Current Issue : October - December Volume : 2012 Issue Number : 4 Articles : 6 Articles
Background: Herlyn-Werner-Wunderlich (HWW) syndrome is a very rare congenital anomaly of the urogenital tract\r\ninvolving M�¼llerian ducts and Wolffian structures, and it is characterized by the triad of didelphys uterus,\r\nobstructed hemivagina and ipsilateral renal agenesis. It generally occurs at puberty and exhibits non-specific and\r\nvariable symptoms with acute or pelvic pain shortly following menarche, causing a delay in the diagnosis.\r\nMoreover, the diagnosis is complicated by the infrequency of this syndrome, because M�¼llerian duct anomalies\r\n(MDA) are infrequently encountered in a routine clinical setting.\r\nCases presentation: two cases of HWW syndrome in adolescents and a differential diagnosis for one case of a\r\ndifferent MDA, and the impact of magnetic resonance (MR) imaging technology to achieve the correct diagnosis.\r\nConclusions: MR imaging is a very suitable diagnostic tool in order to perform the correct diagnosis of HWW\r\nsyndrome....
Background: The ability to measure and quantify myocardial motion and deformation provides a useful tool to\r\nassist in the diagnosis, prognosis and management of heart disease. The recent development of magnetic\r\nresonance imaging methods, such as harmonic phase analysis of tagging and displacement encoding with\r\nstimulated echoes (DENSE), make detailed non-invasive 3D kinematic analyses of human myocardium possible in\r\nthe clinic and for research purposes. A robust analysis method is required, however.\r\nMethods: We propose to estimate strain using a polynomial function which produces local models of the\r\ndisplacement field obtained with DENSE. Given a specific polynomial order, the model is obtained as the least\r\nsquares fit of the acquired displacement field. These local models are subsequently used to produce estimates of\r\nthe full strain tensor.\r\nResults: The proposed method is evaluated on a numerical phantom as well as in vivo on a healthy human heart.\r\nThe evaluation showed that the proposed method produced accurate results and showed low sensitivity to noise\r\nin the numerical phantom. The method was also demonstrated in vivo by assessment of the full strain tensor and\r\nto resolve transmural strain variations.\r\nConclusions: Strain estimation within a 3D myocardial volume based on polynomial functions yields accurate and\r\nrobust results when validated on an analytical model. The polynomial field is capable of resolving the measured\r\nmaterial positions from the in vivo data, and the obtained in vivo strains values agree with previously reported\r\nmyocardial strains in normal human hearts....
Background: The increasing age of coronary artery disease (CAD) patients and the occurrence of sarcopenia in the\r\nelderly population accompanied by ââ?¬Ë?fear of movingââ?¬â?¢ and hospitalization in these patients often results in a\r\nsubstantial loss of skeletal muscle mass and muscle strength. Cardiac rehabilitation can improve exercise tolerance\r\nand muscle strength in CAD patients but less data describe eventual morphological muscular changes possibly by\r\nmore difficult access to imaging techniques. Therefore the aim of this study is to assess and quantify the reliability\r\nand validity of an easy applicable method, the ultrasound (US) technique, to measure the diameter of rectus\r\nfemoris muscle in comparison to the muscle dimensions measured with CT scans.\r\nMethods: 45 older CAD patients without cardiac event during the last 9 months were included in this study. 25\r\npatients were tested twice with ultrasound with a two day interval to assess test-retest reliability and 20 patients\r\nwere tested twice (once with US and once with CT) on the same day to assess the validity of the US technique\r\ncompared to CT as the gold standard. Isometric and isokinetic muscle testing was performed to test potential\r\nzero-order correlations between muscle diameter, muscle volume and muscle force.\r\nResults: An intraclass correlation coefficient (ICC) of 0.97 ((95%CL: 0.92 - 0.99) was found for the test-retest\r\nreliability of US and the ICC computed between US and CT was 0.92 (95%CL: 0.81 - 0.97). The absolute difference\r\nbetween both techniques was 0.01 Ã?± 0.12 cm (p = 0.66) resulting in a typical percentage error of 4.4%. Significant\r\nzero-order correlations were found between local muscle volume and muscle diameter assessed with CT (r = 0.67,\r\np = 0.001) and assessed with US (r = 0.49, p < 0.05). Muscle strength parameters were also significantly correlated\r\nwith muscle diameter assessed with both techniques (range r = 0.45-r = 0.61, p < 0.05).\r\nConclusions: Ultrasound imaging can be used as a valid and reliable measurement tool to assess the rectus\r\nfemoris muscle diameter in older CAD patients...
Background: This paper presents a three-dimensional (3D) method for segmenting corpus callosum in normal\nsubjects and brain cancer patients with glioblastoma.\nMethods: Nineteen patients with histologically confirmed treatment na�¯ve glioblastoma and eleven normal control\nsubjects underwent DTI on a 3T scanner. Based on the information inherent in diffusion tensors, a similarity\nmeasure was proposed and used in the proposed algorithm. In this algorithm, diffusion pattern of corpus callosum\nwas used as prior information. Subsequently, corpus callosum was automatically divided into Witelson subdivisions.\nWe simulated the potential rotation of corpus callosum under tumor pressure and studied the reproducibility of\nthe proposed segmentation method in such cases.\nResults: Dice coefficients, estimated to compare automatic and manual segmentation results for Witelson\nsubdivisions, ranged from 94% to 98% for control subjects and from 81% to 95% for tumor patients, illustrating\ncloseness of automatic and manual segmentations. Studying the effect of corpus callosum rotation by different\nEuler angles showed that although segmentation results were more sensitive to azimuth and elevation than skew,\nrotations caused by brain tumors do not have major effects on the segmentation results.\nConclusions: The proposed method and similarity measure segment corpus callosum by propagating a hypersurface\ninside the structure (resulting in high sensitivity), without penetrating into neighboring fiber bundles\n(resulting in high specificity)....
Background: Changes in maximum standardised uptake values (SUVmax) between serial PET/CT studies are used to\r\ndetermine disease progression or regression in oncologic patients. To measure these changes manually can be\r\ntime consuming in a clinical routine. A semi-automatic method for calculation of SUVmax in serial PET/CT studies\r\nwas developed and compared to a conventional manual method. The semi-automatic method first aligns the serial\r\nPET/CT studies based on the CT images. Thereafter, the reader selects an abnormal lesion in one of the PET\r\nstudies. After this manual step, the program automatically detects the corresponding lesion in the other PET study,\r\nsegments the two lesions and calculates the SUVmax in both studies as well as the difference between the SUVmax\r\nvalues. The results of the semi-automatic analysis were compared to that of a manual SUVmax analysis using a\r\nPhilips PET/CT workstation. Three readers did the SUVmax readings in both methods. Sixteen patients with lung\r\ncancer or lymphoma who had undergone two PET/CT studies were included. There were a total of 26 lesions.\r\nResults: Linear regression analysis of changes in SUVmax show that intercepts and slopes are close to the line of\r\nidentity for all readers (reader 1: intercept = 1.02, R2 = 0.96; reader 2: intercept = 0.97, R2 = 0.98; reader 3: intercept\r\n= 0.99, R2 = 0.98). Manual and semi-automatic method agreed in all cases whether SUVmax had increased or\r\ndecreased between the serial studies. The average time to measure SUVmax changes in two serial PET/CT\r\nexaminations was four to five times longer for the manual method compared to the semi-automatic method for\r\nall readers (reader 1: 53.7 vs. 10.5 s; reader 2: 27.3 vs. 6.9 s; reader 3: 47.5 vs. 9.5 s; p < 0.001 for all).\r\nConclusions: Good agreement was shown in assessment of SUVmax changes between manual and semi-automatic\r\nmethod. The semi-automatic analysis was four to five times faster to perform than the manual analysis. These\r\nfindings show the feasibility of using semi-automatic methods for calculation of SUVmax in clinical routine and\r\nencourage further development of programs using this type of methods....
Background: SPECT/CT combines high resolution anatomical 3D computerized tomography (CT) and single\r\nphoton emission computerized tomography (SPECT) as functional imaging, which provides 3D information about\r\nbiological processes into a single imaging modality. The clinical utility of SPECT/CT imaging has been recognized in\r\na variety of medical fields and most recently in orthopaedics; however, clinical adoption has been limited due to\r\nshortcomings of analytical tools available. Specifically, SPECT analyses are mainly qualitative due to variation in\r\noverall metabolic uptake among patients. Furthermore, most analyses are done in 2D, although rich 3D data are\r\navailable. Consequently, it is difficult to quantitatively compare the position, size, and intensity of SPECT uptake\r\nregions among patients, and therefore difficult to draw meaningful clinical conclusions.\r\nMethods: We propose a method for normalizing orthopaedic SPECT/CT data that enables standardised 3D\r\nvolumetric quantitative measurements and comparison among patients. Our method is based on 3D localisation\r\nusing clinically relevant anatomical landmarks and frames of reference, along with intensity value normalisation\r\nusing clinically relevant reference regions. Using the normalised data, we describe a thresholding technique to\r\ndistinguish clinically relevant hot spots from background activity.\r\nResults: Using an exemplar comparison of two patients, we demonstrate how the normalised, 3D-rendered data\r\ncan provide a richer source of clinical information and allow quantitative comparison of SPECT/CT measurements\r\nacross patients. Specifically, we demonstrate how non-normalized SPECT/CT analysis can lead to different clinical\r\nconclusions than the normalized SPECT/CT analysis, and that normalized quantitative analysis can be a more\r\naccurate indicator of pathology.\r\nConclusions: Conventional orthopaedic frames of reference, 3D volumetric data analysis and thresholding are used\r\nto distinguish clinically relevant hot spots from background activity. Our goal is to facilitate a standardised\r\napproach to quantitative data collection and comparison of clinical studies using SPECT/CT, enabling more\r\nwidespread clinical use of this powerful imaging tool...
Loading....