Bilateral Pulmonary Sequestration in a Preterm Infant

Usefulness of prenatal magnetic resonance imaging in differential diagnosis of fetal congenital cystic adenomatoid malformation and bronchopulmonary sequestration

BACKGROUND

Congenital cystic adenomatoid malformation (CCAM) and bronchopulmonary sequestration (BPS) are the most common lung diseases in fetuses. There are differences in the prognosis and treatment of CCAM and BPS, and the clinical diagnosis and treatment plan is usually prepared prior to birth. Therefore, it is quite necessary to make a clear diagnosis before delivery. CCAM and BPS have similar imaging features, and the differentiation mainly relies on the difference in supply vessels. However, it is hard to distinguish them due to invisible supplying vessels on some images.

AIM

To explore the application value of magnetic resonance imaging (MRI) in the differential diagnosis of fetal CCAM and BPS.

METHODS

Data analysis for 32 fetuses with CCAM and 14 with BPS diagnosed by prenatal MRI at Huzhou Maternal and Child Health Care Hospital and Anhui Provincial Children’s Hospital from January 2017 to January 2020 was performed to observe the source blood vessels of lesions and their direction. Pathological confirmation was completed through CT examination and/or operations after birth.

RESULTS

After birth, 31 cases after birth were confirmed to be CCAM, and 15 were confirmed to be BPS. The CCAM group consisted of 21 macrocystic cases and 10 microcystic cases. In 18 cases, blood vessels were visible in lesions. Blood supply of the pulmonary artery could be traced in eight cases, and in 10 cases, only vessels running from the midline to the lateral down direction were observed. No lesions were found in four macrocystic cases and one microcystic case with CCAM through CT after birth; two were misdiagnosed by MRI, and three were misdiagnosed by prenatal ultrasonography. The BPS group consisted of 12 intralobar cases and three extralobar cases. Blood vessels were visible in lesions of nine cases, in four of which, the systemic circulation blood supply could be traced, and in five of which, only vessels running from the midline to the lateral up direction were observed. Three were misdiagnosed by MRI, and four were misdiagnosed by prenatal ultrasonography.

CONCLUSION

CCAM and BPS can be clearly diagnosed based on the origin of blood vessels, and correct diagnosis can be made according to the difference in the direction of the blood vessels, but it is hard distinguish microcystic CCAM and BPS without supplying vessels. In some CCAM cases, mainly the macrocystic ones, the lesions may disappear after birth.

Congenital Cystic Adenomatoid Malformation Volume Ratio in Prenatal Assessment of Prognosis of Fetal Pulmonary Sequestrations

This study aimed to evaluate the prognosis of pulmonary sequestration (PS) by measuring congenital cystic adenomatoid malformation volume ratio (CVR) value in fetal congenital PS. The fetal CVR in 49 cases of fetal PS diagnosed by prenatal ultrasound in Xiangyang No. 1 People's Hospital from March 2010 to June 2017 were measured, and the clinical outcomes were observed. According to the prenatal ultrasound CVR value, 49 fetuses diagnosed with PS were divided into 2 groups: group 1 with CVR≥1.26, and group 2 with CVR<1.26. The incidence rate of fetal edema, respiratory distress symptoms and survival rate were compared between the two groups. The risk factors of the fetal PS were evaluated by single and multiple Logistic regression analysis. The correlation between CVR and fetal prognosis was analyzed. Of the 49 fetuses, there were 34 cases of PS (ILS) type (69.39%, 34/49), 10 cases of PS (ELS) type I (20.41%, 10/49) and 5 cases of PS (ELS) type II (10.20%, 5/49). Forty-six cases (93.88%, 46/49) were born alive, there was 1 case (CVR ≥1.26) (2.04%, 1/49) of induced abortion, and 2 cases (CVR ≥1.26) (4.08%, 2/49) of stillbirths. In group 1 (n=24), 21 cases were born alive, and the incidence rate of newborn respiratory distress and fetal edema was 100% (21/21) and 79.17% (19/24) respectively. In group 2 (n=25), there were 3 cases (12%,3/25) of newborn respiratory distress, 3 cases (12%, 3/25) of fetal edema, and the rate of live birth was 100%. There were statistically significant differences between the two groups in the incidence of fetal edema, postpartum respiratory symptoms and survival rate. CVR was a risk factor for PS and was associated with fetal prognosis. CVR in the midtrimester of pregnancy is an effective index to evaluate the prognosis of fetal PS. CVR ≥1.26 is associated with an increased risk of fetal edema, infant respiratory distress and intrauterine or postnatal death.