Application of CD34 expression combined with three-phase dynamic contrast-enhanced computed tomography scanning in preoperative staging of gastric cancer

BACKGROUND Accurate preoperative staging of gastric cancer(GC),a common malignant tumor worldwide,is critical for appropriate treatment plans and prognosis.Dynamic three-phase enhanced computed tomography(CT)scanning for preoperative staging of GC has limitations in evaluating tumor angiogenesis.CD34,a marker on vascular endothelial cell surfaces,is promising in evaluating tumor angiogenesis.We explored the value of their combination for preoperative staging of GC to improve the efficacy and prognosis of patients with GC.Medical records of 106 patients with GC treated at the First People's Hospital of Lianyungang between February 2021 and January 2023 were retrospectively studied.All patients underwent three-phase dynamic contrast-enhanced CT scanning before surgery,and CD34 was detected in gastroscopic biopsy specimens.Using surgical and pathological results as the gold standard,the diagnostic results of three-phase dynamic contrast-enhanced CT scanning at different T and N stages were analyzed,and the expression of CD34-marked microvessel density(MVD)at different T and N stages was determined.The specificity and sensitivity of three-phase dynamic contrast-enhanced CT and CD34 in T and N staging were calculated;those of the combined diagnosis of the two were evaluated in parallel.Independent factors affecting lymph node metastasis were analyzed using multiple logistic regression.RESULTS The accuracy of three-phase dynamic contrast-enhanced CT scanning in diagnosing stages T1,T2,T3 and T4 were 68.00%,75.00%,79.41%,and 73.68%,respectively,and for diagnosing stages N0,N1,N2,and N3 were 75.68%,74.07%,85.00%,and 77.27%,respectively.CD34-marked MVD expression increased with increasing T and N stages.Specificity and sensitivity of three-phase dynamic contrast-enhanced CT in T staging were 86.79%and 88.68%;for N staging,89.06%and 92.86%;for CD34 in T staging,64.15%and 88.68%;and for CD34 in N staging,84.38%and 78.57%,respectively.Specificity and sensitivity of joint diagnosis in T staging were 55.68%and 98.72%,and N staging were 75.15%and 98.47%,respectively,with the area under the curve for diagnosis improving accordingly.According to multivariate analysis,a longer tumor diameter,higher pathological T stage,lower differ-entiation degree,and higher expression of CD34-marked MVD were independent risk factors for lymph node metastasis in patients with GC.CONCLUSION With high accuracy in preoperatively determining the invasion depth and lymph node metastasis of GC,CD34 expression and three-phase dynamic contrast-enhanced CT can provide a reliable basis for surgical resection.

Tomography of the dynamic stress coefficient for stress wave prediction in sedimentary rock layer under the mining additional stress

In this study,the tomography of dynamic stress coefficient(TDSC)was established based on a mechanical model of stress wave propagation in bedding planes and a mathematical model of the stress wave attenuation in rock masses.The reliability of the TDSC was verified by a linear bedding plane model and field monitoring.Generally,the TDSC in the dynamic stress propagation of bedding planes increases with the following conditions:(1)the increase of the normal stiffness of the bedding plane,(2)the increase of the incident angle of the stress wave,(3)the decrease of the incident frequency of the stress wave,or(4)the growth of three ratios(the ratios of rock densities,elastic moduli,and the Poisson’s ratios)of rocks on either side of bedding planes.The additional stress weakens TDSC linearly and slowly during the stress wave propagation in bedding planes,and the weakening effect increases with the growth of the three ratios.Besides,the TDSC decreases exponentially in the rock mass as propagation distance increases.In a field case,the TDSC decreases significantly as vertical and horizontal distances increase and its wave range increases as vertical distance increases in the sedimentary rock layers.

Multiphase convolutional dense network for the classification of focal liver lesions on dynamic contrast-enhanced computed tomography

BACKGROUND The accurate classification of focal liver lesions(FLLs)is essential to properly guide treatment options and predict prognosis.Dynamic contrast-enhanced computed tomography(DCE-CT)is still the cornerstone in the exact classification of FLLs due to its noninvasive nature,high scanning speed,and high-density resolution.Since their recent development,convolutional neural network-based deep learning techniques has been recognized to have high potential for image recognition tasks.AIM To develop and evaluate an automated multiphase convolutional dense network(MP-CDN)to classify FLLs on multiphase CT.METHODS A total of 517 FLLs scanned on a 320-detector CT scanner using a four-phase DCECT imaging protocol(including precontrast phase,arterial phase,portal venous phase,and delayed phase)from 2012 to 2017 were retrospectively enrolled.FLLs were classified into four categories:Category A,hepatocellular carcinoma(HCC);category B,liver metastases;category C,benign non-inflammatory FLLs including hemangiomas,focal nodular hyperplasias and adenomas;and category D,hepatic abscesses.Each category was split into a training set and test set in an approximate 8:2 ratio.An MP-CDN classifier with a sequential input of the fourphase CT images was developed to automatically classify FLLs.The classification performance of the model was evaluated on the test set;the accuracy and specificity were calculated from the confusion matrix,and the area under the receiver operating characteristic curve(AUC)was calculated from the SoftMax probability outputted from the last layer of the MP-CDN.RESULTS A total of 410 FLLs were used for training and 107 FLLs were used for testing.The mean classification accuracy of the test set was 81.3%(87/107).The accuracy/specificity of distinguishing each category from the others were 0.916/0.964,0.925/0.905,0.860/0.918,and 0.925/0.963 for HCC,metastases,benign non-inflammatory FLLs,and abscesses on the test set,respectively.The AUC(95%confidence interval)for differentiating each category from the others was 0.92(0.837-0.992),0.99(0.967-1.00),0.88(0.795-0.955)and 0.96(0.914-0.996)for HCC,metastases,benign non-inflammatory FLLs,and abscesses on the test set,respectively.CONCLUSION MP-CDN accurately classified FLLs detected on four-phase CT as HCC,metastases,benign non-inflammatory FLLs and hepatic abscesses and may assist radiologists in identifying the different types of FLLs.

Dynamic Visualization Approach of the Multiphase Flow Using Electrical Capacitance Tomography

Identifying the flow patterns is vital for understanding the complicated physical mechanisms in multiphase flows.For this purpose,electrical capacitance tomography(ECT) technique is considered as a promising visualization method for the flow pattern identification,in which image reconstruction algorithms play an important role.In this paper,a generalized dynamic reconstruction model,which integrates ECT measurement information and physical evolution information of the objects of interest,was presented.A generalized objective functional that simultaneously considers the spatial constraints,temporal constraints and dynamic evolution information of the objects of interest was proposed.Numerical simulations and experiments were implemented to evaluate the feasibility and efficiency of the proposed algorithm.For the cases considered in this paper,the proposed algorithm can well reconstruct the flow patterns,and the quality of the reconstructed images is improved,which indicates that the proposed algorithm is competent to reconstruct the flow patterns in the visualization of multiphase flows.

A SIMULATION STUDY ON DYNAMIC-SAMPLING-MODE FOR FLUORESCENCE MOLECULAR TOMOGRAPHY

Fluorescence tomography can obtain a sufficient dataset and optimal three-dimensional imageswhen projections are captured over 360◦ by CCD camera. Herein a non-stop dynamic samplingmode for fluorescence tomography is proposed in an attempt to improve the optical measurementspeed of the traditional imaging system and stability of the object to be imaged. A series ofsimulations are carried out to evaluate the accuracy of dataset acquired from the dynamicsampling mode. Reconstruction with the corresponding data obtained in the dynamic-modeprocess is also performed with the phantom. The results demonstrate the feasibility of suchan imaging mode when the angular velocity is set to the appropriate value, thus laying thefoundation for real experiments to verify the superiority in performance of this new imagingmode over the traditional one.

Spectral-domain optical coherence tomography dynamic changes and steroid response in multiple evanescent white dot syndrome

Dear Editor,Multiple evanescent white dot syndrome （MEWDS） was first described in 1984 as a rare, acute, unilateral,multifocal retinochoroidal disorder, typically affecting young myopic women. Previous studies with fluorescein angiography （FA） and electrophysiology suggested that MEWDS to be a disease in the retinal pigment epithelium （RPE） or outer retina, while recent studies with spectral- domain optical coherence tomography （SD-OCT） suggested it may be an outer retinal disease due to observation of hyperreflective material in outer retina and subtle disruptionsof the ellipsoid zone without RPE disruption.

Quantitative Assessment of the Effect of Nitric Oxide Synthase Inhibition on Tumor Vascular Activity Using Dynamic Contrast-Enhanced Computed Tomography

Purpose: The purpose of this study was to develop a method to quantitatively assess the effect of nitric oxide synthase (NOS) inhibition on tumor vascular activity using dynamic contrast-enhanced computed tomography (DCE-CT) and to investigate its usefulness using animal experiments. Mate-rials and Methods: The DCE-CT studies were performed in anesthetized Fisher rats bearing tumors using a 4-row multi-slice CT. The scanning started 4 s before a bolus injection of iodinated contrast agent (CA) (150 mgI/kg) from the tail vein using an automatic injector and lasted 60 s at 1-s in-tervals. The contrast enhancement (CE) images were generated by subtracting the CT images before and after the administration of CA. First, the DCE-CT studies were performed before and 15, 30, and 45 min after administration of N-nitro-L-arginine (L-NNA) (1, 3, and 10 mg/kg) or vehicle, and the relative CE values were calculated by normalizing the CE image at each time point by that obtained from the first DCE-CT study. Second, we investigated the case when L-arginine (L-ARG) (200 mg/kg) and L-NNA (1, 3, and 10 mg/kg) were administered after the first and second DCE-CT studies, respectively. Third, we investigated the case when L-NNA (1, 3, and 10 mg/kg) and L-ARG (200 mg/kg) were administered after the first and second DCE-CT studies, respectively. Finally, we investigated the case when L-NNA (1, 3, and 10 mg/kg) and L-ARG (200 mg/kg) were administered simultaneously after the first DCE-CT study. Results: The relative CE value significantly decreased after L-NNA administration in a dose-dependent manner (p-values = 0.0074 and <0.0001 for 0 vs. 3 mg/kg and 0 vs. 10 mg/kg, respectively, at 15 min, 0.0003 and <0.0001 for 0 vs. 3 mg/kg and 0 vs. 10 mg/kg, respectively, at 30 min, and 0.0367 and 0.0004 for 0 vs. 3 mg/kg and 0 vs. 10 mg/kg, respectively, at 45 min). When L-ARG was administered prior to the administration of 1 mg/kg L-NNA, the relative CE value at 45 min was significantly higher than that at 15 min. When L-ARG was administered after L-NNA administration, there was no significant difference between the relative CE values at 15 min and 45 min. These results suggest that when using L-NNA in combination with L-ARG, their effect on tumor vascular activity differs depending on the order of their administration. When L-NNA and L-ARG were administered simultaneously, there was a tendency for the relative CE value to be higher than that when only L-NNA was administered, at all injected doses of L-NNA. Conclusion: Our method using DCE-CT is useful for monitoring the effect of NOS inhibition on tumor vascular activity and for determining the optimal injected dose and timing of NOS inhibitors for anticancer therapy.

Dynamic ^(18)F-fluorodeoxyglucose positron emission tomography/CT in hibernoma: enhanced tracer uptake mimicking liposarcoma

We report on two cases of patients with fat-equivalent masses in computed tomography(CT),referred to our department for dynamic positron emission tomography/CT(dPET/CT)with18F-fluorodeoxyglucose(18FFDG)in order to investigate their dignity.Both qualitative and quantitative information,as derived from dPET/CTs,couldn’t exclude a high-grade liposarcoma:Visual evaluation,revealed a large hypermetabolic focus of intense18F-FDG uptake in each patient(average SUVs 8.3 and 11.3).Regression-based parametric imaging demonstrated an enhanced distribution volume,which correlates to perfusion,and a high phosphorylation rate that correlates to cell viability.Kinetic analysis,based on a two-tissue compartment model demonstrated an enhanced FDG transport k1and an enhanced phosphorylation rate k3.A non-compartmental approach based on fractal dimension revealed also enhanced values.However,final diagnosis was based on biopsy,which revealed hibernoma,a benign brown fat tumor.Brown adipose contains increased numbers of mitochondria and a high-rate of glucose metabolism.Therefore,they have increased FDG uptake.The evaluation of lipomatous lesions on CT,with high FDG uptake,should include the possibility of hibernoma as a differential diagnosis.

Dynamic imaging of a small artery underneath skin surface of a human finger by optical coherence tomography

OCT is a powerful tool for detection of physiological functions of micro organs underneath the human skin surface, besides the clinical application to ophthalmology, as recently demonstrated by the authors’ group. In particular, dynamics of peripheral vessels can be observed clearly in the time-sequential OCT images. Among the vascular system, only the small artery has two physiological functions both for the elastic artery and for muscle-controlled one. It, therefore, is important for dynamic analysis of blood flow and circulation. In the time-sequential OCT images obtained with 25 frames/sec, it is found that the small artery makes a sharp response to sound stress for contraction and expansion while it continues pulsation in synchronization with the heartbeats. This result indicates that the small artery exhibits clearly the two physiological functions for blood flow and circulation. In response to sound stress, blood flow is controlled effectively by thickness change of the tunica media which consists of five to six layers of smooth muscles. It is thus found that the thickness of the tunica media changes remarkably in response to external stress, which shows the activity of the sympathetic nerve. The dynamic analysis of the small artery presented here will allow us not only to understand the mechanism of blood flow control and also to detect abnormal physiological functions in the whole vascular system.

Quantitative Assessment of Protective Effects of Antioxidant Agents against Drug-Induced Nephrotoxicity Using Dynamic Contrast-Enhanced Computed Tomography

Purpose: The purpose of this study was to develop a method for quantifying the extent of renal dysfunction due to drug-induced nephrotoxicity using dynamic contrast-enhanced computed tomography (DCE-CT) and to investigate the protective effects of various antioxidant agents against cis-dichlorodiammineplatinum (cisplatin)-induced nephrotoxicity in rats using this method. Materials and Methods: The DCE-CT studies were performed in 8-week-old male Sprague-Dawley rats. The CT scanning started 4 s before a bolus intravenous injection of iodinated contrast agent (CA) (150 mgI/kg) from the tail vein using an automatic injector and lasted 90 s at 1-s intervals. The contrast clearance per unit renal volume (K1) was estimated from the DCE-CT data using the Patlak model. The renal volume (V) was calculated by manually delineating the kidney on the CT image. The contrast clearance of the entire kid-ney (K) was obtained by . First, to investigate the effect of CA itself, the DCE-CT studies were performed without injecting cisplatin 2, 4, and 7 days after the first DCE-CT study on day 0. Second, to investigate the effect of injected dose of cisplatin, the DCE-CT study was performed after the intraperitoneal (i.p.) injection of cisplatin (1.8 mg/kg) and was repeated every other day for one week. Finally, to investigate the protective effects of antioxidant agents [L-arginine (300 mg/kg), N-acetylcysteine (500 or 1000 mg/kg), methimazole (40 mg/kg), captopril (60 mg/kg), and taurine (750 mg/kg)], the DCE-CT studies were performed on days 0, 2, 4, and 7 after the i.p. injection of cisplatin (3.6 mg/kg). For comparison, the DCE-CT data were also acquired without injecting the antioxidant agents (CDDP group). Results: When cisplatin was not injected, there were no significant changes in the K value as compared to that on day 0 within the studied period. The K valuesignificantly (p < 0.05) decreased with increasing dose of cisplatin. Although some differences were observed in the extent of change in the K value normalized by that on day 0, depending on the antioxidant agents and their injected dose and schedule, the normalized K values on day 7 in the groups injected with the antioxidant agents were significantly higher than those in the CDDP group, suggesting that the antioxidant agents studied here had protective effects against cisplatin-induced nephrotoxicity in varying degrees. Conclusion: Our method appears useful for quantitatively evaluating the protective effects of antioxidant agents against cisplatin-induced nephrotoxicity and for investigating the optimal injected dose and schedule of the agents, because it allows repeated measurements of split renal function in a single animal.

Evaluation of Airway Obstruction at Soft Palate Level in Male Patients with Obstructive Sleep Apnea/Hypopnea Syndrome:Dynamic 3-Dimensional CT Imaging of Upper Airway

This study examined the dynamic characteristics of upper airway collapse at soft palate level in patients with obstructive sleep apnea/hypopnea syndrome（OSAHS） by using dynamic 3-Dimensional（3-D） CT imaging.A total of 41 male patients who presented with 2 of the following symptoms,i.e.,daytime sleepiness and fatigue,frequent snoring,and apnea with witness,were diagnosed as having OSAHS.They underwent full-night polysomnography and then dynamic 3-D CT imaging of the upper airway during quiet breathing and in Muller＇s maneuver.The soft palate length（SPL）,the minimal cross-sectional area of the retropalatal region（mXSA-RP）,and the vertical distance from the hard palate to the upper posterior part of the hyoid（hhL） were compared between the two breathing states.These parameters,together with hard palate length（HPL）,were also compared between mild/moderate and severe OSAHS groups.Association of these parameters with the severity of OSAHS [as reflected by apnea hypopnea index（AHI） and the lowest saturation of blood oxygen（LSaO2）] was examined.The results showed that 31 patients had severe OSAHS,and 10 mild/moderate OSAHS.All the patients had airway obstruction at soft palate level.mXSA-RP was significantly decreased and SPL remarkably increased during Muller＇s maneuver as compared with the quiet breathing state.There were no significant differences in these airway parameters（except the position of the hyoid bone） between severe and mild/moderate OSAHS groups.And no significant correlation between these airway parameters and the severity of OSAHS was found.The position of hyoid was lower in the severe OSAHS group than in the mild/moderate OSAHS group.The patients in group with body mass index（BMI）≥26 had higher collapse ratio of mXSA-RP,greater neck circumference and smaller mXSA-RP in the Muller＇s maneuver than those in group with BMI26（P0.05 for all）.It was concluded that dynamic 3-D CT imaging could dynamically show the upper airway changes at soft palate level in OSAHS patients.All the OSAHS patients had airway obstruction of various degrees at soft palate level.But no correlation was observed between the airway change at soft palate level and the severity of OSAHS.The patients in group with BMI≥26 were more likely to develop airway obstruction at soft palate level than those with BMI26.

A case of occult insulinoma localized by pancreatic dynamic enhanced spiral CT

Insulinomas are the most common category of pancreatic endocrine tumors,with an annual incidence of 1-4 cases per million people.Most are intrapancreatic,benign and solitary.Therefore,they have an excellent prognosis after surgical resection.However,the localization diagnosis of insulinomas still poses a challenge to surgeons and radiologists.In this case,the tumor was occult and could not be found by either abdominal enhanced spiral computed tomography(CT)or ultrasonography.Therefore,we tried a new method of CT scanning and localized the tumor.

Dynamic contrast-enhanced MRI versus ^(18)F-FDG PET/CT: Which is better in differentiation between malignant and benign solitary pulmonary nodules?

Objective： To prospectively compare the discriminative capacity of dynamic contrast enhanced-magnetic resonance imaging（DCE-MRI） with that of^18F-fluorodeoxyglucose（^18F-FDG） positron emission tomography/computed tomography（PET/CT） in the differentiation of malignant and benign solitary pulmonary nodules（SPNs）.Methods： Forty-nine patients with SPNs were included in this prospective study. Thirty-two of the patients had malignant SPNs, while the other 17 had benign SPNs. All these patients underwent DCE-MRI and ^18F-FDG PET/CT examinations. The quantitative MRI pharmacokinetic parameters, including the trans-endothelial transfer constant（K^trans）, redistribution rate constant（Kep）, and fractional volume（Ve）, were calculated using the Extended-Tofts Linear two-compartment model. The ^18F-FDG PET/CT parameter, maximum standardized uptake value（SUV（max））, was also measured. Spearman＇s correlations were calculated between the MRI pharmacokinetic parameters and the SUV（max） of each SPN. These parameters were statistically compared between the malignant and benign nodules. Receiver operating characteristic（ROC） analyses were used to compare the diagnostic capability between the DCE-MRI and ^18F-FDG PET/CT indexes.Results： Positive correlations were found between K^trans and SUV（max）, and between K（ep） and SUV（max）（P〈0.05）.There were significant differences between the malignant and benign nodules in terms of the K^trans, K（ep） and SUV（max） values（P〈0.05）. The areas under the ROC curve（AUC） of K^trans） K（ep） and SUV（max） between the malignant and benign nodules were 0.909, 0.838 and 0.759, respectively. The sensitivity and specificity in differentiating malignant from benign SPNs were 90.6% and 82.4% for K^trans; 87.5% and 76.5% for K（ep）; and 75.0% and 70.6%for SUV（max）, respectively. The sensitivity and specificity of K^trans and K（ep） were higher than those of SUV（max）, but there was no significant difference between them（P〉0.05）.Conclusions： DCE-MRI can be used to differentiate between benign and malignant SPNs and has the advantage of being radiation free.

Enhancement patterns of small hepatocellular carcinoma shown by dynamic MRI and CT

Objectives: To study prospectively the enhancement features of small hepatocellular carcinoma (SHCC) with multi-phase scanning of dynamic MRI and spi- ral CT, and discuss the superiority of dynamic MRI to spiral CT. Methods: Multi-phase dynamic contrast scanning of high field MRI and spiral CT were performed in 53 patients with SHCC. The arterial phase, portal ve- nous phase and delayed phase scanning of spiral CT was done after the pre-contrast scanning of the entire liver. MRI was performed with SE sequence and fast multiplanar spoiled gradient-recalled sequence dy- namic multi-phase contrast scanning. Results: Seventy-six lesions were found in all 53 pa- tients. Sixty-nine and 54 of the 76 lesions enhanced obviously in MRI and spiral CT arterial phase scan- ning respectively. The typical enhancement patterns of SHCC in the arterial phase, portal venous phase and delayed phase scanning of MRI and spiral CT were hyper-hypo-hypointense (dense) and hyper-iso- hypointense (dense). Atypical enhancement patterns were hyper-hyper-hyperintense (dense), hyper-iso- isointense (dense) and hypo-hypo-hypointense (dense). Conclusions: Both MRI and spiral CT multi-phase dynamic contrast-enhanced scanning could demon- strate the enhancement features of SHCC, and arte- rial phase scan of MRI was superior to spiral CT in reflecting the hypervascular characterization of SHCC. In addition, MRI was better than spiral CT in characterization of hepatic lesions combined with SE sequence.

New Insights into the Mesozoic Large-scale Intra-plate Magmatism and Mineralization in South China from Seismic Tomography

A great amount of new S-wave data has been combined to image the mantle structure down to lower mantle depth near the southeastern margin of Eurasia and understand the tectonics in South China since the Mesozoic.Our results reveal a large-scale structure beneath the South China Sea,with a prominent,broad low-velocity feature of at least 1500-km wide in and below the mantle transition zone(MTZ)and a pronounced low-velocity feature of nearly 500-km wide in the lowermost mantle.Together these features may represent the head-and-tail of an upwelling mantle plume that has interacted with and deformed by the subducting plates in the region.The Andaman-Sumatra plate is seen subducting steeply without stagnation in the MTZ over the large-scale low-velocity structure,suggesting that the upwelling mantle may have exerted significant influence on the overlying plate tectonics.Our results suggest a long-term extensional regime near the southeastern margin of Eurasia,which may help to understand the formation of the large-scale intra-plate magmatism and mineralization with accumulation of huge amount of rare metal elements in South China during the Mesozoic,and the continental breakup,the southeastward extrusion of Indochina,and the opening of the South China Sea during the Cenozoic.

WAVELET-BASED ANALYSIS OF CEREBROVASCULAR DYNAMICS IN NEWBORN RATS WITH INTRACRANIAL HEMORRHAGES

Intracranial hemorrhage(I)is a major problem of neonatal intensive care.The incidence of Iistypically asymptomatic and'canmot be effectively detected by standard diagnostic methods.The mechanisms underlying IH are unknown but there is evidence that stress-induced disorders inadrenergic regulation of cerebral venous blood flow (CVBF) are among the main reasons.Quantitative and qualitative:could significantly advance understanding ofthe nature of I in newbornslth1sions of CVBF in newborn rats withan experimental model of stinjection.Our analysis is bas ed on theDoppler optical coheavelet-based approachthat provides sensitiv external factors.Theobtained resultsccompanied by asupprectivity to adrenaline.Weintroducd show that the values0<1.23 estimated ithelodinto the sympathicusindicate abnormal reactions associated with the developent of I.We conclude that t he revealed areactivity of the cerebral veins to adrenaline represents a possible mechanism responsible forpat hological changes in CVBF.

Comparison of clinical value of dynamic contrast-enhanced MRI and SPECT renal dynamic imaging of GFR measurement in the evaluation of renal function in renal transplantation

Objective:To compare the clinical value of dynamic contrast-enhanced MRI(DCE-MRI)and single-photon emission computed tomography(SPECT)renal dynamic imaging in the measurement of glomerular filtration rate(GFR)in the evaluation of renal function in renal transplantation.Methods:A total of 70 recipients who underwent renal transplantation in Baogang Hospital of Inner Mongolia from April of 2015 to April of 2018 were selected as research objects.GFR was measured in renal transplant recipients by use of DCE-MRI and SPECT(GFR-MRI and GFR-SPECT respectively),and was compared with creatinine clearance rate(Ccr).The safety of contrast media was evaluated in DCE-MRI detection.Results:The bias of GFR-MRI against Ccr value was higher than that of GFR-SPECT against Ccr value,with 30%and 50%accuracy of GFR-MRI higher than that of GFR-SPECT,and the difference was statistically significant(p<.05).Pearson correlation analysis showed that GFR-MRI and GFR-SPECT values were positively correlated to Ccr(p<.05),and the correlation coefficient of GFR-MRI and Ccr was higher than that of GFR-SPECT and Ccr,with the difference statistically significant(p<.05).By Bland-Altman analysis,95%confidence interval of GFR-SPECT was 95.49 ml/(min·1.73 m^(2)),and 95%confidence interval of GFR-MRI was 62.35 ml/(min·1.73m^(2)),which was much narrower.Only 2 cases of patients developed mild rash among 70 cases of patients,and recovered spontaneously without any treatment.Conclusions:Compared with SPECT,the bias of GFR measured by DCE-MRI against Ccr is much greater.However,DCE-MRI has a higher accuracy,correlation and consistency in comparison with Ccr,and it has a narrower confidence interval.DCE-MRI can more accurately evaluate renal function in renal transplantation by measuring GFR,and it has a high safety.

应用瑞加诺生负荷D-SPECT评价定量血流分数在经皮冠状动脉介入治疗中的作用

目的应用瑞加诺生负荷动态单光子发射计算机断层扫描(dynamic single-photon emission computed tomography,D-SPECT)评价定量血流分数(quantitative flow ratio,QFR)在经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)中的作用。方法选择2021年6月31日至2023年6月31日在河北医科大学第一医院心内科住院行择期PCI术的200例不稳定型心绞痛患者,年龄(57.56±8.23)岁,按照随机数字表法分为常规组(n=100)和QFR组(n=100),试验采用双盲法进行。常规组根据医师经验行PCI术治疗,QFR组根据QFR测定结果行PCI治疗。所有入选患者术前及PCI术后7 d,应用瑞加诺生负荷D-SPECT,分别采集短轴、垂直长轴、水平长轴的图像,计算心肌17节段分布下心肌灌注总积分、心肌缺血总节段数情况。结果PCI术前两组患者心肌缺血节段数(7.59±3.14 vs.7.48±3.36,P=0.811)、心肌灌注总积分(15.87±7.61 vs.15.63±5.97,P=0.860)差异无统计学意义,QFR组PCI术后7 d的心肌缺血节段数(5.58±3.36 vs.6.51±2.14,P=0.020)和心肌灌注总积分(10.55±4.41 vs.12.96±6.50,P=0.002)显著优于常规组(P<0.05)。结论应用QFR指导PCI可以更好改善患者心肌缺血程度。

肺源性心脏病患者24h动态心电图参数与肺功能的相关性及对不良事件的预测价值

目的探究肺源性心脏病(PHD)患者动态心电图参数与肺功能的相关性及对不良事件的预测价值。方法选取PHD患者73例为观察组,并纳入同期健康志愿者42例为对照组,两组均接受24 h动态心电图和肺功能检测;比较入组时两组被检者及观察组患者治疗前、治疗后第7天时24 h动态心电图参数[24 h RR间期标准差(SDNN)、每5 min时段正常RR间期标准差(SDANN)]和肺功能指标[1秒用力呼气容积(FEV1)/用力肺活量(FVC)、FEV1预计百分比(FEVl%)];随访6个月,根据不良事件发生情况将观察组分为预后良好组和预后不良组,比较两组患者临床特征,分析24 h动态心电图参数与肺功能的相关性及其对PHD不良事件的预测价值。结果观察组入院后SDNN、SDANN、FEV1/FVC、FEVl%低于对照组(P<0.05),73例PHD患者在治疗后第7天时的SDNN、SDANN、FEV1/FVC、FEVl%较治疗前升高(P<0.05);随访6个月,73例PHD患者中有32例出现不良事件,预后不良组急性加重期占比、平均病程均高于预后良好组(P<0.05),预后不良组治疗前、治疗后第7天时SDNN、SDANN、FEV1/FVC、FEVl%均低于预后良好组(P<0.05);Pearson相关分析结果显示,治疗前及治疗后第7天时SDNN、SDANN均与治疗前及治疗后第7天时FEV1/FVC、FEVl%呈正相关(P<0.05);ROC分析结果显示,PHD患者发生不良事件的治疗前、治疗后第7天时SDNN、SDANN的cut-off值分别为72 ms、55 ms、92 ms、91ms,AUC范围在0.702~0.813(P<0.05)。结论PHD患者治疗前及治疗后7 d的SDNN、SDANN与肺功能呈正相关,24 h动态心电图参数对PHD不良事件的具有一定的预测价值。

成年人中心性气道流体力学特征分析

目的运用计算流体力学(CFD)技术对健康成年人中心性气道进行流体力学特征分析,研究空气流场对中心性气道的影响。方法选择4例健康成年人胸部CT影像,其中男性2例,女性2例;年龄26~53岁,平均年龄37.5岁;体质量48.5~74.0 kg,平均体质量60.6 kg。使用Mimics 21医学图像软件将4例健康成年人的胸部CT图像以医学数字成像与通信(DICOM)格式导入,并构建中心性气道的三维模型。对三维模型进行修整,使用Geomagic Studio 12软件。使用Ansys fluent 19.2软件的网格划分模块将模型进行网格划分。划分好网格后,将其导入Ansys 19.2软件进行CFD模拟计算。在模拟计算中,设定相同的潮气量,并对中心性气道内部气流流场变化进行动态分析。结果在基于CT图像数据构建的中心性气道的三维模型基础上,使用了CFD进行数值模拟。结果显示,在施加相同潮气量的情况下,气流入口速度为2.15~4.44 m/s。气道流速在从入口到出口的过程中逐渐降低,并形成了高流速的区域。气道最大流速的变化为3.25~6.77 m/s,并且最大流速靠近气管壁面。气道壁面压力由气管到支气管逐渐降低。在流速越高的区域,气道壁面压力的绝对值越高。气道壁面最大切应力变化为0.888~2.240 Pa,其中气管壁、气管分叉处及二级、三级支气管的切应力相对较大,并随着气管和支气管的直径减小而增加。结论通过对健康成年人中心性气道模型进行CFD模拟,发现气道流速、壁面压力、壁面切应力与气道结构有着密切的关系,呈现出一定的整体空间分布和局部特征。