mri notes

order MR if question about age of hemorrhage

(classically in child abuse cases)

hemorrhage on CT

white 2/2 Hgb/protein concentratino ~56 HU, anemic patient may appear isodense

hyper acute blood 0-72 hyperdense

Early subacute 3 days 1 week still hyperdense

Late subacute hypodense 1 week to months

MRI

2 factors affect MR: oxygenation state of hemoglobin, lysi of initially intact RBC

hyperacute 3-6hours - contains oxyhemoglobin (diamagnetic) - will not see it on GRE/SWI

acute 8-72 hrs - ^ deoxyhemoglobin (paramagnetic) will see on SWI/GRE

chronic hemorrhage - months to years, iron atoms deposited and cannot exit

hyper acute

oxy - isointense T1, bright on T2

acute 1-3 days

deoxy - iso on T1 dark on T2

subacute )3-7days)

bright on TI, dardk on T2

late 7-14 days bright bright - extracellular methemoglobin

chronic >14 days - dark dark T1T2

intracranial vasculature

digital subtractio angiography - gold standard, catheter angiography

do each vessel individually

bolus injection 100ml at 4-6ml/sec

large bore 18guage antecubital to get good cta

MRA/V

TOF - no contrast - moving spins experience different excitations (flow related), slow flow may appear as if vessel is occluded - can see >1.5mm on 1.5T

2D limitations - need adequate flow, aneurysms poorly visualized, underestimated because of slow moving spins

Phase contrast -

TRICKS - time resolved iagin of contrast kinetics: needs contast -time resolved imaging of contrast

giant aneurysm >2.5cm presents w/mass effect

http://www.youtube.com/watch?v=_OJ5qnErsTc&NR=1

ipab

IPAB notes

the independent payment advisory board - us gov agency created in 2010 by ACA (affordable care act)

task

-reduce rate of growth in medicare to target levels w/o adversely impacting coverage/quality

priveleges

-IPAB has the ability to set medicare reimbursement rates independently, only congress has ability overrule IPAB decisions

thesis

-orginally MedPAC (medicare payment advisory commission) could advise congress on proper medicare spending but MedPAC could not legislate, however congress never made MedPAC's suggested cuts. it is believed congressional members were beholden to special interest groups from medical device/supply makers to keep spending high, IPAB was proposed as a way to remove power from congress with these financial conflicts of interest and put medicare spending policy decisions in the hands of healthcare policy experts

IPAB guidelines

-proposals must not involve "rationing" of care

-proposals must not raise medicare premiums

-proposals must not increase cost sharing (deductibles, copayments, coinsurance)

-proposals must not restrict benefits

-proposals must not alter eligibility criteria

who makes up IPAB

-15 members appointed by president, confirmed by senate

-composed of healthcare administrators, physicians, hospital managers, healthcare IT managers, consumer group representatives

-member salary 165,000

-total funding $15 million

notable organizations against IPAB

-pharmaceutical research and manufacturers of america -

-american hospital association

-american medical association - wants "working" physicians to be included as board members

-american academy of neurology - concerned reimbursements will be cut, believes there will not be physician representation on the IPAB board

-nursing home associations - IPAB would adversely impact their ability to lobby congress (this is as i understand it the whole purpose the board was created)

those for it

-medicare benficiaries stand to benefit, provided they can access care

-washington post editorial - reject criticism of IPAB essentially by saying that the current political system is failing greatly

numbers

-IPAB goal- decrease by $28 billion by 2019 - total medicare spending for this period will be 7 trillion!!, thus the savings will amount to 0.04% of total spending

my opinion is that this panel could probably be a benefit to healthcare reform and i support its formation. i understand opposition to IPAB probably stems from the loss of revenue and pre-existing political relationships between special interest lobbyists and congress. disrupting this channel of communication definitely adversely impacts these institutions' profit equilibrium and political position, and those who have spoken out against IPAB probably feel that their interests will be adversely impacted by IPAB proposals. but i happen to believe that congress would sell out the interests of physicians in order to maintain ties with private insurance and hospital lobbying groups who are more integral to their re-election, and because of the inherent instability that those relationships place on my standing as a future physician taken together with the good faith effort of our president and healthcare reform analysts comprising the IPAB (who may be more aligned with interests of office based/general practice physicians), i see more reason to support the formation of the IPAB then to maintain the status quo of medicare reimbursement defined in my eyes by annual emergency medicare reimbursement reduction stopgaps passed at the eleventh hour which continuously place the reimbursement system for physicians in precarious straits.

chest radiology notes

pulmonary edema

cardiogenic

LV failure

valvular -

pulmonary veno-occlusive

12-19 pulmonary hypertension

20-25 interstitial edema (interlobular septa, bronchovascular bundle, subpleural compartment) - kerley lines (septal thickening), pleural effusion

>25 alveolar edema - (25mmhg is normal oncotic pressure of plasma)

batwing pattern, airbronchograms (ARDS), fluid leaks into the alveoli (50% begin in RUL because associated w/mitral regurg b/c r superior pulm vein right above mitral valve and it receives regurg jet _ this is the leading idea

non cardiogenic - high capillary perm - tends to be more permanent when onset (associated with high mortality) toxin

drug

trauma

sepsis

kerley A lines - long emanate from the hila, best seen in upper lobes

B lines short thick extend to pleural base

C lines fine very short, criss cross

no real difference between A B C, merely a historical note

rt pleural effusion predominates in CHF because patient sleeps rt side down! right usually larger than left

re-expansion pulmonary edema - re-exanpsion edema more sever w/chronic edema being drained,

some radiology notes

brain mra no contast

resolution is 3mm (CT angio is better than this)

petrous cavernouse supraclinoid -path of carotid

diffusion of water is restricted (restricted diffusion) in acute infarct (hi on dwi) cytotoxic edema, low on ADC,

dont have a use for contrast on T2 MR

T2 Flair good for fluid containing pathology

corpus callosal lesion

gbm

ms

lymphoma (likes periventricular white matter)

signs in chest radiology

butterfly pattern of cardiogenic pulmonary edema

air bronchogram - parencyhmal process (air blood pus cells tumor) - you can see bronchi,

bronchus cut off sign -atelectasis

veil sign - left lobe atelectsasis

golden s sign - right upper lobe atelectasis

comet tail and crow feet on CT - pleural fibrosis round atelectasis (need to have pleural disease)

juxtaphrenic peak sign - tenting of diaphragm upperwards in cases of upper lobe volume loss (atelectasis or surgical removal)

water bottle shaped heart - pericardial effusion (blood, fluid,etc)

oreo cookie sign - pericardial effusion on lateral radiograph, seen best with patient who has lot of fat

dense calcification in radiograph in center of heart aortic stenosis

reverse 3 sign - coarctation

continuous diaphragm sign - 3 things

- pneumomediastinum/pericardium/peritoneum

air crescent sign - invasive aspergillosis (necrotic consolidation) not an aspergilloma (classically)

deep sulcus sign - deep costophrenic angle in supine patient, classic sign of pneumothorax

scimitar sign - - sign of hypogenic lung syndrome lung will be bi-mono lobed (lung malformation) associated with abberant pulmonary venous return

hampton's hump - wedge shaped opacity sign of infarct from PE

westermark's sign - oligemia (shift in perusion) enlargement of ipsi pulmonary artery

fallen lung sign - ct sign of pneumothorax

halo sign - frquently see in bleeding met (angiosarc) and aspergillos

reverse halo - high density surround normal lung - classically described in COP (cryptogenic organizing pneumonia) - not pathognomonic though, resolves w/steroids

crazy aving - alveolar proteinosis