展开更多
BACKGROUND Anastomosis of the testicular vein with the superior mesenteric vein rarely causes severe gastrointestinal bleeding.To date,there have been few studies describing its appearance on medical imaging.Here,we p...BACKGROUND Anastomosis of the testicular vein with the superior mesenteric vein rarely causes severe gastrointestinal bleeding.To date,there have been few studies describing its appearance on medical imaging.Here,we present multidetector computed tomography three-dimensional and multiplanar reconstruction(MPR)images of a typical digital subtraction angiography showing proven ectopic bleeding and provide the first review of the image performance.CASE SUMMARY A 68-year-old man who had been rushed to the hospital with a four-day history of melena and fainting underwent multiple esophagogastroduodenoscopy procedures that failed to identify the source of bleeding.We used MPR combined with three-dimensional reconstruction images,and found that the testicular vein had anastomosed with the superior mesenteric vein,and they clustered together in the jejunal vessel wall,which caused severe gastrointestinal bleeding.Digital subtraction angiography confirmed the location of bleeding.After transfusion and embolization therapy,the patient’s condition improved.CONCLUSION Computed tomography-MPR combined with three-dimensional images offers significant value in the localization and qualitative assessment of rare gastrointestinal hemorrhage.The features of multiphase spiral scanning can improve the accuracy of the diagnosis.展开更多
基金Supported by Jiangsu Province 333 Talent Key Industry Field Talent Project,No.[2022]21Key Scientific Research Program of Jiangsu Provincial Health Committee,No.ZD2021059+2 种基金Nantong Key Laboratory Project,No.[2020]163The Project of Nantong City Health Committee,No.MS2023027Young Medical Talents Fund of Health and Family Planning Commission of Nantong,No.QA2019006 and No.QNZ2023027.
文摘BACKGROUND Accurate preoperative T staging is essential for determining optimal treatment strategies in colorectal cancer(CRC).Low-keV virtual monoenergetic images(VMIs)have been shown to enhance lesion conspicuity.This study aimed to assess the diagnostic value of dual-layer spectral computed tomography(CT)-derived VMIs,in combination with multiplanar reformation(MPR)and evaluation of peritumoral fat stranding(PFS),for improving the accuracy of T staging in CRC.AIM To assess the diagnostic performance of dual-layer spectral CT(DLSCT)VMIs,particularly at low energy levels,and their integration with personalized MPR for preoperative T staging of CRC.METHODS In this retrospective study,157 patients with pathologically confirmed CRC(mean age:63.5±12.1 years)underwent DLSCT within 1 week before surgery.VMIs ranging from 40 keV to 70 keV(at 10 keV intervals)and conventional polyenergetic images(PEIs)were reconstructed.Objective image quality parameters,including image noise,signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR),were quantified,alongside subjective image quality scores using a 5-point Likert scale.Interobserver agreement was evaluated usingκstatistics.Taking histopathology as the reference standard,the diagnostic accuracy of T staging(T1-2 vs T3-4)was compared across PEIs and VMIs,both with and without MPR and PFS.RESULTS Low-keV VMIs(40-70 keV)demonstrated significantly higher SNR and CNR than PEIs(all P<0.001).Notably,40-keV VMIs achieved noise levels comparable to PEIs(8.17±3.63 vs 8.53±2.90;P=0.673).Subjective image quality peaked at 40-50 keV VMIs(Likert scores 4.85-4.88 vs 3.97 for PEIs;P<0.001),supported by excellent interobserver agreement(κ=0.812-0.913).The combination of 40-50 keV VMIs with MPR yielded the highest T staging accuracy(94.27%)compared to axial PEIs(70.7%),with a sensitivity and specificity of 83.87%and 96.83%,respectively(Youden index=0.81;P<0.05).While PFS enhanced staging accuracy on PEIs(up to 77.07%with MPR),it provided no significant additional benefit for VMIs.CONCLUSION DLSCT VMIs at 40-50 keV significantly enhanced image quality and improved preoperative T staging accuracy of CRC when combined with MPR.These findings underscored the clinical value of low-keV spectral imaging in tailoring individualized treatment strategies.
文摘The formulation for the stress concentration matrix of multiplanar tubular joint with braces subjected to combined load is established in this paper. The formulations for SCF values of multiplanar tubular joints are compared with those by Wordsworth and Efthymiou. The stiffening effect and load-interaction effect are discussed. A spatial offshore jacket with braces subjected to combined load is computed as a numerical example. The maximum stress of each multiplanar tubular joint and its location are found through SCF matrix. Finally, the difference between the maximum stresses of multiplanar tubular joints and their corresponding uniplanar tubular joints are discussed.
文摘BACKGROUND Anastomosis of the testicular vein with the superior mesenteric vein rarely causes severe gastrointestinal bleeding.To date,there have been few studies describing its appearance on medical imaging.Here,we present multidetector computed tomography three-dimensional and multiplanar reconstruction(MPR)images of a typical digital subtraction angiography showing proven ectopic bleeding and provide the first review of the image performance.CASE SUMMARY A 68-year-old man who had been rushed to the hospital with a four-day history of melena and fainting underwent multiple esophagogastroduodenoscopy procedures that failed to identify the source of bleeding.We used MPR combined with three-dimensional reconstruction images,and found that the testicular vein had anastomosed with the superior mesenteric vein,and they clustered together in the jejunal vessel wall,which caused severe gastrointestinal bleeding.Digital subtraction angiography confirmed the location of bleeding.After transfusion and embolization therapy,the patient’s condition improved.CONCLUSION Computed tomography-MPR combined with three-dimensional images offers significant value in the localization and qualitative assessment of rare gastrointestinal hemorrhage.The features of multiphase spiral scanning can improve the accuracy of the diagnosis.
