Mong Andrew, Johnson Ann M, Kramer Sandra S, Coleman Beverly G, Hedrick Holly L, Kreiger Portia, Flake Alan, Johnson Mark, Wilson R Douglas, Adzick N Scott, Jaramillo Diego
Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Pediatr Radiol. 2008 Nov;38(11):1171-9. doi: 10.1007/s00247-008-0962-2. Epub 2008 Aug 13.
Congenital high airway obstruction syndrome (CHAOS) is a rare disorder defined as any fetal abnormality that obstructs the larynx or trachea. Prompt airway intervention at delivery after accurate prenatal diagnosis may allow survival of this otherwise fatal condition.
To identify prenatal MRI findings in CHAOS, to compare these findings with those of fetal US, to determine if imaging alters diagnosis and management decisions, and to correlate prenatal with postnatal imaging findings.
Records and MRI scans of ten fetuses with CHAOS were reviewed, and the findings correlated with outside and same-day fetal US and postnatal imaging findings. Fetal lung volumes were measured on MRI scans.
Large lung volumes were found in 90% of the fetuses. Increased lung signal intensity, inverted diaphragm, and a dilated, fluid-filled lower airway were identified in all. The obstruction level was identified in 90%. MRI changed screening US diagnosis in 70%, but was concordant with the tertiary care US imaging in 90%. Seven fetuses were terminated or died in utero, and three fetuses survived after ex utero intrapartum tracheostomy placement. Autopsy or bronchoscopy performed in 60% confirmed CHAOS. Postnatal chest radiographs and CT showed hyperinflation, while US and fluoroscopy showed diminished diaphragmatic motion.
MRI demonstrates large lung volumes, increased lung signal intensity, inverted diaphragm, and dilated fluid-filled lower airway, and usually identifies the obstruction level. The degree of correlation between MRI and tertiary prenatal US is high, but CHAOS is frequently misdiagnosed on screening US. Correct diagnosis may enable planned airway management. Voluminous lungs and diaphragmatic abnormalities persist on postnatal imaging.
先天性高气道梗阻综合征（CHAOS）是一种罕见疾病，定义为任何阻塞喉部或气管的胎儿异常。在准确的产前诊断后，分娩时及时进行气道干预可能使这种原本致命的疾病得以存活。
识别CHAOS的产前MRI表现，将这些表现与胎儿超声的表现进行比较，确定影像学检查是否改变诊断和管理决策，并将产前影像学表现与产后影像学表现相关联。
回顾了10例CHAOS胎儿的记录和MRI扫描结果，并将这些结果与外部及同日胎儿超声和产后影像学结果进行关联。在MRI扫描上测量胎儿肺容积。
90%的胎儿发现肺容积增大。所有胎儿均发现肺信号强度增加、膈肌倒置以及下气道扩张且充满液体。90%的病例确定了梗阻水平。MRI改变了70%的筛查超声诊断，但与三级医疗超声成像的一致性为90%。7例胎儿在宫内终止妊娠或死亡，3例胎儿在宫外产时气管造口术后存活。60%的病例进行了尸检或支气管镜检查，证实为CHAOS。产后胸部X线片和CT显示肺过度充气，而超声和荧光透视显示膈肌运动减弱。
MRI显示肺容积增大、肺信号强度增加、膈肌倒置以及扩张且充满液体的下气道，并且通常能确定梗阻水平。MRI与三级产前超声之间的相关性程度较高，但CHAOS在筛查超声上经常被误诊。正确的诊断可能有助于进行计划性气道管理。产后影像学检查显示肺容积增大和膈肌异常持续存在。
