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。     

结节型肝细胞癌的螺旋CT多期扫描

目的：描述结节型肝细胞癌的螺旋ＣＴ动脉期、门脉期和延迟期增强特点,比较各期的病灶检出率,重点评价动脉期、延迟期的价值。方法：２６例结节型肝细胞癌病人行螺旋ＣＴ双期、三期动态扫描后,观察病灶的强化方式,统计各期病灶检出数。结果：２６例基于手术病理和影像方法共发现４５ 个病灶,螺旋ＣＴ多期扫描共发现４２个,平扫、肝动脉期、门脉期、延迟期及三期合计的检出率分别为６６．７％ 、８６．７％ 、７１．１％ 、６５．２％ 、９３．３％ 。动脉期检出敏感性明显高于其他各期,三期结合可明显提高对结节型肝癌的检出率。结论：螺旋ＣＴ多期动态扫描能显示肝细胞癌的增强特点,明显提高结节型肝细胞癌的检出敏感性。     

螺旋CT多时相扫描鉴别诊断肝细胞癌和血管瘤

目的:探讨螺旋CT多时相扫描对肝细胞癌和血管瘤的鉴别诊断。材料和方法:对37例患者(肝癌16例,血管瘤21例)行螺旋CT平扫和增强扫描,分析其表现。结果:37例平扫均发现低密度灶。肝细胞癌在动脉期75%有显著增强,呈高密度,在门静脉期和延迟期则呈低密度;血管瘤54%动脉期有典型增强表现,门静脉期100%有增强,24%全部填充,延迟期91%为高密度或等密度。结论:肝细胞癌和血管瘤在螺旋CT多时相增强扫描中,各有其典型的CT表现,两者鉴别的关键是门静脉期。     

螺旋CT对结节型肝细胞癌的多期扫描表现分析

目的：描述结节型肝细胞癌的螺旋CT动脉期、门静脉期和延迟期增强特点,比较各期的病灶的检出率,重点评价动脉期、延迟期的价值。方法：36例结节型肝细胞癌患者行螺旋CT双期、三期动态扫描后,观察病灶的强化方式,统计各期病灶的检出率。结果：36例55个病灶,螺旋CT多期扫描共发现52个,平扫、肝动脉期、门脉期、延迟期及三期合计的检出率分别为70．9％,87．2％、72．7％,68．7％、94．5％。动脉期检出敏感性明显高于其它各期,三期结合可明显提高对结节型肝癌的检出率。结论：螺旋CT多期扫描能显示肝细胞癌的增强特点,明显提高结节型肝细胞癌的检出敏感性。     

肝细胞癌螺旋CT全肝双期动态扫描动脉期、六脉期影像比较

目的：评价螺旋ＣＴ全肝双期动态扫描动脉期、门脉期对肝细胞癌的诊断价值。材料和方法：搜集４３例经活检、手术、血管造影证实的肝细胞癌全肝双期螺旋ＣＴ扫描资料，逐一对比动脉期、门脉期ＣＴｒ影像。结果：①双期扫描动脉期能充分反映肝细胞癌血供特点，瘤灶强化率达８８。４％（３８／４３）。②平扫边缘清楚的肿瘤，双期显示肿瘤边缘部三种形态的包膜。以动脉期显示率最高，③平扫边缘不清的肿瘤，动脉期瘤灶大小与平扫基本符合，门脉期多数有缩小，动脉期能更真实地反映肿瘤范围，④显示肿瘤肝内、外扩散双期优于单期。结论：螺旋ＣＴ全肝双期动态扫描更能全面显示肝细胞癌影像特征并更贴切反映其病理学基础。     

肝细胞癌螺旋CT表现特征与时间窗的相关性研究

目的 探讨肝细胞癌螺旋ＣＴ增强表现及其随时间延迟所致的ＣＴ征象的变化过程。材料与方法 ４１例肝细胞癌患者,其中１３例经手术病理标本证实,其余患者由临床表现和实验室检查诊断。采用Ｓｉｅｍｅｎｓ Ｓｏｍａｔｏｍ Ｐｌｕｓ４Ａ螺旋ＣＴ设备,先作平扫,然后在肿瘤靶平面进行动脉期同层面动态扫描（延迟１４～２１ｓ）、全肝门静脉期扫描（延迟８０～８５ｓ）及病变靶平面平衡期扫描（延迟１７０～２８５ｓ）,着重观察、     

肝细胞癌门静脉癌栓致肝脏灌注异常CT表现

目的：探讨肝细胞癌合并门静脉癌栓致肝脏灌注异常螺旋CT动、门脉双期增强表现特征,以利于准确判断癌灶的范围肝脏血流动力学异常等。材料与方法：1998年4月至2000年7月因肝细胞癌行肝脏螺旋CT动、门脉双期增强扫描的连续性病例245例,随机选择其中门静脉左支、右支或/和主干癌栓的病例共36例作为研究组,并随机选择同期无门静脉癌栓的肝细胞癌36例作为对照组。全肝平扫后,分别于开始注射对比剂后20s、60s行全肝螺旋CT双期扫描。观察平扫、动脉期、门脉期非癌变肝组织、癌灶、门静脉的密度变化。结果：门静脉癌栓发生部位：右支16例,左支4例,右支及主干10列,左、右支及主干6例。动脉期扫描非癌变肝组织高灌注15例,表现为不规则斑片状或三角形均匀性高密度区,门脉期扫描该区域密度与其他部位非癌变肝组织密度一致或略低。门脉期扫描发现异常灌注9例,表现为不规则斑片状或三角形低密度区。结论：门静脉癌栓是引发肝实质灌注异常的重要原因之一,由乙肝病毒感染所致肝硬化较少引起肝实质局灶性灌注异常。螺旋CT动、门脉双期增强扫描,有利于发现肝实质灌注异常、准确判断癌灶的范围。     

螺旋CT肝脏肿瘤早期增强扫描

目的：评价螺旋ＣＴ作肝脏肿瘤早期增强扫描的作用。方法：用螺旋ＣＴ对２５４例肝脏肿瘤患者作全肝早期增强扫描。以２～３ｍｌ／ｓ的速度经肘前静脉注入３００ｍｇＩ／ｍｌ的造影剂９０ｍｌ，在注射造影剂２５～４０ｓ时开始扫描，６０ｓ内扫完全肝。结果：与邻近肝组织相比，１３０例肝细胞性肝癌中有９８例呈高密度；３２例呈等或低密度：早期癌３例、弥漫型４型，病灶直径在１０ｃｍ以上者７例，有明显肝动脉—门静脉瘘者１８例。８７例肝转移瘤中有７４例呈环形增强。３７例海绵状血管瘤中１１处直径小于２ｃｍ病灶呈早期显著增强，较大的病灶呈向心性增强。结论：螺旋ＣＴ作肝脏早期增强扫描可如实显示肿瘤血供和血管受侵的情况，有利于病灶性质的鉴别和多血供多发病灶及小病灶的发现     

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     

螺旋CT和造影剂快速滴注法作肝脏肿瘤早期增强扫描

目的：评价螺旋ＣＴ作肝脏肿瘤早期增强扫描的作用。材料和方法：用螺旋ＣＴ和造影剂快速滴注法对３６例肝脏肿瘤患者作全肝早期增强扫描。以２ｍｌ／ｓ左右的速度经时前静脉注入浓度为３００ｍｇＩ／ｍｌ的非离子型造影剂１００ｍｌ，在开始滴注造影剂７５秒内扫完全肝。结果：所有图像主动脉密度均高于或等于门静脉密度。与邻近肝组织相比，１５例（２０灶）肝细胞性肝癌（ＨＣＣ）呈高密度。１１例ＨＣＣ呈等或较低密度：２例为弥漫型ＨＣＣ；９例有严重肝动脉－门静脉瘘，其中２例门静脉呈逆向增强。７例肝转移瘤呈低密度。３例（５灶）海绵状血管瘤呈向心性增强。结论：螺旋ＣＴ作肝脏早期增强扫描可如实显示肿瘤血供和血管受侵的情况，有利于病灶性质的鉴别和多血供多发病灶及小病灶的发现。     

Detection of hepatocellular carcinoma: comparison of dynamic three-phase computed tomography images and four-phase computed tomography images using multidetector row helical computed tomography

PURPOSE: The purpose of our study was to assess the value of additional early arterial phase computed tomography (CT) imaging in the detection of hepatocellular carcinoma (HCC) by comparing three-phase and four-phase imaging by using multidetector row helical CT. METHODS: Twenty-five patients with 33 HCCs underwent four-phase helical CT imaging. The diagnosis was established by pathologic examination after surgical resection in 19 patients and by biopsy in six. Four-phase CT imaging comprises early arterial, late arterial, portal venous, and delayed phase imaging obtained 25 seconds, 45 seconds, 75 seconds, and 180 seconds after the start of contrast material injection using multidetector row helical CT. Three-phase CT images (late arterial, portal venous, and delayed phase) and four-phase CT images (early arterial, late arterial, portal venous, and delayed phase) were interpreted independently for the detection of HCC by three blinded observers on a segment-by-segment basis. Sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve (Az) for three-phase CT images and four-phase CT images were calculated. The enhancement pattern of HCC was analyzed on early arterial and late arterial phase imaging. RESULTS: The mean sensitivity of three- and four-phase CT images was 94% and 93%, respectively. The differences between sensitivities were not statistically significant (all p > 0.05). The mean specificities of three- and four-phase CT images were 99% and 98%, respectively. The differences between the specificities were not statistically significantly (all p > 0.05). Neither were the mean areas under the ROC curve for four-phase CT images (Az = 0.976) and three-phase CT images (Az = 0.971) statistically significant (p > 0.05). On early arterial phase imaging, 16 HCCs were hyperattenuating and 17 HCCs were isoattenuating. On late arterial phase imaging, 24 HCCs were hyperattenuating and nine HCCs were isoattenuating. CONCLUSIONS: Additional early arterial phase imaging did not improve the detection of HCC compared with three-phase CT images, including late arterial, portal venous, and delayed phase imaging.     

Hepatocellular carcinoma: role of unenhanced and delayed phase multi-detector row helical CT in patients with cirrhosis

PURPOSE: To determine, by using multi-detector row helical computed tomography (CT), the added value of obtaining unenhanced and delayed phase scans in addition to biphasic (hepatic arterial and portal venous phases) scans in the detection of hepatocellular carcinoma (HCC) in patients with cirrhosis. MATERIALS AND METHODS: Local ethical committee approval and patient consent were obtained. One hundred ninety-five patients (129 men, 66 women; mean age, 61 years; age range, 39-78 years) with 250 HCCs underwent multi-detector row helical CT of the liver. A quadruple-phase protocol that included unenhanced, hepatic arterial, portal venous, and delayed phases was performed. Analysis of images from hepatic arterial and portal venous phases combined, hepatic arterial and portal venous phases with the unenhanced phase, hepatic arterial and portal venous phases with the delayed phase, and all phases combined was performed separately by three independent radiologists. Relative sensitivity, positive predictive value, and area under the receiver operating characteristic curve (A(z)) were calculated for each reading session. RESULTS: Mean sensitivity and positive predictive values, respectively, for HCC detection were 88.8% (666 of 750 readings) and 97.8% (666 of 681 readings) for the combined hepatic arterial and portal venous phases, 89.2% (669 of 750 readings) and 97.8% (669 of 684 readings) for hepatic arterial and portal venous phases with the unenhanced phase, 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for hepatic arterial and portal venous phases with the delayed phase, and 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for all four phases combined. The reading sessions in which delayed phase images were available for interpretation showed significantly (P < .05) superior sensitivity and A(z) values. CONCLUSION: Unenhanced phase images are not effective for HCC detection. Because of the significant increase in HCC detection, a delayed phase can be a useful adjunct to biphasic CT in patients at risk for developing HCC.     

中晚期肝癌动脉早期MSCT血管造影

目的 :探讨多层螺旋CT肝脏动脉早期扫描CT血管造影 (MSCTA)在中晚期肝癌的临床应用价值。方法 :63例临床确诊的中晚期肝癌病例 ,用TriggerBolus对比剂示踪软件行自动触发全肝动脉早、晚期 (一次屏气完成 )和门脉期扫描 ,动脉早期图像数据经后处理获得肝脏CT血管造影图像。分析肝脏及癌肿血供系统MSCTA表现 ,以及静脉癌栓、动静脉瘘的MSCTA表现。结果 :动脉早期扫描MSCTA能完整显示中晚期肝癌肝脏及癌肿供血动脉起源、形态、数目 ,显示动静脉瘘征象优于标准肝脏双期扫描。结论 :动脉早期扫描MSCTA在中晚期肝癌具有良好的临床应用前景 ,可作为中晚期肝癌治疗前进行综合评估的影像学检查方法     

螺旋CT双期肝脏增强扫描对肝癌和肝转移瘤的诊断

目的：比较螺旋CT肝脏双期增强扫描的动脉期和门脉期对肝癌和肝转移瘤的检出率。材料和方法：对97例肝癌和47例肝转移瘤病人行螺旋CT双期增强扫描，造影剂注射速度为3ml／S，扫描延迟时间动脉期为30秒，门脉期为65秒。比较动脉期和门脉期对病灶的检出率。结果：207个肝癌病灶，动脉期和门豚期检出率分别为92％和83％，其中对于直径≤3cm病灶的检出率分别为83％和54％（P＜0．005）。482个转移瘤病灶，动脉期和门脉期的检出率分别为70％和96％，动脉期在7例病人中多检出17个病灶。结论：动脉期与门脉期相比，可以显著提高对肝癌和其它多血管肿瘤的检出率，对小的肝癌病灶检出的意义更大。     

Hepatocellular carcinoma: detection with triple-phase multi-detector row helical CT in patients with chronic hepatitis

PURPOSE: To evaluate whether the use of two arterial phase image acquisition series, when combined with portal venous phase imaging at multi-detector row helical computed tomography (CT), would be superior enough to use of a single arterial phase image acquisition series to warrant the increased radiation dose. MATERIALS AND METHODS: Multi-detector row CT was performed in 77 patients with 140 foci of hepatocellular carcinoma (HCC). A triple-phase protocol that included an early arterial phase, a late arterial phase, and a portal venous phase was performed. Images were analyzed separately by three radiologists to document the presence and number of HCC nodules. Separate reading sessions were performed for images from the early arterial phase, images from the late arterial phase, images from both arterial phases combined, and images from all three phases. Sensitivity and positive predictive values were calculated for each reading session. RESULTS: The average sensitivity and positive predictive values, respectively, for the detection of HCC were 48.5% and 96.4% for early arterial phase images, 87.1% and 94.0% for late arterial phase images, 87.1% and 94.0% for images from both arterial phases, and 88.5% and 93.4% for images from all three phases. Analysis of images from both arterial phases together yielded no improvement in either sensitivity or positive predictive value compared with analysis of late arterial phase images alone. Analysis of the combination of late arterial and portal venous phase images resulted in the highest sensitivity value. CONCLUSION: The acquisition of images during two arterial contrast phases does not provide additional benefit over timed conventional biphasic CT technique.     

肝细胞癌的双期增强螺旋CT诊断

目的：探讨双期增强螺旋CT扫描对肝细胞癌诊断的价值。方法：152例HCC患者行螺旋CT双期全肝动态扫描后,观察病灶强化方式,结果：152例共发现206个病灶,HCC的典型表现是动脉期病灶呈均匀或病灶内结节状,片状,环状强化,并可见肿瘤血管影,强化部分在静脉期迅速呈低密度影,本组共有74％（153／206）病灶有此典型表现,结论：双期增强螺旋CT能获取HCC的特征性表现,可作为HCC常规的检查方法。     

Detecting postsurgical recurrent hepatocellular carcinoma with multiphasic helical computed tomography: intrahepatic metastasis or multicentric occurrence?

OBJECTIVE: The aim of this study was to assess the computed tomography (CT) patterns of postoperative recurrent hepatocellular carcinoma (HCC). METHODS: Of 84 patients with histologically proven HCC by hepatectomies, multiphasic helical CT demonstrated 54 HCC lesions of intrahepatic recurrence in 31 (37%) patients. The initial and final appearances of HCC on hepatic arterial phase images were retrospectively determined by the serial CT scans, which were compared with appearances of primary HCC. RESULTS: The initial appearances of 54 recurrent HCCs were identical to the appearances of primary HCC in 41 (76%) lesions. Serial changes from the initial appearance to the final appearance of recurrent HCC were observed in 10 (42%) of 24 lesions. The 13 discordant lesions and the 10 lesions with altered lesion vascularity in our series implied that at least 43% were of multicentric occurrence. CONCLUSION: More than 40% of postoperative recurrent HCCs show intranodular hemodynamic changes. The incompatibility between CT findings of primary and recurrent HCCs implies that these tumors contain nodules of multicentric occurrence.     

Improved diagnosis of hepatic perfusion disorders: value of hepatic arterial phase imaging during helical CT.

The liver has a unique dual blood supply, which makes helical computed tomography (CT) a highly suitable technique for hepatic imaging. Helical CT allows single breath-hold scanning without motion artifacts. Because of rapid image acquisition, two-phase (hepatic arterial phase and portal venous phase) evaluation of the hepatic parenchyma is possible, improving tumor detection and tumor characterization in a single CT study. The arterial and portal venous supplies to the liver are not independent systems. There are several communications between the vessels, including transsinusoidal, transvasal, and transplexal routes. When vascular compromise occurs, there are often changes in the volume of blood flow in individual vessels and even in the direction of blood flow. These perfusion disorders can be detected with helical CT and are generally seen as an area of high attenuation on hepatic arterial phase images that returns to normal on portal venous phase images; this finding reflects increased arterial blood flow and arterioportal shunting in most cases. Familiarity with the helical CT appearances of these perfusion disorders will result in more accurate diagnosis. By recognizing these perfusion disorders, false-positive diagnosis (hypervascular tumors) or overestimation of the size of liver tumors (eg, hepatocellular carcinoma) can be avoided.