Advances in Molecular Targeted Ultrasound Contrast Agents / 中国医学科学院学报

In real-time ultrasound,molecular targeted contrast agent is introduced into the blood circulation through peripheral intravenous injection to enhance the imaging signal of target lesions after binding to the corresponding intravascular receptors,which can realize early diagnosis,staging of diseases,assessment of treatment response,and targeted treatment.In addition,molecular targeted ultrasound contrast agents provide a platform for the delivery of drugs and genes via microbubbles,and nanoscale contrast agents can be infiltrated through vascular endothelium into the interstitial space of the lesion for imaging or treatment.The available studies of molecular targeted ultrasound contrast agents mainly focus on the preclinical trials.Some clinical trials have been conducted in humans and preliminarily confirm the safety and feasibility of targeted ultrasound contrast agents.The molecular targeted ultrasound contrast agents enjoy a broad prospect in clinical application.

The value of cardiac MRI in the risk stratification in patients with hypertrophic cardiomyopathy / 中华心血管病杂志

Objective: To explore the value of cardiac magnetic resonance imaging (CMR) in the risk stratification of hypertrophic cardiomyopathy (HCM). Methods: HCM patients who underwent CMR examination in Fuwai Hospital between March 2012 and May 2013 were retrospectively enrolled. Baseline clinical and CMR data were collected and patient follow-up was performed using telephone contact and medical record. The primary composite endpoint was sudden cardiac death (SCD) or and equivalent event. The secondary composite endpoint was all-cause death and heart transplant. Patients were divided into SCD and non-SCD groups. Cox regression was used to explore risk factors of adverse events. Receiver operating characteristic (ROC) curve analysis was used to assess the performance and the optimal cut-off of late gadolinium enhancement percentage (LGE%) for the prediction of endpoints. Kaplan-Meier and log-rank tests were used to compare survival differences between groups. Results: A total of 442 patients were enrolled. Mean age was (48.5±12.4) years and 143(32.4%) were female. At (7.6±2.5) years of follow-up, 30 (6.8%) patients met the primary endpoint including 23 SCD and 7 SCD equivalent events, and 36 (8.1%) patients met the secondary endpoint including 33 all-cause death and 3 heart transplant. In multivariate Cox regression, syncope(HR=4.531, 95%CI 2.033-10.099, P<0.001), LGE% (HR=1.075, 95%CI 1.032-1.120, P=0.001) and left ventricular ejection fraction (LVEF) (HR=0.956, 95%CI 0.923-0.991, P=0.013) were independent risk factors for primary endpoint; Age (HR=1.032, 95%CI 1.001-1.064, P=0.046), atrial fibrillation (HR=2.977, 95%CI 1.446-6.131, P=0.003),LGE% (HR=1.075, 95%CI 1.035-1.116, P<0.001) and LVEF (HR=0.968, 95%CI 0.937-1.000, P=0.047) were independent risk factors for secondary endpoint. ROC curve showed the optimal LGE% cut-offs were 5.1% and 5.8% for the prediction of primary and secondary endpoint, respectively. Patients were further divided into LGE%=0, 0<LGE%<5%, 5%≤LGE%<15% and LGE%≥15% groups. There were significant survival differences between these 4 groups whether for primary endpoint or secondary endpoint (all P<0.001) and the accumulated incidence of primary endpoint was 1.2% (2/161), 2.2% (2/89), 10.5% (16/152) and 25.0% (10/40), respectively. Conclusion: LGE is an independent risk factor for SCD events as well as all-cause death and heart transplant. LGE is of important value in the risk stratification in patients with HCM.

Diagnostic value of contrast-enhanced ultrasound in hepatic epithelioid hemangioendothelioma / 中华肝脏病杂志

Objective: To investigate the features of contrast-enhanced ultrasound (CEUS) in hepatic epithelioid hemangioendothelioma (HEHE) in order to improve the preoperative diagnosis rate. Methods: CEUS images of 32 pathologically-proven cases of hepatic epithelioid hemangioendothelioma from January 2004 to August 2021 were collected. Lesions were analyzed to observe the features of enhancement mode, enhancement intensity, and distinct enhancement phases. Results: Among the 32 cases, one had a solitary lesion, 29 had multiple lesions, and two had diffuse-type lesions. Contrast-enhanced ultrasound revealed a total of 42 lesions in 32 cases. In terms of arterial phase enhancement, 18 lesions had overall enhancement, six lesions had uneven dendritic enhancement, 16 lesions had rim-like enhancement, and two lesions had just slight peripheral spot enhancement around the lesions. Among the three cases, there were multiple lesions that had overall enhancement and ring enhancement. In terms of the enhancement phase, 20 lesions showed "fast progression", 20 lesions showed "same progression", and two lesions showed "slow progression". During the late arterial or early portal venous phases with rapid washout, all lesions manifested as hypoechoic. With peaked enhanced intensity, 11 lesions had a lower enhancement intensity than the surrounding normal liver parenchyma; 11 lesions had the same enhancement degree as the surrounding normal liver parenchyma; and 20 lesions had a higher enhancement degree than the surrounding normal liver parenchyma. All 16 ring-enhancing lesions had marked hyperenhancement. In the typical enhancing lesions, four showed hyperenhancement, five showed low enhancement, and nine showed isoenhancement. In the dendrite-enhancing lesions, there were two isoenhancing and four hypoenhancing. Contrast-enhanced ultrasound delineated the boundaries of all lesions more clearly than two-dimensional ultrasound. Conclusion: Contrast-enhanced ultrasound has certain value in the diagnosis of hepatic epithelioid hemangioendothelioma.

Multiparametric ultrasound for the assessment of testicular lesions with negative tumoral markers / 亚洲男科学杂志(英文版)

The purpose of this study was to evaluate the diagnostic performance of multiparametric ultrasound (mpUS; grayscale US, color Doppler US, strain elastography, and contrast-enhanced US) in the assessment of testicular lesions with negative tumoral markers. MpUS imaging data, patient age, serum tumor markers, scrotal pain, cryptorchidism, and related clinical information were retrospectively collected for patients who underwent mpUS examination between January 2013 and December 2019. Histologic results or follow-up examinations were used as the reference standard. In total, 83 lesions from 79 patients were included in the analysis. Fifty-six patients were finally diagnosed with benign tumors, and 23 patients were ultimately diagnosed with malignant tumors. Chi-square tests or Fisher's exact tests were used to assess the difference between the two groups. Stepwise multivariate logistic regression analysis showed that lesion diameter (odds ratio [OR] = 1.072, P = 0.005), vascularization on color Doppler US (OR = 4.066, P = 0.001), and hyperenhancement during the early phase (OR = 6.465, P = 0.047) were significant independent risk factors for malignancy; however, when compared with neoplastic lesions, pain (OR = 0.136, P < 0.001), absence of vascularization on color Doppler US (OR = 1.680, P = 0.042), and nonenhancement during the late phase (OR = 3.461, P = 0.031) were strongly associated with nonneoplastic lesions. MpUS features are useful for differentiating testicular lesions with negative tumoral markers and improving the preoperative diagnosis, which may avoid inappropriate radical orchiectomy.

Research progress on animal models of contrast-induced acute kidney injury / 中南大学学报(医学版)

Contrast-induced acute kidney injury (CI-AKI) refers to acute kidney injury that occurs after intravascular contrast media is applied. It is the third most common cause for acute renal failure in hospitalized patients and can cause severe renal impairment and adverse cardiovascular outcomes. In severe cases, it can even lead to the death of the patient. Due to its complicated pathogenesis, the pathogenesis of CI-AKI has not yet been elucidated. Therefore, it is of great significance to further study the pathogenesis for the prevention of CI-AKI. Moreover, a good animal model of CI-AKI is an important tool for in-depth research on the pathogenesis of acute kidney injury induced by contrast agents.

Genetic analysis of a Chinese pedigree affected with Mucopolysaccharidosis type ⅢA / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of a patient with hypertrophic cardiomyopathy as the initial manifestation of Mucopolysaccharidosis type Ⅲ A (MPS Ⅲ A).@*METHODS@#A female patient with MPS Ⅲ A who was admitted to the Affiliated Hospital of Jining Medical University in January 2022 and her family members (seven individuals from three generations) were selected as the study subjects. Clinical data of the proband were collected. Peripheral blood samples of the proband was collected and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing. Heparan-N-sulfatase activity was determined for the disease associated with the variant site.@*RESULTS@#The proband was a 49-year-old woman, for whom cardiac MRI has revealed significant thickening (up to 20 mm) of left ventricular wall and delayed gadolinium enhancement at the apical myocardium. Genetic testing revealed that she has harbored compound heterozygous variants in exon 17 of the SGSH gene, namely c.545G>A (p.Arg182His) and c.703G>A (p.Asp235Asn). Based on guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted to be pathogenic (PM2_Supporting +PM3+PP1Strong+PP3+PP4; PS3+PM1+PM2_Supporting +PM3+PP3+PP4). Sanger sequencing confirmed that her mother was heterozygous for the c.545G>A (p.Arg182His) variant, whilst her father, sisters and her son were heterozygous for the c.703G>A (p.Asp235Asn) variant. Determination of blood leukocyte heparan-N-sulfatase activity suggested that the patient had a low level of 1.6 nmol/(g·h), whilst that of her father, elder and younger sisters and son were all in the normal range.@*CONCLUSION@#The compound heterozygous variants of the SGSH gene probably underlay the MPS ⅢA in this patient, for which hypertrophic cardiomyopathy is an associated phenotype.

Relationship of Microvascular Obstruction with Global and Regional Myocardial Function Determined by Cardiac Magnetic Resonance after ST-Segment Elevation Myocardial Infarction / 中国医学科学杂志(英文版)

Objective To investigate the impact of microvascular obstruction (MVO) on the global and regional myocardial function by cardiac magnetic resonance feature-tracking (CMR-FT) in ST-segment-elevation myocardial infarction (STEMI) patients after percutaneous coronary intervention.Methods Consecutive acute STEMI patients who underwent cardiac magnetic resonance imaging 1 - 7 days after successful reperfusion by percutaneous coronary intervention treatment were included in this retrospective study. Based on the presence or absence of MVO on late gadolinium enhancement images, patients were divided into groups with MVO and without MVO. The infarct zone, adjacent zone, and remote zone were determined based on a myocardial 16-segment model. The radial strain (RS), circumferential strain (CS), and longitudinal strain (LS) of the global left ventricle (LV) and the infarct, adjacent, and remote zones were measured by CMR-FT from cine images and compared between patients with and without MVO using independent-samples t-test. Logistic regression analysis was used to assess the association of MVO with the impaired LV function.Results A total of 157 STEMI patients (mean age 56.66 ± 11.38 years) were enrolled. MVO was detected in 37.58% (59/157) of STEMI patients, and the mean size of MVO was 3.00 ±3.76 mL. Compared with patients without MVO (n =98 ), the MVO group had significantly reduced LV global RS (t= -4.30, P < 0.001), global CS (t= 4.99, P < 0.001), and global LS ( t= 3.51, P = 0.001). The RS and CS of the infarct zone in patients with MVO were significantly reduced (t= -3.38, P = 0.001; t= 2.64, P = 0.01; respectively) and the infarct size was significantly larger (t= 8.37, P < 0.001) than that of patients without MVO. The presence of LV MVO [OR= 4.10, 95%CI: 2.05 - 8.19, P<0.001) and its size [OR=1.38, 95%CI: 1.10-1.72, P=0.01], along with the heart rate and LV infarct size were significantly associated with impaired LV global CS in univariable Logistic regression analysis, while only heart rate (OR=1.08, 95%CI: 1.03 - 1.13, P=0.001) and LV infarct size (OR=1.10, 95%CI: 1.03 - 1.16, P=0.003) were independent influencing factors for the impaired LV global CS in multivariable Logistic regression analysis.Conclusion The infarct size was larger in STEMI patients with MVO, and MVO deteriorates the global and regional LV myocardial function.

Radiación y medios de contraste en embarazo y lactancia: lo que el clínico necesita saber / Radiation and contrast media in pregnancy and lactation: what the clinician needs to know

Introducción: el uso de técnicas de imagenología es habitual e incluso indispensable en algunos procesos diagnósticos. Sin embargo, su indicación en mujeres embarazadas y en período de lactancia es controvertida. Objetivo: presentar una revisión narrativa sobre los riesgos asociados al uso de imágenes con radiación y medio de contraste en embarazo y periodo de lactancia, con énfasis en las recomendaciones y aplicaciones clínicas que el médico tratante debe tener presente al momento de su indicación. Métodos: se realizó una revisión bibliográfica de la literatura relevante sobre los riesgos y consideraciones especiales del uso de medios de contraste en el embarazo y lactancia. Resultados: los riesgos de la radiación ionizante sobre el feto varían de acuerdo al estadio del embarazo, por lo que la indicación del estudio debe ponderar los riesgos y beneficios. En las dosis clínicas en embarazo y lactancia, el uso de contraste yodado como basados en gadolinio no tienen efectos deletéreos en la salud de la madre ni la del feto. Sin embargo, las sociedades internacionales recomiendan limitar su uso. Conclusión: si bien la indicación de estudios de imagen que utilizan radiación ionizante en el embarazo y lactancia es seguro, el médico clínico debe conocer los posibles riesgos de la radiación ionizante en este grupo de pacientes. Respecto a los medios de contraste, el único efecto adverso reportado es la disfunción tiroidea transitoria en hijos de madres que recibieron medios de contraste yodado.

Introduction: the use of imaging techniques is essential in some diagnostic processes. However, its indication in pregnant and lac-tating women is controversial. Objective: To present a narrative review of the risks associated with using images with radiation and contrast media in pregnancy and lactation. Emphasis will be put on the recommendations and clinical applications that the physician must consider before its indication. Methods: a bibliographic review of the relevant literature on the risks and special considerations of contrast media in pregnancy and lactation was performed. Results: the risks of ionising radiation on the fetus vary according to the stage of pregnancy, so the indication of the study must balance the risks and benefits. The use of iodinated and gadolinium-based con-trast agents in clinical doses in pregnancy and lactation has no effects on the health of the mother or the fetus. However, international societies recommend limiting its use. Conclusion: Although the indication for imaging studies using ionising radiation in pregnancy and lactation is safe, the clinician must be aware of the possible risks of ionising radiation in this group of patients. The only adverse effect reported is transient thyroid dysfunction in children of mothers who received iodinated contrast media.

Enhancement patterns of adrenal nodules on magnetic resonance imaging

ABSTRACT Objective: To compare enhancement patterns of typical adrenal adenomas, lipid-poor adenomas, and non-adenomas on magnetic resonance imaging (MRI). Materials and Methods: Evaluation of adrenal nodules larger than 1.0 cm, with at least 2-year follow-up, evaluated on MRI in January 2007 and December 2016. Two different protocols were included - upper abdomen MRI (delayed phase after 3 minutes) and abdomen and pelvis MRI (delayed phase after 7 minutes) - and nodules were divided in typical adenomas (characterized on out-of-phase MRI sequence), lipid-poor adenomas (based on follow-up imaging stability) and non-adenomas (based on pathological finding or follow-up imaging). T2-weighted and enhancement features were analyzed (absolute and relative washout and enhancement curve pattern), similarly to classic computed tomography equations. Results: Final cohort was composed of 123 nodules in 116 patients (mean diameter of 1.8 cm and mean follow up time of 4 years and 3 months). Of them, 98 (79%) nodules had features of typical adenomas by quantitative chemical shift imaging, and demonstrated type 3 curve pattern in 77%, mean absolute and relative washout of 29% and 16%, respectively. Size, oncologic history and T2-weighted features showed statistically significant differences among groups. Also, a threshold greater than 11.75% for absolute washout on MRI achieved sensitivity of 71.4% and specificity of 70.0%, in differentiating typical adenomas from non-adenomas. Conclusion: Calculating absolute washout of adrenal nodules on MRI may help identifying proportion of non-adenomas.

Mecânica Atrial na Cardiomiopatia Hipertrófica: Discriminando Hipertrofia de Fibrose Ventricular / Atrial Mechanics in Hypertrophic Cardiomyopathy: Discriminating between Ventricular Hypertrophy and Fibrosis

Resumo Fundamento A cardiomiopatia hipertrófica (CMH) e a hipertrofia ventricular esquerda (HVE) secundária à hipertensão arterial sistêmica (HAS) podem estar associadas a anormalidades funcionais do átrio esquerdo (AE). Objetivos Caracterizar a mecânica do AE na CMH e na HAS e avaliar qualquer correlação com a extensão da fibrose ventricular esquerda medida por ressonância magnética cardíaca (RMC) em pacientes com CMH. Métodos A função longitudinal do AE derivada do ecocardiograma bidimensional com speckle tracking foi adquirida a partir de cortes apicais de 60 pacientes com CMH e 34 indivíduos controles, pareados por idade. Pacientes com CMH também foram submetidos à RMC, com medida da extensão do realce tardio por gadolínio. A associação com parâmetros de strain do AE foi analisada. Valores p < 0,05 foram definidos como estatisticamente significativos. Resultados A média da fração de ejeção do ventrículo esquerdo não foi diferente entre os grupos. A razão E/e' estava comprometida no grupo CMH e preservada no grupo controle. A mecânica do AE estava significativamente reduzida na CMH em comparação aos pacientes com HAS. O strain rate do AE nas fases de reservatório (SRrAE) e na fase contrátil (SRctAE) foram os melhores parâmetros de discriminação de CMH com uma área sob a curva (AUC) de 0,8, seguido do strain do AE na fase de reservatório (SrAE) (AUC 0,76). O SRrAE e o SRctAE apresentaram elevada especificidade (89% e 91%, respectivamente), e o SrAE apresentou sensibilidade de 80%. Um decréscimo de 2,79% no strain rate do AE na fase de condução (SRcdAE) foi preditor de um aumento de 1 cm na extensão do RT pelo gadolínio (r2=0,42, β 2,79, p=0,027). Conclusões O SRrAE e o SRctAE foram os melhores fatores de discriminação de HVE secundária à CMH. O SRcdAE foi preditor do grau de fibrose ventricular esquerda avaliada por RMC. Esses achados sugerem que a mecânica do AE pode ser um potencial preditor de gravidade de doença na CMH.

Abstract Background Hypertrophic cardiomyopathy (HCM) and left ventricular hypertrophy (LVH) secondary to systemic hypertension (HTN) may be associated with left atrial (LA) functional abnormalities. Objectives We aimed to characterize LA mechanics in HCM and HTN and determine any correlation with the extent of left ventricular (LV) fibrosis measured by cardiac magnetic resonance (CMR) in HCM patients. Methods Two-dimensional speckle tracking-derived longitudinal LA function was acquired from apical views in 60 HCM patients, 60 HTN patients, and 34 age-matched controls. HCM patients also underwent CMR, with measurement of late gadolinium enhancement (LGE) extension. Association with LA strain parameters was analyzed. Statistical significance was set at p<0.05. Results Mean LV ejection fraction was not different between the groups. The E/e' ratio was impaired in the HCM group and preserved in the control group. LA mechanics was significantly reduced in HCM, compared to the HTN group. LA strain rate in reservoir (LASRr) and in contractile (LASRct) phases were the best discriminators of HCM, with an area under the curve (AUC) of 0.8, followed by LA strain in reservoir phase (LASr) (AUC 0.76). LASRr and LASR-ct had high specificity (89% and 91%, respectively) and LASr had sensitivity of 80%. A decrease in 2.79% of LA strain rate in conduit phase (LASRcd) predicted an increase of 1cm in LGE extension (r2=0.42, β 2.79, p=0.027). Conclusions LASRr and LASRct were the best discriminators for LVH secondary to HCM. LASRcd predicted the degree of LV fibrosis assessed by CMR. These findings suggest that LA mechanics is a potential predictor of disease severity in HCM.

Differential diagnosis of benign and malignant breast lesions using quantitative synthetic magnetic resonance imaging / 南方医科大学学报

OBJECTIVE@#To investigate the value of quantitative synthetic magnetic resonance imaging (SyMRI) in distinguishing between benign and malignant breast lesions.@*METHODS@#We retrospectively collected data of preoperative conventional MRI and multi-dynamic multi-echo sequences from 95 patients with breast lesions showing mass-type enhancement on DCE-MRI, including 27 patients with benign lesions and 68 with malignant lesions. The MRI features of the lesions (shape, margin, internal enhancement pattern, time-signal intensity curve, and T2WI signal) were analyzed, and for each lesion, SyMRI-generated quantitative parameters including T1 and T2 relaxation time and proton density (PD) were measured before and after enhancement and recorded as T1p, T2p, PDp and T1e, T2e, and PDe, respectively. The relative change rate of each parameter was calculated. Logistic regression and all-subset regression analyses were performed for variable selection to construct diagnostic models of the breast lesions, and receiver-operating characteristic (ROC) analysis was used to assess the performance of each model for differentiation of benign and malignant lesions.@*RESULTS@#There were significant differences in the MRI features between benign and malignant lesions (P < 0.05). All the SyMRI-generated quantitative parameters, with the exception of T2e and Pdp, showed significant differences between benign and malignant lesions (P < 0.05). Among the constructed diagnostic models, the model based on all the DCE-MRI features combined with SyMRI parameters T2p and T1e (DCE-MRI+T2p+T1e) showed the best performance in the differential diagnosis malignant breast masses with an AUC of 0.995 (95% CI: 0.983-1.000).@*CONCLUSION@#Quantitative SyMRI can be used for differential diagnosis of benign and malignant breast lesions.

Design and Realization of Contrast Medium Biphasic Hyperbaric Injector / 中国医疗器械杂志

A biphasic hyperbaric injector based on BLDC is designed for alternate and mixed injection of contrast medium and normal saline in the process of contrast medium injection in hospital. The driver hardware and algorithm are optimized especially for high-pressure and high-speed injection requirements. The interface APP is designed with parameter-input and real-time pressure-plotting of injector's ports as two main functions. The whole device can realize the preset function and has high stability after testing.

Contrast-enhanced ultrasound as a valuable imaging modality for characterizing testicular lesions / 亚洲男科学杂志(英文版)

Contrast-enhanced ultrasound (CEUS) is a new form of ultrasound (US) that can dynamically display microvessels in a highly sensitive manner. The purpose of this study was to investigate the efficacy of CEUS for characterizing testicular lesions in comparison with conventional US. Forty-seven patients with testicular lesions were enrolled. The histopathology results revealed that 31 cases were neoplastic (11 cases of seminomas, 8 nonseminomatous germ cell tumors, 8 lymphomas, 2 Leydig cell tumors, and 2 nonspecific tumors), and 16 cases were nonneoplastic (8 cases of infarctions, 3 epidermoid cysts, and 5 inflammation). The indicators of shallow lobulated morphology and cystic-solid echogenicity on conventional US were suggestive of germ cell tumors. More indicators on CEUS were found to be useful for characterizing testicular lesions. All the neoplastic lesions showed hyperenhancement on CEUS. Moreover, germ cell tumors presented with heterogeneous enhancement (73.7%, 14/19), a twisted blood vessel pattern, rapid wash-in and wash-out, and peripheral rim hyperenhancement signs. Lymphoma was characterized by nonbranching linear vessel patterns (87.5%, 7/8), rapid wash-in and slow wash-out. In nonneoplastic lesions, infarction and epidermoid cysts showed no enhancement, and abscesses were observed with marginal irregular enhancement. The sensitivity, specificity, and accuracy of CEUS for differentiating between neoplastic and nonneoplastic lesions were 100%, 93.8%, and 97.9%, respectively, and these values were higher than those for conventional US (90.3%, 62.5%, and 80.9%, respectively). CEUS can sensitively reflect the microvascular perfusion in testicular lesions and offers high accuracy for characterizing them.

Research Progress of Targeted Ultrasound Contrast Agent BR55 / 中国医学科学院学报

BR55 is an ultrasound contrast agent targeting vascular endothelial growth factor receptor 2,which can be used to detect tumor neovascularization and improve the diagnostic accuracy.Overseas researchers have used BR55 for human ultrasound molecular imaging,which showed good safety and tolerance.We reviewed the research progress on BR55 applied in the evaluation of tumor neovascularization from the composition,characteristics,animal experiments,and clinical studies of BR55.

A new method for isolating gas vesicles from Microcystis for ultrasound contrast / 生物工程学报

Gas vesicles are a unique class of gas-filled protein nanostructures which are commonly found in cyanobacteria and Halobacterium. The gas vesicles may scatter sound waves and generate harmonic signals, which enabled them to have the potential to become a novel ultrasound contrast agent. However, the current hypertonic cracking method for isolating gas vesicles contains tedious operational procedures and is of low yield, thus not suitable for large-scale application. To overcome these technical challenges, we developed a rapid and efficient method for isolating gas vesicles from Microcystis. The new H2O2-based method increased the yield by three times and shortened the operation time from 24 hours to 7 hours. The H2O2 method is not only suitable for isolation of gas vesicles from laboratory-cultured Microcystis, but also suitable for colonial Microcystis covered with gelatinous sheath. The gas vesicles isolated by H2O2 method showed good performance in ultrasound contrast imaging. In conclusion, this new method shows great potential for large-scale application due to its high efficiency and wide adaptability, and provides technical support for developing gas vesicles into a biosynthetic ultrasonic contrast agent.

Evaluation of non-contrast magnetic resonance imaging as an imaging surveillance tool for hepatocellular carcinoma in at-risk patients

INTRODUCTION@#This study aimed to evaluate the potential of non-contrast-enhanced magnetic resonance (MR) imaging as an imaging surveillance tool for detection of hepatocellular carcinoma (HCC) in at-risk patients and to compare the performance of non-contrast MR imaging with ultrasonography (US) as a screening modality for the same.@*METHODS@#In this retrospective study, patients diagnosed with HCC between 1 January 2010 and 31 December 2015 were selected from our institution's cancer registry. Patients who underwent MR imaging and had US performed within three months of the MR imaging were included. For each MR imaging, two non-contrast MR imaging sequences - T2-weighted fat-saturated (T2-W FS) sequence and diffusion-weighted imaging (DWI) - were reviewed for the presence of suspicious lesions. A non-contrast MR image was considered positive if the lesion was seen on both sequences. The performance of non-contrast MR imaging was compared to that of hepatobiliary US for the detection of HCC.@*RESULTS@#A total of 73 patients with 108 HCCs were evaluated. Sensitivity of non-contrast MR imaging for the detection of HCC using T2-W FS and DWI was 93.2%, which was significantly higher than that of US, which was 79.5% (p = 0.02). In a subgroup of 55 patients with imaging features of liver cirrhosis, the sensitivity of non-contrast MR imaging was 90.9%, which was also significantly higher than that of US, which was 74.5% (p = 0.02).@*CONCLUSION@#Our pilot study showed that non-contrast MR imaging, using a combination of T2-W FS and DWI, is a potential alternative to US as a screening tool for surveillance of patients at risk for HCC.

Differential diagnosis of gallbladder polypoid lesions by micro-flow imaging / 南方医科大学学报

OBJECTIVE@#To explore the value of micro-flow imaging (MFI) in evaluating blood flow characteristics and differential diagnosis of gallbladder polypoid lesions.@*METHODS@#We retrospectively analyzed the clinical data and ultrasound images of 73 patients with gallbladder polypoid lesions, including 24 patients with pathologically confirmed neoplastic polyps (n=24) and 49 with non-neoplastic polyps (n=49). All the patients underwent conventional ultrasound, MFI and contrast enhanced ultrasound (CEUS) before cholecystectomy. The blood flow characteristics of the lesions in color Doppler flow imaging (CDFI) and MFI were compared, and the consistency of the findings by these two modalities with those of CEUS were evaluated by weighted Kappa consistency test. The diagnostic performance of MFI for gallbladder polypoid lesions was assessed.@*RESULTS@#There were significant differences between MFI and CDFI in the evaluation of blood flow characteristics of gallbladder polypoid lesions (χ2=37.684, P < 0.001). MFI showed better performance than CDFI in displaying the blood flow characteristics of the polyps. The consistency in the findings was 0.118 between CDFI and CEUS and 0.816 between MFI and CEUS. The sensitivity, specificity and accuracy of MFI in distinguishing neoplastic polyps from non-neoplastic polyps were 75.00%, 93.88% and 87.67%, respectively.@*CONCLUSION@#MFI has a good consistency with CEUS in displaying the blood flow characteristics of gallbladder polypoid lesions and can accurately distinguish neoplastic polyps from non-neoplastic polyps, thus providing new ultrasound diagnostic evidence to support clinical decisions on optimal treatments of gallbladder polypoid lesions.

Associations of Infarct Size and Regional Myocardial Function Examined by Cardiac Magnetic Resonance Feature Tracking Strain Analysis with the Infarct Location in Patients with Acute ST-Segment Elevation Myocardial Infarction / 中国医学科学杂志(英文版)

Objective To quantitatively evaluate the associations of infarct size, regional myocardial function examined by cardiac magnetic resonance feature tracking (CMR-FT) strain analysis with infarct location in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention.Methods Cardiac magnetic resonance images were retrospectively analyzed in 95 consecutive STEMI patients with successful reperfusion. The patients were divided into the anterior wall myocardial infarction (AWMI) and nonanterior wall myocardial infarction (NAWMI) groups. Infarct characteristics were assessed by late gadolinium enhancement. Global and regional strains and associated strain rates in the radial, circumferential and longitudinal directions were assessed by CMR-FT based on standard cine images. The associations of infarct size, regional myocardial function examined by CMR-FT strain analysis with infarct location in STEMI patients were evaluated by the Spearman or Pearsonmethod. Results There were 44 patients in the AWMI group and 51 in the NAWMI group. The extent of left ventricular enhanced mass was significantly larger in patients with AWMI compared with the NAWMI group (24.47±11.89, 21.06±12.08 %LV; t=3.928, P = 0.008). In infarct zone analysis, strains in the radial, circumferential and longitudinal directions were remarkably declined in the AWMI group compared with the NAWMI group (z=-20.873, -20.918, -10.357, all P < 0.001). The volume (end-systolic volume index), total enhanced mass and extent of enhanced mass of the left ventricular were correlated best with infarct zone strain in the AWMI group (all P < 0.001). Conclusion In STEMI patients treated by percutaneous coronary intervention, myocardial damage is more extensive and regional myocardial function in the infarct zone is lower in the AWMI group compared with the NAWMI group.

Can paricalcitol increase the effectiveness of n-acetylcysteine in contrast induced acute kidney prophylaxis in rats? A biochemical and histopathological study / ¿Puede el paricalcitol aumentar la eficacia de la n-acetilcisteína en la profilaxis renal aguda inducida por contraste en ratas? Un estudio bioquímico e histopatológico

SUMMARY: N-Acetylcysteine (NAC) is used for contrast induced acut kidney injury (CI-AKI) prophylaxis because of its antioxidant effects. Paricalcitol, which has reno-protective effects, is likely to provide a more effective prophylaxis when added to NAC treatment. The study was designed based on this hypothesis. The study was organised to include 4 groups each consisting of 7 rats. Group 1 was the control group, and Group 2 included rats with CI-AKI. Rats in Group 3 were administered NAC at a dose of 100 mg/kg via oral gavage once a day for 5 days. Rats in group 4 were administered paricalcitol at a dose of 0.4 mcg/kg once a day for 5 days in addition to NAC. CI-AKI was induced after the treatments in both groups. The study was terminated on the sixth day. Samples were collected from the rats' sera and kidney tissues to study oxidant and antioxidant parameters; kidney function tests were also studied. There were significant differences between the contrast nephropathy group (Group 2) and NAC and NAC+paricalcitol groups with respect to serum urea and creatinine levels. When the same groups were compared regarding oxidant (TOS-MDA) and antioxidant (TAC-Paraoxonase) parameters, we observed that the oxidant parameters increased in serum and kidney tissue samples with NAC use, and that effect was strengthened by the addition of paricalcitol to NAC treatment. However, despite increased antioxidant effectiveness, we observed no decrease in urea and creatinine levels when paricalcitol was added for CI-AKI in rats. There was no significant difference between Group 3 and Group 4. Paricalcitol provides a more potent antioxidant effect in both serum and kidney tissue samples when added to NAC treatment in rats with CI-AKI. Despite increased antioxidant parameters, however, paricalcitol does not provide a significant decrease in urea and creatinine levels.

RESUMEN: Debido a sus efectos atioxidantes la N- acetilcisteína (NAC) se usa para la profilaxis de la lesión renal aguda inducida por contraste (CI-AKI). Es probable que el paricalcitol, que tiene efectos renoprotectores, proporcione una profilaxis más eficaz cuando se agrega al tratamiento con NAC. En base a esta hipótesis el estudio fue diseñado para incluir cuatro grupos cada uno compuesto por siete ratas. El grupo 1 fue el grupo control y el grupo 2 incluyó ratas con CI-AKI. A las ratas del Grupo 3 se les administró NAC con una dosis de 100 mg/kg por sonda oral una vez al día, durante 5 días. A las ratas del grupo 4 se les administró paricalcitol a una dosis de 0,4 mcg/kg una vez al día durante 5 días, además de NAC. Se indujo CI-AKI después de los tratamientos en ambos grupos. El estudio finalizó el sexto día. Se recolectaron muestras de suero y tejidos renales de ratas para estudiar los parámetros oxidantes y antioxidantes; También se estudiaron las pruebas de función renal. Hubo diferencias significativas entre el grupo de nefropatía por contraste (Grupo 2) y los grupos NAC y NAC+paricalcitol con respecto a los niveles séricos de urea y creatinina. Cuando se compararon los mismos grupos con respecto a los parámetros oxidantes (TOS-MDA) y antioxidantes (TAC-Paraoxonase), observamos que los parámetros oxidantes aumentaron en muestras de suero y tejido renal con el uso de NAC, y ese efecto se vio reforzado por la adición de paricalcitol a tratamiento NAC. Sin embargo, a pesar de una mayor eficacia antioxidante, no observamos una disminución en los niveles de urea y creatinina cuando se agregó paricalcitol para CI-AKI en ratas. No hubo diferencias significativas entre el Grupo 3 y el Grupo 4. El paricalcitol proporciona un efecto antioxidante más potente tanto en muestras de suero como de tejido renal cuando se agrega al tratamiento con NAC en ratas con CI-AKI. Sin embargo, a pesar del aumento de los parámetros antioxidantes, el paricalcitol no proporciona una disminución sig- nificativa en los niveles de urea y creatinina.