1.Social radiology: Where to now?
Biomedical Imaging and Intervention Journal 2012;8(1):1-2
Radiology is a relatively high-cost and high-maintenance aspect of medicine. Expertise is constantly required, from acquisition to its use and quality assurance programmes. However, it is an integral part of healthcare practice, from disease diagnosis, surveillance and prevention to treatment monitoring. It is alarming that two thirds of the world is deficient in or lacks even basic diagnostic imaging. Developing and underdeveloped countries need help in improving medical imaging. Help is coming from various organisations, which are extending hands-on teaching and imparting knowledge, as well as training trainers to increase the pool of skilled practitioners in the use of imaging equipment and other aspects of radiology services. The scene for social radiology is changing and set to positively impact the world in the (near) future.
2.Precocious puberty in children: A review of imaging findings
Faizah MZ ; Zuhanis AH ; Rahmah R ; Raja AA ; Wu LL ; Dayang AA ; Zulfiqar MA
Biomedical Imaging and Intervention Journal 2012;8(1):1-8
Objectives: This review was aimed at determining the imaging findings in patients with precocious puberty.
Results: Within a period of 8 years (from 2002 to 2010) there were 53 patients diagnosed with precocious puberty. Out of the 53 patients, 37 had undergone diagnostic imaging to detect the possible organic causes of precocious puberty. Imaging findings were positive in 31 patients and out of that, 3 patients had 2 findings each (34 abnormalities). Of the patients with positive imaging findings, central precocious puberty (gonadotrophin-dependent) was more common (81%; 25/31) and the causes included: tuber cinereum hamartoma (n = 10), glioma (n = 6), pineal gland tumour (n = 4), hydrocephalous (n = 3), arachnoid cyst (n = 2) and others (n = 3). Peripheral precocious puberty (gonadotrophin-independent) causes included: testicular adrenal rest tumour (n = 3), adrenal carcinoma (n = 1), ovarian granulosa thecal cell tumour (n = 1), and tuberous sclerosis (n = 1).
Conclusion: Positive imaging findings were observed in 84% (31/37) of the subjects. Hypothalamic hamartoma was the most common imaging finding in central precocious puberty while testicular adrenal rest tumour was the most common imaging finding in peripheral precocious puberty
3.Dialysis catheter fibrin sheath stripping: a useful technique after failed catheter exchange
Mohamad Ali AF ; Uhwut E ; Liew SK
Biomedical Imaging and Intervention Journal 2012;8(1):1-3
Fibrin sheath formation around long-term haemodialysis catheter is a common cause of failed dialysis access. Treatment options include pharmacological and mechanical methods. This paper reports a case of failed dialysis access due to fibrin sheath encasement. Pharmacologic thrombolysis, mechanical disruption using guide wire and catheter exchange had failed to address the issue. Eventually, fibrin sheath stripping using the loop snare technique was able to successfully restore the catheter function.
4.Effective connectivity between superior temporal gyrus and Heschl’s gyrus during white noise listening: linear versus non-linear models
Hamid KA ; Yusoff AN ; Rahman MZA ; Mohamad M ; Hamid AIA
Biomedical Imaging and Intervention Journal 2012;8(2):1-13
Purpose: This fMRI study is about modelling the effective connectivity between Heschl’s gyrus (HG) and the
superior temporal gyrus (STG) in human primary auditory cortices.
Materials & methods: Ten healthy male participants were required to listen to white noise stimuli during
functional magnetic resonance imaging (fMRI) scans. Statistical parametric mapping (SPM) was used to generate
individual and group brain activation maps. For input region determination, two intrinsic connectivity models
comprising bilateral HG and STG were constructed using dynamic causal modelling (DCM). The models were estimated
and inferred using DCM while Bayesian Model Selection (BMS) for group studies was used for model comparison and
selection. Based on the winning model, six linear and six non-linear causal models were derived and were again
estimated, inferred, and compared to obtain a model that best represents the effective connectivity between HG and the STG, balancing accuracy and complexity.
Results: Group results indicated significant asymmetrical activation (puncorr < 0.001) in bilateral HG and STG.
Model comparison results showed strong evidence of STG as the input centre. The winning model is preferred by 6 out
of 10 participants. The results were supported by BMS results for group studies with the expected posterior probability,r = 0.7830 and exceedance probability, φ = 0.9823. One-sample t-tests performed on connection values obtained from the winning model indicated that the valid connections for the winning model are the unidirectional parallel connections from STG to bilateral HG (p < 0.05). Subsequent model comparison between linear and non-linear models using BMS prefers non-linear connection (r = 0.9160, φ = 1.000) from which the connectivity between STG and the ipsi- and contralateral HG is gated by the activity in STG itself.
Conclusion: We are able to demonstrate that the effective connectivity between HG and STG while listening to
white noise for the respective participants can be explained by a non-linear dynamic causal model with the activity in STG influencing the STG-HG connectivity non-linearly.
5.Quality assurance of TomoDirect treatment plans using I’mRT MatriXX
Kong CW ; Yu SK ; Cheung KY ; Geng H ; Ho YW ; Lam WW ; Wong WK
Biomedical Imaging and Intervention Journal 2012;8(2):1-7
Purpose: To evaluate the performance of 2D-array I’mRT MatriXX for dose verification of TomoDirect treatment
plans.
Methods: In this study, a 2D-array ion chamber device – the I’mRT MatriXX and Multicube Phantom from IBA –
was used for dose verification of different TomoDirect plans. Pre-treatment megavoltage computed tomography (MVCT)
was performed on the phantom setup for position correction. After the irradiation of treatment plans on the I’mRT MatriXX and Multicube Phantom, the measured doses of coronal planes were compared with those from the planning calculations for verification. The results were evaluated by comparing the absolute dose difference in the high dose region as well as the gamma analysis of the 2D-dose distributions on the coronal plane. The comparison was then repeated with the measured dose corrected for angular dependence of the MatriXX.
Results: When angular dependence is taken into account, the passing rate of gamma analysis is over 90% for all
measurements using the MatriXX. If there is no angular dependence correction, the passing rate of gamma analysis
worsens for treatment plans with dose contribution from the rear. The passing rate can be as low as 53.55% in extreme cases, i.e. where all doses in the treatment plan are delivered from the rear.
Conclusion: It is important to correct the measured dose for angular dependence when verifying TomoDirect
treatment plans using the MatriXX. If left uncorrected, a large dose discrepancy may be introduced to the verification results.
6.A rare case of an appendiceal mass masquerading as a pelvic tumour and causing bilateral hydronephrosis
Abdul Rashid SN ; Ab Hamid S ; Mohamad Saini S ; Muridan R
Biomedical Imaging and Intervention Journal 2012;8(2):1-4
Diagnosing acute appendicitis in children can be difficult due to atypical presenting symptoms. While there are reported cases of acute appendicitis or appendiceal masses causing unilateral hydronephrosis, bilateral hydronephrosis as a complication of appendiceal mass is very rare. We report a case of a child who presented with cardinal symptomatology associated with the urogenital tract. Ultrasound (US) investigation showed a pelvic mass causing bilateral hydronephrosis. An initial diagnosis of a pelvic teratoma was made based on the US and computed tomography (CT) scan findings. The final diagnosis of an appendiceal mass causing bilateral hydronephrosis was established intraoperatively.
7.Radiologist: the newsman of the millennium
Biomedical Imaging and Intervention Journal 2012;8(3):1-3
Modern radiologists have a new cap to wear – The Newsman of the Millennium – thanks to the rapid advances in this field in the last fifty years or so. These advances have literally shifted our speciality from the confines of the “dark room” to the full glare of the “front stage” in the dynamic world of doctor-patient relationships.
Today a final diagnosis is rarely reached without any back-up from the field of radio-diagnosis. Often, the radiologist is the first one to pinpoint the diagnosis or to raise a suspicion of the most probable diagnosis in a given scenario. Things which appear good and glorious when disclosing good news become drastic and distasteful when the news is bad and dreadful. While disclosing an incurable ailment like cancer or a genetic disease, procedural complications, diagnostic errors or accidents, the newsman as well as the patient and referring colleagues undergo tremendous emotional turmoil.
This article focuses on the little-known role of the radiologist as the newsman of the millennium and reviews various strategies that can enable them to wear this hat with satisfaction and to deliver good as well as bad news with courage and confidence
8.Challenges in the delivery of radical radiotherapy for locally advanced non-small cell lung cancer
Tho LM ; McJury M ; Ho GF ; Han S ; Muirhead R
Biomedical Imaging and Intervention Journal 2012;8(3):1-15
Locally advanced non-small cell lung cancer (NSCLC) encompasses a heterogeneous collection of tumour and nodal stages. Despite recent advances, the overall survival for this group remains poor. Radical radiotherapy remains the mainstay of treatment. The complexities involved in the delivery of radical radiotherapy to the lung pertain to tumour volume definition, intra- and inter-fraction motion (namely tumour motion caused by respiration and GTV migration during treatment) and the proximity of organs at risk to the high-dose region. Here we discuss a selection of strategies to manage these complexities. Motion management can be addressed by 4D CT planning, radiotherapy gating and on-board imaging, including cone beam CT. Advanced planning methods such as intensity modulated radiotherapy may potentially allow dose escalation and sparing of normal tissue toxicity. Functional imaging has already improved our ability to stage tumours and more carefully select appropriate candidates for radical treatment. Better imaging also improves GTV definition. However, the complexities of image acquisition and interpretation need to be accounted for and agreed consensus protocols have yet to be defined. Novel imaging methods such as 4D PET-CT and 4D MRI may also yield improvements for the future and these are briefly discussed.
9.Mammographic breast density and other risk factors in Malaysian women with breast cancer
Zulfiqar MA ; Aslinda M ; Norlia A ; Nurismah MI ; Shamsuddin K
Biomedical Imaging and Intervention Journal 2012;8(3):1-7
Aim: This study was performed to: (i) determine the association of breast cancer with dense breasts, and (ii) determine the breast cancer association with early onset of menarche, nulliparity, late age at first childbirth, not breast-feeding, and family history of breast cancer.
Methods: This was a retrospective hospital-based case-control study. The 231 cases were women diagnosed with breast cancer on histology during the study period from July 1998 to April 2005. The 231 controls were age-matched and randomly selected women who did not have breast cancer but had mammography performed during the same time interval. Tabar classification was used to classify the mammographic parenchymal pattern of the 462 samples. The same radiologist analysed the parenchymal pattern based on the craniocaudal and mediolateral oblique views. Statistical analysis was done using the SPSS package.
Results: Majority of women with breast cancer (55%) had dense breasts (29% Type IB, 19% Type IC, 4% Type IV, 3% Type V). Majority of controls (58%) had dense breasts (22% Type IB, 26% Type IC, 6% Type IV, 4% Type V). The majority of women with breast cancer had menarche at 12 years or older (93%), were parous (89%), had the first childbirth before 35 years old (91%), had breast-fed (67%), and did not have family history of breast cancer (84%). For controls, the majority had menarche at 12 years or older (88%) were parous (87%), had the first childbirth before 35 years old (98%), had breast-fed (66%), and did not have family history of breast cancer (85%). All factors explored, including breast density, were not significantly associated with breast cancer. The odds ratio for breast cancer among those with dense breast compared to those with non-dense breast is 0.8 (95% CI=0.6, 1.2).
Conclusion: This study found no association between breast cancer and dense breasts (p=0.398). There was also no association between breast cancer with early onset of menarche (p=0.174), nulliparity (p=0.448), older age at first childbirth (p=0.065), not breast-feeding (p=0.716) and family history of breast cancer (p=0.665).
10.Traumatic retroclival epidural hematoma and unilateral occipital condylar fracture in an adult patient
Chu CY ; Leung WKW ; Chan TM ; Mak YK ; Khoo JLS
Biomedical Imaging and Intervention Journal 2012;8(3):1-6
Retroclival epidural hematoma is rare, with fewer than 30 cases reported in the literature. Almost all of the previously reported cases occurred in children, with only a few cases affecting adults. Among these adult patients, only two suffered from the associated occipital condyle fracture (OCF), which is another rare injury. The patient involved in this study suffered from retroclival epidural hematoma and unilateral occipital condyle fracture, as demonstrated on both CT and MRI scans. The patient also suffered from an associated right brachial plexus injury without any other neurological deficits, a condition that has not previously been reported. This paper reviews the underlying mechanisms of these rare injuries and seeks to form an understanding of them before proposing the mechanism of injury in the patient involved in the study
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