多层螺旋CT技术在胰腺检查中的应用

目的：探讨多层螺旋CT技术在胰腺检查中的价值。方法：对正常志愿60例，胰腺炎16例，胰腺癌28例行多层螺旋CT检查。结果：多层螺旋CT清晰显示胰腺解剖结构和毗邻关系，双期扫描明显提高胰腺炎和胰腺癌CT诊断及胰腺癌可切除性的判断。结论：多层螺旋CT在胰腺疾病的诊断中有很高的价值。     

多层螺旋CT三期增强扫描对胰腺癌诊断价值

目的：评价多层螺旋CT多期增强扫描对胰腺癌的诊断价值。方法：48例胰腺癌患者行多层螺旋CT多期扫描，先作平扫，再以3ml/s的速度通过肘静脉团注对比剂(碘海醇)90～100ml，分别行动脉期(注射后25～25s)，门脉期(70～85s)及平衡期(180～200s)扫描，层厚5mm。分别观察平扫及增强各期正常胰腺的形态、密度的变化，胰腺癌的形态、密度的变化以及转移瘤的发现率。结果：多层螺旋CT扫描速度快，检查时间短，密度分辨率高，可在一次屏气下完成腹部的CT扫描。正常胰腺血供丰富，增强时动脉期、门脉期强化很明显，而胰腺癌为相对乏血管，增强时动脉期、门脉期强化不明显，呈低密度区，动脉期扫描正常胰腺和癌肿的密度差异较大，门脉期及平衡期可兼顾显示胰腺癌及胰外转移瘤。结论：胰腺癌的多层螺旋CT检查应以三期增强扫描作为常规，动脉期对胰腺癌特别是小胰腺癌的诊断有重要的价值。     

螺旋CT双期增强扫描在小胰腺癌诊断中的应用

目的　研究螺旋CT胰腺期、门脉期双期增强扫描在小胰腺癌早期诊断和正确分期中的作用。方法　对14例小胰腺癌患者行螺旋CT双期增强扫描,扫描延迟时间分别为30s和65s,对比剂用量100ml,注射速度3ml/s。观察并比较正常胰腺及肿瘤在两期的增强情况。根据CT征象对肿瘤可切除性进行评价,并与手术结果比较。结果　肿瘤-胰腺对比胰腺期和门脉期分别为(47.08±20.39)HU和(28.77±16.23)HU（t=2.533,P<0.01）。14例肿瘤中,术前认为可以切除11例,术中切除9例。结论　螺旋CT双期增强扫描能更清晰地显示小胰腺癌,胰腺期肿瘤-胰腺对比较门脉期更显著,有利于小胰腺癌的早期诊断和可切除性的判断。     

螺旋CT双期增强扫描在胰腺癌诊断中的价值

目的探讨螺旋CT双期增强扫描在胰腺癌诊断中的价值。方法31例胰腺癌患者均行螺旋CT双期增强扫描,扫描延迟时间分别定为30s(胰腺期)和70s(门脉期),造影剂用量100mL(非离子型),高压注射器团注,速率2.5mL/s～3mL/s。观察并比较肿瘤及正常胰腺在两期的增强情况。根据CT征象对肿瘤可切除性进行评价,并与手术结果比较。结果31例中肿瘤位于胰头颈部19例,钩突部9例,体部3例。发现小胰腺癌3例,直径均小于2cm。肿瘤一胰腺对比胰腺期与门脉期相比有显著性差异(P<0.01)。胰腺期肿瘤增强后呈相对低密度,为特征性CT表现。胰周大血管受侵占不可切除性肿瘤的占62%,胰周小静脉迂曲扩张占32%,肝脏、淋巴结转移灶占38%。结论螺旋CT双期增强扫描对胰腺癌的诊断及可切除性评价具有非常重要的临床价值。     

多层螺旋CT血管成像对胰腺癌侵犯胰周血管的表现及可切除性评价

目的：评价多层螺旋CT血管成像（MSCTA）检查对胰腺癌侵犯胰周主要血管的影像表现及手术可切除性评价。方法：使用16层螺旋CT对胰腺癌患者扫描后,进行动脉期和门脉期胰周主要血管CTA三维成像。以三维图像为主,结合原始图像对胰周血管是否受累进行判别及评价,并与手术对照。结果：51例手术病例与手术结果比较,术前MSCTA判断不能切除的21例中手术均无法切除,术前MSCTA判断能切除的30例中手术结果能切除28例,2例误判,判断符合率为93%。结论：MSCTA对于胰腺癌术前可切除性评估具有重要的临床意义。     

螺旋CT双期增强对胰腺癌病人的术前评估

目的 探讨螺旋CT双期增强对胰腺癌可切除性术前评估的价值。方法 对1999年5月～2003年3月期问行螺旋CT双期增强扫的45例诊断为胰腺癌病人的CT图像与22例手术结果进行对比研究，通过显示胰腺癌的部位、大小以及肿块对周围血管侵犯程度、远处器官转移以及后腹膜淋巴结转移，作出能否切除的术前评价。结果 45例胰腺癌病人中18例位于胰头，16例位于胰体尾，11例位于胰尾；27例患接受手术治疗，其中22例术前SCT认为肿瘤可切除，实际成功切除17例，成功切除的阳性预测值达77％，其他5例SCT认为肿瘤不能切除，实际手术均不能切除。结论 螺旋CT双期增强扫描可作为一种评价胰腺癌术前能否手术切除的有效方法。     

螺旋CT三期增强扫描及后处理对胰腺癌的诊断及术前分期的价值

目的 探讨螺旋CT三期增强扫描及后处理对胰腺癌的诊断价值及手术可切除性的评估.方法 回顾分析41例胰腺癌的螺旋CT三期增强及后处理图像资料,分析肿瘤的部位、大小、强化特征和胰周血管是否受侵等,并与手术结果对照.结果 胰腺癌灶在胰腺期较门脉期强化程度低,病灶与正常胰腺组织问密度差别大,病变显示清晰;与手术结果对比,螺旋CT三期增强及后处理对胰周动脉受侵评价的准确度为80.7%,对转移评价的准确度为75.8%.结论 螺旋CT三期增强及后处理对胰腺癌的诊断有重要价值,有助于术前治疗方案的选择和可切除性的评估.     

螺旋CT在胰腺癌诊断中的应用

应用螺旋ＣＴ双期扫描技术诊断胰腺癌近年来为人们所重视。充分认识螺旋ＣＴ在胰腺扫描中的优势，运用正确的扫描方法，即能得良好的扫描效果，进而提高胰腺癌诊断的准确性，并正确进行 分期及手术切除性评价，同时也有利于小胰腺癌的早期诊断 。     

螺旋CT双期增强扫描对胰腺癌的诊断价值探讨

目的：探讨螺旋CT双期增强扫描在胰腺癌诊断中的价值。方法：对50例胰腺癌患者行螺旋CT双期增强扫描，比较平扫及增强情况并对图像进行分析研究。结果：50例肿瘤位于胰头部34例，胰体部11例，胰尾部5例。平扫肿瘤呈等密度或略低密度。增强后呈相对低密度。结论：螺旋CT双期增强扫描是诊断胰腺癌的理想检查手段，对判断肿瘤侵犯血管程度和能否手术切除的敏感性具有重要诊断价值。     

螺旋CT在胰腺癌诊断中的价值及临床应用

目的：探讨螺旋CT在胰腺癌中的诊断价值及临床应用。方法：回顾性分析了48例胰腺癌患者螺旋CT图像，扫描时间为注射对比剂后40－55s和60s左右，并依照正常胰腺组织和肿瘤在平扫和两期的增强情况、CT征象行术前评估，再与手术结果对照。结果：胰腺－肿瘤增强密度差异值平均分别为胰腺期49.10HU、门静脉期27.0HU，两期差异有显著意义（t=2.543、P＜0.01)。肿块在胰腺期能够清晰显示。25例术前认为可切除的肿瘤，术中仍有7例不能切除。结论：螺旋CT双期扫描能够明显提高胰腺癌的诊断准确率并为临床提供有价值的术前评估。     

64排螺旋CT对急性肠梗阻定位与定性诊断的准确性

目的分析64排螺旋CT对急性肠梗阻的诊断价值。方法 42例手术病理证实的急性肠梗阻患者均行腹部CT扫描,分析其影像表现并与手术结果对照。结果梗阻部位包括:小肠26例,回盲部4例,结肠10例,直肠4例。与手术结果对照,CT对梗阻的定位诊断准确率为95.2%(40/42),定性诊断正确率为81%(34/42)。结论 CT可以清晰显示梗阻部位,对肠梗阻的定性诊断也有一定价值。     

Multi--detector row helical CT of the pancreas: effect of contrast-enhanced multiphasic imaging on enhancement of the pancreas, peripancreatic vasculature, and pancreatic adenocarcinoma.

PURPOSE: To determine the optimal phase for enhancement of the normal pancreas and peripancreatic vasculature and the maximal tumor-to-pancreatic parenchymal enhancement difference by using multiphase, contrast material-enhanced, multi-detector row helical computed tomography (CT). MATERIALS AND METHODS: Forty-nine patients with a normal-appearing pancreas but suspected of having pancreatic abnormality and 28 patients with proved pancreatic adenocarcinoma underwent multiphase, contrast-enhanced, multi-detector row CT during the arterial phase (AP), pancreatic parenchymal phase (PPP), and portal venous phase (PVP). Attenuation values of the normal pancreas, pancreatic adenocarcinoma, celiac and superior mesenteric arteries, and superior mesenteric and portal veins were measured during all three imaging phases. Quantitative analysis of these measurements and subjective qualitative analysis of tumor conspicuity were performed. RESULTS: Maximal enhancement of the normal pancreatic parenchyma occurred during the PPP. Maximal tumor-to-parenchyma attenuation differences during the PPP and PVP were equivalent but greater than that during the AP. Subjective analysis revealed that tumor conspicuity during the PPP and PVP was equivalent but superior to that during the AP. Maximal arterial enhancement was seen during the PPP, and maximal venous enhancement was seen during the PVP. CONCLUSION: A combination of PPP and PVP imaging is sufficient for detection of pancreatic adenocarcinoma, because it provides maximal pancreatic parenchymal and peripancreatic vascular enhancement. AP imaging can be reserved for patients in whom CT angiography is required.     

Dual-phase helical CT of pancreatic adenocarcinoma: assessment of resectability before surgery

OBJECTIVE: The aim of our study was to prospectively evaluate the accuracy of dual-phase helical CT in the preoperative assessment of resectability in patients with suspected pancreatic cancer using surgical and histopathologic correlation. SUBJECTS AND METHODS: Between January 1999 and December 2000, 76 patients with suspected pancreatic cancer underwent preoperative evaluation and staging with dual-phase helical CT (3-mm collimation for pancreatic phase, 5-mm collimation for portal phase). Iodinated contrast material was injected IV (170 mL at a rate of 4 mL/sec); acquisition began at 40 sec during the pancreatic phase and at 70 sec during the portal phase. Three radiologists prospectively evaluated the imaging findings to determine the presence of pancreatic tumor and signs of unresectability (liver metastasis, vascular encasement, or regional lymph nodes metastasis). The degree of tumor-vessel contiguity was recorded for each patient (no contiguity with tumor, contiguity of < 50%, or contiguity of > or =50%). RESULTS: Thirty-nine patients with pancreatic adenocarcinoma were surgically explored. Curative resections were attempted in 34 patients and were successful in 25. The positive predictive value for resectability was 73.5%. Nine patients considered resectable on the basis of CT findings were found to be unresectable at surgery because of liver metastasis (n = 5), vascular encasement (n = 2), or lymph node metastasis (n = 2). We found that the overall accuracy of helical CT as a tool for determining whether a pancreatic adenocarcinoma was resectable was 77% (30/39 patients). CONCLUSION: Dual-phase helical CT is a useful technique for preoperative staging of pancreatic cancer. The main limitation of CT is that it may not reveal small hepatic metastases.     

心率对64层螺旋CT冠状动脉成像图像质量的影响

目的:评价心率对64层螺旋CT冠状动脉成像图像质量的影响.方法:采用GE Light speed 64层螺旋VCT,以心脏扫描模式对心脏动态体模进行扫描.心脏动态体模由3个部分组成:动力部分、解剖结构模拟部分和控制部分.心脏动态体模的心率设置为40、45、50、55、60、65、70、75、80、85、90、95、100、105、110和115次/min,心律齐.以球管转速0.35 s对不同心率下的心脏动态体模进行冠状动脉成像扫描.所有扫描数据在R-R间期90%时相分别进行单扇区和多扇区重建.重建数据传至工作站后处理成像.后处理方法采用VR、MPR重组模式.分别对重建图像进行评分.结果:①心率与图像质量呈负相关(P＜0.01);随着心率的增加,图像质量评分呈下降趋势;②在同一条件下多扇区重建算法较单扇区重建算法提高了图像质量评分.结论:采用心脏动态体模评价心率对64层螺旋CT冠状动脉成像图像质量的影响,对临床研究和应用有着重要价值.     

Isoattenuating pancreatic adenocarcinoma at multi-detector row CT: secondary signs

PURPOSE: To assess the frequency of isoattenuating pancreatic adenocarcinoma with multi-detector row computed tomography (CT) and determine whether there are specific secondary signs that aid in detection. MATERIALS AND METHODS: Fifty-three patients with pancreatic adenocarcinoma underwent contrast material-enhanced biphasic multi-detector row CT with curved planar reformation. Tumors were initially deemed isoattenuating or hypoattenuating to normal pancreatic parenchyma on the basis of visual inspection, and the degree of attenuation was confirmed by calculating the mean attenuation differences between normal pancreatic parenchyma and tumor (tumor-pancreas contrast) during the pancreatic phase. Indirect signs of pancreatic tumor were tabulated in patients with an isoattenuating tumor. RESULTS: Of the 53 patients, six (11%) had isoattenuating tumors with a mean tumor-pancreas contrast of 9.25 HU +/- 11.3 during the pancreatic phase and 4.15 HU +/- 8.5 during the portal venous phase. The secondary signs of pancreatic tumor in these six patients included an interrupted pancreatic duct (n = 5), dilated biliary and pancreatic ducts (n = 1), atrophic distal pancreatic parenchyma (n = 3), and mass effect and/or convex contour abnormality (n = 3). The mean tumor-pancreas contrast for the remaining 47 patients was 74.76 HU +/- 35.61 during the pancreatic phase. CONCLUSION: With no visible tumor-pancreas contrast for isoattenuating tumors, indirect signs such as mass effect, atrophic distal parenchyma, and an interrupted duct sign are important indicators for the presence of tumor.     

胰腺癌的可切除性评价(经动脉双期螺旋CT与血管造影的对比分析)

分别采用经动脉双期螺旋ＣＴ扫描和选择性血管造影,对胰腺癌的可切除性进行术前前瞻性评价,以确定各自的临床应用价值。方法对１５例胰腺癌术前均行选择性造影及经动脉增强双期螺旋ＣＴ扫描,对胰腺癌的临床应用价值。结论经动脉双期螺旋ＣＴ扫描弥补了血管造影的不足,能够更为准确,全面地评价胰腺癌的可切除术,具有较高的临床应用价值。     

16层螺旋CT三维重建技术对颌面部骨折的诊断价值

目的探讨16层螺旋CT三维重建技术在颌面部骨折中的诊断价值。方法对临床怀疑颌面部骨折的20例患者进行16层螺旋CT薄层扫描和多平面重建及最大密度投影和容积再现等三维重建。结果20例患者中18例显示有颌面部骨折,16层螺旋CT的二维、三维重建能够立体直观地显示骨折线的位置、走向、骨折范围、类型及骨折块的移位情况等。结论利用16层螺旋CT扫描的横断图像及重建图像能准确全面地显示颌面部骨折情况,为临床治疗提供有价值的信息。     

Capability of abdominal 320-detector row CT for small vasculature assessment compared with that of 64-detector row CT

Objective

To compare the capability of 320-detector row CT (area-detector CT: ADCT) with step-and-shoot scan protocol for small abdominal vasculature assessment with that of 64-detector row CT with helical scan protocol.

Materials and methods

Total of 60 patients underwent contrast-enhanced abdominal CT for preoperative assessment. Of all, 30 suspected to have lung cancer underwent ADCT using step-and-shoot scan protocol. The other 30 suspected to have renal cell carcinoma underwent 64-MDCT using helical scan protocol. Two experienced radiologists independently assessed inferior epigastric, hepatic subsegmental (in the segment 8), mesenteric marginal (Griffith point) and inferior phrenic arteries by using 5-point visual scoring systems. Kappa analysis was used for evaluation of interobserver agreement. To compare the visualization capability of the two systems, the Mann-Whitney U-test was used to compare the scores for each of the arteries.

Results

Overall interobserver agreements for both systems were almost perfect (κ > 0.80). Visualization scores for inferior epigastric and mesenteric arteries were significantly higher for ADCT than for 64-detector row CT (p < 0.05). No significant difference was found for hepatic subsegmental and inferior phrenic arteries.

Conclusion

Small abdominal vasculature assessment by ADCT with step-and-shoot scan protocol is potentially equal to or better than that by 64-detector row CT with helical scan protocol.