肝脏血管平滑肌脂肪瘤的CT影像表现

目的探讨分析肝脏血管平滑肌脂肪瘤（angiomyolipoma,AML）CT表现及特征。方法回顾性分析8例经手术病理证实,且均进行了CT检查的肝脏AML患者资料。结果8例肝脏AML中脂瘤型1例,以脂肪成分为主,CT显示大片脂肪密度;血管瘤型2例,以血管成分为主,CT增强动脉期明显强化;肌瘤型1例,主要是由平滑肌成分组成,平扫密度均匀,增强呈均一或不均匀强化;混合型4例,三种成分含量相似,增强扫描呈不均匀强化。结论不同病理类型的肝脏AML的CT表现有所不同,CT检查可以清晰的显示出肿瘤的影像特征,了解肝脏AML的病理类型与CT表现之间的关系,有助于提高肝脏AML的cT诊断率。     

全肝CT灌注扫描对于介入术后肝肿瘤活性的观察

目的经动脉导管化疗栓塞术(transarterial chemoembolization,TACE)治疗后患者进行全肝灌注扫描,比较增强CT、全肝灌注扫描和DSA三种检查技术对TACE治疗后肝癌瘤灶活性的检出率。方法 17例经过穿刺病理或血清学证实的肝细胞癌患者曾经行TACE介入治疗:患者于介入术后4周行全肝脏CT灌注扫描。明确经过碘油栓塞治疗的病灶44个被列入观察中。肝脏灌注分数(hepatic arterial fracture,HAF)灌注图高参数信号作为判定术后瘤灶存有活性的标准。分别采用增强CT、全肝CT灌注成像和DSA判定介入治疗后肿瘤活性,最后对不同影像技术的肿瘤活性检出率进行比较。结果 DSA造影的肿瘤活性检出率最高,达86.36%,CTP的检出率84.09%,而增强CT扫描的检出率70.45%最低。并且与前两者相比有显著性差异(P=0.016和0.031)。结论作为无创性检查手段,CTP的肿瘤活性检出力明显强于增强CT,并且接近DSA造影。因此,全肝CT灌注扫描是一种有价值的观测肝癌介入治疗疗效的无创医疗技术。     

Spontaneous rupture of a hepatic angiomyolipoma: CT findings and literature review

Angiomyolipoma is an uncommon lipomatous neoplasm of the liver, usually asymptomatic and identified incidentally. We describe the CT findings of a surgically confirmed case of spontaneously ruptured angiomyolipoma with evidence of internal hemorrhage and hemoperitoneum. The CT features were that of an exophitic, oval, well-defined mass with inhomogeneous attenuation values due to the presence of fat- and soft-tissue densities. A review of the literature identified 49 cases of hepatic angiomyolipoma. Few of these occurred in symptomatic patients and showed intratumoral hemorrhagic foci, but none had a clear rupture with external bleeding. To our knowledge, this is the first reported case with this complication. Received 19 October 1995; Revision received 27 December 1995; Accepted 3 June 1996     

外生型肝细胞癌及肝血管瘤的CT诊断

目的：探讨外生型肝细胞癌及肝血管瘤的CT表现。方法：回顾性分析7例外生型肝细胞癌及3例外生型肝血管瘤的CT和临床资料,10例均经手术、病理或临床证实。结果：外生型肝细胞癌根据肝内有无肿块将其分为单纯型（4例）和混合型（3例）。2例肿块突出肝外,有蒂与肝相连,5例肿块紧邻肝表面。7例肿块平扫均呈低密度,动脉期不均匀强化,门脉期病变密度降低或呈低密度;其中2例出现动静脉短路征象,2例出现肿瘤周围部分肝实质一过性增强,4例出现门静脉癌栓,3例有肝硬化表现。外生型肝血管瘤中,2例为海绵状血管瘤,病灶平扫呈低密度,增强扫描动脉期肿块边缘强化,门脉期强化范围扩大;1例为纤维性血管瘤,表现为门脉期不均匀强化。结论：CT是诊断外生型肝细胞癌和肝血管瘤的有价值的影像学手段。     

Primary malignant tumours in the non-cirrhotic liver

Intrahepatic chlangiocarcinomas (CCs), the second most common primary malignant liver tumours, usually occur in non-cirrhotic liver, and can be classified into three types based on gross morphology: mass-forming; periductal infiltrating; and intraductal growing. Among them, mass-forming intrahepatic CCs are the most common type and characterized by homogeneous mass with an irregular but well-defined margin with peripheral enhancement on late arterial phase and delayed enhancement in central portion of tumours corresponding to the fibrous stroma. Several imaging features such as enhancement pattern and degree of diffusion restriction have been suggested as prognostic markers for mass-forming CCs. Hepatocellular carcinomas (HCCs) are the most common primary malignant liver tumors, and usually arise from the cirrhotic liver. However, approximately 20% of HCCs involve the non-cirrhotic liver (hereafter, non-cirrhotic HCC), and non-cirrhotic HCCs are often detected at an advanced stage due to the lack of surveillance for patients with non-cirrhotic liver. Other primary malignant liver tumours other than CCs and HCCs including angiosarcoma, undifferentiated embryonal sarcoma are quite rare, and imaging diagnosis is often difficult. This review offers a brief overview of epidemiology, risk factors and imaging features of primary malignant tumours in non-cirrhotic liver. Understanding of radiologic appearance and predisposing clinical features as well as differentials of primary malignant tumour in non-cirrhotic liver can be helpful for radiologists to adequately assess these tumours, and subsequently to make optimal management plan.     

CT灌注成像对原发性肝癌、肝转移瘤和肝血管瘤的鉴别诊断价值

目的探讨CT灌注成像对原发性肝癌、肝转移瘤和肝血管瘤的鉴别诊断价值。方法对24例原发性肝癌、11例肝转移瘤和21例肝血管瘤的病灶实性部分,周围肝实质以及正常肝实质的CT灌注参数进行分析。结果比较各组病灶实质部分的参数,原发性肝癌组的肝血流量(HBF)、肝动脉灌注分数(HAF)明显高于肝转移瘤组和肝血管瘤组,原发性肝癌和肝血管瘤组的肝血容量(HBV)高于肝转移瘤组,原发性肝癌组的平均通过时间(MTT)则依次短于肝转移瘤组、血管瘤组,三组间的毛细血管表面通透性(PS)无显著性差异;比较病灶周围实质部分的参数,原发性肝癌组和肝转移瘤组的HBF明显高于肝血管瘤组,而HAF均低于肝血管瘤组,肝转移瘤组的PS高于肝血管瘤组,三组间的HBV、MTT无显著性差异;对于正常肝实质部分,原发性肝癌组的MTT短于肝转移瘤组和肝血管瘤组,原发性肝癌组的HAF高于肝转移瘤组和肝血管瘤组,三组间的HBF、HBV、PS无显著性差异。结论CT灌注成像灌注参数值的测定对于原发性肝癌、肝转移瘤和肝血管瘤的鉴别诊断以及对邻近的肝组织受累情况的评估具有重要的临床意义。     

Tuberose sclerosis complex: analysis of growth rates aids differentiation of renal cell carcinoma from atypical or minimal-fat-containing angiomyolipoma

AIM: To study the radiological characteristics of renal masses in individuals with tuberous sclerosis complex (TSC) using serial CT, and to examine how renal cell carcinoma (RCC) may be differentiated from indeterminate cysts or masses. METHODS: This was a retrospective study of 12 cases of TSC in which dedicated renal CT followed after US had demonstrated cystic or sonographically unusual renal masses. The CT density of all masses was measured and the masses categorized as simple cysts, complex cysts, angiomyolipomas or indeterminate solid masses. Subjects were maintained on regular follow-up with repeat CT or MRI and interval renal US. Indeterminate masses that showed rapid growth were considered suspicious for renal cell carcinoma and biopsy or nephrectomy followed. RESULTS: Comparative data were available for a median of 4 years. In each case the renal masses were multiple and bilateral; mean mass diameter was 3.6 cm. Among a total of 206 masses, 18 were simple cysts and 3 were complex cysts. Of the complex cysts, 1 proved to be an angiomyolipoma on histology and the other 2 showed no growth. Of the solid masses, 133 were typical angiomyolipomas (AMLs) and 52 were indeterminate. On follow-up, only 3 indeterminate masses showed rapid growth (>0.5 cm/year), of which only 1 proved to be an RCC on biopsy. The other 2 were minimal-fat AMLs, and the remainder of the masses showed no or slow growth. CONCLUSION: Many renal masses associated with TSC are radiologically indeterminate. A growth threshold of >0.5 cm/year identified the only RCC in this study (0.5% of all masses). Yearly radiological follow-up of indeterminate renal masses is recommended for individuals with TSC.     

Accuracy of CT during arterial portography in the segmental localisation of liver tumours

Preoperative computed tomography during arterial portography (CTAP) of the liver was performed in 7 patients with 20 malignant liver tumours. CTAP proved accurate for segmental localization of detected lesions (91% accuracy), but had low overall sensitivity (57%) with 10 lesions being less than less in diameter. Correspondence to: R. F. Mcloughlin     

Early modifications of hepatic perfusion measured by functional CT in a rat model of hepatocellular carcinoma using a blood pool contrast agent

Macromolecular contrast-enhanced functional CT was performed to characterize early perfusion changes in hepatocellular carcinoma (HCC). Fourteen rats with chemically induced primary liver tumors ranging pathologically from hyperplasia to HCC and 15 control rats were investigated. Two dynamic CT scans using an experimental macromolecular contrast agent were performed on a single slice 11 and 18 weeks after tumor induction followed by pathological examination. A deconvolution mathematical model was applied, yielding the hepatic perfusion index (HPI), mean transit time (MTT), liver distribution volume (LDV) and arterial, portal and total blood flows (FA, FP, FT). Analysis was performed on one slice per rat, containing overall two hyperplasia, six dysplasia and 15 HCC. On the first scans, HCC at an early pathological stage had a low FP (–30%, P=0.002) but a normal arterial-portal balance. On the scan contemporary to pathology, HCC perfusion parameters showed an inversion of the arterial-portal balance (HPI +212%, P<0.0001), with a high FA (+56%, P=0.002) and a low FP (–69%, P<0.0001). Sensitivity and specificity of detection of HCC by perfusion CT were high (87 and 80%) on late scans; but also on the earlier scans (86 and 65%), even though only one (7%) was visible to the eye. Perfusion-CT allowed early detection of HCC. This technique could contribute in the detection and characterization of liver lesions in clinical studies.     

双螺旋CT增强三期薄层扫描在小肝癌诊断中的价值

目的：探讨双螺旋CT增强三期薄层扫描在小肝癌诊断中的价值。方法：分析100例中采用双螺旋CT增强三期薄层扫描(triple-phase duplex-helical CT，TDHCT)检出的76个(瘤径≤3cm)小肝癌(small hepatocellulat carcinoma，SHCC)的CT图像，由有经验的CT室医师通过医学影像工作站(MIW)和医学影像存储与传输系统(PACS)的医学图像浏览终端，分析、统计SHCC各时相病灶强化类型，计算检出率。依SHCC的典型表现，即动脉期高密度、门静脉期和延迟期为等或低密度，做出诊断。结果：76个SHCC在三期扫描中，动脉期、门静脉期和延迟期检出率分别为86．8％(66／76)、61.8％(47／76)、93．4％(71／76)。小肝癌在动脉期89．3％(59／66)呈高密度，在门静脉期87．2％(41／47)呈低密度，在延迟期100％(71／71)呈低密度。结论：SHCC定性诊断主要依靠其自身形态强化特点，双螺旋CT增强三期薄层扫描能提高SHCC的检出率，TDHCT可提高SHCC诊断和鉴别诊断水平。     

Detection of hypervascular malignant foci in borderline lesions of hepatocellular carcinoma: comparison of dynamic multi-detector row CT, dynamic MR imaging and superparamagnetic iron oxide-enhanced MR imaging

The study object was to retrospectively compare the detection rate of hypervascular foci visualized by CT during hepatic arteriography (CTHA) in borderline nodules, which was observed upon cirrhotic livers, on dynamic MDCT, dynamic gadolinium-enhanced MR (dynamic MR), and SPIO-enhanced MR imaging. Eighty-five nodules in 49 patients with cirrhosis were evaluated. When a part of the nodule showed hyperdensity relative to the surrounding areas of the nodule on CTHA, it was defined as "hypervascular focus." The relationships between the dynamic MDCT and dynamic MR and SPIO-enhanced MR imaging findings of these foci were analyzed using X(2) test. Hypervascular foci were detected in 17 (53%) of 32 on the arterial dominant phase of dynamic MDCT, in 19 (37%) of 51 on the arterial dominant phase of dynamic MR and in 6 (26%) of 23 on SPIO-enhanced MR imaging. Arterial dominant phase of dynamic MDCT demonstrated a significantly higher detection rate of hypervascular foci less than 5 mm in diameter than did dynamic and SPIO MR imaging (p<0.05). Hypervascular foci in borderline nodules could be better visualized by dynamic MDCT than by gadolinium- and SPIO-enhanced MR imaging. Dynamic MDCT is recommended for the follow-up examination of hypovascular borderline lesions.     

Perfusion CT in cirrhotic patients with early stage hepatocellular carcinoma: Assessment of tumor-related vascularization

Purpose

To assess the value of CT-perfusion in determining the quantitative vascularization features of early hepatocellular carcinoma (HCC) in cirrhotic patients.

Materials and methods

A total of 35 cirrhotic patients with single histologically proven HCC not exceeding 3 cm in diameter underwent conventional triple-phase multidetector computed tomography (MDCT) examination. All patients were also examined with CT-perfusion (CTp) technique after i.v. injection of 50 mL of iodinated contrast. Data were analyzed using a dedicated software which generated a quantitative map of liver parenchyma perfusion. The following parameters were assessed: hepatic perfusion (HP); blood volume (BV); arterial perfusion (AP); time to peak (TTP) and hepatic perfusion index (HPI). Univariate Wilcoxon signed rank test was used for statistical analysis.

Results

In the 35 HCCs evaluated, the following quantitative data were obtained: HP (mL/s/100 g): median = 47.0 (1^stqt = 35.5; 3^stqt = 61.2); BV (mL/100 mg): median = 22.5 (1^stqt = 18.4; 3^stqt = 27.7); AP (mL/min): median = 42.9 (1^stqt = 35.8; 3^stqt = 55.6); HPI(%): median = 75.3 (1^stqt = 63.1; 3^stqt = 100); TTP(s): median = 18.7 (1^stqt = 16.8; 3^stqt = 24.5). Perfusion values calculated in cirrhotic liver parenchyma were HP: median = 10.3 (1^stqt = 9.1; 3^stqt = 13.2); BV: median = 11.7 (1^stqt = 9.6; 3^stqt = 15.5); AP: median = 10.4 (1^stqt = 8.6; 3^stqt = 11.3); HPI: median = 17.5 (1^stqt = 14.3; 3^stqt = 19.7); TTP: median = 44.6 (1^stqt = 40.3; 3^stqt = 50.1). HP, BV, HPI and AP were found to be significantly higher in HCC lesion than in liver parenchyma (p < 0.001), while TTP was significantly lower (p < 0.001).

Conclusion

CT-perfusion technique allows obtaining quantitative information about tumor-related vascularization of early HCC, in patients with liver cirrhosis.     

Value of dynamic multidetector CT in different grades of hepatocellular carcinoma

Purpose

To evaluate dynamic multidetector CT (MDCT) in assessment of grades of hepatocellular carcinoma (HCC).

Patients and methods

Forty patients of HCC were assessed. Enhancement patterns were correlated with pathological grades.

Results

Three enhancement patterns were:

1.

Hyperattenuating lesions in portal venous phase.

2.

Hypoattenuating lesions in all phases.

3.

Hyperattenuating lesions in arterial phase.

Conclusion

Arterial and portal biphasic imaging was the most informative in assessment of tumor grades. High grade lesions were hyperattenuating in arterial phase.At initial evaluation, triphasic imaging is advisable, while in diagnosed cases and on follow up, biphasic imaging could be satisfactory.     

Malignant focal hepatic lesions complicating underlying liver disease: dual-phase contrast-enhanced spiral CT sensitivity and specificity in orthotopic liver transplant patients

The aim of this study was to determine the accuracy of contrast-enhanced biphasic spiral CT as a screening tool in the preoperative evaluation of orthotopic liver transplant (OLT) patients. Spiral-CT examinations were performed before liver transplantation in 53 patients. Scans were retrospectively reviewed and compared with pathologic findings in fresh-sectioned livers. When findings between spiral CT and pathology were discordant, formalized livers were reexamined with lesion-by lesion evaluation. Fresh pathologic evaluation revealed 23 liver lesions (16 HCC, 7 macro-regenerative nodules). Malignancy was identified in 13 of 53 patients (24.5%). Pre-transplantation spiral CT depicted 27 liver lesions (23 HCC, 4 macro-regenerative nodules). Malignancy was suspected in 14 patients (26.4%). In 10 of 53 (18.9%), spiral CT and pathologic evaluation were discordant. Subsequent retrospective pathologic evaluation showed malignancy in 4 additional patients. Spiral CT compared with the retrospective pathologic findings revealed 36 real-negative, 14 real-positive, 0 false-positive, and 3 false-negative patients with malignancy. Sensitivity and specificity of spiral CT in detection of malignancy was 82 and 100%, respectively. Contrast-enhanced biphasic spiral CT is an accurate technique in the evaluation of patients preceding OLT. Routine fresh-sectioned liver pathologic findings are not as sensitive as previously estimated.     

Radiomic advances in the transarterial chemoembolization related therapy for hepatocellular carcinoma

Radiomics is a hot topic in the research on customized oncology treatment,efficacy evaluation, and tumor prognosis prediction. To achieve the goal of mining the heterogeneity information within the tumor tissue, the image features concealed within the tumoral images are turned into quantifiable data features.This article primarily describes the research progress of radiomics and clinicalradiomics combined model in the prediction of efficacy, the choice of treatment modality, and survival in tran...     

LI-RADS CT分类标准对肝细胞癌的诊断效能评价

目的：探讨肝脏影像报告和数据管理系统（LI-RADS）CT分级诊断标准对肝细胞癌（HCC）的临床诊断价值。方法：回顾性分析158例肝癌高危患者肝脏病变患者的上腹部CT资料,并根据LI-RADS分类标准对病变进行分析评估,并与临床客观诊断结果进行比较。结果：158例患者的 CT 图像共发现179个肝内病灶,其中 LI-RADS 1～5类病灶共167个：1类和2类48个,临床客观诊断结果均为良性（阴性预测值为100％）;3类4个;4类6个,其中2个病灶的术后病理结果为 HCC（阳性预测值为33．3％）;5类109个,其中103例为 HCC（阳性预测值为94．5％）。受试者工作特征（ROC）曲线下面积为0．89（P＜0．001）。若将LI-RADS 1～2类病灶归为阴性,3～5类病灶归为阳性,LI-RADS对诊断肝癌的总符合率为91．6％（153／167）,检出 HCC 的敏感度为100％（105／105）,特异度为77．4％（48／62）,阳性预测值为88．2％（105／119）,阴性预测值为100％（48／48）。若将LI-RADS 3类病灶排除,1～2类病灶归为阴性,4～5类病灶归为阳性,LI-RADS对肝内已检出病灶的诊断符合率为93．9％（153／163）,检出 HCC 的敏感度为100％（105／105）,特异度为82．8％（48／58）,阳性预测值为91．3％（105／115）,阴性预测值为100％（48／48）。结论：LI-RADS分类标准对 HCC 的CT诊断具有很好的诊断效果,有利于提高CT诊断报告的准确性。     

Multiphase contrast-enhanced CT imaging in hepatocellular carcinoma correlation with immunohistochemical angiogenic activities

RATIONALE AND OBJECTIVES: To evaluate the correlation between enhancement parameters of multiphase contrast-enhanced computed tomography (CT) and immunohistochemical activities of vascular endothelial growth factor (VEGF), VEGF receptors, and CD34 in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty-seven patients underwent curative resection for HCC with no preoperative treatment. We defined several CT enhancement parameters by measuring attenuation values of tumor, liver parenchyma, and aorta. The stored tissue blocks were assayed for immunohistochemical activities of VEGF, two VEGF receptors (Flt-1, Flk-1), and CD34, which were correlated with the enhancement parameters of multiphase contrast-enhanced CT. RESULTS: The VEGF activities in HCC showed moderate positive correlation with phase difference in portal phase, delayed enhancement (DE), tumor-blood ratio, blood pool index, and tumor-parenchyma ratio in arterial phase. The Flk-1 activities in HCC showed moderate positive correlation only with DE. CD34 activity in HCC showed positive correlation with most of the CT parameters except for DE. CONCLUSION: Our study showed that several CT enhancement parameters representing mainly delayed enhancement features were well correlated with VEGF activity in HCC, and might be valuable indicators for assessing angiogenic activity in HCC.     

Imaging features of hepatocellular carcinoma

This pictorial review concentrates on the imaging features of hepatocellular carcinoma as revealed by ultrasonography, computed tomography, magnetic resonance imaging and angiography. Understanding of the pathomorphological characteristics of the disease is important to precise image interpretation.     

Preoperative detection of hepatocellular carcinoma: comparison of combined contrast-enhanced MR imaging and combined CT during arterial portography and CT hepatic arteriography

The aim of this study was to compare Gd-DTPA-enhanced dynamic MR images, superparamagnetic iron oxide (SPIO)-enhanced MR images, combined Gd-DTPA-enhanced dynamic and SPIO-enhanced MR images, vs combined CT arterial portography (CTAP) and CT hepatic arteriography (CTHA), in the detection of hepatocellular carcinoma (HCC) using receiver operating characteristic (ROC) analysis. Twenty-four patients with 38 nodular HCCs (5–60 mm, mean 23.0 mm) were retrospectively analyzed. Image reviews were conducted on a liver segment-by-segment basis. A total of 192 segments, including 36 segments with 38 HCC, were reviewed independently by three radiologists. Each radiologist read four sets of images (set 1, unenhanced and Gd-DTPA-enhanced dynamic MR images; set 2, unenhanced and SPIO-enhanced MR images; set 3, combined Gd-DTPA-enhanced dynamic and SPIO-enhanced MR images; set 4, combined CTAP and CTHA). To minimize any possible learning bias, the reviewing order was randomized and the reviewing procedure was performed in four sessions at 2-week intervals. The diagnostic accuracy (A_z values) for HCCs of combined CTAP and CTHA, combined Gd-DTPA-enhanced dynamic and SPIO-enhanced MR images, Gd-DTPA-enhanced dynamic MR images, and SPIO-enhanced MR images for all observers were 0.934, 0.963, 0.878, and 0.869, respectively. The diagnostic accuracy of combined CTAP and CTHA and combined Gd-DTPA-enhanced dynamic and SPIO-enhanced MR images was significantly higher than Gd-DTPA-enhanced dynamic MR images or SPIO-enhanced MR images (p<0.005). The mean specificity of combined CTAP and CTHA (93%) and combined Gd-DTPA-enhanced dynamic and SPIO-enhanced MR images (95%) was significantly higher than Gd-DTPA-enhanced dynamic MR images (87%) or SPIO-enhanced MR images (88%; p<0.05). Combined Gd-DTPA-enhanced dynamic and SPIO-enhanced MR images may obviate the need for more invasive combined CTAP and CTHA for the preoperative evaluation of patients with HCC.