Evaluation of low-dose pediatric chest CT examination using in-house developed various age-size pediatric chest phantoms.

PURPOSE: This study aims to develop Various Age-size Pediatric Chest Phantoms (VAPC) to evaluate low-dose protocol that approximates clinical conditions achieved by low organ-specific doses and optimal image quality among the challenges of pediatric size variations. METHODS: Three original pediatric data aged 1, 4, and 7 years were used as a reference for developing VAPC phantoms. Six protocols, namely standard dose (STD) and low dose (low mA and low kV) reconstructed using Filtered Back Projection (FBP) and iterative reconstruction (IR) algorithms, were investigated. This study directly measured the lungs, heart, and spinal cord dose using LD-V1 film. Linearity, Modulation Transfer Function (MTF), Contrast to Noise Ratio (CNR), and Noise Power Spectrum (NPS) were evaluated to assess the CT image quality of the VAPC phantom. RESULTS: This study found that the mean organ-specific dose was higher than CTDIvol. A Comparison of mean lung doses showed VAPC phantom 1 (y.o.) received 74.8% and 137.2% more doses than 4 (y.o.) and 7 (y.o.), respectively. Low kV produces a lower organ dose than low mA. The linearity of CT numbers is not biased at low doses. Differences in age measures significantly influenced organ-specific dose, MTF, CNR, and NPS. CONCLUSION: Smaller pediatrics are still exposed to higher doses at low-dose examinations, whereas larger pediatrics have lower contrast resolution and increased image noise. CT number linearity is unbiased. The combination of low kV with FBP produces higher spatial resolution, while low mA with IR effectively reduces noise to detect low-contrast objects better.

Analysis of dual-energy mammography subtraction technique for the dose and image quality evaluation using 3D-printed breast phantom.

This study aimed to quantitatively assess the radiation dose using XR-QA2 and the image quality of the dual-energy subtraction mammography technique on an in-house phantom. The analysis was carried out to investigate the effect of targets/filters on dose value and image quality using an in-house phantom made of PLA + as an object representing compressed breasts. All irradiation parameters were performed in the craniocaudal position with manual mode. Mean glandular dose (MGD) was recorded, followed by the calculation of the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and modulation transfer function (MTF) for image quality assessment parameters. The results showed that the image quality was accepted at dose levels within the IAEA and BAPETEN tolerance limit for 60 mm equivalent compressed breast using dual-energy mammography. Furthermore, the target/filter (W/Rh) reduced the dose by 1.03 mGy compared to the Mo/Mo and Mo/Rh with an enhancement in image quality. This indicated that the target/filter (W/Rh) combination was optimal due to the image quality improvement obtained with lower MGD.

Left ventricle geometry, atrial strain, ventricle strain, and hemodynamics across aortic valve before and after transcatheter aortic valve replacements.

INTRODUCTION: Transcatheter aortic valve replacements (TAVRs) has become widespread throughout the world. To date, there are no echocardiographic studies of TAVR patients from Southeast Asia (SEA). We sought to evaluate (1) changes in echocardiographic and strain values pre- and post-TAVR (2) relationship between aortic stenosis (AS) severity and strain values, (3) left ventricle geometry in severe AS, (4) relationship of flow rate to dimensionless index (DVI) and acceleration time (AT), and (5) effect of strains on the outcome. MATERIALS AND METHODS: Retrospective study of 112 TAVR patients in our centre from 2009 to 2020. The echocardiographic and strain images pre (within 1 month), post (day after), and 6 months post-TAVR were analyzed by expert echocardiographer. RESULTS: The ejection fraction (EF) increased at 6 months (53.02 ± 12.12% to 56.35 ± 9.00%) (p=0.044). Interventricular septal thickness in diastole (IVSd) decreased (1.27 ± 0.21 cm to 1.21 ± 0.23 cm) (p=0.038) and left ventricle internal dimension in diastole (LVIDd) decreased from 4.77 ± 0.64 cm to 4.49 ± 0.65 cm (p=0.001). No changes in stroke volume index (SVI pre vs 6 months p=0.187), but the flow rate increases (217.80 ± 57.61 mls/s to 251.94 ± 69.59 mls/s, p<0.001). Global longitudinal strain (GLS) improved from -11.44 ± 4.23% to -13.94 ± 3.72% (p<0.001), left atrial reservoir strain (Lar-S) increased from 17.44 ± 9.16% to 19.60 ± 8.77% (p=0.033). Eight patients (7.5%) had IVSd < 1.0 cm, and 4 patients (3.7%) had normal left ventricle (LV) geometry. There was linear relationship between IVSd and mean PG (r=0.208, p=0.031), between GLS to aortic valve area (AVA) and aortic valve area index (AVAi) (r = - 0.305, p=0.001 and r= - 0.316, p= 0.001). There was also relationship between AT (r=-0.20, p=0.04) and DVI (r=0.35, p<0.001) with flow rate. Patients who died late (after 6 months) had lower GLS at 6 months. (Alive; -13.94 ± 3.72% vs Died; -12.43 ± 4.19%, p=0.001). CONCLUSION: At 6 months, TAVR cause reverse remodelling of the LV with the reduction in IVSd, LVIDd, and improvement in GLS and LAr-S. There is a linear relationship between GLS and AVA and between IVSd and AVA.

Echocardiographic and electrocardiographic presentations of patients with endomyocardial biopsy-proven cardiac amyloidosis.

OBJECTIVE: Cardiac amyloidosis is under diagnosed and its prevalence is unknown. This is a retrospective, nonrandomised, single centre study of patients with endomyocardial biopsy-proven cardiac amyloidosis focusing on their echocardiographic and electrocardiogram (ECG) presentations. This is the first case series in Malaysia on this subject. METHODS: We identified all of our endomyocardial biopsyproven cardiac amyloidosis patients from January 2010 to January 2018 and reviewed their medical records. All patients echocardiographic and ECG findings reviewed and analysed comparing to basic mean population value. RESULTS: In total there are 13 biopsy-proven cardiac amyloidosis patients. All of the biopsies shows light chain (AL) amyloid. Majority of the patients (8, 61.5%) is male, and most of our patients (8, 61.5%) is Chinese. All seven patients on whom we performed deformation imaging have apical sparing pattern on longitudinal strain echocardiogram. Mean ejection fraction is 49.3%, (SD=7.9). All patients have concentric left ventricular hypertrophy and right ventricular hypertrophy. Diastolic dysfunction was present in all of our patients with nine out of 13 patients (69.2%) having restrictive filling patterns (E/A ≥2.0 E/e' ≥15). On electrocardiogram, 12 (92%) patients have prolonged PR interval (median 200ms, IQR 76.50ms) and 9 (69.2%) patients have pseudoinfarct pattern. CONCLUSION: Echocardiography plays an important role in diagnosing cardiac amyloidosis. The findings of concentric left ventricular hypertrophy with preserved ejection fraction without increased in loading condition should alert the clinician towards its possibility. This is further supported by right ventricular hypertrophy and particularly longitudinal strain imaging showing apical sparing pattern.

Measuring Pressure Interface Of Local Car Seats Under Static And Dynamic Circumstances: A Comparative Study

@# Measuring discomfort towardthe car seat is important as the act of driving requires a driver to remain at the car seat while controlling the car. The seat condition, including sitting position as well as the driver’s posture can lead to discomfort and fatigue. The objective of this study is to investigate a driver’s pressure distribution in static and dynamic circumstances for two types of cars; the sedan and compact car. This study involved both subjective and objective evaluations of 12 respondents. For the subjective evaluation, the Visual Analog Scales (VAS) were used to obtain respondents' perception of discomfort. For the objective evaluation, pressure distribution readings of the seat interface were obtained using piezo capacitive sensors. The findings showed that the highest pressure was recorded for the compact car. Furthermore, the static circumstance showed greater pressure compared to the dynamic state. Subjective evaluation indicated that the right buttocks and the lower back (lumbar)experience the highest discomfort for both types of seats.The type of seat found to contribute to the value of different pressure. Thus, it can be concluded that appropriate seat selection can reduce pressure as well as discomfort.

A comparison of dabigatran and warfarin for stroke prevention in elderly Asian population with nonvalvular atrial fibrillation: An audit of current practice in Malaysia.

INTRODUCTION: Atrial fibrillation (AF) is the most common cardiac arrhythmia with significant morbidity and mortality in relation to thromboembolic stroke. Our study aimed to evaluate the safety and efficacy of dabigatran in stroke prevention in elderly patient with nonvalvular AF with regard to the risk of ischemic stroke and intracranial haemorrhage (ICH) in real-world setting. METHODS: A retrospective cohort study of 200 patients on dabigatran and warfarin from January 2009 till September 2016 was carried out. Data were collected for 100 patients on dabigatran and 100 patients on warfarin. RESULTS: The mean follow-up period was 340.7±322.3 days for dabigatran group and 410.5±321.2 days for warfarin group. The mean time in therapeutic range (TTR) was 52±18.7%. The mean CHA2DS2 -VASc score for dabigatran group was 4.4±1.1 while 5.0±1.5 for warfarin group. None in dabigatran group experienced ischemic stroke compared to one patient in warfarin group (p=0.316). There was one patient in dabigatran group suffered from ICH compared to none in warfarin group (p=0.316). Four patients in warfarin group experienced minor bleeding, while none from dabigatran group (p=0.043). CONCLUSION: Overall bleeding events were significantly lower in dabigatran group compared to warfarin group. In the presence of suboptimal TTR rates and inconveniences with warfarin therapy, non-vitamin-K antagonist oral anticoagulants (NOAC) are the preferred agents for stroke prevention in elderly Asian patients for nonvalvular AF.

Duplication of lower lip and mandible--a rare diprosopus.

Diprosopus or duplication of the lower lip and mandible is a very rare congenital anomaly. We report this unusual case occurring in a girl who presented to our hospital at the age of 4 months. Surgery and problems related to this anomaly are discussed.

Risk-adjusted analysis of patients undergoing laparotomy using POSSUM and P-POSSUM score in Queen Elizabeth Hospital, Sabah.

BACKGROUND: Scoring systems such as POSSUM and P-POSSUM have been developed to help predict mortality and morbidity in patients. The ratio of observed-to-predicted (O/P ratio) mortality and morbidity has been used as a performance indicator to compare different procedures, clinicians or hospitals. The aim of this study was to assess the predictive value of POSSUM compared with P-POSSUM in patients undergoing laparotomy in Queen Elizabeth Hospital, Sabah. METHODS: 381 patients over the age of 12 undergoing general surgical laparotomy between 1 May 2006 and 30 April 2007 were prospectively enrolled. RESULTS: In general, POSSUM over-predicted mortality compared with P-POSSUM (O/P ratio: 0.366 versus 0.721). P-POSSUM was still poor at predicting mortality in the lowest and highest risk groups (O/P ratios: 0 and 0.438). Both systems over-predicted mortality in trauma (O/P ratios: POSSUM, 0.306; P-POSSUM, 0.459), younger patients (O/P ratios: POSSUM, 0.325; P-POSSUM, 0.622) and non-ICU patients (O/P ratios: POSSUM, 0.171; PPOSSUM, 0.421). P-POSSUM was significantly better than POSSUM in other age groups and ICU patients. In terms of morbidity, POSSUM was able to predict morbidity quite accurately with O/P ratio of 0.746 and performed equally well across the subgroup. POSSUM was poor in predicting morbidity in young patients (O/P ratio: 0.652) and non-ICU patients (O/P ratio: 0.543). CONCLUSION: P-POSSUM is a better overall predictor of mortality in patients undergoing laparotomy in this hospital compared to POSSUM. POSSUM is fairly accurate in predicting morbidity. However, further refinement is needed to improve its predictive value in specific areas, and so increase its utility in our local setting.

Incidence and risk factors for pulmonary tuberculosis among the poor in the northern region of Poland.

SETTING: The falling trends in pulmonary tuberculosis (PTB) incidence observed in European countries may be due both to an improving epidemiological situation and to a shift of tuberculosis (TB) towards socially important subpopulations; this trend may cause some TB cases to go unnoticed. Identification of such risk groups should be the basis for prevention programmes aimed at containing the spread of the disease. OBJECTIVE: To evaluate the incidence and risk factors for PTB among the poor. DESIGN: The study material was based on the data of 7380 people living in poverty, including 243 homeless adults, aged between 18 and 96 years. Potential medical and socio-economic risk factors were evaluated with regard to PTB incidence. RESULTS: The TB incidence rate in the group studied was estimated at 730 per 100,000 population. The main risk factor was homelessness, with a TB incidence rate in the homeless group of 4290/100,000. According to our data, socio-economic factors correlated much more closely with a final TB diagnosis than subjective disease symptoms. CONCLUSIONS: Efficient TB control requires prevention programmes aimed at systematic monitoring of the homeless. A population with such a high proportion of TB patients is a dangerous source of TB.

Facial Fractures in Kajang Hospital, Malaysia: A 5-Year Review.

OBJECTIVE: The objective of this study was to determine the demographic data as well as other relevant data pertaining to the management of patients with maxillofacial injury in a Malaysian government regional hospital. STUDY DESIGN: Medical records of 313 patients who sustained maxillofacial injury treated in Kajang Hospital, Selangor, Malaysia over a 5-year period (1998-2002) were collected. Data regarding age, gender and race, etiology of injury, site of injury, other associated injuries and treatment undertaken were analyzed. RESULTS: Two hundred and forty-nine male (79.6%) and 64 female patients (20.4%) were treated for maxillofacial trauma. The patients' age range from 1 to 67 years old, with a median age of 23 years old. A high number of Malays (60.1%) sustained maxillofacial injury, followed by Indians (16%), Chinese (13.4%) and other races (10.5%). Road traffic accident was the main etiology for maxillofacial injury with 230 cases (73.5%), followed by fall (16.6%), assault (5.4%), industrial accident (2.6%), sports injuries (0.6%) and others (1.3%). Mandibular fractures were the most common, occurring in 83.1% of the cases while the midfacial fractures accounted for 16.9%. Majority of patients were treated with closed reduction and intermaxillary fixation (88.1%) and 11.9% underwent open reduction and internal fixation. CONCLUSION: Road traffic accident involving motorcyclists was the main cause of maxillofacial trauma in Malaysia. The most common facial fracture was the mandibular fracture. Non-surgical manipulation of fracture was the most common treatment carried out in this hospital.

Avoiding Osteoradionecrosis - The Dental Surgeo's Nightmaren.

Osteoradionecrosis is a severe debilitating complication; it may occur from radiotherapy to the bones. It is a dental surgeon's nightmare as it may be long standing and difficult to manage. Osteoradionecrosis is characterised by hypoxia, hypocellularity and hypovascularity of the affected tissue. This paper reviews osteoradionecrosis in relation to dental treatment.

Self-evaluation of drivers' skill: a cross-cultural comparison.

In a study conducted in Sweden and the United States, subjects judged their own driving skills in relation to other drivers. The results showed that a majority of subjects regarded themselves as more skillful than the average driver. This result was compared with that obtained from similar studies on the population of Polish amateur and professional drivers. The outcomes of this comparison confirmed the existence of an optimistic tendency to overestimate one's own driving skill. This tendency was observed in various groups of drivers differing in cultural background. Finally, the influence of this tendency upon risk estimates of traffic accidents and inefficiency of safety propaganda are discussed.