communication ouverte vs fermée
Open communication does not guarantee receipt of the findings by the intended recipient (e.g., signing a report in the electronic medical record). It is the most common method of radiology reporting and is appropriate for routine, expected, nonurgent, noncritical results.
Closed-loop communication guarantees receipt of the
findings by the intended recipient (e.g., direct phone call). It should be used for nonroutine, urgent, and critical results, and for final reports that have important differences from preliminary reports.
position pour minimiser risque pntx lors bx lesion abdomen superieur
Placing the patient ipsilateral side down will restrict diaphragmatic motion, compress the ipsilateral lung, and decrease ipsilateral tidal volume. This can be a useful maneuver to minimize the risk of pneumothorax for biopsies in the upper
abdomen.
cest quoi CTDIvol
CTDIvol (volume CT dose index, expressed in mGy) is a measure of the scanner-specific radiation output.
CTDIvol is independent of patient body size and scan length
which is considered the radiation dose delivered to a patient :
CTDIvol
DLP: dose–length product
CTDIvol and DLP
aucun des deux
CTDIvol and DLP should not be considered as, nor reported to be, the radiation dose delivered to the patient
each is a measure of scanner and protocol-specific radiation output (i.e., exposure). Patient size, patient age, and the imaged body part(s) are not considered
effet qui predomine à < 100 msv
Stochastic effects below 100 mSv are speculative and based on the “linear-no-threshold” model
What is the maximum allowed whole-body specific absorption rate for an otherwise healthy patient based on FDA guidelines
max 4-W/kg-per 15-minute limit for whole-body average exposure in patients with normal thermoregulatory function
specific absorption rate (SAR) is a measure of the radio frequency energy deposition within the body per unit mass and is typically expressed in Watts/kilogram. High SAR levels can result in tissue heating and occasionally burns.
dose max cumulative pour foetus par an
the cumulative dose to the fetus cannot exceed 5 mSv.
This is intentionally greater than the dose limit set for the general public (1 mSv/year) to permit women of childbearing age to be
radiation workers.
bias possible dans depistage
LENGHT BIAS and LEAD TIME BIAS
LENGHT BIAS :
Length bias is a type of bias affecting screening studies in which slowly
progressive disease is identified disproportionately more often by the screening test than rapidly progressive disease
Rapidly progressive disease results in death more quickly and therefore has less of an opportunity to be detected by screening. Length bias inflates the apparent survival benefits of screening by diagnosing a greater fraction of patients with clinically indolent disease.
LEAD TIME
positive test results identify a disease earlier but do nothing to affect the outcome. the time the patient dies is the same regardless of whether the screening study is performed, but the screening population appears to live longer
because the disease is detected earlier. Lead-time bias inflates the apparent survival benefits of screening.
SURDIAGNOSTIC
Overdiagnosis bias when the screening test identifies a disease that would otherwise have no effect on patient outcome. This includes entities that are technically malignant but may be clinically irrelevant
Overdiagnosis bias inflates the apparent survival benefits of screening by detecting
disease that would not have affected the survival of the patient.
prévention dommage induit par contraste chez IRC PRE TDM
volume expansion with isotonic fluids : 0.9% NaCl
risk factors for nephrogenic systemic fibrosis
The two key risk factors for nephrogenic systemic fibrosis (NSF) are
(1)
eGFR <30 mL/min/1.73 m2 and
(2) acute kidney injury
tx opioid-induced respiratory
depression
The best next step is to administer 0.2 mg naloxone IV over 30 seconds, with redosing every 2 to 3 minutes until the patient’s respiratory rate is >10.
type et critère reponse RESIST 1.1
complete response (CR): requires all of:
disappearance of all target and non-target lesions
pathological lymph nodes must have reduced to <10 mm in short axis
no new lesions
partial response (PR): requires all of:
at least 30% decrease in SOD of target lesions compared to baseline sum diameters (BSD)
non-progressive disease of non-target lesions
no new lesions
progressive disease (PD):
either one of:
any new lesions OR
at least 20% relative and 5 mm absolute increase of SOD of target lesions compared to smallest SOD ever recorded for the patient
stable disease (SD):
not meeting criteria for PD or PR
antidote fentanyl ? midazolam ?
Naloxone is the reversal agent for opioids (e.g., fentanyl), and flumazenil is the
reversal agent for benzodiazepines (e.g., midazolam).
treatment of oversedation is 0.2 mg for naloxone (may repeat every 2 to 3 minutes)
and 0.1 to 0.2 mg for flumazenil (may repeat every minute; maximum dose is 1 mg)
What single acute skin dose is most likely to cause erythema and epilation early (2-8 wks) after the exposure, but no long-term (> 40 wks) observable effects (Gy)?
2-4
seuil limite de dose en fluro pour causer changement erythemateux de la peau
threshold dose for erythematous skin changes is 2 Gy.
What factor is most important in the development of gadolinium retention in the brain?
Gadolinium deposition in brain tissue is felt to be proportional to the amount of contrast administered
différencier choc vs choc vagal
FC
BRADYCARDIE = CHOC VAGAL
