肝脏转移性平滑肌肉瘤的CT诊断

目的 分析肝脏转移性平滑肌肉瘤(MLL)的CT表现及特点,以提高对MLL的认识.方法 回顾性分析5例经病理证实的MLL的CT表现及临床特征.CT扫描包括平扫、增强扫描动脉期及门脉期,部分病例行延迟期扫描.结果 MLL平扫均为低密度,2例增强扫描出现"牛眼征",符合典型转移瘤表现.较小的MLL增强后动脉期周边明显强化,中央液化坏死无强化.较大的MLL表现为囊实性,肿瘤实质强化明显,血供丰富,部分在延迟期密度仍较背景肝为稍高或等密度.1例术前误诊为肝血管瘤及肝脏局灶结节性增生(FNH).可伴有其他部位转移,5例均未发现门静脉癌栓.结论 在肝脏富血供的占位病变中,有原发病史、无特殊肿瘤标志物、无肝炎病史、特别是CT表现特点,应考虑到MLL的可能.     

小肠平滑肌类来源肉瘤肝转移CT及血管造影表现(附7例报告)

目的　分析小肠平滑肌类来源肉瘤肝转移的CT表现和肝动脉造影表现。材料与方法　回顾性分析 7例小肠平滑肌类肉瘤肝转移病例 ,肝脏转移肿瘤共 46个。 7例均行肝脏CT三期扫描和肝动脉造影。结果　肝脏转移病灶CT平扫呈低密度实性或囊实性占位。肿瘤膨胀生长 ,与周围肝实质分界清楚。动脉期增强扫描肿瘤实质部分明显强化 ,门脉期与周围肝实质强化差异缩小。肿瘤囊变坏死区无强化。肝动脉造影示转移肿瘤血管和染色丰富。结论　小肠平滑肌类来源肉瘤肝转移以肝动脉供血为主 ,为富血供肿瘤 ,类似于肝细胞癌。肿瘤多伴有明显囊变坏死     

肝脏血管外皮细胞瘤的CT诊断(附13例报告)

目的：探讨肝脏血管外皮细胞瘤的CT影像特点。方法：回顾性分析了13例经手术病理证实的肝脏血管外皮细胞瘤于CT增强前及增强后动、静脉期和延迟期的影像表现。结果：13例肝血管外皮细胞瘤中直径＜3．0cm者2例，CT平扫时呈低密度，增强后动脉期呈明显高密度，而静脉期和延迟期又变为等密度。直径为3．0－5．0cm者3例，CT平扫时表现为均匀的低密度，增强后自周边向中心逐渐强化，但强化部分不及血管瘤明显，也不呈斑样增强，延迟扫描病变呈等密度。直径＞5．0cm者8例，CT平扫时均表现为密度不均匀，增强后动脉期的扫描均表现为环状或边缘性强化，但密度不均匀，延迟后中央仍可见坏死囊变的无强化区。结论：多期螺旋CT扫描有助于肝脏血管外皮细胞瘤的诊断，但应注意与肝癌和肝血管瘤的鉴别。     

腹膜后炎性肌纤维母细胞瘤的CT表现

目的：分析腹膜后炎性肌纤维母细胞瘤（IMT）的CT表现，旨在提高对该病的认识及诊断水平。方法：回顾性分析经手术病理证实的6例腹膜后IMT患者，均行CT平扫及增强扫描。结果：6例病变最大径3.4~22.0 cm，5例囊实性，CT平扫呈等低密度，增强扫描动脉期实性成分呈轻中度强化，静脉期及延迟期呈持续强化，囊性成分未见明显强化，2例内见分隔强化。1例囊性，增强扫描囊性成分无强化，周围包膜轻度强化。结论：腹膜后IMT具有一定特征，瘤体较大，形态多不规则，囊实性较多见，增强扫描实性成分呈持续强化。     

胰腺实性假乳头状瘤的CT及MRI诊断

目的:探讨胰腺实性假乳头状瘤(SPTP)的CT及MRI表现.方法:9例经外科手术后病理组织学证实的SPTP,术前5例进行CT及MRI平扫和增强扫描,4例只进行CT平扫和增强扫描.结果:肿瘤3例发生在胰头颈部,6例发生在胰尾部.直径2～11cm,均含有囊壁的囊实性肿块,囊性、实性成分比例各有不同,肿瘤内伴有不同程度的出血,囊壁与周围组织分界清楚,9例均未见钙化灶.增强扫描肿瘤实性部分及囊壁有强化,动脉期呈轻度强化,静脉期及延迟期呈轻中度强化,延迟期肿瘤实性部分强化体积及程度更大,囊性和实性结构变得清晰,但均低于正常胰腺.结论:SPTPCT及MRI表现具有一定的特征性.     

探讨肝脏血管平滑肌脂肪瘤的CT表现

目的探讨分析肝脏血管平滑肌脂肪瘤（angiomyolipoma,AML）的CT表现特征。方法分析9例经病理证实的肝脏AML在CT平扫及增强的表现。结果 9例肝脏AML均为单发,边界清晰,肿块内密度不均,6例呈低密度或略低密度为主,5例由低密度的脂肪成分及略低密度的实性成分组成。增强扫描动脉期所有病例实性成分均明显强化,门静脉期病灶密度仍高于肝实质,平衡期3例仍显示高密度。其中脂肪成分均出现一定强化。7例病灶动脉期出现了＂中心血管影＂,6例出现引流静脉引流至肝静脉。结论肝脏AML的CT表现呈多样性且具有特征性,了解肝脏AML的CT表现,有利于提高术前诊断。     

非功能性胰岛细胞瘤螺旋CT表现与鉴别诊断

目的:探讨螺旋CT在非功能性胰岛细胞瘤诊断和鉴别诊断中的价值。方法:回顾性分析经手术病理证实的5例非功能性胰岛细胞瘤的螺旋CT表现。采用平扫和双期(动脉期和门静脉期)增强扫描,动脉期、门静脉期扫描延迟时间分别为25s、70s。结果:5例肿瘤中位于胰头2例、胰体1例、胰尾2例,平均直径7.6cm(4.5~12.6cm)。实体性肿瘤(n=2)平扫呈稍低密度,囊性者(n=3)囊壁及壁结节(实性成份)呈等或稍低密度,有囊壁钙化者2例。增强扫描示实性者动脉期明显强化,门静脉期中度~明显强化;囊性者动脉期囊壁、壁结节呈中度~明显强化,门静脉期轻度~中度强化,囊性部分在增强扫描前后均呈低密度。5例均不伴有胆总管和胰管扩张。结论:实性非功能性胰岛细胞瘤螺旋CT增强扫描表现有一定特征性;囊性者缺乏特征性改变,需与囊腺瘤(癌)、胰腺癌囊变、胰腺实性-假乳头状瘤、胰腺假性囊肿及胰腺结核等鉴别。     

胰腺实性假乳头状瘤CT表现

目的探讨胰腺实性假乳头状瘤CT表现。方法回顾分析经手术病理证实的15例胰腺实性假乳头状瘤,患者均为女性。年龄15～40岁。术前其中13例均经CT平扫及双期CT增强扫描。其中2例仅行CT平扫。结果 15例中肿瘤位于胰头者8例,肿瘤位于胰体尾者7例。肿瘤直径约4～15cm。CT平扫肿瘤成囊实性,其边界清晰。增强扫描动脉期实性成分成轻度强化,静脉期强化程度增加。结论 CT对胰腺实性假乳头状瘤的诊断具有一定的诊断价值。     

胃肠间质瘤的少见特征性CT表现及其病理学基础

目的探讨胃肠间质瘤(GISTs)的少见特征性的CT表现及其病理学基础。方法回顾经手术及病理证实的9例GISTs患者的临床及影像学资料,9例均行CT平扫及增强扫描。分析其CT表现特征,并与病理结果对照分析。结果浆膜下型6例,呈囊实性(实性部分位于中央,囊性部分呈环形位于周边),边界清晰,增强扫描动脉期实性部分中度强化、门脉期持续强化、延迟期强化稍减退;肌壁间型3例,内含丰富的团状及粗放射状胶原纤维,CT平扫表现为实性均匀密度,增强扫描动脉期呈明显薄环形强化(内可见强化分隔)、门脉期及延迟期呈逐渐向心性填充、强化均匀,其中1例边界清晰,2例边界模糊。结论 GISTs的少见影像学特征临床上出现率较低,认识其少见特征的CT表现有助于与胃肠道其它肿瘤进行鉴别,提高诊断正确率。     

卵巢透明细胞癌的CT、MRI表现

目的：探讨卵巢透明细胞癌（OCCC）的CT、MRI特征,以提高对该病的诊断准确率。方法：回顾性分析经手术病理证实的26例OCCC的CT和MRI资料,6例行CT检查,17例行MRI检查,3例同时行CT和MRI检查,综合分析其影像学特点。结果：26例中,双侧卵巢发病7例,右侧13例,左侧6例。肿瘤呈类圆形、椭圆形,20例边界光滑,肿瘤最大径6.9~27.0 cm,中位值13.7 cm;囊实性肿块19例,实性肿块7例。CT特征：囊性成分平扫CT值17.0~31.0 HU,实性成分平扫CT值29.0~47.0 HU,增强扫描CT值为59.0~84.0 HU;增强扫描囊性成分无强化,实性成分动脉期强化明显,静脉期和延迟期呈持续性强化。MRI表现：肿瘤实性成分T₁WI呈等信号,T₂WI呈稍高、等信号,DWI实性成分呈明显高信号;实性成分动态增强扫描动脉期强化明显,延迟期明显持续性强化,TIC呈"快速上升平台型"。结论：OCCC的CT、MRI表现有一定的特征性,仔细分析,可明显提高诊断正确性。     

肝动脉化疗栓塞治疗肝转移性平滑肌肉瘤的临床体会

目的探讨经肝动脉化疗栓塞治疗肝脏转移性平滑肌肉瘤（MLL）的临床价值。方法对8例经穿刺活检及免疫组化证实的MLL行肝脏CT三期增强扫描及肝动脉灌注化疗栓塞,随访1～3年,依据动脉化疗栓塞前后肝内病灶强化程度、DSA表现及生存期评估疗效。结果单发转移瘤3例、多发5例。治疗后临床症评价,显效6例,有效2例 影像学疗效评价显效3例,有效4例,无效1例。1、2、3年生存率分别为7/8、4/8和3/8。结论肝动脉灌注化疗栓塞是一种安全有效治疗肝脏转移性平滑肌肉瘤的方法。     

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。     

Fungal liver infection in immunocompromised patients: depiction with multiphasic contrast-enhanced helical CT

PURPOSE: To retrospectively assess multiphasic (nonenhanced, arterial phase, and portal venous phase) computed tomography (CT) of the liver for depiction of hepatic fungal infection in immunocompromised patients. MATERIALS AND METHODS: The institutional ethics review board approved the study and waived the requirement for informed consent. Sixty multiphasic hepatic CT examinations were performed in 39 immunocompromised patients who fulfilled the criteria for having probable or proved fungal liver infection. The detection and conspicuity of focal liver lesions were assessed on scans obtained during each CT phase. The lesion enhancement pattern was determined, and, accordingly, lesions were stratified into two groups: lesions suggestive of infection (with ring enhancement patterns or high attenuation) and nonspecific hypoattenuating lesions. Statistical analyses were performed by using logistic regression with generalized estimating equations. RESULTS: A total of 536 liver lesions detected at 36 CT examinations with results positive for fungal infection were assessed. All 36 (100%) examinations yielded positive results during the arterial phase, whereas 25 (69%) of them yielded positive results during the portal venous phase (P < .001). At lesion-by-lesion analysis, the arterial phase scans depicted significantly more lesions (483 of 536 [90%]) than the portal venous phase (329 of 536 [61%]) and nonenhanced (265 of 465 [57%]) scans (P < .001 for both comparisons). In addition, on arterial phase scans, 386 of 483 lesions, as compared with 134 of 329 lesions on portal venous phase scans (P < .001), were judged to have an enhancement pattern suggestive of infection. The CT phases did not differ significantly in terms of the conspicuity of detected lesions. CONCLUSION: In patients suspected of having hepatic fungal infection, arterial phase CT depicts significantly more hepatic lesions than does CT performed during the other phases, and it reveals more lesions with enhancement patterns suggestive of infection. Arterial phase CT should be performed in addition to portal venous phase CT in patients suspected of having hepatic fungal infection.     

Liver metastases from melanoma: detection with multiphasic contrast-enhanced CT.

PURPOSE: To assess the clinical utility of multiphasic computed tomography (CT) of the liver in patients with metastatic melanoma. MATERIALS AND METHODS: Nonenhanced and biphasic hepatic CT examinations were performed in 28 patients with metastatic melanoma, and liver lesion conspicuity was graded. CT studies in 20 patients met the eligibility criteria, and 13 patients had liver lesions. RESULTS: A total of 57 liver lesions were seen on CT studies: 48 on hepatic arterial phase images, 49 on portal venous phase phase images, and 30 on delayed phase images. Of eight lesions overlooked on portal venous phase images, six were seen on nonenhanced images, and six were seen on arterial phase images. Twenty-eight lesions were graded as more conspicuous on portal venous phase images; 10 were graded as more conspicuous on arterial phase images. CONCLUSION: CT images obtained only during the portal venous phase would have resulted in eight (14%) overlooked lesions, which implies that more than one phase is needed for hepatic CT in patients with malignant melanoma. The combination of nonenhanced and portal venous phase CT was as effective as the combination of arterial and portal venous phase CT in these patients. Delayed phase CT did not improve lesion detection either alone or in combination with CT at other phases.     

Unusual enhancement pattern of liver lesions in hepatosplenic candidiasis

Purpose: To describe an unusual enhancement pattern of hepatosplenic candidiasis (HSC) liver lesions in biphasic spiral liver computed tomography (CT).

Material and Methods: Twenty-one patients with suspected HSC were scanned with a biphasic liver CT perfusion protocol. The liver lesions detected were assessed for their morphology and enhancement pattern during both perfusion phases. A liver biopsy was performed in 11/21 patients.

Results: The majority of hepatic lesions in 15/21 patients showed the well-known abscess-like pattern. In 6/21 patients an uncommon central contrast enhancement with a peripheral double ring was detected in the arterial phase. In some cases the lesions showed decreased diameter or even seemed to disappear completely in the portalvenous phase.

Conclusions: CT in the arterial phase showed an unusual enhancement pattern of liver lesions in HSC. Scanning only in the portalvenous phase implies possible pitfalls, because lesions may be overlooked or undersized. Therefore, biphasic liver CT is considered essential in the diagnosis and follow-up of HSC in clinical practice.     

Focal liver lesions: pattern-based classification scheme for enhancement at arterial phase CT

PURPOSE: To present our early experience with a classification scheme for categorizing focal liver lesions on the basis of the enhancement patterns that they exhibit in the arterial phase of computed tomography (CT) and to determine whether particular enhancement patterns suggest particular diagnoses. MATERIALS AND METHODS: The authors reviewed arterial phase CT images in 100 consecutive patients with focal liver lesions, excluding simple cysts. The enhancement pattern of the dominant or representative lesion in each patient was classified into one of five categories-homogeneous, abnormal internal vessels or variegated, peripheral puddles, complete ring, or incomplete ring-by three radiologists blinded to the proved diagnosis. Lesions without enhancement were recorded separately. Agreement was reached by consensus in all cases. Standards of reference included findings at histologic examination, correlative imaging, or clinical and imaging follow-up. RESULTS: Ninety-two percent of the 100 lesions demonstrated arterial phase enhancement. Patterns associated with positive predictive values of 82% or greater and specificity of 80% or greater included abnormal internal vessels or variegated (hepatocellular carcinoma), peripheral puddles (hemangioma), and complete ring (metastasis). CONCLUSION: The appearance of hepatic lesions in the arterial phase of enhancement has potential use in the determination of specific diagnoses. The classification scheme used in this study may be a useful tool for the interpretation of arterial phase CT studies.     

肝脏炎性假瘤的CT表现及鉴别诊断

目的:探讨肝脏炎性假瘤的CT表现和诊断价值.材料和方法:回顾性分析经病理证实的肝脏炎性假瘤19例之CT表现.结果:17例单发病灶,2例多发病灶.19个病灶呈低密度,2个病灶呈等密度;增强扫描动脉期无明显增强,门脉期、延迟期病灶为边缘增强、间隔增强及中心或壁结节增强.结论:大部分炎性假瘤CT三期动态扫描能够正确诊断.     

肝局灶性结节增生的多种影像学表现分析

目的分析肝局灶性结节增生(FNH)的CT、DSA及18FDG正电子发射体层摄影术(PET)的影像表现,认识FNH的多种影像学特征.资料与方法 10例FNH经手术病理证实,回顾分析其多种影像学表现.10例均行CT平扫及动态增强扫描,其中4例行DSA肝动脉造影,2例行18FDG PET显像.结果 10例FNH均为单发性结节,位于肝右叶8例,肝左叶2例.肿瘤直径1.1～9.3 cm,平均5.1 cm.CT检查10例,平扫均为低密度,其中8例病灶(直径均＞3.0 cm)中央区有星芒状的更低密度区;增强扫描,动脉期9个结节明显强化,1个中等强化,病灶中央更低密度区无强化,2个病灶中央或周边见增粗迂曲血管,其中1个尚可见动脉-门脉、动脉-静脉分流现象;门脉期病灶密度稍有下降,8个高于或等于肝实质,2个低于肝实质;延迟期7个等于或略高于肝实质,3个低于肝实质,5个病灶中央更低密度有强化.血管造影:4例FNH的供血动脉均来自肝动脉系统,供血动脉增粗、扭曲, 1例血管分支放射状分布,周围呈环绕状聚集染色,中央局限性缺损,另3个分支血管紊乱并呈抱球征,1个尚见动脉-门脉、动脉-静脉分流.2例18FDG PET显像均未见异常放射性浓聚.结论 FNH CT平扫为低密度,增强扫描以"快进慢出"为主要特征,而血管造影显示肝动脉供血为主,表现为供血动脉增粗、扭曲,呈轮辐状向周围发散.这些影像特征有利于FNH的定性诊断.     

MSCT对肝硬化中非肿瘤性APS的诊断探讨

目的 探讨MDCT对肝硬化中非肿瘤性肝动脉门静脉分流(APS)的诊断价值. 资料与方法 对照数字减影血管造影术(DSA)结果 分析23例肝硬化患者的MDCT增强扫描及多平面重组(MPR)图像的表现. 结果 23例患者中发现28个APS灶,在动脉期均显示为高密度,门脉期为等密度,24个位于肝包膜下.在CT横断面上13个病灶表现为楔形或不规则形,另外15个虽表现为小结节样病灶但在MPR图像上13个也表现为楔形或不规则形.26个病灶DSA表现为门脉小分支早期显影,另2个DSA表现未见异常. 结论 肝硬化患者的MDCT增强扫描动脉期显示肝脏周边较小的楔性、结节样或不规则形高密度灶而在门脉期呈等密度提示非肿瘤性APS.