Ultrasound technology with its advancements is vital for delivering high-quality patient care. Innovations including high-frequency ultrasound, 3D//4D imaging, contrast enhanced ultrasound, elastography, and point-of-care ultrasound, have expanded the capabilities of ultrasound imaging and improved diagnostic accuracy.
B-Mode imaging, also known as brightness mode, is the fundamental technique in ultrasound imaging. It produces two-dimensional images based on the echoes received from tissues and organs. Understanding the principles of B-Mode imaging, such as gain adjustment, depth control, and image optimization, is crucial for obtaining diagnostically valuable images. M-Mode imaging, on the other hand, allows for the visualization of motion over time, enabling assessment of cardiac structures and function, as well as fetal heart rate.
High-frequency ultrasound refers to the use of ultrasound waves with frequencies greater than 10 MHz. This technology enables improved resolution, allowing for detailed imaging of superficial structures like skin, tendons, and small organs. High-frequency ultrasound has found applications in dermatology, ophthalmology, and musculoskeletal imaging.
Traditional 2D ultrasound has been augmented by the advent of 3D ultrasound technology. By acquiring multiple 2D images from different angles, this technique construct a volumetric representation of the imaged area. The addition of 4D ultrasound in real-time motion adds further value by capturing dynamic processes.
Doppler imaging employs the Doppler effect to evaluate blood flow within vessels and assess hemodynamics. Color Doppler assigns color to different blood flow velocities, providing a visual representation of blood flow direction and speed. Spectral Doppler displays blood flow velocities as a waveform, allowing for detailed analysis of flow patterns, resistance, and stenosis.
Contrast enhanced ultrasound employs microbubble contrast agents to enhance the visualization of blood flow and tissue perfusion. By injecting these agents intravenously, sonographers can differentiate between vascular structures and lesions. Elastography is a technique that measures tissue elasticity or stiffness. It assists in differentiating between normal and abnormal tissues, aiding in the diagnosis of various conditions such as liver fibrosis, breast lesions, and thyroid nodules.
Fusion imaging combines ultrasound with other imaging modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET). By overlaying or merging ultrasound images with those obtained from other modalities, the user can precisely locate and characterize abnormalities, guide interventions, and improve diagnostic accuracy. Fusion imaging has proven particularly useful in areas such as interventional radiology, oncology, and urology.
See also Equipment Preparation, Environmental Protection, Handheld Ultrasound, Portable Ultrasound and Ultrasound Accessories and Supplies.

Urologic ultrasound includes the examination of the kidneys, renal vessels, urinary tract, bladder, prostate, and scrotum.
Usual gray scale ultrasound equipment and standard probes are sufficient to examine the kidney parenchyma and renal pelvis, the urinary tract and bladder. Doppler ultrasound is a useful adjunct to kidney ultrasound. High ultrasound system performance is desirable to show the arterial system, because advanced power Doppler is significantly more sensitive to blood flow than standard color Doppler.
Transurethral sonography may be used to examine the bladder and urethra. Transrectal sonography is used to scan and treat the prostate e.g., with brachytherapy or high intensity focused ultrasound. Very small probes are used for these applications. Reflux sonography is especially used in pediatric ultrasound.

See also Ultrasound Imaging Procedures, Ultrasound Picture, Ultrasound Imaging Modes, Lithotripsy, Thermotherapy, Brachytherapy and Ultrasound Therapy.

2D ultrasound imaging is a widely used technique in medical imaging that provides two-dimensional visual representations of internal structures. A handheld device known as a probe or transducer contains piezoelectric crystals that emit and receive ultrasound waves which penetrate tissues and bounce back as echoes. The echoes are detected and converted into electrical signals. These signals are processed and displayed on a monitor, creating a real-time 2D grayscale image, with different shades of gray representing various tissue densities. The brighter areas on the image correspond to structures that reflect more ultrasound waves, while darker areas represent structures that reflect fewer waves or are attenuated by intervening tissues. The 2D-mode (or B-mode) provides cross-sectional views of the scanned area, showing a single plane or slice of the scanned area at a time.

Key Features and Uses of 2D Ultrasound:

Comparison with 3D and 4D Ultrasound:
See also Ultrasound Technology, Sonographer, Ultrasound Elastography, Obstetric and Gynecologic Ultrasound.

As low as reasonably achievable (ALARA) is in ultrasound imaging (ultrasonography) as well as in other medical imaging modalities (MRI, X-RAY, etc.) the guiding principle to keep patient exposure as low as possible for the diagnostic result.

(AUS) Abdominal ultrasound, also known as abdominal sonography, is a medical imaging technique that focuses on the visualization and assessment of the abdominal organs. While 'abdominal ultrasound' is the commonly used term, there are alternative terms that can be used to refer to this imaging modality: (TAE) transabdominal echography, abdominal ultrasonography, sonogram, FAST (Focused Assessment with Sonography for Trauma).
Abdominal ultrasound imaging is an invaluable clinical tool for identifying the underlying cause of abdominal pain. An abdominal ultrasound examination encompasses a comprehensive evaluation of the liver, gallbladder, biliary tree, pancreas, spleen, kidneys, and abdominal blood vessels. It is a cost-effective, safe, and non-invasive medical imaging modality that is typically utilized as the initial diagnostic investigation.
Advanced ultrasound techniques, such as high-resolution ultrasound, endoscopic ultrasound, and contrast-enhanced Doppler, further enhance the detection of small lesions and provide detailed information for precise diagnosis.
To prepare for an abdominal ultrasound, it is recommended to have nothing to eat or drink for at least 8 hours, starting from midnight the night before the examination.

Indications:
FAST (Focused Assessment with Sonography for Trauma) is a rapid diagnostic test used for trauma patients. It sequentially evaluates the presence of free fluid in the pericardium (hemopericardium) and in four specific views of the abdomen. These views include the right upper quadrant (RUQ), left upper quadrant (LUQ), subcostal, and suprapubic views. They aid in identifying hemoperitoneum in patients with potential truncal injuries. The space between the liver and the right kidney (RUQ), known as Morison's pouch, is a location where intraperitoneal fluid can accumulate.
Emergency abdominal ultrasonography is indicated in cases of suspected aortic aneurysm, appendicitis, biliary and renal colic, as well as blunt or penetrating abdominal trauma. It plays a crucial role in the timely assessment and management of these conditions, providing critical information to guide appropriate treatment decisions.

See also Handheld Ultrasound, Pelvic Ultrasound, Pregnancy Ultrasound, Prostate Ultrasound, Interventional Ultrasound and Pediatric Ultrasound.