AJR 2000; 175:1025-1028
© American Roentgen Ray Society
The "High-Riding" Superior Pericardial Recess
CT Findings
Yo Won Choi1,2,
H. Page McAdams2,
Seok Chol Jeon1,
Heung Seok Seo1 and
Chang Kok Hahm1
1
Department of Radiology, Hanyang University Hospital, 17 Haengdang-dong,
Sungdong-ku, Seoul 1333-792, South Korea.
2
Department of Radiology, Duke University Medical Center, Durham, NC
27710.
Received January 4, 2000;
accepted after revision March 16, 2000.
Presented at the annual meeting of the American Roentgen Ray Society,
Washington, DC, May 2000.
Address correspondence to Y. W. Choi.
Abstract
OBJECTIVE. We recently observed patients in whom the superior
pericardial recess extended cephalad ("high-riding") into the
right paratracheal region. In these patients, differentiation from mediastinal
lymphadenopathy or mass was difficult. The purpose of this study was to assess
the prevalence and CT features of the high-riding superior pericardial
recess.
CONCLUSION. Narrow-collimation CT with multiplanar reformations was
useful for confidently diagnosing a high-riding superior pericardial recess
and for distinguishing it from pathologic lesions.
Introduction
The appearance of the various pericardial recesses on CT is generally well
known
[1,2,3,4,5,6,7,8].
The superior pericardial recess
[3,
4], also known as the superior
sinus of the pericardium [1,
2] and as the posterior
division of the superior aortic recess of the pericardium
[6], usually manifests as a
half moon—shaped fluid collection adjacent to the posterior wall of the
ascending aorta. This recess is typically seen on one or two thick-collimation
CT images obtained just cephalad to the right pulmonary artery. Knowledge of
this typical appearance prevents misinterpretation of a normal superior
pericardial recess as either lymphadenopathy
[5] or a cystic mediastinal
mass. However, we recently observed several patients in whom a significant
portion of this recess extended cephalad into the right paratracheal region (a
"high-riding superior pericardial recess). In these patients,
differentiation from lymphadenopathy or mediastinal cyst may be more
difficult. The purpose of this study was to assess the characteristic CT
features and prevalence of the high-riding superior pericardial recess.
Subjects and Methods
We prospectively evaluated all chest CT scans obtained in our institution
from December 1998 to March 1999 for the presence of a high-riding superior
pericardial recess. Patients with pericardial effusion detected on CT were
excluded. A total of 284 consecutive chest CT scans in 276 patients were
evaluated. Indications for CT were a routine check for or evaluation of
metastatic disease, known or suspected lung cancer, pleural effusion,
pulmonary infiltrates, or nodules. CT was usually performed from the lung
apices to the diaphragm on a Somatom 4 Plus helical scanner (Siemens,
Erlangen, Germany) using an 8-mm collimation, a 10-mm table rotation speed,
120 kVp, and 240 mA. In fewer than one third of the patients, additional
narrow-collimation images from the top of the aortic arch to the top of the
left atrium were obtained to confirm mediastinal or lung abnormalities seen on
standard 8-mm-collimation images. All scans were obtained with the patient
supine and at end-inspiration. In most patients, nonionic contrast material
(120 mL of iopromide [Ultravist 300]; Schering, Berlin, Germany) was injected
into an antecubital vein at a rate of 2 mL/sec. The scan delay ranged from 20
to 25 sec.
All CT scans were reviewed by two experienced thoracic radiologists for the
presence of a high-riding superior pericardial recess; conclusions were
reached by consensus. On the basis of the work of Vesely and Cahill
[9], the transverse pericardial
sinus was divided into superior and inferior aortic recesses and left and
right pulmonic recesses. The superior aortic recess was further divided into
anterior, posterior, and right lateral divisions as defined by Kubota et al.
[6]. For purposes of clarity,
we use the term "superior pericardial recess"
[3,
4] in this report to
specifically refer to the posterior division of the superior aortic recess of
the pericardium [6]. For the
purpose of this study, we defined a high-riding superior pericardial recess as
a sharply marginated homogeneous water-attenuation structure that was located
in the paratracheal region between the brachiocephalic vessels and trachea,
was contiguous with the superior pericardial recess on caudal images, and had
no definable wall. We excluded all patients in whom a water-attenuation lesion
was present in the right paratracheal area but neither a superior pericardial
recess in the usual location nor a connection between the lesion and the
inferior portion of the superior pericardial recess was seen. If the
high-riding superior pericardial recess was present, the size, attenuation
measurements, vertical extension, and appearance were recorded.
Results
A high-riding superior pericardial recess was identified in three men and
three women who ranged in age from 45 to 72 years (mean age, 62 years). The
high-riding recess was detected on 8-mm-collimation contrast-enhanced scans in
five patients; additional scans using 1-mm (n = 2), 2-mm (n
= 1), or 3-mm (n = 2) collimation were also obtained in these five
patients. The high-riding recess was detected in the sixth patient on
unenhanced 1-mm-collimation scans obtained at 10-mm intervals. Multiplanar
reformations and region-of-interest measurements of attenuation were performed
in three patients.
On CT, the high-riding superior pericardial recess typically manifested as
a triangular, round, or oval structure that extended along the posterolateral
wall of the ascending aorta from the typical location of the superior
pericardial recess into the right paratracheal region. This recess usually
extended up to the level of the transverse aortic arch and was surrounded
anteriorly by both brachiocephalic veins and the right brachiocephalic artery
(Figs.
1A,1B,1C,1D,2A,2B,2C,3A,3B,3C).
In two patients, the high-riding pericardial recess was clearly molded by
adjacent vascular structures, and in none of the patients was mass effect
seen. In the three patients in whom region-of-interest measurements were
obtained, the attenuation numbers of the high-riding recess were 5, 15, and 20
H. In the three remaining patients, the attenuation of the lesions was judged
to be of water attenuation by visually comparing them with other
water-attenuation structures such as cerebrospinal fluid or the
gallbladder.
View larger version (73K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1A. —"High-riding" superior pericardial recess in 67-year-old
woman with history of tuberculosis in right upper lobe. Contiguous chest CT
scans (3-mm collimation) show triangular water-attenuation lesion (solid
arrows, A and B) in right paratracheal area above aortic
arch, extending to inferior portion of superior pericardial recess in typical
location (open arrow, C). Note that lesion is molded by
adjacent vascular structures. Attenuation of lesion (asterisk,
A) measured 15 H. We saw no evidence of pericardial effusion on caudal
scans (not shown).
|
|
View larger version (64K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1B. —"High-riding" superior pericardial recess in 67-year-old
woman with history of tuberculosis in right upper lobe. Contiguous chest CT
scans (3-mm collimation) show triangular water-attenuation lesion (solid
arrows, A and B) in right paratracheal area above aortic
arch, extending to inferior portion of superior pericardial recess in typical
location (open arrow, C). Note that lesion is molded by
adjacent vascular structures. Attenuation of lesion (asterisk,
A) measured 15 H. We saw no evidence of pericardial effusion on caudal
scans (not shown).
|
|
View larger version (77K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1C. —"High-riding" superior pericardial recess in 67-year-old
woman with history of tuberculosis in right upper lobe. Contiguous chest CT
scans (3-mm collimation) show triangular water-attenuation lesion (solid
arrows, A and B) in right paratracheal area above aortic
arch, extending to inferior portion of superior pericardial recess in typical
location (open arrow, C). Note that lesion is molded by
adjacent vascular structures. Attenuation of lesion (asterisk,
A) measured 15 H. We saw no evidence of pericardial effusion on caudal
scans (not shown).
|
|
View larger version (92K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1D. —"High-riding" superior pericardial recess in 67-year-old
woman with history of tuberculosis in right upper lobe. Oblique coronal
reformatted CT scan reveals connection between high-riding (arrows)
and inferior (arrowhead) portions of superior pericardial recess.
|
|
View larger version (112K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2A. —"High-riding" superior pericardial recess in 62-year-old
woman with bilateral pleural effusion. Contiguous CT scans (3-mm collimation)
show 20-mm-diameter right paratracheal mass (arrows, A and
B) with typical features of high-riding superior pericardial recess,
including low-attenuation, connection with inferior portion of superior
pericardial recess (arrowhead, C), and molded appearance. We
saw no evidence of pericardial effusion on caudal scans (not shown).
|
|
View larger version (129K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2B. —"High-riding" superior pericardial recess in 62-year-old
woman with bilateral pleural effusion. Contiguous CT scans (3-mm collimation)
show 20-mm-diameter right paratracheal mass (arrows, A and
B) with typical features of high-riding superior pericardial recess,
including low-attenuation, connection with inferior portion of superior
pericardial recess (arrowhead, C), and molded appearance. We
saw no evidence of pericardial effusion on caudal scans (not shown).
|
|
View larger version (125K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2C. —"High-riding" superior pericardial recess in 62-year-old
woman with bilateral pleural effusion. Contiguous CT scans (3-mm collimation)
show 20-mm-diameter right paratracheal mass (arrows, A and
B) with typical features of high-riding superior pericardial recess,
including low-attenuation, connection with inferior portion of superior
pericardial recess (arrowhead, C), and molded appearance. We
saw no evidence of pericardial effusion on caudal scans (not shown).
|
|
View larger version (90K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3A. —"High-riding" superior pericardial recess in 67-year-old
woman with history of right lower lobectomy for lung cancer. Preoperative CT
scan (8-mm collimation) at level of great vessels shows low-attenuation lesion
in right paratracheal region (arrow). Pathologic examination at time
of surgery did not reveal metastases.
|
|
View larger version (61K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3B. —"High-riding" superior pericardial recess in 67-year-old
woman with history of right lower lobectomy for lung cancer. Contiguous CT
scans (8-mm collimation) obtained 2 years after surgery show slightly enlarged
right paratracheal lesion (arrows, B), which was incorrectly
presumed to be metastatic lymphadenopathy. Patient refused mediastinoscopy and
received radiation therapy to area. Lesion had not changed in size on
follow-up CT scans (not shown). In retrospect, lesion has typical features of
high-riding superior pericardial recess including connection between
high-riding (arrows, B) and inferior (arrowhead,
C) portions of superior pericardial recess. Note also absence of
pericardial effusion.
|
|
View larger version (69K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3C. —"High-riding" superior pericardial recess in 67-year-old
woman with history of right lower lobectomy for lung cancer. Contiguous CT
scans (8-mm collimation) obtained 2 years after surgery show slightly enlarged
right paratracheal lesion (arrows, B), which was incorrectly
presumed to be metastatic lymphadenopathy. Patient refused mediastinoscopy and
received radiation therapy to area. Lesion had not changed in size on
follow-up CT scans (not shown). In retrospect, lesion has typical features of
high-riding superior pericardial recess including connection between
high-riding (arrows, B) and inferior (arrowhead,
C) portions of superior pericardial recess. Note also absence of
pericardial effusion.
|
|
The high-riding superior pericardial recess ranged from 8 to 20 mm (mean,
14 mm) in short-axis diameter and was more than 10 mm in five patients. In all
six patients, the portion of the superior pericardial recess in the typical
location was much smaller in diameter than the high-riding portion of the
recess. The length of vertical extension into the right paratracheal region
ranged from 28 to 40 mm (mean, 33 mm). In the three cases in which multiplanar
reformations were performed, these reformations helped clearly show the
connection between the high-riding portion and the more inferior portion of
the superior pericardial recess (Fig.
1D).
Discussion
The superior aortic recess is the most superior division of the transverse
sinus of the pericardium. This recess extends upward along the right side of
the ascending aorta, usually to the level of the sternal angle. At a lower
level, the superior aortic recess lies behind the posterior aspect of the
ascending aorta, and it travels anteriorly across the ascending aorta and onto
the upper part of the left pulmonary artery
[9]. All or part of this recess
has also been referred to as the aorticocaval recess
[10], the superior sinus of
the pericardium [1,
2], and the superior
pericardial recess [3,
4]. The posterior division of
the superior aortic recess, which we refer to as the superior pericardial
recess, lies immediately posterior to the ascending aorta and just cephalad to
the right pulmonary artery [6].
Although the superior pericardial recess usually appears just caudad to the
aortic arch, it sometimes extends, as we have shown, from this typical
location cephalad and rightward into the right paratracheal region between the
brachiocephalic vessels and the trachea, even in patients without pericardial
effusion. We call this the "high-riding superior pericardial
recess," which, to our knowledge, has not been previously reported
except in a patient with pericardial effusion
[2].
In five of our patients, the high-riding superior pericardial recess was
more than 10 mm in diameter and thus was large enough to be confused with
mediastinal abnormalities (Figs.
1A,1B,1C,1D,2A,2B,2C,3A,3B,3C).
In fact, the first patient who we encountered with this finding developed a
slowly enlarging low-attenuation lesion in the right paratracheal region after
pulmonary resection for lung cancer. This lesion developed in the absence of
detectable pericardial effusion. Because we treated this patient early in our
experience, we were concerned about the possibility of metastatic
lymphadenopathy. This patient refused biopsy and received radiation therapy to
the area. On follow-up studies, the lesion had not changed in size and showed
features we now believe to be characteristic of a high-riding superior
pericardial recess (Fig.
3A,3B,3C).
Recognition of the characteristic appearance and location of the
high-riding superior pericardial recess should prevent confusion with
mediastinal abnormalities. The high-riding recess typically manifests on CT as
a water-attenuation lesion without definable walls in the right paratracheal
region. The lesion usually extends cephalad to the level of the transverse
aortic arch and is surrounded by the great vessels. It is often molded by
adjacent structures and should not exert mass effect. Careful analysis of
contiguous CT images should reveal that the lesion is continuous with the
inferior portion of the superior pericardial recess, which is seen in a more
typical location posterior to the ascending aorta. Images obtained with
narrow-collimation sections and multiplanar reformation images can be useful
for clearly showing this connection. It should be noted that, in our series,
the inferior portion of the superior pericardial recess was typically much
smaller in diameter than the high-riding portion.
A high-riding superior pericardial recess was diagnosed in only six (2%) of
276 patients evaluated in our study. However, we suspect that the true
incidence of this finding may be higher than 2%. We may have excluded some
cases because we did not see either the inferior portion of the superior
pericardial recess or the connection between them. There are several possible
reasons for not seeing either. First, because for two thirds of our patients
only 8-mm-collimation scans were obtained, we may have excluded some cases in
which the inferior portion of the superior pericardial recess or the
connection was too small to be seen on thick-collimation scans. Interestingly,
in five of the six patients in our series with the diagnosis of high-riding
recesses, narrow-collimation scans were obtained, whereas narrow-collimation
examinations were performed in only one third of the overall study population.
Perhaps we would have diagnosed more cases if narrow-collimation scans had
been obtained in all patients. Second, the inferior portion of the superior
pericardial recess may be just too small to be shown on CT in some patients.
This hypothesis is supported by the study of Aronberg et al.
[1] who showed a marked
disparity between the incidence of this recess seen on CT (49%) and its
incidence in an autopsy series (100%). Third, aortic pulsation artifacts may
have precluded visualization of the connection or the inferior portion of the
superior pericardial recess in some patients. For these reasons, we believe
that we may have inadvertently excluded some cases of high-riding superior
pericardial recesses from our study.
The differential diagnosis for a high-riding superior pericardial recess
includes low-attenuation adenopathy and bronchogenic or pericardial cyst. As
noted previously, visualization of a connection between the high-riding and
inferior portions of the superior pericardial recess on CT should facilitate
differentiation from bronchogenic cyst or lymphadenopathy. Also, internal
homogeneity and an absence of peripheral enhancement on enhanced CT images
should help differentiate a high-riding recess from lymphadenopathy
[11,
12]. We cannot be absolutely
sure, however, that some cases we diagnosed as high-riding pericardial
recesses were not pericardial cysts because we did not obtain pathologic
proof. However, Choe et al. [2]
described a patient with massive pericardial effusion that extended into the
right paratracheal region, resulting in an appearance similar to that seen in
our patients. This report, and our experience, suggests that the superior
pericardial recess may sometimes extend into the paratracheal region resulting
in a cystic paratracheal mass—an unusual location for a pericardial
cyst.
In summary, the superior pericardial recess may occasionally extend
cephalad into the right paratracheal region between the brachiocephalic
vessels and the trachea, simulating a mass or lymphadenopathy on CT.
Recognition that this high-riding portion of the recess is of water
attenuation, that it connects to the inferior portion of the superior
pericardial recess on caudal CT images, and that it does not exert mass effect
on adjacent structures should help avert misdiagnosis. Narrow-collimation CT
with multiplanar reformations can be useful for confidently showing the
connection between the high-riding and inferior portions of the superior
pericardial recess.
References
-
Aronberg DJ, Peterson RR, Glazer HS, et al. The superior sinus of
the pericardium: CT appearance. Radiology
1984;153:489
-492[Abstract/Free Full Text]
-
Choe YH, Im JG, Park JH, Han MC, Kim CW. The anatomy of the
pericardial space: a study in cadavers and patients.
AJR
1987;149:693
-697[Free Full Text]
-
Levy-Ravetch M, Auh YH, Rubenstein WA, Whalen JP, Kazam E. CT of
the pericardial recesses. AJR
1985;144:707
-714[Abstract/Free Full Text]
-
Chiles CE, Baker ME, Silverman PM. Superior pericardial recess
simulating aortic dissection on computed tomography. J Comput
Assist Tomogr 1986;10:421
-423[Medline]
-
Glazer HS, Aronberg DJ, Sagel SS. Pitfalls in CT recognition of
mediastinal lymphadenopathy. AJR
1985;144:267
-274[Free Full Text]
-
Kubota H, Sato C, Ohgushi M, Haku T, Sasaki K, Yamaguchi K. Fluid
collection in the pericardial sinuses and recesses: thin-section helical
computed tomography observations and hypothesis. Invest
Radiol 1996;31:603
-610[Medline]
-
Protopapas Z, Westcott JL. Left pulmonic recess of the pericardium:
findings at CT and MR imaging. Radiology
1995;196:85
-88[Abstract/Free Full Text]
-
Groell R, Schaffler GJ, Rienmueller R. Pericardial sinuses and
recesses: findings at electrocardiographically triggered electron-beam CT.
Radiology
1999;212:69
-73[Abstract/Free Full Text]
-
Vesely TM, Cahill DR. Cross-sectional anatomy of the pericardial
sinuses, recesses, and adjacent structures. Surg Radiol
Anat 1986;8:221
-227[Medline]
-
McAlpine WA. Heart and coronary arteries.
New York: Springer-Verlag, 1975:126
-132
-
Moon WK, Im JG, Yeon KM, Han MC. Mediastinal tuberculous
lymphadenitis: CT findings of active and inactive disease.
AJR
1998;170:715
-718[Abstract/Free Full Text]
-
Glazer HS, Seigel MJ, Sagel SS. Low-attenuation mediastinal masses
on CT. AJR
1989;152:1173
-1177[Free Full Text]
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
|
|
 
H. Ferral, A. E. Garza-Berlanga, and N. H. Patel
Complications of Nonvascular Interventions and Their Management: Case-Based Review
Am. J. Roentgenol.,
June 1, 2009;
192(6_Supplement):
S63 - S77.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. S. Broderick, G. N. Brooks, and J. E. Kuhlman
Anatomic Pitfalls of the Heart and Pericardium
RadioGraphics,
March 1, 2005;
25(2):
441 - 453.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. Kodama, P. J. Fultz, and J. C. Wandtke
Comparing Thin-Section and Thick-Section CT of Pericardial Sinuses and Recesses
Am. J. Roentgenol.,
October 1, 2003;
181(4):
1101 - 1108.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. T. Truong, J. J. Erasmus, G. W. Gladish, B. S. Sabloff, E. M. Marom, J. E. Madewell, M. H. Chasen, and R. F. Munden
Anatomy of Pericardial Recesses on Multidetector CT: Implications for Oncologic Imaging
Am. J. Roentgenol.,
October 1, 2003;
181(4):
1109 - 1113.
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
