眼眶副鼻窦区多层螺旋CT扫描冠状面重建与直接冠状面扫描图像的对比研究

目的分析眼眶、副鼻窦多层螺旋CT扫描MPR冠状面重建与直接冠状面扫描图像,探讨冠状面重建能否代替直接冠状面扫描。方法使用GE lightspeed p lus 4层面螺旋CT扫描仪对116例眼眶、副鼻窦病变患者进行扫描,在横断面图像基础上进行MPR重建。由资深专家对重建冠状面图像与直接冠状面扫描图像进行评价和对比分析。结果116例中,62例同时行MPR重建对眼眶、副鼻窦解剖结构及病变的显示与直接冠状面扫描图像相似,图像质量均为Ⅰ级。54例不能进行直接冠状面扫描者,冠状面重建多数也能达到诊断效果(Ⅰ级32例,Ⅱ级3例)。结论多层螺旋CT扫描对眼眶、副鼻窦的MPR冠状面重建图像能够代替直接冠状面扫描。     

多层螺旋CT诊断颅底骨折的应用价值

目的 :探讨高分辨力多层螺旋CT扫描对颅底骨折诊断价值。方法 :对 48例患者行常规轴位CT扫描与高分辨力薄层轴位扫描及直接冠状位扫描 ,比较常规轴位CT扫描与高分辨力薄层轴位扫描图像对骨折的显示率 ,同时又对薄层扫描MPR冠状位重建图像与直接冠状位扫描图像对骨折的显示进行比较。结果 :前组二者有明显差异 (P <0 0 0 1 ) ,后组图像骨折显示率无明显差异。结论 :多层螺旋高分辨力薄层CT扫描对提高颅底骨折诊断率有明显价值 ,并可替代直接冠状位CT扫描成像     

多层螺旋CT多平面重建在阻塞性黄疸诊断中的应用

目的：探讨多层螺旋CT(MSCT)多平面重建(MPR)在阻塞性黄疸诊断中的临床应用价值。方法：33例经B超检查提示有肝外胆管梗阻的患者，采用10mm层厚、层距，使用血管对比剂行MSCT增强扫描，将肝实质期图像采用2．5mm层厚、1．25mm层距重建，获得轴面源像(ASI)，数据传至工作站后处理，行MPR成像。采用育法对胆管梗阻定位和定性诊断作出评价。结果：MPR成像成功率为100％，MPR像定位和定性准确率分别为100％和97％。结论：MPR像定位和定性准确率高，显示胆管的走行更具优势，因此MPR成像技术是轴位CT的有效补充。     

64层CT多向调整多平面重组诊断长骨病变的价值

目的前瞻性研究64层CT的多向调整多平面重组（MPR）在长骨病变中的应用价值，及其替代直接扫描横断面图像及平片的可能性。方法对平片发现的长骨病变进行64层CT各向同性扫描，然后进行MPR成像，并进行MPR多方向调整，使病变显示于长骨的冠状及矢状长轴面上。其中50例进行了手术并有病理诊断结果，就其长轴面MPR图像、直接扫描CT横断面图像、平片对病变的诊断符合率进行对比，并对比长轴面MPR与直接扫描横断面CT的图像数量。结果64层CT多向调整的长轴面MPR对病变的诊断符合率为96％（48／50例），高于直接扫描CT横断图像（72％，36／50例）及平片（80％，40／50例），3种方法比较，差异有统计学意义（X^2=10．71、6．06，P值均〈0．05），而图像数量明显少于横断面CT（MPR50幅图像，横断面CT300幅图像）。结论多向调整的长轴面MPR解决了多层CT图像数量庞大的问题，并提高了诊断符合率，是长骨病变CT诊断的趋势。     

多层螺旋CT显示正常胸骨及胸骨病变的价值

目的 探讨多层螺旋CT(MSCT)胸骨成像方法及在诊断胸骨疾病中的应用价值.方法 搜集经16层螺旋CT常规胸部容积扫描和薄层低对比图像重建108例,其中胸骨病变组8例、对照组100例.所有病例均应用标准和曲而多平面重组(MPR)、最大密度投影(MIP)、表面阴影法成像(SSD)及容积成像技术(VRT)对重建图像进行后处理,最后由2名CT诊断医师对各种后处理图像进行观察和分析.结果 108例受检者的MSCT后处理图像均能显示胸骨.在显示细微骨质结构方面,矢状位MPR模式优于轴位MPR模式(U=14.107,P=0.000),冠状位曲面MPR模式优于冠状位MPR模式(U=11.882,P=0.000);在显示胸骨形态方面,VRT成像模式优于MIP和SSD 2种成像模式(UVRT:MIP=13.553,UVRT:SSD=12.102,P值均=0.000).8例胸骨病变组中,胸骨骨折5例,胸骨转移瘤3例.结论 冠状位曲面MPR、矢状位MPR和VRT技术是显示胸骨的最佳MSCT成像方法,在评价胸骨疾患方面较常规平片和(或)CT更具优势和应用价值.     

多层螺旋CT诊断眼外伤的临床应用价值

目的探讨多层螺旋CT（MSCT）对眼外伤的诊断价值。方法对82例眼眶骨折的患者进行MSCT常规扫描加多平面重建（MPR）结果分析。结果眼眶内、外侧壁骨折以横断面显示效果最佳,眶顶及眶下壁骨折以冠状面及矢状面显示效果最佳,混合性骨折以冠状位图像显示效果最佳。结论 MSCT扫描结合MPR能减少眼眶骨折的误、漏诊,运用窗技术对周围软组织损伤的诊断也起到重要的作用。     

螺旋CT多平面重建在宫颈癌诊断及分期中价值

目的　探讨螺旋CT多平面重建 (MPR)在宫颈癌诊断和分期中的价值。方法　对 2 0例活检病理证实宫颈癌病人行螺旋CT 3～ 5mm层厚扫描 ,1.5～ 2 .5mm插入重建 ,获取MPR图像。结果　矢状面可全面显示癌块生长特征 ,横断面及冠状面较好地显示宫旁浸润、盆腔转移。结论　盆腔螺旋CTMPR较全面地显示了宫颈癌块生长及侵犯特征 ,在临床诊断分期中具有重要价值。     

喉及下咽癌采用螺旋CT增强扫描及多平面重组的应用价值

目的 探讨螺旋CT增强扫描及多平面重组(MPR)在喉及下咽癌术前分期及术后评价中的临床应用价值。方法 50例喉及下咽癌患者(原发肿瘤40例、术后评价10例)进行轴位螺旋CT平扫及三期增强扫描，同时做MPR成像。将结果与纤维喉镜、手术所见对照分析。结果 螺旋CT增强扫描轴位结合MPR图像对术前肿瘤分期和诊断颈部淋巴结转移的准确性分别是95％及97.5％；25％的病例MPR显示肿瘤侵犯的范围优于轴位；增强图像有助于判断肿瘤的侵犯范围及颈部淋巴结转移，静脉期图像对肿瘤的分期帮助最大；螺旋CT三期增强扫描有利于评价喉及下咽癌的术后状况。结论 螺旋CT增强扫描轴位结合MPR图像，可以更完整地提供喉及下咽癌术前分期及术后评价的全面资料。     

颞骨平行枕眶线多层螺旋CT扫描法及其价值

目的:探讨以平行枕眶线扫描图像为基础的常规轴位和冠状位MPR图像是否能够取代直接轴位和冠状位图像。方法:三位医师分别观察50例颞骨CT扫描图像,分析直接常规轴位(25例)、冠状位(25例)CT扫描图像和其相应的常规轴位、冠状位MPR图像显示颞骨结构的差异。结果:所有观察者均认为直接常规轴位、冠状位CT扫描图像略优于相应的轴位、冠状位MPR图像。直接轴位、冠状位CT扫描图像和相应的轴位、冠状位MPR图像的质量差异较小。结论:以平行枕眶线扫描图像为基础的常规轴位和冠状位MPR图像可取代直接轴位和冠状位扫描图像。     

MSCT多平面及曲面重组技术诊断急性阑尾炎

目的:探讨多层螺旋CT(MSCT)多平面及曲面重组(MPR/CPR)技术在急性阑尾炎诊断中的临床应用价值。方法:25例临床资料完整的急性阑尾炎患者行CT平扫,16例加CT增强扫描。采用10mm层厚、层距,一次屏气下行全腹部CT扫描,将原始横断面CT图像用2.5mm层厚、1.25mm间隔重叠50%重建,获得轴面源像(ASI),然后将ASI像传输至后处理工作站,用Reformat软件行MPR,获得冠状面、矢状面及任意斜面MPR阑尾图像,在MPR基础上,再沿阑尾走行方向管腔中心划曲线,将沿曲线轨迹分布的体素重组,获得CPR阑尾图像。结果:MPR/CPR阑尾成像成功率为100%,图像直观,能清晰地显示急性阑尾炎及其并发症,诊断正确率达96%(24/25)。结论:MPR/CPR技术可获得良好的阑尾图像,能直观地显示阑尾全貌,诊断准确率高。     

螺旋CT多平面重组在副鼻窦检查中的应用

目的 :利用螺旋CT多平面重组技术探讨副鼻窦轴位扫描能否代替直接冠状位扫描。方法 :对 15例能合作的患者 ,均行副鼻窦轴位及冠状位扫描。使用美国GEProspeedFII双排螺旋CT机 ,层厚 5mm ,螺距 0 .75 ,连续横轴位扫描 ,利用多平面重组 (MPR)技术得到冠状位、矢状位重组图像 ;直接冠状位扫描获取冠状位图像 ;将同一患者的两组不同冠状位图像比较 ,主要观察各鼻窦窦壁及窦口。结果 :轴位扫描后重组所获图像亦能从多方位多角度观察 ,清楚显示各鼻窦及窦口。结论 :重组冠状位图像与直接冠状位扫描图像效果相同 ,可以取代直接冠状位扫描。避免后者检查时头部后仰造成的不适 ,患者容易接受 ,值得推广。     

Diagnostic maxillofacial coronal images reformatted from helically acquired thin-section axial CT data

OBJECTIVE. This study was undertaken to determine the sensitivity and specificity of coronal images reformatted from helical thin-section axial CT data obtained for the evaluation of maxillofacial fractures. MATERIALS AND METHODS. Multiple fractures were created in nine cadaver heads by blunt trauma and were then evaluated using a late-generation helical CT scanner. Two neuroradiologists then independently evaluated the axial and reformatted coronal maxillofacial images. Subsequently, they reviewed the axial and direct coronal CT images, which were considered the criterion standard. RESULTS. A total of 87 fractures were identified. An experienced neuroradiologist failed to identify one displaced fracture and two nondisplaced fractures when evaluating the reformatted coronal and direct axial images for an overall sensitivity of 97%. A less experienced neuroradiologist failed to identify a total of five minimally displaced or nondisplaced fractures for an overall sensitivity of 94%. For each radiologist, no significant difference in the time required to interpret the direct versus the reformatted coronal images was seen. CONCLUSION. Interpretation of axial and reformatted coronal images resulted in accurate identification of displaced maxillofacial fractures in cadavers. This study suggests that the added cost and radiation exposure associated with incremental direct coronal CT may not be necessary for detection of clinically significant maxillofacial fractures and that further evaluation of this protocol in live trauma patients is warranted. However, because nondisplaced fractures were not routinely detected using reformatted coronal images, physical examination and clinical suspicion will still also remain necessary to determine the need for further imaging.     

Multidetector CT virtual bronchoscopy to grade tracheobronchial stenosis

OBJECTIVE: The purpose of this study was to compare the efficacy of noninvasive multidetector CT (virtual bronchoscopic images, axial CT slices, coronal reformatted images, and sagittal reformatted images) in depicting and allowing accurate grading of tracheobronchial stenosis with that of flexible bronchoscopy. MATERIALS AND METHODS: Multidetector CT and flexible bronchoscopy were used to examine 200 bronchial sections obtained from 20 patients (15 patients with bronchial carcinoma and five without central airways disease). Multidetector CT was performed using the following parameters: collimation, 4 x 2 mm, pitch, 1.375; and reconstruction intervals, 2 mm. Postprocessing was performed using surface rendering and multiplanar reformatted images. CT images were independently interpreted by two radiologists. The tracheobronchial stenoses revealed on flexible bronchoscopy were graded by a pulmonologist. RESULTS: Virtual bronchoscopic findings, axial CT scans, and multiplanar reformatted images were highly accurate (98% accuracy for virtual bronchoscopic images, 96% for axial slices and coronal reformatted images, and 96.5% for sagittal reformatted images) in revealing tracheobronchial stenosis. In allowing accurate grading of tracheobronchial stenosis, images from virtual bronchoscopy correlated closely (r = 0.91) with those of flexible bronchoscopy. Because use of virtual bronchoscopic images reduced the overestimation of stenosis, these images allowed better assessment of stenosis than did axial CT slices (r = 0.84) or multiplanar reformatted images (r = 0.84) alone. CONCLUSION: Multidetector CT virtual bronchoscopy is a reliable noninvasive method that allows accurate grading of tracheobronchial stenosis. However, it should be combined with the interpretation of axial CT images and multiplanar reformatted images for evaluation of surrounding structures and optimal spatial orientation.     

Petrosal bone: coronal reconstructions from axial spiral CT data obtained with 0.5-mm collimation can replace direct coronal sequential CT scans.

PURPOSE: To investigate whether coronal multiplanar reconstruction (MPR) images of the petrosal bone from axial spiral computed tomographic (CT) data obtained with 0.5-mm collimation can replace direct coronal sequential CT scans obtained with 0.5- or 1.0-mm collimation. MATERIALS AND METHODS: The differences in diagnostic quality between thin-section coronal sequential CT scans of 24 petrosal bones in 12 patients and matched MPR images were assessed by five observers. The matched MPR images were calculated with both trilinear and tricubic interpolation. Image resolution was determined by measuring the three-dimensional point spread function. RESULTS: All observers preferred tricubically interpolated MPR images over trilinearly interpolated images. Subjective differences in image quality between direct coronal scans and matched tricubically interpolated MPR images were small. Only the direct coronal scans with the highest image quality (0.5-mm collimation, 465 mAs) were judged to be slightly better than the matched MPR images. With regard to direct coronal scans obtained at 245 mAs and/or 1.0-mm collimation, either there was no preference or the MPR images were preferred. CONCLUSION: Coronal MPR images from axial spiral CT obtained with 0.5-mm collimation can replace direct coronal sequential CT scans.     

多层螺旋CT图像后处理在颈椎扫描中的应用

目的　研究多层螺旋CT各向同性扫描及后处理图像显示颈椎解剖结构的方法和能力。方法　用 16排螺旋CT各向同性扫描 53例颈椎。对后处理图像中的MPR、MIP、SSD、VRT4种方式相互比较,找出最佳的后处理方式,并与平片的正、侧、左、右前斜位及CT直接扫描轴位图像对椎间盘、椎管长径、椎体及附件、小关节、椎间孔等结构的显示能力进行对照。结果　多层螺旋各向同性扫描的后处理图像,对椎间盘的显示与直接扫描无差异;对其它结构的显示优于平片和常规颈椎扫描模式;能直接显示椎管长轴断层;并且能对位置不正进行校正。VRT的椎间孔显示与平片无差异。结论　应用颈椎CT各向同性扫描基础进行图像后处理,对于颈椎的形态学研究具有重要的价值。     

Coronal multiplanar reconstruction view from whole lung thin-section CT by multidetector-row CT: determination of malignant or benign lesions and differential diagnosis in 68 cases of solitary pulmonary nodule

PURPOSE: The purpose of this study was to evaluate the usefulness of the coronal multiplanar reconstruction (MPR) view in comparison with transverse helical thin-section CT for both the determination of malignant or benign lesions and the differential diagnosis of solitary pulmonary nodules. MATERIALS AND METHODS: Sixty-eight cases of pathologically proved solitary pulmonary nodule less than 3 cm in diameter were enrolled in this study. For the routine study, transverse helical thin-section CT (1.25 mm collimation, FOV 20 cm) covering the areas with solitary pulmonary nodules as well as whole lung helical thin-section CT (2.5 mm collimation, 1.25 mm reconstruction interval, FOV 34.5 cm, pitch 6:1, high-spatial frequency algorithm) were scanned with a multidetector-row CT (MDCT) scanner. From the whole lung thin-section CT data, coronal MPR views (2.5 mm slice thickness) were reconstructed on a workstation. ROC analysis was used for an observer performance study, in which three observers indicated their confidence level for the determination of malignant or benign lesion for the nodules by means of transverse thin-section CT and coronal MPR. In addition, the observers recorded appropriate disease entities as the final diagnosis of each case. Accuracies of the final diagnosis based on the two sets of images were compared with McNemer' s test. RESULTS: In terms of the determination of malignant or benign lesion, there was no significant difference between the two sets of images (coronal MPR and transverse thin-section CT; mean Az=0.853 and 0.854, respectively). In addition, accuracy of the final diagnosis based on coronal MPR views (74%) was almost equal to that based on transverse thin-section CT (71%) (p=0.3). CONCLUSIONS: The diagnostic efficacy of the coronal MPR view is comparable to that of transverse thin-section CT for the evaluation of solitary pulmonary nodules.     

Comparison between coronal reformatted images and direct coronal CT images of the swine lung specimen: assessment of image quality with 64-detector row CT

The aims of this study were to compare the image quality of coronal multiplanar reconstruction (MPR) images from axial spiral images with that of direct coronal spiral and sequential images, and to estimate and analyse the effect of an incremental change on the image quality using 64-detector row CT. 12 swine lungs were used. Five kinds of images from each lung specimen were obtained using 64-detector row CT. All images were analysed by categories and grades, and the direct coronal sequential images were used as the reference standard for the image quality. Statistical analysis was performed for the following categories: (i) inter-observer reliability, (ii) interaction between the observers and images, (iii) image analysis, (iv) anatomical structural analysis of each observer, (v) stair-step artefact and (vi) background noise. The overall image quality and the image quality of all anatomical structures of coronal MPR images with 0.67 mm slice increments were inferior to the image quality of the other images; this difference was statistically significant (p<0.05). Stair-step artefact was detected on coronal MPR images, and was more prominent on coronal MPR images with 0.67 mm slice increments than on coronal MPR images with 0.34 mm slice increments. The most severe background noise was detected on the direct coronal sequential images, but there was no significant difference between the direct coronal sequential images and the direct coronal spiral images. Background noise was least prominent on coronal MPR images with 0.67 mm slice increments. The increment process is important for improving the image quality of MPR images even when using 64-detector row CT. Coronal MPR images with 0.34 mm slice increments using 64-detector row CT showed a similar image quality to that obtained from the direct coronal images, and can be used instead. This means that the coronal MPR images obtained with 64-detector row CT could be as useful for evaluating the lung parenchyma as the axial high-resolution CT images.     

Imaging skeletal anatomy of injured cervical spine specimens: comparison of single-slice vs multi-slice helical CT

Our objective was to compare a single-slice CT (SS-CT) scanner with a multi-slice CT (MS-CT) scanner in the depiction of osseous anatomic structures and fractures of the upper cervical spine. Two cervical spine specimens with artificial trauma were scanned with a SS-CT scanner (HighSpeed, CT/i, GE, Milwaukee, Wis.) by using various collimations (1, 3, 5 mm) and pitch factors (1, 1.5, 2, 3) and a four-slice helical CT scanner (LightSpeed, QX/i, GE, Milwaukee, Wis.) by using various table speeds ranging from 3.75 to 15 mm/rotation for a pitch of 0.75 and from 7.5 to 30 mm/rotation for a pitch of 1.5. Images were reconstructed with an interval of 1 mm. Sagittal and coronal multiplanar reconstructions of the primary and reconstructed data set were performed. For MS-CT a tube current resulting in equivalent image noise as with SS-CT was used. All images were judged by two observers using a 4-point scale. The best image quality for SS-CT was achieved with the smallest slice thickness (1 mm) and a pitch smaller than 2 resulting in a table speed of up to 2 mm per gantry rotation (4 points). A reduction of the slice thickness rather than of the table speed proved to be beneficial at MS-CT. Therefore, the optimal scan protocol in MS-CT included a slice thickness of 1.25 mm with a table speed of 7.5 mm/360° using a pitch of 1.5 (4 points), resulting in a faster scan time than when a pitch of 0.75 (4 points) was used. This study indicates that MS-CT could provide equivalent image quality at approximately four times the volume coverage speed of SS-CT. Electronic Publication     

64层CT容积与常规高分辨率CT图像质量的比较

目的 比较容积高分辨率CT(VHRCT)与常规高分辨率CT(CHRCT)的图像质量,探讨VHRCT的可行性.方法 对Catphan 412模具行VHRCT及CHRCT扣描,测量和记录图像的空间分辨率、噪声及放射剂量并进行比较;对32例患者行VHRCT及CHRCT检查,对图像质量进行评分并比较.模具部分采用配对t检验比较噪声的差异;临床部分采用Wilcoxon配对符号秩和检验比较图像质量的差异.结果 模具研究中,VHRCT横断面图像的空间分辨率与CHRCT相同,均为11 LP/cm,其z轴分辨率为12 LP/cm.剂量相近时,VHRCT的噪声为(69.18±2.77)HU,大于CHRCT的噪声(54.62±2.12)HU,(t=-15.929,P＜0.01);噪声相近时,VHRCT的剂量较CHRCT增加19.09 mGy.临床研究中,VHRCT与CHRCT横断面图像的质量评分分别为3.22与3.24,差异无统计学意义(Z=-0.319,P＞0.05),VHRCT与CHRCT冠状面蕈建图像的质量评分分别为3.05与1.88,差异有统计学意义(Z=-5.088,P＜0.01).结论 对于64层CT,VHRCT的横断面图像质量接近CHRCT,多平面重组图像具有高分辨率可广泛应用,其扫描剂量尚有待优化.