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.

(HyCoSy) Hysterosalpingo contrast sonography is used for evaluation of fallopian tube patency in patients with fertility problems who underwent transvaginal sonography. HyCoSy compared to more invasive techniques such as chromo-laparoscopy is rapidly becoming the screening test of choice to determine tubal patency.
Any body cavity that can be accessed can, in principle, be injected with vascular contrast. The contrast agent is instilled into the uterine cavity via a small Foley type catheter and, using transvaginal echography, the passage of the echogenic contrast along the tubes and into the adnexal peritoneum is tracked.
Hysterosalpingo contrast sonography does not offer the same anatomical and false negative results, e.g., because of tubal spasm, are possible so conventional X-ray salpingography is needed when tubal surgery is an option.

See also Endocavitary Echography, Transvaginal Sonography.

Interventional ultrasound, also known as ultrasonography, encompasses a range of invasive or surgical procedures guided by ultrasound imaging. While its widest application lies in intravascular ultrasound imaging for measuring atherosclerotic plaque, it has proven valuable in various medical fields.
In urology, ultrasound-guided interventions are employed for treatments like high intensity focused ultrasound (HIFU) in prostate conditions. The precise imaging provided by ultrasound aids in targeting the affected area and delivering therapeutic energy effectively.
In intraabdominal conditions, endoscopic ultrasound is frequently utilized. This technique combines ultrasound imaging with an endoscope to visualize and evaluate structures within the gastrointestinal tract, allowing for precise diagnoses and targeted interventions.
Ultrasound-guided procedures play a significant role in several medical specialties, including liver sonography, obstetric and gynecologic ultrasound, and thyroid ultrasound. These procedures involve interventions such as RF thermal ablation or biopsies, which are guided by real-time ultrasound imaging.
For instance, in liver sonography, ultrasound guidance is crucial for performing biopsies or RF thermal ablation, a technique used to treat liver tumors by delivering localized heat to destroy the abnormal tissue. The real-time imaging allows for precise needle placement and monitoring during the procedure.
In obstetric and gynecologic ultrasound, ultrasound-guided procedures, such as biopsies, can be performed to obtain tissue samples for diagnostic purposes. Additionally, ultrasound guidance is valuable during interventions like amniocentesis or fetal blood sampling, enabling accurate and safe procedures.
Thyroid ultrasound procedures often involve ultrasound-guided fine-needle aspiration biopsy (FNAB), which allows for the sampling of thyroid nodules for cytological examination. The ultrasound image helps guide the needle into the targeted area, ensuring accurate sampling and minimizing potential complications.
Overall, ultrasound-guided interventions provide minimally invasive and precise approaches to diagnosis and treatment. The real-time imaging capabilities of ultrasound contribute to enhanced accuracy, safety, and patient outcomes in procedures like biopsies, injections, and drainage.

See also Transurethral Sonography, Endocavitary Echography, and B-Mode Acquisition and Targeting.

The array of elements of microconvex probe is curved with a certain radius. Microconvex probes have a much smaller contact surface, which improves the coupling between the transducer and the skin surface even in complicated areas as the supraclavicular or jugular fossa. Microconvex probes, with large aperture and selection of transmission frequencies are also used in gynecological diagnostic.

See also Transvaginal Echography, Endocavitary Echography and Transrectal Ultrasonography.

A transducer assembly is the configuration of an ultrasound transducer. Electronic array transducers are composed of multiple crystal elements e.g., linear array and phased array transducer assemblies. A handheld mechanical probe may contain a mechanically driven single element transducer, or a rotating wheel transducer. Static B-scanner (obsolete) had a cylindrical probe with a single disk-shaped piezoelectric crystal.
Some probes are designed to be inserted in body cavities (vagina, rectum, esophagus) so that they can get closer to the organ being examined (uterus, prostate gland, heart); getting closer to the region of interest allow for a more detailed view.

See also Endocavitary Echography, Endoscopic Ultrasound, Vaginal Transducer and Rectal Probe.