计算机X线体层扫描和磁共振成像在肝癌定性诊断中的价值

肝脏有双重血供,肝动脉供血占20％左右,门静脉供血占80％左右。而肝细胞癌(HCC)病灶90％以上由肝动脉供血,注射造影剂后有明显强化,病灶和肝实质之间有明显的密度或信号差异。门静脉期扫描时,肝实质强化达到峰值,而HCC病灶的密度或信号下降,两者之间也有明显差异,HCC的这种强化方式被称为“速升速降”型,这也是CT和MRI增强扫描诊断HCC的理论基础。增强动脉期扫描的价值更大,除显示病灶的血供特征外,还有助于发现其他特征,帮助定性。如动静脉瘘是HCC的特征性表现之一,血管造影可清晰地显示,动脉期扫描也可显示。动脉-门静脉瘘的表现分为中央型和周围型。中     

小肝癌的数字减影血管造影、计算机X线体层扫描和磁共振成像诊断进展

原发性肝癌是世界上常见的恶性肿瘤,其发病率高,预后差,因此肝癌的早期发现和诊断对于临床治疗效果有极其重要的作用,是提高肝癌术后生存率的关键。由于大部分血供丰富的病灶由肝动脉供血,因此理想的数字减影血管造影(digitalSubtraction angiography,DSA)、CT和MRI动态增强扫描均能反映其血供特点,随着影像技术的不断发展,小肝癌(直径≤3cm)的病灶检出率已经明显提高。本文将重点介绍小肝癌DSA、CT、MRI的诊断进展及影像学表现。     

螺旋CT三期增强扫描对小肝癌的诊断

目的：研究小肝癌(SHCC)在螺旋CT(SCT)三期增强扫描的表现特征，评价其应用价值。资料与方法：搜集经病理学证实的53例SHCC进行回顾性分析，其中38例行肝动脉插管化疗栓塞治疗(TACE)，15例行经皮射频消融术(RF)。所有病例均行标准化上腹部SCT三期增强扫描，观察SHCC在各期的强化方式。结果：共发现61个病灶，动脉期、门脉期和延迟期的检出率分别为86％、67％和72％，动脉期的敏感性高于延迟期和门脉期，三期综合检出率达92％。结论：SCT三期增强扫描能反映SHCC的血供变化特点，提高了病灶的检出率和诊断的准确性。     

螺旋CT增强三期扫描对原发性小肝癌血供的影像学观察

目的　观察原发性小肝细胞癌(SHCC)的血供特点,提高螺旋CT对SHCC的定性诊断能力。方法　盲法下观察34例经手术病理证实的原发性SHCC患者,术前采用单层动态肝动脉、门静脉及静脉期螺旋CT分别于注入造影剂后2 8～30秒、6 5～70秒及180秒行靶区动态增强扫描,造影剂注射速率为3.0 m/ s,用量90～10 0 ml。结果　共发现37个结节病灶,平扫、动脉期、门静脉期、静脉期的检出率分别为75 .6 %、94 .6 %、97.3%、81.1% ,动脉期和门静脉双期的检出率较平扫和静脉期高(P<0 .0 5 ) ,动脉期与门静脉期、平扫与静脉期检出率无显著性差异(P均>0 .0 5 )。34例中,2 8例肝癌组织为单纯肝动脉供血,其中动脉期强化密度明显高于正常肝脏2 2例,边缘轻度高密度6例;6例为肝动脉和门静脉双重供血,其中4例在三期扫描过程表现为“向心性”强化。结论　原发性SHCC由肝动脉供血者占绝对优势;部分可见肝动脉和门静脉双重供血,并呈现“向心性”强化征象,此征象在与肝脏海绵状血管瘤的鉴别中起重要作用。     

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。     

螺旋CT薄层三期扫描在小肝癌和微小肝癌检查中的作用

提高肝癌的早期检出率并及时治疗是提高肝癌患者生存期的关键 ,而提高肝癌的早期检出率的关键是提高小肝癌(ＳＨＣＣ)或微小肝癌的检出率。ＳＨＣＣ的定义是肿瘤最大直径≤ 3ｃｍ ,微小肝癌的定义是最大直径≤ 1ｃｍ。由于肿瘤较小 ,所以必须采用层厚 5ｍｍ和2ｍｍ的薄层扫描 ,而采用 10ｍｍ层厚的扫描 ,可由于呼吸运动等方面的影响而极易造成漏诊 ,特别是对微小肝癌。三期扫描为平扫、动脉期、门静脉和延迟期 ,在平扫后注射造影剂 ,于 2 5ｓ～ 30ｓ扫动脉期 ,5 0ｓ～ 6 0ｓ扫门静脉期 ,2ｍｉｎ～3ｍｉｎ扫延迟期。高压注射器灌注造影剂速度…     

16层螺旋CT多期动态扫描在肝癌诊断中的应用价值

目的 探讨16层螺旋CT对肝癌多期扫描的影像特征和临床应用价值.方法 对100例肝癌患者先行全肝CT平扫,其中80例无论肿瘤大小(包括23例结节型)先作病灶动脉期扫描,再作全肝静脉期扫描,最后进行病灶平衡期扫描;20例仅行动脉期及静脉期扫描.结果 100例中67例为肿块型(67%),23例为结节型(23%),10例为弥漫型(10%).80例中CT平扫、动脉期、静脉期及平衡期病灶的显示率分别为87%、97%、90%、96%.结论 16层螺旋CT多期扫描能获得肿瘤在各期的增强征象,为肝癌的定性、定量诊断提供更多的影像诊断信息;尤其在肝癌早期,动脉期扫描可得到非常重要的诊断依据.     

原发性肝癌的螺旋CT诊断及临床体会

原发性肝癌是指肝细胞或肝内胆管细胞发生的癌肿，简称肝癌。笔者应用螺旋CT诊断原发性肝癌56例，现将资料报告如下。     

螺旋CT三期增强扫描诊断小肝癌108例

小肝癌(SHCC)CT检查目前常规采用双期或多期增强扫描,大部分在动脉期增强呈高密度,门脉期等密度或低密度,造影剂快进快出的特点反映了SHCC的血供特点,是SHCC的特征性表现.     

多排螺旋CT在小肠梗阻诊断中的价值

小肠梗阻是最常见的急腹症之一,早期准确的诊断梗阻部位和病因可减少并发症和病死率.但是由于小肠走行迂曲,发生在小肠的梗阻定位、定性较为困难.近年来,随着多排螺旋CT(MSCT)和相关后处理技术的普及运用,其在小肠梗阻部位、病因、性质及梗阻程度的诊断中,发挥越来越重要的作用[1～3].本文回顾性分析经手术证实的小肠梗阻的CT表现,旨在探讨MSCT检查对小肠梗阻部位、病因、性质、程度的诊断价值,为临床及时选择合理的治疗方案提供影像学依据.     

Role of multiphase scans by multirow-detector helical CT in detecting small hepatocellular carcinoma

AIM: To evaluate the role of multiphasic scanning by multirow-detector helical CT (MDCT) in detecing small hypervascular hepatocellular carcinoma (SHCC). METHODS: Multiphasic scanning was carried out in 75 patients with SHCC with Marconi MX8000 CT scanner. The early arterial phase (EAP), late arterial phase (LAP) and the portal venous phase (PVP) scans were started at 21 s, 34 s and 85 s respectively. The mean difference of CT values between tumor and liver parenchyma for each scanningphase was measured, and the sensitivity of detection of SHCC in each of these phases and in the combined phase was calculated and statistically analyzed. RESULTS: The mean difference of CT values between tumor and liver parenchyma was significant in 71 lesions≥1 cm in three phases (P&lt;0.05). In 91 tumor foci, the detectability of SHCC was 45.1%, 83.5 % and 92.3 % in EAP, LAP and double arterial phases (DAP), respectively. The early arterial phase plus the portal venous phase and the double arterial phase plus the portal venous phase were 94.5 %, 97.8 %, respectively. Whereas the detectability in LAP plus PVP and in DAP plus PVP had no statistical difference. CONCLUSION: The utility of faster speed and thinner slice MDCT and multiphase scanning protocol can improve the detectability of hypervascular small hepatocellular carcinoma. Among which LAP is superior to EAP in depicting the lesions.     

Role and pitfalls of hepatic helical multi-phase CT scanning in differential diagnosis of small hemangioma and small hepatocellular carcinoma

AIM To compare and analyze the contrast enhancement appearance of small hemangioma (SHHE) and small hepatocellular carcinoma (SHCC) with helical multi-phase CT scanning so as to determine their roles and pitfalls in the differential diagnosis of SHHE and SHCC.METHODS The pre and postcontrast CT scanning of the liver in 73 cases (38 SHHE, 35 SHCC) were carried out. The first phase scan of the entire liver began at 30s after the injection of contrast medium, the second and third phases began at 70s, and 4min respectively. The contrast enhancement patterns and characteristics of all lesions were observed and compared.RESULTS In SHHE, 64.29% (27/42) had typical manifestations in two-phase dynamic scanning, such as peripheral dramatic high-density enhancement of the lesions with progressive opacification from the periphery toward the center, 30.95% (13/42) were hyperdense in both phases and 4.76% (2/42) were hypodense in both phases. In the third phase scanning, 96.67% (28/30) of SHHE were hyperdense and isodense. In SHCC 59.52% (25/42) presented typical appearances, such as hyperdense in the first phase and hypodense in the second phase, 23.81% (10/42) were hyperdense in the first phase and isodense in the second phase with 4.76% (2/42) of hypodense in both phases. In the third phase scanning, 85.71% (24/28) of SHCC were hypodense.CONCLUSION According to the contrast enhancement patterns of SHHE and SHCC in the two-phase or multi-phase scanning by helical CT, diagnosis can be established in the majority of lesions, while some atypical cases needed MRI for further investigation.     

Role and pitfalls of hepatic helical multi-phase CT scanning in differential diagnosis of small hemangioma and small hepatocellular carcinoma

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Multidetector CT in evaluating blood supply of hepatocellular carcinoma after transcatheter arterial chemoembolization

AIM: To assess the value of multidetector-row computed tomography (MDCT) in choosing retreatment methods of hepatocellular carcinoma (HCC) through evaluating the blood supply of low-density area of HCC after transcatheter arterial chemoembolization (TACE). METHODS: Thirty-two patients with HCC after TACE treatment were examined by plain scanning and hepatic multidetector-row CT. The location of low-density area on plain scanning and the enhancement patterns on dynamic contrast-enhanced scanning were observed. At the same time, three-dimensional CT (3D CT) models of the volume rendering, curved multiplanar reformations, surface shaded display and maximum intensity projection reconstruction of the hepatic artery and portal vein were performed in 6 cases. RESULTS: In CT plain scanning data, low density areas of 32 cases of HCC after TACE treatment were divided into three types: peripheral, one-side-located and mixed types. In contrast-enhanced CT scans, the blood supply of low-density area was classified into four types: arterial blood supply (20 cases), portal blood supply (5 cases), arterial combined with portal blood supply (5 cases) and poor blood supply (2 cases). In 6 cases, the relationship between the low-density area and branches of hepatic artery as well as portal vein was shown by 3D CT. CONCLUSION: Hepatic MDCT is an effective method for evaluating the blood supply of low-density area and therapeutic effect of HCC after TACE treatment. Types of blood supply is helpful for the selection of retreatment.     

Adjustment of lipiodol dose according to tumor blood supply during transcatheter arterial chemoembolization for large hepatocellular carcinoma by multidetector helical CT

AIM: To work out an individualized lipiodol dose in transcatheter arterial chemoembolization (TACE) for large hepatocellular carcinoma (HCC) according to its blood supply evaluated by CT. METHODS: One hundred patients with large HCC (more than 8 cm in diameter) were studied by multidetector helical CT. Patterns of blood supply of HCC were divided into sufficient blood supply, poor blood supply, mixed blood supply and arteriovenous (A-V) shunt. The dose of ultra-fluid lipiodol was determined by diameter and blood supply type of HCC. Patients were divided into two groups (50 cases each): lipiodol perfusion group and iodized oil perfusion group according to tumor diameter and the blood supply type of tumor. RESULTS: The confirmation and effective rates were 82%, 84% in the first group and 36%, 46% in the second group (P<0.01). CONCLUSION: A relatively individualized lipiodol dose may be determined according to the blood supply pattern and the tumor diameter by CT imaging.     

Detection of small hepatocellular carcinoma： Comparison of dynamic enhancement magnetic resonance imaging and multiphase multirow-detector helical CT scanning

AIM: To compare the gadolinium-enhanced multiphase dynamic magnetic resonance imaging (MRI) and multiphase multirow-detector helical CT (MDCT) scanning for detection of small hepatocellular carcinoma (HCC). METHODS: MDCT scanning and baseline MRI with SE T1-WI and T2-WI sequence combined with FMPSPGR sequence were performed in 37 patients with 43 small HCCs. Receiver operating characteristic (ROC) curves were plotted to analyze the results for modality. RESULTS: The areas below ROC curve (Az) were calculated. There was no statistical difference in dynamic enhancement MDCT and MRI. The detection rate of small HCC was 97.5%-97.6% on multiphase MDCT scanning and 90.7%-94.7% on MRI, respectively. The sensitivity of detection for small HCC on MDCT scanning was higher than that on dynamic enhancement MRI. The sensitivity of detection for minute HCC (tumor diameter ≤ 1 cm) was 90.0%-95.0% on MDCT scanning and 70.0%-85.0% on MRI, respectively. CONCLUSION: MDCT scanning should be performed for early detection and effective treatment of small HCC in patients with chronic hepatitis and cirrhosis during follow-up.