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Objective:To predict the dose of lumbosacral spine (LS) and pelvic bone marrow (PBM) based on kernel density estimation (KDE) in patients with gynecological tumors.Methods:Fifteen patients with gynecological tumors receiving radiotherapy plans with dose limitation for LS and PBM in our hospital were selected as training data for machine learning. Another 10 cases were selected as the data for model validation. The minimum directional distance between the dose point in the organs and the edge of the planned target volume for the LS and PBM was calculated. Model training was performed by KDE. The accuracy of the model prediction was evaluated by the root mean square error. The model was utilized to predict the actual planned doses of the LS and PBM, and a linear fitting was performed on the predicted dose volume histogram (DVH) and actual results. The prediction effect was assessed by the goodness of fit R 2. Results:In terms of the DVH parameters required by the planner, the prediction doses from the model were similar to those of the verification plans: the difference of PBM V 40Gy was 2.0%, the difference of the mean dose was 1.6 Gy, and the difference of LS V 10Gy was -0.4%. In the unrequired DVH parameters, except for the PBM V 10Gy, the predicted values of the model were significantly high. The difference between the DVH predicted by the model and the actual plan was small, and the R 2 of the LS and PBM were 0.988 and 0.995, respectively. Conclusions:The model based on KDE method can accurately predict the doses of the LS and PBM. This model can also be used as a method to ensure the quality of the plan, and improve the consistency and quality of the plan.
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Radiotherapy characterized by invasive, localization and low toxicity has been recognized as one of the standard cancer therapy regimes, especially for non-surgically resectable advanced cancers. However, inherent and acquired resistance of cancer cells has significantly impeded the efficacy of radiotherapy. Of all the resistance determinants, varieties of anti-apoptotic signaling pathways or anti-survival proteins aberrant activation in malignant tumor cells play crucial roles in radiation insensitivity. This paper mainly focuses on clarifying the roles of the interesting key molecular signals including Ras, insulin-like growth factor type 1 receptor, transforming growth factor-beta, histone deacetylase and heat shock protein 90 in regulating radiotherapy sensitivity, in order to find the potential targets to improve the efficacy of radiotherapy.
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P53 abnormality or mutation is commonly seen in patients with hepatocellular carcinoma (HCC), and therefore, restoration of P53 function has become a research hotspot in the treatment of HCC.This article reviews the association of P53 with Bcl-2 protein family, microRNA, TGFβ, HBV, HCV, and AKT and the role of P53 in regulating cell apoptosis, in order to provide clues for improving the therapeutic outcome of HCC.
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Objective To assess the radiological imaging findings of hepatic inflammatory myofibroblastic tumor and to discuss the appropriate morphological classification.Methods A total of 22 patients with hepatic inflammatory myofibroblastic tumor confirmed by pathology were enrolled.Imaging performance of hepatic inflammatory myofibroblastic tumor were analyzed and the lesions were classified into appropriate type based on the imaging findings.Results Totally 23 lesions were found in 22 patients.The typical imaging features included great enhancement at later phase (13/20),moth eat en central necrosis (12/23) and peripheral shell (12/23).Seed in fruit was the most typical classification (8/23),followed by Seedless fruit (7/23).Conclusion Hepatic inflammatory myofibroblastic tumur typically shows as a single nodular lesion with moth eaten necrosis and peripheral shell like a Seed in fruit.The enhancement at later phase (especially the peripheral enhancement) can be regarded as a particular feature.
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Purpose To analyze the CT and MRI findings as well as follow-up changes of infantile hepatic hemangio-endothelioma (IHE),so as to provide basis for guiding the clinical establishment of therapeutic protocols.Materials and Methods The clinical data of 21 infants with IHE were analyzed retrospectively,including the imageological manifestations in initial diagnosis and during follow-up.Among the infants,3 received non-enhanced and enhanced scan of both CT and MRI,13 received non-enhanced and enhanced scan of CT only,while 5 received non-enhanced and enhanced scan of MRI only.All infants received ultrasonic examination.Results In non-enhanced CT scan,the tumor was marked by multiple or single intrahepatic low-density nidus with clear boundary,while non-enhanced MRI showed low T1WI signal and high T2WI signal.Enhanced scan of single IHE in arterial phase indicated notable nodular,streak-like and annular enhancement of the edge,while that in delayed period suggested a characteristic of progressive enhancement of tumor from periphery to center.There was not enhancement in necrotic zone in the center of large nidi all the time,while streak-like calcification nidi were found in partial nidi.Obvious whole-tumor enhancement was found in most nodes in the multiple nodular IHE,while moderate enhancement in partial nodes.The enhancement in each enhanced period decreased gradually,and most nidi in delayed period showed slightly high-density or isopycnic shadow.3 infants were misdiagnosed with hepatoblastoma and received surgical resection,but none had recurrence during postoperative ultrasonic follow-up.The rest infants were treated with oral administration of Propranolol and then followed up,and the follow-up results showed that most nidi shrunk to different extent while partial nidi disappeared completely.Conclusion IHE is marked by multiple nidi or single nidus,and the characteristic manifestations of CT and MRI are beneficial to promoting the accuracy rate of diagnosis of IHE.Tumor may shrink spontaneously or disappear if Propranolol is orally administered in treatment of IHE.
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Hepatocellular carcinoma ( HCC ) is one of the commonest malignant tumors in China .The therapeutic effects of conventional therapies including surgery resection at early stage ,chemotherapy or radiothera-py are greatly less than expected .One of the most possible reasons is the blockage of apoptosis in HCC cells .This review collects literatures about the studies on the roles of key signal pathways including RA ,STAT3,PDT,p53,β-catenin,TRAIL,microRNA and RAS in HCC therapy .This study may contribute greatly to providing outline in-sights for using apoptosis induction in liver cancer therapy .We hope it can promote the development liver cancer therapy in China .
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Pancreatic adenocarcinoma ( PAC) is still a refractory human digest malignancies due to multi-faceted causes ,late diagnosis and insensitive to traditional chemo -and radio-therapy .Resistance to apoptosis could be one of the most relevant mechanisms for PAC to escape any non -surgical therapy .This review aims to clear up the main deregulated apoptosis signal pathways over the years and to find out the abnormal molecule tar -get(s),and therefore,provide novel concepts for PAC molecular targeting therapy .
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In recent years,hepatocellular carcinoma (HCC)has become the second leading cause of cancer-related death worldwide.Due to the insidious onset of this disease,only 20%-30%of the patients with HCC have the opportunity for surgical resection or liver transplan-tation.At present,interventional therapy has become the first choice for patients with intermediate-stage HCC and some patients with late-stage HCC,and more and more scholars have realized the importance and necessity of comprehensive interventional therapy for HCC.The comprehensive interventional therapy of transcatheter arterial chemoembolization (TACE)in combination with various methods (TACE com-bined with local treatment,TACE sequential surgery,or TACE combined with systemic treatment)provides many therapeutic approaches and achieves good therapeutic effects.However,the indications,timing,and recurrence and metastasis after treatment for such combination ther-apies await further investigation.
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Currently, sorafenib is the multi-target inhibitor for the treatment of advanced primary liver cancer, and can effectively prolong the progression-free survival and overall survival in patients with advanced primary liver cancer. The application of sorafenib in the targeted therapy for liver cancer has become a hot topic. Major targets or signaling pathways include Raf/Mek/Erk, Jak/Stat, PI3K/Akt/mTOR, VEGFR and PDGFR, STAT, microRNA, Wnt/β-catenin, autolysosome, and tumor-related proteins, and sorafenib can regulate the proliferation, differentiation, metastasis, and apoptosis of liver cancer cells through these targets. This article reviews the current research on the action of sorafenib on these targets or signaling pathways to provide useful references for further clinical research on sorafenib.
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Abnormal activation of the mitogen-activated protein kinase (MAPK) signaling pathway is closely associated with the development, progression, and metastasis of liver cancer. This article introduces the expression of MAPK proteins in liver cancer and its role in the proliferation, differentiation, and metastasis of liver cancer, and elaborates on the value of the MAPK signaling pathway in the treatment and prognostic evaluation of liver cancer. It is pointed out that the MAPK signaling pathway plays an important role in the development/progression and treatment of liver cancer and is a potential molecular target for the treatment and prognostic evaluation of liver cancer.
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Objective To assess the image quality of iterative model reconstruction algorithm (IMR) compared with hybrid iterative reconstruction algorithm (iDose4) for hypovascular hepatic metastases.Methods Medical history and pathological results of 33 cases with primary malignant tumor were retrospective analyzed.Follow-up with enhanced CT or enhanced MRI at more than 3 months confirmed hypovascular metastases in these patients.All patients underwent abdominal CT scanning and dynamic enhanced CT scanning.Portal vein phase of low dose scanning data were taken as the research object.According to the different tube currents and reconstruction algorithm,the images were divided into 4 groups.Group A included images with tube current of 175 mAs and IMR post-processing (17 cases).Group B included images with tube current of 175 mAs and iDose4 post-processing (17 cases).Group C included images with tube current of 125 mAs and IMR post-processing (16 cases).Group D included images with tube current of 125 mAs and iDose4 post-processing (16 cases).In the cases with multiple lesions,the largest lesion was selected to evaluate.For each image of the objective evaluation [including noise,the signal-to-noise ratio (SNR),contrast to noise ratio (CNR)] and subjective evaluation (including lesion sharpness,necrosis interface and diagnostic confidence).The CT dose index of each scanning was recorded.The objective evaluation,subjective evaluation indexes were compared by paired samples t test and Wilcoxon signed rank test.Results The tube current of Group A and Group B were (7.7± 1.8) and (12.8±3.7)HU,while CNR were 10.3 ±2.6 and 5.6± 1.4,SNR were 13.2±3.2 and 8.1 ± 2.2,and the differences were statistically significant (t values were 9.966,12.670,9.203;P＜0.01).The tube current of Group C and Group D were (7.2±1.3) and (9.9±1.8)HU,while CNR were 7.4±2.0 and 3.7±0.9,SNR were 13.9±2.9 and 9.8±1.9,and the differences were statistically significant (t values were 9.209,12.320,9.628;P＜0.01).The lesion sharpness score of Group A and Group B were 4.95±0.24 and 4.29±0.59,while the necrosis interface score were 4.76 ± 0.36 and 3.68 ± 0.30,diagnostic confidence score were 4.94± 0.24 and 4.44 ±0.56,and the differences were statistically significant (P＜0.05).The lesion sharpness score of Group C and Group D were 3.94±0.68 and 3.56±0.63,while the necrosis interface score were 3.91±0.64 and 3.03±0.50,diagnostic confidence score were 4.19±0.40 and 3.94±0.44,and the differences were statistically significant (P＜0.05).CTDIvol of 175 mAs group and 125 m As group were (11.83±0.28) and (8.44±0.24) mGy respectively.Conclusion Compared with iDose4,iterative reconstruction technology IMR significantly reduces the image noise and enhances image quality of hypovascular hepatic metastases.
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<p><b>BACKGROUND</b>Little is known about the value of (31)P-magnetic resonance spectroscopy ((31)P-MRS) in in vivo assessment of exhaustive exercise-induced injury in skeletal muscle. We aimed to evaluate the value of a (31)P-MRS study using the quadriceps femoris after a single bout of acute exhaustive swimming in rats, and the correlation between (31)P-MRS and histological changes.</p><p><b>METHODS</b>Sixty male Sprague-Dawley rats were randomly assigned to control, half-exhaustive, and exhaustive exercise groups. (31)P-MRS of the quadriceps femoris of the right lower limb was performed immediately after swimming exercise to detect Pi, PCr, and β-ATP. The Pi/PCr, Pi/β-ATP, PCr/β-ATP, and PCr/(PCr+Pi) were calculated and pH measured. Areas under the receiver operating characteristic curve (AUCs) were calculated to evaluate the diagnostic potential of (31)P-MRS in identifying and distinguishing the three groups. HE staining, electron microscopy and desmin immunostaining after imaging of the muscle were used as a reference standard. The correlation between (31)P-MRS and the mean absorbance (A value) of desmin staining were analyzed with the Pearson correlation test.</p><p><b>RESULTS</b>Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) showed statistically significant intergroup differences (P < 0.05). AUCs of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were 0.905, 0.848, 0.930, and 0.930 for the control and half-exhaustive groups, while sensitivity and specificity were 90%/85%, 95%/55%, 95%/80%, and 90%/85%, respectively. The AUCs of Pi, PCr, Pi/PCr and PCr/(PCr+Pi) were 0.995, 0.980, 1.000, and 1.000 for the control and exhaustive groups, while sensitivity and specificity were 95%/90%, 100%/90%, 100%/95%, and 100%/95%, respectively. The AUCs of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were 0.735, 0.865, 0.903, and 0.903 for the half-exhaustive and exhaustive groups, while sensitivity and specificity were 80%/60%, 90%/75%, 95%/65%, and 95%/70%, respectively. In the half-exhaustive group, some muscle fibers exhibited edema in HE staining, and the unclear Z-discs and the mitochondria with vacuolar degeneration under electron microscopy. Compared with the half-exhaustive group, muscle fiber edema was increased in the exhaustive group, and the Z-discs were broken and the mitochondria exhibited marked vacuolar degeneration under electron microscopy. There were significant difference in A values of desmin staining in the right vastus lateralis among the control, half-exhaustive, and exhaustive groups with 0.58 ± 0.06, 0.30 ± 0.04, and 0.21 ± 0.02, respectively (P < 0.05). Histological examination also showed injury-induced changes in the vastus lateralis among the different intensities groups. Statistically a moderate correlation between (31)P-MRS and desmin was observed, the correlation coefficients of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were -0.706, 0.709, -0.726, and 0.791, respectively (P < 0.01).</p><p><b>CONCLUSIONS</b>(31)P-MRS can effectively reflect the changes in energy metabolism in the skeletal muscle after a single bout of acute exhaustive swimming in rats. Based on the significant correlation between (31)P-MRS parameters and histological changes, the changes of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) can indirectly reflect the degree of exercise-induced injury.</p>
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Animals , Male , Rats , Energy Metabolism , Physiology , Magnetic Resonance Spectroscopy , Methods , Physical Conditioning, Animal , Physiology , Quadriceps Muscle , Metabolism , Rats, Sprague-DawleyABSTRACT
Objective To evaluate the application of CT perfusion in the assessment of muscle perfusion in ischemic rabbit hindlimb treated by implantation of bone marrow mesenchymal stem cells.Methods Twenty rabbits were divided into two groups randomly (each n =10).Bone marrow mesenchymal stem cells were injected into the left ischemic hind limbs of animal models of intravenous injection group,with same volume of normal saline injected into the control group.Twenty-eight days later,the collateral circulation and blood vessel neogenesis were examined by Toshiba Aquilion One 320-MSCT and pathological approaches.t test and Pearson test were used to compare the parameters.Results The results show that rAF,rBV,rClearance,rMVD were 1.15 ±0.67,1.19 ±0.32,0.62 ±0.20,and 1.34 ±0.28 in intravenous injection group and 0.57 ±0.17,0.74 ±0.19,2.06 ±0.15,0.62 ±0.19 in the control group respectively.There was significant difference of rAF,rBV,rClearance and rMVD between the intravenous injection group and the control group(t =5.75,5.01,-2.81,6.43 respectively,P ＜ 0.01).There was significant correlation between rBV,rAF,rC and rMVD (r =0.857,0.811,0.615,P ＜ 0.01).Conclusion CT perfusion imaging is a relatively accurate technique to assess changes of muscle perfusion in ischemic rabbit hindlimb treated by implantation of bone marrow mesenchymal stem cells.
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Objective To explore the method and value of percutanously interventional therapeusis for treatment of obstructive jaundice caused by hepatocellular carcinoma accompanied with bile duct thrombosis.Methods Sixteen cases with bile duct thrombosis proved by pathology and imaging examinations were retrospectively analyzed.According to the clinical symptoms, all the patients received percutaneous transhepatic biliary drainage (PTBD) including permanent external drainage, temporary internal drainage and implantation of covered stents.Serum total bilirubin (TBIL) after the interventional therapeusis were measured and compared with that before the treatments by t test to evaluate the efficacy of these treatments.The relief of clinical symptoms was also reviewed to evaluate the efficacy of these treatments.The patients were followed up within 2 years.Results The PTBD was successfully performed in 16 cases.Permanent external drainage, temporary internal drainage and implantation of covered stents were performed in 2 patients, 7 patients and 7 patients respectively.TBIL after the interventional therapy decreased significantly (t=7.366, P<0.01) to (161.2±80.5) μmol/L averagely from (261.9±77.2)μmol/L before the treatments.All the patients died before the end of followed-up.The average survival time was 204 days (30 to 391 d)and the median survival time was 200 days.Bleeding and infection were the main complications, which could be controlled successfully by routine treatments.Conclusion With high achievement ratio and good efficacy, percutanously interventional therapeusis are good choices for the treatments of obstructive jaundice due to bile duct thrombosis.
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Objective To evaluate dynamic CT and PET-CT features of normal dog liver after radiofrequency ablation(RFA)correlated with the time-related histopathological changes.Methods Fifteen hybrid adult dogs in good health condition were evenly divided into 5 groups(the immediate,1 st,2 nd,4 th and 8 th week group)according to random digits table methods.Twice RFA was performed for each dog liver.The dogs after RFA underwent CT and PET-CT scanning respectively at the time point defined for each group.All dogs were executed through intravenous injection of klorvess liquid after scanning.Liver samples were histologically examined.All images were assessed to determine the ratios(r_(p/p))which referred to the comparison of rimlike enhancement or tracer uptake in the periphery of the necrosis to that in normal liver parenchyma.Those imaging results were compared and correlated with histopathological findings.Results For the immediate group after RFA procedure,central ablation lesions appeared coagulation necrosis and surrounding sinusoids engorged with blood.On the images of enhanced CT,marked rimlike enhancement was noticed in peripheral ablation lesions.While PET-CT showed decreased ~(18)F-FDG uptake surrounded by homogeneous tracer distribution.For the 1 st-4 th week group,central necrosis was gradually getting more severe.Infiltration of the inflammatory cells,granulation tissue formation and fibrous tissue restoration were noticed in peripheral ablation lesions.Rimlike enhancement and increased glucose metabolism appeared surrounding the lesions on CT and PET-CT,especially in the 1st to 2nd week groups.For the 8 th week group after RFA,the enhancement or hypermetabolism metioned above disappeared when perilesional tissue regeneration became more obvious.From the dynamic curve of changes on enhanced CT,marked enhancement occurred in the immediate group after ablation(r_(p/p)=1.34±0.21),reached its peak at the 1st week group(r_(p/p)=1.39±0.20),and then declined gradually.The metabolic changes on PET-CT showed a typical single peak curve,with the peak at the 1st week group(r_(p/p)=1.19±0.09)and similar even metabolism at the immediate and 8 th week group.Conclusions Both CT and PET-CT imaging can well correlate with the histopathological changes after RFA in the normal liver.To avoid the interference of inflammatory reaction when differentiating normal liver tissue from residual tumor,it is better to take radiology examination immediately and 8 weeks after RFA.PET-CT probably has advantages over CT immediately after RAF.After 1 week,PET-CT and CT may have similar diagnostic efficacy.
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Objective This study aimed to investigate the incidence and the cause for duodenalbiliary reflux and reflux cholangitis after metallic stent placement in distal common bile duct Methods After percutaneous transhepatic bile duct puncture and biliary outside drainage was performed, 16 cases with malignant distal biliary stricture underwent metallic stent placement in distal common bile duct Before stent placement, the routine laboratory studies including leukocyte, neutrophil percentage and the levels of total bilirubin and direct bilirubin in blood were performed for all patients. Two to five days [ an average of (3.3 ±0. 9) days ] after stent implantation, the above indexes were tested again, and 1 ml of water containing 185 MBq of 99Tcm-DTPA was given orally before extubation, then 99Tcm radioactivity in the bile was detected 2 hours later. For the measurement data obtained from the experiment, t test or Wilcoxon signed rank test was adopted to compare them, and P ＜ 0. 05 was considered to be statistically different Results In 14 cases, radioactivity was successfully detected in the bile 2-5 days after stent implantation. Twelve of them was detected to have radioactivity in the bile 2 hours before extubation with duodenal-biliary reflux. The technetium count in the bile accounted for 1.82% of the total intake dose. There was no radioactivity in the bile in 2 cases. In 14 patients, there were no symptoms of cholangitis such as high fever, chills, increased jaundice, and so on after stent implantation. The mean of white blood cell count was (7.59 t2. 62) × 109/L, and the median of neutrophil percentage was 0. 74. Compared with those before stent implantation, the difference did not reach statistical significance ( t = 0. 423, Z = 1. 036, P ＞ 0. 05 ).After stent implantation, the median of total bilirubin and direct bilirubin were significantly lower, which were 92. 2 and 74. 3 μmol/L. Compared with those before stenting,the difference was statistically significant (Z= -3. 170, -3. 170, P ＜0.05). Conclusions There is a high incidence of duodenal-biliary reflux after stent implantation in distal common bile duct in the early stage. However, there is no simultaneous cholangitis caused by duodenal-biliary reflux.
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Objective To investigate the capillary blood volume (BV) changes in acute ischemic denervated hindlimb of rabbits and the value of 256-slice detector computed tomography (CT) perfusion imaging in evaluation.Methods A total of 40 healthy, adult white rabbits underwent either right hindlimb femoral artery excision combined femoral nerve denervation (combined modeling group, n = 10), simple femoral artery excision (iachemia group, n = 10), simple femoral nerve denervation (denervation group,n = 10), or simple femoral artery separation (sham-surgery group, n = 10).At 1,7, 14, 21, and 28 days following surgery, CT perfusion scanning (Philips Brilliance 256-row) was performed and CT perfusion images were processed using maximum-slope method with Function CT software on EBW workstation.The ratio of BV (rBV) in muscle tissue between right and left hindlimbs was calculated in each group.At 14 and 28 days, following sacrifice, rabbit bilateral adductor was harvested for immunohistochemical staining.The ratio of microvessei density (rMVD) in muscle tissue between right and left hindlimbs was calculated.The significance of the difference of rBV at each time point was assessed using analysis of variance of factorial design (2 ×2).Pearson correlation analysis was used to study the relationship between rBV and rMVD.Results After surgery, the 1st day rBV of combined modeling group, combined modeling group,denervation group and sham-surgery group is 0.31 ± 0.15 ( n = 6), 0.29 ± 0.12 (n = 6), 0.98 ± 0.08 ( n =6), 0.98 ± 0.07 ( n = 6) respectively.The 7th day following surgery rBV is 1.69 ± 0.45 ( n = 5 ), 1.63 ±0.43(n=6), 0.99 ±0.07(n =6), 1.00 ±0.08(n =6).The 14th day is respectively 1.58 ±0.18(n=5), 1.49 ±0.25(n =6), 0.94 ±0.08(n =6), 1.01 ±0.05(n =6).The 21th day is 1.42 ±0.41 (n=4),1.43 ±0.31(n=4), 0.94 ±0.05(n =5), 1.02 ±0.05(n =5),and the 28th day is 1.00 ±0.25(n=4),0.99 ±0.08(n=4), 0.92 ±0.09(n =5), 1.02 ±0.13(n=5).At each time point with exception of postoperative 28 days(F(A) =0.214,P>0.05), ischemia produced main effects on rBV(F(A) =274.268,30.044,65.787,18.886 ,P < 0.01 ), while simple denervation did not show main effects on each time point.Ischemia and denervation did not yield interaction effects on each time point, rMVD from each group supported above-mentioned changes.The correlation coefficient of rBV to rMVD was r = 0.862 ( P < 0.01 ).Conclusions BV in acute ischemic denervated hindlimb of rabbits shows a dynamic change, and denervation does not obviously influence this process.256-slice detector CT perfusion imaging can be used to noninvasively and semi-quantitatively evaluate the dynamic changes of capillary bed in acute ischemie denervated hindlimb of rabbits.
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Objective Evaluate the influence of medical monochrome liquid crystal display (LCD) with different resolutions on the detection of pulmonary nodules.Methods Ninety-three direct digital radiography (DR) chest images were selected on-line from picture archiving and communication system (PACS),including 38 positive,32 suspected and 23 normal cases.All of the images were confirmed by CT.These positive images were divided into group A and B according to the diameter of nodules.Three experienced radiologists blindly read the 93 images using three types of displays with different resolutions.Regarding the presence of nodule,five-point confidence system was used:definitely absent,probably absent,indefinite,probably present and definitely present.All observers marked their confidence levels of each image according to the presence of pulmonary nodule on different displays.Software SPSS 13.0 was employed for statistical analysis.Results In the group-A cases,the areas under ROC curves were 0.643,0.686 and 0.739,and in the group-B cases,those were 0.813,0.832 and 0.846 respectively.There was no difference in the detection efficacy among different radiodiagnostic systems.Conclusion Regardless of post-processing tools,it was equivalent to detect pulmonary nodules with different diameters of Group A or B among medical monochrome LCDs with different resolutions.
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Objective To assess the influence of medical monochrome liquid crystal displays (LCD) with different resolutions for the detection performance of micro-nodules (diameter <10 mm) on chest radiograms. Methods Eighty-seven DR chest images that were verified with CT were selected from PACS on-line, including 32 positive images, 32 suspected images and 23 normal images. The diameters of all nodules were lower than 10 mm. Three of high-, mid- and low-experienced radiologists who participated in the ROC study interpreted these 87 images using three types of LCDs with different resolutions, respectively. Regarding the presence of nodule, five-point confidence level rating scale was used, i.e. definitely absent, probably absent, possibly present, probably present and definitely present. All observers marked their confidence levels of every image according to the presence of pulmonary nodule on different displays. Software SPSS 13.0 was used for statistical analysis. Results AUC increased with the increasing resolutions and radiologists' experiences in 2MP, 3MP, 5MP displays. For the detection performance of pulmonary nodules (diameter <10 mm), there was no significant difference among different types of displays or different aptitudes of radiologists. Conclusion It's equivalent for the detection performance of pulmonary nodule (diameter <10 mm) on 2MP, 3MP and 5MP medical monochrome LCD when no restriction on the use of image post-processing tools. Highly-experienced radiologist can get the most information when using 5MP display. It is advisable to combine the diagnostic workstation system with high-, mid- and low-resolution monitors, and reasonable equipment scheme between different types of displays and different aptitudes of radiologists could result in better cost-efficacy.
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Objective To evaluate the effect of automatic bone and plaque removal on image quality and grading of steno-occlusive lesions in patients undergoing dual energy CT angiography (DE-CTA) of body artery. Methods DE-CTA was performed in 23 patients with suspected body vascular disease. Separate datasets were calculated for each of the two tubes and used to generate automatically bone-subtracted images (ABS) as well as additional manual bone removes after plaque subtracted images (ABPS). In addition, a weighted average dataset from both dual energy acquisitions resembling routine 3D CT acquisition was used for automatic bone remove (ABR). Residual bone in the ABR dataset was removed manually (ABR-M). Operator time for bone removal was measured, while effectiveness of bone subtraction and the time needed of ABPS and ABR-M was assessed. Compared with MPR, ABR images and stenosis grading in plaque subtracted were assessed with two radiologists. Results The imaging quality of ABR was superior to that of ABS (P<0.05). The time needed of ABPS was (7.8±4.3) min, significantly lower than that of ABR-M (11.4 min±2.5 min, P<0.05). A total of 325 steno-occlusive lesions were assessed. The sensitivity, specificity of DE-CTA and traditional 3D CTA was 95.74%, 96.19% and 92.93%, 97.87%, respectively. Conclusion The imaging quality is good after automatic bone and plaque subtraction of DE-CTA. Automatic plaque subtraction for the first time provides a true CTA imaging which is easy to interpret and reduces the need for further post-processing. The diagnosis of vascular stenosis with DE-CTA is also accurate, and the time spent in post-processing is less than that of traditional 3D angiography.