CMR Patient Safetyand Preparation

Kraig V. Kissinger, BS,RT(R)(MR)Beth Israel Deaconess Medical Center

Boston, Massachusetts

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Patient Safety Screening

• ALL Patients and Personnel must be carefully screened for contraindications to the MR environment.

• Entering the MR environment with certain objects or devices can result in injury or death.

• Physicians, Nurses and Technologists need to work together to make sure the MR exam is a safe experience.

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Patient Safety Screening

• Patients should be asked safety questions several times to be sure of accurate information.

• Patients can forget about experiences that are potentially dangerous or think that those experiences are not relevant to the situation.

• Patients can be uncomfortable sharing certain information if the risks are not understood.

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Patient Safety Screening

• The first safety screening is included on the CMR requisition.

• Check all items in the screening section before sending the requisition.

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Patient Safety Screening

• The second safety screening is completed by the patient.

• If the patient cannot complete the form another person that knows the patient’s history should complete the form.

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Patient Safety Screening

• After the patient has completed the screening form the technologist will review it with the patient and answer any questions as well as verify the information provided.

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Patient Safety Screening

• Patients with Pacemakers or Implanted Defibrillators should NOT have an MR examination.

• Patients with Aneurysm Clips should NOT have an MR examination.

• Patients with heart valve prostheses are safe to have an MR examination.– “an MR procedure is not considered to be hazardous for a patient that

has any of the heart valve prostheses or annuloplasty rings that have been tested. This recommendation includes the Starr-Edwards Model Pre-6000 heart valve prosthesis previously suggested to be a potential risk for a patient undergoing an MR procedure.” [www.mrisafety.com]

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Patient Safety Screening

• Most orthopedic implants are safe for MRI.• Many other devices and implants are NOT safe for MRI

and need to be evaluated for each situation.– Ocular Implants

– Otologic Implants

– Vascular Clips

– Penile Implants

– Biostimulators and Implanted Pumps

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Patient Safety Screening

• Patients with history of gunshot wounds or shrapnel must be evaluated individually.

• Patients with history of injury to the eye involving metal must be evaluated individually and probably will require radiographs of the orbits to rule out residual metal in the eyes.

• Some transdermal drug delivery patches can be unsafe.• Injuries have been reported in patients with tatoos

containing certain inks containing metallic particles.

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Patient Safety Screening

• An extensive list of implants and devices that have been tested can be found at www.mrisafety.com

• If there is a question about safety, the issues should be addressed before the patient is scheduled for MRI.

• If you’re not sure if your patient is safe for MRI check with us.

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Patient Preparation• After safety screening is established patients will change

into a hospital gown.• Lockers are provided for patients to secure their

belongings.– Watch or other jewelry

– Wallet / Credit Cards / Coins

– Keys

– Hair pins or other accessories

– Hearing aids

– Pens

– Cell phones, pagers and other electronic devices

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Patient Preparation• Explain the procedure to the patient.• Make sure the patient understands what they need

to do so that we can get diagnostic images.• Make sure the patient is comfortable so they can

remain still for the procedure.• Practice breath holding.• Establish communication through the intercom.• Make the patient feel that they are in control of the

situation.

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Patient Preparation• Patients will be in a supine position for the exam.

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Patient Preparation• Electrodes will be placed on the patient’s chest for

ECG gating. Accurate gating is ESSENTIAL.

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Patient Preparation• The imaging coil is positioned on the patient’s chest and

secured with a velcro strap.

• The patient needs to understand that it’s important that this device doesn’t move from where we place it.

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Patient Preparation• Reproducible and

comfortable breath holding is required for good image quality.

• Most breath holds are 10-12 seconds.

• If patients have trouble holding their breath we may use supplemental oxygen.

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Patient Preparation• Gradient switching noise can be in excess of 100dB.

• Hearing protection is given in two forms.– Foam ear plugs are given to all patients for noise attenuation.

– Padded headphones further reduce the noise patients hear but also allow for communication between patient and technologist.

– The headphones also allow patients to listen to music during the examination which can help alleviate anxiety.

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CMR Examination• Basic CMR Examination to evaluate LV/RV function.

– Scout Scans

– Functional SSFP Cine Scans in the 2 chamber, HLA, Short Axis and 4 chamber orientations

– T1 weighted transverse images

– Qflow scans perpendicular to the ascending aorta and main pulmonary artery.

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CMR Examination• Scout Scans

– Images through the chest in three orthogonal planes are acquired in one scan.

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CMR Examination• Functional SSFP Cine Scans

– The 2 Chamber view is a single oblique planned on a transverse scout slice parallel to the septum.

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CMR Examination• Functional SSFP Cine Scans

– The HLA (Horizontal Long Axis) view is planned on the 2 Chamber view. The slice plane is adjusted to bisect the mitral valve and LV apex.

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CMR Examination• Functional SSFP Cine Scans

– Short Axis views are planned on the HLA view. The slice plane is adjusted to be parallel to the mitral/tricuspid valve plane.

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CMR Examination• Functional SSFP Cine Scans

– 4 Chamber view is planned on a Short Axis view. The slice plane is rotated to bisect the lateral wall of the LV and the RV free wall.

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CMR Examination• T1 Weighted Axial

– Images are acquired to cover from the aortic arch to the inferior border of the heart as seen on a coronal slice.

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CMR Examination• Qflow of Ascending Aorta

– FH offset from T1 Axial slice at the level of the right pulmonary artery is put into the Qflow scan.

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CMR Examination• Qflow of Main Pulmonary Artery

– A double oblique orientation is planned from an axial and sagittal slice to measure perpendicular to the vessel.

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CMR Examination• The examination described requires approximately 30

minutes to complete depending on the patient.

• Scout scans and functional cine acquisitions are accomplished with breath holding of 10-12 seconds.

• T1 Axials and Qflow acquisitions are performed without breath holding. Multiple signal averages are collected to compensate for respiratory motion. Before these scans the patients are reminded to breathe normally and lie still.

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