兽医脑部超声 Brain Ultrasonography

来源丨《Blackwell’s Five-Minute Veterinary Consult》

翻译丨宠物神经科医生高健

TYPE OF PROCEDURE
检查类型

Ultrasonographic
超声

PROCEDURE EXPLANATION AND RELATED PHYSIOLOGY

检查解释及相关生理学

Ultrasound examination of the brain requires an acoustic window through the skull. Dogs with hydrocephalus often have a persistent bregmatic fontanel that enables imaging of the brain. In these cases, an ultrasound examination is a quicker, less expensive, and more available screening tool than computed tomography (CT) or magnetic resonance imaging (MRI). Ultrasound images of the brain have relatively poor anatomic detail compared to those with CT and especially MRI. Ultrasound imaging of the brain in patients with a closed fontanel may be accomplished through the temporal window or foramen magnum, although these acoustic windows provide a more limited view of the brain in many cases. A portion of the skull can be removed surgically to provide a window for ultrasound; however, this invasive technique requires anesthesia. For these cases, CT and MRI, which are less inva- sive, provide a more complete evaluation of the brain than ultrasound will provide. Ultrasound is excellent for distinguishing fluid versus soft tissue, enabling straightforward identification of hydrocephalus, cysts, and abscesses. Intraoperative ultrasound of the brain is used mainly to aid surgical dissection by identifying nonpalpable and nonvisible le- sions. Ultrasound is used postoperatively to evaluate the completeness of removal of a lesion or look for evidence of complications.

对大脑进行超声检查需要有一个通过颅骨透过超声波的窗口。

患有脑积水的犬通常有一个永久性开放的囟门，
这使得大脑超声检查变得可行。

在这些情况下，
超声检查是一种比计算机断层扫描CT或磁共振成像MRI更快速、更便宜、更有效的筛查工具。

但是与CT，尤其是MRI相比，
超声图像的大脑解剖细节相对较差。

对于囟门闭合的病患，
超声成像可以通过颞窗或枕骨大孔来完成，
尽管在许多情况下，
这些透超声窗提供的大脑图像更有限。

可以通过手术切除颅骨的一部分来以提供透过超声的窗口;
但是，手术是侵入性技术，而且需要麻醉。

对于这些病例，
CT和MRI侵入性较小，
而且能提供比超声更全面的脑部评估。

超声在区分液体和软组织方面非常出色，
可以直接识别脑积水、囊肿和脓肿。

术中脑部超声主要用于通过识别无法触摸和肉眼不可见的病变，
用作辅助手术解剖定位。

超声用于术后评估病变清除的完全程度，
或用作寻找并发症的证据。

INDICATIONS
适应症

Suspected hydrocephalus 
Intraoperative location of brain tumor, cyst, abscess, or hemorrhage

怀疑脑积水

术中脑肿瘤、囊肿、脓肿或出血的定位

CONTRAINDICATIONS

禁忌症

Atlantoaxial instability is a contraindication for ultrasound imaging of the brain through the foramen magnum. Hyperflexion of the head is required for imaging through the foramen magnum and could cause severe injury to the spinal cord if concurrent atlantoaxial instability is present. To assess for possible atlantoaxial subluxation in toy-breed dogs, survey radiographs should be made prior to this ultrasound procedure.

寰枢椎不稳（Atlantoaxial instability）是经枕骨大孔超声成像的禁忌症。

因为通过枕骨大孔成像需要让头部过度屈曲，
如果同时存在寰枢椎不稳定，
可能会对脊髓造成严重损伤（可能引起死亡）。

为了评估玩具品种犬寰枢椎半脱位的可能性，
应在超声检查前进行X线片检查。

POTENTIAL COMPLICATIONS 

潜在并发症

Excess pressure by the ultrasound probe could potentially injure the brain tissue. Judicious use of the ultrasound probe will prevent this complication.

超声波探头施加的过大压力可能会潜在地损伤脑组织。

小心明智地使用超声探头可以防止这种并发症。

CLIENT EDUCATION

宠主教育

The use of ultrasound to image the brain is safe, fast, and economical in screening for hydrocephalus in an animal with an open fontanel. CT or MRI of the brain is often necessary for a complete evaluation of the brain following ultrasound.

Intraoperative ultrasound localization of a brain lesion can reduce the amount of dissection and palpation of the brain tissue, therefore reducing trauma to the brain.

Intraoperative brain ultrasound assists in identifying all abnormal tissue for removal.

超声成像是一种安全、快速、经济的脑积水筛查方法。

脑部CT或MRI对于超声后脑部的全面评估通常是必要的。

术中超声定位脑病变可以减少脑组织的剥离和触诊，
从而减少对大脑的创伤。

术中脑部超声有助于识别是否所有异常组织都进行了切除。

BODY SYSTEMS ASSESSED

所评估的身体系统

Nervous
神经系统

PROCEDURE

检查方式

PATIENT PREPARATION

病患预备

Preprocedure Medication or Preparation
检查方式所用药物或预备

None 无

Anesthesia or Sedation 麻醉或镇静

This is required only if necessary for a surgical procedure or to assist in keeping the patient still during the ultrasound examination.

Sedation is more often required for imaging through the foramen magnum to enable sufficient flexing of the atlanto-occipital joint for imaging.

只有在外科手术或在超声检查中帮助病患保持静止时才需要这样做。

通过枕骨大孔成像时通常需要镇静，以使寰枕关节充分屈曲以便成像。

Patient Positioning

病患摆位

Patients with an open bregmatic fontanel can often be imaged with them standing or sitting.

Lateral recumbency is used in some cases, depending on the temperament of the patient.

囟门未闭的病患，
通常可以站着或坐着进行超声成像。

根据病患的脾性，
在某些情况下采用侧躺位。

Patient Monitoring
病患监测
No special monitoring is needed for use of ultrasound.

使用超声不需要特别的监测。

Equipment or Supplies

设备或耗材

A real-time B-mode ultrasound scanner with a high-frequency transducer

A transducer with a small footprint (contact with skin area) and sector image. This allows the ultrasound beam to get through the opening in the skull and widen out to image more of the brain. A high-resolution linear array transducer may be used but will present a more restricted view of the brain.

The transducer frequency should be ≥7 MHz for the best resolution.

一台带有高频探头的实时B型超声扫描仪。

一个小压面（与皮肤区域接触的面）和扇形图像的探头。

这可以让超声束穿过颅骨的未闭的开口，
并让超声波发散到大脑的更多区域。

可以使用高分辨率线性阵列探头，
但所呈现的大脑视野将会受到更多限制。

为获得最佳分辨率，探头频率应≥7 MHz。

 

TECHNIQUE

技术

Imaging Through the Open Bregmatic Fontanel

经未闭囟门成像

Clip or part the hair, if thick, over the fontanel. If the hair is fine, thin, or both, the transducer may be coupled sufficiently to the skin without the hair being clipped.

Place sufficient ultrasound gel on the skin surface of ultrasound transducer, and place the transducer directly over the open fontanel. Adjust the depth and gain to produce the best image of the brain.

Obtain sagittal and transverse views of the brain by sweeping slowly from side to side in the sagittal plane and rostral to caudal in the transverse plane.

如果毛发较厚，将其剃短或分开，露出囟门的位置。

如果毛发细、薄或又细又薄，
那么只要探头可以与皮肤充分耦合，
那么就不需要剃掉毛发。

在超声探头和皮肤表面之间放足够的超声凝胶，
然后将探头直接放置在未闭的囟门上。

调整深度和增益，以产生最佳的大脑图像。

在矢状面缓慢地从一侧扫到另一侧，
在横断面缓慢地从前侧扫到后侧，
获得大脑矢状面和横断面图像。

Imaging Through the Temporal Window

经颞窗成像

Clip or part the hair and apply acoustic gel to the skin.

The temporal window is located just dorsal to the juncture of the zygomatic arch, with the temporal bone at the juncture of the parietal and temporal bones, where the bone can be thin enough to enable imaging through this window.

The exact location and quality of view obtained through this window vary.

Transverse and dorsal views of the brain are obtained through this window.

把毛发剃短或分开，在皮肤上涂上超声耦合凝胶。

颞窗位于颧弓接点的背侧，
颞骨位于顶骨和颞骨的交界处，
此处的颅骨足够薄，
可以通过该窗口进行成像。

通过该窗口获得的确切位置和图像质量各不相同。

通过这个窗口可以获得大脑的横断面和冠状面成像。

Imaging Through the Foramen Magnum

经枕骨大孔成像

Clip the hair and clean the skin centered on the midline occipital region of the head.

The patient is placed in lateral recumbency, and its head is hyper-flexed.

Apply ultrasound gel to the skin surface or transducer.

Place the ultrasound transducer on the patient’s skin sagittal to the head, and point the transducer toward its nose.

Generally, only sagittal images are obtained from this acoustic window.

One advantage of this window is the ability to evaluate the blood flow in the basilar artery with Doppler.

This view does not enable imaging of the brain rostral to the interthalamic adhesion but enables imaging of the proximal cervical spinal cord.

修剪毛发，清洁头部枕部中线中心的皮肤。

病患侧卧位，头部需要过度屈曲。

在皮肤表面或探头上涂抹超声耦合凝胶。

将超声探头置于病患头部矢状面的皮肤上，并将探头指向病患的鼻子。

一般来说，从这个方向的窗口只能获得矢状面图像。

这个窗口的一个优点是能够用多普勒评估基底动脉的血流。

这个方向的超声不能成像丘脑间连结的前侧，
但可以成像颈部近端的脊髓。

Intraoperative Imaging
术中成像

Place a sterile sleeve over the transducer and cord.

Fill the brain case with normal saline and image through the fluid or place the transducer gently on the surface of the brain by using saline flush or sterile gel to allow sonic coupling of the transducer and brain surface.

The exact positioning of the transducer will depend on the location and size of the surgical opening in the skull. However, brain images should be obtained in at least 2 different planes. Do not agitate the saline solution by shaking it or by filling the brain case rapidly because this produces microbubbles in the solution that, throughout the fluid, produce numerous hyperechoic foci that can interfere with imaging if present in sufficient numbers.

将无菌套套在探头和探头线上。

用生理盐水填充脑缺口并通过液体成像，
或使用生理盐水冲洗或无菌凝胶将探头轻轻放置在脑部表面，
使探头与脑表面进行声波耦合。

探头的确切位置取决于颅骨手术开口的位置和大小。

然而，大脑图像应该至少在两个不同的平面上获取。

不要摇动盐水溶液或快速用盐水溶液填充脑腔隙，
因为这可能会在溶液中产生微气泡，
在整个液体中产生大量高回声灶，
如果存在足够数量的高回声灶，可能会干扰成像。

SAMPLE HANDLING

采样处置

N/A 无

APPROPRIATE AFTERCARE

恰当的后续护理

Postprocedure Patient Monitoring
检查后病患监测

None 无

Nursing Care 一般护理

Clean acoustic gel from the skin surface following the procedure.

检查结束后，清理皮肤表面的超声耦合凝胶。

Dietary Modification 饮食改良

None 无

Medication Requirements 药物需求

None 无

Restrictions on Activity 活动限制

None 无

Anticipated Recovery Time 可能得恢复时间

Immediate 立即

INTERPRETATION 判读

NORMAL FINDINGS OR RANGE

正常发现或正常范围

 The normal brain tissue is relatively hypoechoic, with some echogenic surfaces are observable that reveal the brain anatomy.

 The lateral ventricles should be observed as anechoic fluid filled structures in both hemispheres and can be imaged in both the trans- verse and the sagittal planes.

 The normal ultrasound anatomy of the brain has been described (see Hudson et al. 1989).

 Normal lateral ventricular height measured caudal to the interthalamic adhesion has a normal mean of 0.15 cm.

正常脑组织的回声相对较低，可以观察到一些产回声表面，显示大脑解剖结构。

侧脑室可被观察为双侧大脑半球充满无回声液体的结构，
可在横断面和矢状面成像看到。

脑部的正常超声解剖已经有描述过（见Hudson et al. 1989）。

在丘脑间连结后侧测得的正常侧脑室的高度的平均值为0.15 cm。

ABNORMAL VALUES

异常值

Hydrocephalus is considered present if the height of the lateral ventricules measured caudal to the interthalamic adhesion is >0.35 cm.

如果丘脑间连结处后侧的侧脑室高度测得 >0.35 cm，
则认为存在脑积水。

A ventricle/mantle ratio of >0.25 indicates hydrocephalus. The height of the lateral ventricle measured caudal to the interthalamic adhesion is divided by the cerebral mantle thickness at the same level. The cerebral mantle thickness is measured from the roof of the lateral ventricle to the dorsal brain surface.

脑室/脑幔比值（ventricle/mantle ratio）为>0.25提示脑积水。

侧脑室的高度需要在丘脑间连结的后侧进行测量，
除以在同一水平面上的脑幔厚度（cerebral mantle thickness）。

脑幔厚度是从侧脑室顶部到脑背侧表面测量的。

 A ventricle/hemisphere ratio of >0.19 indicates hydrocephalus.

侧脑室/大脑半球比值为>0.19时，
提示脑积水。

The width of the lateral ventricle is divided by the hemispheric width measured from the third ventricle (midline) to the lateral surface of the brain.

侧脑室的宽度，除以，从第三脑室(中线)到大脑外侧表面的大脑半球宽度。

 The sizes of the lateral ventricles in hydrocephalus do not correlate well with clinical signs, with some patients having occult hydrocephalus (no clinical signs).

脑积水的侧脑室的大小与临床症状没有很好的相关性，
某些病患有隐匿性脑积水（occult hydrocephalus ）(无临床症状)。

 Most brain neoplasms appear as echogenic or mixed echogenic and hypoechoic masses in the relatively hypoechoic brain tissue.

大多数脑肿瘤在相对低回声的脑组织中，
表现为产回声（echogenic）或混合回声（mixed echogenic ）和低回声（hypoechoic）肿块。

 The sonographic appearance of abscesses and hemorrhage varies, depending on the age of the lesion.

脓肿和出血的超声图像，
表现因病变的时间长短而异。

 Fluid with swirling echogenic material may indicate an exudate or hemorrhage. However, some cerebrospinal fluid in the ventricles may have sufficient protein content to show swirling material in the fluid. A sample of the fluid must be obtained for definitive diagnosis.

带有旋流样产回声物质的液体可能提示渗出或出血。

然而，
脑室中的一些脑脊液可能含有足够多的蛋白质含量，
从而使得液体中的显现存在旋流物质。

为了明确诊断，建议必须采集相关液体样本。

CRITICAL VALUES 临界值

None 无

INTERFERING FACTORS 干扰因素

Drugs That May Alter Results of the Procedure

可能影响检查结果的药物

None 无

Conditions That May Interfere with Performing the Procedure

可能影响检查操作的状况

A closed bregmatic fontanel, small foramen magnum, or thick bone in the temporal window requires surgical removal of bone to provide an acoustic window in order to image the brain. In these cases, it is advisable to consider alternative imaging such as CT or MRI to evaluate the brain.

已经闭合的囟门、枕骨大孔太小，或者颞窗的颅骨太厚，
那么就需要手术切除部分颅骨，以提供脑成像的声窗。

在这些情况下，
最好考虑使用CT或MRI等替代成像来评估大脑。

Procedure Techniques or Handling That May Alter Results

可能改变结果的检查、技术或处理

Artifact and acoustic shadowing from a very small opening in the skull or the use of a linear array transducer may not provide a sufficient image to reasonably assess the condition of the brain.

从颅骨非常小的开口或使用线性阵列探头产生的伪影和声影可能无法提供足够好的图像来合理评估大脑的状况。

Influence of Signalment on Performing and Interpreting the Procedure

动物特征对检查执行和判读的影响

Species 物种

None无

Breed 品种

Brachycephalic breeds may have slightly larger lateral ventricles without clinical signs as a breed variation.

短头品种可能有稍大一些的侧脑室，但没有临床症状，
这是一种品种相关变异。

Age 年龄

The brain of mature dogs and cats with a closed fontanel cannot be imaged by this means and must be imaged through the temporal window, through the foramen magnum, or by surgically removing a portion of the skull.

大多数成年犬猫的囟门已经闭合，
无法进行超声成像，
可以尝试通过颞窗，通过枕骨大孔，或通过手术切除一部分颅骨来成像。

Gender 性别

None 无

Pregnancy 怀孕

None 无

CLINICAL PERSPECTIVE 临床意义

 Ultrasound is an easy, safe, and inexpensive means of evaluating the brain for hydrocephalus when an open bregmatic fontanel is present.

评估脑积水时，
当存在开放的未闭合的囟门时，
超声是一种简单、安全、廉价的方法。

 The lateral ventricular size does not always correlate with clinical signs in mild to moderate enlargement.

侧脑室大小在轻度至中度扩张时，
并不总是与临床症状相关。

 CT and MRI are the techniques of choice for presurgical imaging of the brain for most diseases except as stated previously for hydrocephalus.

除了前面提到的脑积水外，
CT和MRI是大多数疾病术前脑成像的首选技术。

 Ultrasound can be very useful intraoperatively for locating lesions in the brain. However, surgery of the brain requires specialized training and knowledge in neurosurgery and is usually best referred to a specialist to provide the optimal outcome for patients.

术中超声对脑部病变的定位非常有用。

然而，
脑部手术需要神经外科方面的专业培训和知识，
通常最好转诊给专科医生，
为病患提供最佳结果。

MISCELLANEOUS 其他

ANCILLARY TESTS 附加检查

A thorough neurologic examination is required to correlate with ultrasound findings.

需要全面的神经系统检查，
再与超声检查结果相关联。

SYNONYMS 同义词

 Cranial ultrasound 颅内超声
 Transcranial ultrasound 经颅超声

SEE ALSO

Blackwell’s Five-Minute Veterinary Consult: Canine and Feline Topics
Hydrocephalus

Related Topics in this Book

 General Principles of Ultrasonography
  Computed Tomography
 Magnetic Resonance Imaging

ABBREVIATIONS 缩写

 CT = computed tomography 计算机断层扫描
 MRI = magnetic resonance imaging 磁共振成像

Suggested Reading 推荐阅读

- Hudson JA, Cartee RE, Simpson ST, et al. Ultrasonographic anatomy of the canine brain. Vet Radiol 1989; 30: 13–21.

- Hudson JA, Simpson ST, Buxton DF, et al. Ultrasonographic diagno- sis of canine hydrocephalus. Vet Radiol 1990; 31: 50–58.

- Saito M, Olby NJ, Spaulding KA, et al. Identification of arachnoid cysts in the quadrigeminal cistern using ultrasonography. Vet Radiol2001; 42: 435–439.

- Saito M, Olby NJ, Spaulding KA, et al. Relationship among basilar artery resistance index, degree of ventriculomegaly, and clinical signs in hydrocephalic dogs. Vet Radiol 2003; 44: 687–694.

- Spaulding KA, Sharp NJH. Ultrasonographic imaging of the lateral cerebral ventricles in the dog. Vet Radiol 1990; 31: 59–64.

INTERNET RESOURCES 网络资源

None 无

AUTHOR NAME 作者名字

George A. Henry

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