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Cardiac function and myocardial perfusion immediately following maximal treadmill exercise inside the MRI room.

Jekic M, Foster EL, Ballinger MR, Raman SV, Simonetti OP - J Cardiovasc Magn Reson (2008)

Bottom Line: We modified a commercial treadmill such that it could be safely positioned inside the MRI room to minimize the distance between the treadmill and the scan table.We observed a 3.1-fold increase in cardiac output and a myocardial perfusion reserve index of 1.9, which agree with reported values for healthy subjects at peak stress.This study successfully demonstrates in-room treadmill exercise CMR in healthy volunteers, but confirmation of feasibility in patients with heart disease is still needed.

View Article: PubMed Central - HTML - PubMed

Affiliation: Dorothy M, Davis Heart and Lung Research Institute, 473 W 12th Ave, Columbus, OH43210, USA. Mihaela.jekic@osumc.edu

ABSTRACT
Treadmill exercise stress testing is an essential tool in the prevention, detection, and treatment of a broad spectrum of cardiovascular disease. After maximal exercise, cardiac images at peak stress are typically acquired using nuclear scintigraphy or echocardiography, both of which have inherent limitations. Although CMR offers superior image quality, the lack of MRI-compatible exercise and monitoring equipment has prevented the realization of treadmill exercise CMR. It is critical to commence imaging as quickly as possible after exercise to capture exercise-induced cardiac wall motion abnormalities. We modified a commercial treadmill such that it could be safely positioned inside the MRI room to minimize the distance between the treadmill and the scan table. We optimized the treadmill exercise CMR protocol in 20 healthy volunteers and successfully imaged cardiac function and myocardial perfusion at peak stress, followed by viability imaging at rest. Imaging commenced an average of 30 seconds after maximal exercise. Real-time cine of seven slices with no breath-hold and no ECG-gating was completed within 45 seconds of exercise, immediately followed by stress perfusion imaging of three short-axis slices which showed an average time to peak enhancement within 57 seconds of exercise. We observed a 3.1-fold increase in cardiac output and a myocardial perfusion reserve index of 1.9, which agree with reported values for healthy subjects at peak stress. This study successfully demonstrates in-room treadmill exercise CMR in healthy volunteers, but confirmation of feasibility in patients with heart disease is still needed.

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Two vacuum mattresses (head and shoulders, and foot to upper thigh) are used for repositioning the subject between rest and stress. Removal of air with a vacuum pump causes the mattresses to form a rigid mold around the subject.
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Figure 4: Two vacuum mattresses (head and shoulders, and foot to upper thigh) are used for repositioning the subject between rest and stress. Removal of air with a vacuum pump causes the mattresses to form a rigid mold around the subject.

Mentions: Before exercise, the subject was positioned on the MRI table using two vacuum mattresses (Vac-Lok Cushions, MEDTEC, Orange City, IA), and slice localization and resting function scans were performed. One vacuum mattress was placed under the head and shoulders and the other under the legs extending from foot to upper thigh (Figure 4). Removal of air with a vacuum pump causes the mattresses to rigidly conform to the body. These devices are commonly used for repositioning of patients undergoing repeated radiation therapy sessions. This system was used to ensure that the subject returned to the same position after exercise such that stress imaging could be performed using the slice planes previously prescribed at rest.


Cardiac function and myocardial perfusion immediately following maximal treadmill exercise inside the MRI room.

Jekic M, Foster EL, Ballinger MR, Raman SV, Simonetti OP - J Cardiovasc Magn Reson (2008)

Two vacuum mattresses (head and shoulders, and foot to upper thigh) are used for repositioning the subject between rest and stress. Removal of air with a vacuum pump causes the mattresses to form a rigid mold around the subject.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2244608&req=5

Figure 4: Two vacuum mattresses (head and shoulders, and foot to upper thigh) are used for repositioning the subject between rest and stress. Removal of air with a vacuum pump causes the mattresses to form a rigid mold around the subject.
Mentions: Before exercise, the subject was positioned on the MRI table using two vacuum mattresses (Vac-Lok Cushions, MEDTEC, Orange City, IA), and slice localization and resting function scans were performed. One vacuum mattress was placed under the head and shoulders and the other under the legs extending from foot to upper thigh (Figure 4). Removal of air with a vacuum pump causes the mattresses to rigidly conform to the body. These devices are commonly used for repositioning of patients undergoing repeated radiation therapy sessions. This system was used to ensure that the subject returned to the same position after exercise such that stress imaging could be performed using the slice planes previously prescribed at rest.

Bottom Line: We modified a commercial treadmill such that it could be safely positioned inside the MRI room to minimize the distance between the treadmill and the scan table.We observed a 3.1-fold increase in cardiac output and a myocardial perfusion reserve index of 1.9, which agree with reported values for healthy subjects at peak stress.This study successfully demonstrates in-room treadmill exercise CMR in healthy volunteers, but confirmation of feasibility in patients with heart disease is still needed.

View Article: PubMed Central - HTML - PubMed

Affiliation: Dorothy M, Davis Heart and Lung Research Institute, 473 W 12th Ave, Columbus, OH43210, USA. Mihaela.jekic@osumc.edu

ABSTRACT
Treadmill exercise stress testing is an essential tool in the prevention, detection, and treatment of a broad spectrum of cardiovascular disease. After maximal exercise, cardiac images at peak stress are typically acquired using nuclear scintigraphy or echocardiography, both of which have inherent limitations. Although CMR offers superior image quality, the lack of MRI-compatible exercise and monitoring equipment has prevented the realization of treadmill exercise CMR. It is critical to commence imaging as quickly as possible after exercise to capture exercise-induced cardiac wall motion abnormalities. We modified a commercial treadmill such that it could be safely positioned inside the MRI room to minimize the distance between the treadmill and the scan table. We optimized the treadmill exercise CMR protocol in 20 healthy volunteers and successfully imaged cardiac function and myocardial perfusion at peak stress, followed by viability imaging at rest. Imaging commenced an average of 30 seconds after maximal exercise. Real-time cine of seven slices with no breath-hold and no ECG-gating was completed within 45 seconds of exercise, immediately followed by stress perfusion imaging of three short-axis slices which showed an average time to peak enhancement within 57 seconds of exercise. We observed a 3.1-fold increase in cardiac output and a myocardial perfusion reserve index of 1.9, which agree with reported values for healthy subjects at peak stress. This study successfully demonstrates in-room treadmill exercise CMR in healthy volunteers, but confirmation of feasibility in patients with heart disease is still needed.

Show MeSH
Related in: MedlinePlus