CT angiography and MRI imaging features do not predict the tumor type and grade of feline injection site sarcoma

Computed tomographic angiography (CTA) and magnetic resonance imaging (MRI) have been described as methods for preoperative surgical planning in cats with feline injection site sarcomas (FISS), however, few published studies have compared these modalities. The objective of this retrospective, secondary analysis study was to determine if imaging features of FISS on CTA and MRI are predictive of neoplastic peritumoral projections. Archived data from a previous prospective study were retrieved for 10 cats with FISS. All cats had been evaluated in a single anesthetic episode with MRI and dual phase CT (CTA) imaging followed by surgical removal. Histopathological grading and targeted histopathology of imaging‐identified peritumoral projections were performed. Two observers evaluated the CTA and MRI studies for FISS shape, margination, size, enhancement pattern, postcontrast uniformity, pre‐ and postcontrast margination, the number of muscles involved, mass mineralization, and bone lysis. Metal was present in the imaging field of three of 10 cats, resulting in one nondiagnostic MRI. Peritumoral projections were detected in all cats with both imaging modalities, and most were benign. At least one neoplastic peritumoral projection was detected in six cats using MRI, five cats using CTA, and three cats with both modalities. Higher grade FISS were larger than low grade using MRI, and FISS were larger using MRI. Other FISS imaging features using MRI and CTA were similar. Findings supported use of either MRI or CTA for detecting neoplastic peritumoral projections in cats with FISS. Authors recommend CTA for cats with known metallic objects in the scan field.     

基于microCT扫描技术的鲤骨骼和显微结构分析

了解活体鲤（Cyprinuscarpio）骨结构、形态、连接、空间分布以及骨骼矿物质组成对鲤的选育、行为学研究以及肉品加工有重要的意义。X射线显微CT技术（microCT）对样品没有破坏,可实现活体检测,并能获取活体任意形态的结构参数。因此,文章通过这项技术来研究活体鲤的骨骼状况。结果显示,脊椎骨与头、尾相连,胸鳍位于头骨后,背鳍、腹鳍和尾鳍与整个脊椎骨并不相连。骨体积分数和骨小梁厚度在腹鳍较高,头尾较低;骨表面积体积比、骨小梁数量和骨小梁间隔在头部较高,腹鳍较低;骨矿物质含量、骨矿物质密度和组织矿物质含量在背鳍最高;骨体积分数在腹鳍最高,胸鳍、背鳍和尾鳍次之,头尾较低。骨小梁厚度、矿物质含量等在背鳍、腹鳍部位较高,这可能与鲤的运动有关,而头骨表面积体积比、骨小梁数量和骨小梁间隔较高可能与头部的复杂结构密切相关。     

THE USE OF COMPUTED TOMOGRAPHY FOR ASSESSMENT OF THE SWIM BLADDER IN KOI CARP (CYPRINUS CARPIO)

Seven normal koi (Cyprinus carpio) and seven koi with negative buoyancy were examined using computed tomography (CT) to assess the swim bladder. The volume of the swim bladder was calculated in all animals. In the healthy koi there was a statistical correlation (r=0.996) between body mass and swim bladder volume with volume (ml) being related to body mass according to the formula 4.9+0.054 × BM (g). In all koi with buoyancy problems, the gas volume of the swim bladder was reduced. Additionally, fluid was found within the swim bladder in three of the abnormal koi. CT proved to be a quick noninvasive technique for the examination of the swim bladder in koi.     

Epidural spread of iohexol following the use of air or saline in the 'loss of resistance' test

ObjectiveTo compare, using CT epidurography, the cranial distribution of contrast after epidural injection when saline or air is used for the loss of resistance (LOR) technique in identifying the epidural space.Study designProspective, randomized, cross-over experimental study.AnimalsNine healthy adult Beagle dogs.MethodsUnder general anaesthesia, a spinal needle (22-gauge, 70 mm) was inserted through the lumbosacral space, and the position in the epidural space confirmed using the LOR technique employing either 0.3 mL per dog of saline or of air. Epidurography using CT was performed before and 5, 10 and 20 minutes after epidural injection of 0.2 mL kg^?1 of iohexol. The cranial distribution of iohexol was recorded as the number of vertebral segments reached from the seventh lumbar vertebrae.ResultsThe median values in vertebral segments of the cranial distribution at 5, 10 and 20 minutes after epidural injection were 19.5, 20.5 and 21.0 respectively with the saline treatment, and 12.0, 15.0 and 16.0 respectively in the air treatment. At all time points spread of contrast was significantly less with the air treatment. All dogs after air treatment had some air bubbles in the epidural space, and in seven, the spinal cord was moderately compressed by the air. No neurological complications were observed after recovery.Conclusions and clinical relevanceThe use of air for the LOR technique is associated with significantly less spread, uneven cranial distribution of the contrast medium and compression of the spinal cord. It is recommended that saline, and not air, should be used to identify the epidural space by this method.     

基于CT图像的岩石破裂过程裂纹分形特征分析

岩石材料存在不同阶次随机分布的微观孔隙和裂纹,其受载后的宏观断裂失稳和破坏与内部微裂纹的分布以及微裂纹的产生、扩展和贯通有密切关系.通过对岩石CT图像中各点材料进行分析,清晰地看到岩石材料中孔洞及裂纹区域的大小分布随应力的变化过程.利用分形维数对裂纹扩展至破裂过程进行分析,揭示岩石裂纹从萌生、扩展到贯通的细观破损机理....     

A retrobulbar meningioma as a cause of unilateral exophthalmos and blindness in a horse

This report describes the unusual diagnosis of a retrobulbar syncytial meningioma in a 16‐year‐old Thoroughbred gelding. The horse initially presented with unilateral left sided exophthalmos and apparent blindness characterised by unilaterally absent menace and pupillary light responses. Magnetic resonance imaging (MRI) identified a well‐defined soft tissue mass intimately associated with the optic nerve. Based on the characteristic MRI appearance, a meningioma was suspected. The eye was enucleated under general anaesthesia and partial excision of the mass was achieved. Histopathology confirmed the diagnosis and the horse underwent a course of adjuvant radiotherapy. Twelve months following surgery the horse is back in work, no neurological abnormalities have been detected and follow‐up computed tomographic imaging of the skull has revealed mild bone sclerosis with no remnants of the mass identified.     

肾透明细胞癌CT与病理的对照分析

目的 探讨肾透明细胞癌的CT征象与病理表现之间的关系,并对两者进行对照分析.方法 对我院2006-09-2010-09月44例经手术后病理证实的肾透明细胞癌病例术前CT征象及术后病理结果,进行回顾对照分析.结果 CT平扫8例病灶为高密度,17例为低密度,19例为混杂密度.CT强化皮质期43例肿瘤实体强化幅度超过正常肾实...     

Tillage system effect on nitrogen rhizodeposited by faba bean and chickpea

The quantification of the below-ground N of legumes is a key to understand its effect on soil N fertility and the N economy of subsequent legume-based rotations. Significant amounts of the N fixed by legumes are incorporated into the soil as fallen leaves and stems. However, the N from roots, nodules and root exudates has rarely been quantified under field conditions, nor have the management effects been evaluated. This study measured the effects of tillage system [no-tillage (NT) and conventional tillage (CT)] on N rhizodeposition in faba bean (Vicia faba L.) and chickpea (Cicer arietinum L.) during a 3-year period (2003–2004, 2005–2006 and 2006–2007) in a Vertisol under rainfed Mediterranean conditions. Faba bean and chickpea plants were labelled in situ with ¹⁵N using stem feeding and leaf feeding, respectively. NT increased the N derived from rhizodeposition (NdfR) with respect to CT (135 vs. 68 kg N ha⁻¹ in faba bean and 115 vs. 97 kg N ha⁻¹ in chickpea). Such differences between tillage methods can be attributed to the more favourable conditions for root growth produced by NT. NdfR was significantly influenced by depth; in faba bean, the greatest amount (70%) was found in the 0–30 cm layer, whereas in chickpea, 41% of the NdfR was concentrated in the 30–60 cm depth. The 54% and 61% of total plant N was NdfR (in faba bean and chickpea, respectively) representing 90% of the below-ground plant N in both crops. Our results show that the N derived from rhizodeposition is an important source for N balance and is a key to soil fertility in rain-fed Mediterranean cropping systems.     

Identification of selected internal wood characteristics in computed tomography images of black spruce: a comparison study

The feasibility of identifying internal wood characteristics in computed tomography (CT) images of black spruce was investigated using two promising classifiers: the maximum likelihood classifier (MLC) and the back propagation (BP) artificial neural network (ANN) classifier. Nine image features including one spectral feature (gray level values), a distance feature, and seven textural features were employed to develop the classifiers. The selected internal wood characteristics to be identified included heartwood, sapwood, bark, and knots. Twenty cross-sectional CT images of a black spruce log were randomly selected to develop the two classifiers. The results suggest that both classifiers produced high classification accuracy. Compared with the MLC classifier (80.9% overall accuracy), the BP ANN classifier had better classification performance (97.6% overall accuracy). Moreover, statistical analysis reveals that the heartwood of the black spruce log used in this study is the easiest to identify by either classifier compared with the other three log features. The results also suggest that the separability of one wood characteristic from the other wood characteristics in black spruce CT images is mainly related to moisture content.     

快速充盈型肝海绵状血管瘤的CT表现及特点

目的探讨快速充盈型肝海绵状血管瘤（ffHCH）的动态增强CT表现特征。方法回顾性分析13例共15个ffHCH病灶的强CT资料,观察病灶部位、大小、三期动态（动脉期、门静脉期及延迟期）强化模式,以及是否伴有动脉-门静脉分流（APS）、假包膜征及肝包膜回缩征等表现。结果ffHCH病灶好发于肝右叶近包膜下区域;直径（2.42±0.64）cm;动脉期病灶完全强化呈高密度,病灶平均CT值明显高于同期正常肝实质（P〈0.05）;门静脉期病灶呈高或等密度,病灶平均CT值仍明显高于肝实质（P〈0.05）;延迟期病灶呈等或稍高密度,但其强化程度与肝实质无统计学意义（P〉0.05）;部分病灶可见APS,发生率33.33%;无假包膜征及肝包膜回缩征。结论ffHCH三期增强CT表现在病灶位置、大小、增强方式和伴发APS等方面有一定特征,有助于该病的诊断。