Objective The aim of this study was to analyze the mechanism of degenerative spondylolisthesis (DS) through measuring vertebra arch angle and facet joint degeneration with 64-slice spiral computed tomography (CT). Methods One hundred and six patients complained of lumbodynia were examined with 64-slice CT. In 28 of 106 patients have lumbar spondylolisthesis, while the other 78 cases have not. The vertebra arch angles of all cases were measured and the facet joint degenerations were analyzed. Results L4--5 vertebra arch angle in DS group were 119. 0°±2. 2°(left) and 118. 8°±1.9° (right) ,respectively. L4--5 vertebra arch angle in control group were 102.9°±1.2°(left) and 104. 7°± 1.2° (right) ,respectively. The joint angle in DS group were 41.1°±1.2°(left) ,and 29.0°±1.2°(right), respectively. The joint angle in control group were 45.5°±2. 1°(left), and 45. 1°±1.2°(right), respectively. There were significant differences of L4--5 vertebra arch angle and more serious of facet joint degeneration( P < 0. 05 ). Conclusion L4 vertebra arch inclination and facet joint degeneration were important to diagnosis of spondylolisthesis.

Objective To study the value of different angle MPR using 64-slice CT in diagnosing spondylolysis.Methods The volume data of isotropic scanning in 50 cases of spondylolysis using 64-slice CT were post-processed by different angle MPR. Four scanning modes were imitated: conventional intervertebral disc scanning mode, transverse scanning, oblique transverse scanning along the direction of vertebral arch, longitudinal and sagittal images of lumbar vertebrae. The detective rate of isthmus fissue, dislocation of disruption end, bone frature piece, false joint of above four methods were analysed. Results The sensitivity of detecting the isthmus fissue was highest by sagittal MPR and oblique transverse MPR images (100%)(u=8.51,P

Objective To evaluate the diagnostic value of oblique axial multiplanar reformation(MPR)imaging in detecting the fracture of geniculate fossa of facial nerve canal and its nearby.Methods 33 cases of facial nerve canal or nearby fracture confirmed by surgery were collected.CT findings(including conventional axial,coronal and oblique axial MPR images)were retrospectively analysed in comparison with that of operation.The diagnostic corresponding rate of two diagnostic modes(the combination of routine axial and coronal imagings,the combination of routine axial,coronal and oblique axial imagings)were compared.Results The fractures of geniculate fossa or the proximate of tympanic segment were seen in 22 cases on pre-operation CT images,including 8 cases on routine axial images,6 cases on routine coronal images and 20 cases on oblique axial MPR images.Local enlargement of geniculate fossa or the proximate of tympanic segment were seen in 26 cases on oblique axial MPR images.There were significant differences between these two diagnostic modes.Conclusion Oblique axial MPR images in combined with routine axial and coronal images can improve the diagnostic corresponding rate of the fracture of geniculate fossa and its nearby.

Objective To optimize the CT pulmonary angiography (CTPA)using right atrium (RA)CT value monitoring to determine the accurate time to peak CT value of pulmonary artery.Methods Sixty patients were randomly divided into two groups and 30 patients for each.Group PT:CTPA acquisition was triggered by pulmonary trunk monitoring,holding breath and 70 mL contrast agent (CA).Group RA:CTPA was performed using triggering from RA with spontaneous respiration and 40 mL CA.Imaging quality, average CT values of pulmonary arteries and veins,as well as their density difference were compared.Results The imaging quality, average CT values of pulmonary arteries and artery-veins density difference were significantly higher in group RA (P <0.05),while the CT values of pulmonary veins were significantly lower in group RA (P <0.05).No significant differences were showed in the proportion of subjects where sixth grade pulmonary arteries were opacified between the two groups (P >0.05).Conclusion CTPA imaging is optimized by triggering from RA CT value monitoring.This technique provides the optimal enhancement of pulmonary artery and minimal contrast filling of pulmonary venous with reduced doses of CA.

Objective To classify the segmental bronchial patterns of the right upper lobe by combining bronchial tree and CT virtual bronchoscopy(CTVE)post-processing techniques from 64-slice spiral CT.Methods Two hundred and four patients with routine thorax scans were enrolled.The segmental bronchi were demonstrated in terms of bronchial tree and CTVE.First,we checked how many patients can be classified with any one of the above post-processing approaches.Then,integrating the two methods,we classified the fight upper segmental bronchial patterns of the 204 patients.At last,the patterns of the right upper bronchus were analyzed.Results bronchial tree post-processing images were stereoscopic and intuitive.It could be used to identify common stem of bifurcation easily,however,it was hard to be used to differentiate short common stem of bifurcation from trifurcation.CTVE demonstrated segmental bronchi from inside of lumen,and can readily show the short common stem of bifurcation and trifurcation of bronchi.Combining two post-processing techniques,the segmental bronchial ramification of the right upper lobe was mainly classified in three types:trifurcation in 76 patients(37.3%),common stem of apical and posterior segmental bronchi in 50 patients(24.5%)and others in 78 patients(38.2%).Conclusion The combination of multiple post-processing of 64-slice CT posses great superiority to classify the pattern of the right upper lobe bronchi.

Objective To assess the clinical application of iterative reconstruction (IR)in the head and neck CT angiography (CTA).Methods 100 patients who underwent the head and neck CTA examination were divided into Group A and Group B at ran-dom.Each group included 50 patients.Group A was performed the conventional-dose scan method (tube voltage 120 kV,tube cur-rent 300 mAs),and images were reconstructed with filtered back projection (FBP);Group B was performed the low-dose scan method [tube voltage 100 kV,dynamic tube current (1 99-399 mAs)],and images were reconstructed with IR.Two experienced radiology physicians reviewed the results of image quality using double blind method,and compared CT dose index volume (CTDIvol)and dose-length product (DLP).Results There were significant differences between radiation dose and image quality of the two groups (P <0.001).Radiation dose of Group B was significantly lower than that of Group A,while image quality of Group B was significantly better than that of Group A.Conclusion In the head and neck CTA applications,compared with FBP,IR recon-struction can reduce radiation dose and improve image quality.

Objective To explore the superiority of dual-phase contrast-enhancement multi-slice computed tomography (MSCT) in observing intracranial tuberculosis.Methods Thirty patients with intracranial tuberculosis,admitted to our hospital from January 2003 to November 2011,were chosen in our study; regular 16-slice spiral CT scan was performed,and then,dual-phase MSCT was performed as follows:contrast-enhanced scan was performed 25 seconds after arrival of contrast material on vascular phase,and 5 minutes after that (lag phase),conventional scanning was performed.According to the different lesions and morphologies of the tuberculosis,they were divided into three types:meningeal thickening,meningeal tuberculoma and parenchymal tuberculoma; the lesion sizes and edge definition and the relationship of the lesions with the surrounding vascular lesions in these three types were scored and calculated,and the differences of the image quality were compared at the vascular phase and lag phase.Results A total of 526 lesions in 30 patients were found,including 22 with meningeal thickening,235 with meningeal tuberculomas/tubercles,and 269 with parenchymal tuberculomas/tubercles.As compared with these three types at the vascular phase (0.36±0.49,0.36±0.52 and 0.41±0.53; 0.00,0.27±0.45 and 0.12±0.32; 1.09±0.68,1.22±0.74 and 1.27±0.75),these three types at the lag phase had significant differences in the scores of lesion sizes (1.64±0.58,1.64±0.58 and 1.59± 0.60) and lesion edge definition (2.00,1.73±0.49 and 1.88±0.34) and the relationship of the lesions with the surrounding vascular lesions (1.82±0.39,2.00±0.06 and 2.00±0.06,P＜0.05).Conclusion Images in the lag phase have advantages on diagnosis of intracranial tuberculosis.

Objective:To investigate the clinical and imaging characteristics of liver density changes in patients with initial-treated drug-sensitive secondary tuberculosis during standardized treatment and after withdrawal when cured.Methods:A retrospective analysis was conducted of 34 patients with initial-treated drug sensitive pulmonary tuberculosis in Beijing Chest Hospital of Capital Medical University and the First Affiliated Hospital of Xinxiang Medical University from January 2014 to April 2019. The chest computed tomography (CT) examination and sputum culture were performed before treatment. The patients received the standardized treatment and they were divided into three groups according to the course of treatment (three, nine and 12 months). Liver density and liver function were followed up during treatment (three, six, nine and 12 months) and after drug withdrawal (3, 6 and 12 months). The measurement data were analyzed by t-test. Results:The average liver density of these three groups gradually decreased during the treatment period, and gradually increased after drug withdrawal. There were five and nine cases of fatty liver occurred at three and six months of treatment in the six-month treatment group, respectively; and six, two and zero cases of fatty liver occurred at three, six, and 12 months after drug withdrawal, respectively. There were four, eight and 11 cases of fatty liver occurred at three, six, and nine months of treatment in the nine-month treatment group, respectively; and seven, two and zero cases occurred at three, six, and 12 months after drug withdrawal, respectively.There were five, 10, 14 and 14 cases of fatty liver occurred at three, six, nine and 12 months of treatment in the 12-month treatment group, respectively; and 12, 10 and five cases occurred at three, six, and 12 months after drug withdrawal, respectively. During the course of treatment, the density of livers of some cases decreased unevenly, and the density of right lobe of the liver was lower than the left lobe. The density of left lobe of the liver was (49.8±4.0) HU, (45.0±3.9) HU, (37.0±9.9) HU, (45.3±8.1) HU, (48.4±6.6) HU at the treatment of six, nine and 12 months and drug withdrawal of three and six months, and the density of right lobe of the liver was (44.0±6.1) HU, (37.2±7.7) HU, (25.5±15.8) HU, (38.5±11.7) HU, (43.8±9.9) HU, the differences were statistically significant ( t=4.611, 4.512, 2.307, 2.803 and 2.291, respectively, all P<0.05), while those were not statistically significant among three months of treatment and 12 months after drug withdrawal ( t=1.573 and 1.199, respectively, both P>0.05). There were two cases showed alanine aminotransferase (ALT) and aspartate amiotransferase (AST) accompanied elevated (ALT>2×upper limits of normal (ULN), AST<2×ULN) at three and six months of treatment, with no abnormalities detected of alkaline phosphatase (ALP) and total bilirubin (TBil). Conclusions:The liver density gradually decreases and uneven fatty liver could appear during anti-tuberculosis treatment, but it gradually returns to normal or relieves after drug withdrawal. The degree of fatty liver is not synchronized with the changes of liver function indexes (ALT, AST, ALP and TBil), which belongs to chronic reversible injury.

Purpose To construct and validate a machine learning-based diagnostic model for distinguishing between Mycobacterium avium-intracellular complex pulmonary disease(MAC-PD)and pulmonary tuberculosis(PTB)via chest CT images.Materials and Methods Retrospective data from patients diagnosed with MAC-PD and PTB between May 2021 and August 2022 at Beijing Chest Hospital,Capital Medical University,which were collected as the training set.The prospective external validation set was obtained from patients at the First Affiliated Hospital of Henan University of Chinese Medicine between September 2022 and May 2023.Clinical and radiological data were analyzed,and multivariable logistic regression,random forest and support vector machine(SVM)models were established and externally validated using the validation set.The diagnostic performance of models were evaluated using receiver operating characteristic curve and precision-recall curve,and the differences of the areas under the curve of various models were compared via the Delong test.Results There were significant differences in age and hemoptysis rate between the two groups(t=30.414,P<0.001;χ2=6.186,P=0.013).There were statistically significant differences in cavity types and morphology between the two groups(χ2=6.546,P=0.011;χ2=24.113,P<0.001),but there was no significant difference in the distribution and characteristics of cavitary lesions(P>0.05).There were significant differences in the types and distribution of bronchiectasis between the two groups(χ2=4.634,P=0.031;χ2=23.145,P<0.001).Compared with logistic regression and random forest models,the SVM model had better differential diagnostic performance,and the area under the receiver operating characteristic curve,sensitivity,specificity,accuracy,positive predictive value and negative predictive value were 0.960(95%CI 0.935-0.985),85.7%,93.6%,90.5%,93.3%,88.0%and 0.885(95%CI 0.803-0.967),respectively,76.7%,80.0%,78.3%,79.3%,77.4%.The precision-recall curve showed that the SVM model had high precision and low recall,that was,the model performs well.Conclusion The machine learning-based models exhibits excellent diagnostic performance and can assist in differentiating MAC-PD and PTB.

Objective To study the clinical and CT findings of bronchiolar adenoma. Methods Patients diagnosed with bronchiolar adenoma confirmed by surgical pathology at Linyi People's Hospital and Yantai Yuhuangding Hospital from 2016 to 2021 were collected. Their clinical and CT imaging features were retrospectively analyzed. Results Finally, 25 patients were collected, including 6 males and 19 females, aged 32-73 (58.6±10.1) years. The immunohistochemical Ki-67 (MIB1) of all lesions was <5%. The lesions were located in the upper and middle lobe of both lungs in 9 patients, lower lobes in 16 patients, extrapulmonary zone in 22 patients, intrapulmonary middle zone in 3 patients, round in 11 patients, irregular in 14 patients, well-defined in 22 patients, pure ground-glass/mixed ground-glass nodules in 6 patients, solid nodules in 19 patients. There were 11 patients with central small cavity, 18 patients with single bronchioles sign, 19 patients without adhesion with adjacent pleura, and 24 patients without mediastinal lymph node enlargement. Conclusion Bronchiolar adenomas usually occur in the middle-aged and elderly, mostly in the lower lobe of both lungs and the distribution of the peripheral lung field, most of the patients do not have any clinical symptoms, and the postoperative prognosis is good. CT may show large nodules or masses, pure ground-glass/mixed ground-glass nodules, irregular solid nodules and central small cavities. Irregular stellate nodules, central small cavity shadow, and single bronchiolar vascular bundle connected with the lesions are relatively specific imaging findings of bronchiolar adenoma.