1,720,983 research outputs found
Efficacy of percutaneous abscess drainage in patients with vancomycin-resistant enterococci
No full textOBJECTIVE. We reviewed a 4-year experience draining fluid collections infected with vancomycin-resistant enterococci to determine the outcome of percutaneous intervention in patients with this highly resistant and increasingly common organism. MATERIALS AND METHODS. Charts of patients from whom vancomycin-resistant enterococci had been isolated during percutaneous drainage were reviewed to determine patient response to drainage, catheter management, and outcome of treatment. RESULTS. Twenty-one patients underwent percutaneous drainage of 28 fluid collections from which vancomycin-resistant enterococci were isolated, including 16 intraabdominal abscesses, seven biliary or urinary obstructions, and five empyemas. The drainage of 27 (96%) of 28 collections were technically successful. In seven patients, drainage provided the first isolation of vancomycin-resistant enterococci from the patient. Five patients also had blood cultures with positive findings for vancomycin-resistant enterococci, and 14 collections were coinfected with other bacteria or with fungi. Twenty collections (71%) or obstructions were successfully treated with percutaneous drainage. Drainage was unsuccessful in treating eight collections in seven patients. CONCLUSION. Despite high-level antibiotic resistance, fluid collections infected with vancomycin-resistant enterococci can be successfully drained percutaneously, resulting in a favorable likelihood of recovery for patients
Can Spleen Serve as an Internal Reference on Diffusion-weighted Imaging (DWI) to Enable Characterization of Hepatic Lesions into Benign and Malignant?
No full textPixel distribution analysis: Can it be used to distinguish clear cell carcinomas from angiomyolipomas with minimal fat?
No full textPurpose: To retrospectively determine if pixel histogram analysis of unenhanced computed tomographic (CT) images can be used to distinguish angiomyolipomas (AMLs) with minimal fat from clear cell renal cell carcinomas (CCRCCs). Materials and Methods: The human studies committee approved this HIPAA-complaint study, with waiver of informed consent. Patients with pathologically proved AMLs lacking visible macroscopic fat at CT and patients with pathologically proved CCRCCs were included. Lesions were measured, and a histogram (number of pixels with each attenuation) was calculated electronically within a central region of interest. The percentage of pixels below the attenuation thresholds -20 HU and 10 HU was calculated in both cohorts. The unpaired Student t test was used to compare the average percentage of subthreshold pixels at each threshold. P < .05 indicated a significant difference. The number of lesions with more than the selected percentage of subthreshold pixels was calculated in both groups, and the chi(2) test was used to test the significance of differences between cohorts. The area under the receiver operating characteristic (ROC) curve was used to determine if any percentage of subthreshold pixels could be used to differentiate between the two cohorts. Results: There were 22 patients with pathologically proved AMLs lacking visible macroscopic fat on CT images. Tuberous sclerosis affected three of these patients. Mean maximal transverse lesion diameter was 20 mm (range, 11-38 mm). There were 28 patients in the CCRCC comparison group. Mean maximal transverse lesion diameter was 26 mm (range, 15-36 mm). Neither the Student t test (P < .2 for all thresholds < 0 HU) nor the chi(2) test (P < .15 for all thresholds < 0 HU) revealed a significant difference between cohorts. A lesion with more low-attenuation pixels was significantly more likely to be characterized as CCRCC than as AML with ROC curve analysis. Conclusion: Once AMLs with visible fat on CT images are excluded, pixel histogram analysis cannot be used to distinguish between AMLs and CCRCCs. (C) RSNA, 2008
Cholangiocarcinoma: Current and novel imaging techniques
No full textThe radiologic manifestations of cholangiocarcinomas are extremely diverse, since these tumors vary greatly in location, growth pattern, and histologic type. Familiarity with the imaging manifestations of cholangiocarcinomas is important for accurate detection and characterization of these tumors and assessment of resectability. Advances in imaging techniques have led to the availability of an array of modalities that, used independently or in combination, can aid in the accurate diagnosis and evaluation of cholangiocarcinomas in preparation for advanced surgical procedures and treatment planning. Response to novel targeted therapies can also be assessed with newer imaging tools. Hence, knowledge of current and emerging imaging applications is essential for correct diagnosis and appropriate management of these tumors
Limited Value of Diffusion-weighted MR Imaging for Differentiating Bland from Malignant Portal Venous Thrombi Response
No full textCan diffusion weighted MR imaging discriminate neoplastic thrombus from bland thrombus in the portal vein?
No full textProtocol modifications for CT perfusion (CTp) examinations of abdomen-pelvic tumors: Impact on radiation dose and data processing time
No full textTo evaluate the effect of CT perfusion (CTp) protocol modifications on quantitative perfusion parameters, radiation dose and data processing time. CTp datasets of 30 patients (21M:9F) with rectal (n = 24) or retroperitoneal (n = 6) tumours were studied. Standard CTp protocol included 50 sec cine-phase (0.5 sec/rotation) and delayed-phase after 70 ml contrast bolus at 5-7 ml/sec. CTp-data was sub-sampled to generate modified datasets (n = 105) with cine-phase(n = 15) alone, varying cine-phase duration (20-40 sec, n = 45) and varying temporal sampling-interval (1-3 sec, n = 45). The estimated CTp parameters (BF,BV,MTT&PS) and radiation dose of standard CTp served as reference for comparison. CTp with 50 sec cine-phase showed moderate to high correlation with standard CTp for BF&MTT (r = 0.96&0.85) and low correlation for BV (0.75, p = 0.04). Limiting cine-phase duration to 30 sec demonstrated comparable results for BF&MTT, while considerable variation in CTp values existed at 20 sec. There was moderate-to-high correlation of CTp parameters with sampling interval of 1&2 sec (r = 0.83-0.97, p > 0.05), while at 3 sec only BF showed high correlation (r = 0.96, p = 0.05). Increasing sampling interval (47-60%) and reducing cine-phase duration substantially reduced dose(30.8-65%) which paralleled reduced data processing time (3-10 min). Limiting CTp cine-phase to 30 sec results in comparable BF&MTT values and increasing cine-phase sampling interval to 2 sec provides good correlation for all CTp parameters with substantial dose reduction and improved computational efficiency
Urologists Perspective and Evolving Imaging Expectations in Patients with Genitourinary Anomalies
No full textPURPOSE/AIM: To review the spectrum of congenital genitourinary anomalies and variants (CGUAV) of the kidneys (position, number, shape), pelvis, ureter
(course, number, shape, termination), bladder, urethra, Muellerian ducts and testis To discuss their clinical implications To explain the role of traditional and
current imaging technologies (US, MDCT, MRI)
CONTENT ORGANIZATION: Embryology of the genitourinary system and normal anatomy Traditional and “modern” genitourinary imaging Review of findings
Implications for clinical management and surgical approach Differential diagnosis and imaging flow chart
SUMMARY: CGUAV although important are less commonly discussed These represent often overlooked but clinically relevant entities with potentially serious clinical
consequences Imaging can enable detection and classification Using imaging, appropriate treatment decisions can be made including recognizing prognostic
implications Simple classification and image based algorithms can facilitate early diagnosis and triage appropriate care, thereby avoiding unnecessary procedures
and long term injur
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