高速多排螺旋CT与DSA对肝癌子灶检出的对比分析

目的　比较高速多排螺旋CT与DSA对肝癌子灶检出的敏感性 ,并研究肝癌子灶的高速多排螺旋CT的三期增强扫描影像特征。方法　对 11例肝癌伴子灶病人行高速多排螺旋CT三期薄层扫描。注射 80ml造影剂后延迟 2 5s后行动脉期扫描 ,延迟60s后行门静脉期扫描 ,12 0s后行延迟期扫描。CT扫描后 5d之内行DSA造影。结果　高速多排螺旋CT显示 40个子灶 ,其中 2 2个子灶≤ 1.0cm ,12个子灶在 1.0～ 2 .0cm之间 ,6个子灶 >2 .0cm。DSA显示 14个子灶 ,均 >1.0cm。CT平扫 3 4个子灶呈低密度 ,4个呈等密度 ;增强后动脉期 3 2个子灶强化 ,8个无强化 ;门静脉期 3 3个呈低密度 ,7个等密度。延迟期 3 9个呈低密度 ,1个呈等密度。结论　肝癌小子灶的发现率高速多排螺旋CT明显优于DSA ,尤其是检出 <1.0cm的子灶更具优势     

多层螺旋CT双动脉期与门静脉期增强扫描对原发性肝癌检出价值的比较

目的 评价多层螺旋CT(MSCT)双动脉期与门静脉期增强扫描对原发性肝癌(HCC)癌灶检出的价值.方法 回顾性分析94例经病理证实的HCC患者的MSCT平扫、动脉早期(20～22 s)、动脉晚期(34～37 s)和门静脉期(60 s)资料,并采用X2检验分别对≤3 cm和>3 cm的病灶在各期相的检出率进行比较.结果 94例术中共发现318个病灶,其中≤3 cm者86个,>3 cm者232个.动脉早期、动脉晚期和门静脉期检出≤3 cm病灶的敏感度分别为39.5%(34个)、67.4%(58个)、44.2%(38个),差异有统计学意义(X2=15.38,P<0.01).上述3期检出>3 cm病灶的敏感度分别为89.6%(208个)、99.6%(231个)和99.1%(230个),差异有统计学意义(X2=39.09,P<0.01);阳性预测值均为100%.上述3期检出病灶的总敏感度分别为76.1%(242个)、90.9%(289个)和84.3%(268个),阳性预测值分别为88.3%(242/274)、86.3%(289/335)和93.7%(268/286),差异均有统计学意义(X2值分别为25.62和9.29,P值均<0.05).结论 双动脉期扫描有利于提高病灶的检出率,特别是对于小HCC,动脉晚期的扫描显得尤其重要.     

Effect of iodine concentration of contrast media on contrast enhancement in multislice CT of the pancreas

The purpose of this study was to determine the influence of two different iodine concentrations of the non-ionic contrast agent, Iomeprol, on contrast enhancement in multislice CT (MSCT) of the pancreas. To achieve this MSCT of the pancreas was performed in 50 patients (mean age 57+/-14 years) with suspected or known pancreatic tumours. The patients were randomly assigned to group A (n=25 patients) or group B (n=25 patients). There were no statistically significant differences in age, height or weight between the patients of the two groups. The contrast agent, Iomeprol, was injected with iodine concentrations of 300 mg ml(-1) in group A (130 ml, injection rate 5 ml s(-1)) and 400 mg ml(-1) in group B (98 ml, injection rate 5 ml s(-1)). Arterial and portal venous phase contrast enhancement (HU) of the vessels, organs, and pancreatic masses were measured and a qualitative image assessment was performed by two independent readers. In the arterial phase, Iomeprol 400 led to a significantly greater enhancement in the aorta, superior mesenteric artery, coeliac trunk, pancreas, pancreatic carcinomas, kidneys, spleen and wall of the small intestine than Iomeprol 300. Portal venous phase enhancement was significantly greater in the pancreas, pancreatic carcinomas, wall of the small intestine and portal vein with Iomeprol 400. The two independent readers considered Iomeprol 400 superior over Iomeprol 300 concerning technical quality, contribution of the contrast agent to the diagnostic value, and evaluability of vessels in the arterial phase. No differences were found for tumour delineation and evaluability of infiltration of organs adjacent to the pancreas between the two iodine concentrations. In conclusion the higher iodine concentration leads to a higher arterial phase contrast enhancement of large and small arteries in MSCT of the pancreas and therefore improves the evaluability of vessels in the arterial phase.     

多层螺旋CT多期增强扫描及后处理对胰岛素瘤的评价

目的:探讨多层螺旋CT(MSCT)多期扫描及后处理对胰岛素瘤检出的价值。方法:13例手术证实的胰岛素瘤均行MSCT平扫及三期增强扫描,观察各期肿瘤增强程度及检出率。结果:13例CT平扫肿瘤均为等密度,动脉期及门脉期肿瘤与胰腺实质密度差为24HU与29HU,动脉期、门脉期及实质期肿瘤的检出率分别为84%、100%及62%。结论:MSCT多期成像对胰岛素瘤诊断具有重要价值,门脉期在检出肿瘤方面略优于动脉期扫描,MSCT薄层扫描及其后处理技术有助于显示肿瘤的空间位置及其与血管的关系。     

多排螺旋CT双动脉期增强扫描对比剂浓度对肝癌检出率的影响

目的:通过多排螺旋CT双动脉期及门脉期增强扫描,以评估对比剂浓度对肝癌检出率的影响.方法:95例肝癌患者随机分为两组行多排螺旋CT肝脏平扫及双动脉期、门脉期增强扫描,其中一组(48例)注射碘帕醇370 mgI/ml( 1.5 ml/kg),另外一组(47例)注射碘帕醇300 mgI/ml (1.85ml/kg),均于30 s注射完毕.扫描后图像由放射科医生阅片并与病理结果进行对比,统计分析两组患者＞ 2cm及≤2cm的肝癌病灶的诊断敏感性.结果:95例患者中共证实有259个肝癌病灶,其中87个≤2cm,172个＞2cm.对于≤2cm的病灶及所有病灶动脉早期及晚期370 mgI/ml组诊断敏感性高于300 mgI/ml组,差别有统计学意义;在门脉期两组患者的诊断敏感性无显著性差异.结论:高浓密度对比剂在动脉早期、晚期可提高肝癌的检出率,特别是对于较小的肝癌病灶(≤2cm).     

Normal enhancement of the small bowel: evaluation with spiral CT

PURPOSE: The purpose of this work was to determine normal contrast enhancement of the small bowel with biphasic spiral CT, using water as oral contrast agent. METHOD: Biphasic spiral CT was performed in 50 healthy patients undergoing evaluation as potential renal donors. All patients received 500 ml of water as oral contrast agent and 150 ml of Omnipaque 350 administered by mechanical injector at a rate of 3 ml/s. Dual phase CT of the abdomen was performed in each patient. Acquisition of early phase images began 30 s after the start of the intravenous injection, and portal phase images were obtained 60 s after initiation of the contrast agent injection. Attenuation measurements (in Hounsfield units) were obtained from the wall of the small bowel (duodenum, jejunum, ileum) in both the arterial and the portal phases. RESULTS: During the arterial phase, the mean (95% confidence interval) attenuation of the duodenum, jejunum, and ileum was 120 (+/- 5), 119 (+/- 5), and 118 (+/- 5) HU, respectively. During the portal phase, the average attenuation of the duodenum, jejunum, and ileum was 111 (+/- 4), 111 (+/- 3), and 107 (+/- 3) HU, respectively. There was no statistically significant difference between the attenuation of the duodenum, jejunum, or ileum within either the arterial or the portal venous phases. There was a statistically significant difference in small bowel enhancement between the arterial and portal venous phases. CONCLUSION: There is no important variation in small bowel attenuation during the 30 and 60 s scanning phases. This study serves as a normal reference that may be helpful when spiral CT is used to evaluate ischemic bowel or inflammatory small bowel diseases.     

原发性肝癌多层面CT双动脉期与门静脉期增强扫描分析

目的：探讨原发性肝癌多层面CT（multi-slices CT,MSCT）双动脉期与门静脉期增强扫描各期强化特征及癌灶的检出率。方法：104例原发性肝癌治疗前行MSCT的平扫与三期扫描（双动脉期与门静脉期扫描）,对比剂用量100 ml,以3 ml/s的速率肘静脉注射,采集时间动脉早期20～22 s,动脉晚期34～37 s,门静脉期60 s。测病灶平扫及各增强期CT值,分析病灶的强化情况及检出情况,以增强各期检出的肿瘤数目为肿瘤灶总数。结果：三期增强扫描共显示470个病灶,34个均匀强化;436个不均匀强化,〈3 cm病灶动脉早期检出117个（56.25%）,动脉晚期检出171个（82.21%）,门静脉期检出137个（65.86%）,≥3 cm的病灶动脉早期检出237个（90.45%）,动脉晚期检出250个（95.41%）,门静脉期检出244个（93.12%）。56个仅在三期增强扫描的一期显示,动脉早期5个,动脉晚期25个,门静脉期26个。结论：动脉晚期的检出率明显高于门静脉期与动脉早期。双动脉期与门静脉期增强扫描有利于提高肝癌检出效率。     

Hepatocellular carcinoma: role of unenhanced and delayed phase multi-detector row helical CT in patients with cirrhosis

PURPOSE: To determine, by using multi-detector row helical computed tomography (CT), the added value of obtaining unenhanced and delayed phase scans in addition to biphasic (hepatic arterial and portal venous phases) scans in the detection of hepatocellular carcinoma (HCC) in patients with cirrhosis. MATERIALS AND METHODS: Local ethical committee approval and patient consent were obtained. One hundred ninety-five patients (129 men, 66 women; mean age, 61 years; age range, 39-78 years) with 250 HCCs underwent multi-detector row helical CT of the liver. A quadruple-phase protocol that included unenhanced, hepatic arterial, portal venous, and delayed phases was performed. Analysis of images from hepatic arterial and portal venous phases combined, hepatic arterial and portal venous phases with the unenhanced phase, hepatic arterial and portal venous phases with the delayed phase, and all phases combined was performed separately by three independent radiologists. Relative sensitivity, positive predictive value, and area under the receiver operating characteristic curve (A(z)) were calculated for each reading session. RESULTS: Mean sensitivity and positive predictive values, respectively, for HCC detection were 88.8% (666 of 750 readings) and 97.8% (666 of 681 readings) for the combined hepatic arterial and portal venous phases, 89.2% (669 of 750 readings) and 97.8% (669 of 684 readings) for hepatic arterial and portal venous phases with the unenhanced phase, 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for hepatic arterial and portal venous phases with the delayed phase, and 92.8% (696 of 750 readings) and 97.3% (696 of 715 readings) for all four phases combined. The reading sessions in which delayed phase images were available for interpretation showed significantly (P < .05) superior sensitivity and A(z) values. CONCLUSION: Unenhanced phase images are not effective for HCC detection. Because of the significant increase in HCC detection, a delayed phase can be a useful adjunct to biphasic CT in patients at risk for developing HCC.     

多层螺旋CT对门静脉海绵样变的诊断价值

目的:分析门静脉海绵样变(CTPV)的多层螺旋CT(MSCT)表现和特征,探讨MSCT对该病的诊断价值.方法:使用16排MSCT对30例CTPV患者,行上腹部CT平扫、动态增强扫描,采用多平面重组(MPR)、最大密度投影(MIP)、容积再现 (VR)等图像后处理技术显示异常的门静脉及侧枝血管情况.结果:CTPV的MSCT平扫示门静脉结构不清,肝门区可见多发的结节状软组织影.增强扫描示动脉期10例有肝实质灌注异常;门静脉期18例患者门静脉主干和(或)左右分支增粗,内可见充盈缺损,4例门静脉显示不清;8例门静脉主干和(或)左右分支在正常范围内;1例门静脉主干变细.胆管周围静脉丛(100%)、胆囊静脉(60%)及胃左静脉(23.3%)呈点状、簇状扩张.MPR、MIP、VR可直观地显示各曲张血管的走行及曲张程度.结论:MSCT及图像后处理系统对CTPV诊断具有重要价值,门静脉栓塞及其周围纡曲扩张的侧枝静脉为其特征性表现.     

肝脏一过性灌注异常的MSCT表现及其原因探讨

目的：探讨肝脏一过性灌注异常的MSCT表现及其形成的原因。方法：32例肝脏一过性灌注异常的病例,全部行MSCT三期增强扫描,延迟时间动脉期20～25s,门脉期50～55s,延迟期300s左右;分析MSCT表现及一过性灌注异常的原因,并与病理对照（其中24例灌注异常病例的原因得到病理证实）。结果：32例肝脏一过性灌注异常中肝脏肿瘤病变18例,其中肝癌9例,肝转移5例,肝血管瘤4例;肝脏非肿瘤性病变14例,其中Budd-Chiari综合征5例,肝放射性损伤3例,肝小静脉闭塞病2例,肝脓肿2例,腹腔脓肿1例,上腔静脉综合征1例。MSCT平扫示肝脏一过性灌注异常表现为等密度,动脉期或/和门脉期表现为正常肝实质一过性强化,其内可见正常血管穿行,走形自然,无占位效应,延迟期呈等密度;根据其形态分为①肝叶、肝段型,共计5例;②楔型或者三角型,共计16例;③弥漫型,共计1例;④结节型,共计2例。结论：正确识别肝脏一过性灌注异常的形态及其产生的原因,有助于与肝内本身病变相鉴别,对提高影像诊断水平及肝功能评估有重要意义。     

胆总管癌MSCT动态增强表现及应用价值

目的：探讨胆总管癌的MSCT动态增强特点及其应用价值。方法收集经病理学证实且MSCT资料完整的胆总管癌62例,并对M SC T各期中肝外胆管癌的显示率、表现进行回顾性分析。结果 C T增强扫描,56例肿瘤动脉期或门脉期明显强化;11例肿瘤延迟期呈延迟性强化。动脉期,37例肿瘤即可被检出,59例肿瘤门脉期清晰显示,61例肿瘤延迟期清晰显示。结论 M SC T增强检查可以准确显示肿瘤特点,是诊断胆总管癌的有效方法之一。     

肝脓肿的多层螺旋CT表现及临床价值(附20例分析)

目的　探讨肝脓肿在多层螺旋CT(MSCT)双期或 /和三期 (动脉期、门静脉期、延迟期 )增强扫描的表现及临床价值 ,特别是在动脉期的表现。方法　观察 2 0例经手术或穿刺证实的肝脓肿在多层螺旋CT双期或 /和三期扫描在动脉期与门静脉期的CT表现 ,特别是在动脉期的表现。动脉期是在注射造影剂后 2 5s开始扫描 ,门静脉期是 65s开始扫描 ,延迟是 5min开始扫描 ,每期全肝扫描所用时间为 8～ 10s。结果　 ( 1)动脉期表现 :肝内低密度或略低密度灶周围肝组织强化明显 ,而病灶本身或边缘无明显强化或轻度强化。 ( 2 )门静脉期表现 :a、环靶征 ;b、环状征 ;C、花瓣征 ;d、分房状征。 ( 3)延迟期表现 :病灶缩小或不变 ,水肿带消失或模糊。结论　多层螺旋CT双期或三期扫描充分反映了肝脓肿的病理变化 ,对早期诊断肝脓肿及鉴别诊断有重要价值     

多层螺旋CT在肝癌肝动脉化疗栓塞中的价值

目的 评价多层螺旋CT（MSCT）在肝癌（HCC）肝动脉化疗栓塞中的价值。方法 对54例肝癌患者分别行MSCT和DSA检查，比较病灶、合并症的显示情况和肿瘤的供血来源，MSCT观察腹腔动脉的解剖和走行应用三维容积再现（VRT）、最大信号强度投影（MIP）或多平面重组（MPR）技术。其中，12例进行了CT血管造影（CTA）检查。结果 54例肝癌患者MSCT发现病灶225个，门静脉瘤栓10例，动静脉瘘14例；DSA发现病灶216个，门静脉瘤栓形成8例，动静脉瘘18例；MSCT和DSA二者比较，MSCT对肿瘤的数目的显示率略高于DSA，但差异无统计学意义（P〉0．05）；MSCT能够显示腹腔动脉及其主要分支的三维结构，优于后前位DSA，观察与腹主动脉夹角较DSA更方便；MSCT发现肝动脉起源变异5例，与DSA完全符合。结论 MSCT对于肝癌肝动脉化疗栓塞有重要指导意义，选择最佳延迟扫描时间是显示病灶和血管的关键。     

Neurologische Notfälle in der Mehrschichtcomputertomographie

Modern MSCT with its broad availability and rapid examination times is the preferred modality in the initial evaluation of neurologic emergencies and by its continual development has become more important within recent years. With increased spatial resolution and new post-processing techniques, non-invasive MSCT angiography is seen to increasingly replace diagnostic DSA. Multidetector CTA is a suitable method for the evaluation of intracranial aneurysms, carotid artery stenoses, arterial dissections, as well as cerebral venous and basilar artery thromboses. Multimodal CT (non-enhanced CCT, CTA and perfusion CT) is used more frequently in the assessment of acute stroke patients, it increases the detection rate of early ischemia and is likely to improve the treatment of acute stroke.     

Hepatocellular carcinoma: detection with triple-phase multi-detector row helical CT in patients with chronic hepatitis

PURPOSE: To evaluate whether the use of two arterial phase image acquisition series, when combined with portal venous phase imaging at multi-detector row helical computed tomography (CT), would be superior enough to use of a single arterial phase image acquisition series to warrant the increased radiation dose. MATERIALS AND METHODS: Multi-detector row CT was performed in 77 patients with 140 foci of hepatocellular carcinoma (HCC). A triple-phase protocol that included an early arterial phase, a late arterial phase, and a portal venous phase was performed. Images were analyzed separately by three radiologists to document the presence and number of HCC nodules. Separate reading sessions were performed for images from the early arterial phase, images from the late arterial phase, images from both arterial phases combined, and images from all three phases. Sensitivity and positive predictive values were calculated for each reading session. RESULTS: The average sensitivity and positive predictive values, respectively, for the detection of HCC were 48.5% and 96.4% for early arterial phase images, 87.1% and 94.0% for late arterial phase images, 87.1% and 94.0% for images from both arterial phases, and 88.5% and 93.4% for images from all three phases. Analysis of images from both arterial phases together yielded no improvement in either sensitivity or positive predictive value compared with analysis of late arterial phase images alone. Analysis of the combination of late arterial and portal venous phase images resulted in the highest sensitivity value. CONCLUSION: The acquisition of images during two arterial contrast phases does not provide additional benefit over timed conventional biphasic CT technique.     

门静脉海绵样变性的螺旋CT诊断

目的：探讨门静脉海绵样变性(CTPV)的CT表现，以提高对本病的认识方法回顾性分析经数字减影血管造影、手术或US证实的CTPV 25例。25例均行CT平扫及双期增强扫描。结果：CTPV螺旋CT表现：a)门静脉狭窄和阻塞；b)门脉走行区结构紊乱，正常结构消失，出现迂曲扩张血管样结构，门静脉期明显强化；c)在动脉期可见周围肝实质短暂灌注异常，表现为局部或带状高密度。结论：CTPV螺旋CT双期扫描具有一定的特征性表现，正确诊断有赖于结合临床资料和影像学征象的综合分析。     

A prospective study comparing different iodine concentrations for triphasic multidetector row CT of the upper abdomen

OBJECTIVES: To investigate the effect of different iodine concentrations at either constant injection or iodine administration rates but constant total iodine load on contrast enhancement of liver, pancreas and spleen by multidetector row CT. MATERIALS AND METHODS: One hundred and twenty consecutive patients (70+/-6 years) underwent triphasic liver CT at a four-channel multidetector-row CT using the non-ionic contrast medium iopromide. Patients were divided into six equal groups-I: 150 ml, 240 mg/ml at 4 ml/s; II: 120 ml, 300 mg/ml at 4 ml/s; III: 97.3 ml, 370 mg/ml at 4 ml/s; IV: 150 ml, 240 mg/ml at 5 ml/s; V: 120 ml, 300 mg/ml, 60 ml at 6 ml/s, 60 ml at 3 ml/s; VI: 97.3 ml, 370 mg/ml at 3.3 ml/s. ROIs were measured in the liver, the pancreas, and the spleen in unenhanced, arterial, portal venous, and equilibrium phase. RESULTS: At a constant injection rate of 4 ml/s, pancreatic enhancement over baseline only in the arterial phase was significantly higher at 370 mg/ml (58+/-15 HU versus 59+/-18 HU versus 74+/-20 HU for groups I-III, respectively (p<0.02)). Comparison of different iodine concentrations at constant iodine administration rate (groups II, IV and VI) and of all six protocols revealed no significant differences at either phase. CONCLUSIONS: At a constant iodine load and constant injection rates, the high-iodinated contrast agent iopromide at 370 mg/ml improves pancreatic enhancement in the arterial phase. At constant iodine load and constant iodine administration rates, there is no significant effect of different iodine concentrations.     

Improved diagnosis of hepatic perfusion disorders: value of hepatic arterial phase imaging during helical CT.

The liver has a unique dual blood supply, which makes helical computed tomography (CT) a highly suitable technique for hepatic imaging. Helical CT allows single breath-hold scanning without motion artifacts. Because of rapid image acquisition, two-phase (hepatic arterial phase and portal venous phase) evaluation of the hepatic parenchyma is possible, improving tumor detection and tumor characterization in a single CT study. The arterial and portal venous supplies to the liver are not independent systems. There are several communications between the vessels, including transsinusoidal, transvasal, and transplexal routes. When vascular compromise occurs, there are often changes in the volume of blood flow in individual vessels and even in the direction of blood flow. These perfusion disorders can be detected with helical CT and are generally seen as an area of high attenuation on hepatic arterial phase images that returns to normal on portal venous phase images; this finding reflects increased arterial blood flow and arterioportal shunting in most cases. Familiarity with the helical CT appearances of these perfusion disorders will result in more accurate diagnosis. By recognizing these perfusion disorders, false-positive diagnosis (hypervascular tumors) or overestimation of the size of liver tumors (eg, hepatocellular carcinoma) can be avoided.     

Liver metastases from melanoma: detection with multiphasic contrast-enhanced CT.

PURPOSE: To assess the clinical utility of multiphasic computed tomography (CT) of the liver in patients with metastatic melanoma. MATERIALS AND METHODS: Nonenhanced and biphasic hepatic CT examinations were performed in 28 patients with metastatic melanoma, and liver lesion conspicuity was graded. CT studies in 20 patients met the eligibility criteria, and 13 patients had liver lesions. RESULTS: A total of 57 liver lesions were seen on CT studies: 48 on hepatic arterial phase images, 49 on portal venous phase phase images, and 30 on delayed phase images. Of eight lesions overlooked on portal venous phase images, six were seen on nonenhanced images, and six were seen on arterial phase images. Twenty-eight lesions were graded as more conspicuous on portal venous phase images; 10 were graded as more conspicuous on arterial phase images. CONCLUSION: CT images obtained only during the portal venous phase would have resulted in eight (14%) overlooked lesions, which implies that more than one phase is needed for hepatic CT in patients with malignant melanoma. The combination of nonenhanced and portal venous phase CT was as effective as the combination of arterial and portal venous phase CT in these patients. Delayed phase CT did not improve lesion detection either alone or in combination with CT at other phases.