THREE-DIMENSIONAL ULTRASOUND (3DUS) IN GASTROENTEROLOGY,
BLADDER AND SMALL PARTS
By Leandro Fernandez, MD.
Director, Advanced Vascular Ultrasound Laboratory (LEAV), La Floresta Medical Institute. Director, Ultrasound Department of Vista Alegre Private Hospital. Director-Instructor, SonoImagen – International School for Advanced Ultrasound affiliated to Jefferson Ultrasound Research and Education Institute (JUREI).
Three-Dimensional Ultrasound (3DUS) is a recent technique used in clinical practice, which has been generally used in Gynecology and Obstetrics. Although there is relatively little experience in other areas, it is growing increasingly. Unfortunately, most people still tend to believe that 3DUS is only about getting nice and amazing pictures of baby faces, legs or genitalia. It is precisely this belief and lack of information what has driven us to present to the public some different and updated applications that have proved to be useful in diagnostic ultrasound, as well as a range of other feasible and promising uses of this outstanding technology, not only in the already known applications in Obstetrics and Gynecology, but also in the rest of the medical specialties.
There are different types of 3DUS:
- Niche Mode (which we refer to as Echo-Tomography)
- VOCAL (Virtual Organ Computer-aided Analysis)
All these techniques can be widely used in diagnostic ultrasound in gastroenterology, bladder and small parts, among other medical areas.
3DUS IN GASTROENTEROLOGY
VIRTUAL CYSTOENDOSCOPY: 3DUS OF THE BLADDER
This is a new application of 3DUS in urology. Combining the volumetric and surface rendering, we are able to see with remarkable detail the internal surface of this organ, thus detecting the presence of tumors, polyps, stones or any other disorders of the wall, urethra, etc. The same types of internal urethral meatus described with optical cystoendoscopy, can be seen with the 3DUS virtual cystoendoscopy.
VOCAL help us calculate the pre and post-micturition volume more accurately than when using 2DUS technology. Despite the undeniable advantages that 3 DUS can offer, it is, of course, necessary to carry out many more studies comparing optical against virtual cystoendoscopy, in order to validate these findings.
3DUS IN SMALL PARTS (THYROID, PARATHYROID, AND TESTICLE)
The assessment of the thyroid and parathyroid glands are properly achieved with 3DUS. We can discriminate normal anatomical structures from pathological ones. The Multiplanar presentation and Niche Mode (Echo-Tomography) are quite useful to determine the extension -inside or outside the organs-, of nodules, cysts or tumors.The evidence of neovascularization is better viewed with 3DUS and probably can suggest malignant origin of a neoplasm. Allowing for the spatial orientation and the number of vessels, it could be possible to determine the degree of potential malignity in a given tumor.
The volume measurement is better assessed with 3DUS and given this, we can perform studies that follow growth in order to decide medical or surgical treatment.
The VOCAL makes it possible to obtain a proper after-treatment follow-up of focal disorders in thyroid and parathyroid.
In my opinion, this method is of great value when we study testicle and epididymis. The inflammatory processes, tumoral diseases or torsion conditions are very well assessed with 3DUS.
Other relevant applications include:
- Hyperemic parenchyma due to epididymal-orchitis is confirmed by vascular 3DUS.
- Focal or multifocal neoplasm is perfectly visualized.
- We are in a better position to determine if we are dealing with an intra or extra testicular lesion.
- The Vascular 3DUS is able to show a very clear depiction of varicocele.
The Multiplanar presentation allows us to get a virtual coronal view of the entire scrotum, the testicle or just a small structure. A very exact differentiation of simple or complex cysts can be ascertained using Surface rendering in combination with Volumetric 3DUS.
As well as in thyroid, VOCAL makes it possible to obtain a proper after-treatment follow-up of focal disorders in the testicle.
Three-dimensional ultrasound is a new and outstanding technique that opens a new vision in diagnostic ultrasonography. It offers a more comprehensive image of anatomical structures and pathological conditions and also permits to observe the exact spatial relationships.New applications in Internal Medicine, Surgery and Radiology are daily emerging, coming from the curiosity of many doctors from all over the world and from the necessity to assess the human body in a accurate and non-invasive approach.
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