STIR, SPIR and SPAIR techniques in magnetic resonance of the breast: a comparative study

The amount of fat is a component that complicates the clinical evaluation and the differential diagnostic between benign and malign lesions in the breast MRI examinations. To overcome this problem, an effective erasing of the fat signal over the images acquisition process, is essentials. This study aims to compare three fat suppression techniques (STIR, SPIR, SPAIR) in the MR images of the breast and to evaluate the best image quality regarding its clinical usefulness. To mimic breast women, a breast phantom was constructed. First the exterior contour and, in second time, its content which was selected based on 7 samples with different components. Finally it was undergone to a MRI breast protocol with the three different fat saturation techniques. The examinations were performed on a 1.5 T MRI system (Philips®). A group of 5 experts evaluated 9 sequences, 3 of each with fat suppression techniques, in which the frequency offset and TI (Inversion Time) were the variables changed. This qualitative image analysis was performed according 4 parameters (saturation uniformity, saturation efficacy, detail of the anatomical structures and differentiation between the fibroglandular and adipose tissue), using a five-point Likert scale. The statistics analysis showed that anyone of the fat suppression techniques demonstrated significant differences compared to the others with (p > 0.05) and regarding each parameter independently. By Fleiss’ kappa coefficient there was a good agreement among observers P(e) = 0.68. When comparing STIR, SPIR and SPAIR techniques it was confirmed that all of them have advantages in the study of the breast MRI. For the studied parameters, the results through the Friedman Test showed that there are similar advantages applying anyone of these techniques.

Image quality and dose analysis for a PA chest X-ray: comparison between AEC mode acquisition and manual mode using the 10 kVp ‘rule’

Purpose - To compare the image quality and effective dose applying the 10 kVp rule with manual mode acquisition and AEC mode in PA chest X-ray. Method - 68 images (with and without lesions) were acquired using an anthropomorphic chest phantom using a Wolverson Arcoma X-ray unit. These images were compared against a reference image using the 2 alternative forced choice (2AFC) method. The effective dose (E) was calculated using PCXMC software using the exposure parameters and the DAP. The exposure index (lgM provided by Agfa systems) was recorded. Results - Exposure time decreases more when applying the 10 kVp rule with manual mode (50%–28%) when compared with automatic mode (36%–23%). Statistical differences for E between several ionization chambers' combinations for AEC mode were found (p = 0.002). E is lower when using only the right AEC ionization chamber. Considering the image quality there are no statistical differences (p = 0.348) between the different ionization chambers' combinations for AEC mode for images with no lesions. Considering lgM values, it was demonstrated that they were higher when the AEC mode was used compared to the manual mode. It was also observed that lgM values obtained with AEC mode increased as kVp value went up. The image quality scores did not demonstrate statistical significant differences (p = 0.343) for the images with lesions comparing manual with AEC mode. Conclusion - In general the E is lower when manual mode is used. By using the right AEC ionising chamber under the lung the E will be the lowest in comparison to other ionising chambers. The use of the 10 kVp rule did not affect the visibility of the lesions or image quality.

Image quality and dose analysis in PA chest x-ray: comparison between AEC and manual mode acquisition using the 10 kVp rule

Purpose: To compare image quality and effective dose when the 10 kVp rule is applied with manual and AEC mode in PA chest X-ray. Methods and Materials: A total of 68 images (with and without lesions) were acquired of an anthropomorphic chest phantom in a Wolverson Arcoma X-ray unit. The images were evaluated against a reference image using image quality criteria and the 2 alternative forced choice (2 AFC) method by five radiographers. The effective dose was calculated using PCXMC software using the exposure parameters and DAP. The exposure index (lgM) was recorded. Results: Exposure time decreases considerably when applying the 10 kVp rule in manual mode (50%-28%) compared to AEC mode (36%-23%). Statistical differences for effective dose between several AEC modes were found (p=0.002). The effective dose is lower when using only the right AEC ionization chamber. Considering image quality, there are no statistical differences (p=0.348) between the different AEC modes for images with no lesions. Using a higher kVp value the lgM values will also increase. The lgM values showed significant statistical differences (p=0.000). The image quality scores did not present statistically significant differences (p=0.043) for the images with lesions when comparing manual with AEC modes. Conclusion: In general, the dose is lower in the manual mode. By using the right AEC ionising chamber the effective dose will be the lowest in comparison to other ionising chambers. The use of the 10 kVp rule did not affect the detectability of the lesions.

Pathogenicity of Entamoeba dispar under xenic and monoxenic cultivation compared to a virulent E. histolytica

Two xenic isolates and cloned cultures of Entamoeba dispar were submitted to monoxenization using Crithidia fasciculata as the associated organism. Growth in monoxenic cultivation and ability of xenic and monoxenic trophozoites to destroy VERO cells and produce lesions in hamster livers were compared to those of a virulent E. histolytica. Parental and cloned E. dispar under monoxenic cultivation showed a remarkable lower growth than the monoxenic E. histolytica and were avirulent in both in vivo and in vitro tests. When xenically cultured, trophozoites of E. dispar showed a moderate lytic activity against VERO cells (1.5 to 41.8% of destruction) but caused severe hepatic lesions in hamsters as those caused by the virulent E. histolytica (29 to 100% in prevalence and 0.86 to 4.00 in lesion degree). Although E. dispar has not been associated with invasive disease in men, the ability of xenic trophozoites to produce prominent tissue damage in experimental conditions has indicated that some strains have a considerable pathogenic potential when in presence of bacteria.

Decreased Vascular Endothelial Growth Factor (VEGF) Expression in Focal Segmental Glomeruloesclerosis Lesions of Patients Under Sirolimus

Background: Proteinuria (PT) with SRL appears not only after conversion from a calcineurin inhibitor (CI), but also in de novo patients. The PT may be related to a hemodynamic effect of CI withdrawal or to a direct effect of SRL in glomerulus (GL). Recently an association between PT in SRL patients and FSGS lesions has been described. It is also known that SRL decrease VEGF synthesis and experimental data suggest that VEGF is essential to podocyte survival and differentiation. Aim: To determine if glomerular lesions and PT in SRL patients could be related to altered glomerular VEGF expression. Material and methods: We evaluated glomerular VEGF expression in 10 biopsies: A-allograft kidney in backtable (n=3); B-native normal kidney (n=1); C-native kidney with FSGS lesions (n=2); D-allograft kidney with FSGS lesions from proteinuric patients under SRL after conversion from CI (n=3); E-allograft kidney in proteinuric patient under SRL with a membranous glomerulonephritis (n=1). We employed indirect immunohistochemistry in paraffin-embedded sections using a mouse monoclonal antibody against human VEGF-C1 (Santa Cruz). Results: The controls biopsies (A; B) showed normal global VEGF expression, with strong podocyte staining. The VEGF expression in the group C was similar to the controls, although no FSGS lesions were observed in the stained GL. The group D showed normal VEGF expression in the apparently normal GL, hypertrophied podocytes with reduction of VEGF in anomalous GL, and no staining in slcerotic lesions. We observed a gradual reduction of VEGF expression with progressive dedifferentiation of podocytes. In the group E the VEGF was globally reduced, with some hypertrophied podocytes expressing decreased VEGF. Conclusion: We confirmed the diminished VEGF expression in injured podocytes of SRL patients.This decreased expression may result from a direct effect of SRL and precede the appearance of FSGS lesions and PT. Further studies are needed with greater number of cases and controls, including early biopsies of patients under SRL.

Focal Malignant Liver Lesions: Diagnosis by Dynamic Incremental CT, Early Phase

The purpose of our study was to evaluate the accuracy of dynamic incremental bolus-enhanced conventional CT (DICT) with intravenous contrast administration, early phase, in the diagnosis of malignancy of focal liver lesions. A total of 122 lesions were selected in 74 patients considering the following criteria: lesion diameter 10 mm or more, number of lesions less than six per study, except in multiple angiomatosis and the existence of a valid criteria of definitive diagnosis. Lesions were categorized into seven levels of diagnostic confidence of malignancy compared with the definitive diagnosis for acquisition of a receiver-operator-characteristic (ROC) curve analysis and to determine the sensitivity and specificity of the technique. Forty-six and 70 lesions were correctly diagnosed as malignant and benign, respectively; there were 2 false-positive and 4 false-negative diagnoses of malignancy and the sensitivity and specificity obtained were 92 and 97%. The DICT early phase was confirmed as a highly accurate method in the characterization and diagnosis of malignancy of focal liver lesions, requiring an optimal technical performance and judicious analysis of existing semiological data.

Melanoma and Satellite Blue Papule

The colors that are seen in dermoscopy depend on the anatomic level of the skin at which the chromophores are seen. Blue color can be found in a variety of melanocytic and nonmelanocytic lesions. An 89-year-old man presented with a 3-year history of a slow-growing, hyperpigmented patch located on the distal third of the right arm. Dermoscopy showed an atypical network, irregularly distributed globules, pigmented internal streaks and a milky-red area. Based on these findings a diagnosis of slow-growing malignant melanoma was made. Simultaneously, a well-defined blue papule was seen on the proximal third of the same arm. Dermoscopy disclosed a homogeneous blue pattern. After clinical and dermoscopic correlation our differential diagnosis for this blue lesion included cutaneous melanoma metastasis, blue nevus and foreign body reaction. The patient recalled its onset 75 years ago after a grenade explosion. We also discuss the blue lesion appearance under reflectance confocal microscopy and high-definition optical coherence tomography. Histopathological examination after excision of the hyperpigmented patch and blue papule revealed a melanoma in situ and a foreign body reaction, respectively. The diagnostic evaluation of a blue lesion should always rely on the integration of all data, especially clinical and dermoscopic features. Other non-invasive techniques, like reflectance confocal microscopy and high-definition optical coherence tomography can also be important aids for its differential diagnosis.

Biodemes and zymodemes of Trypanosoma cruzi strains: correlations with clinical data and experimental pathology

With the objective of establishing biological and biochemical characteristics of a significant number of Trypanosoma cruzi strains from different geographical areas, 138 strains isolated from naturally infected humans, triatomine or vertebrate hosts were studied; 120 were isolated from different areas of Brazil and 18 from other South and Central American countries. Inocula from triatomine or culture forms were injected into suckling Swiss mice, followed by passages into mice 10 to 12 g. Biological characters and histopathological study permitted the inclusion of the strains into three Types or biodemes: I, II, III. Isoenzymic analysis confirmed a correspondence between the biodemes and zymodemes : Type I and Z2b, Type II and Z2, Type III and Z1. Results showed the ubiquitary distribution of the several types of strains. The predominance of the same Type and zymodeme in one geographical area was confirmed : Type II strains among the human cases from eastern Bahia and east of Goiás; Type III strains from humans of north Brazil and Central America and from silvatic vectors or vertebrates from other geographical areas. The biological types of strains correlate with different histopathological lesions considering cardiac involvement and neuronal lesions. These findings suggest that the biological behavior together with isoenzymes patterns and pathological pictures in the vertebrate host can be an important tool for establishing correlations between strains behavior and clinico-pathological manifestations of Chagas' disease in different geographical areas.

Skin lesions simulating blue toe syndrome caused by prolonged contact with a millipede

Venomous animals are those that, by means of a hunting and defense mechanism, are able to inject their prey with a toxic substance produced in their bodies, directly from specialized glands (e.g., tooth, sting, spur) through which the poison passes. Millipedes are poisonous animals; they can be harmful to humans, and their effects usually manifest as erythematous, purpuric, and cyanotic lesions; local pain; and paresthesia. Here, we report a case of skin contact with a millipede for 6h resulting in skin lesions similar to blue toe syndrome.

Expression of annexin A1 in Leishmania-infected skin and its correlation with histopathological features

ABSTRACTINTRODUCTION:The aim of this study was quantify annexin A1 expression in macrophages and cluster of differentiation 4 (CD4) + and cluster of differentiation 8 (CD8)+ T cells from the skin of patients with cutaneous leishmaniasis (n=55) and correlate with histopathological aspects.METHODS:Infecting species were identified by polymerase chain reaction-restriction fragment length polymorphism, and expression of annexin A1 was analyzed by immunofluorescence.RESULTS:All patients (n = 55) were infected with Leishmania braziliensis . Annexin A1 was expressed more abundantly in CD163 + macrophages in infected skin (p < 0.0001) than in uninfected skin. In addition, macrophages in necrotic exudative reaction lesions expressed annexin A1 at higher levels than those observed in granulomatous (p < 0.01) and cellular lesions p < 0.05). This difference might be due to the need to clear both parasites and necrotic tissue from necrotic lesions. CD4 + cells in cellular lesions expressed annexin A1 more abundantly than did those in necrotic (p < 0.05) and granulomatous lesions (p < 0.01). Expression in CD8 + T cells followed the same trend. These differences might be due to the pervasiveness of lymphohistiocytic and plasmacytic infiltrate in cellular lesions.CONCLUSIONS:Annexin A1 is differentially expressed in CD163 + macrophages and T cells depending on the histopathological features of Leishmania -infected skin, which might affect cell activation.

Myocardial repair with long-term and low-dose administration of a nitric oxide synthesis inhibitor. Myofibroblasts, type III collagen and fibronectin

OBJECTIVE: To study the healing process of the myocardium in hypertensive rats undergoing inhibition of nitric oxide synthesis. METHODS: Two groups of animals were studied: one received L-NAME, 12mg/kg/day, and the other was a control group. The presence of type III collagen, fibronectin, and alpha-smooth muscle actin-positive cells was assessed by immunohistochemistry. RESULTS: Fibronectin was seen in both early and late lesions, while type III collagen was seen mainly in areas of incomplete healing, situated among myocytes and around the intramyocardial branches of the coronary arteries. Areas representing early and late lesions showed a population of spindle-shaped cells. Immunohistochemistry showed that these cells were positive for alpha-smooth muscle actin. CONCLUSION: In the myocardium of hypertensive rats, the alpha-smooth muscle actin-positive cells are related to the accumulation of type III collagen and fibronectin in the areas of myocardial damage.

Comparison of pathologic changes in mammalian hosts infected with Schistosoma mansoni, S. japonicum and S. haematobium

The hepatic, intestinal and cardiopulmonary lesions produced by Schistosoma mansoni, S. haematobium and S. japonicum in man and experimental animals often bear striking similarities but usually have distinctive features as well. These are often related to parasitologic differences. Thus S. japonicum and S. haematobium lay their eggs in clusters which elicit the formation of large composite granulomas. The worms of these two species also tend to be sedentary, remaining in a single location for prolonged periods, thus producing large focal lesions in the intestines or urinary tract. Worm pairs of these two species also are gregarious and many worm pairs are often found in a single lesion. The size of circumoval granulomas, and the degree of fibrosis, are T cell dependent. The modulation of granuloma size is largely T cell dependent in mice infected with S. mansoni but is mostly regulated by serum factors in S. japonicum infected mice. In spite of these differences in egg laying and immunoregulation both S. mansoni and S. japonicum produce Symmers' fibrosis in the chimpanzee while S. haematobium does not, despite the presence of numerous eggs in the liver.

Extensor carpi ulnaris (ECU) subsheath: Normal MRI appearance and findings in athletic injuries : 40

Purpose: First, to report ECU subsheath's normal MRI appearance and the findings in athletic injuries. Second, to determine the best MRI sequence for diagnosis. Methods and materials: Sixteen patients (13 males, 3 females, mean age 30.3 years) with ECU subsheath's athletic injuries sustained between January 2003 and June 2009 were retrospectively reviewed. Wrist MRI studies were performed on 1.5-T units and consisted of at least transverse T1 and STIR sequences in pronation, and FS Gd T1 in pronation and supination. Two radiologists assessed the following items, in consensus: injury type (A to C according to Inoue), ECU tendon stability, and associated lesions (ulnar head oedema, extensor retinaculum injury, ECU tendinosis and tenosynovitis). Then, each reader independently rated the sequences' diagnostic value: 0 = questionable, 1 = suggestive, 2 = certain. Follow-up studies were present in 8 patients. ECU subsheath's normal visibility (medial, central and lateral parts) was retrospectively evaluated in 30 consecutive control MRI studies. Results: FS Gd T1 sequences in supination (1.63) and pronation (1.59) were the most valuable for diagnosis, compared to STIR (1.22) and T1 (1). The study group included 9 type A, 1 type B and 6 type C injuries. There were trends towards diminution in pouches' size, signal intensity and enhancement in follow-up studies, along with tendon stabilization within the ulnar groove. In control studies, ECU subsheath's visibility in medial, central and lateral parts were noted in 66.7-80%, 63.3-80% and 30-50% respectively. Conclusion: ECU subsheath's athletic injuries are visible on 1.5-T MRI studies. FS Gd T1 sequences in supination and pronation are the most valuable.

COLOX: a new blood-based test for colorectal cancer screening

INTRODUCTION/OBJECTIVES: Detection rates for adenoma and early colorectal cancer (CRC) are insufficient due to low compliance towards invasive screening procedures, like colonoscopy.Available non-invasive screening tests have unfortunately low sensitivity and specificity performances.Therefore, there is a large unmet need calling for a cost-effective, reliable and non-invasive test to screen for early neoplastic and pre-neoplastic lesions AIMS & Methods: The objective is to develop a screening test able to detect early CRCs and adenomas.This test is based on a nucleic acids multi-gene assay performed on peripheral blood mononuclear cells (PBMCs).A colonoscopy-controlled feasibility study was conducted on 179 subjects.The first 92 subjects was used as training set to generate a statistical significant signature.Colonoscopy revealed 21 subjects with CRC,30 with adenoma bigger than 1 cm and 41 with no neoplastic or inflammatory lesions.The second group of 48 subjects (controls, CRC and polyps) was used as a test set and will be kept blinded for the entire data analysis.To determine the organ and disease specificity 38 subjects were used:24 with inflammatory bowel disease (IBD),14 with other cancers than CRC (OC).Blood samples were taken from each patient the day of the colonoscopy and PBMCs were purified. Total RNA was extracted following standard procedures.Multiplex RT-qPCR was applied on 92 different candidate biomarkers.Different univariate and multivariate statistical methods were applied on these candidates and among them 60 biomarkers with significant p-values (<0.01) were selected.These biomarkers are involved in several different biological functions as cellular movement,cell signaling and interaction,tissue and cellular development,cancer and cell growth and proliferation.Two distinct biomarker signatures are used to separate patients without lesion from those with cancer or with adenoma, named COLOX CRC and COLOX POL respectively.COLOX performances were validated using random resampling method, bootstrap. RESULTS: COLOX CRC and POL tests successfully separate patients without lesions from those with CRC (Se 67%,Sp 93%,AUC 0.87) and from those with adenoma bigger than 1cm (Se 63%,Sp 83%,AUC 0.77),respectively. 6/24 patients in the IBD group and 1/14 patients in the OC group have a positive COLOX CRC CONCLUSION: The two COLOX tests demonstrated a high sensitivity and specificity to detect the presence of CRCs and adenomas bigger than 1 cm.A prospective, multicenter, pivotal study is underway in order to confirm these promising results in a larger cohort.

Experimental infection with Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) amazonensis in the marmoset, Callithrix penicillata (Primates: Callithricidae)

Foureen marmosets (Callithrix penicillata) were inoculated intradermally with promastigotes and/or amastigotes of Leishmania (Viannia) brazilensis (L. (V) b.) strains MHOM/BR/83/LTB-300MHOM/BR/85/LTB-12 MHOM/BR/81/LTB-179 and MHOM/BR/82/LTB-250. The evolution of subsequent lesions was studied for 15 to 75 weeks post-inoculation (PI). All but of the L. (V) b. injected marmosets developed a cutaneous lesion at the point of inoculation after 3 to 9 weeks, characterized by the appearance of subcutaneous nodules containing parasites. parasites were isolated by culture (Difco Blood Agar) from all 11 positive animals. The maximum size of the lesions was variable and ranged between 37 mm² to 107 mm². Ulceration of primary nodules became evident after 3 to 12 weeks in all infected marmosets, but was faster and larger in 5 of the 11 animals. The active lesions persisted in 9 out of 11 Callithrix until the en of the observation period, which varied from 15-75 weeks. In 3 animals spontaneous healing of their lesions (13 to 25 weeks, PI) was observed buth with cryptic parasitism. In another 2 infected animals there was regression followed by reactivation of the cutaneous lesions. The appearance of smaller satellite lesions adjacent to primary ones, as well as metastatic lesions to the ear lobes, were documented in 2 animals. Promastigotes of L. (Leishmania) amazonensis (L.(L)a.) MHOM/BR/77/LTB-16 were inoculated in 1 marmoset. This animal remained chronically infected for 6 months and the lesions developed in a similar manner to L.(V)b. infected marmosets. No significant differences in clinical and parasitological behaviour were observed between promastigote or amastigote derived infections of the 2 species. Both produced chronic, long lasting lesions which eventually healed. The same was true for parameters of size and ulceration. Skin tests converted to parasite in 11 of 15 inected masmosets and in 10 of 12 parasite positive animnals. Moderate levels of circulating antibodies were also observed by IFAT /IgG assays. In spite of the failure to reproduce the mucosal form of the disease, an important aspect of the Callithrix model in experimental cutaneous leishmaniasis lies in the reproduction of 2 clinical events that are common in humans, namely, the chronic ulceration and spontaneous healing of the lesions.