Wireless Sensor Networks for monitoring underwater sediment transport.

Monitoring of the coastline and coastal processes, in particular sediment movement, is vital to ensure that erosion response is appropriate given the dynamic nature of coastal systems. This should take place regularly over long periods and it is important that data are collected from submerged portions of the littoral zone, as well as the visible beach. This highlights two limitations in existing coastal monitoring techniques: 1. they require largely manual operation and 2. are limited to the visible beach, which results in an incomplete picture of what is happening in the coastal zone. Due to the current difficulties in gathering data beneath the sea surface, this paper reviews wireless sensor network (WSN) technology as a means to overcome these limitations. Analysis showed that WSNs are a promising technology for coastal monitoring, not only in terms of overcoming limitations, but also in terms of cost, safety, and the size of areas they are able to monitor. Previous work using WSNs in this environment is somewhat limited, especially as most current methods are largely limited to the visible beach, and do not consider submerged areas of the coastal zone. From consideration of the physical environment, geological and geographical processes, and informed by advances in technology, research gaps are identified, discussed and evaluated to provide strategies for implementation of WSNs to monitor sediment transport.

PET/CT in anal cancer - is it worth doing?

AIM: To evaluate the role of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/ computed tomography (CT) in the current multidisciplinary management of anal cancer, both in initial staging and in follow-up post-treatment. MATERIALS AND METHODS: All patients referred to the region-wide multidisciplinary meeting for anal cancer during the study period received PET/CT imaging in addition to conventional imaging [CT and magnetic resonance imaging (MRI)]. Whether PET/CT altered the stage of the tumour from that suggested by conventional imaging was retrospectively assessed. The effect on management was evaluated. RESULTS: Fifty PET/CT examinations were performed on 44 patients with anal cancer. Thirty were part of initial staging, and 20 were post-chemo/radiotherapy or surgery. Two PET/CTs produced inadequate contemporaneous conventional imaging to allow comparison. Overall PET/CT increased the stage of the anal cancer in 17% of cases (8/48), decreased the stage in 19% (9/48), and did not alter the stage in 65% (31/48). The tumour stage was altered more frequently in initial staging than in follow up imaging. The PET/CT findings altered patient management in 29% (14/48) of cases. The majority (11) of these were cases in which PET/CT was used as part of initial staging. CONCLUSION: PET/CT alters the initial staging sufficiently frequently that it should be used routinely in anal cancer, where it is available. The role of PET/CT in the follow-up of anal cancer is not as clear. Routine follow-up with PET/CT may not be justified, but selected use is of definite benefit in problem solving or if salvage surgery is planned, after multidisciplinary discussion.

Digital tomosynthesis--a new lease of life for the intravenous urogram?

OBJECTIVES: Digital tomosynthesis is a new digital technique based on conventional X-ray tomography. It acquires multiple low-dose projections during a single sweep of the X-ray tube, which are reassembled to provide high-resolution slices at different depths. Suggested uses include visualisation of pulmonary nodules, mammography, angiography, dental imaging and delineation of fractures. This study aims to evaluate its potential role as part of an intravenous urogram (IVU) by assessing the diagnostic quality in imaging the kidneys in clinical practice. METHODS: 100 renal units from consecutive traditional IVU studies were retrospectively compared with 101 renal units imaged using digital tomosynthesis. These were scored for visualisation of the renal outline and collecting system, presence of a renal cyst or mass and overall diagnostic quality. Radiation doses were calculated. RESULTS: 46.5% of traditional IVUs were found to be of diagnostic quality. The IVUs with digital tomosynthesis were of diagnostic quality in 95.5%. This represents a highly statistically significant difference (p<0.0001). There was also a statistically significant dose reduction, with a mean reduction of 56%, for the samples studied. CONCLUSION: Digital tomosynthesis offers a significant increase in the percentage of diagnostic quality tests for assessing renal pathology, compared with traditional IVU, and significantly reduces radiation. It also offers considerable advantages in ease and speed of imaging. For these reasons, in any situation where IVU is still being used to assess the kidneys, digital tomosynthesis is likely to be of considerable benefit in improving diagnostic quality.

Biochemical relapse-free survival in 400 patients treated with I-125 prostate brachytherapy: the Guildford experience.

A total of 1200 patients had undergone I-125 prostate brachytherapy (BXT) in our centre. We present prospective outcome data for the first 400 treated patients. Data were analysed from a prospective database of 400 consecutive patients treated with permanent prostate BXT between March 1999 and December 2003. Patients were stratified into low (49%), intermediate (36%) and high (15%) risk as defined by the Memorial Sloan-Kettering Prognostic Index. Patients received 145 Gy BXT alone (41%), BXT with 3 months neoadjuvant androgen deprivation (NAAD) (39%), 45 Gy external beam radiotherapy (EBRT) with 110 Gy BXT (3%) or a combination of NAAD, 45 Gy EBRT and 110 Gy BXT (17%). Biochemical relapse-free survival (bRFS) and prostate-specific antigen (PSA) nadirs were analysed for treatment received in each risk group. Median follow-up was 54 months (range, 38-96 months) with a mean patient age of 63 years. Prostate cancer-specific survival was 99.5%. Twenty-eight patients (7%) experienced biochemical failure according to the 2006 Radiation Therapy Oncology Group-American Society for Therapeutic Radiology and Oncology (RTOG-ASTRO) Phoenix Consensus definition (PSA nadir plus >or=2 ng ml(-1)): nine low-, fourteen intermediate- and five high-risk patients. When stratified by treatment group for low-, intermediate- and high-risk groups, the 5-year actuarial bRFS was 98, 89 and 100% for BXT; 91, 87 and 88% for NAAD and BXT; 100, 80 and 100% for EBRT and BXT; and 100, 92 and 88% for NAAD, EBRT and BXT, respectively. Overall 4- and 5-year PSA

Ras signaling influences permissiveness of malignant peripheral nerve sheath tumor cells to oncolytic herpes.

Lack of expression of neurofibromin in neurofibromatosis 1 and its lethal derivative, malignant peripheral nerve sheath tumors (MPNSTs), is thought to result in the overactivation of the Ras signaling pathway. Our previous studies have shown that cells with overactivation in the Ras pathway are more permissive to infection with herpes simplex virus 1 and its mutant version R3616. In this study, we show that among five different mouse MPNST cell lines, only the ones with elevated levels of Ras signaling are highly permissive to infection with oncolytic herpes G207. Specific inhibitors of the Ras, ERK, and JNK pathways all reduced the synthesis of viral proteins in MPNST cells. The cell lines that contained lower levels of Ras and decreased activation of downstream signaling components underwent an enhancement in apoptosis upon exposure to G207. Additionally, mouse SW10 Schwann cells were able to become infected by parental herpes but were found to be resistant to G207. The immortalization of these cell lines with the expression of SV40 large T antigen increased the levels of Ras activation and permissiveness to oncolytic herpes. A Ras/Raf kinase inhibitor reduced the synthesis of both herpes simplex virus-1 and G207 proteins in SW10 cells. The results of this study, therefore, introduce Ras signaling as a divergent turning point for the response of MPNST cells to an assault by oncolytic herpes.

The median arcuate ligament syndrome revisited by CT angiography and the use of ECG gating--a single centre case series and literature review.

The significance of median arcuate ligament-associated coeliac axis compression can be readily delineated by CT angiography but is a source of some controversy in the literature, particularly given the relatively high incidence of this finding in otherwise asymptomatic individuals. This case series, with an emphasis on CT findings, aims to (i) illustrate the anatomy, (ii) elude to the variable outcome and uncertainty of those patients diagnosed, (iii) question the reliability of existing imaging techniques, with the additional use of multiphase electrocardiogram (ECG)-gated CT acquisition, and therefore (iv) augment the description of the currently recognized pathophysiology. We propose the clinical usefulness of ECG-gated vascular angiography, other than that necessary to image the coronary arteries, in vascular compression syndromes such as this.

Snore site discrimination using statistical moments of free field snoring sounds recorded during sleep nasendoscopy.

The non-invasive measurement of free field snoring sounds to estimate the site of snoring is an important development in the diagnosis, treatment and management of sleep-related breathing disorders. We investigated characteristics of the probability density function by testing the sensitivity of the statistical moments to amplitude patterns in the snoring acoustic signal. Snoring sounds from 15 patients were recorded whilst performing sleep (under anaesthetic) nasendoscopy evaluation. We demonstrated, using a fuzzy 2-means clustering method, that a combination of the statistical dimensionless moment coefficients of skewness and kurtosis could discriminate between pure palatal and non-palatal snoring subject groups.

Unusual presentation of ulnar artery aneurysm and dissection with associated anomalous radial artery: appearances on multi-detector row CT angiography.

We present a case of ulnar artery aneurysm and dissection associated with a congenitally hypoplastic ipsilateral radial artery. We postulate that the aetiology is due to increased blood flow through the ulnar artery as a consequence of the radial artery anomaly, therefore making the ulnar artery more vulnerable to aneurysm formation and traumatic damage. This might represent a variant of the hypothenar hammer syndrome with associated ulnar artery dissection and recurrent distal embolisation manifesting as Raynaud's phenomenon. Forearm arterial injuries, treatment and the importance of upper limb arterial anatomical variations are also discussed. To our knowledge, this is the first reported case of its type diagnosed by multi-detector row computed tomography angiography.

Benign external compression of the inferior vena cava associated with thrombus formation.

Malignant and benign causes of inferior vena cava (IVC) occlusion and compression are recognized. Cases of benign IVC compression with associated distal thrombus formation have not however been frequently described. We present two cases of benign external IVC compression associated with distal thrombus formation; one resulting from a giant, benign, hepatic cyst, and another due to pelviureteric junction obstruction, resulting in massive hydronephrosis.

Papillary necrosis causing hydronephrosis in renal allograft treated by percutaneous retrieval of sloughed papilla.

Obstructive uropathy is the second most common urological complication in a transplanted kidney. The usual causes of obstruction are ureteral stenosis and calculi. Papillary necrosis as a cause of obstruction in a transplant kidney is extremely rare with only one prior report published. Moreover, percutaneous removal of sloughed papilla in a transplant kidney has not previously been reported. We report an unusual case of a sloughed papilla causing hydronephrosis of a transplant kidney and its successful percutaneous removal. The recognition of renal papillary necrosis is important, not only because it can be a sign of acute rejection but also it because it can lead to obstruction, infection and potentially the loss of the transplant as exemplified by our case. Rapid diagnosis and meticulous retrieval technique are the crucial factors in minimizing the complications due to obstruction of a transplanted kidney by sloughed papilla.

Enlarging vertebrobasilar nonsaccular intracranial aneurysms: frequency, predictors, and clinical outcome of growth.

OBJECT: Vertebrobasilar nonsaccular intracranial aneurysms (NIAs) are characterized by elongation, dilation, and tortuosity of the vertebrobasilar arteries. The goal of this study was to define the frequency, predictors, and clinical outcome of the enlargement of vertebrobasilar NIAs. METHODS: Patients with vertebrobasilar fusiform or dolichoectatic aneurysms demonstrated on imaging studies between 1989 and 2001 were identified. In particular, patients who had undergone serial imaging were included in this study and their medical records were retrospectively reviewed. Prospective information was collected from medical records or death certificates when available. Both initial and serial imaging studies were reviewed. The authors defined NIA enlargement as a change in lesion diameter greater than 2 mm or noted on the neuroradiologist's report. A Cox proportional hazards regression was used to model time from diagnosis of the vertebrobasilar NIA to the first documented enlargement as a function of various predictors. The Kaplan-Meier method was used to study patient death as a function of aneurysm growth. Of the 159 patients with a diagnosis of vertebrobasilar NIA, 52 had undergone serial imaging studies including 25 patients with aneurysm enlargement. Lesion growth significantly correlated with symptomatic compression at the initial diagnosis (p = 0.0028), lesion type (p < 0.001), and the initial maximal lesion diameter (median 15 mm in patients whose aneurysm enlarged compared with median 8 mm in patients whose aneurysm did not enlarge; p < 0.001). The mortality rate was 5.7 times higher in patients with aneurysm growth than in those with no enlargement after adjustment for patient age (p = 0.002). CONCLUSIONS: Forty-eight percent of vertebrobasilar NIAs demonstrated on serial imaging enlarged, and this growth was associated with significant morbidity and death. Significant risk factors for aneurysm enlargement included symptomatic compression at the initial diagnosis, transitional or fusiform vertebrobasilar NIAs, and initial lesion diameter. Further studies are necessary to determine appropriate treatments of this disease entity once enlargement has been predicted or occurs.

Multidetector row CT angiography of the lower limb arteries: a prospective comparison of volume-rendered techniques and intra-arterial digital subtraction angiography.

AIM: To assess whether multi-detector CT angiograms (MDCTA) of the lower limb arteries, compared with conventional digital subtraction angiograms (DSA), could replace invasive arteriography in patients with symptomatic peripheral arterial disease. MATERIALS AND METHODS: In a prospective comparative analysis of MDCTA and DSA in 44 patients, MDCTA was analyzed using volume-rendered images acquired at a workstation and viewed in tandem with the original axial data. Designated arterial segments were graded according to their degree of stenosis. RESULTS: We found agreement for the degree of stenosis in 88.8% and 85.4% of 1024 segments analysed for two observers. The sensitivity for treatable lesions (>50% stenosis) was 79.1% and 72% with a specificity of 93.3% and 92.6%. DSA failed to visualize 7.3% of segments that were visible with MDCTA. These segments were exclusively downstream to long segment occlusions. CONCLUSION: MDCTA using 4-slice machines is insensitive to detecting significant arterial stenoses in the lower limb arteries. MDCTA is superior to DSA in its visualization of arterial territories downstream to significant occlusive disease.

Clinical content detection for medical image retrieval.

Content-based image retrieval (CBIR) is the most widely used method for searching large-scale medical image collections; however this approach is not suitable for high-level applications as human experts are accustomed to manage medical images based on their clinical features rather than primitive features. Automatic detection of clinical features in a large-scale image database and realization of image retrieval by clinical content are still open issues. This paper presents a Markov random field (MRF) based model for clinical content detection. Multiple classifiers are applied to recognize a wide range of clinical features in a large-scale histological image database, and they are further combined to generate more reliable and robust estimation. Spatial contexts will cooperate with local estimations in the MRF based model to make a decision based on global consistency. The detected clinical features will provide a basis for image retrieval. Experiments have been carried out in a large-scale histological image database with promising results.

Endothelial nitric oxide synthase gene polymorphisms predict susceptibility to aneurysmal subarachnoid hemorrhage and cerebral vasospasm.

Rupture of an intracranial aneurysm (subarachnoid hemorrhage) is a potentially devastating condition frequently complicated by delayed cerebral ischemia from sustained contraction of intracranial arteries (cerebral vasospasm). There is mounting evidence linking the formation of intracranial aneurysms and the pathogenesis of post-subarachnoid hemorrhage vasospasm to aberrant bioavailability and action of the vasodilator molecule nitric oxide generated by isoforms of nitric oxide synthase. In humans, the gene encoding the endothelial isoform of nitric oxide synthase (eNOS) is known to be polymorphic, with certain polymorphisms associated with increased cardiovascular disease susceptibility. In this prospective clinical study involving 141 participants, we used gene microarray technology to demonstrate that the eNOS gene intron-4 27-base pair variable number tandem repeat polymorphism (eNOS 27 VNTR) predicts susceptibility to intracranial aneurysm rupture, while the eNOS gene promoter T-786C single nucleotide polymorphism (eNOS T-786C SNP) predicts susceptibility to post-subarachnoid hemorrhage vasospasm. We believe that genetic information such as this, which can be obtained expeditiously at the time of diagnosis, may be used as a helpful adjunct to other clinical information aimed at predicting and favorably modifying the clinical course of persons with intracranial aneurysms.