Cardiac Protocol
Overview
Cardiac MR imaging has become the new gold standard for the evaluation of cardiac anatomy, function and for characterizing cardiac masses. Multi-plan imaging capability of MRI makes it well suited modality for evaluating the complex anatomy of the heart, complex congenital cardiac anomalies, and cardiac functions. Besides high quality morphological imaging, cardiac MRI also allows the evaluation of the myocardial wall motion, calculation of left & right ventricle volumes, mass, stroke volume, ejection fraction , and demonstration of myocardial perfusion of ischemic heart. The other advantage of cardiac MRI is the ability of obtaining blood flow measurements (flow volume and flow velocity) through the cardiac valves, aorta and pulmonary arteries, so that the regurgitation fractions, Qp /Qs and significance of diseases can be evaluated.
Common Indications ICD9 Codes
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745 |
Bulbus Cordis anomalies and anomalies of cardiac septal closure |
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745.0 |
Common truncus |
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745.1 |
Transposition of great vessels |
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745.2 |
Tetraogy of Fallot |
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745.3 |
Common ventricle |
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745.4 |
Ventricular septal defect |
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745.5 |
Ostium secundum type atrioseptal defect |
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745.6 |
Endocardial cushion defect |
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746 |
Other congenital anomalies of the heart |
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746.0 |
Anomalies of pulmonary valve |
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746.1 |
Tricuspid atresia and stenosis |
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746.2 |
Ebstein’s anomaly |
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746.3 |
Congenital stenosis of aortic valve |
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746.4 |
Congenital insufficiency of aortic valve |
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746.5 |
Congenital mitral stenosis |
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746.6 |
Congenital mitral insufficiency |
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746.7 |
Hypoplastic left heart syndrome |
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746.81 |
Subaortic stensis |
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746.82 |
Cor triatrium |
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746.83 |
Infundibular pulmonic stenosis |
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746.87 |
Malposition of heart and cardiac apex |
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746.89 |
Congenital cardiomegaly, pericardial defect, diverticulum |
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394 |
Diseases of mitral valve (rheumatic) |
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|
395 |
Diseases of aortic valve (rheumatic) |
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396 |
Diseases of aortic and mitral valves (rheumatic) |
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|
402 |
Hypertensive heart disease |
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410-414 |
Ischemic heart disease |
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414.1 |
Aneurysm and dissection of heart |
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|
421 |
Acute and subacute endocarditis |
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424.0 |
Mitral valve disorders (except rheumatic) |
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424.1 |
Aortic valve disorders (except rheumatic) |
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424.2 |
Tricuspid valve disorders (except rheumatic) |
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424.3 |
Pulmonary valve disorders (except rheumatic) |
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425 |
Cardiomyopathies |
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427.3 |
Atrial Fibrillation |
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|
428 |
Heart failure |
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|
420 |
Acute pericarditis |
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420.9 |
Acute pericardial effusion |
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|
421 |
Acute and subacute endocarditis |
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422 |
Acute myocarditis |
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423 |
Other diseases of pericardium |
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423.0 |
Hemopericardium |
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423.1 |
Adhesive pericarditis |
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423.2 |
Constructive pericarditis |
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423.9 |
Pericarditis with effusion |
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212.8 |
Benign neoplasm of heart |
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215.4 |
Benign neoplasm of great vessels |
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212.5 |
Benign neoplasm of mediastinum |
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164.9 |
Malign neoplasm of mediastinum |
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164.1 |
Malign neoplasm of the heart (endocardium, epicardium, myocardium, pericardium |
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198.89 |
Secondary malign neoplasm |
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212.7 |
Benign neoplasm |
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V42.1 |
Transplanted heart |
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V42.2 |
Transplanted valve |
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Scheduling Guidelines
First Ask; 1- Why is the cardiac MRI being requested?
2- Do you have pacemaker, or cardiac defibrillator? Is it MR compatible?
3- Have you ever had cardiac surgery? If the answer is ‘yes’ ask ‘when’ and ‘why’.
4- Have you ever been diagnosed for ischemic or congenital heart disease?
Patient Preparation
· Contraindications include the presence of a cardiac pacemaker, cardiac defibrillator, and Swan-Ganz catheter. MR study is also recommended to be delayed for 6 to 8 weeks after an implant or coronary stent placement.
· The cardiac MRI for functional evaluation alone does not require Gd injection. If the patient has a mass, ischemic heart disease or congenital heart disease, then he/she will require Gd injection. If necessary for the further evaluation of cardiopulmonary structures, start an iv line (20 or 22 gauge).
· ECG gating is essential for cardiac imaging. First, prepare the skin for lead placement. If necessary, shave the body hairs for maximum lead-skin contact and scrub the skin with an abrasive to create edema to improve electrical conductivity. Position the ECG electrodes (RA, LA, RL and LL) on the chest of the patient (in supine position, the most motionless area is the posterior chest). It is best to use MRI electrodes which have no metal (only carbon snaps) and a large surface area with abundant lubrication to minimize burns. Do not place leads over bony areas and avoid looping ECG leads which may result in superficial burns and can increase electrical interference from gradient activity. Leads should not be too far away from each other. Click ‘Gating control’ from the Rx manager area, turn on the advanced ECG gating. View R waves for at least 16 heart cycles while patient is lying down still. If there is a difficulty in detecting the R waves, or the R wave amplitude is low (<1mV) reposition the ECG leads. The detected vectors will be I, II, or III leads. Choose the one which has a clean trace. Whenever you change the lead, do not forget to update the R-peak amplitude. If some of the R waves are missing trigger marks, reduce ‘Cardiac Trigger Level’ to 50%.
· Both fast breath-held and respiratory triggered sequences are used in cardiac studies. For respiratory gating and triggering, place the respiratory monitoring bellows around the patient’s abdomen or chest, so the operator will know if the patient is cooperating with breathing instructions.
· Valium (5-10mg po) or Xanax (1-2 mg po) if patient is claustrophobic.
· Provide ear plugs or music headphones.
Coil: In adults 8 channel cardiac phased array coil, in infants knee coil or head coil.
Patient positioning: Supine, feet first. Placing the arms above the head decreases wrap around artifact. But most adults cannot tolerate arms overhead for extended periods and thus along the side or crossed over the chest is acceptable. Place comfortable pillows for head and arm support, and a cushion under the knees to relieve pressure on the lower back.
Landmark: Advance the table into the magnet bore, and landmark at mid-sternum (mid-chest). The upper edge of the posterior coil should be above the cranial edge of scapula. The upper edge of the anterior coil should be at the clavicle level. Do not let the anterior and posterior coil elements touch each other.
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CARDIAC SEQUENCES |
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IMAGING PARAMETERS |
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Plane |
3-plane |
Axial |
Axial |
Oblique |
Oblique |
Oblique |
Oblique |
Coronal |
Oblique |
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Mode |
2D |
2D |
2D |
2D |
2D |
2D |
2D |
3D |
2D |
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Pulse Sequence |
Localizer |
Fast GRE |
FSE-XL |
SE |
Fiesta |
FSE |
FSE-IR |
Fast TOF GRE |
Fast 2D PC |
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Imaging Options |
None |
Fast,Calib |
Gat,Seq,BSP, ZIP512,Fast,Asset |
None |
Gat,Seq, Asset,Fast |
Gat,Seq,VBw BSP,Fast |
Gat,Seq,VBw BSP,Fast |
MPh,ZIP512, ZIP2,Asset,Fast |
Gat,Seq,FC, Fast |
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SCAN TIMING |
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# of Echoes |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
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TE |
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42 |
Min Full |
Minimum |
42 |
42 |
Minimum |
Minimum |
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TR |
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300 |
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Flip Angle |
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40 |
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30 |
30 |
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Bandwidth |
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62.50 |
15.63 |
125.00 |
62.50 |
62.50 |
62.50 |
31.25 |
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ETL |
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32 |
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32 |
32 |
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BSP TI |
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Auto |
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Auto |
Auto |
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Inv Time |
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150 |
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ADDITIONAL PARAMETERS |
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SAT |
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1 |
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Multiphase |
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3 phases/loc |
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ACQUISITION TIMING |
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Freq |
256 |
|
256 |
256 |
256 |
256 |
256 |
512 |
256 |
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Phase |
128 |
|
256 |
256 |
192 |
256 |
256 |
256 |
256 |
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NEX |
1 |
|
1 |
1 |
1 |
1 |
1 |
1 |
1 |
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Phase FOV |
1 |
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0.75 |
1 |
1 |
0.75 |
0.75 |
1 |
1 |
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#acq/locs Bef Pause |
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0 |
1 |
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1 |
1 |
1 |
1 |
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Freq DIR |
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R/L |
R/L |
Unswap |
Unswap |
S/I |
S/I |
S/I |
Unswap |
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Auto Cent Freq |
Water |
Water |
Water |
Water |
Water |
Water |
Water |
Water |
Water |
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Auto Shim |
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Yes |
Yes |
Yes |
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Yes |
Yes |
Yes |
Yes |
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Phase Correct |
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Yes |
Yes |
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Yes |
Yes |
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SCANNING RANGE |
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FOV |
48 |
48 |
28 |
12 |
40 |
28 |
28 |
40 |
32 |
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Slice Thickness |
10 |
8 |
8 |
8 |
8 |
8 |
8 |
4 |
6 |
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Spacing |
10 |
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0 |
0 |
0 |
0 |
0 |
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10 |
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Start – End |
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