Automatic Segmentation of the Eye in 3D Magnetic Resonance Imaging: A novel Statistical Shape Model for treatment planning of Retinoblastoma

Purpose: Proper delineation of ocular anatomy in 3D imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic Resonance Imaging (MRI) is nowadays utilized in clinical practice for the diagnosis confirmation and treatment planning of retinoblastoma in infants, where it serves as a source of information, complementary to the Fundus or Ultrasound imaging. Here we present a framework to fully automatically segment the eye anatomy in the MRI based on 3D Active Shape Models (ASM), we validate the results and present a proof of concept to automatically segment pathological eyes. Material and Methods: Manual and automatic segmentation were performed on 24 images of healthy children eyes (3.29±2.15 years). Imaging was performed using a 3T MRI scanner. The ASM comprises the lens, the vitreous humor, the sclera and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens and the optic nerve, then aligning the model and fitting it to the patient. We validated our segmentation method using a leave-one-out cross validation. The segmentation results were evaluated by measuring the overlap using the Dice Similarity Coefficient (DSC) and the mean distance error. Results: We obtained a DSC of 94.90±2.12% for the sclera and the cornea, 94.72±1.89% for the vitreous humor and 85.16±4.91% for the lens. The mean distance error was 0.26±0.09mm. The entire process took 14s on average per eye. Conclusion: We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor and the lens using MRI. We additionally present a proof of concept for fully automatically segmenting pathological eyes. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor.

PS-GANS: A Patient-Specific, Gravity Assisted Navigation System for Acetabular Cup Placement

In this paper we propose a new system that allows reliable acetabular cup placement when the THA is operated in lateral approach. Conceptually it combines the accuracy of computer-generated patient-specific morphology information with an easy-to-use mechanical guide, which effectively uses natural gravity as the angular reference. The former is achieved by using a statistical shape model-based 2D-3D reconstruction technique that can generate a scaled, patient-specific 3D shape model of the pelvis from a single conventional anteroposterior (AP) pelvic X-ray radiograph. The reconstructed 3D shape model facilitates a reliable and accurate co-registration of the mechanical guide with the patient’s anatomy in the operating theater. We validated the accuracy of our system by conducting experiments on placing seven cups to four pelvises with different morphologies. Taking the measurements from an image-free navigation system as the ground truth, our system showed an average accuracy of 2.1 ±0.7 o for inclination and an average accuracy of 1.2 ±1.4 o for anteversion.

A global ”imaging” view on systems approaches in immunology

The immune system exhibits an enormous complexity. High throughput methods such as the "-omic'' technologies generate vast amounts of data that facilitate dissection of immunological processes at ever finer resolution. Using high-resolution data-driven systems analysis, causal relationships between complex molecular processes and particular immunological phenotypes can be constructed. However, processes in tissues, organs, and the organism itself (so-called higher level processes) also control and regulate the molecular (lower level) processes. Reverse systems engineering approaches, which focus on the examination of the structure, dynamics and control of the immune system, can help to understand the construction principles of the immune system. Such integrative mechanistic models can properly describe, explain, and predict the behavior of the immune system in health and disease by combining both higher and lower level processes. Moving from molecular and cellular levels to a multiscale systems understanding requires the development of methodologies that integrate data from different biological levels into multiscale mechanistic models. In particular, 3D imaging techniques and 4D modeling of the spatiotemporal dynamics of immune processes within lymphoid tissues are central for such integrative approaches. Both dynamic and global organ imaging technologies will be instrumental in facilitating comprehensive multiscale systems immunology analyses as discussed in this review.

The foundations of computer assisted surgery

Using navigation systems in general orthopaedic surgery and, in particular, knee replacement is becoming more and more accepted. This paper describes the basic technological concepts of modern computer assisted surgical systems. It explains the variation in currently available systems and outlines research activities that will potentially influence future products. In general, each navigation system is defined by three components: (1) the therapeutic object is the anatomical structure that is operated on using the navigation system, (2) the virtual object represents an image of the therapeutic object, with radiological images or computer generated models potentially being used, and (3) last but not least, the navigator acquires the spatial position and orientation of instruments and anatomy thus providing the necessary data to replay surgical action in real-time on the navigation system's screen.

Three-dimensional imaging methods for quantitative analysis of facial soft tissues and skeletal morphology in patients with orofacial clefts: a systematic review.

BACKGROUND Current guidelines for evaluating cleft palate treatments are mostly based on two-dimensional (2D) evaluation, but three-dimensional (3D) imaging methods to assess treatment outcome are steadily rising. OBJECTIVE To identify 3D imaging methods for quantitative assessment of soft tissue and skeletal morphology in patients with cleft lip and palate. DATA SOURCES Literature was searched using PubMed (1948-2012), EMBASE (1980-2012), Scopus (2004-2012), Web of Science (1945-2012), and the Cochrane Library. The last search was performed September 30, 2012. Reference lists were hand searched for potentially eligible studies. There was no language restriction. STUDY SELECTION We included publications using 3D imaging techniques to assess facial soft tissue or skeletal morphology in patients older than 5 years with a cleft lip with/or without cleft palate. We reviewed studies involving the facial region when at least 10 subjects in the sample size had at least one cleft type. Only primary publications were included. DATA EXTRACTION Independent extraction of data and quality assessments were performed by two observers. RESULTS Five hundred full text publications were retrieved, 144 met the inclusion criteria, with 63 high quality studies. There were differences in study designs, topics studied, patient characteristics, and success measurements; therefore, only a systematic review could be conducted. Main 3D-techniques that are used in cleft lip and palate patients are CT, CBCT, MRI, stereophotogrammetry, and laser surface scanning. These techniques are mainly used for soft tissue analysis, evaluation of bone grafting, and changes in the craniofacial skeleton. Digital dental casts are used to evaluate treatment and changes over time. CONCLUSION Available evidence implies that 3D imaging methods can be used for documentation of CLP patients. No data are available yet showing that 3D methods are more informative than conventional 2D methods. Further research is warranted to elucidate it.

3D documentation and visualization of external injury findings by integration of simple photography in CT/MRI data sets (IprojeCT).

This study evaluated the feasibility of documenting patterned injury using three dimensions and true colour photography without complex 3D surface documentation methods. This method is based on a generated 3D surface model using radiologic slice images (CT) while the colour information is derived from photographs taken with commercially available cameras. The external patterned injuries were documented in 16 cases using digital photography as well as highly precise photogrammetry-supported 3D structured light scanning. The internal findings of these deceased were recorded using CT and MRI. For registration of the internal with the external data, two different types of radiographic markers were used and compared. The 3D surface model generated from CT slice images was linked with the photographs, and thereby digital true-colour 3D models of the patterned injuries could be created (Image projection onto CT/IprojeCT). In addition, these external models were merged with the models of the somatic interior. We demonstrated that 3D documentation and visualization of external injury findings by integration of digital photography in CT/MRI data sets is suitable for the 3D documentation of individual patterned injuries to a body. Nevertheless, this documentation method is not a substitution for photogrammetry and surface scanning, especially when the entire bodily surface is to be recorded in three dimensions including all external findings, and when precise data is required for comparing highly detailed injury features with the injury-inflicting tool.

Long-term clinical outcomes of biodegradable polymer biolimus-eluting stents versus durable polymer sirolimus-eluting stents in patients with coronary artery disease (LEADERS): 4 year follow-up of a randomised non-inferiority trial

Background The effectiveness of durable polymer drug-eluting stents comes at the expense of delayed arterial healing and subsequent late adverse events such as stent thrombosis (ST). We report the 4 year follow-up of an assessment of biodegradable polymer-based drug-eluting stents, which aim to improve safety by avoiding the persistent inflammatory stimulus of durable polymers. Methods We did a multicentre, assessor-masked, non-inferiority trial. Between Nov 27, 2006, and May 18, 2007, patients aged 18 years or older with coronary artery disease were randomly allocated with a computer-generated sequence to receive either biodegradable polymer biolimus-eluting stents (BES) or durable polymer sirolimus-eluting stents (SES; 1:1 ratio). The primary endpoint was a composite of cardiac death, myocardial infarction, or clinically-indicated target vessel revascularisation (TVR); patients were followed-up for 4 years. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00389220. Findings 1707 patients with 2472 lesions were randomly allocated to receive either biodegradable polymer BES (857 patients, 1257 lesions) or durable polymer SES (850 patients, 1215 lesions). At 4 years, biodegradable polymer BES were non-inferior to durable polymer SES for the primary endpoint: 160 (18·7%) patients versus 192 (22·6%) patients (rate ratios [RR] 0·81, 95% CI 0·66–1·00, p for non-inferiority <0·0001, p for superiority=0·050). The RR of definite ST was 0·62 (0·35–1·08, p=0·09), which was largely attributable to a lower risk of very late definite ST between years 1 and 4 in the BES group than in the SES group (RR 0·20, 95% CI 0·06–0·67, p=0·004). Conversely, the RR of definite ST during the first year was 0·99 (0·51–1·95; p=0·98) and the test for interaction between RR of definite ST and time was positive (pinteraction=0·017). We recorded an interaction with time for events associated with ST but not for other events. For primary endpoint events associated with ST, the RR was 0·86 (0·41–1·80) during the first year and 0·17 (0·04–0·78) during subsequent years (pinteraction=0·049). Interpretation Biodegradable polymer BES are non-inferior to durable polymer SES and, by reducing the risk of cardiac events associated with very late ST, might improve long-term clinical outcomes for up to 4 years compared with durable polymer SES. Funding Biosensors Europe SA, Switzerland.

Pirfenidone in patients with idiopathic pulmonary fibrosis (CAPACITY): two randomised trials

Background Idiopathic pulmonary fibrosis is a progressive and fatal lung disease with inevitable loss of lung function. The CAPACITY programme (studies 004 and 006) was designed to confirm the results of a phase 2 study that suggested that pirfenidone, a novel antifibrotic and anti-inflammatory drug, reduces deterioration in lung function in patients with idiopathic pulmonary fibrosis. Methods In two concurrent trials (004 and 006), patients (aged 40–80 years) with idiopathic pulmonary fibrosis were randomly assigned to oral pirfenidone or placebo for a minimum of 72 weeks in 110 centres in Australia, Europe, and North America. In study 004, patients were assigned in a 2:1:2 ratio to pirfenidone 2403 mg/day, pirfenidone 1197 mg/day, or placebo; in study 006, patients were assigned in a 1:1 ratio to pirfenidone 2403 mg/day or placebo. The randomisation code (permuted block design) was computer generated and stratified by region. All study personnel were masked to treatment group assignment until after final database lock. Treatments were administered orally, 801 mg or 399 mg three times a day. The primary endpoint was change in percentage predicted forced vital capacity (FVC) at week 72. Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, numbers NCT00287729 and NCT00287716. Findings In study 004, 174 of 435 patients were assigned to pirfenidone 2403 mg/day, 87 to pirfenidone 1197 mg/day, and 174 to placebo. In study 006, 171 of 344 patients were assigned to pirfenidone 2403 mg/day, and 173 to placebo. All patients in both studies were analysed. In study 004, pirfenidone reduced decline in FVC (p=0·001). Mean FVC change at week 72 was −8·0% (SD 16·5) in the pirfenidone 2403 mg/day group and −12·4% (18·5) in the placebo group (difference 4·4%, 95% CI 0·7 to 9·1); 35 (20%) of 174 versus 60 (35%) of 174 patients, respectively, had a decline of at least 10%. A significant treatment effect was noted at all timepoints from week 24 and in an analysis over all study timepoints (p=0·0007). Mean change in percentage FVC in the pirfenidone 1197 mg/day group was intermediate to that in the pirfenidone 2403 mg/day and placebo groups. In study 006, the difference between groups in FVC change at week 72 was not significant (p=0·501). Mean change in FVC at week 72 was −9·0% (SD 19·6) in the pirfenidone group and −9·6% (19·1) in the placebo group, and the difference between groups in predicted FVC change at week 72 was not significant (0·6%, −3·5 to 4·7); however, a consistent pirfenidone effect was apparent until week 48 (p=0·005) and in an analysis of all study timepoints (p=0·007). Patients in the pirfenidone 2403 mg/day group had higher incidences of nausea (125 [36%] of 345 vs 60 [17%] of 347), dyspepsia (66 [19%] vs 26 [7%]), vomiting (47 [14%] vs 15 [4%]), anorexia (37 [11%] vs 13 [4%]), photosensitivity (42 [12%] vs 6 [2%]), rash (111 [32%] vs 40 [12%]), and dizziness (63 [18%] vs 35 [10%]) than did those in the placebo group. Fewer overall deaths (19 [6%] vs 29 [8%]) and fewer deaths related to idiopathic pulmonary fibrosis (12 [3%] vs 25 [7%]) occurred in the pirfenidone 2403 mg/day groups than in the placebo groups. Interpretation The data show pirfenidone has a favourable benefit risk profile and represents an appropriate treatment option for patients with idiopathic pulmonary fibrosis.

The use of a decremental dose regimen in patients treated with a chronic low-dose step-up protocol for WHO Group II anovulation: a prospective randomized multicentre study

BACKGROUND: In women with chronic anovulation, the choice of the FSH starting dose and the modality of subsequent dose adjustments are critical in controlling the risk of overstimulation. The aim of this prospective randomized study was to assess the efficacy and safety of a decremental FSH dose regimen applied once the leading follicle was 10-13 mm in diameter in women treated for WHO Group II anovulation according to a chronic low-dose (CLD; 75 IU FSH for 14 days with 37.5 IU increment) step-up protocol. METHODS: Two hundred and nine subfertile women were treated with recombinant human FSH (r-hFSH) (Gonal-f) for ovulation induction according to a CLD step-up regimen. When the leading follicle reached a diameter of 10-13 mm, 158 participants were randomized by means of a computer-generated list to receive either the same FSH dose required to achieve the threshold for follicular development (CLD regimen) or half of this FSH dose [sequential (SQ) regimen]. HCG was administered only if not more than three follicles >or=16 mm in diameter were present and/or serum estradiol (E(2)) values were <1200 pg/ml. The primary outcome measure was the number of follicles >or=16 mm in size at the time of hCG administration. RESULTS: Clinical characteristics and ovarian parameters at the time of randomization were similar in the two groups. Both CLD and SQ protocols achieved similar follicular growth as regards the total number of follicles and medium-sized or mature follicles (>/=16 mm: 1.5 +/- 0.9 versus 1.4 +/- 0.7, respectively). Furthermore, serum E(2) levels were equivalent in the two groups at the time of hCG administration (441 +/- 360 versus 425 +/- 480 pg/ml for CLD and SQ protocols, respectively). The rate of mono-follicular development was identical as well as the percentage of patients who ovulated and achieved pregnancy. CONCLUSIONS: The results show that the CLD step-up regimen for FSH administration is efficacious and safe for promoting mono-follicular ovulation in women with WHO Group II anovulation. This study confirms that maintaining the same FSH starting dose for 14 days before increasing the dose in step-up regimen is critical to adequately control the risk of over-response. Strict application of CLD regimen should be recommended in women with WHO Group II anovulation.

Biolimus-eluting stent with biodegradable polymer versus sirolimus-eluting stent with durable polymer for coronary revascularisation (LEADERS): a randomised non-inferiority trial

BACKGROUND: A novel stent platform eluting biolimus, a sirolimus analogue, from a biodegradable polymer showed promising results in preliminary studies. We compared the safety and efficacy of a biolimus-eluting stent (with biodegradable polymer) with a sirolimus-eluting stent (with durable polymer). METHODS: We undertook a multicentre, assessor-blind, non-inferiority study in ten European centres. 1707 patients aged 18 years or older with chronic stable coronary artery disease or acute coronary syndromes were centrally randomised by a computer-generated allocation sequence to treatment with either biolimus-eluting (n=857) or sirolimus-eluting (n=850) stents. The primary endpoint was a composite of cardiac death, myocardial infarction, or clinically-indicated target vessel revascularisation within 9 months. Analysis was by intention to treat. 427 patients were randomly allocated to angiographic follow-up, with in-stent percentage diameter stenosis as principal outcome measure at 9 months. The trial is registered with ClinicalTrials.gov, number NCT00389220. FINDINGS: We analysed all randomised patients. Biolimus-eluting stents were non-inferior to sirolimus-eluting stents for the primary endpoint at 9 months (79 [9%] patients vs 89 [11%], rate ratio 0.88 [95% CI 0.64-1.19], p for non-inferiority=0.003, p for superiority=0.39). Frequency of cardiac death (14 [1.6%] vs 21 [2.5%], p for superiority=0.22), myocardial infarction (49 [5.7%] vs 39 [4.6%], p=0.30), and clinically-indicated target vessel revascularisation (38 [4.4%] vs 47 [5.5%], p=0.29) were similar for both stent types. 168 (79%) patients in the biolimus-eluting group and 167 (78%) in the sirolimus-eluting group had data for angiographic follow-up available. Biolimus-eluting stents were non-inferior to sirolimus-eluting stents in in-stent percentage diameter stenosis (20.9%vs 23.3%, difference -2.2% [95% CI -6.0 to 1.6], p for non-inferiority=0.001, p for superiority=0.26). INTERPRETATION: Our results suggest that a stent eluting biolimus from a biodegradable polymer represents a safe and effective alternative to a stent eluting sirolimus from a durable polymer in patients with chronic stable coronary artery disease or acute coronary syndromes. FUNDING: Biosensors Europe SA, Switzerland.

Promotion of health in older people: a randomised controlled trial of health risk appraisal in British general practice

BACKGROUND: there is inadequate evidence to support currently formulated NHS strategies to achieve health promotion and preventative care in older people through broad-based screening and assessment in primary care. The most extensively evaluated delivery instrument for this purpose is Health Risk Appraisal (HRA). This article describes a trial using HRA to evaluate the effect on health behaviour and preventative-care uptake in older people in NHS primary care. METHODS: a randomised controlled trial was undertaken in three London primary care group practices. Functionally independent community-dwelling patients older than 65 years (n = 2,503) received a self-administered Health Risk Appraisal for Older Persons (HRA-O) questionnaire leading to computer-generated individualised written feedback to participants and general practitioners (GPs), integrated into practice information-technology (IT) systems. All primary care staff received training in preventative health in older people. The main outcome measures were self-reported health behaviour and preventative care uptake at 1-year follow-up. RESULTS: of 2,503 individuals randomised, 2,006 respondents (80.1%) (intervention, n = 940, control n = 1,066) were available for analysis. Intervention group respondents reported slightly higher pneumococcal vaccination uptake and equivocal improvement in physical activity levels compared with controls. No significant differences were observed for any other categories of health behaviour or preventative care measures at 1-year follow-up. CONCLUSIONS: HRA-O implemented in this way resulted in minimal improvement of health behaviour or uptake of preventative care measures in older people. Supplementary reinforcement involving contact by health professionals with patients over and above routine clinical encounters may be a prerequisite to the effectiveness of IT-based delivery systems for health promotion in older people.

Strabismus and employment: the opinion of headhunters

Abstract. Purpose: The aim of this study was to determine the influence of strabismus on an individual's ability to find employment based on the opinion of Swiss headhunters. Methods: Forty Swiss headhunters retrieved from a Swiss online telephone directory were interviewed using a validated questionnaire in order to determine if strabismus would have an impact on a person's ability to find employment. Photographs of a strabismic man and woman as well as of other computer-generated facial anomalies could be downloaded from the Internet during the interview. Results: 72.5% of headhunters judged that strabismic individuals would have more difficulties in finding a job than orthotropic persons. These difficulties were judged to be stronger in women than in men (P = 0.006), and in exotropic compared to esotropic persons (P = 0.01). Asked about seven facial anomalies, exotropia was found to have the third and esotropia the fourth (women) or fifth (men) most strongly negative impact on finding employment, after having strong acne and a visible missing tooth. Headhunters judged that persons with strabismus are significantly perceived as less attractive and less intelligent by potential employers. Conclusion: Visible strabismus negatively influences individuals' ability to find a job and therefore has an impact on their economic status. Successful strabismus surgery realigns the visual axes, producing a normal facial appearance and therefore eliminating the negative impact of strabismus on employability.

Opinions of dating agents about strabismic subjects' ability to find a partner

AIMS: To determine the influence of strabismus on the ability to find a partner. METHODS: We interviewed Swiss dating agents retrieved from two Swiss online telephone directories using a validated questionnaire to determine whether strabismus has any impact on the ability to find a partner. During the interviews, subjects with internet access could view downloadable, digitally altered photographs of a strabismic man and women, as well as images of other computer-generated facial anomalies. RESULTS: Of the 40 dating agents, 92.5% judged that strabismic subjects have more difficulty finding a partner (p<0.001). Such difficulty was not associated with either gender or age but was perceived as being greater in exotropic than in esotropic persons (p<0.001). Among the seven facial disfigurements, strabismus was believed to have the third largest negative impact on finding a partner, after strong acne and a visible missing tooth. Dating agents also believed that potential partners perceive persons with strabismus as significantly less attractive (p<0.001), erotic (p<0.001), likeable (p<0.001), interesting (p<0.001), successful (p<0.001), intelligent (p = 0.001) and sporty (p = 0.01). CONCLUSIONS: Visible strabismus negatively influences the ability to find a partner. Because strabismus surgery in adults restores a normal functioning condition and reduces not only physical but also psychosocial difficulties, it cannot be considered a cosmetic procedure.

Cyberball: The impact of ostracism on the well-being of early adolescents

We examined the effects of ostracism in early adolescent populations using the cyberball paradigm (Williams, Cheung, & Choi, 2000). Ninety-one Swiss school students, aged 10–14 years, were randomly assigned to the ostracism (24 girls, 23 boys) or the inclusion (23 girls, 21 boys) condition and were led to believe that they were playing cyberball with two other same-sex students. In reality, they were computer-generated confederates. We assessed self-reported levels of mood before and after playing the game as well as sense of belonging, self-esteem, meaningful existence, and control after the game. Compared to nonostracized students, adolescents in the ostracism condition reported significantly lower levels of positive mood after playing the game. Furthermore, they reported a lower sense of belonging and lower levels of self-esteem, meaningful existence, and control. The present results from a non-English-speaking sample correspond well to the few earlier findings in adolescent and adult populations by suggesting that even brief periods of ostracism with unknown others can lead to a significant decrease in well-being in these age groups.