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ABSTRACT: The purpose of this retrospective study was to calculate the positive predictive value (PPV) of sonographic Breast Imaging Reporting and Data System (BI-RADS) categories 3, 4, and 5 in different age groups to investigate whether age influences the PPV of the BI-RADS category in breast ultrasound.
From our sonography-guided core biopsy database of breasts between 2006 and 2008, we identified 2817 BI-RADS category 3, 4, and 5 lesions with known pathological diagnosis in 2587 women, all of whom underwent the earlier breast assessment via ultrasound with a sonographic BI-RADS lexicon and later sonography-guided core biopsy. All lesions were classified into three age groups (< 45, 45 - 59, and > 59 years). The age-related PPVs of each BI-RADS category among three age groups were calculated on the basis of pathological diagnoses and were compared using a χ(2)-test.
The overall PPV of each BI-RADS category was 2.2 % in category 3, 6.5 % in category 4a, 35.2 % in category 4b, 79.6 % in category 4c, and 99.6 % in category 5. The age-related PPVs of category 3 varied significantly among the three age groups (0.9 % versus 3.9 % versus 2.0 % p = 0.048), and notably, the age-related PPV in group 2 was higher than the others. Additionally, there was a significant positive association between the age-related PPVs and increasing age in categories 4a and 4b (4a, p < 0.0001 and 4b, p = 0.0139), but not in categories 4c and 5 (4c, p = 0.1853 and 5, p = 0.2871).
The incidence of female breast cancer differs not only in different sonographic BI-RADS categories, but also in different age groups. Therefore, more attention should be paid to the special age group that we found for sonographic BI-RADS categories 3, 4a, and 4b.
Ultraschall in der Medizin 01/2011; 32 Suppl 1:S8-13. · 2.40 Impact Factor
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ABSTRACT: An increase in lattice constants and an order–disorder phase transition were observed in the magnesium aluminate spinel (MgAl2O4) powders after shock compression. Theoretical calculations on the basis of density functional theory confirm that the remarkable volume expansion in shocked MgAl2O4 powders is closely related to the substantial site disorder in the MgAl2O4 lattice. The calculations also show that the partially inverse MgAl2O4 spinel with an inversion index of 0.7 represents the greatest disordered metastable phase and the most unstable structure.
Journal of Applied Physics 12/2010; 108(11):113522-113522-5. · 2.17 Impact Factor
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ABSTRACT: The properties of MgAl2O4 nanopowders under shock pressure up to 5.3 GPa were investigated. It was found that the lattice constants and residual stresses of shock treated MgAl2O4 nanopowders increase non-linearly with shock velocity. According to the transmission electron microscope (TEM) images, the grain size of nanopowder was found decreased significantly after shock compression. The smaller grain size and high residual stress could lead to high sintering activity, which could be extraordinarily useful to enhance the density of ceramic and make highly transparent ceramic.Graphical abstractThe morphology of unshocked (left) and shocked (right) MgAl2O4 nanopowders were observed by the transmission electron microscope. The grain size of nanopowder was found decreased significantly after shock compression, which will be extraordinarily useful to enhance the density of ceramic and make highly transparent ceramic.
Powder Technology. 200:91-95.
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ABSTRACT: Although phytobezoars are a rare cause of gastrointestinal obstruction, they are most commonly found in patients with previous gastric surgery. It is well known that predisposing factors of phytobezoar formation are ingestion of fruits containing soluble tannin, presence of dilute hydrochloric acid in the stomach, and gastric stasis or delayed emptying. We investigated whether intake of acid-suppressing drugs that neutralize gastric acidity or inhibit gastric acid secretion to constitute a hypo-acidic condition, increases the risk of phytobezoar formation.
Between September 1992 and October 2008, 32 patients (24 male and 8 female) with gastrointestinal phytobezoars were diagnosed either surgically or endoscopically at the Tri-Service General Hospital, Taipei, Republic of China. The data were collected from hospital records and analyzed retrospectively.
Eighteen (56.25%) of all patients had previous gastric surgery and 6 (42.9%) of the 14 patients who had not undergone surgery had diabetes mellitus. The majority of admissions were during winter and spring (between October and March) (P < 0.01) and none of the patients had taken acid-suppressing drugs during the 6 months before detection of gastrointestinal phytobezoars.
In our study, intake of acid-suppressing drugs did not increase the risk of phytobezoar formation in patients with normal gastric motility. Moreover, we believe that the major factor in phytobezoar formation is gastric stasis or delayed emptying, which sufficiently prolongs the retention period of materials in the stomach, while dilute hydrochloric acid is a minor factor.
Acta chirurgica Belgica 110(6):595-7. · 0.43 Impact Factor
