儿童急腹症的超声检查文献综述.doc

Sonography of the Surgical Abdomen in ChildrenKEYWORDS Adolescents Appendicitis Malrotation UltrasoundWith the introduction of the graded-compression sonographic technique and continued advances in ultrasound technology, the use of sonography has increased in the evaluation of the child who has a suspected surgical abdomen. The principalrole of sonography is to characterize the nature of the many conditions associated with acute abdominal symptoms and signs and to differentiate between those requiring urgent surgical intervention and those that do not. This article reviewsthe sonographic evaluation of common important surgical conditions of the abdomen in children. Indications for performing sonography, sonographic features of common lesions, and the sonographic techniques best suited to making a diagnosis areaddressed. 儿童急腹症的超声检查关键词 青少年 阑尾炎 旋转不良 超声随着分级加压超声检查技术的介绍及超声技术的不断前进，超声在评价可疑有急腹症的儿童中的作用已逐步增加。超声的首要角色是表示出那些与急腹症状及征象有关的情况的本质特征，并且区分出哪些需要外科手术及哪些不需要外科手术。本文对儿童腹部普通的而又重要的具有外科条件的超声评价进行了综述。超声应用的指征，普通病变的超声特征及用于诊断的最佳超声技术均在本文提及。ULTRASOUNDTECHNIQUESKnowledge of the patients symptoms, physical findings, and laboratory data is important to focus the examination and increase the likelihood of a correct diagnosis. If the pain is located in the right upper quadrant, the sonogram should focus on the liver, gallbladder, biliary ducts, pancreas, and right kidney. If the pain is in the right lower quadrant, the appendix, small bowel, and pelvicorgans should be interrogated in detail. These distinctions are somewhat artificial, but they can serve as a guideline to investigating acute abdominalpain in children. When the pain is in other locations, the examination should be tailored to these areas.超声技术掌握病人的症状，体格检查及实验室数据是很重要的，可以集中在检查点并提高正确检查的可能性。如果疼痛位于右上腹部，超声图像应集中看肝，胆囊，胆管，胰腺和右肾。如果疼痛位于右下腹部，盲肠，小肠和骨盆器官应该详细检查。这些区分多少有点是人工假设的，但能够在检查儿童急腹症疼痛中充当一个准则。如果疼痛位于其他位置，检查也要相应的置于这些特定区域。Graded-Compression SonographyThe graded compression technique is used in the evaluation of suspected appendicitis, acute bowel diseases, and mesenteric adenitis.1,2 A linear- orcurved-array transducer (5 or 7.5 MHz) is used to compress the right lower quadrant gradually. Gentle, gradual pressure is applied to the anterior abdominal wall, resulting in displacement and compression of normal bowel loops. At the startof the examination, the patient is asked to point with a single finger to the site of maximal tenderness or pain.3 This localization expedites the search for an inflamed appendix, especially an aberrantly located appendix, and reduces the time of the examination.分级加压超声检查法分级加压检查技术被用来评价可疑阑尾炎，急性肠道疾病及肠系膜淋巴结炎。线阵的或扇形的探头用来逐步加压右下腹部。轻轻的逐步的压力作用于前腹壁可导致正常肠袢的位置移动和受压。检查开始，要让病人用单个手指指出压痛或疼痛最大的点。这种定位可以加速派遣向阑尾炎症的扫查，尤其是位置异常的阑尾，可以缩短检查时间。Scanning begins in the transverse plane with identification of the ascending colon, which appears as a nonperistaltic structure containing gas and fluid. The transducer then is moved inferiorly to identify the cecal tip, where the appendix should arise. Pressure is applied gradually to the cecal tip, which displaces gas and fecal material from the cecum and enhances visualization of the appendixand distal small bowel. The normal terminal ileum is easily compressible and displays active peristalsis. The psoas muscle and external iliac vessels should be identified also, because the appendix lies anteriorly to these structures. Gray-scale and color Doppler images are acquired.扫查以鉴定升结肠的切面开始，升结肠是以包含有气体及液体的不蠕动的结构出现。然后探头向下移向盲肠尖端，这里可能有阑尾出现。逐步向盲肠尖端加压，可以将来自盲肠的气体和粪便类物质赶走并加强阑尾和远端小肠的显示效果。正常的回肠末端是容易压缩的并能够展示活跃的蠕动。腰肌和髂外血管应该能够鉴别出，因为阑尾就位于这些结构的前面。要获取灰阶及彩色多普勒图像。Pelvic SonographySonographic assessment of pelvic pathology in children is performed with a transabdominal approach using a distended urinary bladder as the acoustic window. The distended bladder displaces gas-filled bowel loops out of the pelvis,allowing transmission of sound into deeper structures of the pelvis and easier visualization of the ovaries and uterus. In most children adequate bladder filling can be achieved with oral intake of fluid. Bladder catheterization with instillation of sterile fluid may be required if the patient is unable to tolerate large fluid volumes orally. In some instances, placing the patient in a decubitus position and scanning directly over the adnexa will improve visualization of the ovaries. Pelvic sonography is performed with a sector or curved-array transducer.Scans of the pelvic organs are obtained in both the sagittal and transverse planes. Grayscale and color Doppler images are acquired.4骨盆的超声检查儿童骨盆病理学的超声评估是利用膨胀的膀胱作为透声窗进行经腹检查来完成的。膨胀的膀胱可以赶走位于盆腔的充满气体的肠道，从而使得超声可以透射盆腔更深的结构同时使卵巢和子宫更易显示。大部分儿童的膀胱适度充盈通过口服液体即可完成。如果患儿不能忍受口服大量液体，可以通过膀胱导尿术灌注消毒的液体。在有些情况下，让病人卧位并且直接扫查附件位置可以提高卵巢的显示效果。骨盆的超声检查是用扇形或弯曲排列的探头完成的。骨盆器官的扫查可以通过纵切及横切面获得。要获取灰阶及彩色多普勒图像。Endovaginal sonography is an alternative technique in pubertal females who use tampons or who are sexually active. A major advantage of endovaginal over transabdominal scanning is the obviation of bladder filling. The major limitation of this technique is a limited field of view. Because of this problem, transabdominal sonography is used as the initial examination if the patient has not had a previous pelvic sonogram. An endovaginal study can be done if the transabdominal findings are indeterminate or confusing or to characterize ovarian and tubal pathology better.4对于用过填塞物或性生活活跃的青春期女性，阴道超声检查可以作为一个替代技术。阴道超声优于经腹超声的一个主要优点是避免充盈膀胱。这个技术的主要局限性是观察视野的受限。由于这个问题，经腹超声检查被用作检查以前没有做过骨盆超声检查的病人的首要方法。如果经腹的检查所见是不定的，困惑的或者要更好地表现卵巢和输卵管的病状可以应用经阴道超声来进行研究。SURGICAL ABDOMINALCONDITIONSThe most frequent disorders requiring acute surgical intervention in children are acute appendicitis and pyloric stenosis.611 Other conditions include malrotation, intussusception, and acute ovarian and scrotal disorders.16 The differential diagnosis often can be narrowed based on the patients age, the type and location of the pain, the presence or absence of other signs and symptoms, and pertinent laboratory data. Even when these factors are considered, it often is not possible to make a specific diagnosis, and imaging studies, such as sonography, are needed to ensure a correct diagnosis and prompt treatment.腹部的外科情况在儿童中最盛行的要求急性外科手术的疾病是急性阑尾炎和幽门狭窄。其他的情况包括旋转不良，消化问题，急性卵巢和阴囊的疾病。根据病人的年龄，疼痛的类型及定位，其他症状和体征的出现和消失以及病人的实验室数据可缩小鉴别诊断的范围。只要这些因素都考虑了，做出一个特异性的诊断并不是不可能的，研究图像，比如超声，对于做出正确的诊断及迅速的治疗也是必需的。MIDGUTMALROTATIONMalrotation is an urgent diagnosis in infants, particularly when there is associated midgut volvulus. 6 During fetal development, the duodenojejunal junction and the cecum undergo 270 rotation, resulting in retroperitoneal fixation of the duodenojejunal junction in the left upper quadrant at the ligament of Treitz and the cecum in the right lower quadrant. At the completion of rotation, the small bowel is suspended from a broad mesentery, which extends between the ligament of Treitz and the ileocecal valve. The term malrotation refers to a spectrum of incomplete rotation abnormalities,including failure of rotation (colon to the left, small bowel to the right), reverse nonrotation (small bowel to the left, colon to the right), and incomplete rotation (a range of abnormalities between nonrotation and normal rotation). In malrotation, the attachment of the bowel is abnormally short, resulting in a narrowed mesenteric pedicle and an abnormally positioned ligament of Treitz.旋转不良是婴儿的一个急症，尤其是伴有中肠旋转不良。在胚胎发育过程中，十二指肠空肠连接和盲肠要经历270度的旋转，导致两者在腹膜后固定，其中十二指肠空肠连接位于左上象限Treitz 悬韧带位置，盲肠位于右下象限。在旋转过程中，小肠是被宽大的肠系膜悬吊着，肠系膜可以在 Treitz 悬韧带和回盲瓣之间延伸。旋转不良一词涉及一系列旋转不良的异常情况，包括旋转失败（结肠位于左侧，小肠位于右侧），不转位但反位（小肠位于左侧，结肠位于右侧），以及旋转不全（不转位和正常旋转之间的一系列异常）。在旋转不良中，肠的附着异常的短，导致肠系膜蒂狭窄及Treitz悬韧带的异位。Patients who have incomplete rotation have a high frequency of duodenal obstruction caused by peritoneal bands (Ladd bands) extramurally compressing the duodenum, midgut volvulus, or a combination of these abnormalities. Ladd bands represent an attempt at fixation of the incompletely rotated bowel, and they obstruct the second and third portions of the duodenum as they pass from the alpositioned cecum to the posterior peritoneum or lateral abdominal wall. The more serious complication of midgut malrotation is volvulus, which predisposes a patient to bowel ischemia and infarction. Approximately 80% to 90% of patients who have malrotation present in the first month of life with vomiting, which nearly always is bilious. Older children can present with a malabsorption syndrome causedby mesenteric lymphatic stasis or with intermittent abdominal pain and vomiting from episodic volvulus.有旋转不良的病人会有频率极高的十二指肠梗阻，这是由腹壁外的十二指肠旁索带压迫十二指肠，中肠旋转不良或者这些异常问题的联合导致的。十二指肠旁索带代表着在不全旋转的肠的固定中的一种尝试，这些索带能够妨碍十二指肠的第二和第三部分在通过异位的盲肠时到达后腹膜或侧腹壁。中肠旋转不良的更严重的并发症是肠扭转，肠扭转能够使病人肠缺血和坏死。大约80%到90%有旋转不良的病人在生后一月内伴有呕吐，呕吐物几乎全是胆汁。大一点的孩子可以伴有由肠系膜淋巴管淤滞或周期性的腹痛和片段的肠扭转所致的呕吐所导致的吸收不良综合征。The upper gastrointestinal examination is the principal imaging study for evaluating an infant with bilious vomiting and suspected malrotation. If the significance of the bile-stained vomitus is not appreciated, however, a sonogram may be the first examination requested, and thus the radiologist should be familiar with the sonographic findings of malrotation. Normally, the origin of thesuperior mesenteric artery lies to the left of the superior mesenteric vein, just distal to its union with the splenic vein to form the portal vein and just caudal to the pancreas. Reversal of this relationship suggests midgut malrotation.12,13 The relationship between these two vessels is assessed best with transverse images, scanning above the pancreas and moving the transducer in a caudal direction. Spectral Doppler analysis is useful to confirm the relationship of the vessels (Fig. 1). Although vessel inversion is a sign of malrotation, this sign has limited sensitivity and specificity.14 Inversion of the mesenteric vesselshas been noted in 53% to 87% of children who have midgut malrotation; conversely, the prevalence of malrotation with vessel inversion has ranged from 6% to 100%.12,13 The accuracy of sonography does not warrant its use as the primary imaging study to diagnose or exclude the presence of malrotation, and the upper gastrointestinal series remains the study of choice for diagnosing this abnormality.对于评估有胆汁性呕吐和可疑旋转不良的婴儿来说上胃肠道的检查是首要的图像研究法。如果具有胆汁颜色的呕吐物的重要性不被重视，超声显像应该是首要检查，同时放射科医生应该熟悉旋转不良的超声检查所见。通常肠系膜上动脉的起源位于肠系膜上静脉的左侧，位于肠系膜上静脉与脾静脉组成门静脉的联合的远端，位于胰腺的尾端。这种关系的颠倒提示中肠旋转不良。这两个血管之间的关系最好是用横切面图像评价，在胰腺上方扫查并将探头移向尾侧。在确定血管之间关系上频谱多普勒分析是很有用的（图1）。尽管血管倒置是旋转不良的一个标志，但这个标志具有有限的敏感性和特异性。肠系膜血管旋转不良在有中肠旋转不良的儿童中被记录有53%-87%，相反，旋转不良伴有血管倒置的流行其范围在6%-100%不等。超声检查的精确性并不能保证其应用是作为诊断或排除旋转不良的主要研究图像，上胃肠道系统是作为诊断这些异常的研究选择。In volvulus, the midgut rotates around the axis of the superior mesenteric artery. The sonographic finding of volvulus is clockwise twisting of the superior mesenteric vein about the axis of the artery. This appearance has been termed the whirlpool sign.15,16 Other sonographic findings of volvulus include a distended duodenum with a beak-like termination, peritoneal fluid, and thickened echogenic bowel wall from hemorrhage or edema.在肠扭转中，中肠以肠系膜上动脉为轴旋转。肠扭转的声像图所见是肠系膜上静脉围绕动脉的轴作顺时针扭动。这种表现被称作“涡流”标志。肠扭转的其他声像图所见包括扩张的十二指肠伴一个鸟嘴状的终点，腹膜液，以及来自出血或水肿的增厚的肠壁回声。Fig. 1. Malrotation. (A) Transverse view through the upper abdomen demonstrates the superior mesenteric artery (A) lying to the right of superior mesenteric vein (V). ( Spectral Doppler view shows venous waveform in the left-sided vessel which is the superior mesenteric vein. The arrow indicates the superior mesentericartery.图1 旋转不良 （A）穿过上腹部的横轴位显示肠系膜上动脉（A）位于肠系膜上静脉的右侧（B）。（B）多普勒频谱图表示位于左侧的肠系膜上静脉的静脉频谱。箭头指肠系膜上动脉。 PYLORIC STENOSISPyloric stenosis is the most common surgical condition in infants, with an incidence of 2 to 5 cases per 1000 births per year. Patients range in age from 1 week to 12 weeks, with most patients presenting between 4 and 8 weeks of age.17 Thecause of pyloric stenosis remains unknown, but one proposed theory is increased production of gastrin or cholecystokinin, which results in pylorospasm and hypertrophy. Other theories include vagal overstimulation or an underlying abnormality in the submucosal nerve fibers. Patients typically present with recent onset of forceful nonbilious vomiting, typically described as projectile. Other findings include weight loss, hypochloremic alkalosis, and hematemesis. The classic finding on physical examination is an olive-shaped mass in the epigastrium.幽门狭窄幽门狭窄是在婴儿中最常见的外科情况，每年的发病率是每1000个出生的孩子中有2-5个。病人的年龄范围是从1周到12周，大部分病人出现在4到8周。幽门狭窄的病因尚不清楚，但有一个被提议的理论是不断增加的促胃液素或胆囊收缩素的分泌，能导致幽门痉挛和肥厚。其他理论包括迷走神经的过刺激或潜在的粘膜下神经纤维的异常。典型的病人表现为近期强有力的非胆汁性呕吐的开始，被典型地描述为“发射物”。其他检查所见包括体重减轻，低氯血的碱中毒和呕血。体格检查的典型发现是在上腹部有橄榄形的肿块。Sonographic evaluation for pyloric stenosis requires the use of a large-footprint linear transducer operating at a frequency between 5 and 10 MHz, depending on the size of the patient and the distension of the stomach.17,18 A fluid-filled stomachis needed for an optimal examination. Gravity is used to direct the flow of fluid within the stomach as needed during the examination. Scanning is begun with the transducer placed over the stomach near the anteriorly placed antrum.超声评价幽门狭窄要求应用大面积的线阵探头并用5-10兆赫兹的频率操作，这取决于病人的大小和胃的扩张。需要充满液体的胃以达到最优的检查。在检查中也需要重力作用以指示液体在胃里的移动。扫查以探头放在胃上近前面幽门窦的位置开始。Sonographic findings of pyloric stenosis include a thickened, hypoechoic pyloric muscle and an elongated pyloric canal.17,18 In the short-axis view, the hypertrophic pyloric muscle has a target or bulls-eye appearance, reflecting the thickened hypoechoic muscle surrounding the central echogenic mucosa. On longitudinal views, the thickened muscle has a uniform hypoechoic appearance(Fig. 2). Measurements for the diagnosis of hypertrophic pyloric stenosis include muscle thickness of 3.0 mm or greater, channel length of 17 mm or greater, and a transverse serosal-toserosal diameter of 15 mm or greater (see Fig. 2). Additional findings include minimal or absent gastric emptying, exaggerated peristaltic waves that stop abruptly at the distal antrum, and esophageal reflux.幽门狭窄的声像图所见包括增厚的，回声减低的幽门肌肉和伸长的幽门管。在短轴观，肥厚的幽门肌肉表现为靶样或靶心样，是肥厚的幽门肌肉围绕中心的粘膜层的表现。在长轴观，增厚的肌肉有一个均匀一致的回声减低表现（图2）。诊断肥厚性幽门狭窄的测量方法包括肌肉厚度达3mm或更厚，幽门管道长度达17mm或更长，横切面幽门管径达15mm或更大（图2）。其他的发现包括最小限度的胃排空或缺乏，夸大的蠕动波突然在幽门窦停止。楼主没给图2，奉上俺最近的图片 Fig. 2. Pyloric stenosis. (A) Longitudinal view of the pylorus demonstrates a thickened pyloric muscle (between arrows), measuring 8 mm and an elongated pyloric channel (between calipers) measuring 27 mm. ( Axial section shows thickened muscle (calipers) surrounding echogenic central mucosa (arrow), creating a target or bulls-eye pattern.图2 幽门狭窄。（A）幽门长轴观显示增厚的幽门肌肉（箭头之间），测量是8mm，狭长的幽门管（测量键之间）测量为27mm。（B）轴向的断面提示增厚的肌肉（测量键之间）围绕中心有回声的粘膜层（箭头），产生“靶征”或“靶心征”。 The most reliable measurement of hypertrophic pyloric stenosis is muscle thickness. A thickness of 3 mm or more is diagnostic for pyloric stenosis with a sensitivity and specificity of nearly 100%.19 A muscle thickness less than 2.0 mm is unequivocally normal. A thickness between 2 and 2.9 mm is considered abnormal but nonspecific and can be seen in pylorospasm as well as in pyloric stenosis. Borderline muscle thickness measurements can occur in premature infants who have pyloric stenosis. The diagnosis in these infants is based on the thickness of the pyloric muscle, which is increased relative to the rest of the stomach and the length of the pyloric canal length.肥厚性幽门狭窄最可靠的测量方法是肌肉厚度。厚度达3mm或更多是幽门狭窄的诊断特征，其敏感性和特异性几乎为100%。正常肌肉厚度小于2mm。厚度在2mm和2.9mm之间被考虑为不正常但是非特异性的，且在幽门痉挛和幽门狭窄中均可看到。临界的肌肉厚度测量可发生在有幽门狭窄的早产儿。这些婴儿的诊断要基于幽门部肌肉的厚度，这些肌肉的厚度相对于胃部其他肌肉和幽门管的长度是增加的。PitfallsTwo important pitfalls are failure to visualize the pylorus because of gastric overdistention, which causes the pylorus to be displaced posteriorly, and pseudothickening of the pyloric muscle caused by decompression of the stomach.20 Ifthe stomach is overdistended, the pylorus may be displaced behind the stomach and difficult to visualize. Rotating the patient into the supine or left posterior oblique position allows fluid to move into the fundus and permits the pylorus to move anteriorly for adequate evaluation. Equivocal results can occur in infants in whom the pyloric antrum is collapsed. If the stomach is empty or incompletely distended by fluid, feeding the patient a glucose solution or water and positioning the patient in the right anterior oblique position can help distend the antrum and facilitate the diagnosis of a normal pylorus, with a normally distensible antropyloric segment adjacent to the duodenal cap.缺陷两种重要的缺陷是由于胃的过度充盈导致不能观察到幽门，胃的过度充盈可使幽门向后移位和胃的减压导致的幽门肌肉假增厚。如果胃过度充盈，幽门可能移向胃的后方而难于观察。旋转病人于旋后的或左后斜位可使液体移向胃底从而幽门移向前方以得到充分的评价。模棱两可的结果可发生在幽门窦萎陷的婴儿。如果胃是空的或不完全被液体扩张，喂病人一些葡萄糖溶液或水并置病人于右前斜位能帮助扩张幽门窦部并使正常幽门的诊断容易，可发现一个正常的扩张的幽门窦与十二指肠冠相邻。INTUSSUSCEPTIONIntussusception results when a segment of more proximal bowel (the intussusceptum) prolapses into a more distal segment (the intussuscipiens).11 It is the most common acute abdominal disorder of infancy and early childhood, typically affecting patients between 3 months and 3 years of age.11,22,23 The most common type of intussusception is ileocolic followed by ileoileal and colocolic. More than90% of intussusceptions have no pathologic lead points and are termed idiopathic. Idiopathic intussusceptions are believed to result from hypertrophy of lymphoid follicles in the terminal ileum following a viral infection, which subsequently results in increased bowel peristalsis and intussusception. Lead points are more common in children under the age of 3 months or over the age of 3 years. They include Meckels diverticulum, intestinal polyps, enteric duplications, intramural hematoma, and lymphoma.肠套叠当近段小肠的一个节段（肠套叠套入部）脱入远段（肠套叠鞘部）会发生肠套叠。这是婴儿期及幼童时期最常见的急腹症，典型地影响病人是在3月至3岁之间。最常见的肠套叠类型是回结肠型其次是回回肠型和结结肠型。大于90%的肠套叠没有病理学的原发病，被称作“特发性的”。特发性的