201 resultados para 321023 Radiotherapy and Nuclear Medicine
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We report the case of a 9-year-old boy with portal hypertension, due to Budd-Chiari syndrome, and retrohepatic inferior vena cava thrombosis, submitted to a transjugular intrahepatic portosystemic shunt (TIPS) by connecting the suprahepatic segment of the inferior vena cava directly to the portal vein. After 3 months, the withdrawal of anticoagulants promoted the thrombosis of the TIPS. At TIPS revision, thrombosis of the TIPS and the main portal vein and clots at the splenic and the superior mesenteric veins were found. Successful angiography treatment was performed by thrombolysis and balloon angioplasty of a severe stenosis at the distal edge of the stent.
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Endometriosis is a common multifocal gynecologic disease that manifests during the reproductive years, often causing chronic pelvic pain and infertility. It may occur as invasive peritoneal fibrotic nodules and adhesions or as ovarian cysts with hemorrhagic content. Although findings at physical examination may be suggestive, imaging is necessary for definitive diagnosis, patient counseling, and treatment planning. The imaging techniques that are most useful for preoperative disease mapping are transvaginal ultrasonography (US) after bowel preparation, and magnetic resonance (MR) imaging. Initial transvaginal US is a reliable technique for detecting rectosigmoid endometriotic lesions. MR imaging is indicated as a complementary examination in complex cases of endometriosis with extensive adhesions and ureteral involvement. Peritoneal endometriotic implants are typically hypoechoic on transvaginal US images and demonstrate low signal intensity on T2-weighted MR images. Endometriotic implants most commonly are found in retrocervical and rectosigmoid sites, followed by the vagina, bladder, and ureters. Cysts with low-level internal echoes and echogenic peripheral foci at transvaginal US are suggestive of endometriomas. MR imaging has high specificity for identifying endometriomas, which are characterized by high signal intensity on T1-weighted images and low signal intensity on T2-weighted images. Correlation of the radiologic imaging features of endometriotic lesions with their laparoscopic appearances may help improve individual proficiency in the radiologic diagnosis of endometriosis. Supplemental material available at http:// radiographics.rsna.org/lookup/suppl/doi: 10.1148/rg.314105193/-/DC1. (C) RSNA, 2011 radiographics.rsna.org
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OBJECTIVE. The purpose of the study was to investigate patient characteristics associated with image quality and their impact on the diagnostic accuracy of MDCT for the detection of coronary artery stenosis. MATERIALS AND METHODS. Two hundred ninety-one patients with a coronary artery calcification (CAC) score of <= 600 Agatston units (214 men and 77 women; mean age, 59.3 +/- 10.0 years [SD]) were analyzed. An overall image quality score was derived using an ordinal scale. The accuracy of quantitative MDCT to detect significant (>= 50%) stenoses was assessed using quantitative coronary angiography (QCA) per patient and per vessel using a modified 19-segment model. The effect of CAC, obesity, heart rate, and heart rate variability on image quality and accuracy were evaluated by multiple logistic regression. Image quality and accuracy were further analyzed in subgroups of significant predictor variables. Diagnostic analysis was determined for image quality strata using receiver operating characteristic (ROC) curves. RESULTS. Increasing body mass index (BMI) (odds ratio [OR] = 0.89, p < 0.001), increasing heart rate (OR = 0.90, p < 0.001), and the presence of breathing artifact (OR = 4.97, p = 0.001) were associated with poorer image quality whereas sex, CAC score, and heart rate variability were not. Compared with examinations of white patients, studies of black patients had significantly poorer image quality (OR = 0.58, p = 0.04). At a vessel level, CAC score (10 Agatston units) (OR = 1.03, p = 0.012) and patient age (OR = 1.02, p = 0.04) were significantly associated with the diagnostic accuracy of quantitative MDCT compared with QCA. A trend was observed in differences in the areas under the ROC curves across image quality strata at the vessel level (p = 0.08). CONCLUSION. Image quality is significantly associated with patient ethnicity, BMI, mean scan heart rate, and the presence of breathing artifact but not with CAC score at a patient level. At a vessel level, CAC score and age were associated with reduced diagnostic accuracy.
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BACKGROUND AND PURPOSE: Several morphometric MR imaging studies have investigated age- and sex-related cerebral volume changes in healthy human brains, most often by using samples spanning several decades of life and linear correlation methods. This study aimed to map the normal pattern of regional age-related volumetric reductions specifically in the elderly population. MATERIALS AND METHODS: One hundred thirty-two eligible individuals (67-75 years of age) were selected from a community-based sample recruited for the Sao Paulo Ageing and Health (SPAH) study, and a cross-sectional MR imaging investigation was performed concurrently with the second SPAH wave. We used voxel-based morphometry (VBM) to conduct a voxelwise search for significant linear correlations between gray matter (GM) volumes and age. In addition, region-of-interest masks were used to investigate whether the relationship between regional GM (rGM) volumes and age would be best predicted by a nonlinear model. RESULTS: VBM and region-of-interest analyses revealed selective foci of accelerated rGM loss exclusively in men, involving the temporal neocortex, prefrontal cortex, and medial temporal region. The only structure in which GM volumetric changes were best predicted by a nonlinear model was the left parahippocampal gyrus. CONCLUSIONS: The variable patterns of age-related GM loss across separate neocortical and temporolimbic regions highlight the complexity of degenerative processes that affect the healthy human brain across the life span. The detection of age-related Ill GM decrease in men supports the view that atrophy in such regions should be seen as compatible with normal aging.
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A neoadjuvant multimodality approach with chemoradiation therapy (CRT) is the preferred treatment strategy for most distal rectal cancers. Significant downstaging and complete pathologic response may develop after this strategy, and there is still controversy regarding the management of these patients. In this setting, a nonoperative approach has been suggested in select patients with complete clinical response after thorough clinical, endoscopic, and radiologic assessment. However, the assessment of these patients is not straightforward and remains complex. Available data regarding this approach are limited to a single institution`s experience from retrospective analyses. Standardization of the assessment of tumor response and the development of radiological/molecular tools may clarify the role of no immediate surgery in patients with complete clinical response after neoadjuvant CRT. Advances in radiation and medical oncology could potentially lead to significant improvements in complete tumor regression rates, leading to an increase in importance of a minimally invasive approach in patients with rectal cancer. Semin Radiat Oncol 21:234-239 (C) 2011 Elsevier Inc. All rights reserved.
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Objective Predictive factors of damage to the Fallopian tube may guide the treatment of Patients with tubal pregnancy. The aim of the present study was to investigate the association between the depth of trophoblastic invasion into the tubal wall, assessed on postoperative histological examination, with the findings obtained on transvaginal sonograpby (TVS) in women with ampullary Methods Women with ampullary pregnancy undergoing salpingectomy were enrolled into the study. Only women with a finding of either an embryo with cardiac activity or a tubal ring on TVS were included in the analysis, a total of 8.5 patients. Trophoblastic invasion was assessed postoperatively and was histologically classified as Stage I when limited to the tubal mucosa, Stage II when extending to the muscle layer and Stage III in the case of complete tubal wall infiltration. The association between findings on TVS and the stage of trophoblastic invasion was evaluated. Results There was a significant association between the findings on TVS and the depth of trophoblastic invasion (P < 0.001). All patients in whom an embryo with cardiac activity bad been identified were found to have Stage II (17.9%) or Stage III (82.1%) invasion, whereas in those patients who showed a tubal ring on TVS, Stage I invasion was the most frequent finding (41.3%). Conclusions In ampullary pregnancy, the finding on TVS of an embryo with cardiac activity is associated with deeper penetration of trophoblastic tissue into the tubal wall than is the finding of a tubal ring. Copyright (C) 2009 ISUOG, Published by John Wiley & Sons, Ltd.
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Purpose: To determine the incidence of overestimation of Gleason score (GS) in extended prostate biopsy, and consequently circumventing unnecessary aggressive treatment. Methods and Materials: This is a retrospective study of 464 patients who underwent prostate biopsy and radical prostatectomy between January 2001 and November 2007. The GS from biopsy and radical prostatectomy were compared. The incidence of overestimation of GS in biopsies and tumor volume were studied. Multivariate analysis was applied to find parameters that predict upgrading the GS in prostate biopsy. Results: The exact agreement of GS between prostate biopsy and radical prostatectomy occurred in 56.9% of cases. In 29.1% cases it was underestimated, and it was overestimated in 14%. One hundred and six (22.8%) patients received a diagnosis of high GS (8, 9, or 10) in a prostate biopsy. In 29.2% of cases, the definitive Gleason Score was 7 or lower. In cases in which GS was overestimated in the biopsy, tumors were significantly smaller. In multivariate analysis, the total percentage of tumor was the only independent factor in overestimation of GS. Tumors occupying less than 33% of cores had a 5.6-fold greater chance of being overestimated. Conclusion: In the extended biopsy era and after the International Society of Urological Pathology consensus on G, almost one third of tumors considered to have high GS at the biopsy may be intermediate-risk cancers. In that condition, tumors are smaller in biopsy. This should be remembered by professionals involved with prostate cancer to avoid overtreatment and undesirable side effects. (c) 2009 Elsevier Inc.
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Purpose: Intervertebral cervical disc herniation (CDH) is a relatively common disorder that can coexist with degenerative changes to worsen cervicogenic myelopathy. Despite the frequent disc abnormalities found in asymptomatic populations, magnetic resonance imaging (MRI) is considered excellent at detecting cervical spine myelopathy (CSM) associated with disc abnormality. The objective of this study was to investigate the intra- and inter-observer reliability of MRI detection of CSM in subjects who also had co-existing intervertebral disc abnormalities. Materials and methods: Seven experienced radiologists reviewed twice the MRI of 10 patients with clinically and/or imaging determined myelopathy. MRI assessment was performed individually, with and without operational guidelines. A Fleiss Kappa statistic was used to evaluate the intra- and inter-observer agreement. Results: The study found high intra-observer percent agreement but relatively low Kappa values on selected variables. Inter-observer reliability was also low and neither observation was improved with operational guidelines. We believe that those low values may be associated with the base rate problem of Kappa. Conclusion: In conclusion, this study demonstrated high intra-observer percent agreement in MR examination for intervertebral disc abnormalities in patients with underlying cervical myelopathy, but differing levels of intra- and inter-observer Kappa agreement among seven radiologists. (c) 2007 Elsevier Ireland Ltd. All rights reserved.
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The present study aimed to assess the reliability of intra and inter-examiner subacromial impingement index (SII) measures obtained from radiographs. Thirty-six individuals were enrolled and divided into two groups: control group, composed of 18 volunteers in good general health without shoulder problems, and a group of 18 patients with subacromial impingement syndrome (SIS). Radiographic images were taken with the dominant upper limb in neutral rotation, while the volunteers held their arm at 90A degrees of abduction in the frontal plane. The beam of radiation at 30A degrees craniocaudal inclination was used to provide an antero-posterior image view. Three blinded examiners each performed three measurements from the subacromial space (SS) and the anatomical neck of the humerus (NH). The SII was calculated as the ratio of the SS and the NH measures. The mean values of SII were compared using t-tests. The intra-class correlation coefficient (ICC) was used to assess intra- and inter-examiner reliability of the measures. The mean values of SII were greater for the control group (0.12) than for the SIS group (0.08; p = 0.0071). SII measurements showed excellent intra (0.96-0.99) and inter-examiner reliability (0.94) for both the control and SIS group. The results of this study show the potential use of the SII; a greater mean value for the control group compared to the SIS group and excellent reliability for intra- and inter-examiner measurement. Validation studies of the index should be conducted to correlate the index with clinical findings from subacromial impingement syndrome.
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Nuclear actin and nuclear myosins have been implicated in the regulation of geneexpression in vertebrate cells. Myosin V is a class of actin-based motor proteins involved in cytoplasmic vesicle transport and anchorage, spindle-pole alignment and mRNA translocation. In this study, myosin-Va, phosphorylated on a conserved serine in the tail domain (phospho-ser(1650) MVa), was localized to subnuclear compartments. A monoclonal antibody, 9E6, raised against a peptide corresponding to phosphoserine(1650) and flanking regions of the murine myosin Va sequence, was immunoreactive to myosin Va heavy chain in cellular and nuclear extracts of HeLa cells, PC12 cells and B16-F10 melanocytes. Immunofluorescence microscopy with this antibody revealed discrete irregular spots within the nucleoplasm that colocalized with SC35, a splicing factor that earmarks nuclear speckles. Phospho-ser(1650) MVa was not detected in other nuclear compartments, such as condensed chromatin, Cajal bodies, gems and perinucleolar caps. Although nucleoli also were not labeled by 9E6 under normal conditions, inhibition of transcription in HeLa cells by actinomycin D caused the redistribution of phospho-ser(1650) MVa to nucleoli, as well as separating a fraction of phosphoser(1650) MVa from SC35 into near-neighboring particles. These observations indicate a novel role for myosin Va in nuclear compartmentalization and offer a new lead towards the understanding of actomyosin-based gene regulation.
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Purpose: The purpose of our study was to compare signal characteristics and image qualities of MR imaging at 3.0 T and 1.5 T in patients with diffuse parenchymal liver disease. Materials and methods: 25 consecutive patients with diffuse parenchymal liver disease underwent abdominal MR imaging at both 3.0 T and 1.5 T within a 6-month interval. A retrospective study was conducted to obtain quantitative and qualitative data from both 3.0 T and 1.5 T MRI. Quantitative image analysis was performed by measuring the signal-to-noise ratios (SNRs) and the contrast-to-noise ratios (CNRs) by the Students t-test. Qualitative image analysis was assessed by grading each sequence on a 3- and 4-point scale, regarding the presence of artifacts and image quality, respectively. Statistical analysis consisted of the Wilcoxon signed-rank test. Results: the mean SNRs and CNRs of the liver parenchyma and the portal vein were significantly higher at 3.0 T than at 1.5 T on portal and equilibrium phases of volumetric interpolated breath-hold examination (VIBE) images (P < 0.05). The mean SNRs were significantly higher at 3.0 T than at 1.5 T on T1-weighted spoiled gradient echo (SGE) images (P < 0.05). However, there were no significantly differences on T2-weighted short-inversion-time inversion recovery (STIR) images. Overall image qualities of the 1.5 T noncontrast T1- and T2-weighted sequences were significantly better than 3.0 T (P < 0.01). In contrast, overall image quality of the 3.0 T post-gadolinium VIBE sequence was significantly better than 1.5 T (P< 0.01). Conclusions: MR imaging of post-gadolinium VIBE sequence at 3.0 T has quantitative and qualitative advantages of evaluating for diffuse parenchymal liver disease. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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Objective Intrasubstance meniscal signal changes not reaching the articular surface on fast spin echo (FSE) sequences are considered to represent mucoid degeneration on MRI. The aim of this study was to evaluate the association of prevalent intrasubstance signal changes with incident tears of the medial meniscus detected on 3.0 T MRI over a 1-year period. Materials and methods A total of 161 women aged a parts per thousand yen40 years participated in a longitudinal 1-year observational study of knee osteoarthritis. MRI (3.0 T) was performed at baseline and 12-month follow-up. The anterior horn, body, and posterior horn of the medial meniscus were scored by two experienced musculoskeletal radiologists using the Boston-Leeds Osteoarthritis Knee Score (BLOKS) system. Four grades were used to describe the meniscal morphology: grade 0 (normal), grade 1 (intrasubstance signal changes not reaching the articular surface), grade 2 (single tears), and grade 3 (complex tears and maceration). Fisher`s exact test and the Cochran-Armitage trend test were performed to evaluate whether baseline intrasubstance signal changes (grade 1) predict incident meniscal tears/maceration (grades 2 and/or 3) in the same subregion of the medial meniscus, when compared to subregions without pathology as the reference group (grade 0). Results Medial meniscal intrasubstance signal changes at baseline did not predict tears at follow-up when evaluating the anterior and posterior horns (left-sided p-values 0.06 and 0.59, respectively). No incident tears were detected in the body. Conclusion We could not demonstrate an association between prevalent medial meniscal intrasubstance signal changes with incident tears over a 1-year period.
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Purpose: To evaluate the diagnostic image quality of post-gadolinium water excitation-magnetization-prepared rapid gradient-echo (WE-MPRAGE) sequence in abdominal examinations of noncooperative patients at 1.5 Tesla (T) and 3.0T MRI. Materials and Methods: Eighty-nine consecutive patients (48 males and 41 females; mean age +/- standard deviation, 54.6 +/- 16.6 years) who had MRI examinations including postgadolinium WE-MPRAGE were included in the study. Of 89 patients, 33 underwent noncooperative protocol at 1.5T. 10 under-went noncooperative protocol at 3.0T, and 46 underwent cooperative protocol at 3.0T. Postgadolinium WE-MPRAGE, MPRAGE, and three-dimensional gradient-echo sequences of these three different groups were qualitatively evaluated for image quality, extent of artifacts, lesion conspicuity, and homogeneity of fat-attenuation by two reviewers retrospectively, independently, and blindly. The results were compared using Wilcoxon signed rank and Mann-Whitney U tests. Kappa statistics were used to measure the extent of agreement between the reviewers. Results: The average scores indicated that the images were diagnostic for WE-MPRAGE at 1.5T and 3.0T in noncooperative patients. WE-MPRAGE achieved homogenous fat-attenuation in 31/33 (94%) of noncooperative patients at 1.5T and 10/10 (100%) of noncooperative patients at 3.0T. WE-MPRAGE at 3.0T had better results for image quality, extent of artifacts, lesion conspicuity and homogeneity of fat-attenuation compared with WE-MPRAGE at 1.5T. in noncooperative patients (P = 0.0008, 0.0006, 0.0024, and 0.0042: respectively). Kappa statistics varied between 0.76 and 1.00, representing good to excellent agreement. Conclusion: WE-MPRAGE may be used as a T1-weighted postgadolinium fat-attenuated sequence in noncooperative patients, particularly at 3.0T MRI.
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In this paper, methods are presented for automatic detection of the nipple and the pectoral muscle edge in mammograms via image processing in the Radon domain. Radon-domain information was used for the detection of straight-line candidates with high gradient. The longest straight-line candidate was used to identify the pectoral muscle edge. The nipple was detected as the convergence point of breast tissue components, indicated by the largest response in the Radon domain. Percentages of false-positive (FP) and false-negative (FN) areas were determined by comparing the areas of the pectoral muscle regions delimited manually by a radiologist and by the proposed method applied to 540 mediolateral-oblique (MLO) mammographic images. The average FP and FN were 8.99% and 9.13%, respectively. In the detection of the nipple, an average error of 7.4 mm was obtained with reference to the nipple as identified by a radiologist on 1,080 mammographic images (540 MLO and 540 craniocaudal views).