From the Guidelines
Transrectal Ultrasound (TRUS) is the best radiology test for benign prostatic hyperplasia (BPH) as it provides accurate measurements of prostate volume and assessment of the urethra and surrounding tissues 1.
Key Features of TRUS
- A 7.5-10 MHz transducer is typically used
- The patient is usually positioned in the lateral decubitus position
- TRUS has shown utility in guiding transperineal aspiration of the seminal vesicles and detecting abnormalities such as calcifications or calculi in the prostate, ejaculatory ducts, or seminal vesicles 1
Alternative Options
- Multiparametric Magnetic Resonance Imaging (MRI) of the prostate can also be employed, particularly for detecting prostate cancer in the setting of BPH, using a 3-Tesla machine and a combination of T2-weighted, diffusion-weighted, and dynamic contrast-enhanced sequences 1
- MRI is indicated if TRUS is negative or inconclusive, and can be used to evaluate for suspected prostate cancer or ejaculatory duct obstruction 1
From the Research
Diagnostic Performance of Radiology Tests for Benign Prostatic Hyperplasia (BPH)
- The diagnostic performance of various radiology tests for BPH has been evaluated in several studies 2, 3, 4, 5, 6.
- Transrectal ultrasound (TRUS) has been shown to have high diagnostic performance in detecting localized prostate cancer, with sensitivity, negative predictive value, and accuracy of 97.4%, 96.9%, and 87.2%, respectively 2.
- Multiparametric magnetic resonance imaging (MRI) has also been shown to have high diagnostic performance, with a mean area under the receiver operating characteristic curve of 0.774 ± 0.055 2.
- A study comparing the accuracy of computed tomography (CT), MRI, and TRUS in measuring prostate volume found that MRI and CT were equally effective, with correlations of 0.79 and 0.78, respectively, with the anatomic prostatic weight (APW) 4.
- TRUS has been shown to be a useful first-line investigation for detecting prostate neoplasms due to its low cost, easy availability, and comparable efficacy 5.
- MRI has been shown to be valuable in the definition of patients who may benefit from surgery and can be of help for evaluating the risk of a positive margin, especially in the apical resection 6.
Comparison of Radiology Tests for BPH
- A study comparing digital rectal examination (DRE), TRUS, and MRI found that MRI was the most accurate in detecting tumor volume and local extent of prostate cancer, with a linear correlation between predicted tumor volume and pathological tumor volume (r = 0.82, p < 0.0001) 6.
- Another study found that the combination of MRI and magnetic resonance spectroscopy (MRS) showed the highest diagnostic accuracy among the imaging modalities in detecting prostatic neoplasm, followed by MRI, and then by TRUS 5.
- A review of recent developments in ultrasonography modalities and functional MRI in the diagnosis of prostate cancer found that innovative ultrasound techniques and multiparametric MRI can provide benefits in accurately diagnosing prostate cancer 3.