超声引导细针活检对肝脏小占位病变的诊断价值

９４例肝脏小占位病变经超声引导穿刺活检或手术病理均获得确诊。其中肝细胞肝癌５１例、肝转移癌９例、血管内皮肉瘤１例，合计恶性６１例，占６４．９％；良性病变有肝血管瘤、非均匀脂肪肝、局灶性结节状增生、炎性病灶及坏死灶共计３３例，占３５．１％。本项结果表明超声虽然能显示肝癌和一些良性病变的某些与组织病理相关的特征，然而对恶性或良性的鉴别诊断水平不高，其敏感性为６５．６％，特异性为４８．５％，准确性为５９．６％；而超声引导细针活检则能对占位病变提供确切的组织病理诊断，对肝癌诊断的敏感性为９６．７％，特异性为９３．９％，准确性为９５．７％。     

3D DCE MRA在原发性肝癌诊断中的临床应用

目的：探讨单次屏气三维对比增强磁共振造影(3D DCE MRA)在原发性肝癌中的检查技术及临床应用。方法：回顾性分析23例原发性肝癌的3D DCE MRA表现。对原发性肝癌肝动脉期、门静脉期分别进行扫描和重建。结果：肝动脉期可显示肝癌供血动脉血管7例，动静脉瘘6例，肝动脉受挤压变形6例。门静脉期显示门静脉高压18例。门静脉癌栓13例，肝内门静脉受压移位3例。结论：有效地抓住对比剂在各靶血管中的有效浓度，可分别显示肝癌的血供情况、血管破坏情况、门静脉开放程度，为临床治疗提供有价值的影像参考。     

肝肿瘤的双期动态CT诊断

目的：探讨双期动态ＣＴ对肝肿瘤诊断的价值。方法：４８例肝肿瘤患者平扫发现并定位病灶后，用压力注射器以３ｍｌ／ｓ速度从肘静脉经１７号塑料套管针注入造影剂６０ｍｌ，开始注射后１４ｓ行双期动态ＣＴ，同层共扫７次。结果：本方法对原发肝癌、肝血管瘤和肝转移癌的定性诊断准确性分别为９５．７％、１００％和８０％，均明显高于普通增强ＣＴ（Ｐ＜０．０５）。原发肝癌的典型表现是动脉期病灶内结节状、片状强化，并可见肿瘤血管影，强化部分在静脉期迅速呈低密度影；肝血管瘤的特征性表现为动脉期病灶边缘结节状强化，密度类似于主动脉或肝动脉，静脉期强化结节逐渐向病灶中央扩展；肝转移癌的主要表现为动、静脉期病灶边缘环状强化，中央部分无明显强化，静脉期还可见到“牛眼征”。结论：双期动态ＣＴ能获取肝肿瘤的特征性表现，可作为肝脏肿瘤常规的检查方法     

肝癌术后复发的血管造影

目的：探讨肝癌术后复发血管造影的影像学表现及其诊断价值。方法：回顾性分析112例原发性肝癌手术切除后复发的肝动脉造影表现和化疗栓塞治疗的结果。结果：造影表现归纳为3种类型：Ⅰ型（边缘复发型）23例,占20．5％;Ⅱ型（肝内播散型）81例,占72．3％;Ⅲ型（隐匿复发型）8例,占7．1％。造影表现特点：血供相对不丰富,肿瘤结节染色浅淡,病灶常呈多发性;小病灶（直径〈2．0cm）多见。结论：肝癌手术后复发血管造影对于指导原发性肝癌的综合治疗具有十分重要的意义。     

肠系膜上动脉供血型肝癌的血管造影分析及介入治疗

目的：研究肠系膜上动脉供血型(即变异肝动脉起源于肠系膜上动脉)肝癌的血管造影表现及插管技术。方法：回顾分析41例肠系膜上动脉供血型肝癌的DSA及介入治疗资料，统计血管解剖变异的发生率，对其起源、走行、分支、分布等解剖学特征及其与血管插管的关系进行描述和分析。结果：350例肝癌中肠系膜上动脉供血型41例(11．9％)，其中副肝右动脉15例(36．5％)，替代肝右动脉16例(39．0％)，肝总动脉8例(19．5％)，腹腔动脉干起源于肠系膜上动脉2例(5％)。31例肠系膜上动脉发出替代或副肝右动脉者，29例(94．0％)腹腔动脉造影表现为肝右动脉细小或缺如，肝右叶出现无血管区。RH导管超选择性插管成功25例(61％)，未成功者改用Cobra、Simmon导管以及结合微导管技术后获得成功。结论：肠系膜上动脉供血型肝癌是一种比较常见的肝动脉变异性供血，熟忿其血管变异的特点对肝动脉化疗栓塞术具有重要的意义。     

肝动脉注射治疗剂量~（131）Ⅰ－抗人肝癌McAb的RⅡ

在动物实验基础上，以１３１Ⅰ标记抗人肝癌单克隆抗体ＨｅｐａｍａⅠ进行人体显像研究．单抗系小鼠ＩｇＧ１，裸鼠实验显示有良好的肿瘤定位效果。１８例原发性肝癌（ＰＨＣ）患者，以Ｓｅｌｄｉｎｓｅｒｓ法经肝固有动脉注入１３１Ⅰ－ＨｅｐａｍａⅠ，平均剂量为３５５ＭＢｑ／１．５ｍｇＩｇＧ１，术后行全身及肝区γ显像．测定全身重要脏器和癌区的放射性计数比值．结果：显像阳性率７７．７％，最佳时间为注入后９６小时，癌／肝比值在第４８小时为１．６５±０．３３，第９６小时为４．３８±１．４８，第２４０小时为２．２２±０．５７．本研究提示ＨｅｐａｍａⅠ在人体内与肝癌组织有较好亲和力．     

二维及三维超声鉴别诊断肝小血管瘤与小肝癌

目的：研究二维及三维超声在肝内小血管瘤与肝癌鉴别诊断中的作用。方法：选择经手术病理证实、肝组织病理活检或增强CT/MRI检查最长径＆lt;3cm的肝内小占位性病变,66例共87个病灶;其中肝小血管瘤26例33个病灶,小肝癌40例54个病灶（原发性肝癌27例27个病灶、肝转移癌13例27个病灶）患者,行二维及三维超声检查。分别记录PSV、RI、VI。结果：典型的小肝癌及肝小血管瘤二维图像有特征性的改变,血流速度小肝癌高于肝小血管瘤,三维超声的血流指数原发性和转移性小肝癌均高于肝小血管瘤,但原发性和转移性小肝癌之间的血流指数无差异。结论：三维超声可以定量研究肝脏小占位性病变的血流指数,肝小血管瘤及小肝癌的血流指数特点在协助二维及彩色多普勒超声鉴别诊断方面有一定的作用,二维和三维相结合可以更好地定性诊断肝内小病变。     

动态Gd-DTPA增强MRI对肝局灶性病变的诊断价值

目的：探讨动态Ｇｄ－ＤＴＰＡＭＲ扫描对肝局灶性病变的诊断价值。方法：对４１例肝局灶病变进行常规Ｔ１Ｗ、Ｔ２Ｗ和动态Ｇｄ－ＤＴＰＡ增强扫描，比较两种方法对肝局灶病变和诊断正确率，并对动态增强的类型和血液动力学改变进行分析。结果：平扫诊断率为８０％，单纯动态增强为９３％，两者结合起来则正确率提高到１００％（ｐ＜０．０５）。动态增强上，９４％的恶性肿瘤表现为早期强化，后期消退（Ⅰ型）；９０％血管表现为进行性强化（Ⅱ型）；而表现为轻度强化（Ⅲ型）者１００％为恶性肿瘤。不强化（Ⅳ型）者主要为良性病变，占７７％（ｐ＜０．０５）。结论：动态增强扫描对肝局灶病变诊断正确率优于平扫，尤其结合平扫则更能提高对肝局灶病变的诊断和鉴别诊断能力。     

CT在脊椎转移中的应用价值探讨（53例影像学研究）

本文报告５３例（１２３个脊椎）经ＣＴ扫描确定的脊椎转移，其中２６例作Ｘ线平片检查，所有病例均经临床病理证实。原发性以肺癌、乳腺癌、肝癌和前列腺癌较多见，ＣＴ表现呈溶骨性３８例（７１．７％），混合性９例（１６．９％），和成骨性６例（１１．３％）。椎体是脊椎转移瘤最常累及的部位，这与血管进入脊椎的部位有关。转移最初的部位是椎体的后部，椎弓根破坏为堆体后部破坏扩展所致。ＣＴ扫描在发现病变和估价病变方面较     

肝动脉注射治疗剂量^131I—抗人肝癌McAb的RII

在动物实验基础上，以＾１３１Ｉ标记抗人肝癌单克隆抗体Ｈｅｐａｍａ Ｉ进行人体显像研究。单抗系小鼠ＩｇＧ１，裸鼠实验显示有良好的肿瘤定位效果。１８例原发性肝癌（ＰＨＣ）患者，以Ｓｅｌｄｉｎｇｅｒｓ法经肝固有动脉注入＾１３１Ｉ－Ｈｅｐａｍａ Ｉ，平均剂量为３５５ＭＢｑ／１．５ｍｇ ＩｇＧ１，术后行全身及肝区γ显像，测定全身重要脏器和癌区的放射性计数比值。结果：显像阳性率７７．７％，最佳时间为注入后９６     

Patterns of contrast enhancement of benign and malignant hepatic neoplasms during bolus dynamic and delayed CT

Bolus dynamic and delayed computed tomographic (CT) scans of the liver were evaluated in 43 patients with 54 hepatic hemangiomas and 111 patients with primary or secondary malignant hepatic neoplasms. Twelve patterns of contrast enhancement were recognized during the bolus dynamic phase and delayed scanning. A "typical" CT pattern for hemangiomas (present in 29 of 54 hemangiomas [53.7%]) was established: (a) diminished attenuation prior to intravenous contrast medium administration (excluding lesions arising in a liver with diffuse fatty infiltration), (b) peripheral contrast enhancement during the bolus dynamic phase, and (c) complete isodense fill-in on delayed scan images. Using these criteria, we distinguished hemangiomas from malignant neoplasms in most patients. Only one of 63 (1.6%) malignant neoplasms manifested these typical CT criteria of hemangioma. There is an 86% chance that a lesion with the typical CT appearance of hemangioma is actually a hemangioma, even when found in a patient with a known nonhepatic primary neoplasm.     

Importance of evaluating all vascular phases on contrast-enhanced sonography in the differentiation of benign from malignant focal liver lesions

OBJECTIVE: Our objective was to evaluate the accuracy of a blood-pool sonographic contrast agent in the late phase compared with the three vascular phases for differentiation between benign and malignant focal liver lesions. SUBJECTS AND METHODS: In 152 patients (105 with chronic liver disease), 152 solid focal liver lesions characterized either by fine-needle biopsy or by dynamic CT or MRI were studied. The final diagnoses were metastasis for 24, hepatocellular carcinoma for 75, focal nodular hyperplasia for 13, regenerating or dysplastic nodule for 14, hemangioma for 22, cholangiocarcinoma for two, and another focal liver lesion for two. Real-time sonography was performed after a bolus injection of 2.4 mL of SonoVue, using a low mechanical index (< 0.2). All lesions were evaluated in the arterial, portal, and late phases; classified as benign or malignant; and correlated with final diagnoses. RESULTS: For discrimination between malignant and benign focal liver lesions, evaluation of all vascular phases improved the sensitivity from 78.4% to 98% and the accuracy from 80.9% to 92.7%, compared with evaluation of the late phase alone. The increase in accuracy was higher in patients with chronic liver disease (16.3%) than in those without (2.1%). CONCLUSION: Evaluation of SonoVue enhancement in all three vascular phases is superior to evaluation of SonoVue enhancement in the late phase alone, especially in patients with chronic liver disease.     

螺旋CT多时相扫描鉴别诊断肝细胞癌和血管瘤

目的:探讨螺旋CT多时相扫描对肝细胞癌和血管瘤的鉴别诊断。材料和方法:对37例患者(肝癌16例,血管瘤21例)行螺旋CT平扫和增强扫描,分析其表现。结果:37例平扫均发现低密度灶。肝细胞癌在动脉期75%有显著增强,呈高密度,在门静脉期和延迟期则呈低密度;血管瘤54%动脉期有典型增强表现,门静脉期100%有增强,24%全部填充,延迟期91%为高密度或等密度。结论:肝细胞癌和血管瘤在螺旋CT多时相增强扫描中,各有其典型的CT表现,两者鉴别的关键是门静脉期。     

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。     

Magnetic resonance imaging of cavernous hemangioma of the liver: tissue-specific characterization

Twenty-one patients with hepatic hemangioma, five with hepatic cysts, and 25 with primary or metastatic cancer involving the liver were studied by magnetic resonance imaging (MRI). Benign lesions (hemangiomas, cysts) were diagnosed noninvasively by CT, radionuclide studies, and/or sonography and confirmed by follow-up examinations more than 1 year later. Malignant lesions were confirmed by liver biopsy in every case. Identical multisection/multiecho techniques were used in all patients to obtain T1-and T2-weighted spin-echo (SE) and inversion-recovery (IR) images. MRI detected more hemangiomas than any other imaging technique. Of 30 hemangiomas, 25 were spherical or ovoid with a homogeneous appearance and smooth, well defined margins. Cancer tended to have a heterogeneous appearance and poorly defined margins. On T2-weighted SE images obtained with 2000 msec TR and 60, 120, or 180 msec TE, hemangiomas had significantly greater contrast-to-noise ratios (C/N) than liver cancer (p less than 0.001). The SE 2000/120 sequence provided the single most useful image for distinguishing hemangiomas from cancers. When morphologic criteria are used in conjunction with measured C/N, MRI correctly distinguished cavernous hemangiomas from liver cancer with 90% sensitivity, 92% specificity, and an overall accuracy of 90%. Cysts had a low signal intensity on SE 500/30 images and could often be distinguished from hemangiomas and cancers that were nearly isointense relative to liver. IR images were sensitive for lesion detection but provided no tissue-specific information. The data indicate that T2-weighted SE imaging may become the procedure of choice for distinguishing cavernous hemangioma from liver cancer.     

Characterization of liver hemangiomas with pulse inversion harmonic imaging

The purpose of this study was to determine if pulse inversion harmonic imaging (PIHI) can characterize liver hemangiomas. We retrospectively evaluated 39 consecutive patients with liver hemangiomas, 20 typical on conventional US (hyperechoic, homogeneous, or slightly inhomogeneous and with sharp margins) and 19 atypical (11 inhomogeneous with different echogenicity larger than 3 cm, 6 hypoechoic, and 2 isoechoic smaller than 3 cm). Each liver hemangioma was firstly evaluated by PIHI and then confirmed by dynamic helical CT (28 patients) or by 6 months of US follow-up (11 patients). The PIHI was performed by two distinct sweeps on a marker lesion, 30 s (vascular phase) and from 3 to 5 min (late phase) after bolus injection of Levovist (2.5 g, 300 mg/ml). Scans were digitally stored and reviewed using a dedicated software. Contrast enhancement features of marker lesion were subjectively evaluated. Typical hemangiomas on conventional US revealed on PIHI a characteristic rim-like or peripheral globular enhancement on 30-s scan in 4 of 20 cases (20%) and a characteristic isoechoic pattern on late phase in 16 of 20 cases (80%). On PIHI, all (11 of 11) atypical hemangiomas larger than 3 cm and 4 of 8 atypical liver hemangiomas smaller than 3 cm revealed a characteristic rim-like or peripheral globular enhancement on vascular phase with a characteristic centripetal fill-in on late phase. In 4 of 8 atypical liver hemangiomas smaller than 3 cm no characteristic pattern was revealed by PIHI. Pulse inversion harmonic imaging revealed a typical pattern in the majority of liver hemangiomas typical and atypical on conventional US. In few liver hemangiomas atypical on conventional US PIHI did not identify a characteristic pattern and helical CT was necessary for final characterization.     

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.     

Radiologists' performance in the diagnosis of liver tumors with central scars by using specific CT criteria

PURPOSE: To determine the performance of radiologists with differing levels of expertise in the diagnosis of the most common types of liver tumors with central scars (ie, focal nodular hyperplasia [FNH], fibrolamellar hepatocellular carcinoma [HCC], and large hepatic hemangioma) by using specific computed tomographic (CT) findings. MATERIALS AND METHODS: Review of medical records at the University of Pittsburgh Medical Center identified patients with a total of 64 liver tumors that had central scars-including 29 cases of FNH, 20 fibrolamellar HCCs, and 15 large (>3.5 cm in diameter) hemangiomas-and with CT scans available for review. Retrospective review of these scans was performed individually by six radiologists who were blinded to the diagnosis, including two faculty abdominal radiologists, one abdominal imaging fellow, and three radiology residents. Individual performance was evaluated by means of receiver operating characteristic analysis, and interobserver agreement was measured by using the Cronbach alpha. Individual CT findings that may allow differentiation of tumor types were identified with the Kruskal-Wallis test. RESULTS: CT allowed good to excellent interobserver agreement in the diagnosis of tumor type and in recognition of differential findings among the three types. The individual accuracy of diagnosis was very good, with the average area under the receiver operating characteristic curve ranging from 0.81 to 0.90. Although the faculty radiologists performed the best, the differences in performance between the subgroups of readers and the levels of confidence in diagnosis were not statistically significant. The diagnosis of fibrolamellar HCC was the most accurate and had the highest sensitivity, followed by FNH and large hemangioma. Clinical and CT findings that were found to be statistically significant in differentiating tumor types were patient age and sex, tumor size larger than 10 cm, width of tumor scars, invasion of vessels, nodular centripetal enhancement, marked hyperattenuation on arterial phase images, lymphadenopathy, heterogeneity, extrahepatic metastases, surface lobulation, calcification, and isoattenuation with liver tissue on portal venous phase images. CONCLUSION: CT allows accurate differentiation of the most common types of liver tumors with central scars, including FNH, fibrolamellar HCC, and large hemangioma.     

Dynamic sonography of hepatic tumors

OBJECTIVE: Our objectives were to propose and evaluate a dynamic sonography protocol for the characterization of hepatic tumors. SUBJECTS AND METHODS: The subjects were 107 patients with focal liver lesions that initially had been found on conventional sonograms. The final diagnoses for the lesions were hepatocellular carcinoma in 60 patients, cholangiocellular carcinoma in six, metastatic carcinoma in 24, hemangioma in 10, and focal fat-spared region in seven. The pulse inversion harmonic imaging mode and a galactose-based contrast agent (Levovist) were used. Dynamic sonography was designed to obtain vascular-phase (composed of the arterial phase and the portal phase) images of the focal lesion and liver-parenchymal-phase images of the whole liver in a series obtained after a bolus injection of the contrast agent. RESULTS: If the whole-tumor or mosaic enhancement patterns (arterial phase) and/or the reticular enhancement (parenchymal phase) are regarded as positive findings for hepatocellular carcinoma, the sensitivity, specificity, and positive predictive value of dynamic sonography in our study were 92%, 96%, and 96%, respectively. If a ring enhancement (arterial to portal phase) or a clear defect (parenchymal phase) or both are regarded as positive findings for cholangiocellular carcinoma or metastasis, the sensitivity, specificity, and positive predictive value were 90%, 95%, and 88%, respectively. If puddle enhancement (portal phase) is regarded as a positive finding for hemangioma, the figures for sensitivity, specificity, and positive predictive value were 60%, 100%, and 100%, respectively. Also, the tumors that showed no focal sign in the liver parenchymal phase were all benign lesions, such as hemangiomas or focal fat-spared regions. CONCLUSION: Dynamic sonography in a protocol combining pulse inversion harmonic imaging and an IV bolus injection of the contrast agent proved to be an effective tool in characterizing liver tumors.     

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。