BACKGROUND:The development and evolution of atlas are complex,and there are a few research reports. CT imaging can show the normal development process,anatomical structure,developmental variation and deformity of the axis. It has important clinical value to clarify the time of occurrence of ossification center of axis and closure of epiphyseal plate and its evolution process and law.OBJECTIVE:To present the anatomical structure of the normal development and variation of children's axis based on CT images.METHODS:CT images obtained from 732 children aged 0 to 15 years who underwent neck scans between June 2016 and November 2019 were retrospectively analyzed. The observation indicators encompassed the axis odontoid,bilateral pedicle,vertebral ossification center,secondary ossification center at the tip of odontoid,pedicle,base of odontoid,and posterior median epiphyseal plate,as well as any variations or deformities in axis development. The changes in these indicators were analyzed and compared across different age groups. SPSS 17.0 statistical software package was utilized for data classification and statistical analysis. RESULTS AND CONCLUSION:(1) A total of 732 subjects were examined,comprising 718 cases (98.1％) with normal development of the axis and 14 cases (1.9％) exhibiting deformity or dysplasia. (2) The axis demonstrated the presence of five ossification centers,including those of the bilateral pedicles,odontoid process,and vertebral body,which were observed at birth. The median age for the secondary ossification center located at the tip of the odontoid process was determined to be 5.7 years,with an interquartile range of 4.1 to 7 years. The earliest recorded occurrence was observed at 8 months and 22 days,while the latest occurrence was noted at 12 years and 10 months. (3) The median age at which fusion took place was 6 years,with an interquartile range of 5-8 years. The maximum age at which non-fusion was observed was 8 years and 9 months,while the minimum age at which fusion occurred was 4 years and 3 months. (4) The median age at which bilateral epiphyseal plate closure occurred was approximately 3.8 years,with an interquartile range of about 2.9-4.6years. The earliest observed closure was at 2 years and 3 months,while the latest observed unclosure was at 6 years old. (5) The median age at which odontoid base epiphyseal plate closure occurred was 5.2 years,with an interquartile range of 3.5-6.8 years. The minimum age for closure was 2 years and 6 months,and the latest age for non-closure was 9 years and 6 months. (6) The posterior median epiphyseal plate typically closed at a median age of 1.5 years,with an interquartile range of 1.0-2.1 years. However,two cases exhibited delayed closure,occurring at ages 2 years and 5 months,and 14 years,respectively. Theearliest closure observed was at 6 months and 20 days. (7) Axis malformation or developmental abnormalities,including 7 cases of accessory ossification center and accessory epiphyseal plate,3 cases of free ossified small bones in the axis,2 cases of posterior median epiphyseal plate failure,2 cases of secondary ossification centers in the absence of the apex of odontosis,and 1 case of absence at ossification center in the odontoid of the armature vertebrae. (8) It is concluded that the utilization of multi-slice spiral CT scanning in conjunction with the multi-plane reconstruction technique enables comprehensive visualization of the anatomical structure of the axis,facilitating precise assessment of both its typical developmental variations and deformities.

Purpose To explore the value of tumor intratumoral and peritumoral radiomics models based on dynamic contrast-enhanced MRI in predicting benign and malignant breast tumors.Materials and Methods This retrospective study analyzed clinical data and MRI imaging features from 309 patients with pathologically confirmed solitary breast tumors at the Second Affiliated Hospital of Xiamen Medical College from August 2018 to December 2022.The cohort was randomly divided into training(n=248)and testing(n=61)cohorts in an 8∶2 ratio.Using second-phase dynamic contrast-enhanced MRI images,five distinct peritumoral regions were segmented through 3D-Slicer software:intratumoral region,peritumoral 2 mm region,peritumoral 4 mm region,intratumoral combined with peritumoral 2 mm region and intratumoral combined with peritumoral 4 mm region.Radiomic features were extracted from these regions of interest.Machine learning algorithms integrated with Logistic regression analysis were employed for feature selection,with cross-validation techniques determining the optimal radiomic signature combination.Results Of 309 patients,150 were benign tumors and 159 were malignant tumors.The age,maximum diameter and enhancement type of benign and malignant breast tumors were statistically significant(Z/χ2=-7.695,-5.775,30.248;all P<0.001).For the region of interest of intratumoral combined with peritumoral 4 mm region,the area under curve,sensitivity,specificity,accuracy and F1 scores of the training and validation were 0.893,89.1%,75.0%,82.3%,0.838 and 0.881,74.2%,86.7%,80.3%,0.793,respectively.In the training set,the area under curve of intratumoral combined with peritumoral 4 mm region was significantly higher than that of intratumoral,peritumoral 2 mm,peritumoral 4 mm and intratumoral combined with peritumoral 2 mm regional imaging models(Z=2.506,2.982,3.392,2.157;all P<0.05).The Hosmer-Lemeshow test showed that the calibration curve of the model combined with region of interest of intratumoral combined with peritumoral 4 mm region was highly consistent with the ideal curve(training P=0.381,validation P=0.159).The decision curve indicated that the net benefit of the radiomics model in the region of interest of intratumoral combined with peritumoral 4 mm region was the highest when the risk threshold was between 0 and 1.0.Conclusion The radiomics model has good predictive performance in predicting benign or malignant breast tumors,among them the combined region of interest of intratumoral combined with peritumoral 4 mm region provides the best performance and highest benefit.The technology clinical application will provide a non-invasive predictive method for the differential diagnosis of benign and malignant breast tumors.

BACKGROUND:The development and evolution of atlas are complex,and there are a few research reports. CT imaging can show the normal development process,anatomical structure,developmental variation and deformity of the axis. It has important clinical value to clarify the time of occurrence of ossification center of axis and closure of epiphyseal plate and its evolution process and law.OBJECTIVE:To present the anatomical structure of the normal development and variation of children's axis based on CT images.METHODS:CT images obtained from 732 children aged 0 to 15 years who underwent neck scans between June 2016 and November 2019 were retrospectively analyzed. The observation indicators encompassed the axis odontoid,bilateral pedicle,vertebral ossification center,secondary ossification center at the tip of odontoid,pedicle,base of odontoid,and posterior median epiphyseal plate,as well as any variations or deformities in axis development. The changes in these indicators were analyzed and compared across different age groups. SPSS 17.0 statistical software package was utilized for data classification and statistical analysis. RESULTS AND CONCLUSION:(1) A total of 732 subjects were examined,comprising 718 cases (98.1％) with normal development of the axis and 14 cases (1.9％) exhibiting deformity or dysplasia. (2) The axis demonstrated the presence of five ossification centers,including those of the bilateral pedicles,odontoid process,and vertebral body,which were observed at birth. The median age for the secondary ossification center located at the tip of the odontoid process was determined to be 5.7 years,with an interquartile range of 4.1 to 7 years. The earliest recorded occurrence was observed at 8 months and 22 days,while the latest occurrence was noted at 12 years and 10 months. (3) The median age at which fusion took place was 6 years,with an interquartile range of 5-8 years. The maximum age at which non-fusion was observed was 8 years and 9 months,while the minimum age at which fusion occurred was 4 years and 3 months. (4) The median age at which bilateral epiphyseal plate closure occurred was approximately 3.8 years,with an interquartile range of about 2.9-4.6years. The earliest observed closure was at 2 years and 3 months,while the latest observed unclosure was at 6 years old. (5) The median age at which odontoid base epiphyseal plate closure occurred was 5.2 years,with an interquartile range of 3.5-6.8 years. The minimum age for closure was 2 years and 6 months,and the latest age for non-closure was 9 years and 6 months. (6) The posterior median epiphyseal plate typically closed at a median age of 1.5 years,with an interquartile range of 1.0-2.1 years. However,two cases exhibited delayed closure,occurring at ages 2 years and 5 months,and 14 years,respectively. Theearliest closure observed was at 6 months and 20 days. (7) Axis malformation or developmental abnormalities,including 7 cases of accessory ossification center and accessory epiphyseal plate,3 cases of free ossified small bones in the axis,2 cases of posterior median epiphyseal plate failure,2 cases of secondary ossification centers in the absence of the apex of odontosis,and 1 case of absence at ossification center in the odontoid of the armature vertebrae. (8) It is concluded that the utilization of multi-slice spiral CT scanning in conjunction with the multi-plane reconstruction technique enables comprehensive visualization of the anatomical structure of the axis,facilitating precise assessment of both its typical developmental variations and deformities.

Purpose To explore the value of tumor intratumoral and peritumoral radiomics models based on dynamic contrast-enhanced MRI in predicting benign and malignant breast tumors.Materials and Methods This retrospective study analyzed clinical data and MRI imaging features from 309 patients with pathologically confirmed solitary breast tumors at the Second Affiliated Hospital of Xiamen Medical College from August 2018 to December 2022.The cohort was randomly divided into training(n=248)and testing(n=61)cohorts in an 8∶2 ratio.Using second-phase dynamic contrast-enhanced MRI images,five distinct peritumoral regions were segmented through 3D-Slicer software:intratumoral region,peritumoral 2 mm region,peritumoral 4 mm region,intratumoral combined with peritumoral 2 mm region and intratumoral combined with peritumoral 4 mm region.Radiomic features were extracted from these regions of interest.Machine learning algorithms integrated with Logistic regression analysis were employed for feature selection,with cross-validation techniques determining the optimal radiomic signature combination.Results Of 309 patients,150 were benign tumors and 159 were malignant tumors.The age,maximum diameter and enhancement type of benign and malignant breast tumors were statistically significant(Z/χ2=-7.695,-5.775,30.248;all P<0.001).For the region of interest of intratumoral combined with peritumoral 4 mm region,the area under curve,sensitivity,specificity,accuracy and F1 scores of the training and validation were 0.893,89.1%,75.0%,82.3%,0.838 and 0.881,74.2%,86.7%,80.3%,0.793,respectively.In the training set,the area under curve of intratumoral combined with peritumoral 4 mm region was significantly higher than that of intratumoral,peritumoral 2 mm,peritumoral 4 mm and intratumoral combined with peritumoral 2 mm regional imaging models(Z=2.506,2.982,3.392,2.157;all P<0.05).The Hosmer-Lemeshow test showed that the calibration curve of the model combined with region of interest of intratumoral combined with peritumoral 4 mm region was highly consistent with the ideal curve(training P=0.381,validation P=0.159).The decision curve indicated that the net benefit of the radiomics model in the region of interest of intratumoral combined with peritumoral 4 mm region was the highest when the risk threshold was between 0 and 1.0.Conclusion The radiomics model has good predictive performance in predicting benign or malignant breast tumors,among them the combined region of interest of intratumoral combined with peritumoral 4 mm region provides the best performance and highest benefit.The technology clinical application will provide a non-invasive predictive method for the differential diagnosis of benign and malignant breast tumors.

Objective:To establish and verify the prediction model of benign or malignant of solitary pulmonary nodules (SPNs≤20 mm) based on artificial intelligence.Methods:Totally 338 SPNs (≤20 mm) from 279 patients, confirmed by operation and pathology, were selected in Zhongshan Hospital Xiamen University from November 2018 to May 2020. Clinical data (age, gender, smoking history, individual and family history of malignancy), image features (maximum diameter, minimum diameter, solid proportion, volume, lobulation sign, burr sign, vacuole sign, cavity sign, pleural indentation sign, and radiomic features (maximum CT value, minimum CT value, average CT value, median CT value, CT value standard deviation, skewness, peak, energy, entropy) were analyzed retrospectively. All the data of patients were randomly divided into training set (271 SPNs) and test set (67 SPNs). In the training set, the clinical, image features and radiomic features were first selected by the least absolute shrinkage and selection operator (LASSO) regression, then the independent risk factors of SPN (≤20 mm) were screened out by multi-variate logistic regression analysis, and the nomogram prediction models were constructed. Finally, the data of test set were used to verify the prediction model by the ROC curve and calibration curve (CC).Results:In the training set of 271 SPNs, 81 SPNs were benign and 190 malignant. After analysis of LASSO regression and multi-factor logistics regression, the independent predictors of benign or malignant SPN were age, gender, largest diameter, vacuole sign and solid proportion. The prediction model was P=e x/(1+e x), x=-2.583+0.027×age+1.519×gender+0.127×maximum diameter-2.132×solid proportion+1.720×vacuole sign. The results of the model showed that the area under curve (AUC) of ROC was 0.850, and the sensitivity was 73.7%, specificity was 82.7% and accuracy was 82.3%. In the test set of 67 SPNs, 22 SPNs were benign and 45 malignant. The results showed that the AUC of ROC was 0.882, and the sensitivity was 82.2%, specificity was 81.8% and accuracy was 85.1%. The calibration nomogram of prediction model showed that CC from training set or test set well coincided with its individual ideal curve ( Ptraining=0.688, Ptest=0.618). Conclusion:Prediction model of benign or malignant SPN ≤20 mm is established based on AI; it can obtain the prediction probability and has good diagnostic efficiency.

BACKGROUND:The carotid siphon has a complex structure, which is difficult for two-dimensional imaging observation due to shelter from the basicranial bone. Digital subtraction angiography is conducive to display the course of carotid siphon, but there is a lack of anatomical landmarks. Three-dimensional CT imaging is beneficial to show the structure of carotid siphon and have its measurement, which provides a new and effective means in relevant studies.
OBJECTIVE:To clarify the morphology and calcification distribution of the carotid siphon, thereby providing an objective basis for relevant clinical and basic research.
METHODS: A total of 206 patients, over 50 years old, with no lesions or variation under head and neck CT angiography were selected and divided into non-calcification group (n=70) and calcification group (n=136). The carotid siphon was reconstructed on the imaging workstation to observe the classification (“U”, “V”, “C” and “S” types) and calcification distribution, the bending angles of C4 and C5 segments as wel as lumen diameter were measured.
RESULTS AND CONCLUSION:The 70 patients in the non-calcification group were at a mean age of (59.17±10.27) years, and the “U” type accounted for 35.7%, “V” type for 30.7%, “C” type for 27.2%, and “S” type for 6.4%; Among them, 33.3% patients (25/70) had the same type at both sides; the lumen diameter was (4.92±0.63) mm, and the blending angles of C4 and C5 were (87.23±16.66)° and (49.21±16.01)°. In the calcification group, the mean age was (67.39±9.32) years, and there were 41.5% of “U” type, 33.1% of “V” type, 24.3% of “C” type, 1.1% of 24.3%, and among the 136 patients, 43.4% (59/136) showed the same type at both sides; the lumen diameter was (4.90±0.44) mm, and the blending angles of C4 and C5 segments were (84.44±17.20)° and (52.57±14.16)°. There were significant differences in age and “S” type between the two groups (P < 0.05), but no statistical difference in the lumen diameter and blending angles of C4 and C5 (P > 0.05). In the calcification group, the calcification percentage of inwardly and outwardly curved regions was 13.60% and 19.01% for C4, 27.34% and 16.52% for C5, 9.94% and 13.60% for C6. The morphology of the carotid siphon is mostly seen as “U”, “V”, “C” types, and over 50% types are different at both sides. Calcification of the lumen wal is seen most in the inwardly curved region of C5 segment, folowed by the outwardly curved region of C4 segment. The incidence of calcification is increased with age, which is lower in the S-type carotid siphon. The lumen diameter and blending angle of the carotid siphon show no correlation with calcifications.

BACKGROUND:The siphon of internal carotid artery is a complex of bending and surrounding structure, which has become a research hot in the field of medical imaging and regional anatomy. There is little research on the hemodynamics of internal carotid artery. Finite element analysis provides the basis for the related dynamics research. OBJECTIVE:To explicit the hemodynamic characteristics of the normal and stenosis internal carotid artery, and to explore the relevant influential factors. METHODS:Finite element model of the siphon of internal carotid artery was built based on 64-slice spiral CT data, and then, three-dimensional models were constructed using Mimics 10.01 software. There were simulations of the normal and post-stenosis blood flows with ANSYS 13.0 CFX software, to observe the changes of hemodynamics, and to analyze their characteristics and differences. RESULTS AND CONCLUSION:The normal blood flow at the siphon of internal carotid artery was in a laminar state, but rotation and turbulent flow formed at the two angle regions. The velocity of external bending zone was slower than that of the internal. The slower was the velocity, the more obvious was the turbulence. The wal shear force decreased at the angle regions, and the wal shear force of external bending zone was smal er than that of the internal. At the region of arterial stenosis, the blood flow was sped, and at the downstream, turbulent flow and low zone of wal shear force were formed. With the increase of stenosis severity, the turbulent flow and low wal shear force area were expanded. Central stenosis showed more obvious effects than the eccentric one. The degree of stenosis and bending at the siphon of internal carotid artery can directly influence the formation of turbulent flow and low wal shear force area, which are more obvious at the external bending zone and central stenosis.

BACKGROUNDMagnetic resonance imaging (MRI) has advantages in showing pathologic changes of disc space infection, which is important in clinical treatment. The purpose of this study was to describe the MRI findings of disc space infections in relation to chronicity.

METHODSMRI of 60 patients from January 1, 2002 to April 30, 2012 in Ottawa Hospital were retrospectively evaluated by two radiologists blindly. All patients had histological confirmation, with 55 having microbiological confirmation as well. These patients were divided into acute (n = 18), subacute (n = 21) and chronic (n = 21) based on histological findings. The following potential signs of MRI finding were assessed: marrow edema, endplate erosions, disk fluid and height change, paraspinal mass, epidural collection, facet fluid and enhancement in the marrow, disc, paraspinal mass, and epidural involvement. Statistical analysis consisted of t- or F-tests and chi-square test.

RESULTSIn the 60 patients, 83 infected discs (single disc in 45 patients, 2-4 discs in 15 patients) were found, including 22 discs in the acute group, 30 discs in the subacute group, and 31 discs in the chronic group. There was a significant difference in the extent of marrow edema between the acute, subacute and chronic groups (P < 0.05), with a gradually increasing extent from acute to chronic. The extent of endplate erosions increased with chronicity, but was not statistically significant. There were significant differences in the disc fluid, epidural collection, and disc enhancement among the acute, subacute and chronic groups, as well as the facet fluid between acute and chronic groups (P < 0.05). There were no significant differences in the present probability of disc height loss, paraspinal mass, and marrow enhancement among the three groups (P > 0.05).

CONCLUSIONSFrom acute to chronic infections, the extent of marrow edema and endplate erosions appeared to gradually increase. Epidural collections and facet fluid are most frequently found in the acute group, while disc fluid and disc enhancement are more common in the chronic patients.

Adult ; Aged ; Aged, 80 and over ; Discitis ; diagnosis ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Retrospective Studies

BACKGROUND:The hemodynamics changes of aneurysm provide the basis for aneurysm treatment and ruptured aneurysm prevention, while finite element analysis is a good technical means.
OBJECTIVE:To construct the two-way flow-solid coupling model of internal carotid artery aneurysm, and thus simulate its flows.
METHODS:CT angiography data of internal carotid artery aneurysm were recorded with GE Lightspeed 64 spiral CT scanning, and the corresponding three-dimension model was constructed with mimics10.01 software. Then the fluid-solid coupled flow simulations were done depending on Ansys+Fluent software.
RESULTS AND CONCLUSION:The two-way flow-solid coupling model of internal carotid artery aneurysm was built, with the same morphology and anatomy as the three-dimensional CT imaging. In the whole cardiac cycle, the blood flow of aneurysm body was swirl typed and its velocity was slower than that of the aneurysm neck;the deformation, wal shear stress, pressure and von Mises stress of aneurysm wal were the maximum at the neck, and the minimum at the top. Their highest value was at the 0.16 s (rapid ejection period), and their lowest value at the 0.74 s (relaxation period). On the basis of CT angiography data, to construct the two-way flow-solid coupling model of internal carotid artery aneurysm is a simple and practical method. The blood flow simulation of aneurysm is close to the human physiological conditions, and the results wil provide new theoretical basis for the study on the occurrence and development of aneurysm.

Background Magnetic resonance imaging (MRI) has advantages in showing pathologic changes of disc space infection,which is important in clinical treatment.The purpose of this study was to describe the MRI findings of disc space infections in relation to chronicity.Methods MRI of 60 patients from January 1,2002 to April 30,2012 in Ottawa Hospital were retrospectively evaluated by two radiologists blindly.All patients had histological confirmation,with 55 having microbiological confirmation as well.These patients were divided into acute (n=18),subacute (n=21) and chronic (n=21) based on histological findings.The following potential signs of MRI finding were assessed:marrow edema,endplate erosions,disk fluid and height change,paraspinal mass,epidural collection,facet fluid and enhancement in the marrow,disc,paraspinal mass,and epidural involvement.Statistical analysis consisted of t-or F-tests and chi-square test.Results In the 60 patients,83 infected discs (single disc in 45 patients,2-4 discs in 15 patients) were found,including 22 discs in the acute group,30 discs in the subacute group,and 31 discs in the chronic group.There was a significant difference in the extent of marrow edema between the acute,subacute and chronic groups (P ＜0.05),with a gradually increasing extent from acute to chronic.The extent of endplate erosions increased with chronicity,but was not statistically significant.There were significant differences in the disc fluid,epidural collection,and disc enhancement among the acute,subacute and chronic groups,as well as the facet fluid between acute and chronic groups (P ＜0.05).There were no significant differences in the present probability of disc height loss,paraspinal mass,and marrow enhancement among the three groups (P ＞0.05).Conclusions From acute to chronic infections,the extent of marrow edema and endplate erosions appeared to gradually increase.Epidural collections and facet fluid are most frequently found in the acute group,while disc fluid and disc enhancement are more common in the chronic patients.