Letters U
“CT
to the
Angiogram
Differential
Sign”:
Editor
Establishing
the
Diagnosis
From: Michael R. Schuster, MD, and Kathleen A. Scanlan, MD Department of Diagnostic Radiology, University of Wisconsin Hospitals and Clinics 600 Highland Avenue, Madison, WI 53792 Editor:
We have read with interest issue of Radiology by Im el
the
article
(1) and
the
in the
September
subsequent
1990
discussion
of
an associated entity by Walkey (2) in the March 1991 issue. Both Im et al and Walkey describe enhancing pulmonary yessels
in the
midst
of completely
consolidated
pulmonary
paren-
chyma
on dynamic computed tomographic (CT) scans of the as the “CT angiogram sign.” Examples of bronchioboalveolar cell carcinoma and pneumococcal and tuberculous pneumonia were illustrated. We have recently observed a similar appearance in a patient with bymphoma.
chest
Dr Im and colleagues (1) have eloquently described the CT angiogram sign in bronchioloalveolan carcinoma while illustrating several other conditions in which the sign is present. Dr Wabkey (2) has submitted another condition in which it is seen. Our example of pulmonary necrosis, probably secondary to bymphomatous involvement, serves to reinforce the point that radiologic signs and findings are rarely diagnostic of a single condition but produce a list of possible diagnoses. The more specific the sign, the shorter the differential diagnosis. The finding of totally consolidated lung, without air bronchognaphy, and with continued perfusion is uncommon and should lead to a limited differential diagnosis.
References 1. 2.
S
Im J-G, Han MC, Yu EJ, et at. Lobar bronchioloalveolar carcinoma: “angiogram sign” on CT scans. Radiology 1990; 176:749-753. Watkey MM. And what is your sign (letter)? Radiology 1991; 178: 894.
Homemade
Snare
for Removal
of Foreign
Bodies
From: George G. Hamtnell, FRCR Department of Radiology, 185 Pilgrim Road, Boston,
New England MA 02215
Deaconess
Hospital
Editor: In the March 1991 issue of Radiology, Dr Yedlicka and cobleagues (1) report on use of a nitinob gooseneck snare (Microvena, Vadnais Heights, Minn) and describe a high-tech solution to a still relatively uncommon problem. One wonders if the majority of interventional radiologists will find it necessary or cost-effective to keep a full range of these snares in stock or whether they would be better served by making their own snares, depending on the clinical situation with which they are
presented. Homemade
Contrast-enhanced sign of enhanced
lung. This portion cavitation.
A 77-year-old
CT scan
of the
chest
shows
the
CT angiogram
vessels within necrotic (liquid), noncavitated of the right lower lobe ultimately underwent
woman
with
a history
of treated
large
cell lym-
phoma was referred for dynamic contrast material-enhanced CT of the chest to evaluate a right pleural effusion. The patient did indeed have a right effusion, but, in addition, the right lower
lobe
was
compbetely
consolidated
with
the
CT
angio-
gram sign (Figure). Much of the lobe underwent cavitation, and the patient died soon after. Postmortem examination showed fibrosis and scarring in the area of cavitation as well as liquefactive necrosis of much of the remainder of the lobe. Although large cell lymphoma was not recovered from the necrotic lobe, multiple lymph nodes showed similar necrosis and were thought to represent lymphomatous foci that responded to chemotherapy.
(2) and
devices
have
been
devices guide.
described
commercially
available are
produced
for a long
relatively
stiff
time. and
can
(3,4)
The be
retrieval
majority difficult
of the to
In addition, it may be difficult to retrieve an eccentrically positioned intravascular fragment with these devices. This is one situation in which the nitinol gooseneck snare may be advantageous. It is, however, possible to produce a homemade snare that will also grasp eccentrically positioned fragments and that can be modified to fit the contours of the vessel in which a fragment has become lodged. Such a snare can be assembled from an appropriately shaped diagnostic angiographic catheter and guide wire. The catheter shape should be chosen to allow cannulation of the vessel where the intravascular fragment has lodged. In this respect, a cobra or Judkins right coronary-shaped catheter will often be most appropriate. With a small-diameter (ie, 0.015-inch), fixedcore guide wire, even diagnostic catheters with small diameters can
be
used,
providing
they
have
a 0.035-inch
internal
diame-
ten. The
assembly
and
use
of such
a snare
is illustrated
in the
fob-
bowing case. During attempted antegrade cannulation of a common femonal artery before superficial femoral artery dilation, a Radiofocus guide wire (manufactured by Temumo, Piscataway, NJ; distributed by Medi-tech/Boston Scientific, Watertown, Mass), commonly referred to as the “Glidewire,” was used through a one-piece thin-wall needle. During manipulation, a fragment of hydrophffic coating from the guide wire
903
became detached from the wire, although no resistance was felt, and was seen to pass distally into a branch of the deep femoral artery. It was believed that the fragment of coating should
be removed
A snare
to prevent
was constructed
thrombosis
with
of that
a 5-F cobra
used or the introducer ter or dilator. Variations both foreign
artery.
catheter
and a
exchange
0.015-inch fixed-cone guide wire bent loop. To prevent an excessively tight
to provide an eccentric angle forming at the apex of the snare-which could weaken the wire-the two ends of the guide wire were introduced into the patient-end tip of the diagnostic catheter and advanced until approximately 2 inches
of the looped end
guide
wire
of the catheter.
remained
At this
projecting
stage,
both
free
boplasty
of the
may
procedures
(5). The
devices
be necessary
dures are frequently structed from readily
catheter. The snare and catheter were introduced via a 6-F anterial sheath with a hemostatic valve. The snare was advanced to the level of the fragment of guide wire coating (Figure). The
ments.
fragment
was
grasped
catheter.
The
fragment,
with
the
snare,
snare
and
and
withdrawn
catheter
were
into
then
the
this
during fragment
particular
procedure,
of coating
wire
guide
became
is required,
but,
in spite
detached.
When
an alternative
design
of this,
angiography
a barge
2.
been
used
the
for
ends
aortic
of snare
made
performed, available
usually
foreign
of
valvu-
has
body
in which
a homemade materials used
suffice
JW, Canison
for
departments
the
in most
JE, Hunter
removal
these
proce-
snare confor diagnostic
angiography
depart-
DW, Castaneda-Zdniga
GH, eds. Interventional radiology. Philadelphia: 384. Curry JL. Retrieval of detached intravascular
3.
fragments:
be
type
a cathe-
with
WR, Am-
platz K. Nitinot gooseneck snare for removal of foreign bodies: experimental study and clinical evaluation. Radiology 1991; 178: 691-693. Kadir S, Athanasoulis CA. Percutaneous retrieval of intravascular foreign bodies. In: Athanasoulis CA, Pfister RC, Green RE, Robenson
a bow-resistance
of wire should
will
References 1. Yedlicka
removed
intact via the sheath, and angioplasty was completed without further complications. The Glidewime seems to be used frequently through cutting needles in spite of the manufacturer’s specific warnings against doing this. Apparently no resistance to manipulation was felt
use of this
specially
in barge
were projecting from the hub end of the catheter, allowing withdrawal of the snare. The snare was withdrawn into the catheter until only ‘/2 inch of loop projected from the tip of the wire
be replaced
of this form of steerable snare have body retrieval and also for grasping wires used during antegrade transeptab
Although
guide
should
advantage that the components are readily available in the majority of angiography departments, and the size and curve of the snare can be modified to take account of the anatomy involved in a particular situation.
from the patient ends
needle
a proposed
method.
AJR 1969;
Saunders, catheters
extraction of catheter vessels. AJR 1971;
111:467-472. Crook R, Weston M, Wilde RPH, Hantnell GG. Aortic comparison of the techniques and results of transeptal grade methods. Clix Radiol 1990; 42:110-113.
5.
U
Periodic
Benign
Follow-up
Mammographic
or guide
105:894-896.
Dotter CT, Rosch J, Bilbao MK Transluminal and guide fragments from the heart and great
4.
1982;
valvoplasty: and retro-
of Probably
Lesions
From: Clinton Department
B. Sayler, MD of Radiology,
Medical Center 1015 Northwest
Good
Samaritan
Avenue,
22nd
Hospital
Portland,
and
OR 97210
Editor: I am responding to the article by Sickles (1) in the May 1991 issue of Radiology. Congratulations to Dr Sickles on his tenacity in the follow-up of “low-suspicion” lesions. He has answered some
questions,
but
raises
others.
Of particular interest are the 1,853 cases of tiny calcifications that made up approximately 58% of the lesions. My question whether calcifications too small to be seen on regular screenfilm mammograms
is
are significant.
The percentage of mammograms Dr Siddes designated as showing “probably benign” lesions (11.2%) is higher than that found in other studies he cited (ie, Helvie et al [2], 5.4%; Wolfe, et a! [3], 6.4%). I believe that some of the higher percentages were due to tiny calcifications, which most of us do not follow up. There were two malignancies in the 1,853 cases of tiny calcifications, so they were indeed very low in suspicion. An analysis of these calcifications because it would contribute to our
cations. sions
bowed
if there into
were
a benign
a pattern, category
would be of great benefit knowledge of benign calcifi-
then that
we could
would
not
place
need
these
be-
to be fob-
up.
mammographers have considered malignant to look like grains of sand or small irregular spicubated or branching calcifications. The size of these “sand particles” as resolved with traditional mammography is beHistorically,
calcifications
tween
proved Radiograph
shows
a position
tended
to encircle
holding
904
that
just proximal the
loop
Radiology
#{149}
the
guiding
the fragment. stationary
catheter
to the detached enabled
has
fragment
Advancing the
been
and
the catheter
fragment
advanced
the loop
while
to be snared.
to
ex-
0.3 and
is improved solving
1.5 mm.
generators,
to approximately
aluminum
ogy-approved
With
the advent
and microfocus specks
phantom
0.24 mm with
an
[Radiation
of magnification, imthe resolution (as determined by re-
x-ray tubes, American
College
Measurements,
of RadiolMiddle-
ton, Wis]). December
1991