Contrast material-induced nephrotoxicity and intravenous low-osmolality iodinated contrast material: risk stratification by using estimated glomerular filtration rate.

PURPOSE: To determine the effect of intravenous (IV) low-osmolality iodinated contrast material (LOCM) on the development of post-computed tomography (CT) acute kidney injury (AKI), stratified by pre-CT estimated glomerular filtration rate (eGFR), in patients with stable renal function. MATERIALS AND METHODS: Institutional review board approval was obtained and patient consent waived for this HIPAA-compliant, retrospective study. CT examinations performed over a 10-year period on unique adult inpatients with sufficient serum creatinine (SCr) data and stable renal function (difference between baseline and pre-CT SCr within 0.3 mg/dL and 50% of baseline) were identified. A 1:1 propensity score matched cohort analysis with multivariate analysis of effects was performed with post-CT AKI as the primary outcome measure (8826 nonenhanced and 8826 IV contrast agent-enhanced CT studies in 17 652 patients). Propensity matching was performed with respect to likelihood of receiving IV contrast material (19 tested covariates). Post-CT AKI with Acute Kidney Injury Network SCr criteria was the primary endpoint. A stepwise multivariate conditional logistic regression model was performed to identify the effect of IV LOCM on post-CT AKI. RESULTS: After 1:1 propensity matching, IV LOCM had a significant effect on the development of post-CT AKI (P = .04). This risk increased with decreases in pre-CT eGFR (≥ 60 mL/min/1.73 m(2): odds ratio, 1.00; 95% confidence interval: 0.86, 1.16; 45-59 mL/min/1.73 m(2): odds ratio, 1.06; 95% confidence interval: 0.82, 1.38; 30-44 mL/min/1.73 m(2): odds ratio, 1.40; 95% confidence interval: 1.00, 1.97; <30 mL/min/1.73 m(2): odds ratio, 2.96; 95% confidence interval: 1.22, 7.17). CONCLUSION: IV LOCM is a nephrotoxic risk factor in patients with a stable eGFR less than 30 mL/min/1.73 m(2), with a trend toward significance at 30-44 mL/min/1.73 m(2). IV LOCM does not appear to be a nephrotoxic risk factor in patients with a pre-CT eGFR of 45 mL/min/1.73 m(2) or greater.

Anticoagulant therapy and risk of cerebrovascular events after catheter ablation of atrial fibrillation in the elderly.

INTRODUCTION: Factors associated with cerebrovascular events (CVEs) after radiofrequency catheter ablation (RFA) of atrial fibrillation (AF) have not been well defined in elderly patients (≥65 years). The purpose of this study was to determine the prevalence and predictors of CVEs after RFA in patients with AF ≥65 years old, in comparison to patients <65 years, and with or without AF. METHODS AND RESULTS: This study included 508 consecutive patients ≥65 years old (mean age: 70 ± 4 years), who underwent RFA for paroxysmal (297) or persistent (211) AF. A stratified group of 508 patients < 65 years old who underwent RFA for AF served as a control group. All patients were anticoagulated with warfarin for ≥3 months after RFA. A perioperative CVE (≤4 weeks after RFA) occurred in 0.8% and 1% of patients ≥65 and <65 years old, respectively (P = 1). Among the patients ≥65 years old who remained in sinus rhythm after RFA, warfarin was discontinued in 60% and 56% of the patients with a CHADS(2) score of 0 and ≥1, respectively. Paroxysmal AF, no history of CVE, and successful RFA were independent predictors of discontinuing warfarin. During a mean follow-up of 3 ± 2 years, a late CVE (>4 weeks after the RFA) occurred in 15 of 508 (3%) of patients ≥65 years old (1% per year) and in 5 of 508 (1%) patients <65 years old (0.3% per year, P = 0.03). Among patients ≥65 years old, age >75 years old (OR = 4.9, ±95% CI: 3.3-148.5, P = 0.001) was the only independent predictor of a CVE. Among patients <65 years old, body mass index was the only independent predictor of a late CVE (OR = 1.2, ±95% CI: 1.03-1.33, P = 0.02). CONCLUSIONS: The risk of a periprocedural CVE after RFA of AF is similar among patients ≥65 and <65 years old. Late CVEs after RFA are more prevalent in older than younger patients with AF, and age >75 years old is the only independent predictor of late CVEs regardless of the rhythm, anticoagulation status, or the CHADS(2) score (Congestive heart failure, Hypertension, Age ≥ 75 years, Diabetes mellitus and prior Stroke or transient ischemic attack).

Comparative investigation of i.v. iohexol and iopamidol: effect on renal function in low-risk outpatients undergoing CT.

OBJECTIVE: The purpose of our study was to compare the effects of i.v. iohexol and iopamidol on renal function in outpatients undergoing CT. SUBJECTS AND METHODS: We performed a prospective, double-blind, randomized clinical trial of 389 adults with low risk for contrast-induced nephropathy, comparing i.v. iohexol with iopamidol (300 mg I/mL). Serum creatinine (SCr) concentration was measured at baseline and 2 and 3 days after contrast administration. A noninferiority analysis was planned to compare the mean maximum SCr change from baseline between subject groups. Contrast-induced nephropathy rates (three definitions) for both contrast agents were compared as a secondary end point. RESULTS: One hundred ninety and 199 subjects received iohexol and iopamidol, respectively. The mean change in SCr from baseline using the maximum day 2 or 3 measurement was 0.07 ± 0.12 mg/dL (95% CI, 0.05-0.09 mg/dL) for the iohexol group and 0.05 ± 0.12 mg/dL (95% CI, 0.03-0.07 mg/dL) for the iopamidol group. The difference between contrast agents with respect to the mean change in SCr from baseline was -0.02 ± 0.12 mg/dL (95% CI, -0.045 to 0.003 mg/dL; p = 0.08). Contrast-induced nephropathy rates were not statistically different using any definition. CONCLUSION: Although our results were unable to show absolute noninferiority of iohexol compared with iopamidol because of a very small difference in increase in mean SCr from baseline (using a noninferiority margin of 0.04 mg/dL), this difference is likely of minimal or no clinical importance in outpatients undergoing CT with low risk for contrast-induced nephropathy.

Utility of pretreatment mean apparent diffusion coefficient and apparent diffusion coefficient histograms in prediction of outcome to chemoradiation in head and neck squamous cell carcinoma.

PURPOSE: This study aimed to evaluate pretreatment whole-tumor mean apparent diffusion coefficient (ADC) and ADC histogram as predictors of outcome to chemoradiation in patients with head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: Patients with HNSCC underwent pretreatment 3-T diffusion-weighted magnetic resonance imaging with calculation of mean ADC and ADC histograms. Outcomes were determined 2 years after chemoradiation. Positive outcome was defined as no abnormal 18-fluoro deoxy glucose uptake on posttherapy computed tomography-positron emission tomography (or abnormal uptake that was proven benign), no locoregional recurrence or metastatic disease, and no requirement for salvage surgery. Negative outcome was defined as residual abnormal 18-fluoro deoxy glucose avidity that was proven malignant, salvage surgery requirement, locoregional recurrence or metastatic disease, death, or a combination of these. A 2-sample t test was used to compare the mean ADC between patients with positive and negative outcomes. The ADC cut point for dividing the groups was determined by looking at its distribution. A Kaplan-Meier plot was produced, and a log-rank test was conducted with calculation of sensitivity, specificity, and positive and negative predictive values. RESULTS: Nine patients showed positive and 8 showed negative outcomes. Significant difference (P = 0.03) was seen in mean ADC (in 10 mm/s) between patients showing positive and negative outcomes (1.18 and 1.43, respectively). According to the log-rank test, tumors with greater than 45% of their volume below the ADC threshold of 1.15 × 10 mm/s were more likely to have a positive outcome (accuracy, 77%). CONCLUSIONS: Patients with HNSCC demonstrating lower pretreatment ADC and with greater than 45% of volume below ADC threshold of 1.15 × 10 mm/s may have better outcome to chemoradiation at 2 years.

Interleukin 17 as a novel predictor of vascular function in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is associated with enhanced cardiovascular (CV) risk and subclinical vascular disease. The proinflammatory milieu has been linked to premature atherosclerosis and endothelial dysfunction in RA. While interleukin 17 (IL-17) is considered pathogenic in RA, its role in determining vascular dysfunction in this disease has not been systematically assessed. OBJECTIVES: To analyse candidate variables that might determine endothelial function in various vascular territories in a cohort of patients with RA receiving treatment with biological agents, with minimal traditional CV risk factors and low disease activity score. METHODS: Patients with RA (n=50) receiving stable treatment with biological agents underwent measurement of conduit artery endothelial function by brachial artery flow-mediated dilatation; arterial compliance by pulse wave velocity (PWV) assessment; and endothelium-dependent microvascular testing with Endo-Pat2000 device to assess the reactive hyperaemia index (RHI). IL-17 was quantified by ELISA and disease activity was assessed by 28-joint count Disease Activity Score. RESULTS: IL-17 was the main determinant of lower RHI in univariate and multivariate analysis. Traditional and non-traditional CV risk variables determined PWV, with a significant positive association with IL-17 in univariate and multivariate analysis. In contrast, conduit endothelial function was mainly determined by rheumatoid factor titres in univariate and multivariate analysis. Anti-cyclic citrullinated peptide titres, specific disease-modifying antirheumatic drugs or biological agents and disease activity did not determine vascular function. CONCLUSION: In patients with RA treated with biological agents, IL-17 is a main predictor of microvascular function and arterial compliance. This study suggests that IL-17 may play a significant role in development of endothelial dysfunction and cardiovascular disease in RA.

Prevalence and predictors of complications of radiofrequency catheter ablation for atrial fibrillation.

INTRODUCTION: Up to 6% of patients experience complications after radiofrequency catheter ablation (RFA) of atrial fibrillation (AF). The purpose of this study is to determine the prevalence and predictors of periprocedural complications after RFA for AF. METHODS AND RESULTS: The subjects were 1,295 consecutive patients (age = 60 ± 10 years) who underwent RFA (n = 1,642) for paroxysmal (53%) or persistent AF (47%) from January 2007 to January 2010. A complication occurred in 57 patients (3.5%); a vascular access complication in 31 (1.9%); pericardial tamponade in 20 (1.2%); a thromboembolic event in 4 (0.2%); deep venous thrombosis in 1 (<0.01%); and pulmonary vein stenosis in 1 patient (<0.01%). There were no procedure-related deaths. On multivariate analysis, female gender (OR = 2.27; ±95% CI: 1.31-2.57, P < 0.01) and procedures performed in July or August (OR = 2.10; ±95% CI: 1.16-3.80, P = 0.01) were independent predictors of any complication. For vascular complications, treatment with clopidogrel (OR = 4.40; ±95% CI: 1.43-13.53, P = 0.01), female gender (OR = 3.65; ±95% CI: 1.72-7.75, P < 0.01) and performing RFA in July or August (OR = 2.71; ±95% CI: 1.25-5.87, P = 0.01) were independent predictors. The only predictor of cardiac tamponade was prior RFA (OR = 3.32; ±95% CI: 0.95-11.61; P < 0.05). CONCLUSION: Prevalence of perioperative complications for RFA of AF is 3.5% and vascular access complications constitute the majority. The need for clopidogrel therapy should be carefully considered prior to RFA. At teaching institutions close supervision should be exercised during vascular access early in the year. Improvements in ablation technology and elimination of the need for repeat procedures may decrease the risk of pericardial tamponade.

Extra Z-axis coverage at CT imaging resulting in excess radiation dose: frequency, degree, and contributory factors.

OBJECTIVE: To assess the degree of extra scanning beyond the prescribed anatomic boundaries for thoracic and body computed tomographic (CT) scans and to identify associated factors. METHODS: For 442 consecutive chest, abdomen, and/or pelvis CT examinations, the length of extra scanning beyond the prescribed anatomic boundaries was determined. Examinations were grouped according to the locations/types of the prescribed boundaries and compared with regard to length of extra scanning. RESULTS: Of 442 CT examinations, 438 (99%) included extraneous imaging, showing a mean excess scanning length of 43.2 mm per examination (range, 0-180 mm). Significantly more extraneous imaging was performed when soft tissue or vascular structures defined anatomic boundaries compared to when osseous (P < 0.001) or air/soft tissue interfaces (P < 0.0001) defined the boundaries. The average percent of total scan dose attributable to extra imaging was 8.64% to 10.38%. CONCLUSIONS: Computed tomographic scanning beyond the prescribed anatomic boundaries occurs commonly, resulting in moderate extra radiation dose.

Ulcerlike projections developing in noncommunicating aortic dissections: CT findings and natural history.

OBJECTIVE: Aortic ulcerlike projections are focal, contrast-filled outpouchings projecting from the aortic lumen. Our aim was to document the CT findings and natural history of ulcerlike projections developing in patients with preexisting noncommunicating aortic dissection, including intramural hematoma or false lumen thrombosis. MATERIALS AND METHODS: By searching the radiology information system, we found 38 ulcerlike projections arising in an underlying noncommunicating aortic dissection that were identified at CT in 24 patients. Clinical factors were determined from patient records. CT scans were reviewed to determine aortic pathology type and appearance time of ulcerlike projections and to measure the diameters of the aorta and ulcerlike projections for comparison over time. Complications were defined as an increase of at least 20% in the diameters of the ulcerlike projections or aorta, the need for surgical repair, or both. Comparisons of ulcerlike projections with and without complications were performed using various statistical tests. RESULTS: The underlying aortic disease of the 38 ulcerlike projections was intramural hematoma in 26, false lumen thrombosis in nine, and unknown in three. The mean time of ulcerlike projection appearance was 2.4 months (SD, 1.8) for intramural hematoma and 19.3 months (SD, 18.1) for false lumen thrombosis. Nine of the 28 ulcerlike projections with follow-up scans showed stability, size decrease, or resolution; 10 increased in size; and nine were incorporated into an expanded aortic lumen. Four of 36 ulcerlike projections with imaging or clinical follow-up (or both) required surgical repair. The only clinical or imaging feature significantly associated with the development of complications was false lumen thrombosis (p = 0.04). CONCLUSION: Ulcerlike projections forming in noncommunicating dissections may enlarge over time, although they rarely require surgical repair. Given the potential for critical complications, these lesions should be followed with serial CT scans.

Modeling biological rhythms in failure time data.

BACKGROUND: The human body exhibits a variety of biological rhythms. There are patterns that correspond, among others, to the daily wake/sleep cycle, a yearly seasonal cycle and, in women, the menstrual cycle. Sine/cosine functions are often used to model biological patterns for continuous data, but this model is not appropriate for analysis of biological rhythms in failure time data. METHODS: We adapt the cosinor method to the proportional hazards model and present a method to provide an estimate and confidence interval of the time when the minimum hazard is achieved. We then apply this model to data taken from a clinical trial of adjuvant of pre-menopausal breast cancer patients. RESULTS: The application of this technique to the breast cancer data revealed that the optimal day for pre-resection incisional or excisional biopsy of 28-day cycle (i. e. the day associated with the lowest recurrence rate) is day 8 with 95% confidence interval of 4-12 days. We found that older age, fewer positive nodes, smaller tumor size, and experimental treatment were predictive of longer relapse-free survival. CONCLUSION: In this paper we have described a method for modeling failure time data with an underlying biological rhythm. The advantage of adapting a cosinor model to proportional hazards model is its ability to model right censored data. We have presented a method to provide an estimate and confidence interval of the day in the menstrual cycle where the minimum hazard is achieved. This method is not limited to breast cancer data, and may be applied to any biological rhythms linked to right censored data.

Determining the preferred modality for real-time biofeedback during balance training.

Vestibular rehabilitation therapy has been shown to improve balance and gait stability in individuals with vestibular deficits. However, patient compliance with prescribed home exercise programs is variable. Real-time feedback of exercise performance can potentially improve exercise execution, exercise motivation, and rehabilitation outcomes. The goal of this study is to directly compare the effects of visual and vibrotactile feedback on postural performance to inform the selection of a feedback modality for inclusion in a home-based balance rehabilitation device. Eight subjects (46.6±10.6years) with peripheral vestibular deficits and eight age-matched control subjects (45.3±11.1years) participated in the study. Subjects performed eyes-open tandem Romberg stance trials with (vibrotactile, discrete visual, continuous visual, and multimodal) and without (baseline) feedback. Main outcome measures included medial-lateral (M/L) and anterior-posterior mean and standard deviation of body tilt, percent time spent within a no-feedback zone, and mean score on a comparative ranking survey. Both groups improved performance for each feedback modality compared to baseline, with no significant differences in performance observed among vibrotactile, discrete visual, or multimodal feedback for either group. Subjects with vestibular deficits performed best with continuous visual feedback and ranked it highest. Although the control subjects performed best with continuous visual feedback in terms of mean M/L tilt, they ranked it lowest. Despite the observed improvements, continuous visual feedback involves tracking a moving target, which was noted to induce dizziness in some subjects with vestibular deficits and cannot be used during exercises in which head position is actively changed or during eyes-closed conditions.

Proximal thoracic aortic diameter measurements at CT: repeatability and reproducibility according to measurement method.

AIM: To determine the variability in CT measurements of proximal thoracic aortic diameters obtained using double-oblique short axis and semiautomatic centerline analysis techniques. Institutional review board approval, with waiver of informed consent, was obtained for this HIPAA-compliant, retrospective study. Cardiac gated thoracic aortic CT scans were evaluated in 25 patients. Maximum aortic diameter measurements at the annulus, sinuses, sinotubular junction and ascending aorta were generated using double-oblique short axis and semiautomatic centerline analysis techniques. Intraobserver and interobserver variability and variability between techniques were assessed using the Wilcoxon signed rank test, Spearman's correlation coefficients and Bland-Altman plots. Mean intraobserver diameter differences using double oblique views ranged from -0.3 to 0.6 mm. The 95 % confidence interval for difference in diameters was ±2.4 to ±5.1 mm for radiologist #1 and ±2.6 to ±5.2 mm for radiologist #2, depending on location. Mean intraobserver diameter differences using centerline analysis ranged from 0.2 to 2.3 mm, and the 95 % confidence interval for difference in diameters was ±2.0 to ±4.6 mm, depending on location. Significant interobserver differences were seen for both double oblique views and centerline analysis. Measurements obtained using the two methods were strongly correlated (r = 0.81-0.99), although they were consistently larger using centerline analysis (95 % confidence interval, ±1.8 to ±3.2 mm). Although measurement variability of the proximal thoracic aorta was generally low using double oblique and centerline analysis techniques, differences of up to approximately 5 mm in diameter occurred within the 95 % confidence interval. Neither technique was clearly more reliable than the other.

The peroxisome proliferator activated receptor-γ pioglitazone improves vascular function and decreases disease activity in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is associated with heightened mortality due to atherosclerotic cardiovascular disease (CVD). Inflammatory pathways in RA negatively affect vascular physiology and promote metabolic disturbances that contribute to CVD. We hypothesized that the peroxisome proliferator activated receptor-γ (PPAR-γ) pioglitazone could promote potent vasculoprotective and anti-inflammatory effects in RA. METHODS AND RESULTS: One hundred forty-three non-diabetic adult RA patients (76.2% female, age 55.2 ± 12.1 [mean ± SD]) on stable RA standard of care treatment were enrolled in a randomized, double-blind placebo controlled crossover trial of 45 mg daily pioglitazone versus placebo, with a 3-month duration/arm and a 2-month washout period. Pulse wave velocity of the aorta (PWV), brachial artery flow mediated dilatation (FMD), nitroglycerin mediated dilatation (NMD), microvascular endothelial function (reactive hyperemia index [RHI]), and circulating biomarkers of inflammation, insulin resistance, and atherosclerosis risk all were quantified. RA disease activity was assessed with the 28-Joint Count Disease Activity Score (DAS-28) C-reactive protein (CRP) and the Short Form (36) Health Survey quality of life questionnaire. When added to standard of care RA treatment, pioglitazone significantly decreased pulse wave velocity (ie, aortic stiffness) (P=0.01), while FMD and RHI remained unchanged when compared to treatment with placebo. Further, pioglitazone significantly reduced RA disease activity (P=0.02) and CRP levels (P=0.001), while improving lipid profiles. The drug was well tolerated. CONCLUSIONS: Addition of pioglitazone to RA standard of care significantly improves aortic elasticity and decreases inflammation and disease activity with minimal safety issues. The clinical implications of these findings remain to be established. CLINICAL TRIAL REGISTRATION URL: ClinicalTrials.gov Unique Identifier: NCT00554853.

Suboptimal cardiovascular risk factor identification and management in patients with rheumatoid arthritis: a cohort analysis.

INTRODUCTION: Accelerated cardiovascular (CV) disease significantly contributes to increased mortality in rheumatoid arthritis (RA) patients, with a risk comparable to the one observed in patients with type 2 diabetes mellitus (DM). Part of this enhanced risk in RA is attributed to traditional cardiovascular risk factors (CRFs). The aims of this study were to determine how often traditional CRFs are identified and managed by (a) rheumatologists, compared with primary care physicians (PCPs) in RA patients; and (b) PCPs among patients with RA, DM, and the general population (GP). METHODS: A retrospective cohort study compared age/gender/ethnicity-matched patients from three groups: RA, DM, and GP (without RA or DM); n = 251 patients per group. Electronic patient records were reviewed during a continuous 12-month period between June 2007 and April 2011 to assess whether CRFs were identified and managed. RESULTS: In RA patients, PCPs managed obesity, BP, and lipids significantly more often than did rheumatologists. PCPs managed obesity, BP, and lipids significantly more often in diabetic patients than in the other two groups, and more often in the GP than in RA patients. In patients with elevated BMI, PCPs managed weight in 68% of the DM group, 46% of the GP, and 31% of the RA group (P < 0.0001 for all groups; P = 0.006 between RA and GP groups). CONCLUSIONS: Rheumatologists identify and manage CRFs less frequently than PCPs. PCPs manage CRFs less frequently in RA patients, compared to the GP and DM. Given the increased CV risk associated with RA, physicians need to more aggressively manage CRFs in these patients.

Self-expanding metal stents (SEMS) provide superior outcomes compared to plastic stents for pancreatic cancer patients undergoing neoadjuvant therapy.

BACKGROUND: Neoadjuvant therapy is increasingly utilized for pancreatic cancer patients to decrease tumor burden in anticipation of later surgical resection. However, infectious complications such as life threatening cholangitis may occur for those with biliary obstruction. We hypothesized that placement of metal rather than plastic stents in such patients results in lower rates of stent-related complications, leading to improved clinical outcomes. METHODS: Retrospective cohort of pancreatic cancer patients treated by the University of Michigan Multidisciplinary Pancreatic Cancer Destination Program between January 2005 and June 2010. Only patients undergoing neoadjuvant therapy with one or more biliary stents placed for malignant obstruction were studied. Time to stent complication was compared between metal and plastic stents. The complication rate was estimated as the ratio of complications to total stent exposure time and 95% confidence intervals were calculated. RESULTS: 52 patients met inclusion criteria. A total of 113 stents were placed in 52 patients (70 plastic, 43 metal). The complication rate was almost 7 times higher with plastic stents, 0.20 (95% CI, 0.14-0.30), than with metal stents, 0.03 (95% CI, 0.01-0.06). Moreover, the rate of hospitalization for stent-related complications was 3-fold higher in the plastic stent group than the metal stent group. The first quartile estimate of time to stent complication was almost 5 times longer for metal than for plastic stents (44 vs. 200 days) (P<0.0001). CONCLUSION: Compelling evidence indicates that self-expanding metal, not plastic stents should be used for malignant biliary obstruction in patients undergoing neoadjuvant therapy for pancreatic cancer.

Perfusion-weighted MR imaging in cerebral lupus erythematosus.

RATIONALE AND OBJECTIVE: Neuropsychiatric systemic lupus erythematosus (NPSLE) is a diagnostically challenging, severe, and life-threatening condition, which is currently lacking a "gold standard." Our aim with this study is to look for magnetic resonance (MR) perfusion differences in NPSLE, SLE, and healthy control (HC) patients and correlate our findings with clinical parameters. MATERIALS AND METHODS: Twenty-four NPSLE patients, 21 SLE patients, and 21 HC underwent dynamic susceptibility contrast enhanced MR perfusion using a 3-T scanner. Nine prospectively selected intracranial regions of interest were placed in white and gray matter and the cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) values were calculated. Subjects underwent clinical evaluation with SLEDAI and serum antibodies. RESULTS: The SLE patients had higher CBF and CBV compared to the HC overall (P = .01) and in specific areas (P = .03-.048). SLE patients with signs of active disease (elevated SLEDAI and anti-double-stranded DNA) had significantly elevated CBV, CBF, and MTT in the posterior cingulate gyrus (P = .01-.02). No significant difference was seen in the magnetic resonance perfusion measurements of NPSLE patients compared to SLE and HC, although the NPSLE patients also showed higher CBV variability compared to the SLE (P = .0004) and HC cohort (P < .0001). CONCLUSION: SLE patients have increased CBV and CBF compared to healthy controls. The SLE patients with clinical markers for active disease have elevated CBV, CBF, and MTT in the posterior cingulate gyrus. NPSLE patients show increased variability in perfusion measurements, which may explain why susceptibility contrast enhanced MRI has not yet provided a specific target for NPSLE.

Cross-sectional examination interpretation discrepancies between on-call diagnostic radiology residents and subspecialty faculty radiologists: analysis by imaging modality and subspecialty.

PURPOSE: The aim of this study was to identify the rate of discrepancies between radiology residents and faculty radiologists at an academic hospital and to determine the distribution across subspecialties and modalities, specifically CT, MR, and ultrasound. METHODS: Consecutive CT, MR, and ultrasound preliminary interpretations rendered by on-call second-year through fourth-year radiology residents for 9 months on emergency department patients, inpatients, and urgent outpatients formed the study population. All preliminary interpretations were graded using a modified RADPEER(®) system (scores 0 and 1 = concordance; score 2 = minor, clinically insignificant discordance; scores 3 and 4 = clinically significant discordance) by the subspecialty faculty members who rendered the final interpretation. RESULTS: There were 158 clinically significant discrepancies out of 21,482 preliminary interpretations, for a discrepancy rate of 0.7%. There was no statistically significant difference in rates across subspecialties or between adult and pediatric examinations (cardiothoracic, 1%; abdominal, 0.7%; neuroradiology, 0.6%; musculoskeletal, 0.7%; pediatrics, 0.8%). MR and CT interpretations had significantly higher rates than ultrasound (MR, 1.4%; CT, 0.9%; ultrasound, 0.2%; P < .001). Within neuroradiology, there was a significantly higher rate for MR than CT (1.5% vs 0.6%, P < .01), and within abdominal radiology, there was a significantly higher rate for CT than ultrasound (1.1% vs 0.2%, P < .01). CONCLUSIONS: Discrepancy rates in this study were less than or comparable with those reported previously and within or lower than rates for practicing radiologists. Discrepancy rates varied among subspecialties and modalities, suggesting the use of a RADPEER system with attention to modality and subspecialty as a methodology for identifying areas for targeted resident education.

Determinants of vascular function in patients with chronic gout.

Epidemiologic studies have proposed a relationship between hyperuricemia and cardiovascular (CV) risk. However, it is unclear whether uric acid (UA) is an independent risk factor for CV disease (CVD) after controlling for other predisposing conditions. Gout patients might have persistent systemic inflammation, which, in addition to hyperuricemia, may potentiate CVD. This study examined vascular function and markers of CV damage in gout patients when compared with healthy controls. Brachial artery flow-mediated dilatation, arterial compliance, and microvascular function were measured. Circulating apoptotic endothelial cells and endothelial progenitor cells were quantified by FACS and circulating biomarkers of CVD by enzyme-linked immunosorbent assay. Gout patients displayed significant increases in body mass index, C-reactive protein, UA, and triglycerides and decreases in high-density lipoprotein. There were no significant differences in other CV traditional risk factors, adhesion molecules, or chemokines. Gout patients did not differ from controls in vascular function. In univariate and multivariate analysis, UA was not associated with the quantified CV risk parameters. Despite an increase in several CV risk factors, inflammation, and UA, gout patients display normal endothelial function and no increases in biomarkers of CVD. These results do not support the notion that gout is an independent risk factor for premature CVD.

Incidental findings at chest CT: a needs assessment survey of radiologists' knowledge.

RATIONALE AND OBJECTIVES: To assess practice patterns in evaluating incidental findings at chest computed tomography (CT) to determine the need for further education. MATERIALS AND METHODS: A survey was given to 1600 radiologists, presenting four clinical case questions regarding the evaluation/significance of the following incidental findings at chest CT: thyroid lesion; enlarged mediastinal lymph nodes; asymptomatic, small pulmonary embolus; and small lung nodule. The respondents' answers were compared with "truth," as defined by the best evidence available in the medical literature. Additional questions elicited the respondents' demographics and comfort levels in addressing the findings. Analysis of variance models with a Tukey correction for post hoc comparisons and chi-square tests were used to determine if any demographic factors or comfort levels were predictive of higher correct response rates. RESULTS: The overall survey response rate was 28% (445/1600). Correct case response rates ranged from 26% (115/442) to 79% (343/445). Only 6% (28/438) of respondents chose the correct answers for all cases. Up to 80% (353/440) of respondents felt comfortable in addressing findings, and only 57% (252/443) of respondents felt that they needed more training in this area. Fellowship training in cardiothoracic radiology, working in a teaching practice, and subspecialization in abdominal or cardiothoracic radiology were predictive of higher correct response rates. Except for one case question, the comfort level was not predictive of correct response rate. CONCLUSIONS: There was considerable variability among radiologists and substantial deviation from best medical practice with regard to the interpretation/evaluation of incidental findings at chest CT, signifying a significant need for further education.

A survey on the use of premedication prior to iodinated and gadolinium-based contrast material administration.

PURPOSE: The aim of this study was to assess Society of Uroradiology member use of premedication before the intravenous administration of low-osmolality iodinated contrast materials (LOCM) and gadolinium-based contrast materials (GBCM). METHODS: Society of Uroradiology members were invited to complete a Web-based survey concerning the use of premedication. The survey included scenarios concerning intravenous LOCM or GBCM injection in which respondents were asked whether they would recommend premedication or withhold contrast material injection. Results for LOCM questions were compared with those for GBCM questions. Question responses for LOCM were also compared with those from a similar Society of Uroradiology survey published in 1995. RESULTS: Sixty-two of 72 respondents (86%) used standardized premedication regimens. Fifty-nine of 61 described regimens (97%) included oral corticosteroids and 48 (79%) antihistamines. Twenty of 69 respondents (29%) had separate urgent premedication regimens. There was general agreement concerning premedication use; however, responses were inconsistent in patients with severe food or medication allergies, severe symptomatic asthma, or prior mild urticarial reactions. More respondents recommended premedication before LOCM than GBCM administration. More respondents recommended premedication or avoidance of contrast material injection in patients with prior contrast reactions in the current study compared with the 1995 study. CONCLUSIONS: There is frequent agreement among uroradiologists concerning the use of corticosteroid prophylaxis, but there is inconsistency in some clinical situations. The threshold for premedication is often lower for LOCM than GBCM. Since 1995, recommendations for use of premedication have become more widespread.

Effect of work hours, caseload, shift type, and experience on resident call performance.

RATIONALE AND OBJECTIVES: To analyze the independent effects of multiple variables on resident call performance. MATERIALS AND METHODS: Independent radiology resident "on call" cross-sectional imaging interpretation quality assurance (QA) data obtained during a 171-day period at a single tertiary care Level 1 trauma teaching institution was reviewed. Clinically significant resident-faculty discrepancies were compared among three different call types: traditional single-day overnight call (OC, 15 hours/night after 9 daytime hours on weekdays), 7-night nightfloat (NF, 9 hours/night), and weekend day call (WD, 10 hours/day). Logistic regression analyses were performed to evaluate associations. RESULTS: There were 119 (0.89%) clinically significant resident-faculty discordances from 13,424 cross-sectional interpretations: 56 (0.79%) from 7102 interpretations on 172 OC shifts, 39 (0.85%) from 4567 interpretations on 165 NF shifts, and 24 (1.4%) from 1755 interpretations on 49 WD shifts. Individual residents (n = 20) had a mean discrepancy rate of 0.9% (0.45%-1.9%). Overall, 102 (26.2%) of the shifts had at least one discordance. The following were associated with significantly (P < .001) increased discrepancy rates: junior vs. senior residents (odds ratio [OR] = 1.3 [1.2-1.4]), OC vs. NF (OR = 1.5 [1.3-1.6], WD vs. NF (OR = 1.4 [1.2-1.6]), weekend vs. weekday (OR = 1.3 [1.2-1.4]), and increasing cases/hour (OR = 1.6 [1.5-1.7]). Weekend OC shifts had a higher discrepancy rate (OR 1.3[1.2-1.5], P < .001) than weekday OC shifts despite a shorter workday (15 vs. 24 hours). CONCLUSION: Increasing caseload, junior residents, and weekends are associated with a significantly higher discrepancy rate. OC is associated with a significantly higher discrepancy rate than NF. Measured discrepancy rates are low, regardless of call type.