XXXX localization with endorectal MR imaging and MR spectroscopic imaging: effect of clinical data on reader accuracy.

@entity1 @entity263 @entity5 @entity1486
PURPOSE: To determine the effect of digital rectal examination findings, sextant biopsy results, and @entity1486 levels on reader accuracy in the localization of @entity263 with endorectal magnetic resonance (MR) imaging and MR spectroscopic imaging. MATERIALS AND METHODS: This was a retrospective study of 37 @entity1 (mean age, 57 years) with biopsy-proved @entity263 . Transverse T1-weighted, transverse high-spatial-resolution, and coronal T2-weighted MR images and MR spectroscopic images were obtained. Two independent readers, unaware of clinical data, recorded the size and location of suspicious peripheral zone @entity5 nodules on a standardized diagram of the prostate. Readers also recorded their degree of diagnostic confidence for each nodule on a five-point scale. Both readers repeated this interpretation with knowledge of rectal examination findings, sextant biopsy results, and @entity1486 level. Step-section histopathologic findings were the reference standard. Logistic regression analysis with generalized estimating equations was used to correlate @entity5 detection with clinical data, and alternative free-response receiver operating characteristic (AFROC) curve analysis was used to examine the overall effect of clinical data on all positive results. RESULTS: Fifty-one peripheral zone @entity5 nodules were identified at histopathologic evaluation. Logistic regression analysis showed awareness of clinical data significantly improved @entity5 detection rate (P <.02) from 15 to 19 nodules for reader 1 and from 13 to 19 nodules for reader 2 (27%-37% overall) by using both size and location criteria. AFROC analysis showed no significant change in overall reader performance because there was an associated increase in the number of false-positive findings with awareness of clinical data, from 11 to 21 for reader 1 and from 16 to 25 for reader 2. CONCLUSION: Awareness of clinical data significantly improves reader detection of @entity263 nodules with endorectal MR imaging and MR spectroscopic imaging, but there is no overall change in reader accuracy, because of an associated increase in false-positive findings. A stricter definition of a true-positive result is associated with reduced sensitivity for @entity263 nodule detection.
