25 Years of 3D Ultrasound in Prenatal Diagnosis (1989–2014)

Abstract

25 years of 3?D ultrasound in prenatal diagnosis represent an important milestone in recent ultrasound history. The initial stages of 3?D ultrasound were anything but easy. Although there were reports of initial experimental in-vitro ultrasound studies as early as the 1970s and 1980s 1 2, clinical use did not begin until the first commercial 3?D ultrasound unit (Combison 330, Kretztechnik Zipf, Austria) was introduced in 1989 (Fig.?1) 3 4. With this unit it became possible for the first time to produce so-called multiplanar (=?triplanar) images. This means that it was possible to display the three orthogonal two-dimensional image planes at the same time on the monitor (Fig.?2). Volume acquisition via a relatively large abdominal 3?D probe, which ? in contrast to the 2?D probe ? had to be held at a right angle to acquire a longitudinal scan, was unfamiliar (Fig.?3a, b). In contrast to the abdominal 3?D probe that acquired a pyramid-shaped volume with motor-controlled mechanical fan-shaped sweep of the scanning plane, a rotation method was selected for the volume acquisition with the 3?D vaginal probe for reasons of space. However, this had the disadvantage of central overlapping of all sectional planes resulting in limited image quality at the center (Fig.?3c, d). This disadvantage could not be eliminated until it became possible to perform a motor-controlled mechanical fan-shaped sweep of the imaging plane for volume acquisition with the 3?D vaginal probe. The introduction of the so-called surface mode made it possible to visualize surface images of the fetus and embryo with an abdominal as well as a vaginal 3?D probe. Due to the substantial processing power that this required, it initially (1992) took 6?hours to create one surface image with an external computer. Today a surface rendering of one image takes between 20 and 50 milliseconds depending on the volume. Parallel to this so-called internal or integrated system in which the complete 3?D unit is permanently integrated in the ultrasound unit and the 3?D probes are matched to the system (Fig.?4) 5, so-called external 3?D systems (e.?g. TomTec, Echotech, InViVo-System), in which acquisitions can be performed using any conventional 2?D probe, were also developed 5. An electromagnetic position sensor must simply be attached to the probe so that the transducer position and movements can be recorded on the basis of changes in the magnetic field (Fig.?4). After transfer of the individual 2?D images to a workstation, the images and their individual positions are assembled by a computer program to form a volume. The disadvantage of external systems is that the distances between the individual two-dimensional image planes are usually not identical due to the manual probe guidance, resulting in a lower volume quality, and that 4?D display is not possible 5. Due to the initial problems with 3?D ultrasound, many experienced 2?D ultrasound operators were initially skeptical of this new technique. Therefore, 3?D ultrasound was viewed as a difficult, inconvenient, and unn...

Evaluation of Freehand B-Mode and Power-Mode 3D Ultrasound for Visualisation and Grading of Internal Carotid Artery Stenosis

“…But given its invasive character with a frequency of periprocedural neurological complications of up to 2.6% [6], DSA is just recommended if non-invasive imaging modalities like two-dimensional colour-coded duplexsonography (2D-CDS), computed tomography angiography (CTA) or contrast-enhanced magnetic resonance angiography (CE-MRA) have yielded discordant results in before [4]. Three-dimensional ultrasound (3DUS) which is nowadays already routinely used in obstetrics [7] has the potential to visualise extracranial brain-supplying arteries similar to CTA or MRA and might ideally complement 2D-CDS which grades ICAS by predominantly assessing hemodynamic parameters [8, 9]. Studies that evaluated 3DUS for quantification of ICAS showed promising results (in chronological order [10–18]).…”

Fetal Cognitive Functions and 3D/4D Ultrasound

“…It can detect various malformations and clarify suspicious findings, improve diagnostic accuracy, display fascinating fetal activity and also, it supports the advancements in fetal neurobehavioral and cognitive science. 3 Apart from the US, fMRI and fMEG are also methods worth mentioning, as they offer an assessment of fetal brain function, notably the fetal response to the auditory and visual stimuli by fMRI, and the direct measurement of fetal neuronal activity by fMEG. 4 Data on cognitive functions of the fetus could be important in clinical practice for the management of fetal pain, treatment of preterm infants and improvement of the neurological outcome of the fetuses from highrisk pregnancies.…”

30-year anniversary of ultrasound: Clinical use of 3D ultrasound in obstetrics and gynecology (1989–2019)

“…2a, b) [12 -16]. The rapid advances in the field of computer technology and the design of special 3D probes have undoubtedly played an important role in this process [2,7]. However, all of these developments were only possible as a result of the vision of individual ultrasound companies, the dedicated work of engineers, and the ongoing collaboration between developers and users of 3D ultrasound in the clinical routine.…”

“…Of course, there is a learning curve involved in being able to effectively utilize all that 3D ultrasound has to offer. Precise control of image planes, surface images of outer and inner surfaces, transparent images, 3D display of vessels in fetuses and tumors, the ability to perform virtual examination of stored volumes [7,11] not requiring the patient to be present, and loss-free long-term storage of volumes [2,11] represent such major advantages that experienced ultrasound examiners can't imagine being without 3D ultrasound.…”

“…3D ultrasound also has major advantages for ultrasound training [7,11]. A volume containing a fetal abnormality or a tumor can be copied multiple times and loaded on numerous external workstations.…”