螺旋二维及三维CT对颌面骨折的影像学研究

目的探讨螺旋二维CT、三维cT对颌面骨折的临床应用价值。方法对185例颌面骨折患者螺旋CT扫描，应用表面遮盖技术（shaded surface display，SSD）、多层面重建（multiplanar reformation，MPR）、应用Syngo软件勾画删除技术对图像进行分割，比较二维、三维CT诊断准确率。结果三维CT能清楚显示复杂颌面骨折的立体解剖图像与结构关系，并同时获得患者软组织实时图像，二维CT更好的提供细微骨折及深部骨折的信息，二者互补。扫描层厚越薄重建图像越清晰。结论三维CT有利于确定颌面骨折的程度与骨折的移位真实情况，对颌面部骨折的术前诊断和手术计划制定具有较大临床意义，是显示颌骨骨折的影像新技术。     

三维CT在颌面骨折中的应用

目的：评价三维CT影像技术在颌面骨折诊断及治疗中的应用。方法：对18例颌面骨折患者进行三维CT和二维CT检查，通过外科手术验证三维CT诊断的准确性。结果：三维CT成像能立体、精确、多方位地显示骨折部位、范围、移位、旋转、骨缺损范围等情况。结论：三维CT对颌面部骨折后畸形的检查具有独特的诊断价值，同时对手术方案的制定具有指导意义，并能够细化手术方案。     

三维螺旋CT在颌面部骨折中的应用

颌面部骨折是口腔颌面外科的常见病、多发病。目前的常规检查包括颌骨正侧位片、全影片、华氏位片、二维CT扫描等，只能提供二维影像，因此不能全面准确地反映颌骨影像结构。本文报道用三维螺旋CT成像技术应用于38例颌面部骨折的诊断及治疗中，并评价其临床价值。     

二维和三维CT对面中部骨折诊断的对比研究

目的 评价二维CT和三维CT对面中部骨折诊断的价值。方法 对50例面部创伤患者行横断二维CT扫描（层厚3mm），并进行三维重建（表面阴影遮盖显示法，SSD）。扫描范围包括上颌牙列至眼眶上缘。21例患者尚行冠状面CT扫描，以作对照。结果 和三维CT相比，横断二维CT较三维CT更好地显示上颌内壁（5／0侧），上颌外后壁（49／44侧），上颌牙槽（14／12侧），眼眶外壁（34／31侧）和蝶骨翼突区（19／9侧）的骨折。三维CT在显示上颌前壁骨折（60／57侧）和骨折形态方面优于二维CT。横断二维CT和三维CT对鼻骨（20侧）和颧骨颧弓骨折（24侧）的显示呈一致性。由于部分容效应，SSD三维CT通常不能区别正常或异常的眼眶内壁。结论 二维CT是诊断面部骨折的基础，三维CT能对二维CT作有益补充。     

三维CT影像在颌骨骨折诊断与治疗中的临床价值

目的 :探讨三维CT影像在颌面部骨折中的诊断价值。方法 :对 17例颌骨骨折的三维CT影像及二维CT影像进行观察 ,分析其各自的特征并进行比较。结果 :三维CT影像在显示骨折的空间位置方面 ,如骨折线的行走路线 ,骨折片的移位距离与方向等都有独到的优势 ,但在显示上窦前壁线型骨折 ,骨折断端周围的软组织改变等方面不如二维CT影像。结论 :三维CT影像在显示颌面骨折处的空间关系上有很大的诊断意义及治疗指导意义 ,可以弥补二维CT影像的不足 ,但不能取代二维CT影像。     

三维CT在颌面部复杂骨折诊断中的应用

三维CT成像将普通CT二维平面的断层扫描,重建形成立体三维图像,为临床诊断提供了直观立体的影像资料。颌面部由于解剖结构复杂,骨折发生后,传统的二维CT检查难以对骨折部位作出全面准确的显示,偶有漏诊情况发生,影响了诊断与治疗计划的制定。本科对15例颌面复杂骨折患者,采用三维CT重建,报告如下：     

螺旋CT三维重建在颌面部骨折诊断中的价值

目的：探讨螺旋CT三维重建对颌骨骨折的诊断价值。方法：对72例颌面骨折患者采用螺旋CT扫描，使用不同旋转轴，观察不同角度骨折的三维病变图像，结合临床进行CT图像分析。对骨折的部位进行分类和测定。同时根据三维CT影像，从不同角度、不同方向对骨折部位进行检查。结果：螺旋CT三维重建能清楚显示复杂颌面骨折的立体解剖图像及其与周围结构的关系。与x线平片、二维CT影像比较，三维重建在显示颌骨骨折类型、位置、范围、骨折移位、塌陷深度等方面明显占优。对下颌骨和面中部等处的粉碎性骨折，其显示出畸形的立体形态更为直观，尤其对下颌骨骨折的诊断准确率较高，但三维CT对骨折片无移位的线性骨折诊断率较低。结论：螺旋CT三维重建对复杂颌面骨骨折具有较重要的临床应用价值，有利于确定复杂颌面骨骨折的程度与骨折的移位情况。有利于手术方案的设计与实施。     

三维CT平面测量在颧骨骨折诊断中的应用

目的：探索颧骨骨折畸形定量诊断的可行方法，通过计算机辅助二维测量系统对三维CT照片测量、分类、定量诊断颧骨骨折畸形。方法：96例（100侧）颧骨骨折分别于术前术后拍摄华氏位、改良颅底位片，并行二维CT扫描及三维重建。利用计算机辅助测量系统对骨折移位及畸形进行二维影像测量、计算和分析比较。结果：建立了一套颧骨骨折移位和畸形的二维测量方法，用该法对颧骨骨折移位造成的面部畸形进行分类，对各型骨折的移位定量测量。结论：计算机辅助三维CT不同角度影像照片的二维测量系统用于颧骨骨折畸形的定量诊断，可以近似三维地反映颧骨骨折移位情况，临床可行。     

不同影像学检查在颌骨骨折中应用

目的：研究常规X线、二维CT和三维CT在颌骨骨折诊断中的优缺点.方法：对125例不同类型的上、下颌骨骨折的常规X线、二维CT和三维CT的显示情况,以及手术结果进行对照和分析.结果：对于下颌骨体部、角部和升支骨折,3种影像学都能很好的显示,对于髁状突和喙突骨折,三维CT检查优于常规X线和二维CT;常规X线显示上颌骨骨折较差,而二维CT和三维CT显示的准确性比较接近.三维CT可以直观和立体的显示颌骨骨折线.结论：3种影像学检查各有优缺点,为提高骨折显示的准确率,3种方法结合使用是必要的.     

颌骨骨折螺旋CT三维成像的诊断价值

目的：探讨螺旋CT三维成像对颌骨骨折的诊断价值。方法：采用TOSHIBA XPRESS／SX型螺旋CT对53例颌面部外3伤骨折行螺旋扫描，并进行三维骨表面重建，重建厚度为3mm，结果：二维CT和三维CT对颌骨骨折部位的显示无明显差异，但三维CT对骨折全貌，骨折断端及其移位程度的显示明显优于二维CT，结论：螺旋CT三维成像立体，直观，能完整地显示骨折全貌，对颌骨骨折的诊断和手术方案的制定具有重要意义。     

髁突骨折的不同影像学诊断对比研究

目的对比研究常规X线片、二维及三维CT图像临床诊治髁突骨折的价值。方法回顾2007年9月至2008年3月间在中山大学附属口腔医院治疗的17例髁突骨折病例的临床资料,比较常规X线片、二维及三维CT图像对髁突骨折术前诊断的正确率。结果17例患者确诊共有24侧髁突骨折,高、中、低位髁突骨折分别为8、10、6侧。术前诊断：常规X线片显示高、中、低位髁突骨折处数目分别为1（12．5％）、7（70％）、5（83．3％）侧;二维CT显示为6（75％）、9（90％）、5（83．3％）侧：三维CT显示为8（100％）、10（100％）、6（100％）侧。3种影像诊断的正确率差异有统计学意义（P〈0．05）。结论CT应作为临床上诊治髁突骨折的必要辅助检查,尤其对髁突高位骨折,建议行常规三维CT检查。     

Unsharp masking technique as a preprocessing filter for improvement of 3D-CT image of bony structure in the maxillofacial region

We evaluated the usefulness of the unsharp masking technique as a preprocessing filter to improve 3D-CT images of bony structure in the maxillofacial region. The effect of the unsharp masking technique with several combinations of mask size and weighting factor on image resolution was investigated using a spatial frequency phantom made of bone-equivalent material. The 3D-CT images were obtained with scans perpendicular to and parallel to the phantom plates. The contrast transfer function (CTF) and the full width at half maximum (FWHM) of each spatial frequency component were measured. The FWHM was expressed as a ratio against the actual thickness of phantom plate. The effect on pseudoforamina was assessed using sliced CT images obtained in clinical bony 3D-CT examinations. The effect of the unsharp masking technique on image quality was also visually evaluated using five clinical fracture cases. CTFs did not change. FWHM ratios of original 3D-CT images were smaller than 1.0, regardless of the scanning direction. Those in scans perpendicular to the phantom plates were not changed by the unsharp masking technique. Those in parallel scanning were increased by mask size and weighting factor. The area of pseudoforamina decreased with increases in mask size and weighting factor. The combination of mask size 3×3 pixels and weighting factor 5 was optimal. Visual evaluation indicated that preprocessing with the unsharp masking technique improved the image quality of the 3D-CT images. The unsharp masking technique is useful as a preprocessing filter to improve the 3D-CT image of bony structure in the maxillofacial region.     

3D-CT evaluation of facial asymmetry

OBJECTIVE: Recently, 3-dimensional-computed tomography (3D-CT) imaging has been used in the diagnosis and surgical treatment planning of patients with craniofacial deformities. The present authors have developed a 3D-CT imaging procedure for a 3-dimensional coordinate point evaluation system to assess and diagnose patients with facial asymmetry. STUDY DESIGN: The CT data of 16 subjects was selected retrospectively as the control group from patients who had undergone CT examinations to diagnose conditions other than maxillofacial deformities. Anatomical landmarks modified from orthodontic craniometric (cephalometric) points were defined on the 3D-CT images and the asymmetry index of each point was calculated in millimeters. A diagrammatic chart with a baseline indicating the mean asymmetry indices plus the standard deviation in the control group was designed. The resulting diagrammatic chart was used to evaluate the degree of deformity in facial asymmetry patients. RESULTS AND CONCLUSIONS: The topography of facial asymmetry was assessed. The 3D-CT imaging technique as described herein is a practical method of evaluating the morphology of facial asymmetry.     

螺旋CT 扫描和三维重建成像在口腔颌面部骨折的应用

目的:评价螺旋CT在颌面部骨折治疗中的诊断和制定治疗方案中所发挥的作用。方法:68例骨折患者术前均做颌骨螺旋CT扫描和曲面断层片,进行比较分析。结果:螺旋CT能得到分辨率很高、层次连续、图像清晰、能正确显示颌骨解剖结构的影像。结论:三维CT成像有助于对颌面部骨折做出正确的术前诊断和疗效的评价。     

Interpretation of mandibular condyle fractures using 2D- and 3D-computed tomography

Computed tomography (CT) has been increasingly used in the examination of patients with craniofacial trauma. This technique is useful in the examination of the temporomandibular joint and allows the diagnosis of fractures of the mandibular condyle. Aiming to verify whether the three-dimensional reconstructed images from CT (3D-CT) produce more effective visual information than the two-dimensional (2D-CT) ones, we evaluated 2D-CT and 3D-CT examinations of 18 patients with mandibular condyle fractures. We observed that 2D-CT and 3D-CT reconstructed images produced similar information for the diagnosis of fractures of the mandibular condyle, although the 3D-CT allowed a better visualization of the position and displacement of bone fragments, as well as the comminution of fractures. These results, together with the possibility of refining and manipulating perspectives in 3D images, reinforce the importance of its use in the surgical planning and evaluation of treatment. We concluded that 3D-CT presented supplementary information for a more effective diagnosis of mandibular condyle fractures.     

颌骨囊肿及肿瘤中三维螺旋CT容积再现和表面再现技术的对比研究

目的：观察和比较三维螺旋CT表面再现和容积再现技术显示颌面部囊肿及肿瘤的效果,探讨三维成像技术的临床应用价值。方法：对40例颌面部囊肿及肿瘤患者进行螺旋扫描后,在三维后处理工作站进行表面再现和容积再现重建并测量,结合术中所见比较二者在定位定界,显示病损所破坏,骨皮质膨胀等方面的效果。以既往二维CT为基础进行的颌骨手术为对照,比较三维螺旋CT在术中并发症、术后并发症及手术时间上的差别。结果：容积再现技术在定位、定界、显示骨膨胀和破坏方面均优于表面再现技术,测量值更接近术中测量（P〈0.05）。三维螺旋CT在手术中的指导意义优于二维CT,术中及术后并发症少（P〉0.05）;试验组患者术后12个月复发率（7.50%）低于对照组（15.11%）。结论：容积再现技术在定性及定量评估方面较表面再现技术更精确,所获信息更全面,更能反映病损的真实情况。三维螺旋CT,尤其是容积再现技术作为口腔颌面外科的重要诊断手段,对提高手术效果,防止复发有重要意义。     

Validity of computed tomography in diagnosing midfacial fractures

The aim of this study was to evaluate the sensitivity, accuracy, and reliability of two-dimensional computed tomography (2D-CT) scans (axial, coronal, sagittal planes) and three-dimensional computed tomography (3D-CT) reconstructions in diagnosing midfacial fractures in relation to actual fractures identified clinically and during surgery (gold standard). The imaging diagnosis was performed by a radiologist and an oral and maxillofacial surgeon. Sixty-two patients with a total of 429 midfacial fractures were included. Frontal sinus and nose fractures were easily diagnosed. For the three CT planes, there was a statistically significant difference between the CT examination and the gold standard for five to seven of the nine bones evaluated, while for 3D-CT, a difference was observed only for fractures of the orbital floor. The inter-observer agreement between the oral and maxillofacial surgeon and the radiologist was 75.5%. In conclusion, in this study 3D-CT reconstructions showed significantly the best sensitivity, accuracy, and reliability for the diagnosis of midfacial fractures. The sagittal reconstructions were the least diagnostic of the 2D-CT images. For areas where the parameters studied showed less agreement and hence a more difficult diagnosis, we recommend a combination of 3D and 2D-CT images to improve diagnostic accuracy.     

CT interpretation of craniofacial anomalies: a comparative analysis by undergraduate dental students

The aim of this study was to evaluate the accuracy and reproducibility of computed tomography (CT) image interpretation made in axial slices (2D-CT) and 3D reconstructed images (3D-CT) of patients with craniofacial anomalies. The analyses were made by undergraduate dental students, and compared with the diagnoses considered upon surgical intervention. Computed tomography of 43 patients were analyzed independently by three calibrated examiners (undergraduate students) with, respectively, one, two, and three semesters of experience in craniofacial CT training and interpretation. The analysis of 2D-CT and 3D-CT images were performed at distinct times using an independent workstation associated with a specific computer graphics software for volumetric images. The analysis of inter-examiner agreement and of the agreement between observers and the gold standard was performed using the Kappa test. The accuracy evaluation presented a progressively higher value for examiners with progressively broader experience in 2D-CT and 3D-CT image interpretation. 3D-CT analyses allowed a higher inter-examiner agreement (1 - 0.896) than 2D-CT analyses (1 - 0.614). 3D-CT was considered more precise and accurate than 2D-CT for all students' evaluations. The reproducibility and accuracy varied according to the experience in CT interpretation, and the most experienced student achieved results closer to the gold standard.     

64层三维CT骨量预测在牙槽突裂植骨术中的应用

目的:研究64层三维CT在牙槽突裂植骨修复术前预测植骨量的准确性。方法:对12例行牙槽突裂植骨修复术的患者术前利用64层三维CT测量牙槽突裂缺损体积,术中用印模排水法测量实际牙槽突缺损体积,对所得数据进行相关分析。结果:术中排水法测量实际牙槽突缺损体积与术前CT预测体积比较差异无统计学意义(P>0.05);2种体积测量结果之间呈线性相关,相关系数(r=0.998,P<0.01)。术前CT预测牙槽突缺损体积准确性为(96.78±1.96)%。结论:术前64层三维CT扫描可较精确地计算牙槽突裂缺损的体积,可用于预测植骨量。