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Objective:To investigate the predictive value of stone composition prediction method based on dual-source stone energy spectrum CT for uric acid stones.Methods:The clinical data of 204 patients with urinary stones, 159 males and 45 females, admitted to Shanghai Sixth People's Hospital from July 2020 to July 2022 were retrospectively analyzed. The average age was (50.7±14.3) years. There were 187 cases of upper urinary tract (kidney, ureter) stones and 17 cases of lower urinary tract (bladder, urethra) stones. All patients underwent preoperative dual-source stone energy spectroscopy CT, measuring CT values at 150 kV and 100 kV, respectively, and the calculated dual energy ratio (Ratio) was used to predict stone composition. Of the 204 cases in this group, 33 cases underwent percutaneous nephrolithotomy and 171 cases underwent ureteroscopic lithotripsy. Postoperative stone specimens were analyzed for stone composition by infrared spectroscopy. Subject work characteristic (ROC) curves were used to analyze the efficacy of preoperative dual-source stone energy spectrum CT to predict uric acid stones.Results:In 204 patients, preoperative CT predicted 28 cases of uric acid stones and 176 cases of non-uric acid stones, including 136 cases of calcium oxalate stones, 38 cases of hydroxyapatite, and 2 cases of cystine stones. Postoperative IR spectral analysis detected 26 cases of uric acid stones and 178 cases of non-uric acid stones, including 129 cases of calcium oxalate stones, 47 cases of hydroxyapatite, and 2 cases of cystine stones. Compared with the preoperative CT results, there were 2 false positives and no false negatives in the classification of uric acid stones. The ROC curve showed that the sensitivity of the CT value for predicting uric acid stones at 100 kV was 96.2%, the specificity was 99.5%, and the area under the ROC curve (AUC) was 0.995, with the best prediction value of 620 HU.The sensitivity of the CT value for predicting uric acid stones at 150 kV was 96.2%, specificity was 85.5%, AUC was 0.916, and the best predictive value was 597.5 HU. The sensitivity of using Ratio values for predicting uric acid stones was 100.0%, specificity was 97.9%, AUC was 0.996, and the best predictive value was 1.14. The CT values for uric acid stones at 100 kV and 150 kV were (558.58±77.07) HU and (521.12±83.54) HU, CT values for calcium oxalate stones were (1 335.26±301.82) HU and (878.21±200.21) HU, CT values for hydroxyapatite were (1 104.09±203.61) HU and (710.38±178.44) HU, respectively.The CT values of cystine stones were (684.5±67.18) HU and (573.5±67.10) HU, respectively, and the differences between uric acid stones and other components were statistically significant ( P<0.01). The Ratio values of uric acid stones, calcium oxalate stones, hydroxyapatite, and cystine stones were 1.08±0.06, 1.52±0.08, 1.62±0.40, and 1.19±0.02, respectively, and the differences were statistically significant ( P<0.01) when comparing uric acid stones with other components. Conclusion:The CT and Ratio values of dual-source stone energy spectrum CT can effectively distinguish uric acid stones from other types of stones, and the accuracy, sensitivity, and specificity of this method for predicting uric acid stones are high.
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Objective To compare the differences of energy spectrum CT between small cell lung cancer(SCLC)with mediastinal lymph node metastasis and mediastinal sarcoidosis.Methods Twenty-five SCLC patients with mediastinal lymph node metastasis(SCLC group)and 26 patients with mediastinal sarcoidosis(sarcoidosis group)confirmed by bronchoscopy and biopsy in Tangshan People's Hospital from January 2018 to June 2019 were selected as the research objects.The CT value,iodine concentration,water concentration and energy spectrum curve slope under different single energy levels were compared between SCLC group and sarcoidosis group.Results The single-energy CT values of 40-80 keV segments in the arterial phase of the SCLC group were significantly higher than those in the sarcoidosis group(all P 0.05).The single-energy CT values of 40-90 keV segments in venous phase of the SCLC group were significantly higher than those of the sarcoidosis group(all P 0.05).The concentrations of iodine in the arterial phase and venous phase of the SCLC group were(11.56±4.06)μg/cm
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Humans , Lung Neoplasms/diagnostic imaging , Lymph Nodes , Lymphatic Metastasis , Sarcoidosis/diagnostic imaging , Small Cell Lung Carcinoma/diagnostic imaging , Tomography, X-Ray ComputedABSTRACT
【Objective】 To compare the enhancement effects of lean body weight （LBW） and total body weight （TBW） as indexes to calculate the contrast agent dosage under the condition of energy spectrum CT scanning. 【Methods】 A total of 218 patients who received liver enhancement CT from November 2018 to January 2019 were enrolled in this study. There were 101 patients in LBW group and 117 patients in TBW group. Both groups were scanned by energy spectrum CT， and the parameters of scanning and reconstruction were identical. The contrast agent dose was 500 mgI/kg （LBW） in LBW group and 450 mgI/kg （TBW） in TBW group， and the injection rate was 2.8 mL/s. Images were transferred to a GE AW4.7 workstation and the 50 keV monochromatic images were analyzed. We compared the dosage of contrast medium， CT value of aorta in arterial phase （HU-aorta）， hepatic enhancement CT value in venous phase （-liver）， the rate of reaching the enhancement standard and variability in the two groups. 【Results】 Compared with TBW group， LBW group had lower contrast agent dosage， HU-aorta and ∆-liver （P0.05）. The variation rate of HU-aorta and ∆-liver in LBW group was lower than that in TBW group. Using LBW as an index to calculate the dosage of liver enhanced CT also made the enhancement of liver parenchyma more consistent in different patients. 【Conclusion】 Even on the premise of energy spectrum CT scanning， using LBW-based contrast injection in liver enhanced CT can not only reduce contrast dose， but also make the enhancement in liver parenchyma more consistent among different patients.
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BACKGROUND: Ilizarov technique has obvious advantages in the treatment of tibial bone defect and can be used to treat various types of tibial bone defect. However, there are still many shortcomings in this technology, which need to be solved urgently. OBJECTIVE: To review the advantages, shortcomings and improvement strategies of Ilizarov technique in the treatment of tibia bone defect. METHODS: PubMed, CNKI and Wanfang databases from 1971 to 2019 were retrieved with the key words of “bone defect, bone transport, accordion maneuver, ultrasonography, energy spectrum CT, pin site infection” in English and Chinese, respectively. Totally 57 eligible articles were included to systematically summarize the advantages, shortcomings and improvement strategies of Ilizarov technique in the treatment of tibia bone defect. RESULTS AND CONCLUSION: (1) Ilizarov technology has obvious advantages in the treatment of the tibia bone defect, combined with soft tissue injury, infection and deformity of the tibia bone defect. (2) New disinfectants, accordion technology, color Doppler ultrasound and energy spectrum CT are effective treatment methods for complications of bone transport technology, such as pin site infection, poor mineralization of new bone in the transfer area, and difficulty in healing at the docking site. These methods can reduce the incidence of complications. (3) It is still necessary to improve the existing treatment techniques or choose new methods to further reduce the incidence of complications.
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Objective To investigate the relationship between the single energy CT value and the tissue density and further evaluate the mass of thyroid.Methods Different substances respectively composed of liquid and solid,liquid and liquid,thyroid gland were selected,and the relationship was investigated between the single energy CT value and the tissue density.Results The CT value was closely related to the content of high atomic number substance.The CT value of thyroid was closely related to the content of iodine.Conclusion It is feasible to measure the thyroid density by the energy spectrum CT.
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Objective To investigate the minimum dose of contrast medium when using spectral CT in cranial CTA. Methods Three groups of patients were required to undergo head CTA examination because of their condition,but different doses of contrast agents were injected.Among them,group 30 mL, group B, group 40mL, group C and group 50 mL were A. Results In group A,the lowest rate of excellent image (23.33%), B group, C group had higher rate of excellent image (93.33%, 96.67%), comparison of the data P<0.05; C group the highest rate of adverse reaction of contrast agent (P<0.05),data comparison P<0.05, A group, B group significantly adverse reactions of contrast agent there is no difference between the situation (P>0.05). Conclusion The use of 40 mL iodide contrast medium in the procedure of cranial CTA examination is effective and safe.
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Objective To investigate the minimum dose of contrast medium when using spectral CT in cranial CTA. Methods Three groups of patients were required to undergo head CTA examination because of their condition,but different doses of contrast agents were injected.Among them,group 30 mL, group B, group 40mL, group C and group 50 mL were A. Results In group A,the lowest rate of excellent image (23.33%), B group, C group had higher rate of excellent image (93.33%, 96.67%), comparison of the data P<0.05; C group the highest rate of adverse reaction of contrast agent (P<0.05),data comparison P<0.05, A group, B group significantly adverse reactions of contrast agent there is no difference between the situation (P>0.05). Conclusion The use of 40 mL iodide contrast medium in the procedure of cranial CTA examination is effective and safe.
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Objective:To discuss the effect of different reconstruction algorithms for the image quality of the computed tomographic angiography (CTA) with low dose on head and neck through comparing the images obtained from different reconstruction algorithms, which included filtering and reflection projection technique (FBP), adaptive statistical iterative (ASIR) model and based on iterative reconstruction (MBIR) after CTA with low dose was applied on head and neck.Methods:30 patients who were implemented the CTA on head and neck were enrolled in this study. The gem energy spectrum CT was applied to scan their head and neck, and the tube voltage was set in low dose (80 kVp), and 60-80 mL contrast agent (350 mg I/mL) was injected in elbow vein as 4mL/s. The other parameters were chosen as routine requirement. The obtained original images were reconstructed by using FBP, 60% ASIR and MBIR, and then the three kinds images were compared and scored by using relative statistical analysis.Results: For the using of different reconstruction algorithms (FBP, 60% ASIR and MBIR), the results of image noise showed MBIR60% ASIR>FBP, and the differences among them were significant. Finally, about the subjective score of image, the results showed MBIR>60% ASIR>FBP, and their differences also were significant.Conclusion: Under gem energy spectrum CT, the image noise of MBIR is lowest and its image quality is best, and it has diagnosis value and meaning in clinical practice.
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Objective To evaluate the application value with Energy Spectrum CT multi -parameter quanti-tative value in differentiating pulmonary occupying lesions (>0.5cm in diameter).Methods Those were retrospec-tively analyzed on 58 cases in pulmonary occupying lesions performed spectrum dual -phase enhanced CT scan and confirmed by pathology,including malignant group 48 cases;10 cases of benign group.Iodine content(IC)was meas-ured in arterial phase(AP)and venous phase (VP)in iodine based on the image and the level of the aorta,and nor-malized iodine concentrations were calculated in the two phases lesions compared with aorta,and the difference between the two normalized iodine concentrations ICD (ICD =NICvp -NICap).To measure the CT value of lesions on 50keV and 100keV energy image,and calculate the energy attenuation curve slope,namely |Hu (100 kev -50kev)/Hu50 |.The differences of NIC,curve slope,and ICD were compared between benign and malignant pulmonary occupying lesions using independent sample t test method.Results In two phase scan,NIC,curve slope of the venous phase and ICD in malignant group were significantly higher than the benign group,(NIC,curve slope of the venous phase and ICD of the malignant group:NICap:0.180 ±0.051,NICvp:0.463 ±0.086,1.696 ±0.475,ICD:0.284 ± 0.071;NIC,curve slope of the venous phase and ICD of the benign group:NICap:0.123 ±0.062,NICvp:0.290 ± 0.119,1.169 ±0.582,ICD:0.166 ±0.073,),but there was no significant difference between the patients with benign and malignant lesions in curve slope of the arterial phase.Conclusion Energy spectrum CT dual -phase enhanced scan can differentiate the nature of benign and malignant pulmonary occupying lesions,and has certain clinical application value.