Comparison between Computer Tomography and Magnetic Resonance Imaging in the Diagnosis of Small Hepatocellular Carcinoma

Background: Hepatocellular carcinomas (HCCs) less than 2 cm in diameter generally demonstrate a good outcome after curative therapy. However, the diagnosis of small HCC can be problematic and requires one or more dynamic imaging modalities. This study aimed to compare the sensitivity and agreement between CT and MRI for the diagnosis of small HCCs. Methods: CT and/or MRI scans of HCCs (1-2 cm) diagnosed by histopathology or typical vascular pattern according to the 2005 AASLD criteria were blindly reviewed by an abdominal radiologist. The reports were defined as conclusive/typical when arterial enhancement and washout during the portal/delayed phases were observed and as inconclusive when typical vascular patterns were not observed. The sensitivity and Cohen’s kappa (k) for agreement were calculated. Results: In 27 patients, 27 HCC nodules (1-2 cm) were included. Diagnosis with a single-imaging modality (CT or MRI) was 81 % versus 48 % (p = 0.01). The CT sensitivity was significantly higher than MRI (78 % versus 52 %, p = 0.04). Among 27 nodules that underwent both CT and MRI, a discordance in typical enhancement patterns was found (k = 0.319, p = 0.05). In cases with inconclusive CT results, MRI gave only an additional 3.7 % sensitivity to reach a diagnosis. In contrast, further CT imaging following inconclusive MRI results gave an additional 29.6 % sensitivity.Conclusions: A single typical imaging modality is sufficient to diagnose small HCCs. Compared with MRI, multiphasic CT has a higher sensitivity. The limitations of MRI could be explained by the greater need for patient cooperation and the types of MRI contrast agent.     

Computed tomography during arteriography and arterial portography in small hepatocellular carcinoma and dysplastic nodule: a prospective study.

We studied the relationship between the findings of computed tomography during arteriography (CTA) and computed tomography during arterial portography (CTAP), and pathologic findings of 81 small nodular lesions (3 cm or less in diameter) in resected liver specimens. The 81 lesions consisted of 8 dysplastic nodule (DN) lesions, 23 well-differentiated hepatocellular carcinomas (early HCCs) and 50 moderately or poorly differentiated HCCs (advanced HCCs). We also performed standard computed tomography (CT), digital subtraction angiography (DSA), magnetic resonance imaging (MRI), and ultrasonography, and compared sensitivities with CTA, CTAP, or combination of CTA and CTAP with other imaging methods. Forty-four of the 50 advanced HCCs, 12 of the 23 early HCCs, and none of 8 DNs hyperattenuated with CTA and hypoattenuated with CTAP. The sensitivity for the early HCCs was significantly higher for CTA and CTAP in combination as compared with DSA or standard CT. The sensitivity for the advanced HCCs was significantly higher for CTA and CTAP in combination than with DSA. The sequential changes of the blood supply from the portal vein to the hepatic artery during the development of the HCCs were observed. Although CTA and CTAP in combination were useful for the distinction of advanced HCC from early HCC or DN, CTA and CTAP used in combination were not superior to CTA alone in the detection of such lesions.     

Computed Tomography during Arteriography and Arterial Portography in Small Hepatocellular Carcinoma and Dysplastic Nodule: A Prospective Study

We studied the relationship between the findings of computed tomography during arteriography (CTA) and computed tomography during arterial portography (CTAP), and pathologic findings of 81 small nodular lesions (3 cm or less in diameter) in resected liver specimens. The 81 lesions consisted of 8 dysplastic nodule (DN) lesions, 23 well-differentiated hepatocellular carcinomas (early HCCs) and 50 moderately or poorly differentiated HCCs (advanced HCCs). We also performed standard computed tomography (CT), digital subtraction angiography (DSA), magnetic resonance imaging (MRI), and ultrasonography, and compared sensitivities with CTA, CTAP, or combination of CTA and CTAP with other imaging methods. Forty-four of the 50 advanced HCCs, 12 of the 23 early HCCs, and none of 8 DNs hyperattenuated with CTA and hypoattenuated with CTAP. The sensitivity for the early HCCs was significantly higher for CTA and CTAP in combination as compared with DSA or standard CT. The sensitivity for the advanced HCCs was significantly higher for CTA and CTAP in combination than with DSA. The sequential changes of the blood supply from the portal vein to the hepatic artery during the development of the HCCs were observed. Although CTA and CTAP in combination were useful for the distinction of advanced HCC from early HCC or DN, CTA and CTAP used in combination were not superior to CTA alone in the detection of such lesions.     

CT及MR多期动态增强扫描对肝细胞肝癌介入治疗后随诊的对比分析

目的比较多排螺旋CT与MR多期动态增强扫描对肝细胞肝癌（HCC）经肝动脉化疗栓塞（TACE）后肿瘤局灶复发或残存的诊断价值。方法18例结节型HCC患者共38个病灶,TACE介入后22天-11个月分别行多排螺旋CT增强扫描及MRLAVA多期增强扫描,检查平均间隔9天（1～21天）。2位影像诊断医师分别读片,评价肿瘤复发或残存。所有病灶经血管造影、碘油CT、随诊等方法证实。通过计算2种诊断方法的ROC曲线下面积（Az）,比较两者诊断的准确性,并评价CT及MR诊断的敏感性差异。结果38个病灶中24个有肿瘤复发或存活,Az值分别为0．948±0．035和0．762±0．074（P〈0．05）,MRLAVA诊断的准确性显著高于CT扫描。根据诊断复发的评分标准,MRLAVA诊断存活肿瘤组织的敏感性为87．5％（21／24）,CT的敏感性为45．8％（11／24）,MRLAVA多期增强扫描的敏感性显著高于CT增强扫描（P〈0．05）。结论在评估肝细胞肝癌TACE治疗后肿瘤残存或复发方面,MR多期增强扫描优于CT增强扫描。     

An Overview of Hepatocellular Carcinoma with Atypical Enhancement Pattern: Spectrum of Magnetic Resonance Imaging Findings with Pathologic Correlation

BackgroundIn the setting of cirrhotic liver, the diagnosis of hepatocellular carcinoma (HCC) is straightforward when typical imaging findings consisting of arterial hypervascularity followed by portal-venous washout are present in nodules larger than 1 cm. However, due to the complexity of hepatocarcinogenesis, not all HCCs present with typical vascular behaviour. Atypical forms such as hypervascular HCC without washout, isovascular or even hypovascular HCC can pose diagnostic dilemmas. In such cases, it is important to consider also the appearance of the nodules on diffusion-weighted imaging and hepatobiliary phase. In this regard, diffusion restriction and hypointensity on hepatobiliary phase are suggestive of malignancy. If both findings are present in hypervascular lesion without washout, or even in iso- or hypovascular lesion in cirrhotic liver, HCC should be considered. Moreover, other ancillary imaging findings such as the presence of the capsule, fat content, signal intensity on T2-weighted image favour the diagnosis of HCC. Another form of atypical HCCs are lesions which show hyperintensity on hepatobiliary phase. Therefore, the aim of the present study was to provide an overview of HCCs with atypical enhancement pattern, and focus on their magnetic resonance imaging (MRI) features.ConclusionsIn order to correctly characterize atypical HCC lesions in cirrhotic liver it is important to consider not only vascular behaviour of the nodule, but also ancillary MRI features, such as diffusion restriction, hepatobiliary phase hypointensity, and T2-weighted hyperintensity. Fat content, corona enhancement, mosaic architecture are other MRI feautures which favour the diagnosis of HCC even in the absence of typical vascular profile.Key words: hepatocellular carcinoma, liver cirrhosis, magnetic resonance imaging, diffusion magnetic resonance imaging     

经皮肝穿刺射频热凝治疗肝脏恶性肿瘤

Objective To study the therapeutic efficay of percutaneous radiofrequency ablation(PRFA)for hepatic malignancies and to definr its indications and its criteria of the curative effect.Methods In 100 patients with histologically of clinically confirmed hepatocellular carcinoma(HCC)or liver metastases we performed PRFA under ultrasound guidance using Le Veen multipolar array meedle electrode and RF 2000 generator.All patients were followed to identify complications and to assess treatment response.Results PRFA was performed in 76 patients with HCC and in 24 with liver metastases.The Alpha-fetoprotein(AFP)levles of the AFP positive HCC patients with inoperable small HCCs decreased to normal in 75.0%(21/28)and decreased markedly in 21.4%(6/28).Complete necrosis of small hepatic malignancies,documented by magnetic resonance imaging(MRI)was achieved in 85.9%(61/71).If the tumor shows iso-or hyper-intensity on Ti-weighted images,and relative hypointensity on T2-weighted images,and no enhanced intensity on dynamic contrast-enhanced MR imaging,it is considered completely coagulated.Conclusion PRFA is a novel local thermal palliative therapy for small hepatic malignancies that is minimally invasive,safe and effective.In patients with large lesions it can be combined with transarterial chemoembolization(TACE).Critera for curative treatment are normalization of serum AFP and /or MRI or CT scan findings showing complete necrosis.     

Diagnosis of hepatocellular carcinoma: newer radiological tools

With the recent dramatic advances in diagnostic modalities, the diagnosis of hepatocellular carcinoma (HCC) is primarily based on imaging. Ultrasound (US) plays a crucial role in HCC surveillance. Dynamic multiphasic multidetector-row CT (MDCT) and magnetic resonance imaging (MRI) are the standard diagnostic methods for the noninvasive diagnosis of HCC, which can be made based on hemodynamic features (arterial enhancement and delayed washout). The technical development of MDCT and MRI has made possible the fast scanning with better image quality and resolution, which enables an accurate CT hemodynamic evaluation of hepatocellular tumor, as well as the application of perfusion CT and MRI in clinical practice. Perfusion CT and MRI can measure perfusion parameters of tumor quantitatively and can be used for treatment response assessment to anti-vascular agents. Besides assessing the hemodynamic or perfusion features of HCC, new advances in MRI can provide a cellular information of HCC. Liver-specific hepatobiliary contrast agents, such as gadoxetic acid, give information regarding hepatocellular function or defect of the lesion, which improves lesion detection and characterization. Diffusion-weighted imaging (DWI) of the liver provides cellular information of HCC and also has broadened its role in lesion detection, lesion characterization, and treatment response assessment to chemotherapeutic agents. In this article, we provide an overview of the state-of-the art imaging techniques of the liver and their clinical role in management of HCC.     

CT与MRI对鼻咽癌分期影响的研究

[目的]比较MRI与CT对鼻咽癌侵犯范围检查的差异性和对T分期的影响。[方法]回顾性分析84例治疗前同时或短时间内（不超过2周）行CT和MRI检查并经病理活检证实是鼻咽癌的患者资料,用χ^2检验比较两种检查方法对各解剖部位的检出率。按’92鼻咽癌分期标准,分别以CT加临床体检和MRI加临床体检对患者进行临床分期．用χ^2检验比较这两种方法划分的各期病例数的分布情况。[结果]CT和MRI诊断颅底骨质破坏的发生率分别为11．9％和41．7％,两种检查方法比较有显著性差异（χ2=18．970,P±0．000）。CT和MRI诊断海绵窦受侵犯的发生率分别为8.3％和20．2％,两种检查方法比较差异有显著性（χ2=4．861,P=0．027）。对于T分期,用CT和MRI划分的各期病例数分布情况比较有显著性差异（χ2=16．416,P=0．001）。有31例（36．9％）在CT与MRI之间发生了T分期改变,MRI所划分的中晚期患者（Ⅲ期和Ⅳa期）比CT增多。[结论]MRI对鼻咽癌侵犯颅底骨质和海绵窦的检出率高于CT。MRI可使鼻咽癌的T分期升级。     

Ultrasonography, computed tomography and magnetic resonance imaging of hepatocellular carcinoma: toward improved treatment decisions

Detection, characterization, staging, and treatment monitoring are major roles in imaging diagnosis in liver cancers. Contrast-enhanced ultrasonography (CEUS) using microbubble contrast agents has expanded the role of US in the detection and diagnosis of liver nodules in patients at high risk of hepatocellular carcinoma (HCC). CEUS provides an accurate differentiation between benign and malignant liver nodules, which is critical for adequate management of HCC and is also useful for guidance of percutaneous local therapy of HCC and postprocedure monitoring of the therapeutic response. The technology of multidetector-row computed tomography (MDCT) has increased spatial and temporal resolutions of computed tomography (CT). It has made possible a more precise evaluation of the hemodynamics of liver tumor, and the diagnostic accuracy of dynamic MDCT has improved. Perfusion CT can measure tissue perfusion parameters quantitatively and can assess segmental hepatic function. Dynamic MDCT with high spatial and temporal resolution enables us to reconstruct 3- and 4-dimensional imaging, which is very useful for pretreatment evaluation. Dual-energy CT makes possible the differentiation of materials and tissues in images obtained based on the differences in iodine and water densities. Monochromatic images, which can be reconstructed by dual-energy CT data, provide some improvement in contrast and show a higher contrast-to-noise ratio for hypervascular HCCs. Dynamic magnetic resonance imaging with fast imaging sequence of 3-dimensional Fourier transformation T(1)-weighted gradient echo and nonspecific contrast medium can show high detection sensitivity of hypervascular HCC. However, the hepatic tissue-specific contrast medium, gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid, has become an essential contrast medium for liver imaging because of its higher diagnostic ability. It may replace CT during hepatic arteriography and during arterioportography.     

Imaging diagnosis of hepatocellular carcinomas

With the rapid progress of various imaging methods, including ultrasonography (US), computed tomography. (CT), digital subtraction angiography (DSA) and magnetic resonance imaging (MRI), it has become possible to detect small liver cancer less than 2 cm in diameter, and the prognosis of hepatocellular carcinomas is now improving rapidly. However, the accurate detection of smaller lesions about 1 cm in diameter and their differential diagnosis are difficult by conventional imaging methods such as US, CT and arteriography. For this purpose, we stressed the effectiveness of the combined use of CT and arteriography (the so-called CT arteriography), CT during arterial portography or Lipiodol CT. The promising future of MRI in this field is also discussed.     

Diagnosis of Hepatocellular Carcinoma Using C11 Choline PET/CT: Comparison with F18 FDG,ContrastEnhanced MRI and MDCT

Purpose: The aim of this study was to compare C11 choline and F18 FDG PET/CT, gadoxeticenhanced 3T MRI and contrastenhanced CT for diagnosis of hepatocellular carcinoma (HCC). Materials and Methods: Twelve chronic hepatitis B patients suspected of having HCC by abdominal ultrasonography received all diagnostic modalities performed within a oneweek timeslot. PET/CT results were analyzed visually by two independent nuclear medicine physicians and quantitatively by tumor to background ratio (T/B). Nine patients then had histopathological confirmation. Results: Six patients had well differentiated HCC, while two and one patient(s) were noted with moderately and poorly differentiated HCC, respectively. All were detected by both CT and MRI with an average tumor size of 5.73.8 cm. Five patients had positive C11 choline and F18 FDG uptake. Of the remaining four patients, three with well differentiated HCC showed negative FFDG uptake (one of which showed negative results by both tracers) and one patient with moderately differentiated HCC demonstrated no C11 choline uptake despite intense F18 FDG avidity. The overall HCC detection rates with C11 choline and F18 FDG were 78% and 67%, respectively, while the sensitivity of F18 FDG for nonwell differentiated HCC was 100%, compared with 83% of C11 choline. The average T/B of C11 choline in welldifferentiated HCC patients was higher than in moderately and poorly differentiated cases (p0.5) and vice versa with statistical significance for T/B of F18 FDG (p 0.02). Conclusions: Our results suggested better detection rate in C11 choline for well differentiated HCC than F18 FDG PET. However, the overall detection rate of PET/CT with both tracers could not compare with contrastenhanced CT and MRI.     

Evaluation of the diagnostic efficacy of SPIO enhanced MRI in patients with focal hepatic lesions--comparison with CECT and CTAP

The aim of this study was to compare the diagnostic efficacy of superparamagnetic iron oxide (SPIO)-enhanced MRI for the detection and diagnostic accuracy of focal liver lesions with helical contrast enhanced CT (CECT) and CT during arterial portography (CTAP). Thirty-nine patients (25 men and 14 women, mean age 63.5 years) were examined by SPIO-MRI and triple-phase CECT. Eleven of them were also examined by CTAP. There were a total of 96 confirmed focal hepatic lesions, 61 metastatic cancers in 18 patients and 35 hepatocellular carcinomas (HCCs) in 21 patients. Final diagnosis was established by operation in 25 cases, by biopsy in 7 cases, and by progression of disease on follow-up examination in the other 7 cases. The sensitivity of SPIO-MRI for HCC detection was almost equal to CECT, but that of SPIO-MRI for metastatic cancer detection, especially cancers smaller than 1 cm in size, was significantly superior to CECT. The sensitivity of SPIO-MRI for both HCC and metastatic cancer detection was almost equal to that of CTAP, but the specificity of SPIO-MRI for detection of both lesions was significantly superior to that of CTAP because CTAP produced a higher incidence of false-positive findings. In conclusion, SPIO-MRI could take the place of CTAP as a non-invasive excellent modality to determine the distribution of hepatic lesions preoperatively. SPIO-MRI could also be a useful modality to follow liver metastasis postoperatively in patients with advanced digestive cancers.     

Advancement of the imaging for hepatic malignancies

The development of CT and MR imaging technology represents a significant advancement. On CT imaging,the advent of multi-detector row CT (MDCT) scanners enables an increase in both scanning speed and spatial resolution. Multiphasic dynamic study is useful for the detection of hepatocellular carcinomas (HCCs) which are demonstrated as hyperattenuated lesions during the hepatic arterial phase. Many investigators assess the optimal timing for detection of HCCs by using the evolving MDCT, and have demonstrated the high detection rate for HCCs. Thanks to the increase in spatial resolution along the z-axis,we are now able to generate high-quality CT angiography and multiplanar reformations without complicated interpolation steps. These CT angiography and MPR images of patients with malignant hepatic tumors (e.g., HCCs, cholangiocellular carcinomas) are very useful for preoperative evaluation. On the other hand, the development of MR fast imaging techniques allows rapid breath-hold, whole-liver imaging. Superparamagnetic iron oxide (SPIO) is a liver-specific particulate magnetic resonance (MR) imaging contrast agent that is taken up by the reticuloendothelial system of the liver. SPIOenhanced MR imaging is useful for the detection of hepatic metastases. The advent of parallel imaging techniques improves the quality of images obtained with diffusion weighted (DW) imaging of the liver. DW imaging demonstrates high accuracy in the detection of hepatic metastases. Recently, in Japan, positron emission tomography (PET)-CT has also been employed for evaluation of hepatic metastases.     

3T MRI in evaluation of asbestos-related thoracic diseases - preliminary results

Background

3T high-field magnetic resonance imaging (MRI) scanners have recently become available for the clinical use and are being increasingly applied in the field of whole-body imaging and chest imaging as well. The aim of this study was to evaluate the diagnostic potential of 3 T MRI as a complementary imaging modality to CT in detecting the pathological changes of asbestos-related thoracic diseases.

Patients and methods

Fifteen patients with the asbestos-related thoracic disease were scheduled for 3T MRI. Five had a benign form of the disease and 10 had malignant pleural mesothelioma (MPM). From the patients with a benign form of the disease their last CT examination in digital form was acquired and patients with MPM were scheduled for CT examination with contrast media. The protocol of MR imaging consists of T2-weighted cardiac-gated breath-hold turbo spin echo (TSE) sequences in coronal, sagittal and axial plane and T1-weighted cardiac-gated breath-hold TSE black blood in axial plane. In T2-weighted sequences in axial plane, fat saturation was also used. CT examinations were obtained with the administration of the contrast medium from lung apices to the lower end of the liver. Images of 5 mm (mediastinum window) and 3 mm (lung window) in axial plan were reconstructed. MRI signal intensity of lesions and adjacent muscles on Syngo MultiModality Work Place were measured.

Results

Compared to muscles pleural plaques appeared hypo-intense to iso-intense on T1 weighted images (in 100%) and also hypo-intense on T2 fs-weighted images (in 100%). MPM appeared inhomogeneous hypo-intense to iso-intense on T1-weighted and hyperintense on T2 fs-weighted images in all patients (100%).

Conclusions

These preliminary results pointed out that MRI was equal or even better compared with CT examination for detecting possible malignant potential of pleural changes in the asbestos-related pleural disease, using signal intensity measurements of T2 fs-weighted images. The 3T MRI enabled the accurate determination of chest pathology and it could be used for imaging of patients with the asbestos-related thoracic disease. MRI is particularly valuable because a patient is not exposed to the harmful radiation which is important if imaging methods are used repeatedly, like in screening programs or in monitoring of treatment results. This finding turned us to propose 3T MRI imaging technique as a non-ionizing imaging method for the follow-up of patients with the isolated pleural form of the asbestos-related disease.     

Magnetic resonance imaging is appropriate for determining the osteotomy plane for appendicular osteosarcoma after neoadjuvant chemotherapy

There are no standard criteria for determining a sufficient resection margin in the treatment of osteosarcoma. The purposes of this study are to evaluate clinical outcomes using T1-weighted magnetic resonance imaging (MRI) for determining the margin of resection and to compare that with the results of different imaging modalities. Seventeen patients diagnosed with osteosarcoma who underwent en bloc resection with a margin of 2–3 cm based on T1-weighted MRI following chemotherapy were studied. Imaging modalities including conventional radiography, MRI, computed tomography (CT), visual assessment, and histopathological examination were performed and compared. Survival rates were determined. After follow-up of 45.5 ± 13.8 months, no local tumor recurrence was observed in any patient. The 1-, 3-, and 5-year survival rates were 94.1, 82.3, and 76.5%, respectively. The differences in the measurement errors among the five methods were analyzed using pathology as the gold standard. Errors were smallest using T1-weighted and fat-suppressed MRI. There were no significant differences between the measurement results of postoperative histopathological examination and that of T1-weighted imaging or T2 fat-suppressed imaging. The measurement results of radiography and CT were significantly different from that of postoperative pathological findings (P < 0.05). Thus, MRI examination is superior to radiography and CT for determining tumor invasion in patients with osteosarcoma. A resection margin of 2–3 cm determined by MRI provides adequate treatment, while minimizing tissue removal.     

Study of small hepatocellular carcinomas

In order to evaluate the factors affecting patient survival, 32 patients with a solitary hepatocellular carcinoma (HCC) smaller than 5 cm have been studied. Most patients were diagnosed as having a HCC during the periodic follow-up examinations for their underlying liver disease. For HCCs smaller than 2 cm, ultrasonography demonstrated the highest detection rate compared with CT and angiography. In patients with tumors larger than 2 cm, a portal vein thrombus and/or satellite tumors were frequently recognized, resulting in a lower patient survival rate when compared to those with a smaller HCC. Results have indicated that early detection of such tumors without a portal vein thrombus and/or a satellite tumor, and an adequate hepatic resection, such as segmentectomy or subsegmentectomy, are most important factors HCC patient survival.     

Complete remission of multiple recurrent hepatocellular carcinomas by oral administration of enteric-coated tegafur/uracil in a patient with huge hepatocellular carcinoma extending to the inferior vena cava after hepatic resection: analysis of mRNA expression of fluoropyrimidine metabolism enzymes in the primary tumor

We herein report the complete remission of multiple recurrent hepatocellular carcinomas (HCCs) by the oral administration of tegafur/uracil (UFT) alone. A 56-year-old Japanese man with two huge HCCs was admitted and underwent hepatic resection. Intraoperative ultrasonography revealed that the tumor thrombus extended to the inferior vena cava (IVC) with a small tumor in the left hepatic lobe. Right trisectionectomy of the liver, removal of the tumor thrombus in the IVC, and partial resection of the left lobe were performed. Microscopic examination revealed that the larger tumor was moderately to poorly differentiated HCC and the smaller tumor was well-differentiated HCC. The small tumor in the left lobe was diagnosed as an intrahepatic metastasis of the larger tumor. Two months after the surgery, computed tomography (CT) revealed multiple HCC recurrences in the remnant liver, but complete remission was achieved by the administration of UFT alone. To clarify the reason for the good response of the recurrent HCC to UFT, the mRNA expression level of several fluoropyrimidine metabolism enzymes was measured in resected specimens. A lower expression of thymidine phosphorylase (TP) might explain the good response to UFT. The patient is alive without intra- or extrahepatic recurrence more than 6 years after the hepatic resection.     

Histological grade of differentiation of hepatocellular carcinoma: comparison of the efficacy of diffusion-weighted MRI with T2-weighted imaging and angiography-assisted CT

Introduction: The purpose of this study is to determine the usefulness of diffusion‐weighted imaging (DWI) for evaluating the histological grade of differentiation of hepatocellular carcinoma (HCC) compared with T2‐weighted imaging (T2WI) and tumour haemodynamics. Methods: We retrospectively evaluated 32 patients with 42 pathologically confirmed HCC nodules. These patients underwent MRI, CT during arterial portography and CT hepatic arteriography. We evaluated the relationship between the histological grade of differentiation and the apparent diffusion coefficient (ADC) values, conspicuity of tumour on DWI, DWI and T2WI contrast‐to‐noise (C/N) ratios and tumour haemodynamics. Results: There was no correlation between the histological grade of differentiation and the ADC values. The DWI C/N ratio was significantly different among all histological grades, but the T2WI C/N ratio was not. Tumour conspicuity on DWI correlated well with the histological grade of differentiation, but tumour haemodynamics only partially correlated with the histological grade of differentiation. Conclusion: DWI was useful for evaluating the histological grade of differentiation of HCC.     

MRI成像对鼻咽癌的分期、诊断及治疗优势的探讨

 目的
探讨鼻咽癌1992年福州分期和2008年分期差异、CT和MRI对鼻咽癌病变的检出率和原发肿瘤靶区(GTV）勾画和体积
计算的影响。方法收集89例初治鼻咽癌患者的CT和MRI图像,分别按1992年福州分期和2008年分期标准进行,比较
两种检查手段对各解剖部位的检出差异,挑选出CT与MRI检出有差异的39例,在TPS下进行GTV勾画及体积计算。结
果MRI在1992年福州分期中的参与使早期(T1+T2）构成比降低,晚期(T3+T4）构成比升高。鼻咽癌2008年分期使T3
、T4期患者增多。两种分期标准对T2、T3分期差异有统计学意义(P=0.033,0.008);在N1、N2的判断中,差异有统
计学意义(P<0.05)。MRI较CT对头长肌、咽旁间隙、海绵窦、副鼻窦及颅神经的检出率明显提高;在对咽后淋巴结
及颈部肿大淋巴结的形态、包膜、坏死、融合的显示方面明显优于CT。对39例CT和MRI成像有差异的病例进行靶区
勾画,结果显示GTVMRI>GTVCT。结论 根据MRI图像进行1992年福州分期发现了更多的晚期病例,需要进行综合治疗
(放疗+化疗）的患者增多,为治疗方案的选择提供了重要参考。以MRI为基础的2008年分期是指导鼻咽癌治疗的主
要标准。按照MRI图像进行肿瘤靶区勾画能有效避免CT图像对肿瘤组织的漏诊以及对正常组织的误诊,既能加强局
部控制,又能保护正常组织,对于鼻咽癌患者的治疗有利无弊。     

500例原发性肝癌的磁共振表现

背景与目的:磁共振成像(magneticresonanceimaging,MRI)是肝内恶性肿瘤的主要影像学诊断方法之一。本文总结了500例原发性肝癌的MRI表现,以评价钆-二乙烯三胺五乙酸(gadolinium-diethylenetriaminepentaacetic,Gd-DTPA)增强及超顺磁氧化铁(superparamagneticironoxideparticles,SPIO)增强扫描对小肝癌的诊断价值。资料与方法:收集我院行MR检查并经病理确诊为原发性肝癌的患者500例,分别行平扫、平扫+Gd-DTPA增强T1加权扫描、平扫+Gd-DTPA增强T1加权+SPIO增强重T2加权扫描。结果:500例原发性肝癌中,小肝癌有65例(13%),结节型肝癌81例(16.2%),块状型肝癌325例(65%),弥漫型肝癌29例(5.8%);单发310例(62%),多发190例(38%)。全组淋巴结转移率为12%;静脉癌栓率为31.4%。非弥漫型肝癌的肿块最大直径与子灶、异叶转移、淋巴结转移、癌栓之间存在正相关(P<0.05)。65例小肝癌的病灶总数为71个,平扫和增强、Gd-DTPA+SPIO增强和Gd-DTPA增强所发现病灶的平均数之间均存在显著差异(P<0.05)。结论:非弥漫型肝癌的肿块直径越大越容易发生子灶、异叶转移,淋巴结转移及癌栓。MRI诊断小肝癌,增强扫描比平扫有利于发现较多的病灶,而SPIO+Gd-DTPA增强比单纯Gd-DTPA增强发现的病灶多。