Abdomen

Question 1

Benign liver cyts
Demo
RF
Complications

Answer 1

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

Question 2

High T2 liver lesions mistaken for cysts

Answer 2

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

Metastatic NET
Haemangioma
Biliary cystadenoma/carcinoma

Question 3

Liver haemangioma

demo

Answer 3

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”

Question 4

DDx for nodular interrupted CE - liver

Answer 4

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

Question 5

Focal liver fat
locations
RF

Answer 5

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

Question 6

Focal nodular hyperplasia
Demo
RF

No underlying CLCD

Answer 6

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

Question 7

Liver adenomas

Answer 7

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

Question 8

Hepatic metastases

Answer 8

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

Question 9

Calcified liver mets

2

Answer 9

Serous ovarian Ca

Mucinous CRC

Question 10

Hypervascular liver lesions
Benign 4
Malignant 2

Answer 10

Haemangioma
FNH
Adenoma
Hyperplastic regenerative nodules in Budd-Chiari

HCC
Hypervascular mets

Question 11

Cholangiocarcinoma

types 3

Answer 11

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

Peripheral

Hilar

Question 12

Cirrhosis - early RF 5

Answer 12

Maybe inapparent

Hepatomegaly

Heterogeneous perfusion

Enlargement of hilar periportal space

Expansion of intersegmental fissure

Question 13

Regenerating nodules

imaging

Answer 13

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

Question 14

Cirrhosis - advanced

Measure

Answer 14

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

Hypertrophy :
Caudate, lateral seg LL

Caudate: RL ratio > 0.65 ratio

Question 15

Dysplastic nodules

RF

Answer 15

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

Question 16

Focal confluent fibrosis

Answer 16

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

Question 17

Hyperattenuating liver on CT

5

Answer 17

Haemachromatosis
Amiodarone
Type IV glycogen storage disease
Wilsons
Thorotrast

Question 18

Haemosiderosis

Answer 18

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

Question 19

Budd Chiari
Presentation
Causes 5
Types 3

Answer 19

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

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

Question 20

Budd Chiari

RF

Answer 20

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

Question 21

Hepatic infarction

Answer 21

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

Question 22

CT signs of acute appendicitis

6

Answer 22

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

Question 23

CT signs of acute diverticulitis

4

Answer 23

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

Question 24

Epiploic appendagitis vs Omental infarction ( CT)

Answer 24

appendagitis : oval pericolonic dirty fat with HIGH density rim.

Question 25

Signs of strangulation, closed loop or ischaemic bowel

Answer 25

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

Question 26

Feline oesophagus Def Causes 3

Answer 26

Multiple thin horizontal folds in oesophagus ; corrugations Usually normal Reflux Scleroderma(CREST)

Question 27

Scleroderma UGI findings

Answer 27

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

Question 28

Pancreatic rest on UGI

Answer 28

Single Umbilicated filling defect Inferior antrum

Question 29

Crohns Disease SBFT | 4

Answer 29

Ulcers Cobblestoning String sign of Kantor (TI) Fistulae

Question 30

Scleroderma SBFT findings | 2

Answer 30

Dilated atonic bowel | Sacculations ( broad based pseudodiverticulae in antimesenteric)

Question 31

Nodular lymphoid hyperplasia Causes 4 SBFT RF 1

Answer 31

``` Causes: Idiopathic Hypogammaglobinaemia Lymphoma Giardiasis ``` Submucosal nodules Any part GIT commonly SB

Question 32

GVHD | SBFT features 2

Answer 32

Thickened SB | Featureless "ribbon like" bowel

Question 33

Coeliac disease | SBFT features 3

Answer 33

Small bowel dilatation Coarse or obliterated folds Ileojejunal reversal

Question 34

Caecal volvulus | XR RF

Answer 34

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

Question 35

Sigmoid volvulus RF more common

Answer 35

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

Question 36

UC | DCBE RF 6

Answer 36

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

Question 37

CT severity index of pancreatitis grading CTSI Combination of Balthazar score ( 0-4) + necrosis (0,2,4,6) Max score 10

Answer 37

``` 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) ```

Question 38

Pseudocyst features | 4

Answer 38

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

Question 39

Chronic pancreatitis | RF

Answer 39

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

Question 40

Indications for percutaneous drainage of pseudocysts 3 Complications (5-10%) 3

Answer 40

> 5cm or increasing in size Symptomatic Obstruction of bile duct, stomach or duodenum Infection Bleeding Chronic cutaneous fistula

Question 41

Pancreas divisum def demo CT RF

Answer 41

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).

Question 42

Cystic pancreatic malignancies | 5-10%

Answer 42

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

Question 43

Serous pancreatic adenoma

Answer 43

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

Question 44

mucinous cystic pancreatic neoplams

Answer 44

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

Question 45

Solid and papillary epithelial neoplasm (SAPEN)

Answer 45

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

Question 46

IPMN | types 3

Answer 46

hyperplasia--- carcinoma mean 65y 1. main duct : diffuse or segmental dilatation 2. Branch duct : cystic dilatation 3. Combined ERCP : patulous papilla, mucin, mural nodules

Question 47

Islet cell tumours

Answer 47

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% ```

Question 48

Pancreatic Carcinoma | Unresectability criteria

Answer 48

> 5cm Adjacent tissue/organ invasion except duodenum Arterial involv +/- venous invasion Hepatic mets Distant adenopathy Peritoneal carcinomatosis

Question 49

Bosniak II | RF 4

Answer 49

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

Question 50

Bosniak IIF | 4

Answer 50

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

Question 51

Bosniak III | 3

Answer 51

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

Question 52

Bosniak IV | 1

Answer 52

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

Question 53

Solid renal mass | 4

Answer 53

RCC TCC Lymphoma Mets

Question 54

Renal TCC | RF

Answer 54

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

Question 55

CT patterns of renal lymphoma | 5

Answer 55

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

Question 56

Renal oncocytoma | 2

Answer 56

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

Question 57

Renal angiomyolipoma Demo RF 3

Answer 57

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

Question 58

von Hippel Lindau | organ involvement

Answer 58

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

Question 59

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

Answer 59

Unenhanced HU > 10 Rapid contrast washout ___ absolute washout > 60% ___relative washout > 40% Pitfalls Hypervascular mets phaeochromo adrenocortical Ca

Question 60

Indeterminate adrenal lesions with NO washout

Answer 60

Phaeo Adrenocortical carcinoma Mets Lipid poor adenoma

Question 61

Adrenal adenoma

Answer 61

``` 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 ```

Question 62

Phaeochromocytoma | demo

Answer 62

``` 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 ```

Question 63

Macroscopic fat containing adrenal mass

Answer 63

myelolipoma