Measuring threshold and latency of motion perception on a swinging bed

Introduction Our objective was to develop and to evaluate a system to measure latency and threshold of pendular motion perception based on a swinging bed. Materials and methods This prospective study included 30 healthy adults (age: 32 ± 12 years). All subjects were tested twice with a 10 min. interval. A second trial was conducted 2 to 15 days after. A rehabilitation swinging bed was connected to an electronic device emitting a beep at the beginning of each oscillation phase with an adjustable time lag. Subjects were blindfolded and auditory cues other than the beep were minimized. The acceleration threshold was measured by letting the bed oscillate freely until a natural break and asking the patient when he did not perceive any motion. The perception latency was determined by asking the patient to indicate whether the beep and the peak of each oscillation were synchronous. The time lag between sound and peak of the head position was swept from -750 to +750 ms by 50 ms increments. Results The mean acceleration threshold was 9.2±4.60 cm/s2. The range width of the synchronous perception interval was estimated as 535±190 ms. The point of subjective synchronicity defined as the center of this interval was -195±106 ms (n = 30). The test-retest evaluation in the same trial showed an acceptable reproducibility for the acceleration threshold and good to excellent for all parameters related to sound-movement latency. Conclusion Swinging bed combined to sound stimulation can provide reproducible information on movement perception in a simple and non-invasive manner with highly reproducible results.

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CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

European Radiology ◽

10.1007/s00330-021-07692-5 ◽

2021 ◽

Author(s):

Patrick Veit-Haibach ◽

Martin W. Huellner ◽

Martin Banyai ◽

Sebastian Mafeld ◽

Johannes Heverhagen ◽

...

Keyword(s):

Peripheral Arterial Disease ◽

Ct Perfusion ◽

Arterial Disease ◽

Lower Leg ◽

Therapy Control ◽

Non Invasive ◽

Before And After ◽

Invasive Method ◽

The Mean ◽

Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

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Non-Invasive Molecular Survey of Sarcoptic Mange in Wildlife: Diagnostic Performance in Wolf Faecal Samples Evaluated by Multi-Event Capture–Recapture Models

Pathogens ◽

10.3390/pathogens10020243 ◽

2021 ◽

Vol 10 (2) ◽

pp. 243

Author(s):

Julieta Rousseau ◽

Mónia Nakamura ◽

Helena Rio-Maior ◽

Francisco Álvares ◽

Rémi Choquet ◽

...

Keyword(s):

Molecular Detection ◽

High Specificity ◽

Sarcoptes Scabiei ◽

Sarcoptic Mange ◽

Diagnostic Specificity ◽

Non Invasive ◽

Faecal Samples ◽

Capture Recapture ◽

The Mean ◽

Event Capture

Sarcoptic mange is globally enzootic, and non-invasive methods with high diagnostic specificity for its surveillance in wildlife are lacking. We describe the molecular detection of Sarcoptes scabiei in non-invasively collected faecal samples, targeting the 16S rDNA gene. We applied this method to 843 Iberian wolf Canis lupus signatus faecal samples collected in north-western Portugal (2006–2018). We further integrated this with serological data (61 samples from wolf and 20 from red fox Vulpes vulpes, 1997–2019) in multi-event capture–recapture models. The mean predicted prevalence by the molecular analysis of wolf faecal samples from 2006–2018 was 7.2% (CI95 5.0–9.4%; range: 2.6–11.7%), highest in 2009. The mean predicted seroprevalence in wolves was 24.5% (CI95 18.5–30.6%; range: 13.0–55.0%), peaking in 2006–2009. Multi-event capture–recapture models estimated 100% diagnostic specificity and moderate diagnostic sensitivity (30.0%, CI95 14.0–53.0%) for the molecular method. Mange-infected individually identified wolves showed a tendency for higher mortality versus uninfected wolves (ΔMortality 0.150, CI95 −0.165–0.458). Long-term serology data highlights the endemicity of sarcoptic mange in wild canids but uncovers multi-year epidemics. This study developed and evaluated a novel method for surveying sarcoptic mange in wildlife populations by the molecular detection of S. scabiei in faecal samples, which stands out for its high specificity and non-invasive character.

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Point-of-Care Testing Using Invasive and Non-Invasive Hemoglobinometers: Reliable and Valid Method for Estimation of Hemoglobin among Children 6–59 Months

Journal of Tropical Pediatrics ◽

10.1093/tropej/fmaa111 ◽

2020 ◽

Author(s):

Gomathi Ramaswamy ◽

Kashish Vohra ◽

Kapil Yadav ◽

Ravneet Kaur ◽

Tripti Rai ◽

...

Keyword(s):

Point Of Care ◽

Venous Blood ◽

Public Health Problem ◽

Outpatient Department ◽

Point Of Care Testing ◽

Adequate Treatment ◽

Non Invasive ◽

Hematology Analyzer ◽

The Mean ◽

Study Participants

Abstract Introduction Globally around 47.4% of children and in India, 58% of children aged 6–59 months are anemic. Diagnosis of anemia in children using accurate technologies and providing adequate treatment is essential to reduce the burden of anemia. Point-of-care testing (POCT) devices is a potential option for estimation of hemoglobin in peripheral and field settings were the hematology analyzer and laboratory services are not available. Objectives To access the validity of the POCTs (invasive and non-invasive devices) for estimation of hemoglobin among children aged 6–59 months compared with hematology analyzer. Methods The study participants were enrolled from the pediatric outpatient department in Haryana, India, from November 2019 to January 2020. Hemoglobin levels of the study participants were estimated in Sahli’s hemoglobinometer and invasive digital hemoglobinometers (DHs) using capillary blood samples. Hemoglobin levels in non-invasive DH were assessed from the finger/toe of the children. Hemoglobin levels measured in POCTs were compared against the venous blood hemoglobin estimated in the hematology analyzer. Results A total of 120 children were enrolled. The mean (SD) of hemoglobin (g/dl) estimated in auto-analyzer was 9.4 (1.8), Sahli’s hemoglobinometer was 9.2 (1.9), invasive DH was 9.7 (1.9), and non-invasive DH was 11.9 (1.5). Sahli’s hemoglobinometer (95.5%) and invasive DH (92.2%) had high sensitivity for the diagnosis of anemia compared with non-invasive DH (24.4%). In contrast, non-invasive DH had higher specificity (96.7%) compared with invasive DH (83.3%) and Sahli’s hemoglobinometer (70%). Invasive DH took the least time (2–3 min) for estimation of hemoglobin per participant, followed by Sahli’s (4–5 min) and non-invasive DH (5–7 min). Conclusion All three POCT devices used in this study are reasonable and feasible for estimating hemoglobin in under-5 children. Invasive DHs are potential POCT devices for diagnosis of anemia among under-5 children, while Sahli’s can be considered as a possible option, where trained and skilled technicians are available. Further research and development are required in non-invasive DH to improve accuracy. Lay summary In India, anemia is a serious public health problem, where 58% of the children aged 6–59 months are anemic. Point-of-care testing (POCT) using digital hemoglobinometers (DHs) has been recommended as one of the key interventions by the Anemia Mukt Bharat program since 2018 in India. These POCT devices are easy to use, less invasive, can be carried to field, require minimal training and results are available immediately. Therefore this study assessed the validity of POCT devices—invasive DH, non-invasive DH and Sahli’s hemoglobinometer among 6–59 months children in facility setting compared with the gold standard hematology analyzer. A total of 120 children under 6–59 months of age were enrolled from the pediatric outpatient department in Haryana, India, from November 2019 to January 2020. The (mean hemoglobin in g/dl) invasive (9.7) and non-invasive DH (11.9) overestimated hemoglobin value, while Sahli’s (9.2) underestimated hemoglobin compared with hematology analyzer (9.4). Invasive DH (92.2%) and Sahli’s hemoglobinometer (95.5%) reported high ability to correctly identify those with anemia compared with non-invasive DH (24.4%). In contrast, non-invasive DH (96.73%) had higher ability to correctly identify those without the anemia compared with invasive DH (83.3%) and Sahli’s (70%).

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An Estimation Method of Continuous Non-Invasive Arterial Blood Pressure Waveform Using Photoplethysmography: A U-Net Architecture-Based Approach

Sensors ◽

10.3390/s21051867 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1867

Author(s):

Tasbiraha Athaya ◽

Sunwoong Choi

Keyword(s):

Blood Pressure ◽

Cardiovascular Health ◽

Estimation Method ◽

Absolute Error ◽

British Hypertension Society ◽

Non Invasive ◽

Arterial Blood ◽

Blood Pressure Waveform ◽

The Mean ◽

Mimic Iii

Blood pressure (BP) monitoring has significant importance in the treatment of hypertension and different cardiovascular health diseases. As photoplethysmogram (PPG) signals can be recorded non-invasively, research has been highly conducted to measure BP using PPG recently. In this paper, we propose a U-net deep learning architecture that uses fingertip PPG signal as input to estimate arterial BP (ABP) waveform non-invasively. From this waveform, we have also measured systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP). The proposed method was evaluated on a subset of 100 subjects from two publicly available databases: MIMIC and MIMIC-III. The predicted ABP waveforms correlated highly with the reference waveforms and we have obtained an average Pearson’s correlation coefficient of 0.993. The mean absolute error is 3.68 ± 4.42 mmHg for SBP, 1.97 ± 2.92 mmHg for DBP, and 2.17 ± 3.06 mmHg for MAP which satisfy the requirements of the Association for the Advancement of Medical Instrumentation (AAMI) standard and obtain grade A according to the British Hypertension Society (BHS) standard. The results show that the proposed method is an efficient process to estimate ABP waveform directly using fingertip PPG.

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Non-invasive determination of the systolic peak-to-peak gradient in children with aortic stenosis: validation of a mathematical model

Cardiology in the Young ◽

10.1017/s1047951100006569 ◽

2000 ◽

Vol 10 (2) ◽

pp. 115-119 ◽

Cited By ~ 13

Author(s):

Valter C. Lima ◽

Evan Zahn ◽

Christine Houde ◽

Jeffrey Smallhorn ◽

Robert M. Freedom ◽

...

Keyword(s):

Mathematical Model ◽

Pulse Pressure ◽

Linear Regression Analysis ◽

Systolic Pressure ◽

Pressure Gradients ◽

Non Invasive ◽

The Mean ◽

Congenital Aortic Valvar Stenosis ◽

Peak Gradient

AbstractDoppler derived systolic pressure gradients have become widely applied as noninvasively obtained estimates of the severity of aortic valvar stenosis. There is little correlation, however, between the Doppler derived peak instantaneous gradient and the peak-to-peak gradient obtained at catheterisation, the latter being the most applied variable to determine severity in children. The purpose of this study was to validate a mathematical model based on data from catheterisation which estimates the peak-to-peak gradient from variables which can be obtained by noninvasive means (Doppler derived mean gradient and pulse pressure), according to the formula: peak-to-peak systolic gradient=6.02+1.49*(mean gradient)−0.44*(pulse pressure). Simultaneous cardiac catheterization and Doppler studies were performed on 10 patients with congenital aortic valvar stenosis. Correlations between the gradients measured at catheter measured, and those derived by Doppler, were performed using linear regression analysis. The mean gradients correlated well (y=0.67 × + 11.11, r=0.87, SEE=6 mm Hg, p=0.001). The gradients predicted by the formula also correlated well with the peak-to-peak gradients measured at catheter (y=0.66 × + 14.44, r=0.84, SEE=9 mm Hg, p=O.002). The data support the application of the model, allowing noninvasive prediction of the peak-to-peak gradient across the aortic valvar stenosis.

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Spontaneous Blinks as a Criterion of Visual Fatigue during Prolonged Work on Visual Display Terminals

Perceptual and Motor Skills ◽

10.2466/pms.2001.92.1.234 ◽

2001 ◽

Vol 92 (1) ◽

pp. 234-250 ◽

Cited By ~ 27

Author(s):

Kenichi Kaneko ◽

Kazuyoshi Sakamoto

Keyword(s):

Time Lag ◽

Vertical Direction ◽

Visual Display ◽

Hard Copy ◽

Subjective Feeling ◽

Visual Fatigue ◽

Work Time ◽

Mean Values ◽

Significant Difference ◽

The Mean

Visual fatigue caused by prolonged work viewing a Visual Display Terminals (VDT) and of work reading a hard-copy were assessed by electromyogram (EMG) waveform and electrooculogram (EOG) waveform in spontaneous blinks as objective criteria, and by questionnaire of subjective feeling, and by task performance. The duration and the amplitude of the EMG of the orbicularis ocular muscle on the right side and the EOG of the vertical direction to the eyelid were measured for 10 subjects who participated in a figure task consisting of the addition of single-digit numbers on a VDT work or a work with a hard-copy. The mean values of the duration and the amplitude of the EMG and the EOG were evaluated by the averaging of 10 waveforms of the spontaneous blinks for all subjects. The time lag from the EMG to the EOG in the process of the generation of spontaneous blinks was also analyzed. These five parameters were evaluated during the work time. The mean values for the duration of the EMG increased gradually during the work time, but the amplitude did not show significant difference between the prework and a work time. There was no significant change of the duration of the EOG, but the mean amplitude of the EOG decreased as the work time progressed, and the time lag significantly extended. The blinks frequency increased relatively when using a VDT. The rate of fluctuation for these parameters was higher during use of a VDT than use of a hard-copy. The time lag at five hours of VDT work was extended by 90% based on the value at the prework. The symptoms of general fatigue and fatigue of the eyes increased linearly during the VDT work for six hours. The results indicated a significant correlation between the objective parameters for the activity of the spontaneous blinks, i.e., duration and amplitude of EMG and EOG, and the time lag between EMG and EOG, and the subjective feeling was recognized in the time course of the task. These experimental results suggested that the parameters regarding the EMG and the EOG for the spontaneous blinks were effective indices for assessing visual fatigue during prolonged VDT work.

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Non-invasive mid-term ECG monitoring for the detection of atrial fibrillation in an outpatient population

European Heart Journal ◽

10.1093/ehjci/ehaa946.0381 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

J Cai ◽

K.K Yeo ◽

P Wong ◽

C.K Ching

Keyword(s):

Atrial Fibrillation ◽

Public Institution ◽

First Episode ◽

Prior History ◽

Funding Source ◽

Monitoring Device ◽

Ecg Monitoring ◽

Non Invasive ◽

Increased Risk ◽

The Mean

Abstract Background Atrial fibrillation (AF) is a common arrhythmia with significant morbidity due to an increased risk of ischemic stroke. Outpatient electrocardiogram (ECG) monitoring is an integral part of the diagnosis of AF. Conventional 24 hour Holter monitoring can be cumbersome and often fails to diagnose patients with paroxysmal AF. Spyder ECG is a non-invasive ECG monitoring device that allows wireless transmission of ECG information for analysis. It is small and comfortable, allowing for easy application for the screening and detection of AF over a mid-term duration. Purpose This study aims to evaluate the incidence of AF in patients with no prior AF and CHADsVASC score of at least 1 with the use of the Spyder ECG mid-term ECG monitoring device. Methods Patients aged 21 to 85 years old with no prior history of AF and CHADsVASC score of at least 1 were recruited from outpatient clinics of 3 large tertiary hospitals in Singapore from December 2016 to April 2019. Patients wore the Spyder ECG device for up to 2 weeks, during which continuous ECG information was uploaded onto a central cloud database and analysed. Results There were 363 patients recruited. The mean age was 61±10.0 years and 65.1% were male. There were 80.3% Chinese, 11.6% Malay, 7.5% Indian and 20.6% of other races. 68.3% of the patients were non-smokers and 74.0% of them were non-alcohol drinkers. The mean BMI of 25.5±4.7 kg/m2. The patient population had significant co-morbidities. 76.3% of the patients had hypertension, 69.4% of them had hyperlipidemia and 40.5% of them had diabetes mellitus. 10.0% of them had congestive cardiac failure and 56.7% had ischaemic heart disease. 11.3% of patients had a previous stroke and 20.4% had a prior myocardial infarction. 7.8% of the patients had asthma, 5.8% of them had thyroid disease and 9.9% of them had chronic kidney disease. They were monitored for a mean of 5.4±2.9 days each. There were 15 (4.1%) patients in whom AF was detected. The patients with AF wore the device for a mean of 5.7±2.0 SD days. The mean burden of AF was 9.0% of monitored time. 46.7% of the patients with AF had detection of AF on the first day, 26.7% on the second day, 13.3% on the third day and 13.3% on the seventh day. The mean duration of the first episode of AF was 251±325 minutes. 7 out of 15 (46.7%) of patients had first episodes of AF lasting less than 10 minutes. Conclusion Continuous mid-term ECG monitoring was able to detect AF in 15 (4.1%) of a population of 363 patients with no prior AF and CHADsVASC score of at least one, monitored for a mean of 5.4 days. Most episodes (53.3%) of AF were detected after the first day of ECG monitoring. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Duke-NUS Medical School Singapore

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Evaluation of Transient Elastography in Prediction Of De novo Recurrence of Hepatocellular Carcinoma after Radiofrequency Ablation

QJM ◽

10.1093/qjmed/hcab107.013 ◽

2021 ◽

Vol 114 (Supplement_1) ◽

Author(s):

Nadia abdelaty Abdelkader ◽

Moustafa Hamed Abdelaleem ◽

Mohammed El-Gharib Abo El- maaty ◽

Heba Ismail Aly ◽

Sayed Ahmed Sayed

Keyword(s):

Hepatocellular Carcinoma ◽

Radiofrequency Ablation ◽

Transient Elastography ◽

P Value ◽

Hepatic Decompensation ◽

Non Invasive ◽

Prediction Of Mortality ◽

The Mean ◽

One Year

Abstract Background Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide and it is also a common cause of death in patients with chronic liver disease. The curative treatment options for HCC that are currently available are surgical resection, liver transplantation and radiofrequency ablation .Despite progressive improvements in the efficacy of RFA, the survival of patients with HCC who undergo RFA remains disappointing, mainly due to frequent intrahepatic recurrence of HCC after RFA. Aim of the work To evaluate the role of transient elastography (as an indirect indicator to degree of liver fibrosis) in prediction of denovo recurrence of hepatocellular carcinoma after radiofrequency ablation in hepatitis C related hepatocellular carcinoma .And to compare between transient elastography and other non invasive fibrosis indices in prediction of denovo recurrence of hepatocellular carcinoma after radiofrequency ablation hepatitis C related hepatocellular carcinoma Patients and methods This prospective cohrt study was conducted on hepatocellular carcinoma patient, who underwent radiofrequency ablation in Tropical Medicine Department in Eldemerdash and Ain Shams Specialized Hospital, HCC clinic Ain Shams University Hospitals, Cairo, Egypt between march, 2017 and May, 2019. Data of the patient, who underwent radiofrequency ablation during the study period, were reviewed and the patients who fulfilled the inclusion criteria were enrolled into this study. The patients who fulfilled the inclusion criteria and underwent radiofrequency ablation were followed up for 12 months. Results TE revealed 28 patients with F4 and only 2 patients with F3, the mean measurement of liver stiffness was (22.45 ± 10.36) KPa. There was a significant negative correlation between LS and denovo recurrence of HCC (mean of LS in patients with complete response was 17.19 ± 3.32 and the mean of LS in patient with denovo recurrence was 36,94 ± 5.93,with the The best cut off value ≥24.65 (p value < 0.001)). There was no significant correlation between CDC, FIB4, API scores and denovo recurrence of HCC. Also it was found that the LS was significantly associated with prediction of manifestation of hepatic decompensation after RFA (means of LS in patient without manifestation decompensation after RFA (p value <0.001) .Regarding prediction of mortality, LS at cut off value > 42 .75 (p value = 0,031) was significantly associated with prediction of mortality after one year of RFA. As regard serum non invasive fibrosis indices our results showed correlation between FIB4 score and hepatic decompensation after one year of intervention (the mean of FIB4 score in patients ascites and jaundice was 6.05 ± 4.71 (p value = 0.05) ).Therewas no statistically significant correlation between CDS and API with hepatic decompensation after RFA .As regard role of serum non invasive fibrosis indices in prediction of mortality after RFA, FIB4 score, CDS and API were statistically non significant. Conclusion Our data suggest that LS measurement is a useful predictor of HCC de novorecurrence overall survival and possibility of hepatic decompensation after RFA

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Comparison of minimally invasive and non-invasive systems in lengthening total femoral prostheses

The Bone & Joint Journal ◽

10.1302/0301-620x.100b12.bjj-2018-0135.r1 ◽

2018 ◽

Vol 100-B (12) ◽

pp. 1640-1646 ◽

Cited By ~ 2

Author(s):

M. R. Medellin ◽

T. Fujiwara ◽

R. Clark ◽

L. M. Jeys

Keyword(s):

Minimally Invasive ◽

Leg Length Discrepancy ◽

Implant Survival ◽

Leg Length ◽

Range Of Movement ◽

Musculoskeletal Tumor Society ◽

Non Invasive ◽

Length Discrepancy ◽

The Mean

AimsThe aim of this study was to describe, analyze, and compare the survival, functional outcome, and complications of minimally invasive (MI) and non-invasive (NI) lengthening total femoral prostheses.Patients and MethodsA total of 24 lengthening total femoral prostheses, 11 MI and 13 NI, were implanted between 1991 and 2016. The characteristics, complications, and functional results were recorded. There were ten female patients and ten male patients. Their mean age at the time of surgery was 11 years (2 to 41). The mean follow-up was 13.2 years (seven months to 29.25 years). A survival analysis was performed, and the failures were classified according to the Modified Henderson System.ResultsThe overall implant survival was 79% at five, ten, and 20 years for MI prostheses, and 84% at five years and 70% at ten years for NI prostheses. At the final follow-up, 13 prostheses did not require further surgery. The overall complication rate was 46%. The mean revision-free implant survival for MI and NI prostheses was 59 months and 49 months, respectively. There were no statistically significant differences in the overall implant survival, revision-free survival, or the distribution of complications between the two types of prosthesis. Infection rates were also comparable in the groups (9% vs 7%; p = 0.902). The rate of leg-length discrepancy was 54% in MI prostheses and 23% in NI prostheses. In those with a MI prosthesis, there was a smaller mean range of movement of the knee (0° to 62° vs 0° to 83°; p = 0.047), the flexion contracture took a longer mean time to resolve after lengthening (3.3 months vs 1.07 months; p < 0.001) and there was a lower mean Musculoskeletal Tumor Society (MSTS) score (24.7 vs 27; p = 0.295).ConclusionThe survival and complications of MI and NI lengthening total femoral prostheses are comparable. However, patients with NI prosthesis have more accurate correction of leg-length discrepancy, a better range of movement of the knee and an improved overall function.

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Magnetresonanzphasenkontrastgeschwindigkeitsmessungen als noninvasive Nachbeobachtungsmaßnahme nach perkutaner transluminaler Angioplastie

VASA ◽

10.1024/0301-1526.31.4.235 ◽

2002 ◽

Vol 31 (4) ◽

pp. 235-240 ◽

Cited By ~ 3

Author(s):

Heverhagen ◽

Wagner ◽

Bandorski ◽

Hoppe ◽

Alfke

Keyword(s):

Phase Contrast ◽

Ankle Brachial Index ◽

Transluminal Angioplasty ◽

Walking Distance ◽

Slice Thickness ◽

Non Invasive ◽

The Mean ◽

Percutaneous Transluminal ◽

Phase Contrast Sequence

Background: The aim of this study was to evaluate magnetic resonance phase contrast velocimetry (MRVL) as a non-invasive follow up tool to assess restenosis after percutaneous transluminal angioplasty (PTA). Patients and methods: We prospectively investigated 51 consecutive patients who underwent PTA of the femoropopliteal region. MRVL was conducted prior, one day, six weeks, twelve weeks and 24 weeks after PTA using a circular polarized extremity coil and a gradient echo sequence (TR/TE 600/6 ms, flip angle 30°, slice thickness 10 mm). Hemodynamic data, derived from the MR phase contrast sequence, allowed to calculate the degree of area stenosis of the lesion treated with PTA. These data were correlated with clinical hemodynamic parameters (ankle-brachial index and walking distance). Results: The mean grade of area stenosis was 69% ± 27% before PTA, 30% ± 20% one day, 29% ± 23% six weeks, 39% ± 17% twelve weeks and 42% ± 18% 24 weeks after PTA and correlated well with clinical data and the post angioplasty clinical course of the patients. Conclusions: Follow up measurements using MRVL are suitable to assess restenosis after PTA and allow quantifying the grade of recurrent stenosis as well as the hemodynamic consequences.

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