超声造影诊断肝脏局灶性结节状增生的价值

目的：探讨超声造影诊断肝脏局灶性结节状增生的价值。材料和方法：回顾分析了11例肝脏局灶性结节状增生的超声造影表现。9例于造影后经超声引导穿刺确诊,2例经手术确诊。结果：11例病灶动脉期均快速显著增强。9例病灶动脉早期呈轮辐状增强,造影三期回声强于周边肝实质,实质期可见轮辐状低回声；2例病灶动脉早期快速增强,动脉期及门脉期回声强于周边肝实质,实质期回声与肝实质等同,未见轮辐状低回声。结论：超声造影所显示的肝脏局灶性结节状增生的增强特征,有助于临床诊断。部分病灶超声造影表现缺乏特异性,确诊仍需要结合其他影像学方法和穿刺活检。     

肝血管瘤超声造影表现

目的:探讨肝血管瘤超声造影(contrast enhanced ultrasound,CEUS)的表现。方法:应用对比剂Sonovue及对比脉冲序列成像(contrast pulse sequenuce sound,CPS)技术对25例28个肝血管瘤进行超声造影检查,观察对比剂在动脉期、门脉期及延迟期的增强表现。结果:26个(92.9%)病灶动脉期呈环状增强伴附壁结节或球状突起,门脉期呈缓慢向心性充填,21个病灶呈完全充填,5个病灶呈不完全充填,延迟期与周围肝实质期比呈相对高增强;另2个(7.1%)病灶动脉期、门脉期及延迟期均无增强。结论:超声造影肝血管瘤的典型增强表现为动脉期环状增强,门脉期缓慢向心性充填,延迟期呈高增强。     

多排螺旋CT对肝脏孤立性坏死结节的诊断价值

目的探讨肝脏孤立性坏死结节的CT表现特征,以提高诊断准确率。方法对6例肝脏孤立性坏死结节进行常规CT平扫及增强扫描,全部病例均经病理证实,观察并记录病灶的大小、形态、边界、密度及增强特点。结果病灶多位于肝表面和肝浅表实质内,呈圆形或类圆形,边界清楚,最小的1.7cm×2.1cm,最大的4.9cm×3.7cm,CT平扫4例为低密度影,1例为等密度影,其中1例内部密度不均匀,可见片状等密度影,增强后5例病灶在动脉期、门静脉期及延迟期呈内部无增强表现,1例病灶内部见多发斑块状与肝实质等密度强化灶,病灶边缘见细环形强化且在延迟期更明显。结论病灶内部三期基本无强化和周边可伴有或不伴有环形强化为肝脏孤立性坏死结节主要CT表现,MSCT是诊断肝脏孤立性坏死结节有价值的检查方法。     

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。     

超声造影对肝脏转移癌的诊断应用价值

目的:探讨超声造影对肝脏转移癌的诊断应用价值.方法:对49例恶性肿瘤患者肝脏行常规超声检查及低机械指数超声造影检查,对肝内转移性病灶超声造影表现进行分析.结果:经超声造影新发现47个病灶,其中小于1.0cm的病灶占55.3%(26/47).肝转移病灶的增强模式可分为4种:A.病灶周边快速环状强化60/131(45.8%),病灶内部呈低或无增强,之后周边增强部分造影剂迅速退出呈低增强;B.病灶于动脉期呈快速整体强化并迅速廓清51/131(38.9%);C.病灶于动脉期和门脉期基本与肝脏实质同步强化,延迟晚期呈低增强12/131(9.2%);D.病灶于造影三期均低于肝实质呈低增强表现8/119(6.1%).结论:肝脏转移病灶来源和大小不同其增强模式表现亦不相同;实时超声造影可提高对肝脏转移病灶尤其可提高直径小于1.0cm的微小转移灶的检出率.     

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。     

肝局灶性结节增生的DSA表现及介入治疗

目的 探讨肝局灶性结节增生的DSA表现及肝动脉硬化栓塞术对其治疗效果.方法 回顾6例病理证实为肝局灶性结节增生的动脉造影表现,其中4例用平阳霉素碘油乳剂加明胶海绵颗粒或 500～700 μm PVA行肝动脉硬化栓塞.结果 动脉造影示:病灶富血性,供血动脉增粗、迂曲,其中3例供血动脉进入病灶后血管分支呈放射状向周围分布发散,3例供血动脉呈抱球征.所有病例实质期均见病灶中央无染色的放射状分隔,病灶染色均匀,边界清楚.5例见肝静脉引流,1例见门脉引流.4例均成功行肝动脉硬化栓塞术.术后随访1～3.5年,患者症状均消失,2例病灶消失,2例明显缩小,无并发症.结论 对FNH定性诊断,动脉造影虽有一定的特征性,最终诊断仍需依赖病理活检结果.经肝动脉硬化栓塞治疗肝局灶性结节增生是一种安全有效的方法.     

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.     

平扫和动态增强MRI诊断肝脏局灶性结节增生

目的 探讨肝脏避灶性结节增生（ＦＮＨ）的平扫和动态增强的ＭＲＩ表现及诊断价值。方法 回顾分析２２例２２个手术病理证实的肝脏ＦＮＨ的平扫及动态增强ＭＲＩ资料。结果 病灶平均大小为４．０５ｃｍ,４个病灶在Ｔ１ＷＩ及Ｔ２ＷＩ上呈典型等信号肿块,１８个为不典型信号肿块。８个在平扫ＭＲ上显示中央瘢痕。２１个病灶的实质部分在增强后动脉期呈明显均匀强化,在门脉期及延迟期呈等强化或强于肝实质。２个病灶在门脉期和延     

超声造影与彩色多普勒超声诊断肝实质性肿块对照研究

 目的 比较彩色多普勒超声和实时超声造影对肝实质性肿块的诊断价值.方法 应用彩色多普勒超声及超声造影技术对常规二维超声难以定性的27例共31个肝实质性肿块进行检查,结果与手术及病理结果相对照.结果 31个肿块中原发性肝细胞性肝癌24个,肝血管瘤3个,肝脏局灶性结节增生3个,肝孤立性坏死结节1个.彩色多普勒超声在肿块内部或肿块周边能检测到动脉血流频谱者共19例21个肿块;超声造影除一例肝孤立性坏死结节外,其余30个病灶均在不同时相出现不同程度强化现象.如以动脉相呈高回声而门脉相及延迟相呈低回声为恶性肿块的诊断标准,则超声造影对肝癌诊断的准确率为91.67%;如以肿块内部检测到动脉样血流频谱为诊断恶性肿块的诊断标准,则彩色多谱勒超声诊断肝癌的准确率为75%.超声造影诊断肝实质性肿块准确率为93.54%,彩色多普勒超声诊断肝实质性肿块准确率为64.52%.二者差别有统计学意义(P＜0.05).结论 实时超声造影显著提高肝内实质性肿块的诊断准确性,对肝脏实质性肿块良、恶性的诊断及鉴别诊断具有重要价值.     

Solitary Necrotic Nodules of the Liver Mimicking Hepatic Metastasis: Report of Two Cases

We present two cases of solitary necrotic nodules of the liver which on radiologic images mimicked hepatic metastasis. Solitary necrotic nodule of the liver is a rare but benign entity which histopathologically consists of an outer fibrotic capsule with inflammatory cells and a central core of amorphous necrotic material. The lesion was seen on contrast-enhanced CT as an ovoid-shaped hypoattenuating nodule; on CT during hepatic arteriography as enhancing nodule; on intraoperative US as a target-appearing hypoechoic nodule; on T2WI as a hyperintensity nodule, and on dynamic MR as a subtle peripheral enhancing nodule. Although the radiologic features are not specific, solitary necrotic nodule of the liver should be included in the differential diagnosis of hepatic metastasis.     

Specific imaging characteristic of solitary necrotic nodule of the liver: Marked peripheral rim-like enhancement with internal hypointensity on longer delayed MRI

Objectives

To obtain specific imaging findings of solitary necrotic nodule of the liver (SNNL) using longer delayed contrast-enhanced MRI and compare them with those of three mimic hepatic diseases.

Methods

Sixteen patients with SNNL underwent plain and contrast-enhanced triphasic CT and multiphasic MRI with delayed time prolonged to 2 h after contrast bolus injection. Twenty-three patients with mimic lesions including seven with eight HCCs, five with five iCCs and 11 with metastatic lesions served as the control group. Those patients also received plain and multiphasic contrast-enhanced MRI. Imaging features of lesions such as peripheral wash-out time were evaluated.

Results

Among the 16 SNNLs, with a prolonged delayed MRI time, the enhancement degree of tumour periphery increased gradually. When it was up to 1 h, all lesions represented moderate/marked peripheral enhancement with internal hypointensity. However, the peripheral wash-out in seven HCCs (87.5%) and all metastatic lesions except three appeared at 10 or 15 min, one iCC (20%) at 30 min and the other lesions at 1 h.

Conclusions

Longer MRI with a delayed time of 1–2 h may be useful in diagnosis SNNL, revealing the specific imaging characteristic of SNNL as pronounced peripheral enhancement with internal hypointensity.

Key Points

? Longer delayed MRI plays an important role in the diagnosis of SNNL. ? Characteristic imaging feature of SNNL is pronounced peripheral enhancement with internal hypointensity. ? Periphery wash-out time can differentiate SNNL from mimic diseases. ? Imaging findings of SNNL on routine CT and MRI are unspecific.

     

Solitary necrotic nodule of the liver: radiologic–pathologic correlation in a case with unusual imaging features

Solitary necrotic nodule of the liver (SNNL) is rare. Generally thought to be nonmalignant, it is often mistaken for malignancy based on imaging findings alone. We present a case of a hepatitis B carrier who was found to have a new sonographically detected hepatic lesion. The lesion was further evaluated with CT and MRI, and as appearances were suggestive of a hypovascular hepatoma, the lesion was surgically resected. This case is unique in that while it demonstrates several characteristic features of SNNL, several other imaging and histological features have not been previously described.     

Kontrastmittelverst?rkte Sonographie

Due to the imaging of dynamic perfusion, hepatocellular carcinoma can be detected with a sensitivity of >90% using contrast-enhanced sonography. The characterization of liver tumors with contrast-enhanced sonography is comparable to the diagnostic accuracy of contrast-enhanced computed tomography. The dynamic detection of microvascularization with contrast-enhanced sonography allows the differentiation between vascularized tumors and non-vascularized necrotic lesions before, during and after transarterial chemoembolization or percutaneous radiofrequency ablation. Image fusion with volume navigation can be useful in the followup control.     

Value of contrast-enhanced sonography for the characterization of focal hepatic lesions in patients with diffuse liver disease: receiver operating characteristic analysis

OBJECTIVE: Our aim was to assess the diagnostic performance of contrast-enhanced agent detection sonographic imaging to characterize focal hepatic lesions in patients with diffuse liver disease in comparison with baseline sonographic images and to determine whether agent detection imaging can reduce the necessity of further diagnostic workup for lesion characterization. MATERIALS AND METHODS: Contrast-enhanced sonography using 4 g of Levovist at a concentration of 300 mg/mL was performed on 75 focal hepatic lesions in 75 patients with diffuse liver disease. Interval reviews for both baseline without and with contrast-enhanced sonography were performed independently by two radiologists. They were requested to determine the malignity of focal hepatic lesions using a 5-point confidence level and to record the specific diagnoses and the necessity for further imaging for lesion characterization. Radiologists' performances for lesion differentiation using baseline and contrast-enhanced sonography were evaluated using receiver operating characteristic (ROC) analysis. Interobserver agreement was also analyzed. RESULTS: When contrast-enhanced sonography was used, ROC analysis revealed a significant improvement for both reviewers (area under the receiver operating characteristic curve [A(z)] = 0.753 and 0.830 and 0.971 and 0.974 at baseline sonography and contrast-enhanced sonography, respectively; p < 0.002) for differentiating malignant and benign focal liver lesions. Contrast-enhanced sonography also improved specificity from 12% to 91% for reviewer 1 and from 26% to 85% for reviewer 2 compared with baseline sonography. Furthermore, excellent interobserver agreement was achieved for contrast-enhanced sonography (weighted kappa = 0.919), whereas only good agreement was achieved for baseline sonography (weighted kappa = 0.656). A better result for specific diagnosis was obtained by contrast-enhanced sonography (79% and 75%) than by baseline sonography (37% and 48%, p < 0.05). Contrast-enhanced sonography (72% and 63%) outperformed baseline sonography (35% and 28%, p < 0.05) as a confirmatory imaging technique. CONCLUSION: Contrast-enhanced agent detection sonography can be used to characterize focal hepatic lesions in patients with diffuse liver disease reliably and with a higher diagnostic confidence than baseline sonography. Furthermore, contrast-enhanced sonography reduced the need for further diagnostic workups for focal hepatic lesion characterization.     

Hepatic artery pseudoaneurysms in adult living-donor liver transplantation: efficacy of CT and Doppler sonography

OBJECTIVE: The purpose of this study was to evaluate the efficacy of contrast-enhanced CT and Doppler sonography in the diagnosis of hepatic artery pseudoaneurysm after adult living-donor liver transplantation (LDLT). CONCLUSION: Because patients with hepatic artery pseudoaneurysm after LDLT can have diverse clinical presentations, routine imaging follow-up is important for early detection. Although Doppler sonography is limited in showing the pseudoaneurysm, contrast-enhanced CT, especially MDCT with CT arteriography, is effective in showing it in most patients.     

Low mechanical index contrast-enhanced sonographic findings of pyogenic hepatic abscesses

OBJECTIVE: Low mechanical index contrast-specific sonography is a new technique that uses the harmonic capabilities of second-generation contrast agents to produce real-time contrast-enhanced gray-scale images. We describe the contrast-specific sonographic findings of pyogenic hepatic abscesses. CONCLUSION: Contrast-specific sonography was used to assess eight cases of aspiration-confirmed pyogenic liver abscesses. All cases were correlated with multiphasic helical CT findings. Continuous sonographic exploration allowed recognition of morphologic details not detectable on CT images. Contrast-specific sonograms showed features including rim enhancement, arteries along abscess margins and internal septa, dense and persistent septal enhancement, absent microcirculation in fluid and necrotic components, transient arterial phase hypervascularity around abscesses, and portal phase hypovascularity around abscesses. This constellation of findings is suggestive of liver abscess.     

低机械指数实时超声造影评价恶性肿瘤治疗后肝内复发转移的临床研究

目的:探讨低机械指数超声造影成像技术定性诊断恶性肿瘤治疗后肝内可疑复发转移病灶的价值。材料和方法:78个肝脏局灶性病变,同期行实时超声造影、CT增强检查,最终诊断经穿刺活检病理证实62个结节,另13个局部治疗后坏死结节及3个增生结节经综合影像及12~34个月随访证实。结果:超声造影诊断的敏感性96.2%,特异性92.3%,准确性94.9%,阳性预测值92.3%,阴性预测值96.2%。70个结节同期CT增强诊断,结果与最终诊断及超声造影诊断的一致性比较无统计学差别。结论:实时超声造影是定性诊断肝局灶性病变的有效方法,尤其对经肝动脉栓塞后碘油沉积病灶残存血流灌注的评判较CT具有优势。     

超声造影对肾细胞癌的诊断价值

目的探讨超声造影对肾细胞癌的诊断价值。方法对经病理证实的89例肾细胞癌患者进行回顾分析研究,用常规超声和SonoVue超声造影剂分别显示假包膜和肿块内的囊腔、出血及坏死灶,并进行显示率的对比分析。结果常规超声显示出假包膜的有32例(32/89,35.9%),超声造影显示出假包膜有59例(59/89,66.3%);常规超声显示出瘤体内的囊腔、出血和坏死灶有43例(43/89,48.3%),超声造影显示出有68例(68/89,76.4%),两者对肾细胞癌的假包膜和肿块内的囊腔、出血及坏死灶的显示率差异有显著统计学意义(P<0.01)。结论超声造影较常规超声能更清楚显示肾细胞癌的假包膜和瘤体内的囊腔、出血和坏死灶,为超声诊断肾细胞癌提供更多的信息。超声造影对肾细胞癌的明确诊断具有十分重要的临床价值。     

Late-phase pulse-inversion sonography using the contrast agent levovist: differentiation between benign and malignant focal lesions of the liver

OBJECTIVE: We assessed the ability of contrast-enhanced sonography to reveal differences between benign and malignant focal hepatic lesions. SUBJECTS AND METHODS: We examined 67 patients with focal hepatic lesions in a prospective study. The causes of the lesions were confirmed by histology, CT, MR imaging, or scintigraphy. The liver was screened for focal lesions using sonography. Thereafter, 2 g of Levovist (300 mg/mL; 1 mL/sec) was injected IV as a bolus. After a delay of at least 2.5 min without scanning, the liver was examined via three different scans using pulse-inversion sonography. RESULTS: For the discrimination of malignant versus benign liver lesions, contrast-enhanced sonography improved sensitivity from 85% to 100% and specificity from 30% to 63%, as compared with baseline sonography. Receiver operating characteristic analysis revealed a significant improvement in this discrimination (A(z) = 0.692 +/- 0.065 at baseline sonography, A(z) = 0.947 +/- 0.037 with contrast-enhanced sonography, p < 0.001). Furthermore, a lower interobserver variability was found for contrast-enhanced sonography (weighted kappa = 0.947), as compared with baseline sonography (weighted kappa = 0.469). All lesions that had homogeneous enhancement in the late phase of Levovist enhancement were benign. In distinction, 90% of lesions without contrast enhancement in the late phase were malignant. All lesions were malignant that were isoechoic (invisible) on baseline sonography but visible because of lack of enhancement after injection. CONCLUSION: Contrast-enhanced sonography has greater specificity and sensitivity than baseline sonography for the differentiation of benign and malignant liver lesions.