Current Issue : April - June Volume : 2020 Issue Number : 2 Articles : 7 Articles
Background: Diffusion-weighted imaging (DWI) and ultrasound are commonly used methods to examine thyroid\nnodules, but their comparative value is rarely studied. We evaluated the utility of DWI and ultrasound in\ndifferentiating benign and malignant thyroid nodules.\nMethods: A total of 100 patients with 137 nodules who underwent both DWI and ultrasound before operation\nwere enrolled. The T1 and T2 signal intensity ratio (SIR) of each thyroid nodule was calculated by measuring the\nmean signal intensity divided by that of paraspinal muscle. The apparent diffusion coefficient (ADC) value and the\nSIR of benign and malignant thyroid nodules were analyzed by two-sample independent t tests. The sensitivity,\nspecificity, and accuracy of DWI and ultrasound were compared with chi-square tests.\nResults: There was no significant difference in the SIR between benign and malignant thyroid nodules. The ADC\nvalue was significantly different. ...............................
Background and Objective: Nowadays, Computer Tomography is one of the\nbest radiological imaging technics which can give right diagnostic information,\namong the detection of multiphasic adenomas, the detection of cardiac, cerebral\nand vascular abnormalities. Although these good qualities, this technic is\ntoo radiant for the patient. In this paper, we based on the irradiation doses\ndelivered from the current protocols to find a practical method of their optimization\nduring the pediatric cranial scan. Materials and Methods: This\nwork relies on a collection of data from patients in the hospitals, so that analyze\nthem, give the conclusions and, propose an optimal practical method to\ndecrease the irradiation doses. To collect data, we performed a prospective\nstudy of seventeen months (from December 2017 to May 2019) carried out\nsimultaneously in three hospitals of the city: The Centre Medical la Cathedrale\n(H1), the Yaounde Central Hospital (H2) and the Yaounde Gyneaco-Obstetric\nand pediatric hospital (H3). This study included a total of 192 cases of cerebral\ntrauma, of which 11 cases excluded for incomplete information. The dosimetry\nquality control (CTDIvol) using the PMMA phantoms of 16 cm and\n32 cm fulfilled. The scanographic parameters of the patient acquisition protocol\nwere recorded and analyzed. Some of those parameters were modified\nand entered the CT with the help of a biomedical engineer to reduce the delivered\ndose. The relationship between CTDIvol and kV is statistically significant\n(p < 0.05) to identify significant differences in obtained results before\nand after the optimization of protocols. Results: Among patients, 172 are\nboys, and the remaining 9 are girls all were in the 0 to 15 age group. CTDIvol \nvalues varied from 34.2 mGy to 107.8 mGy and PDLs from 107.8 mGy.cm to\n2214.5 mGy.cm in H1. In H2, CTDIvol varied from 5.8 mGy to 44 mGy and\nPDLs from 91.4 mGy.cm to 665.5 mGy.cm. CTDIvol varied between 9.34\nmGy to 92.81 mGy and PDLs from 162.38 mGy.cm to 2713.67 mGy.cm in\nH3. All values are taken at 75th percentile, with or without contrast injection.\nConclusion: The implementation of the optimization of protocols requires\nthe display of the CT parameters to use and to respect during the traumatic\nbrain tests. With displaying and respecting protocol, the CTDIvol decreased\nby almost 50 per cent....
The purpose of this study was to investigate the ability of a management system\n(Delivery Analysis: DA) to detect intrafractional motion during intensity-\nmodulated radiation therapy (IMRT) in tomotherapy mode. Tomotherapy\nhas made it possible to manage internal movements during treatment using\nsoftware DA, which quantifies using the information of the passing dose obtained\nduring the radiation treatment of patients. First, three treatment plans\nfor the test were created (lumbar spine, prostate, and femur). Second, a pelvis\nphantom was moved in the X, Y, and Z directions, and a sinogram was acquired.\nThe magnitudes of the movements were 3 mm, 5 mm, and 10 mm,\nrespectively. Finally, the ability of DA to detect the motion was evaluated by\ncomparing the sinogram obtained by moving the phantom with a reference\nsinogram obtained without movement. The sensitivity of DA could be detected\nwith a shift amount of 3 mm (gamma analysis tolerance 0.3 mm/0.3%).\nThe average gamma analysis of each direction at 0.3 mm/0.3% tolerance at\neach treatment site was 96.1% for the prostate, 93.5% for the lumbar spine,\nand 94.4% for the femur. Additionally, the average gamma pass rate results\nfor the pelvic phantom in the X, Y, Z directions for a 10 mm shift were 96.2%,\n96.3%, and 95.9%, respectively. DA is a powerful tool with high detection\nsensitivity and ability to detect body movement during treatment....
Background: Diabetic retinopathy (DR) is the leading cause of blindness in type 1 Diabetes Mellitus (DM) patients,\nas a consequence of impaired blood flow in the retina. Optical coherence tomography angiography (OCTA) is a\nnewly developed, non-invasive, retinal imaging technique that permits adequate delineation of the perifoveal vascular\nnetwork. It allows the detection of paramacular areas of capillary non perfusion and/or enlargement of the foveal\navascular zone (FAZ), representing an excellent tool for assessment of DR. The relationship of these microvascular\nchanges with systemic factors such as metabolic control or duration of the disease still needs to be elucidated.\nMethods: Prospective, consecutive, large-scale OCTA study. A complete ocular examination including a comprehensive\nseries of OCTA images of different scan sizes captured with 2 OCT devices (Cirrus HD-OCT, Carl Zeiss Meditec, Dublin, CA,\nUSA, and Triton Deep Range Imaging OCT, Topcon Corp, Topcon, Japan) will be obtained as part of the yearly routine follow\nup visits in type 1 DM patients seen in the Diabetes Unit of the Endocrinology department which give written informed\nconsent to participate in the project. The aim of this study is to investigate the relationship between OCTAderived\nparameters and systemic factors, as metabolic control (Hb1Ac, lipid profile, cholesterol, etc), and other\nrelevant clinical factors as demographics or duration of the disease.\nDiscussion: This study is directed to investigate the relationship between the status of the perifoveal vascular\nnetwork and systemic markers of the disease, and in particular to study whether these changes reflect those\noccurring elsewhere in the body affected by diabetic microvascular disease, as the kidneys or the brain. If\nthese relationships were demonstrated, early detection of these microvascular changes by OCTA could lead to\nmodifications in the pharmacological management of type 1 diabetic patients, as a way to reduce the risk of\nfuture complications in both the eye and other organs....
Background: To facilitate translational drug development for liver fibrosis, preclinical trials need to be run in\nparallel with clinical research. Liver function estimation by gadoxetate-enhanced dynamic contrast-enhanced MRI\n(DCE-MRI) is being established in clinical research, but still rarely used in preclinical trials. We aimed to evaluate\nfeasibility of DCE-MRI indices as translatable biomarkers in a liver fibrosis animal model.\nMethods: Liver fibrosis was induced in Sprague-Dawley rats by thioacetamide (200 mg, 150 mg, and saline for the\nhigh-dose, low-dose, and control groups, respectively). Subsequently, DCE-MRI was performed to measure: relative\nliver enhancement at 3-min (RLE-3), RLE-15, initial area-under-the-curve until 3-min (iAUC-3), iAUC-15, and\nmaximum-enhancement (Emax). The correlation coefficients between these MRI indices and the histologic collagen\narea, indocyanine green retention at 15-min (ICG-R15), and shear wave elastography (SWE) were calculated.\nDiagnostic performance to diagnose liver fibrosis was also evaluated by receiver-operating-characteristic (ROC)\nanalysis.\nResults: Animal model was successful in that the collagen area of the liver was the largest in the high-dose group,\nfollowed by the low-dose group and control group. The correlation between the DCE-MRI indices and collagen\narea was high for iAUC-15, Emax, iAUC-3, and RLE-3 but moderate for RLE-15 (r, - 0.81, - 0.81, - 0.78, - 0.80, and -\n0.51, respectively). The DCE-MRI indices showed moderate correlation with ICG-R15: the highest for iAUC-15,\nfollowed by iAUC-3, RLE-3, Emax, and RLE-15 (r, - 0.65, - 0.63, - 0.62, - 0.58, and - 0.56, respectively). The correlation\ncoefficients between DCE-MRI indices and SWE ranged from - 0.59 to - 0.28. The diagnostic accuracy of RLE-3,\niAUC-3, iAUC-15, and Emax was 100% (AUROC 1.000), whereas those of RLE-15 and SWE were relatively low\n(AUROC 0.777, 0.848, respectively).\nConclusion: Among the gadoxetate-enhanced DCE-MRI indices, iAUC-15 and iAUC-3 might be bidirectional\ntranslatable biomarkers between preclinical and clinical research for evaluating histopathologic liver fibrosis and\nphysiologic liver functions in a non-invasive manner....
Motiva Implants® (Establishment Labs Holdings Inc., NY, USA) contains a\nRFID micro transponder RFID(RT) (RT = registered trademark) known as Q\nInside Safety Technology which provides an added safety feature embedded\nin the shell of the Motiva breast implant [1] [2]. Because this RFID micro\ntransponder has Ferric components, a concern over breast MRI imaging susceptibility\nartifact has arisen. Among breast images, a single high risk breast\ncancer patient was imaged at our institution (January 2018). All breast imaging\nmodalities were used to determine if this high risk patient had a recurrence\nof her cancer or any new breast cancer. The MRI showed a susceptibility\nartifact on the posterior margin of the implant but breast ultrasound\nshowed no abnormalities in the area of the susceptibility artifact. By using\nhigh risk screening including Mammography, Tomosynthesis, Breast Ultrasound\nand Breast MRI, an adequate survey of the high risk patient was completed\n[3]. Our high risk clinic examined the patient and the imaging results\nand came to the following conclusion: This patient showed no evidence of recurrent\ncancer and no new masses were identified. The conclusion was BIRADS\n2 benign: normal findings post-mastectomy and implants. Recommendation\nwas for routine high risk screening at yearly interval....
Background: This study aimed to evaluate the significance of MRI-based radiomics model derived from highresolution\nT2-weighted images (T2WIs) in predicting tumor pathological features of rectal cancer.\nMethods: A total of 152 patients with rectal cancer who underwent surgery without any neoadjuvant therapy\nbetween March 2017 and September 2018 were included retrospectively. The patients were scanned using a 3-T\nmagnetic resonance imaging, and high-resolution T2WIs were obtained. Lesions were delineated, and 1029\nradiomics features were extracted. Least absolute shrinkage and selection operator was used to select features, and\nmultilayer perceptron (MLP), logistic regression (LR), support vector machine (SVM), decision tree (DT), random\nforest (RF), and K-nearest neighbor (KNN) were trained using fivefold cross-validation to build a prediction model.\nThe diagnostic performance of the prediction models was assessed using the receiver operating characteristic\ncurves.\nResults: A total of 1029 features were extracted, and 15, 11, and 11 features were selected to predict the degree of\ndifferentiation, T stage, and N stage, respectively. The best performance of the radiomics model for the degree of\ndifferentiation, T stage, and N stage was obtained by SVM [area under the curve (AUC), 0.862; 95% confidence\ninterval (CI), 0.750â??0.967; sensitivity, 83.3%; specificity, 85.0%], MLP (AUC, 0.809; 95% CI, 0.690â??0.905; sensitivity,\n76.2%; specificity, 74.1%), and RF (AUC, 0.746; 95% CI, 0.622-0.872; sensitivity, 79.3%; specificity, 72.2%).\nConclusion: This study demonstrated that the high-resolution T2WIâ??based radiomics model could serve as\npretreatment biomarkers in predicting pathological features of rectal cancer....
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