VOLUME DISPLAY

Three-dimensional Doppler is an area of intense research using both power Doppler and traditional color flow. One particular area of interest has been the detection of abnormal placental adherence (accreta, inccreta, or perccreta) with or without bladder involvement. Three-dimensional color Doppler has allowed the investigators to visualize all three orthogonal planes of the placental myometral unit, a technique which appears to be complimentary to standard 2D sonography in clarifying abnormal neovascularization in patients with placenta accreta.(51, 52) Power Doppler in 3D is currently being studied as a way to visualize the fetal vascular system for prenatal diagnosis of anomalies, although more information is required to determine the utility of these techniques above and beyond the 2D Doppler.(53). Real-time capabilities in the use of Doppler will be necessary in 3D applications with similar frame-rates as those available today in 2D Doppler examinations.

 

TYPES

 

 

Multiplanar reconstruction (MPR)

Surface rendered

Skeletal view

Angio view (3D Doppler)

Volume contrast imaging (VCI)

Glass Body rendering

 

 

MULTIPLANAR RECONSTRUCTION

 

 

 

 

SURFACE RENDERED

 

Some Examples

Facial expressions

Normal ear

Omphalocele

Fetal hydrops

 

 

 

 

 

 

 

 

 

 

SKELETAL VIEW

 

Examples

Normal ribs and scapula

Proximal focal femoral deficiency

Normal spine

 

 

 

 

ANGIO / 3D DOPPLER

 

 

Three-dimensional Doppler has been investigated using both power Doppler and traditional color flow. One particular area of interest has been the detection of abnormal placental adherence (accreta, inccreta, or perccreta) with or without bladder involvement. Three-dimensional color Doppler has allowed the investigators to visualize all three orthogonal planes of the placental myometral unit, a technique which appears to be complimentary to standard 2D sonography in clarifying abnormal neovascularization in patients with placenta accrete  (1,2).

 

 

 

 

Example

Vascular anatomy

 

 

1.      Hull AD, Salerno CC, Saenz CC, Pretorius DH. Three-dimensional ultrasonography and diagnosis of placenta percreta with bladder involvement. J Ultrasound Med 18:853-856, 1999.

2.      Chou MM, Tseng JJ, Ho ESC, Hwang JI. Three-dimensional color power Doppler imaging in the assessment of uteroplacental neovascularization in placenta previa increta/percreta. Am J Obstet Gynecol 185(5):1257-1260, 2001.

 

 

GLASS BODY

 

Example

Placenta accreta

 

 

 

INVERSION MODE

 

The “inversion mode” is a new rendering algorithm that transforms echolucent structures into echogenic voxels. Thus, anechogenic structures such as the heart chambers, lumen of the great vessels, stomach and bladder appear echogenic on the rendered image, whereas structures that are normally echogenic prior to gray-scale inversion become anechoic (1,2).

 

The “inversion mode” can be used at the time of scanning or after the acquisition of volume datasets with both 3D and 4D techniques. This rendering mode provides more anatomical detail than other rendering algorithms, such as the transparent mode, in the evaluation of hollow anatomical structures (2). The quality of the image rendered with the inversion mode depends on the quality of the volume dataset acquired. In a study by Espinosa and co-worhers (3) it was shown that the best results were obtained by a combination of surface smooth and gradient light filters.

The 3D/4D “inversion mode” rendering algorithm can improve the prenatal visualization of a dilated azygos or hemiazygos vein and their spatial relationships with the surrounding cardiovascular structures (2). The “inversion mode” algorithm improves prenatal visualization of both dilated azygos and hemiazygos veins, as well as their spatial relationships with the surrounding vascular structures

 

 

  1. Goncalves LF, Espinoza J, Lee W et.al. Three- and four-dimensional reconstruction of the aortic and ductal arches using inversion mode: a new rendering algorithm for visualization of fluid-filled anatomical structures. Ultrasound Obstet Gynecol 2004; 24: 696-698
  2. Lee W, Goncalves LF, Espinoza J, Romero R. Inversion mode: a volume analysis tool for three-dimensional sonography. J Ultrasound Med 2005; 24: 201-207
  3. Espinoza J, Gonçalves LF, Lee W, Mazor M et.al. A novel method to improve prenatal diagnosis of abnormal systemic venous connections using three- and four-dimensional ultrasonography and inversion mode Ultrasound Obstet Gynecol 2005;25:428-434.

 

VOLUME MEASUREMENTS

 

Another important clinical application of 3D is volume measurements calculations based on 3D volume acquisition.

  • Brummer et al. demonstrated the accuracy of volume based three-dimensional sonography measurement on follicle aspiration performed using transvaginal needle guided technique (1).
  • Other practitioners have also shown that three-dimensional sonographic methods provide accurate volume measurements of both regular and irregular objects thus providing an improvement, both in accuracy and examination time, over estimations using multiple 2D images (2,3).
  • Specific area of study where volume measurements are clinically applicable include:
    • serial fetal lung volume measurements for the prenatal detection of pulmonary hypoplasia.(4-6).
    • volume measurements of the fetal thoraco-lumbar spine as well as kidneys, liver and heart have been established, and fetal liver volumes in normally grown fetuses have been compared to those small-for-gestational-age.(7-12)
    • fetal brain volumes have been calculated using 3D scans with excellent intra and inter observer variability correlating well with other standard biometry at different gestational ages.(13)
    • fetal weight estimates as well as growth parameters and improve the accuracy with which we can predict small-for-gestational-age infants. Fractional limb volume has also been investigated as an additional parameter to further improve accuracy in predicting birth weight, although this remains to be seen in larger scale studies(14-16)
    • volume measurements of the fetal placenta using 3D sonography has not been particularly helpful to date in predicting small-for-gestational-age infants.(17)

 

      1. Brunner M, Obruca A, Bauer P, Feichtinger W,. Clinical application of volume estimation based on three-dimensional ultrasonography. Ultrasound Obstet Gynecol  1995:6:358-361.
      2. Riccabona M, Nelson TR, Pretorius DH, Davidson TE. Distance and volume measurement using three-dimensional ultrasonography. J Ultrasound Med  1995;14:881-886.
      3. Riccabona M, Nelson TR, Pretorius DH. Three-dimensional ultrasound: accuracy of distance and volume measurements. Ultrasound Obstet Gynecol  1996;7:429-434.
      4. Bahmaie A, Hughes SW, Clark T, Milner A, Saunders J, Tillings K, Maxwell DJ. Serial fetal lung volume measurement using three-dimensional ultrasound. Ultrasound Obstet Gynecol  2000;16:154-158.
      5. Laudy JAM . Janssen MMM, Struyk PC, Stijnen T, Wladimiroff JW. Three-dimensional ultrasonography of normal fetal lung volume: a preliminary study. Ultrasound Obstet Gynecol  1998;11:13-16.
      6. Pohls UG, Rempen A. Fetal lung volumetry by three-dimensional ultrasound. Ultrasound Obstet Gyncol  1998;11:6-12.
      7. Schild RL, Wallny T, Fimmers R, Hansmann M. The size of the fetal thoracolumbar spine: a three-dimensional ultrasound study. Ultrasound Obstet Gynecol  2000;16:468-472.
      8. Schild RL, Wallny T, Fimmers R, Hansmann M. Fetal lumbar spine volumetry by three-dimensional ultrasound. Ultrasound Obstet Gynecol 13:335-339, 1999. Hsieh YY, Chang CC, Lee CC, Tsai HD. Fetal renal volume assessment by three-dimensional ultrasonography. Am J Obstet Gynecol  2000;182(2):377-379.
      9. Laudy JAM, Janssen MMM, Struyk PC, Stijnen T, Wallenburg HCS, Wladimiroff JW. Fetal liver volume measurement by three-dimensional ultrasonography: a preliminary study. Ultrasound Obstet Gynecol  1998;12:93-96.
      10. Kuno A, Hayashi Y, Akiyama M, Hata T, Yamashiro C, Yanaka H,Yanagihara T, Hata T. Three-dimensional sonographic measurement of liver volume in the small-for-

Dates. J Ultrasound Med  2002;21:361-366.

      1. Chang FM, Hsu KF, Ko HC, Yao BL, Chang CH, Yu CH, Liang RI,. Chen HY. Fetal heart volume assessment by three-dimensional ultrasound. Ultrasound Obstet

       Gynecol  1997;9:42-48.

12.  Endres LK, Cohen L. Reliability and validity of three-dimensional fetal brain volumes. J Ultrasound Med  2001;20:1265-1269.

13.  Lee W, Deter RL, Ebersole JD, Huang R, Blanckaert K, Romero R. Birth weight prediction by three-dimensional ultrasonography. J Ultrasound Med 2001;20:1283-1292.

14.  Song TB, Moore TR, Lee JY, Kim YH, Kim EK,. Fetal weight prediction by thigh volume measurement with three-dimensional ultrasonography. Obstets & Gynecol  2000;96(2):157-161.

15.  Chang FM, Liang RI, Ko HC, Yao BL, Chang CH, Yu CH. Three-dimensional ultrasound-assessed fetal thigh volumetry in predicting birth weight. Obstets & Gynecol  1997;90(3):331-338.

16.  Hafner E, Philipp K, Schuchter K, Dillinger-Paller B, Philipp T, Bauer P. Second-trimester measurements of placental volume by three-dimensional ultrasound to predict small-for- gestational-age infants. Ultrasound Obstet Gynecol  1998;12:97-102.