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。     

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。     

多层螺旋CT 多期增强扫描对不典型强化的肝癌影像分析及诊断价值

目的：探讨多层螺旋CT（MSCT）多期增强扫描对肝癌少见强化方式的影像分析及诊断价值。方法回顾性分析21例经手术病理证实或临床确诊的不典型强化的肝癌C T资料。结果21例中,小肝癌9例,结节型10例,巨块型2例。平扫17例呈低密度,4例呈等密度,瘤内密度均匀16例,5例密度不均匀。多期增强检查21例中,动脉期5例呈低密度,等密度4例,高密度12例。门脉期7例呈高密度,10例呈等密度,4例病灶呈低密度。延迟期1例呈高密度,2例呈等密度,18例呈低密度。结论 M SC T的多期增强扫描能反映出肝癌少见的强化方式,对其诊断及鉴别有着重要的意义。     

小肝癌的多层螺旋CT诊断

目的：探讨小肝癌的多层螺旋CT影像特点。方法：回顾性分析了27例经手术病理证实的小肝癌干CT增强前及增强后动脉、静脉期和延迟期的影像表现。结果：27俐小肝癌中，直径〈1cm者2例，1．0—3．0cm25例，CT平扫时23例表现为均匀低密度，4例为等密度。增强后动脉期绝大多数病灶有强化表现，均匀或不均匀，少数病灶无明显强化。门静脉期大多数表现为低密度病灶，延迟期大多数表现为低密度病灶。结论：多层螺旋CT三期扫描对小肝癌的诊断有重要价值，但应注意与肝小血管瘤等的鉴别。     

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和MRI诊断肝内胆管细胞癌的价值

目的:探讨螺旋CT和MRI诊断肝内胆管细胞癌的价值。材料和方法:回顾性分析经病理证实的18例肝内胆管细胞癌CT平扫和三期增强扫描,9例MRI平扫和动态增强扫描。结果:CT平扫13个病灶呈低密度,2个病灶呈高密度,4个病灶未能显示,病变检出敏感性为78.9%;CT增强扫描动脉期10个病灶表现呈周边薄环状增强,3个病灶呈高密度,4个病灶无增强呈等密度,2个病灶未能检出,病变检出敏感性为89.4%:门脉期11个病灶呈厚环状增强,4个病灶呈等密度,3个病灶均匀增强,呈高密度,1个肿块未见显示,病变检出敏感性为94.7%;延迟期7个病灶呈不定形轻度增强,呈低密度,4个病灶呈等密度,8个病灶明显增强,呈高密度,病变敏感性为100%。9个病灶MR平扫T1WI呈低信号,T2WI呈高或略高信号,病变检出敏感性为100%动态增强扫描6个病灶表现为缓慢增强型:3个病灶表现为快速增强型:病变检出敏感性为100%。结论:肝内胆管细胞癌螺旋CT三期增强扫描及MR动态增强扫描均具有一定的特异性,对于肝内与其它常见病变的鉴别诊断均有重要价值。     

肝脏血管周上皮样细胞瘤的CT多期扫描诊断价值

目的:探讨肝脏血管周上皮样细胞瘤的多排螺旋CT多期增强扫描特征。方法:回顾性分析7例经手术病理证实为肝脏血管周上皮样细胞瘤患者的临床及CT资料。其中3例行CT平扫、双期增强扫描及延迟扫描,3例行CT平扫、双期增强扫描,1例行CT平扫及单期增强扫描。结果:7例中6例为女性,2例为多发,5例为单发,且均位于肝右叶。CT平扫示肿瘤呈等密度-低密度,边界光整,圆形或类圆形,大小3～35cm;增强扫描动脉期6例病灶呈明显或较明显不均匀强化,1例呈不均匀轻度强化,3例动脉期见粗大血管位于肿瘤边缘或中心,强化方式为快进快出或快进慢出、持续性强化,延迟扫描呈低密度。其中3例含有大量脂肪成分,2例含有少量脂肪成分,2例无明显脂肪成分。结论:多排螺旋CT多期扫描表现结合临床资料对正确诊断肝脏血管周上皮样细胞瘤有重要价值,延迟扫描对本病与肝癌鉴别有很大价值。     

肝脏局灶性结节增生螺旋CT的诊断研究

目的：探讨CT扫描对肝脏局灶性结节增生的诊断价值。方法：采用螺旋CT对22例肝脏局灶性结节增生进行CT平扫及多期增强扫描，增强扫描动脉期18—20s，静脉期50—60s，120—150s后延迟扫描。结果：CT平扫20例呈低密度或稍低密度其中7例病灶中心可见不规则更低密度影，2例为簿密度。增强扫描动脉期均明显强化，其中10例均匀强化，12例强化不均匀。结论：CT多期增强扫描对肝脏局灶性结节增生的诊断具有特征性，且较准确，对临床治疗具有指导意义。     

Evaluation of multi-phase scanning in diagnosing perivascular epithelioid cell tumor of liver by multi-slice CT

目的:探讨肝脏血管周上皮样细胞瘤的多排螺旋CT多期增强扫描特征.方法:回顾性分析7例经手术病理证实为肝脏血管周上皮样细胞瘤患者的临床及CT资料.其中3例行CT平扫、双期增强扫描及延迟扫描,3例行CT平扫、双期增强扫描,1例行CT平扫及单期增强扫描.结果:7例中6例为女性,2例为多发,5例为单发,且均位于肝右叶.CT平扫示肿瘤呈等密度-低密度,边界光整,圆形或类圆形,大小3～35 cm;增强扫描动脉期6例病灶呈明显或较明显不均匀强化,1例呈不均匀轻度强化,3例动脉期见粗大血管位于肿瘤边缘或中心,强化方式为快进快出或快进慢出、持续性强化,延迟扫描呈低密度.其中3例含有大量脂肪成分,2例含有少量脂肪成分,2例无明显脂肪成分.结论:多排螺旋CT多期扫描表现结合临床资料对正确诊断肝脏血管周上皮样细胞瘤有重要价值,延迟扫描对本病与肝癌鉴别有很大价值.     

螺旋CT多期增强扫描对平扫为等密度的肝细胞癌的诊断

目的 分析平扫为等密度的肝细胞癌(hepatocellular carcinoma,HCC)的螺旋CT( spiral CT,SCT)多期增强扫描表现,探讨SCT多期增强扫描对此类HCC的诊断价值.方法 收集本院经手术病理、肝穿刺活检或临床随访证实的CT平扫呈等密度的HCC 14例(占同期702例HCC的1.99%),回顾性分析这类HCC 的SCT多期增强扫描的强化方式及CT征象.结果 14例HCC 的SCT平扫均呈等密度影(假阴性).SCT多期增强扫描表现为"速升速降"型强化的4例,3例可见肿瘤假包膜形成;动脉期仍为等密度,门脉期及延迟期呈低密度影的4例;动脉期、门脉期和延迟期癌灶均呈低密度影的2例;动脉期瘤灶明显强化,门脉期、延迟期表现为等密度的3例;平扫为等密度、多期增强扫描显示动静脉瘘及门静脉癌栓的弥漫型肝细胞癌1例.结论 CT平扫可能会漏诊等密度的肝癌病灶,可疑患者需行增强扫描检查;SCT多期增强扫描能显示平扫为等密度的HCC的血供特点,对其具有重要的诊断价值.     

肝细胞癌的双时相螺旋CT扫描

目的：描述肝细胞癌的双时相螺旋ＣＴ的特征，评价其应用价值。材料与方法：对４９例肝细胞癌患者进行了双时相螺旋ＣＴ扫描。记录病变增强形态、特征，并与病理和血管造影对照。由两位放射科医生以双盲法观察诊断。结果：７４％的肝细胞癌在动脉期呈高密度，７６％在门静脉期呈低密度。１０例门静脉期等密度的病灶在动脉期均呈高密度。动脉期和门静脉期肝细胞癌的检出率为９１％和８１％。结论：双时相螺旋ＣＴ能显示肝细胞癌的增强特点，并提高病变检出率。可在肝细胞癌的检查中作为常规方法应用。     

Multiphasic spiral computed tomography in hepatocarcinoma. An evaluation following different percutaneous ablative procedures

PURPOSE: To report our personal experience with helical CT evaluation of hepatocellular carcinoma treated with various percutaneous interventional procedures. We assessed both nodular response and the spectrum of changes within normal parenchyma. MATERIAL AND METHODS: December 1996 to September 1998 we examined with helical CT 41 patients (73 nodules in all) with hepatocellular carcinoma treated with percutaneous ablation therapies: conventional ethanol injection in 18 subjects (31 nodules), one-shot ethanol injection in 3 (8 nodules), radiofrequency thermal ablation in 16 (25 nodules), and combined chemoembolization and ethanol injection in 4 (9 nodules). CT performed was 4-27 days after the last session, acquiring biphasic volumetric images in 14 patients and triphasic volumetric images in 27. A second treatment with subsequent CT study was performed for 28 lesions; 15 underwent 3 serial studies and 6 underwent 4 studies. RESULTS: Compared with pretreatment findings, the diameter was unchanged in 62% of the nodules and increased in 38%. Morphology was unchanged in 63% of the lesions while in 37% a mild deformation toward the needle path or a more regular and round shape was evident. Borders were unchanged in 37% of the cases and modified in 63%, appearing well-defined in 73% and ill-defined in 27%. The necrotic portion had a low attenuation with a nodule-to-parenchyma gradient more evident on delayed than on venous and finally arterial acquisitions; 8% of the lesions were not recognizable on unenhanced scans. Residual viable tissue was identified in 44% of the nodules and quantified as 100% in 1% of all lesions, > 75% in 3%, > 50% in 4%, > 25% in 12%, < 25% in 23%. It was located centrally in 6% of the cases, peripherally in 12%, and eccentrically in 81%, and the shape was crescent in 66% of the cases, oval in 19%, and different in 16%. During the arterial phase the residual tumor appeared hyperdense in 97% of the nodules and isodense in 3%, while during the portal phase it was hyperdense in 22%, isodense in 28% and hypodense in 50%, and during the delayed phase hypodense in 100%. For what concerns the uninvolved parenchyma, lobar atrophy was present in 4% of the nodules, segmental atrophy in 8%, and subsegmental in 16%; caval thrombosis was found in 1 patient, portal thrombosis in 4. Arterioportal fistulas were identified in 5% of the nodules and areas of transient inhomogeneous attenuation in several cases. Subsegmental biliary dilation was detected in 4% of the lesions. CONCLUSION: Multiple-phase helical CT allows optimal depiction of primitive liver nodules treated with percutaneous interventional procedures and has a central role in the assessment of tumor response. Accurate is also the evaluation of changes or complications involving the surrounding parenchyma. Regarding the ablation effect, two typical features can be identified: after total necrosis nodular volume is unchanged or increased, borders are well-defined, and density is low and homogeneous (especially in delayed phases), while after partial necrosis the diameter is not modified, margins are ill-defined, attenuation is less decreased, and peripheral tumor maintains high density in arterial phase and low density in delayed phases. As for the treatment procedure, we found that thermal ablation with radiofrequency and single-session ethanol injection cause more evident alterations within both nodule and hepatic parenchyma, while after multi-session ethanol injection changes are less dramatic and consequently more difficult to assess.     

Imaging well-differentiated hepatocellular carcinoma with dynamic triple-phase helical computed tomography

To investigate the imaging appearance of well-differentiated hepatocellular carcinoma (HCC) on dynamic CT, a total of 38 histopathologically proven well-differentiated HCC were included in a retrospective study. We reviewed the contrast-enhanced dynamic CT of all 38 tumours for attenuation of each tumour in unenhanced scan, arterial-dominant and delayed portal venous phases. Our results showed that dynamic CT identified 26 (68.4%) out of the 38 lesions. The remaining 12 lesions were isodense compared with surrounding liver parenchyma in each dynamic CT phase. There was no statistically significant difference between the mean size of tumours detected by dynamic CT and that of tumours not detected by dynamic CT (p = 0.1). Of a total of 38 tumours, most were isodense (n = 19) or hypodense (n = 16) in unenhanced scan, mostly hyperdense (n = 18) or isodense (n = 15) in arterial-dominant phase and mostly isodense (n = 22) or hypodense (n = 15) in delayed portal venous phase. Enhancement of tumour was observed in 19 (50.0%) of 38 lesions. In conclusion, the ability of dynamic CT to detect well-differentiated HCC is poor, and negative CT findings cannot exclude the presence of well-differentiated HCC, especially if there is well-grounded clinical suspicion for HCC.     

肝脏局灶性结节增生的螺旋CT和MRI诊断

目的 :分析肝脏局灶性结节增生 (FNH)平扫和动态增强的螺旋CT、MRI表现 ,提高FNH诊断符合率。方法 :对 13例经手术病理证实的FNH影像学表现进行回顾性分析。螺旋CT检查 8例 ,MRI检查 6例 ,其中 1例同时做CT和MRI检查。结果 :8例CT平扫病灶均呈低密度 ,均匀或不均匀。增强动脉期扫描除中心疤痕外 ,所有病灶均有明显均匀强化 ,其中 4例还可见到病灶中心或周边增粗、扭曲的动脉。门脉期和延迟期扫描 4例呈略高密度、4例病灶呈等密度或略低密度 ,4例伴有中心疤痕者均有延迟强化。MRI检查 6例 ,病灶均呈不均匀略长或等T1及T2 信号 ,增强动脉期呈明显强化 ,门脉期及延迟期呈等或略高强化 ,4例MRI平扫显示中央瘢痕者有延迟强化。结论 :平扫和动态增强螺旋CT、MRI能较全面显示FNH的病理特征和血供特点 ,明显地提高与其它富血管恶性肿瘤的鉴别诊断能力     

原发性肝癌的电子束CT增强特征

目的 :探讨原发性肝癌的电子束CT增强特征。材料和方法 :3 2例原发性肝癌行 3 5例次平扫和双期或三期增强扫描。肝动脉期扫描时间约为 2 0～ 2 5s ,门静脉期约为 40～ 5 0s ,平衡期扫描延长至 10 0s甚至 5～ 10min。把肝癌的增强分为 7种方式分析肿瘤增强特征。结果 :共检出 86个肿块和结节 ,动脉期能显示肿瘤的血管、动脉门静脉瘘、假包膜血供、门静脉癌栓。≤ 3 0cm结节动脉期 61%呈均匀高密度增强 ,13个表现为均匀或不均匀等密度 ,6个为低密度。门静脉期低密度肝癌结节 2 8个 (65 % ) ,均匀等密度结节 13个 ,少数表现为不均匀等密度和高密度。 >3 0cm肿块动脉期65 %表现为均匀或不均匀高密度 ,7个为不均匀等密度 ,6个为低密度。在门静脉期肿瘤主要表现为不均匀低密度 79%(2 7/3 4) ,5个表现为不均匀等密度 ,2个为均匀等密度 ,无 1例高密度。无论肿瘤大小平衡期呈等、低密度。结论 :EBCT显示肿瘤的血供特征以及门静脉累及 ,是肝癌和临床怀疑肝癌的重要检查技术     

螺旋CT肝双期扫描在外生性肝癌诊断中的临床应用

目的：探讨螺旋CT肝双期扫描对外生性肝癌的诊断价值。方法：回顾性分析了7例外生性肝癌螺旋CT肝双期扫描的CT表现。结果：7例外生性肝癌与肝脏相连，3例有明显蒂部，2例肝右叶外生性肝癌向下至右侧盆腔内，6例其内可见CT“密度更低区”，3例压迫胃体及胃窦。螺旋CT肝动脉期6例肿瘤内可见不规则纡曲强化血管影。5例门静脉期肿瘤呈低密度；2例门静脉期部分肿瘤组织强化，密度增高。结论：螺旋CT肝双期扫描对外生性肝癌诊断有较高的临床价值。     

肝硬化退变结节及小肝细胞癌的CT诊断（附20例报告）

目的探讨CT扫描对肝硬化退变结节（DN）及小肝细胞癌（SHCC）的诊断准确性。方法20例经手术病理证实的SHCC患者起初均经CT平扫与增强扫描，随后又经数字减影血管造影（DSA）检查。结果20例患者共检出SHCC病灶28个，在平扫CT像上，21个病灶呈略低密度，7个病灶接近于等密度而未显示；于增强扫描动脉期，18个病灶呈轻或中度强化，3个病灶呈低密度，其余7个病灶CT平扫呈等密度的6个出现强化。CT检出病灶直径介于0．8—2．0cm。DSA显示27个肿瘤血管丰富，仅1个未见肿瘤染色。分化较好的SHCC与高度变异性DN的血供状况无明显差别。结论CT增强扫描对SHCC有极高的诊断准确性，它可作为临床可疑SHCC患者的常规检查，一经发现动脉供血结节，若患者肝功能好，则应尽早进行手术或介入治疗。     

肝局灶性结节增生的螺旋CT征象分析

目的:探讨肝局灶性结节增生(FNH)的螺旋CT征象。方法:回顾分析经病理或临床证实的16例FNH患者19个病灶的螺旋CT征象。结果:16例患者中14例为孤立病灶,2例多发;16个病灶密度较均,呈等密度或稍低密度;7个病灶直径≤3cm,12个病灶直径>3cm;8个病灶显示周边假包膜;10个病灶显示中央瘢痕及纤维分隔,其中有8个病灶直径>3cm;所有病灶在动脉期均呈显著高密度,其中16个病灶肿瘤实质均匀强化;5例病灶于动脉期显示周边异常增粗的血管。结论:绝大多数FNH呈孤立界清无包膜的稍低密度或等密度实质性肿块,动脉期明显强化,门脉期、延迟期显示中央瘢痕和假包膜,部分病灶于动脉期显示异常增粗的血管;多发病灶、动脉期不均强化、无中央疤痕显示及假包膜为不典型的CT征象。