Imaging Lecture 4 Flashcards
What is meant by the mass effect?
- Mass effect = displacement of organs away from their normal location by the mass
Rank the most common masses that are seen in the abdominal cavity:
- Spleen
- Liver
- Prostate
- Sublumbar LN
- Renal
Name the regions that are shown in the image below:
Abdominal regions:
- Cranial, Middle and Caudal
- Dorsal and ventral
- Right and left
What structures can be displaced by cranio-ventral mass effect on a lateral view?
Caudal and dorsal displacement of:
- Stomach wall
- Pylorus - gastric axis deviation
- Small Intestine
- Transverse Colon
- Occasionally the kidneys
What is the gastric axis and what is considered normal on a lateral view and a VD?
- The gastric axis is a line drawn from the central fundus to the pylorus
- The normal range - between parallel to ribs and vertical to spine
- On a VD view should be 90 degrees to the spine
What are some differentials for cranio-ventral abdominal masses? (give 3 for if stomach is displaced and 2 for if it is not
- Stomach displaced = hepatomegaly, gallbladder, cranial stomach wall or pyloric mass
- Stomach not displaced = pancreas or lymph nodes
What structures are displaced as a result of a mass in the cranio-dorsal region and what are some possible masses that could cause it?
Caudal and ventral displacement of:
- Stomach fundus
- Small Intestine
- Transverse colon
- Kidneys
- Head spleen
Possible masses:
- Dorsal liver, Stomach wall (these will displace the stomach)
- Head of spleen, pancreas, adrenal glands, lymph nodes, ovary
Identify the abnormality in the radiograph below:
- Can see an abnormal increase in the size of the liver
What organs are displaced in midventral abdominal displacement and what are some differentials for this condition?
- Displacement away from midabdomen of - SI, descending and ascending colon, tail spleen
Ddx:
- tail and body of spleen most common
- enteric mass,
- mesenteric mass
- lymphadenopathy,
- large dorsal masses > 8 cm
- retained testicles
- primary neoplasia,
- metastases
What condition is shown in the image below?
Spleenomegaly - can be seen that both the tail and the head of the spleen has been displaced
What condition is shown in the image below?
Mesenteric lymmph node mass
What structures are normally displaced as a consequence of a mid-dorsal abdominal mass?
Displacement of strucutres away from the mid dorsal abdomen:
- Small intestine
- Descending and/or ascending colon
- Kidneys (if not involved)
Ddx:
- Kidneys most common
- Retroperitoneal mass
- Retroperitoneal fluid
- Lymph nodes
- Vertebral body pathology
- Small adrenal ovarian mass
What species is shown in the image below and what is the condition?
- Cat - Renomegally
What structures are displaced as a result of a caudo-dorsal abdominal mass and what are some Ddx for it?
Displacement of structures:
- Small intestine
- Descending colon
- Bladder flattened against ventral abdominal wall
Ddx:
- Retroperitoneal disease - neoplasia, fluid
- Ruptured ureters
- Iliac lymph nodes
- Vertebral body masses
Where is the pathology in the image below (describe by location e.g. cranioventral) and what is a potential cause?
- Caudodorsal mass
- Entire intestinal tract has been displaced dorsally
- Very hard to see anything we are thinking probably fluid
What organs are displaced as a result of a caudo-ventral abdominal mass?
Cranial and dorsal displacement of:
- Small intestine
- Descending colon
- Bladder appearance: flattened if mass between colon and bladder (uterus) or cranial displacement (from pubis) if mass caudal to bladder (prostate)
Ddx:
- Bladder enlargement
- Prostate or uterus (pregnancy, pyometra)
- Retained testicles
What is the main significant finding in the abdomen below?
Prostatomegaly - the main significant finding in the abdomen below (see the bladder is displaced cranially)
What is the main significant finding in the radiograph below?
Just a big bladder - no pathology - the dog just needs to go for a walk
What is the main condition occuring in the abdomen below and what is the cause?
- Small liver (microhepatica) - the most likely cause of this is a portosystemic shunt
- Notice how the stomach is angled cranially
What is the condition that is shown in the image below? (top is normal for reference) and what are the differentials for this condition?
Hepatomegaly
Differentials for this condition are:
- Endocrine disorders (Hyper-AD, Diabetes mellitus)
- Diffuse inflammation (hepatitis)
- Diffuse infiltrative disease (neoplastic, infectious)
- Congestion (Right heart failure)
- Lipidosis (common in cats and dogs)
Name the condition in the radiograph below (hint examine the distance between the diaphragm and the stomach) and provide some differentials:
- Microheaptica (can be seen by the decreased distance between the diaphragm and the stomach) - alwasy assess this subjectively on both views
Causes of microhepatica:
- Congenital portosystemic shunt
- Cirrhosis
- Diaphragmatic hernia - liver into the thorax
- Can just be normal - some dogs have little livers
Name the condition that is shown in the image below and state the possible differentials for it:
Large spleen (Splenomegaly):
- Idiopathic
- Infiltrative disease (neoplasia)
- Congestion
- Sequestration of RBC’s
- Anesthesia/sedation
- Torsion
