Transrectal ultrasound
Transrectal ultrasound (TRUS) is a medical procedure that utilizes ultrasonic waves to examine the prostate gland, primarily serving as a guide for prostate biopsies rather than as a standalone screening tool for prostate cancer. The technique is particularly relevant in evaluating various prostate conditions, including benign prostatic hyperplasia (BPH), prostatitis, and less commonly seen prostate cancers. While its positive predictive value for cancer detection is limited, TRUS is widely used to help visualize the prostate's structure, as cancerous lesions may present in different forms, appearing either hypoechoic or hyperechoic on imaging.
During the procedure, the patient typically prepares by cleaning the rectum and may need to adjust certain medications beforehand. The ultrasound probe is inserted into the rectum to obtain images, and while some discomfort may occur, the process itself is generally painless. Following the examination, results are interpreted by a radiologist, who may recommend further testing based on findings. Additionally, advancements like MRI integration and microultrasound have enhanced the accuracy of TRUS, allowing for better diagnosis and treatment planning. Overall, patients are encouraged to discuss any concerns with their healthcare provider regarding the procedure, its risks, and its implications for their health.
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Transrectal ultrasound
ALSO KNOWN AS: Prostate sonography; endorectal ultrasound
DEFINITION: Transrectal ultrasound is a procedure that uses ultrasonic waves to evaluate the prostate gland, primarily by acting as a guide for prostate biopsies.
Cancers diagnosed:Prostate cancer
Why performed: Since the positive predictive value of transrectal ultrasound has been shown in several studies to be insufficient for the detection of prostate cancer, it is not a reliable screening test. Therefore, the primary role of transrectal ultrasound is to guide prostate biopsies. The sonographic appearance of prostate cancer is variable, with approximately 60 to 70 percent of cancer appearing hypoechoic (lower in density). The remainder of prostate cancers can appear hyperechoic (higher in density) or a mixture of both, and they can be either nodular or infiltrative. Cystic cancer is rare. Although classic cancer of the prostate presents as a hypoechoic nodule in the peripheral zone, not all such nodules actually represent cancer. conditions that can be visualized on transrectal ultrasound include prostatitis, atrophy, fibrosis, infarct, and benign prostatic hyperplasia (BPH).
Patient preparation: The scan is usually performed as an outpatient procedure. A few days before the procedure, the patient may need to stop certain medications, such as aspirin products and blood thinners. On the day of the procedure, the patient cleans the rectum, as with an enema.
Steps of the procedure: The patient is placed on his side on a table, and the technologist or the radiologist applies a water-based conducting gel to the probe to study the organ or body part of interest, in this case the prostate gland. The transducer is designed to be inserted inside the rectum, and it may feel uncomfortable. The sonographer then rubs the handheld probe or transducer across the surface of the prostate gland. There will be some discomfort from pressure, but the ultrasound waves themselves are painless.
After the procedure: The scan is generated by the computer attached to the ultrasound probe and read by the radiologist. The patient will need to contact his doctor or healthcare provider for the report and any follow-up therapy.
Risks: The study is relatively harmless, as no radiation is involved. Related side effects are soreness and light bleeding from the biopsy if performed. Use of the transrectal probe is a decision made by the healthcare provider, not the sonographer or radiologist. The patient should consult his healthcare provider if he has any questions or concerns regarding the use of the transrectal probe and talk to his health professional about any concerns regarding the need for the ultrasound, its risks, how it will be done, and what the results indicate.
Results: The results are dependent on the type of scan performed and the reason for the study. If evidence of cancer is found, additional tests will be ordered to confirm the diagnosis and suggest a course of treatment. The effectiveness and accuracy of transrectal ultrasound can be improved if a doctor first performs magnetic resonance imaging (MRI). Following the ultrasound, the MRI images can be superimposed over the ultrasound images for a more accurate picture. Microultrasounds can provide more precise and more defined images of the prostate. High-intensity focused ultrasound focal therapy combines therapeutic techniques with ultrasound, treating localized cancers. Measuring prostate specific antigen (PSA) density and using precision point needles have also improved the diagnostic abilities of transrectal ultrasound.
Bibliography
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