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三期增强扫描对小肝癌的诊断

目的　研究小肝癌 (SHCC)在螺旋CT三期 (动脉期、门脉期和延迟期 )增强扫描的表现 ,比较各期的病灶检出率 ,提高诊断水平。方法　 70例SHCC患者行平扫及增强扫描 ,造影剂注射速率为 3ml/s ,然后开始动脉期、门脉期和延迟期的扫描。统计各期的病灶检出数 ,观察病灶在不同时期的特征。结果　共发现 82个病灶 ,动脉期、门脉期和延迟期的检出率分别为 92 .68% ,70 .73 %和 73 .17%。动脉期的敏感性高于延迟期和门脉期。三期联合检出率明显增加达 95 %。结论　SHCC增强扫描表现形式复杂 ,螺旋CT三期扫描可以充分显示SHCC各期的增强表现 ,正确评价其血流变化 ,提高了病灶的检出率和诊断的准确率     

螺旋CT多期增强扫描对诊断肝细胞癌和肝转移瘤的评价

目的：评估螺旋CT多期增强扫描对肝细胞癌与肝转移瘤的诊断价值。方法：回顾分析经手术病理证实的35例肝细胞癌与肝转移瘤螺旋CT多期增强扫描表现。结果：12例巨块型肝癌平扫为低密度，增强扫描动脉期均明显不均匀强化，特点为肿瘤供血血管强化，结节型8例表现为病灶斑片状及边缘强化，肿瘤供血血管不明显，小肝癌5例为动脉期全瘤强化．强化后CT值可增加40HU以上，肝转移瘤动脉期病灶无明显强化。静脉期呈环形轻度强化，呈现典型“牛眼征”。结论：螺旋CT多期增强扫描对明确肿瘤血供和肿瘤生长方式与小肝癌诊断有重要的意义。     

螺旋CT双期动态扫描在小肝癌诊断中的价值

目的：应用螺旋ＣＴ行肝动脉期和门静脉期双期全肝动态扫描，比较二期的病灶检出率并和超声进行检出敏感性和定性准确性的比较研究。材料和方法：４９例小肝癌患者行螺旋ＣＴ双期全肝动态扫描后，统计各期病灶的检出数，观察病灶强化方式，计算检出敏感性并行统计学处理。结果：４９例共发现病灶５３个，肝动脉期、门静脉期及双期合计的检出敏感性分别为：８８．６８％、７１．７０％、９０．５７％，双期扫描和超声（６７．９２％）比较有显著性差异，其定性准确性（９５．８３％）也明显高于超声（８０．５６％）。结论：螺旋ＣＴ双期动态扫描可充分反映小肝癌的血供特点，明显提高小肝癌的检出敏感性，无论检出还是定性均优于超声     

三期螺旋CT扫描对肝转移瘤的诊断价值

目的：分析肝转移瘤三期螺旋CT扫描的影像表现，并评价其诊断价值。方法：回顾性分析63例患者365个肝转移瘤病灶的三期螺旋CT扫描图像。统计各期病灶的检出数，观察病灶增强方式。结果：肝转移瘤在动脉期、门脉期和平衡期的检出数分别为86％、95％和88％。强化方式呈多样性，以边缘环形强化、内部低密度强化为主要特征，门脉期病灶显示更清楚，更易发现病灶。结论：三期螺旋CT扫描可提高肝转移瘤的检出率，有利于肝转移瘤特征的显示，可反映病灶的血供，有利于诊断和鉴别诊断。     

螺旋CT三期增强扫描诊断原发性小肝细胞癌的价值

目的:评价螺旋CT三期增强扫描诊断原发性小肝癌(SHCC)的价值。材料和方法:分析21例经病理证实的小肝细胞癌,螺旋CT平扫及三期增强扫描的CT征象。结果:21例SHCC中,检出26个病灶,其中20个病灶在三期扫描中为典型表现,即动脉期为高密度,门脉期为等密度或低密度,平衡期为低密度,动脉期检出率为92.3%。结论:螺旋CT三期增强扫描能明确肿瘤的血供特点和门脉受累情况,明显提高病灶的检出率,为明确诊断和指导治疗提供了可靠依据     

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。     

多层螺旋CT、数字减影血管造影、碘化油CT对肝内富血管肝癌检出率的比较研究

目的 比较多层螺旋CT双期增强扫描、数字减影血管造影、碘化油CT对肝内富血管肝细胞肝癌结节的检出率.方法 收集诊断明确的结节型原发性肝细胞癌28例,所有患者均先行多层螺旋CT双期增强扫描,然后行肝动脉灌注碘化油栓塞术,术前行肝动脉数字减影血管造影,并于术后3～4周内行多层螺旋CT平扫(碘化油CT).采用盲法对3种影像学方法对肝内富血管肝细胞癌结节的检出率进行统计,并对3种方法对不同大小的肝癌结节的检出率进行比较.结果对＞2 cm的肝癌结节,3种方法具有相同的检出率;对＞1 cm、＜2 cm的结节,3种方法检出率的差异没有统计学意义;对于＜1 cm的结节,多层螺旋CT双期增强扫描检出47个,碘化油CT检出27个,数字减影血管造影只检出16个＜1 cm的结节,与多层螺旋CT双期增强扫描和碘化油CT检出率相比,其差异均有统计学意义.结论 对＜1 cm的肝内富血管肝细胞肝癌结节,多层螺旋CT双期增强扫描和碘化油CT 2种方法可以相互补充.     

原发性肝癌的螺旋CT三期增强特征及其诊断价值

目的：探讨肝癌螺旋CT多期扫描影像特征和临床应用价值。方法：对拟诊为肝癌的56例患者先行全肝CT平扫,其中46例不论肿瘤大小先作病灶动脉期扫描,再作全肝静脉期扫描,最后进行病灶延迟扫描。10例仅行动脉期及静脉期扫描。结果：56例中37例为巨块型,10例为结节型,10例为弥漫型。46例中CT平扫、动脉期、静脉期及延迟期病灶的显示率分别为89%、98%、92%、98%。结论：螺旋CT三期扫描能获得肿瘤在各期增强征象,为肝癌的定性定量诊断提供更多的影像诊断信息;尤其在早期肝癌诊断,动脉期扫描可得到非常重要的诊断依据。     

硬化型肝癌的螺旋CT多期扫描表现

目的：分析总结硬化型肝癌的螺旋CT多期扫描表现，以进一步提高对该病的诊断准确性。材料和方法：经手术证实的7例硬化型肝癌患者行螺旋CT平扫和多期增强扫描。注射造影剂后30s开始动脉期扫描，70s开始门脉期扫描，另有4例加做3—4min的延迟期扫描，观察病灶的强化方式。结果：平扫7个病灶均为低密度。动脉期6个病灶有轻度的不规则环形、点状或结节状强化，1例无强化。门脉期7个病灶均有不同程度的强化，如不规则环形强化、边缘结节状强化或中心强化等，强化范围较动脉期增大。延迟期4个病灶仍有各种各样的强化表现。结论：硬化型肝癌的螺旋CT多期扫描表现特殊，以早期轻度强化、门脉期和(或)延迟期仍有持续强化为主，需认真与血管瘤及炎性假瘤鉴别，了解其CT表现有助于临床正确诊断和治疗方案的选择。     

螺旋CT三期扫描对小肝癌的诊断价值研究

目的：对螺旋CT三期扫描对小肝癌的诊断价值进行研究。方法：本组对象为2010-11～2011-11治疗的30例小肝癌患者,在患者知情同意的情况下进行CT平扫和螺旋CT三期增强扫描,并对检查结果进行统计分析。结果：经螺旋CT三期扫描共检出病灶32个,门脉期病灶共检出病灶25例,以低密度为主。动脉期病灶有27例检出病灶,以高密度为主。平衡期病灶共检出26例,以低密度为主。动脉期的检出率对小肝癌病灶的检出率稍高。结论：螺旋CT三期扫描对小肝癌的检出率高,诊断准确可靠,具有较高的诊断价值,有利于进行及时的治疗。     

肝脏局灶性结节增生的CT多期扫描表现及病理对照研究

目的：评价多层螺旋CT（MSCT）多期扫描对肝脏局灶性结节增生的临床诊断价值。方法回顾性分析12例经病理确诊为肝脏局灶性结节增生的患者,对其MSCT的平扫、动脉期、门脉期及延迟期共4期扫描图像进行分析,并与病理结果进行对照研究。结果本组12例病例男女比例为7∶5,年龄20~65岁,平均年龄34岁。12例患者均进行CT四期扫描,共观察到病灶12个,病灶位于肝脏左外叶2个,左内叶3个,右前叶4个,右后叶3个,最大平面直径范围为1．7~4．8 cm,平均（3．1±1．3）cm。病灶CT平扫呈等密度5个,低密度7个,等密度者无法显示病灶边缘,低密度者2例病灶边界清楚,5例病灶边界显示模糊,其中可见更低密度瘢痕组织3例。CT增强动脉期显示12例病灶均呈明显强化,其中5例可见中央瘢痕或条索状低密度影,中间瘢痕组织无强化,11例病灶边界显示清晰,均未见包膜;门脉期病灶较动脉期密度降低,但仍较肝脏组织密度高,中间瘢痕组织无明显强化,仍呈低密度;延迟期病灶呈等密度为主,瘢痕组织可见强化,与病灶呈等密度分辨不清。结论MSCT多期扫描在肝脏局灶性结节增生的影像表现方面有一定的特征性,在诊断及鉴别诊断中有很好的作用,但确诊还需要病理诊断。     

Helical CT screening for hepatocellular carcinoma in patients with cirrhosis: frequency and causes of false-positive interpretation

OBJECTIVE: The purpose of our study was to determine the specificity of helical CT for depiction of hepatocellular carcinoma in a population of patients with cirrhosis. SUBJECTS AND METHODS: Single-detector helical CT screening was undertaken in 1329 patients with cirrhosis who were referred for transplantation. The patients underwent one or more helical CT examinations over 30 months and were followed up for an additional 19 months or until transplantation. We predominantly used unenhanced and biphasic contrast-enhanced techniques with infusions of 2.5-5.0 mL/sec. Four hundred thirty patients underwent transplantation within this period. Liver specimens were sectioned at 1-cm intervals, with direct comparison of imaging and pathologic findings and histologic confirmations of all lesions. Prospective preoperative helical CT reports were used for the primary data analysis. A retrospective unblinded review was undertaken to determine characteristics of false-positive lesions diagnosed as hepatocellular carcinoma. RESULTS: Thirty-five patients (8%) had false-positive diagnoses for hepatocellular carcinoma based on helical CT. Twenty of these patients (5%) showed hypoattenuating lesions seen during one of the three helical CT examination phases. Fifteen patients (3%) had hyperattenuating lesions seen during the arterial phase. Among the 15 hyperattenuating lesions, CT revealed the causes to be transient benign hepatic enhancement (n = 3), hemangiomas (n = 2), fibrosis (n = 2), peliosis (n = 1), volume averaging (n = 1), low-grade dysplastic nodule (n = 1), or undetermined (n = 5). Of the 20 hypoattenuating lesions, the causes were shown to be fibrosis (n = 8), focal fat (n = 4), infarcted regenerative nodules (n = 2), regenerative nodules (n = 1), fluid trapped at the dome of the liver (n = 1), hemangioma (n = 1), or undetermined (n = 3). Follow-up helical CT in 13 (72%) of 18 patients allowed a change in the diagnosis of hepatocellular carcinoma to a finding of no cancer present. CONCLUSION: Helical CT screening for hepatocellular carcinoma in patients with cirrhosis has a substantial false-positive detection rate. Although most of lesions were hypoattenuating, a few hyperenhancing arterial phase lesions were proven not to be hepatocellular carcinoma. An awareness of imaging characteristics and follow-up imaging can help radiologists avoid a mistaken diagnosis in many patients.     

Small hypervascular hepatocellular carcinoma revealed by double arterial phase CT performed with single breath-hold scanning and automatic bolus tracking

OBJECTIVE: The purpose of this study was to evaluate the usefulness of double arterial phase CT for the detection of small hypervascular hepatocellular carcinomas, using an automated bolus-tracking technique to initiate the hepatic arterial phase CT. MATERIALS AND METHODS: Double arterial and late phase contrast-enhanced helical CT scans were obtained on 287 consecutive patients suspected of having hepatocellular carcinoma. These included 56 patients with 90 small (< or 3 cm) hepatocellular carcinomas and 50 patients with no hepatocellular carcinomas. CT scans of these patients were interpreted by three reviewers. The first arterial phase scan was initiated automatically 10 sec after the bolus-tracking program detected the threshold enhancement of 50 H in the abdominal aorta. Three reviewers interpreted the late phase CT scans in combination with the first, second, or both hepatic arterial phases. Measures of the reviewers' detection of hepatocellular carcinoma included analysis of interobserver variation, sensitivity, specificity, and area under receiver operating characteristic curve (A(z)). RESULTS: The time elapsed from bolus initiation to threshold aortic enhancement ranged from 10 to 24 sec (mean, 13 sec), resulting in initiation of the first arterial phase CT scan from 20 to 34 sec (mean, 23 sec). The combination of late phase CT and both first and second arterial phase images showed significantly better performance than the combination of the late phase and either the first or second arterial phases, although the difference was most evident in comparison with the combination of second arterial and late phases. CONCLUSION: An automated bolus-tracking program can be used to optimize the timing of hepatic arterial phase CT. Multiphasic CT performed using this technique is useful in detection of small hepatocellular carcinoma.     

Focal nodular hyperplasia and hepatocellular adenoma of the liver: differentiation with multiphasic helical CT

OBJECTIVE: Differences of attenuation and enhancement patterns in focal nodular hyperplasia and hepatocellular adenoma were evaluated and quantified using triphasic single-slice helical CT. MATERIALS AND METHODS: Forty-five histologically proven focal nodular hyperplasias in 27 patients and 18 hepatocellular adenomas in six patients were examined with helical CT. Quantitative evaluation included the following: attenuation of lesions, scar, and liver parenchyma during unenhanced, arterial (20 sec after injection), and portal venous phases (70 sec after injection); relative enhancement of lesions and liver (the ratio between attenuation in arterial phase and portal venous phase, respectively, and attenuation in unenhanced phase); and the prevalence of scar and its central vessel in focal nodular hyperplasia. RESULTS: The study showed no significant difference between mean attenuation values of focal nodular hyperplasia (mean +/- SD, 51.2 +/- 5.9 H) and hepatocellular adenoma (mean +/- SD, 56.3 +/- 7.8 H) in the unenhanced phase. In the arterial phase attenuation values were significantly higher in focal nodular hyperplasia (mean +/- SD, 117.9 +/- 15.1 H) than in hepatocellular adenoma (mean +/- SD, 80.1 +/- 10.5 H). In the portal venous phase no significant differences in attenuation values were detected between focal nodular hyperplasia (mean +/- SD, 112.1 +/- 20.4 H) and hepatocellular adenoma (mean +/- SD, 110.2 +/- 12.9 H). For enhancement parameter thresholds separating focal nodular hyperplasia from hepatocellular adenoma, the following were found: the relative enhancement was higher in 100% of the focal nodular hyperplasias and lower than or equal to 1.6 (accuracy, 96%) in 87% of the hepatocellular adenomas. CONCLUSION: Triphasic helical CT combined with quantitative evaluation of liver lesions offers the possibility of detecting differences in liver lesions that are visually similar on CT. The attenuation and relative enhancement in the arterial phase show significant differences that make accurate differentiation between focal nodular hyperplasia and hepatocellular adenoma possible.     

少血供小肝癌的螺旋CT表现并与病理对照

目的 研究螺旋CT双期增强扫描低密度小肝癌的CT表现及其病理学基础。方法 分析经手术病理证实的螺旋CT双期增强扫描表现为低密度的小肝癌25例共27个病灶的CT征象和病理学改变。结果 (1)平扫病灶边界模糊不清者有16个病灶，边界清楚者有11个病灶；增强后病灶边界模糊者只有7个病灶，边界清楚者有20个病灶，同时病灶边缘轮廓轻度不规整。(2)平扫瘤内呈均匀性低密度者有18个病灶，瘤内密度不均匀者有9个病灶；增强后瘤内密度均匀者只有6个病灶，瘤内密度不均匀、有多个小斑点状密度更低区者有21个病灶。结论 螺旋CT双期增强扫描低密度小肝癌的CT表现特点是：平扫病灶边界模糊，增强后病灶边界变清楚并呈轻度不规整，同时病灶内密度不均匀，有多个小斑点状密度更低区。根据该特点可以与肝脏的其他表现为低密度的病变进行鉴别。     

螺旋CT多期扫描诊断肝脏局灶性结节增生研究

目的 探讨肝脏局灶性结节增生(FNH)的螺旋CT平扫和多期增强扫描表现特征,以提高CT对FNH的诊断准确性.资料与方法 回顾性分析16例经病理证实的FNH患者螺旋CT平扫及动脉期、门静脉期、延迟期增强扫描的资料.结果 16例患者16个FNH病灶中,平扫显示所有病灶均为略低密度,位于肝包膜下,其中14个可见更低密度瘢痕,从病灶中心向周围呈辐射状或不规则状.肿块实质呈"快进慢出"强化,中心瘢痕及辐射状分隔、假包膜"延迟强化",延迟期整个肿块密度趋于均匀一致.结论 平扫和多期增强螺旋CT扫描能全面显示FNH的病理特征及血流动力学特点,螺旋CT多期扫描有助于FNH的诊断及鉴别诊断.     

Hepatocellular adenoma: multiphasic CT and histopathologic findings in 25 patients

PURPOSE: To evaluate multiphasic computed tomographic (CT) findings of hepatic adenomas and to correlate these findings with those of histopathologic analysis. MATERIALS AND METHODS: Multiphasic helical CT was performed in 25 patients with 44 hepatic adenomas. Nonenhanced scans were obtained in all cases, along with hepatic arterial-dominant phase (HAP) and portal venous-dominant phase (PVP) images at 25-28 and 60-70 seconds after intravenous contrast material injection at 3-5 mL/sec. Twelve patients with 24 adenomas also underwent delayed-phase (5-10-minute) CT. Two independent readers retrospectively reviewed each case for the number of detectable lesions in each CT phase, morphologic features of tumors, and degrees of enhancement. RESULTS: Thirteen patients had solitary adenomas; 12 patients had two or three adenomas. Both observers agreed on the numbers of lesions detected in all cases and in all phases of enhancement. The detection rate for all 44 adenomas per type of examination was as follows: nonenhanced, 86% (38 of 44); HAP, 100% (44 of 44); PVP, 82% (36 of 44), and delayed, 88% (21 of 24). Tumor margins were well defined in 38 adenomas (86%), and the surface was smooth in 42 adenomas (95%). The right hepatic lobe was the only site of adenoma or was a site along with the left lobe in 29 cases (66%). Tumor fat and calcifications were uncommon (three cases [7%] and two cases [5%], respectively). Other than areas of fat, hemorrhage, or necrosis, the adenomas enhanced nearly homogeneously, especially on PVP and delayed-phase scans. Five patients had coexistent hepatic masses, which were focal nodular hyperplasia (n = 3) or hepatocellular carcinoma (n = 2). CONCLUSION: Hepatic adenomas often have characteristic features at multiphasic CT that may allow their distinction from other hepatic masses.     

螺旋CT对微波凝固治疗肝细胞癌的疗效评价

目的 研究微波凝固治疗肝细胞癌后的螺旋CT表现，评价CT征象与疗效之间的关系。方法 分析经超声引导下行微波凝固治疗的原发性肝细胞癌病人22例、共26个病灶的螺旋CT征象。结果 21个病灶肝动、门脉双期病灶内和边缘部均未见强化。7个病灶肝动脉期病灶周围的肝组织见斑片状轻度至明显的强化。5个病灶肝动脉期病灶内或病灶边缘部见结节样强化。结论 螺旋CT的双期增强扫描可以准确地判断超声引导下微波凝固治疗肝细胞癌的治疗效果，当双期扫描病灶内无强化时，说明病灶无肿瘤残留；当动脉期病灶周围肝组织出现斑片状轻度至明显强化时，属于微波凝固治疗后的正常反应；当动脉期病灶内或病灶边缘部出现结节样强化时，说明病灶内肿瘤有残留复发。     

小肝癌螺旋CT多期扫描不强化的病理基础探讨

目的:分析螺旋CT多期扫描诊断小肝癌的价值,从而探讨少数小肝癌不强化的病理基础。方法:52例小肝癌(SHCC)患者行螺旋CT平扫和多期增强扫描,平扫后分别行动脉期、门脉期和延迟期增强扫描,观察病灶的强化形式。手术病理记录肝脏有无肝硬化、坏死囊变、透明细胞变及脂肪变性等。结果:52例患者共发现病灶72个,CT动脉期扫描有48个病灶有明显强化。SHCC在CT动脉期-门脉期-延迟期扫描中的典型方式为高-低-低密度等高-等-低密度;不典型方式为低-低-低密度和高-等-等密度。术中见肝硬化者占79.2%,18.1%的病灶内见出血坏死,16.7%的病灶出现透明细胞变或全灶为透明细胞癌。结论:大部分小肝癌在动脉期出现强化,多期扫描不强化的占11.1%,不强化主要是坏死造成,脂肪变性和透明细胞变性也是主要原因之一。