BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is becoming a major health problem,resulting in hepatic,metabolic and cardio-vascular morbidity.AIM To evaluate new ultrasonographic tools to detect and measure hepat...BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is becoming a major health problem,resulting in hepatic,metabolic and cardio-vascular morbidity.AIM To evaluate new ultrasonographic tools to detect and measure hepatic steatosis.METHODS We prospectively included 105 patients referred to our liver unit for NAFLD suspicion or follow-up.They underwent ultrasonographic measurement of liver sound speed estimation(SSE)and attenuation coefficient(AC)using Aixplorer MACH 30(Supersonic Imagine,France),continuous controlled attenuation parameter(cCAP)using Fibroscan(Echosens,France)and standard liver ultrasound with hepato-renal index(HRI)calculation.Hepatic steatosis was then classified according to magnetic resonance imaging proton density fat fraction(PDFF).Receiver operating curve(ROC)analysis was performed to evaluate the diagnostic performance in the diagnosis of steatosis.RESULTS Most patients were overweight or obese(90%)and had metabolic syndrome(70%).One third suffered from diabetes.Steatosis was identified in 85 patients(81%)according to PDFF.Twenty-one patients(20%)had advanced liver disease.SSE,AC,cCAP and HRI correlated with PDFF,with respective Spearman correlation coefficient of-0.39,0.42,0.54 and 0.59(P<0.01).Area under the receiver operating characteristic curve(AUROC)for detection of steatosis with HRI was 0.91(0.83-0.99),with the best cut-off value being 1.3(Se=83%,Sp=98%).The optimal cCAP threshold of 275 dB/m,corresponding to the recent EASL-suggested threshold,had a sensitivity of 72%and a specificity of 80%.Corresponding AUROC was 0.79(0.66-0.92).The diagnostic accuracy of cCAP was more reliable when standard deviation was<15 dB/m with an AUC of 0.91(0.83-0.98).An AC threshold of 0.42 dB/cm/MHz had an AUROC was 0.82(0.70-0.93).SSE performed moderately with an AUROC of 0.73(0.62-0.84).CONCLUSION Among all ultrasonographic tools evaluated in this study,including new-generation tools such as cCAP and SSE,HRI had the best performance.It is also the simplest and most available method as most ultrasound scans are equipped with this module.展开更多
Magnetic resonance (MR) imaging has been increasingly used in the evaluation of prostate cancer. As studies have suggested that the majority of cancers arise from the peripheral zone (PZ), MR imaging has focused on th...Magnetic resonance (MR) imaging has been increasingly used in the evaluation of prostate cancer. As studies have suggested that the majority of cancers arise from the peripheral zone (PZ), MR imaging has focused on the PZ of the prostate gland thus far. However, a considerable number of cancers (up to 30%) originate in the transition zone (TZ), substantially contributing to morbidity and mortality. Therefore, research is needed on the TZ of the prostate gland. Recently, MR imaging and advanced MR techniques have been gaining acceptance in evaluation of the TZ. In this article, the MR imaging features of TZ prostate cancers, the role of MR imaging in TZ cancer detection and staging, and recent advanced MR techniques will be discussed in light of the literature.展开更多
Magnetic resonance imaging(MRI),as a noninvasive and powerful method in modern diagnostics,has been advancing in leaps and bounds.Conventional methods to improve MRI based on increasing the static magnetic field stren...Magnetic resonance imaging(MRI),as a noninvasive and powerful method in modern diagnostics,has been advancing in leaps and bounds.Conventional methods to improve MRI based on increasing the static magnetic field strength are restricted by safety concerns,cost issues,and the impact on patient experience;as such,innovative approaches are required.It has been suggested that metamaterials featuring subwavelength unit cells can be used to take full control of electromagnetic waves and redistribute electromagnetic fields,achieve abundant counterintuitive phenomena,and construct versatile devices.Recently,metamaterials with exotic effective electromagnetic parameters,peculiar dispersion relations,or tailored field distribution of resonant modes have shown promising capabilities in MRI.Herein,we outline the principle of the MRI process,review recent advances in enhancing MRI by employing the unique physical mechanisms of metamaterials,and demystify ways in which metamaterial designs could improve MRI,such as by enhancing the imaging quality,reducing the scanning time,alleviating field inhomogeneities,and increasing patient safety.We conclude by providing our vision for the future of improving MRI with metamaterials.展开更多
Introduction:Noninvasive diagnoses of clinically significant portal hypertension(CSPH)and high-risk gastroesophageal varices are clinically relevant but challenging.Four-dimensional(4D)flow magnetic resonance imaging(...Introduction:Noninvasive diagnoses of clinically significant portal hypertension(CSPH)and high-risk gastroesophageal varices are clinically relevant but challenging.Four-dimensional(4D)flow magnetic resonance imaging(MRI)provides comprehensive flow information and is a promising alternative.This study evaluated the efficacy of 4D flow MRI as a noninvasive method for diagnosing CSPH and high-risk varices in patients with liver cirrhosis.Methods:This prospective study enrolled consecutive patients diagnosed with liver cirrhosis at a tertiary referral center between October 2020 and March 2021.Each participant underwent abdominal 4D flow MRI.Hemodynamic parameters within the portal vein,including the average and peak flow velocities,normalized flow volume(Q_(normal)),and regurgitant fraction(R%),were extracted and compared between healthy individuals and patients with CSPH and between participants with high-and low-risk varices.Subsequently,these parameters were incorporated into a logistic regression(LR)model refined using L1 regularization and validated using five-fold cross-validation.The diagnostic efficacy was evaluated using receiver operating characteristic(ROC)curves.Results:Eighty-two participants were enrolled(71 patients diagnosed with liver cirrhosis and 11 healthy individuals serving as controls).Among hemodynamic parameters,patients with CSPH exhibited a notable increase in Q_(normal)of 0.66±0.19 ml*m^(2)/[cycle*kg](P=0.001)and an R%of 1.98(2.05)(P=0.002).Similarly,patients with high-risk varices showed a higher Q_(normal)of 0.61±0.15 ml*m^(2)/[cycle*kg](P<0.001)and R%of 1.88(2.81)(P=0.006).ROC analysis revealed an area under the curve(AUC)for Q_(normal)of 0.93 and 0.91 for R%for diagnosing CSPH,while the LR model showcased a superior AUC of 0.95.For high-risk varices,Q_(normal)and R%showed AUC values of 0.75 and 0.70,respectively,whereas the LR model showed a higher AUC of 0.84.Conclusion:As a noninvasive imaging modality,4D flow MRI exhibits considerable potential for the diagnosis of CSPH and high-risk gastroesophageal varices;thus,it may minimize the reliance on invasive procedures in patients with cirrhosis.展开更多
We attempted to perform risk categories based on the free/total prostate-specific antigen ratio (%fPSA), prostate-specific antigen(PSA) density (PSAD, in ng ml^(−2)), and multiparametric magnetic resonance imaging (mp...We attempted to perform risk categories based on the free/total prostate-specific antigen ratio (%fPSA), prostate-specific antigen(PSA) density (PSAD, in ng ml^(−2)), and multiparametric magnetic resonance imaging (mpMRI) step by step, with the goal ofdetermining the best clinical diagnostic strategy to avoid unnecessary tests and prostate biopsy (PBx) in biopsy-naïve men with PSAlevels ranging from 4 ng ml^(−1) to 10 ng ml^(−1). We included 439 patients who had mpMRI and PBx between August 2018 and July2021 (West China Hospital, Chengdu, China). To detect clinically significant prostate cancer (csPCa) on PBx, receiver-operatingcharacteristic (ROC) curves and their respective area under the curve were calculated. Based on %fPSA, PSAD, and ProstateImaging-Reporting and Data System (PI-RADS) scores, the negative predictive value (NPV) and positive predictive value (PPV) werecalculated sequentially. The optimal %fPSA threshold was determined to be 0.16, and the optimal PSAD threshold was 0.12 for%fPSA ≥0.16 and 0.23 for %fPSA <0.16, respectively. When PSAD <0.12 was combined with patients with %fPSA ≥0.16, the NPVof csPCa increased from 0.832 (95% confidence interval [CI]: 0.766–0.887) to 0.931 (95% CI: 0.833–0.981);the detection rateof csPCa was similar when further stratified by PI-RADS scores (P = 0.552). Combining %fPSA <0.16 with PSAD ≥0.23 ng ml^(−2)predicted significantly more csPCa patients than those with PSAD <0.23 ng ml^(−2) (58.4% vs 26.7%, P < 0.001). Using PI-RADSscores 4 and 5, the PPV was 0.739 (95% CI: 0.634–0.827) when further stratified by mpMRI results. In biopsy-naïve patientswith PSA level of 4–10 ng ml^(−1), stratification of %fPSA and PSAD combined with PI-RADS scores may be useful in the decisionmaking process prior to undergoing PBx.展开更多
Choledochocele is a congenital abnormality of the biliary system,which characterized by a cystic dilatation of intramural segment of the distal common bile duct.Choledochocele manifests as cystic lesions in the duoden...Choledochocele is a congenital abnormality of the biliary system,which characterized by a cystic dilatation of intramural segment of the distal common bile duct.Choledochocele manifests as cystic lesions in the duodenal lumen and resembles duodenal duplication cysts in imaging.We reported a patient with choledochocele.Magnetic resonance cholangiopancreatography showed a thin-walled sac in the duodenal cavity and a fine tubular structure connecting with the end of the common bile duct.Magnetic resonance cholangiopancreatography is a noninvasive and convenient technique in the diagnosis of choledochocele.展开更多
BACKGROUND Diffusion-weighted imaging(DWI)has become a useful tool in the detection,characterization,and evaluation of response to treatment of many cancers,including malignant liver lesions.DWI offers higher image co...BACKGROUND Diffusion-weighted imaging(DWI)has become a useful tool in the detection,characterization,and evaluation of response to treatment of many cancers,including malignant liver lesions.DWI offers higher image contrast between lesions and normal liver tissue than other sequences.DWI images acquired at two or more b-values can be used to derive an apparent diffusion coefficient(ADC).DWI in the body has several technical challenges.This include ghosting artifacts,mis-registration and susceptibility artifacts.New DWI sequences have been developed to overcome some of these challenges.Our goal is to evaluate 3 new DWI sequences for liver imaging.AIM To qualitatively and quantitatively compare 3 DWI sequences for liver imaging:free-breathing(FB),simultaneous multislice(SMS),and prospective acquisition correction(PACE).METHODS Magnetic resonance imaging(MRI)was performed in 20 patients in this prospective study.The MR study included 3 separate DWI sequences:FB-DWI,SMS-DWI,and PACE-DWI.The image quality,mean ADC,standard deviations(SD)of ADC,and ADC histogram were compared.Wilcoxon signed-rank tests were used to compare qualitative image quality.A linear mixed model was used to compare the mean ADC and the SDs of the ADC values.All tests were 2-sided and P values of<0.05 were considered statistically significant.RESULTS There were 56 lesions(50 malignant)evaluated in this study.The mean qualitative image quality score of PACE-DWI was 4.48.This was significantly better than that of SMS-DWI(4.22)and FB-DWI(3.15)(P<0.05).Quantitatively,the mean ADC values from the 3 different sequences did not significantly differ for each liver lesion.FB-DWI had a markedly higher variation in the SD of the ADC values than did SMS-DWI and PACE-DWI.We found statistically significant differences in the SDs of the ADC values for FB-DWI vs PACE-DWI(P<0.0001)and for FB-DWI vs SMS-DWI(P=0.03).The SD of the ADC values was not statistically significant for PACE-DWI and SMS-DWI(P=0.18).The quality of the PACE-DWI ADC histograms were considered better than the SMS-DWI and FB-DWI.CONCLUSION Compared to FB-DWI,both PACE-DWI and SMS-DWI provide better image quality and decreased quantitative variability in the measurement of ADC values of liver lesions.展开更多
The number of patients presenting with spine-related problems has globally increased, with an enormous growing demand for the use of medical imaging to address this problem. The last three decades witnessed great leap...The number of patients presenting with spine-related problems has globally increased, with an enormous growing demand for the use of medical imaging to address this problem. The last three decades witnessed great leaps for diagnostic imaging modalities, including those exploited for imaging the spine. These developments improved our diagnostic capabilities in different spinal pathologies, especially with multi-detector computed tomography and magnetic resonance imaging, via both hardware and software improvisations. Nowadays,imaging may depict subtle spinal instability caused by various osseous and ligamentous failures, and could elucidate dynamic instabilities. Consequently,recent diagnostic modalities can discern clinically relevant spinal canal stenosis.Likewise, improvement in diagnostic imaging capabilities revolutionized our understanding of spinal degenerative diseases via quantitative biomarkers rather than mere subjective perspectives. Furthermore, prognostication of spinal cord injury has become feasible, and this is expected to be translated into better effective patient tailoring to management plans with better clinical outcomes.Meanwhile, our confidence in diagnosing spinal infections and assessing the different spinal instrumentation has greatly improved over the past few last decades. Overall, revolutions in diagnostic imaging over the past few decades have upgraded spinal imaging from simple subjective and qualitative indices into a more sophisticated yet precise era of objective metrics via deploying quantitative imaging biomarkers.展开更多
Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancem...Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography(MDCT) technologies.The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure,function and perfusion in a single imaging session.The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease.Components of reperfusion injury including myocardial edema,hemorrhage,calcium deposition and microvascular obstruction(MO) have been demonstrated using MR and CT technologies.MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials.MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for as-sessing viability in patients where MR imaging is contraindicated.Changes in left ventricular(LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images.Recent MR studies found that transmural infarct,MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality.Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability,perfusion and function.The significance of deposited calcium in acute infarct detected on MDCT requires further studies.Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.展开更多
Acute myocardial infarction (AMI) is a leading cause of death worldwide. It has been clinically classified into 1) ischemic from a primary coronary event (e.g., plaque rupture or thrombotic occlusion), 2) ischemic fro...Acute myocardial infarction (AMI) is a leading cause of death worldwide. It has been clinically classified into 1) ischemic from a primary coronary event (e.g., plaque rupture or thrombotic occlusion), 2) ischemic from a supply-and-demand mismatch and c) ischemic from a percutaneous coronary interventions (PCI). Catheter-based PCI has been frequently used as an alternative to conventional bypass surgery for patients at high risk. However, this method of treatment is associated with microvascular obstruction (MVO) by dislodged microemboli that results in left ventricular (LV) dysfunction/remodeling, perfusion deficits, microinfarction and arrhythmia. The contributions of microemboli after revascularization of AMI have been acknowledged by major cardiac and interventional societies. Recent studies showed that Emboli Detection and Classification (EDAC) Quantifier offers increased sensitivity and capability for detecting dislodged coronary microemboli during PCI. Coronary microembolization can be detected directly by monitoring intra-myocardial contrast opacification on contrast echocardiography, increasing F-18 fluorodeoxyglucose (FDG) uptake on positron emission tomography, loss/diminution of signal on first pass perfusion and hypoenhanced zone on contrast enhanced magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) and indirectly by ST-segment elevation on electro-cardiography (ECG). The relations between volumes/sizes of microemboli, visibility of microinfarct, myocardial perfusion and LV function are still under intensive discussions. Non-invasive imaging can play important role in assessing these parameters. This review shed the light on the techniques used for detecting coronary microemboli, microvascular obstruction and microinfarct and the short- and long-term effects of microemboli on LV function, structure and perfusion.展开更多
Pancreatic vipoma is an extremely rare tumor accounting for less than 2% of endocrine pancreatic neoplasms with a reported incidence of 0.1-0.6 per million. While cross-sectional imaging findings are usually not speci...Pancreatic vipoma is an extremely rare tumor accounting for less than 2% of endocrine pancreatic neoplasms with a reported incidence of 0.1-0.6 per million. While cross-sectional imaging findings are usually not specific, exact localization of the tumor by means of either computed tomography(CT) or magnetic resonance(MR) is pivotal for surgical planning. However, cross-sectional imaging findings are usually not specific and further characterization of the tumor may only be achieved bysomatostatin-receptor scintigraphy(SRS). We report the case of a 70 years old female with a two years history of watery diarrhoea who was found to have a solid, inhomogeneously enhancing lesion at the level of the pancreatic tail at Gadolinium-enhanced MR(Somatom Trio 3T, Siemens, Germany). The tumor had been prospectively overlooked at a contrast-enhanced multi-detector CT(Aquilion 64, Toshiba, Japan) performed after i.v. bolus injection of only 100 cc of iodinated non ionic contrast media because of a chronic renal failure(3.4 mg/mL) but it was subsequently confirmed by SRS. The patient first underwent a successful symptomatic treatment with somatostatin analogues and was then submitted to a distal pancreasectomy with splenectomy to remove a capsulated whitish tumor which turned out to be a well-differentiated vipoma at histological and immuno-histochemical analysis.展开更多
目的:比较超微血管成像(SMI)技术与多参数磁共振(mpMRI)检查对前列腺癌的诊断准确性。方法:选取2022年1月—2023年11月上海市浦东新区人民医院收治的61例可疑前列腺癌患者,均行SMI和mpMRI检查以及经直肠超声(TRUS)引导的系统穿刺+可疑...目的:比较超微血管成像(SMI)技术与多参数磁共振(mpMRI)检查对前列腺癌的诊断准确性。方法:选取2022年1月—2023年11月上海市浦东新区人民医院收治的61例可疑前列腺癌患者,均行SMI和mpMRI检查以及经直肠超声(TRUS)引导的系统穿刺+可疑病灶的靶向穿刺活检术,以病理结果为金标准,绘制受试者工作特征(ROC)曲线并计算曲线下面积(AUC),评估SMI、mpMRI及SMI联合mpMRI诊断前列腺癌的准确率。结果:61例疑似前列腺癌患者中,病理诊断为前列腺腺癌22例,良性39例。SMI检出23例有异常征象,其中17例病理诊断为恶性,SMI诊断前列腺癌的灵敏度为77.27%、特异度84.62%、阳性预测值73.91%、阴性预测值86.84%、准确率81.97%。mpMRI检出24例有异常征象,其中20例病理诊断为恶性,mpMRI诊断前列腺癌的灵敏度为90.91%、特异度为89.74%、阳性预测值83.33%、阴性预测值94.59%、准确率90.16%。SMI联合mpMRI诊断前列腺癌的灵敏度为95.45%、特异度为79.49%、阳性预测值72.41%、阴性预测值96.88%、准确率85.25%。ROC曲线分析结果显示,SMI、mpMRI及SMI联合mpMRI诊断前列腺癌的AUC分别为0.809(95%CI:0.688~0.931)、0.903(95%CI:0.814~0.993)及0.875(95%CI:0.782~0.968),3种诊断方法比较差异无统计学意义(SMI vs mpMRI,Z=-1.591、P=0.112,SMI vs SMI联合mpMRI,Z=-1.427、P=0.153,mpMRI vs SMI联合mpMRI,Z=0.852、P=0.394)。结论:mpMRI诊断前列腺癌的准确率高于SMI,两者联合应用并精准靶向穿刺可提高前列腺癌的检出率。展开更多
文摘BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is becoming a major health problem,resulting in hepatic,metabolic and cardio-vascular morbidity.AIM To evaluate new ultrasonographic tools to detect and measure hepatic steatosis.METHODS We prospectively included 105 patients referred to our liver unit for NAFLD suspicion or follow-up.They underwent ultrasonographic measurement of liver sound speed estimation(SSE)and attenuation coefficient(AC)using Aixplorer MACH 30(Supersonic Imagine,France),continuous controlled attenuation parameter(cCAP)using Fibroscan(Echosens,France)and standard liver ultrasound with hepato-renal index(HRI)calculation.Hepatic steatosis was then classified according to magnetic resonance imaging proton density fat fraction(PDFF).Receiver operating curve(ROC)analysis was performed to evaluate the diagnostic performance in the diagnosis of steatosis.RESULTS Most patients were overweight or obese(90%)and had metabolic syndrome(70%).One third suffered from diabetes.Steatosis was identified in 85 patients(81%)according to PDFF.Twenty-one patients(20%)had advanced liver disease.SSE,AC,cCAP and HRI correlated with PDFF,with respective Spearman correlation coefficient of-0.39,0.42,0.54 and 0.59(P<0.01).Area under the receiver operating characteristic curve(AUROC)for detection of steatosis with HRI was 0.91(0.83-0.99),with the best cut-off value being 1.3(Se=83%,Sp=98%).The optimal cCAP threshold of 275 dB/m,corresponding to the recent EASL-suggested threshold,had a sensitivity of 72%and a specificity of 80%.Corresponding AUROC was 0.79(0.66-0.92).The diagnostic accuracy of cCAP was more reliable when standard deviation was<15 dB/m with an AUC of 0.91(0.83-0.98).An AC threshold of 0.42 dB/cm/MHz had an AUROC was 0.82(0.70-0.93).SSE performed moderately with an AUROC of 0.73(0.62-0.84).CONCLUSION Among all ultrasonographic tools evaluated in this study,including new-generation tools such as cCAP and SSE,HRI had the best performance.It is also the simplest and most available method as most ultrasound scans are equipped with this module.
文摘Magnetic resonance (MR) imaging has been increasingly used in the evaluation of prostate cancer. As studies have suggested that the majority of cancers arise from the peripheral zone (PZ), MR imaging has focused on the PZ of the prostate gland thus far. However, a considerable number of cancers (up to 30%) originate in the transition zone (TZ), substantially contributing to morbidity and mortality. Therefore, research is needed on the TZ of the prostate gland. Recently, MR imaging and advanced MR techniques have been gaining acceptance in evaluation of the TZ. In this article, the MR imaging features of TZ prostate cancers, the role of MR imaging in TZ cancer detection and staging, and recent advanced MR techniques will be discussed in light of the literature.
基金supported by the National Key R&D Program of China(Grant Nos.2021YFA1400602 and 2023YFA1407600)the National Natural Science Foundation of China(Grant Nos.91850206,12374294,and 12004284)the Chenguang Program of Shanghai(Grant No.21CGA22).
文摘Magnetic resonance imaging(MRI),as a noninvasive and powerful method in modern diagnostics,has been advancing in leaps and bounds.Conventional methods to improve MRI based on increasing the static magnetic field strength are restricted by safety concerns,cost issues,and the impact on patient experience;as such,innovative approaches are required.It has been suggested that metamaterials featuring subwavelength unit cells can be used to take full control of electromagnetic waves and redistribute electromagnetic fields,achieve abundant counterintuitive phenomena,and construct versatile devices.Recently,metamaterials with exotic effective electromagnetic parameters,peculiar dispersion relations,or tailored field distribution of resonant modes have shown promising capabilities in MRI.Herein,we outline the principle of the MRI process,review recent advances in enhancing MRI by employing the unique physical mechanisms of metamaterials,and demystify ways in which metamaterial designs could improve MRI,such as by enhancing the imaging quality,reducing the scanning time,alleviating field inhomogeneities,and increasing patient safety.We conclude by providing our vision for the future of improving MRI with metamaterials.
基金supported by the Key Research and Development Program of Jiangsu Province(BE2023767)Research Personnel Cultivation Programme of Zhongda Hospital,Southeast University(CZXMGSP-RC125)+2 种基金the Fundamental Research Fund of Southeast University(3290002303A2)Changjiang Scholars Talent Cultivation Project of Zhongda Hospital of Southeast University(2023YJXYYRCPY03)the Basic Research Fund,First Affiliated Hospital of Gannan Medical University(QD095).
文摘Introduction:Noninvasive diagnoses of clinically significant portal hypertension(CSPH)and high-risk gastroesophageal varices are clinically relevant but challenging.Four-dimensional(4D)flow magnetic resonance imaging(MRI)provides comprehensive flow information and is a promising alternative.This study evaluated the efficacy of 4D flow MRI as a noninvasive method for diagnosing CSPH and high-risk varices in patients with liver cirrhosis.Methods:This prospective study enrolled consecutive patients diagnosed with liver cirrhosis at a tertiary referral center between October 2020 and March 2021.Each participant underwent abdominal 4D flow MRI.Hemodynamic parameters within the portal vein,including the average and peak flow velocities,normalized flow volume(Q_(normal)),and regurgitant fraction(R%),were extracted and compared between healthy individuals and patients with CSPH and between participants with high-and low-risk varices.Subsequently,these parameters were incorporated into a logistic regression(LR)model refined using L1 regularization and validated using five-fold cross-validation.The diagnostic efficacy was evaluated using receiver operating characteristic(ROC)curves.Results:Eighty-two participants were enrolled(71 patients diagnosed with liver cirrhosis and 11 healthy individuals serving as controls).Among hemodynamic parameters,patients with CSPH exhibited a notable increase in Q_(normal)of 0.66±0.19 ml*m^(2)/[cycle*kg](P=0.001)and an R%of 1.98(2.05)(P=0.002).Similarly,patients with high-risk varices showed a higher Q_(normal)of 0.61±0.15 ml*m^(2)/[cycle*kg](P<0.001)and R%of 1.88(2.81)(P=0.006).ROC analysis revealed an area under the curve(AUC)for Q_(normal)of 0.93 and 0.91 for R%for diagnosing CSPH,while the LR model showcased a superior AUC of 0.95.For high-risk varices,Q_(normal)and R%showed AUC values of 0.75 and 0.70,respectively,whereas the LR model showed a higher AUC of 0.84.Conclusion:As a noninvasive imaging modality,4D flow MRI exhibits considerable potential for the diagnosis of CSPH and high-risk gastroesophageal varices;thus,it may minimize the reliance on invasive procedures in patients with cirrhosis.
基金supported by the National Natural Science Foundation of China(grant No.81902578,81974098,and 81974099)the National Key Research and Development Program of China(grant No.SQ2017YFSF090096).
文摘We attempted to perform risk categories based on the free/total prostate-specific antigen ratio (%fPSA), prostate-specific antigen(PSA) density (PSAD, in ng ml^(−2)), and multiparametric magnetic resonance imaging (mpMRI) step by step, with the goal ofdetermining the best clinical diagnostic strategy to avoid unnecessary tests and prostate biopsy (PBx) in biopsy-naïve men with PSAlevels ranging from 4 ng ml^(−1) to 10 ng ml^(−1). We included 439 patients who had mpMRI and PBx between August 2018 and July2021 (West China Hospital, Chengdu, China). To detect clinically significant prostate cancer (csPCa) on PBx, receiver-operatingcharacteristic (ROC) curves and their respective area under the curve were calculated. Based on %fPSA, PSAD, and ProstateImaging-Reporting and Data System (PI-RADS) scores, the negative predictive value (NPV) and positive predictive value (PPV) werecalculated sequentially. The optimal %fPSA threshold was determined to be 0.16, and the optimal PSAD threshold was 0.12 for%fPSA ≥0.16 and 0.23 for %fPSA <0.16, respectively. When PSAD <0.12 was combined with patients with %fPSA ≥0.16, the NPVof csPCa increased from 0.832 (95% confidence interval [CI]: 0.766–0.887) to 0.931 (95% CI: 0.833–0.981);the detection rateof csPCa was similar when further stratified by PI-RADS scores (P = 0.552). Combining %fPSA <0.16 with PSAD ≥0.23 ng ml^(−2)predicted significantly more csPCa patients than those with PSAD <0.23 ng ml^(−2) (58.4% vs 26.7%, P < 0.001). Using PI-RADSscores 4 and 5, the PPV was 0.739 (95% CI: 0.634–0.827) when further stratified by mpMRI results. In biopsy-naïve patientswith PSA level of 4–10 ng ml^(−1), stratification of %fPSA and PSAD combined with PI-RADS scores may be useful in the decisionmaking process prior to undergoing PBx.
文摘Choledochocele is a congenital abnormality of the biliary system,which characterized by a cystic dilatation of intramural segment of the distal common bile duct.Choledochocele manifests as cystic lesions in the duodenal lumen and resembles duodenal duplication cysts in imaging.We reported a patient with choledochocele.Magnetic resonance cholangiopancreatography showed a thin-walled sac in the duodenal cavity and a fine tubular structure connecting with the end of the common bile duct.Magnetic resonance cholangiopancreatography is a noninvasive and convenient technique in the diagnosis of choledochocele.
文摘BACKGROUND Diffusion-weighted imaging(DWI)has become a useful tool in the detection,characterization,and evaluation of response to treatment of many cancers,including malignant liver lesions.DWI offers higher image contrast between lesions and normal liver tissue than other sequences.DWI images acquired at two or more b-values can be used to derive an apparent diffusion coefficient(ADC).DWI in the body has several technical challenges.This include ghosting artifacts,mis-registration and susceptibility artifacts.New DWI sequences have been developed to overcome some of these challenges.Our goal is to evaluate 3 new DWI sequences for liver imaging.AIM To qualitatively and quantitatively compare 3 DWI sequences for liver imaging:free-breathing(FB),simultaneous multislice(SMS),and prospective acquisition correction(PACE).METHODS Magnetic resonance imaging(MRI)was performed in 20 patients in this prospective study.The MR study included 3 separate DWI sequences:FB-DWI,SMS-DWI,and PACE-DWI.The image quality,mean ADC,standard deviations(SD)of ADC,and ADC histogram were compared.Wilcoxon signed-rank tests were used to compare qualitative image quality.A linear mixed model was used to compare the mean ADC and the SDs of the ADC values.All tests were 2-sided and P values of<0.05 were considered statistically significant.RESULTS There were 56 lesions(50 malignant)evaluated in this study.The mean qualitative image quality score of PACE-DWI was 4.48.This was significantly better than that of SMS-DWI(4.22)and FB-DWI(3.15)(P<0.05).Quantitatively,the mean ADC values from the 3 different sequences did not significantly differ for each liver lesion.FB-DWI had a markedly higher variation in the SD of the ADC values than did SMS-DWI and PACE-DWI.We found statistically significant differences in the SDs of the ADC values for FB-DWI vs PACE-DWI(P<0.0001)and for FB-DWI vs SMS-DWI(P=0.03).The SD of the ADC values was not statistically significant for PACE-DWI and SMS-DWI(P=0.18).The quality of the PACE-DWI ADC histograms were considered better than the SMS-DWI and FB-DWI.CONCLUSION Compared to FB-DWI,both PACE-DWI and SMS-DWI provide better image quality and decreased quantitative variability in the measurement of ADC values of liver lesions.
文摘The number of patients presenting with spine-related problems has globally increased, with an enormous growing demand for the use of medical imaging to address this problem. The last three decades witnessed great leaps for diagnostic imaging modalities, including those exploited for imaging the spine. These developments improved our diagnostic capabilities in different spinal pathologies, especially with multi-detector computed tomography and magnetic resonance imaging, via both hardware and software improvisations. Nowadays,imaging may depict subtle spinal instability caused by various osseous and ligamentous failures, and could elucidate dynamic instabilities. Consequently,recent diagnostic modalities can discern clinically relevant spinal canal stenosis.Likewise, improvement in diagnostic imaging capabilities revolutionized our understanding of spinal degenerative diseases via quantitative biomarkers rather than mere subjective perspectives. Furthermore, prognostication of spinal cord injury has become feasible, and this is expected to be translated into better effective patient tailoring to management plans with better clinical outcomes.Meanwhile, our confidence in diagnosing spinal infections and assessing the different spinal instrumentation has greatly improved over the past few last decades. Overall, revolutions in diagnostic imaging over the past few decades have upgraded spinal imaging from simple subjective and qualitative indices into a more sophisticated yet precise era of objective metrics via deploying quantitative imaging biomarkers.
文摘Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography(MDCT) technologies.The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure,function and perfusion in a single imaging session.The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease.Components of reperfusion injury including myocardial edema,hemorrhage,calcium deposition and microvascular obstruction(MO) have been demonstrated using MR and CT technologies.MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials.MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for as-sessing viability in patients where MR imaging is contraindicated.Changes in left ventricular(LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images.Recent MR studies found that transmural infarct,MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality.Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability,perfusion and function.The significance of deposited calcium in acute infarct detected on MDCT requires further studies.Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.
文摘Acute myocardial infarction (AMI) is a leading cause of death worldwide. It has been clinically classified into 1) ischemic from a primary coronary event (e.g., plaque rupture or thrombotic occlusion), 2) ischemic from a supply-and-demand mismatch and c) ischemic from a percutaneous coronary interventions (PCI). Catheter-based PCI has been frequently used as an alternative to conventional bypass surgery for patients at high risk. However, this method of treatment is associated with microvascular obstruction (MVO) by dislodged microemboli that results in left ventricular (LV) dysfunction/remodeling, perfusion deficits, microinfarction and arrhythmia. The contributions of microemboli after revascularization of AMI have been acknowledged by major cardiac and interventional societies. Recent studies showed that Emboli Detection and Classification (EDAC) Quantifier offers increased sensitivity and capability for detecting dislodged coronary microemboli during PCI. Coronary microembolization can be detected directly by monitoring intra-myocardial contrast opacification on contrast echocardiography, increasing F-18 fluorodeoxyglucose (FDG) uptake on positron emission tomography, loss/diminution of signal on first pass perfusion and hypoenhanced zone on contrast enhanced magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) and indirectly by ST-segment elevation on electro-cardiography (ECG). The relations between volumes/sizes of microemboli, visibility of microinfarct, myocardial perfusion and LV function are still under intensive discussions. Non-invasive imaging can play important role in assessing these parameters. This review shed the light on the techniques used for detecting coronary microemboli, microvascular obstruction and microinfarct and the short- and long-term effects of microemboli on LV function, structure and perfusion.
文摘Pancreatic vipoma is an extremely rare tumor accounting for less than 2% of endocrine pancreatic neoplasms with a reported incidence of 0.1-0.6 per million. While cross-sectional imaging findings are usually not specific, exact localization of the tumor by means of either computed tomography(CT) or magnetic resonance(MR) is pivotal for surgical planning. However, cross-sectional imaging findings are usually not specific and further characterization of the tumor may only be achieved bysomatostatin-receptor scintigraphy(SRS). We report the case of a 70 years old female with a two years history of watery diarrhoea who was found to have a solid, inhomogeneously enhancing lesion at the level of the pancreatic tail at Gadolinium-enhanced MR(Somatom Trio 3T, Siemens, Germany). The tumor had been prospectively overlooked at a contrast-enhanced multi-detector CT(Aquilion 64, Toshiba, Japan) performed after i.v. bolus injection of only 100 cc of iodinated non ionic contrast media because of a chronic renal failure(3.4 mg/mL) but it was subsequently confirmed by SRS. The patient first underwent a successful symptomatic treatment with somatostatin analogues and was then submitted to a distal pancreasectomy with splenectomy to remove a capsulated whitish tumor which turned out to be a well-differentiated vipoma at histological and immuno-histochemical analysis.
文摘目的:比较超微血管成像(SMI)技术与多参数磁共振(mpMRI)检查对前列腺癌的诊断准确性。方法:选取2022年1月—2023年11月上海市浦东新区人民医院收治的61例可疑前列腺癌患者,均行SMI和mpMRI检查以及经直肠超声(TRUS)引导的系统穿刺+可疑病灶的靶向穿刺活检术,以病理结果为金标准,绘制受试者工作特征(ROC)曲线并计算曲线下面积(AUC),评估SMI、mpMRI及SMI联合mpMRI诊断前列腺癌的准确率。结果:61例疑似前列腺癌患者中,病理诊断为前列腺腺癌22例,良性39例。SMI检出23例有异常征象,其中17例病理诊断为恶性,SMI诊断前列腺癌的灵敏度为77.27%、特异度84.62%、阳性预测值73.91%、阴性预测值86.84%、准确率81.97%。mpMRI检出24例有异常征象,其中20例病理诊断为恶性,mpMRI诊断前列腺癌的灵敏度为90.91%、特异度为89.74%、阳性预测值83.33%、阴性预测值94.59%、准确率90.16%。SMI联合mpMRI诊断前列腺癌的灵敏度为95.45%、特异度为79.49%、阳性预测值72.41%、阴性预测值96.88%、准确率85.25%。ROC曲线分析结果显示,SMI、mpMRI及SMI联合mpMRI诊断前列腺癌的AUC分别为0.809(95%CI:0.688~0.931)、0.903(95%CI:0.814~0.993)及0.875(95%CI:0.782~0.968),3种诊断方法比较差异无统计学意义(SMI vs mpMRI,Z=-1.591、P=0.112,SMI vs SMI联合mpMRI,Z=-1.427、P=0.153,mpMRI vs SMI联合mpMRI,Z=0.852、P=0.394)。结论:mpMRI诊断前列腺癌的准确率高于SMI,两者联合应用并精准靶向穿刺可提高前列腺癌的检出率。