PNist: interactive volumetric measurements of plexiform neurofibromas in MRI scans

Purpose

Volumetric measurements of plexiform neurofibromas (PNs) are time consuming and error prone, as they require the delineation of the PN boundaries, which is mostly impractical in the daily clinical setup. Accurate volumetric measurements are seldom performed for these tumors mainly due to their great dispersion, size and multiple locations. This paper presents a semiautomatic method for segmentation of PN from STIR MRI scans.

Methods

Plexiform neurofibroma interactive segmentation tool (PNist) is a new tool to segment PNs in STIR MRI scans. The method is based on histogram tumor models computed from a training set.

Results

Experimental results from 28 datasets show an average absolute volume difference of 6.8 % with an average user time of approximately 7 min versus more than 13 min with manual delineation. In complex cases, the PNist user time is less than half in compared to state-of-the-art tools.

Conclusions

PNist is a new method for the semiautomatic segmentation of PN lesions. Its simplicity and reliability make it unique among other state-of-the-art methods. It has the potential to become a clinical tool that allows the reliable evaluation of PN burden and progression.     

CEUS in the study of bladder,method, administration and evaluation,a technical note

Purpose

Contrast-enhanced ultrasound (CEUS) is the application of ultrasound contrast agents (UCAs) to traditional medical sonography. The development of UCAs allowed to overcome some of the limitations of conventional B-mode and Doppler ultrasound techniques and enabled the display of the parenchymal microvasculature. Purpose of this paper is to delineate the elements of a solid and science-based technique in the execution of urinary bladder CEUS.

Methods

We describe the technical execution of urinary bladder CEUS and the use of perfusion softwares to perform contrast enhancement quantitative analysis with generation of time–intensity curves from regions of interest.

Results

During CEUS, normal bladder wall shows a wash-in time of 13 s, a time to peak (TTP) >40 s, a signal intensity (SI) <45 % and a wash-out time >80 s; Low-grade urothelial cell carcinoma (UCC) shows a wash-in time of 13 s, a time to peak TTP >28 s, a SI <45 % and a wash-out time of 40 s; High-grade UCC shows a wash-in time of 13 s, a TTP >28 s, a SI >50 % and a wash-out time of 58 s.

Conclusions

CEUS is a useful tool for an accurate characterization of bladder UCC although it has some drawbacks. To avoid misunderstandings, a widely accepted classification and a standardized terminology about the most significant parameters of this application should be adopted in the immediate future.     

Changes in leisure-time physical activity and subsequent sickness absence: A prospective cohort study among middle-aged employees

ObjectiveThe aim of this study was to examine how changes over time in leisure-time physical activity are associated with subsequent sickness absence.MethodsHelsinki Health Study cohort baseline questionnaire survey data were collected in 2000–2002 among 40–60-year-old employees of the City of Helsinki, Finland. A follow-up survey was conducted in 2007. 4182 (83% women) respondents were available for the analyses. Leisure-time physical activity was asked using identical questions in both surveys. Sickness absence data were derived from the employer's registers (mean follow-up time 2.8 years). Associations of changes over time in leisure-time physical activity with self-certified (≤ 3 days) and medically certified (> 3 days) sickness absence spells were examined, using Poisson regression analysis.ResultsInactive women and men who increased their physical activity to vigorously active had a significantly lower risk of both self-certified (RR = 0.80, 95% CI 0.65–0.97) and medically certified (RR = 0.63, 95% CI 0.49–0.83) subsequent sickness absence spells compared with the persistently inactive. The persistently active with vigorous intensity had the lowest risk of sickness absence. Adjusting for changes in physical health functioning attenuated but did not abolish the lowered risk found.ConclusionsFor reducing sickness absence more emphasis should be given to the potential contribution of vigorous physical activity.     

The effect of age and clinical circumstances on the outcome of red blood cell transfusion in critically ill patients

Introduction

Whether red blood cell (RBC) transfusion is beneficial remains controversial. In both retrospective and prospective evaluations, transfusion has been associated with adverse, neutral, or protective effects. These varying results likely stem from a complex interplay between transfusion, patient characteristics, and clinical context. The objective was to test whether age, comorbidities, and clinical context modulate the effect of transfusion on survival.

Methods

By using the multiparameter intelligent monitoring in intensive care II database (v. 2.6), a retrospective analysis of 9,809 critically ill patients, we evaluated the effect of RBC transfusion on 30-day and 1-year mortality. Propensity score modeling and logistic regression adjusted for known confounding and assessed the independent effect of transfusion on 30-day and 1-year mortality. Sensitivity analysis was performed by using 3,164 transfused and non-transfused pairs, matched according the previously validated propensity model for RBC transfusion.

Results

RBC transfusion did not affect 30-day or 1-year mortality in the overall cohort. Patients younger than 55 years had increased odds of mortality (OR, 1.71; P < 0.01) with transfusion. Patients older than 75 years had lower odds of 30-day and 1-year mortality (OR, 0.70; P < 0.01) with transfusion. Transfusion was associated with worse outcome among patients undergoing cardiac surgery (OR, 2.1; P < 0.01). The propensity-matched population corroborated findings identified by regression adjustment.

Conclusion

A complex relation exists between RBC transfusion and clinical outcome. Our results show that transfusion is associated with improved outcomes in some cohorts and worse outcome in others, depending on comorbidities and patient characteristics. As such, future investigations and clinical decisions evaluating the value of transfusion should account for variations in baseline characteristics and clinical context.

     

Automated patient-ventilator interaction analysis during neurally adjusted non-invasive ventilation and pressure support ventilation in chronic obstructive pulmonary disease

Introduction

Delivering synchronous assist during non-invasive ventilation (NIV) is challenging with flow- or pressure-controlled ventilators, especially in patients with chronic obstructive pulmonary disease (COPD). Neurally adjusted ventilatory assist (NAVA) uses diaphragm electrical activity (EAdi) to control the ventilator. We evaluated patient-ventilator interaction in patients with COPD during NIV with pressure support ventilation (PSV) and NAVA using a recently introduced automated analysis.

Methods

Twelve COPD patients underwent three 30-minute trials: 1) PSV with dedicated NIV ventilator (NIV-PSV_Vision), 2) PSV with intensive care unit (ICU) ventilator (NIV-PSV_Servo-I), and 3) with NIV-NAVA. EAdi, flow, and airway pressure were recorded. Patient-ventilator interaction was evaluated by comparing airway pressure and EAdi waveforms with automated computer algorithms. The NeuroSync index was calculated as the percentage of timing errors between airway pressure and EAdi.

Results

The NeuroSync index was higher (larger error) for NIV-PSV_Vision (24 (IQR 15 to 30) %) and NIV-PSV_Servo-I (21 (IQR 15 to 26) %) compared to NIV-NAVA (5 (IQR 4 to 7) %; P <0.001). Wasted efforts, trigger delays and cycling-off errors were less with NAVA (P <0.05 for all). The NeuroSync index and the number of wasted efforts were strongly correlated (r² = 0.84), with a drastic increase in wasted efforts after timing errors reach 20%.

Conclusions

In COPD patients, non-invasive NAVA improves patient-ventilator interaction compared to PSV, delivered either by a dedicated or ICU ventilator. The automated analysis of patient-ventilator interaction allowed for an objective detection of patient-ventilator interaction during NIV. In addition, we found that progressive mismatch between neural effort and pneumatic timing is associated with wasted efforts.     

New perspective in the treatment of low rectal cancer: Total rectal resection and coloendoanal anastomosis

PURPOSE: Presently abdominoperineal resection still remains the most diffuse modality of treatment of low rectal cancer. However, a new surgical approach is now available to avoid such a demolitive surgery and a definitive colostomy. METHODS: From March 1990 to March 1993, 58 total rectal resections were performed in 55 patients affected with primary or recurring cancers of the low rectum. As a restorative procedure, a colic J-shaped pouch and a handsewn pouch-endoanal anastomosis was adopted. All of the primary lesions were within 7 cm of the anal verge; in 74 percent the distal tumor margin was located less than 6 cm from the cutaneous edge. RESULTS: Histologic clearance of the rectum cut edge was documented in all cases. Seven patients relapsed locally from 7 to 14 months after surgery and in 3 more cases distant metastases were documented. Postoperative morbidity is low. After colostomy closure in 78 percent of patients, perfect continence was achieved and in 74 percent less than two bowel movements a day were recorded. Fifty patients are presently alive, 46 without evidence of disease. The follow-up ranged from 2 to 37 (median, 13) months. CONCLUSION: This experience, along with data obtained from last year's literature, indicates that a conservative surgical procedure, such as total rectal resection and coloendoanal anastomosis, can be considered a feasible and radical option for treatment of low rectal cancer.     

Role of Beta-Blocker Therapy in Heart Failure and Atrial Fibrillation

Heart failure is a serious disorder associated with substantial morbidity and mortality. Approximately 15-30% patients with systolic heart failure are in atrial fibrillation and the proportion increases with severity of heart failure. Patients with heart failure and atrial fibrillation have worse outcome than those in sinus rhythm. Beta-blockers, together with angiotensin-converting enzymes inhibitors, are the standard therapy in patients with chronic heart failure. Retrospective studies have suggested that despite the improvement in left ventricular systolic function after treatment with beta-blockers, the exercise capacity and symptoms in those heart failure patients with atrial fibrillation was not improved as much as those in sinus rhythm. Moreover, the use of bisoprolol in the Cardiac Insufficiency Bisoprolol Study II, unlike those in sinus rhythm, failed to produce any survival benefit in patients with poor systolic function and atrial fibrillation. It seems that those patients with heart failure and atrial fibrillation may have different response to beta-blocker therapy. Prospective trials to clarify the impact of beta-blocker therapy and the optimal therapeutic strategy in this high-risk group of patients are warranted.