Argus Software Research Articles

Evaluating the knowledge and use of property technology among property academics in Australian universities

PurposeWith the increased demand for the application of technology in property activities, there is a growing need for property professionals adept in using digital technology. Hence, it is important to assess the competence of academia in equipping property professionals with digital technology skills. This study, therefore, assesses property academics in Australian universities to identify their level of knowledge and use of digital technology applicable to the property industry.Design/methodology/approachOnline questionnaire surveys were administered to 22 out of 110 property academics contacted through the Australia Property Institute (API) database to achieve this aim. The collected data were analysed using mean score ranking and ANOVA.FindingsThe study found that apart from databases and analytics platforms such as Corelogic RP data, price finder and industry-based software such as the Microsoft Office suite and ARGUS software, the academics were not knowledgeable in most identified and sampled proptech tools. Similarly, most proptech tools were not used or taught to the students. It was also found that early career academics (below five years in academia) were the most knowledgeable group about the proptech tools.Research limitations/implicationsRelying on the API database to contact property academics potentially excludes the position of property academics who may not be affiliated or have contacts with API, hence, the findings of this study should be generalised with caution.Practical implicationsThe study bears huge implications for the property education sector and industry in Australia; a low knowledge and use of nascent tools such as artificial intelligence, machine learning, blockchain, drones, fintech, which have received intense interest, reveals some level of skill gap of students who pass through that system and may need to be upskilled by employers to meet the current day demand.Originality/valueIn response to the clamour for technology-inclined property professionals, this paper presents itself as the first to assess the knowledge levels and application of digital technology by property academics.

RBS Channeling MATLAB Application for Automated Measurement Control and Evaluation for 6MV Tandetron Accelerator

Rutherford backscattering spectrometry (RBS) in channeling regimes (RBS/C), as an ion beam analysis method performed on a Tandetron 6MV accelerator, generally gives precise information about the structure of crystalline samples by combining RBS signals in the random and aligned configurations. This paper presents details about the design and implementation of tailored RBS/C measurements (coarse and fine) and data evaluation application developed in MATLAB for in situ accelerator control system ARGUS, delivered by High Voltage Engineering Europa BV (HVEE). Additionally, we examined two different ways of stepping during the measurement to reduce the possible inaccuracies related with goniometer’s backslash affecting the evaluation of spectra. Verification experiment was carried out using a 2-MeV 4He+-beam directed on a Si (100) substrate. The channeling effect is seen as channeling dips of a lower signal in an otherwise rather homogeneous plane. Implemented application significantly facilitates the RBS/C measurement and analysis of the experiments, and also extends the ion beam analysis portfolio of Advanced Technologies Research Institute. Finally, software is ready-to-use for any Tandetron based ion beam facility with the ARGUS software for accelerator control.

Chrysoeriol ameliorates hyperglycemia by regulating the carbohydrate metabolic enzymes in streptozotocin-induced diabetic rats

The present study aimed to evaluate the effects of chrysoeriol from Cardiospermum halicacabum in streptozotocin induced Wistar rats. Thirty rats were categorized as control, diabetic control supplemented with 0, 20mg/kg chrysoeriol and 600μg/kg BW of glibenclamide for 45-day trial period. Our results indicated that the inclusion of chrysoeriol (20mg/kg), showed a significant reduction in plasma glucose, hemoglobin and glycosylated hemoglobin level with a rising of plasma insulin sensitivity. Further, downregulated enzymes including glucose 6-phosphatase, fructose 1,6-bisphosphatase, and glycogen phosphorylase as well upregulated enzymes such as hexokinase, glucose-6-phosphate dehydrogenase, pyruvate kinase, and hepatic glycogen content. There was a diminish action found in liver glycogen synthase of tested rat with a rise in gamma-glutamyl transpeptidase, towards normal levels upon treatment with chrysoeriol. The histopathological study confirmed that renewal of the beta cells of pancreatic of chrysoeriol and glibenclamide treated rats. In addition, the molecular docking of chrysoeriol against glycolytic enzymes including hexokinase, glucose-6-phosphate dehydrogenase, pyruvate kinase, using Argus software shows chrysoeriol had greatest ligand binding energy as equivalent to glibenclamide, as a standard drug. Thus, chrysoeriol found to be non-toxic with potential regulation on glycemic control and upregulation of the carbohydrate metabolic enzymes.

SAT-540 Primary Aldosteronism Represents Earlier Myocardial Fibrosis Than Essential Hypertension by T1 Mapping

Introduction:Primary aldosteronism (PA) is associated with cardiovascular disease and has increased cardiovascular morbidity. Several studies had demonstrated that PA shows more serious myocardial fibrosis compared with essential hypertension (EH) using late Gadolinium-enhanced (LGE) imaging [1, 2]. However, the early myocardial change may not be detected by LGE. Recently, cardiac MRI T1 mapping emerged to be a sensitive technique in detecting early changes of myocardium quantitatively. Our study aimed to demonstrate the early myocardial change in PA patients by applying the T1-mapping technique.Method:81 (male: 25; age: 48±12 years) PA[3] and 44 (male: 21; age: 47±14 years) EH patients diagnosed by the Department of Endocrinology and metabolism according to the 2016 TES guidelines for PA were recruited from September 2018 to May 2019. All the subjects underwent cardiac MRI examinations on a 3T MRI scanner (MAGNETOM Trio a Tim System, Siemens Healthcare, Erlangen, Germany), including steady-state free-precession (SSFP) cine imaging and modified Look-Locker inversion recovery (MOLLI) imaging for T1 mapping. Functional parameters were obtained from cine images by the Argus software (Siemens Healthcare, Erlangen, Germany).The mid-ventricular native T1 value was acquired using the QMass software (Medis, Leiden, The Netherlands). Native T1 value and cardiac function parameters were analyzed between the two groups. Differences of continuous variables were analyzed by Student’s t-test or Mann-Whitney U-test, and the relationships between native T1 value and physiological variables were analyzed by multiple linear regression method.Results:The age (PA: 48±12 years vs EH: 47±14 years; p=0.720) and BMI (PA: 25.06±3.73 vs EH: 25.17±2.83; P=0.874) between two groups had no significant differences. The PA group had a significant higher aldosterone/renin ratio (ARR) than those in the EH group (114.6 (48.7-474.8)ng/dl:ng/ml.h vs 7.6 (4.2-13.8) ng/dl:ng/ml.h; p<0.001). All functional parameters including LVEDVI (PA: 78.66 (72.4-90.6) ml/m2 vs EH: 75.8 (64.3-85.8) ml/m2; p=0.054); LVESVI (PA: 31.7 (26.2-38.4) ml/m2 vs EH: 29.3 (24.9-36.2) ml/m2; p=0.152); LVEF (PA: 59.9 (53.3-65.0)% VS EH: 59.2(55.3-65.6)%; p=0.679); LVmassi (PA: 58.5(47.7-67.7) g/m2 vs EH: 54.9 (47.6-60.1) g/m2; p=0.463) had no differences between the two groups. However, native T1 values were higher in PA group than those in EH group (1227±40ms vs 1203±45ms). The multiple linear regression analysis showed that gender (Beta=-27.678, p<0.001) and PA (Beta=-17.287, p=0.031) were independently related to the native T1 values.Conclusion:PA patients represent more severe and earlier myocardium damage and this might be related to cardiovascular morbidity. The T1-mapping technique in cardiac MRI is more sensitive to evaluate the left ventricular function and to detect the myocardial fibrosis in PA patients.

Formability of AA6082-T6 at Warm and Hot Stamping Conditions

Forming limit diagrams (FLDs) of AA6082 at warm/hot stamping conditions were determined by using a specially designed test rig. The tests were carried out at various temperatures from 300 to 450°C and forming speeds ranging from 75 to 400 mm/s. The strain was visualized and measured using ARGUS software provided by GOM. The results clearly show that the formability of AA6082-T6 sheet metal, in terms of the limit major strain, increased by 38.9 % when the forming temperature was increased from 300°C to 450°C at a speed of 250 mm/s, and increased by 42.4 % when the forming speed was decreased from 400 to 75 mm/s at a temperature of 400°C. It was verified that hot stamping is a promising technology for manufacturing complex-shaped components.

Early and mid-term outcomes of a novel Endovascular Aneurysm Sealing (EVAS) system in patients with infrarenal abdominal aortic aneurysms.

Endovascular aneurysm sealing (EVAS) using the Nellix system is a promising technology for Abdominal Aortic Aneurysm (AAA) treatment. Long-term data is unavailable regarding the potential modifications of the EndoBags and their content, and the polymer behavior over time. We present our initial clinical experience with this sac anchoring endoprosthesis in 24 patients with a maximum 12 months follow-up. From December 2013 to March 2015, 24 patients with an infrarenal AAA were treated with the Nellix™ System. Computed tomography angiography (CTA) scan control was performed at 30 days, and follow-up magnetic resonance angiography (MRA) and ultrasounds were performed at 30 days, 6 and 12 months. Median and peak systolic velocities in the suprarenal aorta were measured preoperatively and during follow-up using phase contrast sequences and Argus (Siemens, Erlangen, Germany) software of the MRA. We achieved 100% technical success, 0% aneurysm-related mortality and 0% endoleaks. One patient (4%) experienced early acute thrombosis of a single Nellix stent, successfully treated with thrombolysis. Sac shrinkage occurred in 80% of cases with 12-months follow-up. Our preliminary clinical experience is promising, with 100% early technical success and satisfactory sealing of the aneurysm sac. Postprocedural controls during 1-year follow-up revealed no morphologic changes of the aneurysm wall, stable device and endobag position, and gradual dissolution of the air initially trapped within the EndoBags. Aneurysmal sac shrinkage occurs and probably is due to the remodeling of the thrombus around the EndoBags and the dissipation of the air bubbles into the EndoBags.

Variability in cardiac MR measurement of left ventricular ejection fraction, volumes and mass in healthy adults: defining a significant change at 1 year.

Variability in the measurement of left ventricular (LV) parameters in cardiovascular imaging has typically been assessed over a short time interval, but clinicians most commonly compare results from studies performed a year apart. To account for variation in technical, procedural and biological factors over this time frame, we quantified the within-subject changes in LV volumes, LV mass (LVM) and LV ejection fraction (EF) in a well-defined cohort of healthy adults at 12 months. Cardiac MR (CMR) was performed in 42 healthy control subjects at baseline and at 1 year (1.5 T Magnetom® Avanto; Siemens Healthcare, Erlangen, Germany). Analysis of steady-state free precession images was performed manually offline (Argus software; Siemens Healthcare) for assessment of LV volumes, LVM and EF by a single blinded observer. A random subset of 10 participants also underwent repeat imaging within 7 days to determine short-term interstudy reproducibility. There were no significant changes in any LV parameter on repeat CMR at 12 months. The short-term interstudy biases were not significantly different from the long-term changes observed at 1 year. The smallest detectable change (SDC) for LVEF, end-diastolic volume, end-systolic volume and LVM that could be recognized with 95% confidence were 6%, 13 ml, 7 ml and 6 g, respectively. The variability in CMR-derived LV measures arising from technical, procedural and biological factors remains minimal at 12 months. Thus, for patients undergoing repeat annual assessment by CMR, even small differences in LV function, size and LVM (which are greater than the SDC) may be attributed to disease-related factors. The reproducibility and reliability of CMR data at 12 months is excellent allowing clinicians to be confident that even small changes in LV structure and function over this time frame are real.

National multi-centre cost-comparison of trans-catheter aortic valve implantation (TAVI) versus surgical aortic valve replacement (SAVR) in moderate to high-risk patients with severe symptomatic aortic stenosis in New Zealand (NZ)

flow measurement in the main (MPA), right (RPA) and left (LPA) pulmonary arteries on a 1.5T Siemens Avanto MR scanner, using both the standard and the interleaved sequences, in a varying order. Internal consistency of the measurements was checked by the sum MPA flow (RPA + LPA flows). Flow measurements were analysed using Argus software (Siemens), statistical analysis with SPSS Statistics. Results: The mean MPA flow was 5.90 l/min using the standard sequence vs 5.47 l/min with the interleaved sequence (p=0.484). Mean RPA flow was 3.07 l/min vs. 2.75 l/min (p=0.249), and the mean LPA flow was 2.89 l/ min vs. 2.59 l/min (p=0.310). Internal consistency was comparable at 0.29 l/min standard vs. 0.28 l/min interleaved (p=0.959). Conclusion: The interleaved flow sequence produces similar results to the standard sequential method. No advantage for the interleaved sequence was demonstrated, but use thereof has no disadvantage either. In clinical situations where flow should be measured at multiple sites, eg shunt calculation, the interleaved sequence is preferable, with one source of potential error eliminated.

FRI0080 Bone Mineral Density, Sclerostin and Insulin Are Independently Associated with Coronary-Artery Atherosclerosis in Patients with Established Rheumatoid Arthritis

BackgroundRheumatoid arthritis (RA) is associated with premature atherosclerosis and increased prevalence of cardiovascular disease (CVD). Inverse associations have been described between bone mineral density (BMD) and Coronary Artery Calcification (CAC)...

Normative annual changes in left ventricular volumes, mass and function among healthy adults: a prospective cardiac magnetic resonance imaging study

Background Cardiac magnetic resonance imaging (CMR) is routinely performed to monitor progression and response to interventions in congenital and acquired heart diseases. Cross-sectional CMR studies report normalized reference ranges for cardiac parameters according to age decile together with assessments of short-term inter-study variability; however, most clinical imaging is repeated at much greater intervals of time. There are no prospective CMR data defining long-term changes in cardiac structure and function among healthy subjects. Without such data, it is difficult to determine whether serial changes in cardiac parameters observed in patients reflect disease progression or are merely the consequence of normal ageing. We examined the “within patient” changes in left ventricular (LV) volumes, mass and function over 12 months in a well-characterized cohort of healthy adults. Methods We identified 21 healthy controls (age 39 ± 13 yr, male 71%) who did not proceed to uni-nephrectomy after recruitment into an observational study assessing the cardiovascular effects of live kidney donation (NCT01028703). All subjects were asymptomatic and had a 10-year risk of a cardiovascular event of <20% (QRISK-2), a normal stress echocardiogram and normal haematology and biochemistry profiles. Exclusion criteria included: any history of cardiovascular disease, including hypertension; diabetes; glucose intolerance; chronic kidney disease; first degree relative with a proven or potentially inheritable cardiac condition. Subjects underwent CMR imaging (1.5T Magnetom Avanto, Siemens) at baseline and 12 months. Analysis of SSFP images was performed offline (Argus Software, Siemens) by a single blinded observer (W.E.M.) for assessment of LV volumes, systolic function and mass. Baseline studies were repeat analyzed by the same trained observer to assess intra-observer variability. A subset of participants underwent repeat imaging within 1 hour to determine inter-study variability. Results

Antidiabetic and antihyperlipidemic activity of asiatic acid in diabetic rats, role of HMG CoA: In vivo and in silico approaches

Hyperlipidemia is an associated complication of diabetes and also a major risk factor for cardiovascular diseases. The present study was designed to examine the antihyperlipidemic effect of asiatic acid (AA) in streptozotocin (STZ) induced diabetic rats. Diabetes was induced in male Wistar rats by a single intraperitoneal injection of STZ (40mg/kg b.w.). Diabetic rats show increased plasma glucose, total cholesterol, triglycerides, free fatty acids, phospholipids, low density lipoprotein, very low density liprotein, atherogenic index and decreased insulin and high density lipoprotein in diabetic rats. The activity of 3-hydroxy 3-methylglutaryl coenzyme A (HMG CoA) reductase increased significantly in contrast to the activities of lipoprotein lipase and lecithin cholesterol acyltransferase. In addition, the molecular docking of AA against HMG CoA reductase involved in cholesterol biosynthesis using Argus software. Diabetic rats were treated with AA shifted all these parameters towards normalcy. AA has shown best ligand binding energy 11.8122kcal/mol. The antihyperlipidemic effect of AA was compared with glibenclamide; a well-known antihyperglycemic drug. In conclusion, this study indicates that AA showed an antihyperlipidemic effect in addition to its antidiabetic effect in experimental diabetes.

WE‐C‐116‐09: A Novel Flow Quantification Quality Assurance Method Using Power Injector

Purpose: To develop a practical flow quantification quality assurance method based on a simple and compact flow phantom driven by a power injector. Methods: A flow phantom was made using acrylic with U‐shaped tubes built inside the chamber and immersed in stationary saline. A MR power injector equipped with the MR scanner was used to inject up to 110 mL of saline through the tube with 4.76 mm inner diameter at a precise rate of 2.00+/−0.01 mL/s. 2D phase contrast flow quantification was performed with a single imaging slice of 10mm perpendicular to the straight sections of the U‐shape tube on two different models of 1.5T MR scanners (Siemens Espree and Aera). Flow rates in two opposite directions were measured from phase contrast images using Siemens ARGUS software. Eight repeat measurements were performed for each scanner. Results: The flow rates measured on the Espree scanner were +2.15+/−0.06 mL/s with 7.45% difference from the 2mL/s flow rate provided by the power injector and −2.17+/−0.03mL/s with 8.7% difference. On the Aera scanner, the flow rates were +1.90+/−0.03mL/s with 4.8% difference from the 2mL/s produced by the power injector and −1.99+/−0.02mL/s with 0.6% difference. The measured flow rates were different from the true flow rate for both scanners and the error were different between scanners. Conclusion: Our proposed method of quality assurance using a simple flow phantom driven by a power injector was able to detect the errors in flow quantification for both scanner as well as the difference between two scanners. Such method can be implemented on many clinical MR scanners already equipped with a power injector.

Progression of myocardial fibrosis by magnetic resonance imaging in patients with Duchenne and Becker muscular dystrophy

Background Duchenne (DMD) and Becker (BMD) muscular dystrophy (MD) are inherited X-linked disease characterized by progressive skeletal muscle degeneration and myocardial involvement and caused by a mutation on dystrophin gene (Xp21). Dystrophin is a sarcolemal protein that links the cytoskeleton to the basal lamina and is essential for maintenance of the muscular membrane integrity during muscular contraction. In a previous study, our group described for the first time, in a small group of 10 patients, that CMR can identify myocardial fibrosis (MF) and may be useful for detecting the early stages of cardiomyopathy in MD [1]. The evolution of the myocardial fibrosis over time in this group of patient is still unknown. Methods We enrolled 76 pts, 70 pts with DMD and 6 BMD. Mean age was 13.1 ± 4.4 years. 74 patients underwent 2 CMR exams within a mean of 2.3 years, performed on a 1.5-T Siemens Avanto (Erlangen, Germany). Breath-hold LV short-axis and long-axis images were obtained by 2-pulse sequences at the same locations, allowing precise comparisons between LV function (gradient-echo sequence, steady-state free precession) and myocardial structure (inversion-recovery prepared gradient-echo sequence, 10 min after intravenous bolus or 0.2 mmol/kg gadolinium-based contrast), acquired with the following parameters, respectively: TR 2.0/ 9.0, TE 1.07/ 5.0; flip angle 69/50; cardiac phases 20/1; VPS 8/16 to 32; matrix 192 x 162 / 256 x 192; ST 8/8 mm; gap 2/2 and FOV 32 to 38/32 to 38 cm; TI none/150 to 390 ms; receiver bandwidth 930/150 Hz; number of excitations 1/1; acquisition every other heartbeat for MDE. The images were analyzed by two experienced observers. End-systolic LV volume, end-diastolic LV volume and LV ejection fraction were measured by the Simpson method using Argus software, Siemens. For the MDE short axis images, we evaluated the MF mass per patient, using a 5 standard deviation thresholding technique, on a CMR42 software, version 3.4.2 (Circle Cardiovascular Imaging, Calgary, Alberta, Canada). Normal LVEF was defined as above 50%. Test of Wilcoxon was used for comparison of myocardial fibrosis between baseline and follow-up CMR studies. Results Two patients died before the follow-up CMR. For all 74 patients, MF increased significantly from 11.3 ± 12.2 g on the baseline CMR to 15.9 ± 15.4 g, p<0.001. The number of segments with MF increased from 3.7 ± 3.3 to 5.1 ± 3.6, p<0.001. In a sub-group with LV dysfunction (n=11) MF increased from 26.9 ± 13.0 g to 35.5 ± 20.2 g, p=0.021. In a sub-group of patients with normal LVEF and no fibrosis (n=21) on the baseline CMR, MF progressed from 0 g to 1.5 ± 3.7 g, p=0.08. Conclusions Myocardial fibrosis detected by CMR progressively increases in patients with Duchenne and Becker muscular dystrophy over a period of 2.3 years. The progression occurs not only in patients with more advanced cardiomyopathy and LV dysfunction, but also in patients with normal function and no myocardial fibrosis at the baseline CMR.

Fetal cerebral ventricle volumetry: comparison between 3D ultrasound and magnetic resonance imaging in fetuses with ventriculomegaly

Objectives. The aim of this study was to evaluate feasibility of fetal lateral ventricle (LV) volumetry in fetuses with ventriculomegaly and to compare measurements performed by 3D sonographic method virtual organ computer-aided analysis (VOCAL) with those obtained by magnetic resonance imaging (MRI).Methods. This cross-sectional study evaluated 30 fetuses with atrial width (AW) between 10 and 30 mm, from 20 to 36 gestational weeks. Fifty-nine ventricles were measured by two observers. Sonographic volumetric measurements using VOCAL 30° were performed with an ACCUVIX XQ machine (Medison, Korea) and MRI assessments with a Sonata system using ARGUS software (Siemens, Germany). Agreement between both techniques was assessed by intraclass correlation coefficient (ICC) calculation, and proportionate Bland–Altman plots were constructed.Results. A high degree of reliability was observed between VOCAL and MRI measurements (ICC 0.928, 95%CI [0.876;0.958]). Bland–Altman plots confirmed the high correlation (mean of differences: 1.62 cm3 and standard deviation: ± 8.41 cm3).Conclusion. Three-dimensional volumetry of fetal LVs by VOCAL method has good agreement with fetal MRI in fetuses with ventriculomegaly and may be used as an additional tool in patient counseling and prognosis prediction.

Does measurement of exercise/rest calf muscle perfusion reserve with first-pass contrast-enhanced MRI in peripheral arterial disease perform better than exercise-only perfusion ?

Methods Sixteen healthy subjects and 3 symptomatic PAD patients (ABI 0.4-0.9) underwent contrast-enhanced perfusion MRI of the calf before and after plantar-flexion exercise using an MR-compatible pedal at 50 rpm for up to 20 minutes or until limiting symptoms. Contrast-enhanced first-pass images were obtained on a 3T Siemens Trio scanner by infusion of 0.1mM/kg of gadolinium-DTPA followed by a 20 mL saline flush at 4 mL/ second. A spoiled gradient echo dual contrast sequence with slices positioned 32 mm apart allowed for simultaneous acquisition of arterial input and muscle perfusion images. Time-intensity curves (TIC) were generated using ARGUS software (Siemens) for arterial input and the muscle group with the highest signal intensity (tissue function, TF). PI was measured as ratio of the slopes of the TF TIC/arterial input TIC. PR was defined as exercise TF/resting TF. PIR was calculated as exercise PI/rest PI. Ten of the controls and all 3 patients underwent repeat studies on a separate day. For 7 controls and all patients, measurements were normalized to proton density.

Association between proteinuria and left ventricular mass index: a cardiac MRI study in patients with chronic kidney disease

Chronic kidney disease (CKD) is associated with increased cardiovascular morbidity and mortality. We hypothesized that the level of proteinuria would correlate with left ventricular mass, providing a potential link between elevated protein excretion, left ventricular hypertrophy (LVH) and the increased mortality seen in patients with CKD. In order to do this, we assessed the determinants of left ventricular mass, measured using cardiac magnetic resonance (CMR) imaging, in patients with CKD. Patients attending the renal clinic with CKD stages 2-4 and diabetic nephropathy (n = 26) and IgA nephropathy (n = 23) were recruited. They underwent detailed demographic, biochemical and vascular phenotyping and CMR imaging. Proteinuria was measured using spot protein:creatinine ratio (PCR). Left ventricular mass index (LVMI) was calculated from short-axis cine imaging using Argus software and adjusted for body surface area. Log-PCR correlated significantly with LVMI, as did waist circumference, pulse pressure and systolic blood pressure. LVMI was higher in men. When these variables were entered into a linear regression model, log-PCR (P = 0.006) and systolic blood pressure (P < 0.001) independently predicted LVMI. Renal function was not associated with LVMI. Using volume-independent CMR imaging, we have demonstrated that the level of urinary protein excretion is independently and significantly associated with left ventricular mass in patients with CKD. This relationship was independent of blood pressure. This finding provides a novel link between CKD and increased cardiovascular risk.

Visualization of transcoronary ablation of septal hypertrophy in patients with hypertrophic obstructive cardiomyopathy: a comparison between cardiac MRI, invasive measurements and echocardiography

ObjectiveHypertrophic obstructive cardiomyopathy (HOCM) is treated by surgical myectomy or transcoronary ablation of septal hypertrophy (TASH). The aim of this study was to visualize the feasibility, success and short-term results of TASH on the basis of cardiac MRI (CMR) in comparison with cardiac catheterization and echocardiography.MethodsIn this in vivo study, nine patients with HOCM were treated with TASH. Patients were evaluated by transthoracic echocardiography, invasive cardiac angiography and CMR. Follow-up examinations were carried out after 1, 3 and 12 months. MR imaging was performed on a 1.5-T scanner. All images were processed using the semiautomatic Argus software and were evaluated by an attending thoracic radiologist and cardiologist.ResultsThe echocardiographic pressure gradient (at rest) was 69.3 ± 15.3 mmHg before and 22.1 ± 5.7 mmHg after TASH (P < 0.01, n = 9). The flux acceleration over the aortic valve examined (V max) was 5.1 ± 0.6 m/s before and 3.4 ± 0.3 m/s after the TASH procedure (P < 0.05). Also, there was a decrease of septum thickness from 22.0 ± 1.2 to 20.2 ± 1.0 mm (P < 0.05) after 6 ± 3 weeks. The invasively assessed pressure gradient at rest was reduced from 63.7 ± 15.2 to 21.2 ± 11.1 mmHg (P < 0.01) and the post-extrasystolic gradient was reduced from 138.9 ± 12.7 to 45.6 ± 16.5 mmHg (P < 0.01). All differences as well as the quantity of injected ethanol were plotted against the size or amount of scar tissue as assessed in the MRI. There was a statistically significant correlation between the post-extrasystolic gradient decrease and the amount of scar tissue (P = 0.03, r 2 = 0.5). In addition, the correlation between the quantity of ethanol and scar tissue area was highly significant (P < 0.01, r 2 = 0.6), whereas the values for the gradient deviation (P = 0.10, r 2 = 0.34), ΔV max (P = 0.12, r 2 = 0.31), as well as the gradient at rest (P = 0.27, r 2 = 0.17) were not significant.ConclusionTASH was consistently effective in reducing the gradient in all patients with HOCM. In contrast to the variables investigated by echocardiography, the invasively measured post-extrasystolic gradient correlated much better with the amount of scar tissue as assessed by CMR. We conclude that the optimal modality to visualize the TASH effect seems to be a combination of CMR and the invasive identification of the post-extrasystolic gradient.

Assessment of the accuracy and reproducibility of right ventricular volume measurements in patients with congenital heart disease

Methods Data from 24 patients (mean age 19 years; range: 0.2 to 51 years) with CHD who underwent CMR were reviewed. Patients with ventricular level shunts and more than mild tricuspid regurgitation were excluded. Cine steady state free precession imaging was acquired in stacked axial and short-axis slices. RV contours were traced manually. Argus software was used to compute the end systolic volume (ESV) and end diastolic volume (EDV) using Simpson's method, and stroke volume (SV) by subtracting ESV from EDV. RV SV was also measured directly by phase contrast (PC) imaging, acquired in the main pulmonary artery. Flow measurements were made using Argus software. Measurements were made twice by one skilled observer to assess intra-observer variability. A second skilled observer repeated these measurements in a blinded fashion to assess inter-observer variability. Agreement between PC SV and SV measured in the axial and short-axis planes was assessed using Lin's concordance correlation coefficient (CCC). Interand intra-observer variability was also assessed using Lin's CCC.

Quantification of global and regional left atrial function in paroxysmal atrial fibrillation using CMR derived 4-D wall motion analysis

Methods Eight healthy volunteers (6 male, mean 29.7 yrs) and 6 patients (6 male, mean 61.7 yrs) with paroxysmal AF underwent imaging during sinus rhythm on a 1.5 T scanner. Steady state free procession imaging of the LA, acquired in an axial stack and parasagittal at 6 mm slice thickness with no interslice gap, was retrospectively reconstructed into 25 phases per R-R interval. Segmentation of the LA wall was performed manually using ARGUS software (Siemens Medical Solutions). The following landmarks were identified manually at each phase and used to construct a spherical coordinate system: four pulmonary vein ostia and four points on the mitral annulus (superior, inferior, left, right). Using MATLAB, contour points were fitted with a 16-element mesh to obtain a continuous description of changes in atrial radius through space and time. LA volume and radial fractional shortening of each element were calculated for each phase and subject. Elements were separated into superior, inferior, septal and free walls for regional analysis. Differences between patients and volunteers were determined with an unpaired t-test.

Non invasive quantification of coronary endothelial function using 3 T MRI

Materials and methods Thirteen healthy volunteers (ten men, three women) without any coronary risk factors underwent magnetic resonance imaging in a 3 T scanner (Verio, Siemens, Erlangen, Germany). CPT was performed by immersing the right ankle in ice-water during four minutes. Heart rate and blood pressure were monitored throughout the protocol using a Maglife system (Schiller). Coronary sinus flow was measured at rest and during CPT using non breath-hold velocity encoded phase contrast cine MRI (repetition time/echo time: 45 ms/2 ms, slice thickness: 5.5 mm, field of view: 250 × 250 mm2, averages: 11, matrix: 256 × 256, flow encoding: 70 cm/sec, flip angle: 25°, acquisition time: 4 minutes, GRAPPA k-space reduction factor: 4). Myocardial function and morphology were evaluated using SSFP sequence. MBF was calculated combining coronary sinus flow quantification and morphologic data using Argus software (flow and 2D). Coronary endothelial function was assessed by comparing MBF at rest and during CPT. Coronary vascular resistance (CVR) and endothelium-dependent vasodilation index (EDVI) were calculated.