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172
lin receptor antagonist) and sildenafil with improvement in
oxygenation, functional class and pulmonary hemodynamics.
For the lining thrombus and pulmonary hypertension, the
decision was made for anticoagulation with warfarin.
Radiographic Interpretation
There are multiple mismatched perfusion defects on VQ scin-
tigraphy (Fig.18.3) but the salient feature is the extra pulmo-
nary uptake in the kidneys. Free Tc-99m-pertechnetate in the
radiopharmaceutical can give rise to this appearance but
there is no activity in thyroid, salivary glands, or the stomach
to support a fault in the radiopharmaceutical. The other pos-
sibility is the Tc-99m-macroaggregate of albumin (MAA)
bypassing the lungs due to a right to left shunt. These two
conditions can be differentiated by imaging the brain as free
Tc-99m-pertechnetate and other radio contaminants do not
cross the blood brain barrier whilst shunted Tc-99m-MAA
will lodge in the cerebral circulation.
On selected images from CT pulmonary angiography
(Fig.18.1), there is marked dilatation of the main pulmonary
artery with a ratio of MPA: ascending aorta (AA) greater
than 1.0. In addition to the eccentric filling defect in the distal
F . Cardiac magnetic resonance imaging (axial view)
depicting right superior (solid blue arrow) and right inferior (open
blue arrow) pulmonary veins draining into the right atrium. Sinus
venosus defect: white arrow
T. M. Fernandes et al.
173
right PA, there are multiple occlusive and partially occlusive
filling defects in the segmental vessels in both lungs. An
important observation is the dilatation of these segmental
pulmonary arteries, a feature that is not seen in chronic
thromboembolic disease where the segmental vessels become
attenuated with abrupt change in the vessel calibre. There is
mild distortion of the cardiac silhouette due to a pectus exca-
vatum, with dilatation of the right atrium and right ventricle,
right ventricular hypertrophy and flattening of the interven-
tricular septum. Careful analysis of the CT and gradient echo
sequence Cardiac Magnetic Resonance image (Fig. 18.4)
reveals a sinus venosus type atrial septal defect. The right
superior pulmonary vein drains in to the superior vena cava
whilst the middle and inferior pulmonary veins drains in to
the atrium at the level of the ASD.There is normal drainage
of the left inferior pulmonary veins in to the left atrium.
Sinus venosus atrial septal defect (SV-ASD) is an inter-
atrial communication caused by the deficiency of the com-
mon wall between the superior or inferior vena cava and the
right-sided pulmonary veins. It represents 4–11% of atrial
septum defects and is typically associated with partial anoma-
lous right pulmonary venous drainage (PAPVD).
This case illustrates the need for methodical review of the
various imaging modalities. Although pulmonary artery dila-
tation on radiography is not a specific marker of a particular
type of disease, the presence of aneurysmal dilatation should
raise the suspicion of a congenital heart disease. The visual-
ization of kidneys on a VQ scintigram is highly suspicious for
a intracardiac or intrapulmonary shunting but it is important
to image the brain to exclude the possibility of free Tc-99m-
pertechnetate. While it is not customary to use CT for the
visualization of intracardiac shunts, even nonelectrocardio-
gram (ECG)-triggered CT can frequently demonstrate large
shunts. However, it is not common clinical practice to look for
the shunts on CT as traditionally it is the preserve of echocar-
diography and more recently magnetic resonance imaging to
identify and clarify the functional consequences of the under-
lying shunt.
Chapter 18. Case 18: Atrial Septal Defect withChronic…
174
Multiplanar CT reconstructions are particularly useful in
the assessment of the complex anatomy of this type of
ASD. Transthoracic echocardiography can easily miss the
PAPVD. Given that CTPA is a very commonly performed
examination, it is important to remember to look for struc-
tural heart defects. Knowledge of the different types of the
shunts is the key to detection. The cardiac MR can then be
performed as a targeted imaging to quantify the magnitude of
the shunt.
Clinical Comments
Upon presentation, there were several historical and radio-
graphic aspects of this case that raised suspicions that acute
thromboembolic disease was not the primary diagnosis. The
length of time he had been experiencing exertional dyspnea,
the cardiomegaly and massively enlarged central pulmonary
arteries noted on chest radiograph, the degree of pulmonary
hypertension as evidenced by echocardiography, and the
eccentric thrombus noted in several of his enlarged segmen-
tal pulmonary vessels—CT findings that are not seen in
acute thromboembolic disease—were all suggestive of a
more chronic process. And although not well depicted in
Fig.18.1, the vessels beyond the lining thrombus returned to
a normal configuration without the narrowing or vessel
attenuation that one observes in more proximal obstruction
with chronic thromboembolic disease. Even with the knowl-
edge that the patient had severe pulmonary hypertension,
the historical clue that this patient did not have CTEPH was
the presence of clubbing—the physiologic mechanisms by
which someone develops clubbing are simply not operative
in CTEPH.
The development of pulmonary hypertension in patients
with congenital cardiac defects and left-to-right shunting is
not the reason to present this case. The pulmonary vascular
changes that arise as a result, particularly the marked enlarge-
T. M. Fernandes et al.
175
ment of the central PAs, and the “lining thrombus” that can
be observed in these dilated vessels—and mistaken as
“CTEPH”—is the principal lesson to be learned. In the vast
majority of cases like this, the perfusion scintigram shows lit-
tle in the way of perfusion defects, as the organized thrombus
within the vessel is non occlusive (see Case 19, Chap. 19).
However, this patient did exhibit some occlusive clot result-
ing in segmental perfusion defects. Theoretically, in situ clot
may have resulted from a low flow state within these vessels.
This assumption and the basis for the development of lining
thrombus are areas of ongoing investigation.
Points ofEmphasis
• An abnormal VQ scan and angiographic evidence of
thrombus in the pulmonary arteries are necessary to diag-
nose chronic thromboembolic pulmonary hypertension.
However, an atrial septal defect with Eisenmenger’s syn-
drome and the resultant massive central PA enlargement
may
• A perfusion scan with uptake of technetium macro aggre-
gated albumin in the brain and kidneys may be seen with
significant right-to-left shunting.
• Digital clubbing is common in congenital heart disease but
is exceeding rare in chronic thromboembolic pulmonary
hypertension. Clubbing should raise suspicion for alterna-
tive diagnoses in patients being evaluated for CTEPH.
Diagnosis
1. Atrial septal defect with Eisenmenger’s syndrome and pul-
monary hypertension.
2. Partial anomalous pulmonary venous return (right upper
and lower pulmonary veins drain into right atrium).
3. In situ thrombosis of the pulmonary arteries.
Chapter 18. Case 18: Atrial Septal Defect withChronic…
176
Further Reading
Bradlow WM, Babu-Narayan SV, Mohiaddin RH.Pulmonary hyper-
tension in congenital heart disease. In: Cardiac CT and MR for
adult congenital heart disease. New York, NY: Springer; 2014.
p.553–72.
Webb G, Gatzoulis MA.Atrial septal defects in the adult. Circulation.
2006;114(15):1645–53.
T. M. Fernandes et al.
177© Springer Nature Switzerland AG 2020
W. R. Auger, D. Gopalan (eds.), Clinical Cases in Chronic
Thromboembolic Pulmonary Hypertension, Clinical Cases in
Cardiology, https://doi.org/10.1007/978-3-030-17366-1_19
Case Presentation
A 60year old man with a history of emphysema who resides
in a rural environment. He considered himself relatively
healthy until 9months prior to his initial presentation. At that
time, he began to experience dyspnea with exertion when
throwing hay to his cattle. He attributed the breathlessness to
Chapter 19
Case 19: Parenchymal
Lung Disease
andChronic
Thromboemboli
LynetteBrown, DeepaGopalan, andWilliamR.Auger
L. Brown (*)
Asssociate Professor (Clinical), University of Utah,
Salt Lake, UT, USA
Pulmonary Hypertension Program, Intermountain Medical Center,
Murray, UT, USA
e-mail: Lynn.M.Brown@imail.org
D. Gopalan
Department of Radiology, Imperial College Hospitals, London, UK
e-mail: d.gopalan@nhs.net
W. R. Auger
Lewis Katz School of Medicine, Temple University,
Philadelphia, PA, USA
e-mail: Bill.Auger@tuhs.temple.edu
178
his known diagnosis of emphysema; however, he ultimately
developed acute shortness of breath at rest. Imaging demon-
strated bilateral consolidation, a left-sided pneumothorax,
bilateral pulmonary emboli (Fig.19.1) and a chronic appear-
ing right popliteal thrombus. A chest tube was placed and he
was treated with heparin and antibiotics. He was ultimately
discharged home on oxygen and warfarin. He received a total
of 12months of anticoagulation.
The patient presented again 7years later with dyspnea. He
noted initial improvement in his respiratory symptoms after
his discharge from the previous hospitalization; however, the
improvement was short-lived. He was now limited to climbing
less than a flight of stairs without stopping and he was sharing
farm chores with his sons due to his limitations. His 6min walk
distance at that time was 209m with a BORG dyspnea score
of 10. He denied chest pain, lightheadedness and near syn-
cope. He had lower extremity edema (right leg > left leg).
Vital signs upon consultation demonstrated a blood pressure
of 122/70mmHg and a SaO
2
of 93% on 4L/min. His BMI was
26 kg/m
2
. His chest exam was notable for end-expiratory
F . CT angiogram of the chest obtained at initial presenta-
tion
L. Brown et al.
179
wheezes bilaterally. His cardiovascular exam noted a jugular
venous pressure of 8cm, a normal S1 and S2 and no appre-
ciable murmurs. Pulmonary function tests revealed severe
obstruction with a forced expiratory volume (FEV
1
)=1.1L
(35%) and a diffuse capacity adjusted for hemoglobin (DLCO)
of 10.3mL/mmHg/min (33% predicted). Forced vital capacity
was 3.76 L (92%). His echocardiogram showed a mildly
dilated right ventricle and an insufficient tricuspid regurgitant
jet to estimate a right ventricular systolic pressure (RVSP)
estimate. Laboratory assessment showed normal α-1 antitryp-
sin levels, a non-reactive antinuclear antibody, normal thyroid
stimulating hormone and no evidence of hepatitis C virus or
human immunodeficiency virus. Chest x-ray (Fig.19.2) dem-
onstrated flat hemidiaphragms, increased lung volumes and
dilated intralobar pulmonary arteries: Past medical history
was notable for emphysema and systemic hypertension.
On social history, the patient has 5 healthy children. He
worked as a welder and in the oil fields. He currently runs a
small farm with horses and cows only. He has a 12 pack-year
tobacco history and quit 20years ago. He does not drink alco-
hol. There is no history of methamphetamine, cocaine or
fenfluramine exposures. Family history was notable for a
father and brother with emphysema.
F . PA and lateral chest radiograph
Chapter 19. Case 19: Parenchymal Lung Disease…
180
Given the previous history of pulmonary embolism, a
ventilation-perfusion scan was obtained. The study showed
multiple moderate or large segmental perfusion defects
throughout both lungs. Ventilation images showed xenon
retention (Fig.19.3).
Further assessment was obtained via CT pulmonary angio-
gram (Figs.19.4 and 19.5).
Due to concern for chronic thromboembolic pulmonary
hypertension, a right heart catheterization was ultimately
performed. The hemodynamic measurements showed a right
F . Lung scintigraphy showing both ventilation and perfu-
sion abnormalities
F . Follow up CT angiogram of the chest reveals lining
thrombus involving the central pulmonary arteries
L. Brown et al.
181
atrial pressure of 9 mmHg, pulmonary artery pressure of
84/28mmHg with a mean of 47mmHg, pulmonary capillary
wedge pressure of 12 mmHg, cardiac output of 5.52L/min
and pulmonary vascular resistance of 6.3Woods unit. Expert
opinion regarding the patient was subsequently pursued.
Radiographic Interpretation
The series of images in the case exhibit a number of interest-
ing findings.
Figure 19.1 is a single image from a CT pulmonary angiog-
raphy demonstrating a lobar filling defect in the lingula
(block arrow) in keeping with acute pulmonary embolism.
There is evidence for a pneumomediastinum and subcutane-
ous air (arrow heads) and a collapsed lung (thin arrow) with
a chest drain that has been inserted for a large pneumothorax
(not visible on this mediastinal window).
The chest radiograph obtained during a subsequent evalu-
ation reveals severe emphysema on the frontal and lateral
chest radiograph (Fig.19.2) as evidenced by hyperexpanded
lungs and flattened hemi-diaphragms with disorganization of
bronchovascular markings. The heart is not enlarged, though
there is dilatation of the proximal pulmonary arteries.
F . Lung windows of the same CT image displayed in
Figure19.4
Chapter 19. Case 19: Parenchymal Lung Disease…