Volume-rendered three-dimensional spiral CT: musculoskeletal applications.

Spiral computed tomography (CT) is a powerful modality for evaluation of the musculoskeletal system, particularly when coupled with real-time, volume-rendering reconstruction techniques. Including volume-rendered spiral CT in routine musculoskeletal imaging protocols can change management in a significant number of cases. In cases of trauma, subtle fractures--particularly those oriented in the axial plane--are better seen on volume-rendered images. Complex injuries can be better demonstrated with volume-rendered images, and complicated spatial information about the relative positions of fracture fragments can be easily demonstrated to the orthopedic surgeons. The use of intravenously administered contrast material allows simultaneous evaluation of osseous and vascular structures within the affected area. Evaluation of suspected infectious or neoplastic disease is also aided by including volume-rendered imaging in the musculoskeletal spiral CT examination. The extent of disease can be thoroughly evaluated with volume-rendered images, and therapeutic planning--be it surgical or medical--is aided by the anatomic information available from volume-rendered images. Postoperative studies in patients with orthopedic hardware also benefit from volume-rendered imaging. Volume rendering eliminates most streak artifact and produces high-quality images on which the relationships among hardware, bones, and bone fragments are well demonstrated.     

Imaging of the acetabulum in the era of multidetector computed tomography

Acetabular fractures are often complex injuries and the result of high-energy trauma with associated injuries. Understanding and classification of these rare injuries using radiography can be difficult and are much facilitated by the addition of computed tomography (CT). The purpose of this paper is to briefly review some of the underlying physical principles and technical factors for multidetector CT (MDCT) and to describe its use and imaging findings in the evaluation of acetabular fractures. Using MDCT with two-dimensional multiplanar reformatted (MPR) images and three-dimensional volume rendered images, the supplemental oblique radiographic Judet views can be omitted. MDCT is now an indispensable tool in preoperative imaging of acetabular fractures and also in postoperative imaging in complicated cases. Not only is MDCT excellent for a general overview but also for detailed imaging of fracture extent, joint congruency, step-offs or gaps in the joint surface, and entrapped osteochondral fragments.     

The role of 3D CT in the assessment of acetabular fractures.

A total of 16 patients with acetabular fractures were evaluated by plain radiography, axial computed tomography (CT) and three dimensional (3D) CT. It was possible to classify the fracture type in each case from the plain radiographs alone. Axial CT gave additional detail in certain areas, notably the region of the teardrop, the obturator foramen and the acetabular roof. Intra-articular and impacted roof fragments and associated soft tissue injuries were also shown. 3D CT provided the best and most easily interpreted overall assessment of the fractures. In addition to projections equivalent to the plain radiographs, two other views were of particular clinical value in demonstrating surgically inaccessible areas, namely the view of the pelvis from above and the view of the inner aspect of the fractured hemipelvis. However, fracture lines demonstrated on plain radiographs and axial CT were not always apparent on the 3D CT scans. Although 3D CT is a valuable addition to the imaging of acetabular fractures, it is not a substitute for good quality plain radiography and analysis of the axial CT images.     

髋臼骨折的X线及CT诊断分析

目的：总结123侧髋臼骨折的Judet-Letoumel分类表现。比较X线平片检查与CT检查在髋臼骨折诊断中的价值。方法：本组患者109例，其中14例为双侧髋臼骨折，共123侧髋臼骨折，全部经手术证实并行X线平片检查，CT检查，其中36例行CT三维重建。由有经验的医师分别单独依据X线资料，单独依据CT检查资料，或依据X线结合CT资料对骨折进行分析并依据Judet-Letoumel分类法分型，然后由2位手术医师共同根据手术中所见作出最终诊断，比较诊断符合情况。同时对髋臼内能否发现碎骨块进行记录比较。结果：单独依据X线平片诊断符合112例(91．1％)，依据CT资料诊断符合114例(92．6％)，依据X线平片与CT结合诊断符合120例(97．6％)。前两组比较无统计学差异，X线平片与CT结合组与前两组比较有显著性差异。对髋臼内骨折碎块判断：本组123例患者中有77例手术发现髋臼内合并有碎骨片，平片发现32例，显示率为41．5％。CT显示73例，显示率为93．6％，两者比较有显著性差异。结论：X线检查与CT检查对于髋臼骨折Judet-Letoumel分类诊断符合率无明显区别，两者结合可提高诊断准确率。CT检查对髋臼内骨折碎块的诊断价值优于X线平片。     

螺旋CT三维和多平面重建在髋臼骨折中的应用

目的：探讨螺旋CT三维（3D）和多平面重建（MPR）在髋臼骨折中的临床应用价值。方法：27例髋臼骨折的病人先经营骨盆螺旋CT薄层扫描，并在工作站上作髋臼三维和多平面重建。注重观察髋臼骨折的以及CT表现特征。结果：27例病人共计31个髋臼骨折。除1个T形骨折用三维和多平面重建判断为横行骨折外，其余30个骨折轴位CT、三给和多平面重建均显示。三维和多平面重建能更直观的显示病变的具体情况。结论“螺旋CT三维和多平面重建是轴位CT扫描的有价值的补充手段，在髋臼骨折中有很高的应用价值。     

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。     

多层螺旋CT多平面重建及三维重建在复杂髋臼骨折中的临床价值

目的：探讨多层螺旋CT三维重建及多平面重建在复杂髋臼骨折中的临床价值。方法：回顾性分析36例复杂髋臼骨折的MPR、SSD、VR表现。结果：MPR、SSD、VR均显示了36例复杂髋臼骨折及16例股骨头脱位,MPR、SSD、VR还分别显示了骨盆其他骨骨折51、43、46处,MPR及VR显示了SSD没显示的髋关节内碎骨片1例。MPR在显示髋臼骨折线的方向、数量上较SSD、VR理想,SSD、VR图像立体感强,空间位置明确,对复杂髋臼骨折的分类及判断股骨头脱位的方向和距离较MPR好。结论：多层螺旋CT3D图像结合MPR及横断面图像,能立体直观地显示复杂髋臼骨折及关节脱位的空间位置,协助临床诊断和治疗。     

多层螺旋CT三维重建在髋关节损伤诊断中的应用价值

目的　探讨多层螺旋CT三维重建成像在髋关节损伤诊断中的价值。方法　利用西门子Sensation 4多层螺旋CT机按照骨盆常规扫描条件对 2 6例骨盆创伤患者进行容积扫描 ,扫描完后再进行薄层低对比及高对比图像重建 ,然后将重建图像导入CT 3D工作站 ,利用后处理软件MPR、MIP、SSD及VRT分别对髋关节进行成像 ,由 2位CT诊断医生一起对各种后处理图像进行观察和分析。结果　全组病例的薄层重建及三维重建显示髋臼骨折 19例 ,股骨上段骨折 8例 ,髋关节脱位 7例 ,关节腔内碎骨片 5例 ,关节周软组织损伤 2 1例。多层螺旋CT三维重建图像能最全面、直观地显示相应的髋关节骨折、脱位及关节腔内骨片情况 ,尤其是MPR及MIP对骨折、脱位、骨碎片显示率为 10 0 %。结论　多层螺旋CT薄层MPR是一种无创伤性显示髋关节形态的最佳方法 ,其相关CT表现可为临床诊断髋关节损伤、制定手术方案提供可靠依据     

Three-dimensional reformations of computed tomography in the assessment of facial trauma

Three-dimensional (3D) computed tomography (CT) reformations were obtained in 15 patients presenting with facial injuries of differing severity. The 3D images were compared with standard radiographs and high resolution CT, including multiplanar reformations, and assessed under the headings of fracture detection, extent and displacement using a simple scoring system. 3D was valuable in severe trauma with multiple fractures, providing a clear demonstration of fraction extent and fragment displacement. 3D was much less useful in minor trauma in which little or no fragment displacement had occurred, and demonstrated fewer fractures overall than either radiography or CT in all categories of facial injury. When used as part of a high resolution CT examination 3D imaging can provide useful information to both radiologist and surgeon in cases of severe facial trauma.     

MPR及3D成像在骨关节外伤诊断中的临床应用

目的 :探讨多平面重建及三维CT成像在骨关节外伤诊断中的价值。方法 :分析 5 0例骨关节外伤病例 ,均进行多平面重建 (MPR)和三维 ( 3D)重建 ,并与轴位成像 ( 2DCT)进行比较。结果 :MPR和 3D重建图像能很好地显示骨折线、骨折片移位及关节脱位 ,3D重建可立体显示骨折的空间关系。结论 :MPR和 3D图像是轴位图像的重要补充 ,为骨关节外伤的术前分型、治疗方法的选择及手术入路提供了客观依据 ,具有很高的临床应用价值。     

螺旋CT多平面重建、三维表面遮盖法重建及容积重建技术在骨盆骨折中的临床应用

目的 探讨螺旋CT多平面重建（MPR）、三维表面遮盖法重建（SSD）及容积重建技术（VRT）在骨盆骨折诊断中的价值。材料与方法 使用Siemens Plus4螺旋CT机对23例骨盆损伤患者进行扫描,在Siemens工作站进行MPR、SSD及VRT重建观察损伤细节,并与二维CT（2DCT）比较。结果 MPR、SSD及VRT重建图像清晰地显示了术前骨盆骨折的细节。VRT重建可立体直观显示技术后固定针的位置及复位效果。结论 螺旋CT MRP、SSD及VRT是诊断骨盆骨折的有效手段,。对诊断复杂性骨盆骨折应作为首选。VRT对术后固定针的位置及复位效果的判断有较高的价值。     

Diagnosis of pelvic fractures in patients with acute pelvic trauma: efficacy of plain radiographs.

Although CT is widely recognized as an important adjunct to plain films in the evaluation of patients with acute pelvic trauma, accurate diagnosis of orthopedic injuries with plain films alone is often important to determine if immediate external fixation is necessary. The purpose of this study was to determine the efficacy of plain radiographs in the detection of pelvic fractures and dislocations in patients with acute pelvic trauma by using CT as the gold standard. CT scans and plain films collected prospectively in 50 patients with acute pelvic injuries were evaluated independently, and fractures and dislocations were identified and tabulated. Of a total of 162 fractures and dislocations seen on CT, only 14 (9%) were misdiagnosed on plain films. None of these misdiagnoses altered patients' management. Sixteen (80%) of 20 cases of intraarticular fragments in the hip joint associated with acetabular fractures were not identified on plain films. We conclude that plain film examination of the patient with pelvic trauma is sufficient to identify virtually all clinically important fractures and dislocations. Plain radiographs alone are not accurate in detecting fracture fragments within the hip joint.     

螺旋CT多平面和三维重组在距骨骨折中的诊断价值

目的探讨螺旋CT轴位扫描、多平面重组(MPR)和三维(3D)重组图像在距骨骨折中的应用价值。资料与方法16例距骨骨折患者经X线平片检查后行螺旋CT、MPR和3D重组。着重分析骨折线走行与关节面的关系,对关节面塌陷程度等进行比较。结果3D重组、MPR对关节受累情况和骨折线走行显示较好。结论螺旋CT轴位扫描、MPR和3D重组图像相结合,可更好地显示距骨骨折,能为临床术前诊断和治疗提供有价值的影像信息。     

螺旋CT轴位扫描及重建诊断隐匿性骨折的临床价值

目的:探讨螺旋CT轴位扫描及重建(MPR、3D)在隐匿性骨折诊断中的临床价值。方法:选择33例隐匿性骨折患者,将螺旋CT扫描(2~5 mm)的容积数据转输至工作站进行MPR和3D处理,并对轴位、MPR和3D图像进行比较。结果:轴位平扫33例均显示了隐匿性骨折的基本情况,MPR图像25例从多平面、曲面显示了隐匿性骨折及周围结构,3D图像29例通过旋转和切割技术充分暴露病变,直观、逼真地显示隐匿性骨折立体关系。结论:螺旋CT对隐匿性骨折的诊断具有较高应用价值。MPR、3D及轴位图像的联合应用,可为临床医师提供立体、直观、多方位的影像信息,有利于临床治疗方案的选择。     

Interobserver agreement for Letournel acetabular fracture classification with multidetector CT: are standard Judet radiographs necessary?

PURPOSE: To retrospectively evaluate interobserver agreement for Letournel acetabular fracture classification with radiography alone and multidetector computed tomography (CT) alone and to retrospectively assess whether standard Judet views lead to a change in the classification. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was not required for this HIPAA-compliant study, which included 101 imaging studies performed in 99 patients (78 male, 21 female; mean age, 43 years; age range, 15-86 years) with acetabular fractures. Two musculoskeletal radiologists independently classified the fractures with radiography alone and multidetector CT alone. Multiplanar reformatted and three-dimensional (3D) CT images were reviewed at a computer workstation. Readers were shown radiographs at the end of multidetector CT image reading to see if this would change the multidetector CT-based classification. kappa Values were calculated to assess interobserver agreement. For surgically treated patients, the McNemar test was used to compare the accuracy of readers' classifications. The reference standard was a combination of preoperative radiographic and multidetector CT image findings and intraoperative findings. RESULTS: Interobserver agreement was moderate (kappa = 0.42) with radiography and substantial (kappa = 0.70) with multidetector CT. Multidetector CT classification was changed in two cases (one case for each reader) after standard Judet views were added. In 73 surgically treated patients, agreement with the surgeons' classification was higher with multidetector CT than with radiography (P < .01 for one reader, P = .06 for the other reader). CONCLUSION: There is substantial interobserver agreement for Letournel acetabular fracture classification with multiplanar reformatted and 3D multidetector CT images. Standard Judet pelvic radiographs add little information for changing the multidetector CT classification.     

Who is more accurate in the diagnosis of neck of femur fractures, radiologists or orthopaedic trainees?

Objective

Our study aims to compare the sensitivity and specificity between orthopaedic trainees and radiologists in diagnosing occult hip fractures from pelvic radiographs.

Methods

All patients undergoing computed tomography (CT) of the hip for a suspected occult hip fracture at our two centres between November 1, 2010 and October 31, 2011 were retrospectively identified. Two orthopaedic trainees (RJ and ED) independently reviewed the initial radiographs, and if both agreed a fracture was present this was recorded. The reports from the radiologist of the initial radiograph and subsequent CT were recorded, with the CT report used as the standard of reference for comparison of performance.

Results

239 CTs were performed for suspected neck of femur fractures during the study period, compared to only 20 in 2006–07, reflecting a 1,095 % increase. The interpretation of radiographs by the orthopaedic trainees showed a sensitivity of 55.4 % and specificity of 96.6 %. In comparison, the radiologists had a sensitivity of 60.7 % and specificity of 92.9 %; this difference was shown not to be statistically significant. Radiologists and orthopaedic trainees agreed when interpreting the majority of radiographs with a Kappa co-efficient of 0.77 (a statistical measure of inter-rater agreement). In 20 of the 174 cases (11.5 %) where the radiologist and orthopaedic trainees agreed no fracture was present, the subsequent CT revealed a fracture.

Conclusion

Orthopaedic trainees and radiologists have similar accuracy at interpreting pelvic radiographs for suspected hip fractures, so the trainee’s opinion can be relied upon. If uncertainty exists, then either the orthopaedic trainee or radiologist should request further imaging urgently as we believe this will expedite diagnosis and treatment of hip fractures, and ensure judicious use of CT.     

Computed tomography in acetabular trauma

In a retrospective study of 16 acetabular fractures computed tomography (CT) clarified the type and extent of the injury. Computed tomography demonstrated intra-articular fragments of varying size in seven out of eight patients with fractures of the posterior acetabular margin. Abnormalities of the femoral head were also shown in six patients and the possible aetiology of these is discussed. The additional information provided by CT is likely to help in the management of patients with acetabular injuries.     

Computed tomographic findings after anterior dislocation of the hip

Anterior dislocation of the hip is a rare phenomenon, seen in only 5–10% of all hip dislocations. These dislocations can be divided into two types: superior or subspinous and inferior or obturator dislocations. Osteochondral impaction fractures of the femoral head are a known complication of anterior dislocation, but little has been reported on the types of acetabular and pelvic fractures associated with this dislocation. Five anterior dislocations were studied with radiographs and computed tomographic (CT) imaging, and the CT findings are described. Fractures were seen in the femoral head, acetabular roof, and medial wall, as well as in the anterior inferior iliac spine. The most severe injuries occurred after a superior dislocation, but the obturator dislocations demonstrated impaction fractures of the femoral head as well as an intra-articular bone fragment. CT of the acetabuli is recommended after reduction of these dislocations to identify these complications.     

CT三维重建在骨盆骨折及盆腔脏器损伤手术治疗方案设计中的价值

目的：探讨螺旋CT三维重建在骨盆骨折及盆腔脏器损伤手术治疗方案设计中的价值。方法分析2007年1月至2013年12月行手术治疗的骨盆骨折及盆腔脏器损伤的患者CT三维重建影像资料,比较术前与术后影像资料及疗效。采用SPSS 17．0统计软件和χ2检验分析轴位CT及三维CT对骨盆骨折诊断的差异。结果149例骨盆骨折患者通过CT三维重建确诊髂骨骨折19例、骶尾骨骨折43例、耻骨上下支骨折30例及髋臼骨折57例;关节脱位21例、耻骨联合分离5例。轴位CT组与三维CT组间比较在髋臼骨折及骶尾骨骨折上,差异有统计学意义（P＜0．05）。髂骨骨折、耻骨上下支骨折、关节脱位及耻骨联合分离无统计学意义。合并盆腔脏器损伤有17例,其中膀胱破裂8例、后尿道损伤5例,盆腔血肿4例。149例患者术后复位效果中解剖复位64例,满意75例,不满意14例。获得随访20 d至83个月。按Matta疗效标准评定,临床标准：优97例,良45例,可7例,优良率95％;X线标准：优95例,良45例,可9例,优良率94％。结论螺旋CT三维成像多平面重建（MPR）、容积重建（VR）及表面遮盖重建（SSD）以最直观、全面的骨盆骨折及盆腔脏器损伤图像肯定并明确螺旋CT对骨盆骨折的分型;对治疗方案、手术入路、内固定物的选择和制定详细的手术计划可提供正确指导,在骨盆骨折及盆腔脏器损伤术前、术后影像检查中有较高的价值。     

The role of computed tomography in the assessment and treatment of acetabular fractures

The assessment of acetabular fractures by conventional radiology is difficult whilst essential to the planning of orthopaedic treatment. This report details the results of computed tomography (CT) in a study of acetabular fractures in 30 patients. Computed tomography was always superior to conventional radiology, particularly in the evaluation of lesions of the posterior acetabular margin. The standard classification of the fractures did not require modification but was reinforced by the three-dimensional visualisation of the lesions. The particular contribution of CT was in the assessment of associated lesions often not apparent on conventional views of the pelvis: these comprised sacroiliac lesions in 60% of cases, intra-articular loose bodies in 33% of cases and pelvic haematomas in 17% of cases. As a result of CT, treatment was changed in one third of cases. In addition to its role in indicating the need for surgical or orthopaedic treatment, CT sometimes permitted a better choice of surgical technique, especially in respect of sacroiliac lesions causing as yet unexplained sciatica.