螺旋CT双期增强扫描对胰腺实性假乳头状瘤的诊断价值

目的：评价多层螺旋CT双期增强在胰腺实性假乳头状瘤诊断中的价值。方法：多层螺旋CT对8例胰腺实性假乳头状瘤先平扫,再以3ml/s速度高压团注碘海醇（300mg I/ml）80～100ml,分别行动脉期（注药后30～35s）和实质期（注药后60～70s）扫描,测量各期肿瘤的CT值。结果：肿瘤平扫CT值为（41.09±6.38）HU,动脉期为（43.82±10.35）HU,实质期为（48.91±9.93）HU。肿瘤动脉期与实质期强化有显著差异（P〈0.01）。结论：胰腺实性假乳头状瘤在实质期强化显著高于动脉期,为该病特征性的CT表现,螺旋CT双期增强对胰腺实性假乳头状瘤的诊断及鉴别诊断具有临床价值。     

螺旋CT双期扫描对小肝癌的诊断价值

目的评价螺旋CT扫描的动脉期、静脉期以及双期联合应用对小肝癌的诊断价值。方法对27例小肝癌行螺旋CT双期增强扫描,增强动脉期于造影剂注射后25～30s开始扫描,静脉期于65～70s开始扫描,造影剂注射速率为2.5～3.0ml/s,用量70～85ml。结果27例小肝癌共发现34个结节病灶。平扫、动脉期、静脉期、动静脉双期的检出率分别为70%、91%、79%、94%,经统计学分析,动脉期和动静脉双期的检出率较平扫和静脉期高（Ρ＜0.05）,动脉期和动静脉双期间、平扫和静脉期间比较均无统计学意义（Ρ＞0.05）。65%（22/34）的小肝癌动脉期呈均匀高密度,与同期肝组织比较,CT值平均增加25.9±14.4HU;23%（8/34）呈不均匀高密度。79%静脉期呈低密度,与同期肝组织比较,CT值平均减少18.7±8.9HU;21%（7/34）为等密度。双期扫描的定性准确率为97%（31/32）。结论螺旋CT动、静脉双期扫描对小肝癌诊断有很高的敏感性和特异性。     

螺旋CT双期扫描技术及其在胰腺癌诊断中的价值

目的：探讨螺旋CT双期扫描技术及其对胰腺癌的诊断价值。方法：正常人60例及胰腺癌44例分两组行螺旋CT双期扫描：A组40例,分动脉期和门动脉期（注射对比剂后20s和60s）扫描;B组64例,分胰腺期和肝脏期（注射对比剂后35s和70s)扫描。分别测定各期胰腺、病灶及胰周大血管的CT值,计算胰腺期及肝脏期胰周小静脉的显示率,并行统计学处理,对扫描时相的比较采用方差分析及q检验处理,对胰周小静脉的显示率采用x^2检验分析。结果：正常组,胰腺在胰腺期的增强值高于其他3期（F＝13．45,P＜0．0001）胰周大血管在胰腺期显示良好。胰周小静脉的显示率,胰腺期优于肝脏期（x^2=4．44,12．38,4．81,P＜0．05）;异常组,胰腺与病灶的增强差值,胰腺期明显大于其他3期（F＝14．90,P＜0．0001）,发现小胰腺癌4例。胰周大血管受侵者占不可切除性肿瘤的54％（19／35）,胰周小静脉迂曲扩张者占42％（10／42）。肝转移灶占37％（13／35）。结论：胰腺螺旋CT双期扫描宜分为胰腺期和肝脏期,该技术在胰腺癌的诊断中具有非常重要的临床价值。     

螺旋CT双期增强扫描诊断胰岛素瘤(附13例报告)

目的 研究螺旋ＣＴ胰腺双期薄层增强扫描对胰岛素瘤的诊断价值。方法 １３例胰岛素瘤行螺旋ＣＴ胰腺双期薄层增强扫描,１００ｍｌ对比剂,３ｍｌ／ｓ单相注射,延迟２５秒行动脉期扫描,延迟６５秒行门脉期扫描。结果 检出１３例中的１０例（７７％）,检出的１０例在动脉期均表现为高密度,门脉期４例为等密度,５例为略高密度,１例为高密度。３例假阴性中２例在两个时相均表现为等密度,１例在两个时相均表现为高密度,因与脾     

口服甘露醇低张小肠造影诊断小肠淋巴瘤的价值

目的 探讨多层螺旋CT小肠造影(MSCTE)双期动态增强扫描在小肠淋巴瘤中的应用价值.方法 对22例经病理证实的小肠淋巴瘤患者行MSCTE双期动态增强扫描,并在ADW4.2工作站进行后处理.分析小肠淋巴瘤的发病部位、形态、强化方式、淋巴结和供血血管的显示率等特征.结果 22例NHL小肠淋巴瘤中,十二指肠4例,空肠6例,回肠12例,位于末端回肠6例.门脉期CT值平均增高32 HU,12例表现为浸润溃疡型,动脉瘤样扩张型有8例,息肉样肿块型4例.15例肠系膜见多发的淋巴结肿大,MPR重建后6例见来源于肠系膜动脉的供血动脉.MscTE对小肠淋巴瘤的定位、定性与术后病理符合率分别为95.5%和91%.结论 MSCTE在小肠淋巴瘤的诊断中的应用价值较大,大大提高了病灶的检出率.     

Opacification of the urinary tract in portal venous spiral CT without delayed scans

In portal venous spiral CT there is no visible renal contrast excretion within the usual period of scanning. To opacify collecting systems additional delayed scanning is required. We administered an extra pre-dose of contrast medium before the main portal venous bolus in order to opacify the urinary tract and studied its effects on liver attenuation. In 32 patients examined first by non-contrast spiral CT 20 ml of a non-ionic IV CM were injected. Five minutes later, orientating cuts in the liver and along the urinary tract were obtained. Immediately thereafter, a 120-ml bolus was administered at 3 ml/s for portal venous phase helical CT (60-s delay craniocaudad). The quality of renal excretion was graded visually (excellent, fair, poor, none). Hepatic attenuation measurements were performed at comparable regions of interest. In all patients 20 ml CM opacified the renal pelvis after 5 min. Depiction of the ureters was excellent in 14, fair in 11 and poor or none in 7 cases. There was little effect on mean hepatic attenuation by the 20-ml pre-bolus after 5 min: mean enhancement 2.3 HU (range –0.6 to 7.8 HU). Mean hepatic enhancement after the 120-ml portal venous bolus ranged between 23.6 and 74.1 HU (mean 51.5 HU). When opacification of the urinary tract is necessary, pre-administration of a 20-ml bolus 5 min before portal venous scanning may save an extra delayed spiral. The effects on hepatic enhancement are negligible. Received: 29 October 1998; Revision received: 6 January 1999; Accepted: 1 February 1999     

Utility of arterial phase of dynamic CT for detection of intestinal ischemia associated with strangulation ileus

AIM:To clarify the usefulness of arterial phase scans in contrast computed tomography (CT) imaging of stran-gulation ileus in order to make an early diagnosis. METHODS:A comparative examination was carried out with respect to the CT value of the intestinal tract wall in each scanning phase, the CT value of the content in the intestinal tract, and the CT value of ascites fluid in the portal vein phase for a group in which ischemia was observed (Group Ⅰ) and a group in which ischemia was not observed (Group N) based on the pathological findings or intra-surgical findings. Moreover, a comparative examination was carried out in Group Ⅰ subjects for each scanning phase with respect to average differences in the CT values of the intestinal tract wall where ischemia was suspected and in the intestinal tract wall in non-ischemic areas. RESULTS:There were 15 subjects in Group Ⅰ and 30 subjects in Group N. The CT value of the intestinal tract wall was 41.8 ± 11.2 Hounsfield Unit (HU) in Group Ⅰ and 69.6 ± 18.4 HU in Group N in the arterial phase, with the CT value of the ischemic bowel wall being significantly lower in Group Ⅰ. In the portal vein phase, the CT value of the ischemic bowel wall was 60.6 ± 14.6 HU in Group Ⅰ and 80.7 ± 17.7 HU in Group N, with the CT value of the ischemic bowel wall being significantly lower in Group Ⅰ; however, no significant differences were observed in the equilibrium phase. The CT value of the solution in the intestine was 18.6 ± 9.5 HU in Group Ⅰ and 10.4 ± 5.1 HU in Group N, being signifi-cantly higher in Group Ⅰ. No significant differences were observed in the CT value of the accumulation of ascites fluid. The average difference in the CT values between the ischemic bowel wall and the non-ischemic bowel wall for each subject in Group Ⅰ was 33.7 ± 20.1 HU in the arterial phase, being significantly larger compared to the other two phases. CONCLUSION:This is a retrospective study using a small number of subjects; however, it suggests that there is a possibility that CT scanning in the arterial phase is useful for the early diagnosis of strangulation ileus.     

对比剂不同流率对门静脉CT血管成像质量的影响

目的 探讨对比剂不同注射流率对多层螺旋CT肝门静脉成像质量的影响.方法 30例患者随机分为3组,每组10例,年龄与体重无明显差异,行腹部CT增强扫描.按1.5 ml/kg剂量前臂静脉注射浓度为300 mg Ⅰ/ml的非离子型对比剂,注射流率分别为2.0 ml/s、3.0 ml/s和4.0 ml/s.腹主动脉兴趣区智能跟踪技术触发动脉期扫描,动脉期后延迟7 s与20 s行门静脉期扫描.在工作站测量3组CT源图像上门静脉(PV)与肝实质的CT值,并重组PV斜轴位与冠状位最大密度投影(MIP)图像,观察PV显示的分支级别.采用SPSS 11.5软件行统计学分析.结果 2.0 ml/s组、3.0 ml/s组、4.0 ml/s组门静脉CT值分别为(150.80±21.16)HU、(170.90±17.26)HU与(181.90±22.88)HU,2.0 ml/s组与4.0 ml/s组间有明显差别(P=0.017).2.0 ml/s组、3.0 ml/s组、4.0 ml/s组PV与肝实质CT值差别分别是(50.20±17.40)HU、(67.10±23.08)HU与(76.20±22.75)HU,2.0 ml/s组与4.0 ml/s组间有明显差别(P=0.039).2.0 ml/s组、3.0 ml/s组、4.0ml/s组对PV分支显示级别分别为4.20±1.14、4.90±0.99及5.50±0.53,2.0 ml/s组与4.0 ml/s组间有明显差别(P=0.013).结论 注射流率对PV CT血管成像的质量有影响,流率为4.0 ml/s时SCTP质量最佳.     

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.     

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.     

Prediction of viable tumor in hepatocellular carcinoma treated with transcatheter arterial chemoembolization: usefulness of attenuation value measurement at quadruple-phase helical computed tomography

OBJECTIVE: To assess the usefulness of attenuation value measurement at quadruple-phase helical computed tomography (CT) for predicting viable tumor in hepatocellular carcinoma (HCC) treated with transcatheter arterial chemoembolization (TACE). METHODS: Thirty-two patients who had an iodized-oil defect area (IODA) in HCCs treated with TACE were included in our study; these patients were divided into group 1 (n = 21) with viable tumor and group 2 (n = 11) without viable tumor in the IODA. All the patients underwent quadruple-phase helical CT (unenhanced and contrast-enhanced hepatic arterial, portal venous and equilibrium phases) before and after TACE. The attenuation difference of the IODA between unenhanced and each contrast-enhanced phase was measured, and the attenuation degree of the IODA relative to the hepatic parenchyma were subjectively assessed and then compared between the 2 groups. RESULTS: The mean attenuation differences of the IODAs were 28.8, 35.9, and 25.6 Hounsfield unit (HU) in group 1 and 0.4, 1.9, and 2.0 HU in group 2 at the hepatic arterial, portal venous, and equilibrium phases, respectively, with statistically significant difference for each phase (P < 0.05). The IODAs had attenuation difference of more than 20 HU on at least 1 contrast-enhanced phase in group 1 and less than 5 HU at all contrast-enhanced phases in group 2. For the attenuation degree of IODAs relative to the hepatic parenchyma, 12 patients (57%) showed hyperattenuation at the hepatic arterial phase, and remaining nine (43%) at the hepatic arterial phase and all patients at the portal venous and equilibrium phases showed isoattenuation or hypoattenuation in group 1. In group 2, all the patients showed hypoattenuation at all the 3 phases. CONCLUSIONS: The presence of viable tumor of the IODA in HCC treated with TACE can be precisely assessed by measuring attenuation values, strongly suggesting viable tumor when the attenuation difference is more than 20 HU on at least 1 contrast-enhanced phase at quadruple-phase helical CT.     

螺旋CT双期增强扫描诊断边缘型肝胆管癌

目的 :探讨螺旋CT双期扫描诊断边缘型肝胆管癌的价值。材料和方法 :回顾性分析经病理证实的 16例边缘型肝胆管癌的螺旋CT资料。所有病例均于注药后 3 0 ,65s分别获得肝动脉及门静脉双期图像。结果 :肿块直径 4.2～ 8.0cm ,以边缘不规则的低密度为主。增强扫描 11例于双期出现肿块周边菲薄、不连续的环形增强 ,3例周边厚的连续环形增强 ,1例肝动脉期均匀增强 ,1例无明显增强。 3例肿瘤内见线样分隔 ,12例在肝动脉期及门静脉期无明显差异。结论 :边缘型肝胆管癌的特征性CT表现为肝动脉期及门静脉期菲薄、不连续的环形轻度增强 ,在双时相间变化不明显。     

Helical CT of the liver with computer-assisted bolus-tracking technology: scan delay of arterial phase scanning and effect of flow rates

PURPOSE: The purpose of this work was to assess the scan delay and the effect of flow rates on arterial phase scanning of hepatic CT. METHOD: One hundred twenty patients suspected of having hepatocellular carcinoma were examined by three-phase helical CT using computer-assisted bolus-tracking technology. We set the region of interest (ROI) in the abdominal aorta at the level of the celiac artery as a baseline. The triggering threshold was set at 100 HU. A volume of 100 ml of iomeprol (350 mg of I/ml) was administered at 2, 2.5, or 3 ml/s i.v. RESULTS: In all cases, helical CT scanning began after reaching the ROI threshold. Then, portal venous phase scanning was initiated 50 s after arterial phase initiation. The mean delay time from the initiation of contrast agent administration to the beginning of arterial phase scanning was 29.2 +/- 3.8 s (mean +/- SD, range 22-39 s). A faster injection rate significantly shortened the scan delay (p < 0.01). In portal venous phase scanning, calculated areas under the hepatic enhancement curves were almost equal among different injection rates. CONCLUSION: The computer-assisted bolus-tracking technology is a useful method for determining an individual scan delay of arterial phase CT.     

多发嗜铬细胞瘤的CT诊断价值

目的:分析多发嗜铬细胞瘤的影像学表现及动态增强特征,以提高其诊断准确性。方法:经手术病理证实的多发嗜铬细胞瘤9例,其中双侧肾上腺嗜铬细胞瘤7例,Von Hippel-Lindau病1例,腹膜后副神经节瘤并膀胱嗜铬细胞瘤1例。术前经螺旋CT和多层螺旋CT平扫、动脉期(30s)和门脉期(70～80s)扫描。对比剂采用欧乃派克或优维显,注射流率3ml/s。仔细复习CT扫描结果并与手术病理作回顾性对照分析。结果:9例嗜铬细胞瘤共18个病灶中,双侧肾上腺嗜铬细胞瘤7例,双侧肾上腺嗜铬细胞瘤并胰腺神经内分泌瘤和肾细胞肾癌1例(Von Hippel-Lindau病),腹膜后副神经节瘤并膀胱恶性嗜铬细胞瘤1例。良性病灶13个,恶性病灶5个。肿瘤呈圆形或椭圆形15个,不规则形3个。直径3.2～13.7cm,平均5.6cm。病灶直径<5.0cm3个,5.0～10.0cm13个,>10cm2个。肿瘤实质成分平扫CT值为34.2～53.0HU,平均42.7HU;动脉期CT值63.7～91.5HU,平均80.7HU;门脉期CT值75.1～126.4HU,平均98.1HU。8例双侧肾上腺嗜铬细胞瘤16个病灶中,6例两侧病灶大小、形态、密度、动态增强强化程度和强化方式相仿,2例两侧大小不同,坏死、囊变不同,但动态增强强化程度和强化方式相仿。结论:多发嗜铬细胞瘤包括双侧肾上腺嗜铬细胞瘤、副神经节瘤和脏器嗜铬细胞瘤,多位于双侧肾上腺,CT表现与肾上腺嗜铬细胞瘤相仿,同一病例不同肿瘤的大小、形态、坏死囊变、动态增强强化方式和强化程度相仿,少数肿瘤大小不同,坏死囊变存在差异。     

螺旋CT三期增强扫描对肝外末端胆管细胞癌的诊断价值

目的 评价螺旋CT三期增强扫描对肝外末端胆管细胞癌的诊断及鉴别诊断价值，重点探讨延迟期扫描的意义，以进一步提高CT诊断的准确性。方法 47例肝外末端胆管细胞癌均行平扫及三期增强扫描，100mL对比剂以2．5mL／s注射速度，延迟25．338行动脉期扫描；延迟60～708行实质期扫描；延迟3～5min行延迟期扫描。测量胆管细胞癌及正常胰腺组织的强化CT值，观察胆管细胞癌的三期强化特征，并对结果进行统计学分析。结果 47例肝外末端胆管细胞癌平扫表现为等或略低密度，与正常胰腺组织无法区分，动脉期11例为略低密度，9例为等密度，26例为高密度，平均CT值83．25±11．56HU，与正常胰腺组织平均CT值（86．46±21．50HU）相差-7．91±8．01HU，定量比较差异无显著性意义（t=1．3，P〉0．05），实质期35例表现为高密度，12例为略低密度，平均CT值108．161±9．67HU，与正常胰腺组织CT值（86．39±17．46HU）相差18．08±4．35HU，定量比较差异有非常显著性意义（t=5．3，P〈0．01），延迟期均表现为高密度，平均CT值95．31±12．55，与正常胰腺组织平均CT值（70．93±17．49HU）相差22．58±14．01HU，定量比较差异有非常显著性意义（t=8．3，P〈0．01）。结论 螺旋CT三期增强扫描对肝外末端胆管细胞癌的诊断及鉴别诊断有重要价值，尤其是延迟期扫描。     

小肝癌螺旋CT诊断

目的 探讨小肝癌的CT表现特征.方法 37例经手术病理证实的小肝癌分别行螺旋CT平扫及三期扫描,扫描时间分别为动脉期25 s,门脉期70 s,延迟期5 min,用高压注射器经肘静脉注射,速率为2.5~3 ml/s,剂量为1.5 ml/kg,分析其CT表现特征.结果动脉期73%(27/37)肿瘤病灶呈高密度,门静脉期65%(24/37)呈低密度,35%(13/37)呈高密度,其中8例平衡期呈低密度.结论螺旋CT三期扫描能反映出小肝癌的血供特点, 有利于早期诊断.     

Multiphase multislice spiral CT for liver assessment: optimization in cirrhotic patients

PURPOSE: The aim of our study was to optimize a multiphase study protocol with double arterial phase acquisition in a patient population with cirrhosis using a multislice spiral CT scanner. MATERIAL AND METHODS: Thirteen patients (10 males, 3 females, mean age 58 years) with known cirrhosis were selected for the study. All examinations were performed with a multislice spiral CT scanner (Somatom Plus 4 Volume Zoom; Siemens, Erlangen, Germany). Images were acquired using the following parameters: slice collimation, 2.5 mm; slice thickness, 3.0 mm; table feed, 10.8 mm/sec; mAs, 165; kVp, 120. Four scans of the hepatic parenchyma were obtained after the administration of contrast material. The first pass (early arterial phase) was acquired in a cranio-caudal direction; the second pass (late arterial phase) was acquired in a caudo-cranial direction. Early and late arterial phases were obtained during a single breath-hold of 24 sec. The third pass (portal-venous phase) was acquired with a 60-sec delay time after contrast material injection. The fourth pass (equilibrium phase) was obtained with a 180-sec delay time. Optimal delay time to start CT acquisition was assessed by means of injecting a 20-ml minibolus of contrast material and by performing serial dynamic scans every two sec at the level of the hepatic hilum. The time of peak aortic enhancement was used as the start time for the early arterial phase. Attenuation values of aorta, portal vein, and liver parenchyma were calculated in all the acquisitions. CT data from the early arterial phase were used to produce three-dimensional angiographic images of the hepatic and mesenteric circulation. RESULTS: The enhancement of liver parenchyma progressively increased from pre-contrast phase to portal-venous and equilibrium phases. The highest difference in attenuation values between aorta and hepatic parenchyma was observed during the second acquisition (early arterial phase, 247.78+/-106.29 HU) rather than during the third acquisition (late arterial phase, 185.72+/-109.23 HU); this difference was statistically significant (p<0.01). DISCUSSION: Results from our study emphasize the potential of multiphase acquisition in the evaluation of cirrhotic patients; in particular, the use of an early arterial phase is useful for studying the hepatic and mesenteric vascular anatomy, whereas the late arterial and the portal-venous phases are of paramount importance for adequate evaluation of liver parenchyma and focal lesions. Further studies are needed to evaluate whether the benefits deriving from double arterial phase acquisition would justify the increase in cost and patient radiation exposure.     

多层螺旋CT在小肠Crohn病中的应用研究

目的 探讨MSCT双期动态增强扫描在小肠Crohn病中的应用价值.方法 45例经综合方法 诊断,并通过临床治疗证实的小肠Crohn病患者均行MSCT双期动态增强扫描,并在ADW4.2工作站进行后处理.测量患病肠段在不同期相内的CT值,采用方差分析比较其CT值;并测量各期相内患病肠段与正常肠段的CT值筹值,以差别10 HU为界,划分病例数,将不同期相内的病例数采用卡方检验进行比较.结果病变肠段平扫平均CT值为(39.3±3.7)HU,动脉期为(74.8±13.8)HU,门静脉期为(90.2±12.3)HU,差异有统计学意义(F=258.87,P<0.01).病变肠段平扫与动脉期和门静脉期CT值两两比较,差异均有统计学意义(P<0.05).45例中,平扫CT值差值≤10 HU和>10 HU者分别为44和1例,动脉期分别为6和39例,门静脉期分别为2和43例,经X2检验,平扫与动脉期间差异有统计学意义(X2=32.49,P<0.01),平扫与门静脉期间差异有统计学意义(X2=39.22,P<0.01),动脉期与门静脉期间差异无统计学意义(X2=1.10,P>0.05).增强扫描使病灶显示更为清楚,大大提高了小肠Crohn病的检出率.结论 MSCT双期动态增强扫描可对小肠Crohn病作出初步诊断,并可对病变进行全面评价.     

Detection of intestinal bleeding with multi-detector row CT in an experimental setup. How many acquisitions are necessary?

The purpose of the study was to evaluate multi-detector computed tomography (MDCT) acquired in different acquisitions (unenhanced, and arterial and portal venous phase following intravenous contrast medium) for detection of intestinal bleeding using an experimental bowel model. The model consisted of an injector tube with a perforation placed in a 7-m-long small bowel of a pig. The bowel was filled with water/contrast medium solution of 30–40 HU and was incorporated in a phantom model. Intestinal bleeding in different locations and bleeding velocities varying from zero to 0.75 ml/min (0.05 ml/min increments) were simulated. Twenty-six datasets in simulated unenhanced, arterial and portal venous contrast phase using increasing bleeding velocities and ten negative controls were measured using 64-row MDCT. Two radiologists blinded to the experimental settings evaluated the datasets in a random order. The likelihood of intestinal bleeding was assessed using a 5-point scale with subsequent ROC analysis. The overall sensitivity for detecting bleeding was 0.44 for an arterial acquisition alone, 0.68 for a portal venous acquisition, 0.68 for the combination unenhanced/arterial, 0.72 for unenhanced/portal venous and 0.80 for arterial/portal. Bleeding velocities of above 0.25 ml/min were detected with a sensitivity of 0.59 for arterial, 0.88 for portal venous, 0.85 for unenhanced/arterial, 0.94 for unenhanced/portal venous and 0.97 for arterial/portal venous contrast phase protocols, respectively. The specificity was 1.00. MDCT provides the highest sensitivity and specificity in the detection of intestinal bleeding using arterial and portal venous acquisition in comparison to mono-phase protocols.     

Multislice spiral CT angiography in the evaluation of the anatomy of splanchnic vessels: preliminary experience]

PURPOSE: The aim of this study was to optimize the protocol for multislice spiral CT angiography and to assess the ability of the technique to detect the anatomy of splanchnic vessels, using volume rendering as reconstruction algorithm. MATERIAL AND METHODS: The anatomy of splanchnic vessels was studied in 19 patients (11 men, 8 women, age range 38-83 years) undergoing CT of the abdomen and pelvis. All examinations were performed with a multislice spiral CT scanner (Somatom Plus 4 Volume Zoom; Siemens, Erlangen, Germany) using the following parameters: collimation, 1 mm; slice width, 1 mm; table feed, 8 mm/sec; reconstruction interval, 1 mm; mAs, 120; kVp, 120. Before the study, the patients received 800 ml of water as oral contrast agent to opacify the stomach and small bowel. A nonionic contrast medium (130-140 ml; Xenetix 350, Guerbet, Aulnay-Sous-Bois, France) was infused intravenously at a rate of 3-5 ml/sec. Two scans of the abdomen and pelvis were obtained at 20-25 sec (arterial phase) and 60-65 sec (venous phase) after starting contrast medium injection. Image elaboration was performed using Vitrea 2.2 (Vital Images; Minneapolis, Minn., USA), a software with volume-rendering capabilities. RESULTS: All major arterial (celiac trunk, superior mesenteric artery, and inferior mesenteric artery) and venous (portal vein, superior mesenteric vein, inferior mesenteric vein, and splenic vein) vessels could be evaluated with excellent detail in all patients. Side branches, including small collaterals, could also be easily visualized. Volume rendered images always provided better understanding of the 3D anatomic relationships among splanchnic vessels and surrounding organs. DISCUSSION AND CONCLUSIONS: Multislice spiral CT angiography allows for optimal depiction of the anatomy of splanchnic vessels. It can be anticipated that the clinical applications of this imaging modality in the study of splanchnic vessels will be greatly expanded. However, further studies are necessary to rigorously compare the results of multislice spiral CT angiography with conventional angiography in terms of diagnostic accuracy.