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893

Letters

V #{149}

. ,.

.

.:.

,

.,

.

Low-Attenuation

...

::

‘,

Mediastinal

:

.

Masses

on CT

The pictorial essay by Glazer et al. [i] is an excellent review of low-attenuation mediastinal masses seen on CT. However, my colleagues and I [2] have reported a case of a mediastinal neurofibrosarcoma in a 52-year-old man who had no medical history or clinical signs of neurofibromatosis. This homogeneous and water-density (5-. 18 H) mediastinal mass showed slight peripheral enhancement. The neurofibrosarcoma was located in the middle and posterior mediastinum,

in contact

with the anterior

vertebral

bodies.

No bone erosion

versed the pulmonary capillary bed and returned by way of large tortuous anomalous veins that coincided with the abnormal vessels seen on the chest radiograph. The pulmonary venous return was exclusive to the left atrium. Indicator dilution curves showed normal transit

time through

the lungs.

An intrapulmonary

thus was ruled out. It was concluded

venoartenal

noncommunicating arteriovenous malformation. Congenital pulmonary arteriovenous malformation

defect

in the terminal

subsequent

capillary

dilatation

and

shunt

that the patient had an unusual is caused

loops of the splanchnic

formation

of

thin-walled

plexus vascular

by a

with sacs

or lymph node enlargement was observed. The biopsy specimen was obtained via thoracotomy. The patient died 6 months after combined chemotherapy and radiotherapy. Our review of the literature [2]

supplied

confirmed

formations in the skin, mucous membranes, and other organs as part of Rendu-Osler-Weber syndrome [1]. Conversely, only i 5% of pa-

that

neurofibrosarcomas

have

an identical

low-attenuation

locations. Although Glazer et al. [1] state that “various degrees of inhomogeneity and contrast enhancement can be seen in both benign and malignant neural tumors,” they do not refer specifically to neurofibroappearance

sarcoma that this

on CT, in almost

all body

presenting as a low-attenuation mediastinal mass. I think lesion, which is rare in the general population but not in

patients with neurofibromatosis, should be included in the differential diagnosis of low-attenuation mediastinal masses seen on CT. Apostolos H. Karantanas Medical School, University of loannina loannina

451

10, Greece

by a single distended

tients

with this syndrome

The radiologic

mediastinal

masses on

by one or

one third of such lesions with artenovenous mal-

lesions.

of pulmonary

tions includes round or oval homogeneous defined, sometimes lobulated, preferentially

arteriovenous

malforma-

masses that are sharply located in the medial third

of the lung, and range from less than 1 cm to several centimeters in diameter. Identification of feeding and draining vessels is essential for the diagnosis. Angiography confirms the findings and shows the arteriovenous shunt with early venous drainage [2]. Pulmonary arteriovenous malformations usually are recognized in adulthood.

tomatic.

1 . Glazer HS, Siegel MJ, Sagel 55. Low-attenuation

artery and drained

have pulmonary

appearance

Only

iO%

about

They are twice as frequent

REFERENCES

afferent

distended afferent veins. Approximately are multiple, and about 50% are associated two

Hemoptysis,

paradoxical

are diagnosed

dyspnea,

embolism

in infancy

or childhood.

in females as in males. Most are asympcyanosis,

can occur.

clubbing,

Multiple

polycythemia,

pulmonary

and

arteriovenous

CT.AJR 1989;152:1173-1177 2. Karantanas AH, Nicolaou N, Kontoyiannis D, Stefanou D, Pavlidis NA. CT demonstration of a mediastinal neurofibrosarcoma. J Exp Cl/n Cancer Res 1988;7:183-185

Noncommunicating

Pulmonary

Artenovenous

Malformations A 7-year-old boy was referred for evaluation of an asymptomatic cardiac murmur. Results of the physical examination were normal except for a grade 2 short ejection systolic murmur heard widely over the precordium. ECG and echocardiography were normal. A chest radiograph

showed

abnormal

peripheral

erally (Fig. i A). Cardiac

catheterization

uration

of the

on both

sides

heart

pulmonary

showed and

vascularity

bilat-

normal oxygen

normal

central

sat-

vascular

pressures. The systemic arterial Po2 rose to 434 torr when the patient was breathing i 00% oxygen. Pulmonary nary arteries,

angiography which were

showed tortuous

normal distribution (Fig. i B). Contrast

of the pulmomaterial tra-

Fig. 1.-Noncommunicating

pulmonary

arteriovenous

malformation.

A, Chest radiograph shows multiple tortuous vessels distributed throughout both lungs and extending to subpleural region. B, Pulmonary angiogram (venous phase) shows large tortuous pulmonary veins that account for majority of vascular shadows noted In A.

894

LETTERS

October 1990

AJA:155,

malformations can distort the plain film appearance of the pulmonary vascular pattern. Extensive diffuse changes without obvious symptomatology

can,

pulmonary

in

rare

instances,

arteriovenous

be

due

to

noncommunicating

malformations. Paul Stark

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Brigham

and

Women’s

Harvard

Hospital

Medical Boston,

School MA

02115

Erik Bjarke Loma

Linda

University

Medical

Loma

Linda,

Center CA 92354

REFERENCES 1 . Hodgson CH, Burchell HB, Good CA, Ctagett OT. Hereditary hemorrhagic telangiectasia and pulmonary arteriovenous fistula: survey of a large family. N EngI J Med 1959;261 :625-636

shunt. A, Chest

2. White Al Jr. Mitchell SE, Barth KH, et al. Angioarchitecture

and atelectasis

arteriovenous malformations: therapy. AJR 1983;140:681

Cancer,

the

It is not

consideration

before

embolo-

-686

abscess

radiograph

that

announces

a disease its own

process

presence.

either The

as clearly,

malignant

or as

calcifications

shown on the mammogram (Fig. i) are clearly recognizable as a crab. The word “cancer,” of course, is derived from the Latin word for crab. F. I.Jackson Cross Edmonton,

of supine

‘ .

Cancer

Alberta,

Institute

Canada

T6G1Z2

containing

a hypodense

Gram-positive

shunt,

and

the

patient

radiographs

the

and B, Mammogram as a crab (B).

that cleariy are

man

right-sided conversion

of the

of the

effusion

cm

cystic

The cyst peritoneal CT-guided

show lesion

chest

of an obstructed

base

not

aqueductal

pleuritic

any

pleural

right

lobe.

yielded

in the

Plain

effusion

lower

growth.

pain,

stenosis

advent

with

IV antibiotics.

and

spiking

chest

Sonography segment

dyspnea, dry fevers 3 weeks

shunt radiographs

(Fig.

and subsegmental but

serial right

i A)

atelectasis

guided

subsequently of the

to a right-

thoracen-

bacterial

cultures

showed lobe

of the

an 8-

at this

time

showed

the

of soft

Silastic

(polymeric

pleural

silicone)

no

effusion

was

tubing,

at

ventric-

and

the

tube

nevertheless formation

of

migration

is a particularly

in our of

achieved

the

fine-needle

the of

aspiration.

antibiotic shunt

In our

any therapeutic drainage Touho et al. [4]. Our case underscores of suspicion

tions lishing

with

side.

also

Accurate

have

with and

temporary case,

diagnosis

diagnosis

used

either

the

the

potential

shunts and

results

starting

shunts. of the ventricof

its

peritoneal

resolved

were

without

reported

by

a high index

intraabdominal appropriate

intraab-

a combination

of maintaining

if unnecessary

with

to show

involves

abscess

similar

the importance to

]

replacement

hepatic

was

shuntography

[i

ventriculoperitoneal

usually

of the inflam-

with percutaneous

externalization

procedure;

respect

and signs

to transdiaphragmatic

pseudocysts

of ventriculoperitoneal an accurate

due

[3] and radionuclides

therapy or

[3]) were incorrect.

symptoms

right

associated

uloperitoneal

any

and

and CT combined

Others

of infected

[i -3].

were the

material

of aggressive component

presenting

sonography

pseudocysts

Virtually

so symptoms

end of a ventriculoperitoneal

[2] and acute cholecystitis

pleura

contrast

involved, [i].

of the peritoneal

mostly

by using

these include

rare complication. Only three cases have been [2, 3]. In two of these, the initial diagnoses (right

case,

abscess

do occur; pseudocysts.

complica-

delays

in estab-

therapy

are to

be avoided. Charles

liver.

contained internal echoes, thick septa, and the tip of the shunt catheter. CT confirmed these findings (Fig. i B), and fine-needle aspiration of the cyst yielded an exudate

Although

cavity

of

Treatment

of

had

Sonographically

an exudate,

anterior

Complication

ventriculoazygous

shunt.

a right-sided

did

A Rare Shunt

with

ventriculoperitoneal

treated

migration

dominal

Intrahepatic Abscess: Ventriculoperitoneal

a/bus

eter in the pentoneal

mation

(A) shows calcifications

was grown in The infected shunt ventriculoperitoneal

Staphylococcus

has become the method of choice for manageComplications from the presence of a cath-

radiologic

tesis

eftusion

uloperitoneal shunting ment of hydrocephalus.

intrahepatic

B

A 24-year-old

was

of the chest

Similarly,

A

of the

pleural

is visible, but its

to define. cyst containing ventriculo-

no hydrocephalus. with a left-sided

intraabdominal structure can become signs are protean and often misleading

-

..

showed

right-sided

decreasing. IV antibiotics were continued for 2 months, and discharge the patient had a normal temperature and hemogram.

reported previously lower lobe pneumonia

sided

a ventriculoperitoneal

formal drainage of the hepatic abscess was performed, sonography of the liver 3 weeks later was normal, and sonography and plain

Intrahepatic

after

shows

intrahepatic

cocci;

culture. Cranial CT showed was removed and replaced

shunt

cough,

patient

with

of right lower lobe. Tip of shunt (arrow) relative to liver and diaphragm is difticuft

precise position B, CT scan shows peritoneal shunt.

With

Fig. 1.-A recognizable

associated

Crab

often

eloquently,

an important

of pulmonary

Fig. 1.-Intrahepatic

G. Peterfy

Mostafa Montreal,

Montreal Quebec,

General Canada

Atri

Hospital H3G 1A4

AJR:155,

LETTERS

October1990

The

REFERENCES 1 . Bryant

MS. Bremer

AM, Tapas

JJ III, Mollitt

DL, Nguyen

TO, Talbert

JL.

Abdominal complications of ventriculoperitoneal shunt: case reports and review of the literature. Am Surg 1988;54:50-55 2. Fisher RA, Rodziewicz G, Salman WA, White RJ, Vibhakar SD. Liver

Downloaded from www.ajronline.org by 117.253.236.81 on 11/10/15 from IP address 117.253.236.81. Copyright ARRS. For personal use only; all rights reserved

abscess:

895

complication

of a ventnculopentoneal

shunt.

Neurosurgery

1984;

14:480-482 3. Reddy SC. Subcapsular hepatic abscess: a rare complication of ventriculopentoneal shunt. South Med J 1987;80: 1309-1310 4. Touho H, Nakauchi M, Tasawa T, Nakagawa J, Karasawa J. Intrahepatic migration of a peritoneal shunt catheter: case report. Neurosurgery 1987;21 :258-259

findings

of an acute,

Anisakiasis

Simulating

Carcinoma

anisakiasis

of the

bowel

wall.

Barium

enema

showed

is not

a rare

disease

in Japan

and

servative

surgical

Americans for raw definite diagnoses

intervention

should

be supplanted

treatment when intestinal anisakiasis the disease is usually transient.

apple-core lesion phoresis showed larva antigen.

in the ascending that the patient

colon (Fig. 1 B). Immunoelectrowas seropositive for the Anisakis

by more con-

is strongly

suspected

Masafumi

Shirahama

Takafumi

Koga

Satoshi

Uchida

Vuichi

Miyamoto

Yoshiro

Ohta

Saga Prefectural Hospital Saga 840, Japan

an

showed dramatic thinning of the involved bowel wall of the colon, and barium enema on the 14th day showed neither a stenotic nor an

where

fish. In most patients with are made after laparotomy.

lesion at the ascending colon, suggesting carcinoma of the colon (Fig. 1A). Colonic endoscopy showed smooth and edematous mucosal surface without any ulceration. Biopsy of the edemaeosinophilic infiltrate. No drug thersigns and symptoms had almost day. Sonograms on the 1 0th day

suggested reports of

the Netherlands,

Hiromi

apple-core

tous region showed an intensive apy was started. The patient’s disappeared by the fifth hospital

the

habitually eat raw or undercooked fish, reports from North America are quite rare. However, cases of anisakiasis are becoming more frequent in the United States in conjunction with a growing

because

thickening

with

people

A 52-year-old man was admitted because of colicky pain in the right flank. Twenty hours before the onset of the abdominal pain, he had ingested raw fish (mackerel) as sashimi. Physical examination showed a soft, egg-sized mass and tenderness in the right upper quadrant. The WBC count was 9000 ceIls/,I, with 6% eosinophils. Sonograms of the ascending colon near the hepatic flexure showed marked

colitis

Anisakiasis is a parasitic disease of the gastrointestinal tract caused by ingestion of live Anisakis larvae present in fish. Although

However,

of the

segmental

fish, and positive serologic tests forAnisakis larval antigen colonic anisakiasis. To our knowledge, only two case colonic anisakiasis have been published before [1 , 2].

enthusiasm among intestinal anisakiasis,

Colonic Colon

transient

appearance on barium enema of an apple-core lesion, an eosinophilic infiltrate, a peripheral eosinophilia, the recent history of ingesting raw

Kyushu

Ishibashi University

Fukuoka

812, Japan

REFERENCES 1 . Richman RH, Lewicki AM. Right ileocolitis secondary

to anisakiasis.

AJR

1973;1 19:329-331

2. Higashi M, Tanaka K, Kitada T, Nakatake K, Tsuji M. Anisakiasis confirmed by radiology of the large intestine. Gastrointest Radio! 1988;13:85-86

Diagnostic Joint

Imaging

of the Temporomandibular

We read with interest the article by Helms and Kaplan [1 ] on the various techniques for diagnostic imaging of the temporomandibular joint (TMJ). They stated that CT was far better than conventional radiographs for imaging bony disease but that the information obtamed

was

usually

not important

enough

to warrant

using

CT instead

of plain films. We agree that CT is superior to conventional tomography, but we think that CT is an informative technique for showing bony changes of the TMJ and that it should be used more often for diagnostic imaging of this joint in patients who have rheumatoid arthritis.

We have completed rheumatoid

arthritis

a study [2] of the TMJ

and 26 control

subjects

in

26 patients

admitted

for sciatica

with

and

selected on the basis of age and sex to match the rheumatoid arthritis group. Hypocycloidal conventional tomography and direct coronal CT (direct sagittal CT was impossible because of painful cervical spine) were performed. Tomography showed erosive or cystic lesions of the TMJ in 73% of the rheumatoid arthritis group vs 38% of the Fig. 1.-Colonic anisakiasis simulating carcinoma of the colon. A, Eariy in course of disease. Sonograms (top) through ascending colon near hepatic flexure on first hospital day show markedly thickened bowel wall. Barium enema (bottom) on second day shows apple-core lesion at ascending colon. B, Later

in course

decreased thickness shows no apple-core

of disease.

Sonograms

(top)

on 10th day show of colonic wall. Barium enema (bottom) on 14th day lesion. Note minimally rigid outline (arrows).

control group. Direct coronal CT showed erosive or cystic lesions of the joint in 88% of the rheumatoid arthritis group vs 58% of the control group. Direct coronal CT allowed a better estimate of erosions and cysts of the mandibular condyle than tomography did. However,

bony changes tomography

of the articular than by using

fossa were better estimated

direct

coronal

We think that coronal CT examination to show

bone lesions

by using

CT.

is the procedure

of the TMJ in rheumatoid

arthritis

of choice

and that use

LETTERS

896

of

CT

in

association

with

tomography

allows

the

most

accurate

evaluation.

AJR:1 55, October

hemangiomas (tumors) and vascular malformations alies in vessel formation).

Kenneth

Ph. Goupille

B. Fouquet

The Children’s

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Ph. Cotty D. Goga

J.-P. Valat Trousseau

37044,

Hospital

Tours, France

REFERENCES 1 . Helms CA, Kaplan recommendations 31 9-322

P. Diagnostic

of the temporomandibular joint: for use of the various techniques. AJR 1990154:

2. Goupille Ph. Articulation

imaging

temporo-mandibulaire

et polyarthrite

dibular tion

joint with

of the

the remarks

in patients

with

conventional

articular

of Goupille

for showing

a complete

and

examining

examination

CT is

in the temporoman-

arthritis for

that

in associa-

the

bony

changes

of the

bony

changes

of rheumatoid arthritis can be performed. However, we stand by our statement that the information obtained with CT is generally not clinically significant enough to warrant a CT examination or conventional tomography in lieu of plain films. We feel strongly that an examination should not be used just because it can reveal more information. If the extra information does not result in an alteration in treatment, then the cost and the exposure to radiation make it inappropriate to use the procedure in every case. Although the imaging

protocol

recommended

by Goupille

information in patients with rheumatoid not alter their treatment on the basis information

raphy

on bony

changes;

et al. may

result

in more

arthritis, our clinicians of the small increase

would in the

CT and conventional

therefore,

tomog-

are not recommended.

Clyde A. Helms University

of California

Medical

Center

San Francisco,

CA 94143 Phoebe Kaplan

University

of Nebraska

19104

REFERENCES 1 . Buetow PC, Kransdorf MJ, Moser RP Jr, Jelinek JS, Berrey BH. Radiologic appearance of intramuscular hemangioma with emphasis on MA imaging. AJR 1990;154:563-567

2. Burrows PE, Mulliken JB, Fellows KE, Strand AD. Childhood hemangiomas and vascular malformations: angiographic differentiation. AJR 1983;141: 483-488

Reply

et al. that coronal

lesions

rheumatoid

tomography

fossa,

bony

PA

t#{233}moins

Reply

procedure

E. Fellows

of Philadelphia

Philadelphia,

We thank Dr. Fellows for his comments

We acknowledge

Hospital

anom-

rhumatoide:

etude prospective chez 30 polyarthrites rhumatoides et 30 sujets (These M#{233}decine).Tours, France: University of Tours, 1988

an excellent

(congenital

1990

Medical Omaha,

Center NE

68105

on our pictorial essay [1],

which underscore the differences of opinion on the nature of these benign vascular lesions. The article by Burrows et al. [2] defines hemangiomas (tumors) as “benign endothelial cell neoplasms that appear in infancy and usually have a natural history of proliferation

and involution.” In contrast, vascular malformations (congenital anomalies in vessel formation) are “errors of vascular morphogenesis that are present at birth, grow with the child, and never involute but often expand.” These definitions stem from a classification by Mulliken and Glowacki [3] for hemangiomas and vascular malformations that is based on endothelial characteristics, which appeared in Plastic and Reconstructive Surgery in March agrees with this classification.

We classify

soft-tissue

1 982.

hemangiomas

Not

everyone,

broadly

however,

as a spectrum

of

benign neoplasms that closely resemble normal blood vessels [4]. This definition is clearly in accordance with commonly accepted histologic criteria and is that used by Enzinger and Weiss, authors of the current standard text [4] on soft-tissue pathology. Contrary to

Dr. Fellows’s assertions, soft-tissue hemangiomas

we do not consider this classification of a simplification of the pathologic findings

but rather a recognition of the spectrum of histologic features. divide these lesions into two distinct groups, hemangiomas

vascular malformations, lesions that fall between

To and

is an oversimplification and ignores those these extremes or that may have histologic

features of both. The latter type of lesion commonly by pathologists who see a large number of soft-tissue

is encountered tumors.

The paper by Burrows et al. [2] was cited along with a second article [5] with the intention of(1) recognizing previous reports dealing, with the angiographic and CT findings of soft-tissue hemangiomas and (2) increasing the reader’s awareness of the literature as cited in the two papers. We regret that the sentence is respectively,

Radiologic Appearance Hemangioma

of Intramuscular

worded

The authors of the pictorial essay, “Radiologic Appearance of Intramuscular Hemangioma with Emphasis on MR Imaging” [1], which appeared in the March 1990 issue of the AJR, made a mistake in

in such a way as to suggest

papers

included

The intent of our pictorial essay is to show the radiologic

appear-

comparisons

that these

with MR findings.

coauthor. They described our paper as one of two previous reports that have shown “the superiority of MA over CT or angiography in

ance of hemangiomas and to emphasize the MR appearance as a reflection of the underlying gross morphology. As we noted in our opening paragraph-and this cannot be overemphasized-”terminology is often confusing.” However, we have chosen to classify

delineating

these lesions in accordance

their

reference

to the

the

extent

paper

by

of these

Burrows

lesions

et al.

[2], of which I am a

[hemangiomas].”

Our

paper

states nothing of the sort. In fact, it does not even mention CT or MR. Our paper does list clinical and angiographic criteria to differentiate

hemangiomas

from

vascular

malformations;

however,

these

with currently

By perpetuating

old ideas and terminology,

to educate

radiologists

about

Buetow et al. have missed the

differences

between

histologic

Mark

criteria were not used by Buetow et al. [1] in describing their own cases. Instead, they simplified the pathologic changes and called all the lesions hemangiomas. Most are clearly vascular malformations. a chance

accepted

criteria

as presented by Enzinger and Weiss [4]. We trust that other radiologists will find this classification scheme acceptable and may profit from our efforts. J. Kransdorf

Peter C. Buetow James S. Jelinek Walter

Reed Army Medical Center Washington, DC 20307-5001

AJR:155,

LETTERS

October1990

comparison of four MR pulse sequences. AiR 1990;154: 175-1 78 2. Erdman WA, Jayson HT, Redman HC, Miller GL, Parkey RW, Peshock AM. Deep venous thrombosis of extremities: role of MR imaging in the diagnosis. Radiology 1990;174:425-431 3. Erdman WA, Weinreb JC, Cohen JM, Buja LM, Chaney C, Peshock AM. Venous thrombosis: clinical and experimental MA imaging. Radiology

REFERENCES 1 . Buetow PC, Kransdorf MJ, Moser RP Jr. Jelinek JS, Berrey HB. Radiologic appearance of intramuscular hemangioma with emphasis on MR imaging. AJR 1990;154:563-567

2. Burrows PE, Mulliken JB, Fellows KE, Strand RD. Childhood hemangiomas and vascular malformations: angiographic difterentiation. AJR 1983;141:

Downloaded from www.ajronline.org by 117.253.236.81 on 11/10/15 from IP address 117.253.236.81. Copyright ARRS. For personal use only; all rights reserved

897

1986;161

483-488

3. Mulliken JB, Glowacki infants

and children:

J. Hemangiomas

and vascular malformations based on endothelial characteristics.

a classification

Reply

Plast Reconstr Surg 1982;69:412-420 4. Enzinger FM, Weiss SM. Soft-tissue

2nd ed. St. Louis: Mosby,

tumors,

benign angiomatous 1984;8:1143-1146

PM, Korobkin M, et al. Computed lesions of the extremities. J Comput

tomography

Parkey that phase clinical study [1] cited by them was apparently successful in identifying venous thrombi when the Ti -weighted sequence was used. However, no comparison was made with other approaches, and, in particular, a gradientMy colleagues

1988:489-532

5. Rauch AF, Silverman

of

Assist Tomogr

information

recalled MR

Imaging

of Deep

Venous

of chronic

deep

venous

Thrombosis

thrombosis.

of

MR

hardware.

We

have

used

In a recent

report

Ti-weighted

spin-echo

with phase reconstruction data in more than 200 patients with suspected deep venous thrombosis of the extremities. We have

noted

on GRASS

images

“may

(dogs) with

known

deep

venous

reflect

age-related

is only partially of both patients

thrombosis

[3].

changes

correct. We and animals

We

found

of hemoglobin,

et

restoration al.

found

the

of channels

of flow. This explains

why

reliable in showing these changes. We subsequently have found that the phase image affords excellent sensitivity to these recanalization changes, whereas the spin-echo magnitude image allows identification of perivascular edema, which is an indicator of acute disease. Thus, contrary to the conclusion of Totterman et al. , the spin-echo technique can offer excellent sensitivity as well as the ability to

distinguish

was not used.

sequence

with

Our

standard

or other

biochemical

heterogeneity

within

the

using clots prepared

basis.

Saara Totterman University

of Rochester,

School

of Medicine

and Dentistry

Rochester,

NY

14642

1 . Erdman WA, Jayson HT, Aedman HC, Miller GL, Parkey RW, Peshock TM. Deep venous thrombosis of extremities: role of MA imaging in the diagnosis. Radiology 1990;174:425-431 2. Totterman 5, Francis CW, Foster TH, Brenner B, Marder VJ, Bryant AG. Diagnosis of femoropopliteal venous thrombosis with MA imaging: a comparison

of four MA pulse

sequences.

AiR

199014:175-178

3. Erdman WA, Weinreb JC, Cohen JM, Buja LM, Chancy C, Peshock AM. Venous thrombosis: dinical and experimental MA imaging. Radiology 1986;161

:233-238

acute from chronic venous thrombosis. William

A. Erdman

Robert W. Parkey The University

Southwestern

Medical Dallas,

Mesenteric

of Texas

Peripheral

Center at Dallas

gangrene

TX 75235-9071

Aneurysms

Associated

with

ischemia, caused by arterial spasm, are rare yet well-described complications

Ergotism and subsequent associated with

ergotamine therapy for migraine headaches [1]. Although formation of renal artery aneurysm has been associated with chronic ergotism

AEFEAENCES 1 . Totterman Diagnosis

sequence echo

AEFEAENCES

GRASS sequence most

flow-sensitive

state

gradient-recalled

in vitro in the absence of flow, we have observed image heterogeneity similar to that seen in dots in patients. Even the report [3] cited by Erdman and Parkey indicates that they were unable to document that the image heterogeneity seen in clinical thrombi was due to flow in 1 1 of 1 3 cases. We think that additional study is needed to characterize age-related changes in thrombi and to document their biochemical, physical, or histologic

Indeed,

that

did observe, however, the development of age-related heterogeneity within the thrombus and found that this is related to recanalization

and subsequent

a

and

The

for visualization of clots. No attempt was made to draw conclusions about pulse sequences or image reconstruction methods other than those directly reported and compared. On current clinical hardware, application of the gradient-recalled sequences is efficient and provides excellent visualization of thrombi. We also agree with Erdman and Parkey that recanalization of thrombus that restores areas of flow could result in image heterogeneity. However, any cause for spatial heterogeneity of the apparent Ti or T2 could result in similar image heterogeneity. Causes other than flow for changes in Ti and T2 may include alterations in the degree of clot retraction, differences in the concentration or oxygen-

thrombotic material does not change its Ti and T2 characteristics, and thus its MA appearance, over a period of 2 hr to 3 weeks. We

Totterman

in the steady

flow.

contrast

thrombus.

found that the spin-echo with phase technique is accurate (sensitivity, 90%; specificity, 100%) [2] and provides a higher quality image than gradient-reversal methods do. The suggestion of Totterman et al. that the heterogeneous apin the composition of the thrombus” studied this issue by serial imaging

acquisition

in showing

imaging sequences that included three choices of acquisition parameters, including T2-weighted, Ti -weighted, and spin-density images. In this comparison, the gradient-recalled echo sequence provided the greatest clinical efficiency as well as the best image

ation

images

pearance

and I agree with Erdman

be useful

spin-echo

on an evaluation of MA pulse sequences in this disease, Totterman et al. [1] conclude that gradient-recalled acquisition in the steady state is superior to spin-echo imaging because of enhanced ability to distinguish thrombus from flowing blood. We think this is a misleading conclusion because Totterman et al. have not used all the acquired information in their interpretation of the spin-echo images. Phase data, which are acquired as part of all MA imaging acquisitions, are exquisitely sensitive to motion and thus can be used to distinguish flowing blood from stationary thrombus. Unfortunately, phase information is not made available to the user by some manufacturers

can

study [2] compared

MA imaging has an important clinical contribution to make in patients with suspected deep venous thrombosis, especially those with a history

:233-238

in

5, Francis CW, Foster TH, Brenner B, Marder VJ, Bryant AG. of femoropopliteal

venous

thrombosis

with

MR

imaging:

a

to our knowledge, no reports aneurysm have been published. [2],

of associated

mesenteric

artery

LETTERS

898

AJA:155,

October

1990

2. Pajewski M, Modai D, Wisgarten J, Freund E, Manos A, Sterinski A. latrogenic arterial aneurysm associated with ergotamine therapy. Lancet 1981;2:934-935

Downloaded from www.ajronline.org by 117.253.236.81 on 11/10/15 from IP address 117.253.236.81. Copyright ARRS. For personal use only; all rights reserved

3. Clinical importance and management of splanchnic artery aneurysms. J Vasc Surg 1986;3(5):836-840 4. Wells KE, Steed DL, Zajko AB, Webster MW. Recognition and treatment of arterial insufficiency from Cafergot. J Vasc Surg 1986;4:8-15

Vena Caval Filter Jugular Vein For approximately Scientific,

B Fig. 1.-Mesenteric aneurysms associated with ergotism. A, Superior mesenteric angiogram shows fusiform aneurysm of jejunal branch associated with spasm of other jejunal and ileal branches. B, Femoral arteriogram shows occlusion of superficial femoral artery and diffuse spasm of reconstituted distal part of superficial femoral artery.

A 50-year-old eral vascular

woman was referred for routine evaluation

disease.

She had had increasing

bilateral

of penph-

leg cramping

and numbness for 10 years, and recently an ulcer of the left foot had developed. She had taken Cafergot (Sandoz Pharmaceuticals, East Hanover, NJ) for 30 years for persistent migraine headaches. On admission,

however,

with vomiting,

she

diarrhea,

had

acute

abdominal

and hypotension.

distress

Abdominal

CT showed

an

acute retroperitoneal hematoma in the region of the lesser sac. At surgery, a bleeding aneurysmal branch of the superior mesentenc artery was ligated. Subsequent selective superior mesenteric angiography showed a fusiform aneurysm of a jejunal branch and diffuse spasm of other branches (Fig. i A). A femoral arteriogram showed marked spasm involving the proximal left femoral artery and occlusion of the proximal

Mesenteric aneurysms

but few

is

left superficial

artery

(Fig. 1 B).

aneurysms are rare, and the mortality rate for ruptured high [3]. Aneurysm is not often attributed to ergotism,

angiographic

studies

of this

condition,

especially

involving

vessels other than the lower extremities, have been done. It has been suggested [2] that ergotism causes persistent constriction of vasa vasorum,

which

may lead to mural

with

subsequent

formation

from

ergotism

is well known;

of

an

fibrosis

of the intima

aneurysm.

Vascular

spasm,

collateral

and media in chronic

cases, and, rarely, formation of intravascular thrombus have been described [4]. Vasospasm associated with ergotism often responds to conservative therapy such as drug withdrawal or oral nifedipine. It is important to recognize that ergotamine may cause signs and symptoms of peripheral vascular insufficiency. In addition, because radiologists

aneurysm ergotism

often

see

vascular

abnormalities

such

on angiography, an iatrogenic should be investigated.

cause

Mercy

as vasospasm

such

or

as chronic

Richard H. Tupler Surrendra K. Bansal Hospital of Pittsburgh Pittsburgh,

PA

15219

REFERENCES 1 . Tanner review.

JR. St. Anthonys fire, then Can J Surg 1987;4:291-293

the metallic

because

a case

report

and historical

for

prevention

filter (Medi-tech/Boston

of pulmonary

embolism

in

carrier

capsule

is large and rigid,

and it is not

easy to negotiate the more angular pathways from the puncture site to the inferior vena cava. These are some of the reasons for the recent development of new filters with smaller and more flexible delivery systems for easier placement via a greater number of access routes. These filters, which are currently either approved by the Food and Drug Administration or investigational, include the Amplatz filter with a 1 4.3-French the

introducer

bird’s-nest

Inc., Bloomington,

(William filter

with

Cook,

Europe,

a 1 4-French

Bjaerverskov,

introducer

IN), the Gunther filter with a 12-French

(Cook

introducer

(William Cook), the LGM filter with a 1 2-French introducer (LM Medical, Chasseneuil, France), and the Simon nitinol filter with a 9-French

introducer (Nitinol Medical Technologies, Inc., Woburn, MA) [2]. All the new filters can be placed percutaneously via either a femoral or internal jugular approach. Our experience includes placement of the Simon nitinol filter in 32 patients, the bird’s-nest filter in 14 patients, and the LGM filter in 21 patients. We have used either the femoral

vein or the right

internal

jugular

vein for most

of the place-

ments. We report the successful placement of five of the new filters through both the right and the left external jugular veins in four patients. All four patients

had deep

venous

oral veins or the lower inferior jugular

vein could

thrombosis

involving

both

vena cava. In one patient,

be entered

because

of technical

and a Simon nitinol filter was placed successfully

fem-

neither difficulty,

via the left external

vein (Fig. 1). In the other three patients, the right external jugular vein was used as the primary access. In one of these three patients, two filters (one LGM filter and one bird’s-nest filter) were placed in the inferior vena cava. The LGM filter, which was used first, jugular

failed to open after being released, because pencaval tumor. As a result, we used the access to place a bird’s-nest filter above suprarenal inferior vena cava. We placed a

of caval narrowing by same external jugular the LGM filter in the bird’s-nest filter in the

third patient and an LGM filter in the fourth. The external jugular vein usually runs obliquely down the neck in the direction of a line drawn from the angle of the mandible to the midclavicular level where it enters the subclavian vein, but variations can occur. The side of the puncture is chosen according to the degree

of visibility and now:

MA)

venous thromboembolic disease generally has been inserted through surgical cutdown of the right internal jugular vein or the right femoral vein. More recently, this filter has been placed percutaneously. However, this requires using a large, stiff introducer of 29-French outer diameter, which causes mild to moderate patient discomfort and, potentially, local vascular complications [1]. Introduction of the filter via the left femoral vein or the left internal jugular vein is difficult

internal

insufficiency

formation

Via the External

15 years, the Greenfield

Watertown,

Denmark),

associated

Placement

of the external

the head turned visibly

by

having

jugular vein. The patient lies supine with

away from the side of puncture. the

patient

perform

the

The vein is distended

Valsalva

maneuver

or

by

LETTERS

October1990

AJA:155,

899

Complications ular

associated

vein are relatively

with

catheterization

insignificant

of the

in comparison

external

with those

jug-

associ-

with catheterization of the internal jugular vein. These may include easily controllable hematomas at the puncture site and possible thrombotic occlusion [3]. However, no serious complications such as pneumothorax, inadvertent puncture of adjacent arteries, thoracic duct injury, or nerve injuries, which may be encountered with catheterization of the internal jugular vein, have been reported [3]. We had no complications associated with placement of the filter via the external jugular approach in this small series. In conclusion, the external jugular vein is a useful and safe alternative access route for placement of the new inferior vena caval filters when access via the femoral vein or the internal jugular vein is

Downloaded from www.ajronline.org by 117.253.236.81 on 11/10/15 from IP address 117.253.236.81. Copyright ARRS. For personal use only; all rights reserved

ated

impractical.

It should

be considered

when

femoral

catheterization

is

or when the person placing the filter lacks expertise or in internal jugular vein cannulation. Ducksoo Kim

unsuccessful confidence

Jeffrey

B. Siegel

David H. Porter Moms Simon Beth Israel Hospital Harvard

Fig. 1.-Placement of vena caval filter via external jugular vein. A, Radiograph shows guidewire introduced into left brachiocephalic vein (arrowheads) via left external jugular vein (arrows). B, Radiograph shows Simon nitinol filter in place in inferior vena cava.

pressing

a finger

over

the

lower

part

of the

vein.

A superficial

nick

of contrast

medium

is helpful in negotiating catheterization.

or road mapping

an unusual anatomic

After an inferior

venacavogram

with digital

variation

fluoroscopy

School

MA 02215

Barry A. Sacks Beth Israel Hospital Harvard Medical School Boston, MA 02215 Leonard Morse Hospital Natick, MA 01760

is

made in the skin over the vein at the level selected to allow easy manipulation of catheters and sheaths, preferably well above the clavicle. A single-wall puncture needle is advanced into the vein through the puncture site while gentle suction is applied. Once the vein is entered, an angiographic guidewire is advanced into the vein and maneuvered into the superior vena cava through the right atrium and then into the inferior vena cava. The most difficult part of the procedure is negotiating the junction of the external jugular and subclavian veins, where an acute angle and a valve may be present. A steerable wire usually crosses this point easily. Sometimes the injection

Medical

Boston,

REFERENCES 1 . Pals SO, Mirvis SE, DeOrchis DF. Percutaneous insertion of the KimrayGreenfield filter: technical consideration and problems. Radiology 1987; 165:373-376

2. Dorfman GS. Percutaneous inferior vena caval filters. Radiology 1990; 174:987-992 3. Belani KG, Buckley JJ, Gordon JA, et al. Percutaneous cervical central venous lines placement: a comparison of the internal and external jugular vein routes. Anesth Ana!g 1980;59:40-44

and facilitates

is obtained,

the dcliv-

cry catheter is introduced and positioned at the appropriate level in the inferior vena cava. The filter then is inserted in the prescribed fashion.

Although femoral

the first choice

vein,

we now

of entry site for filter placement

use an external

jugular

vein with

is a

increasing

frequency when neither femoral vein is accessible. This is much easier than using the internal jugular approach. Although a Simon nitinol filter was placed successfully via the left external jugular vein, this

may

be more

difficult

than

the corresponding

right-sided

ap-

proach, particularly with filters with somewhat larger and stiffer introducers, because a sharper angle must be negotiated at the junction between the left brachiocephalic vein and the superior vena cava. The

external

jugular

vein

long

has

been

used

as a route

for

Intracranial

Ganglioglioma:

MR Imaging

It was with great interest that we read the excellent article on intracranial ganglioglioma by Castillo et al. [1]. We recently encountered a histologically proved case of ganglioglioma in the posterior fossa in a 6-year-old child. CT scan showed a large hypodense lesion with partial enhancement after administration of IV contrast medium. MR imaging showed a lesion consisting of two parts. A large, cystic part located in the brainstem had low signal intensity on Ti -weighted images.

The solid part of the tumor

was dorsal

to the cystic

compo-

placement of central venous catheters. This vein is close to the skin in the neck, so it is easier to obtain hemostasis at the puncture site, and complications associated with puncture of the deep internal

nent of the tumor and had low to intermediate signal intensity (Fig. 1A). The solid part of the tumor showed marked enhancement after IV administration of gadopentetate dimeglumine (Fig. 1 B). T2-

jugular

weighted

vein

are

minimized.

often is more comfortable

Furthermore,

the

puncture

for the patient than puncture

jugular vein. This route can also facilitate with short necks or kyphosis. In such

of

this

vein

of the internal

filter placement in patients patients, the body of the

mandible may create a steeper and more difficult insertion the jugular vein.

angle into

images

showed

a high

signal

intensity

of the cystic

part

of

the lesion. Unlike the case described by Castillo et al., in our case, marked enhancement of the solid part of the tumor occurred after IV admin-

istration of gadopentetate that gadolinium-enhanced

dimeglumine. We agree with the authors images define the tumor margins better

900

LETTERS

AJA:155,

October1990

AEFERENCE 1 . Castillo M, Davis PC, Takei Y, Hoffman JC Jr. Intracranial ganglioglioma: MA, CT, and clinical findings in 18 patients. AJNR 1990;1 1 : 109-1 14, AJR 1990;154:607-612

Downloaded from www.ajronline.org by 117.253.236.81 on 11/10/15 from IP address 117.253.236.81. Copyright ARRS. For personal use only; all rights reserved

Parasellar

Osteochondroma

Osteochondromas

originating

from

the

base

of the

skull

are

rare

[1]. We report a case in which the tumor originated from the posterior clinoid process in the parasellar region. A 26-year-old woman was admitted because of headache. Radiographs of the skull showed a cauliflower-shaped lesion in the right parasellar region extending posteriorly from the posterior clinoid process (Figs. 1 A and 1 B). CT scans showed a lobulated calcification Fig. 1.-Intracranial

originating

ganglioglioma.

A, Sagittal

TI-weighted MR image shows large, low-signal-intensity cystic part of lesion in brainstem and intermediate-signal-intensity solid part. B, Ti-weighted MR image shows marked enhancement of solid part of tumor after administration of IV gadopentetate dimeglumine.

images do. Multiplanar imaging of MR compared with CT.

by MA is an addi-

clinoid

process

(Fig. 1 C).

that arise from the base of the skull are in

the middle cranial fossa where cranial sutures converge. They ably arise from cartilaginous rests in the basilar synchondroses and have radiologic

features

similar

to those of osteochondro-

mas in any other part of the body [2]. The differential diagnosis includes craniopharyngiomas, parasellar meningiomas, aneurysms of the internal carotid artery, and chondromas [2, 3]. Muhtesem

P. A. Algra

MB

Amsterdam,

the

Netherlands

Agildere

Sassan Senaati Muzaffer Eryilmaz

Ph. Scheltens F. Barkhof J. Valk Free University Hospital 1007

prob[1].

They appear most often in women 20-30 years old. The tumors grow slowly

than unenhanced tional advantage

from the right posterior

Most osteochondromas

Aytekin Hacettepe

Besim

University

Ankara,

Turkey

REFERENCES

1. Castillo M, Hudgkins AP, Hoffman JC. Lockjaw

REFERENCE 1 . Castillo M, Davis PC, Takei Y, Hoffman JC Jr. Intracranial ganglioglioma: MA, CT, and clinical findings in 18 patients. AJNR 1990;1 1 : 1 09-1 14, AJR 1990;154:607-612

osteochondroma:

CT findings.

J ComputAssist

secondary Tomogr

to skull base

1989;13:338-339

2. Gabrielsen OT, Kingman AF. Osteocartilaginous tumors of the base of the skull. AJR 1964;91 :101 6-1 023 3. List CF. Osteochondromas arising from the base of the skull. Surg Gynecol Obstet

1943;76:480-492

Reply

We thank

Algra

et al. for their interest

Ganglioglioma:

MA,

CT,

Gangliogliomas

occur

and

Clinical

throughout

in our paper,

Findings

the CNS;

in

“Intracranial

i 8 Patients”

however,

[1].

we personally

have not seen this tumor arise within the medulla. In our series, 75% gangliogliomas were cystic. On CT, 50% of all cystic

of infratentorial tumors

showed

contrast

enhancement.

The enhancing

always amid the tumor or intimately associated

regions

were

with it. Our experience

with gadolinium-enhanced MA imaging of gangliogliomas is limited to two cases. One was described in our paper, and recently we saw a second case in which the tumor showed enhancement after administration of gadopentetate dimeglumine. The patient in the second case had had partial resection and radiation therapy. Therefore, it was not possible to discern whether the enhancement was inherent

to the tumor or was a result of treatment. In the case presented by Aigra et al., the enhancing part of the tumor is remote to the cyst and, in our opinion,

an astrocytoma case supports

the tumor

is radiologically

indistinguishable

from

or a hemangioblastoma (rare in young children). Their our impression that the radiologic manifestations of

ganglioglioma

are

protean

the differential

diagnosis

and

that

this

tumor

of cystic infratentorial

should

be included

masses. Mauricio Patricia

Emory

in

University Atlanta,

Castillo

C. Davis Hospital GA 30322

Fig. 1.-Parasellar osteochondroma. A and B, Anteroposterior (A) and lateral (B) radiographs of skull show cauliflower-shaped osteochondroma in parasellar re-

gion. C, CT scan shows osteochondroma arises from posterior clinoid process and extends in parasellar region posterioriy. Cauliflower appearance is pathognomonic feature of this tumor.