scholarly journals Predicting lesion size during focused ultrasound thalamotomy: a review of 63 lesions over 3 clinical trials

2018 ◽  
Vol 44 (2) ◽  
pp. E5 ◽  
Author(s):  
Aaron E. Bond ◽  
W. Jeffrey Elias
Keyword(s):  
Clinical Trials ◽  
Focused Ultrasound ◽  
Energy Requirement ◽  
Lesion Size ◽  
Subsequent Treatment ◽  
Energy Requirements ◽  
Maximum Diameter ◽  
Temperature Threshold ◽  
Percentage Increase ◽  
T2 Mri

OBJECTIVEThe goal of this study was to improve the predictability of lesion size during focused ultrasound (FUS) thalamotomy procedures.METHODSTreatment profiles and T2-weighted MRI (T2 MRI) studies obtained in 63 patients who participated in 3 clinical trials of FUS thalamotomy from February 2011 to March 2015 were reviewed retrospectively. Four damage estimate models were compared with lesion sizes measured on postprocedural T2 MRI. Models were based on 54°C × 3 seconds, 240 cumulative equivalent minutes at 43°C, and simple thermal threshold analysis, which recorded the maximum diameter that reached a temperature of at least 51°C and 54°C. Energy requirements per °C thermal rise above 37°C were also recorded.RESULTSLesion diameters from T2 MRI correlated poorly from the day of the procedure to day 1 postprocedure (mean increase 78% [SD 79%]). There was more predictability of lesion size from day 1 to day 30, with a mean reduction in lesion diameter of 11% (SD 24%). Of the 4 models tested, the most correlative model to day 1 findings on T2 MRI was a 51°C threshold. The authors observed an increase in the energy requirement for each subsequent treatment sonication, with the largest percentage increase from treatment sonication 1 to treatment sonication 2 (mean increase 20% in energy required per °C increase in temperature above 37°C).CONCLUSIONSAt the margins, 51°C temperature threshold diameters correlated best to lesion diameters measured at day 1 with T2 MRI. The lesion size from T2 MRI decreases from day 1 to day 30 in a predictable manner, much more so than from the day of the procedure to day 1 postprocedure. Energy requirements per °C rise above 37°C continuously increase with each successive sonication.

scholarly journals Predicting final lesion characteristics during MR-guided focused ultrasound pallidotomy for treatment of Parkinson’s disease

2020 ◽  
pp. 1-8 ◽  
Author(s):  
Timothy R. Miller ◽  
Sijia Guo ◽  
Elias R. Melhem ◽  
Howard M. Eisenberg ◽  
Jiachen Zhuo ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Temperature Rise ◽  
Focused Ultrasound ◽  
Threshold Model ◽  
Average Energy ◽  
Lesion Size ◽  
Temperature Threshold ◽  
Treatment Efficiency ◽  
Mr Thermometry

OBJECTIVEMagnetic resonance–guided focused ultrasound (MRgFUS) ablation of the globus pallidus interna (GPi) is being investigated for the treatment of advanced Parkinson’s disease symptoms. However, GPi lesioning presents unique challenges due to the off-midline location of the target. Furthermore, it remains uncertain whether intraprocedural MR thermometry data can predict final lesion characteristics.METHODSThe authors first performed temperature simulations of GPi pallidotomy and compared the results with those of actual cases and the results of ventral intermediate nucleus (VIM) thalamotomy performed for essential tremor treatment. Next, thermometry data from 13 MRgFUS pallidotomy procedures performed at their institution were analyzed using 46°C, 48°C, 50°C, and 52°C temperature thresholds. The resulting thermal models were compared with resulting GPi lesions noted on postprocedure days 1 and 30. Finally, the treatment efficiency (energy per temperature rise) of pallidotomy was evaluated.RESULTSThe authors’ modeled acoustic intensity maps correctly demonstrate the elongated, ellipsoid lesions noted during GPi pallidotomy. In treated patients, the 48°C temperature threshold maps most accurately predicted postprocedure day 1 lesion size, while no correlation was found for day 30 lesions. The average energy/temperature rise of pallidotomy was higher (612 J/°C) than what had been noted for VIM thalamotomy and varied with the patients’ skull density ratios (SDRs).CONCLUSIONSThe authors’ acoustic simulations accurately depicted the characteristics of thermal lesions encountered following MRgFUS pallidotomy. MR thermometry data can predict postprocedure day 1 GPi lesion characteristics using a 48°C threshold model. Finally, the lower treatment efficiency of pallidotomy may make GPi lesioning challenging in patients with a low SDR.

An equation, suitable for computer use, based on the ARC feeding system to determine the energy requirements of growing and fattening cattle

1972 ◽  
Vol 14 (1) ◽  
pp. 17-23 ◽  
Author(s):  
C. A. Zulberti ◽  
J. T. Reid
Keyword(s):  
Weight Gain ◽  
Computer Use ◽  
Agricultural Research ◽  
Energy Requirement ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Energy Concentration ◽  
Feeding System ◽  
Agricultural Research Council ◽  
Forward Calculation

SUMMARYBased on the Agricultural Research Council's feeding system, equations were developed that allow the calculation of the metabolizable energy requirements for maintenance and weight gain by cattle, separately or combined. A general equation was developed for the straight-forward calculation of the total metabolizable energy requirements of growing and fattening cattle for any combination of body weight, rate of weight gain, age, level of muscular work, and metabolizable energy concentration of the diet. The estimates of energy requirement made by the use of this equation are in excellent agreement with those made by the Agricultural Research Council using an iterative method.In addition to avoiding the awkward iterative process, the equations proposed are readily adaptable to computer use.

Predictors of thermal response and lesion size in patients undergoing magnetic resonance-guided focused ultrasound thalamotomy

2021 ◽  
Vol 91 ◽  
pp. 75-79
Author(s):  
David N. Wilson ◽  
Yael Barnett ◽  
Kain Kyle ◽  
Stephen Tisch ◽  
Benjamin P. Jonker
Keyword(s):  
Magnetic Resonance ◽  
Focused Ultrasound ◽  
Thermal Response ◽  
Lesion Size

scholarly journals Energy Requirement and Food Intake Behaviour in Young Adult Intact Male Cats with and without Predisposition to Overweight

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Brigitta Wichert ◽  
Julia Trossen ◽  
Daniel Uebelhart ◽  
Marcel Wanner ◽  
Sonja Hartnack
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Dry Matter ◽  
Body Condition Score ◽  
Energy Requirement ◽  
Fat Free Mass ◽  
Energy Requirements ◽  
Intact Male ◽  
Feeding Station ◽  
Condition Score

Obesity is a common problem in cats. In the experimental cat family of the institute of animal nutrition besides a “normal” lean phenotype, cats with predisposition to an overweight phenotype are present. To investigate energy requirements and food intake behaviour of intact male cats of different phenotypes, six “normal” lean cats (GL) and six cats disposed to overweight (GO) were used. At the beginning of the experiment, all cats had an ideal body condition score of 5. To reach this the GO cats had to pass a weight-loss program. Energy requirements of the cats were determined using respiration chambers, whereas the amount and frequency of food intake was measured with a feeding station recording the data automatically. Energy requirement at weight constancy of the GO cats was even on fat-free mass (FFM) significantly (P=0.02) lower (162.6 kJ/kg FFM/d) than that of the “normal” lean cats (246 kJ/kg FFM/d). The GO cats also showed a higher food intake34.5±1.5 g dry matter/kg body weight0.67compared to the GL cats (24.0±2.1 g dry matter/kg body weight0.67)(P=0.001). In conclusion quantifiable differences in food intake and behaviour in cats predisposed to overweight compared to “normal” lean cats were found.

Utilisation of the end products of ruminant digestion

1957 ◽  
Vol 1957 ◽  
pp. 3-15 ◽  
Author(s):  
D. G. Armstrong ◽  
K. L. Blaxter ◽  
N. McC. Graham
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Quantitative Data ◽  
Volatile Fatty Acids ◽  
Energy Requirement ◽  
The Body ◽  
Energy Requirements ◽  
Dietary Carbohydrate ◽  
Body Tissues ◽  
End Products

The work of the late Sir Joseph Barcroft and his collaborators (see Elsden & Phillipson, 1948) left little doubt that, in ruminants, the end products of the bacterial dissimilation of dietary carbohydrate included large amounts of the steam-volatile fatty acids—acetic, propionic and butyric acids. More recently, el Shazly (1952a, b) has shown that the steam-volatile fatty acids also arise together with ammonia during the bacterial breakdown of amino-acids in the rumen. Studies by Pfander & Phillipson (1953) and Schambye (1955) further indicate that the acids are absorbed from the digestive tract in amounts that suggest they make a major contribution to the energy requirement of the animal. Quantitative data relative to the amounts absorbed, however, are difficult to obtain. Carroll & Hungate (1954) have calculated that in cattle some 6,000-12,000 Cal. of energy are available from the acids produced by fermentation in the rumen. With sheep, Phillipson & Cuthbertson (1956) have calculated from the results of Schambye (1951a, b; 1955) that at least 600-1,200 Cal. of energy in the form of steam-volatile fatty acids could be absorbed every 24 hrs. Since the fasting heat production of the steer is about 6,500 Cal./24 hrs. and that of the sheep about 1,100 Cal./24 hrs. it is clear that if the fatty acids can be utilised efficiently by the body tissues, they could make a major contribution to the energy requirements, at least those for maintenance.

Combining Low-Dose Radiation Therapy and Magnetic Resonance Guided Focused Ultrasound to Reduce Amyloid-β Deposition in Alzheimer’s Disease

2021 ◽  
pp. 1-4
Author(s):  
Paolo Farace ◽  
Stefano Tamburin
Keyword(s):  
Alzheimer’S Disease ◽  
Clinical Trials ◽  
Radiation Therapy ◽  
White Matter ◽  
Magnetic Resonance ◽  
Low Dose ◽  
Focused Ultrasound ◽  
Amyloid Β ◽  
Low Dose Radiation ◽  
Dose Radiation

Amyloid-β deposition is one of the neuropathological hallmarks of Alzheimer’s disease (AD), but pharmacological strategies toward its reduction are poorly effective. Preclinical studies indicate that low-dose radiation therapy (LD-RT) may reduce brain amyloid-β. Animal models and proof-of-concept preliminary data in humans have shown that magnetic resonance guided focused ultrasound (MRgFUS) can reversibly open the blood-brain-barrier and facilitate the delivery of targeted therapeutics to the hippocampus, to reduce amyloid-β and promote neurogenesis in AD. Ongoing clinical trials on AD are exploring whole-brain LD-RT, which may damage radio-sensitive structures, i.e., hippocampus and white matter, thus contributing to reduced neurogenesis and radiation-induced cognitive decline. However, selective irradiation of cortical amyloid-β plaques through advanced LD-RT techniques might spare the hippocampus and white matter. We propose combined use of advanced LD-RT and targeted drug delivery through MRgFUS for future clinical trials to reduce amyloid-β deposition in AD since its preclinical stages.

Abstract 5662: Comparative Ablation Analysis in a Swine Intracardiac Model: Lesion Effectiveness of Ablation Within the Therapeutic Range of 2 Irrigated, One Non-irrigated and one Cryoablation Catheter

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Robert Robichaux ◽  
Liane Teplitsky ◽  
Heath B Carter ◽  
Michael Blackstone ◽  
Derek Dosdall ◽  
...  
Keyword(s):  
Adverse Events ◽  
Therapeutic Range ◽  
Energy Requirement ◽  
Conduction Block ◽  
Lesion Size ◽  
Right Atrial ◽  
Ablation Procedure ◽  
Catheter Group ◽  
Appropriate Therapy ◽  
Irrigated Catheter

Lesion characteristics including size and transmurality are important factors in the creation of conduction block with respect to catheter ablation. The energy required to create safe and effective lesions may vary from one ablation system to another. Understanding the differences in this energy requirement could allow the operator to titrate the appropriate therapy with each system - generating successful outcomes while minimizing complications. Twenty-two swine underwent an acute ablation procedure whereby 4 lesions were placed with a different catheter in each of the following areas: the left atrium (LA), along the cavo-tricuspid isthmus (CVI) and in right atrial tissue (RA). Four ablation catheters were studied: an 8mm cryoablation catheter, an 8mm standard RF catheter, a 2.5mm insulated open irrigated catheter, and a 3.5mm open irrigated RF catheter. Energy was applied for 30s with the RF catheters and 120sec with cryo, within the therapeutic range for that catheter. Lesion size, RF/Cryo characteristics, popping and other adverse events were recorded. One hundred sixty-three lesions were analyzed. There was no statistical difference between the lesion volumes created by each catheter. The lesion characteristics of the catheters are shown in Table 1 . Transmurality ranged from 75–90% with a trend toward greater transmurality with the 2.5mm irrigated catheter group. There was no evidence of tissue popping or other adverse events. These catheters when used within the therapeutic range on average created similar volume lesions but with wide variation. Cryoablation tended to create the largest lesions but was less likely to be transmural, while the 2.5mm catheter was most likely to deliver transmural lesions. Catheter comparison

The influence of parity on lactation curve coefficients in dairy cows

1998 ◽  
Vol 1998 ◽  
pp. 9-9
Author(s):  
N. C. Friggens ◽  
G. C. Emmans ◽  
R. F. Veerkamp
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Energy Requirement ◽  
Energy Requirements ◽  
High Quality ◽  
Lactation Curve ◽  
Ad Libitum

There are marked differences between heifers, 2nd parity and older cows in their lactation curves, even when they are offered high quality rations ad libitum. These differences indicate different energy requirements, and thus should be taken into account when formulating rations for the different parities. The objective of this study was to quantify how the pattern of milk production relative to time from calving is affected by parity for incorporation into energy requirement predictions.

Multimodal MRI for MRgFUS in essential tremor: post-treatment radiological markers of clinical outcome

2020 ◽  
Vol 91 (9) ◽  
pp. 921-927
Author(s):  
Anish N Kapadia ◽  
Gavin J B Elias ◽  
Alexandre Boutet ◽  
Jürgen Germann ◽  
Aditiya Pancholi ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Clinical Outcome ◽  
Essential Tremor ◽  
Focused Ultrasound ◽  
Lesion Size ◽  
Post Treatment ◽  
Medial Lemniscus ◽  
Invasive Treatment ◽  
Tremor Suppression ◽  
Registration Number

BackgroundMRI-guided focused ultrasound (MRgFUS) thalamotomy is a promising non-invasive treatment option for medication-resistant essential tremor. However, it has been associated with variable efficacy and a relatively high incidence of adverse effects.ObjectivesTo assess the evolution of radiological findings after MRgFUS thalamotomy and to evaluate their significance for clinical outcomes.MethodsNinety-four patients who underwent MRgFUS between 2012 and 2017 were retrospectively evaluated. Lesion characteristics were assessed on routine MRI sequences, as well as with tractography. Relationships between imaging appearance, extent of white matter tract lesioning (59/94, on a 4-point scale) and clinical outcome were investigated. Recurrence was defined as >33% loss of tremor suppression at 3 months relative to day 7.ResultsAcute lesions demonstrated blood products, surrounding oedema and peripheral diffusion restriction. The extent of dentatorubrothalamic tract (DRTT) lesioning was significantly associated with clinical improvement at 1 year (t=4.32, p=0.001). Lesion size decreased over time (180.8±91.5 mm3 at day 1 vs 19.5±19.3 mm3 at 1-year post-treatment). Higher post-treatment oedema (t=3.59, p<0.001) was associated with larger lesions at 3 months. Patients with larger lesions at day 1 demonstrated reduced rates of tremor recurrence (t=2.67, p=0.019); however, lesions over 170 mm3 trended towards greater incidence of adverse effects (sensitivity=0.60, specificity=0.63). Lesion encroachment on the medial lemniscus (Sn=1.00, Sp=0.32) and pyramidal tract (Sn=1.00, Sp=0.12) were also associated with increased adverse effects incidence.ConclusionLesion size at day 1 predicts symptom recurrence, with fewer recurrences seen with larger lesions. Greater DRTT lesioning is associated with treatment efficacy. These findings may have implications for lesion targeting and extent.Trial registration numberNCT02252380.

scholarly journals Maintenance energy requirements and forage intake of purebred vs. crossbred beef cows1

2020 ◽  
Vol 4 (2) ◽  
pp. 1182-1195
Author(s):  
Claire E Andresen ◽  
Aksel W Wiseman ◽  
Adam McGee ◽  
Carla Goad ◽  
Andrew P Foote ◽  
...  
Keyword(s):  
Energy Requirement ◽  
Growth Efficiency ◽  
Energy Requirements ◽  
Maintenance Energy ◽  
Calf Growth ◽  
Crossbred Cows ◽  
Breed Type ◽  
Main Effect ◽  
Forage Intake ◽  
Maintenance Energy Requirement

Abstract The objective of this study was to investigate the impacts of cow breed type and age on maintenance requirements, feed energy utilization, and voluntary forage intake. The main effect of breed type included Angus (ANG; n = 32) and Hereford × Angus (HA; n = 27) lactating cows. The main effect of age included 2- and 3-yr-old (YOUNG; n = 29) and 4- to 8-yr-old (MATURE; n = 30) cows. Within breed type and age class, cows were randomly assigned to 1 of 2 pens for a total of 8 pens, each housing 7 to 9 cow/calf pairs. To determine maintenance energy requirements, cows and calves were limit-fed for 105 d to body weight (BW) and body condition score (BCS) stasis. There were no differences between breeds in cow hip height, BW, average milk yield (P &gt; 0.31), diet digestibility, or cow maintenance energy requirement (P = 0.54). Crossbred cows had greater BCS (P &lt; 0.05) throughout the experiment. Efficiency of calf growth was not different between breeds when expressed as feed intake of the cow/calf pair nor as energy intake of the pair per unit of calf BW gain (P ≥ 0.31). Young cows produced less milk per day and per unit of BW0.75 (P &lt; 0.01); however, there was no effect of cow age on maintenance energy requirement, diet digestibility, or efficiency of calf growth (P &gt; 0.10). Subsequently, a 45-d experiment was conducted to determine voluntary low-quality forage intake. Cows were housed in dry-lot pens equipped with shade, windbreaks, and feed bunks with free-choice access to clean water and a chopped hay ration was provided ad libitum to determine forage intake. Daily forage intake was lower (P = 0.05) for HA compared with ANG (123 vs. 132 g/kg BW0.75, respectively) although there was no difference in BW. However, HA cows sustained greater BCS (P &lt; 0.01). There was no difference (P = 0.60) in forage intake per unit of BW0.75 due to cow age. Results indicate similar calf growth efficiency among breed types although crossbred cows maintained greater body energy stores and consumed less low-quality forage during the voluntary intake experiment. These differences could not be attributed to lower maintenance energy requirements. Neither maintenance energy requirement nor calf growth efficiency was different between young and mature cows.

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