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) 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 classified as inflammatory or noninflammatory)
- IV: asymptomatic inflammatory prostatitis
Contrast enhanced CT is the best imaging tool if abscess suspected and will demonstrate a diffusely enlarged, edematous 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 post transurethral resection of the prostate (TURP). The infection can extend through capsule into 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 hypo-intense to transitional zone
- T2: hyperintense
- T1 C+ (Gd) diffusely enhancing 6
Focal hypoechoic region in the peripheral zone of the gland. Discrete fluid collection suggests abscess formation. Colour Doppler ultrasound demonstrates increase flow in the periphery of the abscess.
Treatment and prognosis
Prostatitis can be complicated by prostatic abscess. Diuretics and anti-inflammatory medications may be an alternative option to treat prostatitis, especially for chronic non-bacterial prostatitis.
- granulomatous prostatitis can be mistaken for prostatic carcinoma, especiallty on transrectal ultrasound 3-4.
- prostate tumours
- infections of the prostate
- benign prostatic hypertrophy
- cystic lesions of the prostate
- prostate cancer
- 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