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Fatty liver disease (FLD) is reversible disease and can be treated, if it is identified at an early stage. However, if diagnosed at the later stage, it can progress to an advanced liver disease such as cirrhosis which may ultimately lead to death. Therefore, it is essential to detect it at an early stage before the disease progresses to an irreversible stage. Several non-invasive computer-aided techniques are proposed to assist in the early detection of FLD and cirrhosis using ultrasound images. In this work, we are proposing an algorithm to discriminate automatically the normal, FLD and cirrhosis ultrasound images using curvelet transform (CT) method. Higher order spectra (HOS) bispectrum, HOS phase, fuzzy, Kapoor, max, Renyi, Shannon, Vajda and Yager entropies are extracted from CT coefficients. These extracted features are subjected to locality sensitive discriminant analysis (LSDA) feature reduction method. Then these LSDA coefficients ranked based on F-value are fed to different classifiers to choose the best performing classifier using minimum number of features. Our proposed technique can characterize normal, FLD and cirrhosis using probabilistic neural network (PNN) classifier with an accuracy of 97.33%, specificity of 100.00% and sensitivity of 96.00% using only six features. In addition, these chosen features are used to develop a liver disease index (LDI) to differentiate the normal, FLD and cirrhosis classes using a single number. This can significantly help the radiologists to discriminate FLD and cirrhosis in their routine liver screening., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective: To determine the reproducibility of three-dimensional (3D) ultrasound (US) over two-dimensional (2D) US in characterizing atherosclerotic carotid plaques using inter- and intra-observer agreement metrics., Methods: A Total of 51 patients with 105 carotid artery plaques were screened using 3D and 2D US probes attached to the same US scanner. Two independent observers characterized the plaques based on the morphological features namely echotexture, echogenicity and surface characteristics. The scores assigned to each morphological feature were used to determine intra- and inter-observer performance. The level of agreement was measured using Kappa coefficient., Results: The first observer with 2D US showed fair (k=0.4-0.59) and very strong (k>0.8) with 3D US intra-observer agreements using three morphological features. The second observer indicated moderate strong (k=0.6-0.79) with 2D US and very strong with 3D US (k>0.8) intra-observer performances. Moderate strong (k=0.6-0.79) and very strong (k>0.8) inter-observer agreements were reported with 2D US and 3D US respectively. The results with 2D and 3D US were correlated 62% using only echotexture and 56% using surface morphology coupled with echogenicity. 3D US gave a lower score than 2D 71% of the time (p=0.005) in disagreement cases., Conclusion: High reproducibility in carotid plaque characterization was obtained using 3D US rather than 2D US. Hence, it can be a preferred imaging modality in routine or follow up plaque screening of patients with carotid artery disease., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Introduction: Inadequate oral care has been implicated in the development of aspiration pneumonia in frail geriatric patients and is a major cause of mortality, due to the colonisation of microbes in vulnerable patients. This type of pneumonia has been associated with an increase in respiratory pathogens in the oral cavity. The aim of this study was to evaluate the effects of chlorhexidine compared to routine oral care in edentulous geriatric inpatients., Methods: A double-blind, parallel-group randomised controlled trial was carried out. The intervention group received oral care with chlorhexidine 0.2%, while the control group received routine oral care with thymol. Nurses provided oral care with assigned solutions of 20 mL once daily over seven days. Oral cavity assessment using the Brief Oral Health Status Examination form was performed before each oral care procedure. Data on medication received and the subsequent development of aspiration pneumonia was recorded. An oral swab was performed on Day 7 to obtain specimens to test for colonisation., Results: The final sample consisted of 35 (control) and 43 (intervention) patients. Chlorhexidine was effective in reducing oral colonisation compared to routine oral care with thymol (p < 0.001). The risk of oral bacterial colonisation was nearly three times higher in the thymol group compared to the chlorhexidine group., Conclusion: The use of chlorhexidine 0.2% significantly reduced oral colonisation and is recommended as an easier and more cost-effective alternative for oral hygiene., (Copyright: © Singapore Medical Association.)

Ultrasound is an important and low cost imaging modality used to study the internal organs of human body and blood flow through blood vessels. It uses high frequency sound waves to acquire images of internal organs. It is used to screen normal, benign and malignant tissues of various organs. Healthy and malignant tissues generate different echoes for ultrasound. Hence, it provides useful information about the potential tumor tissues that can be analyzed for diagnostic purposes before therapeutic procedures. Ultrasound images are affected with speckle noise due to an air gap between the transducer probe and the body. The challenge is to design and develop robust image preprocessing, segmentation and feature extraction algorithms to locate the tumor region and to extract subtle information from isolated tumor region for diagnosis. This information can be revealed using a scale space technique such as the Discrete Wavelet Transform (DWT). It decomposes an image into images at different scales using low pass and high pass filters. These filters help to identify the detail or sudden changes in intensity in the image. These changes are reflected in the wavelet coefficients. Various texture, statistical and image based features can be extracted from these coefficients. The extracted features are subjected to statistical analysis to identify the significant features to discriminate normal and malignant ultrasound images using supervised classifiers. This paper presents a review of wavelet techniques used for preprocessing, segmentation and feature extraction of breast, thyroid, ovarian and prostate cancer using ultrasound images., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objective: To determine the effective radiation dose and image quality resulting from 100 versus 120 kilovoltage (kV) protocols among patients referred for computed tomography pulmonary angiography (CTPA)., Methods: Sixty-six patients with clinical suspicion of pulmonary embolism (PE) were prospectively enrolled. Two CTPA protocols (group A: n=33, 100 kV/115 mAs; group B: n=33, 120 kV/90 mAs) were compared. Two experienced radiologists assessed image quality in terms of diagnostic performance and effect of artefacts. Image quality parameters [CT attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)] and effective radiation dose between the two protocols were compared., Results: The contrast enhancement in central and peripheral pulmonary arteries was significantly higher in group A than in group B (P<0.001) with the identical SNR (P=0.26), whereas the CNR was significantly higher in group A than in group B (P<0.001). The effective radiation dose for the 100 and 120 kV scans was 3.2 and 6.8 mSv, respectively., Conclusions: Reducing the tube voltage from 120 to 100 kV in CTPA allows a significant reduction of radiation dose without significant loss of diagnostic image quality.

In vivo dosimetry is important during radiotherapy to ensure the accuracy of the dose delivered to the treatment volume. A dosimeter should be characterized based on its application before it is used for in vivo dosimetry. In this study, we characterize a new MOSFET-based detector, the MOSkin detector, on surface for in vivo skin dosimetry. The advantages of the MOSkin detector are its water equivalent depth of measurement of 0.07 mm, small physical size with submicron dosimetric volume, and the ability to provide real-time readout. A MOSkin detector was calibrated and the reproducibility, linearity, and response over a large dose range to different threshold voltages were determined. Surface dose on solid water phantom was measured using MOSkin detector and compared with Markus ionization chamber and GAFCHROMIC EBT2 film measurements. Dependence in the response of the MOSkin detector on the surface of solid water phantom was also tested for different (i) source to surface distances (SSDs); (ii) field sizes; (iii) surface dose; (iv) radiation incident angles; and (v) wedges. The MOSkin detector showed excellent reproducibility and linearity for dose range of 50 cGy to 300 cGy. The MOSkin detector showed reliable response to different SSDs, field sizes, surface, radiation incident angles, and wedges. The MOSkin detector is suitable for in vivo skin dosimetry.

Purpose: To investigate the prevalence of incidental sinus abnormalities on CT and MRI imaging of the head, and identify if there is any correlation between patient symptomatology and image findings., Materials and Methods: One hundred and fifteen patients who underwent head CT or MRI for 
non-sinus related indications were included in this study, with image findings being analysed based on the Lund-Mackay Grading System (LMS). These were compared with their symptomatology based on the SNAQ-11 questionnaire. Two reviewers who were blinded to the patients' SNAQ-11 scores analysed the images. Patients were also referred to an ENT surgeon for anterior rhinoscopy in an attempt to seek a correlation between symptomatology and/or imaging findings against clinical assessment., Results: The prevalence of incidental sinus abnormalities is between 14.8% and 37% for CT and 29.5% and 85.2% for MRI, depending upon the cutoff LMS used. There was no significant difference in the incidence rate between the different age groups or genders. Asymptomatic patients had a significantly lower incidence rate of sinus mucosal abnormalities (8.2-57.1%) when compared to the symptomatic patients (33.3-66.7%) (P<0.01). A significant correlation was found between the MRI sinus findings and patients' symptoms (r=0.59, P<0.001) with no correlation demonstrated in the CT group. The mean LM score for the patients with clinical sinusitis was 6.2, while the normal patients had a mean LM score of 2.2., Conclusions: MRI is more sensitive than CT to detect sinus mucosal abnormalities. A significant correlation is noticed between MRI findings and patients' symptomatology.

Rapid technological developments in medicine have taken place in the Asia-Pacific region over the last decades. Radiology, in particular, has seen enormous growth with the latest medical equipment and practices being commonplace in this region. The use of radiation in medicine must be carefully considered with regard to the potential side effects, such as radiation-induced cancer. There are very limited published papers on the use of radiation in medicine in this region. Hence, in this paper, we present an overview of the use of radiation in medicine in the Asia-Pacific region.

We produced an enteric-coated gelatine capsule containing neutron-activated (153)Sm-labelled resin beads for use in gastrointestinal motility studies. In vitro test in simulated gastrointestinal environment and in vivo study on volunteers were performed. Scintigraphic images were acquired from ten volunteers over 24h while blood and urine samples were collected to monitor the presence of (153)Sm. All the capsules remained intact in stomach. This proved to be a safe and practical oral capsule formulation for whole gut transit scintigraphy., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Purpose: To perform a systematic review of the radiation dose and diagnostic accuracy of prospective versus retrospective ECG-gated multislice CT coronary angiography., Materials and Methods: A search of Pubmed/Medline and Sciencedirect databases for English literature was performed to identify studies comparing prospective and retrospective ECG-gated multislice CT angiography in the diagnosis of coronary artery disease. Effective dose, dose length product, image quality and diagnostic value were compared between two groups of studies., Results: 22 studies were included for analysis. The mean effective dose of prospective ECG-gated scans was 4.5 mSv (95% CI: 3.6, 5.3 mSv), which is significantly lower than that of retrospective scans, which is 13.8 mSv (95% CI: 11.5, 16.0 mSv) (p<0.001). The mean dose length product was 225 mGycm (95% CI: 188, 262 mGycm) and 822 mGycm (95% CI: 630, 1013 mGycm) for the prospective and retrospective ECG-gated scans, respectively, indicating a statistically significant difference between these two protocols (p<0.0001). The mean sensitivity and specificity of multislice CT angiography in the diagnosis of coronary artery disease was 97.7% (95% CI: 93.7%, 100%) and 92.1% (95% CI: 87.2%, 97%) for prospective ECG-gated scans; 95.2% (95% CI: 91%, 99.5%) and 94.4% (95% CI: 88.5%, 100%) for retrospective ECG-gated scans, respectively, with no significant difference for sensitivity but significant difference for specificity (p=0.047)., Conclusion: Multislice CT coronary angiography with prospective ECG-gating leads to a significant reduction of radiation dose when compared to that of retrospective ECG-gating, while offering comparable image quality and diagnostic value., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Diabetes is a chronic end organ disease that occurs when the pancreas does not secrete enough insulin or the body is unable to process it properly. Over time, diabetes affects the circulatory system, including that of the retina. Diabetic retinopathy is a medical condition where the retina is damaged because fluid leaks from blood vessels into the retina. Ophthalmologists recognize diabetic retinopathy based on features, such as blood vessel area, exudes, hemorrhages, microaneurysms and texture. In this paper we review algorithms used for the extraction of these features from digital fundus images. Furthermore, we discuss systems that use these features to classify individual fundus images. The classifications efficiency of different DR systems is discussed. Most of the reported systems are highly optimized with respect to the analyzed fundus images, therefore a generalization of individual results is difficult. However, this review shows that the classification results improved has improved recently, and it is getting closer to the classification capabilities of human ophthalmologists.

The purpose of this paper is to perform a systematic review on radiation dose reduction in coronary computed tomography (CT) angiography that is done using different generations of multidetector CT (MDCT) scanners ranging from four-slice to 320-slice CTs, and have different dose-saving techniques. The method followed was to search for references on coronary CT angiography (CTA) that had been published in English between 1998 and February 2011. The effective radiation dose reported in each study based on different generations of MDCT scanners was analysed and compared between the types of scanners, gender, exposure factors and scanning protocols. Sixty-six studies were eligible for inclusion in this analysis. The mean effective dose (ED) for MDCT angiography with retrospective electrocardiogram (ECG) gating without use of any dose-saving protocol was 6.0 ± 2.8, 10.4 ± 4.90 and 11.8 ± 5.9 mSv for four-slice, 16-slice and 64-slice CTs, respectively. More dose-saving strategies were applied in recent CT generations including prospective ECG-gating protocols, application of lower tube voltage and tube current modulation to achieve a noteworthy dose reduction. Prospective ECG-gating protocol was increasingly used in 64, 125, 256 and 320 slices with corresponding ED of 4.1 ± 1.7, 3.6 ± 0.4, 3.0 ± 1.9 and 7.6 ± 1.6 mSv, respectively. Lower tube voltage and tube current modulation were widely applied in 64-slice CT and resulted in significant dose reduction (P < 0.05). This analysis has shown that dose-saving strategies can substantially reduce the radiation dose in CT coronary angiography. The fact that more and more clinicians are opting for dose-saving strategies in CT coronary angiography indicates an increased awareness of risks associated with high radiation doses among them., (© 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.)

Nuclear medicine techniques are well established for the investigation of gastrointestinal (GI) motility and transit. Ion-exchange resins radiolabelled with ⁹⁹mTc and ¹¹¹In are widely used as nonabsorbable radiopharmaceutical markers, with ¹¹¹In being preferred for whole-gut transit studies. This radionuclide, however, is not produced in many countries and may be expensive when obtained through international shipment. This study describes the use of neutron-activated ¹⁵³Sm-resin as an alternative tracer for use in GI scintigraphic investigation. A measure of 50 mg of stable samarium-152 chloride (¹⁵²SmCl₃) was incorporated into 100 mg of cation-exchange resin and irradiated in a neutron flux of 1 × 10¹³ cm⁻² s⁻¹ for 100 s to achieve an activity of 5 MBq after 66 h. Aliquots of ¹¹¹In-radiolabelled resin (5 MBq) were prepared for comparison of labelling and stability. Radiolabelling efficiencies were obtained by washing resin with distilled water, and the activity lost was measured. The radiolabelled resins were immersed in simulated gastric and intestinal fluid environments, and the retention of ¹⁵³Sm³⁺ and ¹¹¹In³⁺ was measured over a 24 h period. At 66 h after production, 91.15 ± 12.42% of ¹⁵³Sm was bound to the resin after washing in distilled water, whereas radiolabelling with ¹¹¹In achieved 99.96 ± 0.02% efficiency. Both radiolabelled resins demonstrated almost 100% stability in simulated intestinal fluid and >90% stability in artificial gastric juice over 24 h. The performance of neutron-activated ¹⁵³Sm-resin is similar to that of ¹¹¹In-resin and can be used as an alternative tracer for GI transit studies when In is not available.

An estimated two thirds of the world's population is currently without access to diagnostic radiology services, and most of them live in resource-limited tropical regions with harsh environments. Most patients are diagnosed and treated in poorly equipped government-funded hospitals and clinics that have insufficiently trained staff and are barely operational. Any available imaging equipment is likely to be functioning suboptimally and be poorly maintained. The root of the problem is usually a lack of know-how and a quality culture, combined with insufficient basic equipment and infrastructure. Radiological imaging is an essential aspect of primary care and used in the critical diagnosis and management of trauma, tuberculosis, pneumonia, acquired immunodeficiency syndrome, cancer, and other respiratory and abdominal diseases. Considerations such as quality management and infrastructure, personnel, equipment, and radiation protection and safety are important to ensure the proper functioning and rational use of a diagnostic radiology facility in the tropics., (© Thieme Medical Publishers.)

Aim: To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature., Methods: A search of articles on coronary CT angiography in the diagnosis of CAD was performed during a 6-year-period between 2005 and 2010 from five main radiology journals namely, Radiology, American Journal of Roentgenology, European Radiology, European Journal of Radiology and British Journal of Radiology. Analysis of the references was focused on the research directions of coronary CT angiography with regard to the type of studies in terms of diagnostic value, application of dose-reduction strategies and resultant effective radiation doses with use of these techniques., Results: One hundred and forty two studies were identified which met the selection criteria and were included in the analysis. 64-slice CT (single source and dual-source CT) dominated 78% of the coronary CT angiography studies. Prior to 2007, research was focused on the diagnostic value of coronary CT angiography, but since 2008 more attention has been paid to radiation dose reduction. Radiation dose was reported in 64 studies, representing 45% of total studies published in the five radiology journals. Various dose-saving strategies have been implemented and prospective electrocardiography-triggering and high pitch techniques were found to be the most effective approaches for radiation dose reduction, with the corresponding mean effective dose being 3.5 ± 1.9 mSv and 1.7 ± 0.6 mSv, respectively., Conclusion: This review shows that the current research in coronary CT angiography has shifted from the previous focus on diagnostic accuracy in CAD to more emphasis on radiation dose reduction.

This study was undertaken to compare the entrance surface dose (ESD) and image quality of adult chest and abdominal X-ray examinations conducted at general practitioner (GP) clinics, and public and private hospitals in Malaysia. The surveyed facilities were randomly selected within a given category (28 GP clinics, 20 public hospitals and 15 private hospitals). Only departmental X-ray units were involved in the survey. Chest examinations were done at all facilities, while only hospitals performed abdominal examinations. This study used the x-ray attenuation phantoms and protocols developed for the Nationwide Evaluation of X-ray Trends (NEXT) survey program in the United States. The ESD was calculated from measurements of exposure and clinical geometry. An image quality test tool was used to evaluate the low-contrast detectability and high-contrast detail performance under typical clinical conditions. The median ESD value for the adult chest X-ray examination was the highest (0.25 mGy) at GP clinics, followed by private hospitals (0.22 mGy) and public hospitals (0.17 mGy). The median ESD for the adult abdominal X-ray examination at public hospitals (3.35 mGy) was higher than that for private hospitals (2.81 mGy). Results of image quality assessment for the chest X-ray examination show that all facility types have a similar median spatial resolution and low-contrast detectability. For the abdominal X-ray examination, public hospitals have a similar median spatial resolution but larger low-contrast detectability compared with private hospitals. The results of this survey clearly show that there is room for further improvement in performing chest and abdominal X-ray examinations in Malaysia.

Objective: The purpose of this article was to develop a low-cost method for high-quality remote capturing and recording of multimedia presentations., Conclusion: The method for making high-quality digital recordings of presentations by using the mix of freely available software presented in this article offers great potential for institutions on a budget as well as others seeking viable alternatives to current methods of presentation recording.

The systematic monitoring of image quality and radiation dose is an ultimate solution to ensuring the continuously high quality of mammography examination. At present several protocols exist around the world, and different test objects are used for quality control (QC) of the physical and technical aspects of screen-film mammography. This situation may lead to differences in radiation image quality and dose reported. This article reviews the global QC perspective for the physical and technical aspects of screen-film mammography with regard to image quality and radiation dose. It points out issues that must be resolved in terms of radiation dose and that also affect the comparison.

Objective: This study was undertaken to estimate mammographic breast glandularity in Malaysian women from radiographic data., Materials and Methods: A mammography X-ray unit was used to expose different thicknesses of phantom material of varying glandular and adipose composition at 27 kV. A least squares method was then used to fit the combined data of phantom glandularity, thickness, and milliampere-seconds. The subsequent fitted equation was then applied to calculate breast glandularity for 705 women who underwent diagnostic mammography, who were drawn equally from the three major ethnic groups of Malaysia: Malay, Chinese, and Indian. The difference in breast glandularity among ethnic groups was tested for significance using the nonparametric Kruskal-Wallis test., Results: The fitted equation gave an absolute error of less than or equal to +/- 8% when applied to the data from phantom exposure. The average breast glandularity of the study sample was 48.9% +/- 18.7%. Breast glandularity was found to decrease with breast thickness and age., Conclusion: No significant difference was seen in breast glandularity among the ethnic groups (p > 0.05, Kruskal-Wallis test).

Background: Medical physics is a relatively small community but it spans great geographical distances, usually with a scarcity of experts whose expertise could greatly benefit students entering into the field. In addition there are many software systems for which an interactive education method would be most advantageous., Objective: To develop a process to optimally use the Internet for real-time interactive remote education of medical physics and to present the experience of the study., Methods: The project is a collaboration of the Department of Medical Physics at the Toronto-Sunnybrook Regional Cancer Centre in Canada and the Department of Radiology at the University of Malaya in Malaysia. A class of medical-physics graduate students at the University of Malaya attended lectures provided by lecturers in Toronto, using the Internet as the main tool of communication., Results: The different methods that can be used to provide the real-time interactive remote education were explored, and various topics-including traditional classroom lectures as well as hands-on workshops-were also delivered., Conclusions: The concept of real-time interactive remote education is viable and holds promise for providing economical and practical tele-education to the medical physics community, but depends heavily on the availability of the Internet in many developing countries.