Three-dimensional imaging of spiral CT diagnosis of maxillofacial fractures in the clinical value
[Abstract] Objective To study the three-dimensional reconstruction of spiral CT diagnosis of maxillofacial fractures in the clinical value and significance. Methods Retrospective analysis of our hospital in January 2006 ~ January 2010 helical CT scanning and post-processing techniques MPR and SSD reconstruction of 50 patients with maxillofacial fractures in patients with imaging data. Results 50 patients were scanned by spiral CT axial images were found in 67 fractures, spiral CT scan images with the image post-processing can be found 80 fractures, 13 missing, missed diagnosis rate of 16.25%. Conclusion The three-dimensional reconstruction of multislice spiral CT technology can be solid, intuitive, a clear indication of maxillofacial bone fractures, to improve the diagnostic accuracy for clinical treatment provide strong guidance, has important clinical value.
[Key words] facial fractures; multi-slice spiral CT; MPR; SSD.
In recent years, the incidence of maxillofacial fracture increased, the anatomical structure of the maxillofacial complex, accurately determine the fracture site, type, shape and size, the shift in guiding the clinical treatment of such great value and significance. In recent years, spiral CT three-dimensional imaging technique (MPR and SSD reconstruction) has been widely used in the diagnosis of maxillofacial bone fractures for clinical treatment of a more convenient and intuitive imaging data [1]. This retrospective analysis of our hospital in January 2006 ~ January 2010 helical CT scanning and post-processing techniques MPR and SSD reconstruction of 50 patients with maxillofacial fractures in patients with CT imaging data, are reported below.
1 Materials and Methods.
1.1 General information.
Our hospital in January 2006 ~ January 2010 were treated 50 cases of patients with maxillofacial fractures, including 39 males and 11 females. Aged 9 to 65 years, mean 40.8 years old. Cause of his injuries: 24 cases of road accident, injured in 12 cases, 7 cases of fall injuries, bruises in 4 cases, 3 cases of other causes. The main clinical manifestations of pain, maxillofacial soft tissue swelling, trismus and so on.
1.2 Instruments and methods.
1.2.1 Instruments Toshiba Astioen4 using spiral CT scan machine.
Scan parameters: slice thickness 1mm, layer from the 1mm, the voltage 140kV, current 120mA, pitch (pitch) 1.35:1, non-continuous scanning interval.
1.2.2 check methods in patients with supine position, the first advanced scanning include 3cm from the superior orbital margin to the lower edge of the mandible 3cm, scanning multi-planar reconstruction after (MPR) and shaded surface display (SSD) technologies such as post-processing analysis. MPR soft tissue window and bone window were observed, and arbitrary orientation imaging, the world is the best imaging study The liver stores the image, reconstruction thickness of 3mm; shaded surface display threshold limit in the 150 ~ 250HU, select the features cutting removal of excess part of the organization, according to any of the lesions display rotation to select the best image storage.
2 results.
50 patients were scanned by spiral CT axial images were found in 67 fractures, spiral CT scan images with the image post-processing can be found 80 fractures, 13 missing, missed diagnosis rate of 16.25%. Three-dimensional reconstruction of spiral CT images clearly show the direct three-dimensional anatomy of mandibular fractures and its relationship with the surrounding structure, accurately show the fracture location, extent, direction of fracture fragment displacement, three-dimensional distance. 50 cases of single fractures in 11 cases, 39 cases of multiple fracture; on 21 cases of jaw fractures, mandible fractures in 29 cases. Cases of mandibular fracture, 4 cases were diagnosed 11 or associated with condylar fractures, of which 3 were the first by two-dimensional CT of mandibular lateral films and not diagnosed, after a rotation angle, confirmed to the hat lateral shift, and because no significant displacement of condyle, the surgeon took a conservative treatment.
3 discussions.
Maxillofacial complex anatomical structures, including nasal bone, lacrimal bone, maxilla, palatine bone, cheekbones and so on. In recent years, increased the rate of traffic accidents, the incidence of maxillofacial fractures is also increasing year by year [2].
Ordinary X-ray films can not accurately show the number of fractures, displacement as well as the location of fracture, clinical application has some limitations. Axial CT images of ordinary Although there is no duplication of facial structures, the lesions showed a significant increase, but the lack of three-dimensional, visual images, for some level of fracture parallel to the scan is still missing [3]. The group axial, MPR data, 50 patients with 80 fractures, axial display 67, missing 13, missed diagnosis rate of 16.25%, the direction of the horizontal line of multi-fracture line, and the case for many parts of complex fractures. MPR reconstruction, including coronal, sagittal, any slope and any surface reconstruction, axial images with the same two-dimensional spatial resolution and density resolution. Its technical parameters by adjusting the window width and window level to switch between the soft tissue window and bone window showed bone lesions in the same time, can clearly show the damage to surrounding soft tissue lesions, such as soft tissue thickening, swelling, product gas, hemorrhage, or open soft tissue injury (Cover Figure 1) [4]. However, only two-dimensional CT images show the plane of a level of bone damage, clinicians using two-dimensional CT diagnosis of plain film there will be errors, it is difficult to establish three-dimensional thinking, the lesion may have some deviations, which might affect the determination of treatment . MPR images show all the fracture group, diagnostic accuracy rate of 100%, no case of missed diagnosis. Studies have also confirmed that the orbital wall, orbital floor and the deep structures such as sieve plate, nasal septum, sphenoid greater wing of the fractures, CT is superior to CT two-dimensional image reconstruction [5].
SSD reconstruction stereoscopic imaging space (Cover Figure 2), can be an excellent show the structure of fractures, especially in three-dimensional structure of overlap between the location of the facial bone fractures, range and surrounding structures adjacent to the relations ( as shown from many angles condyle and glenoid fossa of the spatial relationship), degree of fracture displacement, direction, bone fragments film location, size, number, etc., especially to the whole paper format irregular fracture line clearly shows the abnormal Traveling to improve on the diagnostic accuracy of facial bone fractures [6]. Kreipke so that Lefortil fracture of two-dimensional X-ray and CT showed the fracture line is not well, and three-dimensional CT can directly display the fracture line of the fracture section of the situation and take the line shift for clinical treatment provides a reliable basis . CT three-dimensional reconstruction of another prominent advantage of condylar fractures in the display, can be observed from any point of the lesion, clearly shows the type of condylar fracture, fracture fragment displacement direction, distance and spatial location, the orientation of the articular surface, lower jaw Ramus bone ends move up the range, and the temporomandibular joint fossa relationship between space, representing two-dimensional CT images closer to the real anatomy of the human body structure, to avoid the subjective imagination of the process of understanding differences caused by the misdiagnosis. The group, 29 cases of mandibular fracture cases, 4 cases were diagnosed 11 or accompanied by condylar fractures, 3 cases of mandibular first by two-dimensional CT lateral films and not diagnosed, after a rotation angle, proved to be dislocation shift to the inside, and because no significant displacement of condyle, the surgeon took a conservative treatment.
In summary, the application of multi-slice spiral CT three-dimensional reconstruction technology, intuitive, a clear indication of maxillofacial bone fractures, to improve the diagnostic accuracy for clinical treatment provide strong guidance, has important clinical value.