Newly developed hepatocellular carcinoma (HCC) in chronic liver disease: MR imaging findings before the diagnosis of HCC

PURPOSE: The purpose of this work was to describe the initial magnetic resonance (MR) imaging findings obtained before an imaging diagnosis of overt hepatocellular carcinoma (HCC) in the chronically damaged liver. METHODS: One hundred fifty-two newly diagnosed HCCs diagnosed by dynamic computed tomography (n = 111) or by MR imaging (n = 41), in addition to digital subtraction hepatic arteriography, in 96 patients were subjected to analysis of their MR imaging features within the previous 2 years. RESULTS: Ninety-seven (64%) HCC cases showed no focal lesions distinguishable from background hepatic parenchyma in MR images taken before the indication of typical HCC. The remaining 55 (36%) lesions were readily identified in earlier images and were categorized into 3 groups: nonhypervascular lesions (category I, n = 6), lesions with partially hypervascular foci of "nodule-within-nodule" appearance (category II, n = 12), and homogeneously hypervascular and/or T2-weighted hyperintense lesions (category III, n = 37). The size and doubling time of category III lesions (0.7 cm, 154 days) were smaller and shorter than those of the other lesions (1.2 cm, 377 days). CONCLUSIONS: Before the imaging diagnosis of HCCs, the premalignant or early malignant lesions can be found on the prior MR images just in the minority of the lesions in the cirrhotic liver.     

Hypervascular hepatocellular carcinoma: detection with double arterial phase multi-detector row helical CT

PURPOSE: To assess whether double arterial phase imaging with multi-detector row helical computed tomography improves detection of hypervascular hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifty-one patients with 96 hypervascular HCCs underwent double arterial phase imaging of the entire liver. At measured delay after intravenous administration of 2 mL/kg of contrast medium at a rate of 5 mL/sec, the early and late arterial phase images were obtained serially during a single breath hold with interscan delay of 5.0 seconds. Detector row configuration of 2.5 x 4 mm, pitch of 6, and scanning time of 10.5 seconds for each phase were used. Forty 5-mm-thick reconstruction images were obtained for each phase. Each image set was interpreted separately by three observers, who were unaware of tumor burden in the liver, to detect hypervascular HCC. Sensitivity, positive predictive value, and area below the receiver operating characteristic curve (A(z)) for early and late arterial phases separately and together were calculated. RESULTS: Mean sensitivity and positive predictive value for hypervascular HCC were 54% and 85% for the early arterial phase, 78% and 83% for the late arterial phase, and 86% and 92% for the double arterial phase, respectively. Double arterial phase imaging showed significantly superior sensitivity compared with early or late arterial phase imaging alone for detecting HCC (P <.05). The mean A(z) value for double arterial phase was significantly higher than that for early or late arterial phase imaging alone (P <.05). Double arterial phase imaging showed the lowest number of false-positive lesions. CONCLUSION: Double arterial phase imaging is recommended to improve detection of hypervascular HCCs and reduce false-positive lesions.     

Small hypervascular hepatocellular carcinomas: value of diffusion-weighted imaging compared with "washout" appearance on dynamic MRI

Objective To compare the value of diffusion-weighted MRI (DWI) with the venous "washout" appearance during dynamic MRI for the assessment of small arterial hypervascular lesions in cirrhotic liver. Methods After exclusion of benign hypervascular lesions, including haemangiomas and subcapsular non-tumorous arterioportal shunts, indicated by typical imaging features, a total of 109 small arterial hypervascular lesions (0.5-3.0 cm in the longest diameter) in 65 patients with cirrhosis who underwent gadopentetate dimeglumine-enhanced dynamic MRI and DWI (b=50, 400, 800 s mm(-2)) at 1.5 T during a 16-month period were retrospectively analysed to determine the presence of venous washout during dynamic imaging or sustained hyperintensity upon increasing the b factor size on DWI. Results Among the 99 hypervascular hepatocellular carcinomas (HCCs), sustained hyperintensity on DWI (92/99, 93%) was more prevalent than the washout appearance (72/99, 72%) on dynamic MRI (p<0.001). Depending on the lesion size, subcentimetre-sized HCCs had a significantly lower prevalence of venous washout (13/30, 43%) than the sustained hyperintensity on DWI (27/30, 90%) (p=0.001). In all 10 hypervascular benign conditions, there was no venous washout on dynamic MRI and no sustained hyperintensity on DWI. Sensitivity and specificity for diagnosis of hypervascular HCCs were 92.9% and 100% in DWI and 72% and 100% in dynamic MRI, respectively. Conclusion Compared with the venous washout during dynamic imaging, DWI provides more reliable information in the MRI assessment of small hypervascular HCCs, distinguishing them from atypical hypervascular benign or pseudolesions. DWI could complement the early diagnosis of small hypervascular HCCs that do not display venous washout during dynamic imaging.     

The value of gadobenate dimeglumine-enhanced delayed phase MR imaging for characterization of hepatocellular nodules in the cirrhotic liver

OBJECTIVES: To evaluate the value of 1-hour delayed phase imaging (DPI) of gadobenate dimeglumine (Gd-BOPTA)-enhanced MR imaging for the characterization of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) in patients with cirrhosis. MATERIALS AND METHODS: A total of 37 patients with 42 HCCs and 13 DNs were included in this study and all lesions were histopathologically confirmed except for 15 HCCs. T1-weighted 3-dimensional gradient-echo images were acquired before, immediately after (30, 60, 180 s), and 1 hour after bolus injection of gadobenate dimeglumine at a dose of 0.1 mmol/kg. The lesions were classified as isointense, hypointense, or hyperintense compared with the surrounding liver parenchyma on DPI for qualitative assessment. We performed quantitative analyses of the contrast-to-noise ratio (CNR) and of the relative contrast enhancement of the lesion on the DPI. RESULTS: In the qualitative analysis, among 42 HCCs, 30 (71.4%) were hypointense on DPI, and 10 (23.8%) and 2 (4.8%) were isointense and hyperintense, respectively; only 1 of 13 DNs (7.7%) was hypointense and 10 (76.9%) and 2 (15.4%) were isointense and hyperintense, respectively. In contrast, 25 HCCs (71.4%) of 35 hypervascular HCCs were hypointense on DPI, and no hypervascular DN (0/7) was hypointense with statistical significance (P = 0.0007). When we considered the hypointensity of the hepatic lesions on delayed phase as a sign of HCC in cirrhotic liver, our results gave a sensitivity of 71.4% and a specificity of 91.7%. In the quantitative analysis, the mean CNR of the HCCs and the DNs on the 1-hour DPI was -6.32 +/- 6.27 and -0.07 +/- 3.28, respectively; the difference between the HCCs and the DNs was significant (P < 0.05). CONCLUSIONS: Delayed gadobenate dimeglumine-enhanced MR imaging allows improved characterization of HCC in cirrhotic liver. The relative hypointensity to adjacent normal liver parenchyma is a reliable predictor that this lesion favors HCC rather than DN in cirrhotic liver.     

Arterial enhancing‐only nodules less than 2 cm in diameter in patients with liver cirrhosis: Predictors of hepatocellular carcinoma diagnosis on gadobenate dimeglumine‐enhanced mr imaging

Purpose:

To assess whether gadobenate dimeglumine (Gd‐BOPTA)‐enhanced MR imaging could predict hepatocellular carcinoma (HCC) diagnosis in small arterial enhancing‐only nodules detected by contrast‐enhanced computed tomography (CT) in patients with liver cirrhosis.

Materials and Methods:

We prospectively recruited 125 cirrhotic patients (67 males, and 58 females; age: 68 ± 12.36 years) with 151 small (<2 cm in diameter) arterial enhancing‐only nodules identified by contrast‐enhanced CT. All patients were scanned by MR imaging before and after Gd‐BOPTA injection during the hepatic arterial phase (HAP), portal venous phase (PVP), equilibrium phase (EP), and hepatobiliary phase (HP). Nodule characterization was based on reference imaging criteria (n = 29 nodules), follow‐up (n = 105), or histology (n = 17). Two radiologists (5 and 10 years experience) analyzed the MR images, and logistic regression was conducted to assess how well MR imaging findings could predict HCC diagnosis.

Results:

Final diagnoses included 115 benign nodules and 36 HCCs. Nodule T2 hyperintensity, T1 hypointensity, PVP‐EP hypointensity, and HP hypointensity were the best predictors of HCC on univariate analysis. Nodule T2 hyperintensity, T1 hypointensity, and HP hypointensity, were independent predictors of HCC on multivariate analysis.

Conclusion:

Gd‐BOPTA‐enhanced MR imaging provides imaging findings which may predict a diagnosis of HCC in small arterial enhancing‐only nodules in cirrhotic patients. J. Magn. Reson. Imaging 2013;37:892–902. © 2012 Wiley Periodicals, Inc.     

Double arterial phase dynamic MRI with sensitivity encoding (SENSE) for hypervascular hepatocellular carcinomas

PURPOSE: To investigate the efficacy of SENSE MRI, including the double arterial phase dynamic study, to detect hypervascular hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: MRI of the liver was performed in 40 consecutive patients (20 by conventional MRI and 20 by SENSE MRI). The SENSE technique was used to obtain breath-hold T1-weighted FSE images (TR/TE = 556/12 msec), respiratory-triggered T2-weighted FSE images (TR/TE = 1800/90 msec) with and without fat suppression, and dynamic MR images (TR/TE/FA = 160-168/4.6 msec/70 degrees ). In each arterial dominant phase and portal dominant phase, two scans were consecutively performed with one breath-hold, leading to the double arterial phase and double portal phase images with SENSE. RESULTS: The sensitivity of SENSE MRI for HCCs diagnosed from all MR images, including dynamic study, T1-weighted images, and T2-weighted images, was 91.7%, while that of conventional MRI was 76.3%. The positive predictive value of SENSE MRI for HCCs was 91.7%, while that of conventional MRI was 87.9%. In terms of HCCs < or = 10 mm, the sensitivity and positive predictive values of SENSE MRI were 78.6% and 78.6%, respectively, while those of conventional MRI were 27.3% and 60.0%, respectively. The number of detected HCCs < or = 10 mm was significantly larger in SENSE MRI than in conventional MRI (P < 0.05). The cause of false-positive lesions on SENSE MR images was an arterioportal shunt. CONCLUSION: SENSE MRI with double arterial phase dynamic study showed higher sensitivity compared to the conventional technique. Therefore, SENSE MRI is a promising method for the detection of HCC.     

Optimal phase of dynamic CT for detecting hypervascular hepatocellular carcinoma: evaluation of double arterial phases

PURPOSE: To investigate the appropriate time of arterial phase for the detection of hypervascular hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifty-two hypervascular HCCs of 36 patients were evaluated on double arterial-phase images of the liver. The first and second arterial-phase images were obtained 10 sec after aortic peak enhancement time as determined by test bolus injection. Patients received a low or high concentration of contrast medium, according to their body weight, that was administered intravenously at a rate of 4 mL/sec and injection duration of 23 sec. Three radiologists evaluated the images separately. RESULTS: Sensitivity in detecting hypervascular HCCs was higher in the first arterial phase than in the second arterial phase (p = 0.039). HCCs were not detected as hypervascular nodules in one of 20 cases during 31 or fewer sec, or in 8 of 19 cases during 48 or more sec after the initiation of contrast medium injection. All nodules were detected as hypervascular lesions between 32 and 47 sec after the initiation of contrast medium injection. CONCLUSION: When a single arterial phase is obtained to detect hypervascular HCCs with a 23-sec injection time and an injection rate of 4 mL/sec, a protocol is recommended in which scanning is started at 35 sec and ended within 47 sec after initiating the injection of contrast medium.     

Pretransplantation diagnosis and staging of hepatocellular carcinoma in patients with cirrhosis: value of dual-phase helical CT

OBJECTIVE: The objective of our study was to prospectively evaluate the results of helical CT in the detection of hepatocellular carcinoma (HCC) in patients with cirrhosis undergoing orthotopic liver transplantation. SUBJECTS AND METHODS. Eighty-five patients with cirrhosis were studied preoperatively with biphasic helical CT. Arterial, portal, and equilibrium phase images were obtained after injection of 170 mL of contrast material at 5 mL/sec. The prospective CT interpretation was compared with pathologic results on a lesion-by-lesion basis. RESULTS: Pathologic examination found 85 cases of HCC in 51 patients. Helical CT enabled a correct diagnosis of HCC in 67 of 85 lesions for a sensitivity of 78.8%. HCC nodules were hypervascular in the arterial phase and hypovascular in the equilibrium phase in 63.5% (54/85) of patients. The false-negative rate was 21% (n = 18), and the positive predictive value was 88%. We had nine false-positive findings (11.8%) related to hemangiomas, transient hepatic attenuation differences, and regenerative nodules. Helical CT detected 61% (23/38) of lesions smaller than 2 cm and 93.6% (44/47) of lesions 2 cm or larger. CONCLUSION: Helical CT is a useful preoperative imaging technique in cirrhotic patients who are candidates for orthotopic liver transplantation, although it is relatively insensitive for detection of small lesions (< 2 cm).     

Efficacy of double arterial phase dynamic magnetic resonance imaging with the sensitivity encoding technique versus dynamic multidetector-row helical computed tomography for detecting hypervascular hepatocellular carcinoma

Purpose  The aim of this study was to evaluate the efficacy of double arterial phase dynamic magnetic resonance imaging (MRI) with the sensitivity encoding technique (SENSE dynamic MRI) for detection of hypervascular hepatocellular carcinoma (HCC) in comparison with double arterial phase dynamic multidetector-row helical computed tomography (dynamic MDCT). Materials and methods  A total of 28 patients with 66 hypervascular HCCs underwent both double arterial SENSE dynamic MRI and dynamic MDCT. The diagnosis of HCC was based on surgical resection (n = 7), biopsy (n = 10), or a combination of CT during arterial portography (CTAP), CT during hepatic arteriography (CTA), and/or the 6-month follow-up CT (n = 49). Based on alternative-free response receiving operating characteristic (ROC) analysis, the diagnostic performance for detecting HCC was compared between double arterial phase SENSE dynamic MRI and double arterial phase dynamic MDCT. Results  The mean sensitivity, positive predictive value, and mean Az values for hypervascular HCCs were 72%, 80%, and 0.79, respectively, for SENSE dynamic MRI and 66%, 92%, and 0.78, respectively, for dynamic MDCT. The mean sensitivity for double arterial phase SENSE dynamic MRI was higher than that for double arterial phase dynamic MDCT, but the difference was not statistically significant. Conclusion  Double arterial phase SENSE dynamic MRI is as valuable as double arterial phase dynamic MDCT for detecting hypervascular HCCs.     

Hepatocellular carcinoma in a North American population: Does hepatobiliary MR imaging with Gd‐EOB‐DTPA improve sensitivity and confidence for diagnosis?

Purpose:

To evaluate the value of hepatobiliary phase imaging for detection and characterization of hepatocellular carcinoma (HCC) in liver MRI with Gd‐EOB‐DTPA, in a North American population.

Materials and Methods:

One hundred MRI examinations performed with the intravenous injection of Gd‐EOB‐DTPA in patients with cirrhosis were reviewed retrospectively. Nodules were classified as HCC (n = 70), indeterminate (n = 33), or benign (n = 22). Five readers independently reviewed each examination with and without hepatobiliary phase images (HBP). Lesion conspicuity scores were compared between the two readings. Lesion detection, confidence scores, and receiver operating characteristic (ROC) analysis were compared.

Results:

Lesion detection was slightly improved for all lesion types with the inclusion of the HBP, and was substantially higher for small HCCs (96.0% versus 85.3%). Mean confidence scores for the diagnosis of HCC increased for HCCs overall and each size category (P < 0.001). Diagnostic performance improved with the addition of the HBP (aggregate AROC 87.7% versus 80.0%, P < 0.01), and sensitivity for characterization improved (90.9% versus 78.3%, P < 0.01) while specificity was unchanged.

Conclusion:

Hepatobiliary phase imaging may improve small lesion detection (<1 cm) and characterization of lesions in general, in MRI of the cirrhotic liver with Gd‐EOB‐DTPA. J. Magn. Reson. Imaging 2013;37:398–406. © 2012 Wiley Periodicals, Inc.     

Contrast-enhanced US of hepatocellular carcinoma

PURPOSE: To evaluate the capabilities of contrast-enhanced ultrasound (CEUS) in the characterization of hepatocarcinoma (HCC) in terms of accuracy as compared to spiral CT and diagnostic gain as compared to conventional and Doppler US. MATERIALS AND METHODS: Forty-three patients with viral hepatopathy or cirrhosis diagnosed with HCC (6 histologically and 37 cytologically proven) were retrospectively studied. Between January 2002 and May 2003, all patients were evaluated with CEUS after detection of at least one suspicious nodule on US. CEUS features of HCCs were retrospectively compared with those on conventional and Doppler US, and spiral CT. RESULTS: HCCs varied between 1.2 cm and 18 cm in diameter; 14/43 were small' (< or = 2 cm). In 18/43 patients, HCC was multifocal. Doppler US revealed 24/43 hypervascular nodules. On CEUS, 37/43 (86%) showed contrast enhancement in the arterial phase, 13/37 (35%) with negative colour and power Doppler US examination; in 6/37 (16%) contrast enhancement in the arterial phase was not visible on spiral CT. On CEUS, 6/43 hypovascular HCCs were characterized as malignant in the sinusoidal phase. On CEUS, the sinusoidal phase revealed additional nodules not visible on baseline US in 3/18 multifocal HCCs. CONCLUSIONS: CEUS diagnosis of HCC in cirrhotic liver is possible with a combination of the arterial phase, which shows tumoral hypervascularity in the microcirculation, and the sinusoidal phase, which allows to confirm the malignancy of the nodule.     

Imaging of benign hypervascular hepatocellular nodules in alcoholic liver cirrhosis: differentiation from hypervascular hepatocellular carcinoma

OBJECTIVES: To retrospectively describe imaging analyses of benign hypervascular hyperplastic liver nodules (HHN) that resulted from alcoholic liver cirrhosis and to examine the possibility of imaging differentiation between these nodules and hypervascular hepatocellular carcinoma (HCC). METHODS: Ten histopathologically confirmed HHN arise in alcoholic liver cirrhosis, and 9 HCC were examined. Magnetic resonance imaging (MRI) (10 HHN and 9 HCC), superparamagnetic iron oxide-enhanced T2-weighted MRI (6 HHN and 4 HCC), and dual-phase computed tomography hepatic arteriography (5 HHN and 6 HCC) were performed, respectively. RESULTS: On T1-weighted magnetic resonance images, 7 HHNs showed hyperintensity and 3 showed iso- to hypointensity, and all HCCs showed hypointensity compared with surrounding liver. On T2-weighted magnetic resonance images, 2 HHNs showed hyperintensity and 8 showed iso- to hypointensity. In contrast, 1 HCC showed hypointensity and 8 showed hyperintensity. On superparamagnetic iron oxide-enhanced T2 MRI, all HHNs showed iso- to hypointensity, and all HCCs showed hyperintensity. All HHN and HCCs subjected to dual-phase computed tomography hepatic arteriography showed enhancement on early-phase images and coronalike enhancement on late-phase images. CONCLUSIONS: Imaging findings of highly-well differentiated HCCs possibly overlap with HHN. So, for correct diagnosis of HHN, at first, we should suspect HHN based on clinical findings and MRI findings, and then perform core needle biopsy to verify the radiological diagnosis.     

Three-dimensional dynamic liver MR imaging using sensitivity encoding for detection of hepatocellular carcinomas: comparison with superparamagnetic iron oxide-enhanced mr imaging

PURPOSE: To assess the diagnostic performance of three-dimensional dynamic liver imaging with sensitivity encoding (SENSE), including double arterial phase images and increased resolution, by comparing it to superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging for the detection of hypervascular hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty-seven consecutive patients with 50 HCCs underwent Gd-BOPTA-enhanced dynamic imaging using SENSE and SPIO-enhanced MR imaging with at least a 24-hour interval between examinations. Using a three-dimensional gradient-echo technique applying SENSE, dynamic imaging consisting of double arterial phase-, portal phase- and delayed phase-images, was obtained. Using T2-weighted turbo spin-echo and T2*-weighted fast imaging with steady-state precession sequence, SPIO-enhanced MR imaging was obtained. For qualitative analysis, the diagnostic accuracy of both MR examinations for detecting the 50 HCCs was evaluated using the alternative free-response receiver operating characteristic method. Sensitivity and positive predictive value were also evaluated. RESULTS: The mean sensitivity and positive predictive value of three-dimensional dynamic imaging with SENSE were 91.3% and 89.2%, respectively, and those of SPIO-enhanced imaging were 77.3% and 92.6 %, respectively. There was a significant difference in sensitivity between the two images (P <0.05). The mean Az value of three-dimensional dynamic imaging with SENSE (0.97 +/- 0.01) was significantly higher than that of SPIO-enhanced imaging (0.90 +/- 0.02) (P=0.00). CONCLUSION: Three-dimensional dynamic liver MR imaging using SENSE for acquiring double arterial phase images is more efficient than SPIO-enhanced MR imaging for detecting HCCs.     

Optimizing scanning phases in detecting small (<2 cm) hepatocellular carcinoma: whole-liver dynamic study with multidetector row CT

OBJECTIVE: To define the optimal scanning phases for detecting small hepatocellular carcinomas (HCCs) with whole-liver dynamic helical computed tomography. METHODS: Sixty-one patients with 112 hypervascular HCCs smaller than 2 cm underwent 7-phase dynamic study from the early arterial to the late equilibrium phases of the entire liver. Proof of neoplasms was based on biopsy results and computed tomography with iodized oil. Time-density curves of the individual tumor and the liver were compared. RESULTS: Of 112 hypervascular nodules, the late arterial phase had the best liver-tumor conspicuity (P < 0.001). Ninety-one nodules (81%) had peak liver-tumor contrast in late arterial phase, and only 21 (19%) in the early arterial phase. All the hypervascular HCCs became isoattenuating to the regional parenchyma before the late portal venous phase (120th second). CONCLUSION: The late arterial and late portal venous phases are recommended for detecting small HCC smaller than 2 cm.     

Hepatocellular carcinoma with indeterminate or false-negative findings at initial MR imaging: effect on eligibility for curative treatment initial observations

PURPOSE: To retrospectively evaluate the effect of indeterminate or false-negative findings at magnetic resonance (MR) imaging on eligibility for curative treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This HIPAA-compliant retrospective study was approved by the institutional review board; the need for informed consent was waived. Of 166 patients with cirrhosis in whom HCC was detected with MR imaging, 21 (13 men, eight women; mean age, 60 years) had 33 proved HCCs that were not detected on previous MR images obtained 6-24 months earlier. MR imaging included T1-weighted, T2-weighted, and dynamic contrast material-enhanced T1-weighted imaging. Serial MR images and treatment records were reviewed to evaluate nodule growth and the effect of delayed diagnosis on treatment eligibility. RESULTS: Of 33 HCCs in 21 patients, 24 corresponding nodules (73%) were described on previous MR images as benign or indeterminate. Five additional nodules were visible at retrospective evaluation, but only on arterial phase images. The diameters of these 29 visible but indeterminate nodules were initially 0.6-1.9 cm (mean, 1.1 cm) and increased to 0.9-4.5 cm (mean, 1.9 cm) at HCC diagnosis (mean follow-up, 378 days). The mean doubling time was 856 days for diameter and 285 days for volume. All nine HCCs with a delayed diagnosis of less than 1 year were smaller than 3 cm at diagnosis, and the patients had undergone liver transplantation (n=3) or technically successful ablation or embolization (n=6). All 10 subcentimeter indeterminate nodules were smaller than 2 cm at HCC diagnosis, and none progressed to untreatable HCC. CONCLUSION: Indeterminate nodules smaller than 2 cm did not become untreatable HCC with delayed HCC diagnosis of 6-12 months.     

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。     

Discrimination between neoplastic and non-neoplastic lesions in cirrhotic liver using contrast-enhanced ultrasound

Objectives To assess the value of contrast-enhanced ultrasound (CEUS) in differentiating hepatocellular carcinoma (HCC) from non-neoplastic lesion in cirrhotic liver in comparison with baseline ultrasound. Methods A total of 147 nodules (diameter ≤5.0 cm) in 133 cirrhotic patients (mean age±standard deviation: 52±13 years, range 20-82 years; gender: 111 males and 22 females) were examined with CEUS. There were 116 HCCs, 26 macroregenerative nodules and 5 high-grade dysplastic nodules. CEUS was performed with a real-time contrast-specific mode and a sulphur hexafluoride-filled microbubble contrast agent. Results Hypervascularity was observed in 94.8% (110/116) HCCs, 3.8% (1/26) macroregenerative nodules and 60.0% (3/5) high-grade dysplastic nodules during arterial phase on CEUS. Detection rates of typical vascular pattern (i.e. hypervascularity during arterial phase and subsequent washout) in HCCs with a diameter of ≤2.0 cm, 2.1-3.0 cm and 3.1-5.0 cm were 69.2% (27/39), 97.1% (33/34) and 100.0% (43/43), respectively. CEUS significantly improved the sensitivity [88.8% (103/116) vs 37.1% (43/116), p<0.001], negative predictive value [70.5% (31/44) vs 31.5% (29/92), p<0.001], and accuracy [91.2% (134/147) vs 49.0% (72/147), p<0.001] in differentiating HCCs from non-neoplastic lesions when compared with baseline ultrasound. However, the sensitivity and accuracy of CEUS for HCCs ≤2.0 cm in diameter were significantly lower than those for HCCs of 2.1-3.0 cm and 3.1-5.0 cm in diameter. Conclusions CEUS improves diagnostic performance in differentiating HCCs from non-neoplastic nodules in cirrhotic patients compared with baseline ultrasound. Diagnosis of HCCs ≤2.0 cm diameter by CEUS is still a clinical concern, and thus needs further investigation.     

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。     

Multiple-phase spiral computerized tomography of small hepatocellular carcinoma: technique optimization and diagnostic yield

PURPOSE: Spiral imaging has dramatically increased the diagnostic capabilities of Computed Tomography (CT) in the evaluation of small hepatocellular carcinomas (HCCs, O < 3 cm). We report our experience with multiple-phase CT of small HCC relative to both examination technique and lesion patterns. We compared the yield of biphasic (arterial-dominant + portal-dominant phases) and triphasic (arterial-dominant + portal-dominant + delayed phases) and also reviewed the literature for a meta-analysis of the techniques used. MATERIAL AND METHODS: December 1996 to July 1998, forty-eight patients with small nodular HCCs were examined--98 nodules in all (range 1-9, mean 2 per patient). After baseline CT, a nonionic contrast agent (350 mgI/mL, 130-140 mL, 4 mL/s) was administered through a power injector and a 16-gauge needle. Biphasic volume images were acquired in 19 subjects (early-phase delay 24 s, venous-phase delay 75 s) and triphasic images in 29 (early-phase delay 24 s, venous-phase delay 60 s, delayed-phase delay 100 s). Retrospectively we assessed the number of nodules detected with each protocol in every phase, nodule conspicuity (graded I-IV) relative to surrounding parenchyma, and nodule patterns in the various phases. Nodule patterns were distinguished into homogeneous, peripheral, central and mixed hyperdensity, and homogeneous hypodensity. RESULTS: Thirty-seven lesions were found in the patients examined with the biphasic technique: baseline images showed 35% of the nodules, arterial images 92%, portal images 76% and combined arterial and portal acquisitions 95%. Sixty-one lesions were found in the patients examined with the triphasic technique: baseline images showed 43% of the nodules, arterial images 93%, portal images 70%, and delayed images 77%; combined arterial and portal acquisitions detected 93% of the nodules, combined arterial and delayed images 95%, combined arterial and delayed images 80%. Finally, 95% of lesions were demonstrated when the three phases were combined. Overall conspicuity grades were I in 44% of cases, II in 28%, III in 18% and IV in 10% of cases at baseline scanning; I in 9%, II in 24%, III in 34% and IV in 33% in the arterial phase; I in 28%, II in 41%, III in 18% and IV in 13% in the portal phase; I in 23%, II in 30%, III in 26% and IV in 21% of cases in the delayed phase. At baseline, 10% of lesions were hyperdense (homogeneously and peripherally in 5% each); mixed density was seen in 8%, and hypodensity in 82%. In the arterial phase, 93% of lesions were hyperdense (homogeneously in 80%, peripherally in 10% and centrally in 3%); mixed density was seen in 5%, and hypodensity in 1%. In the portal phase, 4% of lesions were hyperdense (homogeneously in 1% and centrally in 3%); mixed density was seen in 11%, and hypodensity in 85%. In the delayed phase, the lesions appeared mixed in 11% of cases and hypodense in 89%. CONCLUSIONS: Spiral CT scanning of small HCCs requires dedicated and meticulous technique. Multipassage assessment is mandatory, with 2 or 3 dynamic acquisitions of the whole liver. No major difference in nodule detection was demonstrated between these two options and thus the choice rests with the radiologist's preference. Early CT images proved best for lesion detection, followed by delayed, venous, and baseline studies; lesion recognition depends largely on nodular diameter. The same applies to conspicuity, which however depends on tumor volume less. Lesion patterns are quite typical and constant in all phases and are independent of lesion diameter.     

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.