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Transrectal ultrasonography, see there.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


(ul'tra-sownd?) [ ultra- + sound]
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Inaudible sound in the frequency range of approx. 20,000 to 10 billion (109) cycles/sec. Ultrasound has different velocities that differ in density and elasticity from one kind of tissue to the next. This property permits the use of ultrasound in outlining the shape of various tissues and organs in the body. In obstetrics, for example, identifying the size and position of the fetus, placenta, and umbilical cord enables estimation of gestational age, detects some fetal anomalies and fetal death, and facilitates other diagnostic procedures, e.g., amniocentesis. In physical therapy, the thermal effects of ultrasound are used to treat musculoskeletal injuries by warming tissue, increasing tissue extensibility, and improving local blood flow. Ultrasound is used to facilitate movement of certain medications, e.g., pain relievers, into tissue (phonophoresis). Ultrasound is also used with electric current for muscular stimulation. The diagnostic and therapeutic uses of ultrasound require special equipment. See: illustration; phonophoresis; sonographer; ultrasonography

A-mode ultrasound

In ultrasonography a display in which imaging data are represented as echo amplitudes (on the y-axis) and time (on the x-axis), similar to the way electromagnetic waves are represented on an oscilloscope.
Synonym: A-mode; A-mode (amplitude modulation) display

B-mode ultrasound

In ultrasonography, a display that uses dots of differing intensities to represent echoes received from tissues that more strongly or weakly reflect sound waves.
Synonym: ; B-scan

continuous wave ultrasound

A form of ultrasound used in echocardiography in which a dual crystal transducer continuously generates and receives an ultrasound signal. It is used to measure blood velocities, e.g., across heart valves. A serious shortcoming of continuous wave ultrasound is its inability to identify depth accurately.

continuous wave Doppler ultrasound

Doppler ultrasonography that uses spectral Doppler in a constant series of echoes both originating and being received by the same transducer. It is used to study obstruction to blood flow through vessels.

duplex Doppler ultrasound

Doppler ultrasonography that uses a transducer with two functions: pulsed-wave Doppler and B-mode imaging.

endobronchial ultrasound

Abbreviation: EBUS
The use of ultrasonic transducers carried within a bronchoscope to evaluate tissues in or adjacent to the trachea and bronchi. EBUS can be used to identify solid masses to be biopsied. It helps distinguish solid masses, which may be malignant, from blood vessels such as the aorta or pulmonary arteries, which should not be penetrated with a biopsy needle.

endorectal ultrasound

Abbreviation: ERUS
1. An imaging technique in which an ultrasound transducer is placed inside the rectum and used to evaluate the depth of colon and prostate cancers and the extent to which they have spread to neighboring lymph nodes.
2. Transrectal ultrasound.

endovaginal ultrasound

Transvaginal ultrasonography.

high-intensity focused ultrasound

Abbreviation: HIFU
A noninvasive form of thermotherapy in which ultrasonic energy is used to generate heat for therapeutic purposes within the body. HIFU has been used to cauterize internal blood vessels that are bleeding, to cavitate or coagulate growths or solid malignancies, e.g., breast, liver, pancreatic, or prostate cancers. The ultrasound transducer is placed on the skin and the energy from the transducer is directed at radiographically localized tissue depths and volumes.

interventional ultrasound

The use of ultrasonography as a guide for local injections or for the placement of catheters, needles, or probes into body cavities or tumors. Interventional ultrasound is used to treat hepatocellular carcinoma, prostate cancer, and other solid tumors.

intravascular ultrasound

Abbreviation: IVUS
In ultrasonography, a technique for imaging intimal tissue proliferation and blood vessel blockages.

keepsake fetal ultrasound

A colloquialism for a three-dimensional image of an unborn child visualized in the womb with ultrasonography treated as a memento. The image is kept by expectant parents as part of a scrapbook of pregnancy and anticipated childbirth.

M-mode ultrasound

An ultrasonic display mode in which the motion of structures is seen on the vertical axis of the display, used, e.g., to show the movement of the heart's valves and walls during diastole and systole.
Synonym: motion-mode display; time-motion mode ultrasound

pelvic ultrasound

Examination of the pelvis with an ultrasonic transducer placed inside the vagina. It is used in assessment of diseases or conditions affecting the cervix, uterus, fallopian tubes, or ovaries.
Synonym: endovaginal ultrasound.

pulsed-wave Doppler ultrasound, pulsed Doppler ultrasound

quantitative ultrasound

Abbreviation: QUS
Measurement of the density of a body tissue, e.g., bone, by determining how rapidly sound travels through the tissue and how different sonic wavelengths are absorbed. QUS is used to diagnose osteopenia and osteoporosis.

real-time ultrasound

A sonographic procedure that provides rapid, multiple images of an anatomical structure in the form of motion.

time-motion mode ultrasound

M-mode ultrasound.

transrectal ultrasound

Abbreviation: TRUS
Imaging of the prostate gland and periprostatic tissues with an ultrasound transducer inserted into the anus and directed toward the anterior rectum. It is used to identify malignant tumors, guide biopsies, and provide assessments of tumor staging.
Synonym: endorectal ultrasound (2)

transrectal ultrasound

Abbreviation: TRUS
Imaging of the prostate gland and periprostatic tissues with an ultrasound transducer inserted into the anus and directed toward the anterior rectum. It is used to identify malignant tumors, guide biopsies, and provide assessments of tumor staging.
Synonym: endorectal ultrasound (2)
See also: ultrasound
Medical Dictionary, © 2009 Farlex and Partners

Ultrasound, Prostate (Transrectal)

Synonym/acronym: Prostate sonography, TRUS.

Common use

To visualize and assess the prostate gland as an adjunct of prostate-specific antigen (PSA) blood testing and examination to assist in diagnosing disorders such as tumor and cancer. Also used to assist in guiding biopsy of the prostate.

Area of application

Prostate, seminal vesicles.


Done without contrast.


Ultrasound (US) procedures are diagnostic, noninvasive, and relatively inexpensive. They take a short time to complete, do not use radiation, and cause no harm to the patient. High-frequency sound waves of various intensities are delivered by a transducer, a candle-shaped device, which is lubricated, sheathed with a condom, and inserted a few inches into the rectum. The waves are bounced back off internal anatomical structures and fluids, converted to electrical energy, amplified by the transducer, and displayed as images on a monitor. US is often used as a diagnostic and therapeutic tool for guiding minimally invasive procedures such as needle biopsies and fluid aspiration. The contraindications and complications for biopsy and fluid aspiration are discussed in detail in the individual monographs.

Prostate US is used to evaluate the structure, size, and position of the contents of the prostate (e.g., masses). This procedure can evaluate abnormal pathology in prostate tissue, the seminal vesicles, and surrounding perirectal tissue. Prostate US aids in the diagnosis of prostatic cancer by evaluating palpable nodules as a complement to a digital rectal examination (DRE) or in response to an elevated PSA level. The DRE is a simple procedure used to examine, by palpation, the lower rectum and prostate gland. It is performed by the health-care provider (HCP) who inserts a lubricated, gloved finger into the rectum while the patient is properly positioned. Prostate US can also be used to stage carcinoma and to assist in radiation seed placement. Micturition disorders can also be evaluated by this procedure. The examination is helpful in monitoring patient response to therapy for prostatic disease.

This procedure is contraindicated for

    high alert Patients with latex allergy; use of the rectal probe requires the probe to be covered with a condom, usually made from latex. Latex-free covers are available.


  • Aid in the diagnosis of micturition disorders
  • Aid in prostate cancer diagnosis
  • Assess prostatic calcifications
  • Assist in guided needle biopsy of a suspected tumor
  • Assist in radiation seed placement
  • Determine prostatic cancer staging
  • Detect prostatitis

Potential diagnosis

Normal findings

  • Normal size, consistency, and contour of the prostate gland

Abnormal findings related to

  • Benign prostatic hypertrophy or hyperplasia
  • Micturition disorders
  • Perirectal abscess
  • Perirectal tumor
  • Prostate abscess
  • Prostate cancer
  • Prostatitis
  • Rectal tumor
  • Seminal vesicle tumor

Critical findings


Interfering factors

  • Factors that may impair clear imaging

    • Attenuation of the sound waves by pelvic bones, which can impair clear imaging of the prostate
    • Incorrect placement of the transducer over the desired test site; quality of the US study is very dependent upon the skill of the ultrasonographer
    • Metallic objects (e.g., jewelry, body rings) within the examination field, which may inhibit organ visualization and cause unclear images
    • Inability of the patient to cooperate or remain still during the procedure because of age, significant pain, or mental status
    • Gas or feces in the gastrointestinal tract resulting from inadequate cleansing before the study
    • Retained barium from a previous radiological procedure
  • Other considerations

    • Failure to follow pretesting preparations may cause the procedure to be canceled or repeated.

Nursing Implications and Procedure


  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this procedure can assist in evaluating the prostate gland.
  • Obtain a history of the patient’s complaints or clinical symptoms, including a list of known allergens, especially allergies or sensitivities to latex.
  • Obtain a history of the patient’s genitourinary system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Note any recent procedures that can interfere with test results (i.e., barium procedures, surgery, or biopsy). There should be 24 hr between administration of barium and this test.
  • Colonoscopy and computed tomography of the abdomen, if ordered, should be scheduled after this procedure.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
  • Review the procedure with the patient. Address concerns about pain related to the procedure and explain that some pain may be experienced during the test, and there may be moments of discomfort. Inform the patient that the procedure is performed in a US department by a health-care provider (HCP) who specializes in this procedure, with support staff, and takes approximately 30 to 60 min.
  • Inform the patient that a small volume enema will be administered prior to the procedure to help remove gas or feces that could interfere with the rectal probe; after the enema a sterile latex- or sheath-covered probe will be inserted into the rectum.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Note that there are no food or fluid restrictions unless by medical direction. The patient may be asked to restrict anticoagulants, aspirin and other salicylates by medical direction for the appropriate number of days prior to the procedure, especially if it is anticipated that a biopsy will be performed.


  • Potential complications: N/A
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
  • Instruct the patient to void and change into the gown, robe, and foot coverings provided.
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Instruct the patient to cooperate fully and to follow directions. Ask the patient to remain still throughout the procedure because movement produces unreliable results.
  • Place the patient on the examination table on his left side with his knees bent toward the chest; other positions may be used during the examination.
  • Expose the rectal area and drape the patient.
  • Cover the rectal probe with a lubricated condom and insert it into the rectum. Inform the patient that he may feel slight pressure as the transducer is inserted. Water may be introduced through the sheath surrounding the transducer.
  • Ask the patient to breathe normally during the examination. If necessary for better organ visualization, ask the patient to inhale deeply and hold his breath.


  • Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
  • When the study is completed, remove the gel from the skin.
  • Nutritional Considerations: There is growing evidence that inflammation and oxidation play key roles in the development of numerous diseases, including prostate cancer. Research also indicates that diets containing dried beans, fresh fruits and vegetables, nuts, spices, whole grains, and smaller amounts of red meats can increase the amount of protective antioxidants. Regular exercise, especially in combination with a healthy diet, can bring about changes in the body’s metabolism that decrease inflammation and oxidation.
  • Recognize anxiety related to test results. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate. Administer antibiotics as ordered, after biopsy. Educate the patient regarding access to counseling services. Provide contact information, if desired, for the National Cancer Institute ( or the Prostate Cancer Foundation (
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family. Decisions regarding the need for and frequency of routine PSA testing or other cancer screening procedures should be made after consultation between the patient and HCP. Recommendations made by various medical associations and national health organizations regarding prostate cancer screening are moving away from routine PSA screening and toward informed decision making. The American Cancer Society’s (ACS) guidelines recommend that discussions about screening should begin at age 50 yr for men at average risk, 45 yr for men at high risk, and 40 yr for men at the highest risk of developing prostate cancer. The most current guidelines for prostate cancer screening of the general population as well as of individuals with increased risk are available from the ACS ( and the American Urological Association (
  • Depending on the results of this procedure, additional testing may be needed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include biopsy prostate, CT pelvis, cystoscopy, cystourethrography voiding, IVP, KUB study, MRI pelvis, proctosigmoidoscopy, PSA, renogram, retrograde ureteropyelography, and semen analysis.
  • Refer to the Genitourinary System table at the end of the book for related tests by body system.
Handbook of Laboratory and Diagnostic Tests, © 2013 Farlex and Partners
References in periodicals archive ?
On the 30th day after insemination, 58 cows used in study were found to have a positive pregnancy from TRUS examinations.
A 2011 Cochrane review on prophylaxis for TRUS prostate biopsy demonstrated that antibiotics reduced bacteriuria, bacteremia, fever, urinary tract infection (UTI), and hospitalization compared to placebo or no treatment [3].
Calculation of Maximum Inventory of SNF and Radioactivity of TRUs. In this study, the Nuclear Fuel Cycle Simulation System (NFCSS) developed by the International Atomic Energy Agency (IAEA) was used to estimate the amount of SNF and TRUs from Korean NPPs.
Study inclusion criteria were prostate specific antigen 4 ug/L or greater, abnormal digital rectal examination and/ or TRUS suspicious lesions.
Infective complications are considered the most significant, with a noted increase after TRUS biopsy in recent years (Greene et al., 2015; Lee, 2015; Turner et al., 2011).
[9] were able to visualize the prostate by placing the TRUS probe onto the surface of the skin of the perineum.
Typically argon gas or liquid nitrogen is delivered for tumor freezing under TRUS guidance.
RBWRs could potentially use TRUs separated and refined from spent fuel as fuel along with uranium.
Accordingly it highlighted that PD-TRUS had a high NPV and therefore may help to reduce unnecessary biopsies when used as an additional tool during TRUS biopsies.13 A similar study on 108 men with elevated serum PSA levels reported an improved cancer detection rate since PDU could identify appropriate hyper-vascular sites for targeting the biopsy.
For each dimension, the average of TAUS and TRUS were calculated and then plotted against the difference of the two measurements.
All patients with tumor on TRUS biopsy (n = 15) had clinical stage [less than or equal to] T2a disease and a maximal length of cancer per positive core of [less than or equal to] 2 mm.