OBJECTIVE: To retrospectively determine the optimal b value of diffusion-weighted imaging (DWI) for predicting the presence of localized prostate cancer, and to evaluate the utility of DWI under different b values in differentiating between cancers and benign prostatic tissues.
MATERIALS AND METHODS: Eighty patients with suspected prostate cancer underwent MRI including DWI at 3T, followed by radical prostatectomy. DWI was examined under different b values. Apparent diffusion coefficient (ADC) maps were generated by using b = 0, and other b values of 300, 700, 1000 or 2000 s/mm2. For predicting the presence of cancers, four different ADC maps were analyzed independently by two blinded readers. ADCs were measured in benign and malignant tissues.
RESULTS: For predicting the presence of 110 prostate cancers, the sensitivity and area under the curve (AUC) for an experienced reader was significantly greater at b = 1000 (85% and 0.91) than b = 300, 700 or 2000 s/mm2 (p < 0.01). For a less-experienced reader, the AUC was significantly greater at b = 700, 1000 or 2000 than b = 300 s/mm2 (p < 0.01). Mean ADCs of the cancers in sequence from b = 300 to 2000 s/mm2 were 1.33, 1.03, 0.88 and 0.68 × 10-3 mm2/s, which were significantly lower than those of benign tissues (p < 0.001).
CONCLUSION: The optimal b value for 3T DWI for predicting the presence of prostate cancer may be 1000 s/mm2.
Written by:
Koo JH, Kim CK, Choi D, Park BK, Kwon GY, Kim B. Are you the author?
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Korea.
Reference: Korean J Radiol. 2013 Jan;14(1):61-9.
doi: 10.3348/kjr.2013.14.1.61
PubMed Abstract
PMID: 23323032
UroToday.com Prostate Cancer Section
