Biomed Imaging Interv J
· 2010 · PMID 21611038
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PURPOSE: Radiofrequency (RF) catheter ablation has transformed treatment for arrhythmias and has become first-line therapy for some tachycardias. The precise localization of the arrhythmogenic site and the positioning of...PURPOSE: Radiofrequency (RF) catheter ablation has transformed treatment for arrhythmias and has become first-line therapy for some tachycardias. The precise localization of the arrhythmogenic site and the positioning of the RF catheter over that site are problematic: they can impair the efficiency of the procedure and are time consuming (several hours). This study evaluates the feasibility of using only single plane C-arm images in order to estimate the 3D coordinates of RF catheter electrodes in a cardiac phase. MATERIALS AND METHODS: The method makes use of a priori 3D model of the RF mapping catheter assuming rigid body motion equations in order to estimate the 3D locations of the catheter tip-electrodes in single view C-arm fluoroscopy images. Validation is performed on both synthetic and clinical data using computer simulation models. The authors' monoplane reconstruction algorithm is applied to a 3D helix mimicking the shape of a catheter and undergoing solely rigid motion. Similarly, the authors test the feasibility of recovering nonrigid motion by applying their method on true 3D coordinates of 13 ventricular markers from a sheep's ventricle. RESULTS: The results of this study showed that the proposed monoplane algorithm recovers rigid motion adequately when using the spatial positions of a catheter in six consecutive C-arm image frames yielding maximum 3D root mean squares errors of 4.3 mm. On the other hand, the suggested algorithm did not recover nonrigid motion precisely as suggested by a maximum 3D root mean square value of 8 mm. CONCLUSION: Since RF catheter electrodes are rigid structures, the authors conclude that there is promise in recovering the 3D coordinates of the electrodes when making use of only single view images. Future work will involve adding nonrigid motion equations to their algorithm, which will then be applied to actual clinical data.
Tan S, Suraya A, Sa'don S
… +2 more, Ruzi A, Zahiah M
Biomed Imaging Interv J
· 2010 · PMID 21611037
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The authors propose a musculoskeletal (MSK) magnetic resonance imaging (MRI) protocol using selected sequences for common orthopaedic indications. Selected sequences allow optimal visualisation of the indicated pathology...The authors propose a musculoskeletal (MSK) magnetic resonance imaging (MRI) protocol using selected sequences for common orthopaedic indications. Selected sequences allow optimal visualisation of the indicated pathology while screening for other common conditions. The authors emphasise the need for standard positioning of the patient and standard orientation of scan planes to facilitate comparison with follow-up scans.
Abdullah B, Subramaniam R, Omar S
… +5 more, Wragg P, Ramli N, Wui A, Lee C, Yusof Y
Biomed Imaging Interv J
· 2010 · PMID 21611036
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Magnetic Resonance-guided focused Ultrasound Surgery (MRgFUS) is gaining popularity as an alternative to medical and surgical interventions in the management of symptomatic uterine fibroids. Studies have shown that it is...Magnetic Resonance-guided focused Ultrasound Surgery (MRgFUS) is gaining popularity as an alternative to medical and surgical interventions in the management of symptomatic uterine fibroids. Studies have shown that it is an effective non-invasive treatment with minimal associated risks as compared to myomectomy and hysterectomy. MRgFUS can be offered to a majority of patients suffering from symptomatic uterine fibroids. It has been suggested that the use of broader inclusion criteria as well as the mitigation techniques makes it possible to offer MRgFUS to a much larger subset of patients than previously believed. This paper will describe how MRgFUS treatment for uterine fibroids is performed at the University of Malaya Medical Centre, Kuala Lumpur, Malaysia.
Lodhia J, Mandarano G, Ferris Nj
… +2 more, Eu P, Cowell S
Biomed Imaging Interv J
· 2010 · PMID 21611034
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Contrast agents, such as iron oxide, enhance MR images by altering the relaxation times of tissues in which the agent is present. They can also be used to label targeted molecular imaging probes. Unfortunately, no molecu...Contrast agents, such as iron oxide, enhance MR images by altering the relaxation times of tissues in which the agent is present. They can also be used to label targeted molecular imaging probes. Unfortunately, no molecular imaging probe is currently available on the clinical MRI market. A promising platform for MRI contrast agent development is nanotechnology, where superparamagnetic iron oxide nanoparticles (SPIONS) are tailored for MR contrast enhancement, and/or for molecular imaging. SPIONs can be produced using a range of methods and the choice of method will be influenced by the characteristics most important for a particular application. In addition, the ability to attach molecular markers to SPIONS heralds their application in molecular imaging.There are many reviews on SPION synthesis for MRI; however, these tend to be targeted to a chemistry audience. The development of MRI contrast agents attracts experienced researchers from many fields including some researchers with little knowledge of medical imaging or MRI. This situation presents medical radiation practitioners with opportunities for involvement, collaboration or leadership in research depending on their level of commitment and their ability to learn. Medical radiation practitioners already possess a large portion of the understanding, knowledge and skills necessary for involvement in MRI development and molecular imaging. Their expertise in imaging technology, patient care and radiation safety provides them with skills that are directly applicable to research on the development and application of SPIONs and MRI.In this paper we argue that MRI SPIONs, currently limited to major research centres, will have widespread clinical use in the future. We believe that knowledge about this growing area of research provides an opportunity for medical radiation practitioners to enhance their specialised expertise to ensure best practice in a truly multi-disciplinary environment. This review outlines how and why SPIONs can be synthesised and examines their characteristics and limitations in the context of MR imaging.
Singham S, Murugasu P, Macintosh J
… +2 more, Murugasu P, Deshpande A
Biomed Imaging Interv J
· 2010 · PMID 21611033
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Entrapment of renal artery by the diaphragmatic crus is a rare cause of renal artery stenosis. Spiral computed tomography angiography provides a definitive diagnosis and shows the precise relationship of the artery to th...Entrapment of renal artery by the diaphragmatic crus is a rare cause of renal artery stenosis. Spiral computed tomography angiography provides a definitive diagnosis and shows the precise relationship of the artery to the diaphragmatic crus. The authors present a case of hypertension developing in a young 20-year-old female due to entrapment of the left renal artery by the diaphragmatic crus. This condition should be considered in young hypertensive patients with renal artery stenosis without cardiovascular risk factors.
Biomed Imaging Interv J
· 2010 · PMID 21611068
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Many papers have been written on the synthesis of gold nanoparticles but very few included pictures of the process, and none of them used video to show the whole process of synthesis. This paper records the process of sy...Many papers have been written on the synthesis of gold nanoparticles but very few included pictures of the process, and none of them used video to show the whole process of synthesis. This paper records the process of synthesis of gold nanoparticles using video clips. Every process from cleaning of glassware, an important step in the synthesis of metallic nanoparticles, to the dialysis process is shown. It also includes the preparation of aqua regia and the actual synthesis of gold nanoparticles. In some papers, the dialysis process was omitted, but in this paper, it is included to complete the whole process as it is being used for purification.
Nawawi O, Hazman M, Abdullah B
… +4 more, Vijayananthan A, Manikam J, Mahadeva S, Goh K
Biomed Imaging Interv J
· 2010 · PMID 21611067
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PURPOSE: This is a retrospective study to evaluate the results of our early experience of using doxorubicin eluting beads (DEB) to treat patients with early and intermediate hepatocellular carcinoma (HCC). MATERIAL AND M...PURPOSE: This is a retrospective study to evaluate the results of our early experience of using doxorubicin eluting beads (DEB) to treat patients with early and intermediate hepatocellular carcinoma (HCC). MATERIAL AND METHODS: A cohort of 19 patients (84.2% male; 15.8% female; mean age 59.2 years ± 11.0; range, 32-80 years) with documented HCC of size 1.8-10cm (mean, 4.0cm ± 1.8 ) undergoing DEB transarterial chembolisation (TACE) was reviewed. All patients had at least one image examination (multiphase computed tomography or magnetic resonance imaging) after embolisation. RESULTS: A total of 32 procedures were performed. The objective response according to the European Association for the Study of the Liver criteria was 57.9% at 1-month, 42.8% at 6-month and 50.0% at 1-year follow up. There were 4 (21.1%) treatment-related complications (1 liver abscess, 2 pancreatitis and 1 tumour rupture) which resulted in 2 deaths. One death occurred 3 weeks after second embolisation, due to ruptured pancreatic pseudocyst, giving a 5.3% 30-day mortality rate. Another patient died 2 months after embolisation caused by tumour rupture. Eight patients received radiofrequency ablation after embolisation for residual or recurrent tumours. The 1-year survival rate in the DEB TACE only group was 80% while the 1- and 2-year survival rate in the group that received radiofrequency after DEB TACE was 85.7% and 100% respectively. CONCLUSION: DEB TACE is safe and effective in select group of patients. Survival may be improved when combined with other treatment modality.
Biomed Imaging Interv J
· 2010 · PMID 21611066
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Leigh syndrome is a progressive neurodegenerative disorder of childhood. The symmetrical necrotic lesions in the basal ganglia and/or brainstem which appear as hyperintense lesions on T2-weighted MRI is characteristic an...Leigh syndrome is a progressive neurodegenerative disorder of childhood. The symmetrical necrotic lesions in the basal ganglia and/or brainstem which appear as hyperintense lesions on T2-weighted MRI is characteristic and one of the essential diagnostic criteria. Recognising this MR imaging pattern in a child with neurological problems should prompt the clinician to investigate for Leigh syndrome. We present here two cases of Leigh syndrome due to different biochemical/genetic defects, and discuss the subtle differences in their MR neuroimaging features.
Biomed Imaging Interv J
· 2010 · PMID 21611065
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PURPOSE: The purpose of this study was to assess radiographer familiarity and preferences with digital radiography in four teaching hospitals and thereafter make recommendations in line with the migration from screen fil...PURPOSE: The purpose of this study was to assess radiographer familiarity and preferences with digital radiography in four teaching hospitals and thereafter make recommendations in line with the migration from screen film to digital radiography. MATERIALS AND METHODS: A questionnaire was designed to collect data from either qualified or student radiographers from four teaching hospitals. From the four teaching hospitals, there were a total of 205 potential respondents. Among other things, responses regarding experiences and preferences with digital radiography, quality control procedures, patient dose, advantages and disadvantages of digital radiography were sought. The information collected was based on self-reporting by the participants. The study is exploratory in nature and descriptive statistics were generated from the collected data using Microsoft Excel 2007 and StatsDirect software. RESULTS: Sixty-three out of 205 (31%) radiographers from all the four radiology centers responded to the circulated questionnaire. Only 15% (8) of the qualified radiographers had 4 or more years of experience with digital radiography compared to 68% (36) for the same amount of experience with screen-film radiography. Sixty-one percent (38) of the participants had been exposed to digital radiography during their lectures while at university. A small proportion, 16% (10) of the respondents underwent formal training in quality control procedures on the digital X-ray units they were using. Slightly more than half (55%) of the participants felt it was easier for them to retake an image in digital radiography than in screen film radiography. CONCLUSION: The results of this survey showed that the participants are familiar with digital radiography and have embraced this relatively new technology as shown by the fact that they can identify both its advantages and disadvantages as applied to clinical practice. However, there are minimal quality control procedures specific to digital radiography being undertaken as such there is need for formal education, continuing education and manufacturer training with respect to quality control as institutions make the transition from conventional screen film radiology to digital radiology.
Biomed Imaging Interv J
· 2010 · PMID 21611064
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With the advent of multislice CT more than a decade ago, multislice CT angiography has demonstrated a huge potential in the less invasive imaging of cardiovascular disease, especially in the diagnosis of coronary artery...With the advent of multislice CT more than a decade ago, multislice CT angiography has demonstrated a huge potential in the less invasive imaging of cardiovascular disease, especially in the diagnosis of coronary artery disease. The diagnostic accuracy of multislice CT angiography has been significantly augmented with the rapid technical developments ranging from the initial 4-slice, to the current 64-slice and 256 and 320-slice CT scanners. This is mainly demonstrated by the improved spatial and temporal resolution when compared to the earlier type of CT scanners. Traditionally, multislice CT angiography is acquired with retrospective ECG-gating with acquisition of volume data at the expense of increased radiation dose, since data is acquired at the entire cardiac cycle, although not all of them are used for postprocessing or reconstructions. Recently, there is an increasing trend of utilising prospective ECG-gating in cardiac imaging with latest multislice CT scanners (64 or more slices) with significant reduction of radiation dose when compared to retrospective ECG-gating method. However, there is some debate as to the diagnostic value of prospective ECG-gating in the diagnosis of coronary artery disease, despite its attractive ability to reduce radiation dose. This article will review the performance of retrospective ECG-gating in the diagnostic value of coronary artery disease, highlight the potential applications of prospective ECG-gating, and explore the future directions of multislice CT angiography in cardiac imaging.
Akbarzadeh A, Ay M, Ghadiri H
… +2 more, Sarkar S, Zaidi H
Biomed Imaging Interv J
· 2010 · PMID 21611063
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PURPOSE: The consummate 64-slice CT scanner that spawns a new generation of non-invasive diagnostic tool, however revolutionary, brings with it the incidental by-product that is scattered radiation. The extended detector...PURPOSE: The consummate 64-slice CT scanner that spawns a new generation of non-invasive diagnostic tool, however revolutionary, brings with it the incidental by-product that is scattered radiation. The extended detector aperture capability in the 64-slcie CT scanner allows the effects of scattered radiation to be more pronounced and therefore demands that the magnitude and spatial distribution of scatter component be addressed during the imaging process. To this end, corrective algorithms need to be formulated on a basis of a precise understanding of scatter distribution. Relative to a 64-slice CT scanner, here now a unique solution is based upon dedicated blockers operative within various detector rows, calculating scatter profiles and scatter to primary ratios (SPR). MATERIALS AND METHODS: A single dimension blocker array was installed beneath the collimator, and the extrapolated shadow area on the detectors revealed the scatter radiation after exposure. The experiment was conducted using a 64-slice CT scanner manufactured by GE Healthcare Technologies. RESULTS: Variables such as tube voltage, phantom size and phantom-off centring on the scatter profile and the SPR was measured using the dedicated blocker method introduced above. When tube voltage is increased from 80kVp to 140kVp in a 21.5 cm water phantom, the SPR is found to reduce from 219.9 to 39.9 respectively. CONCLUSION: The method developed within this study is applicable to any measurement and is direct with minimal complexity.
Biomed Imaging Interv J
· 2010 · PMID 21611062
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The aim of this case report is to present a multislice computed tomography angiography (CTA) procedure for viewing the plantar arch. A CTA was requested to determine the vascular sufficiency of the plantar arch of a 64-y...The aim of this case report is to present a multislice computed tomography angiography (CTA) procedure for viewing the plantar arch. A CTA was requested to determine the vascular sufficiency of the plantar arch of a 64-year-old patient with necrotic and gangrenous toes. The patient had recently undergone a proximal wedge osteotomy procedure for correction of a hallux valgus deformity. A 16-detector row CT scanner with 1.25 mm slice thickness and 0.625 mm reconstruction interval was used to reconstruct multiplanar reformats, maximum intensity projections and three-dimensional volume rendered images of the foot in question in both arterial and venous phases to determine if pathology of the plantar arch was present. The 3D reconstructed images of CTA demonstrated a loss of continuity of the plantar arch between the first and third metatarsals. This case report shows the diagnostic value of multislice CTA, especially 3D visualisation in the assessment of peripheral vascular branches.
Saidatul A, Azlan C, Megat Amin M
… +2 more, Abdullah B, Ng Kh
Biomed Imaging Interv J
· 2010 · PMID 21611060
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Computed tomography (CT) fluoroscopy is able to give real time images to a physician undertaking minimally invasive procedures such as biopsies, percutaneous drainage, and radio frequency ablation (RFA). Both operators e...Computed tomography (CT) fluoroscopy is able to give real time images to a physician undertaking minimally invasive procedures such as biopsies, percutaneous drainage, and radio frequency ablation (RFA). Both operators executing the procedure and patients too, are thus at risk of radiation exposure during a CT fluoroscopy.This study focuses on the radiation exposure present during a series of radio frequency ablation (RFA) procedures, and used Gafchromic film (Type XR-QA; International Specialty Products, USA) and thermoluminescent dosimeters (TLD-100H; Bicron, USA) to measure the radiation received by patients undergoing treatment, and also operators subject to scatter radiation.The voltage was held constant at 120 kVp and the current 70mA, with 5mm thickness. The duration of irradiation was between 150-638 seconds.Ultimately, from a sample of 30 liver that have undergone RFA, the study revealed that the operator received the highest dose at the hands, which was followed by the eyes and thyroid, while secondary staff dosage was moderately uniform across all parts of the body that were measured.
Kumar K, Andrews M, Jayashankar V
… +2 more, Mishra A, Suresh S
Biomed Imaging Interv J
· 2009 Oct · PMID 21610995
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Due to the isoechoic nature of lesions and their poor contrast with neighbouring tissue, a lesion may remain undetected in ultrasound B mode imaging for cancerous tissue. Imaging of the elastic properties of tissue provi...Due to the isoechoic nature of lesions and their poor contrast with neighbouring tissue, a lesion may remain undetected in ultrasound B mode imaging for cancerous tissue. Imaging of the elastic properties of tissue provides new information which is collateral to tissue pathology. This study provides quantitative analysis of improvements in tumour diagnosis when the ultrasound B mode imaging is combined with elastography. Quantification was based on the textural parameters measured from the ultrasound B mode image and strain measured from the elastogram. The ability of a parameter to discriminate between diseased cases and normal cases was evaluated using receiver operating characteristic (ROC) analysis. Polyacrylamide gel based tissue mimicking phantoms with embedded inclusions of varying stiffness were used for the analysis.
Abdul Rashid S, Rahmat K, Jayaprasagam K
… +2 more, Alli K, Moosa F
Biomed Imaging Interv J
· 2009 Oct · PMID 21610994
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Medullary carcinoma is a rare breast carcinoma with a syncytial growth pattern and high-grade cytology. It can be difficult to diagnose and may be missed on conventional imaging as the findings may overlap with benign le...Medullary carcinoma is a rare breast carcinoma with a syncytial growth pattern and high-grade cytology. It can be difficult to diagnose and may be missed on conventional imaging as the findings may overlap with benign lesions i.e. fibroadenomas. The authors report a case of a 25-year-old female who presented with multifocal breast lumps diagnosed with medullary carcinoma and fibroadenomas. Imaging and pathological correlation with contrast-enhanced MRI are presented in the diagnosis of these lesions.