Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Clin Med II Unit II > 1 Pulmonary Diagnostic Imaging > Flashcards

1 Pulmonary Diagnostic Imaging Flashcards

1
Q

Pulmonary diagnostic imaging that exposes the patient to ionizing radiation

A

Chest Radiography (CXR)

Computed Tomography (CT)

Pulmonary Angiography (CTPA/Direct)

Nuclear Scanning
• V/Q scan
• PET scan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Pulmonary diagnostic imaging that DOESN’T expose the patient to ionizing radiation

A

Ultrasound

Magnetic Resonance Imaging (MRI/MRA)

Bronchoscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

CTs account for ____% of average ionizing radiation exposure each year

A

24%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Often the initial study to evaluate respiratory symptoms

A

Chest X-Ray

X-ray beam penetrates through the body and provides images of structures in and around the thorax (lung parenchyma, pleura, chest wall, diaphragm, mediastinum, and hilum)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

On CXR, air appears ____, fat ______, and bone ______.

A 
Air = black
Far = dark gray
Bone = nearly white
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Indications for chest x-ray

A

Shortness of breath

Persistent cough

Hemoptysis

Chest pain or injury

Fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What views are utilized when taking chest x-rays?

A

Posterior-anterior (PA)
Anterior-posterior (AP)
Lateral
Decubitus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Combo of CXR views most often used

A

PA and lateral

AP is used if bedridden (but may make heart look bigger than it actually is)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The ABCDEFs of viewing chest X-rays

A

Airway (trachea, bronchi)
Bones (ribs, clavicle)
Cardiac (borders, cardiomegaly)
Diaphragm
Edges (look for pneumothorax or effusion)
Fields of lungs (look for infiltrates, nodes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which CXR view allows for best visualization of the right lower lobe?

A

Lateral

Because the RLL is mostly posterior, very little of it can be visualized from a PA view

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an Apical Lordotic view?

A

Variation on an AP view, where patient’s feet are some distance from the film and the lean back upon it.

Indicated when TB is suspected because it gives the best view of the apex of the lungs, where TB typically starts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Example of use of the lateral decubitus view on CXR

A

Subpulmonic effusion

The PA film shows an apparently elevated right diaphragm

On the decubitus view, the effusion flows up along the side of the lung

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the primary benefits of CXRs?

A

Non-invasive

Low radiation exposure

Inexpensive

Convenient - Imaging is fast, easy, and particularly useful in emergency Dx and Tx

Widely available (esp with portable units)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Though uncommon to see, a Hampton’s Hump on CXR indicates…

A

PE - it’s an area of ischemia due to the infarct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Risks and Limitations of CXR

A

Radiation exposure
• 0.1 mSv, minimal but cumulative
• PA/LAT, about what you receive from background radiation in 10 days

Pregnancy - some exposure but smaller risk than CT

Some conditions of the chest cannot be detected (ie very small cancers, pulmonary emboli)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why might you order a CT?

A

Clarify an abnormal CXR

Help diagnose the cause of clinical SSx (SOB, cough, CP, fever)

Characterize pulmonary nodules

Detection and staging of primary and metastatic lung neoplasms

Evaluate suspected mediastinal or hilar masses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Who should get a CT screening for lung cancer?

A

55-80 year olds with a 30 pack year history and currently smoke or quit within the past 15 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Types of CT scans

A

Conventional - 10 mm slice, “step-and-shoot”, 25-30 min

Helical - aka spiral CT, faster, continuous, <5 min

High Resolution (HRCT) - better detail, 1mm slice

Low Dose CT - usually used for lung cancer screening, but less detail

CT Angiography

“Multidetector” or “multislice CT” - capable of conventional and helical scans, but 64x faster (though with higher radiation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does bronchiectasis appear on CT?

A

Thickening/dilation of airways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does subcutaneous emphysema sound like?

A

Rice crispiest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Benefits of CT

A

Fast, widely available

Detailed images

Real-time imaging useful for biopsies

Can be performed even if patient has an implanted device

Less expensive and less sensitive to patient movement than MRI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Risks/Limitations of CT

A

Radiation exposure (~8 mSv or 80 times that of Xray) - about the same a person receives from background radiation in three years

Increased CA risk

Fetal exposure during pregnancy

Problems associated with contrast (allergy, renal problems)

Body habitus >450lbs may not fit in machine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What’s special about kids and CTs?

A

Kids are more radiosensitive than adults

CT has increased risk of leukemia and brain tumors

Radiation risk compounded by longer lifespan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What do we need to know about pregnant women and CTs?

A

In uterine exposure linked to pediatric cancer mortality - always ask LMP prior to imaging

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What type of contrast does CT use?

A

Iodine

Used to enhance differences in densities of various structures - ie a large blood vessel with a tumor encasing/constricting it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When is CT with contrast needed?

A

Masses, cancer, metastatic disease, obstructive processes, PE or dissection (CT angiography)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

When do we want a CT WITHOUT contrast

A

High resolution CT for evaluation of diffuse lung disease and to follow up known pulmonary nodules

28
Q

Special risks of CT with contrast

A

Allergic reaction (mild-moderate vs major)

Potential for contrast induced nephropathy

Development of lactic acidosis if taking Glucophage (Metformin) - consider holding metformin for 48 hours after imaging

29
Q

Tell me more about iodine contrast allergies…

A

Reaction develops within 5-60 min of administration of contrast

SSx - flushing, Pruitt is, urticaria, angioedema, bronchospasm and wheezing, stridor, hypotension, loss of consciousness

Risk factors - prior reaction, asthma, atopy

Can pre-treat with prednisone and diphenhydramine (Benadryl)

30
Q

Is a shellfish allergy a contraindication for CT contrast?

A

Nope.

31
Q

Contrast induced nephropathy is defined as …

A

Serum creatinine >25% from baseline or >0.5 mg/dL

Usually reversible

Best treatment is prevention

Caution using contrast in patients with impaired kidney function

32
Q

In whom should we be concerned for development of contrast induced nephropathy

A

If Creatinine >1.5 mg/dL or GFR <60

Age >60

Hx of renal disease, HTN treated with meds, DM (esp if taking metformin)

Use alternative - either CT w/o contrast, MRI w/o gadolinium, or U/S

33
Q

Patients taking metformin and CT contrast…

A

If eGFR ≥ 30 ml/min, metformin does not need to be withheld

If Acute kidney injury or severe CKD with eGFR <30 ml/min - temporarily hold metformin when contrast administered x 48 hours, resume only after re-evaluation of renal function

34
Q

When do we use angiography?

A

To assess vasculature in the body
• Brain, kidneys, pelvis, legs, lungs, heart, neck
• Injection/timing controlled, dye is where you want it during the scan

Performed in conjunction with imaging modalities
• CT —> CTA
• MRI —> MRA
• X-ray with catheter (direct/conventional)

35
Q

Imaging procedure that provides anatomical detail of blood vessels and is useful for suspected pulmonary embolism, aortic dissection, and superior vena cava syndrome

A

CT Pulmonary Angiography (CTPA)

Identifies vascular malformations and assesses pulmonary arterial invasion by a neoplasm

36
Q

Benefits of CTPA

A

Has largely replaced conventional (catheter-directed) pulmonary angiography

If surgery is warranted, can provide precise anatomical guidance

Less invasive, less expensive, and safer compared to conventional angiography

37
Q

Risks/Limitations of CTPA

A

Can miss sub-segmental PEs

Allergy to contrast material (iodine)

Nephrotoxicity from contrast

Radiation exposure (10-15 mSv)

Body habitus (>450lbs)

38
Q

Gold standard in the evaluation of PE

A

Direct pulmonary angiography

CTA is more useful now but this is still the gold standard

39
Q

How is direct pulmonary angiography performed

A

Needle/catheter inserted into right femoral or internal jugular vein —> R side heart —> pulmonary arteries

Dry injected, x-rays taken

Used if V/Q scan or CTPA inconclusive and still a high clinical suspicion

Invasive and expensive

40
Q

Risks of direct pulmonary angiography

A

Bleeding or hematoma at insertion site

Heart arrhythmia

Allergic reaction to contrast

Impaired kidney function (though usually reversible)

Radiation exposure (5 mSv)

41
Q

How are MRIs used in pulmonary disease?

A

Limited usefulness

Hilar or mediastinal densities, sulcus tumors, possible cysts and lesions of the chest wall

42
Q

Who cannot receive an MRI?

A

Patients with allergy to iodinated contrast or renal disease (GFR <60)

43
Q

Benefits to MRI

A

No bone artifact as with CT

No ionizing radiation

44
Q

Compared to Chest CT, MRI has _______ detailed view of lung parenchyma and __________ special resolution

A

Less detailed, diminished special resolution

45
Q

Contrast material used for MRI and MRA

A

Gadolinium

46
Q

Limitations of MRI/MRA

A

Patient must remain still

Claustrophobia

Body habitus

Risk of nephrogenic systemic fibrosis (irreversible scarring) - avoid use of gadolinium if GFR < 60

47
Q

Contraindications of MRI/MRA

A

Pacemaker or defibrillator

Metal in eye

Aneurysm clip

Cochlear implant

Joint replacements aren’t ferrous and are generally safe

48
Q

Nuclear imaging study used to evaluate for PE

A

Ventilation-Perfusion (V/Q) scan

Also used for pre-op assessment prior to lung resection

49
Q

Imbalance of blood flow and ventilation is called

A

V/Q mismatch

50
Q

Radioactive material used in V/Q scans

A

Technicium-99 and Xenon gas

51
Q

The two phases of V/Q scans

A

IV Phase - Technetium-99m (labeled to human albumin) is injected and follows distribution of blood flow (PERFUSION)

Inhalation Phase - radio-labeled Xenon gas demonstrates distribution of VENTILATION

52
Q

If a patient has a high probability of PE but a normal CXR, you should…

A

Perform V/Q scan to assess for mismatch. Absence of perfusion with normal ventilation indicates PE.

53
Q

Benefits of V/Q scan

A

Allergic reaction to radiopharmaceutical is rare

Low-dose radiation (2-2.5 mSv)

Remains test of choice for diagnosis of PE in pregnant women

Useful in estimating post-op reserve capacity for patients undergoing lung resection

54
Q

Limitations of V/Q scan

A

Sensitive for Dx of PE but poorly specific (PNA or asthmas might be positive too)

Few false negatives but high number of false-positives

Best utilized in those with a normal CXR w/ high suspicion of PE

No absolute contraindications

55
Q

Acquisition of physiologic images based on the detection of radiation emitted from fluorodeoxyglucose (FDG)

A

Positron Emission Tomography (PET)

FDG - radioactively labeled glucose injected into patient and accumulates in tissues/organs with high metabolic activity (ie cancer cells)

56
Q

In PET scans, measurements of the uptake of FDG are made in ________.

A

Standardized Uptake Value (SUV)

SUV > 2.5 raises possibility of malignancy

57
Q

Uses of PET scan

A

Most often used to detect cancer

Useful to evaluate for metastasis from primary site

Used to examine the effects of cancer therapy (can detect recurrence in previously irradiated, scarred areas of the lung)

58
Q

Benefits of PET scans

A

Can detect biochemical changes of anatomy before they are apparent with CT/MRI

However, now being combined with CT or MRI to give anatomic and metabolic info

Radioactivity is short lived

59
Q

Limitations of PET scans

A

Radiation exposure ~14 mSv

False results occur with metabolic imbalances
• False (+) inflammatory lesions - granulomas from Cocci and Histo
• False (-) with slow growing tumors

Time-sensitive - radioactive substance decays quickly

High cost

60
Q

How is ultrasound used in pulmonary diagnostics?

A

Limited use in evaluation of lung parenchyma

Indications include:
• Bedside detection of pleural fluid or PNA
• Guidance for thoracentesis
• Guidance for placement of thoracostomy tubes

Benefits - no ionizing radiation, portable

61
Q

What is the FAST exam?

A

Focused Assessment using Sonography in Trauma

62
Q

“Seashore sign” on thoracic ultrasound indicates…

A

Normal condition - Positive lung motion

63
Q

“Barcode” or “stratosphere sign” on thoracic ultrasound indicates

A

Abnormal finding - no lung motion

64
Q

Diagnostic and therapeutic indications for bronchoscopy

A

Evaluation of PNA, hemoptysis, cough

Dx of tracheoesophageal fistulas and tracheobronchomalacia

Tissue sampling

Removal of excess mucus or FBs

ET tube placement

65
Q

___________ is most commonly used in patients with obstruction of trachea or a proximal bronchus (for removal of FB)

A

Rigid bronchoscopy

66
Q

Benefits of bronchoscopy

A

Safe procedure with very low complication rates (0.08-6.8%)
• Nasal discomfort, sore throat, mild hemoptysis
• Complications are usually minor (hemorrhage, pneumothorax, hypotension, arrhythmia)
• Most occur during or within first few hours post-procedure

67
Q

Contraindications for bronchoscopy

A

Severe refractory hypoxia

Risk of bleeding (anticoagulants, coagulopathy)

Risk of respiratory and CV decompensation (asthma or COPD exacerbation, current or recent MI, poorly controlled CHF, life threatening arrhythmias)

Clin Med II Unit II (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions