Search results for " Resonance"
showing 10 items of 5579 documents
Colorectal Polyps: Detection with Dark-Lumen MR Colonography versus Conventional Colonoscopy
2005
To prospectively compare dark-lumen magnetic resonance (MR) colonography with conventional colonoscopy in the detection of colorectal polyps.Local ethical committee approval and informed consent were obtained. One hundred consecutive patients (56 men, 44 women; mean age +/- standard deviation, 67.7 years +/- 14.7; range, 25-82 years) who were referred for conventional colonoscopy from January 2003 to January 2004 underwent MR colonography and conventional colonoscopy after standard precolonoscopic bowel cleansing. Colonoscopy was performed immediately after MR colonography. For MR colonography, the colon was filled with approximately 2000 mL of tap water. Imaging was performed with a 1.5-T …
Solitary rectal ulcer: ultrasonographic and magnetic resonance imaging patterns mimicking rectal cancer.
2011
The objective of this study was to analyze a series of solitary rectal ulcer syndrome (SRUS) cases initially diagnosed as rectal cancer. We analyzed all the patients (1996-2008) initially referred to our colorectal unit with a diagnosis of rectal cancer but with a final diagnosis of SRUS. Demographic data, the diagnostic work-up, and treatment details were collected in a prospective database and analyzed retrospectively. Out of the 5035 patients registered in the colorectal unit database, 14 (0.28%) had a final diagnosis of SRUS. Nine of them had an initial diagnosis of rectal cancer. Out of these, six were preoperatively staged with endorectal ultrasound and/or magnetic resonance and were …
Evaluation of Mesorectal Fascia in Mid and Low Anterior Rectal Cancer Using Endorectal Ultrasound Is Feasible and Reliable
2014
Accuracy of MRI in assessing mesorectal fascia and predicting circumferential resection margin decreases in low anterior rectal tumors.The purpose of this work was to evaluate the accuracy of endorectal ultrasound in predicting the pathologic circumferential resection margin in low rectal anterior tumors and to compare it with MRI findings.This was a prospective series comparing the preoperative circumferential resection margin assessed by endorectal ultrasound and MRI with pathologic examination.The study was conducted by a specialized colorectal multidisciplinary team at a tertiary teaching hospital.Between 2002 and 2008, 76 patients with mid to low rectal cancer were preoperatively evalu…
Modified Wong's Classification Improves the Accuracy of Rectal Cancer Staging by Endorectal Ultrasound and MRI
2013
BACKGROUND: Douglas Wong proposed a new classification of tumor penetration in the rectal wall (T stage) in an attempt to incorporate the prognostic heterogeneity of T3 rectal cancers into the preoperative staging. OBJECTIVE: This study aimed to evaluate if the accuracy of endorectal ultrasound and MRI in predicting rectal cancer T staging improves when using a modified Wong's classification. DESIGN: This prospective series compares local standard TN staging and a modified Wong's classification. SETTINGS: This study was conducted by a specialized Colorectal Multidisciplinary Team at a tertiary teaching hospital. PATIENTS: Seventy patients underwent surgery for middle or low rectal cancer be…
Avoidance of Overtreatment of Rectal Cancer by Selective Chemoradiotherapy: Results of the Optimized Surgery and MRI-Based Multimodal Therapy Trial.
2020
Background Neoadjuvant chemoradiotherapy (nCRT) in patients with rectal cancer carries a high risk of adverse effects. The aim of this study was to examine the selective application of nCRT based on patient risk profile, as determined by MRI, to find the optimal range between undertreatment and overtreatment. Study Design In this prospective multicenter observational study, nCRT before total mesorectal excision (TME) was indicated in high-risk patients with involved or threatened mesorectal fascia (≤1 mm), or cT4 or cT3 carcinomas of the lower rectal third. All other patients received primary surgery. Results Of the 1,093 patients, 878 (80.3%) were treated according to the protocol, 526 pat…
A multicenter, site-independent, blinded study to compare the diagnostic accuracy of contrast-enhanced magnetic resonance angiography using 1.0M gado…
2007
Abstract Purpose Prospective evaluation of diagnostic accuracy of single field-of-view contrast-enhanced MR Angiography (ceMRA) with 1.0 M gadobutrol compared to intraarterial DSA in body arteries. Materials and methods In an European multicenter study 179 patients underwent ceMRA and DSA. For each indication five prospectively defined vessel segments were evaluated by local investigators onsite and by three site-independent blinded readers (BR) independently. Results The agreement between ceMRA and DSA diagnosis was statistically significant in the onsite (96.6%) and blinded reader (86.6–90.2%) evaluation. Sensitivity, specificity, accuracy, positive (PPV) and negative predictive values (N…
Resovist enhanced MR imaging of the liver: Does quantitative assessment help in focal lesion classification and characterization?
2009
Purpose: To improve characterization of focal liver lesions by a prospective quantitative analysis of percentage signal intensity change, in dynamic and late phases after slow (0.5 mL/s) Resovist administration. Materials and Methods: Seventy-three patients were submitted on clinical indication to MR examination with Resovist. Signal intensity of 92 detected focal lesions (5–80 mm) were measured with regions of interest and normalized to paravertebral muscle in arterial, portal, equilibrium and T1/T2 late phases, by two observers in conference. Five values of percentage variations per patient were obtained and statistically evaluated. Results: The enhancement obtained on dynamic study is mo…
Diagnostic performance of gadobenate dimeglumine enhanced MR angiography of the iliofemoral and calf arteries: a large-scale multicenter trial
2007
OBJECTIVE. The purpose of this study was to compare gadobenate dimeglumine–enhanced MR angiography and unenhanced time-of-flight MR angiography for the detection of significant peripheral arterial occlusive disease using digital subtraction angiography as our reference standard. SUBJECTS AND METHODS. Two hundred seventy-two patients underwent MR angiography and digital subtraction angiography of the iliofemoral arteries. MR angiography was performed before (2D time-of-flight acquisitions) and after (spoiled gradient-echo acquisitions) the administration of 0.1 mmol/kg of gadobenate dimeglumine at 1–2 mL/s. Contrast-enhanced MR angiography and digital subtraction angiography of the calf arte…
Assessment of the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level in patients with emphysema.
2006
Abstract Purpose To assess the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level using CT and MRI in patients with emphysema. Material and methods Forty-five patients with severe emphysema (GOLD III and IV) underwent inspiratory 3D-HRCT and contrast-enhanced MR-perfusion (1.5T; 3.5 mm × 1.9 mm × 4 mm). 3D-HRCT data was analyzed using a software for detection and visualization of emphysema. Emphysema was categorized in four clusters with different volumes and presented as overlay on the CT. CT and lung perfusion were visually analyzed for three lobes on each side using a four-point-score to grade the abnormalities on CT (1: predominantly smal…
Splenic hemangiomas: contrast-enhanced sonographic findings
2012
Objectives The purpose of this study was to illustrate the baseline appearance and enhancement patterns of splenic hemangiomas on contrast-enhanced sonography. Methods Two experienced radiologists retrospectively reviewed by consensus baseline and contrast-enhanced sonographic examinations of 27 patients (14 women and 13 men; mean age, 58.7 years) with 27 splenic hemangiomas (mean size, 2 cm) confirmed by splenectomy, biopsy, computed tomography, and magnetic resonance imaging and follow-up. Results On baseline sonography, 77.8% of the lesions showed a homogeneous echo texture that was mainly hyperechoic. Color Doppler imaging did not show any signal in 81.5% of the cases. After contrast ag…