DIFFERENTIAL DIAGNOSIS IN
ACUTE CARE, 2025/2026 WITH
CORRECT/ACCURATE ANSWERS
Five Densities of Radiographic Densities
1. Air ([MOST RADIOLUCENT] blackest - least dense)
2. Fat
3. Water (soft tissue)
4. Mineral (Bone)
5. Metal ([MOST RADIOPAQUE] - whitest- MOST DENSE)
**Listed from least to most dense**
How does air appear on x-ray?
- Air appears the blackest on radiograph *ABSORBS THE LEAST
XRAY*
How does fat appear on x-ray?
- Fat appears as the darkest shade of GREY -
**Lighter than air but DARKER than soft tissue/fluid**
How do soft tissue and fluids appear on x-ray?
- Both fluid and soft tissue have the same density on conventional
radiographs.
,**It is impossible to differentiate blood from muscle inside the
heart on x-ray.**
How do minerals (specifically calcium = bone) appear on x-ray?
- Most dense NATURALLY occurring material - absorbs most of the
x-ray - lightest shade of grey.
How does metal appear on x-ray?
- Metal is the most dense material viewed on x-ray - absorbs all of
the x-ray - BRIGHTEST WHITE
What are the diagnostic utilities of radiographic studies in health
care?
- Diagnostic radiology uses these imaging results to identify a
wide range of problems, from broken bones to heart conditions
and blood clots. Interventional radiology also uses imaging such
as CT scans, MRI and ultrasounds to guide medical procedures.
What does USPSTF stand for?
- United States Preventive Services Task Force
USPSTF Guideline Ratings
- Grade A: USPSTF recommends this service. There is a high
certainty that the net benefit is substantial; Offer or provide this
service.
- Grade B: The USPSTF recommends this service There is high
certainty that the net benefit is moderate or there is moderate
certainty that the net benefit is moderate or substantial; Offer or
provide this service.
- Grade C: The USPSTF recommends SELECTIVELY offering or
providing this service to individual patients based on professional
judgement and patient preferences. There is at least moderate
, certainty that the net benefit is small; Offer or provide this service
for selected patients depending on individual circumstances.
- Grade D: The USPSTF recommends against this service. There is
moderate or high certainty that the service has no net benefit or
that the harms outweigh the benefits; Discourage the use of this
service.
- I Statement: The USPSTF concludes that the current evidence is
insufficient to assess the balance of benefits and harms of the
service. Evidence is lacking, of poor quality, or conflicting, and the
balance of benefits and harms cannot be determined; Read the
clinical considerations section of USPSTF recommendation
statement. If the service is offered, patients should understand
the uncertainty about the balance of benefits and harms.
Macule
- Description: Flat, in the plane of the skin, nonpalpable
- Potential Cause: Drug rash, viral exanthema, syphilis, HIV
Papule