Purpose:To determine the interobserver reproducibility of the Prostate Imaging Reporting and Data System (PI-RADS) version 2 lexicon.
Materials and Methods:This retrospective HIPAA-compliant study was institutional review board-approved. Six radiologists from six separate institutions, all experienced in prostate magnetic resonance (MR) imaging, assessed prostate MR imaging examinations performed at a single center by using the PI-RADS lexicon. Readers were provided screen captures that denoted the location of one specific lesion per case. Analysis entailed two sessions (40 and 80 examinations per session) and an intersession training period for individualized feedback and group discussion. Percent agreement (fraction of pairwise reader combinations with concordant readings) was compared between sessions. k coefficients were computed.
Results:No substantial difference in interobserver agreement was observed between sessions, and the sessions were subsequently pooled. Agreement for PI-RADS score of 4 or greater was 0.593 in peripheral zone (PZ) and 0.509 in transition zone (TZ). In PZ, reproducibility was moderate to substantial for features related to diffusion-weighted imaging (k = 0.535-0.619); fair to moderate for features related to dynamic contrast material-enhanced (DCE) imaging (k = 0.266-0.439); and fair for definite extraprostatic extension on T2-weighted images (k = 0.289). In TZ, reproducibility for features related to lesion texture and margins on T2-weighted images ranged from 0.136 (moderately hypointense) to 0.529 (encapsulation). Among 63 lesions that underwent targeted biopsy, classification as PI-RADS score of 4 or greater by a majority of readers yielded tumor with a Gleason score of 3+4 or greater in 45.9% (17 of 37), without missing any tumor with a Gleason score of 3+4 or greater.
Conclusion:Experienced radiologists achieved moderate reproducibility for PI-RADS version 2, and neither required nor benefitted from a training session. Agreement tended to be better in PZ than TZ, although was weak for DCE in PZ. The findings may help guide future PI-RADS lexicon updates.q RSNA, 2016
Portomesenteric venous thrombosis following laparoscopic surgery usually manifests as nonspecific abdominal pain. Computed tomography can readily provide the diagnosis and demonstrate the extent of the disease. Treatment should be individualized based on the extent of thrombosis and the presence of bowel ischemia but should include anticoagulation therapy. Venous stasis from increased intra-abdominal pressure, intraoperative manipulation of splanchnic vasculature, and systemic thrombophilic states likely converges to produce this potentially lethal condition.
Objectives
Overutilization of computed tomography (CT) is a growing public health concern due to increasing health care costs and exposure to radiation; these must be weighed against the potential benefits of CT for improving diagnoses and treatment plans. The objective of this study was to determine the national trends of CT and ultrasound (US) utilization for assessment of suspected urolithiasis in emergency departments (EDs), and if these trends are accompanied by changes in diagnosis rates for urolithiasis or other significant disorders, and hospitalization rates.
Methods
This was a retrospective cross-sectional analysis of ED visits from the National Hospital Ambulatory Medical Care Survey (NHAMCS) between 1996 and 2007. The authors determined the proportion of patient visits for flank or kidney pain receiving CT or US testing, and calculated the diagnosis and hospitalization rates for urolithiasis and other significant disorders. Patient-specific and hospital-level variables associated with the use of CT were examined.
Results
Utilization of CT to assess patients with suspected urolithiasis increased from 4.0% to 42.5% over the study period (p-value < 0.001). In contrast, the use of US remained low, at about 5%, until it decreased beginning in 2005 to 2007 to 2.4% (p-value = 0.01). The proportion of patients diagnosed with urolithiasis (approximately 18%, p-value = 0.55), other significant diagnoses (p-values > 0.05), and admitted to the hospital (approximately 11%, p-value = 0.49) did not change significantly. The following characteristics were associated with a higher likelihood of receiving a CT scan: male sex (odd ratio [OR] = 1.83, 95% confidence interval [CI] = 1.22 to 2.77), patients presenting with severe pain (OR = 2.96, 95% CI = 1.14 to 7.65), and those triaged in 15 minutes or less (OR = 2.41, 95% CI = 1.08 to 5.37). CT utilization was lower for patients presenting to rural hospitals (vs. urban areas) (OR = 0.34, 95% CI = 0.19 to 0.61), and those managed by a non-physician health care provider (OR = 0.19, 95% CI = 0.07 to 0.53).
Conclusions
From 1996 to 2007, there was a 10-fold increase in the utilization of CT scan for patients with suspected kidney stone without an associated change in the proportion of diagnosis of kidney stone, diagnosis of significant alternate diagnoses, or admission to the hospital.
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