Download A 2-year Follow-up MR Imaging Study

中華放射醫誌
Chin J Radiol 2004; 29: 171-176
171
Central Diabetes Insipidus in Patients Without
Apparent Initial MR Imaging Findings:
A 2-year Follow-up MR Imaging Study
1,2
M ING -S HIANG YANG
C LAYTON C HI -C HANG C HEN
C HUNG -M ING T SAI 2 S AN -K AN L EE 2
2
Y UNG -Y I C HENG
2
Y EU -S HENG T YAN
1
Y I -F EN WANG
3
Department of Radiology1, Chung- Shan Medical University Hospital
Department of Radiology2, Taichung Veterans General Hospital
3
Department of Radiology , Taipei Veterans General Hospital
The aim of this study is to describe the follow-up
magnetic resonance imaging (MRI) findings in
patients with central diabetes insipidus (CDI)
patients and without having apparent initial
imaging abnormality.
This was a retrospective study. In the past 8 years
(from 1995 to 2002), 26 patients (male 14, female 12,
mean age 20.1 years) were diagnosed as CDI by
water deprivation test, 1-desamino-8-D-arginine
vasopressin (DDAVP) test, and the relationship
between urine-plasma osmolarity. The major clinical manifestations are polyuria and polydipisia. We
retrospectively analyzed the MR images.
The subtle MR images included (1) loss of high
signal intensity (SI) in posterior lobe on T1WI
(26.9%, n=7), (2) an empty sella, (11.5%, n=3), (3)
shallowing of the pituitary fossa (3.8%, n=1), (4)
ectopic bright high signal intensity on T1WI at the
hypothalamus (3.8%, n=1), (5) normal (23%, n=6),
(6) thickened pituitary stalk thickness (PST) (26.9%,
n=7). All these patients were followed at least 2
years with MR images.
Seven patients were initially presented as
increased pituitary stalk thickness (PST). In the following images, 5 of the seven patients had progressive thickened stalk and underwent the biopsy procedure. They were diagnosed as germinoma, histio-
Reprint requests to: Dr. Yeu-Sheng Tyan
Department of Radiology, Chung- Shan Medical University
Hospital.
No. 110, Sec. 1, Jian Guo N. Road, Taichung 402, Taiwan,
R.O.C.
cytosis, and sarcoidosis. Two cases of the PST group
had static imaging findings in the follow-up images
just as in other groups.
In our limited experiences the causes of CDI were
variable. It is most important to follow up the subtle
MR findings. In group with progressive pituitary
stalk thickness, we emphasize the necessities to
make biopsy for definite diagnosis.
Key words: Central diabetes insipidus, MR
imaging; Diabetes insipidus; Germcell neoplasm;
Histiocytosis; Sarcoidosis
Central neurogenic diabetes insipidus (CDI) is a
disorder, characterized by chronic polyuria and polydipsia, secondary to deficiency of arginine vasopressin.
In many patients, especially the children and young
adults, it is caused by the destruction and degeneration
of neurons that originate in the supraoptic and paraventricular nuclei of the hypothalamus [1]. The causes of
CDI include germinoma [2], craniopharyngioma [3],
Langerhan’s cell histiocytosis (LCX), inflammation,
autoimmune and vascular disease [4,5], trauma
resulting from surgery or accident [6], and in rare
occasions, the genetic defects in the synthesis of vasopressin, in which it is inherited as autosomal dominant
or X-linked recessive traits. However, CDI are considered to be idiopathic [7] in 30 to 50% of the cases
The most frequent MR findings in CDI patients
include normal imaging appearance [8], thickened
pituitary stalk [8], invisibility of the posterior lobe high
signal intensity [8] (SI) on T1WI, focal suprasellar or
hypothalamic mass lesions such as germinoma and
craniopharyngioma, etc. Nevertheless, the long-term
follow-up imaging studies of the subtle lesions had not
been recognized very well. The purpose of the study is
172
The images of CDI
mainly to focus on the subtle MR imaging findings
and the follow-up imaging changes.
MATERIAL AND METHODS
In the past 8 years (from 1995 to 2002), 29 cases
were diagnosed as CDI in our hospital. Three cases
were excluded due to apparent causative gross tumor
lesion on the initial images. The total case number is
26. The diagnosis of central diabetes insipidus was
based on clinical history of polyuria and polydipsia,
and the results of physical examination, laboratory
evidence of arginine vasopressin deficiency and the
imaging studies of the brain and pituitary gland. In
cases without any identifiable causes and imaging
findings, include the following images, were considered to be idiopathic.
This was a retrospective study, including
fourteen male and twelve female patients. The mean
age at diagnosis was 20.1 year-old (ranged from 3 to
56 year-old). All of the patients had permanent central
diabetes insipidus, and were treated with desmopressin acetate.
The MRI pulse sequences included pre-contrast
sagittal section T1-weighted imaging (T1WI), both
axial and coronal section T2-weighted imaging
(T2WI), post-Gadolinium DTPA coronal and sagittal
T1WI images and dynamic study of pituitary gland.
All of the pulse sequences were performed in either
one of the two 1.5 Tesla MRI scanners (Horizon, L,
GE Medical system, Milwaukee, USA and Sonata,
Siemens AG, Erlangen, Germany). The parameter for
pituitary gland in T1WI is TR = 400-650 ms, TE = 1220 ms, matrix = 256 × 256 and nex = 4. The parameter
in T2WI is TR = 2000-3000 ms, TE = 70-100 ms,
matrix = 320 × 256 and the nex = 4. The FOV is 16 ×
16 cm in size. The slice thickness is 3 mm and the gap
is 0.3 mm. The pituitary stalk thickness measured on
the mid-sagittal section T1WI image [10]. The criteria
of normal pituitary stalk is defined as 3 to 3.5 mm
wide near the median eminence and 2 mm wide near
its insertion on the pituitary gland [10]. All MR
images were reviewed by two neuroradiologists. All
patients were followed at least two years and at least
five years in PST group. The imaging follow-up
schedule is about 3 to 6 months interval.
RESULTS
The characteristic MRI findings and clinical data
of the 26 patients are listed in the Table 1 and Table 2.
In the thickened pituitary stalk group, about 71.4%
(5/7) of cases showed progressive thickening on the
Table 1. Patient list of general data and images findings.
Case No.
Age
Sex
Image findings
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
8
25
7
40
7
51
7
19
45
12
56
5
11
16
7
34
10
20
44
3
8
19
34
10
15
11
F
M
M
F
M
M
F
F
M
F
M
M
M
M
F
F
F
F
F
M
M
M
F
M
M
F
empty sella
normal
shallowing of pituitary fossa
PLBSD
PST and PLBSD
PLBSD
PLBSD
PST and PLBSD
partial empty sella and PLBSD
normal
normal (post-operative sequale)
other
PST
ectopic neurohypophysis
normal (post-operative sequale)
empty sella
PST
PLBSD
PST
normal
PST
normal (post-operative sequale)
pituitary stalk transection
PST
other
other
PST: pituitary stalk thickness
PLBSD: posterior lobe bright signal disappearance on T1WI
Note 1: case 13 and case 17 progressed to germinoma
Note 2: case 21 and case 23 progressed to histiocytosis. case 19
progressed to sarcoidosis
Note 3: case 12 is Menkes disease. Case 25 and 26 are Wolfram
syndrome.
following images (Fig 1). These five patients all had
received the biopsy procedures. Two of them had
germinoma, two had histiocytosis and one had sarcoidosis. Another two patients in this group did not
reveal any significant change in at least 5 years period.
The loss of brightness of posterior lobe in the
T1WI group (n = 7), in the ectopic posterior lobe of
pituitary gland (n = 1), in the initial normal imaging
finding group (n = 6), and in the empty sella group (n
= 3) did not reveal any significant change in the
following imaging for at least two years.
In the initial normal MR imaging group, three of
the six cases were complicated by previous surgery at
the suprasellar area, such as craniopharyngioma or
meningioma, operation etc. The initial and following
images of the pituitary gland were almost normal.
Other rare causes of CDI also presented in this study,
such as pituitary stalk transection (n = 1) (Fig 2),
Menke’s disease (n = 1). The ectopic short T1 tissue
over median eminence with contrast enhancing pattern
in pituitary transection case could be defined. In
general, it was believed to be the ectopic neurohypophysis tissue. And it was only categorized into the
The images of CDI
1a
173
1b
Figure 1. Histiocytosis: T1WI sagittal section, a.
(650/20/4/256x256), b. (450/10/4/256 × 256), c. T1WI
(450/20/2/256 × 224)
Progressive enlargement of the pituitary stalk is noted in
the serial following images (A, B, arrows). Multiple
levels of vertebra plana over T-, L-spine vertebral bodies
were also seen (C, arrows). Patient received the biopsy
procedure, confirming the diagnosis of histiocytosis.
1c
pituitary transection group in the retrospective study.
In this study, 2 cases were diagnosed as Wolfram
syndrome. They are sibling from a diabetic family.
Their images revealed diffuse central nervous system
degenerative process (Fig 3) with clinical manifestations of diabetes insipidus and diabetes mellitus.
DISCUSSION
Figure 2. Pituitary transection: Sagittal section T1WI
(450/12/4/256 × 256)
A disruption of pituitary stalk (long arrow) is identified in
this patient. Contrast enhancing foci was seen over
median eminence (short arrow). It is thought to be ectopic
neurohypophysis.
In many normal subjects, the posterior pituitary
showed high signal intensity on the sagittal T1weighted magnetic resonance image (MRI). The
absence of this image finding serves as a nonspecific
indicator of central diabetes insipidus, because of the
frequency of hyperintensity decreased with aging in
normal subjects [8]. The posterior pituitary bright
signals on T1WI, initially thought to be due to fat
within the sellar turcica, was attributed to the arginine
vasopressin (AVP) content in the neurosecretory
granules or intracellular lipid droplets in the glial cell
174
The images of CDI
pituicytes of the posterior lobe. This signal, reported
in 90-100% of normal subjects, appears to be closely
related to the normal hypothalamic-neurohypophyseal
axis function [8].
Many patients with central diabetes insipidus
(CDI) did not have posterior pituitary hyperintensity
on T1WI images, indicating that the absence of hyperintensity, although nonspecific, is a cardinal feature of
CDI. The absence of posterior bright signal was the
most common finding in our study.
The size of normal pituitary stalk is 3 to 3.5 mm
in width near the median eminence and 2 mm near its
insertion on the pituitary gland [10]. Thickening of
either the entire pituitary stalk or just the proximal
portion was another common abnormality on MRI
scans. It is quite helpful in differential diagnosis of
idiopathic diabetes insipidus from those associated
with germinomas or Langerhan’s-cell histiocytosis,
but it was not specific for any subtype. Other studies
have reported the thickened pituitary stalk in association with autoimmune or inflammatory disease recognized as “lymphocytic infundibuloneurohypophysitis”
[10], “lymphocytic hypophysitis” [11], or “necrotizing
infundibulohypophysitis” [12].
The follow-up MRI scans of central diabetes
insipidus patients with a thickened pituitary stalk
showed a variable range of changes, from a spontaneous resolution of the abnormality to further enlargement, or without significant change [1]. In the PST
group (n = 7), five patients showed progressive thickening of the stalk and underwent biopsy. Two cases of
thickened pituitary stalk were found to have
germinoma, two with histiocytosis, and the other one
with sarcoidosis. The incidence of progressive change
in the PST group was 71.4% (5/7). Due to the high
incidence of progressive change of pituitary stalk
thickness, the follow-up images and even biopsy are
essential for these patients. Other than the PST group,
the following images did not reveal significant change
for at least two years.
The MR evidence of progressive reduction in the
size of the pituitary gland was usually associated with
a higher risk of an additional endocrine defect. The
decrease in size may be a consequence of vascular
damage or a deficiency of hypothalamic hormones
[13-14]. In the study, no evidence of progressive
reduction of the stalk size was shown.
Some patients, who suffered from CDI, were due
to the complication of operation at the pituitary region
or suprasellar area. In the normal imaging group (n =
6), three of them suffered from CDI were complicated
by previous surgery. The causes might be due to local
vascular injury or direct pituitary gland injury.
Table 2. Summary of images findings in CDI
Findings
Normal
Increased PST***
Loss bright SI of post.lobe (T1WI)
Empty sella
Shallowing of pituitary fossa
Ectopic posterior lobe
Pituitary stalk transection1
Other
Case No. (%)
6 (23%)
7 (26.9%)
7 (26.9%)
3 (11.5%)
1 (3.8%)
1 (3.8%)
(3.8%)
3 (11.5%)
M/F
(4/2)
(4/3)
(3/4)
(0/3)
(1/0)
(1/0)
(0/1)
(1/0)
PST: pituitary stalk thickness
SI: signal intensity
*** 2 cases progressed to histiocytosis, 2 cases progressed to
germinoma, 2 cases were stationary, and 1 case progressed to
sarcoidosis.
Other: Menke’s disease and Wolfram syndrome
Note 1: Two cases have both the PST and loss bright SI of post.lobe
on T1WI.
Note 2: One case have both the partial empty sella and loss bright SI
of post.lobe on T1WI.
Figure 3. Sagittal section T1WI (450/12.5/4/256 × 256):
The eleven years old girl disclosed pineal cyst and
absence of shorter T1 effect of posterior pituitary lobe
(short white arrow). Brain stem atrophy (long white
arrow) was noted, in addition to mid-brain and pons.
Marked neurodegnerative process was also noted.
However, the initial and follow-up images of pituitary
gland were normal. Other rare causes of CDI are
Menkes’s disease and pituitary stalk transection.
Disruption of the pituitary stalk was seen in the images
of a case of pituitary transection. The ectopic short T1
lesion over median eminence with contrast enhancement could be seen in the patient with stalk transection.
It was thought to be ectopic neurohypophysis.
One patient suffered from CDI had shallow
pituitary fossa on the MR images. The shallow
pituitary fossa may impair the normal function due to
too small space for pituitary gland. Local hemodynamic change or other vascular abnormality on the
pituitary gland may result in CDI clinical appearance.
The images of CDI
However the real relationship is still not clear.
Two patients with Wolfram syndrome were identified in the study. They are sibling. They came from a
diabetes family and suffered from CDI and DM. Both
poor visual acuity and hearing impairment were also
noted. MRI revealed marked atrophic change of brain
stem and cerebellum. Both cases could not demonstrate the short T1 effect of posterior pituitary gland.
But they were not categorized into the PLBSD
(posterior lobe bright signal disappearance) group due
to the rare disease and more complicated image
appearance.
CONCLUSION
In the variable causes of CDI, MRI plays an
important role. With subtle MR findings in CDI
patients, follow-up images is most important of all
especially in the thickened pituitary stalk group. High
percentage of progressive change is clearly shown in
this group as compared to other images group.
The progressive increase in the size of the
pituitary gland should alert the physicians to the possibility of tumor growth such as germinoma or histiocytosis. On the other hand, a decrease in size can suggest
the presence of an inflammatory or autoimmune
process. Biopsy should be employed for the patients
with progressive thickening of the pituitary stalk,
since spontaneous recovery may occur in patients with
this feature.
In patients with CDI and normal MRI or questionable increased PST, a regular follow-up at 3-month
interval is highly recommended since normal MRI
does not exclude the possibility of tumor.
◆
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Idiopathic hypothalamic diabetes insipidus, pituitary
stalk thickening, and the occult intracranial germinoma
in children and adolescents. J Clin Endocrinol Metab
1997; 82: 1362-1367
3. Maghie M, Villa A, Arico’ M, et al: Correlation
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4. Imura H, Nako K, Shimatsu A, et al: Lymphocytic
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5. Maghnie M, Genovese E, Sommaruga MG: Evolution
of children central diabetes insipidus into panhypopituitarism with a large hypothalamic mass: is “lymphocytic
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infundibuloneurohypophysitis” in children a different
entity. Eur J Endocrinol 1998; 139: 635-640
6. Verbalis JG, Robinson AG, Moses AM: Postoperative
and post-traumatic diabetes insipidus. Front Horm Res
1985; 13: 247-265
7. Blotner H: Primary or idiopathic diabetes insipidus: a
system disease. Metabolism 1958; 7: 191-200
8. Tien R, Kucharczyk J, Kucharczyk W: MR imaging of
the brain in patients with diabetes insipidus. AJNR Am
J Neuroradiol 1991; 12: 533-542
9. Brooks BS, el Gammal T, Allison JD, et al: Frequency
and variation of the posterior pituitary bright signal on
MR images. AJNR Am J Neuroradiol 1989; 153: 10331038
10. Simmons GE, Suchnicki JE, Rak KM, et al: MR imaging of the pituitary stalk: size, shape, and enhancement
pattern. AJR 1992; 159: 375-377
11. Sheen KC, Chang CC, Chang TC, Liu HM: Thickened
pituitary stalk with central diabetes insipidus: report of
three cases. J Formos Med Assoc. 2001 May; 100: 198204
12. Thodou E, Asa SL, Kontogeorgos G, et al: Lymphocytic
hypophysitis: clinicopatholiogical findings. J Clin
Endocrinol Metab 1995; 80: 2302-2311
13. Ahmed SR, Aiello DP, Page R, et al: Necrotizing
infundibulo-hypophysitis: a unique syndrome of diabetes insipidus and hypopituitarism. J Clin Endocrinol
Metab 1993; 76: 1499-1504
14. Roberston GL: Diabetes insipidus. Endocrinol Metab
Clin North Am 1995; 24: 549-572
15. Maghnie M, Genoveses E, Arico’ M, et al: Evolving
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176
The images of CDI
中央性尿崩症不明顯的初步核磁共振影像表現：
兩年的核磁共振影像追蹤經驗
楊明祥 1,2
陳啟昌 2
鄭永宜 2
中山醫學大學附設醫院　放射線部
台中榮民總醫院　放射線部 2
3
台北榮民總醫院　放射線部
田雨生 1
王憶芬 3
蔡仲明 2
李三剛 2
1
本研究的主要目的是介紹及討論，中央性尿崩症患者不明顯的核磁共振影像表現以及追蹤
影像的變化。
本研究是壹回溯性的研究。在最近 8 年，共搜集 26 位病例，其中男性 14 位，女性 12 位，
平均年齡 20.1 歲。診斷主要是依據 DDAVP 試驗以及血液-尿液之間滲透壓的關係。主要的症狀
為多尿，多渴。本研究是回溯性的分析核磁共振影像表現。
26 位病例中，有 7 位（26.9%）腦下垂體後葉的高訊號消失，有 3 位（11.5%）為空白蝶
鞍，有 1 位（3.8%）腦下垂體窩變淺，有 1 位（3.8%）為異位性腦下垂體後葉.有 6 位（23%）
是正常的核磁共振影像表現.有 7 位（26.9%）是腦下垂體蒂肥厚。
在腦下垂體蒂肥厚組的病人中，其中有 5 位持續變厚並接受手術組織檢體檢查，分別被診
斷為生殖細胞瘤，組織細胞症及類肉瘤病。其中有 2 位與其他它組的病人一樣，追蹤的核磁共
振影像持續不變。
在有限的經驗中，中央性尿崩症的原因相當多，在不明顯的核磁共振影像表現的病人中，
持續追蹤是最重要的。特別在腦下垂體蒂持續變厚的病人，組織檢體檢查尤其重要。
關鍵詞：磁振造像，尿崩症，生殖細胞瘤，組織細胞症，類肉瘤病