Faculty Bibliography

OBJECTIVE: The purpose of this study is to compare the diagnostic accuracy of liver apparent diffusion coefficient (ADC) versus normalized liver ADC using the spleen as a reference organ for the diagnosis of liver fibrosis and cirrhosis. MATERIALS AND METHODS: Fifty-six patients, 34 with liver disease and 22 control subjects, were assessed with breath-hold single-shot echo-planar diffusion-weighted imaging using b values of 0, 50, and 500 s/mm(2). Liver ADC and normalized liver ADC (defined as the ratio of liver ADC to spleen ADC) were compared between patients stratified by fibrosis stage. Receiver operating characteristic (ROC) analysis was used to determine the performance of ADC and normalized liver ADC for prediction of liver fibrosis and cirrhosis. Reproducibility was assessed by measuring coefficient of variation (n = 7). RESULTS: Liver ADC failed to distinguish individual stages of fibrosis, except between stages 0 and 4. There were significant differences in normalized liver ADC between control livers and intermediate stages of fibrosis (stages 2-3) and cirrhosis (stage 4) and between stages 1 and 4, and there was a trend toward significance between stages 0 and 1 (p = 0.051) and stages 1 and 3 (p = 0.06). ROC analysis showed that normalized liver ADC was superior to liver ADC for detection of stage >/= 2 (area under the ROC curve, 0.864 vs 0.655; p = 0.013) and stage >/=3 (0.805 vs 0.689; p = 0.015), without a difference for diagnosing cirrhosis (0.935 vs 0.720; p = 0.185). Normalized liver ADC had higher reproducibility than ADC (mean coefficient of variation, 3.5% vs 12.6%). CONCLUSION: Our results suggest that normalizing liver ADC with spleen ADC improves diagnostic accuracy for detection of liver fibrosis and cirrhosis when using breath-hold diffusion-weighted imaging, with better reproducibility

Study Type - Diagnostic (exploratory cohort)Level of Evidence 2b OBJECTIVE: To evaluate the role of magnetic resonance imaging (MRI) and up-standing ultrasonography (USUS) for the detection of inguinal hernias (IHs) before open radical retropubic prostatectomy (ORRP) and to assess factors associated with the presence of IHs in these men. PATIENTS AND METHODS: From 1 July 2007 to 1 February 2009, 164 men underwent preoperative evaluation for ORRP by one surgeon. Of these men 113 (69%) were evaluated for IHs by physical examination (PE), USUS and MRI. In all 226 groins were examined. Any IH diagnosed by any method was considered a true positive. The sensitivity, negative predictive value (NPV), and concordance were calculated for the three diagnostic methods. Possible predictive factors of IHs were evaluated. RESULTS: Of the 226 groins evaluated, 72 (32%) IHs were diagnosed. USUS had the greatest sensitivity (69.4%) and the highest NPV (87.5%). MRI had fair agreement with PE and USUS, while USUS and PE had moderate agreement with each other. No factor was associated with an increased likelihood of preoperative diagnosis of IH. CONCLUSIONS: This study was limited by the lack of a reference standard to diagnose IH. USUS was the most sensitive method for the detection of IH. We recommend that all men undergoing ORRP should be evaluated for IHs by PE and at least one imaging method and that IHs be repaired at the time of ORRP, obviating the need for a second surgical procedure

OBJECTIVE: The purpose of our study was to assess the utility of the apparent diffusion coefficient (ADC) in distinguishing low-grade and high-grade clear cell renal cell carcinoma (ccRCC). MATERIALS AND METHODS: The cases of 57 patients with pathologically proven ccRCC who underwent preoperative MRI, including diffusion-weighted imaging, were retrospectively assessed. ADC values were obtained from ADC maps calculated using b-value combinations of 0 and 400 s/mm(2) and of 0 and 800 s/mm(2) (hereafter referred to as ADC-400 and ADC-800). Lesions were also evaluated for an array of conventional MRI features. A single expert uropathologist reviewed all slides to determine nuclear grade. The utility of ADC for detecting high-grade ccRCC, alone and in combination with conventional MRI features, was assessed using receiver operating characteristic (ROC) analysis and binary logistic regression. RESULTS: ADC-400 and ADC-800 were significantly lower among high-grade than among low-grade ccRCC (2.24 +/- 0.50 mm(2)/s vs 1.59 +/- 0.57 mm(2)/s for ADC-400, p < 0.001; 1.85 +/- 0.40 mm(2)/s vs 1.28 +/- 0.48 mm(2)/s for ADC-800; p < 0.001). The area under the ROC curve for identifying high-grade ccRCC using ADC-400 and ADC-800 was 0.801 and 0.824 respectively (p = 0.606), with optimal thresholds, sensitivity, and specificity as follows: ADC-400: 2.17 mm(2)/s, 88.5%, 64.5% and ADC-800: 1.20 mm(2)/s, 65.4%, 96.0%. Using multivariate logistic regression, only necrosis (p = 0.0229) and perinephric fat invasion (p = 0.0160) were retained among conventional imaging features as independent risk factors for high-grade ccRCC. The accuracy of the logistic regression model for predicting high-grade ccRCC was significantly improved by inclusion of either ADC-400 (p = 0.0143) or ADC-800 (p = 0.015). CONCLUSION: ADC is significantly lower in high-grade ccRCC compared with low-grade ccRCC and increases the accuracy for detecting high-grade ccRCC compared with conventional MRI features alone

OBJECTIVE: The purpose of this study was to retrospectively describe the MRI features of the pathologically related entities renal oncocytoma and chromophobe renal cell carcinoma (RCC). MATERIALS AND METHODS: Twenty-eight cases of histologically proven renal oncocytoma and 15 of chromophobe RCC evaluated with preoperative MRI from January 2003 through June 2009 at our institution were independently reviewed for an array of MRI features by two radiologists blinded to the final histopathologic diagnosis. These features were tabulated and compared between chromophobe RCC and renal oncocytoma by use of the Mann-Whitney test and binary logistic regression. RESULTS: Renal oncocytoma and chromophobe RCC showed no significant difference in size or any of 16 qualitative imaging features (p = 0.0842-1.0, reader 1; p = 0.0611-1.0, reader 2). Microscopic fat, hemorrhage, cysts, infiltrative margins, perinephric fat invasion, renal vein invasion, enhancement homogeneity, and hypervascularity were each observed in less than 20% of cases by both readers. A central scar and segmental enhancement inversion (a recently described finding in which early contrast-enhanced images show relatively more enhanced and less enhanced intralesional components with inversion of their relative enhancement on later images) were observed by both readers in at least 10% of cases of both renal oncocytoma and of chromophobe RCC with no significant difference between the two entities (p = 0.2092-0.2960). CONCLUSION: We have presented the largest series to date of the MRI features of both renal oncocytoma and chromophobe RCC. These related entities exhibited similar findings, and no MRI features were reliable in distinguishing between them

Background: The possible role of immune system dysregulation in Tourette's disorder (TD) has been increasingly recognized. Studies implicate cytokine imbalances in TD, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-2, and IL-12. Omega-3 Fatty Acids (omega-3FA) are widely used as an alternative treatment for TD and are known to have anti-inflammatory properties. The present study is the first double-blind, placebo-controlled trial examining the therapeutic efficacy and cytokine-specific effects of omega-3FA and olive oil (placebo) in children and adolescents with TD. We hypothesized that: (1) improvement of tics and obsessive compulsive disorder (OCD) symptoms would be positively associated with cytokine plasma concentrations in both treatment groups; (2) these associations would be more pronounced in the omega-3FA group. Methods: Thirty-three children and adolescents with TD (28 males), ages six to 18, were enrolled in a 20-week, double-blind, placebo-controlled trial; 17 were randomly assigned to omega-3FA and 16 to olive oil treatment. Clinician-rated measures included the (Table presented) Yale Global Tic Severity Scale (YGTSS) and the Children's Yale- Brown Obsessive Compulsive Scale (CY-BOCS). Blood samples were collected at 8-9 am after a 12-hour fast at baseline, midpoint, and endpoint weeks and analyzed using enzyme-linked immunosorbent assays. Generalized estimating equations (GEE) based on a binary logistic regression model was used to assess cytokine predictability of OCD and Tic symptom improvement (i.e., CY-BOCS and YGTSS tic score), accounting for age and gender. Spearman correlations characterized associations between cytokines and severity scores. Results: Table 1 and Table 2 show GEE predictabilities and Spearman correlations. Conclusions: Findings suggest that IL-6 and TNF-alpha may play a role in TD treatment response, possibly affected by omega-3FA

Purpose: To determine the frequency of intraductal papillary mucinous neoplasm (IPMN) in patients with and without invasive ductal adenocarcinoma (IDAC). Methods: 82 patients underwent pancreatectomy for pancreas adenocarcinoma. 68/82 subjects underwent at least one preoperative imaging study including CT (n = 43), MRI (n = 25), or both (n = 12). Imaging studies were retrospectively evaluated to determine if IPMN was present in the gland at a location distant from IDAC. In 183 different adult patients undergoing MRI for renal mass, images were evaluated to determine the frequency of IPMN. Fisher's exact test was used to test whether the prevalence of IPMN was greater among patients with pancreas cancer than those without. Results: Five of 68 (7.3%) patients who underwent pancreatic resection for IDAC had IPMN at a site distant from the cancer. Two of 182 (1.1%) patients undergoing MRI for renal cancer had imaging evidence of IPMN. There was a significant difference (p = 0.017) in the prevalence of IPMN between patients with and without IDAC. The odds ratio for IPMN as a predictor of pancreas cancer was estimated as 7.18. Conclusion: IPMN occurs with increased frequency in patients with pancreas cancer as opposed to those without pancreas cancer. and IAP