应用X射线CT图像技术检测红毛丹内部品质的试验研究

水果内部品质检测是当前农产品品质检测的技术难点。进行了利用X射线CT图像技术方法检测红毛丹内在品质-可食率、可溶性固形物含量的试验研究。首先用阈值法去除X射线CT图像背景,然后用面积闭值法来提取果肉区域。红毛丹可食率以分割果肉区域像素值与整个果实区域像素值之比来表示,实验结果表明误判率为8．3％。基于X射线CT值的红毛丹可溶性固形物含量预测模型的相关系数达92％。     

Computed tomographic and radiographic morphology of the pastern and coffin joints of One-Humped Camel (Camelus dromedarius)

The objective of the current study was to describe the structures of the pastern and coffin joints in dromedary camel using x-ray, bone and soft tissue windows computed tomography (CT) and three-dimensional volume rendering (3DVR) of CT imaging. 3DVR of CT was obtained at the slight flexed dorsal view, plantar view, dorsolateral view and lateral view which explained all the surfaces and structures of the digit bony parts even the parts of the articular surface. The processed images of 3DVR of CT showed different patterns of the cortical, cancellous, subchondral bones and medullary cavity of the bones of the digits. The present study showed clearly all the hard and soft tissues in the pastern and coffin joints of the camel in CT images; however, the plantar ligaments of the pastern joint and ligaments of the navicular cartilage identified on CT images. The CT soft tissue window visualized the joint cavity and their pouches and tendon sheath of the flexor tendons better than the bone window CT. The radiographic, CT and 3D images could be used as a normal reference for the interpretation of some clinical diseases in the pastern and coffin joints of the camel.     

实验猕猴全身CT影像学观察

目的：应用CT技术对成年实验猕猴全身进行断层扫描,探讨CT技术对猕猴疾病的临床诊断意义,建立正常成年猴CT影像图谱,为CT技术在猕猴解剖学的研究、疾病的诊断及科学实验方面的应用,提供影像学的基础资料。方法：（1）选择实验猕猴10只,雌雄各半,年龄6～10岁,进行全身CT断层扫描。（2）试验猴全身麻醉后,置于CT诊断床上,取头前尾后仰卧位,采用平扫及增强扫描技术,进行容积数据采集,获取正常猕猴全身CT影像图片。（3）利用CT图像后处理技术对扫描获得的容积数据进行2D或3D图像重组处理。结果：（1）获得实验猕猴活体结构CT连续断层图像数据集。（2）从扫描和重建图像中精选具有解剖意义的图像,编辑建立实验猕猴CT影像图谱。文中展示4幅代表性扫描图片和5幅三维重建图像。（3）从比较解剖学的角度,阐述猕猴结构特点及与人类的区别。结论：（1）CT影像能够较好显示及分辨猕猴的组织器官结构,骨骼、大血管界面清晰;但软组织、神经、肌肉组织等显示不够清晰。（2）试验获得了正常成年猕猴全身的影像学基础资料,为CT技术在猕猴影像学研究、解剖学研究、疾病的临床诊断及科学实验方面的应用,提供了参考。（3）在猕猴CT影像学方面做了初步摸索,对猕猴进行CT扫描的技术参数选择及猕猴各器官组织定量统计数据的建立等有待进一步总结和完善。     

Computed tomographic appearance of equine sinonasal neoplasia

The computed tomography (CT) features of tumors involving the nasal cavity and/or paranasal sinuses of 15 horses were reviewed. The 15 tumors included five neuroendocrine tumors/neuroblastomas, two undifferentiated carcinomas, two myxosarcomas, and one each of nasal adenocarcinoma, hemangiosarcoma, chondroblastic osteosarcoma, anaplastic sarcoma, myxoma, and ossifying fibroma. All tumors except the ossifying fibroma were iso- or hypoattenuating relative to masseter muscle. Thirteen of the fifteen tumors exhibited moderate or marked osteolysis of adjacent cortical bone and 14/15 were characterized by destructive changes of the nasal turbinates, nasal septum, and/or infraorbital canal. Ten horses had moderate or marked involvement of the cribriform plate and six had clear intracranial extension of the mass. CT features were compared to radiographic findings for 10 horses. A mass was observed in 10/10 radiographic studies and mass within the caudal maxillary sinus (7/8) and rostral maxillary sinus (6/7) was identified correctly in most horses. The radiographs were least sensitive for identifying masses within the sphenopalatine sinus (0/5), cranium (0/4), and retrobulbar space (1/7) compared to CT. The radiographs also underestimated potential features of malignancy, such as severity of osteolysis or osseous production. While radiographs are a useful screening tool for identification of sinonasal masses, CT provides greater information regarding mass extent, features of malignancy, and important prognostic indicators.     

The effects of repeated intravenous iohexol administration on renal function in healthy beagles – a preliminary report

Background

Contrast induced nephrotoxicity (CIN) is a well described syndrome in humans undergoing contrast medium examinations. To date CIN has received minimal attention in the veterinary literature despite increasing use of contrast medium examinations in computed tomographic studies.

Methods

This prospective study evaluated the effect of 1290 mg/kg iohexol given intravenously to 5 normal beagle dogs in a divided dose at an interval of 6–8 weeks. Renal function was evaluated by means of scintigraphically determined glomerular filtration rate (GFR) and a variety of laboratory assays.

Results

Only GFR showed a significant decrease (17%) after the second injection but not to a clinically or pathologically significant level.

Conclusions

No clinically significant effect of repeated contrast medium administration was determined in this limited study. However in dogs with reduced renal function the risk of CIN is likely to increase dramatically post contrast administration.     

Comparisons of computed tomography, contrast-enhanced computed tomography and standing low-field magnetic resonance imaging in horses with lameness localised to the foot. Part 2: Lesion identification

Reasons for performing study: No previous study compares computed tomography (CT), contrast‐enhanced computed tomography (CECT) and standing low‐field magnetic resonance imaging (LFMRI) to detect lesions in horses with lameness localised to the foot. This study will help clinicians understand the limitations of these techniques. Objectives: To determine if CT, CECT and LFMRI would identify lesions within the distal limb and document discrepancies with lesion distribution and lesion classification. Methods: Lesions in specific structures identified on CT and MR images of feet (31 limbs) from the same horse were reviewed and compared. Distributions of lesions were compared using a Chi‐squared test and techniques analysed using the paired marginal homogeneity test for concordance. Results: Lesions of the deep digital flexor tendon (DDFT) were most common and CT/CECT identified more lesions than LFMRI. Deep digital flexor tendon lesions seen on LFMRI only were frequently distal to the proximal extent of the distal sesamoid and DDFT lesions seen on CT/CECT only were frequently proximal to the distal sesamoid. Lesions identified on LFMRI only were core (23.3%) or splits (43.3%), whereas lesions identified only on CT were abrasions (29.8%), core (15.8%), enlargement (15.8%) or mineralisation (12.3%). Contrast‐enhanced CT improved lesion identification at the DDFT insertion compared to CT and resulted in distal sesamoidean impar ligament and collateral sesamoidean ligament vascular enhancement in 75% of cases. Low‐field MRI and CT/CECT failed to identify soft tissue mineralisation and bone oedema, respectively. Conclusions and potential relevance: Multiple lesions are detected with CT, CECT and LFMRI but there is variability in lesion detection and classification. LFMRI centred only on the podotrochlear apparatus may fail to identify lesions of the pastern or soft tissue mineralisation. Computed tomography may fail to identify DDFT lesions distal to the proximal border of the distal sesamoid.     

Cerebral Computed Tomography Scan Demonstrating Ischemic Stroke in a Filly After Intravenous Antibiotic Administration

Performing a brain computerized tomography scan (CT scan) on a foal requires specific equipment and anesthesia for large animals. However, the information obtained may demonstrate lesions responsible for the neurological deficits. Especially, CT scan findings may help to understand a mechanism of cerebral ischemia. Indeed, categories of cerebral ischemia are divided in three types: territorial infarctions (downstream of the territory of an artery), watershed infarctions (slow-flow at the junction of two arterial territories), and lacunar infarctions (small-vessel occlusions). Hypersensitivity reactions and type I anaphylactic IgE antibody reactions are severe potential adverse effects of sulfonamide administration, which occur in about three percent of cases. In horses, anaphylaxis is often clinically expressed as hypotension and collapse. Cardiovascular collapse may lead to multiorgan slow-flow leading to infarction with multiorgan failure and death. We report the case of a filly that suffered a presumed watershed cerebral infarction after antibiotic injection, indicated on a brain CT scan. This was attributed to a cerebral slow-flow during cardiovascular collapse, at the posterior junction of the right cerebral arteries. No abnormalities were initially identified on the CT scan; however, a review of the imaging by a radiologist specialized in cerebrovascular diseases detected a limited right occipital cortico-subcortical lesion in the visual cortex, interpreted as an ischemic scar in the watershed area related to hemodynamic infarction. This case highlights that detection of brain lesions by CT scan might require specialized knowledge and careful reading for interpretation particularly in the case of limited lesions.     

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。     

Early diagnosis may hold the key to the successful treatment of nasal and paranasal sinus neoplasia in the horse

Intrasinus neoplasia remains a rare but difficult condition to diagnose and treat in the horse, comprising approximately 8–19% of sinonasal disorders. There are, however, only a few case series upon which to base an approach to diagnosis and management ( Cotchin 1967, 1977 ; Madewell et al. 1976 ; Stunzi and Hauser 1976 ; Sundberg et al. 1977 ; Priester and McKay 1980 ; Boulton 1985 ; Hilbert et al. 1988 ; Dixon and Head 1999 ; Head and Dixon 1999 ; Tremaine and Dixon 2001a,b ). Squamous cell carcinoma (SCC) is the most common neoplasm observed in the equine paranasal sinuses. Evidence from other species would indicate that early recognition of SCC is crucial to the success of treatment and the ideal treatment remains complete excision with margins. Sinus involvement generally precludes this and we must often settle for surgical debulking, with or without adjunctive radio‐ or chemotherapy. In horses, as in other species, early recognition is difficult because clinical signs are nonspecific. Treatment is, therefore, often not attempted due to the extensive nature of lesions at presentation and the limited surgical access. The accompanying article by Kowalczyk et al. (2011 ) showed how 3‐dimensional (3D) imaging can identify the hallmark changes associated with aggressive neoplasia in the equine sinuses ( Kowalczyk et al. 2011 ). The value of computed tomography (CT) and magnetic resonance imaging (MRI) lies in noninvasive early diagnosis as well as lesion monitoring post intervention. Where CT can be performed with the horse in the standing position, avoidance of general anaesthesia offers further value, especially as standing surgical techniques now allow thorough, minimally invasive evaluation and biopsy of the equine sinuses. In combination, standing CT and minimally invasive sinus surgery allow accurate and early diagnosis and monitoring of disease progression, opening the door for advances in surgical and adjunctive treatments for this complex condition.