螺旋CT三维成像在颌面部复杂骨折中的应用

目的　探讨螺旋CT三维成像技术对于颌面部复杂骨折的诊断和临床应用价值。方法　对 2 6例颌面部复杂外伤患者进行螺旋CT薄层扫描和三维重建成像。结果　螺旋CT三维成像能够立体地显示骨折的部位、形态 ,骨折块移位特点和类型等空间信息。结论　螺旋CT三维成像对于显示颌面部复杂骨折的空间关系具有重要的诊断价值 ,更能有效地指导临床实践。     

Three-dimensional computed tomographic reformations of sellar and para-sellar lesions

Summary The purpose of this study was to determine whether diagnostically useful three-dimensional (3D) reformations could be obtained from unmodified high resolution pituitary CT scans. Twelve CT examinations in 9 patients in whom an enhancing tumour or extensive bone destruction was identified around the sella, were studied using 3D images obtained on soft tissue and bone thresholds. 3D images were considered superior to conventional CT sections and reformations for the assessment of the vascular relations of tumours with large supra-sellar components, and in cases of extensive bone erosion. In selected cases, 3D CT imaging may facilitate a faster and more comprehensive appraisal of high resolution CT studies by clarifying otherwise complex spatial relationships.     

High resolution computerized tomography in the study of traumatic pathology of the temporal bone

Thirty-five patients with temporal bone fractures were examined; the fractures were sometimes associated with dislocation of the ossicular chain caused by road fatalities. Computed Tomography (CT) was performed either because of the presence of clinical symptoms associated with trauma of the temporal bone, or because of a hemotympanum discovered during a CT scan of the brain. Thirty-three fractures were detected: 19 longitudinal, 6 transverse, and 8 complex. An incudostapedial dislocation was also detected, together with a displacement of a stapedial prosthesis from the lenticular process of incus, and 3 incus-malleus dislocations associated with fractures. High resolution CT allows the precise definition of the course of the fractures, of the associated dislocation of the ossicular chain, and of facial nerve lesion, thus allowing a more accurate surgical intervention. In the examination of the temporal bone, high resolution CT is preferable to pluridirectional tomography because it is easier and faster to perform. Moreover, high resolution CT helps reduce the radiation dose, and yields higher-quality images with more accurate diagnostic information. High resolution CT also allows the brain and the temporal bone to be studied at the same time.     

Comparison of 4 computed tomographic imaging protocols for lateral tibial plateau fractures.

OBJECTIVE: Many computed tomographic (CT) imaging protocols are used for pretreatment assessment of tibial plateau fractures. This study compares the diagnostic capabilities of 4 CT protocols. METHODS: Lateral tibial plateau fractures were induced in 19 knee specimens and CT scans were obtained with the following protocols: 1) 3-mm collimation, axial acquisition, 2) 3-mm collimation, helical acquisition, 3) mixed-increment collimation, axial acquisition, and 4) 3-mm collimation, helical acquisition with 50% overlap reconstruction of raw data. Two-dimensional coronal and sagittal reformations and 3-dimensional surface reconstruction images were analyzed for maximum fragment depression, peripheral fragment displacement, fracture pattern classification and quality of image. Specimen dissection established maximal articular surface depression, fragment displacement and actual fracture pattern. RESULTS: None of the 2-dimensional reformations from the 4 protocols proved statistically superior for determining maximal fracture depression, fragment displacement, or fracture classification. There was a trend toward more accurate fracture classification with the mixed-increment axial protocol and the overlap protocol than either of the 3-mm protocols, but this was not statistically significant. All protocols were statistically equivalent in predicting fracture pattern classification using 3-dimensional images. However, the 3-dimensional images were of significantly higher quality when obtained with either the mixed-increment axial protocol or the overlap protocol. CONCLUSIONS: There were no statistically significant differences in the objective assessment of tibial plateau fractures among the 4 different protocols. The 3-dimensional images derived from the mixed-increment axial protocol and the 3-mm helical protocol with 50% overlap reconstruction were of superior quality.     

Evaluation of blunt abdominal trauma using PACS-based 2D and 3D MDCT reformations of the lumbar spine and pelvis

OBJECTIVE: The purpose of this study was to show the value of 2D and 3D reformations of CT data from abdominal and pelvic CT performed immediately at the workstation using a PACS-based software program to evaluate the lumbar spine and pelvis in patients with blunt abdominal trauma. MATERIALS AND METHODS: We reviewed the abdominopelvic CT scans and conventional radiographs of the lumbar spine or pelvis of 156 consecutive patients with blunt abdominal trauma. The CT data were compared with the radiographic findings and also with the findings of dedicated repeat CT of the spine or pelvis, when performed. RESULTS: CT depicted 80 fractures of the lumbar spine and 178 pelvic fractures. Radiography showed 40 fractures of the lumbar spine and 138 pelvic fractures. No additional fractures were identified on dedicated repeat CT. CONCLUSION: Conventional radiographs to clear the lumbar spine are no longer required when abdominopelvic CT data are available. CT and reformatted CT data show more fractures than radiography and miss no fractures compared with dedicated CT of the lumbar spine or pelvis. Having these images immediately available through the PACS workstation saves time for the trauma team in the management of critically ill patients.     

Temporal bone: three-dimensional CT. Part II. Pathologic alterations

Three-dimensional (3D) surface renderings were obtained from routine axial computed tomographic (CT) images in 15 patients with a variety of complex temporal bone abnormalities. The 3D CT reformations served as an adjunct to conventional sectional CT examination. While no diagnosis was substantially changed because of the 3D CT images, they did provide a more global perspective in cases of large tumors and fractures and at the postmastoidectomy site. Three-dimensional CT surface reformations are now practical and may be potentially useful for visualizing temporal bone lesions characterized by complex destructive change.     

螺旋CT三维重建在诊断颌面部骨折中的应用

目的　探讨螺旋CT三维重建在颌面部骨折诊断中的准确性和临床应用价值。方法　对 5 0例颌面部骨折患者行螺旋CT扫描后进行三维重建。结果　三维影像在显示颌面部骨折的类型、位置、范围、碎骨块移位、塌陷尤其是不规则骨折线的走行等空间信息方面优于二维影像。二维影像在显示深部结构骨折、细小骨折等方面优于三维影像。结论　三维影像能清晰显示颌面部的空间解剖关系 ,可提供理想的整复模型 ,有较大临床应用价值 ,但二维影像是诊断颌面部骨折基础 ,两者应结合应用。     

CT三维重建在诊断颌面部骨折中的应用

目的探讨CT三维重维在颌面部骨折诊断中的准确性和临床应用价值。材料与方法对41例颌面部骨折患者行螺旋CT扫描后进行三维重建。结果三维影像在显示颌面部骨折的类型、位置、范围、碎骨块移位、塌陷、尤其是不规则骨折线的走行等空间信息方面优于二维影像。二维影像在显示深部结构骨折、细小骨折等方面优于三维影像。结论三维影像能清晰显示颌面部的空间解剖关系,可提供理想的整复模型,有较大临床实用价值,但二维影像是诊断颌面部骨折的基础,两者应结合应用。     

Imaging of high-energy midfacial trauma: what the surgeon needs to know

Treatment goals in severe midfacial trauma are restoration of function and appearance. Restoration of function is directed at multiple organ systems, which support visual acuity, airway patency, mastication, lacrimation, smelling, tasting, hearing, and facial expression. Victims of blunt facial trauma expect to look the same after surgical treatment as before injury. Delicate soft tissues of the midface often make cosmetic reconstructive surgery technically challenging. Generally, clinical evaluation alone does not suffice to fully characterize facial fractures associated with extensive swelling, and the deeper midface is not accessible to physical examination. Properly performed computed tomography (CT) overcomes most limitations of presurgical examination. Thus, operative approaches and sequencing of surgical repair are guided by imaging information displayed by CT. Restoration of function and appearance relies on recreating normal maxillofacial skeletal anatomy, with particular attention to position of the malar eminences, mandibular condyles, vertical dimension and orbital morphology. Due to its pivotal role in surgical planning, CT scans obtained for the evaluation of severe midfacial trauma should be designed to easily depict the imaging information necessary for clinical decision making. Learning objectives: 1. Understand the facial skeletal buttress system; 2. Understand how the pattern of derangement of the buttress system determines the need for and choice of operative approach for repair of fractures in the middle third of the face; 3. Understand the role and importance of CT and CT reformations in the detection and classification of the pattern of buttress system derangement.     

螺旋CT对眼眶内侧壁骨折的诊断价值

目的探讨SCT对眼眶内侧壁骨折的诊断价值。方法通过对48例面部外伤后眼眶内侧壁骨折行轴位、冠位扫描,同时进行多方位MPR及3D成像,综合分析影像特征。结果眼眶内侧壁骨折直接SCT征象为眶壁骨质的连续性中断、粉碎、凹陷和曲度失常。新鲜骨折36例多合并有眼球旁或球后积气、筛窦积液、内直肌增粗等间接征象,陈旧性骨折12例,表现为骨折片移位或塌陷。结论SCT容积扫描能全面准确地诊断眼眶内侧壁骨折并能区分新鲜与陈旧性骨折及骨折程度。     

Four-channel multidetector CT in facial fractures: do we need 2 x 0.5 mm collimation?

OBJECTIVE: Our aim was to optimize acquisition protocols and multiplanar reformation algorithms for the evaluation of facial fractures using multidetector CT (MDCT) and to determine whether 2 x 0.5 mm collimation is necessary. MATERIALS AND METHODS: A cadaveric head with artificial blunt facial trauma was examined using a four-channel MDCT scanner. The influence of acquisition parameters (collimation, 2 x 0.5 mm, 4 x 1 mm, 4 x 2.5 mm; tube current, 120 mAs, 90 mAs, 60 mAs), image reconstruction algorithms (standard vs ultra-high-resolution modes; reconstructed slice thicknesses, 0.5 mm, 1 mm, 3 mm; increment, 0.3 mm, 0.6 mm, 1.5 mm), and reformation algorithms (slice thicknesses, 0.5 mm, 1 mm, 3 mm; overlap, 0.5 mm, 1 mm, 3 mm) on detectability of facial fractures in multiplanar reformations with MDCT was analyzed. RESULTS: Fracture detection was significantly higher with thin multiplanar reformations (0.5 and 0.5 mm, 1 and 0.5 mm, and 1 and 1 mm) (p < or = 0.014) acquired with 2 x 0.5 mm collimation (p < or = 0.046) in ultra-high-resolution mode (p < 0.0005) with 120 mAs (p < or = 0.025). Interobserver variability showed very good agreement (kappa > or = 0.942). Non-ultra-high-resolution mode, lower milliampere-seconds, and thick multiplanar reformations (3 and 0.5 mm, 3 and 1 mm, and 3 and 0.5 mm) showed significantly decreased fracture detectability. CONCLUSION: Although thin multiplanar reformations obtained from thin collimation (2 x 0.5 mm) are statistically superior for the detection of subtle fractures, 4 x 1 mm collimation is sufficient for routine diagnostic evaluation. Ultra-high-resolution mode with 120 mAs is mandatory for detection of clinically relevant fractures.     

Radiologic studies of facial trauma associated with a regional trauma centre

The study of severe facial trauma has been altered by the development of computed tomography (CT). As a regional trauma unit we have gained increasing experience with complex fractures of the face. In those patients most severely injured, high resolution CT has become the imaging modality relied upon to offer the safest and most accurate information. Conventional films still have a role, especially in the less severely traumatized patient. We describe our methods and observations, based upon experience at a trauma unit, in the radiologic investigation of facial injuries.     

Rapid prototyping (stereolithography) in the management of intra-articular calcaneal fractures

The purpose of this study was to evaluate and compare the diagnostic performance of stereolithography vs workstation-based three-dimensional (3D) reformations in intra-articular calcaneal fractures. A total of 30 intra-articular calcaneal fractures were examined using standard radiographs, coronal CT scans, and 2D and 3D reformations. The CT data were transferred to an outside institution, and stereolithograms were produced from photopolymer resin employing a laser beam system. 3D reformations and stereolithograms were analyzed in a blinded fashion by two staff radiologists. Receiver-operating-characteristic (ROC) curves were obtained for six clinically significant fracture components. Standard radiographs, coronal CT scans, and 2D reformations served as the standard of reference. The area under the ROC curves for 3D reformations and stereolithograms were 1.0 and 0.98 for abnormal tuber angles, 0.91 and 0.91 for anterior and middle talo-calcaneal joint involvement, 0.90 and 0.95 for involvement of the posterior talo-calcaneal joint, 0.65 and 0.78 for the presence of a lateral bulge, 0.80 and 0.81 for the involvement of the calcaneocuboidal joint, and 0.62 and 0.67 for the presence of a “tongue-type” fracture. No statistically significant difference was demonstrated for the two methods (Wilcoxon signed-rank test, p = 0.138). Based on our results stereolithograms did not prove to be statistically superior to workstation-based 3D reformations. Stereolithograms may still be useful for teaching purposes and for surgical planning at a thinking-efficacy level. Received 22 January 1996; Revision received 16 April 1996; Accepted 4 June 1996     

CT diagnosis of traumatic injuries of the temporal bone

73 patients with 78 fractures of the temporal bone were examined by high-resolution computed tomography (CT). Analysis of the CT-findings disclosed 55 longitudinal, 12 transverse, 8 combined and 3 atypical fractures. For determination of the fracture type, axial sections usually proved sufficient. However, for precise topographic analysis of the course of the fracture additional coronal sections were necessary in most of the cases. In the radiologic evaluation of temporal bone fractures detection of associated complications is clinically important since these can be surgically corrected. In this series 20 lesions of the ossicular chain were demonstrated by the combined performance of axial and coronal sections and sagittal reformations. High resolution CT demonstrated a lesion of the facial nerve canal in 79% of a patient group with traumatic facial nerve palsy. The most frequent site of injury of the facial nerve canal was the region of the geniculate ganglion. With the use of metrizamide-CT-cisternography the site of cerebrospinal fluid leakage was demonstrated in 7 of 9 patients with liquorrhea. It is concluded that high-resolution CT is the radiologic method of choice for both topographic evaluation of temporal bone fractures and detection and precise localization of fracture-complications.     

Spiral head CT in the evaluation of acute intracranial pathology: a pictorial essay

The purpose of this pictorial essay is to review the benefits of spiral head computed tomography (CT) with routine multiplanar reformations in the evaluation of acute intracranial pathology. This technique is particularly useful in trauma patients for detection of skull base or calvarial fractures, thin tentorial subdural hematomas, or for more specific characterization of intracranial hemorrhage. The benefits of multiplanar reformations have been described for a variety of other diagnoses in the chest, abdomen, extremities, and spine, and their routine use continues to grow with the widespread availability of multi-slice CT scanners. In this article, we describe spiral head CT technique with multiplanar reformations as an alternative to the routinely used sequential technique. Subtle findings and lesions aligned predominantly in the axial plane can often be visualized to better advantage with multiplanar reformations. We also address technical factors for optimizing spiral technique.     

Usefulness of different imaging modalities in the assessment of scapular fractures caused by blunt trauma

Purpose: To analyze the usefulness of chest and scapular trauma radiographs, axial computed tomography (CT), and two- and three-dimensional (2D and 3D) reconstruction CT in detecting fractures of the six anatomical regions of the scapula.

Material and Methods: Forty-four patients, with a median age (range) of 34 (16-60) years, with scapular fractures caused by blunt trauma were prospectively collected between January 2003 and December 2005. Their chest and scapula radiographs, and axial, 2D, and 3D CTs were reviewed blindly and independently by two observers. Each modality was compared with a gold standard to determine its diagnostic usefulness. Our gold standard was consensus reached by all authors together examining all modalities at the same time. We also compared 3D CTs reconstructed from chest and scapula axial views.

Results: Axial and 3D reconstruction tomographic studies were the only useful modalities in assessing fractures in all six anatomical scapular regions. Three-dimensional CTs reconstructed from chest and scapula axial views were equally sensitive and specific.

Conclusion: CT scanning with 3D reconstructions is the most useful imaging modality to detect and define the extent of scapular injury, and this can be done as part of a chest trauma computed tomography protocol.     

Thin section computed tomography in the evaluation of naso-ethmoidal trauma

We reviewed the computed tomography (CT) appearances, plain film radiographs and clinical findings of 17 patients who suffered fractures of the naso-ethmoidal complex. Six patients (35%) with diplopia were noted on CT to have lateral displacement of medial orbital wall fragments into the orbit (medial wall 'blow-in' fractures) leading to displacement of the globe or extra-ocular muscles. Medial displacement of ethmoid bone fragments (medial wall 'blow-out' fractures) with medial rectus entrapment was noted in a further two cases (11%) also. Multiple associated facial fractures were seen in all but one case with CT evidence of frontal bone fracture and intracranial injury in 12 (70%) patients. CT was judged to add valuable information to clinical findings and plain film radiography and was especially helpful where marked soft tissue swelling precluded detailed physical examination of the naso-orbital region. The CT features of naso-ethmoidal trauma are illustrated and discussed and the advantages of CT in the pre-operative evaluation of such injuries are emphasised.     

Spectrum and detection of musculoskeletal findings on trauma-related CT torso examinations

This study aims (1) to evaluate the spectrum of musculoskeletal (MSK) findings detected on trauma-related torso CT exams performed in the emergency department and (2) to identify the findings of high clinical importance that are underreported. Following IRB approval, two fellowship-trained MSK radiologists independently reviewed 200 consecutive trauma CT torso examinations performed at a level 1 trauma center, focusing on MSK findings. Discrepancies were resolved by consensus. Findings were categorized as of high, moderate, or low clinical importance based on criteria established with an orthopedic trauma surgeon. Findings evident on only one series (scout, axial, or sagittal/coronal reformations) were documented. The consensus reading was compared to the final report. Unreported findings of high clinical importance were entered into our departmental QA system. Eighty-two percent (164/200) of the studies had at least one MSK finding. There were 433 total findings of varying importance and the overall detection rate was 61 % (266/433). The detection rate for high importance findings was 80 % (177/221) with the majority representing acute fractures (99 %). For findings of high clinical importance, the lowest detection rates were for fractures of the sternum, proximal humerus, and forearm. Of the high severity findings, 6.3 % (14/221) were detected only on sagittal or coronal reformatted or scout images. Twenty percent of musculoskeletal findings of high clinical importance on trauma-related CT torso exams were not reported. Fractures of the sternum, proximal humerus, and forearm were the most commonly missed fractures and review of scout and multiplanar reformations can increase detection.     

Post-traumatic orbit evaluation by three-dimensional surface reconstructions

Post-traumatic orbital osseous and soft tissue surface evaluation was performed using high resolution computerized tomography and three-dimensional surface reconstructions (3DSR) using specially developed computer software. Four patients with facial fractures involving the orbit are presented as examples of the technique. Orbital volume was measured and surface images prepared using the original CT scans as input to CT computer software developed for this purpose. The results simplify interpretation of the nature and extent of traumatic orbital disruption. The interpretation of serial high resolution CT scans of the orbit (now obtained routinely in fractures involving the orbit) has been augmented by employing three-dimensional surface reconstructions (3DSR).     

Three-dimensional fracture visualisation of multidetector CT of the skull base in trauma patients: comparison of three reconstruction algorithms

The purpose of this study was to retrospectively assess the detection rate of skull-base fractures for three different three-dimensional (3D) reconstruction methods of cranial CT examinations in trauma patients. A total of 130 cranial CT examinations of patients with previous head trauma were subjected to 3D reconstruction of the skull base, using solid (SVR) and transparent (TVR) volume-rendering technique and maximum intensity projection (MIP). Three radiologists independently evaluated all reconstructions as well as standard high-resolution multiplanar reformations (HR-MPRs). Mean fracture detection rates for all readers reading rotating reconstructions were 39, 36, 61 and 64% for SVR, TVR, MIP and HR-MPR respectively. Although not significantly different from HR-MPR with respect to sensitivity (P?=?0.9), MIP visualised 18% of fractures that were not reported in HR-MPR. Because of the relatively low detection rate using HR-MPRs alone, we recommend reading MIP reconstructions in addition to the obligatory HR-MPRs to improve fracture detection.