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Objective: A prerequisite for successful clinical use of functional magnetic resonance imaging (fMRI) is the selection of an appropriate imaging sequence. The aim of this study was to compare 2D and 3D fMRI sequences using different image quality assessment methods.Methods: Descriptive image measures, such as activation volume and temporal signal-to-noise ratio (TSNR), were compared with results from visual grading characteristics (VGC) analysis of the fMRI results.Results: Significant differences in activation volume and TSNR were not directly reflected by differences in VGC scores. The results suggest that better performance on descriptive image measures is not always an indicator of improved diagnostic quality of the fMRI results.Conclusion: In addition to descriptive image measures, it is important to include measures of diagnostic quality when comparing different fMRI data acquisition methods. [ABSTRACT FROM AUTHOR]

Objectives: To qualitatively evaluate late dynamic contrast phases, 10, 20 and 30 min, after administration of Gd-EOB-DTPA with regard to biliary excretion in patients presenting with elevated liver enzymes without clinical signs of cirrhosis or hepatic decompensation and to compare the visual assessment of contrast agent excretion with histo-pathological fibrosis stage, contrast uptake parameters and blood tests., Methods: 29 patients were prospectively examined using 1.5 T MRI. The visually assessed presence or absence of contrast agent for each of five anatomical regions in randomly reviewed time-series was summarized on a four grade scale for each patient. The scores, including a total visual score, were related to the histo-pathological findings, the quantitative contrast agent uptake parameters, expressed as K Hep or LSC_N, and blood tests., Results: No relationship between the fibrosis grade or contrast uptake parameters could be established. A negative correlation between the visual assessment and alkaline phosphatase (ALP) was found. Comparing a sub-group of cholestatic patients with fibrosis score and Gd-EOB-DTPA dynamic parameters did not add any additional significant correlation., Conclusions: No correlation between visually assessed biliary excretion of Gd-EOB-DTPA and histo-pathological or contrast uptake parameters was found. A negative correlation between the visual assessment and alkaline phosphatase (ALP) was found.

Introduction: Helping students learn to apply their newly learned basic science knowledge to clinical situations is a long-standing challenge for medical educators. This study aims to describe how medical students' knowledge of the basic sciences is construed toward the end of their medical curriculum, focusing on how senior medical students explain the physiology of a given scenario. Methods A group of final-year medical students from two universities was investigated. Interviews were performed and phenomenographic analysis was used to interpret students' understanding of the physiology underlying the onset of fatigue in an individual on an exercise bicycle., Results: Three categories of description depict the qualitatively different ways the students conceptualized fatigue. A first category depicts well integrated physiological and bio-chemical knowledge characterized by equilibrium and causality. The second category contains conceptions of finite amount of substrate and juxtaposition of physiological concepts that are not fully integrated. The third category exhibits a fragmented understanding of disparate sections of knowledge without integration of basic science and clinical knowledge., Discussion: Distinctive conceptions of fatigue based with varying completeness of students' understanding characterized the three identified categories. The students' conceptions of fatigue were based on varying understanding of how organ systems relate and of the thresholds that determine physiological processes. Medical instruction should focus on making governing steps in biological processes clear and providing opportunity for causal explanations of clinical scenarios containing bio-chemical as well as clinical knowledge. This augments earlier findings by adding descriptions in terms of the subject matter studied about how basic science is applied by students in clinical settings.

Background: Healthcare students have difficulties achieving a conceptual understanding of 3D anatomy and misconceptions about physiological phenomena are persistent and hard to address. 3D visualization has improved the possibilities of facilitating understanding of complex phenomena. A project was carried out in which high quality 3D visualizations using high-resolution CT and MR images from clinical research were developed for educational use. Instead of standard stacks of slices (original or multiplanar reformatted) volume-rendering images in the quicktime VR format that enables students to interact intuitively were included. Based on learning theories underpinning problem based learning, 3D visualizations were implemented in the existing curricula of the medical and physiotherapy programs. The images/films were used in lectures, demonstrations and tutorial sessions. Self-study material was also developed., Aims: To support learning efficacy by developing and using 3D datasets in regular health care curricula and enhancing the knowledge about possible educational value of 3D visualizations in learning anatomy and physiology., Method: Questionnaires were used to investigate the medical and physiotherapy students' opinions about the different formats of visualizations and their learning experiences., Results: The 3D images/films stimulated the students will to understand more and helped them to get insights about biological variations and different organs size, space extent and relation to each other. The virtual dissections gave a clearer picture than ordinary dissections and the possibility to turn structures around was instructive., Conclusions: 3D visualizations based on authentic, viable material point out a new dimension of learning material in anatomy, physiology and probably also pathophysiology. It was successful to implement 3D images in already existing themes in the educational programs. The results show that deeper knowledge is required about students' interpretation of images/films in relation to learning outcomes. There is also a need for preparations and facilitation principles connected to the use of 3D visualizations.

Medical physiology is known to be a complex area where students develop significant errors in conceptual understanding. Students' knowledge is often bound to situational descriptions rather than underlying principles. This study explores how medical students discern and process underlying principles in physiology. Indepth interviews, where students elaborated on principles related to blood pressure and blood pressure regulation, were carried out with 16 medical students in a problem-based learning curriculum. A qualitative, phenomenographic approach was used, and interviews were audiotaped, transcribed, qualitatively analyzed, and categorized. Four categories were outlined. The underlying principles were conceived as follows: 1) general conditions for body function at a specified time point, 2) transferable phenomena between organ systems and time points, 3) conditionally transferable phenomena between organ systems and time points, and 4) cognitive constructions of limited value in medical physiology. The results offers insights into students' thinking about underlying principles in physiology and suggest how understanding can be challenged to stimulate deep-level processing of underlying principles rather than situational descriptions of physiology. A complex conception of underlying principles includes an ability to problemize phenomena beyond long causal reasoning chains, which is often rewarded in traditional examinations and tests. Keywords for problemized processing are as follows: comparisons, differences, similarities, conditions, context, relevance, multiple sampling, connections, and dependencies.

Phosphorus-31 NMR spectroscopy using slice selection (DRESS) was used to investigate the absolute concentrations of metabolites in the human liver. Absolute concentrations provide more specific biochemical information compared to spectrum integral ratios. Nine patients with histopathologically proven diffuse liver disease and 12 healthy individuals were examined in a 1.5-T MR scanner (GE Signa LX Echospeed plus). The metabolite concentration quantification procedures included: (1) determination of optimal depth for the in vivo measurements, (2) mapping the detection coil characteristics, (3) calculation of selected slice and liver volume ratios using simple segmentation procedures and (4) spectral analysis in the time domain. The patients had significantly lower concentrations of phosphodiesters (PDE), 6.3+/-3.9 mM, and ATP-beta, 3.6+/-1.1 mM, (P<0.05) compared with the control group (10.0+/-4.2 mM and 4.2+/-0.3 mM, respectively). The concentrations of phosphomonoesters (PME) were higher in the patient group, although this was not significant. Constructing an anabolic charge (AC) based on absolute concentrations, [PME]/([PME] + [PDE]), the patients had a significantly larger AC than the control subjects, 0.29 vs. 0.16 (P<0.005). Absolute concentration measurements of phosphorus metabolites in the liver are feasible using a slice selective sequence, and the technique demonstrates significant differences between patients and healthy subjects.

The vascular supply of the rat tympanic membrane (TM) was studied by means of otomicroscopy, angiography, acrylic casts, and light microscopy. The branches of the external carotid artery in the external auditory meatus were found to vascularize 1) the pars flaccida, 2) the manubrial part of the pars tensa, and 3) the junction between the fibrocartilaginous ring of the TM and the tympanic sulcus of the temporal bone. The TM vessels of areas 1 and 2 were found beneath the squamous epithelium, close to mast cells and nerve bundles. Vessels originating from the tympanic cavity (also probably emanating from the external carotid artery) supplied the periphery of the pars tensa with minute branches, localized immediately beneath the tympanal epithelium. The portion of the pars tensa between the manubrial part and the periphery lacked a vascular system. Upon mechanical stimulation (gentle pressure on the handle of the malleus), the normally visible vessels dilated and minute branches appeared. This dilation may be caused, at least partly, by a release of vasoactive substances from mast cells and/or nerves in its vicinity. Even under mechanical stimulation, a large portion of the pars tensa seemed to be devoid of vessels. The nutrition of this part may be served by diffusion, with nutrients originating from the vessels in the tympanal rim and along the handle of the malleus. The architecture of the attachment of the fibrocartilaginous ring to the bony sulcus of the temporal bone is quite unique. Thus, the flow in the dense vascular network between these structures may be affected by an altered tension in the pars tensa.

A patient case with cystadenocarcinoma of the pancreas in a middle-aged woman is described. Nine years prior to the pancreatic malignancy she underwent cystogastrostomy due to a pancreatic cyst presumed to be of non-neoplastic nature. The malignancy occurred at the site of the previous cystogastrostomy and was radically resected. Five years later the patient was well without signs of recurrence. The possibilities of incorrect primary diagnosis or development of a rare pancreatic malignancy in a previous cystogastrostomy are discussed.

With the use of computer assisted tomography (CAT), the volume of intracranial hemorrhages can be calculated. The present work outlines a method that, based on EMI scan printouts, makes possible a calculation of the volume of hemorrhages, tumors, or other pathological changes detectable on CAT with a high degree of accuracy, even when the pathological changes are irregular in shape. Thus, there have been divergences between the estimations of volume of meningiomas using this method and the measure of the volume of the enucleated meningiomas within the range of 0 to +5%. An example of such a meningioma, and the calculation of its volume, is presented.

A case is reported of a giant aneursym of the intracavernous portion of the left internal carotid artery that was treated initially with a left common carotid artery ligation. Six months later the aneurysm was partially removed. During this time the development and evolution of thrombus formation, a serpentine channel, and a hypervascular capsule was easily followed with recreated computerized tomography and angiography of the aneurysm.

The binding relationships between ioglycamide and steroid hormones were determined in a liquid two-phase system with labelled ioglycamide and by direct measurement of ultraviolet light absorption. It was found that an interaction between ioglycamide and steroid hormones, particularly progesterone, existed, relative to the binding to human serum protein.