Notebook: Radiology of Lung Disease 3

INCREASED RADIOLUCENCY, cont'd.
- congenital emphysema is rare
- usually emphysema is correlated w/ lower airway dz
- asthma: difficulty exhaling leads to increased air retained in lungs
- very dark, black lungs may indicate emphysema.
- even if no bronchial pulmonary pattern, may still be feline asthma
- air in stomach: dyspnea has led patient to swallow air.

See focal increased radiolucency more commonly than diffuse.

Air filled structures in the lung
- cavity, cyst, bulla: Cysts are usually congenital with very thin walls. Bullae usually have no apparent walls.
- if related to the bronchi, called bronchiectasis
- term cavitary lesions: masses with air in the center. Differentials same for any other mass. This term can technically be used for any air-filled lesion within the lung. Typically used to describe a lesion with a very thick wall.

Increased radiolucency is less common than increased radiopacity. There are fewer differentials for increased radiolucency.

Why do we have a pleural space:
- main function: keep lungs attached to the chest wall
- small film of fluid creates a negative pressure.
- lubricates lungs (most animals have sm. amt. of fluid in this space)
Side note: elephants lack pleural space.

Pleural effusion
- as soon as we have dz in pleural space, negative pressure will be lost to some degree, causing lung to retract toward the center.
- usually we don't see the pleural space.
- if lungs pull away from chest wall and from each other, we see the pleural space (called pleural fissure line). Vessels taper and disappear; pleural fissure line does not.
- signs: pleural fissure lines, lung lobe retraction, silhouetting.
- bilateral pleural effusion: More common. Top differentials: congestive heart failure, neoplasia, trauma.
- unilateral pleural effusion: Top differential = inflammatory dz

Note to self: see Dr. Seiler's slides for more info.
Read full entry

Notebook: Radiology of Lung Disease 2

ALVEOLAR PULMONARY PATTERN, cont'd.
Atelectasis vs. pneumonia: You may have difficulty discerning the two on laterally projected rads, because both problems present in the ventral lung field. Take an orthogonal view; if you see a mediastinal shift on the VD or DV projection, this indicates atelectasis. If not, pneumonia may be indicated.

Remember: After looking at rads and coming up with differentials, ALWAYS check to see if your problem list matches the clinical signs! (for any rads, any case)

BRONCHIAL PULMONARY PATTERN
- indicates bronchial disease.
- results in thickened appearance of bronchi
- overall pulmonary pattern/ opacity is not that different
- typically all bronchi are affected.
- bronchiectasis: widened bronchi. A sign of chronicity.
- in older animals, bronchi are often mineralized.

Side note: right middle lung lobe is often collapsed in cats with asthma.

INTERSTITIAL PULMONARY PATTERN
- This pattern is usually diffuse.
- interstitial space: connective tissue that makes up the alveolar walls and the connective tissue around the big vessels and bronchi.
- interstitial pulmonary dz: on rads, everything is a little blurred.
- generalized increased opacity in the lungs. Still see all the structures, but they're not as sharp anymore.
- Since this is a hazy pattern by definition, it may be difficult to distinguish interstitial pulmonary pattern from poor radiograph quality. Check for good contrast between trachea, soft tissue and bone. Make sure that outlines of vertebrae are visible; check if you can see the dorsal spinous processes.

Metastatic nodule vs. end-on vessel: End-on vessel will always be brighter than a nodule, because it is a cylindrical structure. Also, it must sit on top of another vessel, which you sould be able to see as well.

Metastatic nodule vs. heterotopic bone: The smaller and the brighter the structure is, the less you have to worry. Heterotopic bone is very small and very bright.

If you are unsure if it's a nodule or not, ask the owner to come back in a week or so for more rads.

IF YOU CAN'T DECIDE ON A PATTERN
- i.e., if characterisitcs of multiple patterns are present
- just call the pattern a mixed pulmonary pattern
- these rads may not help reach a definitive diagnosis.

If lungs are too black: again, rule out artifact first (just as was discussed for whiteness in Radiology of Lung Disease 1).

Read full entry

Notebook: Radiology of Lung Disease 1

Radiographic technique: pull legs forward in left lateral position so that they're not super-imposed on the thorax. For VD projection, make sure the animal is straight. Exposure: use high KVP (reduces contrast, gives a lot of grayscale). Also, use a grid and try to take rads on full inspiration. This is important because we need something that contrasts the structures in the thorax. Also, always take 2 projections of each patient. This is important for best possible assessment because the recumbent lung will be collapsed.

- Anatomy: caudal vena cava is always on the right side.
- When evaulating chest rads: look at extra-thoracic structures first!

Now to the meat of the lecture: Pulmonary parynchema: pleural space, mediastinum, heart, vessels. In normal small animal lungs, the right lung is a bit bigger. Lumen of bronchi will always be black with very thin wall; mainly seen in perihylar area. Vessels are filled with blood. Connective/ interstitial tissue around big vessels and bronchi. Black lung with white lines, white vessels, thin parallel branching lines are the bronchi.

If there's a problem with the radiograph, rule out artifacts or extra-pulmonary diseases. Artifact: It may be that the rads weren't taken at full peak inspiration. Think of the animal's fat content. Legs may not be pulled fully forward.

Alveolar, bronchial, interstitial, vascular patterns and combinations of them.

Alveolar pulmonary pattern: fluid and cells on rad are white. So if all those alveoli are filled with fluid and the round structures are filled with soft tissue opacity, we don't see the difference between the vessels and the lung parynchema anymore. All we see is the air within the bronchi (black outline of bronchial tree). List things that indicate alveolar pulmonary pattern: soft tissue opacity, silhouetting with other soft tissue structures, air bronchograms, lobar sign. May indicate: pneumonia, edema, hemorrhage, atelectasis, neoplasia, torsion, infarct.

Read full entry

Sapna: new, improved, more efficient

As yet another way of evolving to accomodate our audience, we at Sapna Magazine have begun blogging it up, WordPress style. And it was super-easy to implement! Once WordPress was installed on our site, I created some beautiful graphics to go with our new, modern and more mature image.

Not only is the new site prettier, but it's easier for our writers and editors to upload articles. (They love how user-friendly it is!) And our design has already gotten rave reviews from an expert in WordPress theme development. Please contact me [mariamkamal@gmail.com] if you are interested in joining the creative team.



Visit the new site to explore our new issue! The issue features stunning fashion photography done by Billy Rood of Fig Media in Chicago and an interview with Freida Pinto, the gorgeous feature actress in Slumdog Millionaire, which is a favorite for this year's Oscars. Writer Tirusha Dave includes an important factoid at the end of her article: The young kids who play the orphans in Slumdog were actually rescued from the slums of Mumbai. Please read the conclusion of the Freida feature to find out what organizations to support.
Read full entry

a cyber-sample of Sapna

Our new site is launching this week! Check out the Sapna Magazine website this Friday, January 23, to admire our new look.


Read full entry

almost time for a fresh start

Okay, so usually I just write my notes in this blog... But it hasn't been updated in some time, so I thought I'd do a quick traditional blog entry! I've been working to jump-start a project in tiger conservation over break, and I'm very excited, as I think it shows promise. I've also been working on Sapna (sapnamagazine.com) -- I did not design the current site, but we're relaunching our site on January 11th, and I'm working on that design. It's powered by Wordpress, and it'll be much more dynamic than our current site! The excitement is building...
Read full entry

The wonders of diarrhea

There are four mechanisms of diarrhea:
- malabsorption/ maldigestion

• example: result of selective deficiencies of brush border enzymes such as disaccharidases
• other possible causes: loss of enterocyte function, loss of absorptive surface area, non-intestinal causes
• osmotic diarrhea is typically a small intestine problem in small animals and can occur significantly in the colon of large animals.

- hypersecretion despite structurally intact muscosa

• electrolyte and fluid move into the intestinal lumen
• often associated with entertoxins of intraluminal pathogens, such as the heat stable toxin of E. coli and the virulence factors of Shigella and Salmonella

- exudative (due to direct damage to vessels or increased hydrostatic pressure)

• example 1: direct damage can be caused by Salmonellosis
• example 2: increased hydrostatic pressure can result from Johne's disease

- deranged intestinal motility

• hypomotility (abnormal proliferation of microflora) or hypermotility (reduced contact time)
• can be caused by tumors, foreign bodies, intussusception, strictures, acute inflammation

Read full entry

Let's start learning about the nervous system

This packet starts off with some basic definitions. Below I've listed some that I thought might be hard to remember.

gemistocyte a hypertrophied astrocyte

gitter cell mononuclear phagocyte containing myelin debris

hydranencephaly large portion of cerebrum is missing and replaced by fluid-filled membranous sac. No identifiable cortex remains.

lissencephaly smooth-surfaced cerebrum (no gyral development). Usually cortex is thicker than normal (pachygyria).

myelitis inflammation of the spinal cord.

neuronophagia (process of neuronal phagocytosis) accumulation of mononuclear cells around/ at the site of a neuronal cell body undergoing dissolution/ has disappeared.

porencephaly cavities in the brain, usually the cerebrum.

satellitosis accumulation of glial cells (usually oligodendrocytes) around a neuronal cell body.

spina bifida failure of the vertebral arch to develop

spinal dysraphism abnormal spinal cord development with improper union between two contiguous structures.

syringiomyelia cavity in the spinal cord parenchyma, usually in the white matter.

Wallerian degeneration degenerative changes in an axon and its myelin distal to point of injury

Read full entry