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C M R
Daniel Alejandro Benítez
Abstract
Resumen
Advances in technology have made MRI an excellent tool for the
diagnosis, prognosis and therapeutic planning for many pathologies
affecting the cardiovascular system. We will briefly discuss the technique of Cardiac MRI (or CMR) showing an iconographic presentation of image findings in studies performed in our department.
There are two basic sequences, namely: sequence of "dark blood" or
spin echo, and sequence of "bright blood" or gradient echo (GE).
The first is used to obtain anatomical information and the second
is mainly used for a functional cardiac evaluation. The GE sequence
used in most resonators is called Steady-State Free Precession (SSFP).
The study protocol is not based on the conventional orthogonal views
but on views applied to the position of the heart in the thorax. CMR
has revolutionized the study of cardiovascular diseases, obtaining
high-quality images.
El avance de la tecnología ha hecho que la Resonancia Magnética
(RM) brinde una excelente herramienta para el diagnóstico, pronóstico y planeamiento terapéutico de muchas de las patologías que
afectan al sistema cardiovascular. Expondremos resumidamente la
técnica de la Resonancia Magnética Cardíaca (RMC), realizando
una presentación iconográfica de los hallazgos imagenológicos en
los estudios realizados en nuestro servicio. Existen dos secuencias
básicas: la secuencia de “sangre negra” o spin echo, y la secuencia
de “sangre blanca” o gradiente de echo (GE). La primera es utilizada para obtener información anatómica y la segunda principalmente para la valoración funcional cardíaca. La secuencia GE
utilizada en la mayoría de los resonadores es la llamada SteadyState Free Precession (SSFP) o Secuencia de Estado Estacionario de
Precesión Libre. La RMC ha revolucionado el estudio de las patologías cardiovasculares, obteniéndose imágenes de alta calidad.
Key words: Magnetic resonance, cardiopathy, cardiovascular disease.
Palabras clave: Resonancia magnética, patología cardíaca, enfermedad cardiovascular.
Introduction
Cardiovascular diseases significantly affect the
world population and, in Argentina, it constitutes
the leading cause of death. Therefore, the study of
this system for early diagnosis has great relevance.
For a long time, radiology could not provide effective data on alterations affecting the heart and the
great vessels. Due to advances in technology, MRI
has become an excellent tool for the diagnosis,
prognosis and therapeutic planning for many pathologies affecting the cardiovascular system (1).
CMR is a non-invasive, reproducible technique
that has several clinical applications. It has become
the standard reference to evaluate cardiac anatomy
and function. However, the study of the cardiovasContact information:
Daniel Alejandro Benítez.
Diagnostic Imaging Department, Sanatorio Allende - Córdoba Capital.
e-mail: [email protected]
Vol.  / Nº  - Mayo 
cular pathology through MRI requires an ample
knowledge about the cardiac anatomy and function, as well as about the technique used to acquire
images. The purpose of this paper is to explain, in
a simple way, the technique used to conduct CMR
and create an iconographic presentation of the pathologies evaluated through this technique.
Generalities
In every MRI it is important to take into account the
contraindications to perform it, such as Stents, pacemakers or defibrillators (2).
The best spatial and quality image resolution is
currently obtained with 3T equipment; however,
Received: April ,  / Accepted: July , 
Recibido:  de abril de  / Aceptado:  de julio de 

Cardiovascular Magnetic Resonance
most diagnostic centers in our country are equipped with 1.5T resonators, which are still useful for
those purposes (3).
There are two basic sequences in MRI applied to
the study of the heart, namely: sequence of "dark
blood" or spin echo (SE), and sequence of "bright
blood" or gradient echo (GE). Variations are performed on these sequences that allow us to obtain
different information of the cardiovascular system.
Other sequences are: myocardial tagging, phase-encoding for fluid flow quantification, myocardial delayed enhancement, Inversion-Recovery (IR) and
myocardial perfusion.
To obtain clean images of the heart through MRI,
it is necessary to have systems that minimize the
physiological movements of the heart and of the
process of breathing. An electrocardiogram (ECG)
record of the patient is obtained so that the software can synchronize the acquisition of images
with heartbeats. The better the acquisition of the
ECG record, the better the synchronization will be.
Breathing movement decreases performing the
study in sustained expiration or breathing synchronization (4-6).
Basic Sequences
SE or “dark blood” sequence
As the name implies it, this sequence shows the
blood in vessels and heart chambers as hypo-intense. Repetition Time (TR) in this sequence has to
be the same as the R-R interval of the patient's ECG.
Since weighting images depends on TR and TE
(Echo Time), when TR is the same as the R-R interval and short TE, T1 images are obtained. Whereas
when TR is equal to 2 or more R-R intervals, the TE
has to be long in order to obtain T2 images (Fig. 13). They can also be weighted with proton density
(3-6).
Double inversion recovery radio-frequency pulses are applied to suppress the blood signal. When
a R wave (trigger) is detected in the ECG, a nonselective inversion radio-frequency (RF) pulse is applied, immediately followed by a selective reversion
RF pulse. In this way, it is possible for a potential
source of artifact, such as the slow flow of the
blood that can appear bright and can be mixed
with anatomical structures, not to emit signal with

Benítez D.
successive RF pulses applied in the acquisition of
images. The acquisition of an image in a cardiac
cycle is used in many protocols as a previous anatomical reference. Nowadays, high definition images of the heart are not acquired in real-time. They
are divided in lines or groups of lines and each of
them is acquired at the same time as the cardiac
cycle of different heartbeats. That is why the movement of the heart is synchronized with the QRS
complex of the ECG. Fast Spin Echo (FSE) or Turbo
Spin Echo (TSE) sequences acquire several images
with each heartbeat, reducing the duration of the
study, unlike conventional SE which acquires one
image per heartbeat. All of the "dark blood" sequences are used to obtain anatomical information
(3-6).
GE or “bright blood” sequence
In this sequence, the blood emits a signal making
it hyper-intense. It becomes more hyper-intense
when the direction of the flow is perpendicular to
the view of the image. They present a high temporal resolution making it possible to analyze them in
Cine-MR. They are used for functional cardiac studies (Fig. 4-6) (3-6).
There are two types of fast GE sequences. With
the earliest one, the residual transverse magnetization (TM) is discarded (Spoiled GE) and it is not
used for the creation of signal. Examples of this sequence are FLASH, SPGR, T1-FFE, depending on
the brand name. They are produced through the
emission of an excitation radio-frequency pulse, generally smaller than 90°, followed by a reversion
gradient in, at least, two directions, creating a detectable echo signal (3-6).
Steady-State (SS) sequences constitute the second
type of GE sequences. The TM is not discarded but
reoriented to contribute to the formation of a steady
state. They provide a better space-time resolution
and a better contrast between circulating blood and
the myocardium. When there is a balance between
the TM and the longitudinal magnetization (LM)
two types of signals appear. The first type is a postexcitation signal (S+), created by the most recent
RF pulse. The second signal (S-) constitutes the recreation of the echo, prior to the next RF pulse.
There are three types of SS sequences depending
on the signal sampling that is used to create the
image. The S- sampling, that is, the pre-excitation
Revista Argentina de Diagnóstico por Imágenes
Cardiovascular Magnetic Resonance
Benítez D.
signal, is the one of interest for CMR, also called
Steady-State Free Precession (SSFP). Their names
depend on the resonator brand: FIESTA (Fast Imaging Employing Steady-State Acquisition) or FISP
(Fast Imaging with Steady-State Precession) (7-9).
They are very useful in Cine-MR sequences.
Fig. :
a b
c d
CMR Bright blood and dark
blood sequence.
Ventricular fibroma (*) located in
the anteroposterior sector of the
left ventricle (A and C) showing in
T (B) an irregular peripheral hypersignal with intramural septa. The
SPAIR sequence (D) shows a homogeneous hyper-signal.
Fig. : CMR: Cine sequences in four-chama b
c d
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ber (A) and short axis (B) views showing a rounded formation (arrow)
with a thin wall, hypo-intense in T
(C) and hyper-intense in T (D), of
cystic nature, in the lateral wall of the
left ventricle, close to the apex.

Cardiovascular Magnetic Resonance
Benítez D.
Fig. :
a b
c d
CMR: Cine sequences in four-chamber (A and
C) showing an important dilation of the right
atrium (*) with an endocavity image, compatible with a thrombus adhered to the wall
(arrow). Right ventricle with a dysmorphic aspect and decreased size, with parietal thickening (curved arrow). IR sequence after
gadolinium (B) showing an endocardial enhancement of the apex (arrowhead). "Dark blood"
T weighted sequence (D) showing areas of laminar hyper-signal, probably in relation to a replacement of the fibroadipose tissue of the
apex. Findings compatible with endocardial fibroelastosis.
Fig. :
Outflow Tract of the Pulmonary Artery.
a-b
Postsurgical control of pulmonary atresia showing a
narrowing (arrowhead) of the pulmonary valve
(arrow) with irregularities, related to calcifications.
The narrowing conditions a turbulent flow post-valvular (curved arrow) in systole (S).
Fig. :
Cine Sequence in Four-chamber View.
MRI of two patients showing two inter-articular communications. One is of ostium secundum type (arrow)
and the other is of sinus venosus type (arrowhead),
showing an enlargement of the right atrium.
a-b

Revista Argentina de Diagnóstico por Imágenes
Cardiovascular Magnetic Resonance
Benítez D.
Fig. :
Cine Sequence in Four-chamber View.
Slight inter-ventricular and sub-valvular communication with a
diameter of  mm (arrowhead).
Study Protocol
The reconstruction views applied to the thorax (coronal, sagittal and axial) cannot be applied to the
study of the heart since it is located 45° measuring
from the vertebral column, by its long axis. This is
why specific views are used. First, multiplanar localizing images are obtained in the strict orthogonal
planes (axial, sagittal and coronal). These must be
acquired in total expiration. It is necessary to plan
the specific cardiac locators over the multiplanar reconstructions (9). We emphasize that orthogonal
planes help value the thoracic repercussions of the
cardiac pathology and other incidental findings not
necessarily associated with cardiac problems.
The study protocol is based mainly on the following views: "short-axis", "long-axis" or "two-chamber" views which also assess the mitral and
tricuspid valves; "four-chamber" views and views
going out of the left and right ventricle tracts, which
assess the aortic and pulmonary valves. The length
of the study will depend on the pathology; it can
vary from 20 to 60 minutes.
Current Value
CMR produces a reproducible and effective evaluation of the ventricular function, the segmental and
global myocardial contractility, the ischemic cardiopathy, and the myocardium (Fig. 7 and 8). The
myocardial perfusion study through the use of paramagnetic contrast agents, such as gadolinium
with DTPA, for the evaluation of chronic myocardial
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necrosis (11) provides information about the contractility, thickness and viability of the myocardium.
It is useful for the correct assessment of the myocardium and of the complications after an infarction, such as ventricular aneurysm (Fig. 9),
intraventricular thrombosis and valvular dysfunction, among others (Fig. 10). Through the pharmacologic
stress
(dipirydamole,
adenosine,
dobutamine) CMR shows ischemic areas that are
not evident in ECG alterations (12). Infarctions areas
are hyperintense due to contrast uptake (Fig. 11),
whereas in ischemic areas there is no Gadolinium
uptake during the stress test and it is recovered in
the resting phase.
The assessment of the pericardium has always
been an important challenge for imaging techniques. Many times, findings are indirect or inconclusive, or there is a need for a skillful operator to
perform the study. CMR is an accurate and non-ionizing technique that provides effective information
for an adequate diagnosis (Fig. 12-14).
Transthoracic echocardiogram (TTE) is the leading technique for the detection of cardiac tumors.
However, it has some weaknesses: it is operator-dependent, there is a restriction in the visual field (especially in large-sized patients) and the information
on right cavities is limited. CMR not only helps in
the detection of cardiac tumors, but also in its characterization through different sequences (Fig. 15
and 16) and the relation with cardiac and mediastinal structures (13).
Cine-MR has helped with the visualization of the
cardiac valves with an excellent resolution (Fig. 17
and 18), and also with the correct quantification of

Cardiovascular Magnetic Resonance
transvalvular velocity and pressure gradients. It provides an excellent visualization of valve vegetation,
thrombus, valve insertion site, valvular area and
mobility (14). Congenital cardiac pathologies have
been studied with CMR in its early stages and after
surgery producing satisfactory results in children
and adults, since it provides the most accurate ana-
Benítez D.
tomical and functional information (15) (Fig. 1923).
Many systemic pathologies affect the heart and
not only arterial hypertension. CMR helps in their
correct assessment, as shown in figure 24 (Fig. 24),
a patient with an amyloidosis diagnosis.
Fig. :
a-b
Fig. :
a b
c

Cine Sequences in Short Axis (left) and
Four-chamber (right) views.
Note the increase in size of the trabecular left ventricle, with deep inter-trabecular recesses (arrows), compatible with non-compacted myocardium.
IR Sequences after Gadolinium Injection.
Showing focal patched areas of enhancement of the mesocardium at the septum
and inferior wall level without relation to an arterial course (arrowheads), compatible with myocarditis.
Revista Argentina de Diagnóstico por Imágenes
Cardiovascular Magnetic Resonance
Vol.  / Nº  - Mayo 
Benítez D.
Fig. :
Ventricular Aneurysm.
a b
c d
Cine sequences in four-chamber and
short axis (left) views and IR after
Gadolinium injection (right). Left
ventricle increased in size with
aneurysm of the septa and the anterior wall (*), showing a marked parietal and septa narrowing (arrow).
There is a transmural enhancement
of the inter-ventricular septa, of the
anterior wall of the left ventricle
and of the apical region (arrowheads) showing non-viable fibrotic
areas after infarction.
Fig. :
Valvular Dysfunction.
a-b
Cine sequence of the aorta outflow tract. In diastole
(D) there is a reflux jet (arrow) in the aortic valve. In
systole (S) there is an aortic valve stenosis conditioning the turbulent blood flow of the ascending
aorta (arrowhead).
Fig. :
Myocardium Infarction.
a b
c d
Cine sequence in four-chamber
and long axis views showing parietal narrowing and aneurysm
dilation of the apex (arrows),
with an endocavitary thrombus
(*) adhered to the wall. Below,
delayed acquisition IR sequences
after Gadolinium injection showing transmural infarction (arrowheads) compromising the
anteroseptal region and the apex
circumference, evident due to a
delayed enhancement (hypersignal).
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Cardiovascular Magnetic Resonance
Benítez D.
Fig. :
a b
c
Fig. :
a b
c d

Pericardial Effusion.
Cine sequence in four-chamber
(on the left) and the short axis
views during systole (S) and diastole (D) (on the right) showing a
severe pericardial effusion without thickening of the visceral
membranes or parietal pericardium.
Pericarditis.
Cine sequence in short axis view
(B) showing pericardial effusion
(curved arrow). The IR sequence
after gadolinium (C) shows thickening and laminar uptake of the
visceral membrane and the parietal membrane of the pericardium
in a global way (arrowheads).
Fig. :
Pericardial Cyst.
a-b
Right para-atrial cystic image (arrows) showing
communication with the pericardium (arrowhead),
compatible with pericardial cyst.
Revista Argentina de Diagnóstico por Imágenes
Cardiovascular Magnetic Resonance
Benítez D.
Fig. :
a b
c d
Fig. :
a-b
Vol.  / Nº  - Mayo 
Cardiac Tumor.
Male patient with antecedents of
melanoma with metastasis in lung
and liver, showing an endoluminal,
irregular, multi-lobed lesion (*), located in the outflow tract of the
right ventricle. It infiltrates the anterior face of the ventricle and the
valvular plane. In systole, there is a
turbulent blood flow in the pulmonary artery (arrow). After Gadolinium injection there is an intense
and homogeneous enhancement
(arrowhead).
Fig. :
Atrial Myxoma.
a b
c d
Cine sequence in four-chamber
(on the right above) and short
axis (on the left below) views,
showing a protruding lesion with
septal origin in the left atrial cavity (arrowheads). During atrial
systole (Sa) there is an oscillating
movement that makes contact
with the mitral valve (arrow),
with a slight prolapse of it. After
Gadolinium injection, there is a
moderate enhancement (curved
arrow).
Perivalvular Fluid Axial acquisition with dark blood
T weighted image (to the left) and Cine sequence
for the outflow tract of the aorta (to the right), showing the presence of a non-homogeneous fluid
(arrowheads) surrounding the prosthetic aortic
valve (arrow) and extending to the ascending aorta
and the aortic arch, surrounding them in a circumference.
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Cardiovascular Magnetic Resonance
Benítez D.
Fig. :
a b
c d
Fig. :
a-b
Fig. :
a-b

Aortic Valve.
Cine sequences showing bicuspid
aortic valve (above). Normal aortic
valve with its three valves (below).
Open bicuspid (arrow). Normal
and open (arrowhead).
Interventricular Communication.
Cine sequence in four chamber view. Closed interventricular communication. There is a patch (arrow)
over the right face of the inter-ventricular septum.
Systole (S) and diastole (D).
Coarctation.
MIP reconstruction sequence (arrow) and sagittal
acquisition in dark blood T weighted sequence
(arrowhead) showing coarctation of the descending
aorta.
Revista Argentina de Diagnóstico por Imágenes
Cardiovascular Magnetic Resonance
Benítez D.
Fig. :
a-b
Fig. :
a-b
Superior Vena Cava Duplication.
Axial acquisition (to the left) and coronal Cine (to
the right) sequence after Gadolinium injection showing a superior vena cava duplication. The left vena
cava flows into the left atrium (arrowhead). Right
vena cava (arrow), pulmonary artery (*).
Complex Abnormality.
Cine sequence in four-chamber and short axis views
showing a sole left ventricle in performing function
(*). Interatrial communication (arrowhead) with a
sole atrial ventricular valve. It shows an aortic arch
and a descending aorta on the right (arrow). There
is also a slight pericardial effusion (curved arrow).
The patient had a transposition of great vessels and
gastric tuberosity on the right (not shown here).
Fig. :
a bc
d e
Vol.  / Nº  - Mayo 
Transposition of Great
Vessels.
The aorta (Ao) originates in
the right ventricle (VD) showing thickened walls (thin
arrows); the pulmonary artery
(Ap) originates in the left ventricle (VI). There is a pulmonary vein (thick arrow)
flowing into the right atrial
(*); the inferior vena cava is
ascending towards the left
atrial (arrowhead). The curved arrow signals the aorta.

Cardiovascular Magnetic Resonance
Fig. :
a b
c d
Cardiac Amyloidosis.
Outflow tract of the left ventricle in ventricular systole (A) and Cine four-chamber view (C) showing a slight thickening of
the aortic open valve (arrowheads) and thickening of both atrial ventricular valves (arrows). The same patient with delayed sequences after Gadolinium injection showing mural and papillary muscles enhancement (curved arrow). The patient
has a diagnosis of Amyloidosis.
Conclusion
CMR is a technique that is overturning cardiovascular pathologies diagnosis, since it can make a correct characterization of the morphological and
functional alterations observed. To perform and report these studies requires a great knowledge about
the cardiac function and pathologies, as well as the
physics used in the creation of images. This is due
to the fact that a slight change in the acquisition of
images may improve the quality of the study in
each patient. We should not forget that we are part
of a team; therefore, it is necessary to rely on Bioimaging Technicians specially trained for these type
of studies. In many cases, the presence of a cardiologist is necessary to control the patient, especially

Benítez D.
due to the use of medication for the myocardial
stress. This method may not be available in most
centers due to several factors, such as the necessary
training and the cost of the equipment and the
study. However, we believe that CMR will gain
ground and that we should be prepared to perform
the studies in an adequate way so it serves for a correct diagnosis.
Revista Argentina de Diagnóstico por Imágenes
Cardiovascular Magnetic Resonance
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