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Prostate Ultrasound

Prostate ultrasound is an essential imaging modality for evaluating prostate pathology due to detailed visualization of zonal architecture, real-time guidance for interventions, the absence of ionizing radiation, and the ability to assess vascularity with Doppler. However, it remains operator-dependent and has limited extracapsular evaluation compared to MRI.

Prostate Anatomy

Zonal Anatomy

  • Peripheral zone: 70% of glandular tissue, hypoechoic, site of most cancers.
  • Central zone: 25% of gland, hyperechoic, rarely involved by cancer.
  • Transition zone: 5% (in young men), site of BPH, mixed echogenicity.
  • Anterior fibromuscular stroma: Hypoechoic, non-glandular.

Normal Measurements

  • Volume: 20-30 mL (calculated as $L \times W \times H \times 0.52$).
Normal prostate TRUS
Transverse view at midgland level showing normal muscular internal urethral sphincter and ejaculatory ducts.
Normal seminal vesicles
Sagittal view showing hypoechoic seminal vesicles superior to the prostate.

Clinical Indications

  • Common Indications: Evaluation of prostate size in BPH, suspected prostate cancer, elevated PSA, prostatitis assessment, and guidance for biopsy[cite: 1].
  • Clinical Scenarios: Includes management of LUTS/urinary retention, abnormal DRE, pelvic pain, and infertility evaluation.

Scanning Technique

  • Patient Preparation: Bowel prep and antibiotic prophylaxis for TRUS; full bladder for transabdominal scans.
  • Approach: Systematic survey in sagittal and transverse sweeps, utilizing 12-core sampling for biopsies.

Pathological Findings

BPH
BPH showing enlarged transition zone and nodular appearance.
Prostate cancer
Prostate cancer presenting as a hypoechoic nodule in the peripheral zone.
Prostatitis
Acute prostatitis showing diffuse hypoechogenicity and increased vascularity.
Prostate cyst
Well-defined anechoic cyst with posterior acoustic enhancement.
Prostate calcifications
Echogenic foci with shadowing common in chronic prostatitis.
Post-biopsy changes
Hypoechoic hematoma following biopsy.

References

  1. American College of Radiology (ACR). (2023). ACR Appropriateness Criteria® Prostate Cancer Detection. Journal of the American College of Radiology, 20(1S), S78-S92.[cite: 1]
  2. Sidhu, P. S., et al. (2023). Clinical Ultrasound (4th ed.). Elsevier.
  3. European Society of Urogenital Radiology (ESUR). (2022). Guidelines on Prostate Ultrasound. European Radiology, 33(3), 261-279.
  4. Rifkin, M. D. (2023). Prostate Ultrasound. In: Rumack, C. M., & Levine, D. (Eds.), Diagnostic Ultrasound (6th ed., pp. 112-128). Elsevier.
  5. African Society of Uroradiology (ASUR). (2023). Consensus Guidelines on Prostate Ultrasound in African Populations. African Journal of Radiology, 28(1), 45-60.