Low Cost Magnetic Resonance Imaging-Compatible Stepper Exercise Device for Use in Cardiac Stress Tests

Cardiovascular disease is the leading cause of death worldwide. Many cardiovascular diseases are better diagnosed during a cardiac stress test. Current approaches include either exercise or pharmacological stress echocardiography and pharmacological stress magnetic resonance imaging (MRI). MRI is the most accurate noninvasive method of assessing cardiac function. Currently there are very few exercise devices that allow collection of cardiovascular MRI data during exercise. We developed a low-cost exercise device that utilizes adjustable weight resistance and is compatible with magnetic resonance (MR) imaging. It is equipped with electronics that measure power output. Our device allows subjects to exercise with a leg-stepping motion while their torso is in the MR imager. The device is easy to mount on the MRI table and can be adjusted for different body sizes. Pilot tests were conducted with 5 healthy subjects (3 male and 2 female, 29.2 ± 3.9 yr old) showing significant exercise-induced changes in heart rate (+42%), cardiac output (+40%) and mean pulmonary artery (PA) flow (+%49) post exercise. These data demonstrate that our MR compatible stepper exercise device successfully generated a hemodynamically stressed state while allowing for high quality imaging. The adjustable weight resistance allows exercise stress testing of subjects with variable exercise capacities. This low-cost device has the potential to be used in a variety of pathologies that require a cardiac stress test for diagnosis and assessment of disease progression.

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Abstract 2812: A multi-modality robotic ultrasound and bioluminescence system provides a low-cost alternative to magnetic resonance imaging for measurement of orthotopic pancreatic tumors

10.1158/1538-7445.am2021-2812 ◽

2021 ◽

Author(s):

Juan Rojas ◽

Jordan Joiner ◽

Brian Velasco ◽

Alexandra De Lille ◽

Tomek J. Czernuszewicz ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Low Cost ◽

Pancreatic Tumors ◽

Resonance Imaging ◽

Robotic Ultrasound

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Abstract 15075: Exercise Stress Testing and Stress Cardiac Magnetic Resonance Imaging for Detection of Inducible Ischemia in a Large Cohort of Children With Anomalous Aortic Origin of a Coronary Artery

Circulation ◽

10.1161/circ.142.suppl_3.15075 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Amna Qasim ◽

Tam Doan ◽

Tam Dan Pham ◽

Dana Reaves-O’Neal ◽

Silvana M Molossi

Keyword(s):

Magnetic Resonance Imaging ◽

Cardiac Magnetic Resonance ◽

Coronary Artery ◽

Magnetic Resonance ◽

Cardiac Magnetic Resonance Imaging ◽

Exercise Stress ◽

Resonance Imaging ◽

Inducible Ischemia ◽

St Depression ◽

Stress Cardiac Magnetic Resonance

Introduction: The current AATS and AHA/ACC guidelines recommend maximal exercise stress test (mEST) to identify ischemia and direct decision-making in patients (pts) with anomalous aortic origin of a coronary artery (AAOCA). Stress cardiac magnetic resonance imaging (sCMR) has reliably identified myocardial perfusion abnormalities. Hypothesis: We hypothesize that EST and sCMR do not agree in the detection of inducible ischemia in AAOCA. Methods: AAOCA pts <21 years old were prospectively enrolled and evaluated following a standardized approach from 12/2012-12/2019. mEST was performed in pts ≥6 years old, except those who presented with cardiac arrest or physical limitations. Demographic data, coronary anomaly type, EST (symptoms, ST changes, arrhythmias, metabolic parameters) and sCMR data were collected. A mEST was defined as max HR ≥85%ile with a subgroup defined as respiratory exchange ratio (RER) >1.05. Abnormal mEST included: significant ST changes (≥1 mm horizontal or downsloping ST-depression, ≥2 mm upsloping ST depression, ST elevation), high-grade arrhythmia, abnormal peak VO2 (<85% predicted). Continuous and categorical variables were compared using Wilcoxon-Rank sum and Fisher’s exact/χ2 respectively. McNemar’s test was used to determine the agreement between EST and sCMR. Results: Of 147 pts with AAOCA and both EST and sCMR, 140 achieved max HR ≥85%ile on EST. Table 1 compares demographics and EST parameters in pts with inducible ischemia on sCMR (+sCMR) vs without (-sCMR). Significant ST changes were seen in 2/26 (7.7%) pts with +sCMR compared to 8/114 (7%) pts with -sCMR. An abnormal mEST did not agree with sCMR in identifying inducible ischemia (McNemar p < 0.001) in all AAOCA patients who achieved max HR, nor in the sub-group with RER >1.05 (n = 88). Conclusions: mEST does not agree with sCMR in identifying inducible ischemia in patients with AAOCA. Our data suggest that mEST should not be used alone for the detection of inducible ischemia.

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Comparison of Preoperative Assessment of Patient’s Metabolic Equivalents (METs) Estimated from History versus Measured by Exercise Cardiac Stress Testing

Anesthesiology Research and Practice ◽

10.1155/2018/5912726 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5 ◽

Cited By ~ 3

Author(s):

Adam S. Weinstein ◽

Martin I. Sigurdsson ◽

Angela M. Bader

Keyword(s):

Cardiac Failure ◽

Stress Testing ◽

Stress Test ◽

Preoperative Evaluation ◽

Preoperative Assessment ◽

Exercise Stress ◽

Cardiac Stress ◽

Metabolic Equivalents ◽

Cardiac Stress Testing ◽

Cardiac Stress Test

Background. Preoperative anesthetic evaluations of patients before surgery traditionally involves assessment of a patient’s functional capacity to estimate perioperative risk of cardiovascular complications and need for further workup. This is typically done by inquiring about the patient’s physical activity, with the goal of providing an estimate of the metabolic equivalents (METs) that the patient can perform without signs of myocardial ischemia or cardiac failure. We sought to compare estimates of patients’ METs between preoperative assessment by medical history with quantified assessment of METs via the exercise cardiac stress test. Methods. A single-center retrospective chart review from 12/1/2005 to 5/31/2015 was performed on 492 patients who had preoperative evaluations with a cardiac stress test ordered by a perioperative anesthesiologist. Of those, a total of 170 charts were identified as having a preoperative evaluation note and an exercise cardiac stress test. The METs of the patient estimated by history and the METs quantified by the exercise cardiac stress test were compared using a Bland–Altman plot and Cohen’s kappa. Results. Exercise cardiac stress test quantified METs were on average 3.3 METS higher than the METs estimated by the preoperative evaluation history. Only 9% of patients had lower METs quantified by the cardiac stress test than by history. Conclusions. The METs of a patient estimated by preoperative history often underestimates the METs measured by exercise stress testing. This demonstrates that the preoperative assessments of patients’ METs are often conservative which errs on the side of patient safety as it lowers the threshold for deciding to order further cardiac stress testing for screening for ischemia or cardiac failure.

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A low cost, volunteer-based program to prepare children to undergo magnetic resonance imaging without sedation

Children s Health Care ◽

10.1080/02739615.2018.1545581 ◽

2018 ◽

Vol 49 (1) ◽

pp. 1-19

Author(s):

Michele Capurso ◽

Corrado Rossetti ◽

Luca Mutti ◽

Anita Ciani ◽

Valerio Santangelo

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Low Cost ◽

Resonance Imaging

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Cardiac magnetic resonance imaging in clinical practice

Radiologia Brasileira ◽

10.1590/s0100-39842014000100006 ◽

2014 ◽

Vol 47 (1) ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

Adriana Dias Barranhas ◽

Alair Augusto S. M. D. dos Santos ◽

Otavio R. Coelho-Filho ◽

Edson Marchiori ◽

Carlos Eduardo Rochitte ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Clinical Practice ◽

Cardiac Magnetic Resonance ◽

Magnetic Resonance ◽

Cardiac Magnetic Resonance Imaging ◽

Myocardial Viability ◽

Outpatient Basis ◽

Resonance Imaging ◽

Pharmacological Stress ◽

Positive Results

Objective To evaluate and describe indications, mainly diagnoses and cardiac magnetic resonance imaging findings observed in clinical practice. Materials and Methods Retrospective and descriptive study of cardiac magnetic resonance performed at a private hospital and clinic in the city of Niterói, RJ, Brazil, in the period from May 2007 to April 2011. Results The sample included a total of 1000 studies performed in patients with a mean age of 53.7 ± 16.2 years and predominance for male gender (57.2%). The majority of indications were related to assessment of myocardial perfusion at rest and under pharmacological stress (507/1000; 51%), with positive results in 36.2% of them. Suspected myocarditis was the second most frequent indication (140/1000; 14%), with positive results in 63.4% of cases. These two indications were followed by study of arrhythmias (116/1000; 12%), myocardial viability (69/1000; 7%) and evaluation of cardiomyopathies (47/1000; 5%). In a subanalysis, it was possible to identify that most patients were assessed on an outpatient basis (58.42%). Conclusion Cardiac magnetic resonance has been routinely performed in clinical practice, either on an outpatient or emergency/inpatient basis, and myocardial ischemia represented the main indication, followed by investigation of myocarditis, arrhythmogenic right ventricular dysplasia and myocardial viability.

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Low-Cost Magnetic Resonance Imaging

The Journal of Photographic Science ◽

10.1080/00223638.1989.11737025 ◽

1989 ◽

Vol 37 (3-4) ◽

pp. 121-122

Author(s):

S. Pittard ◽

R.E. Ellis ◽

M.E. Fry ◽

R. Jacoby ◽

E.A. Moore ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Low Cost ◽

Resonance Imaging

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Comparison of micro-ultrasound and multiparametric magnetic resonance imaging for prostate cancer: A multicenter, prospective analysis

Canadian Urological Association Journal ◽

10.5489/cuaj.6712 ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

Laurence Klotz ◽

Giovanni Lughezzani ◽

Davide Maffei ◽

Andrea Sanchez ◽

Jose Gregorio Pereira ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Prostate Cancer ◽

Magnetic Resonance ◽

High Resolution ◽

Predictive Value ◽

Low Cost ◽

Resonance Imaging ◽

Multiparametric Magnetic Resonance Imaging ◽

Clinically Significant ◽

Software Fusion

Introduction: High-resolution micro-ultrasound has the capability of imaging prostate cancer based on detecting alterations in ductal anatomy, analogous to multiparametric magnetic resonance imaging (mpMRI). This technology has the potential advantages of relatively low cost, simplicity, and accessibility compared to mpMRI. This multicenter, prospective registry aims to compare the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of mpMRI with high-resolution micro-ultrasound imaging for the detection of clinically significant prostate cancer. Methods: We included 1040 subjects at 11 sites in seven countries who had prior mpMRI and underwent ExactVu micro-ultrasound-guided biopsy. Biopsies were taken from both mpMRI targets (PI-RADS >3 and micro-ultrasound targets (PRIMUS >3). Systematic biopsies (up to 14 cores) were also performed. Various strategies were used for mpMRI target sampling, including cognitive fusion with micro-ultrasound, separate software-fusion systems, and software-fusion using the micro-ultrasound FusionVu system. Clinically significant cancer was those with Gleason grade group ≥2. Results: Overall, 39.5% were positive for clinically significant prostate cancer. Micro-ultrasound and mpMRI sensitivity was 94% vs. 90%, respectively (p=0.03), and NPV was 85% vs. 77%, respectively. Specificities of micro-ultrasound and MRI were both 22%, with similar PPV (44% vs. 43%). This represents the initial experience with the technology at most of the participating sites and, therefore, incorporates a learning curve. Number of cores, diagnostic strategy, blinding to MRI results, and experience varied between sites. Conclusions: In this initial multicenter registry, micro-ultrasound had comparable or higher sensitivity for clinically significant prostate cancer compared to mpMRI, with similar specificity. Micro-ultrasound is a low-cost, single-session option for prostate screening and targeted biopsy. Further larger-scale studies are required for validation of these findings.

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