Three‐dimensional CT observation of position and movability of the scapula in the horse using carcasses of Falabella

The three‐dimensionally real position and movement of the scapula in the lateral side of the ribcage could not be clarified in the horse, since the body size of the horse is too large to apply the CT scanning and image analysis methods. In this study, therefore, we examined the position and the movability of scapula using a carcass of the Falabella which is one of the smallest breeds of the horse. The whole skeletal system in thoracic part of the Falabella could be three‐dimensionally observed by CT scanning method. The three‐dimensional images show that the scapula cranially slides and the ventral part of the scapula dorso‐cranially rotates, when the shoulder joint moves to the most cranial position as simulation. The three‐dimensional rotation angle was approximately 10 degrees. As a result of comparative osteology of the scapula between Falabella and the large draft horse, the infraspinous fossa was caudally enlarged in the larger draft horse, whereas the Falabella had narrower infraspinous fossa. We suggest that it may be due to the adaptational morphological change in the scapula bearing various body weights among breeds. The three‐dimensional CT image analysis and the simulation in carcass contribute to the analysis of the bone movements of the horse during walking and running locomotion as well as the motion analysis from external functional‐morphological data.     

COMPUTED TOMOGRAPHIC ANATOMY AND CHARACTERISTICS OF RESPIRATORY ASPERGILLOSIS IN JUVENILE WHOOPING CRANES

Respiratory diseases are a leading cause of morbidity and mortality in captivity reared, endangered whooping cranes (Grus americana). Objectives of this retrospective, case series, cross‐sectional study were to describe computed tomography (CT) respiratory anatomy in a juvenile whooping crane without respiratory disease, compare CT characteristics with gross pathologic characteristics in a group of juvenile whooping cranes with respiratory aspergillosis, and test associations between the number of CT tracheal bends and bird sex and age. A total of 10 juvenile whooping cranes (one control, nine affected) were included. Seven affected cranes had CT characteristics of unilateral extrapulmonary bronchial occlusion or wall thickening, and seven cranes had luminal occlusion of the intrapulmonary primary or secondary bronchi. Air sac membrane thickening was observed in three cranes in the cranial and caudal thoracic air sacs, and air sac diverticulum opacification was observed in four cranes. Necropsy lesions consisted of severe, subacute to chronic, focally extensive granulomatous pathology of the trachea, primary bronchi, lungs, or air sacs. No false positive CT scan results were documented. Seven instances of false negative CT scan results occurred; six of these consisted of subtle, mild air sacculitis including membrane opacification or thickening, or the presence of small plaques found at necropsy. The number of CT tracheal bends was associated with bird age but not sex. Findings supported the use of CT as a diagnostic test for avian species with respiratory disease and tracheal coiling or elongated tracheae where endoscopic evaluation is impractical.     

Evaluation of 18F‐FDG PET/CT as a diagnostic imaging and staging tool for feline oral squamous cell carcinoma

18F‐fluorodeoxyglucose positron emission tomography combined with computed tomography (18FDG‐PET/CT) has been shown to be effective for staging human oral squamous cell carcinoma (SCC) but its application for cats with oral SCC is unknown. Twelve cats with biopsy‐proven oral SCC were imaged with whole body 18FDG‐PET/CT to determine its value as a diagnostic imaging and staging tool and fine needle aspirates were obtained of accessible regional lymph nodes. All tumors were FDG avid and conspicuous on 18FDG‐PET/CT images, with an average of the maximum standardized uptake value 9.88 ± 5.33 SD (range 2.9–24.9). Soft tissue infiltrative tumors that were subtle and ill defined on CT were highly visible and more extensive on FDG‐PET/CT. Tumors invading the osseous structures were more similar in extent on 18FDG‐PET/CT and CT although they were more conspicuous on PET images. Three cytologically confirmed metastases were hypermetabolic on PET, while two of those metastases were equivocal on CT.     

基于CT研究冻融对高寒草甸土壤孔隙结构的影响

冻融是影响高寒地区土壤结构的重要物理因素,以青海湖流域高寒草甸作为研究对象,通过野外采集原状土柱、室内冻融循环模拟、CT扫描和图像解译等方法,研究冻融循环对高寒草甸冻胀丘和丘间地的土壤大孔隙结构特征的影响。结果表明,随着冻融循环次数的增加,高寒草甸冻胀丘和丘间地土壤大孔隙度均呈现“减小—增加—减小”的趋势,冻融循环对土壤大孔隙度的降低主要在第1次冻融循环内形成的,且大孔隙的平均等效直径、平均体积、平均分枝长度、分枝密度和节点密度的变化规律与大孔隙度变化规律基本一致;冻融循环对高寒草甸冻胀丘土壤大孔隙的影响明显大于丘间地,其土壤大孔隙度随土层深度变化存在2个峰值,受冻融循环的影响,峰值大小和位置有所变动,且30—80 mm土层深度的土壤孔隙结构较草毡层其他位置更为敏感。     

直流电法CT技术检测林木孔洞结构特征

为尝试应用直流电法CT技术检测林木内部孔洞的结构特征，以含有明显孔洞的梧桐树为试验对象。针对该孔洞实际分布特征，分别布置1号无孔洞和2~5号有孔洞截面，测试时在每个截面表层布置48个铜电极，利用并行电法仪器采集全场电位，获得34 592电场射线数，将射线数据绑定发射接收电极坐标，进行电阻率反演，进一步获得测试断面电阻率分布图。结果表明:孔洞区域电阻率值比正常树干电阻率值大2倍，反演图像清晰，孔洞大小、形态响应特征显著。因此，直流电CT技术可以作为检测林木内部孔洞结构特征的一种有效方法。      

PULMONARY ANGIOGRAPHY USING 16 SLICE MULTIDETECTOR COMPUTED TOMOGRAPHY IN NORMAL DOGS

We report a canine computed tomography (CT) pulmonary angiography technique using multidetector CT (MDCT). CT pulmonary angiography using a 16 slice MDCT was performed on five healthy, anesthetized beagles. A helical acquisition with pitch of 1.4 was used. The time delay for the angiographic study was determined using a bolus‐tracking program. A dose of 400 mg I/kg of nonionic contrast medium (Iohexol 300 mg I/ml) was administered to each dog via a cephalic catheter using an angiographic power injector at a rate of 5 ml/s. In two dogs a second study, using a contrast medium dose of 200 and 600 mg I/kg was performed. Arterial enhancement of transverse and reformatted images was classified subjectively as excellent, good, or poor, and assessed objectively by measuring Hounsfield units at the right main pulmonary artery. Angiographic studies were evaluated by two radiologists to determine the number of subsegmental arterial branches visualized. The median number of subsegmental arterial branches identified was five (range: 2–7). Based on the time attenuation curve obtained by the bolus‐tracking program, there was consistent enhancement of the right main pulmonary artery beginning at 6 s and peaking at 8 s in 4/5 dogs. The contrast medium dose of 400 mg I/kg produced good to excellent vascular enhancement in the same 4/5 dogs. A dose of 200 mg I/kg resulted in poor enhancement. CT pulmonary angiography using MDCT and an automated bolus‐tracking program allows rapid, consistent evaluation of the pulmonary vasculature using a single dose of 400 mg I/kg of contrast medium.     

COMPARISON OF SINGLE-SLICE COMPUTED TOMOGRAPHY PROTOCOLS FOR DETECTION OF PULMONARY NODULES IN DOGS

Two dogs (4 and 38 kg) with radiographic evidence of pulmonary nodules were evaluated using single-slice, helical computed tomography (CT). Each thorax was scanned using 12 combinations of examination parameters that included slice collimation width (3 and 5 mm for the small dog and 5 and 7 mm for the large dog), pitch (1, 1.5, and 2), and reconstruction interval (0.5 and 1). Sensitivity, specificity, and accuracy for nodule detection were evaluated for each protocol by three different observers, their results being compared with a consensus evaluation of images acquired with the protocol providing the best theoretic resolution (narrow collimation, pitch of 1, reconstruction interval of 0.5). For all observers, sensitivity and accuracy were significantly increased when using a protocol with narrow collimation ( P <0.0001–0.005 and P =0.0003–0.005, respectively). Pitch and reconstruction interval did not significantly influence the accuracy, sensitivity, or specificity for at least two of the observers. Additionally, nodule size (<3 mm vs. ≥3 mm) did not significantly affect nodule detection. Interobserver repeatability was variable among protocols (κ=0.32–0.78), highlighting the fact that nodule detection may be more dependent on the observer than on the choice of the CT protocol. For single-slice CT, the results of this study suggest that narrow collimation (3–5 mm, depending on the animal's size), a pitch of 2 and a reconstruction interval of 1 should be used in dogs for the detection of pulmonary nodules.     

QUANTITATIVE COMPUTED TOMOGRAPHY EVALUATION OF PULMONARY DISEASE

Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present. Herein we propose that automated volume histogram analysis can yield data that allow differentiation of normal from abnormal lung, and that the magnitude of disease will have an association with objective CT indices. Data from pulmonary CT images from 34 foxes (six uninfected controls and 28 infected with Angiostrongylus vasorum , subdivided by age and infective dose) were available. Lung tissue was segmented from surrounding tissue using an automated segmentation method. A volume histogram showing voxel frequency for each CT number in the range −1024 to −250 HU was created from the entire image stack from each fox. Using these data, the inter-quartile range and the CT number at the 95th percentile were determined. The results showed that segmentation could be readily achieved but that areas of severely diseased lung were excluded. Based on two-way analysis of variance for both the inter-quartile range and the CT number at the 95th percentile, both quantities were significantly affected by the infection status of the animal and were related to worm burden ( P <0.001). The study shows that this form of analysis is readily achieved and provides quantitative data that can be used to assess disease severity, progression, and response to treatment.     

基于扫描技术的木质雕饰家具与工艺品三维数字化研究

通过Handheld 3D、Handyscan300、Filips16排CT 3种扫描形式进行雕饰家具的三维数字化,比较不同雕饰工艺试件的三维重建适用性。探求不同雕饰特点的木质家具三维数字化有效扫描方法。采用3款不同扫描设备进行4组试验,分析不同雕饰工艺木质家具的三维数字化模型状况,探讨不同扫描仪对不同雕饰工艺家具的三维重建影响,探讨其适用性。试验证明Handheld 3D和Handyscan300均可获取高精度浮雕家具的三维数字模型,但是Handheld 3D在获取透雕家具试件数据模型时纵向坐标信息几乎全部丢失,Handyscan300可较好地获取透雕家具试件数据信息,部分纵向坐标信息丢失,经逆行工程修补后可获取较好的三维数字模型。CT扫描获得的图像经三维重建后得到的数字模型精度最高。对不同雕饰工艺的木质家具需根据其工艺特点采用不同型号的激光扫描仪或CT扫描仪进行三维重建,可获得高精度的三维数字模型。通过CT三维断层扫描获取的图像经三维重建后可获取与试件外观高度一致的三维数字模型,并可导成多种文件格式进行后续虚拟展示、数字信息存档、3D打印、机器雕刻等处理。