Current Issue : July - September Volume : 2015 Issue Number : 3 Articles : 7 Articles
Background: The objective of this study was to evaluate the feasibility and diagnostic value of 18F-fluorodeoxyglucose\npositron emission tomography/computed tomography (18F-FDG PET/CT) and 99mTc-methylenediphosphonate (MDP)\nwhole-body bone scanning (BS) for the detection of osteolytic bone metastases.\nMethods: Thirty-four patients with pathologically confirmed malignancies and suspected osteolytic bone metastases\nunderwent 18F-FDG PET/CT and 99mTc-MDP whole-body BS within 30 days. The sensitivity, specificity, and accuracy with\nrespect to the diagnosis of osteolytic bone metastases and bone lesions were compared between the two imaging\nmethods.\nResults: The sensitivity, specificity, and accuracy of 18F-FDG PET/CT for the diagnosis of osteolytic bone metastases\nwere 94.3% (95% confidence interval [CI], 91.6ââ?¬â??96.2%), 83.3% (95% CI, 43.6ââ?¬â??96.9%), and 94.2% (95% CI, 91.5ââ?¬â??96.1%),\nrespectively. It was found that 99mTc-MDP whole-body BS could discriminate between patients with 50.2% (95% CI,\n45.4ââ?¬â??55.1%) sensitivity, 50.0% (95% CI, 18.8ââ?¬â??81.2%) specificity, and 50.2% (95% CI, 45.5ââ?¬â??55.1%) accuracy. 18F-FDG PET/CT\nachieved higher sensitivity, specificity, and accuracy in detecting osteolytic bone metastases than 99mTc-MDP wholebody\nBS (p<0.001).\nConclusions: F-FDG PET/CT has a higher diagnostic value than 99mTc-MDP whole-body BS in the detection of osteolytic\nbone metastases, especially in the vertebra....
Background: The introduction of a standardized SPECT/CT algorithm including a localization scheme, which allows\naccurate identification of specific patterns and thresholds of SPECT/CT tracer uptake, could lead to a better\nunderstanding of the bone remodeling and specific failure modes of unicondylar knee arthroplasty (UKA). The\npurpose of the present study was to introduce a novel standardized SPECT/CT algorithm for patients after UKA and\nevaluate its clinical applicability, usefulness and inter- and intra-observer reliability.\nMethods: Tc-HDP-SPECT/CT images of consecutive patients (median age 65, range 48ââ?¬â??84 years) with 21 knees after\nUKA were prospectively evaluated. The tracer activity on SPECT/CT was localized using a specific standardized UKA\nlocalization scheme. For tracer uptake analysis (intensity and anatomical distribution pattern) a 3D volumetric quantification\nmethod was used. The maximum intensity values were recorded for each anatomical area. In addition, ratios between\nthe respective value in the measured area and the background tracer activity were calculated. The femoral and tibial\ncomponent position (varus-valgus, flexion-extension, internal and external rotation) was determined in 3D-CT. The\ninter- and intraobserver reliability of the localization scheme, grading of the tracer activity and component measurements\nwere determined by calculating the intraclass correlation coefficients (ICC).\nResults: The localization scheme, grading of the tracer activity and component measurements showed high inter- and\nintra-observer reliabilities for all regions (tibia, femur and patella). For measurement of component position there was\nstrong agreement between the readings of the two observers; the ICC for the orientation of the femoral component\nwas 0.73-1.00 (intra-observer reliability) and 0.91-1.00 (inter-observer reliability). The ICC for the orientation of the tibial\ncomponent was 0.75-1.00 (intra-observer reliability) and 0.77-1.00 (inter-observer reliability).\nConclusions: The SPECT/CT algorithm presented combining the mechanical information on UKA component position,\nalignment and metabolic data is highly reliable and proved to be a valuable, consistent and useful tool for analysing\npostoperative knees after UKA. Using this standardized approach in clinical studies might be helpful in establishing the\ndiagnosis in patients with pain after UKA....
Background: Patients with facial cancers can experience disfigurement as they may undergo considerable appearance\nchanges from their illness and its treatment. Individuals with difficulties adjusting to facial cancer are concerned about\nhow others perceive and evaluate their appearance. Therefore, it is important to understand how humans perceive\ndisfigured faces. We describe a new strategy that allows simulation of surgically plausible facial disfigurement on a novel\nface for elucidating the human perception on facial disfigurement.\nMethod: Longitudinal 3D facial images of patients (N = 17) with facial disfigurement due to cancer treatment were\nreplicated using a facial mannequin model, by applying Thin-Plate Spline (TPS) warping and linear interpolation on the\nfacial mannequin model in polar coordinates. Principal Component Analysis (PCA) was used to capture longitudinal\nstructural and textural variations found within each patient with facial disfigurement arising from the treatment. We\ntreated such variations as disfigurement. Each disfigurement was smoothly stitched on a healthy face by seeking a\nPoisson solution to guided interpolation using the gradient of the learned disfigurement as the guidance field vector.\nThe modeling technique was quantitatively evaluated. In addition, panel ratings of experienced medical professionals\non the plausibility of simulation were used to evaluate the proposed disfigurement model.\nResults: The algorithm reproduced the given face effectively using a facial mannequin model with less than 4.4mm\nmaximum error for the validation fiducial points that were not used for the processing. Panel ratings of experienced\nmedical professionals on the plausibility of simulation showed that the disfigurement model (especially for peripheral\ndisfigurement) yielded predictions comparable to the real disfigurements.\nConclusions: The modeling technique of this study is able to capture facial disfigurements and its simulation represents\nplausible outcomes of reconstructive surgery for facial cancers. Thus, our technique can be used to study human\nperception on facial disfigurement....
Background: The disarranged fat stripe of the pronator quadratus muscle (PQ) on radiographs (the PQ sign) is\nreported to be predictive of subtle bone fractures. This study aimed to report the results of magnetic resonance\nimaging (MRI) study in the patients in whom bone injury was not radiographically detected around the wrist joint,\nand the PQ was sonographically swollen following acute trauma.\nMethods: We evaluated sonographically the PQ of 55 patients who showed normal radiographs following acute\ntrauma. The sonographic appearance of the PQ was checked on both longitudinal and transverse images. On the\nlongitudinal image, the probe was positioned along the flexor carpi radialis tendon. For the transverse image, we\nadopted the image of the same level in which the PQ of the unaffected hand showed maximal thickness. The PQ\nwas considered to be swollen with disproportionate hyperechogenicity and/or thickening compared with the\nunaffected side at least in one of the two images. Of the 55 patients, 25 patients whose PQ was considered to be\nswollen underwent MRI study. PQ thickness in millimeters was retrospectively measured on longitudinal and\ntransverse sonographic images.\nResults: Twenty-three patients (92.0%) had occult bone injury, and two adult patients (8.0%) showed only wrist\njoint effusion on MRI. Among these 23, the distal radius was the most frequent location of the occult bone injury\n(20 patients; 9 [36.0%] with an occult fracture line and 11 [44.0%] with bone bruising). In longitudinal image, the\nmean value of the PQ thickness of affected hands was 6.2 (3.7ââ?¬â??9.6 mm; standard deviation [SD], 1.5) and that of\nunaffected hands was 4.5 (2.3ââ?¬â??6.7 mm; SD, 1.2), respectively. In transverse image, that of dominant and nondominant\nhands was 7.6 (4.6ââ?¬â??13.2 mm; SD, 2.0) and 5.5 (3.6ââ?¬â??7.5 mm; SD, 1.1), respectively. The mean difference in PQ thickness\nbetween affected and unaffected hands was 1.7 (0.1ââ?¬â??5.0 mm; SD, 1.1) in longitudinal image and 2.0 (0.3ââ?¬â??6.8 mm;\nSD, 1.7) in transverse image.\nConclusions: Sonographic swelling of the PQ might be indicative of occult bone injury in patients with normal\nradiographs following acute trauma....
Background: Manual segmentations of the whole intracranial vault in high-resolution magnetic resonance images are\noften regarded as very time-consuming. Therefore it is common to only segment a few linearly spaced intracranial areas\nto estimate the whole volume. The purpose of the present study was to evaluate how the validity of intracranial\nvolume estimates is affected by the chosen interpolation method, orientation of the intracranial areas and the linear\nspacing between them.\nMethods: Intracranial volumes were manually segmented on 62 participants from the Gothenburg MCI study using\n1.5 T, T1-weighted magnetic resonance images. Estimates of the intracranial volumes were then derived using\nsubsamples of linearly spaced coronal, sagittal or transversal intracranial areas from the same volumes. The subsamples\nof intracranial areas were interpolated into volume estimates by three different interpolation methods. The linear\nspacing between the intracranial areas ranged from 2 to 50 mm and the validity of the estimates was determined by\ncomparison with the entire intracranial volumes.\nResults: A progressive decrease in intra-class correlation and an increase in percentage error could be seen with\nincreased linear spacing between intracranial areas. With small linear spacing (?15 mm), orientation of the intracranial\nareas and interpolation method had negligible effects on the validity. With larger linear spacing, the best validity was\nachieved using cubic spline interpolation with either coronal or sagittal intracranial areas. Even at a linear spacing of\n50 mm, cubic spline interpolation on either coronal or sagittal intracranial areas had a mean absolute agreement\nintra-class correlation with the entire intracranial volumes above 0.97.\nConclusion: Cubic spline interpolation in combination with linearly spaced sagittal or coronal intracranial areas overall\nresulted in the most valid and robust estimates of intracranial volume. Using this method, valid ICV estimates could be\nobtained in less than five minutes per patient....
Pulmonary regurgitation (PR) is an important determinant of outcome after tetralogy of fallot (TOF) repair. Pulmonary regurgitation frequently occurs after surgical correction of tetralogy of fallot. The physiologic impact of PR on the right ventricle remains incompletely understood. Patients (n = 24) with magnetic resonance imaging after TOF repair were identified. PR was quantified using phase contrast (PC) analysis of main pulmonary artery flow and differential right and left ventricular stroke volumes....
Independent central reading or off-site reading of imaging endpoints is increasingly used in clinical trials. Clinicianreported\noutcomes, such as endoscopic disease activity scores, have been shown to be subject to bias and random\nerror. Central reading attempts to limit bias and improve accuracy of the assessment, two factors that are critical to\ntrial success. Whether one central reader is sufficient and how to best integrate the input of more than one central\nreader into one output measure, is currently not known.\nIn this concept paper we develop the theoretical foundations of a reading algorithm that can achieve both\nobjectives without jeopardizing operational efficiency We examine the role of expert versus competent reader,\nframe scoring of imaging as a classification task, and propose a voting algorithm (VISA: Voting for Image Scoring\nand Assessment) as the most appropriate solution which could also be used to operationally define imaging gold\nstandards. We propose two image readers plus an optional third reader in cases of disagreement (2 + 1) for\nordinary scoring tasks. We argue that it is critical in trials with endoscopically determined endpoints to include the\nscore determined by the site reader, at least in endoscopy clinical trials. Juries with more than 3 readers could\ndefine a reference standard that would allow a transition from measuring reader agreement to measuring reader\naccuracy. We support VISA by applying concepts from engineering (triple-modular redundancy) and voting theory\n(Condorcetââ?¬â?¢s jury theorem) and illustrate our points with examples from inflammatory bowel disease trials,\nspecifically, the endoscopy component of the Mayo Clinic Score of ulcerative colitis disease activity. Detailed\nflow-diagrams (pseudo-code) are provided that can inform program design.\nThe VISA ââ?¬Å?2 + 1ââ?¬Â reading algorithm, based on voting, can translate individual reader scores into a final score in a\nfashion that is both mathematically sound (by avoiding averaging of ordinal data) and in a manner that is\nconsistent with the scoring task at hand (based on decisions about the presence or absence of features, a\nsubjective classification task). While the VISA 2 + 1 algorithm is currently being used in clinical trials, empirical data\nof its performance have not yet been reported....
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