Well-to moderately-differentiated HCC manifesting hyperattenuation on both CT during arteriography and arterial portography

We present a rare case of well- to moderatelydifferentiated hepatocellular carcinoma （HCC） in a 71-year-old woman with hepatitis C virus-related cirrhosis and unusual radiologic features. A 20-mm hypoechoic nodule disclosed by ultrasound in segment two showed hyperattenuation on both computed tomography hepatic arteriography and computed tomography during arterial portography. Contrast-enhanced ultrasound revealed hypervascularity in the early vascular phase and defect in the post-vascular phase, with the same pattern detected by the two imaging techniques. SPIO-MRI revealed a hyperintense nodule. These findings were compatible with those of moderately-differentiated HCC. An ultrasound-guided biopsy showed histological features of well- to moderately-differentiated HCC characterized by more than two-fold the cellularity of the non-tumorous area, fatty change, clear cell change and mild cell atypia with a thin to mid-trabecular pattern. Further studies may provide insights into the correlation between tumor neovascularity in multistep hepatocarcinogenesis and dual hemodynamics, including the artery and the portal vein.     

A case of focal nodular hyperplasia presenting corona enhancement on single-level dynamic CT during hepatic arteriography]

A hepatic nodule was detected in segment 5/6 on abdominal US study in a 28 year-old male. The nodule was 7cm in diameter and the early phase of contrasted US, CT and MRI images showed spoke-wheel like vessels radiating from the center. No defect images were observed on postvascular phase contrasted US and SPIO MRI, which indicated the presence of Kupffer cells in the nodule. The nodule was diagnosed as a focal nodular hyperplasia (FNH) based on histological findings. The late phase of single level dynamic CT during hepatic arteriography (CTHA) showed corona enhancement of the nodule, which is considered to be characteristic of hypervascular metastatic liver tumors, hyperplastic nodules and HCCs. In our case, the drainage flow from the nodule may have been visualized as corona enhancement via the pathway from the sinusoid in the nodular periphery to the one in the adjacent and contiguous parenchyma.     

Contrast-enhanced ultrasound in the diagnosis of nodules in liver cirrhosis

Contrast-enhanced ultrasound(CEUS)using microbubble contrast agents are useful for the diagnosis of the nodules in liver cirrhosis.CEUS can be used as a problem-solving method for indeterminate nodules on computed tomography(CT)or magnetic resonance imaging(MRI)or as an initial diagnostic test for small newly detected liver nodules.CEUS has unique advantages over CT and MRI including no renal excretion of contrast,real-time imaging capability,and purely intravascular contrast.Hepatocellular carcinoma(HCC)is characterized by arterial-phase hypervascularity and later washout(negative enhancement).Benign nodules such as regenerative nodules or dysplastic nodules are usually isoechoic or slightly hypoechoic in the arterial phase and isoechoic in the late phase.However,there are occasional HCC lesions with atypical enhancement including hypovascular HCC and hypervascular HCC without washout.Cholangiocarcinomas are infrequently detected during HCC surveillance and mostly show rimlike or diffuse hypervascularity followed by rapid washout.Hemangiomas are often found at HCC surveillance and are easily diagnosed by CEUS.CEUS can be effectively used in the diagnostic work-up of small nodules detected at HCC surveillance.CEUS is also useful to differentiate malignant and benign venous thrombosis and to guide and monitor the local ablation therapy for HCC.     

Well-differentiated HCC manifesting hyperattenuation on CT during arterial portography

A rare case of well-differentiated minute hepatocellular carcinoma (HCC) with hepatitis C virus-related cirrhosis, with unusual radiologic features, is presented. A 10-mm hypoechoic nodule disclosed by ultrasound in segment six showed hypoattenuation on computed tomography hepatic arteriography and hyperattenuation on computed tomography during arterial portography, indicating that the portal vein may have been the dominant vascularity of the nodule. Contrast-enhanced ultrasound revealed hypovascularity in the early arterial phase, isovascularity in the late vascular phase, and the same perfusion as that surrounding the liver parenchyma in the post-vascular phase, with the same pattern observed on the two imaging techniques. These findings were considered not compatible with those of well-differentiated HCC. Ultrasound-guided biopsy showed histological features of well-differentiated HCC with over two-fold the cellularity of the non-tumorous area with a high nuclear/cytoplasmic ratio, increased cytoplasmic eosinophilia, slight atypia and fatty change with an irregular thin trabecular pattern. Further studies may provide insights into the correlation between tumor neovascularity in multistep hepatocarcinogenesis and dual hemodynamics, including the artery and the portal vein.     

Solitary fibrous tumors in abdomen and pelvis:Imaging characteristics and radiologic-pathologic correlation

AIM:To describe the imaging features of solitary fibrous tumors(SFTs)in the abdomen and pelvis,and the clinical and pathologic correlations.METHODS:Fifteen patients with pathologically confirmed SFTs in the abdomen and pelvis were retrospectively studied with imaging techniques by two radiologists in consensus.Patients underwent unenhanced and contrast-enhanced imaging,as follows:3 with computed tomography(CT)and magnetic resonance imaging(MRI)examination,8 with CT examination only,and 4 with MRI examination only.Image characteristics such as size,shape,margin,attenuation or intensity,and pattern of enhancement were analyzed and correlated with the microscopic findings identified from surgical specimens.In addition,patient demographics,presentation,and outcomes were recorded.RESULTS:Of the 15 patients evaluated,local symptoms related to the mass were found in 11 cases at admission.The size of the mass ranged from 3.4 to 25.1cm(mean,11.5 cm).Nine cases were round or oval,6were lobulated,and 10 displaced adjacent organs.Unenhanced CT revealed a heterogeneous isodense mass in 7 cases,homogeneous isodense mass in 3 cases,and punctuated calcification in one case.On MRI,most of the lesions(6/7)were heterogeneous isointense and heterogeneous hyperintense on T1-weighted images and T2-weighted images,respectively.All tumors showed moderate to marked enhancement.Heterogeneous enhancement was revealed in 11 lesions,and 7of these had cysts,necrosis,or hemorrhage.Early nonuniform enhancement with a radial area that proved to be a fibrous component was observed in 4 lesions,which showed progressive enhancement in the venous and delayed phase.No statistical difference in the imaging findings was observed between the histologically benign and malignant lesions.Three patients had local recurrence or metastasis at follow-up.CONCLUSION:Abdominal and pelvic SFTs commonly appeared as large,solid,well-defined,hypervascular masses with variable degrees of necrosis or cystic change that often displaced adjacent structures.     

Macro-regenerative nodules in biliary atresia： CT/MRI findings and their pathological relations

AIM： To describe the radiological findings of a macro-regenerative nodule （MRN） in the liver of pretransplantation biliary atresia （BA） patients and to correlate it with histological findings.
METHODS： Between August 1990 and November 2007, 144 BA patients underwent liver transplantation （LT） at our institution. The pre-transplantation computer tomograghy （CT） and magnetic resonance imaging （MRI） findings were reviewed and correlated with the post-transplantation pathological findings.
RESULTS： Nine tumor lesions in 7 patients were diagnosed in explanted livers. The post-transplantation pathological findings showed that all the lesions were MRNs without malignant features. No small nodule was detected by either MRI or CT. Of the 8 detectable lesions, 6 （75%） were in the central part of the liver, 5 （63%） were larger than 5 cm, 5 （63%） had intratumor tubular structures, 3 （38%） showed enhancing fibrous septa, 3 （38%） had arterial enhancement in CT, one （13%） showed enhancement in MRI, and one （13%） had internal calcifications.
CONCLUSION： Although varied in radiological appearance, MRN can be differentiated from hepatocellular carcinoma （HCC） in most of BA patients awaiting LT. The presence of an arterial-enhancing nodule does not imply that LT is withheld solely on the basis of presumed malignancy by imaging studies. Liver biopsy may be required in aid of diagnostic imaging to exclude malignancy.     

Hepatic angiomyolipoma pre-operatively diagnosed by imaging

An asymptomatic patient with pre-operatively diagnosed solitary angiomyolipoma is reported. The tumour was a well defined, fat density mass on computerized tomography (CT) and magnetic resonance imaging (MRI), and a hyperechoic nodule with a sharp margin on ultrasonography (US). The lesion was hypervascular on arteriography and CT during hepatic angiography. Chemical shift MRI confirmed the fat component within the lesion. Although a review of the literature shows this tumour to be rare and difficult to differentiate from a malignant lesion pre-operatively, the pre-operative diagnosis of angiomyolipoma is considered feasible when the characteristic findings as described here are present.     

MRI versus 64-row MDCT for diagnosis of hepatocellular carcinoma

AIM: To compare the diagnostic capability of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) for the detection of hepatocellular carcinoma (HCC) tumour nodules and their effect on patient management.METHODS: A total of 28 patients (25 male, 3 female, mean age 67 ± 10.8 years) with biopsy-proven HCC were investigated with 64-row MDCT (slice 3 mm native,arterial and portal-venous phase, 120 mL Iomeprol,4 mL/s, delay by bolus trigger) and MRI (T1fs fl2d TE/TR 2.72/129 ms, T2tse TE/TR 102/4000 ms, 5-phase dynamic contrast-enhanced T1fs fl3d TE/TR 1.56/4.6,Gadolinium-DTPA, slice 4 mm). Consensus reading of both modalities was used as reference. Tumour nodules were analyzed with respect to number, size, and location.RESULTS: In total, 162 tumour nodules were detected by consensus reading. MRI detected significantly more tumour nodules (159 vs 123, P < 0.001) compared to MDCT, with the best sensitivity for early arterial phase MRI. False-negative CT findings included nodules ≤ 5 mm ( n = 5), ≤ 10 mm ( n = 17), ≤ 15 mm ( n = 12 ), ≤ 20 mm ( n = 4 ), and 1 nodule > 20 mm. MRI missed 2 nodules ≤ 10 mm and 1 nodule ≤ 15 mm. On MRI, nodule diameters were greater than on CT (29.2 ± 25.1 mm, range 5-140 mm vs 24.1 ± 22.7 mm, range 4-129 mm, P < 0.005). In 2 patients, MDCT showed only unilobar tumour spread, whereas MRI revealed additional nodules in the contralateral lobe. Detection of these nodules could have changed the therapeutic strategy. CONCLUSION: Contrast-enhanced MRI is superior to 64-row MDCT for the detection of HCC nodules. Patients should be allocated to interventional or operative treatment according to a dedicated MRI-protocol.     

小肝癌多排螺旋计算机X线体层扫描多期扫描价值的探讨

目的 评价多排螺旋CT多期扫描对小肝癌的诊断与检出。方法 75例小肝癌患者,采用MarconiMX8000CT扫描机,动脉早期的延迟时间为21s,动脉晚期延迟时间为34s,门静脉期为80s,每次全肝扫描的时间为6s。结果 71个病灶在动脉早期与动脉晚期及动脉早期与门静脉期肝癌与肝脏密度值差值有显著性(F=3.327,P<0.05)。91个病灶检出率动脉早期低于动脉晚期,分别为45.1％和83.5％,双动脉期对小肝癌的检出率为92.3％。动脉晚期加门静脉期检出率为94.5％,双动脉期加门静脉期检出率97.8％,两者差异无显著性。结论 多排螺旋CT肝脏快速、薄层、多期扫描,使富血供的肝癌得以检出的机会增加。     

A case of well-differentiated cholangiolocellular carcinoma visualized with contrast-enhanced ultrasonography using Sonazoid

We here report the first case of cholangiolocellular carcinoma (CoCC) visualized with contrast-enhanced ultrasonography (CEUS) using a second-generation contrast agent, Sonazoid. A 76-year-old man was admitted to our hospital for evaluation of a hepatic tumor. The tumor was described as having hyper-enhancement in the early phase and persistent enhancement in the late phase by contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), as well as hypervascularity by angiography. CEUS assessment of the nodule showed diffuse and homogeneous enhancement in the pure arterial phase, which became progressively hypoechoic relative to the adjacent liver parenchyma during the portal vein and late phases (mixed vascular phase), and showed a contrast defect with an unclear border in the Kupffer phase. Histologically we diagnosed this hepatic tumor as CoCC. In light of the above findings and the rarity of CoCC, it is helpful to incorporate the results of several imagings, such as CT, MRI, angiography and CEUS with a second-generation contrast agent when clinically diagnosing CoCC.     

Primary gastrointestinal stromal tumor of the liver： A case report

We report a case of primary gastrointestinal stromal tumor （GIST） of the liver. A 17-year-old man with a solid mass in the anterior segment of the right liver was asymptomatic with negative laboratory examinations with the exception of positive HBV. Contrast-enhanced ultrasound （CEUS） revealed a hypervascular lesion in the arterial phase and hypoechoic features during the portal and late phases. However, enhanced spiral computed tomography （CT） showed hypoattenuation in all three phases. Following biopsy, immunohistochemical evaluation demonstrated positive CDl17. Different imaging features of primary GISTs of the liver are due to pathological properties and different working systems between CEUS and enhanced spiral CT.     

Ring-shaped appearance in liver-specific image with Levovist: a characteristic enhancement pattern for hypervascular benign nodule in the liver of heavy drinkers.

BACKGROUND/AIMS: The aim was to clarify the features of contrast-enhanced ultrasound (CEUS) with Levovist for diagnosis of hypervascular benign nodules in the liver of heavy drinkers. PATIENTS AND METHODS: Seven heavy drinkers with hypervascular nodules in the liver were studied. Findings of CEUS with Levovist (wide-band Doppler, 7/7), contrast-enhanced computed tomography (CECT, 7/7) and magnetic resonance imaging (MRI, 5/7) were compared for one nodule in each patient. RESULTS: Diagnosis of all seven nodules on CECT was HCC, whereas pathological results were HCC for four nodules and benign lesion for three nodules. The former four showed compatible findings for HCC on CEUS (4/4) and MRI (2/4). However, the latter three showed characteristic liver-specific sonograms with a ring-shaped appearance--peripheral enhancement with a central non-enhanced area. Two of the three nodules showed decreased signal-intensity in the periphery on SPIO-enhanced MRI. CONCLUSIONS: The ring-shaped appearance on liver-specific sonograms with Levovist may be a useful sign for the differential diagnosis of hypervascular benign nodule from HCC in heavy drinkers.     

Hypervascular hepatocellular carcinoma: Combined dynamic MDCT and SPIO-enhanced MRI versus combined CTHA and CTAP.

Aim: Recently, many diagnostic modalities have been developed for the detection of hepatocellular carcinoma (HCC). Of these, a less invasive and more accurate diagnostic procedure is desirable. This study was undertaken to compare combined dynamic multidetector row helical computerized tomography (MDCT) and superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) with combined CT hepatic arteriography (CTHA) and CT during arterial portography (CTAP) for the detection of hypervascular HCC. Methods: Forty-eight patients with 56 pathologically proved hypervascular HCCs (less than 5.0 cm in diameter) underwent dynamic MDCT and SPIO-enhanced MRI, as well as CTHA and CTAP. The images were reviewed by four independent and blinded readers on a tumor-by-tumor basis. Results: The mean areas under alternative-free response receiver operating characteristic curve (Az) for combined dynamic MDCT and SPIO-enhanced MRI (IV set) and combinedCTHA and CTAP (IA set) were comparable (0.948 and 0.969, respectively, P > 0.05), although the Az value of the IV set was significantly lower than that of the IA set in HCCs smaller than or equal to 1.5 cm (0.867 and 0.937, respectively, P = 0.033). The mean sensitivity and positive predictive value of the IV set were similar to those of the IA set. Conclusions: Combined dynamic MDCT and SPIO-enhanced MRI showed a diagnostic accuracy comparable to intra-arterial contrast-enhanced CT (CTHA and CTAP) for hypervascular HCC, and may be a useful diagnostic option prior to curative treatments of hypervascular HCC, although a limitation exists in detecting HCCs smaller than or equal to 1.5 cm.     

Noninvasive imaging of hepatocellular carcinoma: From diagnosis to prognosis

Hepatocellular carcinoma(HCC) is the most common primary liver cancer and a major public health problem worldwide. Hepatocarcinogenesis is a complex multistep process at molecular, cellular, and histologic levels with key alterations that can be revealed by noninvasive imaging modalities. Therefore, imaging techniques play pivotal roles in the detection, characterization, staging, surveillance, and prognosis evaluation of HCC. Currently, ultrasound is the first-line imaging modality for screening and surveillance purposes. While based on conclusive enhancement patterns comprising arterial phase hyperenhancement and portal venous and/or delayed phase wash-out, contrast enhanced dynamic computed tomography and magnetic resonance imaging(MRI) are the diagnostic tools for HCC without requirements for histopathologic confirmation. Functional MRI techniques, including diffusion-weighted imaging, MRI with hepatobiliary contrast agents, perfusion imaging, and magnetic resonance elastography, show promise in providing further important information regarding tumor biological behaviors. In addition, evaluation of tumor imaging characteristics, including nodule size, margin, number, vascular invasion, and growth patterns, allows preoperative prediction of tumor microvascular invasion and patient prognosis. Therefore, the aim of this article is to review the current state-of-the-art and recent advances in the comprehensive noninvasive imaging evaluation of HCC. We also provide the basic key concepts of HCC development and an overview of the current practice guidelines.     

Pseudolymphoma of the liver associated with primary biliary cirrhosis： A case report and review of literature

We report a case of two pseudolymphomas of the liver in a 63-year-old Japanese woman with primary biliary cirrhosis. One of the lesions was found incidentally during a medical examination, presenting as a 10 mm hypodense nodule that revealed hyperdensity in the early phase and hypodensity in the late phase in computed tomography （CT） after injection of contrast medium. Retrospectively, the 10 mm nodule had first been discovered as a 4 mm nodule during CT 4 years previously. Superparamagnetic iron oxide-enhanced MRI revealed another 4 mm hyperintense nodule in segment 6 in addition to the 10 mm hyperintense nodule in segment 7. CT during arterial portography revealed two hypointense nodules. Findings with other imaging modalities such as ultrasonography, magnetic resonance imaging, and hepatic angiography were consistent with hepatocellular carcinoma. A right posterior segmentectomy was performed, and the lesions were microscopically diagnosed as pseudolymphoma. To the best of our knowledge, only 31 other cases of this disease have ever been reported, with a highly asymmetrical male：female ratio of 1：9.7. Although we could find only one case of transformation of hepatic pseudolymphoma into lymphoma in the liver, the exact nature of development from benign pseudolymphoma to malignant lymphoma is still not fully understood and cases of hepatic lymphoma need to be followed carefully.     

Imaging findings and transcatheter arterial chemoembolization of hepatic malignancy with right atrial embolus in 46 patients

AIM： To analyze the imaging findings of hepatic malignancy with right atrial （RA） embolus.
METHODS： Forty-six patients with an embolus in the RA were diagnosed, including 44 patients with hepatocellular carcinoma （HCC）, 1 patient with cholangiocellular carcinoma and 1 patient with hepatic carcinoma metastasis. The diagnosis was confirmed by clinical examination, serum α-fetoprotein and imaging. Seventeen patients underwent transcatheter arterial chemoembolization （TACE）.
RESULTS： On enhancement computer tomography （CT） or magnetic resonance （MR） imaging, a nodular filling defect in the RA could be easily found, with a slight enhancement in the arterial phase. The coronal images of CT or MR showed the extent of lesion. Lipiodol entered the embolus after TACE, hence reducing the speed of embolus growth. There was a survival benefit for patients receiving anticancer treatment.
CONCLUSION： Patients with HCC, showing a filling defect of the inferior vena cava （IVC）, hepatic vein （HV） and RA on images, can be diagnosed with RA embolus. Encroachment of the RA is very rare in patients with hepatic malignancies. Furthermore, a prolongation of survival time is found in those patients who underwent TACE.     

肝细胞癌癌前病变富血供转化的风险分析

目的探讨慢性肝病患者钆塞酸二钠增强磁共振成像(MRI)诊断高度异型增生结节(HGDN)转化成富血供肝细胞肝癌(HCC)的危险因素。方法回顾性分析2012年1月至2014年12月期间行钆塞酸二钠增强MRI的患者2037例,筛选出51例有慢性肝病背景的HGDN,行至少2次随访钆塞酸二钠增强MRI扫描,并且在首次MRI前后1个月内行CT增强扫描,研究终点为HGDN转化成富血供HCC,截止时间为2019年4月。根据有无富血供转化分为转化组(A组)和未转化组(B组)。线性回归分析HGDN向富血供HCC转化可能的危险因素。结果A组36个结节,B组79个结节,富血供转化率31.3%(36/115)。单变量分析结节长径>10.2mm(P=0.034)、年增长率>2%(P<0.001)、含脂质成分(P=0.007),与其发生富血供转化具有相关性,多变量分析结节年增长率是发生富血供转化的独立危险因素(P<0.0001)。结论慢性肝病患者钆塞酸二钠增强MRI诊断HGDN年增长率可以作为向富血供转化的潜在预测因子。     

Assessment of tumor hemodynamics in small hepatocellular carcinoma: comparison of Doppler ultrasonography, angiography-assisted computed tomography, and pathological findings.

AIM: We evaluated the usefulness of Doppler ultrasonography (DUS) for the analysis of tumor hemodynamics in small hepatocellular carcinoma (HCC). METHODS: We compared Doppler ultrasound (DUS) findings with angiography-assisted computed tomography (Angio-CT) such as CT during arterial portography and during hepatic arteriography in the evaluation of the intratumoral hemodynamics, and with pathologic findings in 45 small HCC nodules (< or =3.0 cm in diameter) of 43 patients. DUS flow pattern of each nodule was categorized into three types: afferent continuous flow (Type 1), afferent pulsatile flow with afferent continuous flow (Type 2), and afferent pulsatile flow without afferent continuous flow (Type 3). Intratumoral blood supply was determined by Angio-CT, and pathologic findings were evaluated on resected or biopsied specimen. RESULTS: Based on Angio-CT findings, Type 1 nodules showed decreased arterial blood supply (ABS) without decreased portal blood supply (PBS). Type 2 nodules showed unchanged ABS but decreased PBS. Type 3 nodules showed both increased ABS and decreased PBS. DUS findings well represented blood supply of HCC evaluated by Angio-CT. In addition, all Type 1 and 2 nodules were well-differentiated HCC, and all Type 3 nodules were moderately or poorly differentiated HCC; DUS findings well reflected differentiation of HCC. CONCLUSIONS: DUS is a non-invasive imaging method and can be used for the evaluation of the stage of malignancy of small HCC.     

Posterior mediastinal angioleiomyoma: report of a case

We describe a case of mediastinal angioleiomyoma in an asymptomatic 72-year-old man, who was admitted to our hospital for a mediastinal tumor discovered during an annual medical examination. The tumor was evaluated by computed tomography (CT) and magnetic resonance imaging (MRI). Unenhanced CT scans demonstrated a tumor that was adjacent to the descending aorta. The tumor was partially enhanced in the early phase of contrast-enhanced CT, and in the late phase there was additional tumor enhancement. With MRI, the tumor displayed a homogeneous low signal intensity on the T1-weighted image and a homogeneous very high signal intensity on the T2-weighted image. Contrast-enhanced MRI demonstrated the same enhancement pattern as CT. The examination results led to a preoperative diagnosis of posterior mediastinal hemangioma, and the patient underwent surgery. The tumor originated from the supreme intercostal vein, and was diagnosed as an angioleiomyoma by histopathologic examination. Because mediastinal angioleiomyomas are very rare, they are difficult to diagnose preoperatively. However, we believe that CT and MRI can be of significant help in the differential diagnosis.     

MRI angiography is superior to helical CT for detection of HCC prior to liver transplantation: an explant correlation

Helical computerized tomography (CT) and magnetic resonance imaging (MRI) are used for staging of hepatocellular carcinoma (HCC) prior to curative treatments but underestimate tumor extension in 30% to 50% of cases when compared with pathologic explants. This study compares a new technology, MRI angiography (MRA), with triphasic helical CT in detection of HCC. Fifty cirrhotic patients, 29 with HCC, undergoing liver transplantation were analyzed. MRA was performed with a 3-D breath-hold fast spoiled gradient-echo sequence by using an effective section thickness of 2 to 2.5 mm. The gold standard was the pathologic examination (liver cut into 5-mm slices). One hundred twenty-seven lesions were identified at the explant: 76 HCC, 13 high-grade dysplastic nodules, 31 macroregenerative nodules, 7 hemangiomas. Diameter of the main HCC nodules was 29 +/- 14 mm and 11 +/- 7 mm for the 47 additional nodules. On a per nodule basis, sensitivity of MRA was superior to CT (58/76 [76%] vs. 43/70 [61%], respectively, P =.001). Sensitivity of MRA for detection of additional nodules decreased with size (>20 mm: 6/6 [100%]; 10-20 mm: 16/19 [84%]; <10 mm: 7/22 [32%]) and was superior to CT for nodules 10 to 20 mm (84% vs. 47%, P =.016). Nonspecific hypervascular nodules >5 mm at MRA were HCC in two thirds of the cases. In conclusion, MRA has a high diagnostic accuracy for HCC > or =10 mm and is more sensitive than triphasic helical CT in nodules sized 10 to 20 mm. MRA is the optimal technique for HCC staging prior to curative therapies.