Texture Image Analysis in Differentiating Malignant from Benign Adrenal Cortical Tumors in Children and Adults

Objective: To investigate the possible role of chromatin texture parameters, nuclear morphology, DNA ploidy and clinical functional status in discriminating benign from malignant adrenocortical tumors (ACT). Patients and Methods: Forty-eight cases of clinically benign (n=40) and clinically malignant (n=8) ACT with a minimum of 5-years` follow-up were evaluated for chromatin texture parameters (run length, standard deviation, configurable run length, valley, slope, peak and other 21 Markovian features that describe the distribution of the chromatin in the nucleus), nuclear morphology (nuclear area, nuclear perimeter, nuclear maximum and minumum diameter, nuclear shape), and DNA ploidy. Nuclear parameters were evaluated in Feulgen-stained 5 mu m paraffin-sections analyzed using a CAS 200 image analyzer. Results: Since ACTs present different biological features in children and adults, patients were divided into two groups: children (<= 15 years) and adults (>15 years). In the group of children DNA ploidy presented a marginal significance (p=0.05) in discriminating ACTs. None of the parameters discriminated between malignant and benign ACT in the adult group. Conclusion: ACTs are uncommon and definitive predictive criteria for malignancy remain uncertain, particularly in children. Our data point to DNA content evaluated by image analysis as a new candidate tool for this challenging task. Texture image analysis did not help to differentiate malignant from benign adrenal cortical tumors in children and adults.

Sclerotic Vertebral Metastases: Pain Palliation Using Percutaneous Image-Guided Cryoablation

Cryoablative therapies have been proposed to palliate pain from soft-tissue or osteolytic bone tumors. A case of a patient with painful thoracic and sacral spine sclerotic metastases successfully treated by image-guided percutaneous cryoablation with the aid of insulation techniques and thermosensors is reported in this case report.

IMAGE QUANTIFICATION FOR RADIATION DOSE CALCULATIONS-LIMITATIONS AND UNCERTAINTIES

Radiation dose calculations in nuclear medicine depend on quantification of activity via planar and/or tomographic imaging methods. However, both methods have inherent limitations, and the accuracy of activity estimates varies with object size, background levels, and other variables. The goal of this study was to evaluate the limitations of quantitative imaging with planar and single photon emission computed tomography (SPECT) approaches, with a focus on activity quantification for use in calculating absorbed dose estimates for normal organs and tumors. To do this we studied a series of phantoms of varying complexity of geometry, with three radionuclides whose decay schemes varied from simple to complex. Four aqueous concentrations of (99m)Tc, (131)I, and (111)In (74, 185, 370, and 740 kBq mL(-1)) were placed in spheres of four different sizes in a water-filled phantom, with three different levels of activity in the surrounding water. Planar and SPECT images of the phantoms were obtained on a modern SPECT/computed tomography (CT) system. These radionuclides and concentration/background studies were repeated using a cardiac phantom and a modified torso phantom with liver and ""tumor"" regions containing the radionuclide concentrations and with the same varying background levels. Planar quantification was performed using the geometric mean approach, with attenuation correction (AC), and with and without scatter corrections (SC and NSC). SPECT images were reconstructed using attenuation maps (AM) for AC; scatter windows were used to perform SC during image reconstruction. For spherical sources with corrected data, good accuracy was observed (generally within +/- 10% of known values) for the largest sphere (11.5 mL) and for both planar and SPECT methods with (99m)Tc and (131)I, but were poorest and deviated from known values for smaller objects, most notably for (111)In. SPECT quantification was affected by the partial volume effect in smaller objects and generally showed larger errors than the planar results in these cases for all radionuclides. For the cardiac phantom, results were the most accurate of all of the experiments for all radionuclides. Background subtraction was an important factor influencing these results. The contribution of scattered photons was important in quantification with (131)I; if scatter was not accounted for, activity tended to be overestimated using planar quantification methods. For the torso phantom experiments, results show a clear underestimation of activity when compared to previous experiment with spherical sources for all radionuclides. Despite some variations that were observed as the level of background increased, the SPECT results were more consistent across different activity concentrations. Planar or SPECT quantification on state-of-the-art gamma cameras with appropriate quantitative processing can provide accuracies of better than 10% for large objects and modest target-to-background concentrations; however when smaller objects are used, in the presence of higher background, and for nuclides with more complex decay schemes, SPECT quantification methods generally produce better results. Health Phys. 99(5):688-701; 2010

Characterization of Superparamagnetic Iron Oxide Coated with Silicone Used as Contrast Agent for Magnetic Resonance Image for the Gastrointestinal Tract

The present work is a report of the characterization of superparamagnetic iron oxide nanoparticles coated with silicone used as a contrast agent in magnetic resonance imaging of the gastrointestinal tract. The hydrodynamic size of the contrast agent is 281.2 rim, where it was determined by transmission electron microscopy and a Fe(3)O(4) crystalline structure was identified by X-ray diffraction, also confirmed by Mossbauer Spectroscopy. The blocking temperature of 190 K was determined from magnetic measurements based on the Zero Field Cooled and Field Cooled methods. The hysteresis loops were measured at different temperatures below and above the blocking temperature. Ferromagnetic resonance analysis indicated the superparamagnetic nature of the nanoparticles and a strong temperature dependence of the peak-to-peak linewidth Delta H(pp), giromagnetic factor g, number of spins N(S) and relaxation time T(2) were observed. This behavior can be attributed to an increase in the superexchange interaction.

Comparative analysis of the expression of cytokeratins (1,10,14,16,4), involucrin, filaggrin and e-cadherin in plane warts and epidermodysplasia verruciformis plane wart-type lesions

Background: Epidermodysplasia verruciformis (EV) is a rare genodermatosis with susceptibility to human papillomavirus (HPV) infection, and high risk of skin cancer considered a model of viral oncogenesis. Methods: Fifteen cases of EV plane wart (PW)-type lesions (EV) and 14 cases of PW in healthy individuals were subjected to immunohistochemical technique for cytokeratins (K) 1, 10, 14, 16, 4, involucrin, filaggrin and e-cadherin. Results: K1/10 showed retarded or negative expression in EV, being substituted by K14. Expression of K14 occurred in the basal and suprabasal layers in both groups, but in EV, its expression was observed up to the more superficial layers. Both groups showed positivity for K16 and K4, involucrin expression in lower levels of the spinous layer and unaltered filaggrin expression. E-cadherin expression was diminished at the koilocytotic foci of both lesions, more superficially in EV. Conclusion: Infection by HPV may alter the differentiation status of the epidermis, leading to a major expression of K14, delayed or absent expression of K1/10 and earlier involucrin expression, especially in EV. It also stimulates the expression of K16 and K4. Filaggrin expression is not altered, and e-cadherin is diminished in superficial koilocytotic cells` foci in EV.

Patient Characteristics as Predictors of Image Quality and Diagnostic Accuracy of MDCT Compared With Conventional Coronary Angiography for Detecting Coronary Artery Stenoses: CORE-64 Multicenter International Trial

OBJECTIVE. The purpose of the study was to investigate patient characteristics associated with image quality and their impact on the diagnostic accuracy of MDCT for the detection of coronary artery stenosis. MATERIALS AND METHODS. Two hundred ninety-one patients with a coronary artery calcification (CAC) score of <= 600 Agatston units (214 men and 77 women; mean age, 59.3 +/- 10.0 years [SD]) were analyzed. An overall image quality score was derived using an ordinal scale. The accuracy of quantitative MDCT to detect significant (>= 50%) stenoses was assessed using quantitative coronary angiography (QCA) per patient and per vessel using a modified 19-segment model. The effect of CAC, obesity, heart rate, and heart rate variability on image quality and accuracy were evaluated by multiple logistic regression. Image quality and accuracy were further analyzed in subgroups of significant predictor variables. Diagnostic analysis was determined for image quality strata using receiver operating characteristic (ROC) curves. RESULTS. Increasing body mass index (BMI) (odds ratio [OR] = 0.89, p < 0.001), increasing heart rate (OR = 0.90, p < 0.001), and the presence of breathing artifact (OR = 4.97, p = 0.001) were associated with poorer image quality whereas sex, CAC score, and heart rate variability were not. Compared with examinations of white patients, studies of black patients had significantly poorer image quality (OR = 0.58, p = 0.04). At a vessel level, CAC score (10 Agatston units) (OR = 1.03, p = 0.012) and patient age (OR = 1.02, p = 0.04) were significantly associated with the diagnostic accuracy of quantitative MDCT compared with QCA. A trend was observed in differences in the areas under the ROC curves across image quality strata at the vessel level (p = 0.08). CONCLUSION. Image quality is significantly associated with patient ethnicity, BMI, mean scan heart rate, and the presence of breathing artifact but not with CAC score at a patient level. At a vessel level, CAC score and age were associated with reduced diagnostic accuracy.

Diffuse plane idiopathic normolipemic xanthoma with hiperesplenism

Diffuse plane normolipemic xanthoma is a rare disease, of a group of clinical syndromes called histiocytoses, characterized by the presence of yellowish or yellow-orange plaques, distributed symmetrically on the cutaneous surface and usually accompanied by xanthelasma. It affects mainly adults and it may cause discrete changes in serum lipids. The case of an 85-year-old female patient who has been showing extensive asymptomatic yellow-orange plaques in the trunk and abdomen for a year is reported. Laboratory tests did not show an increase in serum lipids or the occurrence of reticuloendothelial disorders.

Factors associated with pelvic asymmetry in transverse plane during gait in patients with cerebral palsy

The purpose of this study was to describe the patterns of pelvic rotational asymmetry in the transverse plane and identify the possible factors related to this problem. One thousand and forty-five patients with cerebral palsy (CP) and complete documentation in the gait laboratory were reviewed in a retrospective study. Pelvic asymmetry in the transverse plane was observed in 52.7% of the patients; and to identify the possible causes of pelvic retraction, clinical (Thomas test, popliteal angle, and gastrocnemius tightness) and dynamic parameters (mean rotation of the hip in stance, minimum hip flexion, minimum knee flexion, and peak ankle dorsiflexion) were evaluated. The association between these parameters and pelvic retraction was assessed statistically. The results showed that 75.7% of patients with asymmetric pattern of the pelvis had clinical diagnosis of diplegic spastic CP. Among the patients with asymmetrical CP, the most common pattern was pelvic retraction on the affected side. The relationship between pelvic retraction and internal hip rotation was stronger in patients with asymmetrical diplegic CP than in those with hemiplegic (P<0.001) or symmetrical diplegic CP (P=0.014). All of the patients exhibited a significant association among clinical parameters (Thomas test, popliteal angle, and gastrocnemius tightness) and pelvic retraction. In conclusion, pelvic retraction seems to be a multifactorial problem, and the etiology can change according to topographic classification, which must be taken into account during the decision-making process in patients with CP. J Pediatr Orthop B 18:320-324 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Intra and inter-examiner reliability of the subacromial impingement index

The present study aimed to assess the reliability of intra and inter-examiner subacromial impingement index (SII) measures obtained from radiographs. Thirty-six individuals were enrolled and divided into two groups: control group, composed of 18 volunteers in good general health without shoulder problems, and a group of 18 patients with subacromial impingement syndrome (SIS). Radiographic images were taken with the dominant upper limb in neutral rotation, while the volunteers held their arm at 90A degrees of abduction in the frontal plane. The beam of radiation at 30A degrees craniocaudal inclination was used to provide an antero-posterior image view. Three blinded examiners each performed three measurements from the subacromial space (SS) and the anatomical neck of the humerus (NH). The SII was calculated as the ratio of the SS and the NH measures. The mean values of SII were compared using t-tests. The intra-class correlation coefficient (ICC) was used to assess intra- and inter-examiner reliability of the measures. The mean values of SII were greater for the control group (0.12) than for the SIS group (0.08; p = 0.0071). SII measurements showed excellent intra (0.96-0.99) and inter-examiner reliability (0.94) for both the control and SIS group. The results of this study show the potential use of the SII; a greater mean value for the control group compared to the SIS group and excellent reliability for intra- and inter-examiner measurement. Validation studies of the index should be conducted to correlate the index with clinical findings from subacromial impingement syndrome.

Supporting content-based image retrieval and computer-aided diagnosis systems with association rule-based techniques

In this work, we take advantage of association rule mining to support two types of medical systems: the Content-based Image Retrieval (CBIR) systems and the Computer-Aided Diagnosis (CAD) systems. For content-based retrieval, association rules are employed to reduce the dimensionality of the feature vectors that represent the images and to improve the precision of the similarity queries. We refer to the association rule-based method to improve CBIR systems proposed here as Feature selection through Association Rules (FAR). To improve CAD systems, we propose the Image Diagnosis Enhancement through Association rules (IDEA) method. Association rules are employed to suggest a second opinion to the radiologist or a preliminary diagnosis of a new image. A second opinion automatically obtained can either accelerate the process of diagnosing or to strengthen a hypothesis, increasing the probability of a prescribed treatment be successful. Two new algorithms are proposed to support the IDEA method: to pre-process low-level features and to propose a preliminary diagnosis based on association rules. We performed several experiments to validate the proposed methods. The results indicate that association rules can be successfully applied to improve CBIR and CAD systems, empowering the arsenal of techniques to support medical image analysis in medical systems. (C) 2009 Elsevier B.V. All rights reserved.

An association rule-based method to support medical image diagnosis with efficiency

In this paper, we propose a method based on association rule-mining to enhance the diagnosis of medical images (mammograms). It combines low-level features automatically extracted from images and high-level knowledge from specialists to search for patterns. Our method analyzes medical images and automatically generates suggestions of diagnoses employing mining of association rules. The suggestions of diagnosis are used to accelerate the image analysis performed by specialists as well as to provide them an alternative to work on. The proposed method uses two new algorithms, PreSAGe and HiCARe. The PreSAGe algorithm combines, in a single step, feature selection and discretization, and reduces the mining complexity. Experiments performed on PreSAGe show that this algorithm is highly suitable to perform feature selection and discretization in medical images. HiCARe is a new associative classifier. The HiCARe algorithm has an important property that makes it unique: it assigns multiple keywords per image to suggest a diagnosis with high values of accuracy. Our method was applied to real datasets, and the results show high sensitivity (up to 95%) and accuracy (up to 92%), allowing us to claim that the use of association rules is a powerful means to assist in the diagnosing task.

Effect of image analysis software on neurofunctional activation during processing of emotional human faces

Functional brain imaging techniques such as functional MRI (fMRI) that allow the in vivo investigation of the human brain have been exponentially employed to address the neurophysiological substrates of emotional processing. Despite the growing number of fMRI studies in the field, when taken separately these individual imaging studies demonstrate contrasting findings and variable pictures, and are unable to definitively characterize the neural networks underlying each specific emotional condition. Different imaging packages, as well as the statistical approaches for image processing and analysis, probably have a detrimental role by increasing the heterogeneity of findings. In particular, it is unclear to what extent the observed neurofunctional response of the brain cortex during emotional processing depends on the fMRI package used in the analysis. In this pilot study, we performed a double analysis of an fMRI dataset using emotional faces. The Statistical Parametric Mapping (SPM) version 2.6 (Wellcome Department of Cognitive Neurology, London, UK) and the XBAM 3.4 (Brain Imaging Analysis Unit, Institute of Psychiatry, Kings College London, UK) programs, which use parametric and non-parametric analysis, respectively, were used to assess our results. Both packages revealed that processing of emotional faces was associated with an increased activation in the brain`s visual areas (occipital, fusiform and lingual gyri), in the cerebellum, in the parietal cortex, in the cingulate cortex (anterior and posterior cingulate), and in the dorsolateral and ventrolateral prefrontal cortex. However, blood oxygenation level-dependent (BOLD) response in the temporal regions, insula and putamen was evident in the XBAM analysis but not in the SPM analysis. Overall, SPM and XBAM analyses revealed comparable whole-group brain responses. Further Studies are needed to explore the between-group compatibility of the different imaging packages in other cognitive and emotional processing domains. (C) 2009 Elsevier Ltd. All rights reserved.