Independent component analysis applied to ultrasound speckle texture analysis and tissue characterization

Analysis of ultrasound speckle texture will provide us information about the underlying properties of tissue, could find applications in early lesion detection and tissue characterization. Traditional first and second order statistics based approaches ignore the higher order statistics information in the texture. On the other hand, conventional multichannel filtering or multiresolution analysis approaches rely on the predefined analytical bases which are not fully adaptive to the data being analyzed. In this paper Independent Component Analysis (ICA), which is based on higher order statistics, is proposed to deal with the ultrasound speckle texture analysis problem. ICA image bases obtained from the training images are applied as a filter bank to the testing images. Then the independent features containing higher order statistics information can be extracted from the marginal distributions of the filtered images. ICA is used here as a dimensionality reduction tool to overcome the difficulty of estimating high dimensional joint density of texture. Support Vector Machine (SVM) is then used as a classifier to classify the tissues. By using the digitally simulated tissues and corresponding B-scan images, we can further correlate the change of tissue microstructure or change of imaging conditions with the change of the ICA feature vectors. Our numerical simulation has shown ICA to be a promising technique for ultrasound speckle texture analysis and tissue characterization compared with some traditional methods such as PCA and Gabor transform.

Pararectal paraganglioma

Paragangliomas are neoplasms that arise from neural crest cells and histologically resemble their adrenal counterpart, the phaeochromocytoma. The majority of extra-adrenal tumours develop within the abdomen and are associated with the coeliac, superior and inferior mesenteric ganglia, which run parallel to the aorta. The organ of Zuckerkandl origin is most common. Pararectal paragangliomas are extremely rare. This case report presents ultrasound, magnetic resonance and histological features of such a case.

Induction of experimental ataxic sensory neuronopathy in cats by immunization with purified SGPG

IgM paraproteins in about 50% of the patients with neuropathy associated with IgM gammopathy react with carbohydrate moieties in myelin-associated glycoprotein (MAG) and in sulfated glucuronic glycolipids (SGGLs) in human peripheral nerves. However, the role of anti-MAG/SGGL antibodies in the pathogenesis of neuropathy remains unclear. In order to induce an animal model of neuropathy associated with anti-MAG/SGGL antibodies, cats were immunized with sulfoglucuronyl paragloboside (SGPG). All four cats immunized with SGPG developed clinical signs of sensory neuronopathy within 11 months after initial immunization, characterized by unsteadiness, falling, hind limb weakness and ataxia. In two cats the ataxia and hind limb paralysis were so severe that the animals had to be euthanized. Pathological examination revealed sensory ganglionitis with inflammatory infiltrates in the dorsal root ganglia. No overt signs of pathology were noted in the examined roots or nerves. High titer anti-SGPG/MAG antibodies were detected in all 4 cats immunized with SGPG but not in 3 control cats. Our data demonstrate that immunization of cats with SGPG induced anti-SGPG antibodies and sensory neuronopathy clinically resembling the sensory ataxia of patients with monoclonal IgM anti-MAG/SGPG antibodies. This study suggests that these anti-MAG/SGPG antibodies play a role in the pathogenesis of this neuropathy.

Breakpoint characterization: a new approach for segregation analysis of paracentric inversion in human sperm

Paracentric inversions (PAI) are structural chromosomal rearrangements generally considered to be harmless. Nevertheless, cases of viable recombinants have been reported, indicating the interest of studying the meiotic behaviour of these chromosomal abnormalities. To date, the few studies reported have been performed using either the human-hamster fertilization system or fluorescence in situ hybridization with centromeric or telomeric DNA probes. In order to improve the assessment of meiotic segregation in PAI, we present a new strategy based on the use of bacterial artificial chromosome (BAC) probes which allow a precise localization of chromosome breakpoints and the identification of all meiotic products in human sperm. Sperm samples from carriers of an inv(5) and an inv(14) were used to test this new high-resolution procedure.

Phlegmasia cerulea dolens

Phlegmasia dolens is a rare form of massive venous thrombosis of the lower extremities that is associated with a high degree of morbidity, including venous gangrene, compartment type syndrome, and arterial compromise. We report the sonographic findings in a patient who presented with phlegmasia dolens.

Testicular Torsion: Twists and Turns

Testicular torsion is one of the common causes of acute scrotal pain. This review discusses the clinical and sonographic findings of intravaginal and extravaginal testicular torsion, including the normal sonographic and vascular anatomy of the testis. The role of color flow Doppler and spectral Doppler is also emphasized in the patient's complete, incomplete, and intermittent testicular torsion. Sonographic features of testicular torsion mimics, such as vasculitis, venous thrombosis, scrotal edema, and technical parameters, are also presented. A brief description of new developments such as contrast-enhanced ultrasound, dynamic contrast magnetic resonance imaging, and near-infrared imaging is included.

Structural studies of a new acidic polysaccharide of apricot seeds

This article reports the isolation and structural investigation of an acidic polysaccharide of the seeds of Prunus armeniaca (apricot) - a plant of commercial importance. The polysaccharide is composed of three sugars - mannose (50%), glucose (37.5%) and glucuronic acid (12.5%). The results of methylation analysis, partial depolymerisation, Smith degradation and NMR spectroscopic studies indicate a branched structure consisting of a straight chain of mainly alpha-(1 --> 3)mannan, which is interspersed with 4-O-(beta-D-mannopyranosyl)glucuronic acid residues. The side chain is bound to the alpha-mannan chain in the form of a trisaccharide of the glucose.

Increased carotid intima media thickness and cardiac biomarkers in HIV infected children

OBJECTIVES

To assess carotid intima media thickness (IMT) and cardiac biomarkers in HIV infected children on antiretroviral therapy (ART).

METHODS

This was a single site, cross sectional, controlled observational study. We assessed carotid IMT, homocysteine, high-sensitivity C-reactive protein and myeloperoxidase levels in HIV infected children on stable ART for >or= 6 months. Carotid IMT was reported as internal carotid artery (ICA) and common carotid artery (CCA) thickness; left and right sides were measured separately. Groups were compared using appropriate two-sample tests.

RESULTS

Of the 62 subjects enrolled, 31 were HIV positive (50%), 66% were female, and 69% were African-American. Median CD4% was 32% and 26 patients (84%) had HIV-1 RNA< 400 copies/ml. Sixteen patients had been taking protease inhibitors for a median duration of 27 months. None had hypertension or smoked. HIV infected children had higher HOMA-IR, waist-to-hip ratio, cholesterol, triglycerides, myeloperoxidase and lower homocysteine levels. Left and right CCA IMT, and left and right ICA IMT were significantly higher in the HIV infected group. Significant predictors of carotid IMT measurements in uninfected controls were body mass index and homocysteine, but only the duration of ARV therapy was predictive of IMT in the HIV infected group.

CONCLUSION

Higher levels of carotid IMT and some cardiac markers were found in ART treated HIV infected children when compared to matched uninfected controls. These results suggest that HIV infected children receiving ART may be at increased risk of cardiovascular disease.

Sonographic Evaluation of Ectopic Pregnancy

Ectopic pregnancy is a high-risk condition that occurs in 1.9% of reported pregnancies. Although the clinical triad of pain, bleeding, and amenorrhea is considered very specific for an ectopic pregnancy, ultrasound plays important role in detecting the exact location of the ectopic pregnancy and also in providing guidance for minimally invasive treatment. This article discusses the main sonographic features of ectopic pregnancy at various common and unusual locations. In addition, it provides insight into the role of hormonal markers in the diagnosis and management of ectopic pregnancy.

Renal pseudotumors

OBJECTIVE

Renal cell carcinoma is the most common malignant tumor to involve the kidneys; however, a number of other entities--called renal pseudotumors--may mimic renal neoplasms on imaging. This article presents the imaging features and pathologic correlation of some of the common and uncommon renal pseudomasses.

CONCLUSION

Many renal lesions look similar to renal cell carcinoma on radiologic imaging. The imaging features of renal pseudotumors presented in this article will help radiologists to identify them and to triage these patients for appropriate management.

Endometriosis

Endometriosis is the presence of functional endometrial tissue outside the uterine cavity and the myometrium. It is an important cause of infertility and pelvic pain in women older than 25 years. Endometriomas are relatively common and can mimic other adnexal masses, and ultrasonography is often the first choice of imaging. This pictorial essay presents the sonographic appearance of endometriomas and similar-appearing adnexal masses and their characteristics, which may aid in their differentiation on routine ultrasonographic examination.

Sonography in Benign and Malignant Renal Masses

Ultrasonography and CT have allowed improved detection of renal mass lesions. Though ultrasonography is less sensitive in the characterization of the renal mass lesions, it is often the first imaging modality for evacuation of the kidneys. This article gives an overview of the benign and malignant renal mass lesions and the role of ultrasonography in their characterization.