Potential applications of 7 Tesla magnetic resonance imaging in paediatric neuroimaging:Feasibility and challenges

The integration of 7 Tesla magnetic resonance imaging(7 T MRI)in adult patients has marked a revolutionary stride in radiology.In this article we explore the feasibility of 7 T MRI in paediatric practice,emphasizing its feasibility,applications,challenges,and safety considerations.The heightened resolution and tissue contrast of 7 T MRI offer unprecedented diagnostic accuracy,particularly in neuroimaging.Applications range from neuro-oncology to neonatal brain imaging,showcasing its efficacy in detecting subtle structural abnormalities and providing enhanced insights into neurological conditions.Despite the promise,challenges such as high cost,discomfort,and safety concerns necessitate careful consideration.Research suggests that,with precautions,7 T MRI is feasible in paediatrics,yet ongoing studies and safety assessments are imperative.

3.0 Tesla vs 1.5 Tesla breast magnetic resonance imaging in newly diagnosed breast cancer patients

AIM:To compare 3.0 Tesla(T) vs 1.5T magnetic resonance(MR) imaging systems in newly diagnosed breast cancer patients.METHODS:Upon Institutional Review Board approval,a Health Insurance Portability and Accountability Actcompliant retrospective review of 147 consecutive 3.0T MR examinations and 98 consecutive 1.5T MR examinations in patients with newly diagnosed breast cancer between 7/2009 and 5/2010 was performed.Eleven patients who underwent neoadjuvant chemotherapy in the 3.0T group were excluded.Mammographically occult suspicious lesions(BIRADS Code 4 and 5) additional to the index cancer in the ipsilateral and contralateral breast were identified.Lesion characteristics and pathologic diagnoses were recorded,and results achieved with both systems compared.Statistical significance was analyzed using Fisher’s exact test.RESULTS:In the 3.0T group,206 suspicious lesions were identified in 55%(75/136) of patients and 96%(198/206) of these lesions were biopsied.In the 1.5T group,98 suspicious lesions were identified in 53%(52/98) of patients and 90%(88/98) of these lesions were biopsied.Biopsy results yielded additional malignancies in 24% of patients in the 3.0T group vs 14% of patients in the 1.5T group(33/136 vs 14/98,P = 0.07).Average size and histology of the additional cancers was comparable.Of patients who had a suspicious MR imaging study,additional cancers were found in 44% of patients in the 3.0T group vs 27% in the 1.5T group(33/75 vs 14/52,P = 0.06),yielding a higher positive predictive value(PPV) for biopsies performed with the 3.0T system.CONCLUSION:3.0T MR imaging detected more additional malignancies in patients with newly diagnosed breast cancer and yielded a higher PPV for biopsies performed with the 3.0T system.

3.0 Tesla magnetic resonance imaging: A new standard in liver imaging?

An ever-increasing number of 3.0 Tesla(T) magnets are installed worldwide. Moving from the standard of 1.5 T to higher field strength implies a number of potential advantage and drawbacks, requiring careful optimization of imaging protocols or implementation of novel hardware components. Clinical practice and literature review suggest that state-of-the-art 3.0 T is equivalent to 1.5 T in the assessment of focal liver lesions and diffuse liver disease. Therefore, further technical improvements are needed in order to fully exploit the potential of higher field strength.

3.0 T盆腔MRI联合增强CT成像在结直肠肿瘤鉴别诊断中的应用价值

目的 探讨3.0 T盆腔磁共振(MRI)联合增强CT成像在结直肠肿瘤诊断中的应用价值,以期为临床制定干预措施提供依据。方法 回顾性分析焦作市人民医院2022年4月至2023年8月收治的138例结直肠肿瘤患者的资料,患者入院后均接受3.0 T盆腔MRI及增强CT成像检查,以病理检查结果为“金标准”,比较3.0 T盆腔MRI、增强CT成像对结直肠肿瘤单独、联合诊断结果、诊断效能,分析其对结直肠肿瘤临床分期诊断结果与病理检查结果一致性。结果 经病理检查结果显示,138例结直肠肿瘤患者中,阳性72例,经3.0 T盆腔MRI检查结果显示,阳性60例,经增强CT成像结果显示,阳性58例,经联合诊断结果显示,阳性71例;3.0 T盆腔MRI、增强CT成像联合检查对结直肠肿瘤诊断灵敏度为94.44%、准确度为94.93%,高于单独3.0 T盆腔MRI(灵敏度80.56%、准确度88.41%)及增强CT成像(灵敏度76.39%、准确度85.51%),漏诊率为5.56%,低于单独3.0 T盆腔MRI漏诊率(19.44%)及增强CT成像漏诊率(23.61%)(P<0.05);3.0 T盆腔MRI、增强CT成像及联合诊断结直肠肿瘤临床分期与病理结果一致性Kappa值分别为0.818、0.772、0.923(P<0.05)。结论 3.0 T盆腔MRI联合增强CT成像可用于结直肠肿瘤诊断中,为临床早期鉴别诊断、评估临床分期提供方案,以制定后续治疗措施,改善预后。

肝硬化结节及小肝癌患者3.0T MRI检查结果分析

目的评价3.0 T MRI检查在肝硬化再生性结节(RN)、异型增生性结节(DN)和小肝癌(SHCC)诊断和鉴别诊断中价值。方法回顾性分析经病理检查确诊的69例RN、DN及SHCC患者的3.0 T MRI平扫及容积采集技术(LAVA)三期动态增强扫描特点。结果 RN主要表现为T2WI低信号,动态增强方式呈"缓慢上升型";DN主要表现为T2WI高、低信号,信号较均匀结节的动态方式以"速升缓降型"为主,可有"结中结"(特征表现);SHCC主要表现为T1WI低信号、T2WI高信号,动态增强方式为"速升速降型"。结论肝硬化结节及小肝癌在3.0 T MRI上各有较为典型的表现,临床可据此进行诊断与鉴别诊断;对其他强化类型的肝脏病灶应结合肿瘤血管的扭曲增粗及包膜等表现排除SHCC。

3.0 T MRI动态增强与64层螺旋CT多期扫描诊断肝硬化背景下小肝癌的价值比较

目的比较3.0 T磁共振(MRI)动态增强与64层螺旋CT(64-MDCT)多期扫描对肝硬化背景下小肝癌的诊断价值。方法选择肝硬化合并小肝癌患者55例(66个癌性小结节),分别进行3.0 T MRI动态增强与64-MDCT多期扫描,由两位专家对检查结果进行判定,比较两种检查方法的诊断价值。结果两位观察者通过3.0 T MRI动态增强得到的ROC曲线下面积(AUC)分别为0.893±0.013、0.859±0.027,通过64-MDCT得到的AUC分别为0.657±0.034、0.679±0.026;两位观察者对两种检查方法的诊断价值比较,P均<0.01。两位观察者采用3.0T MRI动态增强诊断肝硬化背景下小肝癌的敏感度、特异度、阴性预测值均高于64-MDCT,P均<0.01。结论 3.0T MRI动态增强对肝硬化背景下小肝癌的诊断价值高于64-MDCT。

3.0 T HR-MRI评估椎-基底动脉粥样硬化斑块在TIA病情发展中的价值

目的分析3.0 T高分辨率磁共振成像(3.0 T HR-MRI)评估椎-基底动脉粥样硬化斑块稳定性在短暂性脑缺血发作(TIA)的应用价值。方法选取2015年2月至2018年2月期间于本院诊治的TIA患者80例,所有患者均行3.0 T HR-MRI检查出椎-基底动脉粥样硬化斑块,记录椎-基底动脉粥样硬化斑块分布和厚度,并根据斑块稳定性将患者分为斑块稳定组(n=38)和斑块不稳定组(n=42),比较两组患者TIA发作次数以及发作持续时间,门诊随访1年,比较两组患者脑梗死或TIA再发时间、TIA再发次数及脑梗死例数。结果椎-基底动脉粥样硬化斑块最容易在背侧壁形成,斑块厚度以0.5~1.5mm为主;斑块不稳定组患者TIA发作次数显著多于斑块稳定组患者(P<0.05),TIA发作持续时间显著长于斑块稳定组患者(P<0.05);随访1年发现,斑块不稳定组患者脑梗死或TIA再次发作时间显著短于斑块稳定组患者(P<0.05),TIA发作次数、脑梗死例数高于斑块稳定组患者(P<0.05)。结论3.0 T HR-MRI能够评估椎-基底动脉粥样硬化斑块分布、厚度等情况,并对斑块进行定性分析,进一步预测TIA病情发展,为脑血管病二级预防提供更多依据。

3.0 T MR扩散张量成像在颈椎病诊断中的应用

目的:探讨3.0 T MR扩散张量成像在颈椎病诊断中的应用效果。方法:从2013年1月开始,至2015年1月结束,一共80例颈椎病患者,采用MR诊断仪对患者进行检查,比较颈椎病患者、健康体检者不同颈髓水平ADC值、FA值、颈髓长轴、前后径、左右径。结果:(1)在健康体检者中,C2-3、C4-5、C6-7之间ADC值、FA值、颈髓长轴、前后径、左右径无明显差异,无统计学意义,P>0.05;颈髓长轴、前后径、左右径之间两两对比,颈髓长轴值高于前后径和左右径,数据比较差异具有统计学意义,P<0.05。前后径和左右径之间对比,无明显差异,无统计学意义,P>0.05。(2)和对照组对比,A组ADC、FA、a1颈髓长轴无明显差异(P>0.05);a2前后径、a3左右径明显更大(P<0.05)。B组、C组、D组ADC值、FA值、颈髓长轴、前后径、左右径明显更大,数据比较差异明显,存在统计学意义,P<0.05.结论:采用扩散张量成像技术对颈椎病患者进行诊断,能够有效地显示颈椎压迫所致的脊髓微结构变化,具有较高的敏感性,3.0 T MR扩散张量成像在颈椎病诊断中的应用效果显著,能够弥补常规MRI难以定量分析颈椎微结构受压情况的缺点。

3.0T MRI弥散张量成像(DTI)在诊断早期糖尿病脑病中的应用

目的探讨3.0T MRI弥散张量成像(DTI)在诊断早期2型糖尿病(T2DM)脑病的应用价值。方法纳入2018年3月—2019年5月该院收治的56例T2DM患者,平均分为A组与B组。用3.0TMRI常规序列(TIWI、T2WI、T2Flair)对A组受试者头颅进行扫描,用3.0TMRI弥散张量成像(diffusion tensor imaging,DTI)对B组受试者头颅进行扫描。根据2组结果来评估DTI成像在诊断早期2型糖尿病(T2DM)脑病的应用价值。结果28例患者DTI检查结果示22例患者脊髓皮质束数量有不同程度减少,6例阴性患者;28例患者3.0T MRI常规序列结果显示16例患者脑组织有不同程度萎缩,脑室不同程度扩大,其中5例可见海马及杏仁核萎缩,12例阴性患者。结论弥散张量成像(DTI)对于早期糖尿病脑病的诊断敏感性高于MRI常规序列,仅检查时间稍长。

飞利浦Ingenia 3.0 T磁共振成像仪射频系统故障三例

磁共振成像无电离辐射且软组织成像效果较好,已成为常规体检和疾病诊断非常重要的医学影像诊疗技术之一。磁共振设备结构复杂,维修及维护成本较高,长期高负荷的运转会导致磁共振设备故障率增加。本文总结了本院飞利浦Ingenia 3.0 T磁共振设备射频系统故障三例,包括de-tuned印刷电路板故障、射频放大器故障及体线圈故障。文中对三例飞利浦磁共振设备射频系统故障的表现进行了描述,对故障产生的原因进行了分析并介绍了故障排除过程,包括观察外观、提取后台日志参数、测量疑似受损部件指标、更换受损部件以及系统测试。通过深入分析射频系统故障案例,分享维修经验,以期提高设备使用率。

Optimal b value of diffusion-weighted imaging on a 3.0T magnetic resonance scanner in Crohn's disease

AIM: To determine the optimal b value of diffusion-weighted imaging for detecting active inflammation in Crohn&#x02019;s disease.

Prostate magnetic resonance imaging at 3 Tesla:Is administration of hyoscine-N-butyl-bromide mandatory?

AIM: To evaluate the value of administration of hyoscine-N-butyl-bromide (HBB) for image quality magnetic resonance imaging (MRI) of the prostate. METHODS: Seventy patients were retrospectively included in the study. Thirty-five patients were examined with administration of 40 milligrams of HBB (Buscopan ; Boehringer, Ingelheim, Germany); 35 patients were examined without HBB. A multiparametric MRI protocol was performed on a 3.0 Tesla scanner without using an endorectal coil. The following criteria were evaluated independently by two experienced radiologists on a five-point Likert scale: anatomical details (delineation between peripheral and transitional zone of the prostate, visualisation of the capsule, depiction of the neurovascular bundles); visualisation of lymph nodes; motion related artefacts; and overall image quality.RESULTS: Comparison of anatomical details between the two cohorts showed no statistically significant difference (3.9 ± 0.7 vs 4.0 ± 0.9, P = 0.54, and 3.8 ± 0.7 vs 4.2 ± 0.6, P = 0.07) for both readers. There was no significant advantage regarding depiction of local and iliac lymph nodes (3.9 ± 0.6 vs 4.2 ± 0.6, P = 0.07, and 3.8 ± 0.9 vs 4.1 ± 0.8, P = 0.19). Motion arte- facts were rated as 'none' to 'few' in both groups and showed no statistical difference (2.3 ± 1.0 vs 1.9 ± 0.9, P = 0.19, and 2.3 ± 1.1 vs 1.9 ± 0.7, P = 0.22). Overall image quality was rated 'good' in average for both cohorts without significant difference (4.0 ± 0.6 vs 4.0 ± 0.9, P = 0.78, and 3.8 ± 0.8 vs 4.2 ± 0.6, P = 0.09). CONCLUSION: The results demonstrated no significant effect of HBB administration on image quality. The study suggests that use of HBB is not mandatory for MRI of the prostate at 3.0 Tesla.

Does sevoflurane sedation in pediatric patients lead to“pseudo”leptomeningeal enhancement in the brain on 3 Tesla magnetic resonance imaging?

BACKGROUND Prominent leptomeningeal contrast enhancement(LMCE)in the brain is observed in some pediatric patients during sedation for imaging.However,based on clinical history and cerebrospinal fluid analysis,the patients are not acutely ill and do not exhibit meningeal signs.Our study determined whether sevoflurane inhalation in pediatric patients led to this pattern of‘pseudo’LMCE(pLMCE)on 3 Tesla magnetic resonance imaging(MRI).AIM To highlight the significance of pLMCE in pediatric patients undergoing enhanced brain MRI under sedation to avoid misinterpretation in reports.METHODS A retrospective cross-sectional evaluation of pediatric patients between 0-8 years of age was conducted.The patients underwent enhanced brain MRI under inhaled sevoflurane.The LMCE grade was determined by two radiologists,and interobserver variability of the grade was calculated using Cohen’s kappa.The LMCE grade was correlated with duration of sedation,age and weight using the Spearman rho rank correlation.RESULTS A total of 63 patients were included.Fourteen(22.2%)cases showed mild LMCE,48(76.1%)cases showed moderate LMCE,and 1 case(1.6%)showed severe LMCE.We found substantial agreement between the two radiologists in detection of pLMCE on post-contrast T1 imaging(kappa value=0.61;P<0.001).Additionally,we found statistically significant inverse and moderate correlations between patient weight and age.There was no correlation between duration of sedation and pLMCE.CONCLUSION pLMCE is relatively common on post-contrast spin echo T1-weighted MRI of pediatric patients sedated by sevoflurane due to their fragile and immature vasculature.It should not be misinterpreted for meningeal pathology.Knowing pertinent clinical history of the child is an essential prerequisite to avoid radiological overcalling and the subsequent burden of additional investigations.

3.0 T高分辨率MR血管壁成像对大动脉炎活动性的判断

目的探讨3.0 T高分辨率MR血管壁成像对大动脉炎活动性的判断效果。方法选取我院2015年1月至2016年1月收治的26例大动脉炎患者,采用3.0 T双梯度MR扫描仪进行检查,分析主动脉及其分支的起始段、甲状腺双侧的颈动脉,并且进一步判断增厚管壁是否存在分层、多环征、内壁强化、血管边界模糊不清等异常情况,比较活动期和非活动期血管壁MRI的图像特征。结果 (1)活动期血管壁MRI图像多环征、强化、边界模糊不清的节段明显多于非活动期,差异有统计学意义(P<0.05)。(2)主动脉分支与双侧颈总动脉的受累情况:左侧锁骨下动脉近段受累分支共23支(88.5%),平均血管壁厚度为(3.69±0.80)mm。90个节段中,35个节段可见血管壁环形增厚,高信号,增强扫描无明显强化;55个节段可见血管壁环形增厚,多环征,边界模糊不清,信号不均匀混杂,增强扫描可见强化明显。结论 3.0 T高分辨率MR血管壁成像对大动脉炎活动性的判断价值较高,能够清晰显示大动脉炎血管壁的精细形态学变化,为诊断和治疗提供可靠依据,具有重要的临床意义。

Imaging for deep brain stimulation:The zona incerta at 7 Tesla

AIM:To evaluate different promising magnetic resonance imaging(MRI) methods at 7.0 Tesla(T) for the pre-stereotactic visualization of the zona incerta(ZI).METHODS:Two neuroradiologists qualitatively and quantitatively examined T2-turbo spin-echo(T2-TSE),T1-weighted gradient-echo,as well as FLASH2D-T2Star and susceptibility-weighted imaging(SWI) for the visualization of the ZI at 7.0 T MRI.Delineation and image quality for the ZI were independently examined using a 6-scale grading system.Inter-rater reliability using Cohen's kappa coefficient(κ) were assessed.Contrast-tonoise ratios(CNR),and signal-to-noise ratios(SNR) for the ZI were calculated for all sequences.Differences in delineation,SNR,and CNR between the sequences were statistically assessed using a paired t-test.For the anatomic validation the coronal FLASH2D-T2Star images were co-registered with a stereotactic atlas(Schaltenbrand-Wahren).RESULTS:The rostral part of the ZI(rZI) could easily be identified and was best and reliably visualized in the coronal FLASH2D-T2Star images.The caudal part was not definable in any of the sequences.No major artifacts in the rZI were observed in any of the scans.FLASH2D-T2Star and SWI imaging offered significant higher CNR values for the rZI compared to T2-TSE images(P > 0.05).The co-registration of the coronal FLASH2D-T2Star images with the stereotactic atlas schema(Schaltenbrand-Wahren) confirmed the correct localization of the ZI in all cases.CONCLUSION:FLASH2D-T2Star imaging(particularly coronal view) provides the reliable and currently optimal visualization of the rZI at 7.0 T.These results can facilitate a better and more precise targeting of the caudal part of the ZI than ever before.

Patient’s Comfort and Technical Quality Exams at 1.5 and 3.0 T Magnetic Resonance Imaging

Increased interest of clinicians for using 3.0 T magnetic resonance imaging (MRI), as imaging modality of choice for their patients, has been evident in the past few years. The aim of this study was to compare the technical quality of the obtained tomography using 3.0 T and 1.5 T MRI, and to compare the subjective feeling of discomfort of patients and subjective acoustic noise experience during imaging using MRI at 3.0 T and 1.5 T. Brain MRI (1.5 and 3.0 T) was performed in 58 patients, according to a standardized protocol. All studies have been randomly described by independent two radiologists. The reference standard for the existence of technical artifact is established on the basis of both radiologists’ consensus. We also compared the subjective feelings of the discomfort and acoustic noise during the both MRI (1.5 T and 3.0 T) exams. Artifacts were significantly more common during 3.0 T MRI in comparison with the 1.5 T MRI (χ2 = 5.286, P < 0.05), as well as in male patients (χ2 = 8.841, P < 0.05), and sub-jective assessments of discomfort and acoustic noise were higher in patients who underwent imaging using 3.0 T MRI, (χ2 = 125.959, df = 1, P < 0.001) and in females (χ2 = 195.449, df = 1, P < 0.001). Additional research is needed to prove that appropriate information for patients about the discomfort during 3.0 T MRI and their psychological preparation is very important element for optimal use of 3.0 T MRI in daily clinical practice.

3.0T磁共振成像联合多层螺旋电子计算机断层扫描对肛瘘临床分型的诊断价值

目的探讨3.0 T磁共振成像(MRI)联合多层螺旋电子计算机断层扫描(MSCT)对肛瘘临床分型的诊断价值。方法回顾性分析2020年1月至2022年5月在石家庄市中医院经手术证实的126例肛瘘病人临床资料,术前均行3.0 T MRI和MSCT检查。根据Parks分类法对比3.0 T MRI和MSCT对肛瘘病人检查的准确率,分析两项联合对肛瘘临床分型的诊断价值。结果3.0 T MRI联合MSCT诊断肛瘘外口的准确率(99.03%)高于MSCT单独诊断(90.29%),联合诊断主瘘管的准确率(100.00%)高于3.0 T MRI、MSCT各自单独诊断(93.65%、91.27%)(P<0.01),联合诊断肛瘘内口、瘘管分支、脓肿与各自单独诊断比较均差异无统计学意义(P>0.05);3.0 T MRI联合MSCT诊断括约肌间型、经括约肌型、括约肌上型、括约肌外型与手术结果的符合率分别为98.48%、100.00%、100.00%、100.00%。结论3.0 T MRI联合MSCT对肛瘘临床分型有良好的诊断价值。

3.0 T磁共振成像及CT在老年低位腰椎间盘突出诊断价值中的对比分析

目的:对比分析3.0 T磁共振成像及CT在老年低位腰椎间盘突出中的诊断价值。方法:选取2021年5月至2023年3月于我院就诊的63例疑似低位腰椎间盘突出患者,以临床最终诊断为金标准,所有患者均行3.0 T磁共振成像及CT检查,观察对比两种检查方式的诊断结果、诊断效能及低位腰椎间盘突出相关影像结果,并对两种检查方式的骨性结果参数进行比较。结果:3.0T磁共振成像的椎间盘变性、脊髓变性、硬膜囊受压检出率高于CT检查(P<0.05),CT的钙化、积气检出率高于3.0 T磁共振成像(P<0.05);3.0 T磁共振成像关节突关节角、腰骶角均高于CT,腰椎曲度、L5S_(1)椎间盘高度低于CT(P<0.05);3.0 T磁共振成像的诊断灵敏度、准确值均高于CT检查,漏诊率低于CT;3.0 T磁共振成像诊断不同类型低位腰椎间盘突出与术后结果的一致性Kappa值高于CT。结论:3.0 T磁共振成像在诊断椎间盘变性、脊髓变性、硬膜囊受压、神经走向中具有明显优势,在诊断钙化、积气中CT检出率更高,因此临床可根据具体情况结合两种检查方式的优点对腰椎间盘突出症进行诊断。

3.0T核磁共振扫描对克罗恩病活动性评估的诊断价值

目的研究3.0TMR影像对评估克罗恩病患者疾病活动性的价值。材料与方法本次研究包括确诊为克罗恩病的36名患者,运用3.0TMR影像资料评估患者病变的分期。基于肠壁异常增厚、肠壁异常强化、肠腔狭窄、"木梳征"、肠系膜增大的淋巴结、瘘道、溃疡及脓肿7个基本征象,制定出MR影像诊断标准。以临床诊断为金标准进行比较。结果本次研究共评估了216组肠段,其中发现76组肠段有异常。受累及肠段的平均厚度为(3.24±0.92)mm。增强后脂肪抑制T1WI显示异常强化肠段62段。7名患者发现肠段狭窄及狭窄后扩张(7/36);20名患者发现"木梳征"(20/36);9名患者发现肠系膜淋巴结肿大(直径>10mm)(9/36);2名患者发现溃疡(2/36);4名患者发现瘘道(4/36);所有的患者中未发现脓肿。3.0TMR影像评估活动性克罗恩病的敏感度为68.0%,特异度为90.9%,阳性预测值为94.4%,阴性预测值为55.6%,Kappa值为0.500。结论 3.0TMR影像学诊断能有效地鉴别活动期和缓解期克罗恩病,与临床诊断之间相关性分析的Kappa值为0.500,提示有较好相关性。

基于USB 3.0的高速CMOS图像传感器数据采集系统

随着高速CMOS图像传感器分辨率和帧率的大幅度提升,无论在数据传输带宽方面还是缓存容量方面都需要图像采集系统能够应对巨大的实时数据量来满足使用要求。基于此,本文提出了一种基于现场可编程门阵列(FPGA)和USB 3.0的高速CMOS图像传感器的数据采集系统实现方式。本文依次从系统电路硬件设计、FPGA和USB 3.0芯片软件功能设计以及上位机软件设计进行阐述,最后对系统进行整体调试并给出了实验结论。测试结果表明本系统能够最大化利用USB 3.0芯片的传输能力,同时实现图像接收过程的零误码率。因此,该系统可较好地满足目前高速高分辨率CMOS图像传感器对数据采集的数据实时性和准确性要求。