单排螺旋CT三期动态增强扫描对鉴别肝脏占位性病变的意义

目的评价单排螺旋CT三期动态增强扫描在显示肝脏占位性病变的强化形式、特征及鉴别诊断中的意义。方法53例由病理证实的肝脏占位性病变患者,包括27例原发性肝癌,10例肝转移瘤,3例肝胆管细胞癌,5例肝脓肿,以及8例肝血管瘤,均经单排螺旋CT三期动态增强扫描。对所有患者肝脏病变的强化形式与特征进行了回顾性分析。结果单排螺旋CT三期动态增强扫描不仅显示了不同肝脏病变的强化形式与特征,而且对良恶性病变的鉴别有重要意义。例如,原发性肝癌于动脉期大部分为不均匀强化或边缘强化,于门静脉期与延迟期呈低密度。肝转移瘤于动脉期边缘呈环形强化或不强化,于门静脉期与延迟期大部分表现“牛眼征”。肝脓肿于动脉期病灶边缘呈宽带状强化,于门静脉期与延迟期表现为典型“双环征”。结论螺旋CT三期动态扫描对鉴别肝脏良恶性占位性病变起重要作用,且可作为常规方法。     

螺旋CT双期扫描诊断肝细胞癌的价值

目的 探讨螺旋CT双期扫描对肝细胞癌的诊断价值一方法采用西门子Somatom Balanrr高速螺旋CT扫描机，对37例肝细胞癌患者进行螺旋CT双期扫描，高压注射器注射造影剂。全盱平扫后，分别于开始注射造影剂后25s．60s行伞肝螺旋CT动脉、门静脉双期扫描、将螺旋CT扫描结果与普通CT扫描进行对照一其中男26例，女11例。年龄37岁～75岁，平均57．8岁。结果 37例中，动脉期肿瘤明显强化31例、轻度强化6例，动-静脉瘘5例。门静脉期，肿瘤全部呈低密度门静脉瘤栓11例。结论 HCC螺旋CT动脉、门静脉双期增强扫描，病灶强化特征可反映其组织病理学改变的特点，诊断准确性高     

肝脏双期螺旋CT扫描的临床应用价值

目的:研究双期螺旋CT最佳扫描技术及其在肝肿瘤或肝癌探测中的应用。材料与方法:35例无肝肿瘤和17例肝肿瘤患者均经双期螺旋CT行肝脏扫描,于动脉期和门静脉期观察了正常肝脏和肝细胞癌病灶中的CT表现。结果:正常肝脏与肝细胞癌的CT表现有明显不同。在12例肝细胞癌患者中确切看到了14个肝细胞癌病灶,其中13个病灶在动脉期呈高密度,12个病灶在门静脉期呈低密度,动脉期和门静脉期肝细胞癌的检出率分别为92.8％和85.7％。结论:选择最优化扫描参数,可清晰显示肝细胞癌的增强特点,并显著提高其病变的检出率,因此,双期螺旋CT扫描可当作探测肝肿瘤或肝细胞癌的常规方法。     

螺旋CT双期增强扫描对门静脉癌栓的诊断价值

目的探讨螺旋CT双期增强扫描对门静脉癌栓的诊断价值。方法对21例门静脉癌栓患者行螺旋CT双期增强扫描,观察门静脉癌栓在CT上的表现,并与常规CT表现进行比较。结果所有21例门静脉显示满意,均显示了癌栓所在部位门脉阻塞征象,13例显示了肝门部侧支血管。结论螺旋CT双期增强扫描是诊断门静脉癌栓的有效方法,尤其在显示侧支循环方面有很大优越性。     

原发性肝癌肿瘤边缘螺旋CT肝双期扫描的表现

目的 :探讨原发性肝癌 (PHCC)边缘螺旋CT肝双期扫描表现特点。材料和方法 :回顾性分析 84例经临床、DSA及病理证实的PHCC边缘肝双期扫描表现。结果 :肝癌边缘形态分为四个类型 :( 1)边缘清楚型 ( 19例 ) ,6例肝动脉期边缘见强化肿瘤血管 ,3例门静脉期边缘部分强化 ;( 2 )完整包膜型 ( 14例 ) ,包膜环形强化门静脉期多见 ;( 3)边缘不清型( 2 7例 ) ,2 4例肝动脉边缘见强化肿瘤血管 ,7例门静脉期边缘部分强化 ;( 4 )混合型 ( 2 4例 )。结论 :螺旋CT肝双期扫描可较好显示PHCC边缘形态特点及血供 ,对了解其生物学特性、介入治疗效果预测有一定临床价值。     

肝内胆管细胞癌的多层螺旋CT诊断价值

目的:探讨肝内胆管细胞癌的CT表现,加深对肝内胆管细胞癌的认识。方法:回顾性分析14例经病理证实的肝内胆管细胞癌的CT影像学表现。结果:14例中8例边界模糊的类圆形低密度肿块,11例伴肝内胆管扩张,6例边界较清晰。增强扫描8例早期肿块周边呈不规则强化;4例周边呈环形或结节状明显强化;2例无明显强化;延时扫描所有病灶均延迟强化。结论:多层螺旋CT扫描显示肝内胆管细胞癌有一定的特征性,具有较高的诊断价值。     

肝脓肿的多层螺旋CT表现及临床价值(附20例分析)

目的　探讨肝脓肿在多层螺旋CT(MSCT)双期或 /和三期 (动脉期、门静脉期、延迟期 )增强扫描的表现及临床价值 ,特别是在动脉期的表现。方法　观察 2 0例经手术或穿刺证实的肝脓肿在多层螺旋CT双期或 /和三期扫描在动脉期与门静脉期的CT表现 ,特别是在动脉期的表现。动脉期是在注射造影剂后 2 5s开始扫描 ,门静脉期是 65s开始扫描 ,延迟是 5min开始扫描 ,每期全肝扫描所用时间为 8～ 10s。结果　 ( 1)动脉期表现 :肝内低密度或略低密度灶周围肝组织强化明显 ,而病灶本身或边缘无明显强化或轻度强化。 ( 2 )门静脉期表现 :a、环靶征 ;b、环状征 ;C、花瓣征 ;d、分房状征。 ( 3)延迟期表现 :病灶缩小或不变 ,水肿带消失或模糊。结论　多层螺旋CT双期或三期扫描充分反映了肝脓肿的病理变化 ,对早期诊断肝脓肿及鉴别诊断有重要价值     

乳头型壶腹癌螺旋CT双期增强的表现

目的 了解螺旋CT双期增强扫描显示乳头型壶腹癌的CT表现。方法 回顾性分析15例手术病理证实的乳头型壶腹癌的CT表现,螺旋CT采用薄层双期（动脉和门脉）增强扫描,动脉期扫描采用层厚5mm,螺距1．0;门脉期扫描层厚和间隔均为5mm。结果 螺旋CT动脉和门脉增强扫描,15例均清晰显示十二指肠乳头部局限性强化的充盈缺损块影,肿瘤瘤径为1－5cm,平均2．3cm。所有病例均可见虢人胆管扩张、胆囊增大、胆总管扩张和胰腺管的扩张,仅有1例伴胰体尾部的明显萎缩。结论 螺旋CT双期增强扫描不仅能准确确定梗阻的平面,还能显示十一指肠乳头部过来腹癌强化的肿块影,这对诊断乳头型壶腹癌是关键的CT征像。     

16层螺旋CT肝脏多期扫描的方法与实用价值

目的:探讨16层螺旋CT肝脏多期扫描的方法及应用价值。方法:150例疑有肝脏病变的患者行16层螺旋CT多期扫描。层厚7.5mm,螺距1.375,扫描时间0.8s/r,静脉团注对比剂80～120ml,分别延时23～28s、45～50s58～65s行肝动脉期(动脉早期)、门静脉流注期(动脉晚期)和肝静脉期(实质期)扫描,并对图像作回顾性分析,比较增强前后腹主动脉、门静脉、肝静脉的CT值变化和后处理图像显示肝动脉、门静脉、肝静脉的能力。结果:16层螺旋CT肝脏多期扫描,肝脏血管增强后与增强前的密度差在91.9HU以上,VR、MIP、MPR图像上100%显示肝动脉(150/150),门静脉显示率为96.7%(145/150),肝静脉显示率为95.3%(143/150)。5例门静脉显示不清的病例中,3例为肝癌合并肝门区淋巴结转移,1例肝癌合并门静脉癌栓形成,1例为严重肝硬化合并腹水、脾肿大;7例肝静脉显示不清中有5例与门静脉显示不清的5例为相同病例,其余2例为严重肝硬化合并腹水。结论:16层螺旋CT肝脏多期扫描对评估肝脏病变、肝脏血管的正常、变异以及病变对血管的影响有很大帮助,但是对于严重肝硬化门静脉高压、门静脉狭窄、门静脉血栓(包括癌栓)形成的病例,显示门静脉和肝静脉不理想。     

胰岛细胞瘤的螺旋CT诊断(附8例报告)

目的:探讨螺旋CT检查在胰岛细胞瘤诊断中的价值。方法:回顾性对照病理分析8例胰岛细胞瘤平扫加增强扫描的螺旋CT表现。结果:胰岛素瘤7例,直径为1.0~2.0 cm。CT平扫加增强扫描未发现肿瘤1例;6例CT平扫为等密度,增强扫描动脉期为高密度,门静脉期为略高密度。无功能性胰岛细胞瘤1例,直径为7.7 cm,CT平扫为略低密度,双期增强扫描呈周边明显强化,肿瘤内部不均匀略强化。结论:螺旋CT双期增强扫描在胰岛细胞瘤诊断中有较大价值。     

胆管细胞型肝癌的CT诊断

目的探讨CT增强及延迟扫描诊断胆管细胞型肝癌的价值。方法对21例经病理证实的胆管细胞型肝癌做了CT平扫、增强及延迟扫描。结果CT平扫全部病灶为低密度,其中14例为囊性,7例为实质性且病灶内见胆管扩张。增强扫描14例囊性病变中有10例出现病灶边缘不连续的较薄环形增强,3例连续环行强化,门静脉期13例均无变化;1例无增强表现。7例实质性病变在增强1 m in后病灶轻度强化,3~8 m in后病灶出现延迟增强,密度等于或大于同层肝组织,扩张的胆管无变化。结论CT增强扫描囊性病灶边缘连续或不连续的薄环形强化且门静脉期无变化,实质性病灶延迟强化及病灶内胆管扩张是胆管型肝癌的特征性表现。     

Effect of electrocardiogram triggering on reproducibility of coronary artery calcium scoring

PURPOSE: To determine the prevalence of arterioportal shunt associated with hepatic hemangiomas, describe the two-phase spiral computed tomographic (CT) findings, and correlate the presence of arterioportal shunt with the size and rapidity of enhancement of hemangiomas. MATERIALS AND METHODS: The study group consisted of 109 hepatic hemangiomas in 69 patients who underwent two-phase spiral CT during 1 year. CT scans were obtained during the hepatic arterial (30-second delay) and portal venous (65-second delay) phases after injection of 120 mL of contrast material (3 mL/sec). Arterioportal shunts were diagnosed when hepatic arterial phase CT scans showed a wedge-shaped or irregularly shaped homogeneous enhancement in the liver parenchyma adjacent to the tumor and when portal venous phase CT scans showed isoattenuation or slight hyperattenuation, compared with normal liver in that area, and when there was no demonstrable cause of these attenuation differences. The presence of arterioportal shunt in hemangioma was correlated with the size of the tumor and the rapidity of intratumoral enhancement. RESULTS: Arterioportal shunt was found in 28 (25.7%) of 109 hemangiomas. There was no statistically significant relationship between lesion size and presence of the arterioportal shunt (P =.653). Arterioportal shunt was more frequently found in hemangiomas with rapid enhancement (P <.01). CONCLUSION: Arterioportal shunts are not uncommonly seen in hepatic hemangiomas at two-phase spiral CT. Hemangiomas with arterioportal shunts tend to show rapid enhancement.     

肝内胆管癌的螺旋CT表现及病理基础(附20例分析)

目的:探讨肝内胆管癌螺旋CT增强扫描表现与病理学的关系,以及螺旋CT的诊断价值。方法:经手术病理证实的20例肝内胆管癌行常规上腹部平扫和增强扫描,增强扫描在注入对比剂后20s和60s分别行动脉期和门静脉期扫描,另有14例加做4～15min的延迟期扫描,分析肝内胆管癌影像特征和病理基础。结果:病灶肿块型16例,浸润狭窄型2例,胆管内生长型2例。增强早期边缘无强化者6例,边缘强化者14例,延迟增强后内部不均匀强化者8例,均匀强化者2例,无强化者4例。病理学上周边强化是由于肿瘤边缘存在活癌组织,而延迟强化是由于肿瘤中心部分存在丰富的纤维组织。此外螺旋CT还清楚显示了肝内胆管扩张,肝叶萎缩,病灶周围异常强化区等间接现象。结论:肝内胆管癌的CT表现与病理密切相关,早期病灶边缘轻度强化,延迟期中心部强化是诊断肝内胆管癌的重要影像依据。     

Multidetector CT of the liver and hepatic neoplasms: effect of multiphasic imaging on tumor conspicuity and vascular enhancement

OBJECTIVE: Our aim was to determine which of three contrast-enhanced phases (early arterial, late arterial, or portal venous) was optimal for achieving maximal enhancement of the celiac artery, portal vein, and hepatic parenchyma. We also wanted to learn which phase provided the maximal tumor-to-parenchyma difference when using multidetector CT (MDCT) with fixed timing delays. MATERIALS AND METHODS: Fifty-two patients with suspected or known hepatic tumors underwent multiphasic contrast-enhanced MDCT using double arterial (early and late arterial) and venous phase acquisitions with fixed timing delays. All patients were administered 150 mL of IV contrast material at an injection rate of 4 mL/sec. Images were acquired at 20 sec for the early arterial phase, 35 sec for the late arterial phase, and 60 sec for the portal venous phase. Attenuation measurements of the celiac artery, portal vein, normal hepatic parenchyma, and the hepatic tumor were compared. Three reviewers independently and subjectively rated tumor conspicuity for each of the three phases. Ratings were compared using kappa statistics. RESULTS: Late arterial phase images showed maximal celiac axis attenuation, whereas portal venous phase images revealed the highest portal vein and normal hepatic parenchymal attenuation. Maximal tumor-to-parenchyma differences for hypovascular tumors was superior in the portal venous phase, but we found no significant differences in maximal tumor-to-parenchyma differences for hypervascular tumors among the evaluated phases. On subjective analysis, interobserver agreement was moderate to very good for the three phases. All three reviewers graded both hypovascular and hypervascular tumor conspicuity as superior in either the late arterial phase or the portal venous phase in most patients. In only one patient was the early arterial phase graded as superior to the late arterial and portal venous phases (by two of the three reviewers). CONCLUSION: When MDCT of the liver is performed using fixed timing delays, maximal vascular and hepatic parenchymal enhancement is achieved on either late arterial phase or portal venous phase imaging. In most patients, early arterial phase imaging does not improve tumor conspicuity by either quantitative or subjective analysis.     

Hepatic angiomyolipoma: various appearances on two-phase contrast scanning of spiral CT.

The purpose of this study was to describe and analyze the various appearances of hepatic angiomyolipoma (AML) on the two-phase contrast scans of spiral CT and find out the valuable signs suggesting the diagnosis. Spiral CT scanning of pre- and post-contrast arterial phase, portal venous phase were performed in 12 cases. We found that 11 of 12 lesions appeared as hypodense, the other one appeared as slightly hyperdense on pre-contrast CT scans. On the arterial phase, 11 lesions were markedly enhanced, with the central vasculature opacification in eight lesions; the only other lesion showed no marked enhancement, but with massive vessels seen within the lesion. On the portal venous phase, eight lesions remained in enhancement with the central vessels also seen in six lesions. Our results revealed that two-phase contrast scanning could demonstrate some characteristic features of AML, such as fat components within the lesions, hypervascular tumors, the absence of capsule. Especially the central vessels within the lesions suggested strongly the diagnosis of AML. As for atypical cases, the diagnosis remained difficult and should be differentiated from other hypervascular lesions by means of other imaging modalities or needle puncture biopsy.     

多层螺旋CT多期增强扫描及后处理对胰岛素瘤的评价

目的:探讨多层螺旋CT(MSCT)多期扫描及后处理对胰岛素瘤检出的价值。方法:13例手术证实的胰岛素瘤均行MSCT平扫及三期增强扫描,观察各期肿瘤增强程度及检出率。结果:13例CT平扫肿瘤均为等密度,动脉期及门脉期肿瘤与胰腺实质密度差为24HU与29HU,动脉期、门脉期及实质期肿瘤的检出率分别为84%、100%及62%。结论:MSCT多期成像对胰岛素瘤诊断具有重要价值,门脉期在检出肿瘤方面略优于动脉期扫描,MSCT薄层扫描及其后处理技术有助于显示肿瘤的空间位置及其与血管的关系。     

肝脏囊性转移瘤的CT和MR征象的比较

目的:分析肝脏囊性转移瘤在CT和MR上的表现,比较CT和MR检查对囊性转移瘤的临床诊断价值.材料和方法:18例(共52个病灶)肝脏囊性转移瘤中10例行CT平扫和增强门脉期扫描.8例行MR T1WI和FMP-SPGR多期动态增强扫描.观察肿瘤的大小、形态、数目、囊壁和壁结节的强化情况.结果:2例为单发病灶外,其余均为多发病灶.病灶呈类圆形或椭圆形.CT上8例见到囊壁不规则增厚,其中6例可见向囊腔内突起的壁结节,1例内有分隔.2例薄壁且均匀的病灶误诊为肝囊肿.T1WI上,7例为低信号,1例为混杂信号.T2WI上,病灶均为明显高信号,2例信号均匀,6例信号不均匀,可见到壁结节为略低信号.增强动脉期所有病灶均无强化表现,门脉期和延迟期,可见到边缘环形强化和壁结节的强化.也有1例见到分隔.结论:CT和MR均可显示肝脏囊性转移瘤的特征,MR在显示病灶的出血、囊变、分隔和囊壁的情况等比CT更为敏感、可靠,在鉴别诊断方面价值更大.     

螺旋CT双期或三期扫描对肝脏占位性病变的诊断

目的：分析肝脏螺旋CT双期或三期扫描表现，探讨其对原发性肝癌、肝转移瘤、肝血管瘤的诊断及鉴别诊断的意义。方法：经临床证实25例，均作螺旋CT平扫、动脉期、门脉期及部分平衡期和延迟期扫描，并分析螺旋CT多期扫描表现。结果：原发性肝癌动脉期明显强化而肝脏无强化，形成鲜明的对比，门脉期呈相对低密度或恢复到平扫时表现。肝血管瘤CT特征为动脉期呈边缘性环状、结节样强化，门脉期病灶边缘强化向中心强化并充满病灶呈高密度，平衡期呈等密度或低密度肝转移瘤表现多样化，周边强化或不均匀强化或不强化。结论：螺旋CT双期或三期扫描已作为对肝脏占位性病变的主要检查方法，并作为常规。     

Detection of focal liver lesions at biphasic spiral CT: randomized double-blind study of the effect of iodine concentration in contrast materials

PURPOSE: To evaluate the effect of iodine concentration on the detection of focal liver lesions at biphasic spiral computed tomography (CT). MATERIALS AND METHODS: One hundred two patients (64 men, 38 women) with neoplastic (n = 85) and nonneoplastic focal lesions (n = 17) were prospectively assigned to biphasic injection group A or B and received 180 mL of iopromide containing 370 or 300 mg of iodine per milliliter, respectively, during spiral CT. Comparison included assessment of quantitative and qualitative parameters. RESULTS: Hepatic time-attenuation curves and mean hepatic enhancement in the portal venous phase and aortic time-attenuation curves in both arterial and portal venous phases were statistically superior in group A compared with group B. There was no significant difference in the mean enhancement in all lesions in either group. In contrast, among patients with hepatocellular carcinoma, mean contrast enhancement in lesions in the arterial phase was significantly superior in group A compared with group B. Blinded readers classified hepatic attenuation and lesion visibility as very good and as improved significantly more often in group A than in group B. CONCLUSION: A decrease in iodine concentration significantly affects aortic and hepatic contrast enhancement and may impair the detectability of focal liver lesions during biphasic spiral CT.