Hypoplastic left heart syndrome and the nutmeg lung pattern in utero: a cause and effect relationship or prognostic indicator?

Abstract

The nutmeg lung MR appearance in HLHS fetuses is associated with increased mortality/OHT (100% in the first 5 months of life compared to 35% with HLHS alone). Not all patients with restrictive lesions develop nutmeg lung, and outcome is not as poor when restriction is present in isolation. Dedicated evaluation for nutmeg lung pattern on fetal MR studies may be useful to guide prognostication and aid clinicians in counseling parents of fetuses with HLHS.

MR imaging of the fetal heart

“…For example, in the rhabdomyoma case described, dedicated fetal brain sequences revealed multiple cerebral masses, as are typically seen in tuberous sclerosis. Additional information regarding lung pathology, such as in the setting of pulmonary venous obstruction (pulmonary lymphangiectasia) or tetralogy with absent pulmonary valve (airway compression), may be very relevant in clinical decision‐making …”

“…Additional information regarding lung pathology, such as in the setting of pulmonary venous obstruction (pulmonary lymphangiectasia) or tetralogy with absent pulmonary valve (airway compression), may be very relevant in clinical decision-making. [45][46][47][48][49] As yet, the prognostic value of fetal lung volume measured by MRI in conditions such as Ebstein Anomaly has not yet been proven, but with semiautomated methods to acquire these data its value may become clear.…”

Fetal echocardiography for planning perinatal and delivery room care of neonates with congenital heart disease

“…87 Several studies have shown that fetal MRI provides information regarding cerebral structural findings and changes in brain metabolism in fetuses with specific CHD that may affect the postnatal prognosis. 74,75,90 In fetuses with HLHS, abnormal lung parenchyma described as "nutmeg lung" was found to be representative of abnormal pulmonary lymphatics 91 ( Figure 10). 74,75,90 In fetuses with HLHS, abnormal lung parenchyma described as "nutmeg lung" was found to be representative of abnormal pulmonary lymphatics 91 ( Figure 10).…”

“…74,75,90 In fetuses with HLHS, abnormal lung parenchyma described as "nutmeg lung" was found to be representative of abnormal pulmonary lymphatics 91 ( Figure 10). 90 Tetralogy of Fallot with APV fetuses with significant airway obstruction and congenital lobar emphysema is at increased risk of severe hypoxia at birth 71 ( Figure 11). 91,92 In a recent study, fetuses with HLHS and MRI findings suggesting "nutmeg lung" in the third trimester had higher mortality and higher incidence of RAS or IAS compared to the group of HLHS without these findings.…”

“…18,88,89 Recently, fetal MRI has also been proposed to assess the lung parenchyma in fetuses diagnosed with complex CHD such as HLHS or TOF with absent pulmonary valve. 74,75,90 In fetuses with HLHS, abnormal lung parenchyma described as "nutmeg lung" was found to be representative of abnormal pulmonary lymphatics 91 (Figure 10). Dilated lymphatics can be primary, due to abnormal development of the pulmonary lymphatic system or can be secondary to obstruction to pulmonary venous flow due to CHD such as HLHS or TAPVR.…”