Article

Transabdominal prostate ultrasound

Transabdominal prostate ultrasound: technique with a full bladder, volume calculation, post-void residual, findings and when to indicate the transrectal route.

What it is and when to indicate it

Transabdominal (suprapubic) prostate ultrasound estimates prostate volume and assesses the bladder and emptying, being useful in lower urinary tract symptoms, suspected benign prostatic hyperplasia, retention and follow-up. It does not replace the transrectal route for detailed characterization or targeted biopsy.

This page organizes the protocol in clear language and does not replace the original guidelines (AIUM, ACR, CBR), supervised training or clinical correlation.

Preparation and technique

• A comfortably full bladder serves as an acoustic window to the prostate
• Curved transducer of 2 to 5 MHz, suprapubic approach angled caudally
• Measure the prostate in three diameters (transverse, anteroposterior and longitudinal)
• Assess the bladder (walls, content, stones) and estimate the post-void residual
• Document in two planes; note a protruding median lobe when present

Prostate volume and PSA density

Volume is the main information from the abdominal route and guides management and PSA interpretation.

• Volume estimated by the ellipsoid formula: 0.52 x three diameters (in cm), result in cm3/grams
• Normal prostate volume generally around 20 to 30 cm3, increasing with age
• PSA density = PSA divided by volume, helps interpret intermediate PSA values
• A median lobe protruding into the bladder suggests an obstructive component
• Correlate volume with symptoms (IPSS) and with the post-void residual

Bladder and repercussions

• Wall thickening and trabeculation suggest chronic obstruction
• Diverticula and bladder stones described when present
• A significant post-void residual reinforces the emptying repercussion
• Upper urinary tract dilation should be searched for in significant obstruction
• An inadequately full bladder limits the prostate assessment — note it

Limits of the abdominal route and when to request transrectal

• The abdominal route estimates volume and assesses the bladder, but does not characterize the peripheral zone well
• It is not adequate for detailed evaluation of suspicious nodules or for biopsy
• Suspected cancer (abnormal exam, elevated PSA) directs to the transrectal route and/or multiparametric MRI
• Obesity and an empty bladder reduce the accuracy of the volume
• Report the limitations and the recommended complementary method

Normal report template

• Prostate of estimated dimensions and volume within the reference for age
• Regular contours, without a significant protruding median lobe
• Bladder with thin walls and anechoic content, with good emptying
• Post-void residual within limits
• Upper urinary tract without dilation in the accessible assessment

Do not overdiagnose

The abdominal route quantifies volume and repercussions; it should not generate conclusions about malignancy. Describe what is seen, correlate with PSA and digital rectal exam, and refer to the transrectal route/MRI when the suspicion is clinically relevant.

Sources

Educational content; it does not replace original guidelines, medical evaluation or supervised training. Main references:

• AIUM-AUA-SRU. Practice Parameter for the Performance of an Ultrasound Examination of the Prostate.
• ACR-AIUM-SPR-SRU. Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.
• Brazilian College of Radiology (CBR). Standardization and technical guidelines for ultrasound.
• Rumack CM, Levine D. Diagnostic Ultrasound (prostate and bladder).
• Radiopaedia. Prostate ultrasound (didactic support, not copied).

Need to contact the Sono Ai Report team?