Most usual ultrasound machines are 2D real-time systems. This types of ultrasound scanners allow to assess both motion and anatomy, including the motion of heart valves, the movement of intestines and lungs and also to guide interventions, like for example a biopsy or a laparoscopic ultrasound.
A standard real-time scanner consists of a mobile console with the monitor on the top and rows of small containers at the bottom to accommodate a variety of scanner probes. The linear, curved or phased array transducers are usually equipped with multiple crystals or in some cases with a moving crystal. A real-time scanner may be e.g., a mechanical scanner or electronic array scanner.

See also Musculoskeletal and Joint Ultrasound.

The 2D-mode (2-Dimensional-mode) is a spatially oriented B-mode (brightness) ultrasound. The imaged structures are displayed 2 dimensional as a function of depth and width. The brightness level is based on the echo signal amplitude.
Most of the ultrasound devices in medical imaging are 2D real-time scanner. The image is created by a rapidly back and forth swept sound beam over the region of interest.

See also Gray Scale.

Also called B-mode echography, B-mode sonography, 2D-mode, and sonogram.
B-mode ultrasound (Brightness-mode) is the display of a 2D-map of B-mode data, currently the most common form of ultrasound imaging.
The development from A-mode to B-mode is that the ultrasound signal is used to produce various points whose brightness depends on the amplitude instead of the spiking vertical movements in the A-mode. Sweeping a narrow ultrasound beam through the area being examined while transmitting pulses and detecting echoes along closely spaced scan lines produces B-scan images. The vertical position of each bright dot is determined by the time delay from pulse transmission to return of the echo, and the horizontal position by the location of the receiving transducer element.
To generate a rapid series of individual 2D images that show motion, the ultrasound beam is swept repeatedly. The returning sound pulses in B-mode have different shades of darkness depending on their intensities. The varying shades of gray reflect variations in the texture of internal organs. This form of display (solid areas appear white and fluid areas appear black) is also called gray scale.

Different types of displayed B-mode images are:
The probe movement can be performed manual (compound and static B-scanner) or automatic (real-time scanner).
The image reconstruction can be parallel or sector type.

See also B-Scan, 4B-Mode, and Harmonic B-Mode Imaging.

Ultrasound is an ideal tool to examine the joints and surrounding soft tissues like tendons, ligaments and joint linings. Musculoskeletal and joint sonography is sensitive, without radiation exposure, easy accessible, quick, and has high patient tolerability with relatively low cost.
A real-time scanner allow the dynamic assessment of the musculoskeletal system and a specific examination for each patient. In addition, joint aspiration and injection accuracy can be improved. Probes with high frequency improve the image resolution and allow visualization of fine anatomic structures of the small parts. As musculoskeletal ultrasound (MSUS) is very operator dependent, experience and training is required. Ultrasound is also often used in the treatment of musculoskeletal disorders.

See also Ultrasound Therapy, Real-Time Mode, Artifact and Ultrasound Biomicroscopy.

Gynecologic ultrasound and obstetric ultrasound are two distinct applications of ultrasound imaging that serve different purposes in the field of women's health. While both involve the use of ultrasound technology to examine the pelvic region, they have different focuses and objectives.

Gynecologic [gynaecologic, Brit.] ultrasound primarily concentrates on the evaluation of the female reproductive organs, including the uterus, ovaries, fallopian tubes, and surrounding structures. It is commonly performed for various gynecological concerns, such as abnormal bleeding, pelvic pain, infertility investigations, and monitoring of reproductive disorders. It can identify signs of inflammation, the presence of free fluid, cysts, and tumors. This non-invasive technique aids in diagnosing and monitoring gynecological pathologies, facilitating early intervention and appropriate treatment. Typically, a transabdominal sonogram is performed with a full bladder to provide an initial assessment. However, if the pelvic ultrasound reveals any abnormalities or fails to provide a clear image of the organs, a more detailed evaluation can be achieved through a transvaginal sonography. This approach allows for improved visualization of the uterus and ovaries by placing the ultrasound probe inside the vagina.

Obstetric ultrasound, also known as prenatal, fetal or pregnancy ultrasound, is the branch of medical imaging that focuses on the use of ultrasound technology to assess the health and development of a fetus during pregnancy. Women with uncomplicated pregnancies commonly undergo an ultrasound examination between the 16th and 20th week of gestation. This routine assessment, performed with a real-time scanner, serves to determine accurate gestational age, monitor fetal size, and assess overall growth. The middle of the pregnancy trimester provides a crucial window for detecting many abnormalities of fetal anatomy. Advanced imaging techniques enable healthcare professionals to identify potential structural issues. Early detection of these abnormalities allows for timely intervention, counseling, and the implementation of appropriate management strategies.
See also Pregnancy Ultrasound, Pelvic Ultrasound, Hysterosalpingo Contrast Sonography and Vaginal Probe.