A prostate ultrasound is an imaging procedure that uses high-frequency sound waves to create real-time pictures of the prostate gland and surrounding tissues. This test is non-invasive or minimally invasive, and provides a visualization of the gland’s size, shape, and internal structure. The procedure is recommended when a healthcare provider needs more information to evaluate the prostate’s condition. The resulting images help doctors determine if further diagnostic steps are necessary or if treatment planning can begin.
Why a Prostate Ultrasound is Recommended
A healthcare provider may recommend a prostate ultrasound for several specific diagnostic purposes. It is often used to investigate symptoms such as difficulty urinating or a weakened urine stream, which can indicate benign prostatic hyperplasia (BPH).
The procedure is also frequently used as a follow-up when a blood test shows elevated levels of Prostate-Specific Antigen (PSA) or when a physical exam reveals an abnormal finding. Ultrasound is valuable for accurately measuring the prostate’s volume, which aids in planning treatments for BPH or determining PSA density. Most significantly, the ultrasound provides a visual guide for a prostate biopsy, which is necessary to definitively diagnose prostate cancer.
Patient Preparation and Expectations
Preparing for a prostate ultrasound involves specific steps that vary depending on the method the physician plans to use.
Transabdominal Preparation
For a transabdominal approach, which involves scanning through the lower abdomen, patients are often instructed to arrive with a full bladder. A full bladder helps push the prostate closer to the abdominal wall, creating a clearer imaging window for the sound waves.
Transrectal Preparation
If a transrectal ultrasound (TRUS) is anticipated, preparation focuses on clearing the rectum to ensure the clearest possible path for the probe. Patients are usually asked to perform a cleansing enema one to four hours before the appointment. It is also common to be instructed to empty the bladder just before the procedure. Furthermore, patients often need to temporarily stop taking blood-thinning medications for about seven to ten days before the procedure, especially if a biopsy is planned, to minimize the risk of bleeding.
Distinguishing the Ultrasound Methods
There are two primary ways a prostate ultrasound can be performed: transabdominal and transrectal.
Transabdominal Ultrasound
The transabdominal method is a non-invasive technique where the ultrasound probe is placed on the lower abdomen. This approach is often used for an initial, general assessment of prostate size.
Transrectal Ultrasound (TRUS)
The transrectal ultrasound (TRUS) is the method most commonly used for detailed imaging and biopsy guidance. For TRUS, a specialized probe is inserted directly into the rectum, which is separated from the prostate by only a thin wall. This proximity allows the transducer to produce much higher-resolution images of the prostate’s internal architecture. TRUS is the preferred method for detecting specific abnormalities and accurately guiding a biopsy needle because it offers superior image quality due to its direct access.
Step-by-Step: The Transrectal Ultrasound Procedure
The transrectal ultrasound procedure is typically an outpatient process that takes between five and fifteen minutes to complete. The patient is positioned on the examination table, most often lying on their left side with their knees drawn toward their chest. This positioning provides the best access for the physician.
Before the probe is inserted, the doctor may perform a brief digital rectal exam to assess the prostate and prepare the area. The ultrasound probe is a specialized, slender instrument, often described as being about the size of an adult index finger. It is covered with a protective sheath and coated with a sterile lubricating gel.
The physician gently inserts the lubricated probe into the rectum, advancing it until it is positioned directly against the prostate. The patient may experience a sensation of pressure or fullness, but the procedure is generally painless.
Once positioned, the probe emits sound waves that are instantly translated into a real-time image displayed on a monitor. The doctor rotates and angles the probe to capture a complete set of images, measuring the prostate’s dimensions and checking for suspicious areas. If a biopsy is performed, the ultrasound images guide the placement of a fine needle to collect tissue samples from specific areas of the gland.
Receiving Results and Follow-Up
Immediately following the procedure, the ultrasound probe is removed, and the patient can typically return to normal activities without restriction. If the procedure included a biopsy, the patient may be advised to avoid strenuous activity or heavy lifting for a couple of days. Follow-up instructions often include taking prescribed antibiotics to prevent infection, which is a particular concern after a biopsy.
The images captured are analyzed by a radiologist or urologist, who generates a formal report. If a biopsy was performed, the tissue samples are sent to a pathology lab for microscopic examination, which can take between one and three weeks. The final results are delivered by the referring physician, who explains the findings to the patient.
The results clarify the prostate’s status, indicating whether the size is normal, if there are signs of BPH, or if abnormal areas were identified. If the pathology report confirms the presence of cancer, the physician will discuss the next steps, such as further testing or beginning a treatment plan based on the aggressiveness of the cells. If the initial results were inconclusive, the provider may recommend continued monitoring or additional imaging.