Current Issue : July - September Volume : 2017 Issue Number : 3 Articles : 7 Articles
To evaluate the rationality and limitations of the seventh edition of the American JointCommittee onCancer (the 7thAJCCedition)\nT-staging system for locally advanced nasopharyngeal carcinoma (NPC). The prognosis of 358 patients with stage T3/T4 NPC\ntreated with intensity-modulated radiotherapy (IMRT) was analyzed with the Kaplanââ?¬â??Meier method or the log-rank test. The 7th\nAJCC staging system of NPC has some limitations in that the T category is neither the significant factor in OS/LRFS nor the\nindependent prognostic factor in OS/LRFS/DMFS/DFS (...
Background: Assessing the liver function provides valuable information to evaluate surgical risk and plan\naccordingly. Current studies focus on whole liver function evaluation. However, assessment of segmental liver\nfunction is equally important in the clinical practice. The purpose of this study was to investigate whether Gd-EOBDTPA-\nenhanced MRI can evaluate the liver function of each segment by using T1 mapping at 3 Tesla MRI.\nMethods: One hundred three patients were classified into one of 4 groups: a normal liver function (NLF) group (n= 38),\na liver cirrhosis with Child-Pugh A (LCA) group (n=33), a liver cirrhosis with Child-Pugh B (LCB) group (n= 21), and a liver\ncirrhosis with Child-Pugh C (LCC) group (n=11). All patients underwent Gd-EOB-DTPA-enhanced MRI scans. T1 relaxation\ntimes were measured on the liver superimposing T1 mapping images. Reduction rate (ââ??³%) of T1 relaxation time of the\nliver parenchyma were calculated.\nResults: After 20 min of Gd-EOB-DTPA enhancement, the T1 relaxation time of all liver segments in the LCC group were\ndifferent from those in all the other groups, and more liver segments from the LCB and LCA groups different from the\nNLF group (p< 0.05). For the LCB group, the areas under the receiver operating characteristic curves (AUCs) of different\nliver segments for hepatobiliary phase (HBP) were 0.654-0.904 on T1 relaxation time, and 0.709-0.905 on ââ??³%. For the LCC\ngroup, the AUCs of different liver segments for HBP were 0.842ââ?¬â??0.997 on T1 relaxation time, and 0.887ââ?¬â??0.990 on ââ??³%.\nConclusions: For LCB patients, segmental liver function evaluation is possible using Gd-EOB-DTPA-enhanced MRI T1\nmapping. For LCC patients, all liver segments can be used to evaluate liver function and both T1 relaxation time and the\nââ??³% of T1 relaxation time have good diagnostic performance....
Background: Accurate T-staging is pivotal for predicting prognosis and selecting appropriate therapies for\nesophageal squamous cell carcinoma (ESCC). The diagnostic performance of fluorodeoxyglucose (FDG) positron\nemission tomography/computed tomography (PET/CT) for its T-staging is uncertain. We investigated use of FDG\nPET/CT for preoperative T-staging of patients with ESCC.\nMethods: Patients with ESCC given preoperative FDG PET/CT scans, either with (CRT[+] group) or without (CRT[âË?â??]\ngroup) neoadjuvant chemoradiotherapy, were retrospectively reviewed. Maximal standardized uptake value\n(SUVmax) of the primary tumors on FDG PET/CT scans were measured, and histopathological results were used as\nthe reference standard. The associations between pathological T-stage and potential factors of age, tumor location,\ntumor grade, tumor size, and tumor SUVmax were analyzed. The cut-off levels of SUVmax for predicting different\nT-stages and for residual viable tumors after neoadjuvant chemoradiotherapy were determined using receiver\noperating characteristic analyses.\nResults: We enrolled 103 patients (45 in the CRT[âË?â??] group; 58 in the CRT[+] group). SUVmax, an independent predictive\nfactor, positively correlated with the pathological T-stage in both groups (CRT[âË?â??] group: à= 0.736, p < 0.001; and CRT[+]\ngroup: à= 0.792, p < 0.001). The overall accuracy of the PET/CT with thresholded SUVmax for predicting the pathological\nT-stage was 73.3% in the CRT[âË?â??] group (SUVmax of T0: 0ââ?¬â??1.9, T1: 2.0ââ?¬â??4.4, T2: 4.5ââ?¬â??6.5, T3: 6.6ââ?¬â??13.0, T4: >13.0) and 67.2% in\nthe CRT[+] group (SUVmax of T0: 0ââ?¬â??3.4, T1: 3.5ââ?¬â??3.9, T2: 4.0ââ?¬â??5.5, T3: 5.6ââ?¬â??6.2, T4: > 6.2). For CRT[âË?â??] group, the accuracy using\nan SUVmax cut-off of 4.4 to differentiate early (T0-1) from locally advanced disease (T2-4) was 82.2% (95% CI, 71.1ââ?¬â??93.\n4%). For CRT[+] group, the accuracy using an SUVmax cut-off of 3.4 to predict residual viable tumors (non-T0) after\ncompletion of chemoradiotherapy was 82.8% (95% CI, 73.0ââ?¬â??92.5%).\nConclusions: The FDG avidity of a primary esophageal tumor significantly positively correlated with the pathological\nT-stage. PET/CT with thresholded SUVmax was useful for predicting T-stage and differentiating residual viable tumors....
Fetal brain magnetic resonance imaging (MRI) is a rapidly emerging diagnostic imaging tool. However, automated fetal brain\nlocalization is one of the biggest obstacles in expediting and fully automating large-scale fetal MRI processing.We propose amethod\nfor automatic localization of fetal brain in 3 T MRI when the images are acquired as a stack of 2D slices that are misaligned due\nto fetal motion. First, the Histogram of Oriented Gradients (HOG) feature descriptor is extended from 2D to 3D images. Then, a\nsliding window is used to assign a score to all possible windows in an image, depending on the likelihood of it containing a brain,\nand the window with the highest score is selected. In our evaluation experiments using a leave-one-out cross-validation strategy,\nwe achieved 96% of complete brain localization using a database of 104 MRI scans at gestational ages between 34 and 38 weeks.We\ncarried out comparisons against templatematching and randomforest based regressionmethods and the proposed method showed\nsuperior performance.We also showed the application of the proposed method in the optimization of fetal motion correction and\nhow it is essential for the reconstruction process. The method is robust and does not rely on any prior knowledge of fetal brain\ndevelopment....
Background: Model-based iterative reconstruction (MBIR) is a promising reconstruction method which could\nimprove CT image quality with low radiation dose. The purpose of this study was to demonstrate the advantage of\nusing MBIR for noise reduction and image quality improvement in low dose chest CT for children with necrotizing\npneumonia, over the adaptive statistical iterative reconstruction (ASIR) and conventional filtered back-projection\n(FBP) technique.\nMethods: Twenty-six children with necrotizing pneumonia (aged 2 months to 11 years) who underwent standard\nof care low dose CT scans were included. Thinner-slice (0.625 mm) images were retrospectively reconstructed using\nMBIR, ASIR and conventional FBP techniques. Image noise and signal-to-noise ratio (SNR) for these thin-slice images\nwere measured and statistically analyzed using ANOVA. Two radiologists independently analyzed the image quality\nfor detecting necrotic lesions, and results were compared using a Friedmanâ��s test.\nResults: Radiation dose for the overall patient population was 0.59 mSv. There was a significant improvement in\nthe high-density and low-contrast resolution of the MBIR reconstruction resulting in more detection and better\nidentification of necrotic lesions (38 lesions in 0.625 mm MBIR images vs. 29 lesions in 0.625 mm FBP images). The\nsubjective display scores (mean �± standard deviation) for the detection of necrotic lesions were 5.0 �± 0.0, 2.8 �± 0.4\nand 2.5 �± 0.5 with MBIR, ASIR and FBP reconstruction, respectively, and the respective objective image noise was 13.\n9 �± 4.0HU, 24.9 �± 6.6HU and 33.8 �± 8.7HU. The image noise decreased by 58.9 and 26.3% in MBIR images as\ncompared to FBP and ASIR images. Additionally, the SNR of MBIR images was significantly higher than FBP images\nand ASIR images.\nConclusions: The quality of chest CT images obtained by MBIR in children with necrotizing pneumonia was\nsignificantly improved by the MBIR technique as compared to the ASIR and FBP reconstruction, to provide a more\nconfident and accurate diagnosis for necrotizing pneumonia....
Purpose. Radiation-induced lung fibrosis (RILF) is a serious late complication of radiotherapy. In vitro studies have demonstrated\nthat pentoxifylline (PTX) has suppressing effects in extracellular matrix production in fibroblasts, while the antifibrotic action of\nPTX alone using clinical dose is yet unexplored. Materials and Methods. We used micro-computed tomography (micro-CT) and\nhistopathological analysis to evaluate the antifibrotic effects of PTX in a rat model of RILF. Results.Micro-CT findings showed that\nlung density, volume loss, andmediastinal shift are significantly increased at 16 weeks after irradiation. Simultaneously, histological\nanalysis demonstrated thickening of alveolar walls, destruction of alveolar structures, and excessive collagen deposition in the\nirradiated lung. PTX treatment effectively attenuated the fibrotic changes based on both micro-CT and histopathological analyses.\nWestern analysis also revealed increased levels of plasminogen activator inhibitor- (PAI-) 1 and fibronectin (FN) and PTX treatment\nreduced expression of PAI-1 and FN by restoring protein kinase A (PKA) phosphorylation but not TGF-...
Introduction. We aimed to assess the efficacy and safety of digital subtraction angiography (DSA) and super-selective mesenteric\nartery embolization (SMAE) in managing lower GI bleeding (LGIB). Method. A retrospective case series of patients with LGIB\ntreated with SMAE in our health service. Patients with confirmed active LGIB, on either radionuclide scintigraphy (RS) or\ncontrast-enhanced multidetector CT angiography (CE-MDCT), were referred for DSA +/âË?â?? SMAE. Data collected included\npatient characteristics, screeningmodality, bleeding territory, embolization technique, technical and clinical success, short-termto\nmedium-term complications, 30-day mortality, and progression to surgery related to procedural failure or complications. Results.\nThere were fifty-five hospital admissions with acute unstable lower gastrointestinal bleeding which were demonstrable on CEMDCT\nor RS over a 31-month period. Eighteen patients proceed to embolization, with immediate success in all. Eight patients\n(44%) had clinical rebleeding after intervention, warranting repeated imaging. Only one case (5.6%) demonstrated radiological\nrebleeding and was reembolized. Complication rate was excellent: no bowel ischaemia, ischaemic stricture, progression to surgery,\nor 30-day mortality. Conclusion. SMAE is a viable, safe, and effective first-line management for localised LGIB. Our results overall\ncompare favourably with the published experiences of other institutions. It is now accepted practice at our institution to manage\nlocalised LGIB with embolization....
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