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Objective@#To investigate whether a deep learning-based model using unenhanced computed tomography (CT) at baseline could predict the malignancy of pulmonary nodules.@*Methods@#A deep learning model was trained and applied for the discrimination of pulmonary nodule in Dr. Wise Lung Analyzer. This study retrospectively recruited 130 consecutive participants with pulmonary nodules detected on CT who undergoing biopsy or surgery from May 2009 to June 2017 in Jinling hospital. A total of 136 pulmonary nodules were included in this study, including 86 malignant nodules and 50 benign ones. All patients underwent CT scans 2 times at least, the first scan was defined as baseline and the last scan before the pathological results was defined as final scan. The ROC curve of deep learning model was plotted and the AUCs were calculated. Delong test was used to examine the difference of AUCs baseline and final scan. The nodules were further divided into subsolid nodule group (pure ground-glass nodule and part solid nodule) (n=87) and solid nodule group (n=49). The difference of AUCs at baseline and final scans was evaluated intra two groups.@*Results@#The AUCs of the deep learning model at final and baseline scans were 0.876 and 0.819, respectively. There was no significant difference between them (P=0.075). The result indicated that the model could predict the consequences of pulmonary nodules well at baseline. In small nodules (longest diameter ≤10mm), the AUC at final scan (0.847) was better than it at baseline scan (0.734), but there was no significant difference between them (P=0.058). In solid nodule group, The AUC at final scan (0.932) was better than it at baseline scan (0.835), but there was no significant difference between them (P=0.066). In subsolid nodule group, the deep learning model exhibited consistent performance at final scan (AUC, 0.759) with the baseline scan (AUC, 0.728, P=0.580).@*Conclusions@#The deep learning model could predict the malignancy of pulmonary nodules including small ones at baseline, and the model exhibited consistent performance between baseline and final scans in subsolid nodules.
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Objective To evaluate the role of non?invasive fractional flow reserve (FFR) derived from coronary CT angiography (CCTA) in assessing the hemodynamic relevance of myocardial bridging (MB). Methods A total of 60 patients without obstructive coronary artery disease but with CCTA?confirmed MB of the left anterior descending coronary artery and 30 patients with negative CCTA findings as control group were retrospectively included in this study. The 60 patients with MB were divided into 2 groups (superficial and deep MB group) according to the depth of MB. Age and sex were matched among three groups. The location, length, depth, and degree of systolic compression of the MB were measured. The FFRCT values (including systolic and diastolic phases) were measured at three points (segments 1 to 2 cm proximal to a MB, mid?tunneled segment and segments 1 to 2 cm distal to the MB) by cFFR software. Patients with FFRCT<0.75 were deemed to have hemodynamic relevance (abnormal group). χ2 test, ANOVA test, Mann?Whitney U test, Kruskal?Wallis H test and logistic regression model were used for statistical analysis. Results The FFRCT values decreased from diastolic phase to systolic phase in deep MB group [0.90 (0.81-0.94) vs. 0.93 (0.91-0.97), Z=-2.172, P=0.03]. Compared to control group, the FFRCT values decreased in both diastolic phase and systolic phase in superficial MB group as well as deep MB group [systole 0.92 (0.90-0.94) control vs. 0.84 (0.77-0.88) superficial vs. 0.67 (0.50-0.88) deep, H=37.193, P<0.001; diastole 0.93 (0.89-0.94) control vs. 0.85 (0.73-0.92) superficial vs. 0.81 (0.65-0.87) deep, H=26.508, P<0.001]. Abnormal FFRCT values (<0.75) were found in 28 (47.7%) MB patients (9 superficial vs. 19 deep). The length (OR=1.067, 95% CI: 1.016-1.122, P=0.010) and depth (OR=2.028, 95%CI: 1.129-3.644, P=0.018) of MB were associated with the abnormal FFRCT values.Conclusions The FFRCT values of coronary artery distal to MB were lower than that without MB. Abnormal FFRCT values are more prevalent in deep MB. MB length and depth demonstrate moderate predictive value for an abnormal FFRCT value.
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Objective To compare the clinical efficacy of laparoscopic vs open choledocholithotomy plus T tube drainage for the treatment of extra-and intrahepatic cholangiolithiasis.Methods 300 patients with cholangiolithiasis undergoing surgical treatment in the Department of Hepatobiliary Surgery,Guizhou Provincial People's Hospital,from January 2012 to December 2016 were evaluated.Patients were divided into laparoscopic lithotomy of common bile duct plus T tube drainage group (n =120)and open surgery (n =180).Results The difference was not statistically significant in operation time (237 ±32) min,(t =0.671,P =0.504),operation success rate (100％),primary cure rate (81.7％),(x2 =0.400,P =0.531),residual stone rate (18.3％),(x2 =0.400,P =0.531),hospitalization costs (26 ±4) × 103 RMB,(t =0.981,P =0.329),perioperative complications including bile leakage(0),biliary bleeding (0),abdominal hemorrhage (0),acute cholangitis (0),(x2 =0.669,P =1.000),abdominal infection (0) and incisional infection (0),(x2 =1.342,P =0.518) and late complications including biliary stricture(0) and stone recurrence (11.7％),(x2 =0.022,P =1.000) between the two groups.While intraoperative blood loss (25 ± 14)ml,(t =-7.191,P =0.000),postoperative recovery time of gastrointestinal function (1.8 ± 0.6) d,(t =-5.847,P =0.000),postoperative hospital stay (10.1 ± 0.3) d,(t =-3.145,P =0.000),postoperative incision liquefaction (0),(x2 =26.415,P =0.000) were in favor of laparoscopy group with statistically significant difference.Conclusions For the treatment of extra-and intrahepatic cholangiolithiasis,it was feasible and effective for laparoscopic lithotomy of common bile duct plus T tube drainage.
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Objective With the improvement of technology and strategy , reduced field-of-view diffusion weighted imaging ( rFOV DWI) has provided more robust imaging .This article was intended to compare the clinical utility between rFOV DWI and con-ventional DWI in the diagnosis of prostate cancer . Methods Retrospective analysis was made on 58 prostate cancer patients under-going verification of biopsy or surgery after 3.0 T MRI rFOV DWI and regular DWI examinations in Nanjing General Hospital of Nan-jing Military Command from August 2014 to September 2015 , among whom prostate cancer and benign prostatic hyperplasia were 31 cases and 27 cases respectively .Independent grading was made by 2 radiol-ogists who were unaware of any clinical data and sequences in the as-pects of distortion on DW images , lesion conspicuity on DWI ( b=1000 ) and ADC images according to a 4-point Likert scale .rFOV and conventional DWI sequences were acquired using b =400,1000,0s/mm2.The IVIM double exponential model software was applied to generate ACD value, slow dispersive coefficient(D value) and parameterized image of volume fraction of fast dispersion (f value).Se-quence analysis was made in suspected peripheral tumor regions of prostate cancer patients and and healthy peripheral zones of patients with benign prostatic hyperplasia respectively to get ACD , D and f values .The ratio values rADC , rD and rf were attained compared with obturator internus .ROC analysis was made on the efficacy of different parameters of two sequences in prostate cancer . Results Image qualities of rFOV DWI were rated superior to conventional DWI (P<0.001,Wilcoxon Signed-Rank Test).Compared with con-ventional DWI, ADC value (0.728 ±0.094 vs 0.789 ±0.116, P<0.05)and D value(0.622 ±0.077 vs 0.651 ±0.099, P<0.05)of peripheral tumor regions in rFOV DWI were lower and the difference was statistically significant , whereas no significant difference was found in f value(P=0.932).No difference was found in area under ROC curve of f value between rFOV DWI and traditional DWI (0.853 vs 0.767, P=0.283). Conclusion The rFOV DWI sequence yielded can efficiently improve image quality , which is of important value to the clinical diagnosis of prostate cancer .
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Objective To establish the animal model of chronic thromboembolic pulmonary hypertension(CTEPH) and to compare the accuracy of dual-energy CT (DECT) pulmonary angiography and histopathology for detecting CTEPH. Methods Eighteen canines were included in the study. All canines underwent paracentesis, embolization, CT scanning, pressure measurement and tranexamic acid feeding. The procedures were repeated every two weeks, until systolic/diastolic pressure in canines was≥30/15 mmHg or mean pulmonary artery pressure ≥ 20 mmHg.And then canines were sacrificed for histopathology examination. For CT pulmonary angiography (CTPA)in DE mode and DECT lung perfused blood volume (Lung PBV) images, the presence or absence of PE or perfusion defects were recorded on a per-canineand aper-lobe basis. With histopathological results as reference standard, the sensitivity, specificity of CTPA and lung PBV to detect PE were computed for two readers. The pairedχ2 test (McNemar test) was used to analyze the difference in diagnostic accuracy between CTPA and Lung PBV. Inter-reader agreement was also calculated with kappa test. Results CTEPH was demonstrated in 13 canines. On a per-canine basis, both readers found uneven and peripheral perfusion defects with DECT in 11 canines (84.6%, 11/13); while 5 canines (38.5%, 5/13) had cutoff or sudden stenosis of pulmonary arteries with CTPA;on a per-lobe basis, both readers had sensitivities of 14.3%(5/35), 83.3%(30/36), specificities of 100.0%(30/30), 100.0%(29/29), accuracies of 53.8%(35/65), 90.8%(59/65)for CTPA and DECT, respectively. DECT had a higher sensitivity(χ2=-4.690,P<0.01)and accuracy(χ2=8.284,P<0.01) in detecting CTEPH. Excellent and moderate inter-reader agreements were observed with CTPA and DECT (Kappa=0.938, 0.572, both P<0.001). Conclusions It is feasible to make a CTEPH animal model with autologous thrombus. DECT shows a higher accuracy than CTPA to detect CTEPH in this canine model study.
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Objective To summarize the image features of primary retrograde type A aortic dissection by CTA examination, aiming to improve the precise diagnosis of this type of specific aortic dissection, and to provide imaging evidence for subsequent therapies.Methods The CTA data of 17 patients with primary retrograde type A aortic dissection treated in Cardiothoracic Surgery Department of Nanjing General Hospital of Nanjing Military Command from January 2010 to December 2014 were retrospectively reviewed.The image features including the dissection type, the location and quantity of intimal tear, the aorta involving area, and the origin of branch vessels were analyzed.Results Nine cases of the total 17 patients had pericardial/pleural effusion.Fourteen patients showed intramural hematoma in ascending aorta, while 3 patients showed active blood flow and thrombosis formation in false lumen of ascending aorta.Five patients showed aortic ulcers and intramural hematoma in descending aorta, and the other 12 patients showed typical dissection image with active blood flow in both true and false lumen,among the 12 patients, there were obvious intimal separations observed in 11 cases, while multiple aortic ulcers in 1 case.Abdominal aorta was involved in l0 cases of the above 11 patients.All of the abdominal branch vessels were originated from true lumen in 2 of the 10 patients,and the other 8 patients showed 1-2 vessels originated from false lumen.Conclusion Primary retrograde type A aortic dissection is relatively rare.However,specific imaging features different from typical aortic dissection can be observed in this type of aortic lesion.Careful viewing of CTA image is extremely necessary for accurate diagnosis.
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Objective To evaluate the value of dual energy CT with Lung Vessels application in diagnosing pulmonary embolism (PE) of children.Methods Forty-seven patients with nephrotic syndrome and aged ≤ 18 years old (32 male,15 female,mean age 15 years) underwent dual-energy CT pulmonary angiography (CTPA).Two radiologists recorded the presence or absence of emboli and counted the clots on a per-patient and per-lobe basis with Lung Vessels,respectively.With conventional CTPA as reference standard,sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) of Lung Vessels application to detect PE were computed for two readers.Inter-reader agreement was also calculated.Results Conventional CTPA detected 51 clots in 35 lung lobes in 13 patients,giving PE incidence was 27.6％ (13/47) for this cohort.On a per-patient basis,readers 1 and 2 detected 25 and 21 patients with PE with Lung Vessels,corresponding to sensitivities,specificities,PPVs,and NPVs of 100.0％ (13/13),58.6％ (17/29),43.3％ (13/30),100.0％ (17/17) and 100.0％ (13/13),76.5％ (21/29),50.0％ (13/26),100.0％ (21/21),respectively.On a per-lung lobe basis,readers 1 and 2 detected 74 and 63 clots with Lung Vessels,respectively,corresponding to sensitivities,specificities,PPVs,and NPVs of 94.3％ (33/35),79.5％ (159/200),44.6％ (33/74),98.7％ (159/161) and 97.1％ (34/36),85.5％ (171/200),54.0％ (34/63),98.8％ (171/173),respectively.On a per-clot basis,134 and 105 clots were detected with Lung Vessels application,corresponding to sensitivities,specificities,PPVs,and NPVs for DECT of 96.1％ (49/51),64.9％ (159/245),36.3％ (49/135),98.7％ (159/161) and94.1％ (48/51),75.0％ (171/228),45.7％ (48/105),98.3％ (171/174)for readers 1 and 2,respectively.Excellent or good inter-reader agreement was observed on a per-patient,per-lobe and per-clot basis (Kappa =0.828,0.859,0.695 ; all P ＜ 0.01).Conclusions Dual-energyCT with Lung Vessels application has a high sensitivity and negative predictive value for PE detection in children.More clots are detected with Lung Vessels application than conventional CTPA,which deserve further investigation.
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Objective To optimize combined CT pulmonary angiography (CTPA) and renal venography (rCTV) and to evaluate its value for the detection of venous thromboembolism in patients with nephrotic syndrome (NS).Methods Ninety NS patients suspected of venous thromboembolism because of abnormal D-dimer value were included in this prospective study.The first 45 patients were defined as group 1 (protocol 1).These patients underwent CTPA,then rCTV 25 s after CTPA,last inferior vena cava scanning after another 25 s.The following 45 patients as group 2 (protocol 2).These patients underwent CTPA and then inferior vena cava scanning 50 s after CTPA,3 patients in group 2 were excluded because of unavailable CTPA or rCTV.Vessel enhancement of CTPA and rCTV,and radiation doses for two protocols were compared with independent sample student t test.Incidence and distribution of pulmonary embolism and renal vein thrombosis were recorded and compared by using Chi-square test.Results Enhancement values of pulmonary trunk for groups 1 and 2 were (335.5 ± 111.3) and (335.0 ± 76.0) HU,right renal vein were (142.7 ±33.3) and (140.7 ±25.9) HU,left renal vein were (141.6 ±26.4) and (138.8 ±33.6) HU respectively,without any statistical difference (t values were 0.026,0.322 and 0.452,P ＞0.05).Radiation dose to the patients receiving protocol 2 were lower than that of patients receiving protocol 1 [volume CT index,(19.7 ± 4.3) vs (13.6 ± 3.0) mGy; dose length product,(1019.9 ± 878.5) vs (532.0 ± 132.9) mGy · cm; both P ＜0.01].Of 87 NS patients,44 venous thromboembolism events were detected,resulting in the incidence of 50.6％ (44/87),including pulmonary embolism in 19 patients,renal vein thrombosis and pulmonary embolism in 17,renal vein thrombosis in 7,and inferior vena cava in one patient.The detection rate were 48.9％ (22/45) and 52.4％ (22/42),there was no significant difference (x2 =0.106,P =0.745).Conclusion Combined CTPA and rCTV with protocol 2 (CTPA and inferior vena cava phase scanning 50 s after CTPA) is suitable to clinical application and pulmonary embolism is the most common thromboembolism complication in NS patients.
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Objective Accumulating reports have suggested that hepatic stellate cells (HSCs) exhibit immunosuppressive ability and may be responsible for the occurrence and development of hepatocellular carcinoma (HCC).The mechanisms through which HSCs affect T-cell-induced adaptive immune responses and the relationship with the regulatory T cells (Treg cells) were studied.Methods We isolated HSCs from wildtype mice to demonstrate the influence of HSCs on T-cell proliferation and explored their effect on Treg cells through mixed leukocyte reactions (MLRs) in vitro.Results We found that activated HSCs could induce T-cell hyporesponsiveness in adaptive immune response by inhibiting the proliferation of T cells andincreasing the quantity of Treg cells.Conclusion Activated HSCs may lead to hypoergia of T cells in adaptive immune reaction and up-regulate the expression of Treg cells,thus facilitating immunotolarance.
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ObjectiveTo evaluate the feasibility of gadolinium-enhanced dual energy CT pulmonary angiography (CTPA) in detecting pulmonary embolism (PE).MethodsIn vitro dual energy CT of phantoms of gadolinium and iodinated contrast agents with different diluted ratio was performed,and CT values were measured at different tube voltages.Ten rabbits which were grouped into 3 ml/kg and 5 ml/kg groups underwent dual energy CT scan.CT values of pulmonary artery trunk and the first branch of pulmonary artery were measured.Sponge gelatin were injected into the femoral vein of 6 rabbits to make PE model next day,then lungs were re-imaged with dual energy CT 2 h after embolization.Creatinine was repeatedly measured before and one day after injection of gadolinium via ear marginal vein or femoral vein sampling.One-way ANOVA test and independent student t test were used to analyze the difference of pulmonary artery enhancement between different groups.Results ( 1 ) Compared with iodinated contrast agent,CT value of gadolinium-based contrast agent at 80 kV was higher than those at 140 kV and averageweighted 120 kV.(2) At 140,80,and average weighted 120 kV,CT values of pulmonary artery trunk [CT values were (463.1 ± 118.0),(664.2 ± 188.0),(522.9 ± 137.7) HU] and of the first branch of pulmonary artery [ CT values were (445.1 ± 82.3 ),(606.7 ± 207.2),(493.4 ± 117.3 ) HU ] were higher than those at 3 ml/kg [ CT value of pulmonary artery trunk was ( 258.1 ± 55.1 ),( 384.0 ± 92.3 ),(295.4 ± 73.6) HU,CT value of the first branch of pulmonary artery (245.0 ± 73.2 ),( 309.1 ± 94.2),(263.8 ±78.5) HU;all P ＜0.05].CT values of pulmonary artery trunk and the first branch of pulmonary artery at 80 kV were higher than those at 140 kV and average-weighted 120 kV ( pulmonary artery trunk:F =6.004,P =0.005 ; the first branch of pulmonary artery: F =4.374,P =0.018).In 6 rabbits,CTPA showed the enhancement cut-off of bilateral pulmonary arteries,gadolinium mapping showed decreased perfusion in the corresponding lung lobes,manifested as blue on color-coded map,while normal lung was color coded as red or yellow.Creatinine was higher by 6.7％ and 20.6％ for group 3 ml/kg and 5 ml/kg.ConclusionsWith similar X-ray attenuation characteristics as iodine,gadolinium-based contrast agent can be used to pulmonary contrast-enhanced dual energy CT imaging,simultaneously providing both CTPA and gadolinium maps to detect PE.
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ObjectiveTo investigate the feasibility and accuracy of dual energy CT (DECT) in detecting acute myocardial ischemic reperfusion injury in a swine model.Methods Acute myocardial ischemic reperfusion injury model was made by ligaturing the left anterior descending coronary artery (LAD)or the first diagonal artery ( D1 ) of swine heart,the first-pass contrast enhanced DECT was performed.And then pigs were sacrificed,and the hearts were removed,triphenyhetrazolium chloride staining was performed.The CT numbers of non-ischemic and ischemic regions were measured.In the short axis of the left ventricle,the ventricular wall was divided into 17 segments for analysis,segments with myocardial perfusion defect in DECT myocardial iodine maps,DECT ( 140,100 kV,weighted average 120 kV) were determined and compared with histopathology.The sensitivity,specificity and inter-modality agreement of DECT in detecting myocardial injury were calculated.One-way ANOVA test was used to analyze the differences between the CT number and weight of infracted myocardium measured on DECT at 140,100 kV,weighted average 120 kV in ischemic and normal regions.ResultsPartial sparse or defective perfusion in the apical anterior and septal wall were demonstrated in DECT myocardial iodine maps.The CT number of injured myocardium was significantly lower than that of normal myocardium at 140,100 kV,weighted average 120 kV.The sensitivity,specificity of DECT myocardial iodine maps were 85.2％ (23/27),86.2％ (94/109),and Kappa value was 0.62,the sensitivity,specificity at 140 kV were 88.9％ (24/27),92.7％ (101/109),and Kappa value was 0.76,the sensitivity,specificity at 100 kV were 85.2％(23/27),89.0％ (97/109),and Kappa value was 0.67,the sensitivity,specificity at weighted average 120 kV were 88.9％ (24/27),91.7％ ( 100/109),and Kappa value was 0.74.There were no significant differences between the weight of infracted myocardium measured on DECT at 140,100 kV,weighted average 120 kV and histopathological results ( F =0.419,P =0.741 ).ConclusionDECT myocardial iodine maps can detect acute myocardial ischemic reperfusion injury in a swine model and have a good correlation with histopathology.
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Objective To determine immune modulatory activity of activated hepatic stellate cells( HSCs) in hepatocellular carcinoma and immune response in tumor microenvironment. Methods Cell proliferation was measured by BrdU incorporation with a microtiter plate reader at 450 nm. The effect of HSCs on T cell proliferation was measured by MLR. Mouse hepatic cancer cell line H22 were implanted on the backs of BALB/c mice to establish the subcutaneous transplanted tumor model. Then the mice were sacrificed after 20 days for anatomical and size determination. Furthermore, Paraffin-embedded tissue was removed by serial tissue sectioning and immunohistochemically examined for expression of T lymphocyte subsets. T lymphocyte subsets in splenocytes were detected by FCM. Apoptotic mononuclear cells were evaluated by FITC-labeled Tunel assay. Results We determined that HSCsCM promoted hepatocellular carcinoma(HCC) cell line proliferation and HSCs inhibit T cell proliferation by MLR in vitro. We also examined normal immune mice to assess the immunosuppression of HSCs in the development of HCC. In the co-transplantation with HSCs group, T cells and their subtypes decreased obviously in the tumors and the spleen. The results showed that co-transplanted HSCs can induce more PD-L1 expression and more mononuclear cell apoptosis in tumor tissue. Conclusion Our results demonstrated that HSCs promote HCC progression partially because of their immune regulatory activity. Our data supply new information to support an integral role for HSCs in promoting HCC progression and suggest that HSCs may serve as a therapeutic target for HCC.
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Objective To evaluate monoenergetic imaging of dual energy CT in the visualization of metal fixation of factures. Methods In total, 29 patients with factures underwent 36 metal fixations,including 11 external fixations implanting in tibiofibula (n = 11 ) and 25 internal fixations (cervical spine,n=10; lumbar spine, n=4; tibiofibula, n=8; radial bone, n=3). They were recruited into this study.After dual energy CT scan, monoenergetic software was used to post-process with the following 6 photon energies: 40, 70, 100, 130, 160, 190 keV. Two radiologists evaluated and rated the reformatted images with 6 different photon energies and average weighted 120 kV images according to the following 4-score scale. Score 1: nonassessable, with marked artifact; score 2: assessable, moderate artifact; score 3: good,mild artifact, good visualization of bony structures; score 4: excellent, no artifact. Kruskal-Wallis was used to perform statistical analysis of image quality for total fixations, external and internal fixations with various selective kev settings and average weighted 120 kV. Results For total fixations, monoenergetic imaging of dual energy CT has 25 fixations with score 3 and 4, but 120 kV has only 4 fixations with score 3 and 4.Monoenergetic imaging of dual energy CT improved image quality of fractures with metal fixation compared to average weighted 120 kV images ( F = 116. 487, P ＜0. 01 ). Images of 130 kev had the best image quality for external metal fixation (9 fixations with score 3 and 4, F = 60. 902, P ＜ 0. 01), while 70 kev was best for internal metal fixation ( F = 122. 149, P ＜ 0. 01). Conclusions Monoenergetic imaging of dual energy CT improves image quality of fractures with metal fixation. Reformatted images at 70 keV and 130 keV havethe optimal image quality for internal and external metal fixation, respectively.
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Objective To investigate the feasibility and accuracy of dual energy CT myocardial iodine maps in detecting acute myocardial infarction in canine model. Methods Myocardial ischemia model was made by ligaturing left anterior descending coronary arteries (LAD) after thoracotomy in six dogs, while another 3 dogs undergoing thoracotomy not ligaturing LAD as control group. Before and three hours after operation, dual-source CT (DSCT) was performed, followed by resting 99Tcm-MIBI single photon emission computed tomography myocardial perfusion imaging. Then, dogs were sacrificed, and the hearts were removed, triphenyltetrazolium chloride staining and conventional HE staining were performed. CT number of non-ischemic and ischemic regions were measured and analyzed. The wall of the left ventricle in the short axis was divided into 17 segments, the segments of myocardial perfusion defect in DSCT myocardial iodine maps, SPECT, and pathology were determined. Student t test was used to analyze the difference of CT number between infarcted and non-infarcted myocardium. Kappa test was used for the accuracy of DSCT myocardial iodine maps and SPECT in detecting myocardial ischemia according to the pathological results. Results No abnormal regions were detected using DSCT myocardial iodine maps in preoperative control and infarction group. After thoracotomy, partial sparse or defective perfusion was consistently noted in six dogs' apical anterior and partition wall in both DSCT myocardial iodine maps and SPECT. In the infarcted group, the attenuation of infarction region (34.75 ± 16.66) HU was significantly decreased compared with preoperative measurements ( 123. 18 ± 15.38 ) HU ( t = 10. 526, P ＜ 0. 01 ); decreased perfusion in the infarcted region was also noted in the DSCT myocardial iodine maps and SPECT. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DSCT myocardial iodine maps and SPECT were 85.0% (34/40) , 84. 1% (95/113) ,65.4% (34/52) ,94. 0%(95/101) ,and 82. 5% (33/40), 90. 3% ( 102/113 ) ,75.0% (33/44) ,93.6% ( 102/109 ), respectively.Kappa values were 0. 63 and 0. 71 for the agreement of DSCT myocardial iodine maps and SPECT.Conclusion DSCT myocardial iodine maps is comparable diagnostic accuracy with rest SPECT myocardial perfusion imaging in detection of acute myocardial infarction in a canine model.
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ObjectiveTo evaluate the image quality of displaying the pulmonary artery and pulmonary emboli at different tube voltages and find the optimal tube voltage.MethodsSixty-six patients underwent contrast-enhanced dual energy CT pulmonary angiography (CTPA) from August 2007 to February 2010.Data obtained with 80 kVp,weighted average 120 kVp,and 140 kVp were divided into group Ⅰ,Ⅱ,and Ⅲ respectively.CT value of pulmonary artery ( grade 1—4),emboli,and muscles were measured.Corresponding signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated.One-way ANOVA analysis and Friedman test were used to analyze statistical significance among these values.Image quality of CTPA from these three groups was assessed.The inter-reader agreement of image quality was performed by kappa test.ResultsCT value of branch 1 to 4 of ptlmonary artery was (446 ± 140) HU,(433±130) HU,(411 ±138) HU,and (392±127) HU in group Ⅰ,(303±91) HU,(290±85) HU,(276±86) HU,and (263 ±85) HU in group Ⅱ,and (244 ±70) HU,(230 ±63) HU,(216 ±72) HU,and (205 ±68) HU in group Ⅲ.There was significant difference for CT values (P ＜0.01) among three groups.CT value of pulmonary artery in 80 kVp images was higher than 140 kyp and 120 Kvp.On quantitative analysis of 37 patients,CNR value of pulmonary clots was 8.3 ± 3.3,8.0 ± 2.9,and 5.6 ± 2.2 in group Ⅰ,Ⅱ,and ⅢⅢ,respectively.CNR values of pulmonary clots in 80 kVp images and 120 kVp images were higher than that in 140 kVp (P ＜0.01 ).There was no statistical difference for image quality of CTPA among the three groups ( P ＞ 0.05 ).Agreement of image quality of CTPA derived from 80 kVp (kappa value =0.789,P ＜0.01 ) was superior to that of 120 kVp (kappa value =0.652,P ＜0.01 ) and 140 kVp ( kappa value = 0.509,P ＜ 0.01 ).Conclusions CT value of pulmonary artery in 80 kVp images was higher than that of weighted average 120 kVp and 140 kVp,and the image quality and CNR was comparable with that of weighted average 120 kVp images.This tube voltage ( 80 kVp) is optimal for CT pulmonary angiography in the evaluation of patients with suspected pulmonary embolism.
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Objective To investigate the feasibility of the adaptive cardio sequence prospective ECG-gated dual-source CT coronary angiography (CTCA).Methods Thirty one patients underwent prospective ECG-gated dual-source CTCA. The patients were divided into two groups: group A, heart rate ≤ 75 times / minutes, 70% of R-R interval was chose; group B, heart rate> 75 times / minutes, 40% of R-R interval was chose. Two experienced radiologists assessed the image quality of 15 segments of coronary arteries in a double blinded fashion in a four score scale. Student t test was used to compare the image quality between two groups. CT dose index(CTDIvol) and effective dose(ED) were also calculated for both groups. Results 437 segments of coronary arteries in 31 patients were included this analysis, 408 segments (93.4%) had assessable image quality, while 29 segments (6.6%) had non assessable image quality. Of 226 segments in group A, 12 segments (5.3%) had non assessable image quality; however, 17 segments (8.1%) of 211 segments in group B had non assessable image quality. The average score of image quality was 3.57±0.64 in 31 patients. There was no statistical difference for mean image quality of group A (3.65±0.39) and group B (3.41±0.43)( t=1.62,P=0.12 ) . There was a statistical difference for mean image quality for segment 10 on a per segment basis ( t = 3.8 ,P＜0.05). CTDIvol and ED were (18.88±5.04) mGy and (4.31±1.05) mSv, respectively.Conclusion Adaptive cardio sequence prospective ECG-gated dual source CT can acquire assessable image quality of coronary artery with lower radiation dose to the patients, which has the potential to be a routine CTCA technique.
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Objective To evaluate the feasibility and value of dual-energy perfusion imaging (DEPI) of dual-source CT(DSCT) in the diagnosis of acute experimental pulmonary embolism. Methods Acute pulmonary embolism ( PE ) model was made in 8 New Zealand rabbits, and non-enhanced and enhanced DSCT scans were performed before and after embelization. Postprocessing of image data was made on the workstation, and CT pulmonary angiography ( CTPA ), DEal and fusion images were obtained. The location and number of the emboli were recorded. The rabbits were killed immediately after DSCT scan, the location and number of the lung lobes with pulmonary emboli were evaluated pathologically. Based on the pathological results, the sensitivity, specificity, positive predictive value ( PPV), and negative predictive value (NPV) of CTA, DEal and fusion images for the diagnosis of PE were calculated. Weighted Kappa values were calculated to evaluate the consistency between CTPA and DEal. Results PE model was made successfully in 7 rabbits. Six rabbits with 30 lobes were evaluated with one exception because of the catheter affecting the quality of lung peffusian image. PE was found pathologically in 18 lobar arteries. On DEPI, the region with PE showed low peffusion area comparing with the normal parenchyma and CTPA showed the filling defect within corresponding pulmonary artery or interruption of the artery. The sensitivity, specificity, PPVand NPV of CTPA were 66. 7% (12/18), 100.0% (12/12), 100.0% (12/12) and 66. 7% (12/18), respectively. The Kappa value was 0. 651 indicating moderate correlation with pathology. The sensitivity, specificity, aPv, and NPV of DEal were 88. 9% ( 16/18), 91.7% ( 11/12, 94. 1% (16/17) and 84. 6% ( 11/13 ), respectively. The Kappa value was 0. 795 indicating excellent correlation with pathology. Conclusion Dual-energy lung perfusion imaging of DSCT can display the blood distribution of rabbit's lung and has a high sensitivity for the diagnosis of acute pulmonary embolism.
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Objective To assess the clinical value of dual-energy intracranial CT angiography (CTA).Methods Forty-one patients suspected of intracranial vascular diseases underwent dual-energy intracranial CT angiography, and 41 patients who underwent conventional subtraction CT were enrolled as the control group.Image quality of intracranial and skull base vessels and radiation dose between dual-energy CTA and conventional subtraction CTA were compared using two independent sample nonparametrie test and independent-samples t test, respectively.Prevalence and size of lesions detected by dual-energy CTA and digital subtraction CTA were compared using paired-samples t test and Spearman correlative analysis. Results The percentage of image quality scored 5 was 70.7% (29/41) for dual-energy CTA and 75.6% (31/41) for conventional subtraction CTA.There was no significant difference between the two groups(Z= -0.455, P=0.650).Image quality of vessels at the skull base in conventional subtraction CTA was superior to that in dual-energy CTA, especially for the petrosal and syphon segment (Z=-4.087, P= 0.000).Radiation exposure of dual energy CTA and conventional CTA were (396.54±17.43) and (1090.95±114.29) mGy · cm respectively.Radiation exposure was decreased by 64% (t=-38.52, P=0.000) by dual energy CTA compared with conventional subtraction CTA.Out of the 41 patients,19 patients were diagnosed as intracranial aneurysm, 2 patients as arteriovenous malformation (AVM), 3 patients with Moya-moya's disease, and the remaining 17 patients with negative results.Nine patients with intracranial aneurysm, 2 patients with AVM, 3 patients with Moya-moya's disease, and 2 patients with negative findings underwent DSA or operation, with concordant findings from both techniques.Diameter of aneurysm neck, long axis and minor axis by dual-energy CTA was (2.90±1.61), (5.23±1.68) and (3.83±1.69) nun, respectively; Diameter of aneurysm neck, long axis and minor axis by DSA was (2.95±1.71), (5.10±1.60) ,(3.83±1.65) nan,respectively.There was no significant difference for the diameters of aneurysm between dual energy CTA and DSA ((t=-0.734,1.936,0.12.5 respectively, P=0.482,0.085,0.903 respectively), and good correlation was found between diameter measurements using the two techniques(r=0.964,0.976,0.973, respectively, all P=0.000) Conclusions Compared with conventional subtraction CTA, dual energy CTA has good image quality for intracranial vessels; however, image quality of the skull base vessels is worse, especially for the petrosal and syphon segment.Dual energy CTA has decreased radiation dose and a high diagnostic accuracy, being a practical imaging madality for diagnosis of intracranial vascular lesions.
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clues for interpretation of myocardial ischemia.
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Objective To evaluate the diagnostic accuracy of digital subtraction bone removal CT angiography (DS-BR-CTA) and dual energy bone removal CTA (DE-CTA) compared with conventional and rotational DSA. Methods A total of 264 patients underwent 3D-DSA were enrolled, 190 of them underwent also DS-BR-CTA, while 74 underwent DE-CTA as well. Aneurysms detected with DS-BR-CTA and DE-CTA were analyzed compared with 3D-DSA on per-patient and per-aneurysm basis. The sensitivity, specificity, positive predictive value and negative predictive value of two methods for diagnosis of aneurysm were calculated. Results Taking DSA as the standard, the sensitivity and specificity of DS-BR-CTA to detect intracranial aneurysms was 96.90％ and 98.36％ on per-patient basis, while 97.37％ and 99.97％ on per-aneurysm basis, and the sensitivity and specificity for the detection of aneurysm ≤3 mm was 88.89% and 98.36%. The sensitivity and specificity of DS-BR-CTA to detect intracranial aneurysms was 98.25% and 100% on per-patient basis, 95.52% and 100% on per-aneurysm basis, and the sensitivity and specificity for the detection of aneurysm ≤3 mm was 90.91% and 100%. Conclusion DE-CTA has a comparable diagnostic accuracy with DS-BR-CTA to diagnose intracranial aneurysms, and can be used in the routine workflow for detection of intracranial aneurysms.