Prostatitis refers to an infection or inflammation of the prostate gland that presents as several syndromes with varying clinical features. Prostatitis is a clinical diagnosis and imaging is useful to evaluate abscess formation.
The National Institutes of Health (NIH) have classified prostatitis into four distinct syndromes 1:
- I: acute bacterial prostatitis
- II: chronic bacterial prostatitis
III: chronic prostatitis and chronic pelvic pain syndrome (CPPS)
- further subclassified as inflammatory or non-inflammatory
- IV: asymptomatic inflammatory prostatitis
Focal hypoechoic region in the peripheral zone of the gland. Discrete fluid collection suggests abscess formation. Colour Doppler ultrasound demonstrates increased flow in the periphery of the abscess.
Contrast-enhanced CT is the best imaging tool if abscess suspected and will demonstrate a diffusely enlarged, oedematous gland with predilection for peripheral zone involvement.
When an abscess is present it is seen as a rim-enhancing, unilocular or multilocular, hypodensity in the peripheral zone. Central zone involvement is encountered in status post-transurethral resection of the prostate (TURP) patients. The infection can extend through the capsule into the periprostatic tissues, seminal vesicles, and peritoneum.
The prostate will be diffusely enlarged, often with associated inflammatory changes of periprostatic fat and of the seminal vesicles 6.
- T1: peripheral zone iso- or hypointense to transition zone
- T2: hyperintense
- T1 C+ (Gd) diffusely enhancing 6
Treatment and prognosis
Antibiotics are the mainstay of treatment for bacterial prostatitis. In cases of chronic non-bacterial prostatitis, diuretics and anti-inflammatory medications may be needed instead.
- 1. Krieger JN, Nyberg L, Nickel JC. NIH consensus definition and classification of prostatitis. JAMA. 1999;282 (3): 236-7. JAMA (link) - Pubmed citation
- 2. Nickel JC. Prostatitis: diagnosis and classification. Curr Urol Rep. 2003;4 (4): 259-60. - Pubmed citation
- 3. Naik KS, Carey BM. The transrectal ultrasound and MRI appearances of granulomatous prostatitis and its differentiation from carcinoma. Clin Radiol. 1999;54 (3): 173-5. - Pubmed citation
- 4. Clements R, Thomas KG, Griffiths GJ et-al. Transrectal ultrasound appearances of granulomatous prostatitis. Clin Radiol. 1993;47 (3): 174-6. - Pubmed citation
- 5. Doble A, Carter SS. Ultrasonographic findings in prostatitis. Urol. Clin. North Am. 1989;16 (4): 763-72. Pubmed citation
- 6. Hricak H, Carrington BM. MRI of the Pelvis. Appleton & Lange. (1991) ISBN:0838565271. Read it at Google Books - Find it at Amazon
Related Radiopaedia articles
- prostate tumours
- infections of the prostate
- benign prostatic hypertrophy
- cystic lesions of the prostate
- prostatic calcification
- prostatic infarction