title: Hypoplastic left heart syndrome and the nutmeg lung pattern in utero: a cause and effect relationship or prognostic indicator?
abstract: BACKGROUND
  Hypoplastic left heart syndrome (HLHS) is the third most common cause of critical congenital heart disease in newborns, and one of the most challenging forms to treat. Secondary pulmonary lymphangiectasia has been recognized in association with HLHS, an appearance described on fetal MRI as the "nutmeg lung."
  
  
  OBJECTIVE
  To investigate the association of fetal nutmeg lung with HLHS survival.
  
  
  METHODS
  A retrospective search of the fetal MRI database was performed. The nutmeg lung pattern was defined as T2 heterogeneous signal with tubular structures radiating peripherally from the hila. Postnatal echocardiograms and charts were reviewed.
  
  
  RESULTS
  Forty-four fetal MR studies met inclusion criteria, of which 4 patients (9%) had the nutmeg lung pattern and 3 of whom also had restrictive lesions. Mortality in this nutmeg lung group was 100% by 5 months of age. Of the 40 patients without nutmeg lung, mortality/orthotopic heart transplant (OHT) was 35%. Of these 40 patients without nutmeg lung, 5 had restriction on echo, 3 of whom died/had OHT before 5 months of age (60% of patients with restriction and non-nutmeg lung). There was a significantly higher incidence of restrictive lesions (P = 0.02) and mortality/OHT (P = 0.02) in patients with nutmeg lung compared to those without.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Radiology Department, The Children's Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA, 10104, USA.
authors.forename: David
authors.initials: D
authors.lastname: Saul
authors.affiliation: Cardiac Center and Fetal Heart Program, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Karl
authors.initials: K
authors.lastname: Degenhardt
authors.affiliation: Center for Fetal Diagnosis and Treatment, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Suzanne D
authors.initials: SD
authors.lastname: Iyoob
authors.affiliation: Pathology Department, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Lea F
authors.initials: LF
authors.lastname: Surrey
authors.affiliation: Radiology Department, The Children's Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA, 10104, USA.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Johnson
authors.affiliation: Center for Fetal Diagnosis and Treatment, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Johnson
authors.affiliation: Cardiac Center and Fetal Heart Program, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Jack
authors.initials: J
authors.lastname: Rychik
authors.affiliation: Radiology Department, The Children's Hospital of Philadelphia, 34th Street and Civic Center Boulevard, Philadelphia, PA, 10104, USA. victoria@email.chop.edu.
authors.forename: Teresa
authors.initials: T
authors.lastname: Victoria
mesh_terms: D015984:Causality; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D046689:Fetal Mortality; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000000981:diagnostic imaging* / Q000196:embryology / Q000401:mortality*; D007223:Infant; D007231:Infant, Newborn; D008168:Lung / Q000000981:diagnostic imaging / Q000196:embryology; D008171:Lung Diseases / Q000151:congenital* / Q000000981:diagnostic imaging / Q000401:mortality; D008200:Lymphangiectasis / Q000151:congenital* / Q000000981:diagnostic imaging / Q000401:mortality; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D008297:Male; D010414:Pennsylvania / Q000453:epidemiology; D011296:Prenatal Diagnosis / Q000706:statistics & numerical data*; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate
keywords: Fetus; Hypoplastic left heart syndrome; Lung; Lymphangiectasia; Magnetic resonance imaging; Nutmeg lung