INTERESTING CLINICAL IMAGES

Computed
tomography

features of
•venous sinus

thrombosis and
infarction

children
venous

•In
Dural sinus and cortical venous

thrombosis occurs regularly in paedi-
atric practice, more often as the re-
sult of dehydration than of infective
meningitis. On non-contrast com-
puted tomography (CT) scanning in
the acute phase, clot is seen as a
high-density within a venous sinus
and is especially well seen in the

S Andronikou
FC Rad D/ag (SA), FRCR (London)

C Weiman
MSChS

E Kader
MSChS

R Joubert
MSChS

Department of Paediatric Radiology,
University of Cape Town and Institute of Child

Health, Red Cross War Memoria/ Children's
Hospital, Rondebosch, Cape Town

Corresponding author: SAndronlkou
Department of Paediatric Radiology, Red
Cross War Memor/a/ Children's Hospita/,

Cape Town, 7700
Te/: (021) 658-5422 (w)

Fax: (021) 658-5101
E-mail: docsav@mweb.co.za

Figure 1: Post-contrast shows a 'delta' sign
(/arge arrow) as well as a fill/ng defect within
the straight sinus (small arrow). The subcortical
white matter is of low density bilaterally, In
keeping with venous Infarction.

14 SA JOURNAL OF RADIOLOGY. October 2000

Figure 2: Non-haemorrhagic venous infarct is seen
as bilateral symmetrical subcortical white matter
low-density involving the centrum semiovale

Figure 3: Bilateral temporal venous infarcts
resulting from thrombosis in both transverse
sinuses (circles)

su perior sagittal, transverse and
straight sinuses as well as the vein of
Galen. During the first few months
of life, however, high signal within the
venous sinuses is a normal finding.
These patients therefore need follow-
up CT to allow differentiation be-
tween this normal finding and a
thrombus, which will show progres-
sive decrease in density over time.
Beyond the acute phase, the adminis-
tration of intravenous contrast may

to page 15

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Computed torrmgrnp hv features of
venous sinus thrombosis and venous
infarction in children

(rom page 14

Figure 4: 'Flame'-shaped densities representing
haemorrhage along thrombosed cortical veins on
the low-density background of oedema

demonstrate the 'delta' sign. This is
contrast-enhanced blood around the
hypodense clot and has the appear-
ance of a hollowed-out triangle.

Venous infarcts are diagnosed by
their characteristic appearance and

Figure 5: Follow-up non-contrasted CT shows
bilateral low-density infarction after resolution of
the haemorrhage

location. Sagittal sinus thrombosis re-
sults in parasagittal infarcts. Straight
sinus and Vein of Galen thrombosis
involve the thalami. Thrombosis of
the vein of Labbe, the transverse and

Hot Topics, Debates,
subjects covered in

the sigmoid sinuses involve the tem-
porallobe. On CT scanning, venous
infarcts are poorly demarcated, often
multi-focal areas oflow or mixed den-
sity that involve the subcortical white
matter. These may produce mild mass
effect on the ventricles. Low density
probably represents oedema, while
high density represents haemorrhage.
Twenty-five per cent of venous infarcts
are haemorrhagie. Haemorrhagie areas
may vary in size and occasionally may
be linear, indicating haematoma within
and around a vein. After administra-
tion of intravenous contrast, gyral en-
hancement is seen overlying the areas
of infarction.

Reference
Barkovich Al. Paediatric NeuToimaging. 2nd ed.
Philadelphia: Lippincott-Raven. 1996; 138,577-
583.

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19 February 2001

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