The prostate is a walnut-shaped gland surrounding the beginning of the urethra in front of the rectum and below the bladder. The prostate can become enlarged (particularly in men over age 50) and develop diseases like prostate cancer or inflammation (prostatitis). A large tumor can be felt by a rectal examination. The most effective way of detecting the early signs of prostate cancer is a combination of a prostate-specific antigen (PSA) blood test and a prostate ultrasound examination.
An abnormally high level of PSA can indicate prostate cancer or other prostate diseases such as benign prostatic hypertrophy or prostatitis. The transrectal sonography is an important diagnostic ultrasound procedure in determining whether there is any benign enlargement of the prostate or any abnormal nodules.
The imaging is performed with a rectal probe, yielding high resolution. High resolution 3D ultrasound provides reliable and accurate determination of the size and the location of cancer. Additionally, ultrasound elastography is a technique in development to improve the specificity and sensitivity of cancer detection. Ultrasound is also used to detect whether cancerous tissue is still only within the prostate or whether it has begun to spread out and to guide a diagnostic biopsy or ultrasound therapy.

See also Brachytherapy, and High Intensity Focused Ultrasound.

(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.

Brachytherapy is a radiation therapy in which radioactive material (radioisotopes) sealed in needles, seeds or wires is placed directly into or near a tumor. Brachytherapy uses ultrasound imaging to visualize the needles for accurate placement of the small seeds or pellets (capsules) directly into e.g., the prostate. Ultrasound imaging allows accurate planning, placement and implantation of the radiation sources. Implantation of the seeds is a minimally invasive procedure.
Radioactive seeds are inserted through the perineum skin (the area between the scrotum and the anus) into the prostate gland. With correct planning, the surgeon can implant the radiation sources for maximum benefits to effective cancer treatment.

See also EchoSeed™, Prostate Ultrasound, Thermotherapy, High Intensity Focused Ultrasound, Urologic Ultrasound, Transurethral Sonography.

The usual applications of endocavitary echography (also called internal echography / endoscopic ultrasound (EUS)) are examinations of the pelvic organs through internally introduced probes, which give a more precise and correct image.
Transrectal ultrasound is a well established method for rectal or prostate carcinoma assessment.
A transvaginal echography uses a small transducer that is inserted directly into the vagina.
Used are high-frequency (10-12 MHz) for superficial organs, endocavitary echography, and intraoperative laparoscopic ultrasound. A sterile cover is slipped over the probe, which is then covered with lubricating ultrasound gel and placed in the cavitary (see Equipment Preparation).

See also Endoscopic Ultrasound, Prostate Ultrasound, Interventional Ultrasound, Transurethral Sonography, Vaginal Probe, Rectal Probe.

(US) Also called echography, sonography, ultrasonography, echotomography, ultrasonic tomography.
Diagnostic imaging plays a vital role in modern healthcare, allowing medical professionals to visualize internal structures of the body and assist in the diagnosis and treatment of various conditions. Two terms that are commonly used interchangeably but possess distinct meanings in the field of medical imaging are 'ultrasound' and 'sonography.'
Ultrasound is the imaging technique that utilizes sound waves to create real-time images, while sonography encompasses the entire process of performing ultrasound examinations and interpreting the obtained images. Ultrasonography is a synonymous term for sonography, emphasizing the use of ultrasound technology in diagnostic imaging. A sonogram, on the other hand, refers to the resulting image produced during an ultrasound examination.
Ultrasonic waves, generated by a quartz crystal, cause mechanical perturbation of an elastic medium, resulting in rarefaction and compression of the medium particles. These waves are reflected at the interfaces between different tissues due to differences in their mechanical properties. The transmission and reflection of these high-frequency waves are displayed with different types of ultrasound modes.
By utilizing the speed of wave propagation in tissues, the time of reflection information can be converted into distance of reflection information. The use of higher frequencies in medical ultrasound imaging yields better image resolution. However, higher frequencies also lead to increased absorption of the sound beam by the medium, limiting its penetration depth. For instance, higher frequencies (e.g., 7.5 MHz) are employed to provide detailed imaging of superficial organs like the thyroid gland and breast, while lower frequencies (e.g., 3.5 MHz) are used for abdominal examinations.

Ultrasound in medical imaging offers several advantages including:

Diagnostic ultrasound imaging is generally considered safe, with no adverse effects. As medical ultrasound is extensively used in pregnancy and pediatric imaging, it is crucial for practitioners to ensure its safe usage. Ultrasound can cause mechanical and thermal effects in tissue, which are amplified with increased output power. Consequently, guidelines for the safe use of ultrasound have been issued to address the growing use of color flow imaging, pulsed spectral Doppler, and higher demands on B-mode imaging. Furthermore, recent ultrasound safety regulations have shifted more responsibility to the operator to ensure the safe use of ultrasound.

See also Skinline, Pregnancy Ultrasound, Obstetric and Gynecologic Ultrasound, Musculoskeletal and Joint Ultrasound, Ultrasound Elastography and Prostate Ultrasound.