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Flashcards in Abdomen Deck (63)
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1

Benign liver cyts
Demo
RF
Complications

Developmental
Common 14%
Round/ovoid
Fluid SI
imperceptible, non CE wall
Single/multiple
Haemorrhage is rare

2

High T2 liver lesions mistaken for cysts

Cystic metastases (hypervascular tumours; colon, ovarian cystadenocarcinoma, squamous cell lung cancer.
sarcomas, melanoma.
GIST,pancreatic mucinous cystadenocarcinoma.

Metastatic NET
Haemangioma
Biliary cystadenoma/carcinoma

3

Liver haemangioma
demo

Common (7-20%)
F>M
R>L lobe
Lobulated, clefted appearance
T2 very bright
CE follows blood pool -continues to enhance on delayed

Interrupted peripheral nodular enhancement
Homogeneous CE by 10-20"

4

DDx for nodular interrupted CE - liver

Treated mets
Haemangioendothelioma: paed, (periph, confluent lesions)
Angiosarcoma : heterogeneous

5

Focal liver fat
locations
RF

Classic locations : falciform ligament, GB fossa, periportal

Geographic low density

Geographic inc CE

No mass effect
Non displaced vessels

Out of phase signal loss

Central high density on CECT

6

Focal nodular hyperplasia
Demo
RF

No underlying CLCD

3%
Young females (80-95%)
Solitary 80%
Lobulated
Subcapsular

iso/low T1; iso/sl high T2

Central scar 50-75%) : low T1/high T2(cf fibrolam HCC)
Homogeneous CE
Scar : delayed CE

Do sulphur colloid if unsure (55%)
Hepatocyte specific contrast

7

Liver adenomas

OCP
Heterogen T1/T2
Can have Haem / FAT
Hetero CE
Can undergo malignant Tx

8

Hepatic metastases

usually hypovascular
HA supply ( high CE in arterial followed by washout - no PV supply)
Hypo on CT - no normal liver cells
High T2, low T! unless blood/melanin

9

Calcified liver mets
2

Serous ovarian Ca
Mucinous CRC

10

Hypervascular liver lesions
Benign 4
Malignant 2

Haemangioma
FNH
Adenoma
Hyperplastic regenerative nodules in Budd-Chiari

HCC
Hypervascular mets

11

Cholangiocarcinoma
types 3

Intrahepatic (20-30%) : mass forming, periductal infiltrating, intraductal

Peripheral

Hilar

12

Cirrhosis - early RF 5

Maybe inapparent

Hepatomegaly

Heterogeneous perfusion

Enlargement of hilar periportal space

Expansion of intersegmental fissure

13

Regenerating nodules
imaging

T1/T2 low
May contain Fe ( siderotic ) - SWI artefact
May contain Cu - non fero

14

Cirrhosis - advanced
Measure

Atrophy - Right lobe, medial segment of left lobe ( expanded GB fossa )

Hypertrophy :
Caudate, lateral seg LL

Caudate: RL ratio > 0.65 ratio

15

Dysplastic nodules
RF

Classically:
T1 high,
T2 low/iso
Does NOT enhance

16

Focal confluent fibrosis

Anterior/medial segments
Wedge shaped
May involve entire segment
Capsular retraction
Delayed Gad enhancement

17

Hyperattenuating liver on CT
5

Haemachromatosis
Amiodarone
Type IV glycogen storage disease
Wilsons
Thorotrast

18

Haemosiderosis

Dyseryhtropoesis
Transfusion
Excessive Fe accumulation in RES ie
Liver ( kuppfer cells), spleen, bone marrow

19

Budd Chiari
Presentation
Causes 5
Types 3

Hepatomegaly, ascites, jaundice
Causes : Idiopathic, IVC webs, tumours, pregnancy, hypercoaguable states

Type
I : IVC +/- secondary HV
II : HV +/- secon IVC
III - venoocclusive

20

Budd Chiari
RF

Delayed of reversed PV inflow

Hepatomegaly
Congestion - low T1/high T2 "nutmeg' liver
Patchy central CE
Peripheral hypoperfusion
Reversed on delays

Small HV/IVC
Intravascular thrombi
Hepatic infarcts
PV thrombosis (20%)

Chronic - atrophy of liver, caudate hypertrophy

21

Hepatic infarction

Rare
Peripheral wedge shaped/geographic
Low density on CT
Low T1/high T2
Changes shape with time
Necrosis (air)
Bile lakes
Eventual atrophy

22

CT signs of acute appendicitis
6

Fat stranding
Diameter >6mm (intraluminal air is usually normal)
Focal caecal thickening
Appendicolith
Paracolic gutter fluid
Adenopathy

23

CT signs of acute diverticulitis
4

Colonic wall thickening (7-10mm)
Pericolic fat infiltration
Abscesses
Extraluminal air

24

Epiploic appendagitis vs Omental infarction ( CT)

appendagitis : oval pericolonic dirty fat with HIGH density rim.

25

Signs of strangulation, closed loop or ischaemic bowel

Excess free fluid
Hazy, paper thin walls
Mesenteric fat stranding
Distended single loop
Non enhancing, thickened walls
Pneumatosis
(Free air)

26

Feline oesophagus
Def
Causes 3

Multiple thin horizontal folds in oesophagus ; corrugations

Usually normal
Reflux
Scleroderma(CREST)

27

Scleroderma UGI findings

Dilated patulous (< achal ) oesophagus
Patulous GEJ
Free reflux
Partially adynamic cf achal(dysmotile)

28

Pancreatic rest on UGI

Single
Umbilicated filling defect
Inferior antrum

29

Crohns Disease SBFT
4

Ulcers
Cobblestoning
String sign of Kantor (TI)
Fistulae

30

Scleroderma SBFT findings
2

Dilated atonic bowel
Sacculations ( broad based pseudodiverticulae in antimesenteric)

31

Nodular lymphoid hyperplasia
Causes 4
SBFT RF 1

Causes:
Idiopathic
Hypogammaglobinaemia
Lymphoma
Giardiasis

Submucosal nodules
Any part GIT
commonly SB

32

GVHD
SBFT features 2

Thickened SB
Featureless "ribbon like" bowel

33

Coeliac disease
SBFT features 3

Small bowel dilatation
Coarse or obliterated folds
Ileojejunal reversal

34

Caecal volvulus
XR RF

Dilated bean shaped loop
LUQ/Subhepatic
1-2 visible haustra
Collapsed left colon
Dilated small bowel
beak on contrast enema

35

Sigmoid volvulus
RF
more common

Dilated inverted U-shaped loop
Apex in LUQ
Ahaustral outer margin
Inferior convergence to left of S1
Descending colon behind loop

36

UC
DCBE RF 6

Granular mucosa
Undermined mucosa
Pseudopolyps-> " filiform' polyps
Thumbprinting
Toxic megacolon
Carcinoma
No skip lesions

37

CT severity index of pancreatitis grading CTSI

Combination of Balthazar score ( 0-4)
+ necrosis (0,2,4,6)

Max score 10

Balthazar
A: normal pancreas 0
B: enlarged pancreas 1
C: inflammatory changes in pancreas + fat 2
D: single fluid collection 3
E: 2 or more fluid collections 4

Necrosis:
none (0)
<30 (2)
30-50 (4)
> 50 (6)

38

Pseudocyst features
4

>4 weeks to develop
No enhancing internal contents (0-30HU)
Wall Ca uncommon
Can occur anywhere
DDx : pseudoaneurysm (thrombosed)

39

Chronic pancreatitis
RF

Pancreatic calcification
Variable size
Dilatation of PD
Dilatation of bile ducts
Pseudocyst/pseudoaneurysm
Venous thrombosis

40

Indications for percutaneous drainage of pseudocysts 3

Complications (5-10%)
3

> 5cm or increasing in size
Symptomatic
Obstruction of bile duct, stomach or duodenum

Infection
Bleeding
Chronic cutaneous fistula

41

Pancreas divisum
def
demo
CT RF

Failure fusion of dorsal and ventral pancreatic primordia
Dorsal--> Wirsung major papilla
Ventral --> Santorini minor papilla

Incidence 5%

CT : bulky head with fat cleft
ERCP gold standard (branches at tip).

42

Cystic pancreatic malignancies
(5-10%)

Serous adenoma
Mucinous cystic neoplasm
Solid and papillary epithelial neoplasms
IPMN
Anaplastic
Cystic islet cell
Cystic met
Lymphoma

43

Serous pancreatic adenoma

Benign
F>M, 65y mean
1/3rd Ca + central stellate scar
Cysts >6, <2cm
Honeycomb appearance
Ass. VHL

44

mucinous cystic pancreatic neoplams

frank or potentially malignant
F>M
mean50y
Tail > body
Ca 15% periphery
Cysts < 6, > 2cm
MUCIN

45

Solid and papillary epithelial neoplasm (SAPEN)

rare, low grade malig
young women mean 24yr
Large encapsulated solid/cystic mass with haemm and necrosis

Tail (50%)
Ca 30%
Fluid debris level

Resection curative

46

IPMN
types 3

hyperplasia--- carcinoma
mean 65y

1.main duct : diffuse or segmental dilatation
2.Branch duct : cystic dilatation
3.Combined

ERCP : patulous papilla, mucin, mural nodules

47

Islet cell tumours

85% functional
Insulinoma MC, > 90% benign and resectable

Gastrinoma: 2nd MC,
60% malignant, small
causes ZE syndrome

Non functioning (15%)
80-90% malignant, large size, ca 25%

48

Pancreatic Carcinoma
Unresectability criteria

> 5cm
Adjacent tissue/organ invasion except duodenum

Arterial involv
+/- venous invasion

Hepatic mets
Distant adenopathy
Peritoneal carcinomatosis

49

Bosniak II
RF 4

hairline thin septa +/- minimal perceived CE
fine ca in walls or septa
short segment of slightly thickened Ca
Uniform high attenuation (<3cm)

50

Bosniak IIF
4

Incresed number of thin septa
minimal smooth thickening of wall or septa
No enhancing solid components
Intra renal high at cysts > 3cm

51

Bosniak III
3

complex cyst
Thickened irregular walls or septa
enhancement of wall or septa
Chunky Calcium

52

Bosniak IV
1

Enhancing soft tissue components adjacent to but independent of wall or septum

53

Solid renal mass
4

RCC
TCC
Lymphoma
Mets

54

Renal TCC
RF

80-90% prior bladder cancer
Polypoid filling defect
Circumferential wall thickening
Infiltrating or discrete mass
+/- calyceal dilatation

55

CT patterns of renal lymphoma
5

Multiple small masses
Spread from retroperitoneal disease
Diffuse infiltration
Perinephric encasement
Single homogeneous mass

56

Renal oncocytoma
2

Rare, benign
RF
Central stellate scar
Spoke wheel pattern of vessels on angio

57

Renal angiomyolipoma
Demo
RF 3

Rare, benign hamartomatous
80% sporadic
20% syndrome assoc _ TS, NF
95% contains macro fat
well defined cortical mass
Typically < 5cm

58

von Hippel Lindau
organ involvement

AD
Haemiangioblastoma ( retina, cerebellum)
Phaeochromocytoms (multiple, sctopic)
Pancreatic cysts , islet cell tum
Renal cysts (60%)
RCC 25-50%, usually multiple

59

Lipid poor adrenal adenoma
(indeterminate lesions 1-4cm with washout)

washout pitfalls

Unenhanced HU > 10
Rapid contrast washout
___ absolute washout > 60%
___relative washout > 40%

Pitfalls
Hypervascular mets
phaeochromo
adrenocortical Ca

60

Indeterminate adrenal lesions with NO washout

Phaeo
Adrenocortical carcinoma
Mets
Lipid poor adenoma

61

Adrenal adenoma

most common adrenal mass
Usually not hyperfunctioning
usually < 4cm
Hypointense on T2
Variable CE
loss of signal on opp phase
(compare with spl or sk muscle)
NB: macroscopic fat does not show signal drop on OP MRI cf microscopic fat in adenoma

62

Phaeochromocytoma
demo

90% adrenal medulla
usually > 3cm at presentation
10% B/L
10% malignant
lightbulb bright T2 not always
late CE
usually no signal drop out opp

63

Macroscopic fat containing adrenal mass

myelolipoma