Treatment of spinal cord injuries in the thoracolumbar region

Forty patients with spinal cord injuries in the thoracolumbar region were studied. Clinical and experimental data support the conservative approach. In some patients acute stabilisation is needed and in a few patients operative decompression may be considered. Promising experimental non-invasive techniques to improve recovery are presented, but there are no convincing clinical results so far. The authors believe that regeneration will be the key area for future research.     

Mesure instantanée, aisée et non invasive de la pression artérielle, de la fréquence cardiaque et du débit cardiaque: application en kinésithérapie

The continuous and non-invasive measurement of the main hemodynamic parameters including heart rate, blood pressure, and stroke volume allows evaluating the hemodynamic changes occurring either during one workout in order to look for beneficial or deleterious hemodynamic effects, or after several sessions (longitudinal approach) to measure the effects of one specific training or treatment. These non-invasive devices do not provide more information than the invasive ones; however, they are easier to implement and may be used in ??intermediate?? and less monitored patients. They contribute not only to enhance knowledge in the field of physiology by quantifying the responses that accompany physiotherapy exercises but also to compare different management strategies, thus improving patient??s care.     

Non-invasive estimation of shunt and ventilation-perfusion mismatch

OBJECTIVE: To investigate whether parameters describing pulmonary gas exchange (shunt and ventilation-perfusion mismatch) can be estimated consistently by the use of non-invasive data as input to a mathematical model of oxygen transport. DESIGN: Prospective study. SETTING: Investigations were carried out in the post-anaesthesia care unit, coronary care unit, and intensive care unit. PATIENTS: Data from ninety-five patients and six normal subjects were included for the comparison. The clinical situations differed, ranging from healthy subjects to patients with acute respiratory failure in the intensive care unit. MEASUREMENTS: The experimental procedure involved changing the inspired oxygen fraction (F(I)O(2)) in 4-6 steps in order to obtain arterial oxygen saturations (S(a)O(2)) in the range from 90-100%. This procedure allows plotting a F(I)O(2)/S(a)O(2) or F(E)O(2)/S(a)O(2) curve, the shape and position of which was quantified using the mathematical model estimating pulmonary shunt and a measure of ventilation-perfusion mismatch (DeltaPO(2)). This procedure was performed using either arterial blood samples at each F(I)O(2) level (invasive approach) or using values from the pulse oximeter (non-invasive approach). MAIN RESULTS: The model provided good fit to data using both the invasive and non-invasive experimental approach. The parameter estimates were linearly correlated with highly significant correlation coefficients; shunt(invasive) vs shunt(non-invasive), r(2) = 0.74, P <0.01, and DeltaPO(2)(invasive) vs DeltaPO(2)(non-invasive), r(2) = 0.97, P <0.001. CONCLUSIONS: Pulmonary gas exchange can be described equally well using non-invasive data. The simplicity of the non-invasive approach makes the method suitable for large-scale clinical use.     

CT for intracardiac thrombi and tumors

Although cardiac tumors are rare, they nevertheless represent an important subgroup, the diagnosis of which is challenging for the primary care physician. Symptoms are not characteristic and serious complications including stroke, myocardial infarction and even sudden death from arrhythmia may be the first signs of tumor. The most common primary cardiac neoplasm is the benign myxoma and the most frequent primary malignant lesion is sarcoma. Cardiac metastases from distant primary carcinomas are now frequently encountered. Echocardiography until the past decade was the only consistently reliable and available non-invasive diagnostic tool. New non-invasive CT and MRI exams are changing the diagnostic approach. Echocardiography and angiocardiography with or without coronary arteriography remain routine methods for evaluating cardiac neoplasms. However, CT provides additional diagnostic information and is regarded as essential for adequate staging and treatment planning, particularly when surgical resection is being considered. This chapter reviews the wide spectrum of intracardiac thrombi and tumors including their incidence and imaging characteristics with particular reference to the CT findings and differential diagnosis.     

Depth-resolved imaging and detection of micro-retroreflectors within biological tissue using Optical Coherence Tomography

A new approach to in vivo biosensor design is introduced, based on the use of an implantable micron-sized retroreflector-based platform and non-invasive imaging of its surface reflectivity by Optical Coherence Tomography (OCT). The possibility of using OCT for the depth-resolved imaging and detection of micro-retroreflectors in highly turbid media, including tissue, is demonstrated. The maximum imaging depth for the detection of the micro-retroreflector-based platform within the surrounding media was found to be 0.91 mm for porcine tissue and 1.65 mm for whole milk. With further development, it may be possible to utilize OCT and micro-retroreflectors as a tool for continuous monitoring of analytes in the subcutaneous tissue.     

On the imperfect synchrony between patient and ventilator

Because patient-ventilator asynchrony (PVA) is recognized as a major clinical problem for patients undergoing ventilatory assistance, automatic methods of PVA detection have been proposed in recent years. A novel approach is airflow spectral analysis, which, when related to visual inspection of airway pressure and flow waveforms, has been shown to reach a sensitivity and specificity of greater than 80% in detecting an asynchrony index of greater than 10%. The availability of automatic non-invasive methods of PVA detection at the bedside would likely be of benefit in intensive care unit practice, but they may be limited by shortcomings, so clear proof of their effectiveness is needed.     

A Trimodal Ultrasound,Photoacoustic and Magnetic Resonance Imaging Approach for Longitudinal Post-operative Monitoring of Stem Cells in the Spinal Cord

Longitudinal monitoring of stem cells in the spinal cord could unveil critical information needed to understand regenerative processes, thereby expediting therapy development and translation. We introduce a post-operative trimodal imaging approach to monitor stem cells in the spinal cord over time. A key aspect of the approach is to label the stem cells with Prussian blue nanocubes (PBNCs), which simultaneously possess optical and magnetic properties for ultrasound-guided photoacoustic (US/PA) and magnetic resonance imaging (MRI) contrast. PBNC-Labeled stem cells were injected into the spinal cord of immunodeficient rats and tracked with US/PA imaging and MRI up to 14 d post-injection. Good agreement was observed between imaging modalities in vivo. Our results suggest that further development of the US/PA/MR imaging approach may create a powerful tool to aid development of regenerative therapies of the spinal cord, and the non-invasive imaging approach can ultimately be deployed in intra- and post-operative environments.     

非侵袭性霉菌性蝶窦炎的临床特征

【目的】探讨非侵性霉菌性蝶窦炎患者的临床表现，诊断及治疗方法。【方法】总结13例非侵袭性霉菌性蝶窦炎患者的临床资料，分析其临床表现、CT资料及在鼻内镜下的手术方法与效果。【结果】13例患者均取得较好疗效，随访半年至一年半，治愈11例；好转2例。【结论】对不明原因的回吸性血涕或头痛要考虑非侵袭性蝶窦炎的可能；鼻窦CT可做出初步诊断；鼻内镜下蝶窦开放术是最佳手术方法。     

A New Method for Measuring the Speed of Sound in Rat Liver ex Vivo Using an Ultrasound System: Correlation of Sound Speed with Fat Deposition

The speed of sound correlates well with the fat content of the liver. Therefore, non-invasive quantification of sound speed in the liver might be of diagnostic value. Here we describe a new non-invasive method that would be clinically applicable for measurement of sound speed in the liver. Sprague–Dawley rats were divided into two groups: a control group and a fatty liver group prepared by keeping the rats on a choline-deficient diet for 6 wk. The livers were subjected to pathologic and biochemical analysis; the speed of sound through the liver tissue was measured using our proposed method and a pulser–receiver as standard. Our results indicated that use of the proposed method makes it feasible to diagnose fatty liver with good accuracy on the basis of sound speed. This approach would have considerable potential for non-invasive diagnosis of fatty liver and would be a valuable adjunct to conventional liver diagnostic procedures.     

非侵袭性真菌性鼻窦炎18例临床分析

目的:探讨非侵袭性真菌性鼻窦炎的诊断、手术方式。方法:回顾近12年我院18例真菌性鼻窦炎患者的临床资料。结果:CT对本病有较高的诊断价值。上颌窦根治手术能彻底切除上颌窦内的真菌病变,但对鼻窦窦口复合体的病变切除不够,影响窦口的通畅引流。鼻内窥镜手术能切除鼻窦窦口复合体的病变,充分开放窦口,但对上颌窦内的真菌病变清除不够。结论:上颌窦根治手术联合鼻内窥镜手术,能充分切除病变,对窦口能通畅引流。     

Modeling diffuse reflectance from homogeneous semi-infinite turbid media for biological tissue applications: a Monte Carlo study

Diffuse reflectance spectroscopy is one of the simplest and widely used techniques for the non-invasive study of biological tissues but no exact analytical solution exists for the problem of diffuse reflectance from turbid media such as biological tissues. In this work, a general treatment of the problem of diffuse reflectance from a homogeneous semi-infinite turbid medium is presented using Monte Carlo simulations. Based on the results of the Monte Carlo method, simple semi-empirical analytical solutions are developed valid for a wide range of collection geometries corresponding to various optical detector diameters. This approach may be useful for the quick and accurate modeling of diffuse reflectance from tissues.     

Clinical improvement and shrinkage of uterine fibroids after thermal ablation by magnetic resonance-guided focused ultrasound surgery.

OBJECTIVE: Hysterectomy or myomectomy are the accepted treatments for symptomatic uterine fibroids. Heat ablation of uterine fibroids has been shown to be an effective alternative treatment. The aim of this study was to determine the clinical efficacy of non-invasive thermal ablation by transcutaneous magnetic resonance-guided high-intensity focused ultrasound (MRgFUS) for the treatment of symptomatic uterine fibroids. METHODS: In this prospective study, MRgFUS ablation of uterine fibroids was performed in 35 symptomatic women scheduled for hysterectomy. Clinical symptoms, patient satisfaction and uterine size were determined at 1 month and 6 months after the procedure. RESULTS: This outpatient procedure was very well tolerated by all women. Sixty-nine percent (24/35) of the treated patients reported either significant or partial improvement in symptoms. Treated fibroids decreased in volume by 12% and 15% at 1 and 6 months, respectively. Minor transient side-effects were observed in two women. Six women underwent hysterectomy during the follow-up period. CONCLUSION: This study demonstrates the clinical efficacy of MRgFUS ablation of uterine fibroids. This novel, non-invasive surgical approach may offer an alternative therapy for women with uterine fibroids.     

Cardiac Positron Emission Tomography: a Clinical Perspective

Cardiac positron emission tomography is a powerful, quantitative, non-invasive imaging modality, which adds valuable diagnostic and prognostic information to the clinical work-up. Myocardial perfusion and viability imaging are, as a result of continuously growing evidence, established clinical indications that may be cost-effective, due to the high diagnostic accuracy of cardiac positron emission tomography, despite high single-test costs. In the field of inflammation imaging, new indications are entering the clinical arena, which may contribute to a better diagnosis and overall patient care, as for instance in patients with cardiac sarcoidosis, prosthetic valve endocarditis and cardiac device infections. This review will discuss the individual strengths and weaknesses of cardiac positron emission tomography and, hence, the resulting clinical usefulness based on the current evidence for an individualized, patient-centered imaging approach.     

非侵袭性鼻窦曲菌病45例临床分析

目的探讨非侵袭性鼻窦曲菌病的病因、诊断及治疗方法,提高首诊准确率。方法回顾性分析本科2001—2008年采用鼻内窥镜手术治疗的非侵袭性鼻窦曲菌病45例患者。结果45例临床症状均消失,鼻内窥镜检查见窦口开放良好,无脓性分泌物,术腔均已上皮化。随访6个月～2年,无一例复发。结论非侵袭性鼻窦曲菌病症状无特异性,CT或MRI检查能提高术前诊断率,内镜鼻窦手术是治疗的首选术式。     

Measurement of muscle activity with magnetic resonance elastography

OBJECTIVE: To non-invasively determine muscle activity. DESIGN: A correlation analysis study. BACKGROUND: Electromyography is traditionally used to measure the electrical activity of a muscle and can be used to estimate muscle contraction intensity. This approach, however, is limited not only in terms of the volume of tissue that can be monitored, but must be invasive if deep lying muscles are studied. We wished to avoid these limitations and used magnetic resonance elastography in an attempt to non-invasively determine muscle activity. This novel approach uses a conventional MRI system. However, in addition to the imaging gradients, an oscillating, motion sensitizing field gradient is applied to detect mechanical waves that have been generated within the tissue. The wavelength correlates with the stiffness of the muscle and hence with the activity of the muscle. METHODS: Six volunteers (mean age: 30.1 years, range: 27-36 years) without orthopedic or neuromuscular abnormalities, lay supine with their legs within the coil of a MRI scanner. The wavelengths of mechanically generated shear waves in the tibialis anterior, medial and lateral head of the gastrocnemius and the soleus were measured as the subjects resisted ankle plantar-flexing (8.2 and 16.4 nm) and dorsi-flexing (20.2 and 40.4 nm) moments. The findings were then compared to EMG data collected under the same loading conditions. RESULTS: Magnetic resonance elastography wavelengths were linearly correlated to the muscular activity as defined by electromyography. (TA, R(2)=0.89, P=0.02; MG, R(2)=0.82, P=0.05; LG, R(2)=0.88, P=0.03; S, R(2)=0.90, P=0.02) CONCLUSIONS: Magnetic resonance elastography may be a promising tool for the non-invasive determination of muscle activity. RELEVANCE: Magnetic resonance elastography has potential as the basis for a new non-invasive approach to study in vivo muscle function.     

Do the Finapres and Colin radial artery tonometer measure the same blood pressure changes following deflation of thigh cuffs?

The objective of this work was to determine if systematic differences exist between blood pressure time series measured by two non-invasive techniques. Cerebral blood flow autoregulation is often measured while a change in blood pressure is induced by deflation of thigh cuffs. To interpret the result a continuous measurement of arterial blood pressure is required. The Finapres is a non-invasive blood pressure monitor that is often used when assessing autoregulation but there is uncertainty about its reliability. A more recent device, the Colin tonometer, uses radial artery tonometry, which may prove to be a more reliable non-invasive method of obtaining a blood pressure waveform. Twenty healthy volunteers were recruited; blood pressure trends following cuff deflation were measured simultaneously with a Finapres and a Colin tonometer. A significant difference was found between the blood pressure waveforms measured with the two devices. The most striking difference was a slower recovery time measured with the Finapres (Wilcoxon signed rank test P < 0.001). Peripheral vasoaction may be distorting the measurement of blood pressure by the Finapres. This would account for the difference that exists between the techniques. Comparison with a direct arterial line would confirm which non-invasive measurement is more accurate.     

The quest for non-invasive delivery of bioactive macromolecules: a focus on heparins.

The development of a non-invasive drug delivery system for unfractionated heparin (UFH) and low molecular weight heparins (LMWHs) has been the elusive goal of several research groups since the initial discovery of this glycosaminogylcan by McLean in 1916. After a brief update on current parenteral formulations of UFH and LMWHs, this review revisits past and current strategies intended to identify alternative routes of administration (e.g. oral, sublingual, rectal, nasal, pulmonary and transdermal). The following strategies have been used to improve the bioavailability of this bioactive macromolecule by various routes: (i) enhancement in cell-membrane permeabilization, (ii) modification of the tight-junctions, (iii) increase in lipophilicity and (iv) protection against acidic pH of the stomach. Regardless of the route of administration, a simplified unifying principle for successful non-invasive macromolecular drug delivery may be: "to reversibly overcome the biological, biophysical and biochemical barriers and to safely and efficiently improve the in vivo spatial and temporal control of the drug in order to achieve a clinically acceptable therapeutic advantage". Future macromolecular drug delivery research should embrace a more systemic approach taking into account recent advances in genomics/proteomics and nanotechnology.     

Radiographic and non-invasive determination of the hip joint center location: effect on hip joint moments

OBJECTIVE: To determine which of four non-invasive measures is most accurate in locating the hip joint center. BACKGROUND: The location of the joint centers must be accurately determined in three dimensions for calculation of the moments of force during gait. It is not known which of the several non-invasive methods available for location of the hip center is most accurate. DESIGN: Hip center location was determined using standardized X-rays and four non-invasive methods which utilized measured distances between bony landmarks in 10 healthy subjects. Hip moments during gait were obtained from optical tracking, force plate and anthropometric data. RESULTS: The most accurate non-invasive method of locating the hip center was by taking the midpoint of a line connecting the antero-superior iliac spine and the symphysis pubis and moving inferiorly 2 cm. Using this approach the hip center was located 0.7 cm medial and 0.8 cm superior to its true location determined using the standardized X-rays. The 95% confidence interval of the maximum error difference in moments measured between this method and the standardized X-rays ranged from -0.15 to 0.4 Nm/kg in the frontal plane, -0.03 to 0.07 Nm/kg in the sagittal plane and -0.05 to -0.03 Nm/kg in the transverse plane. CONCLUSIONS: Locating the hip center based on the distance between the antero-superior iliac spine and the symphysis pubis is a valid technique for estimating the hip center in routine gait analysis.     

Active cycle of breathing techniques in non-invasive ventilation for acute hypercapnic respiratory failure

We hypothesised that applying the active cycle of breathing techniques (ACBT) in patients with acute hypercapnic respiratory failure undergoing non-invasive ventilation would improve patient outcome. Thirty-four patients were randomised so that 17 patients with acute hypercapnic respiratory failure received the ACBT and non-invasive ventilation (ACBT group), and 17 patients received non-invasive ventilation alone (control group). The primary outcome measure was length of time requiring non-invasive ventilation, and secondary outcome measures were change in acute physiology score, change in arterial blood gas values, total duration of non-invasive ventilation, and length of stay in the intensive care unit. Although not significant, there was a greater decrease in arterial carbon dioxide pressure in the ACBT group compared to the control group (-21.41 mmHg vs -17.45 mmHg, p = 0.27). Total duration of ventilation tended to be shorter in the ACBT group than in the control group (64.9 hours vs 84.1 hours, p = 0.15). Length of time in need of non-invasive ventilation was significantly lower in the ACBT group than in the control group (5.0 days vs 6.7 days, p = 0.03). There was no significant difference in length of stay in the intensive care unit between the two groups (8.0 vs 9.4 days, p = 0.31). The use of ACBT may have positive effects in the treatment of patients with acute hypercapnic respiratory failure, resulting in a shorter length of time requiring non-invasive ventilation.     

Dynamic imaging of ictal oscillations using non-invasive high-resolution EEG

Scalp electroencephalography (EEG) has been established as a major component of the pre-surgical evaluation for epilepsy surgery. However, its ability to localize seizure onset zones (SOZ) has been significantly restricted by its low spatial resolution and indirect correlation with underlying brain activities. Here we report a novel non-invasive dynamic seizure imaging (DSI) approach based upon high-density EEG recordings. This novel approach was particularly designed to image the dynamic changes of ictal rhythmic discharges that evolve through time, space and frequency. This method was evaluated in a group of 8 epilepsy patients and results were rigorously validated using intracranial EEG (iEEG) (n=3) and surgical outcome (n=7). The DSI localized the ictal activity in concordance with surgically resected zones and ictal iEEG recordings in the cohort of patients. The present promising results support the ability to precisely and accurately image dynamic seizure activity from non-invasive measurements. The successful establishment of such a non-invasive seizure imaging modality for surgical evaluation will have a significant impact in the management of medically intractable epilepsy.