肝腺瘤的螺旋CT表现

目的探讨肝腺瘤的螺旋CT表现。方法结合文献回顾性分析临床病理确诊的9例10个肝腺瘤的螺旋CT平扫和增强三期扫描(动脉期、门脉期和延迟期)的表现。结果9例10个肝腺瘤的平扫及增强螺旋CT表现如下:病变边界光滑清晰,无明显分叶。位于肝右叶7个,左叶3个。平扫呈等密度1个,均匀略低密度4个,不均匀低密度2个,混杂密度3个。4个病灶周围环以低密度假包膜,包膜完全2个,不完全2个。2个病灶诊断为急性出血,1个为亚急性出血,4个病灶中心可见坏死,2个病灶内可见脂肪变性。增强扫描:动脉期病灶除出血、坏死和脂肪变性部分呈均匀明显强化8个,有2个病灶肿瘤实质部分呈不均匀强化。门脉期和延迟期病灶呈等密度或略低密度。4个病灶周围包膜平扫和动脉期呈低密度,门脉期或延迟期呈轻度强化。结论螺旋CT特别是三期增强扫描对肝腺瘤的定性诊断及鉴别诊断有重要意义。     

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     

细菌性肝脓肿螺旋CT的征象分析

目的 探讨细菌性肝脓肿螺旋CT的征象。方法 回顾性分析39例资料完整并经手术或治疗后证实的细菌性肝脓肿的螺旋CT表现，包括临床、平扫、动态增强表现。结果 临床特点：发热或1个月内发热病史，血常规-白细胞增高；病灶单发24例，2个病灶以上15例，病灶总数57个。平扫表现：肝内低密度灶，边缘模糊或清晰，病灶内密度不均，可见环形带及分房样改变；可伴气体、结石以及胸腔少量积液。增强表现：a)动脉期表现：低密度病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；伴肝段一过性强化12例。b)门静脉期表现：(a)病灶呈不规则强化4例；(b)环征(单、二、三环)30例；(c)多房状征或花瓣征5例。c)延迟期表现：病灶缩小或不变，水肿带消失或模糊，脓肿壁或分隔呈“持续强化征”。结论 临床发热及白细胞增高和螺旋CT扫描病灶表现为病灶积气、动脉期无明显强化或轻度强化、门静脉期呈“环征”强化、延迟期呈“持续强化征”对细菌性肝脓肿的诊断及鉴别诊断有重要价值。     

16层螺旋CT诊断肝局灶结节样增生临床特征分析

目的探讨16层螺旋C T平扫及增强扫描在肝局灶结节样增生临床诊断中的应用价值。方法本研究对经手术病理检查确诊为肝局灶结节样增生的患者进行螺旋CT平扫和三期增强扫描,对其影像学特征进行回顾性分析。结果本组患者C T平扫显示其中单发47例,多发3例,共计55个病灶;呈圆形或类圆形,边缘清晰,其中位于右肝36例,位于左肝14例;病灶大小为2．3cm×1．7cm×1．3cm～7．5cm×6．0cm×5．2cm。CT平扫发现46个病灶为稍低密度,9个病灶为近似等密度。动脉期所有肝局灶结节样增生患者均有明显的高密度,接近于同层腹主动脉密度,其中45个密度均匀,10个密度不均匀,并且病灶内均可见增粗的供血动脉。门脉期所有肝局灶结节样增生患者中有26个病灶为稍高密度,23个病灶为等密度,中央瘢痕仍为低密度,6个病灶为低密度。延迟期所有肝局灶结节样增生患者中有32个病灶为等密度,23个病灶为低密度。FNH患者病灶部位的平扫及动脉CT值与正常肝实质比较有显著性差异（ t ＝16．52、11．32,P ＜0．05）。而在门脉期和延迟期,FNH病灶与正常肝实质比较则无显著性差异（ t ＝0．69、1．03,P ＞0．05）。FNH患者在平扫、动脉期、门脉期、延迟期的大病灶与小病灶的密度值比较无显著性差异（ t ＝0．44、0．68、1．15、0．85,P＞0．05）。结论16层螺旋C T三期增强扫描中有特征性表现,结合临床特点具有重要的临床应用价值。     

肝脏血管平滑肌脂肪瘤多层螺旋CT诊断价值

目的分析肝脏血管平滑肌脂肪瘤(angiomyolipoma,AML)的多层螺旋CT(MSCT)表现,探讨其CT特征。资料与方法回顾性分析10例AML MSCT平扫及增强扫描征象,所有病例均经手术病理证实。结果 10例中平扫均以低密度为主,边界清楚。3例平扫病灶由稍低密度软组织成分和低密度脂肪成分组成。增强扫描动脉期所有病例软组织成分均明显强化,门静脉期病灶密度仍高于肝实质,延迟期4例仍为高密度。病灶内脂肪成分均出现强化。7例病灶动脉期出现中心血管影,4例病灶出现引流静脉引流至肝静脉。结论肝AML MSCT表现有一定特征,MSCT对术前诊断有较高价值。     

肝血管瘤动静脉瘘的动态CT表现

目的 :探讨肝血管瘤动静脉瘘的动态CT表现及其与病灶的大小、位置和强化方式的关系。方法 :盲法下分析3 5例病人共 67个病灶的动态CT扫描影像 :以 3ml/s的速度静脉团注 10 0ml造影剂后行动脉期 (延迟 2 0s)、门静脉期 (延迟60s)和延迟期 (延迟 3～ 5min)扫描。动静脉瘘的CT诊断标准为 :①动静脉直接交通 :动脉期门静脉提前显影 ,且显示为与主动脉相似的时间 密度曲线 ;②肿瘤周围一过性楔形强化区 :动脉期病灶周围显示为楔形或不规则形密度增高影 ,而门静脉期该区域显示为等密度或稍高密度。分析肝血管瘤出现动静脉瘘的几率与病灶的大小、位置和强化方式的关系。结果 :67个肝血管瘤病灶中 18个出现动静脉瘘 ,其中表现为动静脉直接交通 5例 ,17例表现为肿瘤周围一过性强化 ,4例病灶同时表现出上述 2个征象。动静脉瘘的出现与病灶的位置和大小无统计学意义 (P >0 .0 5)。动静脉瘘更倾向于出现在快速强化型血管瘤 (P <0 .0 5)。结论 :肝血管瘤伴发动静脉瘘并非很少见。伴发动静脉瘘肝血管瘤更容易出现在快速充填型血管瘤中     

肝脏螺旋CT动脉期一过性异常强化的征象分析

目的 探讨肝脏螺旋CT动态增强扫描动脉期肝实质一过性异常强化(THPE)产生的原因及临床意义.资料与方法 筛选出符合THPE诊断的患者52例,先作上腹部平扫,注射对比剂开始后25～30 s行肝动脉期扫描,65 s再行门静脉期扫描,对部分病例还行局部病灶延迟扫描,延迟时间为3 min或5 min.结果 52例63处THPE中,42处(66.67%)呈有一平直边缘的"扇形"或"楔形",15处(23.8%)呈不规则片状,3处(4.76%)呈"半环形",3处(4.76%)呈结节状.结论 THPE反映了肝脏双重血供系统的重新分布,其产生的原因多种多样.正确认识和识别THPE,可以避免肝脏病灶的假阳性诊断或对病变范围的过多估计.     

肝局灶性结节增生的CT诊断及病理对照

目的:探讨肝局灶性结节性增生(FNH)CT表现。方法:回顾性分析经病理证实的12例FNH的CT表现,所有病例术前均行CT平扫及双期增强扫描,并对其CT表现及其病理学进行对照分析。结果:12例FNH病灶均呈孤立结节或分叶状肿块,其中10例位于近肝表面包膜下,直径2～6cm。平扫呈等或稍低密度,增强扫描动脉期均为明显全瘤均匀性强化,强化高于正常肝组织而接近于同层腹主动脉,门静脉期9例下降到稍高密度,3例为等密度,其中4例显示典型中央瘢痕组织,1例中央瘢痕延迟扫描后出现强化。12例FNH病灶均无包膜,为孤立的、中央有纤维瘢痕的结节肿块,纤维瘢痕中可见厚壁血管及增生的小胆管。结论:CT可明确诊断典型的FNH。     

非典型肝海绵状血管瘤的CT诊断

目的:探讨非典型肝海绵状血管瘤(HCH)的CT表现及相关病理学基础。方法:回顾性分析18例共21个非典型HCH的CT表现,包括病灶大小、平扫密度、动态增强模式及邻近改变。结果:有13个病灶CT平扫呈非均匀密度。共出现4种非典型动态增强模式:Ⅰ型(5例)表现为动脉期病灶快速均匀强化,门静脉期及延迟期持续强化;Ⅱ型(13例)动脉期肿瘤周边结节状强化,门静脉期及延迟期呈向心性强化,但不能完全填充整个病灶;Ⅲ型(2例)动脉期病灶呈中央强化,门静脉期及延迟期向周边呈离心性强化;Ⅳ型(1例)动脉期病灶无明显强化,门静脉期及延迟期呈轻度周边强化或不规则强化。HCH邻近区域的改变:有9个病灶周围可见动脉-门静脉分流(APVS),4个病灶邻近可见肝包膜回缩(HCR)征。以上非典型CT表现的出现在不同大小的病灶中差异有显著性意义(P<0.05)。结论:HCH非典型CT表现的出现与病变的结构特征密切相关,认识其非典型表现对HCH的诊断和鉴别诊断有重要意义。     

螺旋CT在肝脓肿诊断中的应用

目的：评价螺旋CT、双期扫描对肝脓肿的诊断价值。方法：回顾性分析经临床或病理证实的28例肝脓肿的螺旋CT表现，所有病例均行平扫及螺旋CT双期增强扫描，其中5例经薄层重建后在工作站行表面遮盖重建(SSD)，并经切割处理，显示其冠、矢状位图像。结果：28例中，平扫表现为类圆形边缘不清楚的低密度灶17例，多房或簇状9例，不规则形1例，脓腔内积气1例。增强扫描动脉期28例均表现为病灶边缘极轻或轻度环状强化，其中有15例(53．5％)出现灶周楔形或片状一过性强化；门脉期显示簇状征9例，边缘强化10例，环靶征8例；另1例平扫为不规则形，增强扫描动脉期灶周出现明显楔形一过性强化，门脉期病灶内呈不规则强化，为较特殊表现。5例三维图像直观地显示了脓肿的立体形态和位置。结论：螺旋CT双期扫描对肝脓肿诊断有重要应用价值。动脉期的灶周楔形或片状一过性强化是肝脓肿又一重要CT表现，对诊断有指导意义。     

肝细胞癌肝实质一过性异常强化病理研究

目的:探讨肝细胞癌肝实质一过性异常强化的影像学特征及病理改变。方法:选择肝脏动态增强CT扫描肝细胞癌合并肝实质一过性异常强化征象病例21例,以肝实质一过性异常强化区域为研究对象,并通过手术切除和CT引导下穿刺活检的方法进行病理检查。结果:肝实质一过性异常强化征象表现为肿块以外肝实质动脉期显著强化,门静脉期或延迟期呈等密度,楔形或三角形13例,不规则形9例,叶段形6例。肝实质一过性异常强化征象与癌细胞向周围扩散和肝内转移无相关性。结论:明确肝细胞癌肝实质一过性异常强化的形成机制及病理基础,有助于肿瘤的分期和制定治疗方案。     

肝局灶性结节性增生的影像诊断及病理对照研究

目的探讨肝局灶性结节性增生(focal nodu lar hyperp lasia,FNH)的影像学表现特点。方法经手术切除病理证实为肝局灶性结节性增生17例病例,术前均行螺旋CT平扫及动态增强扫描,其中10例又行MR平扫及动态增强扫描,分别进行影像学及病理学对照分析。结果17例FNH病灶均呈孤立结节或分叶状肿块,多数直径2~5 cm。平扫呈等或略低密度及信号,T2W I为略高信号。动态增强扫描,动脉期病灶均为明显的均质的强化,静脉期及延迟期12例仍略高于肝实质,6例略低于或等于肝实质。11例病灶内显示瘢痕,其中8例呈延迟强化。4例静脉期出现包膜样强化。病理观察:17例FNH均无包膜,增生的肝细胞形成肝板被纤维间隔分割呈结节状,瘢痕区域由纤维结缔组织及厚壁畸形血管组成。结论典型的FNH影像学可明确诊断,不典型的FNH应与肝细胞腺瘤、肝细胞癌、肝血管瘤相鉴别。     

Focal hepatic intrinsically hyperattenuating lesions at unenhanced CT: Not always calcifications

Due to the growing use of CT, there has been an increase in the frequency of detecting focal liver lesions. Intrinsically hyperattenuating hepatic lesions or pseudolesions are not uncommon at unenhanced CT. Hyperattenuating hepatic lesions can be divided into non-calcified and calcified.Causes of intrinsic hyperattenuation include hemorrhage, thrombosis, and calcifications. Focal liver lesions can show hyperattenuation on unenhanced CT in case of severe liver steatosis.Recognition of etiologies associated with hyperattenuation on unenhanced CT can help the radiologist in characterizing focal liver lesions and pseudolesions. In this paper, we describe the spectrum of intrinsically hyperattenuating focal liver lesions and pseudolesions at unenhanced CT.     

Dual phase helical CT versus portal venous phase CT for the detection of colorectal liver metastases: correlation with intra-operative sonography, surgical and pathological findings

AIM: To assess whether dual phase helical computed tomography (DPCT) of the liver improves the detection of colorectal liver metastases compared with portal venous phase (PVP) imaging alone. MATERIALS AND METHODS: DPCT was performed in 33 consecutive patients before laparotomy for resection of colorectal liver metastases. CT comprised 8-mm slice collimation with a pitch of 1 to 1.25; imaging was commenced 20-25 and 65-70 s after the start of injection of 150 ml of contrast medium at 5 ml/s to coincide with hepatic arterial phase (HAP) and PVP contrast enhancement, respectively. Four blinded observers independently reviewed the HAP, PVP and DPCT images recording the site and size of all lesions. Alternative-free response receiver operating characteristic (AFROC) methodology was used to analyse the results, which were correlated with surgery, intra-operative ultrasound and histology. RESULTS: The mean observer sensitivities for malignant lesion detection were 75.3% for DPCT, 69.7% for PVP imaging and 66.7% for HAP imaging alone. There was a statistically significant improvement in malignant lesion detection using DPCT when compared with PVP imaging alone (P < 0.05). The mean areas under the AFROC curves were 0.84 for DPCT and 0.82 for PVP (P < 0.03) imaging alone. CONCLUSION: The detection of colorectal liver metastases was marginally better with DPCT than with PVP imaging alone, but the discovery of additional lesions did not affect the management of any of the patients in this study.     

小肝癌的螺旋CT不典型表现并与病理对照

目的探讨小肝癌(SHCC)在螺旋CT三期增强扫描中的不典型表现及其病理学基础。方法分析经手术病理证实的螺旋CT三期增强扫描中呈不典型表现的小肝癌30例共32个病灶的CT征象和病理学改变。结果30例共发现32个病灶为不典型表现,其中14个病灶在动脉期、门静脉期和延迟期中均呈低密度;10个病灶动脉期强化明显,门静脉期和延迟期为等密度或略高密度;8个病灶动脉期病灶边缘有环形或点状强化,门静脉期和延迟期仍有持续强化。结论SHCC在螺旋CT三期扫描中有多种不典型表现,病灶的血供情况、病理学基础等是产生不典型表现的常见原因。     

SPIO-MR imaging versus double-phase spiral CT in detecting malignant lesions of the liver

PURPOSE: To assess the diagnostic performance of superparamagnetic iron oxide MR (SPIO-MR) imaging compared with double-phase spiral CT in detecting liver metastases and hepatocellular carcinoma. MATERIAL AND METHODS: Thirty-eight patients with a total of 144 malignant lesions of the liver were examined by CT and SPIO-MR. After definition of a gold standard by a panel of experts, the patient images were randomized and presented to a blinded jury of 5 independent observers whose task was to identify as many lesions as possible. The results were tested for statistical significance using multifactorial analysis of variance (alpha=5%). RESULTS: SPIO-MR produced the highest detection rate and was significantly superior (p<0.05) to unenhanced MR imaging and double spiral-phase contrast-enhanced CT (DPS-CECT). Maximum performance in DPS-CECT was obtained during the portal venous contrast phase but was significantly inferior to SPIO-MR imaging. The scores for unenhanced CT and unenhanced MR were significantly lower than for the corresponding enhanced procedures. SPIO-MR imaging produced a higher incidence of false-positive findings (n=39). CONCLUSION: SPIO-MR produced a significantly better detection rate for malignant focal liver lesions compared with double-phase spiral DPS-CECT but was associated with a higher rate of false-positive findings.     

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。     

CT features of an intraductal polypoid mass: Differentiation between hepatocellular carcinoma with bile duct tumor invasion and intraductal papillary cholangiocarcinoma

OBJECTIVE: To determine the CT features capable of differentiating hepatocellular carcinoma (HCC) with bile duct tumor invasion (BDTI) from intraductal cholangiocarcinoma (IDCC). METHODS: Multiphasic CT images of 14 patients with HCC with BDTI and 18 patients with IDCC were retrospectively reviewed. Analysis of the CT findings included the size, location, and margin of the intraductal mass, the enhancement pattern of intraductal lesions, degree of ductal dilatation, presence of downstream ductal dilatation and ductal wall thickening, presence of parenchymal mass and its size, continuity of parenchymal mass with intraductal mass, and liver cirrhosis. Objective evaluation of the enhancement patterns of intraductal tumors was done by measuring the CT attenuation coefficients of the tumors and the uninvolved hepatic parenchyma in each phase. Among these findings, statistically significant variables were then determined using Fisher exact test or Mann-Whitney test. RESULTS: Significant variables that helped differentiating HCC with BDTI from IDCC included the presence of parenchymal mass, liver cirrhosis, and the hyperattenuating intraductal tumor on the hepatic arterial phase (HAP). On unenhanced images, the tumor-to-liver contrast of IDCC (16.7 +/- 8.1) was greater than that of HCC with BDTI (6.4 +/- 10.4), but on HAP, that of HCC with BDTI (26.5 +/- 28.2) was greater than that of IDCC (5.9 +/- 18.7) (P < 0.05). In addition, there was a significant difference in the enhancement ratio of the intraductal tumors on portal venous phase (PVP) between the 2 conditions (P = 0.003). CONCLUSIONS: Several objective and subjective multiphasic CT findings may help differentiating HCC with BDTI from IDCC.     

Ciliated hepatic foregut cyst: radiologic features

Ciliated hepatic foregut cysts (CHFCs) are solitary unilocular cysts in the liver that are histologically similar to bronchogenic cysts. Three cases of CHFC are reported that demonstrated radiologic features similar to those of solid masses. All the lesions were smaller than 3 cm in diameter and were subcapsular. At ultrasonography, one lesion appeared anechoic but the other two were hypoechoic. Unenhanced computed tomography demonstrated the lesions to be hyperattenuating or isoattenuating relative to surrounding liver parenchyma, and no lesions enhanced with administration of contrast material. Magnetic resonance imaging was performed in one case and demonstrated the lesion to be markedly hyperintense with a spin-echo (SE) 2,500/80 (repetition time msec/echo time msec) sequence. All the lesions were resected and found to be filled with viscous mucinous fluid. The CHFCs are not neoplasms and must be differentiated from cystic neoplasms and hypovascular solid tumors. When a subcapsular lesion demonstrated the varied appearance described, a diagnosis of CHFC should be considered.     

Focal nodular hyperplasia: CT findings with emphasis on multiphasic helical CT in 78 patients

PURPOSE: To evaluate features of focal nodular hyperplasia (FNH) at multiphasic helical computed tomography (CT). MATERIALS AND METHODS: Clinical, pathologic, and preoperative imaging findings were retrospectively reviewed in 78 patients. Conventional liver CT was performed in nine patients; helical multiphasic CT, in 69. Diagnosis was based on complete resection (n = 20), biopsy (n = 42), or clinical and imaging follow-up for a minimum of 6 months (n = 16). Number, size, location, margins, surface, homogeneity of enhancement, and presence of a central scar, mass effect, exophytic growth, calcification, pseudocapsule, or vessels feeding or draining the lesion were evaluated. RESULTS: CT depicted 124 tumors (mean diameter, 4.1 cm; range, 1-11 cm); 62 were small (< or =3 cm). FNHs were hypervascular and hyperattenuating to liver on 106 of 106 arterial phase scans and were isoattenuating to liver on 82 of 89 delayed scans. Of the 124 tumors, 111 enhanced homogeneously, 109 had a smooth surface, 101 were subcapsular, 89 had ill-defined margins, and 62 had a central scar that was observed more often in large lesions (40 of 62 lesions) than in small lesions (22 of 62 lesions). FNHs less frequently exerted a mass effect (43 lesions), had vessels around or within the lesion (42 lesions), demonstrated exophytic growth (40 lesions), or showed a pseudocapsule (10 lesions). Only one FNH had calcification. CONCLUSION: Helical CT demonstrates characteristic features that may allow confident diagnosis of FNH. In typical cases, neither biopsy nor further imaging is necessary.