approach to abd imaging + parenchyma

Radiology vs US

R- better for size + shape

US- better for internal architecture + lumens (unless gas)

Purpsoe of Low kV high mA technique in Rx

Avoid scatter, improve contrast resolution

How to improve abd rx - when to take pic

Exp pause

How to improve abd rx - View

VD, R lat

Positive vs negative contrast media

P- white (I, Barium)

N - black (air, CO2, N2O)

Contrast medium - issue with barium

GIT only (oral ROA)

Granulomatous infl in body cavities (dont use if rupture)

Contrast medium - When to use iodinated

GIT, urinary, IV, myelography

Contrast medium - Safest type

Non ionic low osmolarity iodinated

Contrast medium - iodinated side effects

Anaphylaxis, shock in body cavity (better than barium), local irritant, kidney failure

Contrast medium - Side effect of gas

Air embolism

What state of matter does not work with US

Gas

Which to do first - US or rx + why

Rx - no gel artefact

Which cases need CT as blind spots

Pelvic canal

Surgical access assessment

Vascular malformations

Ectopic ureters

Röntgen signs

Number

Size

Shape + margins

Opacity

Location

Opacity types 5

Gas

Fat (dark)

Soft tissue/ fluid (efface fat)

Bone/ mineral

Metal

Mass effect shows what

Swelling, mass, space occupying lesions → displacement

Types of mineralisation + causes

Dystrophic (focal) - tissue damage

Metastasic (diffuse) - hypercalcaemia

Other - urinary calculi, ingesta, osseous neoplasia

Which vit toxicity can lead to metastatic mineralisation

Vit D

Common mineralisation in old cats

Dystrophic from adrenal damage

Abd rx - peritoneum appearance

Some fluid

Fat in omentum + retroperitoneum

Abd rx - Causes of loss of serosal detail

Lack of fat

Peritoneal fluid

Carcinomatosis/ sarcomatosis (many metastatic micro nodules)

Brown fat (higher water content)

Peritonitis

Visceral crowding

Age brown fat disappears

4-6mon

Abd rx - Causes of pneumoperitoneum

Post sx (<4w)

Ruptured GIT/ septic abd

Penetrating trauma

Abd rx - Pneumoperitoeum appearance

Inc contrast between gas+ soft tissue → inc serosal surface brightness

Gas bubbles dont conform to GIT

Abd rx - Common location of pneumoperitoenum

Diaphragm + dor liver margin

Abd rx - Normal liver appearance

Cr

Acute Vencd angle

Pokes past costal arch

Abd rx - Gastric axis

Point in middle of fundus → middle of pylorus

Shows size of liver (displaced axis)

Abd rx - Hepatomegaly appearance

Rounded margins

Extend further cd to costal arch

Cd displaced gastric axis

Mass effect

Abd rx - Causes of hepatomegaly

General - nodular hyperplasia, lymphoma, mets, acute hepatitis, metabolic hepatopathy

Focal - neoplasia, abscess

Abd rx - Microhepatia appearance

Contained within costal arch

Little soft tissue cr to stomach

Cr displaced gastric axis

Abd rx - Microhepatia causes

Portosystemic shunt, primary portal v hypoplasia

Chronic hepatitis, fibrosis, cirrhosis

Abd rx - Normal spleen (tail not visible in cat)

Tail - triangle cd to liver (mobile)

Head - triangle on L superimposing R kidney (fixed)

Body - L

Abd rx - Splenomegaly appearance

Rounded margins

Tail cd displaced (visible in cats)

Abd rx - Splenic mass vs general splenomegaly causes

M- neoplasia (haemangiosarcoma, MCT), haematoma, nodular hyperplasia

G- sed, GA, infiltration (lymphoma), infl (hyperplasia, splenitis)

Retroperitoneum - normal

Dor to peritoneal cavity

Contain kidney, ureter, bladder neck, great vessels, adrenal glands, LN, prostate

Continues with mediastinum + aorta

Fat opacity + streaky

Retroperitoneal mass causes

Any organ (kidney, LN)

Fluid (effusion, H)

Adrenal glands - normal

Not visible

Mineralise in old cats

Adrenal glands - When does mineralisation happen

Cat - old

Dog - neoplasia (adenoma, carcinoma, phaeochromocytoma)

Abd LN - opacity (normally not visible)

Soft tissue

Abd LN - List of them

Retroperitoneal - para aortic, renal, med iliac, int iliac, sacral

Peritoneal - gastric, pancreaticoduodenal, splenic, jejunal, colic