Analysis of the Parotid Glands on an Energy Spectrum CT Iodine Map to Evaluate Irradiation-Induced Acute Xerostomia in Patients With Nasopharyngeal Carcinoma.

Objective: This prospective study aims to evaluate acute irradiation-induced xerostomia during radiotherapy by utilizing the normalized iodine concentration (NIC) derived from energy spectrum computed tomography (CT) iodine maps. Methods: In this prospective study, we evaluated 28 patients diagnosed with nasopharyngeal carcinoma. At 4 distinct stages of radiotherapy (0, 10, 20, and 30 fractions), each patient underwent CT scans to generate iodine maps. The NIC of both the left and right parotid glands was obtained, with the NIC at the 0-fraction stage serving as the baseline measurement. After statistically comparing the NIC obtained in the arterial phase, early venous phase, late venous phase, and delayed phase, we chose the late venous iodine concentration as the NIC and proceeded to analyze the variations in NIC at each radiotherapy interval. Using the series of NIC values, we conducted hypothesis tests to evaluate the extent of change in NIC within the parotid gland across different stages. Furthermore, we identified the specific time point at which the NIC decay exhibited the most statistically significant results. In addition, we evaluated the xerostomia grades of the patients at these 4 stages, following the radiation therapy oncology group (RTOG) xerostomia evaluation standard, to draw comparisons with the changes observed in NIC. Results: The NIC in the late venous phase exhibited the highest level of statistical significance (P < .001). There was a noticeable attenuation in NIC as the RTOG dry mouth grade increased. Particularly, at the 20 fraction, the NIC experienced the most substantial attenuation (P < .001), a significant negative correlation was observed between the NIC of the left, right, and both parotid glands, and the RTOG evaluation grade of acute irradiation-induced xerostomia (P < .001, r = -0.46; P < .001, r = -0.45; P < .001, r = -0.47). The critical NIC values for the left, right, and both parotid glands when acute xerostomia occurred were 0.175, 0.185, and 0.345 mg/ml, respectively, with AUC = 0.73, AUC = 0.75, and AUC = 0.75. Conclusion: The NIC may be used to evaluate changes in parotid gland function during radiotherapy and acute irradiation-induced xerostomia.

Quantitative value of energy spectrum CT material separation technology in nonalcoholic fatty liver / 实用放射学杂志

Objective To investigate the feasibility of energy spectrum CT material separation technology for quantitative evaluation of nonalcoholic fatty liver patients,to compare the accuracy of this method with the conventional liver/spleen CT ratio for grading liver fat content.Methods Sixty patients diagnosed with nonalcoholic fatty liver and 20 healthy volunteers were chosen to undergo liver MR multi-echo(ME)Dixon and energy spectrum CT scans.The proton density fat fraction(PDFF),fat concentration(FC),and liver/spleen CT ratio were then measured for each participant.According to PDFF,nonalcoholic fatty liver patients were divided into mild fatty liver group,moderate fatty liver group,and severe fatty liver group.Results With the increase in PDFF,FC increased and the liver/spleen CT ratio decreased.The difference between FC groups in normal,mild,moderate and severe fatty liver groups was statistically significant(P<0.05),while the difference between the liver/spleen CT ratio of normal group and mild fatty liver group was not statistically significant(P>0.05).The receiver operating characteristic(ROC)curve analysis showed that when the critical value of FC was 351.19 mg/mL,the sensitivity,specificity and area under the curve for normal group and fatty liver group were 0.95,0.1 and 0.99,respectively.Conclusion The energy spectrum CT material separation technology has a good correlation between the fat content measured by the MR ME Dixon,which is superior to the fat content measured by the liver/spleen CT ratio.For patients with nonalcoholic fatty liver,FC in energy spectrum CT has high accuracy in differentiating normal and mild fatty liver.

Optimal combination periprosthetic vasculature visualization and metal artifact reduction by spectral computed tomography using virtual monoenergetic images in total hip arthroplasty.

OBJECTIVES: To investigate the optimal parameters of spectral CT for preferably visualizing the periprosthetic vasculature and metal artifact reduction (MAR) in total hip arthroplasty (THA). METHODS: A total of 34 THA of 30 patients were retrospectively included. Image reconstructions included conventional image (CI), CI combined with MAR (CIMAR), and virtual monoenergetic images (VMI) combined with MAR (VMIMAR) at 50-120 keV. The attenuation and standard deviation of the vessel and artifact, and the width of artifact were measured. Qualitative scoring was evaluated including the vascular contour, the extent of artifact, and overall diagnostic evaluation. RESULTS: The attenuation, noise of the vessel and artifact, and the width of artifact decreased as the energy level increased (p < 0.001). The downtrend was relatively flat at 80-120 keV, and the vascular attenuation dropped to 200 HU at 90 keV. The qualitative rating of vascular contour was significantly higher at CIMAR (3.47) and VMIMAR 60-80 keV (2.82-3.65) compared with CI (2.03) (p ≤ 0.029), and the highest score occurred at 70 and 80 keV (3.65 and 3.56). The score of the extent of artifact was higher at VMIMAR 80 keV than CIMAR (3.53 VS 3.12, p = 0.003). The score of the overall diagnostic evaluation was higher at VMIMAR 70 and 80 keV (3.32 and 3.53, respectively) than CIMAR (3.12) (p ≤ 0.035). CONCLUSION: Eighty kiloelectron volts on VMIMAR, providing satisfactorily reduced metal artifacts and improved vascular visualization, can be an optimal recommended parameter of spectrum CT for the assessment of periprosthetic vasculature in THA patients. CRITICAL RELEVANCE STATEMENT: The metal artifact is gradually reducing with increasing energy level; however, the vascular visualization is worsening. The vascular visualization is terrible above 100 keV, while the vessel is disturbed by artifacts below 70 keV. The best performance is found at 80 keV. KEY POINTS: • VMIMAR can provide both reduced metal artifacts and improved vascular visualization. • Eighty kiloelectron volts on VMIMAR performs best in vascular visualization of total hip arthroplasty patients. • Energy spectrum CT is recommended for routine use in patients with total hip arthroplasty.

GSI CTA evaluation of the vertebrobasilar artery in normal adults at high altitude.

Objective: Vascular geometry is influenced by several factors during its growth and development. Here, we compared the differences in vertebrobasilar geometry among residents of a plateau region at different altitudes and investigated the relationship between vascular geometry and altitude. Methods: Data of some adults in the plateau region who experienced vertigo and headache as the main symptoms but had no evident abnormalities found during imaging examination were collected. They were divided into three groups based on an altitude gradient: group A (1,800-2,500 masl), group B (2,500-3,500 masl), and group C (over 3,500 masl). They underwent head-neck energy-spectrum computed tomography angiography with a gemstone spectral imaging scanning protocol. The following indices were observed: (1) vertebrobasilar geometric configurations (walking, tuning fork, lambda, and no confluence), (2) vertebral artery (VA) hypoplasia, (3) the bending number of bilateral VA intracranial segment, (4) length and tortuosity of the basilar artery (BA), and (5) anteroposterior (AP)-mid-BA angle, BA-VA angle, lateral-mid-BA angle, and VA-VA angle. Results: Of the 222 subjects, 84 of them were included in group A, 76 in group B, and 62 in group C. The number of participants in walking, tuning fork, lambda, and no confluence geometries was 93, 71, 50, and 8, respectively. As altitude increased, the tortuosity of the BA also increased (1.05 ± 0.06 vs. 1.06 ± 0.08 vs. 1.10 ± 0.13, P = 0.005), as did the lateral-mid-BA angle (23.18° ± 9.53° vs. 26.05° ± 10.10° vs. 31.07° ± 15.12°, P = 0.007) and the BA-VA angle (32.98° ± 17.85° vs. 34.51° ± 17.96° vs. 41.51° ± 19.22°, P = 0.024). There was a relatively weak positive correlation between the altitude and the tortuosity of the BA (rs = 0.190, P = 0.005), the lateral-mid-BA angle (rs = 0.201, P = 0.003), and the BA-VA angle (rs = 0.183, P = 0.006) which showed a significant difference. Compared with groups A and B, there were more multibending groups and fewer oligo-bending groups in group C (P < 0.001). There was no difference found in the vertebral artery hypoplasia, actual length of the BA, VA-VA angle, and AP-mid-BA angle among the three groups. Conclusion: As the altitude increased, the tortuosity of the BA and the sagittal angle of the vertebrobasilar arterial system also increased. The increase in altitude can lead to changes in vertebrobasilar geometry.

Energy spectrum CT index-based machine learning model predicts the effect of intravenous thrombolysis in lower limbs.

To develop a noninvasive machine learning (ML) model based on energy spectrum computed tomography venography (CTV) indices for preoperatively predicting the effect of intravenous thrombolytic treatment in lower limbs. A total of 3492 slices containing thrombus regions from 58 veins in lower limbs in a cohort of 18 patients, divided in good and poor thrombolysis prognosis groups, were analyzed. Key indices were selected by univariate analysis and Pearson correlation coefficient test. A support vector machine classifier-based model was developed through ten-fold cross validation. Model performance was assessed in terms of discrimination, calibration, and clinical usefulness at both per-slice and per-vessel levels. Continuous variables and categorical variables were compared between good and poor thrombolysis prognosis group by Mann-Whitney U-test and chi-square test, respectively. A nomogram was built by integrating clinical factors and the energy spectrum CTV index-based score calculated by the model. Six indices selected from 192 indices were used to build the predictive model. The ML model achieved area under the curves (AUCs) of 0.838 and 0.767 [95% CI (confidence interval), 0.825-0.850, 0.752-0.781] in the training and validation datasets at the per-slice level, and the per-vessel level AUCs were 0.945 and 0.876 (95% CI, 0.852-0.988, 0.763-0.948) in the training and validation datasets, respectively. The nomogram showed better performance with the per-vessel level AUC, accuracy, sensitivity and specificity, yielding 0.901(95% CI, 0.793-0.964), 86.2%, 87.9% and 84.0% in the validation dataset, respectively. There was no significant difference in the vessel distribution between good and poor thrombolysis prognosis groups (chi-square test, p = 0.671). The energy spectrum CTV index-based ML model achieved favorable effectiveness in predicting the outcome of vessel-level intravenous thrombolysis. A nomogram integrating clinical factors, and risk score calculated by the developed model showed improved performance and had potential to be used as a noninvasive preoperative tool for clinicians.

Predictive value of dual-source stone energy spectrum CT for uric acid stones / 中华泌尿外科杂志

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.

Prediction of VEGF and EGFR Expression in Peripheral Lung Cancer Based on the Radiomics Model of Spectral CT Enhanced Images.

Background: Energy spectrum CT is an effective method to evaluate the biological behavior of lung cancer. Radiomics is a non-invasive technology to obtain histological information related to lung cancer. Purpose: To investigate the value of the radiomics models on the bases of enhanced spectral CT images of peripheral lung cancer to predict the expression of the vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR). Material and Methods: This study retrospectively analyzed 73 patients with peripheral lung cancer confirmed by postoperative pathology. All patients underwent dual-phase enhanced spectral CT scans before surgery. Regions of interest (ROI) were delineated in the arterial phase and venous phase. Key radiomics features were extracted and models were established to predict the expression of VEGF and EGFR, respectively. All models were established based on the expression levels of VEGF and EGFR in tissues detected by immunohistochemical staining as reference standards. Receiver operating characteristic (ROC) curve and calibration curve were used to evaluate the predictive performance of each model, and decision curve analysis (DCA) was used to evaluate the clinical utility of the models. Results: In predicting the expression level of VEGF, the combined (COMB) model composed of one spectral feature and two radiomics features achieved the best performance with area under ROC (AUC) 0.867 (95% CI: 0.767-0.966), accuracy of 0.812, sensitivity of 0.879, and specificity of 0.667. According to the expression level of EGFR, three importance radiomics features were retained in the arterial and venous phases to establish the multiphase phase model which has the best performance with AUC of 0.950 (95% confidence interval: 0.89-1.00), accuracy of 0.896, sensitivity of 0.868, and specificity of 1. Conclusion: The radiomics model of enhanced spectral CT images of peripheral lung cancer can predict the expression of EGFR and VEGF.

[Differences of Energy Spectrum CT Findings between Small Cell Lung Cancer with Mediastinal Lymph Node Metastasis and Mediastinal Sarcoidosis].

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 90-140 keV segments were not significantly different from 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),and the single-energy CT values of 100-140 keV segments were not significantly different from 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 3 and(13.39±0.87)µg/cm 3,respectively,which were significantly higher than those [(4.43±3.85)µg/cm 3,t=11.564,P=0.026;(7.23±2.71)µg/cm 3,t=13.653,P=0.021] in the sarcoidosis group.The concentrations of water in the arterial and venous phases of the SCLC group were(1040.67±5.62)mg/cm 3 and(1035.23±8.57)mg/cm 3,respectively,which showed no statistically significant difference compared with those [(1028.87±6.94)mg/cm 3,t=3.155,P=1.861;(1021.53±4.68)mg/cm 3,t=3.265,P=1.687] in the sarcoidosis group.The slopes of energy spectrum curve at 40-70 keV,70-100 keV and 100-140 keV in venous phase of the SCLC group were significantly higher than those of the sarcoidosis group(all P <0.05),whereas they showed no significant difference between the two groups in arterial phase(all P >0.05).Conclusion The differences between SCLC with mediastinal lymph node metastasis and mediastinal sarcoidosis can be shown on the single-energy CT values of 40-80 keV in arterial phase and 40-90 keV in venous phase,iodine concentrations in arterial phase and venous phase,and the slope of energy spectrum curve in venous phase.

Study on the correlation between energy spectrum computed tomography imaging and the pathological characteristics and prognosis of cervical cancer.

BACKGROUND: The purpose of this study is to investigate the correlation between energy spectrum computed tomography (CT) imaging and the pathological characteristics and prognosis of cervical cancer. METHODS: All participants underwent energy spectrum CT plain scan and enhanced scan of the cervix, uterine body, and common iliac vein. The correlation between the slope of energy spectrum attenuation curve and pathological characteristics and curative effect was analyzed, and the receiver operating characteristic (ROC) curve of the slope of energy spectrum attenuation curve to distinguish some pathological characteristics and curative effect was constructed. RESULTS: The energy spectrum curves of cervix, uterine body, and common iliac vein all showed a downward trend. The slope of cervix energy spectrum curve showed a significant difference in different differentiation degree (P<0.05), and the slope of energy spectrum curve showed an upward trend. The slope of energy spectrum curve of common iliac vein was significantly different between high and low cell proliferation antigen marker (Ki67) (P<0.05), and the slope of Ki67 high expression was higher than that of Ki67 low expression. Treatment was effective in 17 participants and ineffective in 11. After treatment, the energy spectrum curve slope of cervix and energy spectrum curve slope of common iliac vein in the effective group were significantly increased compared with before treatment (P<0.05), and the energy spectrum curve slope of cervix in the ineffective group was increased compared with before treatment, but the difference was not significant (P>0.05). The area under the curve (AUC) of distinguishing Ki67 expression of energy spectrum curve slope of common iliac vein was 0.7008, sensitivity was 66.67%, and specificity was 62.34%. The AUC of distinguishing the curative effect of cervical energy spectrum curve slope was 0.6131, sensitivity was 56.25%, and specificity was 59.09%. The AUC of distinguishing the curative effect of energy spectrum curve slope of common iliac vein was 0.6563, sensitivity was 60.42%, and specificity was 58.33%. CONCLUSIONS: The energy spectrum curve slope has potential value in the prediction of certain specific pathological types of cervical cancer and the evaluation of curative effect.

Application of LBW index combined with energy spectrum CT in reducing the contrast agent dose of liver enhanced CT / 西安交通大学学报(医学版)

【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.

Differences of Energy Spectrum CT Findings between Small Cell Lung Cancer with Mediastinal Lymph Node Metastasis and Mediastinal Sarcoidosis / 中国医学科学院学报

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

Advantages and improvement strategies of ilizarov technique in the treatment of tibial bone defect / 中国组织工程研究

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.

Rectal clear cell sarcoma-a case report.

Gastrointestinal clear cell sarcomas (GICCSs) are malignant mesenchymal tumour that occur in the wall of gastrointestinal tract, mostly in the ileum and rarely in the rectum. These tumours are highly invasive, and often have metastasized via the lymphatic system or bloodstream by the time of diagnosis. In this case, the patient was admitted for gastric fundus mass, who was subsequently found and confirmed by biopsy as clear cell sarcoma of rectum. Computed tomography (CT) and magnetic resonance imaging (MRI) showed multiple metastatic lesions in lymph node, lung, liver and bone. Furthermore, energy spectrum CT was used to confirm that the nature of gastric fundus mass and rectal lesion were consistent. So, this case may be multiple clear cell sarcomas in the rectum and stomach or clear cell sarcoma in the rectum with gastric fundus metastasis. Unfortunately, after several days of immunotherapy, the patient died due to abnormal liver function. At present, GICCS mainly relies on surgical resection, and the effect of radiotherapy and chemotherapy is not good. Therefore, how to find lesions as earlier as possible and make accurate diagnosis is particularly important. CT and MRI are essential examinations in the diagnosis of tumors. Whether they are helpful for the diagnosis of GICCS is the focus of our attention.

Clinical study of using spectral CT at the minimal dose of contrast medium in cranial CTA / 中国生化药物杂志

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.

Clinical study of using spectral CT at the minimal dose of contrast medium in cranial CTA / 中国生化药物杂志

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.

Effects of different reconstruction algorithms on the image quality of CTA with low dose on head and neck / 中国医学装备

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.

Measuring thyroid density by energy spectrum CT / 医疗卫生装备

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.

Evaluation of energy spectrum CT for the measurement of thyroid iodine content.

BACKGROUND: This study aims to provide a reference for the diagnosis of iodine deficiency disorder by evaluating the normal thyroid iodine content by energy spectrum computed tomography (CT) and calculating the iodine content ratio of thyroid to sternocleidomastoid. METHODS: The thyroid glands of 226 patients were scanned by energy spectrum CT, and the images were analyzed using the GSI Viewer software. Based on the imaging findings, the iodine levels of the thyroid lobes as well as the bilateral sternocleidomastoids were evaluated, and their iodine content ratios were calculated. RESULTS: No statistically significant difference was found in the thyroid iodine content between the left and right thyroid lobes (p > 0.05). However, there was a significant difference in the thyroid iodine content between men and women (p < 0.01). Additionally, the thyroid iodine content was found to decrease gradually with age. The iodine content ratio of thyroid to sternocleidomastoid was 96.6271 ± 33.2442. CONCLUSION: Gemstone energy spectrum CT can be used for the measurement of thyroid iodine content in the human body. It can play a significant role in the diagnosis of iodine deficiency disorder.

Analysis of the application effect with energy spectrum CT multi -parameter quantitative values in pulmonary qccupying lesions / 中国基层医药

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.