多层螺旋CT曲面重建技术在胆总管扩张诊断中的应用

目的:研究胆总管扩张螺旋CT曲面重建技术(CPR)的操作方法、临床应用价值及其局限性。方法:收集20例胆总管扩张患者,将其1～3mm薄层扫描轴位源像(ASI)传到工作站后处理,行扩张胆总管曲面重建成像,作任意曲面显示所要观察的扩张胆总管。经手术病理及随访证实,评估CPR对胆总管扩张病因的定位与定性价值。结果:CPR对扩张胆总管的成像率达100%,均能显示完整的扩张胆总管及梗阻部位,定位准确率达100%,定性准确率达90%。结论:CPR能将不在同一平面的扩张胆总管显示于一个平面上,更好地显示扩张胆总管的连续性,可直观地显示胆总管扩张程度、部位及梗阻端形态,对诊断及鉴别诊断有重要价值。     

多层螺旋CT曲面重组技术在评价肝外胆管梗阻中的应用

目的评价多层螺旋CT曲面重组技术(curved planar reformations,CPR)在肝外胆管梗阻性疾病中的应用价值。方法对53例手术病理和临床证实的肝外胆管梗阻患者的多层螺旋CT薄层原始图像,分别用工作站软件进行肝外胆管和扩张胰管的曲面重组成像,分析CPR对肝外胆管梗阻性疾病定位和定性诊断的能力。结果 53例肝外胆管和全部27例扩张胰管CPR图像清晰,定位准确率为100%,定性准确率为92.5%(49/53)。结论 CPR可以直观清晰地显示肝外胆管和胰管的全貌,对肝外胆管梗阻性疾病的定位和定性诊断有很大价值。     

多层螺旋CT图像后处理在输尿管微小结石中的诊断

目的探讨多层螺旋CT（MSCT）图像后处理在输尿管微小结石诊断中的应用价值。方法对28例共29枚微小结石,应用多排螺旋CT扫描,图像拆薄后进行重建及图像后处理,在横断位、MPR、CPR、MIP、CTU、VR图像上对输尿管微小结石CT征象进行分析。结果对29枚微小结石在MSCT及图像后处理后全部明确诊断。输尿管上段10枚结石,中段8枚,下段11枚。检出率明显优于KUB及BUS。结论MSCT及图像后处理明显提高了输尿管微小结石的检出率,是诊断输尿管微小结石可靠的检查方法。     

Diagnostic value of curved multiplanar reformatted images in multislice CT for the detection of resectable pancreatic ductal adenocarcinoma

The purpose of this study was to assess the usefulness of curved multiplanar reformatted (MPR) images obtained by multislice CT for the depiction of the main pancreatic duct (MPD) and detection of resectable pancreatic ductal adenocarcinoma. This study included 28 patients with pancreatic carcinoma (size range 12–40 mm) and 22 without. Curved MPR images with 0.5-mm continuous slices were generated along the long axis of the pancreas from pancreatic-phase images with a 0.5- or 1-mm slice thickness. Seven blinded readers independently interpreted three sets of images (axial images, curved MPR images, and both axial and curved MPR images) in scrolling mode. The depiction of the MPD and the diagnostic performance for the detection of carcinoma were statistically compared among these images. MPR images were significantly superior to axial images in depicting the MPD, and the use of both axial and MPR images resulted in further significant improvements. For the detection of carcinoma, MPR images were equivalent to axial images, and the diagnostic performance was significantly improved by the use of both axial and MPR images. High-resolution curved MPR images can improve the depiction of the MPD and the diagnostic performance for the detection of carcinoma compared with axial images alone.     

Assessment of hilar and extrahepatic bile duct cancer using multidetector CT: value of adding multiplanar reformations to standard axial images

To retrospectively assess the value of multiplanar reformations (MPRs) compared with standard axial images in the assessment of hilar and extrahepatic bile duct cancer. Forty-eight patients with confirmed bile duct cancer were included as preoperative work-ups; all of these patients underwent contrast-enhanced multidetector CT consisting of axial and MPR images. Two radiologists independently assessed the axial images alone and the combined axial and MPR images in the coronal and sagittal planes for the presence of tumor, its extent, vascular involvement, and resectability. The results were compared with surgical and pathologic findings. For tumor presence and conspicuity, combined axial and MPR images had higher values than the axial only images. For evaluation of tumoral extent, there was no difference between the two image sets for either reader. The accuracy for tumor extent was lower in hilar cancer than in extrahepatic bile duct cancer. For evaluation of vascular involvement and resectability, the area under the receiver operating characteristic curve of axial images was not significantly different from that of the reformatted images.The addition of MPR images to the standard axial images did not significantly improve the diagnostic performance of MDCT in the evaluation of the bile duct cancer.     

Assessment of the pancreatic and intrapancreatic bile ducts using 0.5-mm collimation and multiplanar reformatted images in multislice CT

Our objective was to evaluate the ability of multiplanar reformatted (MPR) images combined with 0.5-mm axial images to depict the pancreatic and intrapancreatic bile ducts and compare the results with those of 0.5-mm axial, 2-mm axial, and 6-mm axial images alone. Seventy-seven patients without obstruction of the main pancreatic ducts (MPD) underwent dual-phase helical scanning of the pancreas using multislice computed tomography (MSCT). The MPR images were generated from 0.5-mm-thick images. Visualization of the pancreatic and intrapancreatic bile ducts and their confluence was graded on a four-point scale by a consensus of two radiologists. The results for 0.5-mm axial images in early-phase CT, 2-mm axial images in early-phase CT, MPR images combined with 0.5-mm axial images in early-phase CT, and 6-mm axial images in late-phase CT were then compared. The relationships of the focal pancreatic lesions with the pancreatic ducts were analyzed. The MPR images combined with 0.5-mm axial images were significantly superior to the other three types of images for the visualization of the pancreatic and intrapancreatic bile ducts and their confluence (p<0.01). The depiction rate of the MPD using MPR images combined with 0.5-mm axial images was 94, 94, 95, and 75%, respectively in the head, neck, body, and tail of the pancreas. Accessory pancreatic ducts, intrapancreatic bile ducts, and duct confluence were depicted in 48, 99, and 92%, respectively. In comparison with evaluation based on axial images alone, the use of MPR images more clearly demonstrated the relationship between the lesions and the pancreatic ducts in 14 of 19 lesions. The MPR images combined with 0.5-mm axial images improve the CT depiction of the pancreatic and intrapancreatic bile ducts in comparison with 0.5-mm axial, 2-mm axial, and 6-mm axial images alone. Electronic Publication     

64层螺旋CT后处理重建技术在梗阻性黄疸中的临床应用

目的探讨64层螺旋CT后处理重建技术在梗阻性黄疸诊断中的临床应用价值。方法回顾性分析43例由手术病理证实的梗阻性黄疸患者的影像资料,包括螺旋CT常规扫描、MPR及CPR技术重建图像对梗阻部位及性质进行分析,并与手术、病理对照。结果 43例梗阻性黄疸中,胆总管结石25例,胆管癌12例,胰腺癌2例,胆总管炎性狭窄4例。CT常规扫描结合MPR、CPR图像诊断准确率为90%,良、恶性梗阻的鉴别诊断准确率为93%。结论多层螺旋CT常规扫描图像结合MPR和CPR图像后处理技术,能直观立体地显示胆道梗阻的部位和程度,直观地显示病变的范围及其与临近结构的关系,对胆道系统梗阻的定位、定性具有较高的诊断价值。     

Improvement in image quality of noncontrast head images in multidetector-row CT by volume helical scanning with a three-dimensional denoising filter

Purpose The aim of this study was to improve the contrast-to-noise ratio on noncontrast head computed tomography (CT) images, which are crucial for assessing patients with acute ischemic stroke. We applied a technique combining volume helical scanning with a three-dimensional (3D) denoising filter. Materials and methods We scanned phantoms for low-contrast resolutions and helical/cone-beam artifacts as well as stroke patients using a 16-row multidetector-row CT (MDCT) unit. Volume helical scans with 1-mm collimation and nonhelical scans with 8-mm thickness were performed. From the 1-mm thick volume data, 8-mm thick contiguous images were generated before and after applying a 3D denoising filter. Results On images stacked from volume data, the contrast-to-noise ratio was significantly improved by the 3D denoising filter and was nearly the same as that on nonhelical images. On stacked volume images, artifacts due to the cone beam and the helical scan were increased with larger helical pitches, but bone-related streak artifacts in the posterior fossa and underneath the calvarium were reduced when compared with nonhelical images. Conclusion Volume helical scan with a 3D denoising filter effectively improves image quality in noncontrast head MDCT images.     

Branch duct-type intraductal papillary mucinous tumor: diagnostic value of multiplanar reformatted images in multislice CT

The object of this study was to evaluate the usefulness of high-resolution multiplanar reformatted (MPR) images obtained by multislice CT in demonstrating connection between pancreatic cystic lesions and the main pancreatic duct. The study included 27 lesions with connection to the main pancreatic duct and 12 lesions without. All but one of the former lesions were branch duct-type intraductal papillary mucinous tumors (IPMTs). Oblique and curved MPR images with 0.5 mm continuous slices were generated from pancreatic-phase axial images reconstructed with 0.5 mm or 1 mm thickness at 0.5 mm intervals over a 260 mm field of view. The diagnostic capabilities for demonstrating connection with the main pancreatic duct were compared among axial images, MPR images, and both axial and MPR images in combination using the Brier score. The diagnosis in MPR images for demonstrating connection was more certain than that in axial images (P<0.05). Compared with MPR images alone, the use of both axial and MPR images resulted in further improvements in diagnostic performance, although the difference was not statistically significant. The use of high-resolution MPR images significantly improves diagnostic performance for demonstrating connection between pancreatic cystic lesions and the main pancreatic duct, which is useful for the diagnosis of branch duct-type IPMT.     

The value of drip infusion cholangiography using multidetector-row helical CT in patients with choledocholithiasis

The purposes of this study were to investigate the feasibility of drip infusion cholangiography computed tomography (CTCh) for choledocholithiasis and to compare the detection of the stone on CTCh with that of MR cholangiopancreatography (MRCP). CTCh examinations were performed after infusion of intravenous biliary contrast material (iotroxic acid meglumine, 100 ml) for patients with suspected biliary diseases and were reconstructed to maximum intensity projection (MIP) and multiplanar reformation (MPR). Of 432 patients who underwent CTCh, we identified 15 who underwent surgery or cholangioscopic removal for choledocholithiasis and 32 patients who underwent cholecystectomy due to cholecystolithiasis. Their MRCP images were compared with the CTCh images. The sensitivity and specificity of CTCh for detecting choledochal stones were 87% and 96% whereas those of MRCP were 80% and 88%. The sensitivity and specificity of CTCh for detecting gallstones were 78% and 100% whereas those of MRCP were 94% and 88%. CTCh allowed high sensitivity and specificity for detecting choledochal stones but diminished the detection for cholecystolithiasis compared with MRCP.     

64层螺旋CT容积扫描及其后处理技术在腰椎峡部裂诊断中的价值

目的探索64层螺旋CT容积扫描及后处理技术在腰椎峡部裂诊断中的价值。方法应用64层螺旋CT对38例腰椎峡部裂患者进行容积扫描,对获得的图像进行MPR、VR及CRP等后处理技术,观察腰椎峡部裂的显示情况,并观察椎体的滑脱情况、椎间盘改变以及周缘骨质的改变。结果对38例患者腰椎的容积扫描图像及后处理图像进行分析,共发现腰椎峡部裂77处,其中Ⅰ°滑脱29例,Ⅱ°滑脱5例,Ⅲ°滑脱1例;在各种后处理技术中,MPR以及任意切割VR对腰椎峡部裂以及腰椎滑脱的显示率最高,均为100%;并且可以清晰的显示椎弓峡部裂位置、宽度以及周围骨质的改变。结论 64层螺旋CT容积扫描及后处理技术在腰椎峡部裂诊断中具有较高的应用价值,并能够为临床治疗提供参考及依据。     

多层螺旋CT对鼻骨骨折的诊断价值

目的探讨多层螺旋CT对鼻骨骨折的诊断价值。方法应用GElightspeed多层螺旋CT机,对50例鼻骨骨折患者的鼻骨冠状位扫描、3D和MPR重建图像进行分析。结果50例均有鼻骨骨折,骨折同时累及上颌骨额突46例,累及鼻泪管1例;鼻中隔骨折15例,鼻额缝分离10例;鼻骨间缝分离5例;并发眶壁骨折3例;上颌窦壁骨折2例。结论多层螺旋CT的冠状位扫描、3D和MPR对于诊断鼻骨骨折具有重要价值。     

Usefulness of FDG-PET/CT in the detection of pancreatic metastases from lung cancer

Objective  The objective of this study was to assess the ability to detect pancreatic metastasis of lung cancer and to clarify the degree of fluorodeoxyglucose (FDG) accumulation and computed tomography (CT) characteristics of pancreatic metastasis from lung cancer. Methods  A total of 573 patients (415 men and 158 women) with lung cancer were retrospectively evaluated. All patients underwent FDG-positron emission tomography (PET)/CT with contrast-enhanced CT for first=stage (313 patients; initial study group) or follow-up study (260 patients; follow-up study group). A lesion was regarded as positive for metastasis on the basis of visual judgment of the degree of increased metabolism by two experienced and independent interpreters, supported by semiquantitative evaluation on the basis of calculation of the maximum standardized uptake value (SUV_max). Results  Abnormal accumulations in the pancreas were detected in 5 of 313 patients (1.60%) in the initial study group, and 6 of 260 patients (2.31%) in the follow-up study group. Seven of these patients had adenocarcinoma, three had small cell carcinoma, and the rest had large cell endocrine carcinoma. Tumor sizes (longitudinal diameter), measured by CT, of these 11 patients ranged from 6 mm to 52 mm (mean ± SD 8.3 mm ± 11.9 mm), and SUV_max for 1 h ranged from 3.37 to 11.1 (mean ± SD 6.12 ± 2.43). Three of these pancreatic lesions were difficult to determine by routine transaxial images, and detection was obvious only by thin-slice images or multiplanar reconstruction images. Contrast-enhanced CT showed gradual fill-in from the peripheral portion to the center. In addition, 10 of 11 cases did not show main pancreatic duct dilatation even if the tumor size was large. Conclusions  Metastases to the pancreas in lung cancer patients are not so rare and radiologists first have an important role to detect the pancreatic mass and then suggest to metastasis as the likely diagnosis. For this purpose, FDG-PET/CT has an advantage in depicting unsuspected pancreatic metastasis from lung cancer, particularly that which is not detected by CT alone.     

16层螺旋CT及其三维重建与多平面重组在胫骨平台骨折诊断中的应用

目的探讨16层螺旋CT(16层SCT)及其三维重建(3-D)与多平面重组(MPR)在胫骨平台骨折诊断中的应用价值。方法39例胫骨平台骨折病例经膝关节常规X线平片检查后，采用16层SCT进行膝关节的多层面螺旋CT扫描，在工作站上作3D及MPR影像后处理，就胫骨平台骨折的平片与16层SCT影像进行比较及综合分析。结果39例胫骨平台骨折中，X线平片漏诊1例髁间隆突骨折、1例内髁骨折及1例双髁骨折，此3例(7．69％)平片漏诊的骨折均为16层SCT予以诊断。16层SCT的3-D影像可清晰显示胫骨平台骨折的立体形态；MPR影像则可明确显示胫骨平台内部的骨质损伤情况如骨折的具体部位、关节面碎裂及塌陷程度、骨折移位距离。结论16层SCT能够显示X线平片难于诊断的胫骨平台隐匿性骨折；3-D及MPR成像技术十分有利于全面观察胫骨平台骨折的形态变化，是16层SCT横轴位扫描的重要补充。     

3D重建及CPR技术在乳腺癌腋窝前哨淋巴结CT淋巴管造影检查中的实验研究

目的 探讨多层螺旋CT 3D重建及曲面重建(CPR)技术在乳腺癌腋窝前哨淋巴结(SLN)CT淋巴管造影(CT-LG)检查中的应用价值.方法 采用VX2肿瘤组织块悬液皮下注射法制作VX2乳腺癌大白兔动物模型,对其行CT-LG检查.所有原始数据传至后处理工作站,运用3D重建及CPR技术显示显影的淋巴管及淋巴结,CT-LG图像上SLN定义为自对比剂注射部位至腋窝方向最先引流的淋巴结,并与SLN活检结果对照.结果 (1)20只荷瘤兔行CT-LG检查后,3D重建及CPR可显示SLN及其引流淋巴管;且70%(14/20)的实验兔成像效果良好,CT-LG共显示22条引流淋巴管,16枚SLN,7枚非SLN.(2)3D图像显示连续且对比剂充填均匀的8条淋巴管在CPR图像上均显示为均匀、连续的线管状高密度影;3D图像大部分显示对比剂充盈良好,局部中断或模糊的14条淋巴管,在CPR图像上均见自对比剂注射部位至腋窝SLN方向的连续的密度不均的线管状高密度影.余6只实验兔CT-LG检查显像效果较差,其中3只SLN显影淋巴管未显影,其CPR图像见自对比剂注射部位至SLN方向显影浅淡的线管状略高密度影,密度不均匀;而2只仅淋巴管起始段显影及1只SLN和淋巴管均未显影的实验兔,CPR图像与3D图像显像效果类似.(3)前哨淋巴结活检(SLNB)共摘取SLN 24枚,病理为转移性18枚,阴性6枚.淋巴结长径及CT-LG显像SLN出现充盈缺损在转移性和阴性SLN中有统计学差异(P=0.041和P=0.001);淋巴结短径、形状及边缘清晰与否在二者间无统计学意义(均P>0.05).结论 CT-LG检查中3D重建及CPR技术均可有效显示腋窝SLN及淋巴管的形态,且CPR技术显示更清楚、细致;淋巴结长径及CT-LG显像SLN的充盈缺损有助于鉴别转移性和阴性SLN.     

贲门胃底癌MSCT增强扫描及多平面重组的临床应用价值

目的:探讨MSCT增强扫描及多平面重建对贲门胃底癌临床应用价值。方法:48例经胃镜诊断为贲门胃底癌并经手术证实的患者行MSCT平扫、增强双期扫描及多平面重建,分析其CT表现。结果:局限贲门区5例;贲门胃底区43例,其中侵犯下段食管12例,侵至胃体小弯侧14例,胃体及胃窦均受累6例。病灶厚度11～42 mm,中位厚度20 mm。病灶分层强化41例,单层强化7例。周围淋巴结转移26例,肝脏转移5例。浆膜侵犯9例。结论:MSCT增强扫描及多平面重建对贲门胃底癌诊断效果良好,具有重要的临床应用价值。     

PET/CT for the staging and follow-up of patients with malignancies

Positron emission tomography (PET) and computed tomography (CT) complement each other's strengths in integrated PET/CT. PET is a highly sensitive modality to depict the whole-body distribution of positron-emitting biomarkers indicating tumour metabolic activity. However, conventional PET imaging is lacking detailed anatomical information to precisely localise pathologic findings. CT imaging can readily provide the required morphological data. Thus, integrated PET/CT represents an efficient tool for whole-body staging and functional assessment within one examination. Due to developments in system technology PET/CT devices are continually gaining spatial resolution and imaging speed. Whole-body imaging from the head to the upper thighs is accomplished in less than 20 min. Spatial resolution approaches 2–4 mm. Most PET/CT studies in oncology are performed with ¹⁸F-labelled fluoro-deoxy-d-glucose (FDG). FDG is a glucose analogue that is taken up and trapped within viable cells. An increased glycolytic activity is a characteristic in many types of cancers resulting in avid accumulation of FDG. These tumours excel as “hot spots” in FDG-PET/CT imaging. FDG-PET/CT proved to be of high diagnostic value in staging and restaging of different malignant diseases, such as colorectal cancer, lung cancer, breast cancer, head and neck cancer, malignant lymphomas, and many more. The standard whole-body coverage simplifies staging and speeds up decision processes to determine appropriate therapeutic strategies. Further development and implementation of new PET-tracers in clinical routine will continually increase the number of PET/CT indications. This promotes PET/CT as the imaging modality of choice for working-up of the most common tumour entities as well as some of the rare malignancies.     

16层螺旋CT在足、腕骨病变诊断中的临床应用

目的:探讨16层螺旋CT及其三维重建(3D)与多平面重组(MPR)在足、腕骨病变诊断中的临床应用价值.方法:32例足、腕骨病例均采用16层螺旋CT进行扫描,在工作站上进行3D及MPR影像后处理,并对结果进行比较和综合分析.结果:32例病例中正常足骨5例,腕骨3例,拇指外翻畸形2例,跟骨粉碎性骨折后致慢性骨髓炎,骨质疏松2例,距骨骨折5例,舟月骨骨折并月骨缺血性坏死1例,跟骨结核6例,腕骨骨髓炎、骨质疏松3例,跟骨粉碎性骨折5例.16层螺旋CT的3D图像可清晰显示正常小关节及其病变的立体形态,MPR图像则可以多平面多角度地观察骨关节的大小、形态、密度等的改变,对病变显示满意.结论:多层螺旋CT重建能提供骨关节病变非常有价值的空间关系信息,其表现接近病理解剖,临床应用价值大,有利于临床医师选择治疗方案、制订手术计划.     

CT灌注成像在肺癌诊断及疗效评估中的价值

CT灌注成像作为一种无创性活体评价组织血流灌注状态的功能成像技术,在肺癌的鉴别诊断、疗效评价等方面显示出独特的优势。近年来,随着医学影像设备及扫描技术的进展,医学影像正在由传统的以病理解剖为基础的形态学向着形态学与反映分子水平的功能影像相结合的方向发展。就CT灌注成像原理及其在肺癌鉴别诊断,以及与肿瘤标记物表达间的相关性和疗效评估方面的价值予以综述。     

16层螺旋CT多平面重组和容积再现图像在中足跖跗骨复杂骨折中的临床应用价值

目的评价16层螺旋CT多平面重建(MPR)与容积再现(VR)对中足复杂骨折的诊断价值。方法 18例中足骨骨折患者先经X线平片(DR)和常规轴位CT扫描,而后将容积数据传送至工作站进行MPR与VR三维重建,并与DR及常规轴位CT比较。结果 18例中有中足跖跗骨折76处,其中64处骨折累及跖跗关节面。在DR像上,10例跖跗骨折为阴性,其余8例仅显示18处骨折,显示率为23.7%。常规轴位CT像显示骨折60处,显示率为78.9%。MPR对跖跗骨折的显示率为100%。VR图像对足舟骨、骰骨、跖骨及楔骨骨折的显示率分别为100%、75%、70.9%及60%,平均显示率为68.4%。VR图像能通过图像多角度旋转观察骨折细节,对怀疑累及关节面的骨折,利用勾画、删除技术及多方位切割技术对中足骨进行分离、重组、单独显示关节面情况。结论利用16层螺旋CT的MPR结合VR图像能显著提高中足跖跗骨折,尤其是深部骨折的诊断准确性。