Noise and thermal performance of a sub-attofarad capacitance sensor for precision measurements, with applications in gravitational wave detectors.

We describe the design principles, fabrication, and characterization of a precision AC resonant capacitance bridge (RCB) sensor, based on a resonant differential planar printed circuit board transformer with a solid (ungapped) MnZn ferrite core, demonstrating a short-term sensitivity at 293 K of 0.225 ± 0.005 aF/√Hz at around 120 kHz resonance frequency and 1 Hz Fourier measurement frequency. At 120 K, the RCB short term noise sensitivity is 0.118 ± 0.005 aF/√Hz. We compare the ungapped configuration to five different RCBs: three with a core gap of 65 µm and two with a core gap of 130 µm. Their average room temperature short term noise sensitivities are 0.30 ± 0.01 and 0.45 ± 0.01 aF/√Hz, while the cryogenic operation of these transformers at 120 K resulted in averaged sensitivities of 0.23 ± 0.01 and 0.36 ± 0.01 aF/√Hz, respectively. Multi-hour room temperature runs, with one core of each of the three gap types, proved the stability of their long-term sensitivities of 0.234 ± 0.005, 0.338 ± 0.009, and 0.435 ± 0.010 aF/√Hz for the ungapped (40-h duration) and the 65 and 130 µm (28-h duration) cores, respectively. At 0.1 mHz, a critical frequency for space gravitational wave detectors, the respective sensitivities are 0.25 ± 0.02, 0.35 ± 0.02, and 0.53 ± 0.07 aF/√Hz. Measurements with the ungapped transformer configuration for temperatures from 325 to 349 K further validate the dependence of the noise model on temperature and permeability. The performance of our RCB with an ungapped core matches the calculated performance value and shows an improvement in signal-to-noise ratio of two or more compared with capacitance bridges developed for similar applications. A further factor of about two noise reductions is achieved by cooling to 120 K.

Understanding breast cancer screening--past, present, and future.

This article provides an up-to-date overview of breast cancer mammography screening and briefly discusses its history, controversies, current guidelines, practices across Asia, and future directions. An emphasis is made on shared decision-making--instead of giving just a 'yes' or 'no' answer to patients, the focus should be on providing sufficient information about the pros and cons of screening to help women make a personal, informed choice. Frontline experts, including breast surgeons, oncologists, breast radiologists, and their representative professional associations should all participate in guideline panels, with the goal of improving cancer detection, reducing mortality, and improving patient outcome.

Apparent diffusion coefficient in differentiation between malignant and benign breast masses: does size matter?

AIM: To determine whether lesion size affects the diagnostic performance of apparent diffusion coefficient (ADC) in the evaluation of breast masses. MATERIALS AND METHODS: Consecutive breast lesions detected at magnetic resonance imaging (MRI) from June 2010 to July 2013 were retrospectively reviewed. Differences in the ADCs of benign and malignant mass lesions were compared. Receiver operating characteristics analysis was performed to evaluate diagnostic performance of ADC regarding lesion size (≤ 1 cm or >1 cm) and their T2W signal intensities. RESULTS: Seventy-four malignant lesions (77.9%) and 21 (22.1%) benign lesions were included. Twenty-two of the 95 (23.2%) masses measured ≤ 1 cm (mean 0.73 ± 0.4; range 0.51-0.8 cm) and 73/95 (76.9%) masses measured >1 cm (mean 2.11 ± 0.1; range 1.1-3.3 cm). The mean ADC was significantly lower for malignant than for benign lesions (mean for malignant lesion, 0.89 ± 0.29 × 10(-3) mm(2)/s; mean for benign lesions, 1.27 ± 0.42 × 10(-3) mm(2)/s; p<0.01). The optimal ADC cut-off for differentiating benign and malignant lesion was 1.088 × 10(-3) mm(2)/s with a sensitivity of 85.9% and specificity of 77% for lesions >1 cm. The sensitivity and specificity were lowered to 60% and 50%, respectively, for lesions of size ≤ 1. Maximal sensitivity and specificity were reached when the ADC value was used to evaluate T2-dark lesions. CONCLUSION: Diffusion-weighted MRI is useful for characterizing masses that are hypointense on T2-weighted images. Lower sensitivity and specificity were found for breast lesions ≤ 1 cm.

Sonographic appearance of thyroid glands in patients treated with intensity-modulated radiotherapy or conventional radiotherapy for nasopharyngeal carcinoma.

BACKGROUND: This study aimed to investigate the sonographic appearances of the thyroid glands in nasopharyngeal carcinoma (NPC) patients whose cervical lymph nodes were treated with conventional radiotherapy (RT) or intensity-modulated radiotherapy (IMRT). The post-RT sonographic appearances of the thyroid glands in NPC patients were also correlated with the thyroid function. METHODS: One hundred and three NPC patients who had completed RT of cervical lymph nodes using the anterior cervical field, 30 NPC patients who had completed RT of cervical lymph nodes using IMRT, and 61 healthy subjects were included in the study. Thyroid glands were sonographically assessed for their size, echogenicity, vascularity, and internal architecture. Thyroid function tests were also performed on each subject. RESULTS: In comparison with the patients with abnormal thyroid function, the thyroid glands of the patients with normal thyroid function tended to be homogeneous and to have greater volume and echogenicity index (p < 0.05). Compared with those of the healthy subjects, the thyroid glands of patients previously treated with IMRT and those treated with the anterior cervical field showed significantly lower thyroid volume, lower incidence and number of nodules, and higher vascularity index (p < 0.05). CONCLUSIONS: The patient's history of previous RT should be taken into consideration in the sonographic examination of the thyroid gland post-RT. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:210-223, 2015.

Localisation of occult breast lesion: a comparative analysis of hookwire and radioguided procedures.

OBJECTIVES: For occult breast lesions, to retrospectively compare the performance of radioguided and hookwire methods in terms of ease of localisation and surgical procedures, and the ability to obtain a specimen with a clear margin. DESIGN: Retrospective study. SETTING: Regional hospital, Hong Kong. PATIENTS: All patients who underwent occult breast lesion localisation by either ultrasonography- or stereotactic-guided radioguided occult lesion localisation or hookwire localisation from August 2003 to December 2007 were included. MAIN OUTCOME MEASURES: Demographic data, localisation and operation procedure time, size of specimens and margin clearance. RESULTS: In all, 165 patients (mean age, 52 years) having these procedures were assessed. In 98 instances, the procedure (hookwire=53, radioguided=45) was for diagnostic purposes and in 67 (hookwire=23, radioguided=44) for therapy. Both techniques attained a very high success rate (>95%). For radioguided occult lesion localisation, there was a significantly shorter mean localisation time than for hookwire localisation (18 min versus 31 min; P<0.001), while the mean operating time was similar. Radioguided occult lesion localisation entailed larger specimens and fewer cases with close or involved margins, or recourse to intra-operative re-excision or a second operation, but these differences were not statistically significant. Within the radioguided occult lesion localisation group, there were 42 patients who had a simultaneous sentinel lymph node biopsy (sentinel node and occult lesion localisation), with a 98% success rate although no lymph node metastasis was revealed. CONCLUSION: Radioguided occult lesion localisation excels in yielding a much shorter localisation time and is as good as hookwire localisation in terms of specimen margin clearance and need for re-excision. It also offers the advantage of enabling simultaneous sentinel lymph node biopsy for invasive cancers. Therefore it is a recommended procedure that should be used more widely.

Mammary angiosarcoma in two patients at either end of the age spectrum.

Angiosarcoma of the breast is rare and has a poor prognosis due to its aggressive nature. This is a report of two patients with mammary angiosarcomas, each with different clinical presentations, and at either end of the age spectrum. One is an 18-year-old woman who presented with a rapidly enlarging breast mass, and the other a 72-year-old woman whose breast mass was found during screening mammography. The radiological features of mammary angiosarcoma are summarised in this report.

Case of fibromatosis of male breast.

Extra-abdominal fibromatosis of the breast is rare with the clinical and radiological features closely resembled malignant breast tumour. We describe, in a 40-year-old Chinese male patient with a palpable left breast mass, the clinical, radiological and pathological features of this benign though locally aggressive tumour.

Opportunistic breast cancer screening in Hong Kong; a revisit of the Kwong Wah Hospital experience.

OBJECTIVE: To analyse the performance of opportunistic breast screening in local Well Women Clinics during the 5-year period from 1998 to 2002, with reference to international as well as our own earlier experience (1991 to 1993 to 1995). DESIGN: Prospective study. SETTING: Well Women Clinics in regional Hong Kong hospitals. PARTICIPANTS: Women attending the Well Women Clinics of the Tung Wah Group of Hospitals for breast cancer screening. MAIN OUTCOME MEASURES: All screening-detected breast cancers. RESULTS: After 46 637 screening mammograms and excluding palpable masses detected by the patients themselves, 232 women were detected with cancers, yielding a crude detection rate of 5.0 per 1000. Age range for cancer detection was 35 to 72 (median, 49) years. Clinic staff detected palpable lumps in 83 patients, constituting 36% of the detected cancers, of which 15 (6.5% of all detected cancers) were not identified by mammography. The cancer detection rate was 5.9 per 1000 in the age-group 40-49 years and 3.7 per 1000 in those 50 years or older. The cancer detection rate was 58.5 per 1000 in the high-risk group (aged <40 years with positive family history). The minimal cancer detection rate was 2.2 per 1000, representing 45% of all cancers whose pathology was available to us. Ductal carcinoma in situ comprised 28% of all such cancers. Our recall rates were 4.6% for additional views only, 3.3% for ultrasound only, and 2.3% for both. Positive predictive values for abnormal mammograms and biopsies were 4.9% and 26.0%, respectively. CONCLUSION: Mammographic screening has been reported to reduce mortality up to 35% in western countries. However, data concerning Asian Chinese populations are meagre. Our Well Women Clinics pioneered large-scale self-referred breast screening in Hong Kong. Despite the lower incidence of breast cancers than in Occidental populations, our screening programme performed comparably to those in the West, and has improved over time. Our screening service for self-referred women detected breast cancers even at an early stage, which facilitated a better prognosis and more treatment options, whilst appearing to be highly acceptable to our community. Besides, it could provide training and expertise in breast radiology and mammography, which are essential prerequisites for establishing population screening.

Imaging of gastrointestinal stromal tumour (GIST).

Gastrointestinal stromal tumour (GIST) represents the most common kind of mesenchymal tumour that arises from the alimentary tract. GIST is currently defined as a gastrointestinal tract mesenchymal tumour containing spindle cells (or less commonly epithelioid cells or rarely both) and showing CD117 (c-kit protein) positivity. Targeted molecular therapy of non-resectable GIST using imatinib, a specific tyrosine kinase receptor inhibitor, represents a real milestone in the management of solid malignancy. Imaging studies, both anatomical and functional, are playing an increasingly important role in management of patients with GIST. This review illustrates the radiological appearance of GISTs and the site-specific roles of each imaging tool. Clinical features and radiological differential diagnosis of GIST are also discussed.

Meta-analysis of the use of low-dose beta-adrenergic blocking therapy in idiopathic or ischemic dilated cardiomyopathy.

We concluded that low-dose beta-adrenergic blocking agents are beneficial in the treatment of patients with ischemic or idiopathic cardiomyopathy. Low-dose beta blockers appear to improve NYHA functional class and LVEF.

Regiospecific intestinal absorption of the HIV protease inhibitor L-735,524 in beagle dogs.

PURPOSE: To evaluate regional intestinal absorption and the feasibility of sustained release dosage form development for an HIV protease inhibitor, L-735,524, METHODS: L-735,524 free base or sulfate salt was administered orally as suspension, solution or in solid dosage forms to fasted or fed Beagle dogs. Delayed-release dosage forms with "slow" or "fast" in vitro dissolution rates were evaluated in vivo to assess plasma concentration profiles. In addition, drug was administered directly into the jejunum or colon of animals, and drug concentrations determined in portal circulation to characterize absorption from these sites. RESULTS: L-735,524 sulfate was well absorbed orally form a solution or capsule formulation if fasted animals' stomachs were preacidified with citric acid solution. A free base suspension, delivered in divided doses to fed animals, was also well absorbed. Prototype extended release dosage forms of L-735,524 produced a reduction in peak plasma levels but failed to prolong absorption and extend plasma concentrations compared to an immediate release capsule. Administration of L-735,524 sulfate solution (pH < 3) as bolus solution or by infusion into the jejunum resulted in rapid but incomplete absorption compared to oral gavage. The free base suspension (pH 6.5) delivered into jejunal or colonic regions did not produce measurable systemic plasma concentrations. CONCLUSIONS: Extended release formulations did not prolong absorption of L-735,524 in dogs. Optimal L-735,524 absorption was dependent on solubility in an acidic environment in the duodenum.

Acute pulmonary embolism as the cause of global T wave inversion and QT prolongation. A case report.

A 57-year-old man without prior history of organic heart disease was admitted with a diagnosis of unstable angina because of chest pain and new electrocardiographic (ECG) changes of global T wave inversion and QT interval prolongation. Left and right heart catheterization with coronary angiography, pulmonary angiography, ventilation-perfusion scintigraphy, and echocardiography showed absence of coronary artery disease but unequivocally acute pulmonary embolism. Within days following anticoagulant therapy, the lengthened QT interval became normalized while the global T wave inversion persisted. A follow-up ECG 15 months later revealed complete resolution of the T wave inversion. The possible pathophysiologic mechanism of the ECG changes is discussed.

Elevated serum levels of creatine kinase BB in autosomal dominant osteopetrosis type II--a family study.

A markedly elevated BB isoenzyme fraction of serum creatine kinase was noted in four male siblings and correlated with typical radiographic findings of autosomal dominant osteopetrosis Type II (ADO Type II). Patients with other sclerosing bone diseases had no elevation of CK-BB. The precision of the electrophoretic mobility patterns and correlation by I-125 tagged radioimmunoassay method confirms that this is CK-BB. We postulate that the dysfunctional and/or immature osteoclasts in ADO are more dependent on CK-BB than on the usual tricarboxylic acid cycle for the production of energy. The correlation of marked elevation of serum CK-BB with radiographic evidence of ADO Type II may prove to be of value as a biologic marker in the early diagnosis of the illness and lead to better understanding of the metabolism of bone.

Intranasal absorption of flurazepam, midazolam, and triazolam in dogs.

Intranasal delivery of flurazepam, midazolam, and triazolam was studied in a dog model as a possible alternate route of drug administration for treatment of insomnia. Four beagles received each hypnotic by both intranasal and oral routes on two separate occasions. Plasma concentrations for each hypnotic after dosing were measured by electron-capture gas-liquid chromatography. The mean intranasal absorption rates (tmax) of flurazepam, midazolam, and triazolam were 1.7, 2.0, and 2.6 times faster, respectively, compared with oral dosing. The mean dose-normalized peak concentrations (Cmax) after intranasal delivery were 16.4, 2.9, and 3.4 times higher, respectively, versus oral administration. The mean dose-normalized AUCs estimated for these compounds after nasal administration were 2.4-, 2.5-, and at least 2-fold larger than after oral administration for midazolam, triazolam, and flurazepam, respectively. If these observations can be extrapolated to humans, the faster absorption achieved by the intranasal route would appear to benefit insomniacs characterized by difficulty in falling asleep because of an anticipated faster sedative effect onset. The higher peak concentrations and larger amounts absorbed in the case of intranasal midazolam and triazolam delivery may lead to dose reduction.