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Clinical indications when MRI is the procedure of choice: case examples

from CSMCJan 19 2013

Louise Thomson MBChB

Cardiac Imaging / Nuclear Medicine Physician

Disclosures

• Research funding– Giliad pharmaceuticals

• Off label use – Delayed enhancement and stress perfusion are off

label uses of Gadolinium contrast , which is notlabel uses of Gadolinium contrast , which is not FDA approved for cardiac MRI.

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Imaging with CT vs MRI

CT MRI

• Axial

• High spatial resolution

• Single energy– HU to define tissue type

• Cannot measure flow

• Contrast essential for

• Any imaging plane

• Limited spatial resolution

• Multiple sequence types– Tissue characterization

• Can measure flow

• Contrast not essential forContrast essential for visualizing vessels/heart

• Ok with PPM/ICD

• Radiation

Contrast not essential for visualizing vessels/heart

• Maybe ok with PPM/ICD

• Zero radiation

Clinical indications

CT MRI

• Coronary calcium

• Coronary anatomy – Extent and severity of

atherosclerotic change

• Cardiac structure/function– Congenital

• Coronary anatomy– Proximal coronary disease

• Cardiac structure/function– Congenital

– Mass

– Infiltrative/cardiomyopathies

– Mass

• Chest vascular anatomy– Pulmonary veins/arteries

– Aorta / arch branch vessels

• Myocardial viability

• Chest vascular anatomy– Pulmonary veins/arteries

– Aorta/arch branch vessels

• Pericardial disease

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When MRI is the test of choice• Diagnosis and characterization of the extent of

disease in cardiomyopathy:M di i– Myocarditis

– Sarcoidosis

– Restrictive – amyloid, iron overload, hypertrophic

– RV cardiomyopathies

• Pericarditis for evaluation of constriction

d / l• Cardiac mass/ malignancy

• Congenital heart disease

• Viability imaging CAD prior to high risk revasc.

Case

43 yo man presented with 3 hour chest pain. P i t d i i h d f hillPrior to admission had fever, chills, sore throat, myalgia and fatigue with swollen nodes.

Troponin 7.89 increased to peak 40.3.

ECG non ischemicECG non ischemic.

Coronary angiography normal, LVEF 55%

CT pulm angio: Negative for PE.

Endomyocardial biopsy performed, negative.

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Intense delayed hyperenhancement in a patchy distribution involving subepicardium.

A di i fA diagnosis of myocarditis confirmed by MRI.

50 yr old man presents with 3 hr CP after returning from Mexico where he had an illness for a week with fever and diarrhea as well as intermittent left arm pain

Case

and diarrhea as well as intermittent left arm pain.

Hypertension and elevated cholesterol

Elevated Troponin (1.1) and transient inferior ST elevation.

Normal coronary arteries at (invasive) catheterization.

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Regional wall motion abnormalities may be minimal and LVEF normal/ mildly decreased. Patchy enhancement involving mid myocardium.

Myocarditis

• Acute myocardial dedema

• Patchy LGE

• Diagnostic and prognostic value

• Guide biopsy• Guide biopsy

• Intramural septal or patchy subepicardial LGE

Kindermann I et al. J Am Coll Cardiol 2012;59:779-92LEJT 2012

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Myocarditis

• CMR is the primary non invasive tool for di idiagnosis

• Presence of LGE is the best independent predictor of death in pt with viral myocarditis. HR 8.4 all cause mortality, HR 12.8 cardiac mortality. (superior to LVEF, LVEDV, NYHA y ( p , ,class)

Grun S et al. J Am Coll Cardiol. 2012;59:1604–15.

Case

• 48 yo presents with syncope during exercise, ECG h ith RBBB i d i tinew ECG changes with RBBB, axis deviation.

Hypertensive.

• Normal coronary arteries at angiogram.

• ETT exercise induced heart block

• Echo LVH• Echo: LVH

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Stage 3

RBBB, Exercise induced AV block with decline in HR at peak workload.

Stage 4

CMR

Images from cine (done with contrast) and delayed enhancement. LVEF normal. Abnormal septal signal intensity and intense delayed enhancement.Endomyocardial biopsy: Granuloma on electron microscopy. Diagnosis: cardiac sarcoidosis. No extracardiac manifestations of disease

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Cardiac Sarcoidosis• Cardiac involvement in 20

– 50% in post mortem 50% in post mortem studies in pt with sarcoidosis

• Cardiac only disease may occur

• Patchy/nodular LGE, basal and subepicardial

McDermott et al. World J Cardiology 2012; 4: 103-111Donnell et al. Radiology 2012; 262: 403-422

LEJT 2012

Cardiac Sarcoidosis

• Patients with di l dmyocardial damage

on DE-CMR had a 9 fold higher rate of adverse events and 11.5 fold higher rate of cardiac death than patients without damage.

Patel MR et al, Detection of myocardial damage in patients with Sarcoidosis. Circulation 2009;120:1969-1977LEJT 2012

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Case

• 69 yo man presented with SOB and malaise d f d t b i CHFand found to be in CHF.

• Prior history CAD, hypertension, chronic renal impairment, prostate cancer, Hepatitis C

• MRI to differentiate ischemic from non ischemic cardiomyopathyischemic cardiomyopathy.

Thickened myocardiumPleural effusionsStiff ventricle with diastolic dysfunctionDiffuse enhancement after contrast.

Triple inversion F d

Cine

recovery. Fat saturated TSE.

T1 weighted Delayed enhancement

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• Myocardial biopsy negative. Amyloid and iron t i ti (N t d th t th bistains negative. (Note made that the biopsy

contained fibrous connective tissue and endothelial lining of endocardial derivation. No myocardial fibers identified).

• Bone marrow biopsy: Plasma cell myeloma p y y(35-50%).

• Diagnosis: amyloidosis secondary to myeloma.

Case

• 72 yo referred for evaluation of hypertrophic di th R t SOBOEcardiomyopathy. Reports SOBOE.

• PHx hypertension. BP 163/93

• ECG RBBB and increased precordial voltage, decreased limb lead voltage.

• Echo marked LVH diastolic dysfunction and• Echo marked LVH, diastolic dysfunction and increased echogenicity of thick septum.

• Clinical dilema: Hypertrophic heart disease or infiltrative cardiomyopathy?

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Thickened myocardiumStiff ventricle with diastolic dysfunctionDiffuse enhancement after contrast.

• Endomyocardial biopsy positive

• Staining positive for antibodies to prealbumin (transthyretin) and negative for amyloid A and beta 2 microglobulin.

• Diagnosis: Senile amyloid.

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CMR delayed enhancement imaging in Cardiac Amyloidosis

• In populations with known cardiac amyloid LGE mayIn populations with known cardiac amyloid, LGE may be present in ~70% pt.

• There is a characteristic pattern

• LGE is prognostically important

• How CMR compares to Tc99m PYP is not defined

• Reliance on TI scout pattern in very diffuse infiltrate

• Myocardial T1 mapping will aid in detection of diffuse infiltrative processes such as this.

LEJT 2012

Austin et al JACC Cardiovasc Imaging 2009;2:1369–77.

CMR after cardiac transplantation

Triple IR tissue characterization, cine and delayed enhancement imaging. Septal hypertrophy has variable signal on TSE pre contrast and is enhancing on delayed contrast imaging, consistent with presence of rejection in this transplanted heart.

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Hypertrophic Cardiomyopathy

• Accurate LV volumes, EFmass, EF

• Late Gadolinium Enhancement (LGE) in middle third of hypertrophied wallyp p

• Prognostic value

• Earlier detection than echo

Vogel-Claussen J et al Radiographics 2006;26:795-810

LEJT 2012

Hypertrophic Cardiomyopathy

• Prevalence of LGE varies 40 – 80%

• Presence of LGE associated with 7x increase in risk of NSVT.

• Studies to date are underpowered to address whether LGE is an independent predictor of sudden cardiac death or cardiovascularsudden cardiac death or cardiovascular mortality.

Kwon et al; Int J Cardiovasc Imaging. 2008;24:617–25

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Bruder O., Wagner A., Jensen C.J.; et al. Myocardial scar visualized by cardiovascular magnetic resonance imaging predicts major adverse events in patients with hypertrophic cardiomyopathy, J Am Coll Cardiol 56 2010 875-887

LEJT 2012

Apical hypertrophy, difficult to see by echo and easily characterized by MRI. Bright

h fenhancement of the apex after contrast, indicating presence of fibrosis within the hypertrophied myocardial segments

LEJT 2012

segments.

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LGE in Dilated CM• Mid wall pattern LGE in up to 40%

• Prognostic value for prediction of cardiac g pdeath and VT

• Fibrosis detected by CMR is a substrate for inducible VT in DCM

• Pt with LGE having ICD have 8x greater risk of adverse outcome (CHF hospitalization, ICD discharge and cardiac death).

Lehrke et al; Heart. 2011;97:727–32Assomull et al; J Am Coll Cardiol. 2006;48:1977–85Wu et al; J Am Coll Cardiol. 2008;51:2414–21Iles et al; J Am Coll Cardiol 2011;57:821–8.

Case

• 45 yo with sickle cell disease

• Repeated admissions from 2008-2011 with transfusions 4 x / year.

• Echo 2008 LVEF 49%, 2011 LVEF 47% with LV dilation. Prior chelation therapy but lost to hematology follow up for 4 yearshematology follow up for 4 years.

• Re admitted with sickle cell crisis.

• MRI for quantitation of myocardial iron.

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TE 2.59

TE 11.51

TE 4.82

TE 7.05

TE 9.28

TE 13.74

TE 15.97

TE 18.2

Iron content reduces signal intensity of tissue. Liver is black, vertebrae are black on the lateral image.

TSE images acquired with increasing TE msec, allowing a plot of the TE vs myocardial intensity, and from that the calculation of the T2* (normal 50msec)

T2* <20 msec is definitely abnormal.

Myocardial Siderosis

• Iron overload cardiomyopathy is a leadingcardiomyopathy is a leading cause of death in chronic blood transfusion therapy

• Reversible- chelation

• Echo may be normal, and may occur without liver iron or increased ferritinor increased ferritin

• MRI quantitation of iron overload has prognostic value and may be used to monitor response to treatment.

LEJT 2012

Kirk et al; Circulation. 2009;120:1961–8

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Pericardial effusion

• 33 yo woman presented to the ER for the d ti i th ith h tsecond time in a month with cough, sputum

persisting despite antibiotic and steroid. Interval increase in cardiac silhouette size noted on CXR.

• Echo demonstrated pericardial effusion and pfeatures suggestive of tamponade. Admitted for pericardiocentesis with 600ml clear yellow fluid removed.

Pericardial thickening and enhancement with effusion and respiratory variation in LV h D

Cine SSFP Post contrast

shape – D shape in inspiration.

Delayed enhancement

Expiration Inspiration

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Cardiac mass

67 year old with abdominal pain and bloating, nephrotic syndrome and breathlessness. TTE shows a cardiac mass. MRI to evaluate prior to planned cardiac surgery.

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F18 FDG PET/CTNov 11th 2011

Disease in nodalDisease in nodal regions of the neck, chest, abdomen, and in the skeleton.

F18 FDG PET/CTDec 20th 2011

Disease resolvedDisease resolved.

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Circulation 2005;112(6):855-861 Utility of Cardiac Magnetic Resonance Imaging in the Diagnosis of Hypertrophic Cardiomyopathy. Rickers, Maron et al

Echo and CMR wall thickness measures similar

In 3/48 echo did not demonstrate LVH (6%)

Echo underestimated anterolateral free wall thickness in 20%

E h i d t ll thi k (>30 ) i 10% ti t

“CMR enhances the assessment of LV hypertrophy, particularly in the anterolateral LV free wall, and represents a powerful supplemental imaging test with distinct diagnostic advantages for selected HCM patients”.

Echo missed extreme wall thickness (>30mm) in 10% patients

Is this hypertrophic cardiomyopathy?

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Coronary Artery Imaging

• Is MRI ready for prime time?

• When would MRI be helpful as an alternative to CTA.

• What advances have been made in MR coronary imaging?

Advances in MR coronary artery imaging

• Free breathing (1997) with respiratory i tnavigator

• T2 preparation to suppress myocardial signal and enhance contrast (1999)

• First multicenter trial (2001 NEJM)

• Development of SSFP imaging technique• Development of SSFP imaging technique (increased signal)

• Whole heart MRA (2003)

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127/138 patients at 7 hospitals prior to angiography between 2005- 2007.Whole heart MRA at 1.5T without contrast.sl nitrate prior to imaging. Scan time 9.5 +- 3.7min

Free breathing navigator gated whole heart coronary MRA with SSFP, radial k space sampling, SENSE acceleration.

1.3 x 1.3 x 1.7mm reconstructed to 512 x512 x 150 matrix, interpolated 0.6 x 0.6 x 0.8mm. Patient specific acquisition window and abdominal restraint.

• Sensitivity 88%, Specificity 72%, PPV 71%, NPV 88%

• NPV for left main stenosis or 3VD 99%

• AUC 0.87

When compared to invasive angiogram, including lesions with a reference diameter >2mm

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• Improved efficiency of the image acquisition by use of novel• Improved efficiency of the image acquisition by use of novel respiratory motion correction

• Whole heart MRA with 1mm3 isotropic spatial resolution and scan time 6.8 ± 0.9minutes

• 100% success in acquisition vs 43% with standard sequence

• Scan time reduced by factor of 2.5.

MRI Coronary Imaging

60-year-old women with stable angina

CTA MRA x-ray Angiography

Slide courtesy Dr D. Li PhD

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77-year-old man with stable angina

Slide courtesy Dr D. Li PhD

Comparison of MRA and CTA for detecting ≥50%

27 patients who had at least one coronary calcification with calcium score > 100

stenosis: overall sensitivity, specificity, and overall AUC

MRA CTA p value

sensitivity 0.806 0.750 0.564

specificity 0.746 0.476 0.002

AUC 0 831 0 651 0 030AUC 0.831 0.651 0.030

AUC (Area under ROC curve) indicates diagnostic performance of CTA or MRA. > 0.8 is considered to have good diagnostic accuracy

Slide courtesy Dr D. Li PhD

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1.5T1 x 1 x 1mmNo contrast

SingleSingle volumetric acquisition

Free breathing

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Coronary imaging

• Whole heart MRA continues to improve

• The whole heart MRA is good for rapid evaluation of coronary anatomy to exclude presence of coronary anomalies and to detect severe proximal coronary stenosis.

• Image spatial resolution remains inferior toImage spatial resolution remains inferior to CTA and invasive angiography.

Protocol for Magnetic Resonance Imaging of Patients With Permanent Pacemakers and

Implantable Defibrillators at 1.5 Tesla

Saman Nazarian, Ariel Roguin, Menekhem M. Zviman, Albert C. Lardo, Timm L. Dickfeld, Ronald D. Berger, David A.

Bluemke, and Henry R. Halperin

68 MRI examinations in 55 patients56% had a permanent pacemaker

No symptoms consistent with device movement, torque or heating. N i i t i hibiti f i44% had an ICD

Of all patients13% had a bi-ventricular pacing system 22% were pacemaker dependent

No inappropriate inhibition of pacingNo unexpected or rapid activation of pacing

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Patient with Bi-V Device

TaggingGradient Echo

• Smaller

Cardiac MRI with Implanted Devices

1998 2002

• Less magnetic materials • Improved electromagnetic interference protection