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A patient had suffered dry eyes, dry mouth and bilateral
swelling of the parotid gland for a long time. Saxon's and Schirmer's tests
were positive. SS-A and SS-B antibodies were detected. Ultrasonography
showed bilateral swelling of the parotid gland. Both the glands were characterized
by multiple hypoechoic areas. An MRI was ordered.
Axial SE T1 image shows the swelling
of both the glands and the presence of multiple hypointense areas. These
areas are hyperintense on axial SE T2 image and
do not enhance after intravenous administration of Gd-DTPA.
Sicca syndrome (primary Sjogren syndrome)
Sjogren syndrome is an autoimmune disease characterized
by the triad of xerostomia, keratoconjunctivitis sicca and a systemic autoimmune
disease such as rheumatoid arthritis, systemic lupus erithematosus, progressive
systemic sclerosis or mixed connective tissue disease.
The diagnosis of this condition requires the presence of at least two of
the three features (1-3).
Sjogren syndrome takes in two forms: the sicca syndrome (primary form)
which includes patients with xerostomia and keratoconjunctivitis sicca
without any underlying systemic autoimmune disease and the so called secondary
Sjogren syndrome (secondary form) which comprises patients with an underlying
systemic autoimmune disease (1).
There are several methods for the diagnosis of Sjogren syndrome.
Saxon's and Schirmer's tests are reliable screening methods and the immunoserological
tests (rheumatoid factor, SS-A and/or SS-B antibodies) are very helpful,
but they do not allow to assess the pathologic changes of the salivary
glands (2).
Histologic examination of the minor salivary gland biopsy specimens is
considered the method of choice to confirm the clinical diagnosis of Sjogren
syndrome. But it is invasive, painful and has surgical risk. The biopsy
results may fail to correlate with clinical and laboratory features. Furthermore
the salivary glands abnormalities of elderly people, especially those more
than 80 years old, may be similar to those found in the Sjogren syndrome
patients (2-3).
Syalography represents the gold standard in many institutions. However
it is invasive, can adversely affect ingestion and taste; furthermore it
requires radiation exposure (2).
MR imaging is noninvasive and requires no radiation. The presence of multiple
spots of hypointensity and hyperintensity scattered throughout the parotid
gland respectively on SE T1 and T2 images is pathognomonic of Sjogren syndrome,
since no parotid disease has got this MR picture (1).
Some investigators suggested the dilatation of the ductal system is responsible
of the hypointense and hyperintese areas on SE T1 and T2 images (1). Our
case confirmed this hypothesis, since hypointense spots on T1w images did
not enhance after the administration of Gd-DTPA.
However the role of MR imaging in Sjogren syndrome is still controversial,
though this method may be very specific.
The "salt and pepper" pattern was found in one report in only
the 46% of the patients (1). Moreover ultrasonography and CT are as noninvasive
as MR imaging and are less expensive.They seems to be better than MR imaging
in the diagnosis of inflammatory salivary disease and salivary stones because
of their superiority in depicting ductal stones and calcifications within
the gland (1).
On the other hand a recent report asserts that quantitative analysis of
MR images can significantly improve sensitivity and specificity in the
diagnosis of Sjogren syndrome (3).
Further investigations are needed to definitely establish the role of MR
imaging in Sjogren syndrome.
1) Takashima S, Takeuchi N, Morimoto S, Tomiyama N, Ikezoe
J, Shogen K, Kozuka T, Okumura T. MR imaging of Sjogren syndrome: correlation
with syalography and pathology. JCAT 1991; 15 (3):393-400
2) Vogl TJ, Dresel SHJ, Grevers G, Spath M, Bergman C, Balzer J, Lissner
J. Sjogren's syndrome: MR imaging of the parotid gland. Eur Radiol 1996;
6: 46-51
3) Izumi M, Eguchi K, Ohki M, Uetani M, Hayashi K, Kita M, Nagataki S,
Nakamura T. MR imaging of the parotid gland in Sjogren's syndrome: a proposal
for new diagnostic criteria. AJR 1996; 166: 1483-1487
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