Chimera of digital radiography in spine surgery: False diagnosis of implant failure

BackgroundDigital radiographs of the whole spine are made using marginally superimposed imaging plates exposed simultaneously to be combined by interpolation of the overlapping area. Post-processing artefacts in these radiographs leading to the misdiagnosis of implant breakage have not yet been described in the literature.MethodsAn erroneous fusion of a digital spine x-ray after scoliosis surgery created an image showing two broken rods, whereas both rods proved complete continuity intraoperatively. Following an interdisciplinary error analysis, the chain of errors was systematically reconstructed. Using the digital imaging material of patients operatively treated the same way; the reproducibility of the error was analyzed. Erroneous image fusions were produced by slight displacement of existing, not yet combined x-ray images of these patients.ResultsUnder certain requirements, the false impression of implant breakage could be reproduced. Especially in the case of missing or malpositioned radiopaque markers, the hazard to overlook an erroneous image fusion is present. Within the post-processing step performed by qualified staff, control is indispensable and manual correction can be crucial.ConclusionsThis experimental study and causal analysis show the clinical relevance of post-processing artefacts in digital radiography. To prevent false diagnosis and maltreatment, the knowledge of possible sources of error is indispensable.     

Comparison of conventional time-intensity curves vs. maximum intensity over time for post-processing of dynamic contrast-enhanced ultrasound

Our aim was to prospectively compare two post-processing techniques for dynamic contrast-enhanced ultrasound and to evaluate their impact for monitoring antiangiogenic therapy.Thus, mice with epidermoid carcinoma xenografts were examined during administration of polybutylcyanoacrylate-microbubbles using a small animal ultrasound system (40 MHz). Cine loops were acquired and analyzed using time-intensity (TI) and maximum intensity over time (MIOT) curves. Influences of fast (50 μl/2 s) vs. slow (50 μl/10 s) injection of microbubbles on both types of curves were investigated. Sensitivities of both methods for assessing effects of antiangiogenic treatment (SU11248) were examined. Correlative histological analysis was performed for vessel-density. Mann-Whitney test was used for statistical analysis.Microbubble injection rates significantly influenced upslope, time-to-peak and peak enhancement of conventional TI curves (p < 0.05) but had almost no impact on maximum enhancement of MIOT curves (representing relative blood volume). Additionally, maximum enhancement of MIOT curves captured antiangiogenic therapy effects more reliably and earlier (already after 1 day of therapy; p < 0.05) than peak enhancement of TI curves. Immunohistochemistry validated the significantly (p < 0.01) lower vessel densities in treated tumors and high correlation (R² = 0.95) between vessel-density and maximum enhancement of MIOT curves was observed.In conclusion, MIOT is less susceptible to variations of the injection's speed. It enables to assess changes of the relative blood volume earlier and with lower standard deviations than conventional TI curves. It can easily be translated into clinical practice and thus may provide a promising tool for cancer therapy monitoring.     

MSCT血管成像及图像后处理技术在经门脉左支肝内门体静脉分流术中的应用

目的MSCT血管成像与图像后处理技术在经门脉左支肝内门体静脉分流术(TIPS)中的临床应用价值。方法回顾性分析河南省驻马店市第一人民医院78例接受CT上腹部扫描患者的临床资料,分为肝硬化组、正常组,对其原始数据进行图像后处理,评估其分支分型、肝静脉间与和下腔静脉的夹角、门静脉MSCT显示结果、门静脉各段紧密接触面,评估肝脏体积与左、右肝体积。结果78例扫描者肝静脉分型:Ⅰ型52例,Ⅱ型26例;门静脉分型:Ⅰ型61例,Ⅱ型9例,Ⅲ型5例,Ⅳ型3例;肝硬化组的肝右静脉[(63.85±6.47)°]、肝左静脉与下腔静脉夹角[(68.75±6.93)°]均较正常组[(53.27±5.49)°、(56.72±5.76)°]大,肝中静脉与肝左静脉夹角[(64.31±6.58)°]大于正常组[(56.72±5.69)°,P<0.05];肝硬化组门静脉主干长度与直径、门静脉左支直径、门静脉分叉夹角均大于正常组(P<0.05);肝硬化组门静脉左支与肝脏紧密接触面积[(33.69±3.42)%]较正常组[(41.87±4.25)%]小(P<0.05);肝硬化组全肝体积、右肝体积小于正常组,而左肝体积大于正常组(P<0.05)。结论MSCT血管成像及图像后处理技术应用在TIPS术者,可准确评估其血管解剖信息。肝硬化状态下门静脉右支上壁和后壁,左支顶部、矢状部有密切联系,可作为门静脉安全穿刺点。     

多层螺旋CT血管成像对主动脉夹层动脉瘤的诊断价值

目的探讨多层螺旋CT血管成像(MSCTA)对主动脉夹层动脉瘤的诊断价值及对临床治疗的指导意义.方法 13例夹层动脉瘤均进行了MSCTA胸腹联合检查,将原始数据在SGI工作站进行MPR, SSD, MIP及VR等后处理.结果 13例均很好地显示了主动脉全程及其分支,真腔、假腔、内膜片及夹层动脉瘤的部位、范围得到满意显示.结论 MSCTA是诊断夹层动脉瘤准确、快捷、有效的首选检查方法,具有较高的临床应用价值.     

Multidetector CT of bowel obstruction: value of post-processing

The value of imaging in patients with suspicion of bowel obstruction is dependent on the ability to answer questions relevant to the clinical management of patients. Is there mechanical obstruction? Is it a small bowel obstruction (SBO) or a large bowel obstruction (LBO)? What is the transition point? What is the cause of the obstruction? What is the severity of the obstruction? The results of studies published more than 10 years ago using axial and single-slice helical CT gave rise to findings based on axial slices that enables CT to answer these different questions. With the recent advent of multislice CT, large numbers of thin sections can be generated with short image intervals, which is well suited to postprocessing. Postprocessing techniques include standard reformatting methods such as sagittal, coronal and oblique reformatting, curved reformatting, maximum and minimum-intensity projection, variable thickness viewing, and volume and surface rendering. This pictorial review illustrates the added value of postprocessing for answering different questions concerning patients with suspicion of bowel obstruction.     

MSCT肺动脉造影及图像后处理在慢性血栓栓塞性肺动脉高压诊断中的应用

目的：探讨多层螺旋CT肺动脉血管成像（Multi-slice spiral pulmonary angiography,MSCTPA）对慢性血栓栓塞性肺动脉高压（Chronic thromboembolic pulmonary hypertension,CTEPH）的诊断价值。方法：17例患者采用16层螺旋C耳阡肺？动脉血管成像,将获得的原始数据进行多平面重组（MPR）、最大密度投影（MIP）、容积重建（VR）等多种后处理技术。结果：17例均很好地显示肺动脉及各级分支的栓子均能得到满意显示。结论：MSCTPA是肺栓塞安全、蒯性诊断方法,其图像后处理技术更为直观全面的显示CTEPH的栓子的形态、部位、范围。     

16层螺旋CT后处理技术在气管异物检查中的应用

目的探讨16层螺旋CT后处理技术在气管及支气管异物检查中的方法,评价应用价值。方法对32例临床疑为气管、支气管异物的患者进行检查。首先进行常规成像,然后进行二维重建技术:多平面重建(MPR)、曲面重建(CMPR);三维重建技术:最小密度投影(MinIp)、容积再现(VR)及三维显示技术:CT仿真内窥镜(CTVE)等技术方法成像。结果 6例未发现异常,26例误吸异物存在于气管、支气管中。其中位于主气管4例,左主支气管8例,右侧主支气管13例;左、右主气管内均有异物的1例,均获得满意的后重建图像。后重建图像实现单独或联合显示气管、支气管树等结构,并任意切割、旋转及三维解剖测量,较常规图像清楚、直观,显示解剖、异物位置全面、准确。以上病例均行纤维支气管镜检查或临床证实。结论 16层螺旋CT扫描及多种后处理技术的运用是气管、支气管异物准确诊断的方法,无创伤、定位准、简便易行。后重建图像处理技术能很好显示气管、支气管树结构及异物的位置关系,为影像诊断及临床制定科学的方案提供可靠的解剖依据。     

多层螺旋CT后处理技术在周围型小肺癌诊断中的价值

目的评价多层螺旋CT后处理技术在周围型小肺癌诊断中的价值。方法收集行MSCT扫描且经病理证实的周围型小肺癌（直径≤20mm）36例,分别以MPR、SSD、VR技术进行重建,并与横断面薄层图像对比分析。结果MPR显示血管集束征、分叶征、细短毛刺征,SSD显示胸膜凹陷,VR显示血管集束征、分叶征敏感性均较横断薄层图像提高10％以上。结论MSCT后处理技术在显示肺癌征象上较横断面图像具有较高的价值,特别是多种后处理方法联合应用更有不可替代的优势。     

HRCT常规重建与后处理对CSOM及中耳胆脂瘤诊断价值

目的探讨高分辨率CT扫描常规轴位、冠状位重建图像及图像后处理技术对慢性化脓性中耳炎及中耳胆脂瘤的诊断价值。方法对经手术病理证实并行64排螺旋CT容积扫描慢性化脓性中耳炎及中耳胆脂瘤共105例(107耳)进行回顾性分析。在常规轴位及冠状位重建图像基础上,综合运用图像后处理技术,根据主要CT表现:1、鼓室、鼓窦腔软组织密度影;2、听骨链骨质破坏情况;3、鼓室、鼓窦壁骨质破坏情况;进行术前分型,并将手术阳性结果与CT表现进行比较分析。结果慢性化脓性中耳炎59耳,其中单纯型8耳,肉芽型36耳,硬化灶肉芽型15耳;中耳胆脂瘤48耳,术前CT分型准确率为89%。对主要CT征象,常规轴位+冠状位显示率为88%,结合图像后处理技术,显示率为95%。对于所有可CT显示的术中阳性发现,均可以用多平面重组进行显示;容积再现及多平面容积再现对锤骨、砧骨破坏能较好显示,对镫骨破坏显示受到一定限制;曲面重组对面神经骨管破坏显示较满意,对听骨链骨质破坏也有一定的价值。结论 HRCT能对CSOM及中耳胆脂瘤进行较准确的术前分类、分型,常规轴位、冠状位重建图像能较全面、准确地对解剖和病变进行显示,各种图像后处理技术特别是MPR能提高CSOM及中耳胆脂瘤细微病变显示率和诊断准确率,具有很高的临床应用价值。