Echogenic and Cystic Fetal Lung Lesions: Evaluation by Prenatal Sonography and Postnatal Imaging

Abstract

Objectives: We set out to review our unit’s experience in evaluating fetal lung lesions and the accuracy of prenatal diagnosis, and to illustrate the prenatal sonographic and postnatal radiological features of detected lesions. Methods: Retrospective review of women whose fetuses were diagnosed with echogenic and / or cystic lung lesions in our institution. Their prenatal ultrasound, postnatal radiological, clinical, and histological data were retrieved for appraisal. Results: In a 3-year period, 24 patients were referred to our unit with a cystic and / or echogenic fetal lung lesion. Of the 18 cases confirmed surgically and / or histologically, 15 were correctly diagnosed by prenatal ultrasound, with congruent postnatal radiological diagnosis. Of those misdiagnosed on prenatal ultrasound, postnatal imaging provided the correct diagnoses in most cases. Prenatal sonograms and postnatal images were reviewed in parallel for various congenital entities, with special attention to the cases misdiagnosed on imaging grounds. Fetal lung lesions were receded from view on prenatal ultrasound in later gestation in four cases. Their postnatal imaging findings were all abnormal. Conclusion: Through appreciating the spectrum of imaging appearances of fetal lung lesions, which can be very similar, and acknowledging diagnostic pitfalls, we hope to refine diagnostic imaging accuracy. This could facilitate optimal prenatal counselling and postnatal management planning. Diagnoses made with prenatal ultrasound in our unit were correct in the majority of fetuses in this study. In-utero regression of fetal lung lesions in the course of prenatal ultrasounds may not indicate genuine resolution. Discrepancies in diagnoses gleaned from prenatal ultrasounds and postnatal imaging have been observed. Postnatal imaging should therefore be considered in all cases for confirmation and management planning.

目的：回顧本部門評估胎兒肺病變的經驗，包括產前診斷的準確度；並說明探測到的病變的產前超 聲和產後放射學影像特徵。 方法：回顧本院發現有胎兒肺回聲異常和/或囊性肺病變的產婦紀錄；收集並評估她們的產前超聲、 產後放射學影像、臨床及組織學資料。

結果：3年內共24名因發現有胎兒肺囊性和/或回聲異常病變的產婦轉介至本部門。憑手術及／或組 織學檢查而被確認診斷的18例中，15例是憑著產前超聲作出正確診斷，結果與產後放射學檢查一 致。產前超聲誤診的病例中，多數由產後放射學影像提供了正確診斷。針對各種先天性病患，同時 回顧了產前超聲圖和產後放射圖像，並特別留意誤診病例。在妊娠後期的產前超聲檢查中，發現4例 胎兒的肺部病變有緩解的跡象。他們出生後的影像學檢查結果均屬異常。

結論：：通過檢視胎兒肺部病變的不同影像（它們可表現得非常相似），可以確認診斷誤區，從而改 善影像診斷的準確性。這樣有利於進行最佳的產前諮詢和產後治療規劃。本研究中大多數胎兒的產 前超聲檢查都診斷正確。但在產前超聲檢查過程中發現的胎兒肺部病變於子宮內消退的現象只是表 面上的，不代表疾病真正消失。由產前超聲和產後放射影像分別獲得的診斷也會存在差異。因此任 何病例都應進行產後放射學檢查以確認診斷和規劃治療。