基于1.5T磁共振成像系统观察湖羊颅脑形态解剖结构

通过磁共振(magnetic resonance imaging,MRI)影像技术探讨湖羊颅脑影像解剖结构。使用1.5T磁共振扫描仪对10只健康湖羊进行扫查,采用自旋回波(SE)序列,快速自旋回波(FSE)序列以及液体衰减反转恢复(FLAIR)3种序列对湖羊脑部矢状面、横断面及冠状面进行成像。对获得的影像进行详细的解剖结构注释,并且测量了湖羊间脑、颅脑、端脑、第三脑室、第四脑室高度及下垂体的长度、宽度和高度。得到了一套完整的湖羊颅脑磁共振影像解剖图谱及正常湖羊脑解剖结构测量数据。本研究结果可为湖羊及其他绵羊颅脑疾病的影像学诊断提供依据,同时也为医学实验动物模型的研究提供了有价值的参考。     

优质生长性能湖羊的选择

试验旨在对湖羊体高、体长、胸围等体尺参数与体重进行相关性分析,为机械测量判定湖羊生长性状提供参考。选取2月龄、4月龄、6月龄、9月龄、12月龄的湖羊共139只,测量记录体重、胸围、管围、体高、体长等参数,对测得参数进行线性回归分析。结果显示,体高、体长、月龄对湖羊体重具有较强的相关性（R=0.90）。高体高、高体重的母湖羊产双羔及以上的比例超过50%,产双羔及以上羔羊数占总产羔数的69.89%,平均产羔率达到163.16%。研究表明,可通过选择高体高、高体长的湖羊性状提高生长性能,为机器视角中选择优质生长性能湖羊提供依据。     

犬急性水肿型胰腺炎MRI多序列扫描及增强扫描的影像特征

探究犬胰腺磁共振成像(magnetic resonance imaging, MRI)扫描序列总结归纳犬急性水肿型胰腺炎(acute edematous pancreatitis, AEP)的MRI影像表现。选用10只成年本地杂种犬为研究对象，手术经副胰管逆行注入牛磺胆酸钠与胰蛋白酶混合液建立犬急性水肿型胰腺炎模型，然后进行MRI扫描。MRI多序列扫描图像主观与客观分析结果显示，门控采集快速自旋回波T2加权成像(FSE-T2WI-TRIG)序列与门控采集脂肪抑制快速自旋回波T2加权成像(FSE-T2WI-FS-TRIG)序列评分较高，可作为犬胰腺首选MRI扫描序列，必要时可进行造影增强扫描。FSE-T2WI-TRIG、FSE-T2WI-FS-TRIG序列AEP表现为胰腺体积呈弥散性增大，外形不规则，胰腺实质T2WI信号呈不均匀增高，强度高于同层肝组织信号。胰腺与周围脂肪界限稍有不清，胰腺周围伴有渗出，呈条片状T2WI高信号。造影后胰腺实质不均匀强化，平均强化峰值时间为注射造影剂后60～90 s,存在明显延迟强化。研究结果表明，本研究筛选的MRI扫描序列可用于临床上犬AEP的检查，同时A...     

湖羊Lrh-1基因cDNA序列及组织表达谱分析

本研究以湖羊肝脏为材料对肝受体类似物-1(Liver receptor homolog-1,Lrh-1;NR5A2)基因序列进行RT-PCR和RACE测定,并用DNAman、Tmpred、Signal P 3.0、Expasy等生物信息学分析软件和在线工具,对Lrh-1cDNA序列及其蛋白的理化特性、跨膜结构、信号肽和二级结构进行生物信息学分析,同时采用实时荧光定量PCR方法检测湖羊Lrh-1基因的组织表达谱。结果表明,湖羊Lrh-1基因cDNA序列全长1 488bp,与牛的核酸序列相似度最高,为98%,编码区共编码495个氨基酸,氨基酸序列与牛、人、马、猴、犬、小鼠、褐鼠的氨基酸同源性分别为98%、97%、96%、97%、97%、86%和86%;Lrh-1mRNA在湖羊脑、消化及生殖系统组织中均有表达且具有组织特异性,其中在下丘脑组织中的表达量相对最高。     

湖羊的遗传多样性及保种效果评价研究

本研究采用微卫星标记技术,评估了湖州市5个保种场的湖羊遗传多样性,并对保种效果进行了分析。结果显示,5个湖羊群体间的等位基因数差异不显著,目前的保种方法保留了湖羊等位基因;5个湖羊群体各微卫星位点观测杂合度（Ho）差异极其显著,其中3个群体遗传多样性较高;期望杂合度（He）差异不显著;多态信息含量（PIC）差异不显著,且均值都高于0.5,处于高度多态,表明群体具有丰富的遗传多样性和选择潜力。进一步计算了5个湖羊群体的遗传距离,进行了聚类分析,构建了各群体的进化树,结果表明,5个群体的湖羊家系数均达到保种要求,其中4个群体杂合个体较多,可能受外源基因影响。本研究对湖羊的遗传多样性及保种效果进行了有效评估,并提出了存在的问题,有利于湖羊的种质保护和开发利用。     

高温环境下湖羊直肠温度和血液生化指标的监测

本研究以南方特色绵羊品种湖羊为研究对象，在夏季高温环境下，连续监测10 d湖羊直肠温度变化，测定血常规指标，并比较不同年龄、不同性别的湖羊在高温环境下血常规指标的差异；以湖羊高温环境下直肠温度的变化为基础，结合血常规指标，在湖羊群体内鉴别高温应激敏感和高温应激抗性湖羊个体。结果显示，湖羊最高直肠温度出现在环境温度最高的时段（11：00~15：00），最低温度一般出现在03：00左右，且以24 h为周期循环；平均最高直肠温度和最低直肠温度差在湖羊个体间差异显著（P<0.05）；高温暴露后湖羊群体淋巴细胞（LYM）、红细胞（RBC）、血红蛋白（HGB）数量及平均血红蛋白浓度（MCHC）均超出了绵羊正常参考值，且在不同性别和年龄上有一定的差异：母羊嗜碱性细胞、红细胞、血红蛋白、红细胞压积均有高于公羊的趋势，但差异不显著（P>0.05）；1周岁湖羊淋巴细胞（P>0.05）、嗜碱性细胞计数（P<0.01）及百分比（P<0.05）均高于半岁湖羊；依据温度变化结合血常规指标变化在湖羊群体中鉴别了高温应激敏感和抗性的湖羊个体，在测试的母羊群体中高温应激敏感湖羊占35.3%，高温应激抗性湖羊占26.5%。肌酸激酶（CK）含量在高温应激敏感和抗性湖羊个体间差异显著（P<0.05）。综合以上结果，高温环境下湖羊不同个体间直肠温度变化差异显著；从血常规指标来看，高温应激对母羊和1岁湖羊的影响比较大。试验结果为深入研究夏季高温应激对湖羊的影响及抗高温应激差异的分子机制提供了一定的依据。     

不同蛋白源日粮添加乳酸链球菌素对育肥湖羊瘤胃发酵及微生物菌群结构的影响

本试验旨在探究不同蛋白源日粮条件下添加乳酸链球菌素（nisin）对育肥湖羊瘤胃发酵及微生物菌群结构的影响。试验采用2×2因子设计,两因子分别为蛋白源[豆粕（SBM）、干玉米酒精糟及其可溶物（DDGS）]和nisin （添加水平为0或30.5 mg·kg^-1 DM）,两两组合,配制4种等氮等能日粮。选取32只体重（23±2） kg的断奶湖羊公羔,按照随机区组设计,根据体重分为2个区组（低体重组,16只;高体重组,16只）,每个区组的湖羊随机分配到4个组并分别饲喂对应日粮,单栏饲喂。试验预饲期1周,正式期9周,试验期结束时每组从高、低体重区组中各随机选取3只湖羊（共24只）进行屠宰,采集瘤胃内容物,提取微生物基因组DNA,利用Illumina MiSeq测序和Real-time qPCR方法分析瘤胃微生物菌群结构。研究结果表明,除Ruminococcaceae NK4A214 group和Unclassified Bacteroidetes相对丰度外,日粮蛋白源与nisin对其他所有测定指标（瘤胃发酵参数、瘤胃菌群数量、瘤胃细菌多样性及相对丰度等）均不存在交互作用（P>0.05）。日粮添加nisin对所有测定指标均无显著影响（P>0.05）。与饲喂豆粕湖羊相比,饲喂DDGS湖羊瘤胃乙酸、氨态氮浓度及总支链脂肪酸（BCVFA）浓度显著降低（P<0.05）。qPCR结果显示,饲喂不同蛋白源日粮湖羊瘤胃总菌、真菌及甲烷菌数量均无显著差异（P≥0.053）,但相对于饲喂豆粕湖羊而言,饲喂DDGS湖羊瘤胃内原虫和嗜氨梭菌（C.aminophilum）数量显著降低（P<0.05）。Illumina-MiSeq测序结果表明,饲喂DDGS湖羊瘤胃内细菌Chao1指数和ACE指数显著升高（P<0.05）。不同日粮处理组在门水平上的优势菌门均为Bacteroidetes及Firmicutes;在属水平各处理组的主要优势菌属为Prevotella 1、Christensenellaceae R-7 group和Ruminococcaceae NK4A214 group。饲喂不同蛋白源湖羊瘤胃细菌在门水平上并未产生显著影响（P≥0.14）;在属水平上,饲喂DDGS湖羊瘤胃Pseudobutyrivibrio和Roseburia丰度均显著高于饲喂豆粕湖羊（P<0.05）,而Butyrivibrio 2以及Ruminococcaceae UCG-005的相对丰度显著低于饲喂豆粕湖羊（P<0.05）。综上所述,使用DDGS作为日粮蛋白源改变了湖羊瘤胃发酵参数及微生物菌群结构,原虫和C.aminophilum数量的降低可能是导致瘤胃氨态氮浓度显著降低的主要原因;日粮添加30.5 mg·kg^-1 DM的nisin对育肥期湖羊瘤胃发酵参数及微生物菌群结构均无显著影响。     

滩羊和湖羊背最长肌全基因组甲基化差异分析

本研究旨在通过不同品种绵羊背最长肌的全基因组甲基化差异分析,鉴定差异甲基化区域（DMR）和差异甲基化基因（DMG）,为解析绵羊骨骼肌发育差异奠定基础。采用全基因组重亚硫酸盐测序（WGBS）技术开展了周岁龄滩羊、湖羊和滩湖F2代背最长肌全基因组DNA的甲基化水平检测和差异甲基化区域分析,探讨品种间DNA甲基化水平的差异。结果显示,全基因组范围内滩羊、湖羊和滩湖F2代胞嘧啶（C）甲基化（mC）率分别为3.55%、3.18%和3.56%,3个群体的甲基化水平基本一致。对滩羊和湖羊的甲基化水平进行比较,在不同序列环境下共检测到97 731个DMRs和10 784个DMGs。在CG、CHH、CHG序列环境下3个群体甲基化水平无显著差异。对DMGs通过基因本体（GO）和相关信号通路（KEGG）分析,共检测到419个GO条目和20个信号通路,显著富集在细胞过程、细胞组分、结合、长期抑制等相关条目中。筛选出5个与肌肉调控有关的候选基因ACTA2、ROCK1、CALD1、MYH3、MYH10。本研究绘制了滩羊、湖羊和滩湖F2代全基因组甲基化图谱,为表观遗传调控肌肉发育研究和肉质候选基因的筛选提供理论参考。     

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。     

HSD17B12基因对湖羊垂体细胞促性腺激素合成的影响

旨在探索湖羊垂体中17β-羟类固醇脱氢酶12（HSD17B12）基因对垂体激素分泌的影响。本研究挑选体重相近（40 kg左右）且健康的性成熟湖羊公羊（9月龄）3只，采集垂体组织进行HSD17B12基因CDS区扩增及蛋白同源性分析，确定其CDS区序列。利用免疫组化分析HSD17B12在性成熟雄性湖羊垂体中的表达定位。体外分离湖羊垂体细胞，利用RNA干扰和细胞转染技术体外干扰HSD17B12，qPCR鉴定激素相关基因的表达水平，并利用流式细胞仪检测细胞增殖、凋亡、周期等的变化。结果表明，HSD17B12基因CDS区长度为939 bp，并且在物种间保守性较高。此外， HSD17B12在湖羊垂体组织大部分细胞中均呈现阳性表达。在垂体细胞干扰HSD17B12后，可以造成细胞增殖效率显著降低（P<0.05），细胞凋亡比率显著增加（P<0.05），细胞周期发生显著改变（P<0.05），且垂体促性腺激素合成相关基因FSHβ、LHβ和生长激素基因GH表达水平均显著降低（P<0.05）。结果提示，在湖羊垂体细胞中干扰HSD17B12的表达，可通过影响细胞增殖、周期和凋亡水平的变化而显著降低促性腺激素及生长激素的分泌。本研究初步证明了HSD17B12基因在湖羊垂体中的重要作用，为进一步探索其中的作用机制提供一定的基础。     

Magnetic resonance imaging of the palmar aspect of the equine podotrochlear apparatus: normal appearance

The purpose of this study was to describe the normal magnetic resonance (MR) imaging characteristics of the palmar structures of the equine podotrochlear apparatus by means of retrospective evaluation of MR imaging studies of 16 cadaver limbs. The articular aspect of the distal sesamoid bone was not evaluated in this study. Equine digits were imaged with a human knee radiofrequency coil in a 1.5 T magnetic field, using spin echo (SE) T1-weighted, turbo spin echo proton density (TSE PD)-weighted with and without fat saturation (FS), and FS TSE T2-weighted sequences. The limbs were dissected after imaging to validate the absence of gross abnormalities of the flexor aspect of the distal sesamoid bone, of the deep digital flexor tendon, and the distal impar sesamoidean ligament. Seven deep digital flexor tendons were subjected to histologic examination to exclude any microscopic tendon pathology. The anatomic structures of the podotrochlear apparatus were easily identified on MR images. Compact bone of the flexor cortex of the distal sesamoid bone had low intensity signal on all sequences. In 11 digits an increased signal was seen within the thickness of the sagittal eminence of the flexor cortex in SE T1-weighted images and in TSE PD-weighted images without FS. Trabecular bone had a granular appearance and high signal in SE T1-weighted sequences and TSE images without FS. The deep digital flexor tendon had low signal on FS T2-weighted images, while on short echo time sequences (T1- and PD-weighted sequences), the tendon signal varied depending on the relative orientation between its fibers and the static magnetic field. Seven tendons had stippled appearance due to small intratendonous foci of slightly increased signal on transverse T1-weighted images. MR imaging provides a thorough evaluation of the anatomical structure of the podotrochlear apparatus: A good knowledge of the MR imaging appearance and anatomy and an awareness of potential pitfalls will improve diagnostic specificity for the detection of pathologic changes.     

Comparison of Feline Brain Anatomy in 0.25 and 3 Tesla Magnetic Resonance Images

The intention of the comparison of both low and high field was to examine which anatomical brain structures of cats were visible on low field images, as in clinical veterinary practice, 3 Tesla (T) magnets were of limited availability. The research was performed on 20 European short‐haired male and female cats, aged 1–3 years, with body weight of 2–4 kg. 0.25 T magnetic resonance images of neurocranium were acquired in all using T2‐weighted fast spin echo sequences with repetition time (TR) of 4010 ms and echo time (TE) of 90 ms in dorsal and transverse plane, and T2‐weighted fast spine echo sequences with TR of 4290 ms and TE of 120 ms in sagittal plane. Based on a detailed catalogue of feline brain structures visible at 3 T in previously published studies, it was examined which structures were visible on low field images. Anatomic structures were identified and compared to assess the reliability of diagnoses made based on low‐field magnetic resonance imaging. In low‐field scans, 92 structures were identified. Elements of auditory, visual, motor pathways, hippocampus and cerebral ventricular system were distinguished. Low‐field as well as high‐field magnetic resonance imaging support the identification of local tissue lesions, metastasis, focal ischaemia and haemorrhage, disorders associated with ventricular system dilation and hydrocephalus. It also produced accurate images of the hippocampus, which contributes to reliable diagnoses of various forms of epilepsy in cats. Due to technical limitations, a low‐field scanner is unlikely to visualize microtraumas, local inflammations, small haematomas or metastatic tumours.     

EVALUATION OF THE WARP‐TURBO SPIN ECHO SEQUENCE FOR 3 TESLA MAGNETIC RESONANCE IMAGING OF STIFLE JOINTS IN DOGS WITH STAINLESS STEEL TIBIAL PLATEAU LEVELING OSTEOTOMY IMPLANTS

Susceptibility artifacts caused by ferromagnetic implants compromise magnetic resonance imaging (MRI) of the canine stifle after tibial plateau leveling osteotomy (TPLO) procedures. The WARP‐turbo spin echo sequence is being developed to mitigate artifacts and utilizes slice encoding for metal artifact reduction. The aim of the current study was to evaluate the WARP‐turbo spin echo sequence for imaging post TPLO canine stifle joints. Proton density weighted images of 19 canine cadaver limbs were made post TPLO using a 3 Tesla MRI scanner. Susceptibility artifact sizes were recorded and compared for WARP vs. conventional turbo spin echo sequences. Three evaluators graded depiction quality for the tibial tuberosity, medial and lateral menisci, tibial osteotomy, and caudal cruciate ligament as sufficient or insufficient to make a diagnosis. Artifacts were subjectively smaller and local structures were better depicted in WARP‐turbo spin echo images. Signal void area was also reduced by 75% (sagittal) and 49% (dorsal) in WARP vs. conventional turbo spin echo images. Evaluators were significantly more likely to grade local anatomy depiction as adequate for making a diagnosis in WARP‐turbo spin echo images in the sagittal but not dorsal plane. The proportion of image sets with anatomic structure depiction graded adequate to make a diagnosis ranged from 28 to 68% in sagittal WARP‐turbo spin echo images compared to 0–19% in turbo spin echo images. Findings indicated that the WARP‐turbo spin echo sequence reduces the severity of susceptibility artifacts in canine stifle joints post TPLO. However, variable depiction of local anatomy warrants further refinement of the technique.     

MAGNETIC RESONANCE IMAGING FEATURES OF SINONASAL DISORDERS IN HORSES

Diseases of paranasal sinuses and nasal passages in horses can be a diagnostic challenge because of the complex anatomy of the head and limitations of many diagnostic modalities. Our hypothesis was that magnetic resonance (MR) imaging would provide excellent anatomical detail and soft tissue resolution, and would be accurate in the diagnosis of diseases of the paranasal sinuses and nasal passages in horses. Fourteen horses were imaged. Inclusion criteria were lesions located to the sinuses or nasal passages that underwent MR imaging and subsequent surgical intervention and/or histopathologic examination. A low field, 0.3 tesla open magnet was used. Sequences in the standard protocol were fast spin echo T2 sagittal and transverse, spin echo T1 transverse, short‐tau inversion recovery (STIR) dorsal, gradient echo 3D T1 MPR dorsal (plain and contrast enhanced), spin echo T1 fatsat (contrast enhanced). Mean scan time to complete the examination was 53 min (range 39–99 min). Lesions identified were primary or secondary sinusitis (six horses), paranasal sinus cyst (four horses), progressive ethmoid hematoma (two horses), and neoplasia (two horses). The most useful sequences were fast spin echo T2 transverse and sagittal, STIR dorsal and FE3D MPR (survey and contrast enhanced). Fluid accumulation, mucosal thickening, presence of encapsulated contents, bone deformation, and thickening were common findings observed in MR imaging. In selected horses, magnetic resonance imaging is a useful tool in diagnosing lesions of the paranasal sinuses and nasal passages.     

MAGNETIC RESONANCE IMAGING OF THE CANINE BRAIN AT 7 T

The purpose of this study was to describe relevant canine brain structures as seen on T2-weighted images following magnetic resonance (MR) imaging at 7 T and to compare the results with imaging at 1.5 T. Imaging was performed on five healthy laboratory beagle dogs using 1.5 and 7 T clinical scanners. At 1.5 T, spin echo images were acquired, while gradient echo images were acquired at 3 T. Image quality and conspicuity of anatomic structures were evaluated qualitatively by direct comparison of the images obtained from the two different magnetic fields. The signal-to-nose ratio (SNR) and contrast-to-noise ratio (CNR) were calculated and compared between 1.5 and 7 T. The T2-weighted images at 7 T provided good spatial and contrast resolution for the identification of clinically relevant brain anatomy; these images provided better delineation and conspicuity of the brain stem and cerebellar structures, which were difficult to unequivocally identify at 1.5 T. However, frontal and parietal lobe and the trigeminal nerve were difficult to identify at 7 T due to susceptibility artifact. The SNR and CNR of the images at 7 T were significantly increased up to 318% and 715% compared with the 1.5 T images. If some disadvantages of 7 T imaging, such as susceptibility artifacts, technical difficulties, and high cost, can be improved, 7 T clinical MR imaging could provide a good experimental and diagnostic tool for the evaluation of canine brain disorders.     

A study of the comparative anatomy of the brain of domestic ruminants using magnetic resonance imaging

Although magnetic resonance imaging has been used to examine the brain of domestic ruminants, detailed information relating the precise anatomical features in these species is lacking. In this study the brain structures of calves (Bos taurus domesticus), sheep (Ovis aries), goats (Capra hircus) and a mesaticephalic dog (Canis lupis familiaris) were examined using T2-weighed Turbo Spin Echo sequences; three-dimensional models based on high-resolution gradient echo scans were used to identify brain sulci and gyri in two-dimensional images. The ruminant brains examined were similar in structure and organisation to those of other mammals but particular features included the deep depression of the insula and the pronounced gyri of the cortices, the dominant position of the visual (optic nerve, optic chiasm and rostral colliculus) and olfactory (olfactory bulb, olfactory tracts and piriform lobe) systems, and the relatively large size of the diencephalon.     

COMPARISON OF CONVENTIONAL SPIN-ECHO AND FAST SPIN-ECHO MAGNETIC RESONANCE IMAGING IN THE CANINE BRAIN

T2-weighted fast spin echo and conventional spin echo are two magnetic resonance (MR) pulse sequences used to image the brain. Given the same scan parameters the resolution of fast spin-echo images will be inferior to that of conventional spin-echo images. However, fast spin-echo images can be acquired in a shorter time allowing scan parameters to be optimized for increased resolution without increasing the time to an unacceptable level. MR imaging of the brain of 54 dogs, suspected of having parenchymal brain abnormalities was performed using a 1.5 T scanner. Acquisition time ranged from 4 min 24 s to 7 min 16 s (average = 5 min 15 s) for fast spin-echo scans and from 6 min 32 s to 11 min 26s (average = 7 min 55s) for conventional spin-echo scans. All reviewers consistently rated the resolution of fast spin-echo images higher than the conventional spin-echo images (P = 0.000). The potential disadvantages of fast spin-echo acquisitions (motion artifacts, blurring, and increased hyperintensity of fat) did not affect the resolution of the images. Fast spin echo offers increased resolution in a comparable time to conventional spin echo by increased number of excitations and finer matrix size, thus improving the signal-to-noise ratio and spatial resolution, respectively.     

Availability of NMR microscopic observation of mouse embryo disorder: examination in malformations induced by maternal administration of retinoic acid

Nuclear magnetic resonance (NMR) microscopy is a magnetic resonance imaging method with enhanced spatial resolution due to the use of a high static magnetic field and high magnetic field gradients. It is considered to be a useful tool for non-invasive and continuous investigation of tissue and organs at the histological level. In this study, we applied NMR microscopy to assessment of morphology in mouse embryos using a developmental disorder model induced by retinoic acid administration. Pregnant mice were given 50 mg/kg all-trans retinoic acid at 8.5 dpc. Embryos were collected at several time points after treatment and examined by NMR microscopy after fixation. Two-dimensional and three-dimensional spin echo sequences were used. Tissue contrast on two-dimensional images changed according to length of repetition time and echo time, and also to developmental stage of embryos. Two-dimensional and three-dimensional images nondestructively demonstrated defects in development of the skeleton and soft tissue, e.g. hypoplasia of vertebrae in the lumbar and tail regions and dysplasia of the spinal cord, in embryos exposed to retinoic acid. These morphological abnormalities were confirmed by conventional assessment after imaging. Although further improvements are required, NMR microscopy will provide a new approach for multi-parameter assessment of embryonic development under physiological and pathological conditions.