Detection of hepatocellular carcinoma: value of adding delayed phase imaging to dual-phase helical CT

OBJECTIVE: The purpose of the study was to compare power Doppler sonography with intraarterial CO(2)-enhanced sonography for revealing vascularity in treated and untreated hepatic tumors. SUBJECTS AND METHODS: Fifty-five patients with 93 liver tumors were prospectively examined with power Doppler sonography and CO(2)-enhanced sonography. These tumors included 29 hepatocellular carcinomas in patients with no previous treatment, 26 treated hepatocellular carcinomas, and 38 hemangiomas. The vascular depiction of power Doppler sonography was compared with that obtained in the early phase of CO(2)-enhanced sonography. The results of angiography were also recorded for comparison. RESULTS: In the hepatocellular carcinomas, power Doppler sonography was the same as CO(2)-enhanced sonography in 18 (62%) of 29 tumors, was inferior to CO(2)-enhanced sonography in nine (31%) of 29 tumors, and was superior to CO(2)-enhanced sonography in two (7%) of 29 tumors. In the treated hepatocellular carcinomas, power Doppler sonography was the same as CO(2)-enhanced sonography in 15 (58%) of 26 tumors and was inferior in 11 (42%) of 26 tumors. In hemangiomas, the same vascularity was found in both studies in 15 (39%) of 38 tumors, CO(2)-enhanced sonography was superior in 22 (58%) of 38 tumors, and power Doppler sonography was superior in one (3%) of 38 tumors. As a whole, 45% of the 93 tumors showed better vascular depiction on CO(2)-enhanced sonography. However, 19.4% of tumors were hypovascular using power Doppler sonography but hypervascular using CO(2)-enhanced sonography. CONCLUSION: Power Doppler sonography is a useful technique for screening hepatic tumor vascularity. CO(2)-enhanced sonography is superior to power Doppler sonography in depicting tumor vascularity in treated hepatocellular carcinomas and in hemangiomas, especially small hemangiomas.     

原发性肝癌的螺旋CT三期增强特征及其诊断价值

目的：探讨肝癌螺旋CT多期扫描影像特征和临床应用价值。方法：对拟诊为肝癌的56例患者先行全肝CT平扫,其中46例不论肿瘤大小先作病灶动脉期扫描,再作全肝静脉期扫描,最后进行病灶延迟扫描。10例仅行动脉期及静脉期扫描。结果：56例中37例为巨块型,10例为结节型,10例为弥漫型。46例中CT平扫、动脉期、静脉期及延迟期病灶的显示率分别为89%、98%、92%、98%。结论：螺旋CT三期扫描能获得肿瘤在各期增强征象,为肝癌的定性定量诊断提供更多的影像诊断信息;尤其在早期肝癌诊断,动脉期扫描可得到非常重要的诊断依据。     

MnDPDP-enhanced MRI vs dual-phase spiral CT in the detection of hepatocellular carcinoma in cirrhosis

The objectives of this study were twofold: (a) to assess safety and tolerability of the hepatobiliary MR contrast agent MnDPDP; and (b) to investigate the sensitivity of MnDPDP-enhanced MRI, in comparison with dual-phase spiral CT, in the detection of hepatocellular carcinoma (HCC) in cirrhosis. Fifty patients with liver cirrhosis and histologically proven HCC were enrolled in a prospective phase-IIIB clinical trial. All patients underwent evaluation with dual-phase spiral CT and pre-contrast and post-contrast MRI at 1.5 T. The MR examination protocol included spin-echo (SE) and gradient-recalled-echo (GRE) T1-weighted images acquired before and 60–120 min after administration of 0.5 μmol/kg (0.5 ml/kg) MnDPDP (Teslascan, Nycomed Amersham, Oslo, Norway); and fast T2-weighted SE images obtained solely before contrast injection. Gold standard was provided by findings at Lipiodol CT in combination with follow-up spiral CT studies, which were repeated at 4-month intervals over a 10- to 27-month (mean ± SD 20.1 ± 5.1 months) follow-up period. No serious adverse event occurred. Eighty tumors ranging 0.8–9.1 cm in diameter (mean ± SD 3.2 ± 2.4 cm) were detected by Lipiodol CT or confirmed as cancerous foci by follow-up CT studies. Pre-contrast MRI detected 38 of 80 lesions (48 %); MnDPDP-enhanced MRI, 65 of 80 lesions (81 %); pre-contrast plus post-contrast MRI, 69 of 80 lesions (86 %); and dual-phase spiral CT, 64 of 80 lesions (80 %). The difference between unenhanced and MnDPDP-enhanced MRI was statistically significant (p < 0.001). The difference between MRI (pre-contrast plus post-contrast) and dual-phase spiral CT was not statistically significant (p = 0.33). The confidence in the final diagnosis, however, was significantly higher for MRI as compared with spiral CT (p < 0.001). MnDPDP is a safe and well-tolerated hepatobiliary MR contrast agent. Magnetic resonance imaging with use of MnDPDP is significantly more sensitive than unenhanced MRI and as good as dual-phase spiral CT for detection of HCC in cirrhosis. Received: 29 February 2000; Revised: 8 June 2000; Accepted: 9 June 2000     

双层螺旋CT对喉癌诊断与治疗价值的评价

喉癌是耳鼻喉科常见肿瘤,手术治疗仍是目前喉癌的主要治疗方法,范围较广泛者先行放射治疗,再行手术根除是理想方案。CT在喉癌术前检查已得到广泛应用[1],在喉癌术前诊断和分期中的价值已得到公认。本文收集了38例经病理证实的喉癌行回顾性分析,现报告如下。1材料和方法1·1一般资料38例患者中,男32例,女6例,男女比例约5·5∶1;年龄43~69岁,平均56岁。35例为鳞癌,2例为腺癌,1例为类癌。临床都有咽部不适、疼痛,大部分有声音嘶哑,1例呼吸困难,4例吞咽困难,1例咯血,多数有颈部肿块。22例行术前放射治疗,其中14例为早期喉癌。1·2检查方法全部…     

Dynamic contrast-enhanced CT imaging of hepatocellular carcinoma in cirrhosis: feasibility of a prolonged dual-phase imaging protocol with tracer kinetics modeling

Dynamic contrast-enhanced (DCE) CT imaging of four patients with hepatocellular carcinoma (HCC) was performed using a dual-phase imaging protocol designed with initial rapid dynamic imaging to capture the initial increase in contrast medium enhancement in order to assess perfusion, followed by a delayed imaging phase with progressively longer intervals to monitor subsequent tissue enhancement behaviour in order to assess tissue permeability. The DCE CT images were analysed using a dual-input two-compartment distributed parameter model to yield separate estimates for blood flow and permeability, as well as fractional intravascular and extravascular volumes. The HCCs and surrounding cirrhotic liver tissues were found to exhibit enhancement curves that can be appropriately described by two distinct compartments separated by a semipermeable barrier. Early contrast arrival was also found for HCC as compared with background liver. These findings are consistent with the current understanding of sinusoidal capillarization and hepatocarcinogenesis.     

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。     

Hepatocellular carcinoma: role of unenhanced and delayed phase multi-detector row helical CT in patients with cirrhosis

PURPOSE: To determine, by using multi-detector row helical computed tomography (CT), the added value of obtaining unenhanced and delayed phase scans in addition to biphasic (hepatic arterial and portal venous phases) scans in the detection of hepatocellular carcinoma (HCC) in patients with cirrhosis. MATERIALS AND METHODS: Local ethical committee approval and patient consent were obtained. One hundred ninety-five patients (129 men, 66 women; mean age, 61 years; age range, 39-78 years) with 250 HCCs underwent multi-detector row helical CT of the liver. A quadruple-phase protocol that included unenhanced, hepatic arterial, portal venous, and delayed phases was performed. Analysis of images from hepatic arterial and portal venous phases combined, hepatic arterial and portal venous phases with the unenhanced phase, hepatic arterial and portal venous phases with the delayed phase, and all phases combined was performed separately by three independent radiologists. Relative sensitivity, positive predictive value, and area under the receiver operating characteristic curve (A(z)) were calculated for each reading session. RESULTS: Mean sensitivity and positive predictive values, respectively, for HCC detection were 88.8% (666 of 750 readings) and 97.8% (666 of 681 readings) for the combined hepatic arterial and portal venous phases, 89.2% (669 of 750 readings) and 97.8% (669 of 684 readings) for hepatic arterial and portal venous phases with the unenhanced phase, 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for hepatic arterial and portal venous phases with the delayed phase, and 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for all four phases combined. The reading sessions in which delayed phase images were available for interpretation showed significantly (P < .05) superior sensitivity and A(z) values. CONCLUSION: Unenhanced phase images are not effective for HCC detection. Because of the significant increase in HCC detection, a delayed phase can be a useful adjunct to biphasic CT in patients at risk for developing HCC.     

螺旋CT对结节型肝细胞癌的多期扫描表现分析

目的：描述结节型肝细胞癌的螺旋CT动脉期、门静脉期和延迟期增强特点,比较各期的病灶的检出率,重点评价动脉期、延迟期的价值。方法：36例结节型肝细胞癌患者行螺旋CT双期、三期动态扫描后,观察病灶的强化方式,统计各期病灶的检出率。结果：36例55个病灶,螺旋CT多期扫描共发现52个,平扫、肝动脉期、门脉期、延迟期及三期合计的检出率分别为70．9％,87．2％、72．7％,68．7％、94．5％。动脉期检出敏感性明显高于其它各期,三期结合可明显提高对结节型肝癌的检出率。结论：螺旋CT多期扫描能显示肝细胞癌的增强特点,明显提高结节型肝细胞癌的检出敏感性。     

Pretransplantation surveillance for possible hepatocellular carcinoma in patients with cirrhosis: epidemiology and CT-based tumor detection rate in 430 cases with surgical pathologic correlation

PURPOSE: To determine the prevalence of clinically unsuspected hepatocellular carcinoma (HCC) with advanced cirrhosis and assess the sensitivity of helical computed tomographic (CT) surveillance for tumor detection in these patients. MATERIALS AND METHODS: Prospective direct correlation of CT findings with explanted liver specimen findings was performed in 430 transplant recipients with cirrhosis. The prevalence of clinically unsuspected HCC according to liver disease cause was evaluated. Serum alpha-fetoprotein (AFP) values in patients with and those without tumor were recorded. Prospective and retrospective CT tumor detection was evaluated with respect to CT technique and time from CT to transplantation. RESULTS: HCC was found in 59 (14%) of 430 transplant recipients without suspicion of tumor before referral for transplantation. HCC was most prevalent with hepatitis B (27%) and hepatitis C (22%). Serum AFP values were not sensitive for detection of most small tumors. With triphasic helical CT, the prospective and retrospective rates of identifying patients with tumor were 59% and 68%, respectively; the prospective and retrospective tumor nodule detection rates were 37% and 44%, respectively. Tumor detection rates were highest with CT performed within 67 days before transplantation. CONCLUSION: Clinically unsuspected HCC is most prevalent with cirrhosis secondary to hepatitis B or C, and, when evaluated at CT, is best detected with triphasic contrast material-enhanced helical imaging performed within 67 days before transplantation.     

CT diagnosis and staging of pancreatic carcinoma

The current use of multidector row helical CT (MDCT) and imaging postprocessing techniques represents an additional step forward in the use of helical CT for detection and staging of pancreatic carcinoma. Although no large series have been published detailing the accuracy of MDCT compared to single detector row helical CT, the additional resolution of the MDCT thin-section images and use of postprocessing techniques should certainly equal, if not exceed, the accuracy of the helical CT.     

多层螺旋CT薄层增强3期扫描在诊断小肝癌中的作用

目的：检验多层螺旋CT薄层增强3期扫描（triple-phase helical CT，THCT）在小肝癌（SHCC）诊断中的作用。方法：研究分析100例SHCC患者的CT图像。采用高质量扫描模式，扫描参数为：层厚5mm，螺距3；增强3期扫描（以下简称3期扫描（分别为平扫、注射对比剂后20-25s动脉期扫描、45-50s门静脉期扫描、3min延迟期扫描，120kV，270-300mA。高压注射器单相注射，非离子型对比剂注射流率为3ml/s（剂量为1.2-1.5ml/kg）。通过放射科影像存储与传输系统（PACS）的医学图像浏览及诊断报告书写终端分析SHCC的CT图像，确定肿瘤强化特点。分析SHCC强化特点与其组织学分类和分级间的关系。统计学分析CMH X^2检验和Fisher确切概率法检验。结果：SHCC在3期扫描上81例为典型表现，即动脉期为高密度、门静脉期和延迟期为低密度或等密度；19例为非典型表现。SHCC3期扫描检出率统计学上差异有非常显著意义（X^2值为211.953，P=0.001），以延迟期检出率最高。SHCC中以梁型较多，与其他分类比较，统计学上差异有非常显著意义（Fisher确切概率法，P=0.00604）。SHCC在病理组织分级上差异无显著意义（X^2值为2.133，P=0.144）。结论：大多数的SHCC在3期扫描上呈典型表现。SHCC定性诊断主要靠增强的动态变化特点，延迟期检出率最高，薄层THCT扫描能提高SHCC检出率，综合3期扫描的表现可提高诊断和鉴别诊断能力。     

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。     

Imaging diagnosis of hepatocellular carcinoma. Addendum to hepatocellular carcinoma: diagnosis, staging and treatment strategies

This addendum is aimed to review and discuss the updated non-invasive diagnostic algorithm recently published by the American Association for the Study of Liver Diseases (AASLD).     

螺旋CT诊断胃癌及其在TNM分期中的应用价值

目的 :探讨螺旋CT对胃癌及TNM分期的诊断价值。方法 :利用螺旋CT采用统一服水量、低张剂、同样扫描方式 ,一次屏气完成兴趣区扫描 ,对 30例正常组成人进行胃壁测量 ,得出正常值作为对照组。对 30例胃癌患者进行螺旋CT征象、手术、胃镜病理结果进行回顾性分析 ,并进行TNM分期 ,17例手术患者术前评估已被证实。结果 :螺旋CT能清楚显示粘膜变化、胃癌发生部位、形态及胃壁增厚情况 ,增厚胃壁有明显强化 ,且有分层现象 ,能清晰显示 >8.0mm肿大淋巴结 ,对胃癌向周围脏器的侵犯及转移均能明确显示。对胃癌的显示率达 10 0 % ,对邻近器官的侵犯与转移显示率10 0 %。结论 :螺旋CT对胃癌的显示率及TNM分期有无可比拟的优点 ,成为胃癌很有价值的检查方法     

Helical CT screening for hepatocellular carcinoma in patients with cirrhosis: frequency and causes of false-positive interpretation

OBJECTIVE: The purpose of our study was to determine the specificity of helical CT for depiction of hepatocellular carcinoma in a population of patients with cirrhosis. SUBJECTS AND METHODS: Single-detector helical CT screening was undertaken in 1329 patients with cirrhosis who were referred for transplantation. The patients underwent one or more helical CT examinations over 30 months and were followed up for an additional 19 months or until transplantation. We predominantly used unenhanced and biphasic contrast-enhanced techniques with infusions of 2.5-5.0 mL/sec. Four hundred thirty patients underwent transplantation within this period. Liver specimens were sectioned at 1-cm intervals, with direct comparison of imaging and pathologic findings and histologic confirmations of all lesions. Prospective preoperative helical CT reports were used for the primary data analysis. A retrospective unblinded review was undertaken to determine characteristics of false-positive lesions diagnosed as hepatocellular carcinoma. RESULTS: Thirty-five patients (8%) had false-positive diagnoses for hepatocellular carcinoma based on helical CT. Twenty of these patients (5%) showed hypoattenuating lesions seen during one of the three helical CT examination phases. Fifteen patients (3%) had hyperattenuating lesions seen during the arterial phase. Among the 15 hyperattenuating lesions, CT revealed the causes to be transient benign hepatic enhancement (n = 3), hemangiomas (n = 2), fibrosis (n = 2), peliosis (n = 1), volume averaging (n = 1), low-grade dysplastic nodule (n = 1), or undetermined (n = 5). Of the 20 hypoattenuating lesions, the causes were shown to be fibrosis (n = 8), focal fat (n = 4), infarcted regenerative nodules (n = 2), regenerative nodules (n = 1), fluid trapped at the dome of the liver (n = 1), hemangioma (n = 1), or undetermined (n = 3). Follow-up helical CT in 13 (72%) of 18 patients allowed a change in the diagnosis of hepatocellular carcinoma to a finding of no cancer present. CONCLUSION: Helical CT screening for hepatocellular carcinoma in patients with cirrhosis has a substantial false-positive detection rate. Although most of lesions were hypoattenuating, a few hyperenhancing arterial phase lesions were proven not to be hepatocellular carcinoma. An awareness of imaging characteristics and follow-up imaging can help radiologists avoid a mistaken diagnosis in many patients.     

肾癌的螺旋CT双期扫描及CT分期

目的：探讨肾癌的螺旋CT双期扫描表现及CT分期的价值。方法：对36例手术病理证实的肾癌患者CT双期扫描图像进行分析。结果：CT平扫等密度者17例，低密度者15例，高密度者4例；增强扫描动脉期呈均质强化者7例，不均质强化者29例；高强化者27例，弱强化者9例；实质期肾静脉癌栓者10例(占28％)，下腔静脉癌栓者3例，淋巴结转移者6例。结论：螺旋CT双期扫描可对肾癌做出明确诊断，CT分期对指导治疗方案有较大价值。     

Hepatic arterial and portal venous phase helical CT in patients treated with transcatheter arterial chemoembolization for hepatocellular carcinoma: added value of unenhanced images

PURPOSE: To evaluate the additional diagnostic value of unenhanced computed tomographic (CT) images in the depiction of viable tumor in patients who were treated with transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) and followed up with biphasic helical CT that included the acquisition of unenhanced images. MATERIALS AND METHODS: We performed helical CT (with unenhanced, arterial, and portal phases) in 54 patients who had been treated with TACE for HCC. Image analysis was first performed with only those images obtained in the arterial and portal venous phases of helical CT. A second analysis was then performed with unenhanced images, arterial images, and portal venous images that focused on the additional value of unenhanced images. The value of additional unenhanced images was evaluated by means of interobserver agreement (kappa statistic) and receiver operating characteristic (ROC) analysis. RESULTS: The two readers detected 128 and 129 lesions. Unenhanced images were valuable for 32 of 129 lesions (23 patients) for reader 1 and for 29 of 128 lesions (21 patients) for reader 2. Although there was no significant difference between biphasic CT alone and biphasic CT with unenhanced images, results of ROC analysis showed higher diagnostic performance with biphasic CT with unenhanced images than with biphasic CT alone for detecting viable tumor. CONCLUSION: The study data demonstrate the diagnostic value of unenhanced images interpreted in conjunction with biphasic CT images for follow-up of patients who have previously been treated with TACE for HCC.