Evaluation of the fetal secondary palate by 3-dimensional ultrasonography.
OBJECTIVE
Diagnosis of cleft lip and palate remains a challenge with 2-dimensional ultrasonography, particularly when clefting involves only the secondary palate. The utility of 3-dimensional ultrasonography (3DUS) has enhanced our ability to detect clefts. We report our experience with a modification of the flipped face technique to aid in the diagnosis of clefting of the secondary palate.


METHODS
Ninety-two volumes of 92 fetal faces were evaluated. Thirty-six volumes were acquired prospectively. Fifty-six volumes had previously been acquired and included 8 with clefting of the secondary palate. Volumes were obtained on 3DUS systems and reviewed by 4 blinded readers on personal computer workstations. Volumes were manipulated so that an upright profile was visualized. The palate was then rendered using a thin, curved render box. Statistical analysis was performed using the Fisher exact test for categorical data. Intraclass correlations were computed to assess inter-rater agreement.


RESULTS
The mean gestational age at image acquisition +/- SD was 22 +/- 5 weeks. Image quality of the secondary palate was obtained and rated as adequate by at least 2 reviewers in 34% (31 of 92) of volumes. The sensitivity of cleft detection ranged from 33% to 63%, and the specificity ranged from 84% to 95%. The low sensitivity was mainly due to artifacts/shadowing. The inter-rater reliability was 0.62 (95% confidence interval, 0.47-0.76).


CONCLUSIONS
Three-dimensional ultrasonography can be used to diagnose clefts of the secondary palate. This evaluation is limited by the fetal position and artifacts from shadowing of adjoining structures. Pseudoclefts can be created, and optimal imaging cannot be obtained in all fetuses.
Ramos
Gladys A
GA
Department of Reproductive Medicine, University of California, San Diego, La Jolla, California, USA.
Romine
Lorene E
LE
Gindes
Liat
L
Wolfson
Tanya
T
McGahan
Michele C
MC
D'Agostini
Deborah
D
Lee
Sujin
S
Jones
Marilyn C
MC
Pretorius
Dolores H
DH
D000465:Algorithms; D002971:Cleft Lip / Q000000981:diagnostic imaging* / Q000196:embryology; D002972:Cleft Palate / Q000000981:diagnostic imaging* / Q000453:epidemiology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods*