Development and validation of a CT-based radiomics model for differentiating pneumonia-like primary pulmonary lymphoma from infectious pneumonia: A multicenter study / 中华医学杂志(英文版)

BACKGROUND@#Pneumonia-like primary pulmonary lymphoma (PPL) was commonly misdiagnosed as infectious pneumonia, leading to delayed treatment. The purpose of this study was to establish a computed tomography (CT)-based radiomics model to differentiate pneumonia-like PPL from infectious pneumonia.@*METHODS@#In this retrospective study, 79 patients with pneumonia-like PPL and 176 patients with infectious pneumonia from 12 medical centers were enrolled. Patients from center 1 to center 7 were assigned to the training or validation cohort, and the remaining patients from other centers were used as the external test cohort. Radiomics features were extracted from CT images. A three-step procedure was applied for radiomics feature selection and radiomics signature building, including the inter- and intra-class correlation coefficients (ICCs), a one-way analysis of variance (ANOVA), and least absolute shrinkage and selection operator (LASSO). Univariate and multivariate analyses were used to identify the significant clinicoradiological variables and construct a clinical factor model. Two radiologists reviewed the CT images for the external test set. Performance of the radiomics model, clinical factor model, and each radiologist were assessed by receiver operating characteristic, and area under the curve (AUC) was compared.@*RESULTS@#A total of 144 patients (44 with pneumonia-like PPL and 100 infectious pneumonia) were in the training cohort, 38 patients (12 with pneumonia-like PPL and 26 infectious pneumonia) were in the validation cohort, and 73 patients (23 with pneumonia-like PPL and 50 infectious pneumonia) were in the external test cohort. Twenty-three radiomics features were selected to build the radiomics model, which yielded AUCs of 0.95 (95% confidence interval [CI]: 0.94-0.99), 0.93 (95% CI: 0.85-0.98), and 0.94 (95% CI: 0.87-0.99) in the training, validation, and external test cohort, respectively. The AUCs for the two readers and clinical factor model were 0.74 (95% CI: 0.63-0.83), 0.72 (95% CI: 0.62-0.82), and 0.73 (95% CI: 0.62-0.84) in the external test cohort, respectively. The radiomics model outperformed both the readers' interpretation and clinical factor model ( P <0.05).@*CONCLUSIONS@#The CT-based radiomics model may provide an effective and non-invasive tool to differentiate pneumonia-like PPL from infectious pneumonia, which might provide assistance for clinicians in tailoring precise therapy.

Application value of spectral CT multi-parameter imaging in predicting gastric cancer lymph node metastasis / 中华消化外科杂志

Objective:To investigate the application value of spectral computed tomo-graphy (CT) multi-parameter imaging in predicting gastric cancer lymph node metastasis.Methods:The retrospective case-control study was conducted. The clinicopathological data of 86 patients with gastric cancer who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2014 to June 2017 were collected. There were 53 males and 33 females, aged from 22 to 87 years, with a median age of 53 years. All patients received abdominal plain scan and arterial and venous phase contrast spectral scan. Images of plain scan, 70 keV monochromatic and iodine-based images in arterial and venous phase were analyzed on post-processing working station. Observation indicators: (1) gastric cancer lymph node metastasis; (2) analysis of influencing factors for lymph node metastasis in gastric cancer; (3) introduction of special cases. Count data were described as absolute numbers. Univariate analysis was performed using the chi-square test or rank sum test. Multivariate analysis was conducted using the Logistic regression model.Results:(1) Gastric cancer lymph node metastasis: of the 86 patients, 64 cases had lymph nodes metastasis and 22 had no lymph nodes metastasis. (2) Analysis of influencing factors for lymph node metastasis in gastric cancer: results of univariate analysis showed that tumor growth pattern, tumor diameter, infiltration of peritumor fat, CT value in arterial phase, CT value in venous phase, iodine value in venous phase were related factors affecting lymph nodes metastasis in gastric cancer ( χ2=6.753, Z=-3.180, χ2=7.649, Z=-2.051, -2.971, -2.547, P<0.05). Results of multivariate analysis showed that infiltration of peritumor fat and the iodine value in venous phase were greater than 12(100 μg/cm 3) and not greater than 16(100 μg/cm 3), or greater than 16(100 μg/cm 3) were independent risk factors affecting lymph nodes metastasis in gastric cancer ( odds ratio=13.154, 3.761, 7.583, 95% confidence interval as 2.597-66.620, 1.893-8.572, 4.769-16.692, P<0.05). (3) Introduction of special cases: case 1 was male, aged 46 years. Results of preoperative spectral CT enhanced scan showed gastric antrum space occupying lesion combined with enlarged lymph nodes. During enhancement arterial phase, spectral CT 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed gastric wall thickening with mild to moderate enhancement, clear fat space in serosa and enlarged lymph nodes in lesser curvature. The spectral CT 70 keV monochromatic images and corresponding iodine-based images below pylorus level in the transverse view showed subpyloric enlarged lymph nodes. During enhancement venous phase, the 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed layered enhancement of gastric antrum lesions and mucosal enhancement, with a high iodine value. The patient was diagnosed as gastric antrum cancer with lymph node metastasis, no serosal or peritumoral fat invasion. Results of postoperative pathological examination showed moderately differentiated adenocarcinoma of gastric antrum with serosal invasion and lymph node metastasis. Case 2 was male, aged 53 years. Results of preoperative spectral CT enhanced scan showed gastric cancer of lesser curvature combined with enlarged lymph nodes. During enhancement arterial phase, 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed gastric wall heterogeneous thickening of lesser curvature, with moderate enhancement, obscure peritumor fat space, unclear serosa, and multiple enlarged lymph nodes in lesser curvature. During enhancement venous phase, 70 keV monochromatic images in the transverse view showed unclear boundary between lesions and enlarged lymph nodes in lesser curvature, obscure peritumor fat. During enhancement arterial phase, 70 keV monochromatic images of celiac trunk layer in the transverse view showed parasplenic artery lymph nodes, with circular enhancement and no enhancement in central necrotic elements. The patient was diagnosed as gastric cancer of lesser curvature with lymph node metastasis, serosal and peritumor fat invasion. Results of postoperative pathological examination showed poorly differentiated adenocarcinoma of gastric antrum with serosal invasion and lymph node metastasis. Conclusion:The infiltration of peritumor fat and iodine value in venous phase are independent factors affecting gastric cancer lymph node metastasis.

Diagnostic value of wide-detector energy spectrum CT combined with high concentration iodine contrast agent in Budd-Chiari syndrome / 中华放射学杂志

Objective:To investigate the diagnostic value of energy spectrum CT combined with high concentration iodine contrast agent (400 mg/ml) for hepatic venous system CT angiography in patients with Budd-Chiari syndrome (BCS).Methods:A total of 48 patients with BCS who underwent the hepatic venous system CT angiography were prospectively collected from March to August 2019 at the First Affiliated Hospital of Zhengzhou University. Patients were randomly divided into control group (350 mg /ml) and study group (400 mg /ml). In the control group, the dosage of iodine contrast agent was 1.6 ml/kg, and the flow rate was 4.0 ml/s. In the study group, the dosage of iodine contrast agent was 1.4 ml/kg. Double-flow rate injection protocol was used in the study group, i.e. 3.50 ml/s (80% dosage), 1.75 ml/s (20% dosage), 3.50 ml/s (40 ml normal saline). Revolution CT scanner was used for energy spectrum scanning. Quantitative parameters, qualitative visual parameters and radiation dose were compared between the two groups. Wilcoxon test, t test, χ 2 test and Mann-Whitney U test were used. Results:The dosage of iodine contrast agent in the study group [(94.53±16.02) ml] was lower than that in the control group [(106.40±20.19) ml, t=2.257, P<0.05]. The injection speed of the control group was higher than that of the study group (4.00 ml/s and 3.15 ml/s). CT values of portal vein, hepatic vein, inferior vena cava, and hepatic parenchyma, signal to noise ratio, contrast noise ratio, CT dose index, dose length product, effective dose and subjective scores showed no significant differences between the 2 groups (all P>0.05). Conclusion:For patients with BCS, high quality images could be obtained to meet the requirement of diagnosis in hepatic vein system CT angiography using high concentration iodine contrast agent (400 mg/ml) with low dosage of contrast agent and low flow rate.

CT imaging features of hepatic perivascular epithelioid cell tumor / 实用放射学杂志

Objective To investigate the CT feasures of hepatic perivascular epithelioid cell tumors (PEComa),to improve the understanding and diagnosis of this disease.Methods CT findings and clinical data of 13 patients with hepatic PEComa were analyzed retrospectively.Results Among the 1 3 PEComa patients,2 cases were multiple focis and 1 1 cases were single lesion.The maximum diameter of the lesions ranges from 26 mm to 96 mm,with mean diameter (52.77±24.94)mm.The density of 6 cases large lesions was heterogeneous on plain CT image,and the atery phase showed significantly inhomogeneous enhancement and the enhancement decreased in venous phase.7 cases of small lesions was homogeneous in density and showed uniform enhancement in arterial phase.The adjacent organs were compressed in 4 cases,the hepatic artery was located at the margin or inside the tumor in 4 cases,the portal vein or its branch passed through the tumor in 2 cases,and the inferior vena cava was compressed and shifted in 1 case.Conclusion CT manifestations of hepatic PEComa have some characteristics,when the tumor shows homogeneous in density and uniform enhancement in arterial phase,and the enhancement decreases in venous phase,with the thick vessel in the center or at the peripheral,it may prompt diagnosis.

AnalysisofgenderdifferencesincoronaryarterydiseaseinpatientswithHIVinfectionbasedonCCTA / 实用放射学杂志

Objective Toanalyzethedifferencesofthecoronaryarterycalciumscore,andtheprevalence,severity,characteristics ofcoronaryarteryplaquesbetweenAIDSinfectedfemaleandmale.Methods 158AIDSpatients(72femalesand86 males)and102 HIVGuninfectedpatients(49femalesand53 males)withsuspectedcoronaryarterydiseaseinourhospitalwereenrolledbetween March2017andFebruary2018.Patientsunderwentcoronarycomputedtomographyangiography (CCTA)bythethirdgenerationdual sourceforceCT.Thedifferencesofcoronaryarteryplaquesbetweengenderswereassessed.Results In HIVGuninfectedpatients,the prevalenceoftotalplaque,mixedplaque,severestenosisandtwoGvesseldiseasewassignificantlyhigherinmalethanfemale(allP＜0.05) andtheprevalenceofnonGcalcifiedplaquewassignificantlylowerinmalethanfemale(allP＜0.05).InAIDSpatients,theprevalence oftotalplaque,calcifiedplaque,severestenosisandCACS＞100wassignificantlyhigherin malethanfemale(allP＜0.05)andthe prevalenceofnonGcalcifiedplaqueandmixedplaquesignificantlywaslowerinmalethanfemale(allP＜0.05).Theprevalenceofthree ormorevesselsdiseasein maleAIDSpatientswassignificantlyhigherthanfemaleAIDSpatients.Conclusion MaleAIDSpatients havehighercoronarycalcifiedscoreandheaviercoronaryatherosclerosisburdens.Inaddition,femaleAIDSpatientshavelesscoronary atherosclerosisburdens,butmixedplaqueseemtobemorefrequently.

Application of low-tube current using adaptive statistic iterative reconstruction in the accuracy of spinal quantitative CT / 中华放射医学与防护杂志

Objective To investigate the reproducibility and accuracy of spinal BMD (bone mineral density) by low mA using adaptive statistic iterative reconstruction based on phantom model.Methods European spine phantom (ESP) was scanned with 5 different tube currents (40,60,80,100 and 120 mA) on the GE Revolution prototype.All data were transferred to the quantitative CT (QCT) PRO workstation for measuring the bone mineral density (BMD).And all data were reconstructed using different adaptive statistical iterative reconstruction veo (ASiR-V) weighting percentages from ASiR-V 0 filtered back projection(FBP) to ASiR-V 100％,at interval of 20％.Quantitative measurements of CT value,noise,and contrast noise ratio (CNR) of L1,L2 and L3 were measured in each group.The singlefactor analysis of variance (ANOVA) was used to compare the bone mineral density values of different mA and ASiR-V weighting percentages.Results Volume CT dose index(CTDIvol) and dose length product (DLP) were positively correlated with tube current(r =1).The BMD of ESP phantoms had no statistically significant differences among the multi-center lumbar spines L1,L2 and L3 at different doses under the same ASiR-V weighting percentages (P ＞ 0.05),as well as at the same dose under different ASiR-V weighting percentages(P ＞ 0.05).The error of bone density accuracy was within 6％.Conclusions Low dosage of 120 kV and 40 mA using ASiR-V without affecting the accuracy of BMD has the potential effect to reduce radiation dose without compromising image quality.

CT Diagnosis of Rare Primary Renal Malignant Tumors in Children / 中国医学影像学杂志

Purpose To analyze the CT features of rare primary renal malignant tumors in children, and to improve the understanding and diagnosis of this disease. Materials and Methods The clinical and imaging data of 18 children with rare primary renal malignant tumors confirmed by pathology were retrospectively analyzed. Plain CT scan and enhanced CT scan were performed in all 18 cases, and their CT features were analyzed. Results For 18 patients, 7 cases were clear cell sarcoma of kidney, the mean diameter of tumor was (10.5±3.6) cm. The plain CT scan showed inhomogeneous low density. Most of the tumors were prominent outside the kidney, with 2 cases of small, patchy calcifications. Enhanced CT scan showed mild, moderate and inhomogeneous enhancement in the cortical stage, with varying degrees of necrosis. It could be seen as fish-like. There was stripe-like enhancement and vascular shadow passing through the lesion, which was further enhanced in the parenchymal phase. In 6 cases of renal cell carcinoma, the average diameter of the tumor was (5.5±1.5) cm. The plain CT scan showed the boundary of the renal tissue was clear and the false capsule, with 4 cases of coarse nodular calcification, and there was a low density cystic necrosis area and a slightly higher density bleeding shadow in the tumor. The enhanced CT scan showed mild and moderate inhomogeneous enhancement in the cortical phase of the lesion, and in the parenchymal phase, it could be slightly lower or slightly higher than that in the cortical phase. In the 5 cases of renal neuroblastoma, the average diameter was (13.9±7.7) cm, plain CT scan showed mixed density, with 2 cases of irregular calcification. Enhanced CT scan showed mild enhancement of the cortical phase of the tumor, and small blood vessels around the mass of the tumor. Some were tortuous and thicken, and the degree of enhancement was increased in parenchymal terms. Conclusion Primary renal malignant tumors in children that our team analyzed are relatively rare. In clinic, we should consider the possibility of these kinds of tumors in children with malignant kidney occupying, so as to reduce missed diagnosis and misdiagnosis.

Influence of low-tube current in combination with simultaneous iterative reconstruction algorithm on bone mineral density of T12 and image quality of chest in phantom / 中国医学影像技术

Objective To investigate the influence of low-tube current in combination with simultaneous iterative reconstruction algorithm on bone mineral density (BMD) of T12 and image quality with a chest phantom.Methods An adult male chest phantom was selected.CT scan of the chest was performed at tube voltage of 120 kV and five different tube currents (20,30,40,50,60 mAs) in combination with filtered back projection (FBP),iDose4 (Level 4) and iterative model reconstruction (IMR,Level 2),respectively.BMD of T12 in chest phantom and objective evaluation results on different tube currents and simultaneous iterative reconstruction techniques were compared.The subjective scoring of mediastinum and lung window imaging qualities at tube current of 20 mAs with IMR and tube current of 60 mAs with FBP were compared.The consistency between two observers was evaluated.Results There was no significant difference between BMD values nor CT values on different tube currents and simultaneous iterative reconstruction techniques of chest phantom (all P＞ 0.05),but the differences between SD values were statistically significant (P＜ 0.001).SD values obtained with IMR were lower than those of iDose4 and FBP at same tube currents (all P＜0.001).At tube current of 60 mAs with FBP,the consistency of two observers in mediastinum window was the best (Kappa=1,P＜0.001),while in lung window was medium (Kappa=0.64,P=0.002).At tube current of 20 mAs with IMR,the consistency of two observers in mediastinum window was medium (Kappa=0.64,P=0.002),while in lung window was the best (Kappa=1.00,P＜0.001).Conclusion Low-tube current in combination with simultaneous iterative reconstruction algorithm can reduce radiation dose without affecting the accuracy of BMD.

Assessment of right ventricular systolic function in patients with moderate and severe pulmonary hypertension by real-time three-dimensional echocardiography / 中华超声影像学杂志

Objective To explore the application value of real time three-dimensional echocardiography (RT-3DE) on right ventricular systolic function in patients with moderate and severe pulmonary hypertension (PH).Methods Twenty-five patients with moderate PH (group Ⅱ) and 25 patients with severe PH(group Ⅲ) were selected,30 normal cases were selected to be control group(group Ⅰ).Tricuspid annular systolic peak velocity (S'),right ventricular Tei index(RIMP),tricuspid annular planet systolic excursion(TAPSE) and right ventricular fractional area change(RVFAC) were measured by conventional ultrasound echocardiography.Right ventricular end diastolic volume (RVEDV),right ventricular end systolic volume (RVESV),right ventricular stroke volume (RVSV) and right ventricular ejection fraction (RVEF) were measured by RT-3DE.The correlation between all the parameters and pulmonary artery systolic blood pressure (PASP),and the correlation between RVEF and S',RIMP,TAPSE,RVFAC were analyzed respectively.Results The differences of RVEDV,RVESV,TAPSE,RVFAC in each group were all statistically significant (all P ＜0.01);RIMP,RVEF between group Ⅰ and group Ⅱ,as well as between group Ⅰ and group Ⅲ were statistically significant (all P ＜0.01);S',RVSV only between group Ⅰ and group Ⅲ was statistically significant (P ＜0.01).The correlation coefficients of RVEF and RIMP,S',TAPSE,RVFAC were-0.707,0.402,0.574,0.763,respectively (all P ＜ 0.01).The best parameters associated with RVEF in each group were RVFAC,RIMP,RVFAC,which correlation coefficients were 0.787,-0.679,0.744,respectively (all P ＜0.01).Conclusions RT-3DE is a objective and accurate method to evaluate the right ventricular volume and RVEF in patients with moderate and severe PH,and it can select out the sensitive indicators to evaluate those patients' right ventricular systolic function from conventional echocardiographic parameters,provide important reference value for clinical.

CT features of renal carcinoma associated with xp11 .2 translocations/TFE3 genes fusions / 实用放射学杂志

Objective To analyze the CT features of renal carcinoma associated with Xp11.2 translocations/TFE3 gene fusions (Xp11.2 RCC),and to improve the diagnostic accuracy.Methods Clinical data,CT imaging and pathological features of 12 cases with pathology proved Xp11.2 RCC were analyzed retrospectively.Results All the 12 cases were solid masses.11 cases were oval or quasi-circular,1 case was irregular.Tumors were iso-density or hyperdensity on CT plain scan images.The density was heterogene-ous,combined with necrosis in 11 cases and spotty or patchy calcification in 7 cases.After injection of contrast,moderate or obvious enhancement of tumors was found,1 case had retroperitoneal lymph node metastasis,1 case was found with mass formation in the re-nal hilus,1 case had adrenal metastasis.Another one was found with psoas major muscle and lumbar 5 invaded.Conclusion The Xp11 .2 RCC has certain CT characteristics.This disease should be considered when a renal tumor is iso-density or hyperdensity on the CT plain scan images and has moderate or obvious enhancement,combined with necrosis or calcification.

CT and pathological analysis of peripheral primitive neuroectodermal tumors in abdomen-pelvis region / 实用放射学杂志

Objective To analyze the correlations of clinical characteristics,CT and pathology features of peripheral primitive neuroectrodermal tumors (pPNET)in abdomen-pelvis region,and to improve the understanding of the disease.Methods The clinical information,CT and pathological features of 23 confirmed pPNET patients in abdomen-pelvis region were analyzed retrospectively.Results (1)All patients had preoperative clinical and imaging data integrallty.(2)23 cases showed soft tissue masses with fuzzy boundary and the average diameter were 10.72 cm.Among all,9 cases showed with varying degrees of sac necrosis,while 2 cases showed with platelet hemorrhage and 4 cases with speckled calcifications.Most showed slight-to-moderate heterogeneous enhancement and the necrosis and cystic are-as showed more obvious.12 cases showed with different degree of recurrence,invasion or distant metastasis.5 cases combined with tumor emboli and 4 cases with tumor feeding vessels.(3)Immunohistochemical examination showed CD99 expressed in 1 9 patients, CD56 in 11,vimentin(Vim)in 12,synaptophysin(Syn)in 11,neuron specific enolase(NSE)in 4,FLI-1 in 4 and epithelial membrane antigen (EMA)in 4 patients.Conclusion pPNET is common among young patients with a high degree of malignancy.CT features include large mass with invasive growth,commonly combined heterogenous density,necrosis and cystic changes.Persistent enhancement is observed during nephrographic phase.

Impact of reconstruction techniques on low dose chest CT image quality：comparison of FBP,iDose4 and IMR / 实用放射学杂志

Objective To investigate the impact of different reconstruction algorithms ,including filtered back projection (FBP) , hybrid iterative reconstruction technique (iDose4 ,Philips Healthcare) and iterative model reconstruction (IMR ,Philips Healthcare) on image quality of the low dose chest CT .Methods 30 consecutive patients underwent chest CT on a 256‐slice CT (80 kVp ,80 mAs) were enrolled .Raw data were reconstructed with FBP ,iDose4 ,IMR_soft (L1_Body_Soft_Tissue) and IMR_routine(L1_Body_Routine) algorithms respectively ,and reconstructed thickness was 1 mm ,increment 0 .5 mm .SD ,SNR and CNR were measured and recor‐ded .Image quality was assessed using 4‐point scale (poor to excellent) with lung and mediastinum window ,respectively .We com‐pared quantitative and qualitative parameters among three reconstructions .Results SD of four groups were 55 .7 ± 20 .7 ,37 .0 ± 13 .0 , 13 .4 ± 4 .9 and 19 .5 ± 7 .0 ,repectively .Compared with FBP group ,SD reduced by 33 .5% ,75 .9% ,65% (all ,P0 .05) .The image quality score of lung window in IMR_routine group was the highest in groups ,but was no significantly different with IMR_soft group ,and was significantly different with FBP group and iDose4 group ,respectively .The image quality score of mediastinum window in IMR_soft group was the highest in groups , but was no significantly different with IMR_routine group and was significantly different with FBP group and iDose4 group ,respec‐tively .Conclusion Compared with FBP technique ,iDose4 and IMR techniques can distinctly reduce image noise and improve image quality on low dose CT ,especially IMR algorithm .

Application of optimizing contrast medium injection protocol for dual-source CT high-pitch spiral acquisition in children with complex congenital heart disease / 中华放射学杂志

Objective To explore clinical value of optimizing the contrast medium injection protocol for dual-source CT high-pitch spiral acquisition in children with complex congenital heart disease.Methods Sixty patients with complex congenital heart disease were prospectively recruited and randomly divided into group A and group B by the random number table method.Patients in group A received a conventional contrast medium injection protocol,i.e.a diluted contrast material with fast and slow rate respectively,and then a flush with normal saline.The volume of contrast medium was 2.0 ml/kg.Patients in group B received an optimized injection protocol,i.e.a four-phase diluted contrast material with contrast/ saline ratio of 8:2,6:4,4:6,2:8 respectively.The volume of contrast medium was 1.0-1.5 ml/kg.Attenuation and noise were measured in superior vena cava,right atrium,right ventricle,the main pulmonary artery,left atrium,left ventricle,ascending and the descending aorta in the two groups and compared by t test.The image uniformity was assessed by t test.Subjective image quality and artifacts of superior vena cava were analyzed by the Mann-Whitney U test.Diagnostic accuracy was evaluated by x2 test.All the patients undergone the surgical treatment and demonstrated 121 abnormalities (22 species) of internal and external heart structure,i.e.56 in group A and 65 in group B.Results There was no significant difference in diagnostic accuracy between group A and group B (A:96.9％,52/56,vs.B:96.4％,62/65;x2=0.28,P=0.59).While,significant difference was found in the amount of consumed iodine between the two groups [A:(15.7±6.5) ml vs.B:(10.4±2.4) ml;t=4.14,P＜0.01].Furthermore,the image uniformity in group B was statistically higher than that in group A[A:(36.5± 18.0)HU vs.B:(272.0± 124.5)HU;t=10.30,P＜0.01].As for subjective image quality,no significant difference were observed (A:3.3±0.5 vs.B:3.5±0.5;Z=396.00,P=0.39);while significant difference was found in artifacts of superior vena cava (A:3.2±0.9 vs.B:3.7 ± 0.7;Z=300.50,P=0.02).Conclusion The optimized contrast medium injection protocol for children with complex congenital heart disease could eliminate the image artifacts of superior vena cava and improve the image quality.

Spectral CT monochromatic imaging of hepatocellular carcinoma: effect of image fusion on image quality / 中华放射学杂志

Objective To assess the effects of image fusion of CT spectral monochromatic imaging on image quality in small hepatocellular carcinoma (HCC).Methods Thirty patients with 40 pathologically proven small HCCs (≤3 cm) underwent upper abdominal plain CT and dual-phase enhanced spectral CT scan were analyzed retrospectively.Conventional 140 kVp polychromatic images (group A) and monochromatic images with energy levels from 40 to 140 keV were reconstructed by using spectral imaging viewer.Monochromatic images with highest CNR (group B)and 70 keV images with lowest noise (group C) were fused to generate fused images (group D) with image fusion software.Objective evaluation of 40 HCCs [contrast-to-noise ratio (CNR) of lesion,image noise in HU] and subjective rating score of 30 patients (image noise score,overall image quality score,and lesion conspicuity score) among the four groups were compared by using One-way ANOVA and Kruskal-Wallis H test.Results CNR (1.3±0.6,2.1±0.6,1.5±0.6 and 2.4± 1.3 respectively) and image noise [(20±7),(32±9),(18±3) and (24±6) HU respectively] among group A,B,C and D all had statistical differences (F =5.724 and 13.619,both P values ＜ 0.01).CNR in group D was higher as compared with group A and C (both P values ＜ 0.05),but was similar to group B (P ＞ 0.05).Image noise in group D was lower than group B and higher than group C,but showed no difference from group A (all P values ＞ 0.05).Image noise scores [(3.5±0.5),(3.3±0.4),(3.6±0.5)and(3.5±0.4)point,respectively],overall image quality scores [(3.2 ± 0.4),(3.3 ± 0.3),(3.1 ± 0.3) and (3.7 ± 0.4) point respectively] and lesion conspicuity scores [(3.3 ±0.4),(3.9±0.4),(3.2±0.4) and (3.7 ±0.4) point,respectively] among the four groups all had statistical differences (Z =9.581,37.495 and 43.436,all P values ＜ 0.05).Scores of the four groups were all greater than 3 and met the clinical diagnostic level.Group D was higher than group B in image noise score,higher than the other three groups in overall image quality score,higher than group A in lesion conspicuity score (all P values ＜ 0.05).Conclusion Combined use of CT spectral monochromatic imaging and image fusion can improve overall image quality while maintaining or increasing CNR in small HCC.

Diagnosis and differential diagnosis of ovarian thecoma-fibroma in multi-slice CT / 实用放射学杂志

Objective To analyze the imaging features of ovarian thecoma-fibroma in multi-slice CT (MSCT )and improve the di-agnostic level.Methods CT features of 26 patients with 28 pathologically confirmed lesions were analyzed retrospectively.Correla-tion between tumor length and ascites and menopause was analyzed.Results Of 26 patients (28 lesions),24 patients were unilateral, 2 patients were bilateral.Of 28 lesions,there were 18 ovarian thecoma,6 fibrothecoma and 4 fibroma.The longest diameter of tumor ranged from 34.74 mm to 227.64 mm (mean value 101.06 mm±42.25 mm).The longest diameter of tumor in the group of ascites (n=1 7)was larger than that of without ascites.All the tumors had well-defined border,with 24 of them round or oval in shape,4 lobulated;with 22 of them solid in composition,4 mixed,2 cystic;with 20 of them inhomogeneous in density.The tumors showed no or mild enhancement,0-5 HU added CT value in 1 1,5-10 HU in 1 1,10 -20 HU in 6,with 4 cases showing multiple slim blood vessels during the arterial phase.Conclusion The typical imaging features of ovarian thecoma-fibroma were unilateral,oval,solid mass with well-defined border,no or mild enhancement (less than 20 HU)and accompanied by ascites.These characteristics will be helpful in the diagnosis and differential diagnosis of ovarian thecoma-fibroma.

Feasibility study of contrast-enhanced hepatic CT with low tube voltage using iterative model reconstruction technique / 中华放射医学与防护杂志

Objective To investigate the feasibility of contrast-enhanced CT with low tube voltage using iterative model reconstruction (IMR) technique.Methods Sixty patients were randomly assigned into 2 groups (group A and group B, 30 each) according to random number table.All patients underwent contrast-enhanced hepatic CT.Group A was scanned with 100 kV at arterial phase(AP) and 120 kV at portal vein phase (PVP), while group B was scanned with 120 kV at AP and 100 kV at PVP.All protocols were performed at the same tube current of 250 mAs.Raw data were reconstructed with IMR for AP images in group A and PVP images in group B;and reconstructed with FBP for AP images in group B and PVP images in group A.Images of 4 different groups were obtained: A1(AP,100 kV,IMR) , B1(AP,120 kV, FBP), A2(PVP, 120 kV,FBP) and B2(PVP, 100 kV, IMR).Subjective evaluation indexes for image quality including low-contrast detectability, lesion edge sharpness, image distortion and diagnostic confidence.Objective evaluation indexes included CT attenuation of hepatic parenchyma, image noise, SNR and CNR, which were assessed and compared between groups A1 and B1, groups A2 and B2.Effective radiation doses were calculated.Results Effective dose in group A1 was reduced 35.1％ compared toB1 (t=ll.05, P＜0.01), while a reduction of 37.7％ in group B2 compared to A2 (t=11.64,P ＜ 0.01).Subjective image quality score of low-contrast detectability and lesion edge sharpness were significantly higher in group A1 compared to B1 (Z =6.391, 3.200, P ＜ 0.01), as well as in group B2 compared to A2 (Z =6.559, 3.409, P ＜ 0.01).No differences were found in image distortion and diagnostic confidence between groups A1 and B1, groups A2 and B2, respectively (P ＞ 0.05).Significantly lower image noise and higher SNR/CNR were found in group A1 compared to group B1 (t =12.889, 15.458, 1.325, P ＜ 0.01) , as well as in group B2 compared to group A2(t =15.163, 15.308, 3.136, P ＜0.01).Conclusions Significant radiation dose reduction and image quality improvement in contrast-enhanced hepatic CT can be reached by using low tube voltage protocol combining with IMR technique.

Echocardiography Combined with Flash CT in Diagnosis of Partial Anomalous Pulmonary Venous Connection / 中国医学影像学杂志

PurposeTo investigate clinical significance of echocardiography combined with Flash CT in diagnosis of partial anomalous pulmonary venous connection (PAPVC). Materials and Methods Twenty-eight cases of PAPVC were recruited in the study. All the subjects underwent both preoperative echocardiography and coarse pitch Flash CT scanning. Imaging findings were compared with the results of surgery, including the type of PAPVC, size of atrial septal defect (ASD), and other combined malformations. Results Among 28 patients, 16 cases and 5 suspicious cases (4 cases of PAPVC and 1 case of pulmonary vein embolism) were diagnosed by echocardiography. Six cases were missed, and 1 case was misdiagnosed. CT misdiagnosed 1 case. The accurate diagnosis rate of echocardiography (71.4%, 20/28) was lower than that of Flash CT (96.4%, 27/28) (P<0.05). There were 44 combined malformations in 28 cases, 43 lesions were diagnosed by echocardiography, and 34 lesions were diagnosed by Flash CT. The accurate diagnosis rate of echocardiography (97.7%, 43/44) was higher than that of Flash CT (77.3%, 34/44) (P<0.05). The average DLP was (15.5±3.2) mGy·cm and average effective dose (ED) was (0.354±0.058) mSv.Conclusion Flash CT has a higher diagnosis accuracy of PAPVC but a lower diagnostic accuracy of combined malformations when compared with echocardiography. Moreover, echocardiography can make comprehensive evaluation in valve disease, pulmonary artery pressure and cardiac function. Flash CT combined with echocardiography may improve preoperative diagnosis.

Diagnostic value of spectrum CT volume helical shuttle technology in detection of pulmonary arteriovenous malformations / 实用放射学杂志

Objective To access the diagnostic value of volume helical shuttle (VHS)technology of spectrum CT in detection of the pulmonary arteriovenous malformations (PAVM).Methods Thirteen patients with PAVM confirmed by surgery and clinical data underwent CT pulmonary artery angiography with VHS technology,which were regarded as group A.The consecutive images at four different phases were gotten Meanwhile,other thirty patients underwent conventional CT pulmonary artery angiography using bolus tracking scan,regarded as Group B.The enhancement degrees of the pulmonary trunk were measured,and the image quality was also subjectively assessed by two radiologists separately,which were compared between two groups.Results In group A,the proportion of optimal phase in each of the four phases was 15.38% (2/13),46.15% (6/13),30.77% (4/13)and 7.7% (1/13),respectively.The mean CT value in pulmonary trunk was (329.21±41.63)HU in group A and (281.74±49.83)HU in group B,exhibiting no difference (P =0.989). The percentage of enhancement degree of pulmonary trunk more than 300 HU in group A was more than that in group B (P=0.000).However, the image quality of the main pulmonary artery,lobar pulmonary artery or segmental pulmonary artery was not significantly different between two groups (P >0.05).There were no statistically differences in mean DLP between group A of (715.54±195.37)mGy/cm and group B of (558.36±186.81)mGy/cm (t=3.737,P=0.068).Conclusion Spectrum CT VHS with higher image quality and enhancement degree is superior to conventional CT scan,which can be used to reduce the influence of individual circulation difference on image quality.

The clinical value of multi-slice spiral CT in diagnosis of non-angle caused nutcracker syndrome / 实用放射学杂志

Objective To evaluate the diagnostic value of multi-slice spiral CT for non-angle caused nutcracker syndrome(NCS). Methods A total of 177 cases of clinical suspected nutcracker syndrome patients recevied multi-slice spiral CT examination,,inclu-ding 33 patients with negative results,144 cases patients with positive results.The analysis was performed by measuring the angle between superior mesenteric artery(SMA)and the abdominal aorta(AA),and the ratio of the diameter of the narrowest and expan-sion in the left renal vein.Results Within 33 cases of nutcracker-negative patients,the angle of SMA and AA was (46.06 ± 24.46)°;the ratio was (2.11±0.76).144 cases was diagnosed as nutcracker-positive patients,the angle of SMA and AA was (23. 10±9.63)°;the ratio was (3.83±1.24).There was positive correlation between angle and ratio in NCS (P<0.0001).Among9 ca-ses of nutcracker syndrome caused by non-angle factors three were oppressed by the uncinate process pancreas,two cases were caused by the malformations of the left renal vein,one case was posterior nutcracker syndrome,one case was oppressed by portal veinOne case of pressured renal vein due to tortuosity renal vein coiled renal artery.One case of the left renal vein compression lumen narrowing,causing significant downward pressure on the left renal vein.Conclusion Spiral CT angiography reconstruction can clear-ly show the cause and the location of the left renal vein compression,which may provide helpful information in diagnosing nutcracker syndrome caused by non-angle factors.

Value of SCT in staging and subtyping of renal cell carcinoma / 中华泌尿外科杂志

Objective To analyze the value of multi-slice spiral CT (SCT) scan in staging and subtyping of renal cell carcinoma (RCC). Methods The preoperative kidney SCT data and postoperative pathology results of 64 patients with RCC were retrospectively analyzed. The patients′ ages ranged from 33-78 years (average 54 years). There were 44 males and 20 females in the study group. According to the CUA Guidelines, the staging and subtyping of RCC were performed through the combined information of preoperative SCT attenuation in unenhanced, corticomedullary phase and enhancement pattern. The results were compared with the postoperative histopathological results. Results The SCT results showed 38 cases were clear cell RCC, 14 cases were papillary RCC and 12 cases were chromophobic cell RCC. Histopathological results showed that 40 cases were clear cell RCC, 16 cases were papillary RCC and 8 cases were chromophobic cell RCC. According to the standard of 40 HU of CT attenuation value, the sensitivity, specificity and accuracy were 75%, 79% and 78% for diagnosis of papillary RCC in the unenhanced phase. The sensitivity, specificity and accuracy by the standard of 90 HU of CT attenuation value was 90%, 88% and 89% for diagnosis of clear cell RCC in the corticomedullary phase. In chromophobic RCC, homogeneous enhancement was more common than in papillary RCC and clear cell RCC. There was no significant difference of staging and subtyping of RCC between SCT and pathological results (P>0.05). The accuracy of SCT in staging and subtyping of RCC was 88% in staging, and 89% in subtyping. Conclusions SCT is a useful preoperative tool to stage and subtype RCC