Objective To investigate the image quality, radiation dose and diagnostic value of the low-tube-voltage high-pitch dual-source computed tomography(DSCT) with sinogram affirmed iterative reconstruction(SAFIRE) for non-...Objective To investigate the image quality, radiation dose and diagnostic value of the low-tube-voltage high-pitch dual-source computed tomography(DSCT) with sinogram affirmed iterative reconstruction(SAFIRE) for non-enhanced abdominal and pelvic scans. Methods This institutional review board-approved prospective study included 64 patients who gave written informed consent for additional abdominal and pelvic scan with DSCT in the period from November to December 2012. The patients underwent standard non-enhanced CT scans(protocol 1) [tube voltage of 120 k Vp/pitch of 0.9/filtered back-projection(FBP) reconstruction] followed by high-pitch non-enhanced CT scans(protocol 2)(100 k Vp/3.0/SAFIRE). The total scan time, mean CT number, signal-to-noise ratio(SNR), image quality, lesion detectability and radiation dose were compared between the two protocols. Results The total scan time of protocol 2 was significantly shorter than that of protocol 1(1.4±0.1 seconds vs. 7.6±0.6 seconds, P<0.001). There was no significant difference between protocol 1 and protocol 2 in mean CT number of all organs(liver, 55.4±6.3 HU vs. 56.1±6.8 HU, P=0.214; pancreas, 43.6±5.9 HU vs. 43.7±5.8 HU, P=0.785; spleen, 47.9±3.9 HU vs. 49.4±4.3 HU, P=0.128; kidney, 32.2±2.3 HU vs. 33.1±2.3 HU, P=0.367; abdominal aorta, 44.8±5.6 HU vs. 45.0±5.5 HU, P=0.499; psoas muscle, 50.7±4.1 HU vs. 50.3±4.5 HU, P=0.279). SNR on images of protocol 2 was higher than that of protocol 1(liver, 5.0±1.2 vs. 4.5±1.1, P<0.001; pancreas, 4.0±1.0 vs. 3.6±0.8, P<0.001; spleen, 4.7±1.0 vs. 4.1±0.9, P<0.001; kidney, 3.1±0.6 vs. 2.8±0.6, P<0.001; abdominal aorta, 4.1±1.0 vs. 3.8±1.0, P<0.001; psoas muscle, 4.5±1.1 vs. 4.3±1.2, P=0.012). The overall image noise of protocol 2 was lower than that of protocol1(9.8±3.1 HU vs. 11.1±3.0 HU, P<0.001). Image quality of protocol 2 was good but lower than that of protocol 1(4.1±0.7 vs. 4.6±0.5, P<0.001). Protocol 2 perceived 229 of 234 lesions(97.9%) that were detected in protocol 1 in the abdomen and pelvis. Radiation dose of protocol 2 was lower than that of protocol 1(4.4±0.4 m Sv vs. 7.3±2.4 m Sv, P<0.001) and the mean dose reduction was 41.4%. Conclusion The high-pitch DSCT with SAFIRE can shorten scan time and reduce radiation dose while preserving image quality in non-enhanced abdominal and pelvic scans.展开更多
Truncus arteriosus is an uncommon congenital cardiac abnormality which is characterized by a single arterial trunk origin from the heart that supplies both the systemic,pulmonary and coronary circulation.We present a ...Truncus arteriosus is an uncommon congenital cardiac abnormality which is characterized by a single arterial trunk origin from the heart that supplies both the systemic,pulmonary and coronary circulation.We present a preterm newborn female patient with type 2 truncusarteriosus,left superior vena cava and aberrant subclavian artery diagnosed with low dose dual-source cardiac computed tomography(CT).We discuss that low dose dual-source cardiac CT has more advantages than other imaging methods and it is an important modality for assessment of patients with conotruncal anomalies such as truncusarteriosus.展开更多
Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible ligh...Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible light,whereas PCCT utilizes photon-counting detectors that directly transform X-ray photons into electric signals.This direct conversion allows photon-counting detectors to sort photons into discrete energy levels,thereby enhancing image quality through superior noise reduction,improved spatial and contrast resolution,and reduced artifacts.In pediatric applications,PCCT offers substantial benefits,including lower radiation doses,which may help reduce the risk of malignancy in pediatric patients,with perhaps greater potential to benefit those with repeated exposure from a young age.Enhanced spatial resolution facilitates better visualization of small structures,vital for diagnosing congenital heart defects.Additionally,PCCT’s spectral capabilities improve tissue characterization and enable the creation of virtual monoenergetic images,which enhance soft-tissue contrast and potentially reduce contrast media doses.Initial clinical results indicate that PCCT provides superior image quality and diagnostic accuracy compared to conven-tional CT,particularly in challenging pediatric cardiovascular cases.As PCCT technology matures,further research and standardized protocols will be essential to fully integrate it into pediatric imaging practices,ensuring optimized diagnostic outcomes and patient safety.展开更多
AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA scree...AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA screening indicators to detect concurrent DR at an early stage.METHODS:A total of 200 patients who treated in the ophthalmology department of the Seventh Affiliated Hospital,Sun Yat-sen University from 2022 to 2023 were included,including 95 first-diagnosed DR patients and 105 patients without DR,and all patients underwent OCTA examination and a collection of demographics and renal function parameters.After a quality check,automated measurements of the foveal avascular zone area,vessel density(VD),and perfusion density(PD)of both 3 mm×3 mm and 6 mm×6 mm windows were obtained.RESULTS:Using random forest and multivariate Logistic regression methods,we developed a diagnostic model for DR based on 12 variables(age,FBG,SBP,DBP,HbA1c,ALT,ALP,urea/Scr,DM duration,HUA,DN,and CMT).Adding specific OCTA parameters enhanced the efficacy of the existing diagnostic model for DR(outer vessel density in 6 mm×6 mm window,AUC=0.837 vs 0.819,P=0.03).In the study of DN patients,the parameters in the 6 mm×6 mm window improved the diagnostic efficacy of DR(inner VD;outer VD;full VD;outer PD;full PD).CONCLUSION:The outer VD in the 6 mm×6 mm window can enhance the efficacy of the traditional DR diagnostic model.Meanwhile,compared with the 3 mm×3 mm window,the microvascular parameters in the 6 mm×6 mm window focusing on DN patients can be more sensitive to diagnosing the occurrence of DR.展开更多
Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism....Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.展开更多
Background:Pulmonary atresia(PA)is a group of heterogeneous complex congenital heart disease.Only one study modality might not get a correct diagnosis.This study aims to investigate the diagnostic power of dualsource ...Background:Pulmonary atresia(PA)is a group of heterogeneous complex congenital heart disease.Only one study modality might not get a correct diagnosis.This study aims to investigate the diagnostic power of dualsource computed tomography(DSCT)for all intracardiac and extracardiac deformities in patients with PA compared with transthoracic echocardiography(TTE).Materials and Methods:This retrospective study enrolled 79 patients and divided them into three groups according to their main diagnosis.All associated malformations and clinical information,including treatments,were recorded and compared among the three groups.The diagnostic power of DSCT and TTE on all associated malformations were compared.The surgical index(McGoon ratio,pulmonary arterials index(PAI),and total neopulmonary arterial index)and radiation dose were calculated on the basis of DSCT.Results:Of the patients,32,30,and 17 were divided into the groups of PA with ventricular septal defect(VSD),PA with VSD and major aortopulmonary collateral arteries,and PA with other major malformations,respectively.Consequently,182,162,and 13 intracardiac,extracardiac,and other major malformations were diagnosed,respectively.Moreover,DSCT showed a better diagnostic performance in extracardiac deformities(154 vs.117,p<0.001),whereas TTE could diagnose intracardiac deformities better(159 vs.139,p=0.001).The McGoon ratio,PAI,and treatment methods were significantly different among the three groups(p=0.014,p=0.008,and p=0.018,respectively).Conclusion:More than one imaging modality should be used to make a correct diagnosis when clinically suspecting PA.DSCT is superior to TTE in diagnosing extracardiac deformities and could be used to roughly calculate surgical indices to optimize treatment strategy.展开更多
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im...BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.展开更多
Angiomyolipomas(AMLs)represent the most common benign solid renal tumors.The frequency of their detection in the general population is increasing owing to advances in imaging technology.The objective of this review is...Angiomyolipomas(AMLs)represent the most common benign solid renal tumors.The frequency of their detection in the general population is increasing owing to advances in imaging technology.The objective of this review is to discuss computed tomography(CT)and magnetic resonance imaging findings for both typical and atypical renal AMLs,along with their associated complications.AMLs are typically defined as solid triphasic tumors composed of varying amounts of dysmorphic and tortuous blood vessels,smooth muscle components and adipose tissue.In an adult,a classical renal AML appears as a solid,heterogeneous renal cortical mass with macroscopic fat.However,up to 5%of AMLs contain minimal fat and cannot be reliably diagnosed by imaging.Fat-poor AMLs can appear as hyperattenuating masses on unenhanced CT and as hypointense masses on T2WI;other AMLs may be isodense or exhibit cystic components.Hemorrhage is the most common complication,and AMLs with hemorrhage can mimic other tumors,making their diagnosis challenging.Understanding the variable and heterogeneous nature of this neoplasm to correctly classify renal AMLs and to avoid misdiagnosis of other renal lesions is crucial.展开更多
The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an ...The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.展开更多
Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other s...Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other seasons.The phenomenon significantly disrupts radio wave signals essential to communication and navigation systems.The national network of Global Navigation Satellite System(GNSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB studies.To explore this,we conducted preliminary 3D tomography of total electron content(TEC)data captured by GNSS receivers following a geomagnetic storm on December 3,2023,when at least four EPB clusters occurred in the Southeast Asian sector.TEC and extracted TEC depletion with a 120-minute running average were then used as inputs for a 3D tomography program.Their 2D spatial distribution consistently captured the four EPB clusters over time.These tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International Reference Ionosphere(IRI)profile.Validation of the results demonstrates the capability of the Indonesian GNSS network to measure peak ionospheric density.These findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GNSS networks,with extensive longitudinal coverage.展开更多
BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significan...BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.AIM To establish a noninvasive radiomic model based on computed tomography enterography(CTE)for MH assessment in SBCD patients.METHODS Seventy-three patients diagnosed with SBCD were included and divided into a training cohort(n=55)and a test cohort(n=18).Radiomic features were obtained from CTE images to establish a radiomic model.Patient demographics were analysed to establish a clinical model.A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features.The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic(ROC)curve analysis and decision curve analysis(DCA),respectively.RESULTS Of the 73 patients enrolled,25 patients achieved MH.The radiomic-clinical nomogram had an area under the ROC curve of 0.961(95%confidence interval:0.886-1.000)in the training cohort and 0.958(0.877-1.000)in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone,as demonstrated by DCA.CONCLUSION These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients.展开更多
The Tan-Lu Fault Zone is a large NNE-trending fault zone that has a substantial effect on the development of eastern China and its earthquake disaster prevention efforts. Aiming at the azimuthally anisotropic structur...The Tan-Lu Fault Zone is a large NNE-trending fault zone that has a substantial effect on the development of eastern China and its earthquake disaster prevention efforts. Aiming at the azimuthally anisotropic structure in the upper crust and seismogenic tectonics in the Hefei segment of this fault, we collected phase velocity dispersion data of fundamental mode Rayleigh waves from ambient noise cross-correlation functions of ~400 temporal seismographs in an area of approximately 80 × 70 km along the fault zone. The period band of the dispersion data was ~0.5–10 s. We inverted for the upper crustal three-dimensional(3-D) shear velocity model with azimuthal anisotropy from the surface to 10 km depth by using a 3-D direct azimuthal anisotropy inversion method. The inversion result shows the spatial distribution characteristics of the tectonic units in the upper crust. Additionally, the deformation of the Tan-Lu Fault Zone and its conjugated fault systems could be inferred from the anisotropy model. In particular, the faults that have remained active from the early and middle Pleistocene control the anisotropic characteristics of the upper crustal structure in this area. The direction of fast axes near the fault zone area in the upper crust is consistent with the strike of the faults, whereas for the region far away from the fault zone, the direction of fast axes is consistent with the direction of the regional principal stress caused by plate movement. Combined with the azimuthal anisotropy models in the deep crust and uppermost mantle from the surface wave and Pn wave, the different anisotropic patterns caused by the Tan-Lu Fault Zone and its conjugated fault system nearby are shown in the upper and lower crust. Furthermore,by using the double-difference method, we relocated the Lujiang earthquake series, which contained 32 earthquakes with a depth shallower than 10 km. Both the Vs model and earthquake relocation results indicate that earthquakes mostly occurred in the vicinity of structural boundaries with fractured media, with high-level development of cracks and small-scale faults jammed between more rigid areas.展开更多
AIM:To explore the morphological and functional parameters to evaluate the effectiveness of intravitreal injections of ranibizumab(IVR)in treating macular edema(ME)secondary to retinal vein occlusion(RVO).METHODS:This...AIM:To explore the morphological and functional parameters to evaluate the effectiveness of intravitreal injections of ranibizumab(IVR)in treating macular edema(ME)secondary to retinal vein occlusion(RVO).METHODS:This retrospective study involved 65 RVO patients(65 eyes)who received IVR and were followedup for more than 3mo.ME was categorized into cystoid macular edema(CME),diffuse retinal thickening(DRT),and serous retinal detachment(SRD)according to optical coherence tomography(OCT)images.The comparison of best corrected visual acuity(BCVA;logMAR)and central macular thickness(CMT)among different follow-up points and those among 3 groups were performed by Kruskal-Wallis test.The correlation between BCVA and baseline parameters during treatment was analyzed using Spearman correlation analysis.RESULTS:BCVA tended to improve in all groups,with marked improvement in CME and DRT groups.CMT showed the greatest reduction after 1wk,and remained stable over the following 3mo.DRT patients had the worst BCVA and the highest CMT at baseline,but the differences became smaller after IVR treatment.CMT in SRD group was significantly better than in CME and DRT groups 3mo after IVR.Most patients of CME and SRD groups transitioned to a normal pattern at 3mo follow-up.DRT patients were most likely to transform into the other morphological groups,while SRD patients showed minimal transitions.BCVA at baseline was identified as the most important prognostic indicator in all 3 groups.Additionally,DRT patients with a longer clinical course,higher CMT and central retinal vein occlusion(CRVO)tend to exhibit worse BCVA after treatment.In addition,CRVO patients are more likely to have worse BCVA at 2 and 3mo follow-up compared with branch retinal vein occlusion(BRVO)patients in CME group.SRD patients with higher baseline CMT were prone to experiencing worse BCVA after treatment.CONCLUSION:The effectiveness of IVR is strongly correlated with baseline BCVA in all 3 groups.Baseline parameters including clinical course,CMT,and RVO position are also useful in predicting the BCVA at different time points after treatment.展开更多
Malignant tumours always threaten human health.For tumour diagnosis,positron emission tomography(PET)is the most sensitive and advanced imaging technique by radiotracers,such as radioactive^(18)F,^(11)C,^(64)Cu,^(68)G...Malignant tumours always threaten human health.For tumour diagnosis,positron emission tomography(PET)is the most sensitive and advanced imaging technique by radiotracers,such as radioactive^(18)F,^(11)C,^(64)Cu,^(68)Ga,and^(89)Zr.Among the radiotracers,the radioactive^(18)F-labelled chemical agent as PET probes plays a predominant role in monitoring,detecting,treating,and predicting tumours due to its perfect half-life.In this paper,the^(18)F-labelled chemical materials as PET probes are systematically summarized.First,we introduce various radionuclides of PET and elaborate on the mechanism of PET imaging.It highlights the^(18)F-labelled chemical agents used as PET probes,including[^(18)F]-2-deoxy-2-[^(18)F]fluoro-D-glucose([^(18)F]-FDG),^(18)F-labelled amino acids,^(18)F-labelled nucleic acids,^(18)F-labelled receptors,^(18)F-labelled reporter genes,and^(18)F-labelled hypoxia agents.In addition,some PET probes with metal as a supplementary element are introduced briefly.Meanwhile,the^(18)F-labelled nanoparticles for the PET probe and the multi-modality imaging probe are summarized in detail.The approach and strategies for the fabrication of^(18)F-labelled PET probes are also described briefly.The future development of the PET probe is also prospected.The development and application of^(18)F-labelled PET probes will expand our knowledge and shed light on the diagnosis and theranostics of tumours.展开更多
Objective To evaluate the image quality （IQ） and radiation dose of 128-slice dual-source computed tomography （DSCT） coronary angiography using prospectively electrocardiogram （ECG）-triggered sequen- tial scan mo...Objective To evaluate the image quality （IQ） and radiation dose of 128-slice dual-source computed tomography （DSCT） coronary angiography using prospectively electrocardiogram （ECG）-triggered sequen- tial scan mode compared with ECG-gated spiral scan mode in a population with atrial fibrillation. Methods Thirty-two patients with suspected coronary artery disease and permanent atrial fibrilla- tion referred for a second-generation 128-slice DSCT coronary angiography were included in the prospec- tive study. Of them, 17 patients （sequential group） were randomly selected to use a prospectively ECG.~triggered sequential scan, while the other 15 patients （spiral group） used a retrospectively ECG-gated spiral scan. The IQ was assessed by two readers independently, using a four-point grading scale from excel- lent （grade 1） to non-assessable （grade 4）, based on the American Heart Association 15-segment model. IQ of each segment and effective dose of each natient were comDared between the two groups. Results The mean heart rate （HR） of the sequential group was 96±27 beats per minute （bpm） with a variation range of 73±25 bpm, while the mean HR of the spiral group was 86±22 bpm with a variationrange of 65±24 bpm. Both of the mean FIR （t= 1.91, P=0.243） and HR variation range （t=0.950, P=0.350） had no significant difference between the two groups. In per-segment analysis, IQ of the sequential group vs. spiral group was rated as excellent （grade 1） in 190/244 （78%） vs. 177/217 （82%） by readerl and 197/245 （80%） vs. 174/214 （81%） by reader2, as non-assessable （grade 4） in 4/244 （2%） vs. 2/217 （1%） by readerl and 6/245 （2%） vs. 4/214 （2%） by reader2. Overall averaged IQ per-patient in the sequential and spiral group showed equally good （1.27＋0.19 vs. 1.25＋0.22, Z=-0.834, P=0.404）. The effective radiation dose of the sequential group reduced significantly compared with the spiral group （4.88±1.77 mSv vs. 10.20±3.64 mSv; t=-5.372, P=0.000）. Conclusion Compared with retrospectively ECG-gated spiral scan, prospectively ECG-triggered sequential DSCT coronary angiography provides similarly diagnostically valuable images in patients with atrial fibrillation and significantly reduces radiation dose.展开更多
Background:To evaluate the qualitative and quantitative differences between intracardiac and extracardiac vascular malformations in patients with a single atrium(SA),single ventricle(SV)and single atrium-single ventri...Background:To evaluate the qualitative and quantitative differences between intracardiac and extracardiac vascular malformations in patients with a single atrium(SA),single ventricle(SV)and single atrium-single ventricle(SA-SV)using dual-source CT(DSCT),and to compare the diagnostic performances of DSCT and transthoracic echocardiography(TTE).Methods:This retrospective study included 24 SA,75 SV and 24 SA-SV patients who underwent both DSCT and TTE before surgery.The diagnostic values of DSCT and TTE for intracardiac and extracardiac malformations were compared according to the surgical results.The diameters of the major artery and vein were measured and calculated based on DSCT and compared among the three groups.Results:The most common malformation was pulmonary artery disease in SA(50.0%)and SA-SV(45.8%)groups and patent ductus arteriosus(33.3%)in SV group.Although there was no statistical difference,arterial development was relatively poor in the SA group.All groups showed the trend of pulmonary artery stenosis(SA vs.SV vs.SA-SV:50.0%vs.30.7%vs.33.3%).There was a significant difference in mean pulmonary vein index among the groups(p=0.017).The diagnostic sensitivity of DSCT was superior to that of TTE for extracardiac malformations.Conclusions:The most common malformation in SA and SA-SV patients is pulmonary artery stenosis.SV patients are most likely to be complicated with patent ductus arteriosus.DSCT is more advantageous than TTE for diagnosing combined extracardiac malformations and can accurately measure the diameter of arteriovenous vessels.展开更多
Biliary tract cancer(BTC)is a group of heterogeneous sporadic diseases,including intrahepatic,hilar,and distal cholangiocarcinoma,as well as gallbladder cancer.BTC is characterized by high invasiveness and extremely p...Biliary tract cancer(BTC)is a group of heterogeneous sporadic diseases,including intrahepatic,hilar,and distal cholangiocarcinoma,as well as gallbladder cancer.BTC is characterized by high invasiveness and extremely poor prognosis,with a global increased incidence due to intrahepatic cholangiocarcinoma(ICC).The 18Ffludeoxyglucose positron emission tomography(PET)computed tomography(18F-FDG PET/CT)combines glucose metabolic information(reflecting the glycolytic activity of tumor cells)with anatomical structure to assess tumor metabolic heterogeneity,systemic metastasis,and molecular characteristics noninvasively,overcoming the limitations of traditional imaging in the detection of micrometastases and recurrent lesions.18F-FDG PET/CT offers critical insights in clinical staging,therapeutic evaluation,and prognostic prediction of BTC.This article reviews research progress in this field over the past decade,with a particular focus on the advances made in the last 3 years,which have not been adequately summarized and recognized.The research paradigm in this field is shifting from qualitative to quantitative studies,and there have been significant breakthroughs in using 18F-FDG PET/CT metabolic information to predict gene expression in ICC.Radiomics and deep learning techniques have been applied to ICC for prognostic prediction and differential diagnosis.Additionally,PET/magnetic resonance imaging is increasingly demonstrating its value in this field.展开更多
Soft tissue sarcomas(STS)are rare malignant tumors originating from mesoder-mal tissues with a poor prognosis,accounting for approximately 1%of all malig-nancies and comprising around 50 distinct subtypes.Conventional...Soft tissue sarcomas(STS)are rare malignant tumors originating from mesoder-mal tissues with a poor prognosis,accounting for approximately 1%of all malig-nancies and comprising around 50 distinct subtypes.Conventional imaging mo-dalities,such as computed tomography(CT)and magnetic resonance imaging(MRI),primarily provide anatomical information,whereas 18F-fluorodeoxyglucose positron emission tomography/CT(18F-FDG PET/CT)integrates functional metabolic and anatomical imaging,serving as a critical complementary tool in the diagnosis and management of STS.This article reviews recent advances in the application of 18F-FDG PET/CT for STS.The advantages of 18F-FDG PET/CT in STS include:(1)Early detection of metabolic activity changes in tumors,partic-ularly when morphological alterations are insignificant;(2)Effective differen-tiation between benign and malignant soft tissue tumors,as well as aiding in distinguishing high-grade from low-grade sarcomas;(3)Identification of occult metastatic lesions,improving staging accuracy,and facilitating restaging in cases of recurrence or metastasis;(4)Utilization of parameters such as maximum stan-dardized uptake value and metabolic tumor volume to assist in tumor grading and prognostic evaluation;and(5)Monitoring treatment response to guide adjust-ments in personalized therapeutic strategies.However,18F-FDG PET/CT has limitations in diagnosis of certain STS subtypes(e.g.,myxoid liposarcoma),detection and biopsy of metastatic lymph nodes,necessitating integration with clinical evaluation and other imaging techniques.18F-FDG PET/CT is poised to play an increasingly vital role in the precision diagnosis and treatment of STS.展开更多
BACKGROUND Malignant pleural mesothelioma(MPM),a rare aggressive malignancy,is primarily caused by asbestos exposure.MPM typically affects older adults(median age,76 years),is uncommon in those under age 50 years and ...BACKGROUND Malignant pleural mesothelioma(MPM),a rare aggressive malignancy,is primarily caused by asbestos exposure.MPM typically affects older adults(median age,76 years),is uncommon in those under age 50 years and shows male predominance.Based on the American Society of Clinical Oncology guidelines,F-18 fluorodeoxyglucose positron emission tomography/computed tomography(F-18 FDG PET/CT)is essential for initial MPM staging.Integrating quantitative FDG metabolic data with computed tomography(CT)anatomy optimizes biopsy accuracy and staging.CASE SUMMARY A 21-year-old female college student presented with fever(peak 38.4°C),cough,and white mucoid sputum after cold exposure.Initial evaluation revealed elevated C-reactive protein[C-reactive protein(CRP);65.52 mg/L]and Mycoplasma pneumoniae IgM.Despite resolution of fever following a 14-day moxifloxacin regimen,persistent cough prompted chest CT,which demonstrated left pleural mass-like thickenings.Levofloxacin therapy for 2 weeks failed to alleviate symptoms,accompanied by 2.5-kg weight loss over 1 month.Re-evaluation showed rising CRP(88.87 mg/L)with stable CT lesions,and negative T-cell spot test for tuberculosis and tumor markers.Contrast-enhanced CT revealed heterogeneously enhancing masses,while PET/CT detected two broad-based pleural lesions with intense FDG avidity.CT-guided biopsy confirmed epithelioid MPM.Thoracoscopy exposed diffuse fragile,hemorrhagic nodules implanting on diaphragmatic and parietal pleura,confirming metastatic MPM with partial resection performed.This presentation challenges conventional imaging paradigms of MPM,underscoring its diagnostic complexity.CONCLUSION MPM should still be considered an important differential diagnosis in young patients presenting with solitary pleural masses and no history of typical asbestos exposure.F-18 FDG PET/CT,while serving as an essential component of initial staging for MPM,has some inherent limitations.展开更多
Dual-energy CT(DECT)is an advancement in CT technology that allows for the acquisition of images at two different energy levels.Two main post-processing tools,which form the backbone of DECT,include material decomposi...Dual-energy CT(DECT)is an advancement in CT technology that allows for the acquisition of images at two different energy levels.Two main post-processing tools,which form the backbone of DECT,include material decomposition and virtual monoenergetic images.Material decomposition helps in the generation of virtual nonenhanced,iodine,pulmonary lung blood volume,lung vessel,automated bone removal,and renal stone characterization images.DECT offers a broad spectrum of clinical applications in pediatric imaging,including vascular,neurological,thoracic,abdominal,skeletal,and oncologic assessments.Additionally,it contributes to shorter scan times and enables the use of lower contrast media volumes while maintaining diagnostic image quality.This technique provides unique qualitative and quantitative information about the composition of the tissue,allowing differentiation of materials,including iodinated contrast agents.The radiation dose of DECT is equivalent to or lower than that of a singleenergy CT,adding to the advantages of DECT,especially in children who are more sensitive to the harmful effects of radiation.In this minireview we outlined the basic principles of the DECT technique and its post-processing techniques with emphasis on clinical applications in pediatric imaging.展开更多
文摘Objective To investigate the image quality, radiation dose and diagnostic value of the low-tube-voltage high-pitch dual-source computed tomography(DSCT) with sinogram affirmed iterative reconstruction(SAFIRE) for non-enhanced abdominal and pelvic scans. Methods This institutional review board-approved prospective study included 64 patients who gave written informed consent for additional abdominal and pelvic scan with DSCT in the period from November to December 2012. The patients underwent standard non-enhanced CT scans(protocol 1) [tube voltage of 120 k Vp/pitch of 0.9/filtered back-projection(FBP) reconstruction] followed by high-pitch non-enhanced CT scans(protocol 2)(100 k Vp/3.0/SAFIRE). The total scan time, mean CT number, signal-to-noise ratio(SNR), image quality, lesion detectability and radiation dose were compared between the two protocols. Results The total scan time of protocol 2 was significantly shorter than that of protocol 1(1.4±0.1 seconds vs. 7.6±0.6 seconds, P<0.001). There was no significant difference between protocol 1 and protocol 2 in mean CT number of all organs(liver, 55.4±6.3 HU vs. 56.1±6.8 HU, P=0.214; pancreas, 43.6±5.9 HU vs. 43.7±5.8 HU, P=0.785; spleen, 47.9±3.9 HU vs. 49.4±4.3 HU, P=0.128; kidney, 32.2±2.3 HU vs. 33.1±2.3 HU, P=0.367; abdominal aorta, 44.8±5.6 HU vs. 45.0±5.5 HU, P=0.499; psoas muscle, 50.7±4.1 HU vs. 50.3±4.5 HU, P=0.279). SNR on images of protocol 2 was higher than that of protocol 1(liver, 5.0±1.2 vs. 4.5±1.1, P<0.001; pancreas, 4.0±1.0 vs. 3.6±0.8, P<0.001; spleen, 4.7±1.0 vs. 4.1±0.9, P<0.001; kidney, 3.1±0.6 vs. 2.8±0.6, P<0.001; abdominal aorta, 4.1±1.0 vs. 3.8±1.0, P<0.001; psoas muscle, 4.5±1.1 vs. 4.3±1.2, P=0.012). The overall image noise of protocol 2 was lower than that of protocol1(9.8±3.1 HU vs. 11.1±3.0 HU, P<0.001). Image quality of protocol 2 was good but lower than that of protocol 1(4.1±0.7 vs. 4.6±0.5, P<0.001). Protocol 2 perceived 229 of 234 lesions(97.9%) that were detected in protocol 1 in the abdomen and pelvis. Radiation dose of protocol 2 was lower than that of protocol 1(4.4±0.4 m Sv vs. 7.3±2.4 m Sv, P<0.001) and the mean dose reduction was 41.4%. Conclusion The high-pitch DSCT with SAFIRE can shorten scan time and reduce radiation dose while preserving image quality in non-enhanced abdominal and pelvic scans.
文摘Truncus arteriosus is an uncommon congenital cardiac abnormality which is characterized by a single arterial trunk origin from the heart that supplies both the systemic,pulmonary and coronary circulation.We present a preterm newborn female patient with type 2 truncusarteriosus,left superior vena cava and aberrant subclavian artery diagnosed with low dose dual-source cardiac computed tomography(CT).We discuss that low dose dual-source cardiac CT has more advantages than other imaging methods and it is an important modality for assessment of patients with conotruncal anomalies such as truncusarteriosus.
文摘Photon-counting computed tomography(PCCT)represents a significant advancement in pediatric cardiovascular imaging.Traditional CT systems employ energy-integrating detectors that convert X-ray photons into visible light,whereas PCCT utilizes photon-counting detectors that directly transform X-ray photons into electric signals.This direct conversion allows photon-counting detectors to sort photons into discrete energy levels,thereby enhancing image quality through superior noise reduction,improved spatial and contrast resolution,and reduced artifacts.In pediatric applications,PCCT offers substantial benefits,including lower radiation doses,which may help reduce the risk of malignancy in pediatric patients,with perhaps greater potential to benefit those with repeated exposure from a young age.Enhanced spatial resolution facilitates better visualization of small structures,vital for diagnosing congenital heart defects.Additionally,PCCT’s spectral capabilities improve tissue characterization and enable the creation of virtual monoenergetic images,which enhance soft-tissue contrast and potentially reduce contrast media doses.Initial clinical results indicate that PCCT provides superior image quality and diagnostic accuracy compared to conven-tional CT,particularly in challenging pediatric cardiovascular cases.As PCCT technology matures,further research and standardized protocols will be essential to fully integrate it into pediatric imaging practices,ensuring optimized diagnostic outcomes and patient safety.
文摘AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR),and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA screening indicators to detect concurrent DR at an early stage.METHODS:A total of 200 patients who treated in the ophthalmology department of the Seventh Affiliated Hospital,Sun Yat-sen University from 2022 to 2023 were included,including 95 first-diagnosed DR patients and 105 patients without DR,and all patients underwent OCTA examination and a collection of demographics and renal function parameters.After a quality check,automated measurements of the foveal avascular zone area,vessel density(VD),and perfusion density(PD)of both 3 mm×3 mm and 6 mm×6 mm windows were obtained.RESULTS:Using random forest and multivariate Logistic regression methods,we developed a diagnostic model for DR based on 12 variables(age,FBG,SBP,DBP,HbA1c,ALT,ALP,urea/Scr,DM duration,HUA,DN,and CMT).Adding specific OCTA parameters enhanced the efficacy of the existing diagnostic model for DR(outer vessel density in 6 mm×6 mm window,AUC=0.837 vs 0.819,P=0.03).In the study of DN patients,the parameters in the 6 mm×6 mm window improved the diagnostic efficacy of DR(inner VD;outer VD;full VD;outer PD;full PD).CONCLUSION:The outer VD in the 6 mm×6 mm window can enhance the efficacy of the traditional DR diagnostic model.Meanwhile,compared with the 3 mm×3 mm window,the microvascular parameters in the 6 mm×6 mm window focusing on DN patients can be more sensitive to diagnosing the occurrence of DR.
基金supported by the Research Project of the Shanghai Health Commission,No.2020YJZX0111(to CZ)the National Natural Science Foundation of China,Nos.82021002(to CZ),82272039(to CZ),82171252(to FL)+1 种基金a grant from the National Health Commission of People’s Republic of China(PRC),No.Pro20211231084249000238(to JW)Medical Innovation Research Project of Shanghai Science and Technology Commission,No.21Y11903300(to JG).
文摘Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.
基金This study was approved by the Institutional Ethics Committee of West China Hospital,Sichuan University (Chengdu, Sichuan, ChinaNo. 14-163)+1 种基金This study has received funding by Sichuan Science and Technology Program(2020YJ0229)1⋅3⋅5 Project for Disciplines of Excellence,West China Hospital,Sichuan University(ZYGD18013)。
文摘Background:Pulmonary atresia(PA)is a group of heterogeneous complex congenital heart disease.Only one study modality might not get a correct diagnosis.This study aims to investigate the diagnostic power of dualsource computed tomography(DSCT)for all intracardiac and extracardiac deformities in patients with PA compared with transthoracic echocardiography(TTE).Materials and Methods:This retrospective study enrolled 79 patients and divided them into three groups according to their main diagnosis.All associated malformations and clinical information,including treatments,were recorded and compared among the three groups.The diagnostic power of DSCT and TTE on all associated malformations were compared.The surgical index(McGoon ratio,pulmonary arterials index(PAI),and total neopulmonary arterial index)and radiation dose were calculated on the basis of DSCT.Results:Of the patients,32,30,and 17 were divided into the groups of PA with ventricular septal defect(VSD),PA with VSD and major aortopulmonary collateral arteries,and PA with other major malformations,respectively.Consequently,182,162,and 13 intracardiac,extracardiac,and other major malformations were diagnosed,respectively.Moreover,DSCT showed a better diagnostic performance in extracardiac deformities(154 vs.117,p<0.001),whereas TTE could diagnose intracardiac deformities better(159 vs.139,p=0.001).The McGoon ratio,PAI,and treatment methods were significantly different among the three groups(p=0.014,p=0.008,and p=0.018,respectively).Conclusion:More than one imaging modality should be used to make a correct diagnosis when clinically suspecting PA.DSCT is superior to TTE in diagnosing extracardiac deformities and could be used to roughly calculate surgical indices to optimize treatment strategy.
文摘BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases.
文摘Angiomyolipomas(AMLs)represent the most common benign solid renal tumors.The frequency of their detection in the general population is increasing owing to advances in imaging technology.The objective of this review is to discuss computed tomography(CT)and magnetic resonance imaging findings for both typical and atypical renal AMLs,along with their associated complications.AMLs are typically defined as solid triphasic tumors composed of varying amounts of dysmorphic and tortuous blood vessels,smooth muscle components and adipose tissue.In an adult,a classical renal AML appears as a solid,heterogeneous renal cortical mass with macroscopic fat.However,up to 5%of AMLs contain minimal fat and cannot be reliably diagnosed by imaging.Fat-poor AMLs can appear as hyperattenuating masses on unenhanced CT and as hypointense masses on T2WI;other AMLs may be isodense or exhibit cystic components.Hemorrhage is the most common complication,and AMLs with hemorrhage can mimic other tumors,making their diagnosis challenging.Understanding the variable and heterogeneous nature of this neoplasm to correctly classify renal AMLs and to avoid misdiagnosis of other renal lesions is crucial.
基金Funded by Chinese National Natural Science Foundation of China(No.U2006224)。
文摘The paper presents experimental investigation results of crack pattern change in cement pastes caused by external sulfate attack(ESA).To visualize the formation and development of cracks in cement pastes under ESA,an X-ray computed tomography(X-ray CT)was used,i e,the tomography system of Zeiss Xradia 510 versa.The results indicate that X-CT can monitor the development process and distribution characteristics of the internal cracks of cement pastes under ESA with attack time.In addition,the C3A content in the cement significantly affects the damage mode of cement paste specimens during sulfate erosion.The damage of ordinary Portland cement(OPC)pastes subjected to sulfate attack with high C3A content are severe,while the damage of sulfate resistant Portland cement(SRPC)pastes is much smaller than that of OPC pastes.Furthermore,a quadratic function describes the correlation between the crack volume fraction and development depth for two cement pastes immermed in sulfate solution.
基金the National Institute of Information and Communication Technology International Exchange Program 2024−2025(No.2024−007)for their invaluable support in this research.3D tomography software is available at Prof.Kosuke Heki’s(Hokkaido University,Japan)personal homepage(https://www.ep.sci.hokudai.ac.jp/~heki/software.htm).support from the 2024 Japan Student Services Organization Research Follow-up Fellowship for a 90-day research visit at the Institute for Space−Earth Environmental Research,Nagoya University,Japan.PA also acknowledges the support received from Telkom University under the“Skema Penelitian Terapan Periode I Tahun Anggaran 2024”,and the Memorandum of Understanding for Research Collaboration on Regional Ionospheric Observation(No:092/SAM3/TE-DEK/2021).
文摘Equatorial Plasma Bubbles(EPBs)are ionospheric irregularities that take place near the magnetic equator.EPBs most commonly occur after sunset during the equinox months,although they can also be observed during other seasons.The phenomenon significantly disrupts radio wave signals essential to communication and navigation systems.The national network of Global Navigation Satellite System(GNSS)receivers in Indonesia(>30°longitudinal range)provides an opportunity for detailed EPB studies.To explore this,we conducted preliminary 3D tomography of total electron content(TEC)data captured by GNSS receivers following a geomagnetic storm on December 3,2023,when at least four EPB clusters occurred in the Southeast Asian sector.TEC and extracted TEC depletion with a 120-minute running average were then used as inputs for a 3D tomography program.Their 2D spatial distribution consistently captured the four EPB clusters over time.These tomography results were validated through a classical checkerboard test and comparisons with other ionospheric data sources,such as the Global Ionospheric Map(GIM)and International Reference Ionosphere(IRI)profile.Validation of the results demonstrates the capability of the Indonesian GNSS network to measure peak ionospheric density.These findings highlight the potential for future three-dimensional research of plasma bubbles in low-latitude regions using existing GNSS networks,with extensive longitudinal coverage.
基金Supported by Natural Science Foundation of Anhui Medical University,No.2023xkj130.
文摘BACKGROUND Mucosal healing(MH)is the major therapeutic target for Crohn's disease(CD).As the most commonly involved intestinal segment,small bowel(SB)assessment is crucial for CD patients.Yet,it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.AIM To establish a noninvasive radiomic model based on computed tomography enterography(CTE)for MH assessment in SBCD patients.METHODS Seventy-three patients diagnosed with SBCD were included and divided into a training cohort(n=55)and a test cohort(n=18).Radiomic features were obtained from CTE images to establish a radiomic model.Patient demographics were analysed to establish a clinical model.A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features.The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic(ROC)curve analysis and decision curve analysis(DCA),respectively.RESULTS Of the 73 patients enrolled,25 patients achieved MH.The radiomic-clinical nomogram had an area under the ROC curve of 0.961(95%confidence interval:0.886-1.000)in the training cohort and 0.958(0.877-1.000)in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone,as demonstrated by DCA.CONCLUSION These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients.
基金financially supported by the National Key Research and Development Program of China (2022YFC3005600)the Foundation of the Anhui Educational Commission (2023AH051198)+1 种基金the National Natural Science Foundation of China (42125401 and 42104063)the Joint Open Fund of Mengcheng National Geophysical Observatory (MENGO-202201)。
文摘The Tan-Lu Fault Zone is a large NNE-trending fault zone that has a substantial effect on the development of eastern China and its earthquake disaster prevention efforts. Aiming at the azimuthally anisotropic structure in the upper crust and seismogenic tectonics in the Hefei segment of this fault, we collected phase velocity dispersion data of fundamental mode Rayleigh waves from ambient noise cross-correlation functions of ~400 temporal seismographs in an area of approximately 80 × 70 km along the fault zone. The period band of the dispersion data was ~0.5–10 s. We inverted for the upper crustal three-dimensional(3-D) shear velocity model with azimuthal anisotropy from the surface to 10 km depth by using a 3-D direct azimuthal anisotropy inversion method. The inversion result shows the spatial distribution characteristics of the tectonic units in the upper crust. Additionally, the deformation of the Tan-Lu Fault Zone and its conjugated fault systems could be inferred from the anisotropy model. In particular, the faults that have remained active from the early and middle Pleistocene control the anisotropic characteristics of the upper crustal structure in this area. The direction of fast axes near the fault zone area in the upper crust is consistent with the strike of the faults, whereas for the region far away from the fault zone, the direction of fast axes is consistent with the direction of the regional principal stress caused by plate movement. Combined with the azimuthal anisotropy models in the deep crust and uppermost mantle from the surface wave and Pn wave, the different anisotropic patterns caused by the Tan-Lu Fault Zone and its conjugated fault system nearby are shown in the upper and lower crust. Furthermore,by using the double-difference method, we relocated the Lujiang earthquake series, which contained 32 earthquakes with a depth shallower than 10 km. Both the Vs model and earthquake relocation results indicate that earthquakes mostly occurred in the vicinity of structural boundaries with fractured media, with high-level development of cracks and small-scale faults jammed between more rigid areas.
基金Supported by the Suzhou Medical Innovation Application Research Project(SZM2023027).
文摘AIM:To explore the morphological and functional parameters to evaluate the effectiveness of intravitreal injections of ranibizumab(IVR)in treating macular edema(ME)secondary to retinal vein occlusion(RVO).METHODS:This retrospective study involved 65 RVO patients(65 eyes)who received IVR and were followedup for more than 3mo.ME was categorized into cystoid macular edema(CME),diffuse retinal thickening(DRT),and serous retinal detachment(SRD)according to optical coherence tomography(OCT)images.The comparison of best corrected visual acuity(BCVA;logMAR)and central macular thickness(CMT)among different follow-up points and those among 3 groups were performed by Kruskal-Wallis test.The correlation between BCVA and baseline parameters during treatment was analyzed using Spearman correlation analysis.RESULTS:BCVA tended to improve in all groups,with marked improvement in CME and DRT groups.CMT showed the greatest reduction after 1wk,and remained stable over the following 3mo.DRT patients had the worst BCVA and the highest CMT at baseline,but the differences became smaller after IVR treatment.CMT in SRD group was significantly better than in CME and DRT groups 3mo after IVR.Most patients of CME and SRD groups transitioned to a normal pattern at 3mo follow-up.DRT patients were most likely to transform into the other morphological groups,while SRD patients showed minimal transitions.BCVA at baseline was identified as the most important prognostic indicator in all 3 groups.Additionally,DRT patients with a longer clinical course,higher CMT and central retinal vein occlusion(CRVO)tend to exhibit worse BCVA after treatment.In addition,CRVO patients are more likely to have worse BCVA at 2 and 3mo follow-up compared with branch retinal vein occlusion(BRVO)patients in CME group.SRD patients with higher baseline CMT were prone to experiencing worse BCVA after treatment.CONCLUSION:The effectiveness of IVR is strongly correlated with baseline BCVA in all 3 groups.Baseline parameters including clinical course,CMT,and RVO position are also useful in predicting the BCVA at different time points after treatment.
文摘Malignant tumours always threaten human health.For tumour diagnosis,positron emission tomography(PET)is the most sensitive and advanced imaging technique by radiotracers,such as radioactive^(18)F,^(11)C,^(64)Cu,^(68)Ga,and^(89)Zr.Among the radiotracers,the radioactive^(18)F-labelled chemical agent as PET probes plays a predominant role in monitoring,detecting,treating,and predicting tumours due to its perfect half-life.In this paper,the^(18)F-labelled chemical materials as PET probes are systematically summarized.First,we introduce various radionuclides of PET and elaborate on the mechanism of PET imaging.It highlights the^(18)F-labelled chemical agents used as PET probes,including[^(18)F]-2-deoxy-2-[^(18)F]fluoro-D-glucose([^(18)F]-FDG),^(18)F-labelled amino acids,^(18)F-labelled nucleic acids,^(18)F-labelled receptors,^(18)F-labelled reporter genes,and^(18)F-labelled hypoxia agents.In addition,some PET probes with metal as a supplementary element are introduced briefly.Meanwhile,the^(18)F-labelled nanoparticles for the PET probe and the multi-modality imaging probe are summarized in detail.The approach and strategies for the fabrication of^(18)F-labelled PET probes are also described briefly.The future development of the PET probe is also prospected.The development and application of^(18)F-labelled PET probes will expand our knowledge and shed light on the diagnosis and theranostics of tumours.
文摘Objective To evaluate the image quality （IQ） and radiation dose of 128-slice dual-source computed tomography （DSCT） coronary angiography using prospectively electrocardiogram （ECG）-triggered sequen- tial scan mode compared with ECG-gated spiral scan mode in a population with atrial fibrillation. Methods Thirty-two patients with suspected coronary artery disease and permanent atrial fibrilla- tion referred for a second-generation 128-slice DSCT coronary angiography were included in the prospec- tive study. Of them, 17 patients （sequential group） were randomly selected to use a prospectively ECG.~triggered sequential scan, while the other 15 patients （spiral group） used a retrospectively ECG-gated spiral scan. The IQ was assessed by two readers independently, using a four-point grading scale from excel- lent （grade 1） to non-assessable （grade 4）, based on the American Heart Association 15-segment model. IQ of each segment and effective dose of each natient were comDared between the two groups. Results The mean heart rate （HR） of the sequential group was 96±27 beats per minute （bpm） with a variation range of 73±25 bpm, while the mean HR of the spiral group was 86±22 bpm with a variationrange of 65±24 bpm. Both of the mean FIR （t= 1.91, P=0.243） and HR variation range （t=0.950, P=0.350） had no significant difference between the two groups. In per-segment analysis, IQ of the sequential group vs. spiral group was rated as excellent （grade 1） in 190/244 （78%） vs. 177/217 （82%） by readerl and 197/245 （80%） vs. 174/214 （81%） by reader2, as non-assessable （grade 4） in 4/244 （2%） vs. 2/217 （1%） by readerl and 6/245 （2%） vs. 4/214 （2%） by reader2. Overall averaged IQ per-patient in the sequential and spiral group showed equally good （1.27＋0.19 vs. 1.25＋0.22, Z=-0.834, P=0.404）. The effective radiation dose of the sequential group reduced significantly compared with the spiral group （4.88±1.77 mSv vs. 10.20±3.64 mSv; t=-5.372, P=0.000）. Conclusion Compared with retrospectively ECG-gated spiral scan, prospectively ECG-triggered sequential DSCT coronary angiography provides similarly diagnostically valuable images in patients with atrial fibrillation and significantly reduces radiation dose.
基金This work was supported by Sichuan Science and Technology Program[2020YJ0229]1·3·5 Project for Disciplines of Excellence,West China Hospital,Sichuan University[ZYGD18013].
文摘Background:To evaluate the qualitative and quantitative differences between intracardiac and extracardiac vascular malformations in patients with a single atrium(SA),single ventricle(SV)and single atrium-single ventricle(SA-SV)using dual-source CT(DSCT),and to compare the diagnostic performances of DSCT and transthoracic echocardiography(TTE).Methods:This retrospective study included 24 SA,75 SV and 24 SA-SV patients who underwent both DSCT and TTE before surgery.The diagnostic values of DSCT and TTE for intracardiac and extracardiac malformations were compared according to the surgical results.The diameters of the major artery and vein were measured and calculated based on DSCT and compared among the three groups.Results:The most common malformation was pulmonary artery disease in SA(50.0%)and SA-SV(45.8%)groups and patent ductus arteriosus(33.3%)in SV group.Although there was no statistical difference,arterial development was relatively poor in the SA group.All groups showed the trend of pulmonary artery stenosis(SA vs.SV vs.SA-SV:50.0%vs.30.7%vs.33.3%).There was a significant difference in mean pulmonary vein index among the groups(p=0.017).The diagnostic sensitivity of DSCT was superior to that of TTE for extracardiac malformations.Conclusions:The most common malformation in SA and SA-SV patients is pulmonary artery stenosis.SV patients are most likely to be complicated with patent ductus arteriosus.DSCT is more advantageous than TTE for diagnosing combined extracardiac malformations and can accurately measure the diameter of arteriovenous vessels.
文摘Biliary tract cancer(BTC)is a group of heterogeneous sporadic diseases,including intrahepatic,hilar,and distal cholangiocarcinoma,as well as gallbladder cancer.BTC is characterized by high invasiveness and extremely poor prognosis,with a global increased incidence due to intrahepatic cholangiocarcinoma(ICC).The 18Ffludeoxyglucose positron emission tomography(PET)computed tomography(18F-FDG PET/CT)combines glucose metabolic information(reflecting the glycolytic activity of tumor cells)with anatomical structure to assess tumor metabolic heterogeneity,systemic metastasis,and molecular characteristics noninvasively,overcoming the limitations of traditional imaging in the detection of micrometastases and recurrent lesions.18F-FDG PET/CT offers critical insights in clinical staging,therapeutic evaluation,and prognostic prediction of BTC.This article reviews research progress in this field over the past decade,with a particular focus on the advances made in the last 3 years,which have not been adequately summarized and recognized.The research paradigm in this field is shifting from qualitative to quantitative studies,and there have been significant breakthroughs in using 18F-FDG PET/CT metabolic information to predict gene expression in ICC.Radiomics and deep learning techniques have been applied to ICC for prognostic prediction and differential diagnosis.Additionally,PET/magnetic resonance imaging is increasingly demonstrating its value in this field.
文摘Soft tissue sarcomas(STS)are rare malignant tumors originating from mesoder-mal tissues with a poor prognosis,accounting for approximately 1%of all malig-nancies and comprising around 50 distinct subtypes.Conventional imaging mo-dalities,such as computed tomography(CT)and magnetic resonance imaging(MRI),primarily provide anatomical information,whereas 18F-fluorodeoxyglucose positron emission tomography/CT(18F-FDG PET/CT)integrates functional metabolic and anatomical imaging,serving as a critical complementary tool in the diagnosis and management of STS.This article reviews recent advances in the application of 18F-FDG PET/CT for STS.The advantages of 18F-FDG PET/CT in STS include:(1)Early detection of metabolic activity changes in tumors,partic-ularly when morphological alterations are insignificant;(2)Effective differen-tiation between benign and malignant soft tissue tumors,as well as aiding in distinguishing high-grade from low-grade sarcomas;(3)Identification of occult metastatic lesions,improving staging accuracy,and facilitating restaging in cases of recurrence or metastasis;(4)Utilization of parameters such as maximum stan-dardized uptake value and metabolic tumor volume to assist in tumor grading and prognostic evaluation;and(5)Monitoring treatment response to guide adjust-ments in personalized therapeutic strategies.However,18F-FDG PET/CT has limitations in diagnosis of certain STS subtypes(e.g.,myxoid liposarcoma),detection and biopsy of metastatic lymph nodes,necessitating integration with clinical evaluation and other imaging techniques.18F-FDG PET/CT is poised to play an increasingly vital role in the precision diagnosis and treatment of STS.
基金Supported by the Tianjin Science and Technology Project,No.TJWJ2025RC008。
文摘BACKGROUND Malignant pleural mesothelioma(MPM),a rare aggressive malignancy,is primarily caused by asbestos exposure.MPM typically affects older adults(median age,76 years),is uncommon in those under age 50 years and shows male predominance.Based on the American Society of Clinical Oncology guidelines,F-18 fluorodeoxyglucose positron emission tomography/computed tomography(F-18 FDG PET/CT)is essential for initial MPM staging.Integrating quantitative FDG metabolic data with computed tomography(CT)anatomy optimizes biopsy accuracy and staging.CASE SUMMARY A 21-year-old female college student presented with fever(peak 38.4°C),cough,and white mucoid sputum after cold exposure.Initial evaluation revealed elevated C-reactive protein[C-reactive protein(CRP);65.52 mg/L]and Mycoplasma pneumoniae IgM.Despite resolution of fever following a 14-day moxifloxacin regimen,persistent cough prompted chest CT,which demonstrated left pleural mass-like thickenings.Levofloxacin therapy for 2 weeks failed to alleviate symptoms,accompanied by 2.5-kg weight loss over 1 month.Re-evaluation showed rising CRP(88.87 mg/L)with stable CT lesions,and negative T-cell spot test for tuberculosis and tumor markers.Contrast-enhanced CT revealed heterogeneously enhancing masses,while PET/CT detected two broad-based pleural lesions with intense FDG avidity.CT-guided biopsy confirmed epithelioid MPM.Thoracoscopy exposed diffuse fragile,hemorrhagic nodules implanting on diaphragmatic and parietal pleura,confirming metastatic MPM with partial resection performed.This presentation challenges conventional imaging paradigms of MPM,underscoring its diagnostic complexity.CONCLUSION MPM should still be considered an important differential diagnosis in young patients presenting with solitary pleural masses and no history of typical asbestos exposure.F-18 FDG PET/CT,while serving as an essential component of initial staging for MPM,has some inherent limitations.
文摘Dual-energy CT(DECT)is an advancement in CT technology that allows for the acquisition of images at two different energy levels.Two main post-processing tools,which form the backbone of DECT,include material decomposition and virtual monoenergetic images.Material decomposition helps in the generation of virtual nonenhanced,iodine,pulmonary lung blood volume,lung vessel,automated bone removal,and renal stone characterization images.DECT offers a broad spectrum of clinical applications in pediatric imaging,including vascular,neurological,thoracic,abdominal,skeletal,and oncologic assessments.Additionally,it contributes to shorter scan times and enables the use of lower contrast media volumes while maintaining diagnostic image quality.This technique provides unique qualitative and quantitative information about the composition of the tissue,allowing differentiation of materials,including iodinated contrast agents.The radiation dose of DECT is equivalent to or lower than that of a singleenergy CT,adding to the advantages of DECT,especially in children who are more sensitive to the harmful effects of radiation.In this minireview we outlined the basic principles of the DECT technique and its post-processing techniques with emphasis on clinical applications in pediatric imaging.
