Multilevel Modeling of Fetal and Placental Growth Using Echo-Planar Magnetic Resonance Imaging

Abstract

Objective: To quantify longitudinal increses in fetal, fetal liver, and fetal brain volume using echo-planar magnetic resonance imaging and to quantify the results using appropriate statistical modeling.

Methods: Fifty-six singleton fetuses were studied using echo-planar (snap-shot) magnetic resonance imaging, between 19 weeks and term. They were assessed at a variety of different gestations and on a different number of occasions, thereby requiring multilevel statistical modeling to analyze the pattern of fetal growth.

Results: Fetal volume varied according to the following equation: square root (√) [fetal volume] = -37.71 + 2.17·gestational age (GA) - 0.004·GA². The equation for fetal liver volume was √[fetal liver volume] = 9.47 + 0.56·GA - 0.02·GA², for fetal brain volume was √[fetal brain volume] = 15.50 + 0.69·GA - 0.014·GA², and for placental volume √[placental volume] = 28.54 + 0.95·GA - 0.039·GA², where GA is the gestational age in weeks -30.

Conclusion: The assessment of fetal, fetal organ, and placental volume was feasible using echo-planar magnetic resonance imaging from 20 weeks to term. Multilevel statistical modeling can be applied to analyze sets of data with different measurements on different occasions. This information is useful clinically to assess abnormal fetal growth.

Keywords

Fetal assessment echo-planar MRI

Get full access to this article

View all access options for this article.

References

1. Baker PN , Johnson IR , Gowland PA , et al. Measurement of fetal liver, brain and placental volumes with echo-planar magnetic resonance imaging. Br J Obstet Gynaecol 1995;102:35-39.

2. Johnson IR , Stehling MK , Blamire AM , et al. Study of internal structure of the human fetus in utero by echo-planar magnetic resonance imaging. Am J Obstet Gynecol 1990;163:601-607.

3. Baker PN , Johnson IR , Harvey PR , Gowland PA , Mansfield P . A three-year follow up of children imaged in utero using echoplanar magnetic resonance. Am J Obstet Gynecol 1994;170:32-34.

4. Myers C , Duncan KR , Gowland PA , Johnson IR , Baker PN . Failure to detect intrauterine growth restriction following in utero exposure to MRI. Br J Radiol 1998;71:549-551.

5. Laudy JA , Janssen MM , Struyk PC , Stijnen T , Wallenburg HC , Wladimiroff JW . Fetal liver volume measurement by three-dimensional ultrasonography: A preliminary study. Ultrasound Obstet Gynecol 1998;12:93-96.

6. Lee A , Kratochwil A , Stumpflen I , Deutinger J , Bernaschek G . Fetal lung volume determination by three-dimensional ultrasonography. Am J Obstet Gynecol 1996;175:588-592.

7. King DL , King DL Jr , Shao MY . Evaluation of in vitro measurement of a three-dimensional ultrasound canner. J Ultrasound Med 1991;10:77-82.

8. Riccabonna M , Nelson TR , Pretorus DH . Three-dimensional ultrasound: Accuracy of distance and volume measurements. Ultrasound Obstet Gynaecol 1996;7:429-434.

9. Benacerraf BR , Gelman R , Frigoletto FD . Sonographically estimated fetal weights: Accuracy and limitation. Am J Obstet Gynecol 1988;159:1118-1121.

10.

10. Campbell S , Wilkin D . Ultrasonic measurement of fetal abdominal circumference in estimation of fetal weight. Br J Obstet Gynaecol 1975;82:689-697.

11.

11. Howseman AM , Stehling MK , Chapman B , et al. Improvements in snap-shot nuclear magnetic resonance imaging. Br J Radiol 1988;61:822-828.

12.

12. National Radiological Protection Board . NRPB Safety Bulletin. Vol. 2, No.1 Chilton, UK: Her Majesty's Stationery Office (HMSO), 1991.

13.

13. Boulby P , Gowland P , Adams V , Spiller RC . Use of echo-planar imaging to demonstrate the effect of posture on the intragastric distribution and emptying of an oil/water meal. Neurogastroenterol Motil 1997;9:41-47.

14.

14. Goldstein H . Multilevel Statistical models. 2nd ed. London: Edward Arnold, 1995

15.

15. Rasbash J , Woodhouse G . MLn command reference. London: Multilevel Models Project, Institute of Education, 1995

16.

16. Altman DG , Bland JM . Units of analysis. BMJ 1997;314:1874-1876.

17.

17. Garden AS , Roberts N . Fetal and fetal organ volume estimations with magnetic resonance imaging. Am J Obstet Gynecol 1996;175:442-448.

18.

18. Gong QY , Roberts N , Garden AS , Whitehouse GH . Fetal and fetal brain volume estimation in the third trimester using gradient echo MR imaging. Magn Reson Imaging 1998;16:235-240.

19.

19. Duncan K , Baker PN , Johnson IR , Gowland P . Treat patients with kindness during magnetic resonance imaging. BMJ 1996;312:1421-1421.

20.

20. Baker PN , Johnson IR , Gowland PA , et al. Fetal weight estimation by echo-planar magnetic resonance imaging. Lancet 1994;343:644-645.

21.

21. Goldstein H . Flexible models for the analysis of growth data with an application to height prediction. Rev Epidemiol Sante Publ 1989;37:477-484.

22.

22. Royston P . Calculation of unconditional and conditional reference intervals for foetal size and growth from longitudinal measurements. Stat Med 1995;14:1417-1436.

23.

23. Kirkinen P , Partanen K , Vainio P , Ryynanen M . MRI in obstetrics: A supplementary method for ultrasonography. Ann Med 1996;28:131-136.

24.

24. Sonigo PC , Rypens FF , Carteret M , Delezoide AL , Brunelle FO . MR imaging of fetal cerebral anomalies. Pediatr Radiol 1998;28:212-222.

25.

25. Hubbard AM , Adzick NS , Cromblehome TM , Haselgrove JC . Left sided congenital diaphragmatic hernia: Value of prenatal MR imaging in preparation for fetal surgery. Radiology 1997;203:636-640.