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687
Letters .
;,
..
:
.
....
.,.
.
.
:
.
.
‘
!‘
Ruptured Membrane
Pulmonary on CT
Hydatid
Cyst
and Folded
Pulmonary hydatid disease is a serious problem of worldwide importance. It usually has a wide range of radiologic features that must be distinguished from those of other benign or malignant lesions of the lung [1 -4]. Hydatid cysts caused by Echinococcus granulosus, the common etiologic agent, are fluid-filled cavities with an outer layer, the pericyst, and an inner layer, the endocyst
[1 , 2, 4j. Although
most of these lesions
until they rupture,
a
the clinical [2-4].
status
Ruptured graphs, [1 ,
cause
no signs or symptoms
cyst makes the diagnosis
complicated
some
and
the
radiologic
more difficult because appearances
cysts have several well-known of which
are highly
features
are
on chest radio-
suggestive
2, 4]. One of them, the “water-lily
both
changed
but not always sign,” is associated
year-old woman, had been admitted after an automobile accident. In the first two patients, conventional radiographs showed cavities with the typical water-lily sign. In the third patient, the findings on chest radiographs simulated those of an encysted hydropneumothorax.
In all three patients,
CT showed
thin-walled
cavities
probably
partly filled
with air in the left lower lobe. Scans obtained at mediastinal window settings showed detached and regularly arranged membrane layers
in the dependent part of the cysts (Figs. appearance of a folded blanket. In two cyst was confirmed at surgery. Slow endocyst and nearly complete loss of uniform features
layering of the membrane seen in our cases are
established
by conventional
1 and 2). The layers had the cases, the presence of the retraction of the collapsing cystic fluid may explain the
within similar
tomography
the cavities. Thus, to the “membrane
and bronchography
specific with a
the CT sign”
[2].
Nilgun
Maden
Oyar [k-nit Tekin
Orhan
collapsed endocyst floating on top of the remaining fluid in a cavity [1 , 4]. Although CT is a valuable imaging method for visualizing collapsed
-
Hadi Ozer
membranes, we describe a CT feature in three cases that is the counterpart of the water-lily sign seen on chest
Ege University
School of Medicine
Bornova,
lzmir,
Turkey
radiographs.
Two of our patients, a 26-year-old woman and a 1 2-year-old had spontaneous expectoration of salty fluid. The third patient,
boy, a 34-
REFERENCES 1 . Aggarwal
S, Kumar A, Mukhopadhyay S. Berry M. A new radiologic sign of ruptured pulmonary hydatid cyst (letter). MR 1989;152:431-432 2. Beggs I. The radiology of hydatid disease. AiR 1985;145:639-648 3. Lewall DB, McCorkell SJ. Rupture of echinococcal cysts: diagnosis, classification, and dinical implications. AiR 1986;146:391-394 4. Saksouk FA, FahI MH, Riak GK. Computed tomography of pulmonary hydatid disease. J Comput Assist Tomogr 1986;10:226-232
Pneumopyopericardium
After
Penetrating
Chest
Injury Pneumopyopencardium
: Fig. 1.-CT scan shows a huge In left lower lobe with regular layerIng of hydatid endocyst in dependent part of cyst. Note also atelectasis of lungs and a shift of me-
cavfty
dlastinum.
Fig. 2.-CT scan at mediastinal window levels shows regular layering of collapsed hydatid endocyst with small air bubbles captured be-
tween folds of membrane.
is uncommon
[1 -3].
Its causes
include
trauma and perforation of an inflammatory or suppurative focus into the pericardium [1 -3]. Since the introduction of antibiotics, the mcidance of pericardial suppuration has markedly declined [3]. I report a case of delayed pneumopyopencardium complicated by cardiac tamponade that occurred after penetrating chest injury.
A 25-year-old man was stabbed in the chest. Physical examination showed a 2-cm stab wound in the fourth intercostal space just to the left of the sternal
border.
A chest
ties. The wound was sutured,
radiograph
showed
no abnormali-
and the patient was discharged.
Three
688
LETTERS
Fig.
1.-Chest
shows sac.
air-fluid
level
radiograph in pericardial
AJR:158,
subsegment of a population term follow-up of the whole population.
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It is possible
selected population,
to produce
biopsy
March
1992
for biopsy and ignoring longwe now have a highly biased
yield
rates
that
approach
1 0O%.
All that is needed is to restrict biopsy to those patients who have clear-cut signs of breast cancer. It is clear from the work of Swets et al. [2] that “expert readers” produce receiver-operating-characteristic curves for mammography that are essentially identical. That being the case, if these expert readers evaluated the same screened population, the positive predictive values could be different only if each reader chose to operate at a different
point
on
the
curve.
If the
and thus increase the positive weeks
later the patient was admitted to the hospital in critical condition. He had a body temperature of 39.2#{176}C, a thready pulse, and blood pressure of 80/60 mm Hg with a pulsus paradoxus of 20 mm
lignant lesions positives must
rejection
heard at the apex synchronous with the heart beat. ECG showed a sinus tachycardia of 1 00 beats per minute and diffuse elevation of the ST segment. A chest radiograph showed a pericardial air-fluid
prevalence
level (Fig. 1). The diagnosis
was pneumopyopericardium grossly externally.
with cardiac
purulent pericardial fluid was The patient’s postoperative
will be detected. be accompanied
of it as a screening
Another
factor
dium only may occur. Pericardial laceration is usually of no significance unless infection occurs. The resultant purulent pericarditis may not be suspected until cardiac tamponade occurs. Antibiotics alone are inadequate in the treatment of pericardial suppuration. The pen-
positive predictive
with thorough
pericandial
drainage
but subxiphoid is preferred
J Thorac Surg 1948;17:62-71 microbiologic and therapeutic
aspects 1975;59:68-78 3. Klacsmann PG, Bulkley BH, Hutchins GM. The changed spectrum of purulent pencarditis: an 86 year autopsy experience in 200 patients. Am J 1977;63:666-673
4. Demetriades
D, Van der Veen BW. Penetrating over two years in South Africa.
experience 1034-1041
Positive Detected
The article
by Bassett
rates for mammography masses
those detected the clinical
Trauma
1983;23:
design
for Mammographically
et al. [1] clearly
detected
with an examining
shows
with mammography
because
(i.e., the clinician
that
biopsy
predictive
dated
values
is in order.
of a population
to a huge population
determining
the
yield
were smaller
of the tautology operated
than
that follows
on palpable
masses,
It is a
biopsy
yield
value) and make
be a multifaceted
medical
it the
driving
force
decision-making
for what
in fact
task. Myron Moskowitz University of Cincinnati Cincinnati, OH 45267
REFERENCES 1 . Bassett LW, Uu TH, Giuliano AE, Gold RH. The prevalence of in palpable vs impalpable, mammographically detected lesions. 157:21-24 2. Swets JA, Getty DJ, Pickett RM, et al. Enhancing and evaluating accuracy. In: Medical decision-making. Philadelphia: Hanley 1991:9-18
carcinoma AiR 1991; diagnostic & Relfus,
Reply
We thank Dr. Moskowitz his words
of caution
for his insightful
against
practice
extrapolating
to a huge
comments, biopsy
population
yield
particularly rates
from
of asymptomatic
Biopsy
yield
that had surgery
of asymptomatic rates
(positive
recommended for almost any mammographic abnormality, even when the abnormality has characteristically benign features. This bettersafe-than-sorry approach is undoubtedly influenced by many factors, including lack of training and experience, medicolegal concerns, and
failure to obtain follow-up
results of recommended
biopsies.
than
Dr. Moskowitz expresses a legitimate concern that increasing the threshold for what we call abnormal (choosing a different point on
rates or positive
the receiver-operating-characteristic curve) in order to increase the biopsy yield for carcinoma will increase the number of false-negatives.
hand.
of caution
If the
the use of mammography results in excessive numbers of unnecessary biopsies [1]. In some practices in our community, biopsy is
can be equal to those for clinical examination.
by palpation
value is the
examined.
screened women. It was not our intent to do so. Our purpose was to compare results of clinical examination and mammography in one breast surgeon’s practice in order to respond to the allegations that
and the mammographer examined impalpable abnormalities). given that smaller masses can be detected with mammography A word
should
one surgeon’s
Predictive Values Carcinomas
In this study,
injuries of the heart: J
being
to me that it is not only irrational, but probably counterto embrace a single statistical parameter (in this case
pericar-
REFERENCES
Med
predictive
in the population
[1-4].
Paul Mank Baragwanath Hospital Johannesburg, South Africa
1 . Meyer HW. Pneumopyopericardium. 2. Rubin RH, Moellering RC. Clinical, of purulent pencarditis. Am J Med
in falsein true-
true-positive rate of a test is 90%, achieved at a false-positive rate of 1 %, in a screened population of 100,000 women who have 160 cancers, the positive predictive value is 13%. If the number of cancers in that population were 250, the positive predictive value would be 18%. These are approximations of the frequency of breast cancer in women 45 and 55 years old, respectively. It seems productive,
diotomy
reduction reduction
tool.
that can alter the positive
of the disease
Penetrating wounds of the heart usually cause laceration of both pericardium and myocardium [4], although laceration of the pericar-
cardial space can be drained percutaneously,
However, the by a concomitant
positives. Failure to appreciate these basic fundamentals is what led to the enthusiastic adoption of thermography, and the subsequent
Hg and a markedly elevated jugulovenous pressure. Auscultation of the heart revealed diminished heart sounds with a “splashing” sound
tamponade. At thoracotomy, found, which was drained course was uneventful.
is to limit overcalls value, well-established ma-
motivation
predictive
cannot
screened
predictive
be extrapBy value) of a
women.
Does
it follow
that
for
mammograms
of asymptomatic
women,
we
should produce biopsy yield rates that are very low in order to pick up as many cancers as possible? Arguments against such an ag-
AJR:158,
March
LETTERS
1992
gressive approach include the increased anxiety, morbidity, and costs associated with these biopsies and, over time, decreased compliance of referring physicians that may be detrimental
with recommendations to the acceptance
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raphy [2]. A low threshold
for interpreting
for biopsy-effects of screening mammog-
a complete workup of all women except those with obviously malignant abnormalities can greatly reduce the number of women who have excisional biopsy. The workup of women who have abnormalities found during screening includes appropriate additional mammo-
and, in some cases, fine-needle
REFERENCES 1 . Bassett LW, Uu TH, Giuliano AE, Gold RH. The prevalence of carcinoma in palpable vs impalpable, mammographically detected lesions. AJR 1991; 157:21
the results of a two-view
screening examination as abnormal can be maintained without committing to a low excisional biopsy yield for carcinoma. This is because
graphic views, sonography,
689
or core
2. Howard CA
-24 J. Using mammography
for cancer
control:
an unrealized
potential.
1987;37:33-48
3. Tab#{227}r L, Fagerberg G, Duffy SW, Day NE, Gad A, GrOntoft 0. Update of the Swedish Two-County Program of Mammographic Screeningfor Breast Cancer. Radio! Clin North Am (in press) 4. Moskowitz M. Guidelines for screening for breast cancer: is a revision in order? Radio! Clin North Am (in press) 5. Murphy WA, Destouet JM, Monsees BS. Professional quality assurance for mammography
screening
Radiology
programs.
1990;175:319-320
biopsies.
What then is the ideal threshold for recommending biopsies, and what is the appropriate rate ofcarcinomas detected in these biopsies? Experts Cancer
are far from a consensus Detection Demonstration
about these issues. Project, conducted
In the Breast nationwide in
1973-1 978, the proportion of recommended biopsies varied considerably; it was eight times greater in the most aggressive center compared with the least aggressive [2]. Reduction in mortality has been reported in large screening trials that did not use aggressive
biopsy protocols.
For example, one large population-based European screening trial achieved a 31% decrease in mortality in women invited to screening, with a biopsy yield of one cancer in two biopsies in the initial screening and three cancers per four biopsies subsequently
[3]. On the other hand, a more aggressive approach to biopsies might further reduce mortality, and when used in combination screening intervals, might also be successful in reducing
with shorter mortality in
women less than 50 years old-women in whom tumor growth rates are generally more rapid and for whom current screening strategies are not effective [4]. Finally, we concur
ducting
that it would
a large screening
be irrational
program
for radiologists
to embrace
con-
a single statistical
parameter, such as positive predictive value, and make it the driving force for the screening outcome. However, community-based radiologists, who are performing the bulk of mammographic examinations,
may not be able to access statistical practices. pressure
parameters, Nonetheless, to establish
the data necessary
to calculate
all
let alone apply the results meaningfully to their these same radiologists are under increasing a mechanism for auditing the results of the
biopsies they have recommended [5]. These audits may be difficult to complete when biopsies are performed at various locations, sometimes at clinics or hospitals remote from the facility where the screening mammograms were performed. However, mechanisms for obtaining the results of surgical pathologic examinations of specimens from recommended biopsies can usually be worked out so that true-
Mammographic Fat Necrosis A 36-year-old of deep
venous
Appearance
of Coumadin-Induced
obese woman was admitted thrombosis
of the lower
treated initially with hepanin and subsequently warfanin). taneously
with a clinical diagnosis
extremity.
The patient
with Coumadin
Two days later, edema and ecchymosis in the left breast. Physical examination
was
(sodium
developed sponshowed that the
left breast was much larger than the normal-sized right breast. A large ecchymosis involved the entire left breast and extended into the axilla. A 5-cm nonclotted blood-filled blister the areola, and a 5- to 6-cm area of induration the areola. The breast was tender to palpation.
was 24.6 sec (normal,
was present lateral to was noted medial to The prothrombin time
1 1 .5-1 3.5 sec), which was within the thera-
peutic range. A diagnosis of Coumadin-induced skin necrosis was made, and the Coumadin was discontinued. Subsequently, the blister ruptured, and the skin necrosis was treated with Neosporin (E.
Fougera & Co., Melville, NY) dressings. receiving
subcutaneous
hepanin
At discharge,
the patient was
therapy.
Two months later, the patient was referred for mammography because of a palpable mass in the left breast. Physical examination of the breast revealed a large firm mass at 8 o’clock and a large area of skin discoloration at 2 to 3 o’clock associated with several firm palpable nodules. A mammogram showed skin thickening laterally and multiple oil cysts (fat necrosis) both medially and laterally in the left breast (Fig. 1). The oil cysts varied in size from less than 1 cm to
2 cm. The distribution was superficial, corresponding
to the areas of
positive rates for biopsies can be derived. Arriving at valid falsenegative rates is usually more difficult, sometimes impossible. Therefore, for many radiologists, the true-positive rate for biopsies may
provide the most realistic valuefor
their results with results and in the literature. Although far from perfect, this method does provide an opportunity to recognize inappropriate biopsy rates and make provisions for correported
recting
at continuing
deficiencies.
computer
networks
statistical
parameters
education
It is hoped
comparing courses
that
the establishment
of national
and registries for cancer patients will eventually make it possible for all radiologists to access follow-up data on all their patients and will facilitate the computation of all recommended for their individual
practices. W. Bassett Tsung-Han Liu Armando E. Giuliano
Lawrence
Richard H. Gold University
of California,
Los Angeles, School of Medicine Los Angeles, CA 90024-1721
Fig. 1.-A and B, Craniocaudal(A) and oblique (B) mammograms of left breast of a woman treated with Coumadin show skin thickening laterally
and multiple oil cysts, indicating fat necrosis.
690
LETTERS
induration
and skin necrosis
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nation. The right breast Anticoagulant-induced
described
March 1992
AJR:158,
on the initial physical exami-
was normal. necrosis of the breast
has been reported in numerous cases, but the mammographic appearance has been doscnibed in only four patients [1 -3]. This rare complication usually occurs in middle-aged, obese women between the third and fifth days of treatment with the anticoagulant. The prothrombin time is almost always within therapeutic range(1 .5-2.5 times normal control values). Proposed mechanisms include a direct toxic effect causing capillary rupture followed by thrombotic occlusion of the subcutaneous and subdermal veins, which leads to necrosis of the skin and subcutaneous tissues [4]. Surgical debridement with skin grafting is some-
times necessary. required
[4].
If the necrosis
Other
reported
is extensive,
areas
a mastectomy
of involvement
are
may be
the
buttocks
and thighs, areas of abundant
subcutaneous
fat. In patients receiving
anticoagulants,
to distinguish
idiosyncratic
necrosis
it is important
from intraparenchymal
and prognosis
hemorrhage,
of each are different
because
skin
or fat
the treatment
[4].
IA
lB
Karen S. Baker Carol
University
of Kentucky Lexington,
Fig. 1.-Radiographs of two postmortem specImens show anatomy associated wIth postedcold Impression on the esophagus. Cart = cartilage. A, Anteroposterlor view of up-
B. Stelling
Medical Center KY 40536-0084
per esophagus venous plexus lum.
REFERENCES 1 . Hermann G, Schwartz IS, Slater G. Breast mass in a 69-year-old woman. JAMA 1986;255:939-940 2. McCrea ES. Hemorrhage into the breast. J Can Assoc Radio! 1981; 32:62-63
B,
3. Andersson
I, Adler DD, Ljungberg 0. Breast necrosis associated with thromboembolic disorders. Acta Radio! 1987;28:517-521 Kagan RJ, Glassford GH. Coumadin-induced breast necrosis. Am Surg 1981;47:509-510
4.
Lateral
vIew
of
plexus. (ReprInted from [2].)
with
permIssIon
Fig. shows caused
The
Postcncoid
Dr. Dodds,
large-sized
in his superb
swallow
examinations.
article
on swallowing
used
to
confirm the presence of submucosal veins in the esophagus on its ventral aspect, at and just inferior to the posteroinferior margin of the cricoid cartilage (Figs. 1A and 1 B). These veins of the upper esophagus were previously described and demonstrated in great detail by Butler [3], who stated that the ventral pharyngolaryngeal venous plexus lies in the esophageal submucosa and consists of one to five veins lying close to the midline. They are up to 4 mm in diameter and frequently are dilated because of vanicosis. These veins are found in
both sexes at all ages and must be regarded general
direction
of the veins
is longitudinal,
but they
may be
by many cross anastamoses. They are in the esophageal covering the dorsal surface of the cnicoid cartilage and form longitudinal masses on each side of the midline separated of 2-6 mm. Each half of the plexus is 2 cm wide.
and I think that this submucosal
postcricoid impression when barium descends
Some films show streamlining of the barium column as the barium cascades downward over the venous impression (Fig. 1 C). The impression was called postcricoid merely to describe its p0-
sition: just inferior and posterior
wall two
by a gap
venous plexus causes the
by indenting the esophageal lumen, so that and distends the lumen, the mucosa prolapses over the venous indentation and produces a filling defect on the ventral surface of the barium column. This defect or impression is so constant in its position that it does not appear logical that it could be produced solely by prolapse of a mucosal fold without an underlying cause.
to the inferior margin of the cncoid
cartilage.
As stated by Butler [3] and confirmed by others, including Seaman [4] and Clements et al. [5], the impression has no clinical significance. Radiologically, neoplasm [6].
however,
it may
be mistaken
West Vancouver,
as a normal feature.
joined
Fraser
swallow
streamlInIng of barium by postcrlcoid venous
behind the cricoid
[2], Fraser and I reported the results of injection studies
The
2.-Barium
venous
impression.
on the Esophagus
[1], states that no lamina that would impression on the esophagus noted on barium In our article on the postcricoid impression
veins are located
the postcncoid
explain
Impression
with postcdcoid Injected with bar-
for webs
[2] or for a
R. G. Pitman V7S 2R1
B.C., Canada
REFERENCES 1 . Dodds WJ, Stewart El, Logemann JA. Physiology and radiology normal oral and pharyngeal phases of swallowing. AiR
of the 1990;
154:953-963
2. Pitman RG, Fraser GM. The post.cricoid
impression on the oesophagus. C!in Radio! 1965;16:34-39 3. Butler H. The veins of the esophagus. Thorax 1951;6:276-296 4. Seaman WB. Significance of webs in hypopharynx and upper esophagus.
Radiology
1967;89:32-38
5. ClementsJl, Cox GW, Torres
WE, Weens HS. Cerval esophageal websa roentgen-anatomic correlation: observation of the pharyngo-esophagus. AJR 1974;121 :221 -231 6. Friedland GW, Filly R. The postcncoid impression masquerading as an esophageal tumour. Am J Dig Dis 1975;20:287-291
LETTERS
March 1992
AJR:158,
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Reply Dr. Pitman has questioned the opinion expressed by me and my colleagues [1] about the underlying cause of the postcricoid defect. His interest logically follows from the exquisite work he did investigating this area in 1 965 [2]. His work, and that of others, leaves no doubt about the presence of a venous plexus posterior to the cricoid. We question, however, if these small veins are substantial enough to cause the appearance of a 5- to 1 0-mm mass protruding into the lumen during pharyngography. As described in the article by Butler
[3], another hypopharynx plexus
venous plexus occurs on the dorsal aspect of the at the level of the inferior constrictor muscle. This dorsal
is of similar
size,
yet produces
no recognizable
mass
effect
on the barium column. We agree that the postcricoid defect is a common, benign finding that should not be mistaken for a more ominous process. We remain unconvinced, however, about the contribution of the underlying yenous plexus to account for this finding, and in our opinion, as stated
in our article, the main cause is a mucosal plication. Wylie
Medical
J. Dodds
College of Wisconsin Milwaukee, WI 53226
REFERENCES 1 . Dodds WJ, Stewart El, Logemann JA. Physiology and radiology of the normal oral and pharyngeal phases of swallowing. AJR 1990; 154:953-963 2. Pitman RG, Fraser GM. The post-cncoid impression on the oesophagus. C/in Radio! 1965;16:34-39
3. Butler H. The veins of the esophagus.
69i
lymph nodes. Several months before admission, he had been treated prophylactically with aerosolized pentamidine for presumed P. carinii pneumonia. Specimens obtained at autopsy from the visceral organs in which calcifications were found all stained positive for MAI. Special staining showed no evidence of P. carinll. It was presumed that the calcifications were due to disseminated MAI infection. However, further pathologic testing of the tissues with a monoclonal antibody highly specific for P. carinii (Dako clone 3F6) showed widespread evidence of previous P. carinll infection throughout the specimens, even though no histologic evidence of P. carinll was present. Antibody specific for P. carinll antigen was associated with these calcifications. It was assumed that these calcifications were due to P. carinll that had most likely undergone degeneration. MAI also was present in the organs, but not necessarily in regions of calcifications. Both patients presented by Tower et al. had been treated with aerosolized pentamidine. As was stated, dissemination of P. carinll
may be associated with this regimen [2]. It was indicated that special stains for P. carinll were used; however, no mention of antigen testing was made. If antigen testing was done, and the results were negative, then MAI or cytomegalovirus may have been the etiologic agent for the calcifications in these cases. However, if biopsy with special staining alone was used to determine previous infection with P. carinll, organisms may not have been seen, and it may have been falsely
that calcifications
concluded
were due to other etiologic
agents.
Scott St. Amour The Jewish Hospital of St. Louis The Washington University Medical Center St. Louis, MO 63110
Thorax 1951;6:276-296 REFERENCES
Latex
Retention
Balloon
for Barium
Enemas
Anaphylactic reactions to latex retention balloons used for barium enemas are a growing concern. According to my recent experience in Japan, such retention balloons are rarely needed. In 200 barium enemas I performed, a balloon catheter (36-French Foley catheter with silicone balloon) was needed in only two cases. As a former radiology trainee in the United States and now a practicing radiologist
in Japan, I think that retention States. It available catheters the habit
balloons
are
overused
in the
United
may be that some radiologists have only retention catheters in their departments or that some routinely use retention because this is what they learned in their residency. Once of using retention balloons is established, it may be difficult
to do barium enemas without
using the balloons.
these
can be performed
Reply
We thank Dr. St. Amour for his letter drawing
satisfactorily
without
using
devices.
[1] and also to the liver biopsy
agents
and that biopsy
confirmation
Calcifications
Sunnybrook
I read with interest a recent article by Towers
Recently
visceral
an AIDS patient at the Jewish Hospital calcifications
in the
liver,
spleen,
kidneys,
Toronto,
et al. [1] reporting may be (MAI) or
and
abdominal
Health
Science
University Ontario, Canada
Centre
of Toronto M4N 3M5
REFERENCE 1 . Towers
of St. Louis had
J. Towers
Mark
Cynthia E. Withers Paul A. Hamilton and colleagues
in AIDS
that widespread visceral calcifications in AIDS patients caused by infection with Mycobactenium avium-intracellulare cytomegalovirus rather than with Pneumocystis carinii.
of the infectious
is necessary.
Tsukuba Medical Center Hospital Tsukuba-shi, lbaraki 305, Japan
Visceral
to a
specimens from the second patient mentioned in the discussion. The sections and specimens were both negative for P. carinii, whereas control sections were distinctly positive. These results are consistent with our suggestion that visceral calcifications in AIDS may not always
be due to P. carinll Yoichi Kikuchi
our attention
specific monoclonal antibody immunohistochemical technique for demonstration of Pneumocystis carinll (Monoclonal mouse anti-Pneumocystis carinll, M778; Dakopatts A/S, Copenhagen, Denmark). We have obtained and applied this agent to multiple sections of liver and
kidney from the patient we described
The use of latex retention balloon catheters involves added risk, extra cost, and extra discomfort for the patient. I encourage American radiologists to use such catheters less often. I think that they will find
that barium enemas
1 . Towers MJ, Withers CE, Hamilton PA, Kolin A, Walmsley S. Visceral calcification in patients with AIDS may not always be due to Pneumocystis carinll. AJR 1991;156:745-747 2. Telzak EE, Cote RJ, Gold JWM, Campbell SW, Armstrong D. Extrapulmonary Pneumocystis carinii infections. Rev Infect Dis 1990;12:380-386
MJ, Withers CE, Hamilton PA, Kolin A, Waimsley S. Visceral in patients with AIDS may not always be due to Pneumocystis AJR 1991;156:745-747
calcification carinll.
LETTERS
692
Ewing
Sarcoma
Manifested
as Acute
AJR:158,
raphy compared
Abdomen
issues
We were interested to read a a 15-year-old Downloaded from www.ajronline.org by 109.161.206.147 on 11/08/15 from IP address 109.161.206.147. Copyright ARRS. For personal use only; all rights reserved
found
recent
case of the day [1 ] in which
girl who had had chronic groin pain for 2 years was
to have a Ewing
sarcoma
of the superior
pubic
ramus.
A 6-year-old girl recently was admitted to our hospital because she had had pain in the right iliac fossa, anorexia, and vomiting for 24 hr. She had previously been well. She had tenderness with guarding in the right lower quadrant and mild leukocytosis. A diagnosis of acute appendicitis was made, and laparotomy was performed. At surgery, the appendix was normal. However, a large hematoma was observed extending from the pelvis and displacing the bladder to the left. Subsequent plain radiography, radionuclide bone
scanning,
remarkably
and contrast-enhanced to that described
CT scanning showed a lesion by O’Connor et al. [1], but on examination confirmed the diagnosis of
similar
the right side. Histologic Ewing sarcoma. The most common
manifestations
of Ewing sarcoma
are pain and
swelling related to the bone symptoms such as anorexia,
involved. However, systemic signs and intermittent fever, and malaise are not uncommon. Hemorrhage and necrosis, common histologic features of these tumors, may produce local pain, erythema, and increased temperature so that they mimic infection. Approximately 20% of Ewing sarcomas are situated within the bones of the pelvis [2], and it is not surprising that these tumors occasionally mimic an acute abdomen. Chronic abdominal or groin pain is probably the more common manifestation, but acute pain may be an indication and has been reported in a 39-year old woman [3] (i.e., well outside the characteristic age range for these tumors).
W. W. Gibbon
G. M. Roberts University Hospital Cardiff, United
of Wales Kingdom
REFERENCES 1 . O’Connor
JF, Martin 1991;156:1314-1320 2. Dahlin DC, Coventry of 165 cases. J Bone 3. Jasani N, O’Connor
LC, Chen H, et al. Pediatric case of the day. AJR
right-sided
MB, Scanlon PW. Ewing’s sarcoma: a critical analysis Joint Surg (Am] 1961;43-A:185-192 RE, Bouzoukis JK. An unusual diagnosis for acute pain in a 39 year old woman (letter). Am J Emerg Med
groin
1991;9:96-98
Sonography Candidates
vs MR Imaging in Children for Liver Transplantation
Who
Are
the authors’
with MR in their series. Let us examine some specific
their
article.
conclusion
that
Only
21 of their
“randomly
tion. It is not clear if this haphazard approach affected the results, but we consider it essential to obtain the spectral Doppler waveform and determine flow direction in the portal vein of every candidate for liver transplantation if the comparison ofsonographic and MR findings is to be credible. Failure to recognize interruption of the inferior vena
cava, a preduodenal portal vein, or polysplenia on sonograms occur only for want of careful attention. Their MR demonstration
can
of siderotic intrasplenic nodules with no corresponding sonographic findings is noteworthy, but Bisset et al. [1) neglected to mention use of the lesser omental thickness/aortic diameter ratio [3] in sonographic detection of portal hypertension. Although it may be possible to measure the dimensions of the recipient’s native liver more precisely with MR than with sonography, this provides no particular advantage in children. The size match in children is based on body weight, and reduction techniques are used if the donor liver is too large. The size of a partial liver graft depends
on the size of the donor organ and is empirically
determined
transplantation (Tzakis AG, personal communication). Portal veins less than 4 mm in diameter were a particular
for Bisset portal
vessels
et al. An expert
sonographer
should
during difficulty
be able to detect
veins 2 or 3 mm in diameter, although demonstration of the may entail meticulous technique. The admittedly “preliminary”
results of Bisset et al. raise questions about the consistency of the and do not substantiate the authors’ assertion that MR
sonograms
has eclipsed sonography for assessment of the portal vein. Our intent is not to minimize the capabilities of MR; on the contrary, we enthusiastically endorse the potential of MR for evaluating progressive liver disease and suspected portal hypertension in children. However, children whose underlying disease has already been fully evaluated and who have been referred to a liver transplantation center need not then be subjected to a costlier examination (i.e., MR imaging) that may mandate sedation. Sonography is less expensive, rarely requires sedation, generally is quicker, entails little discomfort, and can accomplish the crucial objectives: (1) determination of patency and diameter of the extrahepatic segment of the portal vein; (2)
detection
of unsuspected
abnormalities
patency of the superior thrombosis.
such as hydronephrosis
that
portion of the portal vein or does not show mesentenc
veins in children
MR
Children’s
technique of choice for these children merits
comment. During the past decade, real-time sonography-with its more recent embellishments of spectral and color Doppler imaginghas been the hub for preoperative imaging of these children [2]. It would not be prudent to embrace MR as a replacement for sonography in this key role without thoroughly examining the evidence for recommending
36 patients,
selected, at the discretion of the sonographer’ had Doppler assessment to determine the direction of portal venous flow. By definition, selection at the sonographer’s discretion cannot be a random sales-
define the extrahepatic
by Bisset et al. [1] is a welcome contribution to the sparse literature on MR imaging of children who are candidates However,
1992
may need to be dealt with before transplantation; and (3) detection of an occult malignant neoplasm in the diseased native liver, a finding that places the child on the urgent transplant list. MR is an attractive alternative to angiography [4] if sonography does not satisfactorily
The recent article
for liver transplantation. should be the imaging
from
March
with portal
venous
A’Delbert Bowen Hospital of Pittsburgh Gregory A. Applegate Emanuel Kanal
The Pittsburgh
NMR Institute
University
of Pittsburgh
Pittsburgh,
PA
15213
such a departure.
Any attempt to compare the results of sonography with those of another imaging technique must take into account the immensely important operator dependency of real-time sonography. The information provided by mapping deep abdominal vessels, identttying collateral vessels in portal hypertension, and detecting anomalies is directly related to the sonographer’s proficiency and to the effort expended in the search. Bisset et al. [1] acknowledge that operator error may have contributed to the relatively poor showing of sonog-
REFERENCES 1 . Bisset G III, Strife J, Balistreri
plantation: 2.
value
of
MR
155:351-356 Ledesma-Medina J, Dominguez atnicliver transplantation. Part
imaging. Radio!ogy
WF. Evaluation of children for liver transimaging and sonography. AJR 1990; R, Bowen
A, Young LW, Bron KM. Peril-
I. Standardization ofpreoperative diagnostic
1985;157:335-338
3. Patriquin H, Tessier G, Gnignon A, Boisvert
J. Lesser
omental
thickness
in
LETTERS
March 1992
AJR:158,
normal
children:
baseline
for detection
of portal
hypertension.
AiR
1985;
145:693-696
4.
Spritzer CE, Peic NJ, Lee JN, Evans AJ, Sostman HD, Riederer SJ. Rapid MR imaging of blood flow with a phase-sensitive, limited-flip-angle, gradient-recalled pulse sequence: preliminary experience. Radio!ogy 1990;
Downloaded from www.ajronline.org by 109.161.206.147 on 11/08/15 from IP address 109.161.206.147. Copyright ARRS. For personal use only; all rights reserved
176:255-262
693
Our data were obtained
before the application
of color flow tech-
niques. Certainly, with these advances, vascular anatomy and detection of flow can be determined in even the smallest patients. We still think, on the basis of our data, that global anatomy (liver volume, collateral vessels, portal vein size, etc.) is better visualized with MR imaging. Although we still use sonography as our initial screening examination, we do not consider the workup of the child with endstage liver disease complete without MR imaging.
Reply
George
We thank Dr. Bowen and his colleagues for their interest in our article on end-stage liver disease [1]. We recognize that they have a large experience with pro- and postoperative examination of candidates for liver transplantation. Therefore, their criticisms bear careful consideration. We would like to address several specific issues. First, Bowen et al. question our prudence in embracing MR imaging recent
University
REFERENCES 1 . Bisset
GS III, Strife JL, Balistreri WF. Evaluation of children for liver transplantation: value of MR imaging and sonography. AJR 1990;
as a replacement for sonography. It was not stated, nor was it our intention,
compared
provided
that MR should be substituted for sonography. We simply our data from the two techniques and concluded that MR more useful information for the management of children with
end-stage
liver disease.
currently perform the examinations Bowen et al. ency of real-time
We
article.
self-evident
At Children’s
Hospital
Medical
Center,
both sonography
and MR in such children
provide valuable,
complementary
we
because
information.
focus on the immensely
important operator dependsonography. Certainly, this is emphasized in our did not think it necessary to inundate the reader with this concept. Bowen at al. state that they “consider it essential
to obtain the spectral Doppler waveform and determine flow direction in the portal vein of every candidate for liver transplantation.” It is not clear as to why they believe this. Certainly it is essential to show the size and patency of the portal vein. However, in any patient with endstage liver disease (who is being considered for transplantation), information on of significant neglected to diameter ratio.
the direction of portal clinical value. Bowen
mention
venous flow may or may not be et al. also point out that we
use of the lesser
omental
thickness/aortic
155:351-356
2. Brunelle F, Alagille D, Pariente D, Chaumont
et al. [2] found ratios of greater than 2:1 in who had portal hypertension. In 30% of patients
dures: a comprehensive
The Looking-Down
that
off-axis
perineum,
hypertension.
Ann
View
for Pelvic
MR Imaging
of MR is the ability to do multiplanar Previous reports [1-3] suggest that multiplanar imaging is for diagnosis of pathologic changes in the pelvis, an area
ratio
of portal
decompression.
A significant advantage imaging. desirable
anatomy
predictor
approach to portosystemic
Surg 1974;179:791-798
only 52% of patients with documented portal hypertension, the ratios overlapped those of control subjects, ranging between 1 :1 and 2:1 [2]. Therefore, this poor
P. Etude #{233}chographiquede
‘hypertension portale chez l’enfant. Ann Radio! (Paris) 1981;24: 121-130 3. Ledesma-Medina J, Dominguez R, Bowen A, Young LW, Bron KM. Pediatric liver transplantation. Part I. Standardization of preoperative diagnostic imaging. Radio!ogy 1985;157:335-338 4. Qin Y, Cauteren MV, Osteaux M, Willems G. Determination of liver volume in vivo in rats using MRI. Eur J Radio! 1990;1 1 :191 -1 95 5. Warren WD, Salam AA, Smith RB. The meso-spleno-renal shunt prose-
for which MR imaging is wall suited. Baumgartner
Brunelle
is an extremely
S. Bisset Ill
Janet L. Strife Children’s Hospital Medical Center of Cincinnati, College of Medicine Cincinnati, OH 45229-2899
The
imaging
of the cervix.
additional sagittal,
perspective coronal,
at al. [1] reported showing the zonal We think that the off-axis view provides an
of the pelvis
is helpful
in
of the pelvis not obtained
or transverse
imaging.
and the normal anatomy
It
through
conventional
can be used to show the
and pathologic
changes
(SE 600/25).
A line drawn
in the
detection of intrasplenic siderotic nodules (detected readily by MR and not noted on sonography in our study) is very specific. Bowen et al. state that “an expert sonographer should be able to
detect portal veins 2 or 3 mm in diameter.” However, in their own published series [3], the portal vein was identified in only 68% (26/ 38) of patients before liver transplantation. In this same series, the inferior
vena cava was visualized
in whom the authors performed inadequacy
in only 74% (28/38).
were “not sure,” abdominal
In six children
angiography
was
to define the anatomy [3]. Was this an operator-dependent or lack of meticulous technique? In our population,
whom a diligent search was made to locate sonography, MR imaging was more sensitive.
the portal
in
vein by
Bowen et al. also question the advantages of being able to measure the size of the native liver. As pointed out in our manuscript,
not all
patients had transplantation. Many of these patients were managed medically. Certainly, MR is superior to sonography for measuring liver
volume [4]. This is related to a lack of spatial resolution differentiation
on sonography.
Determination
of hepatic
and tissue volume
can
be used for diagnosis of some diseases and for evaluation of nosponses to therapy [4]. This in vivo estimation of volume also can be used to monitor liver perfusion after portosystemic shunt procedures [5]. In patients with hepatic neoplasms, the volume of the liver can be used as a parameter for estimating tumor growth rate [4]. These represent
several
advantages
that have not been fully explored.
Fig.
1.-Sagittal
localizer
MR image
from
symphysls pubis to sacral promontory forms a 90#{176} angle at pubic symphysis. Diagonal lines show subsequent positions for imaging. Fig. 2.-”Looking down” MR Image of pelvis shows perineum, vagina (1), air in the rectum (2), bulbospongiosus muscle (straight solid arrow), superficial perineal (ColIc) fascIa (open arrows), and vaginal artery branch of internal iliac artery (curved arrow). Deep margin of bulbospongiosus muscle Identifies plane of inferior fascia of urogenItal diaphragm. surgery, a benign fibroma was found deep to urogenital diaphragm.
At
LETTERS
694
female
The resultant
pelvis.
view permits a perspective
AJR:1 58, March
1992
for preoper-
ative planning
before gynecologic surgery such as myomectomy. We have termed this the pelvic “looking down” view. The technologist is instructed to define a line from the superior
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margin of the symphysis projection. pubis
The
angle
between
be approximately
should
for slight differences
projection.
pubis to the sacral promontory formed
line
in the sagittal
and
the
90#{176} (Fig. 1). The angle
in uterine
T2-weighted
this
symphysis
can
be varied
axis or pelvic tilt as seen in the sagittal
spin-echo
images are obtained
by using a 5-
mm slice thickness with a 2.5-mm intenslice gap. This pulse sequence is chosen to maximize contrast between urinary bladder, uterus, ovaries, and other abnormalities that may be present, such asfibroids. The resultant image is displayed in a plane parallel to the short axis of the true pelvis and thus approximately parallel to the vagina and pelvic floor. Depending on the angle of the uterus (anteflexed, neutral, or retroflexed), the pelvic floor is seen from a surgical perspective, with the right adnexa on the observer’s right and the left adnexa on
the observer’s left, as if the observer from above (Fig. 2). Unlike
in the
structures
standard
coronal
the
relationship
dimension
the view is a blend between a traditional
of adjacent
can be appreciated,
transverse
so
view and the true
coronal plane of the pelvis. The vagina, vaginal fornices, region of the urogenital diaphragm, perineum, and pelvic floor musculature are visible. In addition, flow-void phenomenon from patent vessels may permit visualization of the uterine artery and the artery to the vagina
as well as potential fibroids.
The anatomic
feeding position
B
and B, Transvaginal sonograms of urethral leiomyoma. Trans(A) shows a well-defined, hypoechoic, homogeneous mass. Urethra, which is not distinguishable, is located between probe and tumor. On longitudinal image (B), tumor has a more rounded appearance, and Fig. 1.-A verse image
dilated
proximal
urethra
is seen
on left side of mass.
is looking down into the pelvis
plane,
in the anteropostenor
A
vessels
in patients
of the uterine
the mass was located anterior to the urethra. was not invaded, the tumor could be easily
examination, grayish tint. benign
the cut surface appeared
Microscopic urethral lelomyoma.
examination
to be regular, confirmed
permits
1340 Ottignies-Louvain
Allan M. Haggar Henry Ford Hospital Murray
Hospital
A. Howe
Radiology Associates Toledo, OH 43623
REFERENCES
1001-1002
2.
H, Alpers C, Crooks LE, Sheldon PE. Magnetic resonance imaging ofthefemale pelvis: initial experience. AJR 1983;141 :1119-1128 3. Hricak H, Williams RD, Spring DB, et al. Anatomy and pathology of the male pelvis by magnetic resonance imaging. AJR 1983;141 :1101-1110 Hricak
Leiomyoma Transvaginal
of the Urethra: Sonography
Appearance
of
Michel Donnay Clinique St. Pierre Ia Neuve, Belgium
REFERENCE 1 . Ohtani M, Yanagizawa R, Shoji F, Fukutani K, Yokoyama of the male urethra. Eur Uro! 1982;8:372-373
Accessory
1 . Baumgartner BR, Bernardino ME. MR imaging of the cervix: oft-axis space scan to improve visualization of zonal anatomy. AJR 1989;1 53:
diagnosis
Michel Wacquez
apptox-
Detroit, Ml 48202
with a slightly
the
with large uterine
arteries
the urethra On gross
Jean L. Jonion Carl C. Pauls
imation of the position of the broad ligament.
Toledo
Because removed.
Occipital
M. Leiomyoma
Ventricle
The radiologic literature has little information on accessory occipital ventricles. A report by Hon at al. [1] described the results of a detailed investigation of small, separate, radiolucent structures seen at the tip
of the occipital studies
horn of the lateral ventricle
established
that the medial
on CT scans. Histologic
and lateral
walls
of the ventricle
on
Leiomyoma of the urethra in women is a rare condition. To date, only 20 cases have been reported [1 J. In all cases, diagnosis was made only after excision biopsy. We report a case in which the diagnosis was suspected before surgery because of the sonographic appearance. A 54-year-old woman complained of dysuria, which was attributed
to a mass protruding showed a nontender meatus. Voiding thra. Transvaginal
from the urethral meatus. Physical examination mass 1 cm in diameter in the upper lip of the
cystourethrography showed a dilated proximal uresonography showed a 3.6- by 2.0-cm well-defined
homogeneous mass in the region of the urethra, which was not clearly identified. This mass was lobulated on the transverse view and round on the longitudinal view (Fig. 1). Because the sonohypoechoic,
graphic
appearance
ofthe
lesion was similar
with benign prostatic hypertrophy, such as leiomyoma, was suggested
to the findings
in patients
a benign tumor of the urethra, as the diagnosis. During surgery,
Fig. 1.-CT drop-shaped, sory occipital
scan isolated ventricle.
shows tearright acces-
Fig. 2.-CT intraventricular
scan of patient with blood shows left ac-
cessory occipital questered.
ventricle
is se-
AJR:158,
in the occipital
region
may fuse, resulting
in a sequestered
portion
ever, is the situation
of
Downloaded from www.ajronline.org by 109.161.206.147 on 11/08/15 from IP address 109.161.206.147. Copyright ARRS. For personal use only; all rights reserved
was 21 .3% on CT scans,
bilateral, and 29.5% on autopsy specimens. CT scans, the prevalence was 17%. Recognition
of an accessory
cause it could be misinterpreted
occipital
of which
in which the accessory
Hon et al. used the term
Although
the occipital tnicle
is accurate
ventricle
is important
as a focal lesion,
Johannesburg
be-
such as a lacunar Johannesburg
of letters
being submitted must
disclose
or published
financial
elsewhere
associations
with
ventricle of occipital yenE. Tobias
Roger Scott Brenthurst Clinic 2000, South Africa Peter Goldschmidt Hillbrow Hospital 2000, South Africa
REFERENCE
the tip of is that the More confusing, how-
1 . Hori A, Bardosi
A, Tsuboi K, Maki Y. Accessory occipital lobe. J Neurosurg 1984;61 :767-771
Letters are published at the discretion of the Editor and are subject to editing. Letters to the Editor must not be more than two double-spaced, typewritten pages. One or two figures may be included. Abbreviations should not be used. Limit the number of authors to four, or we will list only the first three and add “and colleagues” to the end of the list. See Author Guidelines. Material
cerebral
Milton
ventricle is opposite so the natural assumption
ventricular structure.
is isolated,
and concise.
one third were
In our own series of 450
of the accessory ventricle (Fig. 2). In some instances, the accessory horn,
accessory
lobe, we think that the phrase accessory
infarct or a cysticercosis lesion. The shape of the accessory ventricle vanes from round to oval or even triangular (Fig. 1 ). Intraventnicular hemorrhage is a useful demonstration of the complete separateness
the contralateral occipital accessory ventricle is a
ventricle
a short contralateral ventricle (Fig. 1).
ventricle. The ependymal layer of the separated ventricle atrophies. The process is similar to that which leads to coarctation of the anterior horn of the lateral ventricle, although in this region, true sequestration does not occur. In the study by Hon et aI., the prevalence of this finding
695
LETTERS
March 1992
should
or other
not be duplicated
possible
conflicts
in letters,
and authors
of interest.
Letters concerning a paper published in the AJR will be sent to the authors of the paper for a reply to be published in the same issue. Opinions expressed in the Letters to the Editor do not necessarily reflect the opinions of the Editor.
cerebral ventricle
of the