Objective To analyse the CT findings of Bochdalek hernia in adult.Methods The CT scan of 42 cases were reviewed showing a mass abutting the upper surface of the diaphragm, the defect was located in the posteromedial aspect of hemidiaphragm with continuity of subdiaphragmatic and supradiaphramatic densities through the diaphramatic defect. Among these, 25 cases were male and 17 cases female. The average age was 64 years, 71.4%≥60 old.Results 53 Bochdalek hernias were identified in 42 cases, 11 cases were bilateral, 21 cases were on the left and 10 cases were on the right side. The diaphragmatic defects diameter ranged 0.5～6.7 cm, the median was 2.8 cm. The range of Bochdalek hernias diameter was 1.5～9.0 cm, with median of 3.7 cm. There was a significant association between diaphragmatic defects and size of hernias (r s=0.72,P

To evaluate the features of mediastinal tuberculous lymphadenopathy in adults on CT, especially on enhanced CT scan. Methods Seventeen patients with adult mediastinal tuberculous lymphadenopathy proved by operation, biopsy, and (or) anti tuberculous therapy were evaluated on chest film and CT scan, and 6 patients were performed with enhanced CT scan. Results The chest film finding was intrathoracic mass and (or) hilar mass only in 6 patients, but CT detected 37 enlarged nodes in all patients. Most of the enlarged nodes were located in 2R and (or) 4R (59.4%). 30 nodes (81 1%) presented as low density in the center of nodes, and there were marked enhancement at the periphery areas of the nodes after enhancement in all 6 patients (100 0%). Conclusion CT scan, especially the enhanced CT scan, is the first method of choice to diagnose the mediastinal tuberculous lymphadenopathy in adults.

Objective To review the serial CT findings of cryptogenic organizing pneumonia(COP)and semiquantitatively analyze the changes after corticosteroid therapy.Methods The clinical and radiological features of 13 patients with COP confirmed by pathology were retrospectively collected and analyzed.The lung lesions extent on CT scans was estimated using semi-quantitative method.Changes of overall disease extent were evaluated by comparing the initial CT images and the follow-up CT scans after corticosteroid therapy.Results CT images of all cases revealed diffuse and bilateral lesions,mainly located in lower zone,distributed as predominantly subpleural and(or)along the bronchovascular bundle.The two most common manifestations of lung abnormality on initial scans were ground-glass opacity(GGO)(13 cases)and consolidation(12 cases),the average areas of which were 13％ and 10％ respectively.The treatment with antibiotics was ineffective.After treatment with corticosteroid,the lesions resolved completely in 2 patients ; the disease was decreased in extent in 8 patients ; and the lesion showed no change in extent in one patient,while the disease progressed in extent in 2 patients on follow-up CT.The most common CT findings were GGO(10 cases)and reticulation(5 cases),followed by consolidation(4 cases),the average areas of which were 19％,2％ and 1％ respectively.Conclusion The CT features of the patients with COP are characteristic.The most lesions resolved or improved after corticosteroid therapy on follow-up CT scans.The estimation of disease extent with semi-quantitative method is helpful for the clinicians to evaluate the therapeutic effect.

Objective To compare radiation dose and image quality between prospective electrocardiograph(ECG)-triggered axial seau and retrospective ECG-gated helical scan in coronary 64-slice CT angiography(CTA).Methods Seventy-seven consecutive patients[group A.Average body mass index (BMI):24.6,heart rate＜70 bpm]underwent 64-slice CTA using prospective ECG-triggered axial scan protocol(120 kV,mA tailored to BMI).For each patient,the simulated radiation dose using retrospective ECG-gated scan protocol without ECG-driven X-ray current modulation technology was calculated and recorded at sanle kV and mA.Retrospective ECG-gated scan protocol was performed on 30 consecutive patients in another group(group B.Average BMI:23.9,heart rate＜70 bpm).The image quality was blindly evaluated between group A and B(paired t-test was used and P＜0.05 as a significant difference).Results There Was a significant difference(t=18.50,P＜0.01)between radiation dose of group A (3.37 mSv)and that of group B(18.13 mSv),decreased by 81.4%.The image quality of group A could fulfill clinical diagnostic needs.The average radiation dose of using simulated helical scan without optimization was 17.29 mSv,which wag similar to that of group B(18.13 mSv)(t=0.87,P＞0.05).Condusion Prospective ECG-triggered axial scan in 64-slice coronary CTA Call significantly reduce radiation exposure and the image quality can fulfill clinical diagnostic needs.

Objective To evaluate the effect of spectral CT monochromatic imaging on the detection of hepatic tumors. Methods Forty-two patients with hepatic tumors (14 patients with hepatocellular carcinoma, 12 patients with metastatic tumor, 16 patients with hemangioma) underwent CT spectral imaging. During arterial phase, portal phase and venous phase, 140 kVp polychromatic images and 70 keV monochromatic images were obtained. Paired-sample t tests were used to compare the image quality score,liver noise and tumor-to-liver contrast-to-noise ratio (CNR) between the two image data sets. The detection rates of various tumors during each phase were compared. Results The image quality scores of various tumors during three phases were (4. 30 ± 0. 25) and (3.63 ± 0. 22) averagely for the 70 keV and 140 kVp images. The liver noises were (8. 82 ± 0. 82) and ( 10. 66 ± 1.10) , and the CNRs were 5.39 and 3. 89,respectively. The image quality score, the liver noise and the CNR of 70 keV images were significantly greater than those of 140 kVp images (P ＜0. 05 ). The detection rates of various tumors during each phase were higher with 70 keV images (78％-100％) than with 140 kVp images (65％-96％), except the hepatic metastatic tumors and the hepatic hemangiomas during the arterial phase. The detection rate was more increased for the small lesions less than 1 cm (57％-100％ vs. 14％-91％ ). Conclusion By substantially improving the image quality and increasing the tumor-to-liver conspicuity, the 70 keV monochromatic imaging of spectral CT improves the detection of hepatic tumors and is more sensitive for the detection of small lesions.

Objective To evaluate the muscle mass in elderly patients with inguinal hernia using CT scan.Methods 30 male (age 70-90 years) hospitalized patients scheduled to receive surgery for inguinal hernia were selected into study group, 10 male health volunteers (40-50 years) were involved in adult control group, and 10 men of the same age as the study receiving annual physical examination were enrolled as elderly control group.General information were recorded;CT scanning of the stomach muscles and thigh muscles were conducted, and the muscle area was calculated using a special software.Results The index of grip strength in the study group was significantly lower than the adult control group [(36.44 ± 14.15) kg vs.(77.30 ± 22.69) kg, P =0.001], the calf circumference in the study group was significantly less than the adult control group [(25.18 ±2.31) cm vs.(27.62 ±2.33) cm, P =0.006].There was no significant difference in L3 abdominal area, subcutaneous fat area, abdominal fat area, and vertical spinal muscular volume between the study group and the adult control group;while the L3 abdominal muscle area and vertical spinal muscular mass was significantly less in the study group than in the adult control group [(12 094.23 ± 1 970.30) mm2 vs.(17462.00±1 600.58) mm2, P=0.001;(1 642.60±266.90) mm2 vs.(2 003.50±350.91) mm2,P =0.007].L3 skeletal muscle index of the study group was 50.64 ±7.52 and 66.7％ (20/30) of the study group had sarcopenia (≤52.4％).The CT findings of abdominal muscle of the study group were not significantly different from those of the elderly control group.The thigh muscle mass in the study group was significantly less than that in the control group (P =0.001), but there was no significant inter-group difference in thigh fat and femur areas (P ＞ 0.05).Conclusion The muscle mass and strength in elderly patients with inguinal hernia are significantly lower than those of adult controls, for which CT scan can be applied for assessment.

Objective To investigate the radiation dose and image quality of spectral and conventional CT scan in neck.Methods Sixty patients with enhanced neck CT scan were analyzed retrospectively.The 30 patients with spectral CT scan were included in spectral CT group,and the 30 patients with conventional CT scan were included in conventional CT group.The tube voltage,tube current and rotation speed of the spectral CT group were fast switching with 80 and 140 kVp,630 mA and 0.5 s,respectively.The scanning parameters of conventional CT group were 120 kVp,auto tube current (100 to 600 mA),and 0.6 s,respectively.The objective evaluation [noise and (contrast to noise ratio) CNR] and subjective scores in the upper,middle and lower neck were evaluated.The radiation dose was also evaluated in the two groups.The independent-samples t test was used in comparison of the radiation dose.The independent-samples t test and the rank sum test were used to compare the objective and subjective image quality.Results The CT dose index of spectral and conventional scan in the neck were 17.77 mGy and (17.26±2.18) mGy,respectively without significant difference (t=-1.26,P=0.218).The noises of 65 keV images in upper,middle and lower neck were (4.5 ± 0.8),(4.5 ± 0.9),(5.2 ± 1.0) HU,and the noises of conventional CT images in above-mentioned regions were (4.5± 1.1),(4.1± 1.0),(5.0± 1.7) HU.There was no significant differences (t=0.102,-1.362,-0.621;P＞0.05).The subjective scores of 65 keV images in upper,middle and lower neck were (4.1 ± 0.3),(4.7 ± 0.5),(3.8 ± 0.7),while the subjective scores of conventional CT images in associated region were (4.1±0.4),(4.6 ±0.5),(3.5 ±0.6),wihtout significant differences (Z=-0.286,-0.531,-1.568;P＞0.05).The noises of 55 keV images in upper,middle and lower neck were (5.4±0.9),(5.6± 1.1),(6.6± 1.6) HU,which were significantly higher than noise of conventional images (t=-3.614,-5.560,-3.784;P＜0.05).The subjective scores of 55 keV images in upper and middle neck were (3.7±0.5),(4.2±0.4),which were significantly lower than those of conventional images (Z=-2.541,-3.136;P＜0.05).The subjective score of 55 keV images in lower neck was (3.3±0.8),which was no significant difference in comparison with conventional image (Z=-1.318,P＞0.05).There was no significant difference between the CNR of conventional images and CNR of spectral images with 65 keV and 55 keV in upper,middle and lower neck (P＞0.05).Conclusion The radiation dose and the image quality of spectral CT scan are same to the conventional CT scan in the neck,the 65 keV monochromatic images can be used routinely.

Objective To analyze the correlation between anterior circulation artery stenosis and lacune or lacunar infarct(LI) in elderly patients.Methods A retrospective analysis of data was performed in 111 patients with intracranial artery atherosclerosis,ischemic cerebral infarction or transient ischemic attack from January to December 2016 in our hospital.All the patients underwent non-contrast brain MRI or CT scan,as well as one-stop dynamic whole brain 4D CT angiography and CT perfusion scan(CTA-CTP/ perfusion).Imaging data were retrospectively analyzed.Intracranial 4D CTA was produced by using MIP and CPR post processing.The correlation of intracranial internal carotid artery(ICA)and middle cerebral artery (MCA)stenosis with lacunar infarct or lacune was analyzed by chi-square test using IBM SPSS Statistics 22.0 software.Results The average age of 111 patients was(68.4± 6.8)years.A total of 19 phases with 6080 images were obtained by one-stop scanning.The optimal phase of artery visualization was selected from 19 phases for evaluating artery stenosis.Intracranial ICA and/or MCA stenosis were revealed in 94 patients,including 73(65.8％)patients with LI or lacune and 21 patients(18.9％)without LI or lacune.17 patients without intracranial ICA or anterior circulation of MCA stenosis included 7 patients(6.3 ％)with LI or lacune and 10 patients(9.0％)without LI or lacune.Anterior circulation vessels stenosis was positively correlated with lacunar infarction or lacune(x2 =7.794,P=0.005).94 patients with anterior circulation vessels stenosis were further divided into 2 subgroups:unilateral and bilateral stenosis.39 cases showed unilateral vessels stenosis,including 25 cases (26.6 ％) with LI or lacunein,and 14 cases (14.9 ％) without LI or lacunein.And 55 cases showed bilateral vessel stenosis,including 48 cases (51.1％)with LI or lacune,and 7 case (7.4 ％) without LI or lacune.The risk for LI or lacunein was statistically higher in bilateral vessel stenosis than in unilateral vessel stenosis(x2 =7.061,P=0.008).Patients with anterior circulation vessels stenosis combined with LI or lacune were 73 cases,including 31 cases of grade Ⅰ,19 cases of grade Ⅱ,14 cases of grade Ⅲ,and 9 cases of grade Ⅳaccording to Trial criteria(NASCET)classification,with no significant difference between the different grades of anterior circulation vessels stenosis.Conclusions A correlation between ICA or MCA stenosis and lacunar infarction or lacune may exist.Risk for lacunar infarction or lacune is higher in patients with bilateral artery stenosis than in patients with unilateral artery stenosis.

Objective:To assess the prognostic value of the collateral status and clot burden score based on four-dimensional computed tomography angiography(4D CTA)in anteriorcir culation is chemics troke patients with large ischemic core after endovascular treatment.Methods:Clinical and imaging data of 36 anterior circulation ischemic stroke patients with large infarct core (infarct core≥50.0 ml) after endovascular treatment at our institution from March 2016 to September 2020 were retrospectively reviewed. According to the modified Rankin Scale (mRS) score, patients were divided into the good outcome (mRS score 0-2) and poor outcome (mRS score 3-6) groups. Mann-Whitney U and Fisher tests were used to compare the 4D CTA collateral circulation score, clot burden score, and baseline clinical data between the good and poor outcome groups. Multivariate logistic regression was used to analyze the risk factors associated with the poor outcome (mRS score 3-6) and mortality in patients with large infarct core stroke. Finally, based on the 90-day outcome, a ROC curve was used to obtain the cut-off values for poor prognosis (mRS 3-6) and death, respectively. Results:Ten patients (27.8%) had good outcome and 26 (72.2%) had poor outcome. The patients in the poor outcome group had older median age, higher blood glucose, lower 4D CTA collateral circulation score, lower clot burden score, larger infarct core volume, and higher hemorrhagic transformation and brain hernia (all P<0.05). Multivariate logistic regression showed that the poor collateral circulation score on 4D CTA( OR=0.18, 95% CI: 0.03-0.99, P<0.05)and clot burden score( OR=0.64, 95% CI: 0.44-0.93, P<0.05) were independent predictors of the poor prognosis. The ROC curves revealed that the cut-off value of infarct core for distinguishing between good prognosis and poor prognosis was 63.7 ml, while that for distinguishing between survival and death was 130.3 ml. Conclusions:Endovascular treatment may improve the prognosis of patients with large infarct core of anterior circulation is chemic stroke if the patients have good 4D CTA collateral circulation score and high clot burden score.