A multichannel feature-based approach for longitudinal lung CT registration in the presence of radiation induced lung damage

Quantifying parenchymal tissue changes in the lungs is imperative in furthering the study of radiation induced lung damage (RILD). Registering lung images from different time-points is a key step of this process. Traditional intensity-based registration approaches fail this task due to the considerable anatomical changes that occur between timepoints. This work proposes a novel method to successfully register longitudinal pre- and post-radiotherapy (RT) lung computed tomography (CT) scans that exhibit large changes due to RILD, by extracting consistent anatomical features from CT (lung boundaries, main airways, vessels) and using these features to optimise the registrations. Pre-RT and 12 month post-RT CT pairs from fifteen lung cancer patients were used for this study, all with varying degrees of RILD, ranging from mild parenchymal change to extensive consolidation and collapse. For each CT, signed distance transforms from segmentations of the lungs and main airways were generated, and the Frangi vesselness map was calculated. These were concatenated into multi-channel images and diffeomorphic multichannel registration was performed for each image pair using NiftyReg. Traditional intensity-based registrations were also performed for comparison purposes. For the evaluation, the pre- and post-registration landmark distance was calculated for all patients, using an average of 44 manually identified landmark pairs per patient. The mean (standard deviation) distance for all datasets decreased from 15.95 (8.09) mm pre-registration to 4.56 (5.70) mm post-registration, compared to 7.90 (8.97) mm for the intensity-based registrations. Qualitative improvements in image alignment were observed for all patient datasets. For four representative subjects, registrations were performed for three additional follow-up timepoints up to 48 months post-RT and similar accuracy was achieved. We have demonstrated that our novel multichannel registration method can successfully align longitudinal scans from RILD patients in the presence of large anatomical changes such as consolidation and atelectasis, outperforming the traditional registration approach both quantitatively and through thorough visual inspection.

How Greek nurses perceive and overcome the barriers in implementing treatment for pressure ulcers: 'against the odds'

OBJECTIVE

Although the occurrence of pressure ulcers (PUs) is now considered as an indicator of poor quality nursing care, questions and concerns remain regarding situations where PUs were unavoidable, irrespective of the care provided. The aim of this study was to explore Greek nurses' perceptions about the barriers involved and to identify the factors that influence care planning in PU treatment.

METHOD

A grounded theory approach was used and semi-structured interviews were conducted with nurses who provided pressure care to clients in a rehabilitation centre in Greece. Data were analysed using the constant comparative method.

RESULTS

We interviewed seven nurses. Findings revealed one main category entitled 'anarchy' in delivery of care consisted of the following three subcategories: interdisciplinary conflicts; total trust in traditional knowledge; and devaluation of other's work/role and a core category 'Against the odds': the perceived value of prevention and treatment can overcome the barriers in treating PUs.

CONCLUSION

This study gives an overview of the views and beliefs of nurses about the problems and barriers involved in PU prevention and treatment. The study reveals that although some barriers to good practice may exist, nurses can hold a positive attitude toward PU prevention and treatment, and their perceived value of prevention and treatment may help nurses to overcome the barriers in managing PUs.

Characterization of a rabbit antihuman mechano growth factor (MGF) polyclonal antibody against the last 24 amino acids of the E domain

The human insulin-like growth factor-1 (IGF-1) gene gives rise to multiple, heterogeneous mRNA transcripts by alternative splicing, thus producing different IGF-1 isoforms. The mechano growth factor (MGF) is an IGF-1 isoform that was found to be markedly up-regulated in exercised or damaged muscle. The specific E domain of the MGF splice variant may act as an independent growth factor. The aim of the present study was to characterize a rabbit antihuman MGF polyclonal antibody. New-Zealand rabbits were immunized by injections of a purified synthetic peptide corresponding to the last 24 amino acids of the human C-terminal of the MGF E domain. Western blotting and immunohistochemical techniques were used to characterize the specificity of the polyclonal anti-MGF antiserum. The anti-MGF antiserum was found to recognize the MGF E-peptide and not the common part of the IGF-1 isoforms, i.e. the mature IGF-1 peptide. Furthermore, it specifically bound to the MGF protein in human skeletal and in rat cardiac muscle, apparently due to the considerable homology between the human and rat MGF E-peptide sequences. Immunostaining analysis showed that this polyclonal anti-MGF antibody was able to detect MGF in human muscle and in rat cardiomyocytes and vessels' smooth muscle cells. We conclude that this rabbit polyclonal anti-human/rat MGF antibody could become a valuable tool in the study of IGF-1 isoforms in human and rat tissues.

Evaluation of modal damping factor as a diagnostic tool for osteoporosis and its relation with serum osteocalcin and collagen I N-telopeptide for monitoring the efficacy of alendronate in ovariectomized rats

Osteoporosis is a metabolic bone disease characterized by reduced bone mass and deterioration of bone microarchitecture. It results from the shift of the osteoblast-osteoclast activity equilibrium in favor of the later. Although, a number of biochemical markers, such as collagen I N-telopeptide (NTx) and osteocalcin (OC), have been used for monitoring bone remodeling, a new, monitoring, non-invasive method, which is based on the measurement of the dynamic characteristic of bone and is known as modal damping factor (MDF), has not been evaluated as a diagnostic tool for osteoporosis. Bisphosphonates, such as alendronate, have an established role in the treatment of osteoporosis. The aim of the present study was, therefore, to evaluate the effects of alendronate on the levels of MDF, serum NTx and OC on osteoporosis induced by ovariectomy in rats. Furthermore, the effects of alendronate on osteoporosis have been histologically evaluated. Fifteen adult female Wistar rats were bilaterally ovariectomized and osteoporosis was histologically confirmed and by the use of peripheral quantitative computerized tomography (pQCT). MDF was applied to assess the bone structural integrity. The serum levels of NTx (37.4+/-0.5 nM bone collagen equivalents, BCE) and OC (111.0+/-8.2 ng/mL) were found to significantly increase following ovariectomy (72.0+/-2.9 nM BCE and 213.5+/-12.1 ng/mL, respectively, p<0.001). As assessed by histology and the levels of NTx and OC in sera, animals treated with alendronate presented a statistically significant deceleration in the progression of the disease in comparison to the no-therapy control group (alendronate group NTx levels: 146.3+/-8.9 nM BCE versus no-therapy control group NTx levels: 265.3+/-14.0 nM BCE, p<0.001, alendronate group OC levels: 205.6+/-18.2 ng/mL versus no-therapy group OC levels: 353.9+/-26.1 ng/mL, p<0.001). Data obtained from the vibration analysis performed illustrated that the change in damping was equal or greater to the change in total and trabecular density, respectively. Damping increased with decreasing bone density, as expected, given that damping accounts for the structural integrity of bone (MDF value before ovariectomy: 0.058+/-0.003 versus MDF value after ovariectomy: 0.098+/-0.003, p<0.001). The higher damping values correspond to more deteriorated structures. In particular, both total and trabecular density were significantly decreased following ovariectomy (total density before ovariectomy: 702.4+/-19.0 versus total density after ovariectomy: 542.2+/-12.8, p<0.001, trabecular density before ovariectomy: 445.3+/-13.0 versus trabecular density after ovariectomy: 396.7+/-8.4, p<0.05). MDF value of the alendronate group (0.07+/-0.002) was significantly lower (p<0.001) as compared to MDF value after ovariectomy (0.098+/-0.003) and that of the no-therapy group (0.1+/-0.004, p<0.001). The administration of alendronate seemed to have no effect on either total or trabecular density, since both parameters continued to decrease (alendronate group total density: 549.4+/-12.3, alendronate group trabecular density: 368.4+/-14.7). However, when this was compared to the no-therapy group, a statistically significant difference of total density at the 0.05 level was observed (no-therapy total density: 464.8+/-9.1). The results of this study suggest that combined measurements of MDF, NTx and OC may be a potential diagnostic tool for osteoporosis and monitoring bone integrity during treatment with bisphosphonates. Furthermore, administration of alendronate showed to offer a critical deceleration in the progression of osteoporosis.

[@HOME is a new Eu-Project in Tele Home care]

@Home is a robust platform for real-time remote monitoring of patients at their home by doctors at the hospital. Health monitoring sensors, which have the capability to measure quick and easy vital parameters such as blood pressure, pulse rate, temperature, oxygen saturation (SpO2), as well as ECG 12 leads are used. Additionally, an advantage of the platform is that all the sensors are wearable and the patient is able to walk around indoors or outdoors. Moreover, the sensors are able to convey the recorded data over Bluetooth, a short-range wireless communication, to any Bluetooth enabled device such as Desktop computer or a Pocket PC.