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(Radiology. 2000;217:236-239.)
© RSNA, 2000

Obstetric Imaging

Fetal Lip and Primary Palate: Three-dimensional versus Two-dimensional US1

Donna D. Johnson, MD, Dolores H. Pretorius, MD, Nancy E. Budorick, MD, Marilyn C. Jones, MD, Karen V. Lou, RDMS, Gina M. James, RDMS and Thomas R. Nelson, PhD

1 From the Department of Obstetrics and Gynecology, Medical University of South Carolina, 96 Jonathan Lucas St, Ste 634, PO Box 250619, Charleston, SC 29425 (D.D.J.); and the Departments of Radiology (D.H.P., N.E.B., K.V.L., G.M.J., T.R.N.) and Pediatrics (M.C.J.), University of California, San Diego, La Jolla. From the 1997 RSNA scientific assembly. Received March 26, 1999; revision requested May 10; revision received March 16, 2000; accepted April 4. Address correspondence to D.D.J. (e-mail: johnsodo@musc.edu).


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
PURPOSE: To determine if three-dimensional (3D) ultrasonography (US) improves the ability to define the location and extent of facial clefting prenatally compared with two-dimensional (2D) US.

MATERIALS AND METHODS: Thirty-one fetuses suspected of having a facial cleft were examined prospectively with 2D and 3D US. Follow-up was performed in all fetuses.

RESULTS: Twenty-eight fetuses had a cleft lip at birth. The location of the cleft lip was correctly identified in all fetuses with 3D US and in 26 of 28 with 2D US. Twenty-two fetuses had a cleft primary palate. Nineteen and nine of 22 cleft palates were identified by using 3D and 2D US, respectively. Three fetuses suspected of having a facial cleft at 2D US had a normal palate at 3D US and at birth.

CONCLUSION: Three-dimensional US is useful to identify the location and extent of facial clefting. The advantages of 3D US are the following: (a) The face may be viewed in a standard orientation, (b) the defect may be viewed systematically by using an interactive display, and (c) the rendered image provides landmarks for the planar images. Patient decisions may be affected, since they can view the abnormality on a recognizable 3D rendered image.

Index terms: Face, abnormalities, 262.1481 • Fetus, abnormalities, 262.1481, 262.1482 • Fetus, US, 856.12981, 856.12989 • Palate, 262.1481, 262.1482 • Ultrasound (US), comparative studies, 856.12981, 856.12989 • Ultrasound (US), three-dimensional, 856.12981, 856.12989


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Facial clefting is one of the most common congenital malformations, accounting for 13% of all congenital anomalies (1). Although in many neonates the cleft lip and/or palate is isolated, 29% may be associated with an underlying disorder (2). Prenatal diagnosis of a cleft lip and/or palate is associated with an even higher incidence of congenital abnormalities (3). Consequently, prenatal detection of a facial cleft should alert the sonographer to carefully examine the fetus for other anomalies and may aid in the management of the pregnancy.

Ultrasonography (US) can be used to identify clefting in the lip and primary palate (anterior alveolar ridge); to our knowledge, neither a cleft secondary palate nor an isolated cleft palate has yet been identified prenatally. The US detection rates of facial clefting have been reported to be as low as 21%–30% (4–6). However, tertiary care providers have been more successful, and Nyberg et al (7) have developed a US classification of clefts identified prenatally that is valuable for counseling and prognosis. Since 80% of cleft lips are associated with a cleft palate and the identification of a cleft palate may alter obstetric management, the sonographer should attempt to define the extent of facial clefting in utero (7).

Preliminary reports suggest that three-dimensional (3D) US may improve visualization of the fetal face and the detection of some facial anomalies (8–10). The objective of this study was to determine whether 3D US can improve our ability to define the location and extent of lip and palate clefting prenatally.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
After obtaining approval for this study from the institutional review board and informed consent from the patient, 31 consecutive fetuses suspected of having a facial cleft were examined prospectively with two-dimensional (2D) and 3D US. The fetuses with a possible facial cleft, as revealed at 2D US, were recruited at three prenatal diagnosis referral centers for 3D US. The patients received no additional charge for participating in this study. The gestational age at enrollment and interpretation of the study findings ranged from 15 to 35 weeks (mean gestational age, 24.8 weeks ± 5.0 [SD]) Five of these fetuses had been included in another study of the fetal lips (9).

At our prenatal diagnosis centers, the fetal face, including the fetal lips and palate, are evaluated during every examination regardless of the indication for referral. Two-dimensional fetal evaluations were performed transabdominally with a 128 XP (Acuson, Mountain View, Calif) or Ultramark 9 or HDI (ATL, Bellevue, Wash) unit. Frontal, sagittal, and transverse planes of the fetal face were used to evaluate the integrity of the fetal lip. The transverse plane was used to evaluate the continuity of the fetal primary palate.

Three-dimensional scans were obtained with the Combison 530 or Voluson 530D (Medison America, Pleasanton, Calif) unit. Volume image data were obtained with a motor driven 5.0-MHz abdominal transducer in all patients and also a 7.5-MHz transvaginal annular array transducer in one patient. Both transducers mechanically performed a single 180° sweep through an object while the transducer housing remained stationary (11). One to seven volume data sets of the fetal face were acquired per patient with acquisition times ranging from 2 to 6 seconds per volume. A normal or slow scan sweep speed was used. Volume data were acquired from transverse, frontal, and sagittal scanning planes during periods of no fetal movement, and acquisition was repeated if fetal movement occurred.

The display and processing of the 3D volume data of the fetal face have been previously described in detail (8,9). Briefly, the volume data were displayed in two formats: three orthogonal planar images and a 3D rendered image of the surface of the fetal face. The planar images were rotated with the interactive display into a standard anatomic orientation so that the three planar images corresponded to the frontal, sagittal, and transverse planes of the face. The three orthogonal planar images were the same as those seen at 2D US. The major difference is that the orthogonal planar images are derived from a volume of images and several transverse, frontal, and sagittal planes are visible in one volume.

Next, a region of interest that contained the entire face was isolated from the volume data with a rectangular cube to create a subvolume. The subvolume was then rendered by using computer software to produce a 3D rendered image. Light-weighted and surface rendering with additional thresholding was used to create an image of the surface of the fetal face (Fig 1). Three-dimensional rendered images were computed over a 60°–70° angular range of viewing with six to seven images from each set of volume data. Rendering of the 3D image required 1–5 minutes of computer time. Once the sonographer or physician learned to use the interactive display, no additional skills or scanning ability was required to render a 3D image. The 3D rendered image was displayed and reviewed simultaneously with the three planar views (Fig 2). Two volume data sets, each containing the entire face and with the least amount of US artifact, were chosen for rendering.



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  		Figure 1. Three-dimensional rendered US image viewed frontally shows a facial cleft (arrows) in a fetus at 22 weeks gestational age. After viewing the rotating 3D image, the family elected to continue the pregnancy.

 


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  		Figure 2. A, Coronal, B, sagittal, C, transverse, and D, 3D rendered US images of a cleft lip (arrows) and palate in a fetus at 21 weeks gestational age. Image in D is viewed frontally. White line indicates plane depicted in C.

 
Findings of each 2D examination were interpreted by a radiologist or perinatologist who routinely performs and interprets results of fetal anatomic surveys. After 2D US was performed, the patient was informed of the results. Options for the pregnancy were discussed with the patient and included karyotyping and termination of pregnancy. These study findings were then discussed with the patient, and 3D US was scheduled. The 3D US findings were interpreted by one of three authors (D.H.P., N.E.B., D.D.J.). The patient was again informed of the findings and options. The patient was asked if the 3D rendered image had an effect on her decision. At the time of the 3D US interpretation, results of some 2D examinations were known; however, the neonatal outcome was not known.

Both sets of images were evaluated for continuity of the upper lip and primary palate. At 3D US, the primary palate was identified in the transverse plane by visualizing the two front tooth buds and by rotating the volume for symmetric viewing of the anterior alveolar ridge (12). The rendered image was used as a reference for viewing the transverse plane through the palate (Fig 2). The integrity of the lip and palate was determined by using the multiplanar information with the rendered image. The rendered image was never interpreted without confirmation on the planar images. At both 2D and 3D US, the lip or primary palate was considered normal if the entire structure was seen and was continuous, equivocal if the structure was not entirely visualized, or abnormal if the structure was seen and was not continuous. Neonatal outcome was obtained at autopsy or from primary physicians.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Thirty-one fetuses were scanned at 2D and 3D US and follow-up was performed in all fetuses. A cleft lip was identified in 28 fetuses at birth. At examination, 19 (68%) fetuses had a unilateral cleft lip, five (18%) had a bilateral cleft lip, and four (14%) had a median cleft lip. The location of the cleft lip was correctly detected in all of the fetuses at 3D US and in 26 (93%) at 2D US. Three fetuses were suspected of having a unilateral cleft lip with 2D US, but the lip was normal with 3D US and at birth. These results are summarized in the Table.


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  		US Results and Neonatal Outcome of Facial Clefting
 
The primary palate was adequately visualized to comment on the anatomy in 22 (71%) of 31 fetuses at 2D US. Of the nine primary palates not revealed at 2D US, three were better visualized at 3D US, but three were not. In addition, two primary palates were visualized at 2D US but were not completely seen at 3D US. The secondary palate was not visualized with 2D or 3D US. These results are summarized in the Table.

In the 28 fetuses with a cleft lip, 22 also had a cleft palate, five had a normal palate, and the status of one palate was not determined at autopsy. Nineteen (86%) of 22 cleft palates were detected or suspected at 3D US. In contrast, only nine (41%) were detected at 2D US (P < .005). These results are summarized in the Table.

Visualization of the 3D rendered image was useful for seven patients. In three fetuses, a normal lip was seen on the 3D rendered image. The family of one fetus was considering termination of pregnancy but elected to continue the pregnancy after viewing the size of the cleft on the reconstructed 3D image of the face (Fig 1). The families of three fetuses were considering termination of pregnancy and elected to proceed after viewing a cleft lip or palate on the 3D rendered image.


   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
The findings of this study demonstrate that 3D US can be used in identifying and localizing facial clefting, as well as normal facial anatomy, in utero. Three fetuses were suspected of having a cleft lip at 2D US, but a normal lip and palate were seen at 3D US. Furthermore, the location of the cleft lip was correctly identified in all fetuses at 3D US, whereas one cleft lip was misclassified at 2D US. These results were not unexpected, as we have previously shown that the presence of a normal lip can be confirmed more often with 3D US than 2D US, particularly in younger fetuses (9).

Prenatal detection of a cleft palate associated with a cleft lip may be difficult, and the accuracy of US in detecting facial clefting, especially smaller lesions, has not been well established. In this study, nine (41%) of 22 cleft palates were correctly identified with 2D US and 19 (86%) of 22 were detected with 3D US. In the Routine Antenatal Diagnostic Imaging and Ultrasound Study (6), 30% of cleft lips and/or palates were detected in fetuses that underwent screening US. Likewise, in a retrospective study (5), only 25% of cases of fetal facial clefting were diagnosed prenatally. In another tertiary care center study (7), 65 fetuses were examined at US; findings of facial clefting at US and neonatal examination agreed in 63. However, 43 (69%) of these fetuses had large defects (bilateral or median clefts), whereas, in this series, seven (25%) of 28 fetuses with a cleft had a large lesion (Fig 3). Although one possible explanation for the low detection rates in these studies is that the face is not routinely visualized at low-risk US examinations, it is also clear that 2D visualization of the fetal face requires extensive experience.



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  		Figure 3. Three-dimensional rendered frontal oblique US image shows a median cleft lip (arrow) in a fetus at 32 weeks gestational age.

 
The classic teaching is to view the fetal face from a frontal view to detect a cleft lip (12,13). Although at US the primary palate is viewed transversely or axially to determine if it is involved in the facial cleft, continuity of the upper lip is not typically determined in the transverse view. Babcock et al (14) demonstrated that normal fetal midfacial anatomy in utero could be demonstrated in the transverse and coronal views. One observation in this study is that the transverse view of the upper lip is useful to confirm the presence of a cleft lip, and the location of the cleft can often be seen more easily in this plane. Three-dimensional US provides sequential transverse views of the upper lip. Sequential transverse views are difficult to obtain with 2D US and may explain why three fetuses were thought to have a cleft lip but did not.

Several advantages of 3D US in assessing the primary palate were identified in this study. First, viewing of the fetal face in the standard anatomic orientation allowed confident interpretation, as well as review with family and colleagues. Second, by using the interactive display, the planar views could be manipulated and scrutinized systematically without concern for fetal movement. Third, the planar and surface-rendered image could be manipulated to ensure that loss of signal in the palate defect was not due to transducer angulation and that the view of the face was truly symmetric. Fourth, in larger palate defects, the hypoechoic area in the palate could be followed on more than one transverse planar image. Fifth, the rendered image was an important reference image; the exact location of the planar images could be identified relative to the surface-rendered image (Fig 2). This feature decreases the likelihood that the mandible will be mistaken for the palate or that the opening of the nares or nasal passage will be mistaken for a palate defect.

With the 3D rendered image, various display methods can be used to view different structures of interest with the same volume data (15). We found that the mixture of surface and light rendering was optimal for viewing facial clefts. In one fetus, maximum-intensity weighting improved the imaging of a cleft lip and palate in a fetal face that was adjacent to the placenta. Although the facial cleft may be seen on the 3D rendered image, all rendered images should be interpreted with planar images to avoid the pitfall of a pseudocleft, which we have previously reported (9). Although the 3D surface image was used as a reference image, the planar images were used to evaluate the palate in this study.

Parameters affecting acquisition of volume data may also affect image interpretation. Volume data were acquired from frontal, transverse, and sagittal scanning planes, but this did not change the image quality and did not affect interpretation. Since images can be obtained in several planes, this feature may actually reduce the scanning time necessary to view the fetal lips and palate. Also, different sweep speeds were used to obtain more planar images in the volume data to increase the number of planar images of the primary palate, but the greater number of images did not provide additional diagnostic information.

Care was affected in seven of 31 patients after the family viewed volume-rendered images of the fetuses. The patient does not have to be a trained observer to detect the cleft on 3D images, in contrast to 2D images. These lifelike rendered images allow the patient to form her own opinion about the size of the cleft and about how disfiguring it is instead of depending solely on the interpretation of the physician. In addition, the rendered image allowed the family to see that their fetus had an abnormality. The possibility of other associated anomalies appeared easier to understand.

In conclusion, accurate characterization of facial clefting is an important aspect of US diagnosis. Three-dimensional US may be useful in defining the location and extent of facial clefting in utero. The defect may be viewed systematically by using an interactive display without concern for fetal movement, with the rendered image providing useful landmarks for the planar images. Regardless of the type of US used, the integrity of the primary palate is difficult to assess at US in utero, and the patient should be counseled accordingly. Three-dimensional US may affect a family’s decision, since a recognizable image of their fetus is now available to them.


   ACKNOWLEDGMENTS
 
The 3D US equipment is on loan from Medison America (Pleasanton, Calif).


   FOOTNOTES
 
Abbreviations: 3D = three-dimensional, 2D = two-dimensional

Author contributions: Guarantor of integrity of entire study, D.H.P.; study concepts, T.R.N., D.H.P., D.D.J., N.E.B., M.C.J.; study design, D.D.J., N.E.B., D.H.P.; definition of intellectual content, D.H.P., D.D.J., N.E.B.; literature research, D.D.J.; clinical studies, D.D.J., D.H.P., N.E.B.; data acquisition, D.D.J., D.H.P., N.E.B., K.V.L., G.M.J.; data analysis, D.D.J., D.H.P., N.E.B., M.C.J.; statistical analysis, D.D.J.; manuscript preparation, D.D.J., D.H.P.; manuscript editing and review, all authors.


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Gorlin RJ, Vervenka J, Pruzansky S. Facial clefting and its syndromes. Birth Defects Orig Arctic Ser 1971; 7:3-41.
  2. Benacerraf BR, Mulliken JB. Fetal cleft lip and palate: sonographic diagnosis and postnatal outcome. Plast Reconstr Surg 1993; 92:1045-1051.[Medline]
  3. Jones M. Etiology of facial cleft: prospective evaluation of 428 patients. Cleft Palate J 1988; 25:16-20.[Medline]
  4. Levi S, Hyjazi Y, Schaaps JP, Defoort P, Colon R, Buekens P. Sensitivity and specificity of routine antenatal screening for congenital anomalies by ultrasound: the Belgian multicentric study. Ultrasound Obstet Gynecol 1991; 1:102-110.[Medline]
  5. Chitty LS, Hunt GH, Moore J, Lobb MO. Effectiveness of routine ultrasonography in detecting fetal structural abnormalities in low risk population. Br Med J 1991; 303:1165-1169.
  6. Crane JP, LeFevre ML, Winborn RC, et al. A randomized trial of prenatal ultrasonographic screening: impact on the detection, management, and outcome of anomalous fetuses. Am J Obstet Gynecol 1994; 171:392-399.[Medline]
  7. Nyberg DA, Sickler GK, Hegge FN, Kramer DJ, Kropp RJ. Fetal cleft lip with and without cleft palate: US classification and correlation with outcome. Radiology 1995; 195:677-684.[Abstract/Free Full Text]
  8. Pretorius DH, Nelson TR. Fetal face visualization using three-dimensional ultrasonography. J Ultrasound Med 1995; 14:349-356.[Abstract]
  9. Pretorius DH, House M, Nelson TO, Hollenbach KA. Evaluation of normal and abnormal lips in fetuses: comparison between three- and two-dimensional sonography. AJR Am J Roentgenol 1995; 165:1233-1237.[Abstract/Free Full Text]
  10. Merz E, Weber G, Bahlmann F, Miric-Tesanic D. Application of transvaginal and abdominal three-dimensional ultrasound for the detection or exclusion of malformations of the fetal face. Ultrasound Obstet Gynecol 1997; 9:237-243.[Medline]
  11. Kirbach D, Whittingham TA. Three-dimensional ultrasound: the Kretztechnik Voluson approach. Eur J Ultrasound 1994; 1:85-89.
  12. Nyberg DA, Mahoney BS, Pretorius DH, eds. Diagnostic ultrasound of fetal anomalies Chicago, Ill: Year–Book Medical, 1990.
  13. Romero R, Pilu G, Jeanty P, Ghidini A, Hobbins JC. Prenatal diagnosis of congenital anomalies Norwalk, Conn: Appleton & Lange, 1988.
  14. Babcock CJ, McGahan JP, Chong BW, Nemzek WR, Salamat MS. Evaluation of fetal midface anatomy related to facial clefts: use of US. Radiology 1996; 201:113-118.[Abstract/Free Full Text]
  15. Riccabona M, Pretorius DH, Nelson TR, Johnson D, Budorick N. Three-dimensional ultrasound: display modalities in obstetrics. J Clin Ultrasound 1997; 25:157-167.[Medline]



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