双能量CT碘定量参数评估肝硬化患者肝脏血流灌注重分布及肝功能的临床价值

【摘要】目的：通过研究肝硬化患者双能量CT碘定量参数肝动脉供血比重碘分数（AIF）及门静脉血流碘含量（PVIC）改变,探讨AIF及PVIC反映肝硬化患者血流灌注分布情况及肝功能的临床价值。方法：选择55例经临床确诊肝硬化患者（研究组）及26例健康者（对照组）,进行上腹部CT扫描,增强动脉期、门静脉期、延迟期为能谱成像（GSI）模式扫描,应用能谱分析软件进行后处理。分别在动脉期、静脉期物质分离碘基图上于肝脏左外叶、左内叶及右叶各取1个直径10mm的ROI,测得ROI的碘浓度均值为增强扫描动脉期碘浓度（Ia）及门静脉期碘浓度（Ip）,计算AIF、PVIC。对肝硬化组及正常对照组AIF、PVIC进行单因素分析,组间均数两两比较;肝硬化组AIF、PVIC分别与肝功能CTP分级评分进行Spearman相关性分析,P<0.05认为差异具有统计学意义。结果：肝硬化组Child-Pugh B级、C级AIF与正常对照组均数差异具有统计学意义（F=68.650,P<0.01）,且Child-Pugh B级、C级AIF均高于正常对照组,分别为 (31.70±5.07)%,(47.74±5.75) % vs (21.06±4.29)%, AIF与肝硬化CTP分级评分呈正相关(r1=0.780,r2=0.848,P<0.01)。肝硬化组Child-Pugh A、B、C级PVIC与正常对照组均数差异均具有统计学意义（F=14.949,P<0.01）,且均低于正常对照组,分别为（1.72±0.51）、（1.37±0.38）、（0.94±0.27）和（2.08±0.54） mg/mL;肝硬化组Child-Pugh A、B、C级PVIC呈逐级递减,差异具有统计学意义（P<0.05）,与肝硬化CTP分级评分呈负相关(r1=-0.608,r2=-0.548,P<0.01)。结论：双能量CT参数AIF及PVIC的改变反映了肝硬化后门静脉对肝脏的血流灌注相对减少,且随肝硬化程度加重而呈逐级递减,Child-Pugh B级、C级出现肝动脉血流灌注增多;AIF及PVIC与肝硬化的临床分级相关,可作为评估肝功能储备状况的参考依据。     

CT能谱成像在诊断肝癌和血管平滑肌脂肪瘤中的价值

目的探讨CT能谱成像在鉴别诊断肝癌和血管平滑肌脂肪瘤中的价值。方法 33例肝脏占位病变患者,其中肝癌25例,血管平滑肌脂肪瘤8例,行宝石CT的能谱扫描模式(GSI)扫描,获得动脉期和门静脉期的能谱系列图像。测量病灶、正常肝组织和腹主动脉的能谱参数,并计算不同能量水平下病灶-肝脏对比噪声比(contrastto noise ratio,CNR),标准化碘浓度(normalized iodine concentration,NIC)和病灶与正常肝组织碘浓度比值(lesion-to-normal hepatic tissue ratio,LNR),对上述结果进行独立样本t检验。结果肝癌和血管平滑肌脂肪瘤的动脉期最佳单能量均为50 keV,门静脉期最佳单能量分别为70 keV、40 keV;动脉期最佳CNR分别为3.60±2.19、9.08±0.56,门静脉期最佳CNR分别为1.78±0.94、1.65±0.32;动脉期NIC分别为(0.26±0.09)mg/ml,(0.59±0.03)mg/ml,门静脉期NIC分别为(0.50±0.15)mg/ml,(0.78±0.03)mg/ml;动脉期LNR值分别为2.98±0.52,5.85±0.43,门静脉期LNR值分别为0.97±0.15,1.36±0.05。肝癌的动脉期和门静脉期NIC和LNR均低于血管平滑肌脂肪瘤。两者两期的NIC、LNR、钙(脂肪)浓度和脂肪(钙)浓度均有统计学差异(P<0.05),但其水(碘)浓度在两期中均无统计学差异(P>0.05)。结论 CT能谱成像的单能量图像、碘基图像和碘物质定量分析对肝癌和血管平滑肌脂肪瘤的检出和鉴别诊断有较大价值。     

能谱CT成像鉴别肺结节性质的初步研究

目的:评价动脉期与静脉期能谱CT鉴别肺结节(≤3cm)性质的应用价值。方法:回顾性分析接受能谱CT双期扫描且经病理证实的肺结节48例,其中恶性结节与良性结节均为24例。分别测量动脉期(AP)和静脉期(VP)碘基物质密度图像上病灶和同层面主动脉的碘含量(IC),并计算两期病灶相对于主动脉的标准化的碘浓度值(NIC)及两期标准化碘含量之差ICD(ICD=NICVP-NICAP)。采用独立样本t检验的方法,比较良、恶性肺结节之间两期NIC及ICD的差异性,评估这些参数定量分析病灶的能力以及鉴别疾病的敏感度和特异度。结果:两期扫描中,恶性结节的两期NIC及ICD均显著高于良性结节:(NICAP0.198±0.038 vs.0.126±0.027,t=7.613,P<0.001;NICVP 0.473±0.118 vs.0.309±0.058,t=6.138,P<0.001;0.275±0.120 vs.0.183±0.051,t=3.469,P=0.002)。当NICAP阈值定为0.157、NICVP阈值定为0.420,ICD阈值定为0.256时,鉴别两组的敏感度及特异度分别为83.3%及87.5%、66.7%及100%、54.2%及100%。结论:能谱CT双期增强扫描可以对良、恶性肺结节的性质进行鉴别,且具有较高的敏感度和特异度及一定的临床应用价值。     

能谱CT定量参数与肺癌临床病理参数关系及对预后的预测价值

目的 探讨能谱CT定量参数与肺癌临床病理参数关系及对预后的预测价值。方法 选取我院肺癌患者82例，根据病理结果82例肺癌患者设为观察组，同期82例肺炎性结节为对照组。检测不同临床病理参数、不同预后患者能谱CT定量参数和CT定量参数对肺癌患者生存率预测价值。结果 观察组NICVP、NICAP、ICD高于对照组，且观察组中病理类型为腺癌、浸润程度为T3+T4、有淋巴结转移患者NICVP、NICAP、ICD高于病理类型为鳞癌、浸润程度为T1+T2、无淋巴结转移患者(P<0.05);Spearman相关性分析可知，NICVP、NICAP、ICD与肺癌患者病理类型、浸润程度、淋巴结转移有关(P<0.05);2年死亡肺癌患者NICVP、NICAP、ICD高于2年生存患者(P<0.05);Logistic回归分析发现，NICVP、NICAP、ICD为2年死亡患者重要危险因素(P<0.05);绘制ROC曲线显示，NICVP、NICAP、ICD联合预测肺癌患者2年死亡的敏感度为80.95%,特异度为82.50%。结论 肺癌患者的能谱CT定量参数NICVP、NICAP、ICD较肺炎...     

能谱CT评估肝硬化食管静脉曲张程度的价值研究

目的 通过能谱CT碘基值与胃镜下食管静脉曲张(EV)程度进行比较,探讨能谱CT碘基值能否评估EV程度及出血风险,为临床治疗提供重要参考价值.方法 42例肝硬化患者分别进行能谱CT扫描及胃镜检查,分别记录动脉期、静脉期肝左叶、肝右叶、尾状叶、腹主动脉、门静脉、胃左静脉碘基值及胃镜下EV程度.胃镜下无、轻度EV为曲张非严重组,中、重度EV为曲张严重组.比较肝硬化组不同肝功能分级之间及胃镜下EV不同组别之间动/静脉期标准化碘浓度(A/VNIC)、胃左静脉指数(LGI)差异.绘制ROC曲线.结果 肝硬化Child-C级的ANIC较Child-A、B级高,分别为(0.09±0.04)、(0.05土0.02).胃镜下EV严重组较非严重组VNIC低,分别为(0.36±0.04)、(0.42±0.07);LGI高,分别为(1.04±0.16)、(0.76±0.31).胃镜下严重胃底静脉曲张(GV)组较非严重曲张组LGI高,分别为(1.04±0.10)、(0.89±0.29).出血组较未出血组VNIC低,分别为(0.36±0.04)、(0.42±0.08);LGI高,分别为(1.02±0.17)、(0.76 ±0.32).LGI临界值为0.86时,ROC曲线下面积为0.84,诊断严重EV敏感性为92％,特异性为80％.LGI临界值为0.95时,ROC曲线下面积为0.73,诊断严重GV敏感性为92％,特异性为62％.结论 能谱CT胃左静脉指数可以用来评估EV程度及出血风险,进而减少频繁地胃镜随访,为临床治疗提供重要的参考价值.     

能谱CT在预测肝硬化门脉高压食管静脉曲张出血风险的应用

＿目的：通过能谱CT探讨肝硬化门脉高压血流动力学改变来预测食管静脉曲张出血风险。方法：41名肝硬化患者行能谱CT扫描,分别记录肝左叶、肝右叶、肝尾状叶、脾脏、门静脉、胃左静脉碘基值,门静脉主干及脾静脉主干内径,比较门脉高压组（门静脉内径≥15 mm或脾静脉内径≥10 mm）与非门脉高压组（门静脉内径＜15 mm或脾静脉内径＜10 mm）、CT下食管静脉曲张组与未曲张组、出血组与未出血组之间能谱参数差异。将出血组与未出血组的能谱参数绘制ROC曲线,选取截点,确定能谱参数对出血风险的诊断价值。结果：胃左静脉指数 GLI （胃左静脉碘基值／门静脉碘基值）与脾静脉主干内径呈正相关（r＝0．358,P＝0．035）。CT下食管静脉曲张组GLI（0．99±0．26）较未曲张组高（0．78±0．22）,P＝0．02。出血组GLI （1．01±0．21）较未出血组高（0．83±0．28）,P＝0．037。GLI临界值为0．87时曲线下面积为0．71,诊断出血风险的敏感性82．4％,特异性65％。结论：胃左静脉指数可以作为预测食管静脉曲张出血风险指标。     

CT能谱成像在鉴别小肝癌和小血管瘤中的价值

目的 探讨CT能谱成像在鉴别小肝癌和小血管瘤中的应用价值.方法 60例肝脏占位病变患者,其中小肝癌(small hepatocellular carcinoma,SHCC)30例,肝小血管瘤(small hepatic hemangioma,SHH)30例,均行宝石CT双能量扫描,获得动脉期(arterial phase,AP)和门脉期(portal venous phase,PP)的能谱系列图像.测量病灶、正常肝组织和腹主动脉的能谱参数,并计算不同能量水平下病灶-肝脏对比噪声比(contrast to noise ratio,CNR),标准化碘浓度 (normalized iodine concentration,NIC)和病灶与正常肝组织碘浓度比值 (lesion-to-normal hepatic tissue ratio,LNR),对上述结果 进行独立样本t检验.结果 小肝癌和小血管瘤的动脉期最佳单能量均为50 keV,门脉期最佳单能量分别为70 keV、50 keV;动脉期最佳CNR分别为3.58± 2.12、10.03±2.72,门脉期最佳CNR分别为1.79±0.92、3.08±2.38;动脉期NIC分别为(0.25±0.08) mg/mL,(0.46±0.18) mg/mL,门脉期NIC分别为(0.52±0.15) mg/mL和(0.87±0.25) mg/mL;动脉期LNR值分别为2.97±0.50,6.01±2.29,门脉期LNR值分别为0.98±0.18,1.58±0.38.小肝癌的动脉期和门脉期NIC和LNR值均低于小血管瘤.两者2期的NIC、LNR、钙(脂肪)浓度和脂肪(钙)浓度均有统计学差异(P<0.05),但其水(碘)浓度在2期中均无统计学差异(P>0.05).结论 CT能谱成像的单能量图像、碘基图像和碘物质定量分析对小肝癌和小血管瘤的检出和鉴别诊断有价值.     

CT能谱成像对肝脏局灶性病变鉴别诊断价值的初步研究

目的 初步探讨能谱CT对常见肝脏局灶性病变的诊断和鉴别的临床应用价值.方法 51例肝脏局灶性病变患者,其中肝癌18例,单发微小转移瘤4例,异型增生结节(大再生结节)3例,单发肝脏小囊肿7例,血管瘤12例(18处病灶),肝脓肿5例,血管平滑肌脂肪瘤2例.均采用宝石能谱成像(GSI)模式扫描,获得平扫、动脉期、门静脉期的70 keY单能量图像和碘基、水基图像,利用GSI分析功能,观察不同肝脏占位性病变各期的能谱衰减曲线特点及基物质含量,比较不同局灶性病变间各期的碘基值、水基值及能谱曲线斜率[能谱曲线斜率=(HU40keV-HU90keV)/50]的差异,分别行独立样本t检验.结果 肝脏小囊肿斜率(1.20±0.50)与血管平滑肌脂肪瘤斜率(-1.40±0.62)因具有特异的组织构成,平扫即表现出特征性能谱曲线;肝血管瘤边缘部分碘含量在动脉期[(37.3±11.8) mg/mL]、门静脉期[(39.2±16.4) mg/mL]均高于小肝癌(15.8±7.3和23.6±4.5)、肝脓肿[(13.2±4.9) mg/mL和(21.9±10.2) mg/mL]和肝微小转移瘤[(9.5±7.2) mg/mL和(25.0±8.3) mg/mL];肝癌动脉期碘含量[(15.8±7.3 mg/mL]、能谱曲线斜率(2.14±0.92)高于异型增生结节(10.8±3.2和1.15±0.53),上述参数差异均具有统计学意义(P＜0.05).结论 通过CT能谱成像的能谱曲线、碘基含量可以反映肝脏局灶性病变的特有组织成分和血供特点,有助于肝脏局灶性病变的鉴别诊断.     

CT能谱成像在胰岛素瘤诊断中的初步研究

目的:探讨CT能谱成像分析在胰岛素瘤诊断中的价值。方法:回顾性分析采用能谱CT能谱模式双期增强扫描并经手术病理证实的30例胰岛素瘤患者的病例资料。分别采用70keV单能图像、碘基图像和最佳keV能量图像进行重建,比较不同图像模式下胰岛素瘤的检出率和病灶的对比噪声比(CNR)。结果:本组胰岛素瘤动脉期和门静脉期70keV单能图像、最佳keV能量图像和碘基图像上CNR分别为3.18±2.21、3.77±2.37、3.13±2.18和1.77±1.25、2.20±1.38、1.87±1.08。配对t检验结果显示,70keV单能图像、最佳keV能量图像和碘基图的CNR,动脉期图像均明显优于门静脉期(t=3.139,P=0.005;t=3.196,P=0.004;t=3.05,P=0.003)。动脉期最佳keV能量图像上病灶CNR大于70keV单能量图像;动脉期和门静脉期70keV能量、最佳keV能量图像、碘基图、能谱多参数图像对胰岛素瘤的检出率分别为73.3%(22/30)、86.7%(26/30)、86.7%(26/30)、96.7%(29/30)和53.3%(16/30)、73.3%(22/30)、73.3%(22/30)、76.7%(23/30)。结论:在诊断胰岛素瘤方面,不同能谱扫描模式下动脉期图像均优于门静脉期,最佳keV能量图像和碘基图优于70keV单能量图像。能谱CT多参数图像联合应用有利于提高对胰岛素瘤的诊断准确性。     

Spectral CT imaging in preoperative diagnosis of pancreatic insulinoma:a preliminary study

目的:探讨CT能谱成像分析在胰岛素瘤诊断中的价值.方法:回顾性分析采用能谱CT能谱模式双期增强扫描并经手术病理证实的30例胰岛素瘤患者的病例资料.分别采用70 keV单能图像、碘基图像和最佳keV能量图像进行重建,比较不同图像模式下胰岛素瘤的检出率和病灶的对比噪声比(CNR).结果:本组胰岛素瘤动脉期和门静脉期70 keV单能图像、最佳keV能量图像和碘基图像上CNR分别为3.18±2.21、3.77±2.37、3.13±2.18和1.77±1.25、2.20±1.38、1.87±1.08.配对t检验结果显示,70 keV单能图像、最佳keV能量图像和碘基图的CNR,动脉期图像均明显优于门静脉期(t=3.139,P=0.005;t=3.196,P=0.004;t=3.05,P=0.003).动脉期最佳keV能量图像上病灶CNR大于70 keV单能量图像;动脉期和门静脉期70 keV能量、最佳keV能量图像、碘基图、能谱多参数图像对胰岛素瘤的检出率分别为73.3％(22/30)、86.7％(26/30)、86.7％(26/30)、96.7％(29/30)和53.3％(16/30)、73.3％(22/30)、73.3％(22/30)、76.7％(23/30).结论:在诊断胰岛素瘤方面,不同能谱扫描模式下动脉期图像均优于门静脉期,最佳keV能量图像和碘基图优于70 keV单能量图像.能谱CT多参数图像联合应用有利于提高对胰岛素瘤的诊断准确性.     

能谱CT碘参数在不同分化胃腺癌中的诊断价值

目的 探讨能谱CT碘参数在定量评价低分化胃腺癌中的诊断价值.方法 收集经手术病理证实且术前均行双期能谱扫描(GSI)的61例中低分化腺癌患者;所有图像重建后经GSI viewer软件分别测量双期病变和同层主动脉的CT值、碘基值(IC)、水基值(WC)及病变的平扫CT值,并计算病变双期的标准化碘浓度(NIC)及强化率(CER);采用独立样本t检验对数据进行统计学分析,并绘制受试者工作特征(ROC)曲线评估相应参数的诊断效能.结果 中分化和低分化腺癌的IC值(100 μg/cm3)动脉期分别为8.73±4.05和11.07±4.80,静脉期分别为16.89±4.89和21.18±5.96;NIC值动脉期分别为0.10±0.06和0.13±0.06,静脉期分别为0.38±0.10和0.49±0.12,即中分化腺癌组双期的IC值及NIC值均低于低分化腺癌组,但仅静脉期IC值及NIC值差异有统计学意义(tIC静=2.87, PIC静=0.01;tNIC静=3.38, PNIC静<0.01),而中分化腺癌与低分化的双期WC及强化率差异均无统计学意义(P均>0.05).结论 能谱CT碘参数在术前定量评估中分化与低分化胃腺癌中有一定的诊断价值,即碘参数在一定程度上可反映胃腺癌的分化程度.     

双源CT双能量技术鉴别甲状腺良恶性结节的临床应用研究

目的 探讨双源CT能量成像在鉴别甲状腺良恶性结节中的临床应用价值.方法 收集91例经双源CT双能量扫描的甲状腺结节患者,获得单能量40~190 keV图像及碘图,计算线性融合图像与各单能量图像对比噪声比(CNR),测量动静脉期良恶性结节各单能量图像CT值、碘图正常甲状腺、结节、同层面颈动脉碘浓度值,绘制良恶性结节CT值衰减趋势图,计算曲线斜率、正常甲状腺与甲状腺结节内碘浓度差异(ICD)、碘浓度差异比(ICDNR)、标准化碘浓度比(NIC),采用配对样本t检验并绘制受试者工作特征(ROC)曲线比较上述定量参数值诊断恶性结节效能.结果 动、静脉期甲状腺结节在不同能量水平下CNR均有统计学差异(P<0.0001),动脉期最佳CNR在70 keV为11.61±1.71,静脉期最佳CNR在60 keV为10.55±1.09;良恶性结节动脉期单能谱曲线斜率(λ)分别为1.66±0.48,3.31±1.33,ICD分别为(2.83±1.23)mg/mL,(2.10±0.98)mg/mL,ICDNR分别为0.50±0.23,0.38±0.27,差异均有统计学意义(F=-89.43,4.036,2.791,P均<0.05),λ恶性结节大于良性,ICD及ICDNR良性结节大于恶性;静脉期曲线斜率分别为3.85±2.47,1.24±1.26,NIC分别为0.57±0.32,0.39±0.13,差异有统计学意义(F=8.651,4.893,P均<0.05),均良性结节大于恶性;动脉期ICDNR曲线下面积(AUC)最大为0.913,诊断敏感度为100%,特异度为87.5%.结论 动、静脉期分别采用70 keV及60 keV单能量图像可提高甲状腺结节检出率,能量相关定量参数值对良恶性结节鉴别诊断有较大临床应用价值.     

Dual energy spectral CT imaging for the evaluation of small hepatocellular carcinoma microvascular invasion

ObjectiveTo study the clinical value of dual-energy spectral CT in the quantitative assessment of microvascular invasion of small hepatocellular carcinoma.MethodsThis study was approved by our ethics committee. 50 patients with small hepatocellular carcinoma who underwent contrast enhanced spectral CT in arterial phase (AP) and portal venous phase (VP) were enrolled. Tumour CT value and iodine concentration (IC) were measured from spectral CT images. The slope of spectral curve, normalized iodine concentration (NIC, to abdominal aorta) and ratio of IC difference between AP and VP (RIC_AP–VP: [RIC_AP–VP = (IC_AP−IC_VP)/IC_AP]) were calculated. Tumours were identified as either with or without microvascular invasion based on pathological results. Measurements were statistically compared using independent samples t test. The receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of tumours microvascular invasion assessment. The 70 keV images were used to simulate the results of conventional CT scans for comparison.Results56 small hepatocellular carcinomas were detected with 37 lesions (Group A) with microvascular invasion and 19 (Group B) without. There were significant differences in IC, NIC and slope in AP and RIC_AP–VP between Group A (2.48 ± 0.70 mg/ml, 0.23 ± 0.05, 3.39 ± 1.01 and 0.28 ± 0.16) and Group B (1.65 ± 0.47 mg/ml, 0.15 ± 0.05, 2.22 ± 0.64 and 0.03 ± 0.24) (all p < 0.05). Using 0.188 as the threshold for NIC, one could obtain an area-under-curve (AUC) of 0.87 in ROC to differentiate between tumours with and without microvascular invasion. AUC was 0.71 with CT value at 70 keV and improved to 0.81 at 40 keV.ConclusionDual-energy Spectral CT provides additional quantitative parameters than conventional CT to improve the differentiation between small hepatocellular carcinoma with and without microvascular invasion.Clinical Application/RelevanceQuantitative iodine concentration measurement in spectral CT may be used to provide a new method to improve the evaluation for small hepatocellular carcinoma microvascular invasion.     

Spectral CT: Preliminary Studies in the Liver Cirrhosis

Objective

To investigate the value of spectral CT imaging in the diagnosis and classification of liver cirrhosis during the arterial phase (AP) and portal venous phase (PVP).

Materials and Methods

Thirty-eight patients with liver cirrhosis (Child-Pugh class A/B/C: n = 10/14/14), and 43 patients with healthy livers, participated in this study. The researchers used abdominal spectral CT imaging during AP and PVP. Iodine concentration, derived from the iodine-based material-decomposition image and the iodine concentration ratio (IC_ratio) between AP and PVP, were obtained. Statistical analyses {two-sample t test, One-factor analysis of variance, and area under the receiver operating characteristic curve (A [z])} were performed.

Results

The mean normalized iodine concentration (NIC) (0.5 ± 0.12) during PVP in the control group was significantly higher than that in the study group (0.4 ± 0.10 on average, 0.4 ± 0.08 for Class A, 0.4 ± 0.15 for Class B, and 0.4 ± 0.06 for Class C) (All p < 0.05). Within the cirrhotic liver group, the mean NIC for Class C during the AP (0.1 ± 0.05) was significantly higher than NICs for Classes A (0.1 ± 0.06) and B (0.1 ± 0.03) (Both p < 0.05). The IC_ratio in the study group (0.4 ± 0.15), especially for Class C (0.5 ± 0.14), was higher than that in the control group (0.3 ± 0.15) (p < 0.05).The combination of NIC and IC_ratio showed high sensitivity and specificity for differentiating healthy liver from cirrhotic liver, especially in Class C cirrhotic liver.

Conclusion

Spectral CT Provides a quantitative method with which to analyze the cirrhotic liver, and shows the potential value in the classification of liver cirrhosis.     

正常肝脏双源CT双能量扫描碘含量及能谱曲线测量的研究

目的探讨正常肝脏碘含量及能谱曲线特征,建立正常肝脏碘含量及能谱曲线斜率参考值。方法对133例非器质性病变患者行双源CT双能量增强扫描,将扫描获得的数据上传至工作站进行后处理及分析,测量肝脏、腹主动脉含碘值,并计算标化含碘值(NIC)及能谱曲线斜率。结果正常肝脏在门脉期的NIC值及能谱曲线斜率分别为0.44±0.06和1.44±0.25;不同年龄、不同性别组间正常肝脏NIC值及能谱曲线斜率的差异均无统计学意义(P>0.05)。结论双源CT双能量扫描可获得正常肝脏碘含量及能谱曲线,可为肝脏疾病的诊断提供参考。     

CT 能谱成像定量评估胃癌 Lauren 分型的应用价值

目的：探讨 CT 能谱成像(GSI)定量评估胃癌 Lauren 分型的价值。方法对52例胃镜确诊胃癌的患者于术前行 CT GSI 增强扫描,通过 GSI Viewer 分析软件获得单能量图、碘基图,测得病灶的 CT 值、碘浓度,计算标准化碘浓度比,并与术后病理对照,采用单因素方差分析多重比较进行统计学分析。结果肠型、混合型、弥漫型胃癌的动脉期碘浓度、标化碘浓度比、40~70 keV、40~140 keV、70~140 keV 各能量区间能谱曲线斜率分别为12.86±6.80(100μg/mL)、0.13±0.06、2.50±1.26、0.99±0.51、0.34±0.20,18.54±6.49(100μg/mL)、0.19±0.07、3.56±1.24、1.42±0.50、0.50±0.18和24.52±9.68(100μg/mL)、0.24±0.09、4.73±1.76、1.90±0.73、0.68±0.29。其中,肠型胃癌的各组数值均明显低于弥漫型胃癌,2组间差异有统计学意义(P <0.05);肠型-混合型、混合型-弥漫型两两比较,除肠型-混合型碘浓度比 P 值为0.037,其余各指标组间差异均无显著性(P >0.05)。结论GSI 能谱曲线斜率、碘浓度、标准化碘浓度比有助于术前评估胃癌的 Lauren 分型。     

不同病理类型甲状腺恶性肿瘤的能谱参数初步研究

目的分析不同病理类型的甲状腺恶性肿瘤的影像表现及能谱参数。方法回顾性分析67例甲状腺恶性肿瘤的形态学表现及能谱参数。采用Discovery CT750HD CT扫描机能谱模式扫描,在最佳单能量影像上对病灶进行形态学征象分析。应用能谱分析与测量软件对不同病理类型病灶的碘含量(IC)、水含量(WC)、标化碘含量(NIC)、能谱曲线斜率(K)等参数进行计算和分析,采用单因素方差分析对不同病理类型的病灶能谱参数进行比较,组间多重比较采用LSD-t法。结果甲状腺恶性肿瘤形态学表现为单发57例(85.1%),形态不规则46例(68.7%),边界不清楚45例(67.2%),密度不均匀48例(71.6%),21例(31.3%)可见钙化灶。不同病理类型的甲状腺恶性肿瘤的病灶WC间差异无统计学意义(P0.05)。乳头状癌、滤泡癌、髓样癌的IC、NIC及K值均高于未分化癌和淋巴瘤(P0.05)。结论不同病理类型甲状腺恶性肿瘤形态学表现及能谱参数有一定差异,了解其差异有助于该类病变的诊断及鉴别诊断。     

The evaluation of haemodynamics in cirrhotic patients with spectral CT

Objective:

To evaluate haemodynamics in cirrhotic patients with portal hypertension using spectral CT imaging.

Methods:

118 cirrhotic patients with portal hypertension were included in the study group (further divided into Child–Pugh A, B and C subgroups). The control group consisted of 21 subjects with normal liver functionality. All subjects underwent three-phase spectral CT scans. Material decomposition images with water and iodine as basis material pairs were reconstructed. The iodine concentrations for the hepatic parenchyma in both arterial and portal venous phases were measured. The arterial iodine fraction (AIF) was obtained by dividing the iodine concentration in the hepatic arterial phase by that in the portal venous phase. AIF values from the study and control groups were compared using analysis of variance and between subgroups using a post-hoc test with Bonferroni correction, with a statistical significance of p<0.05.

Results:

The AIF was 0.25±0.05 in the control group, and 0.29±0.10, 0.37±0.12 and 0.43±0.14 in the study group with Child–Pugh Grades A, B and C, respectively. The difference in AIF between the control and study groups was statistically significant. The differences were statistically significant between the subgroups with multiple comparisons except between the control group and the Child–Pugh A group (p=0.685).

Conclusion:

AIF measured in spectral CT could be used to evaluate the liver haemodynamics of cirrhotic patients.

Advances in knowledge:

The AIF, provided by spectral CT, could be used as a new parameter to observe liver haemodynamics.Portal hypertension in patients with hepatic cirrhosis usually leads to changes in not only liver morphology but also liver perfusion and haemodynamics [1]. At present, a CT liver perfusion scan is one of the imaging means to obtain liver haemodynamics. Perfusion parameters, such as liver blood volume, blood flow (BF), mean transit time (MTT) and hepatic perfusion index (HPI), can be obtained by perfusion scans using the cine mode or dynamic shuttle mode and mathematic calculations [2–4]. Liver haemodynamic changes in cirrhotic patients with portal hypertension can be detected by calculating the liver perfusion parameters, including decreasing liver BF and increasing liver HPI, that are related to decreased liver function [1,5].However, some drawbacks of CT liver perfusion scan limit its clinical usefulness. Many patients cannot endure the long breath-hold time necessary for perfusion scans. As a result, motion artefacts often occur [6–8]. Another concern is the relatively high radiation dosage involved in cine scans [9–11]. As a substitutional method for obtaining CT liver perfusion parameters, an arterial enhancement fraction (AEF) parameter was calculated from a simulated multiphasic liver CT by Kim et al [12], which was found to correlate strongly with HPI measured with perfusion CT.Recently, a new CT scanning mode, the spectral CT mode, was introduced. This scanning mode is based on the single tube fast switching between low (80 kV) and high (140 kV) energy data sets. Spectral CT produces both monochromatic and material decomposition image sets [13]. One of the properties of spectral CT is that it enables accurate assessment of the concentration of certain materials, such as iodine, the active ingredient of contrast medium, in tissues or tumours [14]. The liver has two sets of blood systems, the hepatic artery and the portal vein blood supply. In contrast-enhanced CT, liver density changes in the hepatic arterial and portal venous phases reflect the hepatic artery and portal vein perfusion. A previous study using an animal model has indicated that there is a close correlation between liver blood perfusion parameters HPI and the iodine concentration ratio in the hepatic arterial and portal venous phases in the hepatic parenchyma [hepatic arterial iodine fraction(AIF)] after contrast injection [15]. The objective of this study was to compare the AIF obtained in spectral CT imaging of cirrhotic patients with portal hypertension to that of the control group with normal liver functionality and to evaluate the possibility of estimating the liver haemodynamics of cirrhotic patients using the AIF.     

Hepatocellular carcinoma and focal nodular hyperplasia of the liver: differentiation with CT spectral imaging

Objectives

To investigate the value of CT spectral imaging in differentiating hepatocellular carcinoma (HCC) from focal nodular hyperplasia (FNH) during the arterial phase (AP) and portal venous phase (PP).

Methods

Fifty-eight patients with 42 HCCs and 16 FNHs underwent spectral CT during AP and PP. The lesion–liver contrast-to-noise ratio (CNR) at different energy levels, normalised iodine concentrations (NIC) and the lesion–normal parenchyma iodine concentration ratio (LNR) were calculated. The two-sample t test compared quantitative parameters. Two readers qualitatively assessed lesion types according to imaging features. Sensitivity and specificity of the qualitative and quantitative studies were compared.

Results

In general, CNRs at low energy levels (40–70 keV) were higher than those at high energy levels (80–140 keV). NICs and LNRs for HCC differed significantly from those of FNH: mean NICs were 0.25 mg/mL?±?0.08 versus 0.42 mg/mL?±?0.12 in AP and 0.52 mg/mL?±?0.14 versus 0.86 mg/mL?±?0.18 in PP. Mean LNRs were 2.97?±?0.50 versus 6.15?±?0.62 in AP and 0.99?±?0.12 versus 1.22?±?0.26 in PP. NICs and LNRs for HCC were lower than those of FNH. LNR in AP had the highest sensitivity and specificity in differentiating HCC from FNH.

Conclusions

CT spectral imaging may help to increase detectability of lesions and accuracy of differentiating HCC from FNH.

Key Points

? CT spectral imaging may help to detect hepatocellular carcinoma (HCC). ? CT spectral imaging may help differentiate HCC from focal nodular hyperplasia. ? Quantitative analysis of iodine concentration provides greater diagnostic confidence. ? Treatment can be given with greater confidence.     

一站式能谱及灌注成像鉴别诊断孤立性肺结节

目的：探讨一站式能谱及灌注成像在孤立性肺结节(SPN)鉴别诊断中的应用价值。方法47例接受一站式能谱及灌注成像且经病理证实为 SPN 患者分为恶性组(28例)、良性组(19例),分别测量肺内病灶的血容量(BV)、血流量(BF)、平均通过时间(MTT)、表面通透性(PS)数值及动、静脉期的碘浓度(IC)、标准碘浓度(NIC)、能谱曲线斜率(40~100 keV)。采用独立样本 t 检验的方法,比较2组各参数间的差异。结果恶性结节的灌注参数 BF、BV、PS 值高于良性结节,有显著性差异(P <0.05),恶性结节 MTT 与良性结节无显著性差异(P>0.05);肺恶性结节动、静脉期 IC、NIC、能谱曲线斜率均高于良性结节,有显著性差异(P<0.05)。结论一站式能谱及灌注成像技术具有实现能谱及灌注成像同时完成的优势,可提供更多参数,在 SPN 鉴别诊断中具有一定应用价值。