Application of EVP Technology in Lateral Radiography of Hip Joints

目的 探讨视觉增强影像处理软件(enhanced visualization image processing,EVP)技术在髋关节侧位数字化X线摄影(DR)中的应用价值.资料与方法 对40例患者的髋关节侧位DR图像应用EVP技术进行重建,由两位影像科高年资医师对DR原始图像和EVP重建图像进行对比分析,评价髋关节各构成骨整体以及周边软组织显示情况.结果 经EVP技术处理的髋关节侧位DR图像对髋关节各构成骨整体以及周围软组织的显示明显优于原始图像(P＜0.05).结论 EVP技术能有效提高髋关节侧位DR图像的质量.     

鼻骨数字化摄影中EVP的应用

目的：探讨EVP软件在鼻骨侧位数字化影像处理中的价值。方法：对50例鼻骨侧位数字化影像应用不同的EVP技术参数进行影像处理,由2名放射科经验丰富的医生对处理后的影像进行评估,评价影像对鼻骨整体、周边软组织及前颅窝骨质的显示情况。结果：50例经过优化参数的EVP软件处理影像与原始EVP参数影像及非EVP影像对鼻骨整体显示清晰的分别为44例、35例和19例（χ^2=28.32,P〈0.01）;对鼻骨周边软组织显示清晰的分别为41例、31例和12例（χ^2=35.23,P〈0.01）;对前颅窝骨质显示清晰的分别为33例、22例和4例（χ^2=35.93,P〈0.01）。结论：对于鼻骨整体、周边软组织及前颅窝骨质的显示优化参数后的EVP影像明显强于原始EVP参数影像及非EVP影像。     

组织均衡技术在髋关节水平侧位数字X线摄影中的应用

目的:探讨组织均衡技术在髋关节水平侧位数字X线摄影中的应用价值。方法:回顾性分析我院200例行髋关节DR水平侧位摄影患者的常规图像和经过组织均衡技术处理过的图像,分析2组图像的差别。由3位影像科专家采取双盲法对2种方法产生的图像进行评价,主观图像质量分4级(优质、较好、一般、差)进行评分。结果:200例应用组织均衡技术后图像为优质174例,较好23例,一般3例,差0例,优质图像占87.0%;常规DR图像中优质22例,较好141例,一般37例,差0例,优质图像占11.0%;2种方法产生的图像质量差异有统计学意义(P0.01)。结论:组织均衡技术的应用在显示髋关节的细部结构完整性和清晰度方面都较常规DR图像有优势,避免了反复调节窗宽、窗位,提高了工作效率,可为临床提供更丰富的诊断信息。     

数字X线摄影组织均衡技术在鼻骨外伤诊断中的价值

目的:探讨数字X线摄影(DR)组织均衡技术在鼻骨外伤诊断中的价值。方法:回顾性分析100例鼻骨外伤患者的常规条件DR摄影图像和通过组织均衡技术进行处理的图像,比较两组图像的差别,由3位影像学专家采用双盲法对不同方法产生的图像质量进行评价,主观图像质量分3级(优质、标准、可接受)进行评分。结果:100例应用组织均衡技术得到优质图像75例,标准图像17例,可接受图像8例;而常规条件摄影的优质图像为9例,标准图像18例,可接受图像73例。两种方法产生的图像质量差异有统计学意义(P<0.01)。结论:运用组织均衡技术能使鼻骨的图像质量明显提高,将低密度的鼻骨与软组织以及高密度的头颅骨、眼眶同时显示,图像层次丰富,对清晰显示侧位鼻骨极有价值。     

胸部双能量减影摄影对气胸的诊断价值

目的 探讨双能量减影摄片技术对气胸的诊断价值.方法 收集在本院行双能量胸部摄影,经CT检查证实为气胸的42例患者,由1位高年资放射科医师及1位高年资胸外科医生共同阅片,对其标准数字化摄影(DR)图像与双能量数字减影(DES)软组织图像进行分析,评价两者对气胸的显示情况.结果 对于大、中量气胸(13例,肺压缩≥20%),标准DR图像及DES软组织图像均能清楚显示(100%),但对于少量气胸(肺压缩＜20%),尤其肺压缩边缘与肋骨、锁骨、肩胛骨重叠者,DES软组织图像比标准DR图像检出率更高,对肺压缩边缘的显示更清晰,差异有统计学意义.结论 双能量减影摄片技术能提高气胸的诊断率,降低漏诊率,是对DR图像诊断气胸的有效补充.     

多排螺旋CT三维骨重建在创伤性骨折诊断中的临床应用

目的评价多排螺旋CT表面遮盖显示(SSD),容积再现技术(VR),多平面重组(MPR),最大密度投影(MIP)等在骨外伤中的临床应用价值。方法对60例骨关节外伤患者进行螺旋CT轴位容积扫描,常规层厚5mm,3.75mm,重建间隔取层厚的1/2或以上,螺距0.75～1,利用原始轴位图像进行SSD,VR,MIP三维重建,分析比较各种技术成像在显示骨折线、骨碎片移位、塌陷程度及其空间关系的优势。结果60例骨关节外伤患者中,颅面骨折见于27例,多发肋骨骨折并错位7例,骨盆多发骨折3例,髋关节复杂骨折3例,胫骨平台粉碎性骨折7例,跟骨骨折5例,足舟状骨骨折2例,以及脊椎压缩性骨折6例。SSD,VR,MPR,MIP几种方法均能从不同角度显示骨折情况,取得满意效果。结论多排螺旋CT的VR,SSD,MIP等重建技术的综合运用对各部位骨折均显示效果良好,有利于临床制定治疗方案。     

数字化双能量减影技术在胸部结节性病变诊断中的应用价值

目的探讨数字化双能量减影(dual-energy subtraction,DES)摄片技术在胸部结节性病变临床诊断中的优势。资料与方法搜集在本院行DES胸部摄影和CT检查,发现胸部结节的36例患者及证实无胸部结节的16例患者的资料,由两名高年资放射科医师对其普通数字化摄影(DR)图像与DES图像采用双盲法进行分析,评价两者对胸部结节的显示情况。结果DES软组织图像比普通DR图像检出更多的结节,同时对结节边缘的显示更清晰,有利于定位定性诊断。结论DES能将骨与软组织单独分开显示,分别得出标准影像、软组织影像和骨组织影像,有效地去除胸廓骨组织影的遮挡影响,提高肺结节性病变的可视性,是对DR图像诊断胸部结节的有效补充。     

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。     

常规数字化X线摄影与组织均衡技术在鼻骨外伤诊断的比较

目的：探讨数字化X线摄影（DR）中组织均衡技术在鼻骨外伤诊断中的应用价值。方法：对94例鼻骨外伤患者分别行常规鼻骨侧位摄片,对直接获得的图像和采用组织均衡技术进行后处理获得的图像进行比较,比较两组影像的图像质量情况。结果：常规摄影技术得到的图像需反复调节不同的窗宽、窗位,才能显示密度、厚度不同的鼻骨与软组织;组织均衡技术可在同一帧图像上清晰显示鼻骨及其邻近软组织。结论：采用组织均衡技术能将密度和厚度不同的鼻骨及其邻近组织在同一帧图像上清晰显示。     

髋关节外伤螺旋CT重建技术的应用

目的：探讨螺旋CT多平面重建(MPR)、三维表面遮盖法重建(SSE))及容积再现(VR)在髋臼骨折及股骨头脱位中的临床应用价值。方法：对25例髋关节外伤的患者进行螺旋CT容积扫描，然后在工作站上进行MPR、SSD、VR成像，结合轴位扫描图像，观察这三种重建图像在显示骨折线、骨碎片以及股骨头脱位方向和程度的效果。结果：MPR对判断股骨头的脱位方向和程度有帮助；SSD显示髋臼骨折和股骨头脱位的立体效果较好；VR虽然立体效果稍逊于SSD．但能显示骨折的细微结构。结论：MPR、SSD、VR三种重建方法可互为补充，能够立体直观、整体地显示髋臼骨折和股骨头脱位．为决定治疗方案和选择适当的手术入路提供了依据.     

An option for optimising the radiographic technique for horizontal beam lateral (HBL) hip radiography when using digital X-ray equipment

AimTo investigate the optimum technique for the horizontal beam lateral (HBL) hip projection considering image quality and radiation dose.MethodsUsing digital radiography equipment an anthropomorphic phantom was positioned for a HBL projection of the hip. Radiographic exposures were undertaken across a range of acquisition parameters (tube potentials, source to image distances, object to detector distances, with and without an anti-scatter radiation grid/additional copper filtration). Each acquisition combination was imaged three times and the dose area product (DAP) and post-AEC mAs recorded. 168 images were acquired. A single observer evaluated five anatomical areas on all images using a two-alternative force choice technique. The reference image was selected based on the current locally accepted technique. 50 images out of the original 168 were independently assessed by a further four observers to ensure reliability of the results.ResultsImage quality, when comparing all the images to the reference, was improved on in two cases; however the radiation dose had increased. 18 images had equal image quality with some having an 80% reduction in the DAP. In terms of the diagnostic acceptability, 51 were considered acceptable with a lower radiation dose.ConclusionBy optimising acquisition factors for the HBL hip projection the radiation dose to the patient can be reduced. Based on the findings the factors proposed for HBL hip projections are 90 kVp, 135 cm SID, 45 cm ODD, grid and 0.1 mm copper filtration.     

双能量数字减影胸片对于不同肺野区域内结节性病变的检出差异(ROC分析)

目的　评价双能量数字减影胸片和常规DR胸片对于不同肺野区域内结节性病变的检出差异。方法　 2 0名正常成年志愿者前胸粘贴模拟结节 ,拍摄双能量数字减影正位胸片 ,应用ROC分析比较常规DR胸片与减影后软组织图像的诊断结果。结果　在双上、中肺野 ,软组织图像的曲线下面积大于常规DR胸片 ;在双上肺野、双中肺野外带 2种方法具有显著性差异。结论　双能量数字减影技术对双上肺野及双中肺野外带胸部结节性病变的检出具有优势 ,故应结合减影及常规胸片 ,以助诊断。     

Digital chest imaging: selenium radiography versus storage phosphor imaging. Comparison of visualization of specific anatomic regions of the chest.

RATIONALE AND OBJECTIVES: To compare selenium- versus phosphor-based digital chest imaging for visualization of various anatomic regions of the chest. METHODS: Thirteen observers analyzed pairs of posteroanterior (PA) and lateral chest radiographs of 63 patients. One radiograph in each pair was obtained with a digital selenium chest radiography system, and the other with a storage phosphor-based technique. Each observer rated the visibility and the radiographic quality of 21 anatomic regions. RESULTS: The observers rated visualization obtained with the selenium system as better than that obtained with the storage phosphor system in 12 anatomic regions (right lower lobe, retrodiaphragmatic, upper lobes, minor fissure, hilum, carina, azygoesophageal recess, ribs, soft tissue, upper mediastinum on the PA image, and major fissure and sternum on the lateral image). Five regions were equally appreciated (retrocardiac on the PA, lower lobes, lingual-middle lobe, soft tissue, and subdiaphragmatic region on lateral images). Four regions were rated better on phosphor imaging than on selenium films (thoracic spine on PA, upper lobes, lower, and upper thoracic spine on lateral films) (17,199 observations, P < 0.05, sign test). CONCLUSIONS: On PA images the digital selenium chest system provides better visualization of most anatomic structures than the phosphor system. Lateral images show an almost equal preference.     

Traumatic injuries: imaging of peripheral musculoskeletal injuries

The current dominant role of conventional radiography must be reassessed at increasingly shorter intervals in view of the continuing emergence of new imaging modalities that are available to diagnose peripheral musculoskeletal injuries. In comparison with conventional radiography, digital radiographic techniques offer advantages for optimization of image quality and dose, such as a wider dynamic range and post-processing of images. Currently, digital luminescence radiography (storage phosphor radiography) is the most commonly used digital method for obtaining radiographs, using the established positioning projections and routines of the film-screen technique. A new process, radiography with flat-panel amorphous silicon detectors, is still under development. Computed tomography is a valuable tool for diagnosing injuries of the peripheral musculoskeletal system, especially when three-dimensional data sets are acquired; these allow reformating images in all planes desired (2D technique) or in a volumetric format (3D technique). Established indications for CT in the peripheral skeleton are hip fractures, wrist injuries and calcaneal fractures; however, CT may be used as a supplement to radiography in every region of the body. Sonography is beginning to play an increasingly important role in trauma. Muscle and tendon injuries are the most common indications, but worthwhile information can be gained of the shoulder, elbow, hip, and knee joints, supplementing conventional or digital radiography. Magnetic resonance imaging effectively visualizes traumatic changes of the skeleton and the peripheral soft tissues. It is the method of choice to detect occult fractures. It can be used to diagnose muscle and tendon injuries. Joint injuries, especially in the knee and the shoulder joint, are common indications for MRI in the posttraumatic setting.     

Enhanced visualization processing: effect on workflow.

RATIONALE AND OBJECTIVES: Soft-copy viewing of digital radiographs allows for image processing to improve visualization of anatomy and lesions, but it can take more time than film-based viewing. Enhanced visualization processing (EVP) was developed to increase the latitude of an image without reducing the vital contrast, potentially reducing the need for the radiologist to manipulate images. This study examined the influence of processing radiographic images with EVP on workflow in a picture archiving and communications system (PACS). MATERIALS AND METHODS: Portable computed radiographic chest images were obtained and processed either with EVP or without. A security camera with a videocassette recorder was positioned above the PACS workstation. Four radiologists reviewed the images during their normal work schedule. The current diagnostic image was used to determine if the case contained EVP or non-EVP images. The videotapes of the sessions were reviewed to determine diagnostic viewing times and how zoom and/or window and level manipulation was used. RESULTS: Viewing time was significantly longer for the non-EVP than the EVP cases. The difference occurred with all readers. Window and level manipulation was used on 35% of the EVP and 41% of the non-EVP images. Zoom was used on 64% of the EVP and 69% of the non-EVP images. Average time spent using zoom and window and level manipulation was significantly shorter with the EVP than with the non-EVP images. CONCLUSION: EVP of chest images displayed on PACS monitors significantly improved workflow as measured by viewing time. EVP decreased use of window and level manipulation and zooming and the amount of time each one was used.     

The advantages of MRI in the detection of occult hip fractures

While the displaced hip fracture can be visualized easily by plain radiography, the non-displaced fracture may be radiographically occult and require different imaging modalities, e.g., MRI for proper visualization. The accuracy of readers and cost advantages of utilizing MRI have not been assessed. Therefore, we undertook a study of these factors. The medical records of all patients who had visited the emergency room from June 2002 until May 2003 with a clinically suspected hip fracture, negative or equivocal plain film and subsequent MRI examination were retrospectively reviewed. Two senior and two junior radiologists independently evaluated both the MR images and radiographs of all 33 patients in a blinded study. One of three possible evaluations was described for the images of each modality: absence, presence or possibility of fracture. The economic consequences of using MRI in the detection of occult hip fractures were calculated. For all four doctors participating in this study, MRI proved to be far more sensitive and specific in the detection of occult hip fractures than radiography. Using the MR images, the senior radiologists identified the occult hip fracture patients with 100% accuracy and were in complete agreement. The agreement between junior and senior radiologists was high (average =0.75). MRI also detected soft tissue injuries in 39% of the patients that could not be identified with radiography. Adoption of the new protocol using MRI saves hospitals from €242 to 627 per patient. By shortening the time to diagnosis and permitting a superior visualization of both bone and soft tissue injuries, MR imaging prevents unnecessary hospitalization and delays in definitive treatment. MR images should be assessed by senior radiologists.     

动态范围压缩技术在CR足部影像中的应用

目的探讨动态范围压缩技术在体厚差别较大的足部CR图像处理中的应用价值。方法回顾性分析成人足部CR图像50例,采用动态范围压缩技术处理用以观察趾周软组织、第1趾甲沟、第5趾骨远侧节、距骨小粱、跟骰关节间隙的清晰显示率,并与常规CR处理图像进行比较。结果经动态范围压缩技术处理后,显示全足组织结构更加清晰,与常规CR图像相比,两者在统计学上存在显著差异(t=7.732,P<0.05)。结论对体厚差别较大的足部CR图像,应用动态范围压缩技术使大量有用信息得以充分利用,能在同一幅图像上同时显示软组织、骨骼及关节结构,具有较大的临床应用价值。     

Metal artifact reduction image reconstruction algorithm for CT of implanted metal orthopedic devices: a work in progress

Introduction  Despite recent advances in CT technology, metal orthopedic implants continue to cause significant artifacts on many CT exams, often obscuring diagnostic information. We performed this prospective study to evaluate the effectiveness of an experimental metal artifact reduction (MAR) image reconstruction program for CT. Materials and methods  We examined image quality on CT exams performed in patients with hip arthroplasties as well as other types of implanted metal orthopedic devices. The exam raw data were reconstructed using two different methods, the standard filtered backprojection (FBP) program and the MAR program. Images were evaluated for quality of the metal–cement–bone interfaces, trabeculae ≤1 cm from the metal, trabeculae 5 cm apart from the metal, streak artifact, and overall soft tissue detail. The Wilcoxon Rank Sum test was used to compare the image scores from the large and small prostheses. Interobserver agreement was calculated. Results  When all patients were grouped together, the MAR images showed mild to moderate improvement over the FBP images. However, when the cases were divided by implant size, the MAR images consistently received higher image quality scores than the FBP images for large metal implants (total hip prostheses). For small metal implants (screws, plates, staples), conversely, the MAR images received lower image quality scores than the FBP images due to blurring artifact. The difference of image scores for the large and small implants was significant (p = 0.002). Interobserver agreement was found to be high for all measures of image quality (k > 0.9). Conclusion  The experimental MAR reconstruction algorithm significantly improved CT image quality for patients with large metal implants. However, the MAR algorithm introduced blurring artifact that reduced image quality with small metal implants.