Multislice computed tomography angiography in the diagnosis of coronary artery disease

Multislice CT angiography represents one of the most exciting technological revolutions in cardiac imaging and it has been increasingly used in the diagnosis of coronary artery disease. Rapid improvements in multislice CT scanners over the last decade have allowed this technique to become a potentially effective alternative to invasive coronary angiography in patients with suspected coronary artery disease. High diagnostic value has been achieved with multislice CT angiography with use of 64- and more slice CT scanners. In addition, multislice CT angiography shows accurate detection and analysis of coronary calcium, characterization of coronary plaques, as well as prediction of the disease progression and major cardiac events. Thus, patients can benefit from multislice CT angiography that provides a rapid and accurate diagnosis while avoiding unnecessary invasive coronary angiography procedures. The aim of this article is present an overview of the clinical applications of multislice CT angiography in coronary artery disease with a focus on the diagnostic accuracy of coronary artery disease; prognostic value of coronary artery disease with regard to the prediction of major cardiac events; detection and quantification of coronary calcium and characterization of coronary plaques. Limitations of multislice CT angiography in coronary artery disease are also briefly discussed, and future directions are highlighted.

SPECTRUM OF FUNCTIONING ISLET CELL TUMOR ON MULTISLICE COMPUTED TOMOGRAPHY:EXPERIENCE ON 70 PATIENTS

Objective To review experience in preoperative detection of islet cell tumors using multislice computed tomography （MSCT） and summarize various imaging features of functioning islet cell tumors on enhanced MSCT. Methods Seventy patients with clinical or pathological diagnosis of functioning pancreatic islet cell tumor between October 2003 and February 2007 were included in this retrospective study. Seventy-four enhanced MSCT scans in these patients were identified. All MSCT scans were interpreted by two experienced radiologists by consensus interpretation. Surgery and pathology reports were used to confirm the diagnosis, localization, and size of tumors. Results Totally, 73 functioning islet cell tumors including 65 benign insulinomas, 2 benign glucagonomas, 3 malignant insulinomas, and 3 malignant glucagonomas were pathologically diagnosed. Tumors in only two cases were not found by MSCT. In 67 benign lesions, 32 showed typical enhancement style, 21 showed prolonged enhancement in portal venous phase, 4 showed delayed enhancement, 4 had iso-dense enhancement with normal pancreatic parenchyma, 2 had no enhancement at all in arterial phase and portal venous phase, and 4 had inhomogeneous enhancement with necrosis or cyst-formation. Patchy or spotty calcifications were found in 3 of the 67 tumors. In 6 malignant islet cell tumors, vessel invasion （2/6） and bowel invasion （1/6） were seen. Different enhancement patterns were shown. All hepatic metastases showed hyper-enhancement during their arterial phase. Conelttsions Pancreatic islet cell tumor may display a wide spectrum of presentations in MSCT. Tumors with unusual appearances often present as diagnostic challenges. Non-contrast and post-contrast multiphase scans are recommended for the localization of functioning islet cell tumors.

Coronary computed tomography angiography in coronary artery disease

AIM: To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature.METHODS: A search of articles on coronary CT angiography in the diagnosis of CAD was performed during a 6-year-period between 2005 and 2010 from f ive main radiology journals namely, Radiology, American Journal of Roentgenology, European Radiology, European Journal of Radiology and British Journal of Radiology. Analysis of the references was focused on the research directions of coronary CT angiography with regard to the type of studies in terms of diagnostic value, application of dose-reduction strategies and resultant effective radiation doses with use of these techniques.RESULTS: One hundred and forty two studies were identified which met the selection criteria and were included in the analysis. 64-slice CT (single source anddual-source CT) dominated 78% of the coronary CT angiography studies. Prior to 2007, research was focused on the diagnostic value of coronary CT angiography, but since 2008 more attention has been paid to radiation dose reduction. Radiation dose was reported in 64 studies, representing 45% of total studies published in the f ive radiology journals. Various dose-saving strategies have been implemented and prospective electrocardiography-triggering and high pitch techniques were found to be the most effective approaches for radiation dose reduction, with the corresponding mean effective dose being 3.5 ± 1.9 mSv and 1.7 ± 0.6 mSv, respectively.CONCLUSION: This review shows that the current research in coronary CT angiography has shifted from the previous focus on diagnostic accuracy in CAD to more emphasis on radiation dose reduction.

Computed Tomography Diagnosis of Acute Appendicitis—Pictorial Essay

Acute appendicitis is a common surgical emergency with varied clinical presentations. Early diagnosis is absolutely necessary to minimize morbidity whereas delayed or missed diagnosis can cause adverse consequences. Computed tomography is a highly accurate imaging technique for diagnosing appendicitis. Hence it plays a valuable role in selected patients with suspected appendicitis;[1]. In this essay, we review the normal Computed tomography anatomy of the appendix and the right lower quadrant and illustrate the Computed tomography signs of appendicitis and important differential diagnostic entities. The Computed tomography appearance of complications of acute appendicitis is also presented, as are issues concerning clinical presentation and duration of the symptoms. Computed tomography signs can be varied and overlooked as they say what is easy to see is also easy to miss.

Multislice spiral CT angiography in evaluation of liver transplantation candidates

BACKGROUND: Orthotopic liver transplantation has be- come the treatment of choice for patients with end-stage liver disease. This study was designed to study whether multislice spiral CT angiography (MSCTA) could be used for preoperative evaluation for orthotopic liver transplanta- tion candidates. METHODS: Eighty consecutive potential candidates for liver transplantation were evaluated with dual-phase three-di- mensional CT angiography (3DCTA). The arterial-phase was used to create vascular maps of the celiac axis (inclu- ding the origin of the hepatic common artery, left gastric artery and splenic artery) and origin of the superior mesen- teric artery. The portal venous-phase was used to analyze portal vein thrombosis and collateral vascularization of the portal vein. Statistical analyses were made using the chi- square test for differences between hepatic arterial anatomy of 80 patients and Michel's anatomy of 200 patients. Appearance of MSCTA and operative results of 16 patients were analyzed. RESULTS; Sixty-two patients (77.5%) showed conven- tional and 18 (22.5%) nonconventional hepatic arterial anatomy. A significant difference was found between the two groups in anatomy of the hepatic artery (P <0.05). Celiac axis stenosis was observed in 6 patients, SA aneu- rysm in 2, small-caliber hepatic arterial vessels in 2, and portal vein thrombosis in 15. Vascular structures of 16 ope- rative patients were well defined. CONCLUSION: As a noninvasive examination, MSCTA can provide a comprehensive preoperative vascular evalua- tion for liver transplantation candidates.

视网膜母细胞瘤MSCT MRI表现及其诊断价值分析

目的:对比多层螺旋电子计算机断层扫描(MSCT)、磁共振成像(MRI)检测方法在视网膜母细胞瘤(Rb)检测中的诊断价值。方法:选择2019年1月到2023年6月期间于我院治疗的125例疑似Rb患者,采用MSCT、MRI进行检测,通过病理检测结果为诊断金标准,分析不同检测方法对Rb检测的灵敏度、特异度、准确性,以及与病理检测结果的一致性。结果:患者经MRI、MSCT、病理检测的Rb阳性率分别为44.00%(55/125)、52.80%(66/125)、45.60%(57/125),差异无统计学意义(P>0.05);MRI检测结果与病理检测结果比对的Kappa值为0.644,低于MSCT检测的Kappa值0.729;MRI检测的灵敏度为78.94%,低于MSCT检测的灵敏度92.98%,差异有统计学意义(P<0.05);MRI检测的特异度(85.29%)高于MSCT检测(80.88%),准确率(82.40%)低于MSCT检测(86.40%),差异无统计学意义(P>0.05);MSCT视野下Rb患者眼球壁有不规则增厚,玻璃体腔内见不规则片状软组织密度影,病灶内见斑片状钙化;MRI视野下Rb患者眼环不均匀增厚,玻璃体腔内可见不规则团片状异常信号影,T1WI呈等信号,T2WI呈稍高、低混杂信号影,增强扫描见病灶明显不均匀强化。结论:与MRI检测相比,MSCT检测与病理检测结果的一致性高,并具有更高的灵敏度,具有较高的诊断价值。

Quantitative and qualitative assessment of non-obstructive left main coronary artery plaques using 64-multislice computed tomography compared with intravascular ultrasound

Background There are few reports of quantitative and qualitative measuring of left main coronary artery （LMCA） plaques by multislice computed tomography coronary angiography （MSCTA）, especially when compared with intravascular ultrasound （IVUS） as reference standard. The aim of this study was to evaluate the use of 64-MSCTA in the diagnosis of LMCA disease, and the accuracy of MSCTA in the quantitative and qualitative assessment of the LMCA lesion as compared with IVUS.Methods A total of 91 patients （53 men, 38 women, mean age （64.78±9.19） years） were examined by 64-MSCTA and IVUS. Compared with the IVUS, the sensitivity, specificity, positive and negative predictive values （PPV and NPV） of the MSCTA on the diagnosis of LMCA diseases were calculated. Also, kappa index （K） for the agreement between MSCTA and IVUS was calculated. Minimal lumen area （MLA）, external elastic membrane cross-sectional area （EEM-CSA） and plaque burden were measured by two blinded and independent operators on MSCTA cross-sectional reconstruction and compared with the parameters measured from IVUS by manually tracing. The CT value of soft, fibrous and calcific plaques was measured using IVUS classification of the plaques.Results The sensitivity, specificity, PPV and NPV of MSCTA for detecting LMCA plaques were 93.1%, 84.2%, 95.7%, 76.2%, respectively. Kappa index （K=0.744, P〈0.001） indicated excellent agreement between MSCTA and IVUS. The Pearson index between MLA on IVUS and MLA on MSCTA was 0.815 （P 〈0.01）. The Pearson index of plaque burden and EEM-CSA between IVUS and MSCTA was 0.736 and 0.740 respectively （both P 〈0.01）. The CT value of soft plaque, fibrous plaque and calcific plaque compared with IVUS were （52.52±15.71） HU, （108.32±43.44） HU and （604.16±377.67） HU （P〈0.001）. Receiver operating characteristic curve analysis of CT value of non-calcific plaques for predicting soft plaques showed the cutpoint was 54.35 HU, with a sensitivity of 83.3% and specificity of 94.4%. Conclusions Sixty-four section MSCTA is an effective diagnostic tool for the detection of LMCA plaques with higher sensitivity and specificity. The correlation of quantitative and qualitative analysis between MSCTA and IVUS was excellent. The CT value of plaques can help the diagnosis of plaque composition.

Role of contrast enhanced ultrasound in detection of abdominal aortic abnormalities in comparison with multislice computed tomography

Conventional ultrasound （US） is the most widely used imaging modality in routine clinical practice worldwide. The limitations of conventional ultrasound in the detection of aortic lesions versus multi-slice computed tomography angiography （MS-CTA） are well known.

The accuracy and optimal slice thickness of multislice helical computed tomography for right and left ventricular volume measurement

Background Multislice helical computed tomography (MSCT) has been used to depict coronary anatomy noninvasively, and proved useful for evaluating ventricular function. The aim of our study was to assess the accuracy of ventricular volume as measured by MSCT.Methods Fourteen human left ventricular (LV) and 15 right ventricular (RV) casts were scanned by MSCT. A series of LV and RV short-axis images were reconstructed later with slice thickness of 2.0 mm, 3.5 mm, 5.0 mm, 7.0 mm, and 10.0 mm. Ventricular volume was calculated by the multislice tomographic Simpson’s method. True LV and RV cast volumes were determined by water displacement. Results Both calculated LV and RV volumes correlated highly with the corresponding true volumes (all r>0.95, P<0.01). But with slice thickness from 2.0 mm to 10.0 mm, MSCT scanning overestimated the corresponding true volume by (3.21±5.95) ml to (12.58±8.56) ml for LV and (10.22±8.45) ml to (23.91±12.24) ml for RV (all P<0.01). There was a very high correlation between the overestimation and the selected slice thickness for both LV and RV volume measurements (r=0.998 and 0.996, P<0.01, respectively). However, when slice thickness was reduced to 5.0 mm, the overestimation for both LV and RV volume measurements became nonsignificant for slice thickness from 2.0 mm to 5.0 mm. Conclusions Both LV and RV volumes can be accurately estimated by MSCT. Thinner slice has more accurate calculated volume. However, 5.0 mm slice thickness is thin enough for an accurate measurement of LV or RV volume.

MSCTE和MSCTA联合运用在小肠梗阻病因诊断中的价值

目的探讨多层CT小肠造影(MSCTE)和多层CT血管造影(MSCTA)联合运用在小肠梗阻病因诊断中的价值。方法回顾性分析57例行MSCTE和MSCTA检查,并经过手术和病理检查证实为小肠梗阻患者的影像学资料。使用Siemens Somatom Sensation 64层螺旋CT进行检查,经过后处理方法[多平面重建(MPR)、最大密度投影(MIP)、容积再现技术(VRT)、曲面重建法(CPR)],分析其图像在小肠梗阻病因诊断中的作用。结果所有病例中,肿瘤15例,粘连14例,腹外疝8例,炎症6例,内疝或扭转5例,肠套叠3例,胆石或粪石4例,血管性2例。组Ⅰ:常规横断位结合MPR、CPR对病因诊断的准确性为89.5%(51/57);组Ⅱ:常规横断位结合MPR、CPR和CTA技术(VRT、MIP)对病因诊断的准确性为94.7%(54/57);组Ⅱ的诊断准确性明显高于组Ⅰ(P<0.05)。结论 MSCTA和MSCTE的联合运用可以明显提高小肠梗阻病因诊断的准确性,具有较高的临床应用价值。

肺硬化性血管瘤的MSCT诊断

目的:探讨肺硬化性血管瘤的MSCT表现特点,以期提高影像诊断准确率。方法:回顾性分析19例经手术及病理证实的肺硬化性血管瘤的患者资料,女性18例,男性1例,平均年龄为52.5岁;采用16层螺旋CT扫描仪,120kV,160 mAs,层厚5mm,层间距5mm,高压团注非离子型对比剂100ml(300mg/ml)增强扫描,流速2.5ml/s,延迟30s扫描,回顾性1.5mm薄层重建及多平面重组(MPR)分析。结果:全部为单发实性类圆形肺结节或肿块,最大径67mm,平均直径23mm,分布无偏向性,边界清晰。8例(42.1%)见斑点状钙化灶,4例(21.1%)见分叶征,3例(15.8%)见空气新月征,4例(21.1%)病灶跨叶间胸膜生长,1例(5.26%)见胸膜牵拉凹陷,8例(80%)增强CT扫描均显示贴边血管征。结论:肺硬化性血管瘤多见于中年女性,表现为肺内单发结节或肿块,MSCT表现有一定的特点,病灶可跨叶间裂生长,明显强化及贴边血管征有助于本病的诊断。

MSCT诊断先天性肺静脉异位引流临床价值

目的评价多排螺旋CT(MSCT)血管造影在先天性肺静脉异位引流中的临床价值。方法收集2005年至2009年94例MSCT诊断的肺静脉异位引流患者,其中78例经手术证实,(男性40例,女性38例)进行回顾性分析,并将CT诊断结果与术后诊断对照。结果 78例行手术治疗的肺静脉异位引流病例中,完全性肺静脉异位引流者共29例,其中心上型7例、心脏型14例、心下型3例、混合型5例;部分性肺静脉异位引流者共49例。与术后诊断相比,诊断正确符合率100%。结论 MSCT诊断肺静脉异位引流具有极高的诊断准确率,是一种很好的无创检查方法,一次检查不仅解决心内结构连接异常外,还可同时了解合并畸形或其它并发症的诊断问题,对外科医师的手术处理有良好的指导作用。

膝骨关节炎MSCT、MRI的影像学特征及联合应用的诊断价值

目的探讨膝骨关节炎多层螺旋计算机断层扫描(MSCT)、磁共振成像(MRI)的影像学特征,分析两者联合诊断的效能。方法回顾性分析2017年1月—2018年3月北京市和平里医院接收的疑似膝骨关节炎受检者78例的临床资料,分别实施MSCT、MRI检查。所有受试者行关节镜检查明确膝骨关节炎的发生情况,将其作为"金标准"。总结MSCT、MRI的影像学表现,绘制受试者工作特征(ROC)曲线,分析不同方法的诊断效能。结果全组受试者中共有102膝确诊为膝骨关节炎,MSCT、MRI诊断该病均有典型的特征;MSCT、MRI、两者联合诊断膝骨关节炎的敏感性分别为86.27%(95%CI:0.786,0.897)、95.10%(95%CI:0.824,0.959)、98.04%(95%CI:0.855,0.987);特异性分别为77.78%(95%CI:0.712,0.798)、90.74%(95%CI:0.866,0.913)、98.15%(95%CI:0.890,0.985);准确性分别为83.33%、93.89%、98.08%;AUC分别为0.712(95%CI:0.502,0.851)、0.806(95%CI:0.671,0.855)、0.913(95%CI:0.782,0.974)(P<0.05)。联合诊断的敏感性、特异性、准确性和AUC均高于单独诊断。结论MSCT、MRI诊断膝骨关节炎有典型的影像学特征,且两者联合诊断的效能更佳。

MSCT对肠系膜非肿瘤性病变的诊断

目的探讨多层螺旋CT(MSCT)对肠系膜非肿瘤性病变的诊断价值。方法回顾性分析经手术病理及随访观察证实的84例肠系膜非肿瘤性病变的CT表现与诊断,其中72例经穿刺/手术病理证实,其余按照CT标准做出诊断。应用GE LightSpeed Pro 16 CT机进行腹部平扫和双期增强扫描,并采用1.25mm层厚和1mm重建间隔在ADW4.2工作站获取最大密度投影(MIP)和多平面重建(MPR)图像,评价不同病变时肠系膜及其血管及邻近脏器的改变。结果 84例中:肠系膜水肿30例,其中肝硬化所致10例,肾衰所致4例,门脉、肠系膜上静脉栓塞4例,肠系膜上动脉栓塞4例,肠系膜扭转4例,肠系膜上静脉、门脉广泛积气2例,肠脂垂炎2例;炎性渗出34例,其中胆囊炎、阑尾炎、附件炎各6例,胰腺炎、升结肠憩室炎2例,肠系膜脓肿4例,肠穿孔5例,淋巴结炎3例;肠系膜血管挫伤10例,其中4例合并肠破裂;其他病变10例,包括脂肪沉积2例,肠系膜脂膜炎8例。肠系膜非肿瘤性病变的主要MSCT表现:肠系膜密度增高82例,其中弥漫性发布39例,节段性分布43例,表现为肠系膜雾状线条状增高即云雾状肠系膜。肠间隙内积液37例,9例同时伴积气。环绕肠系膜根部的脂肪肿块样改变8例,肠系膜增厚呈缆绳样改变2例,肠系膜旋转4例,肠系膜血管内对比剂缺损8例、积气2例,肠系膜上动脉增粗4例。3例淋巴结炎表现为回盲部多发小结节,边缘模糊。结论常见的肠系膜非肿瘤性病变病种多、表现相近,大部分具有特征性的CT表现,必须结合病史,方可提高定性诊断符合率。

MSCT在齿状突骨折中的诊断价值

目的分析齿状突骨折的CT表现,探讨多层螺旋CT扫描在诊断齿状突骨折中的价值。方法回顾性分析CT确诊的52例齿状突骨折的MSCT资料,包括横断面骨窗、软组织窗及经冠状面、矢状面多平面重建。结果根据骨折部位将齿状突骨折分为三型:Ⅰ型为尖端骨折3例;Ⅱ型为基底骨折35例;Ⅲ型为枢椎椎体部骨折14例。结论MSCT扫描对诊断急性或陈旧性齿状突骨折及确定骨折类型具有重要价值;对于临床上怀疑齿状突骨折,行MSCT扫描是必要的。

儿童肾母细胞瘤的MSCT诊断

目的探讨儿童肾母细胞瘤的MSCT表现特点,以期提高影像诊断准确率。方法回顾性分析45例经手术及病理证实为肾母细胞瘤的患儿资料,男23例,女22例,最小年儿童肾母细胞瘤多见于4岁以下儿童,最小年龄为3个月,最大年龄为11岁,平均2.9岁;采用Philips Brilliance 16,先予平扫,再使用2ml/kg造影剂欧乃派克静脉团注后立即扫描,并行多平面重建(MPR)及最大密度投影(MIP)重建。结果全部为密度不均匀肿块,单侧多见,上极多于下极,肿瘤不均匀强化,常伴坏死、出血,少数有钙化;残存肾呈新月形强化为典型CT表现,肿块可跨过中线,但不包绕腹膜后大血管;腹膜后、膈脚后淋巴结转移最多见。MPR、MIP重建可清晰显示血管受累情况。结论儿童肾母细胞瘤多见于4岁以下儿童,MSCT表现有一定的特点,肿瘤呈不均匀强化,残存肾呈新月形强化为其典型表现,有助于本病的诊断。

肺癌MSCT灌注成像与病理分型的相关性研究

目的:对肺癌MSCT灌注成像及相关灌注参数进行分析,研究肺癌MSCT灌注成像与病理类型之间的关系,探讨其临床应用价值。方法:对32例肺癌患者,先行常规CT扫描,确定肿瘤的中心层面,然后采用电影技术对肿瘤中心层面进行连续扫描,以获得该层面内组织的时间-密度曲线,计算出血流量(BF)、血容量(BV)、平均通过时间(MTT)、表面渗透性(PS),以此评价肿瘤灌注情况,并与病理分型进行对比分析。结果:中心型肺癌与周围性肺癌各灌注参数均无明显差异(P>0.05)。对各型肺癌的灌注参数进行分析得出:各型肺癌BF、PS值大小关系为鳞癌<腺癌(P<0.05),鳞癌<小细胞癌(P<0.05),腺癌BF、PS值小于小细胞癌但两者之间的差异无统计学意义(P>0.05);各型肺癌BV值大小顺序为鳞癌<腺癌<小细胞癌(P<0.05);各型肺癌MTT值之间无明显差异。结论:肺癌MSCT灌注成像反映各型肺癌血流特点及肿瘤内部微血管密度变化,有利于肺癌病理分型诊断。

先天性冠状动脉瘘超声及64-MSCT诊断

目的:评价超声(US)和64层螺旋CT(64-MSCT)血管造影对先天性冠状动脉瘘(CAF)的诊断价值。方法:回顾性分析7例手术证实冠状动脉瘘的US(7例)和64-MSCT(3例),分析其影像表现及特点。结果:病变均为单侧性(右侧3例,左侧4例),引流入右心肺动脉系统4例,左心3例。征象包括扩大的冠状动脉及其起源、瘘口及注入心腔或大血管腔;US可观察其血流动力学变化,64-MSCT能显示其病变整体、周围结构及钙化。结论:US可作为先天性冠状动脉瘘的常规检查,64-MSCT显示病变全面,可作为补充选择。

MSCT对健康成人肾上腺体积的测量研究

目的探讨MSCT对健康成人肾上腺体积的测量研究。方法选取2013年1月～2014年6月190例健康体检者作为研究对象，采用多层螺旋CT行增强扫描测量。肾上腺体积的大小，着重观察健康成人双侧肾上腺的检出率及其与性别、年龄、体重、身高、血压等参数的关系。结果健康成人双侧肾上腺检出率为100％，左侧平均体积为（2803．18±869．74）mm3，明显大于右侧的（2010．82±726．33）mm3，比较差异有统计学意义（P〈0．05）；男性肾上腺总体积、左侧平均体积、右侧平均体积分别为（5436．91±1576．07）mm3、（3021．48±930．45）mm3、（2448．07±764．95）mm3，均明显大于女性的，（4260．83±1510．34）mm3、（2589．85±880．61）mm3、（1634．90±796．38）mm3，差异有统计学意义（P〈0．05）；双侧肾上腺体积56岁后缩小；肾上腺体积与体重呈正相关，与身高、血压无明显相关性。结论MSCT可简便、准确测量肾上腺体积，是测量肾上腺的有效方法，为肾上腺病变的影像学诊断提供可靠依据，值得临床推广使用。

对比剂不同注射流速对先天性心脏病新生儿MSCT图像质量的影响

目的探讨先天性心脏病新生儿行多层螺旋CT(MSCT)扫描的最佳对比剂注射流速,以提高MSCT扫描图像质量。方法将80例怀疑先天性心脏病的新生儿随机分为四组,均行MSCT扫描,对比剂注射流速分别设为0.3、0.5、0.7、0.9mL/s。采用Likert 5分制评估图像质量并记录每组患儿血管峰值压力。结果0.3、0.5、0.7、0.9mL/s组注射时分别有0例、1例、5例、9例患儿血管存在渗漏风险,其中0.9mL/s组有2例出现对比剂外渗,四组血管渗漏风险发生率比较,差异有统计学意义(P<0.01)。四组图像质量评分比较,差异有统计学意义(P<0.01);0.3mL/s组显著差于其他三组(均P<0.05);其他三组组间比较,差异无统计学意义(均P>0.05)。结论随着注射流速的增加,图像质量逐步提高,但血管安全性逐步降低,临床上可根据新生儿体质量、血管情况及病情严重程度等进行合理选择。