Jani J, Peralta C F A, Van Schoubroeck D, Deprest J, Nicolaides K H
University Hospital Gasthuisberg, Leuven, Belgium.
Ultrasound Obstet Gynecol. 2006 May;27(5):545-50. doi: 10.1002/uog.2735.
To examine the relationship between the fetal lung area and lung area to head circumference ratio (LHR) and lung volume by three-dimensional (3D) ultrasonography in normal fetuses and in fetuses with unilateral congenital diaphragmatic hernia (CDH).
In 64 fetuses with CDH at median 26 (range, 20-32) weeks of gestation the contralateral lung volume, lung area and LHR were measured and the values were compared to those of 650 normal fetuses at 12-32 weeks. In the normal fetuses both lungs were assessed but in the 64 fetuses with CDH only the contralateral lung was measured because the ipsilateral lung could be visualized adequately in only 40 (62.5%) of the cases. Regression analysis was used to assess the significance of the association between lung volume and lung area or LHR. In the fetuses with CDH, the observed to expected ratios for lung area and LHR were calculated. The expected lung area and LHR were the normal median for a given lung volume. The significance of the differences between the observed to expected lung area and LHR in fetuses with CDH and normal fetuses was determined. In the 64 fetuses with CDH and in 64 normal fetuses, matched for gestational age, the lung length between the apex and the superior aspect of the diaphragm dome was also recorded.
In normal fetuses the median lung area and LHR in both the left and right lungs increased significantly with lung volume. In the fetuses with CDH, the lung area and lung volume for gestation were substantially lower than in normal fetuses and the ratios of observed to expected lung area and LHR for a given lung volume were significantly lower than the respective values in normal fetuses. Additionally, the mean lung length was 13% greater and the mean lung area was 44% smaller than the respective values in the normal controls matched for gestational age.
The finding of a significant association between LHR and lung volume has validated the use of LHR in the assessment of lung growth. However, the study has also demonstrated that in fetuses with CDH, LHR underestimates the actual lung volume, because the herniated viscera cause a greater lateral, rather than vertical, compression of the contralateral lung.
通过三维超声检查，研究正常胎儿及单侧先天性膈疝（CDH）胎儿的肺面积、肺面积与头围比值（LHR）和肺容积之间的关系。
对64例孕26周（范围20 - 32周）中位孕周的CDH胎儿，测量其对侧肺容积、肺面积和LHR，并将这些值与650例12 - 32周正常胎儿的值进行比较。在正常胎儿中评估双侧肺，但在64例CDH胎儿中仅测量对侧肺，因为仅在40例（62.5%）病例中患侧肺能得到充分显示。采用回归分析评估肺容积与肺面积或LHR之间关联的显著性。在CDH胎儿中，计算肺面积和LHR的观察值与预期值之比。预期肺面积和LHR为给定肺容积的正常中位数。确定CDH胎儿与正常胎儿的肺面积和LHR观察值与预期值差异的显著性。在64例CDH胎儿及64例孕周匹配的正常胎儿中，记录从肺尖到膈顶上方的肺长度。
在正常胎儿中，左右肺的肺面积中位数和LHR均随肺容积显著增加。在CDH胎儿中，其孕周对应的肺面积和肺容积显著低于正常胎儿，给定肺容积下的肺面积和LHR观察值与预期值之比显著低于正常胎儿的相应值。此外，与孕周匹配的正常对照组相比，平均肺长度大13%，平均肺面积小44%。
LHR与肺容积之间存在显著关联这一发现验证了LHR在评估肺生长中的应用。然而，该研究还表明，在CDH胎儿中，LHR低估了实际肺容积，因为疝入的内脏对患侧肺造成更大的横向而非纵向压迫。
