Preoperative detection of hepatocellular carcinoma: ferumoxides-enhanced versus mangafodipir trisodium-enhanced MR imaging

OBJECTIVE: The purpose of our study was to compare the diagnostic accuracy and lesion conspicuity of ferumoxides-enhanced MR imaging with those of mangafodipir trisodium-enhanced MR imaging for the preoperative detection of hepatocellular carcinoma. SUBJECTS AND METHODS: Twenty-one patients with 39 hepatocellular carcinomas underwent ferumoxides-enhanced and mangafodipir trisodium-enhanced MR imaging. The diagnosis was established by pathologic examination after surgical resection in all patients. Five MR sequences were obtained 30 min after ferumoxides administration, and two MR sequences were obtained before and 15 min after mangafodipir trisodium administration. Three observers independently interpreted both MR images of all sequences on a segment-by-segment basis. The diagnostic accuracy of MR imaging was assessed using receiver operating characterizing analysis. Lesion (hepatocellular carcinoma > 10 mm in diameter)-to-liver contrast-to-noise ratio was calculated on MR images. RESULTS: Ferumoxides-enhanced MR imaging (A(z) = 0.971) was significantly more accurate (p < 0.05) than mangafodipir trisodium-enhanced MR imaging (A(z) = 0.950). The mean sensitivity of ferumoxides-enhanced MR imaging (86%) was significantly greater (p < 0.05) than that of mangafodipir trisodium-enhanced MR imaging (44%) in lesions smaller than 10 mm. The mean lesion-to-liver contrast-to-noise ratio of hepatocellular carcinoma on ferumoxides-enhanced MR imaging (13.7 +/- 8.8) was significantly greater than on mangafodipir trisodium-enhanced MR imaging (5.4 +/- 5.1) (p < 0.01). CONCLUSION: Ferumoxides-enhanced MR imaging has superior diagnostic accuracy in lesions smaller than 10 mm and superior lesion conspicuity compared with mangafodipir trisodium-enhanced MR imaging for the preoperative detection of hepatocellular carcinoma.     

Depiction of vasculature in small hepatocellular carcinoma, and dysplastic nodules evaluated with carbon dioxide ultrasonography and angiography

Purpose: To evaluate the vascularity in dysplastic nodules and well-differentiated and moderately to poorly differentiated hepatocellular carcinomas (HCCs) less than 2 cm using carbon-dioxide (CO₂) US and angiography.Material and Methods: A total of 115 pathologically proven small liver tumors (0.7∼2.0 cm) were included in the study. There were 31 dysplastic nodules, 49 well-differentiated HCCs and 35 moderately to poorly differentiated HCCs. A comparative study of angiography and CO₂ US was carried out.Results: Of the dysplastic nodules, 28 out of 31 tumors were hypo- or isovascular at CO₂ US. Twenty-seven out of 31 tumors were hypovascular at angiography. Of the well-differentiated HCCs, 38/49 showed hypervascularity at CO₂ US while 24/49 tumors were hypervascular at angiography. All moderately to poorly differentiated HCCs showed hypervascularity at CO₂ US, compared to 30/35 tumors at angiography.Conclusion: Most of the dysplastic nodules were hypovascular and most of the moderately to poorly differentiated HCCs were hypervascular. The vascularity of well-differentiated HCCs was in between the above tumors. Both CO₂ US and angiography were equally effective in demonstrating the vascularities in dysplastic nodules and moderately to poorly differentiated HCCs. CO₂ US was significantly superior to angiography when identifying the vascularity in well-differentiated HCCs.     

The uptake transporter OATP8 expression decreases during multistep hepatocarcinogenesis: correlation with gadoxetic acid enhanced MR imaging

Objectives

To clarify the changes in organic anion-transporting polypeptide 8 (OATP8) expression and enhancement ratio on gadoxetic acid-enhanced MR imaging in hepatocellular nodules during multistep hepatocarcinogenesis.

Methods

In imaging analysis, we focused on 71 surgically resected hepatocellular carcinomas (well, moderately and poorly differentiated HCCs) and 1 dysplastic nodule (DN). We examined the enhancement ratio in the hepatobiliary phase of gadoxetic acid enhanced MR imaging [(1/postcontrast T1 value?1/precontrast T1 value)/(1/precontrast T1 value)], then analysed the correlation among the enhancement ratio, tumour differentiation grade and intensity of immunohistochemical OATP8 expression. In pathological analysis, we focused on surgically resected 190 hepatocellular nodules: low-grade DNs, high-grade DNs, early HCCs, well-differentiated, moderately differentiated and poorly differentiated HCCs, including cases without gadoxetic acid-enhanced MR imaging. We evaluated the correlation between the immunohistochemical OATP8 expression and the tumour differentiation grade.

Results

The enhancement ratio of HCCs decreased in accordance with the decline in tumour differentiation (P?R?=?0.28) and with the decline of OATP8 expression (P?R?=?0.81). The immunohistochemical OATP8 expression decreased from low-grade DNs to poorly differentiated HCCs (P?R?=?0.15).

Conclusions

The immunohistochemical expression of OATP8 significantly decreases during multistep hepatocarcinogenesis, which may explain the decrease in enhancement ratio on gadoxetic acid-enhanced MR imaging.     

Contrast-enhanced dynamic magnetic resonance imaging findings of hepatocellular carcinoma and their correlation with histopathologic findings

PURPOSE: To investigate the correlations of contrast-enhanced magnetic resonance (MR) imaging findings of large (> 5 cm) hepatocellular carcinomas with tumor size and histopathologic findings. MATERIALS AND METHODS: MR imaging was performed in 30 patients with a histopathologic diagnosis of hepatocellular carcinoma. The imaging protocol included non-contrast, hepatic arterial, portal venous and late phases. The signal intensities relative to the liver, enhancement patterns and the morphologic features of the lesions were evaluated in relation to size and degree of differentiation. RESULTS: On histopathologic examination, 12 of 30 (40%) tumors were well-differentiated (grade 1), 6 of 30 (20%) were moderately differentiated (grades 2 and 3) and 12 of 30 (40%) were poorly differentiated (grade 4). Tumor size, tumor boundry, serum alpha-fetoprotein level and portal vein invasion were found to have statistically significant correlations with the degree of differentiation (p < 0.05). Portal vein invasion, capsule formation and tumor surface characteristics showed statistically significant correlations with tumor size (p < 0.05). CONCLUSION: MR imaging findings of hepatocellular carcinomas larger than 5 cm are partially dependent on tumor size and degree of differentiation.     

Sequential hemodynamic change in hepatocellular carcinoma and dysplastic nodules: CT angiography and pathologic correlation

OBJECTIVE: The purpose of this study was to clarify the hemodynamic changes associated with hepatocarcinogenesis using CT angiography. MATERIALS AND METHODS: Eighty-six hepatocellular lesions were confirmed at pathology in 49 patients who underwent CT with both hepatic arteriography and arterioportography. These images were compared with lesion-to-liver vascular ratios of cumulative arteries, preexisting hepatic arteries, and portal veins in resected specimens. Lesions were classified in five groups according to intranodular hemodynamics determined by CT hepatic arteriography and CT during arterioportography: group 1, isoattenuating on both procedures; group 2, hypoattenuating on CT hepatic arteriography and isoattenuating on CT during arterioportography; group 3, hypoattenuating on both procedures; group 4, isoattenuating on CT hepatic arteriography and hypoattenuating on CT during arterioportography; and group 5, hyperattenuating on CT hepatic arteriography and hypoattenuating on CT during arterioportography. RESULTS: Among 86 lesions, we identified seven low-grade dysplastic nodules, eight high-grade dysplastic nodules, 14 well-differentiated hepatocellular carcinomas, 45 moderately differentiated hepatocellular carcinomas, and 12 poorly differentiated hepatocellular carcinomas. The lesions were classified as group 1 (n = 5), group 2 (n = 13), group 3 (n = 6), group 4 (n = 2), or group 5 (n = 60). Intranodular hemodynamics was significantly correlated with pathologic grading (p < 0.001). For correlations between combinations of the groups and pathologic gradings, the order "groups 1-2-3-4-5" was the most significant (p < 0.001). CONCLUSION: During hepatocarcinogenesis, most hepatocellular nodules show deterioration of arterial blood flow before loss of portal blood flow. Vascular imaging of hepatic nodules may predict malignant abnormality via the early loss of hepatic arterial flow seen before portal flow changes.     

Detection of hepatocellular carcinoma arising in cirrhotic livers: comparison of gadolinium- and ferumoxides-enhanced MR imaging.

OBJECTIVE: We prospectively compared the detectability of hepatocellular carcinoma (HCC) arising in cirrhotic livers using dynamic gadolinium-enhanced fast low-angle shot (FLASH), ferumoxides-enhanced T2-weighted turbo spin-echo, and ferumoxides-enhanced T2*-weighted FLASH MR imaging. SUBJECTS AND METHODS: Fifty-three patients with HCC (32 men and 21 women) who were 33-86 years old (mean, 63 years old) were enrolled in a prospective MR study to assess hepatic lesions using both gadopentetate dimeglumine and ferumoxides. Dynamic gadolinium-enhanced imaging was obtained before and 30, 60, and 180 sec after rapid bolus injection of gadopentetate dimeglumine (0.1 mmol/kg). Ferumoxides-enhanced T2-weighted turbo spin-echo imaging and ferumoxides-enhanced T2*-weighted FLASH imaging were performed between 30 min and 2 hr after i.v. infusion of ferumoxides (10 micromol/kg). Images were analyzed qualitatively and quantitatively. A receiver operating characteristic curve study was performed to compare the diagnostic value of gadolinium-enhanced imaging with that of ferumoxides-enhanced imaging for the detection of HCC. RESULTS: Quantitative analysis revealed a significantly higher percentage of signal-intensity loss and higher liver-lesion contrast-to-noise ratio on ferumoxides-enhanced T2*-weighted FLASH imaging than on ferumoxides-enhanced T2-weighted turbo spin-echo imaging. The percentage of signal-intensity loss and liver-lesion contrast-to-noise ratio on ferumoxides-enhanced images was significantly higher in patients with mild liver cirrhosis (Child's class A) than in patients with severe liver cirrhosis (Child's class C). Qualitative analysis showed that dynamic gadolinium-enhanced images revealed significantly higher lesion conspicuity than did ferumoxides-enhanced T2-weighted turbo spin-echo images. According to receiver operating characteristic analysis, dynamic gadolinium-enhanced FLASH imaging achieved the highest sensitivity, and ferumoxides-enhanced T2*-weighted FLASH imaging was the second most sensitive. We found that ferumoxides-enhanced turbo spin-echo imaging was the least valuable technique for revealing HCC lesions. Gadolinium-enhanced imaging revealed more HCC lesions than did ferumoxides-enhanced imaging, particularly for lesions smaller than 2 cm in diameter. CONCLUSION: Ferumoxides-enhanced imaging revealed fewer findings, such as lesion conspicuity of HCCs arising in cirrhotic livers, than did gadolinium-enhanced FLASH imaging.     

肝内局灶性病变菲立磁增强MRI-组织病理相关性研究

目的分析肝内局灶性病变菲立磁增强信号强度变化与Kupffer细胞计数的关系。方法搜集行菲立磁增强MR扫描并经手术病理证实的12例16个肝细胞癌(HCC)病灶以及良性病变9例16个病灶,分别计算局灶性病变相对于肝组织的Kupffer细胞的比率以及菲立磁增强前后T1WI、T2WI信号的相对比率,并进行相关性分析。结果良、恶性肝内局灶性病变间Kupffer细胞比率差异有统计学意义,随着HCC分化程度的降低,病灶内Kupffer细胞计数比率呈下降趋势(P<005)。T2WI强化比率与Kupffer细胞计数比率呈负相关(r=-0780,P<005);T1WI强化比率与Kupffer细胞计数比率呈正相关(r=0389,P<005)。结论肝内局灶性病变间Kupffer细胞计数比率的明显差异是菲立磁增强MRI鉴别肝内良、恶性病灶的基础,T2WI序列能有效地鉴别肝内良、恶性疾病,是鉴别肝内良恶性局灶性病变的MR检查首选序列。     

Benign versus malignant hepatic nodules: MR imaging findings with pathologic correlation.

According to the currently used nomenclature, there are only two types of hepatocellular nodular lesions: regenerative lesions and dysplastic or neoplastic lesions. Regenerative nodules include monoacinar regenerative nodules, multiacinar regenerative nodules, cirrhotic nodules, segmental or lobar hyperplasia, and focal nodular hyperplasia. Dysplastic or neoplastic nodules include hepatocellular adenoma, dysplastic foci, dysplastic nodules, and hepatocellular carcinoma (HCC). Many of these types of hepatic nodules play a role in the de novo and stepwise carcinogenesis of HCC, which comprises the following steps: regenerative nodule, low-grade dysplastic nodule, high-grade dysplastic nodule, small HCC, and large HCC. State-of-the-art magnetic resonance (MR) imaging facilitates detection and characterization in most cases of hepatic nodules. State-of-the-art MR imaging includes single-shot fast spin-echo imaging, in-phase and opposed-phase T1-weighted gradient-echo imaging, T2-weighted fast spin-echo imaging with fat saturation, and two-dimensional or three-dimensional dynamic multiphase contrast material-enhanced imaging.     

Spin-echo and dynamic gadoliniumenhanced flash MR imaging of hepatocellular carcinoma: Correlation with histopathologic findings

Evaluation of histologic subtype and degree of differentiation in hepatocellular carcinoma (HCC) is essential because it affects patient prognosis and treatment planning. To evaluate the histologic subtype of HCC with magnetic resonance (MR) imaging, conventional spin-echo and dynamic studies were correlated with histopathologic and angiographic findings in 72 HCCs. Dynamic MR imaging was performed with the fast low-angle shot (FLASH) technique after administration of gadopentetate dimeglumine. There was considerable overlap in signal intensity between various tumor grades on both T1- and T2-weighted images. On dynamic MR images, the peak contrast enhancement ratio correlated with tumor grade (well-differentiated, 29.5 ± 24.7; moderately differentiated, 63.5 ± 24.1; poorly differentiated, 86.9 ± 26.4) or degree of dilatation of the sinusoidlike vascular space between tumor cells. The maximum contrast-to-noise ratio in tumor (relative to surrounding liver) was achieved within 60 seconds in 45 HCCs (mostly of the trabecular or pseudoglandular type). Enhancement was slight or minimal in 17 tumors (mostly small, well-differentiated tumors). In 10 tumors, the degree of enhancement increased with time, with maximum enhancement in the delayed phase (most frequently in scirrhous HCC). These dynamic patterns correlated with angiographic findings. These data indicate that the degree and pattern of enhancement on dynamic MR images reflect tumor differentiation and architecture of HCC.     

Detection of malignant hepatic lesions before orthotopic liver transplantation: accuracy of ferumoxides-enhanced MR imaging

OBJECTIVE: The purpose of this study was to evaluate the diagnostic accuracy of ferumoxides-enhanced MR imaging for screening malignant hepatic lesions before orthotopic liver transplantation. MATERIALS AND METHODS: The study comprised 48 patients who underwent MR imaging within 6 months before transplantation. Imaging techniques included unenhanced and ferumoxides-enhanced T1-weighted gradient-echo and T2-weighted fast spin-echo sequences and ferumoxides-enhanced T2(*)-weighted gradient-echo sequences. Qualitative and quantitative analyses were performed; the gold standard was the histopathologic reports of explanted livers. RESULTS: Twenty patients had malignant hepatic lesions, and 24 hepatocellular carcinomas were histopathologically proven. The mean area under the receiver operating characteristic curve and the mean sensitivity were significantly greater for the image sets with ferumoxides-enhanced gradient-echo sequences than for those without these sequences. The mean sensitivity and specificity of all sequences were 85% and 74% on a per-patient basis, respectively. The mean contrast-to-noise ratio was significantly greater for the ferumoxides-enhanced T2(*)-weighted gradient-echo sequences than for any other sequences and for the ferumoxides-enhanced T1-weighted gradient-echo sequences than for unenhanced sequences and the ferumoxides-enhanced T2-weighted fast spin-echo sequences. CONCLUSION: Ferumoxides-enhanced gradient-echo sequences improved the diagnostic accuracy and the sensitivity for detecting malignant hepatic lesions in patients with end-stage cirrhosis of the liver. However, the specificity was not improved even after the administration of ferumoxides because of the false-positive lesions that were mainly the result of fibrotic changes.     

Delayed MR imaging of hepatocellular carcinoma enhanced by gadobenate dimeglumine (Gd-BOPTA).

The purpose of this study was to determine the efficacy of gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging for evaluation of hepatocellular carcinoma HCC. MR images were obtained in 14 patients with 31 HCC nodules as a part of a phase III clinical trial. T1- and T2-weighted images were obtained before and after iv administration of 0.1 mmol/kg of Gd-BOPTA. Two blinded readers evaluated pre- and delayed postcontrast images separately for detection of tumor nodules. Quantitative measurements of signal-to-noise (SNR) and tumor/liver contrast-to-noise (CNR) ratios were also performed. A signal/intensity ratio was calculated. Tumor enhancement was correlated with histologic findings. Consensus agreement of precontrast T1- and T2-weighted images revealed 23/31 HCC nodules in 14 patients; postcontrast T1-weighted images demonstrated 24/31 HCC nodules in the same number of patients. Combining both pre- and postcontrast images, 27/31 lesions were detected. Four patients had four well-differentiated HCC nodules detected only on postcontrast images, while three well-differentiated lesions in two patients were only seen on precontrast images. Quantitative evaluation showed an SNR ratio increase in both liver parenchyma and HCC nodules, as well as a significant increase in the absolute CNR ratio on postcontrast T1-weighted gradient-recalled images (P < 0.05). Well-differentiated HCC lesions showed a greater enhancement than poorly differentiated HCC lesions.     

Effect of superparamagnetic iron oxide-enhanced MRI of the liver with hepatocellular carcinoma and hyperplastic nodule

PURPOSE: To evaluate the possibility of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) of the liver in predicting the histologic grade of hepatocellular carcinoma (HCC) and differentiating HCC from benign hyperplastic nodule (HPN). MATERIALS AND METHODS: Thirty patients with 31 histologically proved HCC and HPN underwent MRI (1.5 Tesla). HCCs were graded into well-differentiated HCC (HCCw; n = 10) and moderately to poorly differentiated HCC (HCCmp; n = 15). HPN was categorized into dysplastic nodule (DN; n = 1) and focal nodular hyperplasia (FNH; n = 6). T2-weighted fast spin echo images were obtained before and after administration of SPIO. Signal-to-noise ratios (SNR) of the lesion and surrounding liver parenchyma and contrast-to-noise ratios (CNR) were calculated pre- and postcontrast study. Relative enhancement ratios (RER), also known as signal intensity reduction ratios of the lesions, were also calculated. RESULTS: HCCw, HCCmp, DN, and FNH decreased in SNR after injection of SPIO. RER of HCCw was 19.5 +/- 13.3%, that of HCCmp was 6.8 +/- 5.8%, DN was 44.0%, and FNH was 42.9 +/- 4.8%. Significant statistical differences were seen between HCCw and HCCmp and HCC and HPN in RER. HCCw, HCCmp, and DN increased in CNR, and FNH decreased in CNR, but no lesion showed a statistically significant difference in CNR. CONCLUSION: SPIO-enhanced MR images may help to predict the histologic grade of HCC and distinguish HCC from HPN.     

Diffusion-weighted magnetic resonance imaging of focal hepatic nodules in an experimental hepatocellular carcinoma rat model

RATIONALE AND OBJECTIVES: We sought to investigate the value of diffusion-weighted MR imaging in evaluating focal hepatic nodules in an experimental hepatocellular carcinoma (HCC) rat model. MATERIALS AND METHODS: Forty rats with chemically induced primary hepatic nodules ranging pathologically from regenerative nodules (RNs) to dysplastic nodules (DNs) to HCC were examined with diffusion-weighted imaging. The apparent diffusion coefficient (ADC) values of hepatic nodular lesions were calculated. Tukey's HSD post hoc test was used to compare the difference in ADC values between different hepatic nodular lesions. RESULTS: Eight RNs, 16 DNs, 7 well-differentiated HCCs (HCCwell), 11 moderately differentiated HCCs (HCCmod), and 14 poorly differentiated HCCs (HCCpoor) were evaluated. There was no significant difference between RNs and DNs (P > 0.05). Although the ADC values of HCCwell were slightly lower than those of DNs, there was no significant difference between them (P > 0.05). The ADC values of HCCmod and HCCpoor were significantly higher (P < 0.05) than those of other nodules, and no significant difference was seen between HCCmod and HCCpoor (P > 0.05). CONCLUSION: Diffusion-weighted magnetic resonance imaging can be useful in characterizing focal hepatic nodular lesions, but ADC values cannot be used efficiently to distinguish HCCwell from DNs.     

High‐b‐value diffusion‐weighted MR imaging of hepatocellular lesions: Estimation of grade of malignancy of hepatocellular carcinoma

Purpose:

To evaluate the effectiveness of diffusion‐weighted magnetic resonance imaging (DWI) in estimating the grade of malignancy of hepatocellular carcinoma.

Materials and Methods:

Dynamic contrast‐enhanced computed tomography (CE‐CT) and DWI (b value, 1000 s/mm²) were performed on 73 patients. Using DW images, the lesions were classified as “visible” or “invisible.” The apparent diffusion coefficient (ADC) of the lesions was measured. Furthermore, the lesions were classified as hypervascular or iso‐hypovascular using arterial phase CE‐CT images. The image findings for each lesion type were compared.

Results:

The 73 patients had 98 hepatocellular lesions, of which 12 were histologically diagnosed as dysplastic nodules; 39, well‐differentiated HCCs; 33, moderately differentiated HCCs; and 14, poorly differentiated HCCs. The mean ADC values of moderately poorly‐differentiated HCCs were significantly lower than well‐differentiated HCCs and dysplastic nodules (P < 0.01). On DW images, >90% of moderately (30/33) and poorly differentiated HCCs (13/14) were visible, while 51% of well‐differentiated HCCs (20/39) and all dysplastic nodules were invisible. Of 22 iso‐hypovascular lesions, 4 were visible on DW images and were poorly differentiated HCCs, whereas 18 were invisible and were dysplastic nodules (12/18) or well‐differentiated HCCs (6/18).

Conclusion:

A combination of hypovascularity and visibility on DW images can help distinguish poorly differentiated HCCs from low‐grade hepatocellular lesions (dysplastic nodules and well‐differentiated HCCs). J. Magn. Reson. Imaging 2009;30:1005–1011. © 2009 Wiley‐Liss, Inc.     

Gd-EOB-DTPA enhanced MRI for hepatocellular carcinoma: quantitative evaluation of tumor enhancement in hepatobiliary phase.

OBJECTIVE: The purpose of this study was to evaluate the utility of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for the quantitative evaluation of hepatocellular carcinoma (HCC) and dysplastic nodules in the hepatobiliary phase. MATERIAL AND METHODS: The subjects comprised 12 patients with 27 lesions (22 HCCs and 5 dysplastic nodules). Chemical-shift-selective fat-suppressed T1-weighted sequences were obtained before and 10, 20, and 40 min after the injection of Gd-EOB-DTPA. Quantitative analyses were performed with the enhancement ratio of the lesion and the contrast-to-noise (C/N) ratio. RESULTS: The enhancement ratios of the HCCs were 44.0+/-36.5, 44.7+/-46.8, and 47.7+/-52.8 (%) at 10, 20, and 40 min, respectively, after the injection of Gd-EOB-DTPA. The enhancement ratios of the dysplastic nodules were 36.2+/-34.3, 44.3+/-37.3, and 40.1+/-46.8 (%). The C/N ratios of the HCCs were 0.2+/-6.6 for the precontrast image, and -9.2+/-12.6, -9.9+/-14.8, and -12.7+/-15.7 at 10, 20, and 40 min, respectively, after the injection of Gd-EOB-DTPA. The C/N ratios of the dysplastic nodules were 1.4+/-8.0, -13.7+/-11.1, -13.3+/-7.6, and -13.1+/-10.4. No significant differences were found between the HCCs and the dysplastic nodules in the enhancement ratio and the C/N ratio. Only two HCCs showed a positive C/N ratio value, and these HCCs were pathologically confirmed to be a well differentiated and a moderately differentiated carcinoma, respectively. CONCLUSION: HCCs and some of the dysplastic nodules showed hypointensity in the hepatobiliary phase in Gd-EOB-DTPA-enhanced MRI. No specific enhancement was observed, regardless of tumor differentiation.     

微小肝细胞结节性病变CTHA及CTAP的诊断价值

目的:分析肝细胞结节性病变在CTHA 和CTAP 上的不同表现,评价其对早期肝细胞癌的诊断价值。方法:对32例肝细胞结节性病变患者行CTHA、CTAP和组织学检查。结果:18 个中、低分化型肝细胞癌结节均显示为CTHA高密度、CTAP低密度;7个再生性结节和腺瘤样增生中有4个结节CTHA和CTAP均呈等密度;其余21 个结节根据恶性程度的不同,显示为由高分化到低分化不同类型的CTHA和CTAP表现。结论:CTHA和CTAP可提高早期肝细胞癌的检出率,且可用以推测肝细胞结节性病变的恶性程度,指导临床治疗。     

Iron oxide-enhanced MR imaging of hepatocellular carcinoma of woodchuck]

To determine the utility of iron oxide-enhanced MR imaging for primary hepatocellular carcinoma (HCC), MR imagings of an adult woodchuck with two nodules of HCC was obtained before and after an injection of iron oxide. On postcontrast images, signal intensity decreased in one nodule and did not change in the other. Pathologically, the former was well-differentiated HCC with trabecular pattern and the latter was with pseudograndular and scirrhous pattern. Iron oxide particles were noted within the former. Iron oxide-enhanced MR imaging is a promising method for differentiation of pathological subtypes of HCC, however well-differentiated one with reticuloendothelial cells might be overlooked.     

Ferumoxide-enhanced MR imaging of hepatocellular carcinoma: correlation with histologic tumor grade and tumor vascularity

PURPOSE: To evaluate ferumoxide-enhanced MR imaging findings of hepatocellular carcinomas (HCCs) in correlation with the histologic tumor grades and the tumor vascularity evaluated by CT hepatic arteriography (CTHA) and CT during arterial portography (CTAP) combined. MATERIALS AND METHODS: By searching the radiologic, surgical, and pathologic reports of our institution between January 1999 and February 2001, we identified 43 patients with 51 pathologically confirmed HCCs who underwent ferumoxide-enhanced MR imaging and combination CTHA and CTAP within two weeks. The HCCs consisted of 17 well-differentiated, 28 moderately differentiated, and six poorly differentiated tumors. The MR and CT were retrospectively reviewed by two radiologists in consensus for signal intensity on MR images and vascularity on CT. The Spearman's rank correlation coefficient was calculated to correlate the frequency of tumors with ferumoxide uptake with the histologic tumor grades and the tumor vascularity on CTHA and CTAP. RESULTS: A total of 45 tumors (88%) did not take up ferumoxide, and thus showed distinct, homogeneous hyperintensity. Six tumors (12%) ranging 5-16 mm in size (mean, 11 mm) took up ferumoxide, and thus showed isointensity, mixed intensity, or hypointensity, including five of 17 (29%) well-differentiated tumors and one of 28 (4%) moderately differentiated tumors. Five of the six tumors (83%) showed hyper- or hypovascularity on CTHA or hypovascularity on CTAP. The frequency of tumors with ferumoxide uptake showed weak correlation with tumor grades (coefficient = 0.26, P < 0.01) and vascularity on CTHA (-0.35, P < 0.05) and CTAP (0.39, P < 0.01). CONCLUSION: Although a small number of well-differentiated HCC take up ferumoxide and show iso-, mixed, or hypointensity, most such tumors show increased hepatic arterial or decreased portal venous perfusion. The present results suggest the limitation of reticuloendothelial contrast imaging, particularly in the diagnosis of small, well-differentiated HCC.     

Preoperative detection of hepatocellular carcinoma: ferumoxides-enhanced mr imaging versus combined helical CT during arterial portography and CT hepatic arteriography

OBJECTIVE: The purpose of this study was to compare ferumoxides-enhanced MR imaging with combined helical CT during arterial portography and CT hepatic arteriography for preoperative detection of hepatocellular carcinomas. SUBJECTS AND METHODS: Twenty patients with 30 hepatocellular carcinomas underwent ferumoxides-enhanced MR imaging and combined helical CT during arterial portography and CT hepatic arteriography. The diagnosis was established by pathologic examination after surgical resection in 18 patients and by biopsy in two. The MR protocol included fast spin-echo with two echo times, T2(*)-weighted fast multiplanar gradient-recalled acquisition in the steady state, proton density-weighted fast multiplanar spoiled gradient-recalled echo, and T1-weighted fast multiplanar spoiled gradient-recalled echo images. The MR images of all sequences and the paired CT during arterial portography and CT hepatic arteriography images were independently evaluated by three radiologists on a segment-by-segment basis. Diagnostic accuracy was assessed with receiver operating characteristic analysis. RESULTS: The accuracies (A(z) values) of ferumoxides-enhanced MR imaging and combined CT during arterial portography and CT hepatic arteriography for all observers were 0.964 and 0.948, respectively. The mean sensitivities of MR imaging and CT were 93% and 91%, respectively. The differences were not statistically significant. The mean specificity of MR imaging (99%) was significantly higher than that of combined CT during arterial portography and CT hepatic arteriography (94%). CONCLUSION: Ferumoxides-enhanced MR imaging can be used successfully in place of combined CT during arterial portography and CT hepatic arteriography for the preoperative evaluation of patients with hepatocellular carcinomas.     

Differentiation of hepatocellular carcinomas from hyperplastic nodules induced in rat liver with ferrite-enhanced MR imaging.

The potential of superparamagnetic ferrite particles in magnetic resonance (MR) imaging to help differentiate between hyperplastic nodular lesions in the liver and hepatocellular carcinomas was evaluated with chemically induced liver tumors in cirrhotic rats. Ferrite particles decreased the signal intensity of hyperplastic nodules but not that of hepatocellular carcinomas, and stainable iron was found in the former but not in the latter with Prussian blue iron stain. T1-weighted spin-echo images made little contribution to the differentiation between these two lesions, while T2-weighted spin-echo images were effective for this purpose, since ferrite particles cause T2 shortening. Ferrite-enhanced MR imaging may be useful in differentiating these two lesion types according to their signal intensity changes on images, because Kupffer cells are present in hyperplastic nodular lesions but rarely in hepatocellular carcinomas.