Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3715_Библиотеки_им_академика_М_И_Перельмана
.pdf
116
https://t.me/medicina_free
8 Imaging Studies andHaemodynamics inChronic Constrictive Pericarditis
a
e
Fig. 8.23 Frontal chest radiograph (a) and volume rendered images (b–d) show extensive pericardial calcication along the diaphragmatic surface and free walls of both ventricles. Four-chamber
(e), short-axis (f) and two-chamber (g and h) reconstructions of CT angiography show peripherally
calcied pericardial collection along the right atrium and right ventricle with pericardial calcication along the diaphragmatic surface and free walls of both ventricles. Note is made of biatrial
dilation and tubular ventricles. (LA- Left atrium, LV-Left ventricle, RA-Right atrium, RV-Right
ventricle)
a
b
f
b
c
g
d
h
c
de
Fig. 8.24 Frontal chest radiograph (a) shows plaque-like calcication along the diaphragmatic
surface of the heart. Note is made of bilateral pleural effusion. Four-chamber (b) and short-axis (c)
reconstructions of CT angiography and volume rendered images (d and e) show extensive nearcircumferential pericardial calcication. Note is made of biatrial dilation and tubular ventricles.
(LA- Left atrium, LV-Left ventricle, RA-Right atrium, RV-Right ventricle)
d
8.3 Computed Tomography
https://t.me/medicina_free
117
a
b
c
ef
Fig. 8.25 Frontal chest radiograph (a) shows plaque-like calcication along the atrioventricular
groove. Four-chamber (b) and short-axis (c) reconstructions of CT angiography and volume rendered images (d, e and f) show extensive pericardial calcication predominantly along the atrioventricular groove. Note is made of biatrial dilation. (LA- Left atrium, LV-Left ventricle, RA-Right
atrium, RV-Right ventricle)
8.3.3 Scout Images
Scout images are acquired in the axial, coronal, and sagittal planes to plan the subsequent cardiac views. Axial fast spin-Echo (FSE) images and Half-Fourier acquisition single shot turbo spin echo (HASTE) are ECG gated rapid acquisitions and do
not require to hold breath. They can detect dilation of veins, lung and mediastinal
pathologies, pleural effusion, and ascites.
8.3.4 Real Time Cine Steady-State Free Precision Imaging
Cine steady-state free precision images are typically acquired in single breath-hold
and are obtained in vertical long-axis, short-axis, and four-chamber planes. Tissues
with a high T2/T1 ratio, e.g. fat, uid, and blood, will appear bright in this sequence;
tissues with low T2/T1 ratio, e.g. myocardium, will appear darker intermediate in
this sequence. This sequence has low spatial resolution and high temporal resolution.
The functional consequences of constrictive pericarditis, namely cardiac volumes, global and regional myocardial function and cardiac masses, are evaluated in
this sequence. This sequence is useful in assessment of rapid physiologic changes.
With this sequence, respiratory variation of the septal motion can be evaluated and
helps in the diagnosis of constrictive pericarditis.
118
https://t.me/medicina_free
8 Imaging Studies andHaemodynamics inChronic Constrictive Pericarditis
a
c
e
b
d
f
g
Fig. 8.26 Frontal (a) and left lateral (b) chest radiographs show calcication along the diaphragmatic surface and left border of the heart. Four-chamber (c) and short-axis (d) reconstructions of
CT angiography and volume rendered images (e–g) show extensive pericardial calcication predominantly along the free wall of the ventricles and the atrioventricular groove. Note is made of
biatrial dilation. (LA- Left atrium, LV-Left ventricle, RA-Right atrium, RV-Right ventricle)
cd
8.3 Computed Tomography
https://t.me/medicina_free
119
a
Fig. 8.27 Volume rendered images (a–c) show extensive pericardial calcication predominantly
along the free wall and diaphragmatic surface of bilateral ventricles and the atrioventricular
groove. Volume rendered image (d) shows thick calcic spurs inltrating into the right ventricular
myocardium. (LA- Left atrium, LV-Left ventricle, RA-Right atrium, RV-Right ventricle)
b
a
b
Fig. 8.28 Volume rendered images (a and b) show extensive pericardial calcication (*) along the
right atrioventricular groove and over the right ventricular (RV) free wall and RV outow tract.
(LV: left ventricle; RA: right atrium)
120
https://t.me/medicina_free
8 Imaging Studies andHaemodynamics inChronic Constrictive Pericarditis
8.3.5 Myocardial Tagging withSpatial Modulation
ofMagnetization
Myocardial tagging with spatial modulation of magnetization (SPAMM) is typically performed in vertical long-axis, short-axis, and four-chambers projections.
Tags are visible as dark bands in the myocardium and they fade over time. Normally
during a cardiac cycle, the continuity of the tags is lost between the visceral and
parietal pericardium. However, in constrictive pericarditis this feature is altered,
making it useful in the detection of pericardial adhesion and myocardial involvement.
8.3.6 T1 andT2 Weighted Images
T1 and T2 weighted images are obtained in vertical long-axis, short-axis, and
four -chamber projections. These sequences help in the morphologic assessment of
the pericardium, like thickness, effusion, and masses.
8.3.7 T2-Weighted Triple Inversion Fast Spin-Echo
andSTIR Imaging
T2-weighted triple-inversion fast spin-echo and short tau inversion-recovery (STIR)
images are obtained in vertical long-axis, short-axis, and four-chamber projections.
They are similar to T2-weighted fast spin-echo images but with fat suppression
which enables detection of myocardial oedema and pericardial uid or oedema.
8.3.8 Early Post Contrast T1-Weighted Fast
Spin-Echo Imaging
T1-weighted fast spin-echo sequences are obtained 15seconds after IV injection of
0.1–0.2mmol/kg of gadolinium-based contrast agent, in vertical long-axis, shortaxis, and four-chamber projections. They detect pericardial contrast enhancement
found in acute or chronic inammatory pericarditis and in pericardial tumors.
8.3.9 Delayed Enhancement Imaging
Phase sensitive inversion recovery delayed enhanced images are acquired 5 and
15minutes after injection of 0.1–0.2mmol/kg of gadolinium-based contrast agent. The
sequence is acquired in vertical long-axis, short-axis, and four-chamber planes. This
sequence also helps in detection of pericardial and myocardial inammation and masses.
8.3 Computed Tomography
https://t.me/medicina_free
121
8.3.10 Velocity-Encoded Phase-Contrast Imaging
Velocity-encoded phase-contrast images are acquired at the level of the ascending
aorta. Aortic ow can be quantied with this sequence. Furthermore, right and left
atrial pressure curves can be estimated by analyses of ow and velocity patterns in
superior caval vein and pulmonary veins at this same level.
(b) Structural evaluation
The great majority of patients with chronic constrictive pericarditis exhibit a
more or less generalized pericardial thickening. The thickening is maximally pronounced over the right sided cardiac chambers and atrioventricular groove. Since
the cardiac constriction is caused by decreased pericardial compliance and not by
isolated thickened pericardium, the latter cannot be used as an absolute criterion.
Meanwhile, up to 18% of patients with histologically proven constrictive pericarditis have normal or near normal pericardial thickness. In constrictive pericarditis, the
true value of cardiac magnetic resonance is tissue characterization [155, 156, 214].
Although the normal pericardial thickness on necropsy ranges between 0.5 and
1mm, on cardiac magnetic resonance up to 5mm thickening is taken as normal.
The key features of constrictive pericarditis on cardiac magnetic resonance are
listed in Tables 8.2 and 8.3. Such pericardial thickening on cardiac magnetic resonance produces a signal intensity which is equal to that of the myocardium, often as
a low intensity, dark signal stripe [74].
Pericardial thickness>4mm in a patient with symptoms of right heart failure is an
indicator of constrictive pericarditis. The underlying cardiac chambers may be constricted by a thickened abnormal pericardium, resulting in a attened or tubular shaped
appearance (Figs.8.29, 8.30, 8.31, 8.32, 8.33, 8.34, 8.35, and 8.36). Other features of
constriction due to elevated cardiac lling pressure include dilation of caval and hepatic
veins, unilateral or bilateral atrial enlargement, narrow atrioventricular groove, pleural
effusion, and ascites. In the superior caval vein, systolic ow is decreased, absent, or
reversed, but in diastole, forward ow is increased with increased late backow.
In healthy persons, the pericardium moves synchronously with heart during the
cardiac cycle. However in patients with constriction, pericardial motion is reduced
or is even absent. The tethering and restricted ventricular expansion adjacent to
thickened areas can also be demonstrated using tagging as described above.
(c) Haemodynamic evaluation
Evaluation of hemodynamic changes in addition to detailed structural evaluation
is an advantage of cardiac magnetic resonance imaging. The consequences of
encasement of the heart by a rigid pericardium are basically vefold:
a. Dissociation between intrathoracic and intracardiac pressures, isolating the heart
from normal respiratory changes in intrathoracic pressures;
b. Increased cardiac lling pressure with equalization of end-diastolic pressures in
all cardiac chambers;
c. Increased ventricular coupling (interdependence);
d. Increased systemic venous pressures; and
e. Low cardiac output.
122
https://t.me/medicina_free
Table 8.2 MRI sequences and planes used to evaluate the pericardium
Sequence Planes Information
Scouts Axial, sagittal, coronal Localizing
HASTE FSE Axial Dene anatomy and plan
Cine SSFP Vertical long-axis, horizontal
Myocardial tagging LV short-axis ×3(i.e.,base,mid,distal),
T1 and T2 FSE Vertical long-axis, short-axis,
T2 FSE STIR Vertical long-axis, short-axis,
Velocity-encodeda
phase-contrast
Early contrastenhanced
T1-weighted FSE
Delayed
enhancement
Real-time imaging Short-axis, mid ventricle Evaluate ventricular
Note– HASTE Half-Fourier acquisition single shot turbo spin echo, FSE Fast spin-echo, SSFP
Steady-state free precession, STIR Short tau inversion-recovery, LVOT Left ventricular outow
tract, LV left ventricular
a
Velocity encoding=200cm/s
8 Imaging Studies andHaemodynamics inChronic Constrictive Pericarditis
subsequent views
Evaluate function, volumes,
long-axis, short-axis, four-chamber,
LVOT
vertical long-axis, four-chamber,
LVOT
four-chamber, LVOT
four-chamber, LVOT
Mid ascending aorta Asses aortic ow and ow
Vertical long-axis, short-axis,
four-chamber, LVOT
Vertical long-axis, short-axis,
four-chamber, LVOT
masses
Evaluate pericardial movement
Assess pericardial morphology
Evaluate pericardial edema due
to inammation
pattern of superior caval vein
and pulmonary vein
Evaluate inammation, masses
Evaluate pericardial
inammation, and brosis,
masses
interdependence
Table 8.3 MRI features that differentiate thickening and effusion
Features Effusion Thickening
Signal in T1-and
T2-weighted images
Signal in SSFP and
GRE
Margins Smooth Irregular or nodular
Location Follows distribution typical of effusion Dose not follow typical
Decubitus position Change in conguration No change in
Tagging Loss of tags with cardiac cycle Persistent lines
Contrast
enhancement
Dark (hypointense) on T1 weighted images
and bright (hyperintense) on T2 weighted
images
High Low
None May be present it
Gray (except in
calcication)
distribution of effusion
conguration
throughout cardiac cycle
associated with
inammation
bc
8.3 Computed Tomography
https://t.me/medicina_free
123
a
Figs. 8.29 Four chamber MRI cine image (a) shows tubular ventricles with indentation (thick
white arrow) along the LV free wall. Short axis cine image (b) shows thin pericardial collection
with thickened pericardium (arrowheads) adherent along the inferolateral wall of LV.Short-axis
image from tagged cine sequence (c) shows adherence and immobility of the pericardialmyocardial interface. (LA- Left atrium, LV-Left ventricle, RA-Right atrium, RV-Right ventricle)
Fig. 8.30 Four-chamber cine images (a and b) show tubular ventricles with biatrial dilation.
Thickened pericardium in the region of right atrioventricular groove and free wall of right ventricle
is noted (arrowheads in b). Short axis cine image (c) shows early diastolic straightening of the
interventricular septum. (LA- Left atrium, LV-Left ventricle, RA-Right atrium, RV-Right ventricle)
Since the pressure difference between the ventricles determines the position and
conguration of the ventricular septum, this information can be used to determine
the degree of ventricular coupling [31, 44, 50, 52, 53, 72, 83, 203]. In healthy persons, the ventricular septum is convex to the right side due to the higher left ventricular pressure. There is always a positive left-to-right transseptal pressure gradient
throughout the cardiac cycle, with only minimal respiratory variation. In patients
with pericardial constriction, a noncompliant rigid pericardium limits the outward
expansion of the right ventricle during early right ventricle lling (which precedes
left ventricle lling). This results in increased right ventricle pressure. When transmitted to the compliant septum, this increase in right ventricular pressure produces
septal attening or even transient inversion to the left side (“diastolic septal bounce”)
in early diastolic lling. Because of the dissociation between intrathoracic and
b
ca
124
https://t.me/medicina_free
8 Imaging Studies andHaemodynamics inChronic Constrictive Pericarditis
b
Fig. 8.31 Four-chamber cine image (a) shows tubular ventricles with indentation (thick white
arrow) along the free wall of the left ventricle. Short axis cine image (b) shows thin pericardial
collection with thickened pericardium (arrowheads) adherent along the inferolateral wall of the left
ventricle. Short axis image from a tagged cine sequence (c) shows adherence and immobility of the
pericardial-myocardial interface. (LA- Left atrium, LV-Left ventricle, RA-Right atrium, RV-Right
ventricle)
ca
c
a
Fig. 8.32 Four-chamber cine images (a and b) show thickened pericardium in the region of right
atrioventricular groove and free wall of right ventricle (arrowheads in a). There is severe indentation (thick white arrow) of the RV wall with formation of a RV apical aneurysm (* in b). TruFisp
axial images (c and d) show dilation of the inferior caval vein (IVC) and hepatic veins (HV). (LALeft atrium, LV-Left ventricle, RA-Right atrium, RV-Right ventricle)
b
d
intracardiac pressure, this pattern is strongly inuenced by respiration. Diastolic
interventricular septal attening is a nding that has a sensitivity of 62–81% and
specicity of 93–100% in the diagnosis of constrictive pericarditis [44, 46, 54, 55,
73]. However, minimal septal attening may be seen rarely in healthy persons.
Other conditions in which diastolic bounce is seen include right ventricle volume
overload, cor pulmonale, and in post cardiac surgery patients with bundlebranch block.
de
8.3 Computed Tomography
https://t.me/medicina_free
125
a
Fig. 8.33 Four-chamber cine images (a and b) show tubular ventricles with biatrial dilation. Note
is made of tricuspid regurgitation (white arrow in a represents regurgitation jet) and mitral regurgitation (white arrow in b represents regurgitation jet). Short-axis cine image (c) shows early bulging of the interventricular septum towards the left. (LA- Left atrium, LV-Left ventricle, RA-Right
atrium, RV-Right ventricle)
a
b
b
c
c
Fig. 8.34 Frontal (a) and left lateral (b) chest radiographs show calcication along the diaphragmatic surface of the heart. Four-chamber T2-weighted MRI image (c) shows biatrial dilation and
tubular ventricles with thickened pericardium. Four-chamber image from a cine sequence (d)
shows jet of tricuspid regurgitation. Four-chamber image from a tagged cine sequence (e) shows
adherence and immobility of the myocardial-pericardial interface. (LA- Left atrium, LV-Left ventricle, RA-Right atrium, RV-Right ventricle)
Соседние файлы в папке Библиотека им академика М.И. Перельмана