Hepatocellular carcinoma metastatic to bones (Case report with review of literature)

A seventy year old man presented with bone pains. Investigation revealed a metastatic bone lesion in the humerus. The primary was found in the liver. The patient achieved good palliation with chemotherapy and radiotherapy and survived for one year.

Biomedical imaging modalities: a tutorial

The introduction of advanced imaging technologies has improved significantly the quality of medical care available to patients. Non-invasive imaging modalities allow a physician to make increasingly accurate diagnoses and render precise and measured modes of treatment. Current uses of imaging technologies include laboratory medicine, surgery, radiation therapy, nuclear medicine, and diagnostic radiology. This paper provides an overview of most of the popular imaging modalities currently in clinical use. It is hoped that a general understanding of the modality from which an image is derived will help researchers in the subsequent analysis of the image data.

Segmentation of multidimensional cardiac images

One of the initial steps in the analysis of three-dimensional (3D)/four-dimensional (4D) images is Segmentation, which entails partitioning the images into relevant subsets such as object and background. In this paper, we present a multidimensional segmentation algorithm to extract object surfaces from Multidimensional Cardiac Computed Tomography (CT) scans. We propose the Generalized Morphological operators for segmentation in multidimensions. A priori knowledge of the approximate location of the object surface is communicated to the algorithm via the definition of the Search Space. The algorithm uses this definition of the Search Space to obtain the Surface Candidate elements. The search space specification reduces the computational cost and increases the reliability of the detected features.

Morphological pyramids with alternating sequential filters

The aim of this paper is to find a relationship between alternating sequential filters (ASF) and the morphological sampling theorem (MST) developed by Haralick et al. (1987). The motivation behind this approach is to take advantage of the computational efficiency offered by the MST to implement morphological operations. First, we show alternative proofs for opening and closing in the sampled and unsampled domain using the basis functions. These proofs are important because they show that it possible to obtain any level of a morphological pyramid in one step rather than the traditional two-step procedure. This decomposition is then used to show the relationship of the open-closing in the sampled and unsampled domain. An upper and a lower bound, for the above relationships, are presented. Under certain circumstances, an equivalence is shown for open-closing between the sampled and the unsampled domain. An extension to more complicated algorithms using a union of openings and an intersection of closings is also proposed. Using the Hausdorff metric, it is shown that a morphologically reconstructed image cannot have a better accuracy than twice the radius of the reconstruction structuring element. Binary and gray scale examples are presented.

Algorithm for the automated alignment of radiographs for image subtraction

The results of this study indicate that automated alignment of pairs of radiographs produces subtractions that are indistinguishable in quality from subtractions aligned manually by an experienced aligner. In developing the algorithm for automated alignment, care was taken that the criteria used for establishing a window appropriate for testing the quality of alignment were the same for both alignment techniques.

Visualization and interactive exploration of multidimensional confocal images

A confocal image analysis system is developed for automatic extraction of surface representation of biological structures. A visualization system is also developed to manipulate these surface representations and to obtain morphometrical parameters and provides a powerful tool for biomedical research such as microstructural characterization, morphogenesis, cell differentiation, tissue organization, and embryo development.

Methods used in the structure determination of foot-and-mouth disease virus

The structure of foot-and-mouth disease virus (FMDV) strain O1 BFS 1860 has been determined to 2.9 A resolution using the molecular-replacement method [Acharya, Fry, Stuart, Fox, Rowlands & Brown (1989). Nature (London), 337, 709-716]. Crystals of the virus with average dimensions 0.12 x 0.06 x 0.12 mm belong to space group I23, a = 345 A with 1/12 of the icosahedral particle per asymmetric unit giving fivefold noncrystallographic redundancy. Oscillation diffraction photographs were collected at the SERC Synchrotron Radiation Source at Daresbury in accordance with strict disease security regulations. The ambiguity in particle orientation was resolved using a self-rotation function and starting estimates of the phases to 8 A were derived from the known structures of two picornaviruses similarly oriented in the I23 unit cell. The phases were refined and extended using iterative averaging and solvent flattening with the implementation of a simple automatic envelope-determination procedure to increase the phasing power available.

Analysis of bone X-rays using morphological fractals

The authors have applied mathematical morphology for fractal analysis on bone X-ray images. The digitized gray level image is treated as a three-dimensional surface whose fractal dimension is calculated by performing a series of dilations on this surface and plotting the area of the resulting set of surfaces against the size of the structuring element. This approach has the added advantage of encoding structural information via the use of a structuring element. The algorithm has been applied to several bone radiographs, and the results demonstrate that the fractal dimension using mathematical morphology gives a robust texture measure of trabecular bone structures.

Structural and serological evidence for a novel mechanism of antigenic variation in foot-and-mouth disease virus

Changes resulting in altered antigenic properties of viruses nearly always occur on their surface and have been attributed to the substitution of residues directly involved in binding antibody. To investigate the mechanism of antigenic variation in foot-and-mouth disease virus (FMDV), variants that escape neutralization by a monoclonal antibody have been compared crystallographically and serologically with parental virus. FMDVs form one of the four genera of the Picornaviridae. The unenveloped icosahedral shell comprises 60 copies each of four structural proteins VP1-4. Representatives from each of the genera have similar overall structure, but differences in the external features. For example, human rhinovirus has a pronounced 'canyon' that is proposed to contain the cell attachment site, whereas elements of the attachment site for FMDV, which involves the G-H loop (residues 134-160) and C-terminus (200-213) of VP1, are exposed on the surface. Moreover, this G-H loop, which is a major antigenic site of FMDV, forms a prominent, highly accessible protrusion, a feature not seen in other picornaviruses. It is this loop that is perturbed in the variant viruses that we have studied. The amino acid mutations characterizing the variants are not at positions directly involved in antibody binding, but result in far-reaching perturbations of the surface structure of the virus. Thus, this virus seems to use a novel escape mechanism whereby an induced conformational change in a major antigenic loop destroys the integrity of the epitope.

The structure of foot-and-mouth disease virus: implications for its physical and biological properties

The structure of foot-and-mouth disease virus has been solved at a resolution of 2.9 A by X-ray diffraction techniques. The overall structural organisation of the particle is similar to that seen in other picornaviruses but there are several unique features. Many of these help to explain its characteristic physical and biological properties. In particular the canyon or pit found at the surface of other picornaviruses is lacking, which has important implications for cell attachment and the process of infection. Also there are 60 large disordered protrusions at the surface corresponding to the major antigenic site. This disorder is of particular interest in relation to the striking ability of linear synthetic peptides to induce protective immunity against foot-and-mouth disease.

The three-dimensional structure of foot-and-mouth disease virus at 2.9 A resolution

The structure of foot-and-mouth disease virus has been determined at close to atomic resolution by X-ray diffraction without experimental phase information. The virus shows similarities with other picornaviruses but also several unique features. The canyon or pit found in other picornaviruses is absent; this has important implications for cell attachment. The most immunogenic portion of the capsid, which acts as a potent peptide vaccine, forms a disordered protrusion on the virus surface.

Comparison of modified mallampati test between sitting and supine positions for prediction of difficult intubation

Background: Modified Mallampati test is a standard method of assessing the airway for predicting potentially difficult laryngoscopy and intubation. This test requires the patient to be in sitting position for airway evaluation. Although applicable to the majority of patients, airway evaluation in sitting position may not always be convenient or advisable. Objectives: To compare modified Mallampati grades between sitting and supine position and to find out their corelation to Cormack and Lehane laryngoscopy grade. Materials: This prospective study was conducted in 215, ASA I and II patients undergoing various routine surgical procedures under general anaesthesia, in BPKIHS, Dharan over a period of 3 months. The airway assessment was done using modified Mallampati grade in sitting and supine positions. Mallampati grade of III or IV was defined as the predictor of difficult airway. The laryngoscopy grade was assessed using the Cormack and Lehane grading scale. Grade III or IV of Cormack and Lehane grades was defined as the difficult laryngoscopy and assumed as the predictor of difficult intubation. Statistical measures including sensitivity, specificity, positive and negative predictive values and accuracy were used for comparing the two positions for predicting difficult or ease of intubation. Results: Out of 215 patients, majority 146(68%) were females. Mallampati grade III or IV was observed in more patients in supine position compared to sitting position (48.3% vs. 35.8%, p = 0.008). Difficult laryngoscopy was observed in 13(6%) patients. Sensitivity of modified Mallampati test was 77% in both the positions. Predictive value of Mallampati grading for difficult intubation were 13% and 10% and for easy intubation were 96% and 97% respectively in sitting and supine position. Specificity and accuracy of modified Mallampati test were both 67% in sitting position, where as they were 54% and 55% respectively in supine position. Conclusion: Modified Mallampati grade significantly worsens in supine position compared to sitting. However, airway evaluation in both the positions almost equally predicts for difficult intubation. DOI: http://dx.doi.org/10.3126/hren.v10i1.6000 HREN 2012; 10(1): 12-15