title: Discrepancy in fetal head biometry between ultrasound and MRI in suspected microcephalic fetuses.
abstract: Background Microcephaly is one of the most common fetal structural abnormalities, and prenatal microcephaly is considered a group I malformation of cortical development diagnosed according to ultrasound (US) skull measurements. Purpose To evaluate the agreement between fetal head US and magnetic resonance imaging (MRI) biometric measurements of suspected microcephalic fetuses. Material and Methods This institutional review board-approved retrospective study with waived informed consent included 180 pregnant women and was conducted at our medical center from March 2011 to April 2013. Biparietal diameter (BPD) and occipitofrontal diameter (OFD) results of fetal head US normograms were compared to normograms for MRI. We used Pearson and Spearman rho non-parametric correlation coefficients to assess the association between two quantitative variables, paired t-test for paired quantitative variables, and McNemar test for paired qualitative variables. Results The average BPD but not the average OFD percentiles in fetal head US differed significantly from the MRI results ( P < 0.0001). When looking at the accepted microcephaly threshold, both BPD and OFD percentiles differed significantly from MRI ( P < 0.0001 and P < 0.004, respectively). There was no correlation between US-measured skull biometry and MRI-measured brain biometry. Estimated cerebrospinal fluid volumes were significantly lower in the study group compared to 120 fetuses with normal findings in prenatal head US and MRI. Also, we have created a MRI-based normogram of fetal head circumference and gestational age. Conclusion The diagnosis of microcephaly by US alone may be insufficient and ideally should be validated by MRI before a final diagnosis is established.
authors.affiliation: 1 Department of Diagnostic Imaging, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Gal
authors.initials: G
authors.lastname: Yaniv
authors.affiliation: 2 Department of Obstetrics and Gynecology, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Eldad
authors.initials: E
authors.lastname: Katorza
authors.affiliation: 1 Department of Diagnostic Imaging, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Vered
authors.initials: V
authors.lastname: Tsehmaister Abitbol
authors.affiliation: 3 The Institute for Research in Military Medicine, The Faculty of Medicine, The Hebrew University of Jerusalem, Israel.|4 The IDF Medical Corps.|5 Department of Pediatrics, Safra Children's Hospital, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Arik
authors.initials: A
authors.lastname: Eisenkraft
authors.affiliation: 1 Department of Diagnostic Imaging, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ronen
authors.initials: R
authors.lastname: Bercovitz
authors.affiliation: 1 Department of Diagnostic Imaging, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Salim
authors.initials: S
authors.lastname: Bader
authors.affiliation: 1 Department of Diagnostic Imaging, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Chen
authors.initials: C
authors.lastname: Hoffmann
mesh_terms: D001699:Biometry / Q000379:methods*; D005260:Female; D006257:Head / Q000000981:diagnostic imaging* / Q000196:embryology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008831:Microcephaly / Q000000981:diagnostic imaging* / Q000196:embryology; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal / Q000379:methods*
keywords: Ultrasound; biparietal diameter; magnetic resonance imaging (MRI); microcephaly; normogram; occipitofrontal diameter