Case report rafdiology Autoimmune pancreatitis

1. Case 1

2. Autoimmune pancreatitis
(lymphoplasmacytic sclerosing pancreatitis)

3. Autoimmune pancreatitis is a unique form of pancreatitis caused by
autoimmune disease associated with elevation of IgG4.
The disease is most common in men aged 40 to 65.
Presentation is often obstructive jaundice with history of recurrent mild
abdominal pains. Extrapancreatic manifestations occur in 30% of patients and
may include inflammatory bowel disease, especially ulcerative colitis, long-
segment bile duct strictures, lung nodules, lymphadenopathy, lymphocytic infiltrates
in the liver and kidneys, retroperitoneal fibrosis, and Sjögren syndrome.

4. Masslike Enlargement of Pancreatic Head Due to
Autoimmune Pancreatitis With Pancreaticobiliary
Obstruction. (A) Transverse sonogram shows
dilation of the main pancreatic duct (arrow). (B)
Transverse sonogram shows biliary ductal dilation.
(C) Oblique sonogram shows enlarged and
hypoechoic pancreatic head (arrows).
(A) (B)
(C)

5. CT findings
(a) diffuse or focal swelling of the pancreas with characteristic tight halo of edema;
(b) extensive peripancreatic stranding and edema are absent;
(c) diffuse or segmental narrowing of the pancreatic duct and/or the common
bile duct;
(d) absence of dilation of the pancreatic duct and absence of parenchymal
atrophy proximal to the pancreatic mass (these findings are typically present with
adenocarcinoma);

6. (e) fluid collections and parenchymal calcifications are typically absent;
(f) peripancreatic blood vessels are usually not involved
(g) the kidneys are involved in one-third of cases showing round, wedge-like, or
diffuse peripheral patchy areas of decreased contrast enhancement.(Contrast
enhancement is helpful as autoimmune pancreatitis demonstrates reduced
enhancement during the pancreatic phase (40 s) but near normal enhancement on
portal venous phase (70s) .
(I) Imaging findings normalize following steroid treatment.

7. Other sites also seem to be involved:
 peripancreatic lymph nodes >1 cm
 kidney: inflammatory pseudotumors; hypoattenuating lesions
 retroperitoneal fibrosis
 pleural effusions
 common bile duct strictures
 mediastinal nodes

9. MRI findings
■ T1: decreased signal intensity
■ T2: minimal increased signal intensity
■ T1 C+ (Gd): delayed parenchymal enhancement on dynamic imaging
■ DWI/ADC:
 shows diffusion restriction with high DWI signal and low ADC signal
 the reduction in ADC values can be lower than with pancreatic cancer
 DWI signal may be useful as a marker for determining the indication for steroid
therapy

10. MRCP:
multiple intrahepatic duct strictures and common bile duct; diffuse narrowing of
the main pancreatic duct.
ERCP:
can be normal. Biliary duct abnormalities are common with strictures of the
common bile duct and short intrahepatic duct strictures representing Primary
sclerosing cholangitis
Typically shows diffuse irregularity and narrowing of the main pancreatic
duct (distinct from pancreatic carcinoma).

11. Treatment
Treatment with steroids usually leads to the resolution both of morphological
changes and a return to normal pancreatic function, with remission seen in 98% of
cases .

13. Ddx
■ Pancreatic ductal adenocarcinoma
■ Pancreatic lymphoma
■ Pancreatic metastases

14. Pancreatic ductal adenocarcinoma
A 72-year-old man with PDAC. Axial portal
venous phase CT image (a) shows MPD
stricture (arrow) at the pancreatic body
with upstream dilatation without visible
obstructing mass. Axial portal venous
phase CT images (b and c) obtained 6
months later show the progression of the
MPD stricture (arrow) with worsened
upstream ductal dilatation and pancreatic
atrophy. There is a small hypoattenuating
mass (arrowheads in c) associated with
an enlarged necrotic metastatic
portacaval lymph node (asterisk)

15. Pancreatic lymphoma
5-year-old girl with 3-week history of abdominal
pain, intermittent nausea and vomiting, and
jaundice. Unenhanced CT scan shows diffuse
enlargement of pancreatic head (white arrows) with
marked dilatation of intrahepatic bile ducts (black
arrows).

17. Case 2

18. CHORDOMA

19. Chordomas are uncommon malignant tumors of the axial skeleton that
account for 1% of intracranial tumors and 4% of all primary bone tumors.
They originate from embryonic remnants of the primitive notochord (earliest
fetal axial skeleton, extending from the Rathke’s pouch to the tip of the
coccyx).
Since chordomas arise in bone, they are usually extradural and result in
local bone destruction.

20. They are locally aggressive,slow growing but highly recurrent
Metastatic spread of chordomas is observed in 7-14% of patients with lymph node,
pulmonary, bone, cerebral.

21. Epidemiology
Chordomas can occur at any age but are usually seen in adults (30-70
years).
Those located in the spheno-occipital region most commonly occur in
patients 20-40 years of age, whereas sacrococcygeal chordomas are
typically seen in a slightly older age group (peak around 50 years ).

22. Location
Chordomas occur in the midline along the spinal axis from the clivus to the sacrum,
anterior to the spinal cord.
Chordomas are distributed as follows:
50% sacral,
35% skull base
15% in the vertebral bodies (most commonly the C2 vertebrae, followed by the
lumbar spine and then the thoracic spine).

23. Radiography
Chordomas have 4 pathognomonic characteristics on plain film evaluation:
expansion of the bone, osteoprosis, trabeculation, and calcification.The usual
radiographic pattern is lytic, with frequent calcification or sequestered bone
fragments.
for intracranial chordomas, plain films are no longer used. In addition, although
plain films are often the first examination for sacrococcygeal and spinal chordomas,
CT scanning and MRI are necessary for the diagnosis.

24. Sacrococcygeal chordoma. Plain
radiograph of the pelvis showing
expansion of the sacrum, bone
rarefaction, and large mass of
soft tissue with some
trabeculations.

25. Figure: (a and b) Frontal and lateral
radiographs of the sacrum. Destructive lytic
lesion, with better demonstration on the lateral
view (black arrows).

26. CT findings
 centrally located
 well-circumscribed
 destructive lytic lesion, sometimes with marginal sclerosis
 expansile soft-tissue mass
 usually hyper attenuating relative to adjacent brain; however, inhomogenous
areas may be seen due to necrosis or hemorrhage
 soft-tissue mass is often disproportionately large relative to the bony destruction
 irregular intratumoral calcifications
 moderate to marked enhancement

27. Figure: (a and b) Plain CT pelvis.
Destructive sacral lytic lesion with soft-
tissue mass containing intratumoral
calcifications. (c) Plain CT pelvis. The
mass eroded the right sacral foramen,
extended across the right sacroiliac
joint, and invaded the right iliac bone
(white arrow). It also extended to the left
sacroiliac joint (white dotted arrow).

28. MRI findings
 T1
intermediate to low-signal intensity
small foci of hyperintensity (intratumoral hemorrhage or a mucus pool)
 T2: most exhibit very high signal
 T1 C+ (Gd)
heterogeneous enhancement with a honeycomb appearance corresponding to low
T1 signal areas within the tumor
greater enhancement has been associated with poorer
prognosis

29. Figure: (a-c) Contrast MRI pelvis.
Expansile pelvic mass centered
at the sacrococcygeal junction
showing a low to intermediate T1-
weighted signal with presence of
T1-weighted hyperintense foci
indicating intra lesional
hemorrhage or proteinaceous
contents high T2-weighted signal
on fat-saturation images and
moderate heterogeneous contrast
enhancement. (d) Contrast MRI
pelvis. Preserved intervening fat
plane with the rectum anteriorly
(white arrow). Focal breaching of
tumor capsule invading into
subcutaneous fat posteriorly
(black arrow).

30. Figure 13: (a-c) Contrast MRI pelvis. A lobulated sacral mass with T1-weighted
isointense and T2-weighted hyperintense signal showing mild contrast enhancement.
(d) Contrast MRI pelvis. It invaded the right sacroiliac joint and the right ilium (white
arrow). There was also involvement of the left sacroiliac joint (white dotted arrow).

31. Sacral Chordomas are the most common primary malignant tumors in the
sacrum .they are usually presented as a bulky, local aggressive pelvic mass at the
time of diagnosis.
Frontal radiographs may have limited roles in the early stage of the disease
since there is poor visualization of bony erosions at the sacrococcygeal regions due
to overlapping colonic shadows in the pelvic region. Complementary lateral view
would better demonstrate early erosive changes .
In the late stage of the disease, destructive osteolytic lesions with the presence of
presacral soft-tissue mass could be depicted on the radiographs.

32. Tumoral extension
Tumoral extension is important to ascertain for preoperative planning and is
observed as follows:
Proximal extension : Bone and sacral canal
Distal-lateral extension : Gluteus maximus, hamstrings, and sciatic nerve and notch
Anterior extension : Retroperitoneal lymph nodes and rectum
Posterior extension : Subcutaneous fat

33. Ddx
■ Chondrosarcoma
■ metastases
■ multiple myeloma
■ Lymphoma
■ Giant cell tumor

36. Perimesencephalic subarachnoid
hemorrhage
(PMSAH)

37. Subarachnoid hemorrhage (SAH)
is bleeding in the subarachnoid space between the arachnoid and the pia
mater.

38. Causes
■ Trauma (Most common cause)
■ spontaneous
 Ruptured berry aneurysm 85%
 Perimesencephalic SAH 10%
 Other Causes 5%

39. The first choice of imaging modality in a patient with a clinical suspicion of SAH is a
non-enhanced CT scan (NECT).
NECT is positive for SAH in 98% within 12 hours of onset.
If the suspicion is strong, but the CT is negative, a lumbar puncture is performed to
detect blood in the CSF.
MRI has a lower sensitivity for detecting a SAH than CT in the acute phase.
MRI sometimes detects a SAH in the subacute phase.
The most sensitive sequence are the T2*gradient echo and FLAIR.

40. CT images of a patient with a
spontaneous SAH.

41. Perimesencephalic SAH is a type of non aneurysmal SAH that
represent approximately 10%–15% of all spontaneous SAH cases.
PMSAH’s are characterized by the absence of an aneurysm or other source
of bleeding on 4-vessel digital subtraction angiography and subarachnoid
blood located predominantly in the perimesencephalic cistern .The
prognosis for PMSAH is usually much better than that of aneurysmal
subarachnoid hemorrhage with a benign clinical course and low risk of
rebleeding or vasospasm.

42. ■ Patients with PMSAH tend to be younger and less hypertensive as compared to
those with aneurysmal SAH
■ The clinical presentation of patients with PMSAH is similar to those of patients
with aneurysmal SAH: Sudden onset of headache, meningeal irritation,
photophobia and etc
■ The patients were commonly classified Hunt-Hess Grade I or II

43. Etiology
■ 95% of cases of perimesencephalic subarachnoid hemorrhage have a normal
cerebral angiogram and the source of bleeding is not identified;
■ The causes of PMSAH suggest a venous or capillary rupture at the level of the
tentorial hiatus.
■ The other 5% of cases are due to a vertebrobasilar aneurysm and the prognosis
is worse

44. Imaging criteria for the diagnosis of
PMSAH
■ (1) The epicenter of the hemorrhage is immediately anterior to midbrain and
pons
■ (2) Possible extension of blood to the proximal part of the interhemispheric
fissure
■ (3) Extension of blood to the basal part of the Sylvian fissure is permitted
■ (4) Absence of frank amount of intraventricular blood; small amount of
sedimented blood in the occipital horns are permissible
■ (5) Absence of intracerebral hematoma
■ (6) Negative high-quality four-vessel angiography

45. Axial NECT of a 49- year-old woman with a "thunderclap"
headache shows SAH around the midbrain in the
perimesencephalic cisterns. Note the absence of blood in
the sylvian fissures and anterior suprasellar subarachnoid
space.
Axial graphic shows a classic PMSAH.
Hemorrhage is confined to the
interpeduncular fossa and ambient
(perimesencephalic) cisterns

46. Axial NECT in the same patient
shows the subarachnoid blood
extends inferiorly in front of the
pons.
Coronal CTA in the same patient with
reconstructed view through the basilar artery
bifurcation shows no evidence for aneurysm.
The high density in the vessels is easily
discernible even with the presence of
significant SAH. DSA (not shown) confirmed
the absence of aneurysm. This case illustrates
classic findings in PMSAH.

47. There are specific criteria for non-aneurysmal perimesencephalic SAH,
which, negate the need for DSA if fulfilled with a negative CTA :
■ SAH in perimesencephalic cisterns anterior to midbrain
■ if SAH extension into the anterior interhemispheric fissure, not extending into all
of the fissure
■ if SAH extension into the proximal Sylvian fissure, not extending into the lateral
fissure
■ if layering interventricular extension, no frank IVH
■ no intraparenchymal hemorrhage

48. Treatment and prognosis
■ CTA is recommended for perimesencephalic subarachnoid hemorrhage to
investigate for possible aneurysmal cause. Overall, PMSAH has an excellent
prognosis with better outcomes compared to aneurysmal SAH
■ Patients with a perimesencephalic nonaneurysmal subarachnoid hemorrhage
are not at risk for rebleeding in the initial years after the hemorrhage and have a
normal life expectancy.

49. Role of CTA and DSA
In a SAH we usually will find an aneurysm with CTA.
If the CTA does not show an aneurysm we usually continue with a DSA because it
has a higher sensitivity.
However if the CTA does not show an aneurysm and the clinical and CT-findings
are compatible with a perimesenphalic hemorrhage, no further investigation is
necessary

50. To diagnose a perimesencephalic nonaneurysmal SAH, the
patient has to meet all the criteria in the table.
If all these criteria apply and the CTA does not show an aneurysm,
you do not have to perform a DSA.

51. Here another example of a nonaneurysmal perimesencephalic SAH.
Left image: NECT showed a small amount of subarachnoidal blood anterior to the
brainstem.
Right image: more cranially, the pentagon, ambiens cistern and the proximal part of Sylvian’s
fissures, did not show any blood.
This is a typical presentation of nonaneurysmal perimesencephalic SAH.
The blood is solely located around the brainstem.

52. This patient complained of sudden onset headache with
the sensation of a “burst” inside his head.
Neurological exam was normal, except for a stiff neck.
The NECT showed a small amount of subarachnoidal
blood anterior of the brainstem.
CTA showed no abnormalities.
DSA was not performed.

53. DDX
 Aneurysmal SAH
More extensive hemorrhage
Basilar bifurcation aneurysm may have PMSAH pattern
 Traumatic SAH
peripheral pattern(perisylvian ,convexity) more common than perimesencephalic
pattern
 Artifact: FLAIR
Incomplete CSF suppression
Pulsation artifact

55. DDX
■Molar pregnancy
■Leiomyoma
■Arteriovenous malformations

56. Molar pregnancy

59. Leiomyoma

62. AVM

65. Sacral chordomas usually destroying the sacral foramina, and
affecting the sacral nerve roots.
They could also invade the greater sciatic foramen posteromedially and
threaten the sciatic nerve. Laterally, they could grow across the sacroiliac
joints and spread to the iliac bones .
Posterolaterally, they could invade the pelvic muscles such as piriformis
and gluteus maximus directly. Anteriorly, the mass could bulge into the
mesorectum. However, invasion into the rectum is characteristically
spared since the presacral fascia is tough and limits the spread of the
disease.

66. Sacrococcygeal chordomas
are often massive, well-delineated tumors that shift the fatty tissue of the pelvis
and involve bone structures and the epidural area. Peripheral sclerosis may be
observed in approximately 50% of patients, and frequently, a discrepancy is found
between a large soft-tissue component and the area of bone involvement. In
addition, regional lymph nodes are usually invaded.Spinal chordomasInfrequently,
chordomas arise in the mobile (ie, cervical, thoracic, lumbar) spine (15%). [27]
The cervical spine is the most common site for spinal tumors, with a
predominance in the C2 vertebra; the thoracic [28] and lumbar areas of the spine
are involved less frequently.Initially, the presentation of a chordoma on CT scan is
of bone destruction centered in the vertebral body, with an associated, anteriorly
or laterally situated, paraspinal soft-tissue mass that may contain calcification.
Following vertebral body involvement, the pedicles, laminae, and spinal process
then become involved as well; however, adjacent intervertebral disc spaces are
usually spared.

67. The arrows indicate the interpeduncular cistern
anteriorly and the ambient cistern posteriorly.
The differential diagnosis of high signal in the
subarachnoid space on MRI is large:
 pus in meningitis
 blood in SAH
 leptomeningeal metastases
 ruptured dermoid
 flow artifacts
In this case it was the result of a SAH.

68. Case 4