Ultrasound of the Prostate (Prostate Sonography)

Prostate sonography (synonym: ultrasound of the prostate) is a diagnostic imaging procedure from the medical specialty of urology that uses ultrasound to take images of the internal organs in the pelvic region. It is a non-invasive diagnostic procedure that does not require X-rays.Prostate ultrasonography is primarily used to evaluate prostate tissue or diagnose changes in the prostate. The prostate gland, also known as the prostate gland, is located in the male pelvis between the urinary bladder and the intestine.Furthermore, prostate sonography can be used to determine the prostate volume (prostate volumetry). In addition to the prostate, the vesicula seminalis (seminal vesicles), the urinary bladder, the ductus deferentes (vas deferens) and parts of the urethra (urethra) are assessed. Another field of application of prostate sonography is the surgical planning of interventions on the prostate, such as prostatectomy (removal of the prostate). This includes, for example, preoperative tumor staging (stage determination). For other indications, see below. Two procedures are available for performing prostate ultrasonography:

  • Transrectal ultrasound (TRUS; synonym: transrectal prostate sonography, TPS) – Endosonographic imaging of the prostate through the rectum, i.e., the ultrasound probe is inserted through the anus (anus) into the rectum (rectum). Since the prostate is in direct positional relationship with the rectum, it can be very easily and accurately detected by the ultrasound waves.
  • Suprapubic ultrasound – imaging of the prostate via the lower abdomen. This variant is rarely used in today’s clinical practice, because the accuracy of the examination is surpassed by transrectal ultrasound.

Indications (areas of application)

  • Annually from the age of 40 as a preventive measure.
  • Pathological palpation findings (palpation findings) (DRU; digital rectal examination).
  • Determination of the volume of the prostate
  • If changes in the prostate gland are suspected:
  • Changes in the vesicles seminalis (seminal vesicles).
  • Micturition disorders (disorders during urination)
  • Residual urine determination (determination of the amount of urine (urine) that remains in the urinary bladder after a normal micturition).
  • Suspected bladder outlet obstruction (partial or complete blockage of the urinary bladder, preventing urine from passing out through the urinary tract)
  • Detection (determination) of the causes of urinary retention.
  • Tightness test of urethra-bladder neck anastomosis (“surgical connection of urethra and bladder neck) after radical prostatectomy (surgical removal of prostate with capsule, the end pieces of the vas deferens, seminal vesicles and regional lymph nodes).
  • Sonographically guided prostate biopsy (ultrasound-guided prostate puncture or biopsy; see “ultrasound-guided prostate puncture” below).

Contraindications

There are no contraindications to performing transrectal prostate ultrasonography, as it is a noninvasive diagnostic procedure that does not use X-rays. However, if a biopsy (tissue sampling) is also performed, the patient’s blood clotting should be checked to prevent bleeding.

Before the examination

Routine prostate sonography does not require any preparations.During ultrasound-guided prostate puncture, it is recommended that the rectum be cleansed using a microenema, as this clears the rectum of both intestinal air and fecal debris. Furthermore, this reduces the rate of infection.

Procedure

During the examination, the patient lies either laterally in the fetal position (right or left) or in the lithotomy position. The ultrasound probe is covered with a condom. Before inserting the probe, the urologist first performs a digital rectal examination (examination of the rectum/ rectum with a finger; DRU). Frequently, a conspicuous palpation finding forms the basis for the indication for sonography.The ultrasound probe is then slowly inserted into the rectum and the prostate is sampled by slowly advancing it. In addition to the prostate, the vesicula seminalis (seminal vesicles), the urinary bladder, the ductus deferentes (vas deferens), and portions of the urethra (urethra; pars praeprostatica (from the urinary bladder wall to the prostate), pars prostatica (prostate portion), and pars membranacea (pelvic floor portion)) are assessed. Special attention is paid to the condition of the prostate tissue; inhomogeneities may indicate a neoplasm or inflammation. Prostate carcinoma: On transrectal sonography, carcinomas are predominantly visualized as echo-deficient areas (hypoechogenicity). In one study, 71% of carcinomas had a hypoechogenic appearance, and 27% were isoechogenic. It should be noted that hypoechogenicity is also carcinoma in only a small proportion (30%).The sonographic malignancy criteria (criteria of malignancy) of a prostate carcinoma are:

  • Irregular boundary
  • Nodular or cluster conspicuity (cluster, bundle, swarm, pile),
  • Extension of the conspicuity on the outside of the peripheral zone.
  • Increased blood flow

Bladder outlet obstruction (partial or total blockage of the urinary bladder, preventing urine from passing out through the urinary tract): This is done by determining the detrusor thickness (detrusor vesicae muscle; muscles involved in emptying the urinary bladder). If this is ≥ 2 mm with a bladder filling ≥ 250 ml, then bladder outlet obstruction is very likely (∼ 95%). Chronic prostatitis (inflammation of the prostate): in this case, dystrophic calcifications can be detected. Prostate volumetry is an integral part of the examination, as it provides important diagnostic parameters. Here, the volume is calculated from the longitudinal and the cross section. Its volume is 20 to 30 cubic centimeters (cm3/ml) and its normal weight is about 15 to 20 grams. If the prostate sonography is abnormal, there is an indication for a puncture or biopsy. The biopsy is performed as a so-called systematic biopsy (SB) with transrectal ultrasound in B-scan mode (B-TRUS; echo signals are visualized as two-dimensional sectional images in grayscale). Meanwhile, similar to multiparametric or also functional magnetic resonance imaging (mp-MRI, magnetic resonance imaging), there is also the simultaneous application of structural (B-TRUS) and functional TRUS techniques under the term multiparametric TRUS (mpTRUS). This procedure leads to increased diagnostic accuracy in prostate cancer diagnosis through functional tissue information, such as tissue hardness or blood flow pattern.It seems likely that with multiparametric MRI the number of unnecessary biopsies could be reduced without increasing the risk of missing a clinically relevant prostate cancer; the diagnosis-free survival of patients with category 1 and 2 index lesions was 99.6% at 3 years. Ultrasound-guided prostate puncture (synonym: sonographically guided prostate puncture) can be used to detect and evaluate prostate carcinoma, among other procedures. Prostate carcinoma is usually detected by histologic (fine tissue) examination of prostate lung biopsies. A prostate biopsy (tissue removal) is only performed in cases of reasonable suspicion, such as abnormal palpation of the prostate or suspicious ultrasound findings in transrectal sonography or abnormal PSA values. Prostate-specific antigen is a so-called tumor marker that can be elevated in a prostate tumor and provides an indication of the presence of this disease.

After the examination

No special measures are necessary after prostate ultrasonography.

Possible complications

Since this is a noninvasive procedure, no complications are usually expected. Only the insertion of the ultrasound probe represents an unfamiliar and uncomfortable situation for the patient.

Your benefit

Transrectal prostate ultrasonography is for your prostate cancer screening and can protect you from cancer detected too late.Regular examination is for maintaining your health and vitality. Prostate cancer detected in time can be cured.